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1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * xlog.c
4 : : * PostgreSQL write-ahead log manager
5 : : *
6 : : * The Write-Ahead Log (WAL) functionality is split into several source
7 : : * files, in addition to this one:
8 : : *
9 : : * xloginsert.c - Functions for constructing WAL records
10 : : * xlogrecovery.c - WAL recovery and standby code
11 : : * xlogreader.c - Facility for reading WAL files and parsing WAL records
12 : : * xlogutils.c - Helper functions for WAL redo routines
13 : : *
14 : : * This file contains functions for coordinating database startup and
15 : : * checkpointing, and managing the write-ahead log buffers when the
16 : : * system is running.
17 : : *
18 : : * StartupXLOG() is the main entry point of the startup process. It
19 : : * coordinates database startup, performing WAL recovery, and the
20 : : * transition from WAL recovery into normal operations.
21 : : *
22 : : * XLogInsertRecord() inserts a WAL record into the WAL buffers. Most
23 : : * callers should not call this directly, but use the functions in
24 : : * xloginsert.c to construct the WAL record. XLogFlush() can be used
25 : : * to force the WAL to disk.
26 : : *
27 : : * In addition to those, there are many other functions for interrogating
28 : : * the current system state, and for starting/stopping backups.
29 : : *
30 : : *
31 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
32 : : * Portions Copyright (c) 1994, Regents of the University of California
33 : : *
34 : : * src/backend/access/transam/xlog.c
35 : : *
36 : : *-------------------------------------------------------------------------
37 : : */
38 : :
39 : : #include "postgres.h"
40 : :
41 : : #include <ctype.h>
42 : : #include <math.h>
43 : : #include <time.h>
44 : : #include <fcntl.h>
45 : : #include <sys/stat.h>
46 : : #include <sys/time.h>
47 : : #include <unistd.h>
48 : :
49 : : #include "access/clog.h"
50 : : #include "access/commit_ts.h"
51 : : #include "access/heaptoast.h"
52 : : #include "access/multixact.h"
53 : : #include "access/rewriteheap.h"
54 : : #include "access/subtrans.h"
55 : : #include "access/timeline.h"
56 : : #include "access/transam.h"
57 : : #include "access/twophase.h"
58 : : #include "access/xact.h"
59 : : #include "access/xlog_internal.h"
60 : : #include "access/xlogarchive.h"
61 : : #include "access/xloginsert.h"
62 : : #include "access/xlogreader.h"
63 : : #include "access/xlogrecovery.h"
64 : : #include "access/xlogutils.h"
65 : : #include "access/xlogwait.h"
66 : : #include "backup/basebackup.h"
67 : : #include "catalog/catversion.h"
68 : : #include "catalog/pg_control.h"
69 : : #include "catalog/pg_database.h"
70 : : #include "common/controldata_utils.h"
71 : : #include "common/file_utils.h"
72 : : #include "executor/instrument.h"
73 : : #include "miscadmin.h"
74 : : #include "pg_trace.h"
75 : : #include "pgstat.h"
76 : : #include "port/atomics.h"
77 : : #include "postmaster/bgwriter.h"
78 : : #include "postmaster/startup.h"
79 : : #include "postmaster/walsummarizer.h"
80 : : #include "postmaster/walwriter.h"
81 : : #include "replication/origin.h"
82 : : #include "replication/slot.h"
83 : : #include "replication/slotsync.h"
84 : : #include "replication/snapbuild.h"
85 : : #include "replication/walreceiver.h"
86 : : #include "replication/walsender.h"
87 : : #include "storage/bufmgr.h"
88 : : #include "storage/fd.h"
89 : : #include "storage/ipc.h"
90 : : #include "storage/large_object.h"
91 : : #include "storage/latch.h"
92 : : #include "storage/predicate.h"
93 : : #include "storage/proc.h"
94 : : #include "storage/procarray.h"
95 : : #include "storage/reinit.h"
96 : : #include "storage/spin.h"
97 : : #include "storage/sync.h"
98 : : #include "utils/guc_hooks.h"
99 : : #include "utils/guc_tables.h"
100 : : #include "utils/injection_point.h"
101 : : #include "utils/pgstat_internal.h"
102 : : #include "utils/ps_status.h"
103 : : #include "utils/relmapper.h"
104 : : #include "utils/snapmgr.h"
105 : : #include "utils/timeout.h"
106 : : #include "utils/timestamp.h"
107 : : #include "utils/varlena.h"
108 : :
109 : : #ifdef WAL_DEBUG
110 : : #include "utils/memutils.h"
111 : : #endif
112 : :
113 : : /* timeline ID to be used when bootstrapping */
114 : : #define BootstrapTimeLineID 1
115 : :
116 : : /* User-settable parameters */
117 : : int max_wal_size_mb = 1024; /* 1 GB */
118 : : int min_wal_size_mb = 80; /* 80 MB */
119 : : int wal_keep_size_mb = 0;
120 : : int XLOGbuffers = -1;
121 : : int XLogArchiveTimeout = 0;
122 : : int XLogArchiveMode = ARCHIVE_MODE_OFF;
123 : : char *XLogArchiveCommand = NULL;
124 : : bool EnableHotStandby = false;
125 : : bool fullPageWrites = true;
126 : : bool wal_log_hints = false;
127 : : int wal_compression = WAL_COMPRESSION_NONE;
128 : : char *wal_consistency_checking_string = NULL;
129 : : bool *wal_consistency_checking = NULL;
130 : : bool wal_init_zero = true;
131 : : bool wal_recycle = true;
132 : : bool log_checkpoints = true;
133 : : int wal_sync_method = DEFAULT_WAL_SYNC_METHOD;
134 : : int wal_level = WAL_LEVEL_REPLICA;
135 : : int CommitDelay = 0; /* precommit delay in microseconds */
136 : : int CommitSiblings = 5; /* # concurrent xacts needed to sleep */
137 : : int wal_retrieve_retry_interval = 5000;
138 : : int max_slot_wal_keep_size_mb = -1;
139 : : int wal_decode_buffer_size = 512 * 1024;
140 : : bool track_wal_io_timing = false;
141 : :
142 : : #ifdef WAL_DEBUG
143 : : bool XLOG_DEBUG = false;
144 : : #endif
145 : :
146 : : int wal_segment_size = DEFAULT_XLOG_SEG_SIZE;
147 : :
148 : : /*
149 : : * Number of WAL insertion locks to use. A higher value allows more insertions
150 : : * to happen concurrently, but adds some CPU overhead to flushing the WAL,
151 : : * which needs to iterate all the locks.
152 : : */
153 : : #define NUM_XLOGINSERT_LOCKS 8
154 : :
155 : : /*
156 : : * Max distance from last checkpoint, before triggering a new xlog-based
157 : : * checkpoint.
158 : : */
159 : : int CheckPointSegments;
160 : :
161 : : /* Estimated distance between checkpoints, in bytes */
162 : : static double CheckPointDistanceEstimate = 0;
163 : : static double PrevCheckPointDistance = 0;
164 : :
165 : : /*
166 : : * Track whether there were any deferred checks for custom resource managers
167 : : * specified in wal_consistency_checking.
168 : : */
169 : : static bool check_wal_consistency_checking_deferred = false;
170 : :
171 : : /*
172 : : * GUC support
173 : : */
174 : : const struct config_enum_entry wal_sync_method_options[] = {
175 : : {"fsync", WAL_SYNC_METHOD_FSYNC, false},
176 : : #ifdef HAVE_FSYNC_WRITETHROUGH
177 : : {"fsync_writethrough", WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, false},
178 : : #endif
179 : : {"fdatasync", WAL_SYNC_METHOD_FDATASYNC, false},
180 : : #ifdef O_SYNC
181 : : {"open_sync", WAL_SYNC_METHOD_OPEN, false},
182 : : #endif
183 : : #ifdef O_DSYNC
184 : : {"open_datasync", WAL_SYNC_METHOD_OPEN_DSYNC, false},
185 : : #endif
186 : : {NULL, 0, false}
187 : : };
188 : :
189 : :
190 : : /*
191 : : * Although only "on", "off", and "always" are documented,
192 : : * we accept all the likely variants of "on" and "off".
193 : : */
194 : : const struct config_enum_entry archive_mode_options[] = {
195 : : {"always", ARCHIVE_MODE_ALWAYS, false},
196 : : {"on", ARCHIVE_MODE_ON, false},
197 : : {"off", ARCHIVE_MODE_OFF, false},
198 : : {"true", ARCHIVE_MODE_ON, true},
199 : : {"false", ARCHIVE_MODE_OFF, true},
200 : : {"yes", ARCHIVE_MODE_ON, true},
201 : : {"no", ARCHIVE_MODE_OFF, true},
202 : : {"1", ARCHIVE_MODE_ON, true},
203 : : {"0", ARCHIVE_MODE_OFF, true},
204 : : {NULL, 0, false}
205 : : };
206 : :
207 : : /*
208 : : * Statistics for current checkpoint are collected in this global struct.
209 : : * Because only the checkpointer or a stand-alone backend can perform
210 : : * checkpoints, this will be unused in normal backends.
211 : : */
212 : : CheckpointStatsData CheckpointStats;
213 : :
214 : : /*
215 : : * During recovery, lastFullPageWrites keeps track of full_page_writes that
216 : : * the replayed WAL records indicate. It's initialized with full_page_writes
217 : : * that the recovery starting checkpoint record indicates, and then updated
218 : : * each time XLOG_FPW_CHANGE record is replayed.
219 : : */
220 : : static bool lastFullPageWrites;
221 : :
222 : : /*
223 : : * Local copy of the state tracked by SharedRecoveryState in shared memory,
224 : : * It is false if SharedRecoveryState is RECOVERY_STATE_DONE. True actually
225 : : * means "not known, need to check the shared state".
226 : : */
227 : : static bool LocalRecoveryInProgress = true;
228 : :
229 : : /*
230 : : * Local state for XLogInsertAllowed():
231 : : * 1: unconditionally allowed to insert XLOG
232 : : * 0: unconditionally not allowed to insert XLOG
233 : : * -1: must check RecoveryInProgress(); disallow until it is false
234 : : * Most processes start with -1 and transition to 1 after seeing that recovery
235 : : * is not in progress. But we can also force the value for special cases.
236 : : * The coding in XLogInsertAllowed() depends on the first two of these states
237 : : * being numerically the same as bool true and false.
238 : : */
239 : : static int LocalXLogInsertAllowed = -1;
240 : :
241 : : /*
242 : : * ProcLastRecPtr points to the start of the last XLOG record inserted by the
243 : : * current backend. It is updated for all inserts. XactLastRecEnd points to
244 : : * end+1 of the last record, and is reset when we end a top-level transaction,
245 : : * or start a new one; so it can be used to tell if the current transaction has
246 : : * created any XLOG records.
247 : : *
248 : : * While in parallel mode, this may not be fully up to date. When committing,
249 : : * a transaction can assume this covers all xlog records written either by the
250 : : * user backend or by any parallel worker which was present at any point during
251 : : * the transaction. But when aborting, or when still in parallel mode, other
252 : : * parallel backends may have written WAL records at later LSNs than the value
253 : : * stored here. The parallel leader advances its own copy, when necessary,
254 : : * in WaitForParallelWorkersToFinish.
255 : : */
256 : : XLogRecPtr ProcLastRecPtr = InvalidXLogRecPtr;
257 : : XLogRecPtr XactLastRecEnd = InvalidXLogRecPtr;
258 : : XLogRecPtr XactLastCommitEnd = InvalidXLogRecPtr;
259 : :
260 : : /*
261 : : * RedoRecPtr is this backend's local copy of the REDO record pointer
262 : : * (which is almost but not quite the same as a pointer to the most recent
263 : : * CHECKPOINT record). We update this from the shared-memory copy,
264 : : * XLogCtl->Insert.RedoRecPtr, whenever we can safely do so (ie, when we
265 : : * hold an insertion lock). See XLogInsertRecord for details. We are also
266 : : * allowed to update from XLogCtl->RedoRecPtr if we hold the info_lck;
267 : : * see GetRedoRecPtr.
268 : : *
269 : : * NB: Code that uses this variable must be prepared not only for the
270 : : * possibility that it may be arbitrarily out of date, but also for the
271 : : * possibility that it might be set to InvalidXLogRecPtr. We used to
272 : : * initialize it as a side effect of the first call to RecoveryInProgress(),
273 : : * which meant that most code that might use it could assume that it had a
274 : : * real if perhaps stale value. That's no longer the case.
275 : : */
276 : : static XLogRecPtr RedoRecPtr;
277 : :
278 : : /*
279 : : * doPageWrites is this backend's local copy of (fullPageWrites ||
280 : : * runningBackups > 0). It is used together with RedoRecPtr to decide whether
281 : : * a full-page image of a page need to be taken.
282 : : *
283 : : * NB: Initially this is false, and there's no guarantee that it will be
284 : : * initialized to any other value before it is first used. Any code that
285 : : * makes use of it must recheck the value after obtaining a WALInsertLock,
286 : : * and respond appropriately if it turns out that the previous value wasn't
287 : : * accurate.
288 : : */
289 : : static bool doPageWrites;
290 : :
291 : : /*----------
292 : : * Shared-memory data structures for XLOG control
293 : : *
294 : : * LogwrtRqst indicates a byte position that we need to write and/or fsync
295 : : * the log up to (all records before that point must be written or fsynced).
296 : : * The positions already written/fsynced are maintained in logWriteResult
297 : : * and logFlushResult using atomic access.
298 : : * In addition to the shared variable, each backend has a private copy of
299 : : * both in LogwrtResult, which is updated when convenient.
300 : : *
301 : : * The request bookkeeping is simpler: there is a shared XLogCtl->LogwrtRqst
302 : : * (protected by info_lck), but we don't need to cache any copies of it.
303 : : *
304 : : * info_lck is only held long enough to read/update the protected variables,
305 : : * so it's a plain spinlock. The other locks are held longer (potentially
306 : : * over I/O operations), so we use LWLocks for them. These locks are:
307 : : *
308 : : * WALBufMappingLock: must be held to replace a page in the WAL buffer cache.
309 : : * It is only held while initializing and changing the mapping. If the
310 : : * contents of the buffer being replaced haven't been written yet, the mapping
311 : : * lock is released while the write is done, and reacquired afterwards.
312 : : *
313 : : * WALWriteLock: must be held to write WAL buffers to disk (XLogWrite or
314 : : * XLogFlush).
315 : : *
316 : : * ControlFileLock: must be held to read/update control file or create
317 : : * new log file.
318 : : *
319 : : *----------
320 : : */
321 : :
322 : : typedef struct XLogwrtRqst
323 : : {
324 : : XLogRecPtr Write; /* last byte + 1 to write out */
325 : : XLogRecPtr Flush; /* last byte + 1 to flush */
326 : : } XLogwrtRqst;
327 : :
328 : : typedef struct XLogwrtResult
329 : : {
330 : : XLogRecPtr Write; /* last byte + 1 written out */
331 : : XLogRecPtr Flush; /* last byte + 1 flushed */
332 : : } XLogwrtResult;
333 : :
334 : : /*
335 : : * Inserting to WAL is protected by a small fixed number of WAL insertion
336 : : * locks. To insert to the WAL, you must hold one of the locks - it doesn't
337 : : * matter which one. To lock out other concurrent insertions, you must hold
338 : : * of them. Each WAL insertion lock consists of a lightweight lock, plus an
339 : : * indicator of how far the insertion has progressed (insertingAt).
340 : : *
341 : : * The insertingAt values are read when a process wants to flush WAL from
342 : : * the in-memory buffers to disk, to check that all the insertions to the
343 : : * region the process is about to write out have finished. You could simply
344 : : * wait for all currently in-progress insertions to finish, but the
345 : : * insertingAt indicator allows you to ignore insertions to later in the WAL,
346 : : * so that you only wait for the insertions that are modifying the buffers
347 : : * you're about to write out.
348 : : *
349 : : * This isn't just an optimization. If all the WAL buffers are dirty, an
350 : : * inserter that's holding a WAL insert lock might need to evict an old WAL
351 : : * buffer, which requires flushing the WAL. If it's possible for an inserter
352 : : * to block on another inserter unnecessarily, deadlock can arise when two
353 : : * inserters holding a WAL insert lock wait for each other to finish their
354 : : * insertion.
355 : : *
356 : : * Small WAL records that don't cross a page boundary never update the value,
357 : : * the WAL record is just copied to the page and the lock is released. But
358 : : * to avoid the deadlock-scenario explained above, the indicator is always
359 : : * updated before sleeping while holding an insertion lock.
360 : : *
361 : : * lastImportantAt contains the LSN of the last important WAL record inserted
362 : : * using a given lock. This value is used to detect if there has been
363 : : * important WAL activity since the last time some action, like a checkpoint,
364 : : * was performed - allowing to not repeat the action if not. The LSN is
365 : : * updated for all insertions, unless the XLOG_MARK_UNIMPORTANT flag was
366 : : * set. lastImportantAt is never cleared, only overwritten by the LSN of newer
367 : : * records. Tracking the WAL activity directly in WALInsertLock has the
368 : : * advantage of not needing any additional locks to update the value.
369 : : */
370 : : typedef struct
371 : : {
372 : : LWLock lock;
373 : : pg_atomic_uint64 insertingAt;
374 : : XLogRecPtr lastImportantAt;
375 : : } WALInsertLock;
376 : :
377 : : /*
378 : : * All the WAL insertion locks are allocated as an array in shared memory. We
379 : : * force the array stride to be a power of 2, which saves a few cycles in
380 : : * indexing, but more importantly also ensures that individual slots don't
381 : : * cross cache line boundaries. (Of course, we have to also ensure that the
382 : : * array start address is suitably aligned.)
383 : : */
384 : : typedef union WALInsertLockPadded
385 : : {
386 : : WALInsertLock l;
387 : : char pad[PG_CACHE_LINE_SIZE];
388 : : } WALInsertLockPadded;
389 : :
390 : : /*
391 : : * Session status of running backup, used for sanity checks in SQL-callable
392 : : * functions to start and stop backups.
393 : : */
394 : : static SessionBackupState sessionBackupState = SESSION_BACKUP_NONE;
395 : :
396 : : /*
397 : : * Shared state data for WAL insertion.
398 : : */
399 : : typedef struct XLogCtlInsert
400 : : {
401 : : slock_t insertpos_lck; /* protects CurrBytePos and PrevBytePos */
402 : :
403 : : /*
404 : : * CurrBytePos is the end of reserved WAL. The next record will be
405 : : * inserted at that position. PrevBytePos is the start position of the
406 : : * previously inserted (or rather, reserved) record - it is copied to the
407 : : * prev-link of the next record. These are stored as "usable byte
408 : : * positions" rather than XLogRecPtrs (see XLogBytePosToRecPtr()).
409 : : */
410 : : uint64 CurrBytePos;
411 : : uint64 PrevBytePos;
412 : :
413 : : /*
414 : : * Make sure the above heavily-contended spinlock and byte positions are
415 : : * on their own cache line. In particular, the RedoRecPtr and full page
416 : : * write variables below should be on a different cache line. They are
417 : : * read on every WAL insertion, but updated rarely, and we don't want
418 : : * those reads to steal the cache line containing Curr/PrevBytePos.
419 : : */
420 : : char pad[PG_CACHE_LINE_SIZE];
421 : :
422 : : /*
423 : : * fullPageWrites is the authoritative value used by all backends to
424 : : * determine whether to write full-page image to WAL. This shared value,
425 : : * instead of the process-local fullPageWrites, is required because, when
426 : : * full_page_writes is changed by SIGHUP, we must WAL-log it before it
427 : : * actually affects WAL-logging by backends. Checkpointer sets at startup
428 : : * or after SIGHUP.
429 : : *
430 : : * To read these fields, you must hold an insertion lock. To modify them,
431 : : * you must hold ALL the locks.
432 : : */
433 : : XLogRecPtr RedoRecPtr; /* current redo point for insertions */
434 : : bool fullPageWrites;
435 : :
436 : : /*
437 : : * runningBackups is a counter indicating the number of backups currently
438 : : * in progress. lastBackupStart is the latest checkpoint redo location
439 : : * used as a starting point for an online backup.
440 : : */
441 : : int runningBackups;
442 : : XLogRecPtr lastBackupStart;
443 : :
444 : : /*
445 : : * WAL insertion locks.
446 : : */
447 : : WALInsertLockPadded *WALInsertLocks;
448 : : } XLogCtlInsert;
449 : :
450 : : /*
451 : : * Total shared-memory state for XLOG.
452 : : */
453 : : typedef struct XLogCtlData
454 : : {
455 : : XLogCtlInsert Insert;
456 : :
457 : : /* Protected by info_lck: */
458 : : XLogwrtRqst LogwrtRqst;
459 : : XLogRecPtr RedoRecPtr; /* a recent copy of Insert->RedoRecPtr */
460 : : XLogRecPtr asyncXactLSN; /* LSN of newest async commit/abort */
461 : : XLogRecPtr replicationSlotMinLSN; /* oldest LSN needed by any slot */
462 : :
463 : : XLogSegNo lastRemovedSegNo; /* latest removed/recycled XLOG segment */
464 : :
465 : : /* Fake LSN counter, for unlogged relations. */
466 : : pg_atomic_uint64 unloggedLSN;
467 : :
468 : : /* Time and LSN of last xlog segment switch. Protected by WALWriteLock. */
469 : : pg_time_t lastSegSwitchTime;
470 : : XLogRecPtr lastSegSwitchLSN;
471 : :
472 : : /* These are accessed using atomics -- info_lck not needed */
473 : : pg_atomic_uint64 logInsertResult; /* last byte + 1 inserted to buffers */
474 : : pg_atomic_uint64 logWriteResult; /* last byte + 1 written out */
475 : : pg_atomic_uint64 logFlushResult; /* last byte + 1 flushed */
476 : :
477 : : /*
478 : : * Latest initialized page in the cache (last byte position + 1).
479 : : *
480 : : * To change the identity of a buffer (and InitializedUpTo), you need to
481 : : * hold WALBufMappingLock. To change the identity of a buffer that's
482 : : * still dirty, the old page needs to be written out first, and for that
483 : : * you need WALWriteLock, and you need to ensure that there are no
484 : : * in-progress insertions to the page by calling
485 : : * WaitXLogInsertionsToFinish().
486 : : */
487 : : XLogRecPtr InitializedUpTo;
488 : :
489 : : /*
490 : : * These values do not change after startup, although the pointed-to pages
491 : : * and xlblocks values certainly do. xlblocks values are protected by
492 : : * WALBufMappingLock.
493 : : */
494 : : char *pages; /* buffers for unwritten XLOG pages */
495 : : pg_atomic_uint64 *xlblocks; /* 1st byte ptr-s + XLOG_BLCKSZ */
496 : : int XLogCacheBlck; /* highest allocated xlog buffer index */
497 : :
498 : : /*
499 : : * InsertTimeLineID is the timeline into which new WAL is being inserted
500 : : * and flushed. It is zero during recovery, and does not change once set.
501 : : *
502 : : * If we create a new timeline when the system was started up,
503 : : * PrevTimeLineID is the old timeline's ID that we forked off from.
504 : : * Otherwise it's equal to InsertTimeLineID.
505 : : *
506 : : * We set these fields while holding info_lck. Most that reads these
507 : : * values knows that recovery is no longer in progress and so can safely
508 : : * read the value without a lock, but code that could be run either during
509 : : * or after recovery can take info_lck while reading these values.
510 : : */
511 : : TimeLineID InsertTimeLineID;
512 : : TimeLineID PrevTimeLineID;
513 : :
514 : : /*
515 : : * SharedRecoveryState indicates if we're still in crash or archive
516 : : * recovery. Protected by info_lck.
517 : : */
518 : : RecoveryState SharedRecoveryState;
519 : :
520 : : /*
521 : : * InstallXLogFileSegmentActive indicates whether the checkpointer should
522 : : * arrange for future segments by recycling and/or PreallocXlogFiles().
523 : : * Protected by ControlFileLock. Only the startup process changes it. If
524 : : * true, anyone can use InstallXLogFileSegment(). If false, the startup
525 : : * process owns the exclusive right to install segments, by reading from
526 : : * the archive and possibly replacing existing files.
527 : : */
528 : : bool InstallXLogFileSegmentActive;
529 : :
530 : : /*
531 : : * WalWriterSleeping indicates whether the WAL writer is currently in
532 : : * low-power mode (and hence should be nudged if an async commit occurs).
533 : : * Protected by info_lck.
534 : : */
535 : : bool WalWriterSleeping;
536 : :
537 : : /*
538 : : * During recovery, we keep a copy of the latest checkpoint record here.
539 : : * lastCheckPointRecPtr points to start of checkpoint record and
540 : : * lastCheckPointEndPtr points to end+1 of checkpoint record. Used by the
541 : : * checkpointer when it wants to create a restartpoint.
542 : : *
543 : : * Protected by info_lck.
544 : : */
545 : : XLogRecPtr lastCheckPointRecPtr;
546 : : XLogRecPtr lastCheckPointEndPtr;
547 : : CheckPoint lastCheckPoint;
548 : :
549 : : /*
550 : : * lastFpwDisableRecPtr points to the start of the last replayed
551 : : * XLOG_FPW_CHANGE record that instructs full_page_writes is disabled.
552 : : */
553 : : XLogRecPtr lastFpwDisableRecPtr;
554 : :
555 : : slock_t info_lck; /* locks shared variables shown above */
556 : : } XLogCtlData;
557 : :
558 : : /*
559 : : * Classification of XLogInsertRecord operations.
560 : : */
561 : : typedef enum
562 : : {
563 : : WALINSERT_NORMAL,
564 : : WALINSERT_SPECIAL_SWITCH,
565 : : WALINSERT_SPECIAL_CHECKPOINT
566 : : } WalInsertClass;
567 : :
568 : : static XLogCtlData *XLogCtl = NULL;
569 : :
570 : : /* a private copy of XLogCtl->Insert.WALInsertLocks, for convenience */
571 : : static WALInsertLockPadded *WALInsertLocks = NULL;
572 : :
573 : : /*
574 : : * We maintain an image of pg_control in shared memory.
575 : : */
576 : : static ControlFileData *ControlFile = NULL;
577 : :
578 : : /*
579 : : * Calculate the amount of space left on the page after 'endptr'. Beware
580 : : * multiple evaluation!
581 : : */
582 : : #define INSERT_FREESPACE(endptr) \
583 : : (((endptr) % XLOG_BLCKSZ == 0) ? 0 : (XLOG_BLCKSZ - (endptr) % XLOG_BLCKSZ))
584 : :
585 : : /* Macro to advance to next buffer index. */
586 : : #define NextBufIdx(idx) \
587 : : (((idx) == XLogCtl->XLogCacheBlck) ? 0 : ((idx) + 1))
588 : :
589 : : /*
590 : : * XLogRecPtrToBufIdx returns the index of the WAL buffer that holds, or
591 : : * would hold if it was in cache, the page containing 'recptr'.
592 : : */
593 : : #define XLogRecPtrToBufIdx(recptr) \
594 : : (((recptr) / XLOG_BLCKSZ) % (XLogCtl->XLogCacheBlck + 1))
595 : :
596 : : /*
597 : : * These are the number of bytes in a WAL page usable for WAL data.
598 : : */
599 : : #define UsableBytesInPage (XLOG_BLCKSZ - SizeOfXLogShortPHD)
600 : :
601 : : /*
602 : : * Convert values of GUCs measured in megabytes to equiv. segment count.
603 : : * Rounds down.
604 : : */
605 : : #define ConvertToXSegs(x, segsize) XLogMBVarToSegs((x), (segsize))
606 : :
607 : : /* The number of bytes in a WAL segment usable for WAL data. */
608 : : static int UsableBytesInSegment;
609 : :
610 : : /*
611 : : * Private, possibly out-of-date copy of shared LogwrtResult.
612 : : * See discussion above.
613 : : */
614 : : static XLogwrtResult LogwrtResult = {0, 0};
615 : :
616 : : /*
617 : : * Update local copy of shared XLogCtl->log{Write,Flush}Result
618 : : *
619 : : * It's critical that Flush always trails Write, so the order of the reads is
620 : : * important, as is the barrier. See also XLogWrite.
621 : : */
622 : : #define RefreshXLogWriteResult(_target) \
623 : : do { \
624 : : _target.Flush = pg_atomic_read_u64(&XLogCtl->logFlushResult); \
625 : : pg_read_barrier(); \
626 : : _target.Write = pg_atomic_read_u64(&XLogCtl->logWriteResult); \
627 : : } while (0)
628 : :
629 : : /*
630 : : * openLogFile is -1 or a kernel FD for an open log file segment.
631 : : * openLogSegNo identifies the segment, and openLogTLI the corresponding TLI.
632 : : * These variables are only used to write the XLOG, and so will normally refer
633 : : * to the active segment.
634 : : *
635 : : * Note: call Reserve/ReleaseExternalFD to track consumption of this FD.
636 : : */
637 : : static int openLogFile = -1;
638 : : static XLogSegNo openLogSegNo = 0;
639 : : static TimeLineID openLogTLI = 0;
640 : :
641 : : /*
642 : : * Local copies of equivalent fields in the control file. When running
643 : : * crash recovery, LocalMinRecoveryPoint is set to InvalidXLogRecPtr as we
644 : : * expect to replay all the WAL available, and updateMinRecoveryPoint is
645 : : * switched to false to prevent any updates while replaying records.
646 : : * Those values are kept consistent as long as crash recovery runs.
647 : : */
648 : : static XLogRecPtr LocalMinRecoveryPoint;
649 : : static TimeLineID LocalMinRecoveryPointTLI;
650 : : static bool updateMinRecoveryPoint = true;
651 : :
652 : : /* For WALInsertLockAcquire/Release functions */
653 : : static int MyLockNo = 0;
654 : : static bool holdingAllLocks = false;
655 : :
656 : : #ifdef WAL_DEBUG
657 : : static MemoryContext walDebugCxt = NULL;
658 : : #endif
659 : :
660 : : static void CleanupAfterArchiveRecovery(TimeLineID EndOfLogTLI,
661 : : XLogRecPtr EndOfLog,
662 : : TimeLineID newTLI);
663 : : static void CheckRequiredParameterValues(void);
664 : : static void XLogReportParameters(void);
665 : : static int LocalSetXLogInsertAllowed(void);
666 : : static void CreateEndOfRecoveryRecord(void);
667 : : static XLogRecPtr CreateOverwriteContrecordRecord(XLogRecPtr aborted_lsn,
668 : : XLogRecPtr pagePtr,
669 : : TimeLineID newTLI);
670 : : static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags);
671 : : static void KeepLogSeg(XLogRecPtr recptr, XLogSegNo *logSegNo);
672 : : static XLogRecPtr XLogGetReplicationSlotMinimumLSN(void);
673 : :
674 : : static void AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli,
675 : : bool opportunistic);
676 : : static void XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible);
677 : : static bool InstallXLogFileSegment(XLogSegNo *segno, char *tmppath,
678 : : bool find_free, XLogSegNo max_segno,
679 : : TimeLineID tli);
680 : : static void XLogFileClose(void);
681 : : static void PreallocXlogFiles(XLogRecPtr endptr, TimeLineID tli);
682 : : static void RemoveTempXlogFiles(void);
683 : : static void RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr lastredoptr,
684 : : XLogRecPtr endptr, TimeLineID insertTLI);
685 : : static void RemoveXlogFile(const struct dirent *segment_de,
686 : : XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo,
687 : : TimeLineID insertTLI);
688 : : static void UpdateLastRemovedPtr(char *filename);
689 : : static void ValidateXLOGDirectoryStructure(void);
690 : : static void CleanupBackupHistory(void);
691 : : static void UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force);
692 : : static bool PerformRecoveryXLogAction(void);
693 : : static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version);
694 : : static void WriteControlFile(void);
695 : : static void ReadControlFile(void);
696 : : static void UpdateControlFile(void);
697 : : static char *str_time(pg_time_t tnow, char *buf, size_t bufsize);
698 : :
699 : : static int get_sync_bit(int method);
700 : :
701 : : static void CopyXLogRecordToWAL(int write_len, bool isLogSwitch,
702 : : XLogRecData *rdata,
703 : : XLogRecPtr StartPos, XLogRecPtr EndPos,
704 : : TimeLineID tli);
705 : : static void ReserveXLogInsertLocation(int size, XLogRecPtr *StartPos,
706 : : XLogRecPtr *EndPos, XLogRecPtr *PrevPtr);
707 : : static bool ReserveXLogSwitch(XLogRecPtr *StartPos, XLogRecPtr *EndPos,
708 : : XLogRecPtr *PrevPtr);
709 : : static XLogRecPtr WaitXLogInsertionsToFinish(XLogRecPtr upto);
710 : : static char *GetXLogBuffer(XLogRecPtr ptr, TimeLineID tli);
711 : : static XLogRecPtr XLogBytePosToRecPtr(uint64 bytepos);
712 : : static XLogRecPtr XLogBytePosToEndRecPtr(uint64 bytepos);
713 : : static uint64 XLogRecPtrToBytePos(XLogRecPtr ptr);
714 : :
715 : : static void WALInsertLockAcquire(void);
716 : : static void WALInsertLockAcquireExclusive(void);
717 : : static void WALInsertLockRelease(void);
718 : : static void WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt);
719 : :
720 : : /*
721 : : * Insert an XLOG record represented by an already-constructed chain of data
722 : : * chunks. This is a low-level routine; to construct the WAL record header
723 : : * and data, use the higher-level routines in xloginsert.c.
724 : : *
725 : : * If 'fpw_lsn' is valid, it is the oldest LSN among the pages that this
726 : : * WAL record applies to, that were not included in the record as full page
727 : : * images. If fpw_lsn <= RedoRecPtr, the function does not perform the
728 : : * insertion and returns InvalidXLogRecPtr. The caller can then recalculate
729 : : * which pages need a full-page image, and retry. If fpw_lsn is invalid, the
730 : : * record is always inserted.
731 : : *
732 : : * 'flags' gives more in-depth control on the record being inserted. See
733 : : * XLogSetRecordFlags() for details.
734 : : *
735 : : * 'topxid_included' tells whether the top-transaction id is logged along with
736 : : * current subtransaction. See XLogRecordAssemble().
737 : : *
738 : : * The first XLogRecData in the chain must be for the record header, and its
739 : : * data must be MAXALIGNed. XLogInsertRecord fills in the xl_prev and
740 : : * xl_crc fields in the header, the rest of the header must already be filled
741 : : * by the caller.
742 : : *
743 : : * Returns XLOG pointer to end of record (beginning of next record).
744 : : * This can be used as LSN for data pages affected by the logged action.
745 : : * (LSN is the XLOG point up to which the XLOG must be flushed to disk
746 : : * before the data page can be written out. This implements the basic
747 : : * WAL rule "write the log before the data".)
748 : : */
749 : : XLogRecPtr
750 : 2526993 : XLogInsertRecord(XLogRecData *rdata,
751 : : XLogRecPtr fpw_lsn,
752 : : uint8 flags,
753 : : int num_fpi,
754 : : uint64 fpi_bytes,
755 : : bool topxid_included)
756 : : {
757 : 2526993 : XLogCtlInsert *Insert = &XLogCtl->Insert;
758 : 2526993 : pg_crc32c rdata_crc;
759 : 2526993 : bool inserted;
760 : 2526993 : XLogRecord *rechdr = (XLogRecord *) rdata->data;
761 : 2526993 : uint8 info = rechdr->xl_info & ~XLR_INFO_MASK;
762 : 2526993 : WalInsertClass class = WALINSERT_NORMAL;
763 : 2526993 : XLogRecPtr StartPos;
764 : 2526993 : XLogRecPtr EndPos;
765 : 2526993 : bool prevDoPageWrites = doPageWrites;
766 : 2526993 : TimeLineID insertTLI;
767 : :
768 : : /* Does this record type require special handling? */
769 [ + + ]: 2526993 : if (unlikely(rechdr->xl_rmid == RM_XLOG_ID))
770 : : {
771 [ - + ]: 8929 : if (info == XLOG_SWITCH)
772 : 0 : class = WALINSERT_SPECIAL_SWITCH;
773 [ + + ]: 8929 : else if (info == XLOG_CHECKPOINT_REDO)
774 : 4 : class = WALINSERT_SPECIAL_CHECKPOINT;
775 : 8929 : }
776 : :
777 : : /* we assume that all of the record header is in the first chunk */
778 [ + - ]: 2526993 : Assert(rdata->len >= SizeOfXLogRecord);
779 : :
780 : : /* cross-check on whether we should be here or not */
781 [ + - ]: 2526993 : if (!XLogInsertAllowed())
782 [ # # # # ]: 0 : elog(ERROR, "cannot make new WAL entries during recovery");
783 : :
784 : : /*
785 : : * Given that we're not in recovery, InsertTimeLineID is set and can't
786 : : * change, so we can read it without a lock.
787 : : */
788 : 2526993 : insertTLI = XLogCtl->InsertTimeLineID;
789 : :
790 : : /*----------
791 : : *
792 : : * We have now done all the preparatory work we can without holding a
793 : : * lock or modifying shared state. From here on, inserting the new WAL
794 : : * record to the shared WAL buffer cache is a two-step process:
795 : : *
796 : : * 1. Reserve the right amount of space from the WAL. The current head of
797 : : * reserved space is kept in Insert->CurrBytePos, and is protected by
798 : : * insertpos_lck.
799 : : *
800 : : * 2. Copy the record to the reserved WAL space. This involves finding the
801 : : * correct WAL buffer containing the reserved space, and copying the
802 : : * record in place. This can be done concurrently in multiple processes.
803 : : *
804 : : * To keep track of which insertions are still in-progress, each concurrent
805 : : * inserter acquires an insertion lock. In addition to just indicating that
806 : : * an insertion is in progress, the lock tells others how far the inserter
807 : : * has progressed. There is a small fixed number of insertion locks,
808 : : * determined by NUM_XLOGINSERT_LOCKS. When an inserter crosses a page
809 : : * boundary, it updates the value stored in the lock to the how far it has
810 : : * inserted, to allow the previous buffer to be flushed.
811 : : *
812 : : * Holding onto an insertion lock also protects RedoRecPtr and
813 : : * fullPageWrites from changing until the insertion is finished.
814 : : *
815 : : * Step 2 can usually be done completely in parallel. If the required WAL
816 : : * page is not initialized yet, you have to grab WALBufMappingLock to
817 : : * initialize it, but the WAL writer tries to do that ahead of insertions
818 : : * to avoid that from happening in the critical path.
819 : : *
820 : : *----------
821 : : */
822 : 2526993 : START_CRIT_SECTION();
823 : :
824 [ + + ]: 2526993 : if (likely(class == WALINSERT_NORMAL))
825 : : {
826 : 2526989 : WALInsertLockAcquire();
827 : :
828 : : /*
829 : : * Check to see if my copy of RedoRecPtr is out of date. If so, may
830 : : * have to go back and have the caller recompute everything. This can
831 : : * only happen just after a checkpoint, so it's better to be slow in
832 : : * this case and fast otherwise.
833 : : *
834 : : * Also check to see if fullPageWrites was just turned on or there's a
835 : : * running backup (which forces full-page writes); if we weren't
836 : : * already doing full-page writes then go back and recompute.
837 : : *
838 : : * If we aren't doing full-page writes then RedoRecPtr doesn't
839 : : * actually affect the contents of the XLOG record, so we'll update
840 : : * our local copy but not force a recomputation. (If doPageWrites was
841 : : * just turned off, we could recompute the record without full pages,
842 : : * but we choose not to bother.)
843 : : */
844 [ + + ]: 2526989 : if (RedoRecPtr != Insert->RedoRecPtr)
845 : : {
846 [ + - ]: 294 : Assert(RedoRecPtr < Insert->RedoRecPtr);
847 : 294 : RedoRecPtr = Insert->RedoRecPtr;
848 : 294 : }
849 [ + - ]: 2526989 : doPageWrites = (Insert->fullPageWrites || Insert->runningBackups > 0);
850 : :
851 [ + - + + ]: 4993299 : if (doPageWrites &&
852 [ + + ]: 2526989 : (!prevDoPageWrites ||
853 [ + + ]: 2526712 : (XLogRecPtrIsValid(fpw_lsn) && fpw_lsn <= RedoRecPtr)))
854 : : {
855 : : /*
856 : : * Oops, some buffer now needs to be backed up that the caller
857 : : * didn't back up. Start over.
858 : : */
859 : 287 : WALInsertLockRelease();
860 [ + - ]: 287 : END_CRIT_SECTION();
861 : 287 : return InvalidXLogRecPtr;
862 : : }
863 : :
864 : : /*
865 : : * Reserve space for the record in the WAL. This also sets the xl_prev
866 : : * pointer.
867 : : */
868 : 5053404 : ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
869 : 2526702 : &rechdr->xl_prev);
870 : :
871 : : /* Normal records are always inserted. */
872 : 2526702 : inserted = true;
873 : 2526702 : }
874 [ - + ]: 4 : else if (class == WALINSERT_SPECIAL_SWITCH)
875 : : {
876 : : /*
877 : : * In order to insert an XLOG_SWITCH record, we need to hold all of
878 : : * the WAL insertion locks, not just one, so that no one else can
879 : : * begin inserting a record until we've figured out how much space
880 : : * remains in the current WAL segment and claimed all of it.
881 : : *
882 : : * Nonetheless, this case is simpler than the normal cases handled
883 : : * below, which must check for changes in doPageWrites and RedoRecPtr.
884 : : * Those checks are only needed for records that can contain buffer
885 : : * references, and an XLOG_SWITCH record never does.
886 : : */
887 [ # # ]: 0 : Assert(!XLogRecPtrIsValid(fpw_lsn));
888 : 0 : WALInsertLockAcquireExclusive();
889 : 0 : inserted = ReserveXLogSwitch(&StartPos, &EndPos, &rechdr->xl_prev);
890 : 0 : }
891 : : else
892 : : {
893 [ + - ]: 4 : Assert(class == WALINSERT_SPECIAL_CHECKPOINT);
894 : :
895 : : /*
896 : : * We need to update both the local and shared copies of RedoRecPtr,
897 : : * which means that we need to hold all the WAL insertion locks.
898 : : * However, there can't be any buffer references, so as above, we need
899 : : * not check RedoRecPtr before inserting the record; we just need to
900 : : * update it afterwards.
901 : : */
902 [ + - ]: 4 : Assert(!XLogRecPtrIsValid(fpw_lsn));
903 : 4 : WALInsertLockAcquireExclusive();
904 : 8 : ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
905 : 4 : &rechdr->xl_prev);
906 : 4 : RedoRecPtr = Insert->RedoRecPtr = StartPos;
907 : 4 : inserted = true;
908 : : }
909 : :
910 [ + - ]: 2526706 : if (inserted)
911 : : {
912 : : /*
913 : : * Now that xl_prev has been filled in, calculate CRC of the record
914 : : * header.
915 : : */
916 : 2526706 : rdata_crc = rechdr->xl_crc;
917 : 2526706 : COMP_CRC32C(rdata_crc, rechdr, offsetof(XLogRecord, xl_crc));
918 : 2526706 : FIN_CRC32C(rdata_crc);
919 : 2526706 : rechdr->xl_crc = rdata_crc;
920 : :
921 : : /*
922 : : * All the record data, including the header, is now ready to be
923 : : * inserted. Copy the record in the space reserved.
924 : : */
925 : 5053412 : CopyXLogRecordToWAL(rechdr->xl_tot_len,
926 : 2526706 : class == WALINSERT_SPECIAL_SWITCH, rdata,
927 : 2526706 : StartPos, EndPos, insertTLI);
928 : :
929 : : /*
930 : : * Unless record is flagged as not important, update LSN of last
931 : : * important record in the current slot. When holding all locks, just
932 : : * update the first one.
933 : : */
934 [ + + ]: 2526706 : if ((flags & XLOG_MARK_UNIMPORTANT) == 0)
935 : : {
936 [ + + ]: 2526324 : int lockno = holdingAllLocks ? 0 : MyLockNo;
937 : :
938 : 2526324 : WALInsertLocks[lockno].l.lastImportantAt = StartPos;
939 : 2526324 : }
940 : 2526706 : }
941 : : else
942 : : {
943 : : /*
944 : : * This was an xlog-switch record, but the current insert location was
945 : : * already exactly at the beginning of a segment, so there was no need
946 : : * to do anything.
947 : : */
948 : : }
949 : :
950 : : /*
951 : : * Done! Let others know that we're finished.
952 : : */
953 : 2526706 : WALInsertLockRelease();
954 : :
955 [ + - ]: 2526706 : END_CRIT_SECTION();
956 : :
957 : 2526706 : MarkCurrentTransactionIdLoggedIfAny();
958 : :
959 : : /*
960 : : * Mark top transaction id is logged (if needed) so that we should not try
961 : : * to log it again with the next WAL record in the current subtransaction.
962 : : */
963 [ + - ]: 2526706 : if (topxid_included)
964 : 0 : MarkSubxactTopXidLogged();
965 : :
966 : : /*
967 : : * Update shared LogwrtRqst.Write, if we crossed page boundary.
968 : : */
969 [ + + ]: 2526706 : if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ)
970 : : {
971 [ + + ]: 39294 : SpinLockAcquire(&XLogCtl->info_lck);
972 : : /* advance global request to include new block(s) */
973 [ + + ]: 39294 : if (XLogCtl->LogwrtRqst.Write < EndPos)
974 : 39192 : XLogCtl->LogwrtRqst.Write = EndPos;
975 : 39294 : SpinLockRelease(&XLogCtl->info_lck);
976 : 39294 : RefreshXLogWriteResult(LogwrtResult);
977 : 39294 : }
978 : :
979 : : /*
980 : : * If this was an XLOG_SWITCH record, flush the record and the empty
981 : : * padding space that fills the rest of the segment, and perform
982 : : * end-of-segment actions (eg, notifying archiver).
983 : : */
984 [ + - ]: 2526706 : if (class == WALINSERT_SPECIAL_SWITCH)
985 : : {
986 : 0 : TRACE_POSTGRESQL_WAL_SWITCH();
987 : 0 : XLogFlush(EndPos);
988 : :
989 : : /*
990 : : * Even though we reserved the rest of the segment for us, which is
991 : : * reflected in EndPos, we return a pointer to just the end of the
992 : : * xlog-switch record.
993 : : */
994 [ # # ]: 0 : if (inserted)
995 : : {
996 : 0 : EndPos = StartPos + SizeOfXLogRecord;
997 [ # # ]: 0 : if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ)
998 : : {
999 : 0 : uint64 offset = XLogSegmentOffset(EndPos, wal_segment_size);
1000 : :
1001 [ # # ]: 0 : if (offset == EndPos % XLOG_BLCKSZ)
1002 : 0 : EndPos += SizeOfXLogLongPHD;
1003 : : else
1004 : 0 : EndPos += SizeOfXLogShortPHD;
1005 : 0 : }
1006 : 0 : }
1007 : 0 : }
1008 : :
1009 : : #ifdef WAL_DEBUG
1010 : : if (XLOG_DEBUG)
1011 : : {
1012 : : static XLogReaderState *debug_reader = NULL;
1013 : : XLogRecord *record;
1014 : : DecodedXLogRecord *decoded;
1015 : : StringInfoData buf;
1016 : : StringInfoData recordBuf;
1017 : : char *errormsg = NULL;
1018 : : MemoryContext oldCxt;
1019 : :
1020 : : oldCxt = MemoryContextSwitchTo(walDebugCxt);
1021 : :
1022 : : initStringInfo(&buf);
1023 : : appendStringInfo(&buf, "INSERT @ %X/%08X: ", LSN_FORMAT_ARGS(EndPos));
1024 : :
1025 : : /*
1026 : : * We have to piece together the WAL record data from the XLogRecData
1027 : : * entries, so that we can pass it to the rm_desc function as one
1028 : : * contiguous chunk.
1029 : : */
1030 : : initStringInfo(&recordBuf);
1031 : : for (; rdata != NULL; rdata = rdata->next)
1032 : : appendBinaryStringInfo(&recordBuf, rdata->data, rdata->len);
1033 : :
1034 : : /* We also need temporary space to decode the record. */
1035 : : record = (XLogRecord *) recordBuf.data;
1036 : : decoded = (DecodedXLogRecord *)
1037 : : palloc(DecodeXLogRecordRequiredSpace(record->xl_tot_len));
1038 : :
1039 : : if (!debug_reader)
1040 : : debug_reader = XLogReaderAllocate(wal_segment_size, NULL,
1041 : : XL_ROUTINE(.page_read = NULL,
1042 : : .segment_open = NULL,
1043 : : .segment_close = NULL),
1044 : : NULL);
1045 : : if (!debug_reader)
1046 : : {
1047 : : appendStringInfoString(&buf, "error decoding record: out of memory while allocating a WAL reading processor");
1048 : : }
1049 : : else if (!DecodeXLogRecord(debug_reader,
1050 : : decoded,
1051 : : record,
1052 : : EndPos,
1053 : : &errormsg))
1054 : : {
1055 : : appendStringInfo(&buf, "error decoding record: %s",
1056 : : errormsg ? errormsg : "no error message");
1057 : : }
1058 : : else
1059 : : {
1060 : : appendStringInfoString(&buf, " - ");
1061 : :
1062 : : debug_reader->record = decoded;
1063 : : xlog_outdesc(&buf, debug_reader);
1064 : : debug_reader->record = NULL;
1065 : : }
1066 : : elog(LOG, "%s", buf.data);
1067 : :
1068 : : pfree(decoded);
1069 : : pfree(buf.data);
1070 : : pfree(recordBuf.data);
1071 : : MemoryContextSwitchTo(oldCxt);
1072 : : }
1073 : : #endif
1074 : :
1075 : : /*
1076 : : * Update our global variables
1077 : : */
1078 : 2526706 : ProcLastRecPtr = StartPos;
1079 : 2526706 : XactLastRecEnd = EndPos;
1080 : :
1081 : : /* Report WAL traffic to the instrumentation. */
1082 [ - + ]: 2526706 : if (inserted)
1083 : : {
1084 : 2526706 : pgWalUsage.wal_bytes += rechdr->xl_tot_len;
1085 : 2526706 : pgWalUsage.wal_records++;
1086 : 2526706 : pgWalUsage.wal_fpi += num_fpi;
1087 : 2526706 : pgWalUsage.wal_fpi_bytes += fpi_bytes;
1088 : :
1089 : : /* Required for the flush of pending stats WAL data */
1090 : 2526706 : pgstat_report_fixed = true;
1091 : 2526706 : }
1092 : :
1093 : 2526706 : return EndPos;
1094 : 2526993 : }
1095 : :
1096 : : /*
1097 : : * Reserves the right amount of space for a record of given size from the WAL.
1098 : : * *StartPos is set to the beginning of the reserved section, *EndPos to
1099 : : * its end+1. *PrevPtr is set to the beginning of the previous record; it is
1100 : : * used to set the xl_prev of this record.
1101 : : *
1102 : : * This is the performance critical part of XLogInsert that must be serialized
1103 : : * across backends. The rest can happen mostly in parallel. Try to keep this
1104 : : * section as short as possible, insertpos_lck can be heavily contended on a
1105 : : * busy system.
1106 : : *
1107 : : * NB: The space calculation here must match the code in CopyXLogRecordToWAL,
1108 : : * where we actually copy the record to the reserved space.
1109 : : *
1110 : : * NB: Testing shows that XLogInsertRecord runs faster if this code is inlined;
1111 : : * however, because there are two call sites, the compiler is reluctant to
1112 : : * inline. We use pg_attribute_always_inline here to try to convince it.
1113 : : */
1114 : : static pg_attribute_always_inline void
1115 : 2526706 : ReserveXLogInsertLocation(int size, XLogRecPtr *StartPos, XLogRecPtr *EndPos,
1116 : : XLogRecPtr *PrevPtr)
1117 : : {
1118 : 2526706 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1119 : 2526706 : uint64 startbytepos;
1120 : 2526706 : uint64 endbytepos;
1121 : 2526706 : uint64 prevbytepos;
1122 : :
1123 : 2526706 : size = MAXALIGN(size);
1124 : :
1125 : : /* All (non xlog-switch) records should contain data. */
1126 [ + - ]: 2526706 : Assert(size > SizeOfXLogRecord);
1127 : :
1128 : : /*
1129 : : * The duration the spinlock needs to be held is minimized by minimizing
1130 : : * the calculations that have to be done while holding the lock. The
1131 : : * current tip of reserved WAL is kept in CurrBytePos, as a byte position
1132 : : * that only counts "usable" bytes in WAL, that is, it excludes all WAL
1133 : : * page headers. The mapping between "usable" byte positions and physical
1134 : : * positions (XLogRecPtrs) can be done outside the locked region, and
1135 : : * because the usable byte position doesn't include any headers, reserving
1136 : : * X bytes from WAL is almost as simple as "CurrBytePos += X".
1137 : : */
1138 [ + + ]: 2526706 : SpinLockAcquire(&Insert->insertpos_lck);
1139 : :
1140 : 2526706 : startbytepos = Insert->CurrBytePos;
1141 : 2526706 : endbytepos = startbytepos + size;
1142 : 2526706 : prevbytepos = Insert->PrevBytePos;
1143 : 2526706 : Insert->CurrBytePos = endbytepos;
1144 : 2526706 : Insert->PrevBytePos = startbytepos;
1145 : :
1146 : 2526706 : SpinLockRelease(&Insert->insertpos_lck);
1147 : :
1148 : 2526706 : *StartPos = XLogBytePosToRecPtr(startbytepos);
1149 : 2526706 : *EndPos = XLogBytePosToEndRecPtr(endbytepos);
1150 : 2526706 : *PrevPtr = XLogBytePosToRecPtr(prevbytepos);
1151 : :
1152 : : /*
1153 : : * Check that the conversions between "usable byte positions" and
1154 : : * XLogRecPtrs work consistently in both directions.
1155 : : */
1156 [ + - ]: 2526706 : Assert(XLogRecPtrToBytePos(*StartPos) == startbytepos);
1157 [ + - ]: 2526706 : Assert(XLogRecPtrToBytePos(*EndPos) == endbytepos);
1158 [ + - ]: 2526706 : Assert(XLogRecPtrToBytePos(*PrevPtr) == prevbytepos);
1159 : 2526706 : }
1160 : :
1161 : : /*
1162 : : * Like ReserveXLogInsertLocation(), but for an xlog-switch record.
1163 : : *
1164 : : * A log-switch record is handled slightly differently. The rest of the
1165 : : * segment will be reserved for this insertion, as indicated by the returned
1166 : : * *EndPos value. However, if we are already at the beginning of the current
1167 : : * segment, *StartPos and *EndPos are set to the current location without
1168 : : * reserving any space, and the function returns false.
1169 : : */
1170 : : static bool
1171 : 0 : ReserveXLogSwitch(XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
1172 : : {
1173 : 0 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1174 : 0 : uint64 startbytepos;
1175 : 0 : uint64 endbytepos;
1176 : 0 : uint64 prevbytepos;
1177 : 0 : uint32 size = MAXALIGN(SizeOfXLogRecord);
1178 : 0 : XLogRecPtr ptr;
1179 : 0 : uint32 segleft;
1180 : :
1181 : : /*
1182 : : * These calculations are a bit heavy-weight to be done while holding a
1183 : : * spinlock, but since we're holding all the WAL insertion locks, there
1184 : : * are no other inserters competing for it. GetXLogInsertRecPtr() does
1185 : : * compete for it, but that's not called very frequently.
1186 : : */
1187 [ # # ]: 0 : SpinLockAcquire(&Insert->insertpos_lck);
1188 : :
1189 : 0 : startbytepos = Insert->CurrBytePos;
1190 : :
1191 : 0 : ptr = XLogBytePosToEndRecPtr(startbytepos);
1192 [ # # ]: 0 : if (XLogSegmentOffset(ptr, wal_segment_size) == 0)
1193 : : {
1194 : 0 : SpinLockRelease(&Insert->insertpos_lck);
1195 : 0 : *EndPos = *StartPos = ptr;
1196 : 0 : return false;
1197 : : }
1198 : :
1199 : 0 : endbytepos = startbytepos + size;
1200 : 0 : prevbytepos = Insert->PrevBytePos;
1201 : :
1202 : 0 : *StartPos = XLogBytePosToRecPtr(startbytepos);
1203 : 0 : *EndPos = XLogBytePosToEndRecPtr(endbytepos);
1204 : :
1205 : 0 : segleft = wal_segment_size - XLogSegmentOffset(*EndPos, wal_segment_size);
1206 [ # # ]: 0 : if (segleft != wal_segment_size)
1207 : : {
1208 : : /* consume the rest of the segment */
1209 : 0 : *EndPos += segleft;
1210 : 0 : endbytepos = XLogRecPtrToBytePos(*EndPos);
1211 : 0 : }
1212 : 0 : Insert->CurrBytePos = endbytepos;
1213 : 0 : Insert->PrevBytePos = startbytepos;
1214 : :
1215 : 0 : SpinLockRelease(&Insert->insertpos_lck);
1216 : :
1217 : 0 : *PrevPtr = XLogBytePosToRecPtr(prevbytepos);
1218 : :
1219 [ # # ]: 0 : Assert(XLogSegmentOffset(*EndPos, wal_segment_size) == 0);
1220 [ # # ]: 0 : Assert(XLogRecPtrToBytePos(*EndPos) == endbytepos);
1221 [ # # ]: 0 : Assert(XLogRecPtrToBytePos(*StartPos) == startbytepos);
1222 [ # # ]: 0 : Assert(XLogRecPtrToBytePos(*PrevPtr) == prevbytepos);
1223 : :
1224 : 0 : return true;
1225 : 0 : }
1226 : :
1227 : : /*
1228 : : * Subroutine of XLogInsertRecord. Copies a WAL record to an already-reserved
1229 : : * area in the WAL.
1230 : : */
1231 : : static void
1232 : 2526706 : CopyXLogRecordToWAL(int write_len, bool isLogSwitch, XLogRecData *rdata,
1233 : : XLogRecPtr StartPos, XLogRecPtr EndPos, TimeLineID tli)
1234 : : {
1235 : 2526706 : char *currpos;
1236 : 2526706 : int freespace;
1237 : 2526706 : int written;
1238 : 2526706 : XLogRecPtr CurrPos;
1239 : 2526706 : XLogPageHeader pagehdr;
1240 : :
1241 : : /*
1242 : : * Get a pointer to the right place in the right WAL buffer to start
1243 : : * inserting to.
1244 : : */
1245 : 2526706 : CurrPos = StartPos;
1246 : 2526706 : currpos = GetXLogBuffer(CurrPos, tli);
1247 [ + - ]: 2526706 : freespace = INSERT_FREESPACE(CurrPos);
1248 : :
1249 : : /*
1250 : : * there should be enough space for at least the first field (xl_tot_len)
1251 : : * on this page.
1252 : : */
1253 [ + - ]: 2526706 : Assert(freespace >= sizeof(uint32));
1254 : :
1255 : : /* Copy record data */
1256 : 2526706 : written = 0;
1257 [ + + ]: 11098317 : while (rdata != NULL)
1258 : : {
1259 : 8571611 : const char *rdata_data = rdata->data;
1260 : 8571611 : int rdata_len = rdata->len;
1261 : :
1262 [ + + ]: 8615178 : while (rdata_len > freespace)
1263 : : {
1264 : : /*
1265 : : * Write what fits on this page, and continue on the next page.
1266 : : */
1267 [ + + - + ]: 43567 : Assert(CurrPos % XLOG_BLCKSZ >= SizeOfXLogShortPHD || freespace == 0);
1268 : 43567 : memcpy(currpos, rdata_data, freespace);
1269 : 43567 : rdata_data += freespace;
1270 : 43567 : rdata_len -= freespace;
1271 : 43567 : written += freespace;
1272 : 43567 : CurrPos += freespace;
1273 : :
1274 : : /*
1275 : : * Get pointer to beginning of next page, and set the xlp_rem_len
1276 : : * in the page header. Set XLP_FIRST_IS_CONTRECORD.
1277 : : *
1278 : : * It's safe to set the contrecord flag and xlp_rem_len without a
1279 : : * lock on the page. All the other flags were already set when the
1280 : : * page was initialized, in AdvanceXLInsertBuffer, and we're the
1281 : : * only backend that needs to set the contrecord flag.
1282 : : */
1283 : 43567 : currpos = GetXLogBuffer(CurrPos, tli);
1284 : 43567 : pagehdr = (XLogPageHeader) currpos;
1285 : 43567 : pagehdr->xlp_rem_len = write_len - written;
1286 : 43567 : pagehdr->xlp_info |= XLP_FIRST_IS_CONTRECORD;
1287 : :
1288 : : /* skip over the page header */
1289 [ + + ]: 43567 : if (XLogSegmentOffset(CurrPos, wal_segment_size) == 0)
1290 : : {
1291 : 21 : CurrPos += SizeOfXLogLongPHD;
1292 : 21 : currpos += SizeOfXLogLongPHD;
1293 : 21 : }
1294 : : else
1295 : : {
1296 : 43546 : CurrPos += SizeOfXLogShortPHD;
1297 : 43546 : currpos += SizeOfXLogShortPHD;
1298 : : }
1299 [ + - ]: 43567 : freespace = INSERT_FREESPACE(CurrPos);
1300 : : }
1301 : :
1302 [ - + # # ]: 8571611 : Assert(CurrPos % XLOG_BLCKSZ >= SizeOfXLogShortPHD || rdata_len == 0);
1303 : 8571611 : memcpy(currpos, rdata_data, rdata_len);
1304 : 8571611 : currpos += rdata_len;
1305 : 8571611 : CurrPos += rdata_len;
1306 : 8571611 : freespace -= rdata_len;
1307 : 8571611 : written += rdata_len;
1308 : :
1309 : 8571611 : rdata = rdata->next;
1310 : 8571611 : }
1311 [ + - ]: 2526706 : Assert(written == write_len);
1312 : :
1313 : : /*
1314 : : * If this was an xlog-switch, it's not enough to write the switch record,
1315 : : * we also have to consume all the remaining space in the WAL segment. We
1316 : : * have already reserved that space, but we need to actually fill it.
1317 : : */
1318 [ - + # # ]: 2526706 : if (isLogSwitch && XLogSegmentOffset(CurrPos, wal_segment_size) != 0)
1319 : : {
1320 : : /* An xlog-switch record doesn't contain any data besides the header */
1321 [ # # ]: 0 : Assert(write_len == SizeOfXLogRecord);
1322 : :
1323 : : /* Assert that we did reserve the right amount of space */
1324 [ # # ]: 0 : Assert(XLogSegmentOffset(EndPos, wal_segment_size) == 0);
1325 : :
1326 : : /* Use up all the remaining space on the current page */
1327 : 0 : CurrPos += freespace;
1328 : :
1329 : : /*
1330 : : * Cause all remaining pages in the segment to be flushed, leaving the
1331 : : * XLog position where it should be, at the start of the next segment.
1332 : : * We do this one page at a time, to make sure we don't deadlock
1333 : : * against ourselves if wal_buffers < wal_segment_size.
1334 : : */
1335 [ # # ]: 0 : while (CurrPos < EndPos)
1336 : : {
1337 : : /*
1338 : : * The minimal action to flush the page would be to call
1339 : : * WALInsertLockUpdateInsertingAt(CurrPos) followed by
1340 : : * AdvanceXLInsertBuffer(...). The page would be left initialized
1341 : : * mostly to zeros, except for the page header (always the short
1342 : : * variant, as this is never a segment's first page).
1343 : : *
1344 : : * The large vistas of zeros are good for compressibility, but the
1345 : : * headers interrupting them every XLOG_BLCKSZ (with values that
1346 : : * differ from page to page) are not. The effect varies with
1347 : : * compression tool, but bzip2 for instance compresses about an
1348 : : * order of magnitude worse if those headers are left in place.
1349 : : *
1350 : : * Rather than complicating AdvanceXLInsertBuffer itself (which is
1351 : : * called in heavily-loaded circumstances as well as this lightly-
1352 : : * loaded one) with variant behavior, we just use GetXLogBuffer
1353 : : * (which itself calls the two methods we need) to get the pointer
1354 : : * and zero most of the page. Then we just zero the page header.
1355 : : */
1356 : 0 : currpos = GetXLogBuffer(CurrPos, tli);
1357 [ # # # # : 0 : MemSet(currpos, 0, SizeOfXLogShortPHD);
# # # # #
# ]
1358 : :
1359 : 0 : CurrPos += XLOG_BLCKSZ;
1360 : : }
1361 : 0 : }
1362 : : else
1363 : : {
1364 : : /* Align the end position, so that the next record starts aligned */
1365 : 2526706 : CurrPos = MAXALIGN64(CurrPos);
1366 : : }
1367 : :
1368 [ + - ]: 2526706 : if (CurrPos != EndPos)
1369 [ # # # # ]: 0 : ereport(PANIC,
1370 : : errcode(ERRCODE_DATA_CORRUPTED),
1371 : : errmsg_internal("space reserved for WAL record does not match what was written"));
1372 : 2526706 : }
1373 : :
1374 : : /*
1375 : : * Acquire a WAL insertion lock, for inserting to WAL.
1376 : : */
1377 : : static void
1378 : 2526989 : WALInsertLockAcquire(void)
1379 : : {
1380 : 2526989 : bool immed;
1381 : :
1382 : : /*
1383 : : * It doesn't matter which of the WAL insertion locks we acquire, so try
1384 : : * the one we used last time. If the system isn't particularly busy, it's
1385 : : * a good bet that it's still available, and it's good to have some
1386 : : * affinity to a particular lock so that you don't unnecessarily bounce
1387 : : * cache lines between processes when there's no contention.
1388 : : *
1389 : : * If this is the first time through in this backend, pick a lock
1390 : : * (semi-)randomly. This allows the locks to be used evenly if you have a
1391 : : * lot of very short connections.
1392 : : */
1393 : : static int lockToTry = -1;
1394 : :
1395 [ + + ]: 2526989 : if (lockToTry == -1)
1396 : 281 : lockToTry = MyProcNumber % NUM_XLOGINSERT_LOCKS;
1397 : 2526989 : MyLockNo = lockToTry;
1398 : :
1399 : : /*
1400 : : * The insertingAt value is initially set to 0, as we don't know our
1401 : : * insert location yet.
1402 : : */
1403 : 2526989 : immed = LWLockAcquire(&WALInsertLocks[MyLockNo].l.lock, LW_EXCLUSIVE);
1404 [ + + ]: 2526989 : if (!immed)
1405 : : {
1406 : : /*
1407 : : * If we couldn't get the lock immediately, try another lock next
1408 : : * time. On a system with more insertion locks than concurrent
1409 : : * inserters, this causes all the inserters to eventually migrate to a
1410 : : * lock that no-one else is using. On a system with more inserters
1411 : : * than locks, it still helps to distribute the inserters evenly
1412 : : * across the locks.
1413 : : */
1414 : 401 : lockToTry = (lockToTry + 1) % NUM_XLOGINSERT_LOCKS;
1415 : 401 : }
1416 : 2526989 : }
1417 : :
1418 : : /*
1419 : : * Acquire all WAL insertion locks, to prevent other backends from inserting
1420 : : * to WAL.
1421 : : */
1422 : : static void
1423 : 12 : WALInsertLockAcquireExclusive(void)
1424 : : {
1425 : 12 : int i;
1426 : :
1427 : : /*
1428 : : * When holding all the locks, all but the last lock's insertingAt
1429 : : * indicator is set to 0xFFFFFFFFFFFFFFFF, which is higher than any real
1430 : : * XLogRecPtr value, to make sure that no-one blocks waiting on those.
1431 : : */
1432 [ + + ]: 96 : for (i = 0; i < NUM_XLOGINSERT_LOCKS - 1; i++)
1433 : : {
1434 : 84 : LWLockAcquire(&WALInsertLocks[i].l.lock, LW_EXCLUSIVE);
1435 : 168 : LWLockUpdateVar(&WALInsertLocks[i].l.lock,
1436 : 84 : &WALInsertLocks[i].l.insertingAt,
1437 : : PG_UINT64_MAX);
1438 : 84 : }
1439 : : /* Variable value reset to 0 at release */
1440 : 12 : LWLockAcquire(&WALInsertLocks[i].l.lock, LW_EXCLUSIVE);
1441 : :
1442 : 12 : holdingAllLocks = true;
1443 : 12 : }
1444 : :
1445 : : /*
1446 : : * Release our insertion lock (or locks, if we're holding them all).
1447 : : *
1448 : : * NB: Reset all variables to 0, so they cause LWLockWaitForVar to block the
1449 : : * next time the lock is acquired.
1450 : : */
1451 : : static void
1452 : 2527001 : WALInsertLockRelease(void)
1453 : : {
1454 [ + + ]: 2527001 : if (holdingAllLocks)
1455 : : {
1456 : 12 : int i;
1457 : :
1458 [ + + ]: 108 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
1459 : 192 : LWLockReleaseClearVar(&WALInsertLocks[i].l.lock,
1460 : 96 : &WALInsertLocks[i].l.insertingAt,
1461 : : 0);
1462 : :
1463 : 12 : holdingAllLocks = false;
1464 : 12 : }
1465 : : else
1466 : : {
1467 : 5053978 : LWLockReleaseClearVar(&WALInsertLocks[MyLockNo].l.lock,
1468 : 2526989 : &WALInsertLocks[MyLockNo].l.insertingAt,
1469 : : 0);
1470 : : }
1471 : 2527001 : }
1472 : :
1473 : : /*
1474 : : * Update our insertingAt value, to let others know that we've finished
1475 : : * inserting up to that point.
1476 : : */
1477 : : static void
1478 : 30100 : WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt)
1479 : : {
1480 [ - + ]: 30100 : if (holdingAllLocks)
1481 : : {
1482 : : /*
1483 : : * We use the last lock to mark our actual position, see comments in
1484 : : * WALInsertLockAcquireExclusive.
1485 : : */
1486 : 0 : LWLockUpdateVar(&WALInsertLocks[NUM_XLOGINSERT_LOCKS - 1].l.lock,
1487 : 0 : &WALInsertLocks[NUM_XLOGINSERT_LOCKS - 1].l.insertingAt,
1488 : 0 : insertingAt);
1489 : 0 : }
1490 : : else
1491 : 60200 : LWLockUpdateVar(&WALInsertLocks[MyLockNo].l.lock,
1492 : 30100 : &WALInsertLocks[MyLockNo].l.insertingAt,
1493 : 30100 : insertingAt);
1494 : 30100 : }
1495 : :
1496 : : /*
1497 : : * Wait for any WAL insertions < upto to finish.
1498 : : *
1499 : : * Returns the location of the oldest insertion that is still in-progress.
1500 : : * Any WAL prior to that point has been fully copied into WAL buffers, and
1501 : : * can be flushed out to disk. Because this waits for any insertions older
1502 : : * than 'upto' to finish, the return value is always >= 'upto'.
1503 : : *
1504 : : * Note: When you are about to write out WAL, you must call this function
1505 : : * *before* acquiring WALWriteLock, to avoid deadlocks. This function might
1506 : : * need to wait for an insertion to finish (or at least advance to next
1507 : : * uninitialized page), and the inserter might need to evict an old WAL buffer
1508 : : * to make room for a new one, which in turn requires WALWriteLock.
1509 : : */
1510 : : static XLogRecPtr
1511 : 24094 : WaitXLogInsertionsToFinish(XLogRecPtr upto)
1512 : : {
1513 : 24094 : uint64 bytepos;
1514 : 24094 : XLogRecPtr inserted;
1515 : 24094 : XLogRecPtr reservedUpto;
1516 : 24094 : XLogRecPtr finishedUpto;
1517 : 24094 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1518 : 24094 : int i;
1519 : :
1520 [ + - ]: 24094 : if (MyProc == NULL)
1521 [ # # # # ]: 0 : elog(PANIC, "cannot wait without a PGPROC structure");
1522 : :
1523 : : /*
1524 : : * Check if there's any work to do. Use a barrier to ensure we get the
1525 : : * freshest value.
1526 : : */
1527 : 24094 : inserted = pg_atomic_read_membarrier_u64(&XLogCtl->logInsertResult);
1528 [ + + ]: 24094 : if (upto <= inserted)
1529 : 4039 : return inserted;
1530 : :
1531 : : /* Read the current insert position */
1532 [ - + ]: 20055 : SpinLockAcquire(&Insert->insertpos_lck);
1533 : 20055 : bytepos = Insert->CurrBytePos;
1534 : 20055 : SpinLockRelease(&Insert->insertpos_lck);
1535 : 20055 : reservedUpto = XLogBytePosToEndRecPtr(bytepos);
1536 : :
1537 : : /*
1538 : : * No-one should request to flush a piece of WAL that hasn't even been
1539 : : * reserved yet. However, it can happen if there is a block with a bogus
1540 : : * LSN on disk, for example. XLogFlush checks for that situation and
1541 : : * complains, but only after the flush. Here we just assume that to mean
1542 : : * that all WAL that has been reserved needs to be finished. In this
1543 : : * corner-case, the return value can be smaller than 'upto' argument.
1544 : : */
1545 [ + - ]: 20055 : if (upto > reservedUpto)
1546 : : {
1547 [ # # # # ]: 0 : ereport(LOG,
1548 : : errmsg("request to flush past end of generated WAL; request %X/%08X, current position %X/%08X",
1549 : : LSN_FORMAT_ARGS(upto), LSN_FORMAT_ARGS(reservedUpto)));
1550 : 0 : upto = reservedUpto;
1551 : 0 : }
1552 : :
1553 : : /*
1554 : : * Loop through all the locks, sleeping on any in-progress insert older
1555 : : * than 'upto'.
1556 : : *
1557 : : * finishedUpto is our return value, indicating the point upto which all
1558 : : * the WAL insertions have been finished. Initialize it to the head of
1559 : : * reserved WAL, and as we iterate through the insertion locks, back it
1560 : : * out for any insertion that's still in progress.
1561 : : */
1562 : 20055 : finishedUpto = reservedUpto;
1563 [ + + ]: 180495 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
1564 : : {
1565 : 160440 : XLogRecPtr insertingat = InvalidXLogRecPtr;
1566 : :
1567 : 160440 : do
1568 : : {
1569 : : /*
1570 : : * See if this insertion is in progress. LWLockWaitForVar will
1571 : : * wait for the lock to be released, or for the 'value' to be set
1572 : : * by a LWLockUpdateVar call. When a lock is initially acquired,
1573 : : * its value is 0 (InvalidXLogRecPtr), which means that we don't
1574 : : * know where it's inserting yet. We will have to wait for it. If
1575 : : * it's a small insertion, the record will most likely fit on the
1576 : : * same page and the inserter will release the lock without ever
1577 : : * calling LWLockUpdateVar. But if it has to sleep, it will
1578 : : * advertise the insertion point with LWLockUpdateVar before
1579 : : * sleeping.
1580 : : *
1581 : : * In this loop we are only waiting for insertions that started
1582 : : * before WaitXLogInsertionsToFinish was called. The lack of
1583 : : * memory barriers in the loop means that we might see locks as
1584 : : * "unused" that have since become used. This is fine because
1585 : : * they only can be used for later insertions that we would not
1586 : : * want to wait on anyway. Not taking a lock to acquire the
1587 : : * current insertingAt value means that we might see older
1588 : : * insertingAt values. This is also fine, because if we read a
1589 : : * value too old, we will add ourselves to the wait queue, which
1590 : : * contains atomic operations.
1591 : : */
1592 [ + + + + ]: 321928 : if (LWLockWaitForVar(&WALInsertLocks[i].l.lock,
1593 : 160964 : &WALInsertLocks[i].l.insertingAt,
1594 : 160964 : insertingat, &insertingat))
1595 : : {
1596 : : /* the lock was free, so no insertion in progress */
1597 : 160184 : insertingat = InvalidXLogRecPtr;
1598 : 160184 : break;
1599 : : }
1600 : :
1601 : : /*
1602 : : * This insertion is still in progress. Have to wait, unless the
1603 : : * inserter has proceeded past 'upto'.
1604 : : */
1605 [ + + ]: 780 : } while (insertingat < upto);
1606 : :
1607 [ + + + + ]: 160440 : if (XLogRecPtrIsValid(insertingat) && insertingat < finishedUpto)
1608 : 28 : finishedUpto = insertingat;
1609 : 160440 : }
1610 : :
1611 : : /*
1612 : : * Advance the limit we know to have been inserted and return the freshest
1613 : : * value we know of, which might be beyond what we requested if somebody
1614 : : * is concurrently doing this with an 'upto' pointer ahead of us.
1615 : : */
1616 : 40110 : finishedUpto = pg_atomic_monotonic_advance_u64(&XLogCtl->logInsertResult,
1617 : 20055 : finishedUpto);
1618 : :
1619 : 20055 : return finishedUpto;
1620 : 24094 : }
1621 : :
1622 : : /*
1623 : : * Get a pointer to the right location in the WAL buffer containing the
1624 : : * given XLogRecPtr.
1625 : : *
1626 : : * If the page is not initialized yet, it is initialized. That might require
1627 : : * evicting an old dirty buffer from the buffer cache, which means I/O.
1628 : : *
1629 : : * The caller must ensure that the page containing the requested location
1630 : : * isn't evicted yet, and won't be evicted. The way to ensure that is to
1631 : : * hold onto a WAL insertion lock with the insertingAt position set to
1632 : : * something <= ptr. GetXLogBuffer() will update insertingAt if it needs
1633 : : * to evict an old page from the buffer. (This means that once you call
1634 : : * GetXLogBuffer() with a given 'ptr', you must not access anything before
1635 : : * that point anymore, and must not call GetXLogBuffer() with an older 'ptr'
1636 : : * later, because older buffers might be recycled already)
1637 : : */
1638 : : static char *
1639 : 2570273 : GetXLogBuffer(XLogRecPtr ptr, TimeLineID tli)
1640 : : {
1641 : 2570273 : int idx;
1642 : 2570273 : XLogRecPtr endptr;
1643 : : static uint64 cachedPage = 0;
1644 : : static char *cachedPos = NULL;
1645 : 2570273 : XLogRecPtr expectedEndPtr;
1646 : :
1647 : : /*
1648 : : * Fast path for the common case that we need to access again the same
1649 : : * page as last time.
1650 : : */
1651 [ + + ]: 2570273 : if (ptr / XLOG_BLCKSZ == cachedPage)
1652 : : {
1653 [ + - ]: 2498898 : Assert(((XLogPageHeader) cachedPos)->xlp_magic == XLOG_PAGE_MAGIC);
1654 [ + - ]: 2498898 : Assert(((XLogPageHeader) cachedPos)->xlp_pageaddr == ptr - (ptr % XLOG_BLCKSZ));
1655 : 2498898 : return cachedPos + ptr % XLOG_BLCKSZ;
1656 : : }
1657 : :
1658 : : /*
1659 : : * The XLog buffer cache is organized so that a page is always loaded to a
1660 : : * particular buffer. That way we can easily calculate the buffer a given
1661 : : * page must be loaded into, from the XLogRecPtr alone.
1662 : : */
1663 : 71375 : idx = XLogRecPtrToBufIdx(ptr);
1664 : :
1665 : : /*
1666 : : * See what page is loaded in the buffer at the moment. It could be the
1667 : : * page we're looking for, or something older. It can't be anything newer
1668 : : * - that would imply the page we're looking for has already been written
1669 : : * out to disk and evicted, and the caller is responsible for making sure
1670 : : * that doesn't happen.
1671 : : *
1672 : : * We don't hold a lock while we read the value. If someone is just about
1673 : : * to initialize or has just initialized the page, it's possible that we
1674 : : * get InvalidXLogRecPtr. That's ok, we'll grab the mapping lock (in
1675 : : * AdvanceXLInsertBuffer) and retry if we see anything other than the page
1676 : : * we're looking for.
1677 : : */
1678 : 71375 : expectedEndPtr = ptr;
1679 : 71375 : expectedEndPtr += XLOG_BLCKSZ - ptr % XLOG_BLCKSZ;
1680 : :
1681 : 71375 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1682 [ + + ]: 71375 : if (expectedEndPtr != endptr)
1683 : : {
1684 : 30100 : XLogRecPtr initializedUpto;
1685 : :
1686 : : /*
1687 : : * Before calling AdvanceXLInsertBuffer(), which can block, let others
1688 : : * know how far we're finished with inserting the record.
1689 : : *
1690 : : * NB: If 'ptr' points to just after the page header, advertise a
1691 : : * position at the beginning of the page rather than 'ptr' itself. If
1692 : : * there are no other insertions running, someone might try to flush
1693 : : * up to our advertised location. If we advertised a position after
1694 : : * the page header, someone might try to flush the page header, even
1695 : : * though page might actually not be initialized yet. As the first
1696 : : * inserter on the page, we are effectively responsible for making
1697 : : * sure that it's initialized, before we let insertingAt to move past
1698 : : * the page header.
1699 : : */
1700 [ + + - + ]: 30100 : if (ptr % XLOG_BLCKSZ == SizeOfXLogShortPHD &&
1701 : 1582 : XLogSegmentOffset(ptr, wal_segment_size) > XLOG_BLCKSZ)
1702 : 1582 : initializedUpto = ptr - SizeOfXLogShortPHD;
1703 [ + + + + ]: 28518 : else if (ptr % XLOG_BLCKSZ == SizeOfXLogLongPHD &&
1704 : 116 : XLogSegmentOffset(ptr, wal_segment_size) < XLOG_BLCKSZ)
1705 : 1 : initializedUpto = ptr - SizeOfXLogLongPHD;
1706 : : else
1707 : 28517 : initializedUpto = ptr;
1708 : :
1709 : 30100 : WALInsertLockUpdateInsertingAt(initializedUpto);
1710 : :
1711 : 30100 : AdvanceXLInsertBuffer(ptr, tli, false);
1712 : 30100 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1713 : :
1714 [ + - ]: 30100 : if (expectedEndPtr != endptr)
1715 [ # # # # ]: 0 : elog(PANIC, "could not find WAL buffer for %X/%08X",
1716 : : LSN_FORMAT_ARGS(ptr));
1717 : 30100 : }
1718 : : else
1719 : : {
1720 : : /*
1721 : : * Make sure the initialization of the page is visible to us, and
1722 : : * won't arrive later to overwrite the WAL data we write on the page.
1723 : : */
1724 : 41275 : pg_memory_barrier();
1725 : : }
1726 : :
1727 : : /*
1728 : : * Found the buffer holding this page. Return a pointer to the right
1729 : : * offset within the page.
1730 : : */
1731 : 71375 : cachedPage = ptr / XLOG_BLCKSZ;
1732 : 71375 : cachedPos = XLogCtl->pages + idx * (Size) XLOG_BLCKSZ;
1733 : :
1734 [ + - ]: 71375 : Assert(((XLogPageHeader) cachedPos)->xlp_magic == XLOG_PAGE_MAGIC);
1735 [ + - ]: 71375 : Assert(((XLogPageHeader) cachedPos)->xlp_pageaddr == ptr - (ptr % XLOG_BLCKSZ));
1736 : :
1737 : 71375 : return cachedPos + ptr % XLOG_BLCKSZ;
1738 : 2570273 : }
1739 : :
1740 : : /*
1741 : : * Read WAL data directly from WAL buffers, if available. Returns the number
1742 : : * of bytes read successfully.
1743 : : *
1744 : : * Fewer than 'count' bytes may be read if some of the requested WAL data has
1745 : : * already been evicted.
1746 : : *
1747 : : * No locks are taken.
1748 : : *
1749 : : * Caller should ensure that it reads no further than LogwrtResult.Write
1750 : : * (which should have been updated by the caller when determining how far to
1751 : : * read). The 'tli' argument is only used as a convenient safety check so that
1752 : : * callers do not read from WAL buffers on a historical timeline.
1753 : : */
1754 : : Size
1755 : 0 : WALReadFromBuffers(char *dstbuf, XLogRecPtr startptr, Size count,
1756 : : TimeLineID tli)
1757 : : {
1758 : 0 : char *pdst = dstbuf;
1759 : 0 : XLogRecPtr recptr = startptr;
1760 : 0 : XLogRecPtr inserted;
1761 : 0 : Size nbytes = count;
1762 : :
1763 [ # # # # ]: 0 : if (RecoveryInProgress() || tli != GetWALInsertionTimeLine())
1764 : 0 : return 0;
1765 : :
1766 [ # # ]: 0 : Assert(XLogRecPtrIsValid(startptr));
1767 : :
1768 : : /*
1769 : : * Caller should ensure that the requested data has been inserted into WAL
1770 : : * buffers before we try to read it.
1771 : : */
1772 : 0 : inserted = pg_atomic_read_u64(&XLogCtl->logInsertResult);
1773 [ # # ]: 0 : if (startptr + count > inserted)
1774 [ # # # # ]: 0 : ereport(ERROR,
1775 : : errmsg("cannot read past end of generated WAL: requested %X/%08X, current position %X/%08X",
1776 : : LSN_FORMAT_ARGS(startptr + count),
1777 : : LSN_FORMAT_ARGS(inserted)));
1778 : :
1779 : : /*
1780 : : * Loop through the buffers without a lock. For each buffer, atomically
1781 : : * read and verify the end pointer, then copy the data out, and finally
1782 : : * re-read and re-verify the end pointer.
1783 : : *
1784 : : * Once a page is evicted, it never returns to the WAL buffers, so if the
1785 : : * end pointer matches the expected end pointer before and after we copy
1786 : : * the data, then the right page must have been present during the data
1787 : : * copy. Read barriers are necessary to ensure that the data copy actually
1788 : : * happens between the two verification steps.
1789 : : *
1790 : : * If either verification fails, we simply terminate the loop and return
1791 : : * with the data that had been already copied out successfully.
1792 : : */
1793 [ # # ]: 0 : while (nbytes > 0)
1794 : : {
1795 : 0 : uint32 offset = recptr % XLOG_BLCKSZ;
1796 : 0 : int idx = XLogRecPtrToBufIdx(recptr);
1797 : 0 : XLogRecPtr expectedEndPtr;
1798 : 0 : XLogRecPtr endptr;
1799 : 0 : const char *page;
1800 : 0 : const char *psrc;
1801 : 0 : Size npagebytes;
1802 : :
1803 : : /*
1804 : : * Calculate the end pointer we expect in the xlblocks array if the
1805 : : * correct page is present.
1806 : : */
1807 : 0 : expectedEndPtr = recptr + (XLOG_BLCKSZ - offset);
1808 : :
1809 : : /*
1810 : : * First verification step: check that the correct page is present in
1811 : : * the WAL buffers.
1812 : : */
1813 : 0 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1814 [ # # ]: 0 : if (expectedEndPtr != endptr)
1815 : 0 : break;
1816 : :
1817 : : /*
1818 : : * The correct page is present (or was at the time the endptr was
1819 : : * read; must re-verify later). Calculate pointer to source data and
1820 : : * determine how much data to read from this page.
1821 : : */
1822 : 0 : page = XLogCtl->pages + idx * (Size) XLOG_BLCKSZ;
1823 : 0 : psrc = page + offset;
1824 [ # # ]: 0 : npagebytes = Min(nbytes, XLOG_BLCKSZ - offset);
1825 : :
1826 : : /*
1827 : : * Ensure that the data copy and the first verification step are not
1828 : : * reordered.
1829 : : */
1830 : 0 : pg_read_barrier();
1831 : :
1832 : : /* data copy */
1833 : 0 : memcpy(pdst, psrc, npagebytes);
1834 : :
1835 : : /*
1836 : : * Ensure that the data copy and the second verification step are not
1837 : : * reordered.
1838 : : */
1839 : 0 : pg_read_barrier();
1840 : :
1841 : : /*
1842 : : * Second verification step: check that the page we read from wasn't
1843 : : * evicted while we were copying the data.
1844 : : */
1845 : 0 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1846 [ # # ]: 0 : if (expectedEndPtr != endptr)
1847 : 0 : break;
1848 : :
1849 : 0 : pdst += npagebytes;
1850 : 0 : recptr += npagebytes;
1851 : 0 : nbytes -= npagebytes;
1852 [ # # # ]: 0 : }
1853 : :
1854 [ # # ]: 0 : Assert(pdst - dstbuf <= count);
1855 : :
1856 : 0 : return pdst - dstbuf;
1857 : 0 : }
1858 : :
1859 : : /*
1860 : : * Converts a "usable byte position" to XLogRecPtr. A usable byte position
1861 : : * is the position starting from the beginning of WAL, excluding all WAL
1862 : : * page headers.
1863 : : */
1864 : : static XLogRecPtr
1865 : 5053415 : XLogBytePosToRecPtr(uint64 bytepos)
1866 : : {
1867 : 5053415 : uint64 fullsegs;
1868 : 5053415 : uint64 fullpages;
1869 : 5053415 : uint64 bytesleft;
1870 : 5053415 : uint32 seg_offset;
1871 : 5053415 : XLogRecPtr result;
1872 : :
1873 : 5053415 : fullsegs = bytepos / UsableBytesInSegment;
1874 : 5053415 : bytesleft = bytepos % UsableBytesInSegment;
1875 : :
1876 [ + + ]: 5053415 : if (bytesleft < XLOG_BLCKSZ - SizeOfXLogLongPHD)
1877 : : {
1878 : : /* fits on first page of segment */
1879 : 3315 : seg_offset = bytesleft + SizeOfXLogLongPHD;
1880 : 3315 : }
1881 : : else
1882 : : {
1883 : : /* account for the first page on segment with long header */
1884 : 5050100 : seg_offset = XLOG_BLCKSZ;
1885 : 5050100 : bytesleft -= XLOG_BLCKSZ - SizeOfXLogLongPHD;
1886 : :
1887 : 5050100 : fullpages = bytesleft / UsableBytesInPage;
1888 : 5050100 : bytesleft = bytesleft % UsableBytesInPage;
1889 : :
1890 : 5050100 : seg_offset += fullpages * XLOG_BLCKSZ + bytesleft + SizeOfXLogShortPHD;
1891 : : }
1892 : :
1893 : 5053415 : XLogSegNoOffsetToRecPtr(fullsegs, seg_offset, wal_segment_size, result);
1894 : :
1895 : 10106830 : return result;
1896 : 5053415 : }
1897 : :
1898 : : /*
1899 : : * Like XLogBytePosToRecPtr, but if the position is at a page boundary,
1900 : : * returns a pointer to the beginning of the page (ie. before page header),
1901 : : * not to where the first xlog record on that page would go to. This is used
1902 : : * when converting a pointer to the end of a record.
1903 : : */
1904 : : static XLogRecPtr
1905 : 2546761 : XLogBytePosToEndRecPtr(uint64 bytepos)
1906 : : {
1907 : 2546761 : uint64 fullsegs;
1908 : 2546761 : uint64 fullpages;
1909 : 2546761 : uint64 bytesleft;
1910 : 2546761 : uint32 seg_offset;
1911 : 2546761 : XLogRecPtr result;
1912 : :
1913 : 2546761 : fullsegs = bytepos / UsableBytesInSegment;
1914 : 2546761 : bytesleft = bytepos % UsableBytesInSegment;
1915 : :
1916 [ + + ]: 2546761 : if (bytesleft < XLOG_BLCKSZ - SizeOfXLogLongPHD)
1917 : : {
1918 : : /* fits on first page of segment */
1919 [ + + ]: 1688 : if (bytesleft == 0)
1920 : 1 : seg_offset = 0;
1921 : : else
1922 : 1687 : seg_offset = bytesleft + SizeOfXLogLongPHD;
1923 : 1688 : }
1924 : : else
1925 : : {
1926 : : /* account for the first page on segment with long header */
1927 : 2545073 : seg_offset = XLOG_BLCKSZ;
1928 : 2545073 : bytesleft -= XLOG_BLCKSZ - SizeOfXLogLongPHD;
1929 : :
1930 : 2545073 : fullpages = bytesleft / UsableBytesInPage;
1931 : 2545073 : bytesleft = bytesleft % UsableBytesInPage;
1932 : :
1933 [ + + ]: 2545073 : if (bytesleft == 0)
1934 : 2499 : seg_offset += fullpages * XLOG_BLCKSZ + bytesleft;
1935 : : else
1936 : 2542574 : seg_offset += fullpages * XLOG_BLCKSZ + bytesleft + SizeOfXLogShortPHD;
1937 : : }
1938 : :
1939 : 2546761 : XLogSegNoOffsetToRecPtr(fullsegs, seg_offset, wal_segment_size, result);
1940 : :
1941 : 5093522 : return result;
1942 : 2546761 : }
1943 : :
1944 : : /*
1945 : : * Convert an XLogRecPtr to a "usable byte position".
1946 : : */
1947 : : static uint64
1948 : 7580126 : XLogRecPtrToBytePos(XLogRecPtr ptr)
1949 : : {
1950 : 7580126 : uint64 fullsegs;
1951 : 7580126 : uint32 fullpages;
1952 : 7580126 : uint32 offset;
1953 : 7580126 : uint64 result;
1954 : :
1955 : 7580126 : XLByteToSeg(ptr, fullsegs, wal_segment_size);
1956 : :
1957 : 7580126 : fullpages = (XLogSegmentOffset(ptr, wal_segment_size)) / XLOG_BLCKSZ;
1958 : 7580126 : offset = ptr % XLOG_BLCKSZ;
1959 : :
1960 [ + + ]: 7580126 : if (fullpages == 0)
1961 : : {
1962 : 4973 : result = fullsegs * UsableBytesInSegment;
1963 [ + + ]: 4973 : if (offset > 0)
1964 : : {
1965 [ + - ]: 4972 : Assert(offset >= SizeOfXLogLongPHD);
1966 : 4972 : result += offset - SizeOfXLogLongPHD;
1967 : 4972 : }
1968 : 4973 : }
1969 : : else
1970 : : {
1971 : 15150306 : result = fullsegs * UsableBytesInSegment +
1972 : 7575153 : (XLOG_BLCKSZ - SizeOfXLogLongPHD) + /* account for first page */
1973 : 7575153 : (fullpages - 1) * UsableBytesInPage; /* full pages */
1974 [ + + ]: 7575153 : if (offset > 0)
1975 : : {
1976 [ + - ]: 7572676 : Assert(offset >= SizeOfXLogShortPHD);
1977 : 7572676 : result += offset - SizeOfXLogShortPHD;
1978 : 7572676 : }
1979 : : }
1980 : :
1981 : 15160252 : return result;
1982 : 7580126 : }
1983 : :
1984 : : /*
1985 : : * Initialize XLOG buffers, writing out old buffers if they still contain
1986 : : * unwritten data, upto the page containing 'upto'. Or if 'opportunistic' is
1987 : : * true, initialize as many pages as we can without having to write out
1988 : : * unwritten data. Any new pages are initialized to zeros, with pages headers
1989 : : * initialized properly.
1990 : : */
1991 : : static void
1992 : 30113 : AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
1993 : : {
1994 : 30113 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1995 : 30113 : int nextidx;
1996 : 30113 : XLogRecPtr OldPageRqstPtr;
1997 : 30113 : XLogwrtRqst WriteRqst;
1998 : 30113 : XLogRecPtr NewPageEndPtr = InvalidXLogRecPtr;
1999 : 30113 : XLogRecPtr NewPageBeginPtr;
2000 : 30113 : XLogPageHeader NewPage;
2001 : 30113 : int npages pg_attribute_unused() = 0;
2002 : :
2003 : 30113 : LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE);
2004 : :
2005 : : /*
2006 : : * Now that we have the lock, check if someone initialized the page
2007 : : * already.
2008 : : */
2009 [ + + + + ]: 65657 : while (upto >= XLogCtl->InitializedUpTo || opportunistic)
2010 : : {
2011 : 35557 : nextidx = XLogRecPtrToBufIdx(XLogCtl->InitializedUpTo);
2012 : :
2013 : : /*
2014 : : * Get ending-offset of the buffer page we need to replace (this may
2015 : : * be zero if the buffer hasn't been used yet). Fall through if it's
2016 : : * already written out.
2017 : : */
2018 : 35557 : OldPageRqstPtr = pg_atomic_read_u64(&XLogCtl->xlblocks[nextidx]);
2019 [ + + ]: 35557 : if (LogwrtResult.Write < OldPageRqstPtr)
2020 : : {
2021 : : /*
2022 : : * Nope, got work to do. If we just want to pre-initialize as much
2023 : : * as we can without flushing, give up now.
2024 : : */
2025 [ + + ]: 3932 : if (opportunistic)
2026 : 13 : break;
2027 : :
2028 : : /* Advance shared memory write request position */
2029 [ + - ]: 3919 : SpinLockAcquire(&XLogCtl->info_lck);
2030 [ + - ]: 3919 : if (XLogCtl->LogwrtRqst.Write < OldPageRqstPtr)
2031 : 0 : XLogCtl->LogwrtRqst.Write = OldPageRqstPtr;
2032 : 3919 : SpinLockRelease(&XLogCtl->info_lck);
2033 : :
2034 : : /*
2035 : : * Acquire an up-to-date LogwrtResult value and see if we still
2036 : : * need to write it or if someone else already did.
2037 : : */
2038 : 3919 : RefreshXLogWriteResult(LogwrtResult);
2039 [ + + ]: 3919 : if (LogwrtResult.Write < OldPageRqstPtr)
2040 : : {
2041 : : /*
2042 : : * Must acquire write lock. Release WALBufMappingLock first,
2043 : : * to make sure that all insertions that we need to wait for
2044 : : * can finish (up to this same position). Otherwise we risk
2045 : : * deadlock.
2046 : : */
2047 : 3846 : LWLockRelease(WALBufMappingLock);
2048 : :
2049 : 3846 : WaitXLogInsertionsToFinish(OldPageRqstPtr);
2050 : :
2051 : 3846 : LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
2052 : :
2053 : 3846 : RefreshXLogWriteResult(LogwrtResult);
2054 [ + + ]: 3846 : if (LogwrtResult.Write >= OldPageRqstPtr)
2055 : : {
2056 : : /* OK, someone wrote it already */
2057 : 1 : LWLockRelease(WALWriteLock);
2058 : 1 : }
2059 : : else
2060 : : {
2061 : : /* Have to write it ourselves */
2062 : 3845 : TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_START();
2063 : 3845 : WriteRqst.Write = OldPageRqstPtr;
2064 : 3845 : WriteRqst.Flush = 0;
2065 : 3845 : XLogWrite(WriteRqst, tli, false);
2066 : 3845 : LWLockRelease(WALWriteLock);
2067 : 3845 : pgWalUsage.wal_buffers_full++;
2068 : 3845 : TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
2069 : :
2070 : : /*
2071 : : * Required for the flush of pending stats WAL data, per
2072 : : * update of pgWalUsage.
2073 : : */
2074 : 3845 : pgstat_report_fixed = true;
2075 : : }
2076 : : /* Re-acquire WALBufMappingLock and retry */
2077 : 3846 : LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE);
2078 : 3846 : continue;
2079 : : }
2080 : 73 : }
2081 : :
2082 : : /*
2083 : : * Now the next buffer slot is free and we can set it up to be the
2084 : : * next output page.
2085 : : */
2086 : 31698 : NewPageBeginPtr = XLogCtl->InitializedUpTo;
2087 : 31698 : NewPageEndPtr = NewPageBeginPtr + XLOG_BLCKSZ;
2088 : :
2089 [ - + ]: 31698 : Assert(XLogRecPtrToBufIdx(NewPageBeginPtr) == nextidx);
2090 : :
2091 : 31698 : NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * (Size) XLOG_BLCKSZ);
2092 : :
2093 : : /*
2094 : : * Mark the xlblock with InvalidXLogRecPtr and issue a write barrier
2095 : : * before initializing. Otherwise, the old page may be partially
2096 : : * zeroed but look valid.
2097 : : */
2098 : 31698 : pg_atomic_write_u64(&XLogCtl->xlblocks[nextidx], InvalidXLogRecPtr);
2099 : 31698 : pg_write_barrier();
2100 : :
2101 : : /*
2102 : : * Be sure to re-zero the buffer so that bytes beyond what we've
2103 : : * written will look like zeroes and not valid XLOG records...
2104 : : */
2105 [ + - + - : 31698 : MemSet(NewPage, 0, XLOG_BLCKSZ);
+ - + - #
# ]
2106 : :
2107 : : /*
2108 : : * Fill the new page's header
2109 : : */
2110 : 31698 : NewPage->xlp_magic = XLOG_PAGE_MAGIC;
2111 : :
2112 : : /* NewPage->xlp_info = 0; */ /* done by memset */
2113 : 31698 : NewPage->xlp_tli = tli;
2114 : 31698 : NewPage->xlp_pageaddr = NewPageBeginPtr;
2115 : :
2116 : : /* NewPage->xlp_rem_len = 0; */ /* done by memset */
2117 : :
2118 : : /*
2119 : : * If online backup is not in progress, mark the header to indicate
2120 : : * that WAL records beginning in this page have removable backup
2121 : : * blocks. This allows the WAL archiver to know whether it is safe to
2122 : : * compress archived WAL data by transforming full-block records into
2123 : : * the non-full-block format. It is sufficient to record this at the
2124 : : * page level because we force a page switch (in fact a segment
2125 : : * switch) when starting a backup, so the flag will be off before any
2126 : : * records can be written during the backup. At the end of a backup,
2127 : : * the last page will be marked as all unsafe when perhaps only part
2128 : : * is unsafe, but at worst the archiver would miss the opportunity to
2129 : : * compress a few records.
2130 : : */
2131 [ - + ]: 31698 : if (Insert->runningBackups == 0)
2132 : 31698 : NewPage->xlp_info |= XLP_BKP_REMOVABLE;
2133 : :
2134 : : /*
2135 : : * If first page of an XLOG segment file, make it a long header.
2136 : : */
2137 [ + + ]: 31698 : if ((XLogSegmentOffset(NewPage->xlp_pageaddr, wal_segment_size)) == 0)
2138 : : {
2139 : 18 : XLogLongPageHeader NewLongPage = (XLogLongPageHeader) NewPage;
2140 : :
2141 : 18 : NewLongPage->xlp_sysid = ControlFile->system_identifier;
2142 : 18 : NewLongPage->xlp_seg_size = wal_segment_size;
2143 : 18 : NewLongPage->xlp_xlog_blcksz = XLOG_BLCKSZ;
2144 : 18 : NewPage->xlp_info |= XLP_LONG_HEADER;
2145 : 18 : }
2146 : :
2147 : : /*
2148 : : * Make sure the initialization of the page becomes visible to others
2149 : : * before the xlblocks update. GetXLogBuffer() reads xlblocks without
2150 : : * holding a lock.
2151 : : */
2152 : 31698 : pg_write_barrier();
2153 : :
2154 : 31698 : pg_atomic_write_u64(&XLogCtl->xlblocks[nextidx], NewPageEndPtr);
2155 : 31698 : XLogCtl->InitializedUpTo = NewPageEndPtr;
2156 : :
2157 : 31698 : npages++;
2158 : : }
2159 : 30113 : LWLockRelease(WALBufMappingLock);
2160 : :
2161 : : #ifdef WAL_DEBUG
2162 : : if (XLOG_DEBUG && npages > 0)
2163 : : {
2164 : : elog(DEBUG1, "initialized %d pages, up to %X/%08X",
2165 : : npages, LSN_FORMAT_ARGS(NewPageEndPtr));
2166 : : }
2167 : : #endif
2168 : 30113 : }
2169 : :
2170 : : /*
2171 : : * Calculate CheckPointSegments based on max_wal_size_mb and
2172 : : * checkpoint_completion_target.
2173 : : */
2174 : : static void
2175 : 974 : CalculateCheckpointSegments(void)
2176 : : {
2177 : 974 : double target;
2178 : :
2179 : : /*-------
2180 : : * Calculate the distance at which to trigger a checkpoint, to avoid
2181 : : * exceeding max_wal_size_mb. This is based on two assumptions:
2182 : : *
2183 : : * a) we keep WAL for only one checkpoint cycle (prior to PG11 we kept
2184 : : * WAL for two checkpoint cycles to allow us to recover from the
2185 : : * secondary checkpoint if the first checkpoint failed, though we
2186 : : * only did this on the primary anyway, not on standby. Keeping just
2187 : : * one checkpoint simplifies processing and reduces disk space in
2188 : : * many smaller databases.)
2189 : : * b) during checkpoint, we consume checkpoint_completion_target *
2190 : : * number of segments consumed between checkpoints.
2191 : : *-------
2192 : : */
2193 : 1948 : target = (double) ConvertToXSegs(max_wal_size_mb, wal_segment_size) /
2194 : 974 : (1.0 + CheckPointCompletionTarget);
2195 : :
2196 : : /* round down */
2197 : 974 : CheckPointSegments = (int) target;
2198 : :
2199 [ + - ]: 974 : if (CheckPointSegments < 1)
2200 : 0 : CheckPointSegments = 1;
2201 : 974 : }
2202 : :
2203 : : void
2204 : 964 : assign_max_wal_size(int newval, void *extra)
2205 : : {
2206 : 964 : max_wal_size_mb = newval;
2207 : 964 : CalculateCheckpointSegments();
2208 : 964 : }
2209 : :
2210 : : void
2211 : 6 : assign_checkpoint_completion_target(double newval, void *extra)
2212 : : {
2213 : 6 : CheckPointCompletionTarget = newval;
2214 : 6 : CalculateCheckpointSegments();
2215 : 6 : }
2216 : :
2217 : : bool
2218 : 11 : check_wal_segment_size(int *newval, void **extra, GucSource source)
2219 : : {
2220 [ + - + - : 11 : if (!IsValidWalSegSize(*newval))
+ - - + ]
2221 : : {
2222 : 0 : GUC_check_errdetail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
2223 : 0 : return false;
2224 : : }
2225 : :
2226 : 11 : return true;
2227 : 11 : }
2228 : :
2229 : : /*
2230 : : * At a checkpoint, how many WAL segments to recycle as preallocated future
2231 : : * XLOG segments? Returns the highest segment that should be preallocated.
2232 : : */
2233 : : static XLogSegNo
2234 : 7 : XLOGfileslop(XLogRecPtr lastredoptr)
2235 : : {
2236 : 7 : XLogSegNo minSegNo;
2237 : 7 : XLogSegNo maxSegNo;
2238 : 7 : double distance;
2239 : 7 : XLogSegNo recycleSegNo;
2240 : :
2241 : : /*
2242 : : * Calculate the segment numbers that min_wal_size_mb and max_wal_size_mb
2243 : : * correspond to. Always recycle enough segments to meet the minimum, and
2244 : : * remove enough segments to stay below the maximum.
2245 : : */
2246 : 21 : minSegNo = lastredoptr / wal_segment_size +
2247 : 14 : ConvertToXSegs(min_wal_size_mb, wal_segment_size) - 1;
2248 : 21 : maxSegNo = lastredoptr / wal_segment_size +
2249 : 14 : ConvertToXSegs(max_wal_size_mb, wal_segment_size) - 1;
2250 : :
2251 : : /*
2252 : : * Between those limits, recycle enough segments to get us through to the
2253 : : * estimated end of next checkpoint.
2254 : : *
2255 : : * To estimate where the next checkpoint will finish, assume that the
2256 : : * system runs steadily consuming CheckPointDistanceEstimate bytes between
2257 : : * every checkpoint.
2258 : : */
2259 : 7 : distance = (1.0 + CheckPointCompletionTarget) * CheckPointDistanceEstimate;
2260 : : /* add 10% for good measure. */
2261 : 7 : distance *= 1.10;
2262 : :
2263 : 14 : recycleSegNo = (XLogSegNo) ceil(((double) lastredoptr + distance) /
2264 : 7 : wal_segment_size);
2265 : :
2266 [ + + ]: 7 : if (recycleSegNo < minSegNo)
2267 : 6 : recycleSegNo = minSegNo;
2268 [ + - ]: 7 : if (recycleSegNo > maxSegNo)
2269 : 0 : recycleSegNo = maxSegNo;
2270 : :
2271 : 14 : return recycleSegNo;
2272 : 7 : }
2273 : :
2274 : : /*
2275 : : * Check whether we've consumed enough xlog space that a checkpoint is needed.
2276 : : *
2277 : : * new_segno indicates a log file that has just been filled up (or read
2278 : : * during recovery). We measure the distance from RedoRecPtr to new_segno
2279 : : * and see if that exceeds CheckPointSegments.
2280 : : *
2281 : : * Note: it is caller's responsibility that RedoRecPtr is up-to-date.
2282 : : */
2283 : : bool
2284 : 21 : XLogCheckpointNeeded(XLogSegNo new_segno)
2285 : : {
2286 : 21 : XLogSegNo old_segno;
2287 : :
2288 : 21 : XLByteToSeg(RedoRecPtr, old_segno, wal_segment_size);
2289 : :
2290 [ - + ]: 21 : if (new_segno >= old_segno + (uint64) (CheckPointSegments - 1))
2291 : 0 : return true;
2292 : 21 : return false;
2293 : 21 : }
2294 : :
2295 : : /*
2296 : : * Write and/or fsync the log at least as far as WriteRqst indicates.
2297 : : *
2298 : : * If flexible == true, we don't have to write as far as WriteRqst, but
2299 : : * may stop at any convenient boundary (such as a cache or logfile boundary).
2300 : : * This option allows us to avoid uselessly issuing multiple writes when a
2301 : : * single one would do.
2302 : : *
2303 : : * Must be called with WALWriteLock held. WaitXLogInsertionsToFinish(WriteRqst)
2304 : : * must be called before grabbing the lock, to make sure the data is ready to
2305 : : * write.
2306 : : */
2307 : : static void
2308 : 23488 : XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
2309 : : {
2310 : 23488 : bool ispartialpage;
2311 : 23488 : bool last_iteration;
2312 : 23488 : bool finishing_seg;
2313 : 23488 : int curridx;
2314 : 23488 : int npages;
2315 : 23488 : int startidx;
2316 : 23488 : uint32 startoffset;
2317 : :
2318 : : /* We should always be inside a critical section here */
2319 [ + - ]: 23488 : Assert(CritSectionCount > 0);
2320 : :
2321 : : /*
2322 : : * Update local LogwrtResult (caller probably did this already, but...)
2323 : : */
2324 : 23488 : RefreshXLogWriteResult(LogwrtResult);
2325 : :
2326 : : /*
2327 : : * Since successive pages in the xlog cache are consecutively allocated,
2328 : : * we can usually gather multiple pages together and issue just one
2329 : : * write() call. npages is the number of pages we have determined can be
2330 : : * written together; startidx is the cache block index of the first one,
2331 : : * and startoffset is the file offset at which it should go. The latter
2332 : : * two variables are only valid when npages > 0, but we must initialize
2333 : : * all of them to keep the compiler quiet.
2334 : : */
2335 : 23488 : npages = 0;
2336 : 23488 : startidx = 0;
2337 : 23488 : startoffset = 0;
2338 : :
2339 : : /*
2340 : : * Within the loop, curridx is the cache block index of the page to
2341 : : * consider writing. Begin at the buffer containing the next unwritten
2342 : : * page, or last partially written page.
2343 : : */
2344 : 23488 : curridx = XLogRecPtrToBufIdx(LogwrtResult.Write);
2345 : :
2346 [ + + ]: 67484 : while (LogwrtResult.Write < WriteRqst.Write)
2347 : : {
2348 : : /*
2349 : : * Make sure we're not ahead of the insert process. This could happen
2350 : : * if we're passed a bogus WriteRqst.Write that is past the end of the
2351 : : * last page that's been initialized by AdvanceXLInsertBuffer.
2352 : : */
2353 : 63609 : XLogRecPtr EndPtr = pg_atomic_read_u64(&XLogCtl->xlblocks[curridx]);
2354 : :
2355 [ + - ]: 63609 : if (LogwrtResult.Write >= EndPtr)
2356 [ # # # # ]: 0 : elog(PANIC, "xlog write request %X/%08X is past end of log %X/%08X",
2357 : : LSN_FORMAT_ARGS(LogwrtResult.Write),
2358 : : LSN_FORMAT_ARGS(EndPtr));
2359 : :
2360 : : /* Advance LogwrtResult.Write to end of current buffer page */
2361 : 63609 : LogwrtResult.Write = EndPtr;
2362 : 63609 : ispartialpage = WriteRqst.Write < LogwrtResult.Write;
2363 : :
2364 [ + + ]: 63609 : if (!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
2365 : : wal_segment_size))
2366 : : {
2367 : : /*
2368 : : * Switch to new logfile segment. We cannot have any pending
2369 : : * pages here (since we dump what we have at segment end).
2370 : : */
2371 [ + - ]: 381 : Assert(npages == 0);
2372 [ + + ]: 381 : if (openLogFile >= 0)
2373 : 120 : XLogFileClose();
2374 : 381 : XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
2375 : : wal_segment_size);
2376 : 381 : openLogTLI = tli;
2377 : :
2378 : : /* create/use new log file */
2379 : 381 : openLogFile = XLogFileInit(openLogSegNo, tli);
2380 : 381 : ReserveExternalFD();
2381 : 381 : }
2382 : :
2383 : : /* Make sure we have the current logfile open */
2384 [ + - ]: 63609 : if (openLogFile < 0)
2385 : : {
2386 : 0 : XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
2387 : : wal_segment_size);
2388 : 0 : openLogTLI = tli;
2389 : 0 : openLogFile = XLogFileOpen(openLogSegNo, tli);
2390 : 0 : ReserveExternalFD();
2391 : 0 : }
2392 : :
2393 : : /* Add current page to the set of pending pages-to-dump */
2394 [ + + ]: 63609 : if (npages == 0)
2395 : : {
2396 : : /* first of group */
2397 : 23558 : startidx = curridx;
2398 : 23558 : startoffset = XLogSegmentOffset(LogwrtResult.Write - XLOG_BLCKSZ,
2399 : : wal_segment_size);
2400 : 23558 : }
2401 : 63609 : npages++;
2402 : :
2403 : : /*
2404 : : * Dump the set if this will be the last loop iteration, or if we are
2405 : : * at the last page of the cache area (since the next page won't be
2406 : : * contiguous in memory), or if we are at the end of the logfile
2407 : : * segment.
2408 : : */
2409 : 63609 : last_iteration = WriteRqst.Write <= LogwrtResult.Write;
2410 : :
2411 [ + + ]: 107616 : finishing_seg = !ispartialpage &&
2412 : 44007 : (startoffset + npages * XLOG_BLCKSZ) >= wal_segment_size;
2413 : :
2414 [ + + ]: 63609 : if (last_iteration ||
2415 [ + + - + ]: 40125 : curridx == XLogCtl->XLogCacheBlck ||
2416 : 40051 : finishing_seg)
2417 : : {
2418 : 23558 : char *from;
2419 : 23558 : Size nbytes;
2420 : 23558 : Size nleft;
2421 : 23558 : ssize_t written;
2422 : 23558 : instr_time start;
2423 : :
2424 : : /* OK to write the page(s) */
2425 : 23558 : from = XLogCtl->pages + startidx * (Size) XLOG_BLCKSZ;
2426 : 23558 : nbytes = npages * (Size) XLOG_BLCKSZ;
2427 : 23558 : nleft = nbytes;
2428 : 23558 : do
2429 : : {
2430 : 23558 : errno = 0;
2431 : :
2432 : : /*
2433 : : * Measure I/O timing to write WAL data, for pg_stat_io.
2434 : : */
2435 : 23558 : start = pgstat_prepare_io_time(track_wal_io_timing);
2436 : :
2437 : 23558 : pgstat_report_wait_start(WAIT_EVENT_WAL_WRITE);
2438 : 23558 : written = pg_pwrite(openLogFile, from, nleft, startoffset);
2439 : 23558 : pgstat_report_wait_end();
2440 : :
2441 : 23558 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_NORMAL,
2442 : 23558 : IOOP_WRITE, start, 1, written);
2443 : :
2444 [ + - ]: 23558 : if (written <= 0)
2445 : : {
2446 : 0 : char xlogfname[MAXFNAMELEN];
2447 : 0 : int save_errno;
2448 : :
2449 [ # # ]: 0 : if (errno == EINTR)
2450 : 0 : continue;
2451 : :
2452 : 0 : save_errno = errno;
2453 : 0 : XLogFileName(xlogfname, tli, openLogSegNo,
2454 : 0 : wal_segment_size);
2455 : 0 : errno = save_errno;
2456 [ # # # # ]: 0 : ereport(PANIC,
2457 : : (errcode_for_file_access(),
2458 : : errmsg("could not write to log file \"%s\" at offset %u, length %zu: %m",
2459 : : xlogfname, startoffset, nleft)));
2460 [ # # ]: 0 : }
2461 : 23558 : nleft -= written;
2462 : 23558 : from += written;
2463 : 23558 : startoffset += written;
2464 [ - + ]: 23558 : } while (nleft > 0);
2465 : :
2466 : 23558 : npages = 0;
2467 : :
2468 : : /*
2469 : : * If we just wrote the whole last page of a logfile segment,
2470 : : * fsync the segment immediately. This avoids having to go back
2471 : : * and re-open prior segments when an fsync request comes along
2472 : : * later. Doing it here ensures that one and only one backend will
2473 : : * perform this fsync.
2474 : : *
2475 : : * This is also the right place to notify the Archiver that the
2476 : : * segment is ready to copy to archival storage, and to update the
2477 : : * timer for archive_timeout, and to signal for a checkpoint if
2478 : : * too many logfile segments have been used since the last
2479 : : * checkpoint.
2480 : : */
2481 [ + + ]: 23558 : if (finishing_seg)
2482 : : {
2483 : 21 : issue_xlog_fsync(openLogFile, openLogSegNo, tli);
2484 : :
2485 : : /* signal that we need to wakeup walsenders later */
2486 : 21 : WalSndWakeupRequest();
2487 : :
2488 : 21 : LogwrtResult.Flush = LogwrtResult.Write; /* end of page */
2489 : :
2490 [ - + # # : 21 : if (XLogArchivingActive())
+ - ]
2491 : 0 : XLogArchiveNotifySeg(openLogSegNo, tli);
2492 : :
2493 : 21 : XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
2494 : 21 : XLogCtl->lastSegSwitchLSN = LogwrtResult.Flush;
2495 : :
2496 : : /*
2497 : : * Request a checkpoint if we've consumed too much xlog since
2498 : : * the last one. For speed, we first check using the local
2499 : : * copy of RedoRecPtr, which might be out of date; if it looks
2500 : : * like a checkpoint is needed, forcibly update RedoRecPtr and
2501 : : * recheck.
2502 : : */
2503 [ + - + - ]: 21 : if (IsUnderPostmaster && XLogCheckpointNeeded(openLogSegNo))
2504 : : {
2505 : 0 : (void) GetRedoRecPtr();
2506 [ # # ]: 0 : if (XLogCheckpointNeeded(openLogSegNo))
2507 : 0 : RequestCheckpoint(CHECKPOINT_CAUSE_XLOG);
2508 : 0 : }
2509 : 21 : }
2510 : 23558 : }
2511 : :
2512 [ + + ]: 63609 : if (ispartialpage)
2513 : : {
2514 : : /* Only asked to write a partial page */
2515 : 19602 : LogwrtResult.Write = WriteRqst.Write;
2516 : 19602 : break;
2517 : : }
2518 [ + + ]: 44007 : curridx = NextBufIdx(curridx);
2519 : :
2520 : : /* If flexible, break out of loop as soon as we wrote something */
2521 [ + + + + ]: 44007 : if (flexible && npages == 0)
2522 : 11 : break;
2523 [ + + ]: 63609 : }
2524 : :
2525 [ + - ]: 23488 : Assert(npages == 0);
2526 : :
2527 : : /*
2528 : : * If asked to flush, do so
2529 : : */
2530 [ + + + + ]: 23488 : if (LogwrtResult.Flush < WriteRqst.Flush &&
2531 : 19643 : LogwrtResult.Flush < LogwrtResult.Write)
2532 : : {
2533 : : /*
2534 : : * Could get here without iterating above loop, in which case we might
2535 : : * have no open file or the wrong one. However, we do not need to
2536 : : * fsync more than one file.
2537 : : */
2538 [ + - + - ]: 19642 : if (wal_sync_method != WAL_SYNC_METHOD_OPEN &&
2539 : 19642 : wal_sync_method != WAL_SYNC_METHOD_OPEN_DSYNC)
2540 : : {
2541 [ # # # # ]: 0 : if (openLogFile >= 0 &&
2542 : 0 : !XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
2543 : : wal_segment_size))
2544 : 0 : XLogFileClose();
2545 [ # # ]: 0 : if (openLogFile < 0)
2546 : : {
2547 : 0 : XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
2548 : : wal_segment_size);
2549 : 0 : openLogTLI = tli;
2550 : 0 : openLogFile = XLogFileOpen(openLogSegNo, tli);
2551 : 0 : ReserveExternalFD();
2552 : 0 : }
2553 : :
2554 : 0 : issue_xlog_fsync(openLogFile, openLogSegNo, tli);
2555 : 0 : }
2556 : :
2557 : : /* signal that we need to wakeup walsenders later */
2558 : 19642 : WalSndWakeupRequest();
2559 : :
2560 : 19642 : LogwrtResult.Flush = LogwrtResult.Write;
2561 : 19642 : }
2562 : :
2563 : : /*
2564 : : * Update shared-memory status
2565 : : *
2566 : : * We make sure that the shared 'request' values do not fall behind the
2567 : : * 'result' values. This is not absolutely essential, but it saves some
2568 : : * code in a couple of places.
2569 : : */
2570 [ + + ]: 23488 : SpinLockAcquire(&XLogCtl->info_lck);
2571 [ + + ]: 23488 : if (XLogCtl->LogwrtRqst.Write < LogwrtResult.Write)
2572 : 18889 : XLogCtl->LogwrtRqst.Write = LogwrtResult.Write;
2573 [ + + ]: 23488 : if (XLogCtl->LogwrtRqst.Flush < LogwrtResult.Flush)
2574 : 19645 : XLogCtl->LogwrtRqst.Flush = LogwrtResult.Flush;
2575 : 23488 : SpinLockRelease(&XLogCtl->info_lck);
2576 : :
2577 : : /*
2578 : : * We write Write first, bar, then Flush. When reading, the opposite must
2579 : : * be done (with a matching barrier in between), so that we always see a
2580 : : * Flush value that trails behind the Write value seen.
2581 : : */
2582 : 23488 : pg_atomic_write_u64(&XLogCtl->logWriteResult, LogwrtResult.Write);
2583 : 23488 : pg_write_barrier();
2584 : 23488 : pg_atomic_write_u64(&XLogCtl->logFlushResult, LogwrtResult.Flush);
2585 : :
2586 : : #ifdef USE_ASSERT_CHECKING
2587 : : {
2588 : 23488 : XLogRecPtr Flush;
2589 : 23488 : XLogRecPtr Write;
2590 : 23488 : XLogRecPtr Insert;
2591 : :
2592 : 23488 : Flush = pg_atomic_read_u64(&XLogCtl->logFlushResult);
2593 : 23488 : pg_read_barrier();
2594 : 23488 : Write = pg_atomic_read_u64(&XLogCtl->logWriteResult);
2595 : 23488 : pg_read_barrier();
2596 : 23488 : Insert = pg_atomic_read_u64(&XLogCtl->logInsertResult);
2597 : :
2598 : : /* WAL written to disk is always ahead of WAL flushed */
2599 [ + - ]: 23488 : Assert(Write >= Flush);
2600 : :
2601 : : /* WAL inserted to buffers is always ahead of WAL written */
2602 [ + - ]: 23488 : Assert(Insert >= Write);
2603 : 23488 : }
2604 : : #endif
2605 : 23488 : }
2606 : :
2607 : : /*
2608 : : * Record the LSN for an asynchronous transaction commit/abort
2609 : : * and nudge the WALWriter if there is work for it to do.
2610 : : * (This should not be called for synchronous commits.)
2611 : : */
2612 : : void
2613 : 2836 : XLogSetAsyncXactLSN(XLogRecPtr asyncXactLSN)
2614 : : {
2615 : 2836 : XLogRecPtr WriteRqstPtr = asyncXactLSN;
2616 : 2836 : bool sleeping;
2617 : 2836 : bool wakeup = false;
2618 : 2836 : XLogRecPtr prevAsyncXactLSN;
2619 : :
2620 [ + + ]: 2836 : SpinLockAcquire(&XLogCtl->info_lck);
2621 : 2836 : sleeping = XLogCtl->WalWriterSleeping;
2622 : 2836 : prevAsyncXactLSN = XLogCtl->asyncXactLSN;
2623 [ + + ]: 2836 : if (XLogCtl->asyncXactLSN < asyncXactLSN)
2624 : 2815 : XLogCtl->asyncXactLSN = asyncXactLSN;
2625 : 2836 : SpinLockRelease(&XLogCtl->info_lck);
2626 : :
2627 : : /*
2628 : : * If somebody else already called this function with a more aggressive
2629 : : * LSN, they will have done what we needed (and perhaps more).
2630 : : */
2631 [ + + ]: 2836 : if (asyncXactLSN <= prevAsyncXactLSN)
2632 : 21 : return;
2633 : :
2634 : : /*
2635 : : * If the WALWriter is sleeping, kick it to make it come out of low-power
2636 : : * mode, so that this async commit will reach disk within the expected
2637 : : * amount of time. Otherwise, determine whether it has enough WAL
2638 : : * available to flush, the same way that XLogBackgroundFlush() does.
2639 : : */
2640 [ - + ]: 2815 : if (sleeping)
2641 : 0 : wakeup = true;
2642 : : else
2643 : : {
2644 : 2815 : int flushblocks;
2645 : :
2646 : 2815 : RefreshXLogWriteResult(LogwrtResult);
2647 : :
2648 : 2815 : flushblocks =
2649 : 2815 : WriteRqstPtr / XLOG_BLCKSZ - LogwrtResult.Flush / XLOG_BLCKSZ;
2650 : :
2651 [ + - + + ]: 2815 : if (WalWriterFlushAfter == 0 || flushblocks >= WalWriterFlushAfter)
2652 : 98 : wakeup = true;
2653 : 2815 : }
2654 : :
2655 [ + + ]: 2815 : if (wakeup)
2656 : : {
2657 : 98 : volatile PROC_HDR *procglobal = ProcGlobal;
2658 : 98 : ProcNumber walwriterProc = procglobal->walwriterProc;
2659 : :
2660 [ + + ]: 98 : if (walwriterProc != INVALID_PROC_NUMBER)
2661 : 14 : SetLatch(&GetPGProcByNumber(walwriterProc)->procLatch);
2662 : 98 : }
2663 [ - + ]: 2836 : }
2664 : :
2665 : : /*
2666 : : * Record the LSN up to which we can remove WAL because it's not required by
2667 : : * any replication slot.
2668 : : */
2669 : : void
2670 : 4 : XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn)
2671 : : {
2672 [ - + ]: 4 : SpinLockAcquire(&XLogCtl->info_lck);
2673 : 4 : XLogCtl->replicationSlotMinLSN = lsn;
2674 : 4 : SpinLockRelease(&XLogCtl->info_lck);
2675 : 4 : }
2676 : :
2677 : :
2678 : : /*
2679 : : * Return the oldest LSN we must retain to satisfy the needs of some
2680 : : * replication slot.
2681 : : */
2682 : : static XLogRecPtr
2683 : 7 : XLogGetReplicationSlotMinimumLSN(void)
2684 : : {
2685 : 7 : XLogRecPtr retval;
2686 : :
2687 [ - + ]: 7 : SpinLockAcquire(&XLogCtl->info_lck);
2688 : 7 : retval = XLogCtl->replicationSlotMinLSN;
2689 : 7 : SpinLockRelease(&XLogCtl->info_lck);
2690 : :
2691 : 14 : return retval;
2692 : 7 : }
2693 : :
2694 : : /*
2695 : : * Advance minRecoveryPoint in control file.
2696 : : *
2697 : : * If we crash during recovery, we must reach this point again before the
2698 : : * database is consistent.
2699 : : *
2700 : : * If 'force' is true, 'lsn' argument is ignored. Otherwise, minRecoveryPoint
2701 : : * is only updated if it's not already greater than or equal to 'lsn'.
2702 : : */
2703 : : static void
2704 : 0 : UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force)
2705 : : {
2706 : : /* Quick check using our local copy of the variable */
2707 [ # # # # : 0 : if (!updateMinRecoveryPoint || (!force && lsn <= LocalMinRecoveryPoint))
# # ]
2708 : 0 : return;
2709 : :
2710 : : /*
2711 : : * An invalid minRecoveryPoint means that we need to recover all the WAL,
2712 : : * i.e., we're doing crash recovery. We never modify the control file's
2713 : : * value in that case, so we can short-circuit future checks here too. The
2714 : : * local values of minRecoveryPoint and minRecoveryPointTLI should not be
2715 : : * updated until crash recovery finishes. We only do this for the startup
2716 : : * process as it should not update its own reference of minRecoveryPoint
2717 : : * until it has finished crash recovery to make sure that all WAL
2718 : : * available is replayed in this case. This also saves from extra locks
2719 : : * taken on the control file from the startup process.
2720 : : */
2721 [ # # # # ]: 0 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint) && InRecovery)
2722 : : {
2723 : 0 : updateMinRecoveryPoint = false;
2724 : 0 : return;
2725 : : }
2726 : :
2727 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
2728 : :
2729 : : /* update local copy */
2730 : 0 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
2731 : 0 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
2732 : :
2733 [ # # ]: 0 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint))
2734 : 0 : updateMinRecoveryPoint = false;
2735 [ # # # # ]: 0 : else if (force || LocalMinRecoveryPoint < lsn)
2736 : : {
2737 : 0 : XLogRecPtr newMinRecoveryPoint;
2738 : 0 : TimeLineID newMinRecoveryPointTLI;
2739 : :
2740 : : /*
2741 : : * To avoid having to update the control file too often, we update it
2742 : : * all the way to the last record being replayed, even though 'lsn'
2743 : : * would suffice for correctness. This also allows the 'force' case
2744 : : * to not need a valid 'lsn' value.
2745 : : *
2746 : : * Another important reason for doing it this way is that the passed
2747 : : * 'lsn' value could be bogus, i.e., past the end of available WAL, if
2748 : : * the caller got it from a corrupted heap page. Accepting such a
2749 : : * value as the min recovery point would prevent us from coming up at
2750 : : * all. Instead, we just log a warning and continue with recovery.
2751 : : * (See also the comments about corrupt LSNs in XLogFlush.)
2752 : : */
2753 : 0 : newMinRecoveryPoint = GetCurrentReplayRecPtr(&newMinRecoveryPointTLI);
2754 [ # # # # ]: 0 : if (!force && newMinRecoveryPoint < lsn)
2755 [ # # # # ]: 0 : elog(WARNING,
2756 : : "xlog min recovery request %X/%08X is past current point %X/%08X",
2757 : : LSN_FORMAT_ARGS(lsn), LSN_FORMAT_ARGS(newMinRecoveryPoint));
2758 : :
2759 : : /* update control file */
2760 [ # # ]: 0 : if (ControlFile->minRecoveryPoint < newMinRecoveryPoint)
2761 : : {
2762 : 0 : ControlFile->minRecoveryPoint = newMinRecoveryPoint;
2763 : 0 : ControlFile->minRecoveryPointTLI = newMinRecoveryPointTLI;
2764 : 0 : UpdateControlFile();
2765 : 0 : LocalMinRecoveryPoint = newMinRecoveryPoint;
2766 : 0 : LocalMinRecoveryPointTLI = newMinRecoveryPointTLI;
2767 : :
2768 [ # # # # ]: 0 : ereport(DEBUG2,
2769 : : errmsg_internal("updated min recovery point to %X/%08X on timeline %u",
2770 : : LSN_FORMAT_ARGS(newMinRecoveryPoint),
2771 : : newMinRecoveryPointTLI));
2772 : 0 : }
2773 : 0 : }
2774 : 0 : LWLockRelease(ControlFileLock);
2775 : 0 : }
2776 : :
2777 : : /*
2778 : : * Ensure that all XLOG data through the given position is flushed to disk.
2779 : : *
2780 : : * NOTE: this differs from XLogWrite mainly in that the WALWriteLock is not
2781 : : * already held, and we try to avoid acquiring it if possible.
2782 : : */
2783 : : void
2784 : 26979 : XLogFlush(XLogRecPtr record)
2785 : : {
2786 : 26979 : XLogRecPtr WriteRqstPtr;
2787 : 26979 : XLogwrtRqst WriteRqst;
2788 : 26979 : TimeLineID insertTLI = XLogCtl->InsertTimeLineID;
2789 : :
2790 : : /*
2791 : : * During REDO, we are reading not writing WAL. Therefore, instead of
2792 : : * trying to flush the WAL, we should update minRecoveryPoint instead. We
2793 : : * test XLogInsertAllowed(), not InRecovery, because we need checkpointer
2794 : : * to act this way too, and because when it tries to write the
2795 : : * end-of-recovery checkpoint, it should indeed flush.
2796 : : */
2797 [ + - ]: 26979 : if (!XLogInsertAllowed())
2798 : : {
2799 : 0 : UpdateMinRecoveryPoint(record, false);
2800 : 0 : return;
2801 : : }
2802 : :
2803 : : /* Quick exit if already known flushed */
2804 [ + + ]: 26979 : if (record <= LogwrtResult.Flush)
2805 : 6965 : return;
2806 : :
2807 : : #ifdef WAL_DEBUG
2808 : : if (XLOG_DEBUG)
2809 : : elog(LOG, "xlog flush request %X/%08X; write %X/%08X; flush %X/%08X",
2810 : : LSN_FORMAT_ARGS(record),
2811 : : LSN_FORMAT_ARGS(LogwrtResult.Write),
2812 : : LSN_FORMAT_ARGS(LogwrtResult.Flush));
2813 : : #endif
2814 : :
2815 : 20014 : START_CRIT_SECTION();
2816 : :
2817 : : /*
2818 : : * Since fsync is usually a horribly expensive operation, we try to
2819 : : * piggyback as much data as we can on each fsync: if we see any more data
2820 : : * entered into the xlog buffer, we'll write and fsync that too, so that
2821 : : * the final value of LogwrtResult.Flush is as large as possible. This
2822 : : * gives us some chance of avoiding another fsync immediately after.
2823 : : */
2824 : :
2825 : : /* initialize to given target; may increase below */
2826 : 20014 : WriteRqstPtr = record;
2827 : :
2828 : : /*
2829 : : * Now wait until we get the write lock, or someone else does the flush
2830 : : * for us.
2831 : : */
2832 : 20014 : for (;;)
2833 : : {
2834 : 20362 : XLogRecPtr insertpos;
2835 : :
2836 : : /* done already? */
2837 : 20362 : RefreshXLogWriteResult(LogwrtResult);
2838 [ + + ]: 20362 : if (record <= LogwrtResult.Flush)
2839 : 127 : break;
2840 : :
2841 : : /*
2842 : : * Before actually performing the write, wait for all in-flight
2843 : : * insertions to the pages we're about to write to finish.
2844 : : */
2845 [ + + ]: 20235 : SpinLockAcquire(&XLogCtl->info_lck);
2846 [ + + ]: 20235 : if (WriteRqstPtr < XLogCtl->LogwrtRqst.Write)
2847 : 65 : WriteRqstPtr = XLogCtl->LogwrtRqst.Write;
2848 : 20235 : SpinLockRelease(&XLogCtl->info_lck);
2849 : 20235 : insertpos = WaitXLogInsertionsToFinish(WriteRqstPtr);
2850 : :
2851 : : /*
2852 : : * Try to get the write lock. If we can't get it immediately, wait
2853 : : * until it's released, and recheck if we still need to do the flush
2854 : : * or if the backend that held the lock did it for us already. This
2855 : : * helps to maintain a good rate of group committing when the system
2856 : : * is bottlenecked by the speed of fsyncing.
2857 : : */
2858 [ + + ]: 20235 : if (!LWLockAcquireOrWait(WALWriteLock, LW_EXCLUSIVE))
2859 : : {
2860 : : /*
2861 : : * The lock is now free, but we didn't acquire it yet. Before we
2862 : : * do, loop back to check if someone else flushed the record for
2863 : : * us already.
2864 : : */
2865 : 348 : continue;
2866 : : }
2867 : :
2868 : : /* Got the lock; recheck whether request is satisfied */
2869 : 19887 : RefreshXLogWriteResult(LogwrtResult);
2870 [ + + ]: 19887 : if (record <= LogwrtResult.Flush)
2871 : : {
2872 : 257 : LWLockRelease(WALWriteLock);
2873 : 257 : break;
2874 : : }
2875 : :
2876 : : /*
2877 : : * Sleep before flush! By adding a delay here, we may give further
2878 : : * backends the opportunity to join the backlog of group commit
2879 : : * followers; this can significantly improve transaction throughput,
2880 : : * at the risk of increasing transaction latency.
2881 : : *
2882 : : * We do not sleep if enableFsync is not turned on, nor if there are
2883 : : * fewer than CommitSiblings other backends with active transactions.
2884 : : */
2885 [ - + # # : 19630 : if (CommitDelay > 0 && enableFsync &&
# # ]
2886 : 0 : MinimumActiveBackends(CommitSiblings))
2887 : : {
2888 : 0 : pgstat_report_wait_start(WAIT_EVENT_COMMIT_DELAY);
2889 : 0 : pg_usleep(CommitDelay);
2890 : 0 : pgstat_report_wait_end();
2891 : :
2892 : : /*
2893 : : * Re-check how far we can now flush the WAL. It's generally not
2894 : : * safe to call WaitXLogInsertionsToFinish while holding
2895 : : * WALWriteLock, because an in-progress insertion might need to
2896 : : * also grab WALWriteLock to make progress. But we know that all
2897 : : * the insertions up to insertpos have already finished, because
2898 : : * that's what the earlier WaitXLogInsertionsToFinish() returned.
2899 : : * We're only calling it again to allow insertpos to be moved
2900 : : * further forward, not to actually wait for anyone.
2901 : : */
2902 : 0 : insertpos = WaitXLogInsertionsToFinish(insertpos);
2903 : 0 : }
2904 : :
2905 : : /* try to write/flush later additions to XLOG as well */
2906 : 19630 : WriteRqst.Write = insertpos;
2907 : 19630 : WriteRqst.Flush = insertpos;
2908 : :
2909 : 19630 : XLogWrite(WriteRqst, insertTLI, false);
2910 : :
2911 : 19630 : LWLockRelease(WALWriteLock);
2912 : : /* done */
2913 : 19630 : break;
2914 [ + + ]: 20362 : }
2915 : :
2916 [ - + ]: 20014 : END_CRIT_SECTION();
2917 : :
2918 : : /* wake up walsenders now that we've released heavily contended locks */
2919 : 20014 : WalSndWakeupProcessRequests(true, !RecoveryInProgress());
2920 : :
2921 : : /*
2922 : : * If we flushed an LSN that someone was waiting for, notify the waiters.
2923 : : */
2924 [ + - + - ]: 20014 : if (waitLSNState &&
2925 : 40028 : (LogwrtResult.Flush >=
2926 : 20014 : pg_atomic_read_u64(&waitLSNState->minWaitedLSN[WAIT_LSN_TYPE_PRIMARY_FLUSH])))
2927 : 0 : WaitLSNWakeup(WAIT_LSN_TYPE_PRIMARY_FLUSH, LogwrtResult.Flush);
2928 : :
2929 : : /*
2930 : : * If we still haven't flushed to the request point then we have a
2931 : : * problem; most likely, the requested flush point is past end of XLOG.
2932 : : * This has been seen to occur when a disk page has a corrupted LSN.
2933 : : *
2934 : : * Formerly we treated this as a PANIC condition, but that hurts the
2935 : : * system's robustness rather than helping it: we do not want to take down
2936 : : * the whole system due to corruption on one data page. In particular, if
2937 : : * the bad page is encountered again during recovery then we would be
2938 : : * unable to restart the database at all! (This scenario actually
2939 : : * happened in the field several times with 7.1 releases.) As of 8.4, bad
2940 : : * LSNs encountered during recovery are UpdateMinRecoveryPoint's problem;
2941 : : * the only time we can reach here during recovery is while flushing the
2942 : : * end-of-recovery checkpoint record, and we don't expect that to have a
2943 : : * bad LSN.
2944 : : *
2945 : : * Note that for calls from xact.c, the ERROR will be promoted to PANIC
2946 : : * since xact.c calls this routine inside a critical section. However,
2947 : : * calls from bufmgr.c are not within critical sections and so we will not
2948 : : * force a restart for a bad LSN on a data page.
2949 : : */
2950 [ + - ]: 20014 : if (LogwrtResult.Flush < record)
2951 [ # # # # ]: 0 : elog(ERROR,
2952 : : "xlog flush request %X/%08X is not satisfied --- flushed only to %X/%08X",
2953 : : LSN_FORMAT_ARGS(record),
2954 : : LSN_FORMAT_ARGS(LogwrtResult.Flush));
2955 : :
2956 : : /*
2957 : : * Cross-check XLogNeedsFlush(). Some of the checks of XLogFlush() and
2958 : : * XLogNeedsFlush() are duplicated, and this assertion ensures that these
2959 : : * remain consistent.
2960 : : */
2961 [ + - ]: 20014 : Assert(!XLogNeedsFlush(record));
2962 : 26979 : }
2963 : :
2964 : : /*
2965 : : * Write & flush xlog, but without specifying exactly where to.
2966 : : *
2967 : : * We normally write only completed blocks; but if there is nothing to do on
2968 : : * that basis, we check for unwritten async commits in the current incomplete
2969 : : * block, and write through the latest one of those. Thus, if async commits
2970 : : * are not being used, we will write complete blocks only.
2971 : : *
2972 : : * If, based on the above, there's anything to write we do so immediately. But
2973 : : * to avoid calling fsync, fdatasync et. al. at a rate that'd impact
2974 : : * concurrent IO, we only flush WAL every wal_writer_delay ms, or if there's
2975 : : * more than wal_writer_flush_after unflushed blocks.
2976 : : *
2977 : : * We can guarantee that async commits reach disk after at most three
2978 : : * wal_writer_delay cycles. (When flushing complete blocks, we allow XLogWrite
2979 : : * to write "flexibly", meaning it can stop at the end of the buffer ring;
2980 : : * this makes a difference only with very high load or long wal_writer_delay,
2981 : : * but imposes one extra cycle for the worst case for async commits.)
2982 : : *
2983 : : * This routine is invoked periodically by the background walwriter process.
2984 : : *
2985 : : * Returns true if there was any work to do, even if we skipped flushing due
2986 : : * to wal_writer_delay/wal_writer_flush_after.
2987 : : */
2988 : : bool
2989 : 29 : XLogBackgroundFlush(void)
2990 : : {
2991 : 29 : XLogwrtRqst WriteRqst;
2992 : 29 : bool flexible = true;
2993 : : static TimestampTz lastflush;
2994 : 29 : TimestampTz now;
2995 : 29 : int flushblocks;
2996 : 29 : TimeLineID insertTLI;
2997 : :
2998 : : /* XLOG doesn't need flushing during recovery */
2999 [ - + ]: 29 : if (RecoveryInProgress())
3000 : 0 : return false;
3001 : :
3002 : : /*
3003 : : * Since we're not in recovery, InsertTimeLineID is set and can't change,
3004 : : * so we can read it without a lock.
3005 : : */
3006 : 29 : insertTLI = XLogCtl->InsertTimeLineID;
3007 : :
3008 : : /* read updated LogwrtRqst */
3009 [ - + ]: 29 : SpinLockAcquire(&XLogCtl->info_lck);
3010 : 29 : WriteRqst = XLogCtl->LogwrtRqst;
3011 : 29 : SpinLockRelease(&XLogCtl->info_lck);
3012 : :
3013 : : /* back off to last completed page boundary */
3014 : 29 : WriteRqst.Write -= WriteRqst.Write % XLOG_BLCKSZ;
3015 : :
3016 : : /* if we have already flushed that far, consider async commit records */
3017 : 29 : RefreshXLogWriteResult(LogwrtResult);
3018 [ + + ]: 29 : if (WriteRqst.Write <= LogwrtResult.Flush)
3019 : : {
3020 [ - + ]: 18 : SpinLockAcquire(&XLogCtl->info_lck);
3021 : 18 : WriteRqst.Write = XLogCtl->asyncXactLSN;
3022 : 18 : SpinLockRelease(&XLogCtl->info_lck);
3023 : 18 : flexible = false; /* ensure it all gets written */
3024 : 18 : }
3025 : :
3026 : : /*
3027 : : * If already known flushed, we're done. Just need to check if we are
3028 : : * holding an open file handle to a logfile that's no longer in use,
3029 : : * preventing the file from being deleted.
3030 : : */
3031 [ + + ]: 29 : if (WriteRqst.Write <= LogwrtResult.Flush)
3032 : : {
3033 [ + + ]: 16 : if (openLogFile >= 0)
3034 : : {
3035 [ + - ]: 15 : if (!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
3036 : : wal_segment_size))
3037 : : {
3038 : 0 : XLogFileClose();
3039 : 0 : }
3040 : 15 : }
3041 : 16 : return false;
3042 : : }
3043 : :
3044 : : /*
3045 : : * Determine how far to flush WAL, based on the wal_writer_delay and
3046 : : * wal_writer_flush_after GUCs.
3047 : : *
3048 : : * Note that XLogSetAsyncXactLSN() performs similar calculation based on
3049 : : * wal_writer_flush_after, to decide when to wake us up. Make sure the
3050 : : * logic is the same in both places if you change this.
3051 : : */
3052 : 13 : now = GetCurrentTimestamp();
3053 : 13 : flushblocks =
3054 : 13 : WriteRqst.Write / XLOG_BLCKSZ - LogwrtResult.Flush / XLOG_BLCKSZ;
3055 : :
3056 [ + - + + ]: 13 : if (WalWriterFlushAfter == 0 || lastflush == 0)
3057 : : {
3058 : : /* first call, or block based limits disabled */
3059 : 1 : WriteRqst.Flush = WriteRqst.Write;
3060 : 1 : lastflush = now;
3061 : 1 : }
3062 [ + - ]: 12 : else if (TimestampDifferenceExceeds(lastflush, now, WalWriterDelay))
3063 : : {
3064 : : /*
3065 : : * Flush the writes at least every WalWriterDelay ms. This is
3066 : : * important to bound the amount of time it takes for an asynchronous
3067 : : * commit to hit disk.
3068 : : */
3069 : 12 : WriteRqst.Flush = WriteRqst.Write;
3070 : 12 : lastflush = now;
3071 : 12 : }
3072 [ # # ]: 0 : else if (flushblocks >= WalWriterFlushAfter)
3073 : : {
3074 : : /* exceeded wal_writer_flush_after blocks, flush */
3075 : 0 : WriteRqst.Flush = WriteRqst.Write;
3076 : 0 : lastflush = now;
3077 : 0 : }
3078 : : else
3079 : : {
3080 : : /* no flushing, this time round */
3081 : 0 : WriteRqst.Flush = 0;
3082 : : }
3083 : :
3084 : : #ifdef WAL_DEBUG
3085 : : if (XLOG_DEBUG)
3086 : : elog(LOG, "xlog bg flush request write %X/%08X; flush: %X/%08X, current is write %X/%08X; flush %X/%08X",
3087 : : LSN_FORMAT_ARGS(WriteRqst.Write),
3088 : : LSN_FORMAT_ARGS(WriteRqst.Flush),
3089 : : LSN_FORMAT_ARGS(LogwrtResult.Write),
3090 : : LSN_FORMAT_ARGS(LogwrtResult.Flush));
3091 : : #endif
3092 : :
3093 : 13 : START_CRIT_SECTION();
3094 : :
3095 : : /* now wait for any in-progress insertions to finish and get write lock */
3096 : 13 : WaitXLogInsertionsToFinish(WriteRqst.Write);
3097 : 13 : LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
3098 : 13 : RefreshXLogWriteResult(LogwrtResult);
3099 [ - + # # ]: 13 : if (WriteRqst.Write > LogwrtResult.Write ||
3100 : 0 : WriteRqst.Flush > LogwrtResult.Flush)
3101 : : {
3102 : 13 : XLogWrite(WriteRqst, insertTLI, flexible);
3103 : 13 : }
3104 : 13 : LWLockRelease(WALWriteLock);
3105 : :
3106 [ + - ]: 13 : END_CRIT_SECTION();
3107 : :
3108 : : /* wake up walsenders now that we've released heavily contended locks */
3109 : 13 : WalSndWakeupProcessRequests(true, !RecoveryInProgress());
3110 : :
3111 : : /*
3112 : : * If we flushed an LSN that someone was waiting for, notify the waiters.
3113 : : */
3114 [ + - + - ]: 13 : if (waitLSNState &&
3115 : 26 : (LogwrtResult.Flush >=
3116 : 13 : pg_atomic_read_u64(&waitLSNState->minWaitedLSN[WAIT_LSN_TYPE_PRIMARY_FLUSH])))
3117 : 0 : WaitLSNWakeup(WAIT_LSN_TYPE_PRIMARY_FLUSH, LogwrtResult.Flush);
3118 : :
3119 : : /*
3120 : : * Great, done. To take some work off the critical path, try to initialize
3121 : : * as many of the no-longer-needed WAL buffers for future use as we can.
3122 : : */
3123 : 13 : AdvanceXLInsertBuffer(InvalidXLogRecPtr, insertTLI, true);
3124 : :
3125 : : /*
3126 : : * If we determined that we need to write data, but somebody else
3127 : : * wrote/flushed already, it should be considered as being active, to
3128 : : * avoid hibernating too early.
3129 : : */
3130 : 13 : return true;
3131 : 29 : }
3132 : :
3133 : : /*
3134 : : * Test whether XLOG data has been flushed up to (at least) the given
3135 : : * position, or whether the minimum recovery point has been updated past
3136 : : * the given position.
3137 : : *
3138 : : * Returns true if a flush is still needed, or if the minimum recovery point
3139 : : * must be updated.
3140 : : *
3141 : : * It is possible that someone else is already in the process of flushing
3142 : : * that far, or has updated the minimum recovery point up to the given
3143 : : * position.
3144 : : */
3145 : : bool
3146 : 1836354 : XLogNeedsFlush(XLogRecPtr record)
3147 : : {
3148 : : /*
3149 : : * During recovery, we don't flush WAL but update minRecoveryPoint
3150 : : * instead. So "needs flush" is taken to mean whether minRecoveryPoint
3151 : : * would need to be updated.
3152 : : *
3153 : : * Using XLogInsertAllowed() rather than RecoveryInProgress() matters for
3154 : : * the case of an end-of-recovery checkpoint, where WAL data is flushed.
3155 : : * This check should be consistent with the one in XLogFlush().
3156 : : */
3157 [ - + ]: 1836354 : if (!XLogInsertAllowed())
3158 : : {
3159 : : /* Quick exit if already known to be updated or cannot be updated */
3160 [ # # # # ]: 0 : if (!updateMinRecoveryPoint || record <= LocalMinRecoveryPoint)
3161 : 0 : return false;
3162 : :
3163 : : /*
3164 : : * An invalid minRecoveryPoint means that we need to recover all the
3165 : : * WAL, i.e., we're doing crash recovery. We never modify the control
3166 : : * file's value in that case, so we can short-circuit future checks
3167 : : * here too. This triggers a quick exit path for the startup process,
3168 : : * which cannot update its local copy of minRecoveryPoint as long as
3169 : : * it has not replayed all WAL available when doing crash recovery.
3170 : : */
3171 [ # # # # ]: 0 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint) && InRecovery)
3172 : : {
3173 : 0 : updateMinRecoveryPoint = false;
3174 : 0 : return false;
3175 : : }
3176 : :
3177 : : /*
3178 : : * Update local copy of minRecoveryPoint. But if the lock is busy,
3179 : : * just return a conservative guess.
3180 : : */
3181 [ # # ]: 0 : if (!LWLockConditionalAcquire(ControlFileLock, LW_SHARED))
3182 : 0 : return true;
3183 : 0 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
3184 : 0 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
3185 : 0 : LWLockRelease(ControlFileLock);
3186 : :
3187 : : /*
3188 : : * Check minRecoveryPoint for any other process than the startup
3189 : : * process doing crash recovery, which should not update the control
3190 : : * file value if crash recovery is still running.
3191 : : */
3192 [ # # ]: 0 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint))
3193 : 0 : updateMinRecoveryPoint = false;
3194 : :
3195 : : /* check again */
3196 [ # # # # ]: 0 : if (record <= LocalMinRecoveryPoint || !updateMinRecoveryPoint)
3197 : 0 : return false;
3198 : : else
3199 : 0 : return true;
3200 : : }
3201 : :
3202 : : /* Quick exit if already known flushed */
3203 [ + + ]: 1836354 : if (record <= LogwrtResult.Flush)
3204 : 1832922 : return false;
3205 : :
3206 : : /* read LogwrtResult and update local state */
3207 : 3432 : RefreshXLogWriteResult(LogwrtResult);
3208 : :
3209 : : /* check again */
3210 [ + + ]: 3432 : if (record <= LogwrtResult.Flush)
3211 : 429 : return false;
3212 : :
3213 : 3003 : return true;
3214 : 1836354 : }
3215 : :
3216 : : /*
3217 : : * Try to make a given XLOG file segment exist.
3218 : : *
3219 : : * logsegno: identify segment.
3220 : : *
3221 : : * *added: on return, true if this call raised the number of extant segments.
3222 : : *
3223 : : * path: on return, this char[MAXPGPATH] has the path to the logsegno file.
3224 : : *
3225 : : * Returns -1 or FD of opened file. A -1 here is not an error; a caller
3226 : : * wanting an open segment should attempt to open "path", which usually will
3227 : : * succeed. (This is weird, but it's efficient for the callers.)
3228 : : */
3229 : : static int
3230 : 382 : XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
3231 : : bool *added, char *path)
3232 : : {
3233 : 382 : char tmppath[MAXPGPATH];
3234 : 382 : XLogSegNo installed_segno;
3235 : 382 : XLogSegNo max_segno;
3236 : 382 : int fd;
3237 : 382 : int save_errno;
3238 : 382 : int open_flags = O_RDWR | O_CREAT | O_EXCL | PG_BINARY;
3239 : 382 : instr_time io_start;
3240 : :
3241 [ + - ]: 382 : Assert(logtli != 0);
3242 : :
3243 : 382 : XLogFilePath(path, logtli, logsegno, wal_segment_size);
3244 : :
3245 : : /*
3246 : : * Try to use existent file (checkpoint maker may have created it already)
3247 : : */
3248 : 382 : *added = false;
3249 : 764 : fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3250 : 382 : get_sync_bit(wal_sync_method));
3251 [ + + ]: 382 : if (fd < 0)
3252 : : {
3253 [ + - ]: 14 : if (errno != ENOENT)
3254 [ # # # # ]: 0 : ereport(ERROR,
3255 : : (errcode_for_file_access(),
3256 : : errmsg("could not open file \"%s\": %m", path)));
3257 : 14 : }
3258 : : else
3259 : 368 : return fd;
3260 : :
3261 : : /*
3262 : : * Initialize an empty (all zeroes) segment. NOTE: it is possible that
3263 : : * another process is doing the same thing. If so, we will end up
3264 : : * pre-creating an extra log segment. That seems OK, and better than
3265 : : * holding the lock throughout this lengthy process.
3266 : : */
3267 [ - + - + ]: 14 : elog(DEBUG2, "creating and filling new WAL file");
3268 : :
3269 : 14 : snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
3270 : :
3271 : 14 : unlink(tmppath);
3272 : :
3273 [ + - ]: 14 : if (io_direct_flags & IO_DIRECT_WAL_INIT)
3274 : 0 : open_flags |= PG_O_DIRECT;
3275 : :
3276 : : /* do not use get_sync_bit() here --- want to fsync only at end of fill */
3277 : 14 : fd = BasicOpenFile(tmppath, open_flags);
3278 [ + - ]: 14 : if (fd < 0)
3279 [ # # # # ]: 0 : ereport(ERROR,
3280 : : (errcode_for_file_access(),
3281 : : errmsg("could not create file \"%s\": %m", tmppath)));
3282 : :
3283 : : /* Measure I/O timing when initializing segment */
3284 : 14 : io_start = pgstat_prepare_io_time(track_wal_io_timing);
3285 : :
3286 : 14 : pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_WRITE);
3287 : 14 : save_errno = 0;
3288 [ + - ]: 14 : if (wal_init_zero)
3289 : : {
3290 : 14 : ssize_t rc;
3291 : :
3292 : : /*
3293 : : * Zero-fill the file. With this setting, we do this the hard way to
3294 : : * ensure that all the file space has really been allocated. On
3295 : : * platforms that allow "holes" in files, just seeking to the end
3296 : : * doesn't allocate intermediate space. This way, we know that we
3297 : : * have all the space and (after the fsync below) that all the
3298 : : * indirect blocks are down on disk. Therefore, fdatasync(2) or
3299 : : * O_DSYNC will be sufficient to sync future writes to the log file.
3300 : : */
3301 : 14 : rc = pg_pwrite_zeros(fd, wal_segment_size, 0);
3302 : :
3303 [ + - ]: 14 : if (rc < 0)
3304 : 0 : save_errno = errno;
3305 : 14 : }
3306 : : else
3307 : : {
3308 : : /*
3309 : : * Otherwise, seeking to the end and writing a solitary byte is
3310 : : * enough.
3311 : : */
3312 : 0 : errno = 0;
3313 [ # # ]: 0 : if (pg_pwrite(fd, "\0", 1, wal_segment_size - 1) != 1)
3314 : : {
3315 : : /* if write didn't set errno, assume no disk space */
3316 [ # # ]: 0 : save_errno = errno ? errno : ENOSPC;
3317 : 0 : }
3318 : : }
3319 : 14 : pgstat_report_wait_end();
3320 : :
3321 : : /*
3322 : : * A full segment worth of data is written when using wal_init_zero. One
3323 : : * byte is written when not using it.
3324 : : */
3325 : 14 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_INIT, IOOP_WRITE,
3326 : : io_start, 1,
3327 [ + - ]: 14 : wal_init_zero ? wal_segment_size : 1);
3328 : :
3329 [ + - ]: 14 : if (save_errno)
3330 : : {
3331 : : /*
3332 : : * If we fail to make the file, delete it to release disk space
3333 : : */
3334 : 0 : unlink(tmppath);
3335 : :
3336 : 0 : close(fd);
3337 : :
3338 : 0 : errno = save_errno;
3339 : :
3340 [ # # # # ]: 0 : ereport(ERROR,
3341 : : (errcode_for_file_access(),
3342 : : errmsg("could not write to file \"%s\": %m", tmppath)));
3343 : 0 : }
3344 : :
3345 : : /* Measure I/O timing when flushing segment */
3346 : 14 : io_start = pgstat_prepare_io_time(track_wal_io_timing);
3347 : :
3348 : 14 : pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_SYNC);
3349 [ + - ]: 14 : if (pg_fsync(fd) != 0)
3350 : : {
3351 : 0 : save_errno = errno;
3352 : 0 : close(fd);
3353 : 0 : errno = save_errno;
3354 [ # # # # ]: 0 : ereport(ERROR,
3355 : : (errcode_for_file_access(),
3356 : : errmsg("could not fsync file \"%s\": %m", tmppath)));
3357 : 0 : }
3358 : 14 : pgstat_report_wait_end();
3359 : :
3360 : 14 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_INIT,
3361 : : IOOP_FSYNC, io_start, 1, 0);
3362 : :
3363 [ + - ]: 14 : if (close(fd) != 0)
3364 [ # # # # ]: 0 : ereport(ERROR,
3365 : : (errcode_for_file_access(),
3366 : : errmsg("could not close file \"%s\": %m", tmppath)));
3367 : :
3368 : : /*
3369 : : * Now move the segment into place with its final name. Cope with
3370 : : * possibility that someone else has created the file while we were
3371 : : * filling ours: if so, use ours to pre-create a future log segment.
3372 : : */
3373 : 14 : installed_segno = logsegno;
3374 : :
3375 : : /*
3376 : : * XXX: What should we use as max_segno? We used to use XLOGfileslop when
3377 : : * that was a constant, but that was always a bit dubious: normally, at a
3378 : : * checkpoint, XLOGfileslop was the offset from the checkpoint record, but
3379 : : * here, it was the offset from the insert location. We can't do the
3380 : : * normal XLOGfileslop calculation here because we don't have access to
3381 : : * the prior checkpoint's redo location. So somewhat arbitrarily, just use
3382 : : * CheckPointSegments.
3383 : : */
3384 : 14 : max_segno = logsegno + CheckPointSegments;
3385 [ + - + - ]: 28 : if (InstallXLogFileSegment(&installed_segno, tmppath, true, max_segno,
3386 : 14 : logtli))
3387 : : {
3388 : 14 : *added = true;
3389 [ - + - + ]: 14 : elog(DEBUG2, "done creating and filling new WAL file");
3390 : 14 : }
3391 : : else
3392 : : {
3393 : : /*
3394 : : * No need for any more future segments, or InstallXLogFileSegment()
3395 : : * failed to rename the file into place. If the rename failed, a
3396 : : * caller opening the file may fail.
3397 : : */
3398 : 0 : unlink(tmppath);
3399 [ # # # # ]: 0 : elog(DEBUG2, "abandoned new WAL file");
3400 : : }
3401 : :
3402 : 14 : return -1;
3403 : 382 : }
3404 : :
3405 : : /*
3406 : : * Create a new XLOG file segment, or open a pre-existing one.
3407 : : *
3408 : : * logsegno: identify segment to be created/opened.
3409 : : *
3410 : : * Returns FD of opened file.
3411 : : *
3412 : : * Note: errors here are ERROR not PANIC because we might or might not be
3413 : : * inside a critical section (eg, during checkpoint there is no reason to
3414 : : * take down the system on failure). They will promote to PANIC if we are
3415 : : * in a critical section.
3416 : : */
3417 : : int
3418 : 382 : XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
3419 : : {
3420 : 382 : bool ignore_added;
3421 : 382 : char path[MAXPGPATH];
3422 : 382 : int fd;
3423 : :
3424 [ + - ]: 382 : Assert(logtli != 0);
3425 : :
3426 : 382 : fd = XLogFileInitInternal(logsegno, logtli, &ignore_added, path);
3427 [ + + ]: 382 : if (fd >= 0)
3428 : 368 : return fd;
3429 : :
3430 : : /* Now open original target segment (might not be file I just made) */
3431 : 28 : fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3432 : 14 : get_sync_bit(wal_sync_method));
3433 [ + - ]: 14 : if (fd < 0)
3434 [ # # # # ]: 0 : ereport(ERROR,
3435 : : (errcode_for_file_access(),
3436 : : errmsg("could not open file \"%s\": %m", path)));
3437 : 14 : return fd;
3438 : 382 : }
3439 : :
3440 : : /*
3441 : : * Create a new XLOG file segment by copying a pre-existing one.
3442 : : *
3443 : : * destsegno: identify segment to be created.
3444 : : *
3445 : : * srcTLI, srcsegno: identify segment to be copied (could be from
3446 : : * a different timeline)
3447 : : *
3448 : : * upto: how much of the source file to copy (the rest is filled with
3449 : : * zeros)
3450 : : *
3451 : : * Currently this is only used during recovery, and so there are no locking
3452 : : * considerations. But we should be just as tense as XLogFileInit to avoid
3453 : : * emplacing a bogus file.
3454 : : */
3455 : : static void
3456 : 0 : XLogFileCopy(TimeLineID destTLI, XLogSegNo destsegno,
3457 : : TimeLineID srcTLI, XLogSegNo srcsegno,
3458 : : int upto)
3459 : : {
3460 : 0 : char path[MAXPGPATH];
3461 : 0 : char tmppath[MAXPGPATH];
3462 : 0 : PGAlignedXLogBlock buffer;
3463 : 0 : int srcfd;
3464 : 0 : int fd;
3465 : 0 : int nbytes;
3466 : :
3467 : : /*
3468 : : * Open the source file
3469 : : */
3470 : 0 : XLogFilePath(path, srcTLI, srcsegno, wal_segment_size);
3471 : 0 : srcfd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
3472 [ # # ]: 0 : if (srcfd < 0)
3473 [ # # # # ]: 0 : ereport(ERROR,
3474 : : (errcode_for_file_access(),
3475 : : errmsg("could not open file \"%s\": %m", path)));
3476 : :
3477 : : /*
3478 : : * Copy into a temp file name.
3479 : : */
3480 : 0 : snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
3481 : :
3482 : 0 : unlink(tmppath);
3483 : :
3484 : : /* do not use get_sync_bit() here --- want to fsync only at end of fill */
3485 : 0 : fd = OpenTransientFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
3486 [ # # ]: 0 : if (fd < 0)
3487 [ # # # # ]: 0 : ereport(ERROR,
3488 : : (errcode_for_file_access(),
3489 : : errmsg("could not create file \"%s\": %m", tmppath)));
3490 : :
3491 : : /*
3492 : : * Do the data copying.
3493 : : */
3494 [ # # ]: 0 : for (nbytes = 0; nbytes < wal_segment_size; nbytes += sizeof(buffer))
3495 : : {
3496 : 0 : int nread;
3497 : :
3498 : 0 : nread = upto - nbytes;
3499 : :
3500 : : /*
3501 : : * The part that is not read from the source file is filled with
3502 : : * zeros.
3503 : : */
3504 [ # # ]: 0 : if (nread < sizeof(buffer))
3505 : 0 : memset(buffer.data, 0, sizeof(buffer));
3506 : :
3507 [ # # ]: 0 : if (nread > 0)
3508 : : {
3509 : 0 : int r;
3510 : :
3511 [ # # ]: 0 : if (nread > sizeof(buffer))
3512 : 0 : nread = sizeof(buffer);
3513 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_READ);
3514 : 0 : r = read(srcfd, buffer.data, nread);
3515 [ # # ]: 0 : if (r != nread)
3516 : : {
3517 [ # # ]: 0 : if (r < 0)
3518 [ # # # # ]: 0 : ereport(ERROR,
3519 : : (errcode_for_file_access(),
3520 : : errmsg("could not read file \"%s\": %m",
3521 : : path)));
3522 : : else
3523 [ # # # # ]: 0 : ereport(ERROR,
3524 : : (errcode(ERRCODE_DATA_CORRUPTED),
3525 : : errmsg("could not read file \"%s\": read %d of %zu",
3526 : : path, r, (Size) nread)));
3527 : 0 : }
3528 : 0 : pgstat_report_wait_end();
3529 : 0 : }
3530 : 0 : errno = 0;
3531 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_WRITE);
3532 [ # # ]: 0 : if ((int) write(fd, buffer.data, sizeof(buffer)) != (int) sizeof(buffer))
3533 : : {
3534 : 0 : int save_errno = errno;
3535 : :
3536 : : /*
3537 : : * If we fail to make the file, delete it to release disk space
3538 : : */
3539 : 0 : unlink(tmppath);
3540 : : /* if write didn't set errno, assume problem is no disk space */
3541 [ # # ]: 0 : errno = save_errno ? save_errno : ENOSPC;
3542 : :
3543 [ # # # # ]: 0 : ereport(ERROR,
3544 : : (errcode_for_file_access(),
3545 : : errmsg("could not write to file \"%s\": %m", tmppath)));
3546 : 0 : }
3547 : 0 : pgstat_report_wait_end();
3548 : 0 : }
3549 : :
3550 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_SYNC);
3551 [ # # ]: 0 : if (pg_fsync(fd) != 0)
3552 [ # # # # : 0 : ereport(data_sync_elevel(ERROR),
# # ]
3553 : : (errcode_for_file_access(),
3554 : : errmsg("could not fsync file \"%s\": %m", tmppath)));
3555 : 0 : pgstat_report_wait_end();
3556 : :
3557 [ # # ]: 0 : if (CloseTransientFile(fd) != 0)
3558 [ # # # # ]: 0 : ereport(ERROR,
3559 : : (errcode_for_file_access(),
3560 : : errmsg("could not close file \"%s\": %m", tmppath)));
3561 : :
3562 [ # # ]: 0 : if (CloseTransientFile(srcfd) != 0)
3563 [ # # # # ]: 0 : ereport(ERROR,
3564 : : (errcode_for_file_access(),
3565 : : errmsg("could not close file \"%s\": %m", path)));
3566 : :
3567 : : /*
3568 : : * Now move the segment into place with its final name.
3569 : : */
3570 [ # # ]: 0 : if (!InstallXLogFileSegment(&destsegno, tmppath, false, 0, destTLI))
3571 [ # # # # ]: 0 : elog(ERROR, "InstallXLogFileSegment should not have failed");
3572 : 0 : }
3573 : :
3574 : : /*
3575 : : * Install a new XLOG segment file as a current or future log segment.
3576 : : *
3577 : : * This is used both to install a newly-created segment (which has a temp
3578 : : * filename while it's being created) and to recycle an old segment.
3579 : : *
3580 : : * *segno: identify segment to install as (or first possible target).
3581 : : * When find_free is true, this is modified on return to indicate the
3582 : : * actual installation location or last segment searched.
3583 : : *
3584 : : * tmppath: initial name of file to install. It will be renamed into place.
3585 : : *
3586 : : * find_free: if true, install the new segment at the first empty segno
3587 : : * number at or after the passed numbers. If false, install the new segment
3588 : : * exactly where specified, deleting any existing segment file there.
3589 : : *
3590 : : * max_segno: maximum segment number to install the new file as. Fail if no
3591 : : * free slot is found between *segno and max_segno. (Ignored when find_free
3592 : : * is false.)
3593 : : *
3594 : : * tli: The timeline on which the new segment should be installed.
3595 : : *
3596 : : * Returns true if the file was installed successfully. false indicates that
3597 : : * max_segno limit was exceeded, the startup process has disabled this
3598 : : * function for now, or an error occurred while renaming the file into place.
3599 : : */
3600 : : static bool
3601 : 17 : InstallXLogFileSegment(XLogSegNo *segno, char *tmppath,
3602 : : bool find_free, XLogSegNo max_segno, TimeLineID tli)
3603 : : {
3604 : 17 : char path[MAXPGPATH];
3605 : 17 : struct stat stat_buf;
3606 : :
3607 [ + - ]: 17 : Assert(tli != 0);
3608 : :
3609 : 17 : XLogFilePath(path, tli, *segno, wal_segment_size);
3610 : :
3611 : 17 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
3612 [ + - ]: 17 : if (!XLogCtl->InstallXLogFileSegmentActive)
3613 : : {
3614 : 0 : LWLockRelease(ControlFileLock);
3615 : 0 : return false;
3616 : : }
3617 : :
3618 [ + - ]: 17 : if (!find_free)
3619 : : {
3620 : : /* Force installation: get rid of any pre-existing segment file */
3621 : 0 : durable_unlink(path, DEBUG1);
3622 : 0 : }
3623 : : else
3624 : : {
3625 : : /* Find a free slot to put it in */
3626 [ + + ]: 18 : while (stat(path, &stat_buf) == 0)
3627 : : {
3628 [ - + ]: 1 : if ((*segno) >= max_segno)
3629 : : {
3630 : : /* Failed to find a free slot within specified range */
3631 : 0 : LWLockRelease(ControlFileLock);
3632 : 0 : return false;
3633 : : }
3634 : 1 : (*segno)++;
3635 : 1 : XLogFilePath(path, tli, *segno, wal_segment_size);
3636 : : }
3637 : : }
3638 : :
3639 [ + - ]: 17 : Assert(access(path, F_OK) != 0 && errno == ENOENT);
3640 [ - + ]: 17 : if (durable_rename(tmppath, path, LOG) != 0)
3641 : : {
3642 : 0 : LWLockRelease(ControlFileLock);
3643 : : /* durable_rename already emitted log message */
3644 : 0 : return false;
3645 : : }
3646 : :
3647 : 17 : LWLockRelease(ControlFileLock);
3648 : :
3649 : 17 : return true;
3650 : 17 : }
3651 : :
3652 : : /*
3653 : : * Open a pre-existing logfile segment for writing.
3654 : : */
3655 : : int
3656 : 0 : XLogFileOpen(XLogSegNo segno, TimeLineID tli)
3657 : : {
3658 : 0 : char path[MAXPGPATH];
3659 : 0 : int fd;
3660 : :
3661 : 0 : XLogFilePath(path, tli, segno, wal_segment_size);
3662 : :
3663 : 0 : fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3664 : 0 : get_sync_bit(wal_sync_method));
3665 [ # # ]: 0 : if (fd < 0)
3666 [ # # # # ]: 0 : ereport(PANIC,
3667 : : (errcode_for_file_access(),
3668 : : errmsg("could not open file \"%s\": %m", path)));
3669 : :
3670 : 0 : return fd;
3671 : 0 : }
3672 : :
3673 : : /*
3674 : : * Close the current logfile segment for writing.
3675 : : */
3676 : : static void
3677 : 120 : XLogFileClose(void)
3678 : : {
3679 [ + - ]: 120 : Assert(openLogFile >= 0);
3680 : :
3681 : : /*
3682 : : * WAL segment files will not be re-read in normal operation, so we advise
3683 : : * the OS to release any cached pages. But do not do so if WAL archiving
3684 : : * or streaming is active, because archiver and walsender process could
3685 : : * use the cache to read the WAL segment.
3686 : : */
3687 : : #if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
3688 : : if (!XLogIsNeeded() && (io_direct_flags & IO_DIRECT_WAL) == 0)
3689 : : (void) posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED);
3690 : : #endif
3691 : :
3692 [ + - ]: 120 : if (close(openLogFile) != 0)
3693 : : {
3694 : 0 : char xlogfname[MAXFNAMELEN];
3695 : 0 : int save_errno = errno;
3696 : :
3697 : 0 : XLogFileName(xlogfname, openLogTLI, openLogSegNo, wal_segment_size);
3698 : 0 : errno = save_errno;
3699 [ # # # # ]: 0 : ereport(PANIC,
3700 : : (errcode_for_file_access(),
3701 : : errmsg("could not close file \"%s\": %m", xlogfname)));
3702 : 0 : }
3703 : :
3704 : 120 : openLogFile = -1;
3705 : 120 : ReleaseExternalFD();
3706 : 120 : }
3707 : :
3708 : : /*
3709 : : * Preallocate log files beyond the specified log endpoint.
3710 : : *
3711 : : * XXX this is currently extremely conservative, since it forces only one
3712 : : * future log segment to exist, and even that only if we are 75% done with
3713 : : * the current one. This is only appropriate for very low-WAL-volume systems.
3714 : : * High-volume systems will be OK once they've built up a sufficient set of
3715 : : * recycled log segments, but the startup transient is likely to include
3716 : : * a lot of segment creations by foreground processes, which is not so good.
3717 : : *
3718 : : * XLogFileInitInternal() can ereport(ERROR). All known causes indicate big
3719 : : * trouble; for example, a full filesystem is one cause. The checkpoint WAL
3720 : : * and/or ControlFile updates already completed. If a RequestCheckpoint()
3721 : : * initiated the present checkpoint and an ERROR ends this function, the
3722 : : * command that called RequestCheckpoint() fails. That's not ideal, but it's
3723 : : * not worth contorting more functions to use caller-specified elevel values.
3724 : : * (With or without RequestCheckpoint(), an ERROR forestalls some inessential
3725 : : * reporting and resource reclamation.)
3726 : : */
3727 : : static void
3728 : 8 : PreallocXlogFiles(XLogRecPtr endptr, TimeLineID tli)
3729 : : {
3730 : 8 : XLogSegNo _logSegNo;
3731 : 8 : int lf;
3732 : 8 : bool added;
3733 : 8 : char path[MAXPGPATH];
3734 : 8 : uint64 offset;
3735 : :
3736 [ + - ]: 8 : if (!XLogCtl->InstallXLogFileSegmentActive)
3737 : 0 : return; /* unlocked check says no */
3738 : :
3739 : 8 : XLByteToPrevSeg(endptr, _logSegNo, wal_segment_size);
3740 : 8 : offset = XLogSegmentOffset(endptr - 1, wal_segment_size);
3741 [ + - ]: 8 : if (offset >= (uint32) (0.75 * wal_segment_size))
3742 : : {
3743 : 0 : _logSegNo++;
3744 : 0 : lf = XLogFileInitInternal(_logSegNo, tli, &added, path);
3745 [ # # ]: 0 : if (lf >= 0)
3746 : 0 : close(lf);
3747 [ # # ]: 0 : if (added)
3748 : 0 : CheckpointStats.ckpt_segs_added++;
3749 : 0 : }
3750 [ - + ]: 8 : }
3751 : :
3752 : : /*
3753 : : * Throws an error if the given log segment has already been removed or
3754 : : * recycled. The caller should only pass a segment that it knows to have
3755 : : * existed while the server has been running, as this function always
3756 : : * succeeds if no WAL segments have been removed since startup.
3757 : : * 'tli' is only used in the error message.
3758 : : *
3759 : : * Note: this function guarantees to keep errno unchanged on return.
3760 : : * This supports callers that use this to possibly deliver a better
3761 : : * error message about a missing file, while still being able to throw
3762 : : * a normal file-access error afterwards, if this does return.
3763 : : */
3764 : : void
3765 : 0 : CheckXLogRemoved(XLogSegNo segno, TimeLineID tli)
3766 : : {
3767 : 0 : int save_errno = errno;
3768 : 0 : XLogSegNo lastRemovedSegNo;
3769 : :
3770 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
3771 : 0 : lastRemovedSegNo = XLogCtl->lastRemovedSegNo;
3772 : 0 : SpinLockRelease(&XLogCtl->info_lck);
3773 : :
3774 [ # # ]: 0 : if (segno <= lastRemovedSegNo)
3775 : : {
3776 : 0 : char filename[MAXFNAMELEN];
3777 : :
3778 : 0 : XLogFileName(filename, tli, segno, wal_segment_size);
3779 : 0 : errno = save_errno;
3780 [ # # # # ]: 0 : ereport(ERROR,
3781 : : (errcode_for_file_access(),
3782 : : errmsg("requested WAL segment %s has already been removed",
3783 : : filename)));
3784 : 0 : }
3785 : 0 : errno = save_errno;
3786 : 0 : }
3787 : :
3788 : : /*
3789 : : * Return the last WAL segment removed, or 0 if no segment has been removed
3790 : : * since startup.
3791 : : *
3792 : : * NB: the result can be out of date arbitrarily fast, the caller has to deal
3793 : : * with that.
3794 : : */
3795 : : XLogSegNo
3796 : 0 : XLogGetLastRemovedSegno(void)
3797 : : {
3798 : 0 : XLogSegNo lastRemovedSegNo;
3799 : :
3800 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
3801 : 0 : lastRemovedSegNo = XLogCtl->lastRemovedSegNo;
3802 : 0 : SpinLockRelease(&XLogCtl->info_lck);
3803 : :
3804 : 0 : return lastRemovedSegNo;
3805 : 0 : }
3806 : :
3807 : : /*
3808 : : * Return the oldest WAL segment on the given TLI that still exists in
3809 : : * XLOGDIR, or 0 if none.
3810 : : */
3811 : : XLogSegNo
3812 : 0 : XLogGetOldestSegno(TimeLineID tli)
3813 : : {
3814 : 0 : DIR *xldir;
3815 : 0 : struct dirent *xlde;
3816 : 0 : XLogSegNo oldest_segno = 0;
3817 : :
3818 : 0 : xldir = AllocateDir(XLOGDIR);
3819 [ # # ]: 0 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3820 : : {
3821 : 0 : TimeLineID file_tli;
3822 : 0 : XLogSegNo file_segno;
3823 : :
3824 : : /* Ignore files that are not XLOG segments. */
3825 [ # # ]: 0 : if (!IsXLogFileName(xlde->d_name))
3826 : 0 : continue;
3827 : :
3828 : : /* Parse filename to get TLI and segno. */
3829 : 0 : XLogFromFileName(xlde->d_name, &file_tli, &file_segno,
3830 : 0 : wal_segment_size);
3831 : :
3832 : : /* Ignore anything that's not from the TLI of interest. */
3833 [ # # ]: 0 : if (tli != file_tli)
3834 : 0 : continue;
3835 : :
3836 : : /* If it's the oldest so far, update oldest_segno. */
3837 [ # # # # ]: 0 : if (oldest_segno == 0 || file_segno < oldest_segno)
3838 : 0 : oldest_segno = file_segno;
3839 [ # # # ]: 0 : }
3840 : :
3841 : 0 : FreeDir(xldir);
3842 : 0 : return oldest_segno;
3843 : 0 : }
3844 : :
3845 : : /*
3846 : : * Update the last removed segno pointer in shared memory, to reflect that the
3847 : : * given XLOG file has been removed.
3848 : : */
3849 : : static void
3850 : 3 : UpdateLastRemovedPtr(char *filename)
3851 : : {
3852 : 3 : uint32 tli;
3853 : 3 : XLogSegNo segno;
3854 : :
3855 : 3 : XLogFromFileName(filename, &tli, &segno, wal_segment_size);
3856 : :
3857 [ - + ]: 3 : SpinLockAcquire(&XLogCtl->info_lck);
3858 [ + + ]: 3 : if (segno > XLogCtl->lastRemovedSegNo)
3859 : 2 : XLogCtl->lastRemovedSegNo = segno;
3860 : 3 : SpinLockRelease(&XLogCtl->info_lck);
3861 : 3 : }
3862 : :
3863 : : /*
3864 : : * Remove all temporary log files in pg_wal
3865 : : *
3866 : : * This is called at the beginning of recovery after a previous crash,
3867 : : * at a point where no other processes write fresh WAL data.
3868 : : */
3869 : : static void
3870 : 0 : RemoveTempXlogFiles(void)
3871 : : {
3872 : 0 : DIR *xldir;
3873 : 0 : struct dirent *xlde;
3874 : :
3875 [ # # # # ]: 0 : elog(DEBUG2, "removing all temporary WAL segments");
3876 : :
3877 : 0 : xldir = AllocateDir(XLOGDIR);
3878 [ # # ]: 0 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3879 : : {
3880 : 0 : char path[MAXPGPATH];
3881 : :
3882 [ # # ]: 0 : if (strncmp(xlde->d_name, "xlogtemp.", 9) != 0)
3883 : 0 : continue;
3884 : :
3885 : 0 : snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
3886 : 0 : unlink(path);
3887 [ # # # # ]: 0 : elog(DEBUG2, "removed temporary WAL segment \"%s\"", path);
3888 [ # # # ]: 0 : }
3889 : 0 : FreeDir(xldir);
3890 : 0 : }
3891 : :
3892 : : /*
3893 : : * Recycle or remove all log files older or equal to passed segno.
3894 : : *
3895 : : * endptr is current (or recent) end of xlog, and lastredoptr is the
3896 : : * redo pointer of the last checkpoint. These are used to determine
3897 : : * whether we want to recycle rather than delete no-longer-wanted log files.
3898 : : *
3899 : : * insertTLI is the current timeline for XLOG insertion. Any recycled
3900 : : * segments should be reused for this timeline.
3901 : : */
3902 : : static void
3903 : 7 : RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr lastredoptr, XLogRecPtr endptr,
3904 : : TimeLineID insertTLI)
3905 : : {
3906 : 7 : DIR *xldir;
3907 : 7 : struct dirent *xlde;
3908 : 7 : char lastoff[MAXFNAMELEN];
3909 : 7 : XLogSegNo endlogSegNo;
3910 : 7 : XLogSegNo recycleSegNo;
3911 : :
3912 : : /* Initialize info about where to try to recycle to */
3913 : 7 : XLByteToSeg(endptr, endlogSegNo, wal_segment_size);
3914 : 7 : recycleSegNo = XLOGfileslop(lastredoptr);
3915 : :
3916 : : /*
3917 : : * Construct a filename of the last segment to be kept. The timeline ID
3918 : : * doesn't matter, we ignore that in the comparison. (During recovery,
3919 : : * InsertTimeLineID isn't set, so we can't use that.)
3920 : : */
3921 : 7 : XLogFileName(lastoff, 0, segno, wal_segment_size);
3922 : :
3923 [ - + - + ]: 7 : elog(DEBUG2, "attempting to remove WAL segments older than log file %s",
3924 : : lastoff);
3925 : :
3926 : 7 : xldir = AllocateDir(XLOGDIR);
3927 : :
3928 [ + + ]: 45 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3929 : : {
3930 : : /* Ignore files that are not XLOG segments */
3931 [ + + - + ]: 38 : if (!IsXLogFileName(xlde->d_name) &&
3932 : 28 : !IsPartialXLogFileName(xlde->d_name))
3933 : 28 : continue;
3934 : :
3935 : : /*
3936 : : * We ignore the timeline part of the XLOG segment identifiers in
3937 : : * deciding whether a segment is still needed. This ensures that we
3938 : : * won't prematurely remove a segment from a parent timeline. We could
3939 : : * probably be a little more proactive about removing segments of
3940 : : * non-parent timelines, but that would be a whole lot more
3941 : : * complicated.
3942 : : *
3943 : : * We use the alphanumeric sorting property of the filenames to decide
3944 : : * which ones are earlier than the lastoff segment.
3945 : : */
3946 [ + + ]: 10 : if (strcmp(xlde->d_name + 8, lastoff + 8) <= 0)
3947 : : {
3948 [ - + ]: 3 : if (XLogArchiveCheckDone(xlde->d_name))
3949 : : {
3950 : : /* Update the last removed location in shared memory first */
3951 : 3 : UpdateLastRemovedPtr(xlde->d_name);
3952 : :
3953 : 3 : RemoveXlogFile(xlde, recycleSegNo, &endlogSegNo, insertTLI);
3954 : 3 : }
3955 : 3 : }
3956 : : }
3957 : :
3958 : 7 : FreeDir(xldir);
3959 : 7 : }
3960 : :
3961 : : /*
3962 : : * Recycle or remove WAL files that are not part of the given timeline's
3963 : : * history.
3964 : : *
3965 : : * This is called during recovery, whenever we switch to follow a new
3966 : : * timeline, and at the end of recovery when we create a new timeline. We
3967 : : * wouldn't otherwise care about extra WAL files lying in pg_wal, but they
3968 : : * might be leftover pre-allocated or recycled WAL segments on the old timeline
3969 : : * that we haven't used yet, and contain garbage. If we just leave them in
3970 : : * pg_wal, they will eventually be archived, and we can't let that happen.
3971 : : * Files that belong to our timeline history are valid, because we have
3972 : : * successfully replayed them, but from others we can't be sure.
3973 : : *
3974 : : * 'switchpoint' is the current point in WAL where we switch to new timeline,
3975 : : * and 'newTLI' is the new timeline we switch to.
3976 : : */
3977 : : void
3978 : 0 : RemoveNonParentXlogFiles(XLogRecPtr switchpoint, TimeLineID newTLI)
3979 : : {
3980 : 0 : DIR *xldir;
3981 : 0 : struct dirent *xlde;
3982 : 0 : char switchseg[MAXFNAMELEN];
3983 : 0 : XLogSegNo endLogSegNo;
3984 : 0 : XLogSegNo switchLogSegNo;
3985 : 0 : XLogSegNo recycleSegNo;
3986 : :
3987 : : /*
3988 : : * Initialize info about where to begin the work. This will recycle,
3989 : : * somewhat arbitrarily, 10 future segments.
3990 : : */
3991 : 0 : XLByteToPrevSeg(switchpoint, switchLogSegNo, wal_segment_size);
3992 : 0 : XLByteToSeg(switchpoint, endLogSegNo, wal_segment_size);
3993 : 0 : recycleSegNo = endLogSegNo + 10;
3994 : :
3995 : : /*
3996 : : * Construct a filename of the last segment to be kept.
3997 : : */
3998 : 0 : XLogFileName(switchseg, newTLI, switchLogSegNo, wal_segment_size);
3999 : :
4000 [ # # # # ]: 0 : elog(DEBUG2, "attempting to remove WAL segments newer than log file %s",
4001 : : switchseg);
4002 : :
4003 : 0 : xldir = AllocateDir(XLOGDIR);
4004 : :
4005 [ # # ]: 0 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
4006 : : {
4007 : : /* Ignore files that are not XLOG segments */
4008 [ # # ]: 0 : if (!IsXLogFileName(xlde->d_name))
4009 : 0 : continue;
4010 : :
4011 : : /*
4012 : : * Remove files that are on a timeline older than the new one we're
4013 : : * switching to, but with a segment number >= the first segment on the
4014 : : * new timeline.
4015 : : */
4016 [ # # # # ]: 0 : if (strncmp(xlde->d_name, switchseg, 8) < 0 &&
4017 : 0 : strcmp(xlde->d_name + 8, switchseg + 8) > 0)
4018 : : {
4019 : : /*
4020 : : * If the file has already been marked as .ready, however, don't
4021 : : * remove it yet. It should be OK to remove it - files that are
4022 : : * not part of our timeline history are not required for recovery
4023 : : * - but seems safer to let them be archived and removed later.
4024 : : */
4025 [ # # ]: 0 : if (!XLogArchiveIsReady(xlde->d_name))
4026 : 0 : RemoveXlogFile(xlde, recycleSegNo, &endLogSegNo, newTLI);
4027 : 0 : }
4028 : : }
4029 : :
4030 : 0 : FreeDir(xldir);
4031 : 0 : }
4032 : :
4033 : : /*
4034 : : * Recycle or remove a log file that's no longer needed.
4035 : : *
4036 : : * segment_de is the dirent structure of the segment to recycle or remove.
4037 : : * recycleSegNo is the segment number to recycle up to. endlogSegNo is
4038 : : * the segment number of the current (or recent) end of WAL.
4039 : : *
4040 : : * endlogSegNo gets incremented if the segment is recycled so as it is not
4041 : : * checked again with future callers of this function.
4042 : : *
4043 : : * insertTLI is the current timeline for XLOG insertion. Any recycled segments
4044 : : * should be used for this timeline.
4045 : : */
4046 : : static void
4047 : 3 : RemoveXlogFile(const struct dirent *segment_de,
4048 : : XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo,
4049 : : TimeLineID insertTLI)
4050 : : {
4051 : 3 : char path[MAXPGPATH];
4052 : : #ifdef WIN32
4053 : : char newpath[MAXPGPATH];
4054 : : #endif
4055 : 3 : const char *segname = segment_de->d_name;
4056 : :
4057 : 3 : snprintf(path, MAXPGPATH, XLOGDIR "/%s", segname);
4058 : :
4059 : : /*
4060 : : * Before deleting the file, see if it can be recycled as a future log
4061 : : * segment. Only recycle normal files, because we don't want to recycle
4062 : : * symbolic links pointing to a separate archive directory.
4063 : : */
4064 [ + - ]: 3 : if (wal_recycle &&
4065 [ + - ]: 3 : *endlogSegNo <= recycleSegNo &&
4066 [ + - ]: 3 : XLogCtl->InstallXLogFileSegmentActive && /* callee rechecks this */
4067 [ + - - + ]: 3 : get_dirent_type(path, segment_de, false, DEBUG2) == PGFILETYPE_REG &&
4068 : 6 : InstallXLogFileSegment(endlogSegNo, path,
4069 : 3 : true, recycleSegNo, insertTLI))
4070 : : {
4071 [ - + - + ]: 3 : ereport(DEBUG2,
4072 : : (errmsg_internal("recycled write-ahead log file \"%s\"",
4073 : : segname)));
4074 : 3 : CheckpointStats.ckpt_segs_recycled++;
4075 : : /* Needn't recheck that slot on future iterations */
4076 : 3 : (*endlogSegNo)++;
4077 : 3 : }
4078 : : else
4079 : : {
4080 : : /* No need for any more future segments, or recycling failed ... */
4081 : 0 : int rc;
4082 : :
4083 [ # # # # ]: 0 : ereport(DEBUG2,
4084 : : (errmsg_internal("removing write-ahead log file \"%s\"",
4085 : : segname)));
4086 : :
4087 : : #ifdef WIN32
4088 : :
4089 : : /*
4090 : : * On Windows, if another process (e.g another backend) holds the file
4091 : : * open in FILE_SHARE_DELETE mode, unlink will succeed, but the file
4092 : : * will still show up in directory listing until the last handle is
4093 : : * closed. To avoid confusing the lingering deleted file for a live
4094 : : * WAL file that needs to be archived, rename it before deleting it.
4095 : : *
4096 : : * If another process holds the file open without FILE_SHARE_DELETE
4097 : : * flag, rename will fail. We'll try again at the next checkpoint.
4098 : : */
4099 : : snprintf(newpath, MAXPGPATH, "%s.deleted", path);
4100 : : if (rename(path, newpath) != 0)
4101 : : {
4102 : : ereport(LOG,
4103 : : (errcode_for_file_access(),
4104 : : errmsg("could not rename file \"%s\": %m",
4105 : : path)));
4106 : : return;
4107 : : }
4108 : : rc = durable_unlink(newpath, LOG);
4109 : : #else
4110 : 0 : rc = durable_unlink(path, LOG);
4111 : : #endif
4112 [ # # ]: 0 : if (rc != 0)
4113 : : {
4114 : : /* Message already logged by durable_unlink() */
4115 : 0 : return;
4116 : : }
4117 : 0 : CheckpointStats.ckpt_segs_removed++;
4118 [ # # ]: 0 : }
4119 : :
4120 : 3 : XLogArchiveCleanup(segname);
4121 [ - + ]: 3 : }
4122 : :
4123 : : /*
4124 : : * Verify whether pg_wal, pg_wal/archive_status, and pg_wal/summaries exist.
4125 : : * If the latter do not exist, recreate them.
4126 : : *
4127 : : * It is not the goal of this function to verify the contents of these
4128 : : * directories, but to help in cases where someone has performed a cluster
4129 : : * copy for PITR purposes but omitted pg_wal from the copy.
4130 : : *
4131 : : * We could also recreate pg_wal if it doesn't exist, but a deliberate
4132 : : * policy decision was made not to. It is fairly common for pg_wal to be
4133 : : * a symlink, and if that was the DBA's intent then automatically making a
4134 : : * plain directory would result in degraded performance with no notice.
4135 : : */
4136 : : static void
4137 : 4 : ValidateXLOGDirectoryStructure(void)
4138 : : {
4139 : 4 : char path[MAXPGPATH];
4140 : 4 : struct stat stat_buf;
4141 : :
4142 : : /* Check for pg_wal; if it doesn't exist, error out */
4143 [ + - ]: 4 : if (stat(XLOGDIR, &stat_buf) != 0 ||
4144 : 4 : !S_ISDIR(stat_buf.st_mode))
4145 [ # # # # ]: 0 : ereport(FATAL,
4146 : : (errcode_for_file_access(),
4147 : : errmsg("required WAL directory \"%s\" does not exist",
4148 : : XLOGDIR)));
4149 : :
4150 : : /* Check for archive_status */
4151 : 4 : snprintf(path, MAXPGPATH, XLOGDIR "/archive_status");
4152 [ - + ]: 4 : if (stat(path, &stat_buf) == 0)
4153 : : {
4154 : : /* Check for weird cases where it exists but isn't a directory */
4155 [ + - ]: 4 : if (!S_ISDIR(stat_buf.st_mode))
4156 [ # # # # ]: 0 : ereport(FATAL,
4157 : : (errcode_for_file_access(),
4158 : : errmsg("required WAL directory \"%s\" does not exist",
4159 : : path)));
4160 : 4 : }
4161 : : else
4162 : : {
4163 [ # # # # ]: 0 : ereport(LOG,
4164 : : (errmsg("creating missing WAL directory \"%s\"", path)));
4165 [ # # ]: 0 : if (MakePGDirectory(path) < 0)
4166 [ # # # # ]: 0 : ereport(FATAL,
4167 : : (errcode_for_file_access(),
4168 : : errmsg("could not create missing directory \"%s\": %m",
4169 : : path)));
4170 : : }
4171 : :
4172 : : /* Check for summaries */
4173 : 4 : snprintf(path, MAXPGPATH, XLOGDIR "/summaries");
4174 [ - + ]: 4 : if (stat(path, &stat_buf) == 0)
4175 : : {
4176 : : /* Check for weird cases where it exists but isn't a directory */
4177 [ + - ]: 4 : if (!S_ISDIR(stat_buf.st_mode))
4178 [ # # # # ]: 0 : ereport(FATAL,
4179 : : (errmsg("required WAL directory \"%s\" does not exist",
4180 : : path)));
4181 : 4 : }
4182 : : else
4183 : : {
4184 [ # # # # ]: 0 : ereport(LOG,
4185 : : (errmsg("creating missing WAL directory \"%s\"", path)));
4186 [ # # ]: 0 : if (MakePGDirectory(path) < 0)
4187 [ # # # # ]: 0 : ereport(FATAL,
4188 : : (errmsg("could not create missing directory \"%s\": %m",
4189 : : path)));
4190 : : }
4191 : 4 : }
4192 : :
4193 : : /*
4194 : : * Remove previous backup history files. This also retries creation of
4195 : : * .ready files for any backup history files for which XLogArchiveNotify
4196 : : * failed earlier.
4197 : : */
4198 : : static void
4199 : 0 : CleanupBackupHistory(void)
4200 : : {
4201 : 0 : DIR *xldir;
4202 : 0 : struct dirent *xlde;
4203 : 0 : char path[MAXPGPATH + sizeof(XLOGDIR)];
4204 : :
4205 : 0 : xldir = AllocateDir(XLOGDIR);
4206 : :
4207 [ # # ]: 0 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
4208 : : {
4209 [ # # ]: 0 : if (IsBackupHistoryFileName(xlde->d_name))
4210 : : {
4211 [ # # ]: 0 : if (XLogArchiveCheckDone(xlde->d_name))
4212 : : {
4213 [ # # # # ]: 0 : elog(DEBUG2, "removing WAL backup history file \"%s\"",
4214 : : xlde->d_name);
4215 : 0 : snprintf(path, sizeof(path), XLOGDIR "/%s", xlde->d_name);
4216 : 0 : unlink(path);
4217 : 0 : XLogArchiveCleanup(xlde->d_name);
4218 : 0 : }
4219 : 0 : }
4220 : : }
4221 : :
4222 : 0 : FreeDir(xldir);
4223 : 0 : }
4224 : :
4225 : : /*
4226 : : * I/O routines for pg_control
4227 : : *
4228 : : * *ControlFile is a buffer in shared memory that holds an image of the
4229 : : * contents of pg_control. WriteControlFile() initializes pg_control
4230 : : * given a preloaded buffer, ReadControlFile() loads the buffer from
4231 : : * the pg_control file (during postmaster or standalone-backend startup),
4232 : : * and UpdateControlFile() rewrites pg_control after we modify xlog state.
4233 : : * InitControlFile() fills the buffer with initial values.
4234 : : *
4235 : : * For simplicity, WriteControlFile() initializes the fields of pg_control
4236 : : * that are related to checking backend/database compatibility, and
4237 : : * ReadControlFile() verifies they are correct. We could split out the
4238 : : * I/O and compatibility-check functions, but there seems no need currently.
4239 : : */
4240 : :
4241 : : static void
4242 : 1 : InitControlFile(uint64 sysidentifier, uint32 data_checksum_version)
4243 : : {
4244 : 1 : char mock_auth_nonce[MOCK_AUTH_NONCE_LEN];
4245 : :
4246 : : /*
4247 : : * Generate a random nonce. This is used for authentication requests that
4248 : : * will fail because the user does not exist. The nonce is used to create
4249 : : * a genuine-looking password challenge for the non-existent user, in lieu
4250 : : * of an actual stored password.
4251 : : */
4252 [ + - ]: 1 : if (!pg_strong_random(mock_auth_nonce, MOCK_AUTH_NONCE_LEN))
4253 [ # # # # ]: 0 : ereport(PANIC,
4254 : : (errcode(ERRCODE_INTERNAL_ERROR),
4255 : : errmsg("could not generate secret authorization token")));
4256 : :
4257 : 1 : memset(ControlFile, 0, sizeof(ControlFileData));
4258 : : /* Initialize pg_control status fields */
4259 : 1 : ControlFile->system_identifier = sysidentifier;
4260 : 1 : memcpy(ControlFile->mock_authentication_nonce, mock_auth_nonce, MOCK_AUTH_NONCE_LEN);
4261 : 1 : ControlFile->state = DB_SHUTDOWNED;
4262 : 1 : ControlFile->unloggedLSN = FirstNormalUnloggedLSN;
4263 : :
4264 : : /* Set important parameter values for use when replaying WAL */
4265 : 1 : ControlFile->MaxConnections = MaxConnections;
4266 : 1 : ControlFile->max_worker_processes = max_worker_processes;
4267 : 1 : ControlFile->max_wal_senders = max_wal_senders;
4268 : 1 : ControlFile->max_prepared_xacts = max_prepared_xacts;
4269 : 1 : ControlFile->max_locks_per_xact = max_locks_per_xact;
4270 : 1 : ControlFile->wal_level = wal_level;
4271 : 1 : ControlFile->wal_log_hints = wal_log_hints;
4272 : 1 : ControlFile->track_commit_timestamp = track_commit_timestamp;
4273 : 1 : ControlFile->data_checksum_version = data_checksum_version;
4274 : 1 : }
4275 : :
4276 : : static void
4277 : 1 : WriteControlFile(void)
4278 : : {
4279 : 1 : int fd;
4280 : 1 : char buffer[PG_CONTROL_FILE_SIZE]; /* need not be aligned */
4281 : :
4282 : : /*
4283 : : * Initialize version and compatibility-check fields
4284 : : */
4285 : 1 : ControlFile->pg_control_version = PG_CONTROL_VERSION;
4286 : 1 : ControlFile->catalog_version_no = CATALOG_VERSION_NO;
4287 : :
4288 : 1 : ControlFile->maxAlign = MAXIMUM_ALIGNOF;
4289 : 1 : ControlFile->floatFormat = FLOATFORMAT_VALUE;
4290 : :
4291 : 1 : ControlFile->blcksz = BLCKSZ;
4292 : 1 : ControlFile->relseg_size = RELSEG_SIZE;
4293 : 1 : ControlFile->slru_pages_per_segment = SLRU_PAGES_PER_SEGMENT;
4294 : 1 : ControlFile->xlog_blcksz = XLOG_BLCKSZ;
4295 : 1 : ControlFile->xlog_seg_size = wal_segment_size;
4296 : :
4297 : 1 : ControlFile->nameDataLen = NAMEDATALEN;
4298 : 1 : ControlFile->indexMaxKeys = INDEX_MAX_KEYS;
4299 : :
4300 : 1 : ControlFile->toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
4301 : 1 : ControlFile->loblksize = LOBLKSIZE;
4302 : :
4303 : 1 : ControlFile->float8ByVal = true; /* vestigial */
4304 : :
4305 : : /*
4306 : : * Initialize the default 'char' signedness.
4307 : : *
4308 : : * The signedness of the char type is implementation-defined. For instance
4309 : : * on x86 architecture CPUs, the char data type is typically treated as
4310 : : * signed by default, whereas on aarch architecture CPUs, it is typically
4311 : : * treated as unsigned by default. In v17 or earlier, we accidentally let
4312 : : * C implementation signedness affect persistent data. This led to
4313 : : * inconsistent results when comparing char data across different
4314 : : * platforms.
4315 : : *
4316 : : * This flag can be used as a hint to ensure consistent behavior for
4317 : : * pre-v18 data files that store data sorted by the 'char' type on disk,
4318 : : * especially in cross-platform replication scenarios.
4319 : : *
4320 : : * Newly created database clusters unconditionally set the default char
4321 : : * signedness to true. pg_upgrade changes this flag for clusters that were
4322 : : * initialized on signedness=false platforms. As a result,
4323 : : * signedness=false setting will become rare over time. If we had known
4324 : : * about this problem during the last development cycle that forced initdb
4325 : : * (v8.3), we would have made all clusters signed or all clusters
4326 : : * unsigned. Making pg_upgrade the only source of signedness=false will
4327 : : * cause the population of database clusters to converge toward that
4328 : : * retrospective ideal.
4329 : : */
4330 : 1 : ControlFile->default_char_signedness = true;
4331 : :
4332 : : /* Contents are protected with a CRC */
4333 : 1 : INIT_CRC32C(ControlFile->crc);
4334 : 1 : COMP_CRC32C(ControlFile->crc,
4335 : : ControlFile,
4336 : : offsetof(ControlFileData, crc));
4337 : 1 : FIN_CRC32C(ControlFile->crc);
4338 : :
4339 : : /*
4340 : : * We write out PG_CONTROL_FILE_SIZE bytes into pg_control, zero-padding
4341 : : * the excess over sizeof(ControlFileData). This reduces the odds of
4342 : : * premature-EOF errors when reading pg_control. We'll still fail when we
4343 : : * check the contents of the file, but hopefully with a more specific
4344 : : * error than "couldn't read pg_control".
4345 : : */
4346 : 1 : memset(buffer, 0, PG_CONTROL_FILE_SIZE);
4347 : 1 : memcpy(buffer, ControlFile, sizeof(ControlFileData));
4348 : :
4349 : 1 : fd = BasicOpenFile(XLOG_CONTROL_FILE,
4350 : : O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
4351 [ + - ]: 1 : if (fd < 0)
4352 [ # # # # ]: 0 : ereport(PANIC,
4353 : : (errcode_for_file_access(),
4354 : : errmsg("could not create file \"%s\": %m",
4355 : : XLOG_CONTROL_FILE)));
4356 : :
4357 : 1 : errno = 0;
4358 : 1 : pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_WRITE);
4359 [ + - ]: 1 : if (write(fd, buffer, PG_CONTROL_FILE_SIZE) != PG_CONTROL_FILE_SIZE)
4360 : : {
4361 : : /* if write didn't set errno, assume problem is no disk space */
4362 [ # # ]: 0 : if (errno == 0)
4363 : 0 : errno = ENOSPC;
4364 [ # # # # ]: 0 : ereport(PANIC,
4365 : : (errcode_for_file_access(),
4366 : : errmsg("could not write to file \"%s\": %m",
4367 : : XLOG_CONTROL_FILE)));
4368 : 0 : }
4369 : 1 : pgstat_report_wait_end();
4370 : :
4371 : 1 : pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_SYNC);
4372 [ + - ]: 1 : if (pg_fsync(fd) != 0)
4373 [ # # # # ]: 0 : ereport(PANIC,
4374 : : (errcode_for_file_access(),
4375 : : errmsg("could not fsync file \"%s\": %m",
4376 : : XLOG_CONTROL_FILE)));
4377 : 1 : pgstat_report_wait_end();
4378 : :
4379 [ + - ]: 1 : if (close(fd) != 0)
4380 [ # # # # ]: 0 : ereport(PANIC,
4381 : : (errcode_for_file_access(),
4382 : : errmsg("could not close file \"%s\": %m",
4383 : : XLOG_CONTROL_FILE)));
4384 : 1 : }
4385 : :
4386 : : static void
4387 : 4 : ReadControlFile(void)
4388 : : {
4389 : 4 : pg_crc32c crc;
4390 : 4 : int fd;
4391 : 4 : char wal_segsz_str[20];
4392 : 4 : int r;
4393 : :
4394 : : /*
4395 : : * Read data...
4396 : : */
4397 : 4 : fd = BasicOpenFile(XLOG_CONTROL_FILE,
4398 : : O_RDWR | PG_BINARY);
4399 [ + - ]: 4 : if (fd < 0)
4400 [ # # # # ]: 0 : ereport(PANIC,
4401 : : (errcode_for_file_access(),
4402 : : errmsg("could not open file \"%s\": %m",
4403 : : XLOG_CONTROL_FILE)));
4404 : :
4405 : 4 : pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_READ);
4406 : 4 : r = read(fd, ControlFile, sizeof(ControlFileData));
4407 [ + - ]: 4 : if (r != sizeof(ControlFileData))
4408 : : {
4409 [ # # ]: 0 : if (r < 0)
4410 [ # # # # ]: 0 : ereport(PANIC,
4411 : : (errcode_for_file_access(),
4412 : : errmsg("could not read file \"%s\": %m",
4413 : : XLOG_CONTROL_FILE)));
4414 : : else
4415 [ # # # # ]: 0 : ereport(PANIC,
4416 : : (errcode(ERRCODE_DATA_CORRUPTED),
4417 : : errmsg("could not read file \"%s\": read %d of %zu",
4418 : : XLOG_CONTROL_FILE, r, sizeof(ControlFileData))));
4419 : 0 : }
4420 : 4 : pgstat_report_wait_end();
4421 : :
4422 : 4 : close(fd);
4423 : :
4424 : : /*
4425 : : * Check for expected pg_control format version. If this is wrong, the
4426 : : * CRC check will likely fail because we'll be checking the wrong number
4427 : : * of bytes. Complaining about wrong version will probably be more
4428 : : * enlightening than complaining about wrong CRC.
4429 : : */
4430 : :
4431 [ - + # # : 4 : if (ControlFile->pg_control_version != PG_CONTROL_VERSION && ControlFile->pg_control_version % 65536 == 0 && ControlFile->pg_control_version / 65536 != 0)
# # ]
4432 [ # # # # ]: 0 : ereport(FATAL,
4433 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4434 : : errmsg("database files are incompatible with server"),
4435 : : errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d (0x%08x),"
4436 : : " but the server was compiled with PG_CONTROL_VERSION %d (0x%08x).",
4437 : : ControlFile->pg_control_version, ControlFile->pg_control_version,
4438 : : PG_CONTROL_VERSION, PG_CONTROL_VERSION),
4439 : : errhint("This could be a problem of mismatched byte ordering. It looks like you need to initdb.")));
4440 : :
4441 [ + - ]: 4 : if (ControlFile->pg_control_version != PG_CONTROL_VERSION)
4442 [ # # # # ]: 0 : ereport(FATAL,
4443 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4444 : : errmsg("database files are incompatible with server"),
4445 : : errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d,"
4446 : : " but the server was compiled with PG_CONTROL_VERSION %d.",
4447 : : ControlFile->pg_control_version, PG_CONTROL_VERSION),
4448 : : errhint("It looks like you need to initdb.")));
4449 : :
4450 : : /* Now check the CRC. */
4451 : 4 : INIT_CRC32C(crc);
4452 : 4 : COMP_CRC32C(crc,
4453 : : ControlFile,
4454 : : offsetof(ControlFileData, crc));
4455 : 4 : FIN_CRC32C(crc);
4456 : :
4457 [ + - ]: 4 : if (!EQ_CRC32C(crc, ControlFile->crc))
4458 [ # # # # ]: 0 : ereport(FATAL,
4459 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4460 : : errmsg("incorrect checksum in control file")));
4461 : :
4462 : : /*
4463 : : * Do compatibility checking immediately. If the database isn't
4464 : : * compatible with the backend executable, we want to abort before we can
4465 : : * possibly do any damage.
4466 : : */
4467 [ + - ]: 4 : if (ControlFile->catalog_version_no != CATALOG_VERSION_NO)
4468 [ # # # # ]: 0 : ereport(FATAL,
4469 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4470 : : errmsg("database files are incompatible with server"),
4471 : : /* translator: %s is a variable name and %d is its value */
4472 : : errdetail("The database cluster was initialized with %s %d,"
4473 : : " but the server was compiled with %s %d.",
4474 : : "CATALOG_VERSION_NO", ControlFile->catalog_version_no,
4475 : : "CATALOG_VERSION_NO", CATALOG_VERSION_NO),
4476 : : errhint("It looks like you need to initdb.")));
4477 [ + - ]: 4 : if (ControlFile->maxAlign != MAXIMUM_ALIGNOF)
4478 [ # # # # ]: 0 : ereport(FATAL,
4479 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4480 : : errmsg("database files are incompatible with server"),
4481 : : /* translator: %s is a variable name and %d is its value */
4482 : : errdetail("The database cluster was initialized with %s %d,"
4483 : : " but the server was compiled with %s %d.",
4484 : : "MAXALIGN", ControlFile->maxAlign,
4485 : : "MAXALIGN", MAXIMUM_ALIGNOF),
4486 : : errhint("It looks like you need to initdb.")));
4487 [ + - ]: 4 : if (ControlFile->floatFormat != FLOATFORMAT_VALUE)
4488 [ # # # # ]: 0 : ereport(FATAL,
4489 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4490 : : errmsg("database files are incompatible with server"),
4491 : : errdetail("The database cluster appears to use a different floating-point number format than the server executable."),
4492 : : errhint("It looks like you need to initdb.")));
4493 [ + - ]: 4 : if (ControlFile->blcksz != BLCKSZ)
4494 [ # # # # ]: 0 : ereport(FATAL,
4495 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4496 : : errmsg("database files are incompatible with server"),
4497 : : /* translator: %s is a variable name and %d is its value */
4498 : : errdetail("The database cluster was initialized with %s %d,"
4499 : : " but the server was compiled with %s %d.",
4500 : : "BLCKSZ", ControlFile->blcksz,
4501 : : "BLCKSZ", BLCKSZ),
4502 : : errhint("It looks like you need to recompile or initdb.")));
4503 [ + - ]: 4 : if (ControlFile->relseg_size != RELSEG_SIZE)
4504 [ # # # # ]: 0 : ereport(FATAL,
4505 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4506 : : errmsg("database files are incompatible with server"),
4507 : : /* translator: %s is a variable name and %d is its value */
4508 : : errdetail("The database cluster was initialized with %s %d,"
4509 : : " but the server was compiled with %s %d.",
4510 : : "RELSEG_SIZE", ControlFile->relseg_size,
4511 : : "RELSEG_SIZE", RELSEG_SIZE),
4512 : : errhint("It looks like you need to recompile or initdb.")));
4513 [ + - ]: 4 : if (ControlFile->slru_pages_per_segment != SLRU_PAGES_PER_SEGMENT)
4514 [ # # # # ]: 0 : ereport(FATAL,
4515 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4516 : : errmsg("database files are incompatible with server"),
4517 : : /* translator: %s is a variable name and %d is its value */
4518 : : errdetail("The database cluster was initialized with %s %d,"
4519 : : " but the server was compiled with %s %d.",
4520 : : "SLRU_PAGES_PER_SEGMENT", ControlFile->slru_pages_per_segment,
4521 : : "SLRU_PAGES_PER_SEGMENT", SLRU_PAGES_PER_SEGMENT),
4522 : : errhint("It looks like you need to recompile or initdb.")));
4523 [ + - ]: 4 : if (ControlFile->xlog_blcksz != XLOG_BLCKSZ)
4524 [ # # # # ]: 0 : ereport(FATAL,
4525 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4526 : : errmsg("database files are incompatible with server"),
4527 : : /* translator: %s is a variable name and %d is its value */
4528 : : errdetail("The database cluster was initialized with %s %d,"
4529 : : " but the server was compiled with %s %d.",
4530 : : "XLOG_BLCKSZ", ControlFile->xlog_blcksz,
4531 : : "XLOG_BLCKSZ", XLOG_BLCKSZ),
4532 : : errhint("It looks like you need to recompile or initdb.")));
4533 [ + - ]: 4 : if (ControlFile->nameDataLen != NAMEDATALEN)
4534 [ # # # # ]: 0 : ereport(FATAL,
4535 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4536 : : errmsg("database files are incompatible with server"),
4537 : : /* translator: %s is a variable name and %d is its value */
4538 : : errdetail("The database cluster was initialized with %s %d,"
4539 : : " but the server was compiled with %s %d.",
4540 : : "NAMEDATALEN", ControlFile->nameDataLen,
4541 : : "NAMEDATALEN", NAMEDATALEN),
4542 : : errhint("It looks like you need to recompile or initdb.")));
4543 [ + - ]: 4 : if (ControlFile->indexMaxKeys != INDEX_MAX_KEYS)
4544 [ # # # # ]: 0 : ereport(FATAL,
4545 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4546 : : errmsg("database files are incompatible with server"),
4547 : : /* translator: %s is a variable name and %d is its value */
4548 : : errdetail("The database cluster was initialized with %s %d,"
4549 : : " but the server was compiled with %s %d.",
4550 : : "INDEX_MAX_KEYS", ControlFile->indexMaxKeys,
4551 : : "INDEX_MAX_KEYS", INDEX_MAX_KEYS),
4552 : : errhint("It looks like you need to recompile or initdb.")));
4553 [ + - ]: 4 : if (ControlFile->toast_max_chunk_size != TOAST_MAX_CHUNK_SIZE)
4554 [ # # # # ]: 0 : ereport(FATAL,
4555 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4556 : : errmsg("database files are incompatible with server"),
4557 : : /* translator: %s is a variable name and %d is its value */
4558 : : errdetail("The database cluster was initialized with %s %d,"
4559 : : " but the server was compiled with %s %d.",
4560 : : "TOAST_MAX_CHUNK_SIZE", ControlFile->toast_max_chunk_size,
4561 : : "TOAST_MAX_CHUNK_SIZE", (int) TOAST_MAX_CHUNK_SIZE),
4562 : : errhint("It looks like you need to recompile or initdb.")));
4563 [ + - ]: 4 : if (ControlFile->loblksize != LOBLKSIZE)
4564 [ # # # # ]: 0 : ereport(FATAL,
4565 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4566 : : errmsg("database files are incompatible with server"),
4567 : : /* translator: %s is a variable name and %d is its value */
4568 : : errdetail("The database cluster was initialized with %s %d,"
4569 : : " but the server was compiled with %s %d.",
4570 : : "LOBLKSIZE", ControlFile->loblksize,
4571 : : "LOBLKSIZE", (int) LOBLKSIZE),
4572 : : errhint("It looks like you need to recompile or initdb.")));
4573 : :
4574 [ + - ]: 4 : Assert(ControlFile->float8ByVal); /* vestigial, not worth an error msg */
4575 : :
4576 : 4 : wal_segment_size = ControlFile->xlog_seg_size;
4577 : :
4578 [ + - ]: 4 : if (!IsValidWalSegSize(wal_segment_size))
4579 [ # # # # ]: 0 : ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4580 : : errmsg_plural("invalid WAL segment size in control file (%d byte)",
4581 : : "invalid WAL segment size in control file (%d bytes)",
4582 : : wal_segment_size,
4583 : : wal_segment_size),
4584 : : errdetail("The WAL segment size must be a power of two between 1 MB and 1 GB.")));
4585 : :
4586 : 4 : snprintf(wal_segsz_str, sizeof(wal_segsz_str), "%d", wal_segment_size);
4587 : 4 : SetConfigOption("wal_segment_size", wal_segsz_str, PGC_INTERNAL,
4588 : : PGC_S_DYNAMIC_DEFAULT);
4589 : :
4590 : : /* check and update variables dependent on wal_segment_size */
4591 [ + - ]: 4 : if (ConvertToXSegs(min_wal_size_mb, wal_segment_size) < 2)
4592 [ # # # # ]: 0 : ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4593 : : /* translator: both %s are GUC names */
4594 : : errmsg("\"%s\" must be at least twice \"%s\"",
4595 : : "min_wal_size", "wal_segment_size")));
4596 : :
4597 [ + - ]: 4 : if (ConvertToXSegs(max_wal_size_mb, wal_segment_size) < 2)
4598 [ # # # # ]: 0 : ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4599 : : /* translator: both %s are GUC names */
4600 : : errmsg("\"%s\" must be at least twice \"%s\"",
4601 : : "max_wal_size", "wal_segment_size")));
4602 : :
4603 : 4 : UsableBytesInSegment =
4604 : 4 : (wal_segment_size / XLOG_BLCKSZ * UsableBytesInPage) -
4605 : : (SizeOfXLogLongPHD - SizeOfXLogShortPHD);
4606 : :
4607 : 4 : CalculateCheckpointSegments();
4608 : :
4609 : : /* Make the initdb settings visible as GUC variables, too */
4610 : 4 : SetConfigOption("data_checksums", DataChecksumsEnabled() ? "yes" : "no",
4611 : : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
4612 : 4 : }
4613 : :
4614 : : /*
4615 : : * Utility wrapper to update the control file. Note that the control
4616 : : * file gets flushed.
4617 : : */
4618 : : static void
4619 : 16 : UpdateControlFile(void)
4620 : : {
4621 : 16 : update_controlfile(DataDir, ControlFile, true);
4622 : 16 : }
4623 : :
4624 : : /*
4625 : : * Returns the unique system identifier from control file.
4626 : : */
4627 : : uint64
4628 : 0 : GetSystemIdentifier(void)
4629 : : {
4630 [ # # ]: 0 : Assert(ControlFile != NULL);
4631 : 0 : return ControlFile->system_identifier;
4632 : : }
4633 : :
4634 : : /*
4635 : : * Returns the random nonce from control file.
4636 : : */
4637 : : char *
4638 : 0 : GetMockAuthenticationNonce(void)
4639 : : {
4640 [ # # ]: 0 : Assert(ControlFile != NULL);
4641 : 0 : return ControlFile->mock_authentication_nonce;
4642 : : }
4643 : :
4644 : : /*
4645 : : * Are checksums enabled for data pages?
4646 : : */
4647 : : bool
4648 : 995236 : DataChecksumsEnabled(void)
4649 : : {
4650 [ + - ]: 995236 : Assert(ControlFile != NULL);
4651 : 995236 : return (ControlFile->data_checksum_version > 0);
4652 : : }
4653 : :
4654 : : /*
4655 : : * Return true if the cluster was initialized on a platform where the
4656 : : * default signedness of char is "signed". This function exists for code
4657 : : * that deals with pre-v18 data files that store data sorted by the 'char'
4658 : : * type on disk (e.g., GIN and GiST indexes). See the comments in
4659 : : * WriteControlFile() for details.
4660 : : */
4661 : : bool
4662 : 0 : GetDefaultCharSignedness(void)
4663 : : {
4664 : 0 : return ControlFile->default_char_signedness;
4665 : : }
4666 : :
4667 : : /*
4668 : : * Returns a fake LSN for unlogged relations.
4669 : : *
4670 : : * Each call generates an LSN that is greater than any previous value
4671 : : * returned. The current counter value is saved and restored across clean
4672 : : * shutdowns, but like unlogged relations, does not survive a crash. This can
4673 : : * be used in lieu of real LSN values returned by XLogInsert, if you need an
4674 : : * LSN-like increasing sequence of numbers without writing any WAL.
4675 : : */
4676 : : XLogRecPtr
4677 : 11 : GetFakeLSNForUnloggedRel(void)
4678 : : {
4679 : 11 : return pg_atomic_fetch_add_u64(&XLogCtl->unloggedLSN, 1);
4680 : : }
4681 : :
4682 : : /*
4683 : : * Auto-tune the number of XLOG buffers.
4684 : : *
4685 : : * The preferred setting for wal_buffers is about 3% of shared_buffers, with
4686 : : * a maximum of one XLOG segment (there is little reason to think that more
4687 : : * is helpful, at least so long as we force an fsync when switching log files)
4688 : : * and a minimum of 8 blocks (which was the default value prior to PostgreSQL
4689 : : * 9.1, when auto-tuning was added).
4690 : : *
4691 : : * This should not be called until NBuffers has received its final value.
4692 : : */
4693 : : static int
4694 : 6 : XLOGChooseNumBuffers(void)
4695 : : {
4696 : 6 : int xbuffers;
4697 : :
4698 : 6 : xbuffers = NBuffers / 32;
4699 [ + - ]: 6 : if (xbuffers > (wal_segment_size / XLOG_BLCKSZ))
4700 : 0 : xbuffers = (wal_segment_size / XLOG_BLCKSZ);
4701 [ + - ]: 6 : if (xbuffers < 8)
4702 : 0 : xbuffers = 8;
4703 : 12 : return xbuffers;
4704 : 6 : }
4705 : :
4706 : : /*
4707 : : * GUC check_hook for wal_buffers
4708 : : */
4709 : : bool
4710 : 12 : check_wal_buffers(int *newval, void **extra, GucSource source)
4711 : : {
4712 : : /*
4713 : : * -1 indicates a request for auto-tune.
4714 : : */
4715 [ + + ]: 12 : if (*newval == -1)
4716 : : {
4717 : : /*
4718 : : * If we haven't yet changed the boot_val default of -1, just let it
4719 : : * be. We'll fix it when XLOGShmemSize is called.
4720 : : */
4721 [ - + ]: 6 : if (XLOGbuffers == -1)
4722 : 6 : return true;
4723 : :
4724 : : /* Otherwise, substitute the auto-tune value */
4725 : 0 : *newval = XLOGChooseNumBuffers();
4726 : 0 : }
4727 : :
4728 : : /*
4729 : : * We clamp manually-set values to at least 4 blocks. Prior to PostgreSQL
4730 : : * 9.1, a minimum of 4 was enforced by guc.c, but since that is no longer
4731 : : * the case, we just silently treat such values as a request for the
4732 : : * minimum. (We could throw an error instead, but that doesn't seem very
4733 : : * helpful.)
4734 : : */
4735 [ + - ]: 6 : if (*newval < 4)
4736 : 0 : *newval = 4;
4737 : :
4738 : 6 : return true;
4739 : 12 : }
4740 : :
4741 : : /*
4742 : : * GUC check_hook for wal_consistency_checking
4743 : : */
4744 : : bool
4745 : 6 : check_wal_consistency_checking(char **newval, void **extra, GucSource source)
4746 : : {
4747 : 6 : char *rawstring;
4748 : 6 : List *elemlist;
4749 : 6 : ListCell *l;
4750 : 6 : bool newwalconsistency[RM_MAX_ID + 1];
4751 : :
4752 : : /* Initialize the array */
4753 [ + - + - : 198 : MemSet(newwalconsistency, 0, (RM_MAX_ID + 1) * sizeof(bool));
+ - - + +
+ ]
4754 : :
4755 : : /* Need a modifiable copy of string */
4756 : 6 : rawstring = pstrdup(*newval);
4757 : :
4758 : : /* Parse string into list of identifiers */
4759 [ + - ]: 6 : if (!SplitIdentifierString(rawstring, ',', &elemlist))
4760 : : {
4761 : : /* syntax error in list */
4762 : 0 : GUC_check_errdetail("List syntax is invalid.");
4763 : 0 : pfree(rawstring);
4764 : 0 : list_free(elemlist);
4765 : 0 : return false;
4766 : : }
4767 : :
4768 [ - + # # : 6 : foreach(l, elemlist)
- + - + ]
4769 : : {
4770 : 0 : char *tok = (char *) lfirst(l);
4771 : 0 : int rmid;
4772 : :
4773 : : /* Check for 'all'. */
4774 [ # # ]: 0 : if (pg_strcasecmp(tok, "all") == 0)
4775 : : {
4776 [ # # ]: 0 : for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
4777 [ # # # # ]: 0 : if (RmgrIdExists(rmid) && GetRmgr(rmid).rm_mask != NULL)
4778 : 0 : newwalconsistency[rmid] = true;
4779 : 0 : }
4780 : : else
4781 : : {
4782 : : /* Check if the token matches any known resource manager. */
4783 : 0 : bool found = false;
4784 : :
4785 [ # # ]: 0 : for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
4786 : : {
4787 [ # # # # : 0 : if (RmgrIdExists(rmid) && GetRmgr(rmid).rm_mask != NULL &&
# # ]
4788 : 0 : pg_strcasecmp(tok, GetRmgr(rmid).rm_name) == 0)
4789 : : {
4790 : 0 : newwalconsistency[rmid] = true;
4791 : 0 : found = true;
4792 : 0 : break;
4793 : : }
4794 : 0 : }
4795 [ # # ]: 0 : if (!found)
4796 : : {
4797 : : /*
4798 : : * During startup, it might be a not-yet-loaded custom
4799 : : * resource manager. Defer checking until
4800 : : * InitializeWalConsistencyChecking().
4801 : : */
4802 [ # # ]: 0 : if (!process_shared_preload_libraries_done)
4803 : : {
4804 : 0 : check_wal_consistency_checking_deferred = true;
4805 : 0 : }
4806 : : else
4807 : : {
4808 : 0 : GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
4809 : 0 : pfree(rawstring);
4810 : 0 : list_free(elemlist);
4811 : 0 : return false;
4812 : : }
4813 : 0 : }
4814 [ # # ]: 0 : }
4815 [ # # ]: 0 : }
4816 : :
4817 : 6 : pfree(rawstring);
4818 : 6 : list_free(elemlist);
4819 : :
4820 : : /* assign new value */
4821 : 6 : *extra = guc_malloc(LOG, (RM_MAX_ID + 1) * sizeof(bool));
4822 [ + - ]: 6 : if (!*extra)
4823 : 0 : return false;
4824 : 6 : memcpy(*extra, newwalconsistency, (RM_MAX_ID + 1) * sizeof(bool));
4825 : 6 : return true;
4826 : 6 : }
4827 : :
4828 : : /*
4829 : : * GUC assign_hook for wal_consistency_checking
4830 : : */
4831 : : void
4832 : 6 : assign_wal_consistency_checking(const char *newval, void *extra)
4833 : : {
4834 : : /*
4835 : : * If some checks were deferred, it's possible that the checks will fail
4836 : : * later during InitializeWalConsistencyChecking(). But in that case, the
4837 : : * postmaster will exit anyway, so it's safe to proceed with the
4838 : : * assignment.
4839 : : *
4840 : : * Any built-in resource managers specified are assigned immediately,
4841 : : * which affects WAL created before shared_preload_libraries are
4842 : : * processed. Any custom resource managers specified won't be assigned
4843 : : * until after shared_preload_libraries are processed, but that's OK
4844 : : * because WAL for a custom resource manager can't be written before the
4845 : : * module is loaded anyway.
4846 : : */
4847 : 6 : wal_consistency_checking = extra;
4848 : 6 : }
4849 : :
4850 : : /*
4851 : : * InitializeWalConsistencyChecking: run after loading custom resource managers
4852 : : *
4853 : : * If any unknown resource managers were specified in the
4854 : : * wal_consistency_checking GUC, processing was deferred. Now that
4855 : : * shared_preload_libraries have been loaded, process wal_consistency_checking
4856 : : * again.
4857 : : */
4858 : : void
4859 : 3 : InitializeWalConsistencyChecking(void)
4860 : : {
4861 [ + - ]: 3 : Assert(process_shared_preload_libraries_done);
4862 : :
4863 [ + - ]: 3 : if (check_wal_consistency_checking_deferred)
4864 : : {
4865 : 0 : struct config_generic *guc;
4866 : :
4867 : 0 : guc = find_option("wal_consistency_checking", false, false, ERROR);
4868 : :
4869 : 0 : check_wal_consistency_checking_deferred = false;
4870 : :
4871 : 0 : set_config_option_ext("wal_consistency_checking",
4872 : 0 : wal_consistency_checking_string,
4873 : 0 : guc->scontext, guc->source, guc->srole,
4874 : : GUC_ACTION_SET, true, ERROR, false);
4875 : :
4876 : : /* checking should not be deferred again */
4877 [ # # ]: 0 : Assert(!check_wal_consistency_checking_deferred);
4878 : 0 : }
4879 : 3 : }
4880 : :
4881 : : /*
4882 : : * GUC show_hook for archive_command
4883 : : */
4884 : : const char *
4885 : 7 : show_archive_command(void)
4886 : : {
4887 [ - + # # : 7 : if (XLogArchivingActive())
- + ]
4888 : 0 : return XLogArchiveCommand;
4889 : : else
4890 : 7 : return "(disabled)";
4891 : 7 : }
4892 : :
4893 : : /*
4894 : : * GUC show_hook for in_hot_standby
4895 : : */
4896 : : const char *
4897 : 323 : show_in_hot_standby(void)
4898 : : {
4899 : : /*
4900 : : * We display the actual state based on shared memory, so that this GUC
4901 : : * reports up-to-date state if examined intra-query. The underlying
4902 : : * variable (in_hot_standby_guc) changes only when we transmit a new value
4903 : : * to the client.
4904 : : */
4905 : 323 : return RecoveryInProgress() ? "on" : "off";
4906 : : }
4907 : :
4908 : : /*
4909 : : * GUC show_hook for effective_wal_level
4910 : : */
4911 : : const char *
4912 : 7 : show_effective_wal_level(void)
4913 : : {
4914 [ - + ]: 7 : if (wal_level == WAL_LEVEL_MINIMAL)
4915 : 7 : return "minimal";
4916 : :
4917 : : /*
4918 : : * During recovery, effective_wal_level reflects the primary's
4919 : : * configuration rather than the local wal_level value.
4920 : : */
4921 [ # # ]: 0 : if (RecoveryInProgress())
4922 : 0 : return IsXLogLogicalInfoEnabled() ? "logical" : "replica";
4923 : :
4924 [ # # ]: 0 : return XLogLogicalInfoActive() ? "logical" : "replica";
4925 : 7 : }
4926 : :
4927 : : /*
4928 : : * Read the control file, set respective GUCs.
4929 : : *
4930 : : * This is to be called during startup, including a crash recovery cycle,
4931 : : * unless in bootstrap mode, where no control file yet exists. As there's no
4932 : : * usable shared memory yet (its sizing can depend on the contents of the
4933 : : * control file!), first store the contents in local memory. XLOGShmemInit()
4934 : : * will then copy it to shared memory later.
4935 : : *
4936 : : * reset just controls whether previous contents are to be expected (in the
4937 : : * reset case, there's a dangling pointer into old shared memory), or not.
4938 : : */
4939 : : void
4940 : 3 : LocalProcessControlFile(bool reset)
4941 : : {
4942 [ + - + - ]: 3 : Assert(reset || ControlFile == NULL);
4943 : 3 : ControlFile = palloc_object(ControlFileData);
4944 : 3 : ReadControlFile();
4945 : 3 : }
4946 : :
4947 : : /*
4948 : : * Get the wal_level from the control file. For a standby, this value should be
4949 : : * considered as its active wal_level, because it may be different from what
4950 : : * was originally configured on standby.
4951 : : */
4952 : : WalLevel
4953 : 0 : GetActiveWalLevelOnStandby(void)
4954 : : {
4955 : 0 : return ControlFile->wal_level;
4956 : : }
4957 : :
4958 : : /*
4959 : : * Initialization of shared memory for XLOG
4960 : : */
4961 : : Size
4962 : 15 : XLOGShmemSize(void)
4963 : : {
4964 : 15 : Size size;
4965 : :
4966 : : /*
4967 : : * If the value of wal_buffers is -1, use the preferred auto-tune value.
4968 : : * This isn't an amazingly clean place to do this, but we must wait till
4969 : : * NBuffers has received its final value, and must do it before using the
4970 : : * value of XLOGbuffers to do anything important.
4971 : : *
4972 : : * We prefer to report this value's source as PGC_S_DYNAMIC_DEFAULT.
4973 : : * However, if the DBA explicitly set wal_buffers = -1 in the config file,
4974 : : * then PGC_S_DYNAMIC_DEFAULT will fail to override that and we must force
4975 : : * the matter with PGC_S_OVERRIDE.
4976 : : */
4977 [ + + ]: 15 : if (XLOGbuffers == -1)
4978 : : {
4979 : 6 : char buf[32];
4980 : :
4981 : 6 : snprintf(buf, sizeof(buf), "%d", XLOGChooseNumBuffers());
4982 : 6 : SetConfigOption("wal_buffers", buf, PGC_POSTMASTER,
4983 : : PGC_S_DYNAMIC_DEFAULT);
4984 [ + - ]: 6 : if (XLOGbuffers == -1) /* failed to apply it? */
4985 : 0 : SetConfigOption("wal_buffers", buf, PGC_POSTMASTER,
4986 : : PGC_S_OVERRIDE);
4987 : 6 : }
4988 [ + - ]: 15 : Assert(XLOGbuffers > 0);
4989 : :
4990 : : /* XLogCtl */
4991 : 15 : size = sizeof(XLogCtlData);
4992 : :
4993 : : /* WAL insertion locks, plus alignment */
4994 : 15 : size = add_size(size, mul_size(sizeof(WALInsertLockPadded), NUM_XLOGINSERT_LOCKS + 1));
4995 : : /* xlblocks array */
4996 : 15 : size = add_size(size, mul_size(sizeof(pg_atomic_uint64), XLOGbuffers));
4997 : : /* extra alignment padding for XLOG I/O buffers */
4998 : 15 : size = add_size(size, Max(XLOG_BLCKSZ, PG_IO_ALIGN_SIZE));
4999 : : /* and the buffers themselves */
5000 : 15 : size = add_size(size, mul_size(XLOG_BLCKSZ, XLOGbuffers));
5001 : :
5002 : : /*
5003 : : * Note: we don't count ControlFileData, it comes out of the "slop factor"
5004 : : * added by CreateSharedMemoryAndSemaphores. This lets us use this
5005 : : * routine again below to compute the actual allocation size.
5006 : : */
5007 : :
5008 : 30 : return size;
5009 : 15 : }
5010 : :
5011 : : void
5012 : 6 : XLOGShmemInit(void)
5013 : : {
5014 : 6 : bool foundCFile,
5015 : : foundXLog;
5016 : 6 : char *allocptr;
5017 : 6 : int i;
5018 : 6 : ControlFileData *localControlFile;
5019 : :
5020 : : #ifdef WAL_DEBUG
5021 : :
5022 : : /*
5023 : : * Create a memory context for WAL debugging that's exempt from the normal
5024 : : * "no pallocs in critical section" rule. Yes, that can lead to a PANIC if
5025 : : * an allocation fails, but wal_debug is not for production use anyway.
5026 : : */
5027 : : if (walDebugCxt == NULL)
5028 : : {
5029 : : walDebugCxt = AllocSetContextCreate(TopMemoryContext,
5030 : : "WAL Debug",
5031 : : ALLOCSET_DEFAULT_SIZES);
5032 : : MemoryContextAllowInCriticalSection(walDebugCxt, true);
5033 : : }
5034 : : #endif
5035 : :
5036 : :
5037 : 6 : XLogCtl = (XLogCtlData *)
5038 : 6 : ShmemInitStruct("XLOG Ctl", XLOGShmemSize(), &foundXLog);
5039 : :
5040 : 6 : localControlFile = ControlFile;
5041 : 6 : ControlFile = (ControlFileData *)
5042 : 6 : ShmemInitStruct("Control File", sizeof(ControlFileData), &foundCFile);
5043 : :
5044 [ + - - + ]: 6 : if (foundCFile || foundXLog)
5045 : : {
5046 : : /* both should be present or neither */
5047 [ # # ]: 0 : Assert(foundCFile && foundXLog);
5048 : :
5049 : : /* Initialize local copy of WALInsertLocks */
5050 : 0 : WALInsertLocks = XLogCtl->Insert.WALInsertLocks;
5051 : :
5052 [ # # ]: 0 : if (localControlFile)
5053 : 0 : pfree(localControlFile);
5054 : 0 : return;
5055 : : }
5056 : 6 : memset(XLogCtl, 0, sizeof(XLogCtlData));
5057 : :
5058 : : /*
5059 : : * Already have read control file locally, unless in bootstrap mode. Move
5060 : : * contents into shared memory.
5061 : : */
5062 [ + + ]: 6 : if (localControlFile)
5063 : : {
5064 : 3 : memcpy(ControlFile, localControlFile, sizeof(ControlFileData));
5065 : 3 : pfree(localControlFile);
5066 : 3 : }
5067 : :
5068 : : /*
5069 : : * Since XLogCtlData contains XLogRecPtr fields, its sizeof should be a
5070 : : * multiple of the alignment for same, so no extra alignment padding is
5071 : : * needed here.
5072 : : */
5073 : 6 : allocptr = ((char *) XLogCtl) + sizeof(XLogCtlData);
5074 : 6 : XLogCtl->xlblocks = (pg_atomic_uint64 *) allocptr;
5075 : 6 : allocptr += sizeof(pg_atomic_uint64) * XLOGbuffers;
5076 : :
5077 [ + + ]: 2597 : for (i = 0; i < XLOGbuffers; i++)
5078 : : {
5079 : 2591 : pg_atomic_init_u64(&XLogCtl->xlblocks[i], InvalidXLogRecPtr);
5080 : 2591 : }
5081 : :
5082 : : /* WAL insertion locks. Ensure they're aligned to the full padded size */
5083 : 6 : allocptr += sizeof(WALInsertLockPadded) -
5084 : 6 : ((uintptr_t) allocptr) % sizeof(WALInsertLockPadded);
5085 : 6 : WALInsertLocks = XLogCtl->Insert.WALInsertLocks =
5086 : 6 : (WALInsertLockPadded *) allocptr;
5087 : 6 : allocptr += sizeof(WALInsertLockPadded) * NUM_XLOGINSERT_LOCKS;
5088 : :
5089 [ + + ]: 54 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
5090 : : {
5091 : 48 : LWLockInitialize(&WALInsertLocks[i].l.lock, LWTRANCHE_WAL_INSERT);
5092 : 48 : pg_atomic_init_u64(&WALInsertLocks[i].l.insertingAt, InvalidXLogRecPtr);
5093 : 48 : WALInsertLocks[i].l.lastImportantAt = InvalidXLogRecPtr;
5094 : 48 : }
5095 : :
5096 : : /*
5097 : : * Align the start of the page buffers to a full xlog block size boundary.
5098 : : * This simplifies some calculations in XLOG insertion. It is also
5099 : : * required for O_DIRECT.
5100 : : */
5101 : 6 : allocptr = (char *) TYPEALIGN(XLOG_BLCKSZ, allocptr);
5102 : 6 : XLogCtl->pages = allocptr;
5103 : 6 : memset(XLogCtl->pages, 0, (Size) XLOG_BLCKSZ * XLOGbuffers);
5104 : :
5105 : : /*
5106 : : * Do basic initialization of XLogCtl shared data. (StartupXLOG will fill
5107 : : * in additional info.)
5108 : : */
5109 : 6 : XLogCtl->XLogCacheBlck = XLOGbuffers - 1;
5110 : 6 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_CRASH;
5111 : 6 : XLogCtl->InstallXLogFileSegmentActive = false;
5112 : 6 : XLogCtl->WalWriterSleeping = false;
5113 : :
5114 : 6 : SpinLockInit(&XLogCtl->Insert.insertpos_lck);
5115 : 6 : SpinLockInit(&XLogCtl->info_lck);
5116 : 6 : pg_atomic_init_u64(&XLogCtl->logInsertResult, InvalidXLogRecPtr);
5117 : 6 : pg_atomic_init_u64(&XLogCtl->logWriteResult, InvalidXLogRecPtr);
5118 : 6 : pg_atomic_init_u64(&XLogCtl->logFlushResult, InvalidXLogRecPtr);
5119 : 6 : pg_atomic_init_u64(&XLogCtl->unloggedLSN, InvalidXLogRecPtr);
5120 [ - + ]: 6 : }
5121 : :
5122 : : /*
5123 : : * This func must be called ONCE on system install. It creates pg_control
5124 : : * and the initial XLOG segment.
5125 : : */
5126 : : void
5127 : 1 : BootStrapXLOG(uint32 data_checksum_version)
5128 : : {
5129 : 1 : CheckPoint checkPoint;
5130 : 1 : PGAlignedXLogBlock buffer;
5131 : 1 : XLogPageHeader page;
5132 : 1 : XLogLongPageHeader longpage;
5133 : 1 : XLogRecord *record;
5134 : 1 : char *recptr;
5135 : 1 : uint64 sysidentifier;
5136 : 1 : struct timeval tv;
5137 : 1 : pg_crc32c crc;
5138 : :
5139 : : /* allow ordinary WAL segment creation, like StartupXLOG() would */
5140 : 1 : SetInstallXLogFileSegmentActive();
5141 : :
5142 : : /*
5143 : : * Select a hopefully-unique system identifier code for this installation.
5144 : : * We use the result of gettimeofday(), including the fractional seconds
5145 : : * field, as being about as unique as we can easily get. (Think not to
5146 : : * use random(), since it hasn't been seeded and there's no portable way
5147 : : * to seed it other than the system clock value...) The upper half of the
5148 : : * uint64 value is just the tv_sec part, while the lower half contains the
5149 : : * tv_usec part (which must fit in 20 bits), plus 12 bits from our current
5150 : : * PID for a little extra uniqueness. A person knowing this encoding can
5151 : : * determine the initialization time of the installation, which could
5152 : : * perhaps be useful sometimes.
5153 : : */
5154 : 1 : gettimeofday(&tv, NULL);
5155 : 1 : sysidentifier = ((uint64) tv.tv_sec) << 32;
5156 : 1 : sysidentifier |= ((uint64) tv.tv_usec) << 12;
5157 : 1 : sysidentifier |= getpid() & 0xFFF;
5158 : :
5159 : 1 : memset(&buffer, 0, sizeof buffer);
5160 : 1 : page = (XLogPageHeader) &buffer;
5161 : :
5162 : : /*
5163 : : * Set up information for the initial checkpoint record
5164 : : *
5165 : : * The initial checkpoint record is written to the beginning of the WAL
5166 : : * segment with logid=0 logseg=1. The very first WAL segment, 0/0, is not
5167 : : * used, so that we can use 0/0 to mean "before any valid WAL segment".
5168 : : */
5169 : 1 : checkPoint.redo = wal_segment_size + SizeOfXLogLongPHD;
5170 : 1 : checkPoint.ThisTimeLineID = BootstrapTimeLineID;
5171 : 1 : checkPoint.PrevTimeLineID = BootstrapTimeLineID;
5172 : 1 : checkPoint.fullPageWrites = fullPageWrites;
5173 : 1 : checkPoint.logicalDecodingEnabled = (wal_level == WAL_LEVEL_LOGICAL);
5174 : 1 : checkPoint.wal_level = wal_level;
5175 : 1 : checkPoint.nextXid =
5176 : 1 : FullTransactionIdFromEpochAndXid(0, FirstNormalTransactionId);
5177 : 1 : checkPoint.nextOid = FirstGenbkiObjectId;
5178 : 1 : checkPoint.nextMulti = FirstMultiXactId;
5179 : 1 : checkPoint.nextMultiOffset = 1;
5180 : 1 : checkPoint.oldestXid = FirstNormalTransactionId;
5181 : 1 : checkPoint.oldestXidDB = Template1DbOid;
5182 : 1 : checkPoint.oldestMulti = FirstMultiXactId;
5183 : 1 : checkPoint.oldestMultiDB = Template1DbOid;
5184 : 1 : checkPoint.oldestCommitTsXid = InvalidTransactionId;
5185 : 1 : checkPoint.newestCommitTsXid = InvalidTransactionId;
5186 : 1 : checkPoint.time = (pg_time_t) time(NULL);
5187 : 1 : checkPoint.oldestActiveXid = InvalidTransactionId;
5188 : :
5189 : 1 : TransamVariables->nextXid = checkPoint.nextXid;
5190 : 1 : TransamVariables->nextOid = checkPoint.nextOid;
5191 : 1 : TransamVariables->oidCount = 0;
5192 : 1 : MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
5193 : 1 : AdvanceOldestClogXid(checkPoint.oldestXid);
5194 : 1 : SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
5195 : 1 : SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
5196 : 1 : SetCommitTsLimit(InvalidTransactionId, InvalidTransactionId);
5197 : :
5198 : : /* Set up the XLOG page header */
5199 : 1 : page->xlp_magic = XLOG_PAGE_MAGIC;
5200 : 1 : page->xlp_info = XLP_LONG_HEADER;
5201 : 1 : page->xlp_tli = BootstrapTimeLineID;
5202 : 1 : page->xlp_pageaddr = wal_segment_size;
5203 : 1 : longpage = (XLogLongPageHeader) page;
5204 : 1 : longpage->xlp_sysid = sysidentifier;
5205 : 1 : longpage->xlp_seg_size = wal_segment_size;
5206 : 1 : longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
5207 : :
5208 : : /* Insert the initial checkpoint record */
5209 : 1 : recptr = ((char *) page + SizeOfXLogLongPHD);
5210 : 1 : record = (XLogRecord *) recptr;
5211 : 1 : record->xl_prev = 0;
5212 : 1 : record->xl_xid = InvalidTransactionId;
5213 : 1 : record->xl_tot_len = SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort + sizeof(checkPoint);
5214 : 1 : record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
5215 : 1 : record->xl_rmid = RM_XLOG_ID;
5216 : 1 : recptr += SizeOfXLogRecord;
5217 : : /* fill the XLogRecordDataHeaderShort struct */
5218 : 1 : *(recptr++) = (char) XLR_BLOCK_ID_DATA_SHORT;
5219 : 1 : *(recptr++) = sizeof(checkPoint);
5220 : 1 : memcpy(recptr, &checkPoint, sizeof(checkPoint));
5221 : 1 : recptr += sizeof(checkPoint);
5222 [ + - ]: 1 : Assert(recptr - (char *) record == record->xl_tot_len);
5223 : :
5224 : 1 : INIT_CRC32C(crc);
5225 : 1 : COMP_CRC32C(crc, ((char *) record) + SizeOfXLogRecord, record->xl_tot_len - SizeOfXLogRecord);
5226 : 1 : COMP_CRC32C(crc, (char *) record, offsetof(XLogRecord, xl_crc));
5227 : 1 : FIN_CRC32C(crc);
5228 : 1 : record->xl_crc = crc;
5229 : :
5230 : : /* Create first XLOG segment file */
5231 : 1 : openLogTLI = BootstrapTimeLineID;
5232 : 1 : openLogFile = XLogFileInit(1, BootstrapTimeLineID);
5233 : :
5234 : : /*
5235 : : * We needn't bother with Reserve/ReleaseExternalFD here, since we'll
5236 : : * close the file again in a moment.
5237 : : */
5238 : :
5239 : : /* Write the first page with the initial record */
5240 : 1 : errno = 0;
5241 : 1 : pgstat_report_wait_start(WAIT_EVENT_WAL_BOOTSTRAP_WRITE);
5242 [ + - ]: 1 : if (write(openLogFile, &buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
5243 : : {
5244 : : /* if write didn't set errno, assume problem is no disk space */
5245 [ # # ]: 0 : if (errno == 0)
5246 : 0 : errno = ENOSPC;
5247 [ # # # # ]: 0 : ereport(PANIC,
5248 : : (errcode_for_file_access(),
5249 : : errmsg("could not write bootstrap write-ahead log file: %m")));
5250 : 0 : }
5251 : 1 : pgstat_report_wait_end();
5252 : :
5253 : 1 : pgstat_report_wait_start(WAIT_EVENT_WAL_BOOTSTRAP_SYNC);
5254 [ + - ]: 1 : if (pg_fsync(openLogFile) != 0)
5255 [ # # # # ]: 0 : ereport(PANIC,
5256 : : (errcode_for_file_access(),
5257 : : errmsg("could not fsync bootstrap write-ahead log file: %m")));
5258 : 1 : pgstat_report_wait_end();
5259 : :
5260 [ + - ]: 1 : if (close(openLogFile) != 0)
5261 [ # # # # ]: 0 : ereport(PANIC,
5262 : : (errcode_for_file_access(),
5263 : : errmsg("could not close bootstrap write-ahead log file: %m")));
5264 : :
5265 : 1 : openLogFile = -1;
5266 : :
5267 : : /* Now create pg_control */
5268 : 1 : InitControlFile(sysidentifier, data_checksum_version);
5269 : 1 : ControlFile->time = checkPoint.time;
5270 : 1 : ControlFile->checkPoint = checkPoint.redo;
5271 : 1 : ControlFile->checkPointCopy = checkPoint;
5272 : :
5273 : : /* some additional ControlFile fields are set in WriteControlFile() */
5274 : 1 : WriteControlFile();
5275 : :
5276 : : /* Bootstrap the commit log, too */
5277 : 1 : BootStrapCLOG();
5278 : 1 : BootStrapCommitTs();
5279 : 1 : BootStrapSUBTRANS();
5280 : 1 : BootStrapMultiXact();
5281 : :
5282 : : /*
5283 : : * Force control file to be read - in contrast to normal processing we'd
5284 : : * otherwise never run the checks and GUC related initializations therein.
5285 : : */
5286 : 1 : ReadControlFile();
5287 : 1 : }
5288 : :
5289 : : static char *
5290 : 2 : str_time(pg_time_t tnow, char *buf, size_t bufsize)
5291 : : {
5292 : 4 : pg_strftime(buf, bufsize,
5293 : : "%Y-%m-%d %H:%M:%S %Z",
5294 : 2 : pg_localtime(&tnow, log_timezone));
5295 : :
5296 : 2 : return buf;
5297 : : }
5298 : :
5299 : : /*
5300 : : * Initialize the first WAL segment on new timeline.
5301 : : */
5302 : : static void
5303 : 0 : XLogInitNewTimeline(TimeLineID endTLI, XLogRecPtr endOfLog, TimeLineID newTLI)
5304 : : {
5305 : 0 : char xlogfname[MAXFNAMELEN];
5306 : 0 : XLogSegNo endLogSegNo;
5307 : 0 : XLogSegNo startLogSegNo;
5308 : :
5309 : : /* we always switch to a new timeline after archive recovery */
5310 [ # # ]: 0 : Assert(endTLI != newTLI);
5311 : :
5312 : : /*
5313 : : * Update min recovery point one last time.
5314 : : */
5315 : 0 : UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
5316 : :
5317 : : /*
5318 : : * Calculate the last segment on the old timeline, and the first segment
5319 : : * on the new timeline. If the switch happens in the middle of a segment,
5320 : : * they are the same, but if the switch happens exactly at a segment
5321 : : * boundary, startLogSegNo will be endLogSegNo + 1.
5322 : : */
5323 : 0 : XLByteToPrevSeg(endOfLog, endLogSegNo, wal_segment_size);
5324 : 0 : XLByteToSeg(endOfLog, startLogSegNo, wal_segment_size);
5325 : :
5326 : : /*
5327 : : * Initialize the starting WAL segment for the new timeline. If the switch
5328 : : * happens in the middle of a segment, copy data from the last WAL segment
5329 : : * of the old timeline up to the switch point, to the starting WAL segment
5330 : : * on the new timeline.
5331 : : */
5332 [ # # ]: 0 : if (endLogSegNo == startLogSegNo)
5333 : : {
5334 : : /*
5335 : : * Make a copy of the file on the new timeline.
5336 : : *
5337 : : * Writing WAL isn't allowed yet, so there are no locking
5338 : : * considerations. But we should be just as tense as XLogFileInit to
5339 : : * avoid emplacing a bogus file.
5340 : : */
5341 : 0 : XLogFileCopy(newTLI, endLogSegNo, endTLI, endLogSegNo,
5342 : 0 : XLogSegmentOffset(endOfLog, wal_segment_size));
5343 : 0 : }
5344 : : else
5345 : : {
5346 : : /*
5347 : : * The switch happened at a segment boundary, so just create the next
5348 : : * segment on the new timeline.
5349 : : */
5350 : 0 : int fd;
5351 : :
5352 : 0 : fd = XLogFileInit(startLogSegNo, newTLI);
5353 : :
5354 [ # # ]: 0 : if (close(fd) != 0)
5355 : : {
5356 : 0 : int save_errno = errno;
5357 : :
5358 : 0 : XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
5359 : 0 : errno = save_errno;
5360 [ # # # # ]: 0 : ereport(ERROR,
5361 : : (errcode_for_file_access(),
5362 : : errmsg("could not close file \"%s\": %m", xlogfname)));
5363 : 0 : }
5364 : 0 : }
5365 : :
5366 : : /*
5367 : : * Let's just make real sure there are not .ready or .done flags posted
5368 : : * for the new segment.
5369 : : */
5370 : 0 : XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
5371 : 0 : XLogArchiveCleanup(xlogfname);
5372 : 0 : }
5373 : :
5374 : : /*
5375 : : * Perform cleanup actions at the conclusion of archive recovery.
5376 : : */
5377 : : static void
5378 : 0 : CleanupAfterArchiveRecovery(TimeLineID EndOfLogTLI, XLogRecPtr EndOfLog,
5379 : : TimeLineID newTLI)
5380 : : {
5381 : : /*
5382 : : * Execute the recovery_end_command, if any.
5383 : : */
5384 [ # # # # ]: 0 : if (recoveryEndCommand && strcmp(recoveryEndCommand, "") != 0)
5385 : 0 : ExecuteRecoveryCommand(recoveryEndCommand,
5386 : : "recovery_end_command",
5387 : : true,
5388 : : WAIT_EVENT_RECOVERY_END_COMMAND);
5389 : :
5390 : : /*
5391 : : * We switched to a new timeline. Clean up segments on the old timeline.
5392 : : *
5393 : : * If there are any higher-numbered segments on the old timeline, remove
5394 : : * them. They might contain valid WAL, but they might also be
5395 : : * pre-allocated files containing garbage. In any case, they are not part
5396 : : * of the new timeline's history so we don't need them.
5397 : : */
5398 : 0 : RemoveNonParentXlogFiles(EndOfLog, newTLI);
5399 : :
5400 : : /*
5401 : : * If the switch happened in the middle of a segment, what to do with the
5402 : : * last, partial segment on the old timeline? If we don't archive it, and
5403 : : * the server that created the WAL never archives it either (e.g. because
5404 : : * it was hit by a meteor), it will never make it to the archive. That's
5405 : : * OK from our point of view, because the new segment that we created with
5406 : : * the new TLI contains all the WAL from the old timeline up to the switch
5407 : : * point. But if you later try to do PITR to the "missing" WAL on the old
5408 : : * timeline, recovery won't find it in the archive. It's physically
5409 : : * present in the new file with new TLI, but recovery won't look there
5410 : : * when it's recovering to the older timeline. On the other hand, if we
5411 : : * archive the partial segment, and the original server on that timeline
5412 : : * is still running and archives the completed version of the same segment
5413 : : * later, it will fail. (We used to do that in 9.4 and below, and it
5414 : : * caused such problems).
5415 : : *
5416 : : * As a compromise, we rename the last segment with the .partial suffix,
5417 : : * and archive it. Archive recovery will never try to read .partial
5418 : : * segments, so they will normally go unused. But in the odd PITR case,
5419 : : * the administrator can copy them manually to the pg_wal directory
5420 : : * (removing the suffix). They can be useful in debugging, too.
5421 : : *
5422 : : * If a .done or .ready file already exists for the old timeline, however,
5423 : : * we had already determined that the segment is complete, so we can let
5424 : : * it be archived normally. (In particular, if it was restored from the
5425 : : * archive to begin with, it's expected to have a .done file).
5426 : : */
5427 [ # # # # ]: 0 : if (XLogSegmentOffset(EndOfLog, wal_segment_size) != 0 &&
5428 [ # # # # ]: 0 : XLogArchivingActive())
5429 : : {
5430 : 0 : char origfname[MAXFNAMELEN];
5431 : 0 : XLogSegNo endLogSegNo;
5432 : :
5433 : 0 : XLByteToPrevSeg(EndOfLog, endLogSegNo, wal_segment_size);
5434 : 0 : XLogFileName(origfname, EndOfLogTLI, endLogSegNo, wal_segment_size);
5435 : :
5436 [ # # ]: 0 : if (!XLogArchiveIsReadyOrDone(origfname))
5437 : : {
5438 : 0 : char origpath[MAXPGPATH];
5439 : 0 : char partialfname[MAXFNAMELEN];
5440 : 0 : char partialpath[MAXPGPATH];
5441 : :
5442 : : /*
5443 : : * If we're summarizing WAL, we can't rename the partial file
5444 : : * until the summarizer finishes with it, else it will fail.
5445 : : */
5446 [ # # ]: 0 : if (summarize_wal)
5447 : 0 : WaitForWalSummarization(EndOfLog);
5448 : :
5449 : 0 : XLogFilePath(origpath, EndOfLogTLI, endLogSegNo, wal_segment_size);
5450 : 0 : snprintf(partialfname, MAXFNAMELEN, "%s.partial", origfname);
5451 : 0 : snprintf(partialpath, MAXPGPATH, "%s.partial", origpath);
5452 : :
5453 : : /*
5454 : : * Make sure there's no .done or .ready file for the .partial
5455 : : * file.
5456 : : */
5457 : 0 : XLogArchiveCleanup(partialfname);
5458 : :
5459 : 0 : durable_rename(origpath, partialpath, ERROR);
5460 : 0 : XLogArchiveNotify(partialfname);
5461 : 0 : }
5462 : 0 : }
5463 : 0 : }
5464 : :
5465 : : /*
5466 : : * Check to see if required parameters are set high enough on this server
5467 : : * for various aspects of recovery operation.
5468 : : *
5469 : : * Note that all the parameters which this function tests need to be
5470 : : * listed in Administrator's Overview section in high-availability.sgml.
5471 : : * If you change them, don't forget to update the list.
5472 : : */
5473 : : static void
5474 : 0 : CheckRequiredParameterValues(void)
5475 : : {
5476 : : /*
5477 : : * For archive recovery, the WAL must be generated with at least 'replica'
5478 : : * wal_level.
5479 : : */
5480 [ # # # # ]: 0 : if (ArchiveRecoveryRequested && ControlFile->wal_level == WAL_LEVEL_MINIMAL)
5481 : : {
5482 [ # # # # ]: 0 : ereport(FATAL,
5483 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
5484 : : errmsg("WAL was generated with \"wal_level=minimal\", cannot continue recovering"),
5485 : : errdetail("This happens if you temporarily set \"wal_level=minimal\" on the server."),
5486 : : errhint("Use a backup taken after setting \"wal_level\" to higher than \"minimal\".")));
5487 : 0 : }
5488 : :
5489 : : /*
5490 : : * For Hot Standby, the WAL must be generated with 'replica' mode, and we
5491 : : * must have at least as many backend slots as the primary.
5492 : : */
5493 [ # # # # ]: 0 : if (ArchiveRecoveryRequested && EnableHotStandby)
5494 : : {
5495 : : /* We ignore autovacuum_worker_slots when we make this test. */
5496 : 0 : RecoveryRequiresIntParameter("max_connections",
5497 : 0 : MaxConnections,
5498 : 0 : ControlFile->MaxConnections);
5499 : 0 : RecoveryRequiresIntParameter("max_worker_processes",
5500 : 0 : max_worker_processes,
5501 : 0 : ControlFile->max_worker_processes);
5502 : 0 : RecoveryRequiresIntParameter("max_wal_senders",
5503 : 0 : max_wal_senders,
5504 : 0 : ControlFile->max_wal_senders);
5505 : 0 : RecoveryRequiresIntParameter("max_prepared_transactions",
5506 : 0 : max_prepared_xacts,
5507 : 0 : ControlFile->max_prepared_xacts);
5508 : 0 : RecoveryRequiresIntParameter("max_locks_per_transaction",
5509 : 0 : max_locks_per_xact,
5510 : 0 : ControlFile->max_locks_per_xact);
5511 : 0 : }
5512 : 0 : }
5513 : :
5514 : : /*
5515 : : * This must be called ONCE during postmaster or standalone-backend startup
5516 : : */
5517 : : void
5518 : 4 : StartupXLOG(void)
5519 : : {
5520 : 4 : XLogCtlInsert *Insert;
5521 : 4 : CheckPoint checkPoint;
5522 : 4 : bool wasShutdown;
5523 : 4 : bool didCrash;
5524 : 4 : bool haveTblspcMap;
5525 : 4 : bool haveBackupLabel;
5526 : 4 : XLogRecPtr EndOfLog;
5527 : 4 : TimeLineID EndOfLogTLI;
5528 : 4 : TimeLineID newTLI;
5529 : 4 : bool performedWalRecovery;
5530 : 4 : EndOfWalRecoveryInfo *endOfRecoveryInfo;
5531 : 4 : XLogRecPtr abortedRecPtr;
5532 : 4 : XLogRecPtr missingContrecPtr;
5533 : 4 : TransactionId oldestActiveXID;
5534 : 4 : bool promoted = false;
5535 : 4 : char timebuf[128];
5536 : :
5537 : : /*
5538 : : * We should have an aux process resource owner to use, and we should not
5539 : : * be in a transaction that's installed some other resowner.
5540 : : */
5541 [ + - ]: 4 : Assert(AuxProcessResourceOwner != NULL);
5542 [ + - + - ]: 4 : Assert(CurrentResourceOwner == NULL ||
5543 : : CurrentResourceOwner == AuxProcessResourceOwner);
5544 : 4 : CurrentResourceOwner = AuxProcessResourceOwner;
5545 : :
5546 : : /*
5547 : : * Check that contents look valid.
5548 : : */
5549 [ + - ]: 4 : if (!XRecOffIsValid(ControlFile->checkPoint))
5550 [ # # # # ]: 0 : ereport(FATAL,
5551 : : (errcode(ERRCODE_DATA_CORRUPTED),
5552 : : errmsg("control file contains invalid checkpoint location")));
5553 : :
5554 [ + - - - : 4 : switch (ControlFile->state)
- - - ]
5555 : : {
5556 : : case DB_SHUTDOWNED:
5557 : :
5558 : : /*
5559 : : * This is the expected case, so don't be chatty in standalone
5560 : : * mode
5561 : : */
5562 [ - + # # : 4 : ereport(IsPostmasterEnvironment ? LOG : NOTICE,
+ + - + #
# ]
5563 : : (errmsg("database system was shut down at %s",
5564 : : str_time(ControlFile->time,
5565 : : timebuf, sizeof(timebuf)))));
5566 : 4 : break;
5567 : :
5568 : : case DB_SHUTDOWNED_IN_RECOVERY:
5569 [ # # # # ]: 0 : ereport(LOG,
5570 : : (errmsg("database system was shut down in recovery at %s",
5571 : : str_time(ControlFile->time,
5572 : : timebuf, sizeof(timebuf)))));
5573 : 0 : break;
5574 : :
5575 : : case DB_SHUTDOWNING:
5576 [ # # # # ]: 0 : ereport(LOG,
5577 : : (errmsg("database system shutdown was interrupted; last known up at %s",
5578 : : str_time(ControlFile->time,
5579 : : timebuf, sizeof(timebuf)))));
5580 : 0 : break;
5581 : :
5582 : : case DB_IN_CRASH_RECOVERY:
5583 [ # # # # ]: 0 : ereport(LOG,
5584 : : (errmsg("database system was interrupted while in recovery at %s",
5585 : : str_time(ControlFile->time,
5586 : : timebuf, sizeof(timebuf))),
5587 : : errhint("This probably means that some data is corrupted and"
5588 : : " you will have to use the last backup for recovery.")));
5589 : 0 : break;
5590 : :
5591 : : case DB_IN_ARCHIVE_RECOVERY:
5592 [ # # # # ]: 0 : ereport(LOG,
5593 : : (errmsg("database system was interrupted while in recovery at log time %s",
5594 : : str_time(ControlFile->checkPointCopy.time,
5595 : : timebuf, sizeof(timebuf))),
5596 : : errhint("If this has occurred more than once some data might be corrupted"
5597 : : " and you might need to choose an earlier recovery target.")));
5598 : 0 : break;
5599 : :
5600 : : case DB_IN_PRODUCTION:
5601 [ # # # # ]: 0 : ereport(LOG,
5602 : : (errmsg("database system was interrupted; last known up at %s",
5603 : : str_time(ControlFile->time,
5604 : : timebuf, sizeof(timebuf)))));
5605 : 0 : break;
5606 : :
5607 : : default:
5608 [ # # # # ]: 0 : ereport(FATAL,
5609 : : (errcode(ERRCODE_DATA_CORRUPTED),
5610 : : errmsg("control file contains invalid database cluster state")));
5611 : 0 : }
5612 : :
5613 : : /* This is just to allow attaching to startup process with a debugger */
5614 : : #ifdef XLOG_REPLAY_DELAY
5615 : : if (ControlFile->state != DB_SHUTDOWNED)
5616 : : pg_usleep(60000000L);
5617 : : #endif
5618 : :
5619 : : /*
5620 : : * Verify that pg_wal, pg_wal/archive_status, and pg_wal/summaries exist.
5621 : : * In cases where someone has performed a copy for PITR, these directories
5622 : : * may have been excluded and need to be re-created.
5623 : : */
5624 : 4 : ValidateXLOGDirectoryStructure();
5625 : :
5626 : : /* Set up timeout handler needed to report startup progress. */
5627 [ + + ]: 4 : if (!IsBootstrapProcessingMode())
5628 : 3 : RegisterTimeout(STARTUP_PROGRESS_TIMEOUT,
5629 : : startup_progress_timeout_handler);
5630 : :
5631 : : /*----------
5632 : : * If we previously crashed, perform a couple of actions:
5633 : : *
5634 : : * - The pg_wal directory may still include some temporary WAL segments
5635 : : * used when creating a new segment, so perform some clean up to not
5636 : : * bloat this path. This is done first as there is no point to sync
5637 : : * this temporary data.
5638 : : *
5639 : : * - There might be data which we had written, intending to fsync it, but
5640 : : * which we had not actually fsync'd yet. Therefore, a power failure in
5641 : : * the near future might cause earlier unflushed writes to be lost, even
5642 : : * though more recent data written to disk from here on would be
5643 : : * persisted. To avoid that, fsync the entire data directory.
5644 : : */
5645 [ - + # # ]: 4 : if (ControlFile->state != DB_SHUTDOWNED &&
5646 : 0 : ControlFile->state != DB_SHUTDOWNED_IN_RECOVERY)
5647 : : {
5648 : 0 : RemoveTempXlogFiles();
5649 : 0 : SyncDataDirectory();
5650 : 0 : didCrash = true;
5651 : 0 : }
5652 : : else
5653 : 4 : didCrash = false;
5654 : :
5655 : : /*
5656 : : * Prepare for WAL recovery if needed.
5657 : : *
5658 : : * InitWalRecovery analyzes the control file and the backup label file, if
5659 : : * any. It updates the in-memory ControlFile buffer according to the
5660 : : * starting checkpoint, and sets InRecovery and ArchiveRecoveryRequested.
5661 : : * It also applies the tablespace map file, if any.
5662 : : */
5663 : 4 : InitWalRecovery(ControlFile, &wasShutdown,
5664 : : &haveBackupLabel, &haveTblspcMap);
5665 : 4 : checkPoint = ControlFile->checkPointCopy;
5666 : :
5667 : : /* initialize shared memory variables from the checkpoint record */
5668 : 4 : TransamVariables->nextXid = checkPoint.nextXid;
5669 : 4 : TransamVariables->nextOid = checkPoint.nextOid;
5670 : 4 : TransamVariables->oidCount = 0;
5671 : 4 : MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
5672 : 4 : AdvanceOldestClogXid(checkPoint.oldestXid);
5673 : 4 : SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
5674 : 4 : SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
5675 : 8 : SetCommitTsLimit(checkPoint.oldestCommitTsXid,
5676 : 4 : checkPoint.newestCommitTsXid);
5677 : :
5678 : : /*
5679 : : * Clear out any old relcache cache files. This is *necessary* if we do
5680 : : * any WAL replay, since that would probably result in the cache files
5681 : : * being out of sync with database reality. In theory we could leave them
5682 : : * in place if the database had been cleanly shut down, but it seems
5683 : : * safest to just remove them always and let them be rebuilt during the
5684 : : * first backend startup. These files needs to be removed from all
5685 : : * directories including pg_tblspc, however the symlinks are created only
5686 : : * after reading tablespace_map file in case of archive recovery from
5687 : : * backup, so needs to clear old relcache files here after creating
5688 : : * symlinks.
5689 : : */
5690 : 4 : RelationCacheInitFileRemove();
5691 : :
5692 : : /*
5693 : : * Initialize replication slots, before there's a chance to remove
5694 : : * required resources.
5695 : : */
5696 : 4 : StartupReplicationSlots();
5697 : :
5698 : : /*
5699 : : * Startup the logical decoding status with the last status stored in the
5700 : : * checkpoint record.
5701 : : */
5702 : 4 : StartupLogicalDecodingStatus(checkPoint.logicalDecodingEnabled);
5703 : :
5704 : : /*
5705 : : * Startup logical state, needs to be setup now so we have proper data
5706 : : * during crash recovery.
5707 : : */
5708 : 4 : StartupReorderBuffer();
5709 : :
5710 : : /*
5711 : : * Startup CLOG. This must be done after TransamVariables->nextXid has
5712 : : * been initialized and before we accept connections or begin WAL replay.
5713 : : */
5714 : 4 : StartupCLOG();
5715 : :
5716 : : /*
5717 : : * Startup MultiXact. We need to do this early to be able to replay
5718 : : * truncations.
5719 : : */
5720 : 4 : StartupMultiXact();
5721 : :
5722 : : /*
5723 : : * Ditto for commit timestamps. Activate the facility if the setting is
5724 : : * enabled in the control file, as there should be no tracking of commit
5725 : : * timestamps done when the setting was disabled. This facility can be
5726 : : * started or stopped when replaying a XLOG_PARAMETER_CHANGE record.
5727 : : */
5728 [ + - ]: 4 : if (ControlFile->track_commit_timestamp)
5729 : 0 : StartupCommitTs();
5730 : :
5731 : : /*
5732 : : * Recover knowledge about replay progress of known replication partners.
5733 : : */
5734 : 4 : StartupReplicationOrigin();
5735 : :
5736 : : /*
5737 : : * Initialize unlogged LSN. On a clean shutdown, it's restored from the
5738 : : * control file. On recovery, all unlogged relations are blown away, so
5739 : : * the unlogged LSN counter can be reset too.
5740 : : */
5741 [ + - ]: 4 : if (ControlFile->state == DB_SHUTDOWNED)
5742 : 8 : pg_atomic_write_membarrier_u64(&XLogCtl->unloggedLSN,
5743 : 4 : ControlFile->unloggedLSN);
5744 : : else
5745 : 0 : pg_atomic_write_membarrier_u64(&XLogCtl->unloggedLSN,
5746 : : FirstNormalUnloggedLSN);
5747 : :
5748 : : /*
5749 : : * Copy any missing timeline history files between 'now' and the recovery
5750 : : * target timeline from archive to pg_wal. While we don't need those files
5751 : : * ourselves - the history file of the recovery target timeline covers all
5752 : : * the previous timelines in the history too - a cascading standby server
5753 : : * might be interested in them. Or, if you archive the WAL from this
5754 : : * server to a different archive than the primary, it'd be good for all
5755 : : * the history files to get archived there after failover, so that you can
5756 : : * use one of the old timelines as a PITR target. Timeline history files
5757 : : * are small, so it's better to copy them unnecessarily than not copy them
5758 : : * and regret later.
5759 : : */
5760 : 4 : restoreTimeLineHistoryFiles(checkPoint.ThisTimeLineID, recoveryTargetTLI);
5761 : :
5762 : : /*
5763 : : * Before running in recovery, scan pg_twophase and fill in its status to
5764 : : * be able to work on entries generated by redo. Doing a scan before
5765 : : * taking any recovery action has the merit to discard any 2PC files that
5766 : : * are newer than the first record to replay, saving from any conflicts at
5767 : : * replay. This avoids as well any subsequent scans when doing recovery
5768 : : * of the on-disk two-phase data.
5769 : : */
5770 : 4 : restoreTwoPhaseData();
5771 : :
5772 : : /*
5773 : : * When starting with crash recovery, reset pgstat data - it might not be
5774 : : * valid. Otherwise restore pgstat data. It's safe to do this here,
5775 : : * because postmaster will not yet have started any other processes.
5776 : : *
5777 : : * NB: Restoring replication slot stats relies on slot state to have
5778 : : * already been restored from disk.
5779 : : *
5780 : : * TODO: With a bit of extra work we could just start with a pgstat file
5781 : : * associated with the checkpoint redo location we're starting from.
5782 : : */
5783 [ - + ]: 4 : if (didCrash)
5784 : 0 : pgstat_discard_stats();
5785 : : else
5786 : 4 : pgstat_restore_stats();
5787 : :
5788 : 4 : lastFullPageWrites = checkPoint.fullPageWrites;
5789 : :
5790 : 4 : RedoRecPtr = XLogCtl->RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
5791 : 4 : doPageWrites = lastFullPageWrites;
5792 : :
5793 : : /* REDO */
5794 [ - + ]: 4 : if (InRecovery)
5795 : : {
5796 : : /* Initialize state for RecoveryInProgress() */
5797 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
5798 [ # # ]: 0 : if (InArchiveRecovery)
5799 : 0 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_ARCHIVE;
5800 : : else
5801 : 0 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_CRASH;
5802 : 0 : SpinLockRelease(&XLogCtl->info_lck);
5803 : :
5804 : : /*
5805 : : * Update pg_control to show that we are recovering and to show the
5806 : : * selected checkpoint as the place we are starting from. We also mark
5807 : : * pg_control with any minimum recovery stop point obtained from a
5808 : : * backup history file.
5809 : : *
5810 : : * No need to hold ControlFileLock yet, we aren't up far enough.
5811 : : */
5812 : 0 : UpdateControlFile();
5813 : :
5814 : : /*
5815 : : * If there was a backup label file, it's done its job and the info
5816 : : * has now been propagated into pg_control. We must get rid of the
5817 : : * label file so that if we crash during recovery, we'll pick up at
5818 : : * the latest recovery restartpoint instead of going all the way back
5819 : : * to the backup start point. It seems prudent though to just rename
5820 : : * the file out of the way rather than delete it completely.
5821 : : */
5822 [ # # ]: 0 : if (haveBackupLabel)
5823 : : {
5824 : 0 : unlink(BACKUP_LABEL_OLD);
5825 : 0 : durable_rename(BACKUP_LABEL_FILE, BACKUP_LABEL_OLD, FATAL);
5826 : 0 : }
5827 : :
5828 : : /*
5829 : : * If there was a tablespace_map file, it's done its job and the
5830 : : * symlinks have been created. We must get rid of the map file so
5831 : : * that if we crash during recovery, we don't create symlinks again.
5832 : : * It seems prudent though to just rename the file out of the way
5833 : : * rather than delete it completely.
5834 : : */
5835 [ # # ]: 0 : if (haveTblspcMap)
5836 : : {
5837 : 0 : unlink(TABLESPACE_MAP_OLD);
5838 : 0 : durable_rename(TABLESPACE_MAP, TABLESPACE_MAP_OLD, FATAL);
5839 : 0 : }
5840 : :
5841 : : /*
5842 : : * Initialize our local copy of minRecoveryPoint. When doing crash
5843 : : * recovery we want to replay up to the end of WAL. Particularly, in
5844 : : * the case of a promoted standby minRecoveryPoint value in the
5845 : : * control file is only updated after the first checkpoint. However,
5846 : : * if the instance crashes before the first post-recovery checkpoint
5847 : : * is completed then recovery will use a stale location causing the
5848 : : * startup process to think that there are still invalid page
5849 : : * references when checking for data consistency.
5850 : : */
5851 [ # # ]: 0 : if (InArchiveRecovery)
5852 : : {
5853 : 0 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
5854 : 0 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
5855 : 0 : }
5856 : : else
5857 : : {
5858 : 0 : LocalMinRecoveryPoint = InvalidXLogRecPtr;
5859 : 0 : LocalMinRecoveryPointTLI = 0;
5860 : : }
5861 : :
5862 : : /* Check that the GUCs used to generate the WAL allow recovery */
5863 : 0 : CheckRequiredParameterValues();
5864 : :
5865 : : /*
5866 : : * We're in recovery, so unlogged relations may be trashed and must be
5867 : : * reset. This should be done BEFORE allowing Hot Standby
5868 : : * connections, so that read-only backends don't try to read whatever
5869 : : * garbage is left over from before.
5870 : : */
5871 : 0 : ResetUnloggedRelations(UNLOGGED_RELATION_CLEANUP);
5872 : :
5873 : : /*
5874 : : * Likewise, delete any saved transaction snapshot files that got left
5875 : : * behind by crashed backends.
5876 : : */
5877 : 0 : DeleteAllExportedSnapshotFiles();
5878 : :
5879 : : /*
5880 : : * Initialize for Hot Standby, if enabled. We won't let backends in
5881 : : * yet, not until we've reached the min recovery point specified in
5882 : : * control file and we've established a recovery snapshot from a
5883 : : * running-xacts WAL record.
5884 : : */
5885 [ # # # # ]: 0 : if (ArchiveRecoveryRequested && EnableHotStandby)
5886 : : {
5887 : 0 : TransactionId *xids;
5888 : 0 : int nxids;
5889 : :
5890 [ # # # # ]: 0 : ereport(DEBUG1,
5891 : : (errmsg_internal("initializing for hot standby")));
5892 : :
5893 : 0 : InitRecoveryTransactionEnvironment();
5894 : :
5895 [ # # ]: 0 : if (wasShutdown)
5896 : 0 : oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
5897 : : else
5898 : 0 : oldestActiveXID = checkPoint.oldestActiveXid;
5899 [ # # ]: 0 : Assert(TransactionIdIsValid(oldestActiveXID));
5900 : :
5901 : : /* Tell procarray about the range of xids it has to deal with */
5902 : 0 : ProcArrayInitRecovery(XidFromFullTransactionId(TransamVariables->nextXid));
5903 : :
5904 : : /*
5905 : : * Startup subtrans only. CLOG, MultiXact and commit timestamp
5906 : : * have already been started up and other SLRUs are not maintained
5907 : : * during recovery and need not be started yet.
5908 : : */
5909 : 0 : StartupSUBTRANS(oldestActiveXID);
5910 : :
5911 : : /*
5912 : : * If we're beginning at a shutdown checkpoint, we know that
5913 : : * nothing was running on the primary at this point. So fake-up an
5914 : : * empty running-xacts record and use that here and now. Recover
5915 : : * additional standby state for prepared transactions.
5916 : : */
5917 [ # # ]: 0 : if (wasShutdown)
5918 : : {
5919 : 0 : RunningTransactionsData running;
5920 : 0 : TransactionId latestCompletedXid;
5921 : :
5922 : : /* Update pg_subtrans entries for any prepared transactions */
5923 : 0 : StandbyRecoverPreparedTransactions();
5924 : :
5925 : : /*
5926 : : * Construct a RunningTransactions snapshot representing a
5927 : : * shut down server, with only prepared transactions still
5928 : : * alive. We're never overflowed at this point because all
5929 : : * subxids are listed with their parent prepared transactions.
5930 : : */
5931 : 0 : running.xcnt = nxids;
5932 : 0 : running.subxcnt = 0;
5933 : 0 : running.subxid_status = SUBXIDS_IN_SUBTRANS;
5934 : 0 : running.nextXid = XidFromFullTransactionId(checkPoint.nextXid);
5935 : 0 : running.oldestRunningXid = oldestActiveXID;
5936 : 0 : latestCompletedXid = XidFromFullTransactionId(checkPoint.nextXid);
5937 [ # # ]: 0 : TransactionIdRetreat(latestCompletedXid);
5938 [ # # ]: 0 : Assert(TransactionIdIsNormal(latestCompletedXid));
5939 : 0 : running.latestCompletedXid = latestCompletedXid;
5940 : 0 : running.xids = xids;
5941 : :
5942 : 0 : ProcArrayApplyRecoveryInfo(&running);
5943 : 0 : }
5944 : 0 : }
5945 : :
5946 : : /*
5947 : : * We're all set for replaying the WAL now. Do it.
5948 : : */
5949 : 0 : PerformWalRecovery();
5950 : 0 : performedWalRecovery = true;
5951 : 0 : }
5952 : : else
5953 : 4 : performedWalRecovery = false;
5954 : :
5955 : : /*
5956 : : * Finish WAL recovery.
5957 : : */
5958 : 4 : endOfRecoveryInfo = FinishWalRecovery();
5959 : 4 : EndOfLog = endOfRecoveryInfo->endOfLog;
5960 : 4 : EndOfLogTLI = endOfRecoveryInfo->endOfLogTLI;
5961 : 4 : abortedRecPtr = endOfRecoveryInfo->abortedRecPtr;
5962 : 4 : missingContrecPtr = endOfRecoveryInfo->missingContrecPtr;
5963 : :
5964 : : /*
5965 : : * Reset ps status display, so as no information related to recovery shows
5966 : : * up.
5967 : : */
5968 : 4 : set_ps_display("");
5969 : :
5970 : : /*
5971 : : * When recovering from a backup (we are in recovery, and archive recovery
5972 : : * was requested), complain if we did not roll forward far enough to reach
5973 : : * the point where the database is consistent. For regular online
5974 : : * backup-from-primary, that means reaching the end-of-backup WAL record
5975 : : * (at which point we reset backupStartPoint to be Invalid), for
5976 : : * backup-from-replica (which can't inject records into the WAL stream),
5977 : : * that point is when we reach the minRecoveryPoint in pg_control (which
5978 : : * we purposefully copy last when backing up from a replica). For
5979 : : * pg_rewind (which creates a backup_label with a method of "pg_rewind")
5980 : : * or snapshot-style backups (which don't), backupEndRequired will be set
5981 : : * to false.
5982 : : *
5983 : : * Note: it is indeed okay to look at the local variable
5984 : : * LocalMinRecoveryPoint here, even though ControlFile->minRecoveryPoint
5985 : : * might be further ahead --- ControlFile->minRecoveryPoint cannot have
5986 : : * been advanced beyond the WAL we processed.
5987 : : */
5988 [ - + # # ]: 4 : if (InRecovery &&
5989 [ # # ]: 0 : (EndOfLog < LocalMinRecoveryPoint ||
5990 : 0 : XLogRecPtrIsValid(ControlFile->backupStartPoint)))
5991 : : {
5992 : : /*
5993 : : * Ran off end of WAL before reaching end-of-backup WAL record, or
5994 : : * minRecoveryPoint. That's a bad sign, indicating that you tried to
5995 : : * recover from an online backup but never called pg_backup_stop(), or
5996 : : * you didn't archive all the WAL needed.
5997 : : */
5998 [ # # ]: 0 : if (ArchiveRecoveryRequested || ControlFile->backupEndRequired)
5999 : : {
6000 [ # # # # ]: 0 : if (XLogRecPtrIsValid(ControlFile->backupStartPoint) || ControlFile->backupEndRequired)
6001 [ # # # # ]: 0 : ereport(FATAL,
6002 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
6003 : : errmsg("WAL ends before end of online backup"),
6004 : : errhint("All WAL generated while online backup was taken must be available at recovery.")));
6005 : : else
6006 [ # # # # ]: 0 : ereport(FATAL,
6007 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
6008 : : errmsg("WAL ends before consistent recovery point")));
6009 : 0 : }
6010 : 0 : }
6011 : :
6012 : : /*
6013 : : * Reset unlogged relations to the contents of their INIT fork. This is
6014 : : * done AFTER recovery is complete so as to include any unlogged relations
6015 : : * created during recovery, but BEFORE recovery is marked as having
6016 : : * completed successfully. Otherwise we'd not retry if any of the post
6017 : : * end-of-recovery steps fail.
6018 : : */
6019 [ + - ]: 4 : if (InRecovery)
6020 : 0 : ResetUnloggedRelations(UNLOGGED_RELATION_INIT);
6021 : :
6022 : : /*
6023 : : * Pre-scan prepared transactions to find out the range of XIDs present.
6024 : : * This information is not quite needed yet, but it is positioned here so
6025 : : * as potential problems are detected before any on-disk change is done.
6026 : : */
6027 : 4 : oldestActiveXID = PrescanPreparedTransactions(NULL, NULL);
6028 : :
6029 : : /*
6030 : : * Allow ordinary WAL segment creation before possibly switching to a new
6031 : : * timeline, which creates a new segment, and after the last ReadRecord().
6032 : : */
6033 : 4 : SetInstallXLogFileSegmentActive();
6034 : :
6035 : : /*
6036 : : * Consider whether we need to assign a new timeline ID.
6037 : : *
6038 : : * If we did archive recovery, we always assign a new ID. This handles a
6039 : : * couple of issues. If we stopped short of the end of WAL during
6040 : : * recovery, then we are clearly generating a new timeline and must assign
6041 : : * it a unique new ID. Even if we ran to the end, modifying the current
6042 : : * last segment is problematic because it may result in trying to
6043 : : * overwrite an already-archived copy of that segment, and we encourage
6044 : : * DBAs to make their archive_commands reject that. We can dodge the
6045 : : * problem by making the new active segment have a new timeline ID.
6046 : : *
6047 : : * In a normal crash recovery, we can just extend the timeline we were in.
6048 : : */
6049 : 4 : newTLI = endOfRecoveryInfo->lastRecTLI;
6050 [ + - ]: 4 : if (ArchiveRecoveryRequested)
6051 : : {
6052 : 0 : newTLI = findNewestTimeLine(recoveryTargetTLI) + 1;
6053 [ # # # # ]: 0 : ereport(LOG,
6054 : : (errmsg("selected new timeline ID: %u", newTLI)));
6055 : :
6056 : : /*
6057 : : * Make a writable copy of the last WAL segment. (Note that we also
6058 : : * have a copy of the last block of the old WAL in
6059 : : * endOfRecovery->lastPage; we will use that below.)
6060 : : */
6061 : 0 : XLogInitNewTimeline(EndOfLogTLI, EndOfLog, newTLI);
6062 : :
6063 : : /*
6064 : : * Remove the signal files out of the way, so that we don't
6065 : : * accidentally re-enter archive recovery mode in a subsequent crash.
6066 : : */
6067 [ # # ]: 0 : if (endOfRecoveryInfo->standby_signal_file_found)
6068 : 0 : durable_unlink(STANDBY_SIGNAL_FILE, FATAL);
6069 : :
6070 [ # # ]: 0 : if (endOfRecoveryInfo->recovery_signal_file_found)
6071 : 0 : durable_unlink(RECOVERY_SIGNAL_FILE, FATAL);
6072 : :
6073 : : /*
6074 : : * Write the timeline history file, and have it archived. After this
6075 : : * point (or rather, as soon as the file is archived), the timeline
6076 : : * will appear as "taken" in the WAL archive and to any standby
6077 : : * servers. If we crash before actually switching to the new
6078 : : * timeline, standby servers will nevertheless think that we switched
6079 : : * to the new timeline, and will try to connect to the new timeline.
6080 : : * To minimize the window for that, try to do as little as possible
6081 : : * between here and writing the end-of-recovery record.
6082 : : */
6083 : 0 : writeTimeLineHistory(newTLI, recoveryTargetTLI,
6084 : 0 : EndOfLog, endOfRecoveryInfo->recoveryStopReason);
6085 : :
6086 [ # # # # ]: 0 : ereport(LOG,
6087 : : (errmsg("archive recovery complete")));
6088 : 0 : }
6089 : :
6090 : : /* Save the selected TimeLineID in shared memory, too */
6091 [ - + ]: 4 : SpinLockAcquire(&XLogCtl->info_lck);
6092 : 4 : XLogCtl->InsertTimeLineID = newTLI;
6093 : 4 : XLogCtl->PrevTimeLineID = endOfRecoveryInfo->lastRecTLI;
6094 : 4 : SpinLockRelease(&XLogCtl->info_lck);
6095 : :
6096 : : /*
6097 : : * Actually, if WAL ended in an incomplete record, skip the parts that
6098 : : * made it through and start writing after the portion that persisted.
6099 : : * (It's critical to first write an OVERWRITE_CONTRECORD message, which
6100 : : * we'll do as soon as we're open for writing new WAL.)
6101 : : */
6102 [ + - ]: 4 : if (XLogRecPtrIsValid(missingContrecPtr))
6103 : : {
6104 : : /*
6105 : : * We should only have a missingContrecPtr if we're not switching to a
6106 : : * new timeline. When a timeline switch occurs, WAL is copied from the
6107 : : * old timeline to the new only up to the end of the last complete
6108 : : * record, so there can't be an incomplete WAL record that we need to
6109 : : * disregard.
6110 : : */
6111 [ # # ]: 0 : Assert(newTLI == endOfRecoveryInfo->lastRecTLI);
6112 [ # # ]: 0 : Assert(XLogRecPtrIsValid(abortedRecPtr));
6113 : 0 : EndOfLog = missingContrecPtr;
6114 : 0 : }
6115 : :
6116 : : /*
6117 : : * Prepare to write WAL starting at EndOfLog location, and init xlog
6118 : : * buffer cache using the block containing the last record from the
6119 : : * previous incarnation.
6120 : : */
6121 : 4 : Insert = &XLogCtl->Insert;
6122 : 4 : Insert->PrevBytePos = XLogRecPtrToBytePos(endOfRecoveryInfo->lastRec);
6123 : 4 : Insert->CurrBytePos = XLogRecPtrToBytePos(EndOfLog);
6124 : :
6125 : : /*
6126 : : * Tricky point here: lastPage contains the *last* block that the LastRec
6127 : : * record spans, not the one it starts in. The last block is indeed the
6128 : : * one we want to use.
6129 : : */
6130 [ + - ]: 4 : if (EndOfLog % XLOG_BLCKSZ != 0)
6131 : : {
6132 : 4 : char *page;
6133 : 4 : int len;
6134 : 4 : int firstIdx;
6135 : :
6136 : 4 : firstIdx = XLogRecPtrToBufIdx(EndOfLog);
6137 : 4 : len = EndOfLog - endOfRecoveryInfo->lastPageBeginPtr;
6138 [ + - ]: 4 : Assert(len < XLOG_BLCKSZ);
6139 : :
6140 : : /* Copy the valid part of the last block, and zero the rest */
6141 : 4 : page = &XLogCtl->pages[firstIdx * XLOG_BLCKSZ];
6142 : 4 : memcpy(page, endOfRecoveryInfo->lastPage, len);
6143 : 4 : memset(page + len, 0, XLOG_BLCKSZ - len);
6144 : :
6145 : 4 : pg_atomic_write_u64(&XLogCtl->xlblocks[firstIdx], endOfRecoveryInfo->lastPageBeginPtr + XLOG_BLCKSZ);
6146 : 4 : XLogCtl->InitializedUpTo = endOfRecoveryInfo->lastPageBeginPtr + XLOG_BLCKSZ;
6147 : 4 : }
6148 : : else
6149 : : {
6150 : : /*
6151 : : * There is no partial block to copy. Just set InitializedUpTo, and
6152 : : * let the first attempt to insert a log record to initialize the next
6153 : : * buffer.
6154 : : */
6155 : 0 : XLogCtl->InitializedUpTo = EndOfLog;
6156 : : }
6157 : :
6158 : : /*
6159 : : * Update local and shared status. This is OK to do without any locks
6160 : : * because no other process can be reading or writing WAL yet.
6161 : : */
6162 : 4 : LogwrtResult.Write = LogwrtResult.Flush = EndOfLog;
6163 : 4 : pg_atomic_write_u64(&XLogCtl->logInsertResult, EndOfLog);
6164 : 4 : pg_atomic_write_u64(&XLogCtl->logWriteResult, EndOfLog);
6165 : 4 : pg_atomic_write_u64(&XLogCtl->logFlushResult, EndOfLog);
6166 : 4 : XLogCtl->LogwrtRqst.Write = EndOfLog;
6167 : 4 : XLogCtl->LogwrtRqst.Flush = EndOfLog;
6168 : :
6169 : : /*
6170 : : * Preallocate additional log files, if wanted.
6171 : : */
6172 : 4 : PreallocXlogFiles(EndOfLog, newTLI);
6173 : :
6174 : : /*
6175 : : * Okay, we're officially UP.
6176 : : */
6177 : 4 : InRecovery = false;
6178 : :
6179 : : /* start the archive_timeout timer and LSN running */
6180 : 4 : XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
6181 : 4 : XLogCtl->lastSegSwitchLSN = EndOfLog;
6182 : :
6183 : : /* also initialize latestCompletedXid, to nextXid - 1 */
6184 : 4 : LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
6185 : 4 : TransamVariables->latestCompletedXid = TransamVariables->nextXid;
6186 : 4 : FullTransactionIdRetreat(&TransamVariables->latestCompletedXid);
6187 : 4 : LWLockRelease(ProcArrayLock);
6188 : :
6189 : : /*
6190 : : * Start up subtrans, if not already done for hot standby. (commit
6191 : : * timestamps are started below, if necessary.)
6192 : : */
6193 [ - + ]: 4 : if (standbyState == STANDBY_DISABLED)
6194 : 4 : StartupSUBTRANS(oldestActiveXID);
6195 : :
6196 : : /*
6197 : : * Perform end of recovery actions for any SLRUs that need it.
6198 : : */
6199 : 4 : TrimCLOG();
6200 : 4 : TrimMultiXact();
6201 : :
6202 : : /*
6203 : : * Reload shared-memory state for prepared transactions. This needs to
6204 : : * happen before renaming the last partial segment of the old timeline as
6205 : : * it may be possible that we have to recover some transactions from it.
6206 : : */
6207 : 4 : RecoverPreparedTransactions();
6208 : :
6209 : : /* Shut down xlogreader */
6210 : 4 : ShutdownWalRecovery();
6211 : :
6212 : : /* Enable WAL writes for this backend only. */
6213 : 4 : LocalSetXLogInsertAllowed();
6214 : :
6215 : : /* If necessary, write overwrite-contrecord before doing anything else */
6216 [ + - ]: 4 : if (XLogRecPtrIsValid(abortedRecPtr))
6217 : : {
6218 [ # # ]: 0 : Assert(XLogRecPtrIsValid(missingContrecPtr));
6219 : 0 : CreateOverwriteContrecordRecord(abortedRecPtr, missingContrecPtr, newTLI);
6220 : 0 : }
6221 : :
6222 : : /*
6223 : : * Update full_page_writes in shared memory and write an XLOG_FPW_CHANGE
6224 : : * record before resource manager writes cleanup WAL records or checkpoint
6225 : : * record is written.
6226 : : */
6227 : 4 : Insert->fullPageWrites = lastFullPageWrites;
6228 : 4 : UpdateFullPageWrites();
6229 : :
6230 : : /*
6231 : : * Emit checkpoint or end-of-recovery record in XLOG, if required.
6232 : : */
6233 [ + - ]: 4 : if (performedWalRecovery)
6234 : 0 : promoted = PerformRecoveryXLogAction();
6235 : :
6236 : : /*
6237 : : * If any of the critical GUCs have changed, log them before we allow
6238 : : * backends to write WAL.
6239 : : */
6240 : 4 : XLogReportParameters();
6241 : :
6242 : : /* If this is archive recovery, perform post-recovery cleanup actions. */
6243 [ + - ]: 4 : if (ArchiveRecoveryRequested)
6244 : 0 : CleanupAfterArchiveRecovery(EndOfLogTLI, EndOfLog, newTLI);
6245 : :
6246 : : /*
6247 : : * Local WAL inserts enabled, so it's time to finish initialization of
6248 : : * commit timestamp.
6249 : : */
6250 : 4 : CompleteCommitTsInitialization();
6251 : :
6252 : : /*
6253 : : * Update logical decoding status in shared memory and write an
6254 : : * XLOG_LOGICAL_DECODING_STATUS_CHANGE, if necessary.
6255 : : */
6256 : 4 : UpdateLogicalDecodingStatusEndOfRecovery();
6257 : :
6258 : : /* Clean up EndOfWalRecoveryInfo data to appease Valgrind leak checking */
6259 [ - + ]: 4 : if (endOfRecoveryInfo->lastPage)
6260 : 4 : pfree(endOfRecoveryInfo->lastPage);
6261 : 4 : pfree(endOfRecoveryInfo->recoveryStopReason);
6262 : 4 : pfree(endOfRecoveryInfo);
6263 : :
6264 : : /*
6265 : : * All done with end-of-recovery actions.
6266 : : *
6267 : : * Now allow backends to write WAL and update the control file status in
6268 : : * consequence. SharedRecoveryState, that controls if backends can write
6269 : : * WAL, is updated while holding ControlFileLock to prevent other backends
6270 : : * to look at an inconsistent state of the control file in shared memory.
6271 : : * There is still a small window during which backends can write WAL and
6272 : : * the control file is still referring to a system not in DB_IN_PRODUCTION
6273 : : * state while looking at the on-disk control file.
6274 : : *
6275 : : * Also, we use info_lck to update SharedRecoveryState to ensure that
6276 : : * there are no race conditions concerning visibility of other recent
6277 : : * updates to shared memory.
6278 : : */
6279 : 4 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6280 : 4 : ControlFile->state = DB_IN_PRODUCTION;
6281 : :
6282 [ - + ]: 4 : SpinLockAcquire(&XLogCtl->info_lck);
6283 : 4 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_DONE;
6284 : 4 : SpinLockRelease(&XLogCtl->info_lck);
6285 : :
6286 : 4 : UpdateControlFile();
6287 : 4 : LWLockRelease(ControlFileLock);
6288 : :
6289 : : /*
6290 : : * Wake up the checkpointer process as there might be a request to disable
6291 : : * logical decoding by concurrent slot drop.
6292 : : */
6293 : 4 : WakeupCheckpointer();
6294 : :
6295 : : /*
6296 : : * Wake up all waiters. They need to report an error that recovery was
6297 : : * ended before reaching the target LSN.
6298 : : */
6299 : 4 : WaitLSNWakeup(WAIT_LSN_TYPE_STANDBY_REPLAY, InvalidXLogRecPtr);
6300 : 4 : WaitLSNWakeup(WAIT_LSN_TYPE_STANDBY_WRITE, InvalidXLogRecPtr);
6301 : 4 : WaitLSNWakeup(WAIT_LSN_TYPE_STANDBY_FLUSH, InvalidXLogRecPtr);
6302 : :
6303 : : /*
6304 : : * Shutdown the recovery environment. This must occur after
6305 : : * RecoverPreparedTransactions() (see notes in lock_twophase_recover())
6306 : : * and after switching SharedRecoveryState to RECOVERY_STATE_DONE so as
6307 : : * any session building a snapshot will not rely on KnownAssignedXids as
6308 : : * RecoveryInProgress() would return false at this stage. This is
6309 : : * particularly critical for prepared 2PC transactions, that would still
6310 : : * need to be included in snapshots once recovery has ended.
6311 : : */
6312 [ + - ]: 4 : if (standbyState != STANDBY_DISABLED)
6313 : 0 : ShutdownRecoveryTransactionEnvironment();
6314 : :
6315 : : /*
6316 : : * If there were cascading standby servers connected to us, nudge any wal
6317 : : * sender processes to notice that we've been promoted.
6318 : : */
6319 : 4 : WalSndWakeup(true, true);
6320 : :
6321 : : /*
6322 : : * If this was a promotion, request an (online) checkpoint now. This isn't
6323 : : * required for consistency, but the last restartpoint might be far back,
6324 : : * and in case of a crash, recovering from it might take a longer than is
6325 : : * appropriate now that we're not in standby mode anymore.
6326 : : */
6327 [ + - ]: 4 : if (promoted)
6328 : 0 : RequestCheckpoint(CHECKPOINT_FORCE);
6329 : 4 : }
6330 : :
6331 : : /*
6332 : : * Callback from PerformWalRecovery(), called when we switch from crash
6333 : : * recovery to archive recovery mode. Updates the control file accordingly.
6334 : : */
6335 : : void
6336 : 0 : SwitchIntoArchiveRecovery(XLogRecPtr EndRecPtr, TimeLineID replayTLI)
6337 : : {
6338 : : /* initialize minRecoveryPoint to this record */
6339 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6340 : 0 : ControlFile->state = DB_IN_ARCHIVE_RECOVERY;
6341 [ # # ]: 0 : if (ControlFile->minRecoveryPoint < EndRecPtr)
6342 : : {
6343 : 0 : ControlFile->minRecoveryPoint = EndRecPtr;
6344 : 0 : ControlFile->minRecoveryPointTLI = replayTLI;
6345 : 0 : }
6346 : : /* update local copy */
6347 : 0 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
6348 : 0 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
6349 : :
6350 : : /*
6351 : : * The startup process can update its local copy of minRecoveryPoint from
6352 : : * this point.
6353 : : */
6354 : 0 : updateMinRecoveryPoint = true;
6355 : :
6356 : 0 : UpdateControlFile();
6357 : :
6358 : : /*
6359 : : * We update SharedRecoveryState while holding the lock on ControlFileLock
6360 : : * so both states are consistent in shared memory.
6361 : : */
6362 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
6363 : 0 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_ARCHIVE;
6364 : 0 : SpinLockRelease(&XLogCtl->info_lck);
6365 : :
6366 : 0 : LWLockRelease(ControlFileLock);
6367 : 0 : }
6368 : :
6369 : : /*
6370 : : * Callback from PerformWalRecovery(), called when we reach the end of backup.
6371 : : * Updates the control file accordingly.
6372 : : */
6373 : : void
6374 : 0 : ReachedEndOfBackup(XLogRecPtr EndRecPtr, TimeLineID tli)
6375 : : {
6376 : : /*
6377 : : * We have reached the end of base backup, as indicated by pg_control. The
6378 : : * data on disk is now consistent (unless minRecoveryPoint is further
6379 : : * ahead, which can happen if we crashed during previous recovery). Reset
6380 : : * backupStartPoint and backupEndPoint, and update minRecoveryPoint to
6381 : : * make sure we don't allow starting up at an earlier point even if
6382 : : * recovery is stopped and restarted soon after this.
6383 : : */
6384 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6385 : :
6386 [ # # ]: 0 : if (ControlFile->minRecoveryPoint < EndRecPtr)
6387 : : {
6388 : 0 : ControlFile->minRecoveryPoint = EndRecPtr;
6389 : 0 : ControlFile->minRecoveryPointTLI = tli;
6390 : 0 : }
6391 : :
6392 : 0 : ControlFile->backupStartPoint = InvalidXLogRecPtr;
6393 : 0 : ControlFile->backupEndPoint = InvalidXLogRecPtr;
6394 : 0 : ControlFile->backupEndRequired = false;
6395 : 0 : UpdateControlFile();
6396 : :
6397 : 0 : LWLockRelease(ControlFileLock);
6398 : 0 : }
6399 : :
6400 : : /*
6401 : : * Perform whatever XLOG actions are necessary at end of REDO.
6402 : : *
6403 : : * The goal here is to make sure that we'll be able to recover properly if
6404 : : * we crash again. If we choose to write a checkpoint, we'll write a shutdown
6405 : : * checkpoint rather than an on-line one. This is not particularly critical,
6406 : : * but since we may be assigning a new TLI, using a shutdown checkpoint allows
6407 : : * us to have the rule that TLI only changes in shutdown checkpoints, which
6408 : : * allows some extra error checking in xlog_redo.
6409 : : */
6410 : : static bool
6411 : 0 : PerformRecoveryXLogAction(void)
6412 : : {
6413 : 0 : bool promoted = false;
6414 : :
6415 : : /*
6416 : : * Perform a checkpoint to update all our recovery activity to disk.
6417 : : *
6418 : : * Note that we write a shutdown checkpoint rather than an on-line one.
6419 : : * This is not particularly critical, but since we may be assigning a new
6420 : : * TLI, using a shutdown checkpoint allows us to have the rule that TLI
6421 : : * only changes in shutdown checkpoints, which allows some extra error
6422 : : * checking in xlog_redo.
6423 : : *
6424 : : * In promotion, only create a lightweight end-of-recovery record instead
6425 : : * of a full checkpoint. A checkpoint is requested later, after we're
6426 : : * fully out of recovery mode and already accepting queries.
6427 : : */
6428 [ # # # # : 0 : if (ArchiveRecoveryRequested && IsUnderPostmaster &&
# # ]
6429 : 0 : PromoteIsTriggered())
6430 : : {
6431 : 0 : promoted = true;
6432 : :
6433 : : /*
6434 : : * Insert a special WAL record to mark the end of recovery, since we
6435 : : * aren't doing a checkpoint. That means that the checkpointer process
6436 : : * may likely be in the middle of a time-smoothed restartpoint and
6437 : : * could continue to be for minutes after this. That sounds strange,
6438 : : * but the effect is roughly the same and it would be stranger to try
6439 : : * to come out of the restartpoint and then checkpoint. We request a
6440 : : * checkpoint later anyway, just for safety.
6441 : : */
6442 : 0 : CreateEndOfRecoveryRecord();
6443 : 0 : }
6444 : : else
6445 : : {
6446 : 0 : RequestCheckpoint(CHECKPOINT_END_OF_RECOVERY |
6447 : : CHECKPOINT_FAST |
6448 : : CHECKPOINT_WAIT);
6449 : : }
6450 : :
6451 : 0 : return promoted;
6452 : 0 : }
6453 : :
6454 : : /*
6455 : : * Is the system still in recovery?
6456 : : *
6457 : : * Unlike testing InRecovery, this works in any process that's connected to
6458 : : * shared memory.
6459 : : */
6460 : : bool
6461 : 12232238 : RecoveryInProgress(void)
6462 : : {
6463 : : /*
6464 : : * We check shared state each time only until we leave recovery mode. We
6465 : : * can't re-enter recovery, so there's no need to keep checking after the
6466 : : * shared variable has once been seen false.
6467 : : */
6468 [ + + ]: 12232238 : if (!LocalRecoveryInProgress)
6469 : 12231425 : return false;
6470 : : else
6471 : : {
6472 : : /*
6473 : : * use volatile pointer to make sure we make a fresh read of the
6474 : : * shared variable.
6475 : : */
6476 : 813 : volatile XLogCtlData *xlogctl = XLogCtl;
6477 : :
6478 : 813 : LocalRecoveryInProgress = (xlogctl->SharedRecoveryState != RECOVERY_STATE_DONE);
6479 : :
6480 : : /*
6481 : : * Note: We don't need a memory barrier when we're still in recovery.
6482 : : * We might exit recovery immediately after return, so the caller
6483 : : * can't rely on 'true' meaning that we're still in recovery anyway.
6484 : : */
6485 : :
6486 : 813 : return LocalRecoveryInProgress;
6487 : 813 : }
6488 : 12232238 : }
6489 : :
6490 : : /*
6491 : : * Returns current recovery state from shared memory.
6492 : : *
6493 : : * This returned state is kept consistent with the contents of the control
6494 : : * file. See details about the possible values of RecoveryState in xlog.h.
6495 : : */
6496 : : RecoveryState
6497 : 0 : GetRecoveryState(void)
6498 : : {
6499 : 0 : RecoveryState retval;
6500 : :
6501 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
6502 : 0 : retval = XLogCtl->SharedRecoveryState;
6503 : 0 : SpinLockRelease(&XLogCtl->info_lck);
6504 : :
6505 : 0 : return retval;
6506 : 0 : }
6507 : :
6508 : : /*
6509 : : * Is this process allowed to insert new WAL records?
6510 : : *
6511 : : * Ordinarily this is essentially equivalent to !RecoveryInProgress().
6512 : : * But we also have provisions for forcing the result "true" or "false"
6513 : : * within specific processes regardless of the global state.
6514 : : */
6515 : : bool
6516 : 6929655 : XLogInsertAllowed(void)
6517 : : {
6518 : : /*
6519 : : * If value is "unconditionally true" or "unconditionally false", just
6520 : : * return it. This provides the normal fast path once recovery is known
6521 : : * done.
6522 : : */
6523 [ + + ]: 6929655 : if (LocalXLogInsertAllowed >= 0)
6524 : 6929373 : return (bool) LocalXLogInsertAllowed;
6525 : :
6526 : : /*
6527 : : * Else, must check to see if we're still in recovery.
6528 : : */
6529 [ - + ]: 282 : if (RecoveryInProgress())
6530 : 0 : return false;
6531 : :
6532 : : /*
6533 : : * On exit from recovery, reset to "unconditionally true", since there is
6534 : : * no need to keep checking.
6535 : : */
6536 : 282 : LocalXLogInsertAllowed = 1;
6537 : 282 : return true;
6538 : 6929655 : }
6539 : :
6540 : : /*
6541 : : * Make XLogInsertAllowed() return true in the current process only.
6542 : : *
6543 : : * Note: it is allowed to switch LocalXLogInsertAllowed back to -1 later,
6544 : : * and even call LocalSetXLogInsertAllowed() again after that.
6545 : : *
6546 : : * Returns the previous value of LocalXLogInsertAllowed.
6547 : : */
6548 : : static int
6549 : 4 : LocalSetXLogInsertAllowed(void)
6550 : : {
6551 : 4 : int oldXLogAllowed = LocalXLogInsertAllowed;
6552 : :
6553 : 4 : LocalXLogInsertAllowed = 1;
6554 : :
6555 : 8 : return oldXLogAllowed;
6556 : 4 : }
6557 : :
6558 : : /*
6559 : : * Return the current Redo pointer from shared memory.
6560 : : *
6561 : : * As a side-effect, the local RedoRecPtr copy is updated.
6562 : : */
6563 : : XLogRecPtr
6564 : 32286 : GetRedoRecPtr(void)
6565 : : {
6566 : 32286 : XLogRecPtr ptr;
6567 : :
6568 : : /*
6569 : : * The possibly not up-to-date copy in XlogCtl is enough. Even if we
6570 : : * grabbed a WAL insertion lock to read the authoritative value in
6571 : : * Insert->RedoRecPtr, someone might update it just after we've released
6572 : : * the lock.
6573 : : */
6574 [ + + ]: 32286 : SpinLockAcquire(&XLogCtl->info_lck);
6575 : 32286 : ptr = XLogCtl->RedoRecPtr;
6576 : 32286 : SpinLockRelease(&XLogCtl->info_lck);
6577 : :
6578 [ + + ]: 32286 : if (RedoRecPtr < ptr)
6579 : 17 : RedoRecPtr = ptr;
6580 : :
6581 : 64572 : return RedoRecPtr;
6582 : 32286 : }
6583 : :
6584 : : /*
6585 : : * Return information needed to decide whether a modified block needs a
6586 : : * full-page image to be included in the WAL record.
6587 : : *
6588 : : * The returned values are cached copies from backend-private memory, and
6589 : : * possibly out-of-date or, indeed, uninitialized, in which case they will
6590 : : * be InvalidXLogRecPtr and false, respectively. XLogInsertRecord will
6591 : : * re-check them against up-to-date values, while holding the WAL insert lock.
6592 : : */
6593 : : void
6594 : 2544284 : GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p)
6595 : : {
6596 : 2544284 : *RedoRecPtr_p = RedoRecPtr;
6597 : 2544284 : *doPageWrites_p = doPageWrites;
6598 : 2544284 : }
6599 : :
6600 : : /*
6601 : : * GetInsertRecPtr -- Returns the current insert position.
6602 : : *
6603 : : * NOTE: The value *actually* returned is the position of the last full
6604 : : * xlog page. It lags behind the real insert position by at most 1 page.
6605 : : * For that, we don't need to scan through WAL insertion locks, and an
6606 : : * approximation is enough for the current usage of this function.
6607 : : */
6608 : : XLogRecPtr
6609 : 13 : GetInsertRecPtr(void)
6610 : : {
6611 : 13 : XLogRecPtr recptr;
6612 : :
6613 [ - + ]: 13 : SpinLockAcquire(&XLogCtl->info_lck);
6614 : 13 : recptr = XLogCtl->LogwrtRqst.Write;
6615 : 13 : SpinLockRelease(&XLogCtl->info_lck);
6616 : :
6617 : 26 : return recptr;
6618 : 13 : }
6619 : :
6620 : : /*
6621 : : * GetFlushRecPtr -- Returns the current flush position, ie, the last WAL
6622 : : * position known to be fsync'd to disk. This should only be used on a
6623 : : * system that is known not to be in recovery.
6624 : : */
6625 : : XLogRecPtr
6626 : 0 : GetFlushRecPtr(TimeLineID *insertTLI)
6627 : : {
6628 [ # # ]: 0 : Assert(XLogCtl->SharedRecoveryState == RECOVERY_STATE_DONE);
6629 : :
6630 : 0 : RefreshXLogWriteResult(LogwrtResult);
6631 : :
6632 : : /*
6633 : : * If we're writing and flushing WAL, the time line can't be changing, so
6634 : : * no lock is required.
6635 : : */
6636 [ # # ]: 0 : if (insertTLI)
6637 : 0 : *insertTLI = XLogCtl->InsertTimeLineID;
6638 : :
6639 : 0 : return LogwrtResult.Flush;
6640 : : }
6641 : :
6642 : : /*
6643 : : * GetWALInsertionTimeLine -- Returns the current timeline of a system that
6644 : : * is not in recovery.
6645 : : */
6646 : : TimeLineID
6647 : 3 : GetWALInsertionTimeLine(void)
6648 : : {
6649 [ + - ]: 3 : Assert(XLogCtl->SharedRecoveryState == RECOVERY_STATE_DONE);
6650 : :
6651 : : /* Since the value can't be changing, no lock is required. */
6652 : 3 : return XLogCtl->InsertTimeLineID;
6653 : : }
6654 : :
6655 : : /*
6656 : : * GetWALInsertionTimeLineIfSet -- If the system is not in recovery, returns
6657 : : * the WAL insertion timeline; else, returns 0. Wherever possible, use
6658 : : * GetWALInsertionTimeLine() instead, since it's cheaper. Note that this
6659 : : * function decides recovery has ended as soon as the insert TLI is set, which
6660 : : * happens before we set XLogCtl->SharedRecoveryState to RECOVERY_STATE_DONE.
6661 : : */
6662 : : TimeLineID
6663 : 0 : GetWALInsertionTimeLineIfSet(void)
6664 : : {
6665 : 0 : TimeLineID insertTLI;
6666 : :
6667 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
6668 : 0 : insertTLI = XLogCtl->InsertTimeLineID;
6669 : 0 : SpinLockRelease(&XLogCtl->info_lck);
6670 : :
6671 : 0 : return insertTLI;
6672 : 0 : }
6673 : :
6674 : : /*
6675 : : * GetLastImportantRecPtr -- Returns the LSN of the last important record
6676 : : * inserted. All records not explicitly marked as unimportant are considered
6677 : : * important.
6678 : : *
6679 : : * The LSN is determined by computing the maximum of
6680 : : * WALInsertLocks[i].lastImportantAt.
6681 : : */
6682 : : XLogRecPtr
6683 : 7 : GetLastImportantRecPtr(void)
6684 : : {
6685 : 7 : XLogRecPtr res = InvalidXLogRecPtr;
6686 : 7 : int i;
6687 : :
6688 [ + + ]: 63 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
6689 : : {
6690 : 56 : XLogRecPtr last_important;
6691 : :
6692 : : /*
6693 : : * Need to take a lock to prevent torn reads of the LSN, which are
6694 : : * possible on some of the supported platforms. WAL insert locks only
6695 : : * support exclusive mode, so we have to use that.
6696 : : */
6697 : 56 : LWLockAcquire(&WALInsertLocks[i].l.lock, LW_EXCLUSIVE);
6698 : 56 : last_important = WALInsertLocks[i].l.lastImportantAt;
6699 : 56 : LWLockRelease(&WALInsertLocks[i].l.lock);
6700 : :
6701 [ + + ]: 56 : if (res < last_important)
6702 : 8 : res = last_important;
6703 : 56 : }
6704 : :
6705 : 14 : return res;
6706 : 7 : }
6707 : :
6708 : : /*
6709 : : * Get the time and LSN of the last xlog segment switch
6710 : : */
6711 : : pg_time_t
6712 : 0 : GetLastSegSwitchData(XLogRecPtr *lastSwitchLSN)
6713 : : {
6714 : 0 : pg_time_t result;
6715 : :
6716 : : /* Need WALWriteLock, but shared lock is sufficient */
6717 : 0 : LWLockAcquire(WALWriteLock, LW_SHARED);
6718 : 0 : result = XLogCtl->lastSegSwitchTime;
6719 : 0 : *lastSwitchLSN = XLogCtl->lastSegSwitchLSN;
6720 : 0 : LWLockRelease(WALWriteLock);
6721 : :
6722 : 0 : return result;
6723 : 0 : }
6724 : :
6725 : : /*
6726 : : * This must be called ONCE during postmaster or standalone-backend shutdown
6727 : : */
6728 : : void
6729 : 3 : ShutdownXLOG(int code, Datum arg)
6730 : : {
6731 : : /*
6732 : : * We should have an aux process resource owner to use, and we should not
6733 : : * be in a transaction that's installed some other resowner.
6734 : : */
6735 [ + - ]: 3 : Assert(AuxProcessResourceOwner != NULL);
6736 [ + + + - ]: 3 : Assert(CurrentResourceOwner == NULL ||
6737 : : CurrentResourceOwner == AuxProcessResourceOwner);
6738 : 3 : CurrentResourceOwner = AuxProcessResourceOwner;
6739 : :
6740 : : /* Don't be chatty in standalone mode */
6741 [ - + # # : 3 : ereport(IsPostmasterEnvironment ? LOG : NOTICE,
+ + - + #
# ]
6742 : : (errmsg("shutting down")));
6743 : :
6744 : : /*
6745 : : * Signal walsenders to move to stopping state.
6746 : : */
6747 : 3 : WalSndInitStopping();
6748 : :
6749 : : /*
6750 : : * Wait for WAL senders to be in stopping state. This prevents commands
6751 : : * from writing new WAL.
6752 : : */
6753 : 3 : WalSndWaitStopping();
6754 : :
6755 [ - + ]: 3 : if (RecoveryInProgress())
6756 : 0 : CreateRestartPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_FAST);
6757 : : else
6758 : : {
6759 : : /*
6760 : : * If archiving is enabled, rotate the last XLOG file so that all the
6761 : : * remaining records are archived (postmaster wakes up the archiver
6762 : : * process one more time at the end of shutdown). The checkpoint
6763 : : * record will go to the next XLOG file and won't be archived (yet).
6764 : : */
6765 [ - + # # : 3 : if (XLogArchivingActive())
+ - ]
6766 : 0 : RequestXLogSwitch(false);
6767 : :
6768 : 3 : CreateCheckPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_FAST);
6769 : : }
6770 : 3 : }
6771 : :
6772 : : /*
6773 : : * Log start of a checkpoint.
6774 : : */
6775 : : static void
6776 : 1 : LogCheckpointStart(int flags, bool restartpoint)
6777 : : {
6778 [ - + ]: 1 : if (restartpoint)
6779 [ # # # # ]: 0 : ereport(LOG,
6780 : : /* translator: the placeholders show checkpoint options */
6781 : : (errmsg("restartpoint starting:%s%s%s%s%s%s%s%s",
6782 : : (flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
6783 : : (flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
6784 : : (flags & CHECKPOINT_FAST) ? " fast" : "",
6785 : : (flags & CHECKPOINT_FORCE) ? " force" : "",
6786 : : (flags & CHECKPOINT_WAIT) ? " wait" : "",
6787 : : (flags & CHECKPOINT_CAUSE_XLOG) ? " wal" : "",
6788 : : (flags & CHECKPOINT_CAUSE_TIME) ? " time" : "",
6789 : : (flags & CHECKPOINT_FLUSH_UNLOGGED) ? " flush-unlogged" : "")));
6790 : : else
6791 [ - + + - ]: 1 : ereport(LOG,
6792 : : /* translator: the placeholders show checkpoint options */
6793 : : (errmsg("checkpoint starting:%s%s%s%s%s%s%s%s",
6794 : : (flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
6795 : : (flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
6796 : : (flags & CHECKPOINT_FAST) ? " fast" : "",
6797 : : (flags & CHECKPOINT_FORCE) ? " force" : "",
6798 : : (flags & CHECKPOINT_WAIT) ? " wait" : "",
6799 : : (flags & CHECKPOINT_CAUSE_XLOG) ? " wal" : "",
6800 : : (flags & CHECKPOINT_CAUSE_TIME) ? " time" : "",
6801 : : (flags & CHECKPOINT_FLUSH_UNLOGGED) ? " flush-unlogged" : "")));
6802 : 1 : }
6803 : :
6804 : : /*
6805 : : * Log end of a checkpoint.
6806 : : */
6807 : : static void
6808 : 7 : LogCheckpointEnd(bool restartpoint)
6809 : : {
6810 : 7 : long write_msecs,
6811 : : sync_msecs,
6812 : : total_msecs,
6813 : : longest_msecs,
6814 : : average_msecs;
6815 : 7 : uint64 average_sync_time;
6816 : :
6817 : 7 : CheckpointStats.ckpt_end_t = GetCurrentTimestamp();
6818 : :
6819 : 14 : write_msecs = TimestampDifferenceMilliseconds(CheckpointStats.ckpt_write_t,
6820 : 7 : CheckpointStats.ckpt_sync_t);
6821 : :
6822 : 14 : sync_msecs = TimestampDifferenceMilliseconds(CheckpointStats.ckpt_sync_t,
6823 : 7 : CheckpointStats.ckpt_sync_end_t);
6824 : :
6825 : : /* Accumulate checkpoint timing summary data, in milliseconds. */
6826 : 7 : PendingCheckpointerStats.write_time += write_msecs;
6827 : 7 : PendingCheckpointerStats.sync_time += sync_msecs;
6828 : :
6829 : : /*
6830 : : * All of the published timing statistics are accounted for. Only
6831 : : * continue if a log message is to be written.
6832 : : */
6833 [ + + ]: 7 : if (!log_checkpoints)
6834 : 6 : return;
6835 : :
6836 : 2 : total_msecs = TimestampDifferenceMilliseconds(CheckpointStats.ckpt_start_t,
6837 : 1 : CheckpointStats.ckpt_end_t);
6838 : :
6839 : : /*
6840 : : * Timing values returned from CheckpointStats are in microseconds.
6841 : : * Convert to milliseconds for consistent printing.
6842 : : */
6843 : 1 : longest_msecs = (long) ((CheckpointStats.ckpt_longest_sync + 999) / 1000);
6844 : :
6845 : 1 : average_sync_time = 0;
6846 [ + - ]: 1 : if (CheckpointStats.ckpt_sync_rels > 0)
6847 : 0 : average_sync_time = CheckpointStats.ckpt_agg_sync_time /
6848 : 0 : CheckpointStats.ckpt_sync_rels;
6849 : 1 : average_msecs = (long) ((average_sync_time + 999) / 1000);
6850 : :
6851 : : /*
6852 : : * ControlFileLock is not required to see ControlFile->checkPoint and
6853 : : * ->checkPointCopy here as we are the only updator of those variables at
6854 : : * this moment.
6855 : : */
6856 [ - + ]: 1 : if (restartpoint)
6857 [ # # # # ]: 0 : ereport(LOG,
6858 : : (errmsg("restartpoint complete: wrote %d buffers (%.1f%%), "
6859 : : "wrote %d SLRU buffers; %d WAL file(s) added, "
6860 : : "%d removed, %d recycled; write=%ld.%03d s, "
6861 : : "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, "
6862 : : "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, "
6863 : : "estimate=%d kB; lsn=%X/%08X, redo lsn=%X/%08X",
6864 : : CheckpointStats.ckpt_bufs_written,
6865 : : (double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers,
6866 : : CheckpointStats.ckpt_slru_written,
6867 : : CheckpointStats.ckpt_segs_added,
6868 : : CheckpointStats.ckpt_segs_removed,
6869 : : CheckpointStats.ckpt_segs_recycled,
6870 : : write_msecs / 1000, (int) (write_msecs % 1000),
6871 : : sync_msecs / 1000, (int) (sync_msecs % 1000),
6872 : : total_msecs / 1000, (int) (total_msecs % 1000),
6873 : : CheckpointStats.ckpt_sync_rels,
6874 : : longest_msecs / 1000, (int) (longest_msecs % 1000),
6875 : : average_msecs / 1000, (int) (average_msecs % 1000),
6876 : : (int) (PrevCheckPointDistance / 1024.0),
6877 : : (int) (CheckPointDistanceEstimate / 1024.0),
6878 : : LSN_FORMAT_ARGS(ControlFile->checkPoint),
6879 : : LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo))));
6880 : : else
6881 [ - + + - ]: 1 : ereport(LOG,
6882 : : (errmsg("checkpoint complete: wrote %d buffers (%.1f%%), "
6883 : : "wrote %d SLRU buffers; %d WAL file(s) added, "
6884 : : "%d removed, %d recycled; write=%ld.%03d s, "
6885 : : "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, "
6886 : : "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, "
6887 : : "estimate=%d kB; lsn=%X/%08X, redo lsn=%X/%08X",
6888 : : CheckpointStats.ckpt_bufs_written,
6889 : : (double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers,
6890 : : CheckpointStats.ckpt_slru_written,
6891 : : CheckpointStats.ckpt_segs_added,
6892 : : CheckpointStats.ckpt_segs_removed,
6893 : : CheckpointStats.ckpt_segs_recycled,
6894 : : write_msecs / 1000, (int) (write_msecs % 1000),
6895 : : sync_msecs / 1000, (int) (sync_msecs % 1000),
6896 : : total_msecs / 1000, (int) (total_msecs % 1000),
6897 : : CheckpointStats.ckpt_sync_rels,
6898 : : longest_msecs / 1000, (int) (longest_msecs % 1000),
6899 : : average_msecs / 1000, (int) (average_msecs % 1000),
6900 : : (int) (PrevCheckPointDistance / 1024.0),
6901 : : (int) (CheckPointDistanceEstimate / 1024.0),
6902 : : LSN_FORMAT_ARGS(ControlFile->checkPoint),
6903 : : LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo))));
6904 [ - + ]: 7 : }
6905 : :
6906 : : /*
6907 : : * Update the estimate of distance between checkpoints.
6908 : : *
6909 : : * The estimate is used to calculate the number of WAL segments to keep
6910 : : * preallocated, see XLOGfileslop().
6911 : : */
6912 : : static void
6913 : 7 : UpdateCheckPointDistanceEstimate(uint64 nbytes)
6914 : : {
6915 : : /*
6916 : : * To estimate the number of segments consumed between checkpoints, keep a
6917 : : * moving average of the amount of WAL generated in previous checkpoint
6918 : : * cycles. However, if the load is bursty, with quiet periods and busy
6919 : : * periods, we want to cater for the peak load. So instead of a plain
6920 : : * moving average, let the average decline slowly if the previous cycle
6921 : : * used less WAL than estimated, but bump it up immediately if it used
6922 : : * more.
6923 : : *
6924 : : * When checkpoints are triggered by max_wal_size, this should converge to
6925 : : * CheckpointSegments * wal_segment_size,
6926 : : *
6927 : : * Note: This doesn't pay any attention to what caused the checkpoint.
6928 : : * Checkpoints triggered manually with CHECKPOINT command, or by e.g.
6929 : : * starting a base backup, are counted the same as those created
6930 : : * automatically. The slow-decline will largely mask them out, if they are
6931 : : * not frequent. If they are frequent, it seems reasonable to count them
6932 : : * in as any others; if you issue a manual checkpoint every 5 minutes and
6933 : : * never let a timed checkpoint happen, it makes sense to base the
6934 : : * preallocation on that 5 minute interval rather than whatever
6935 : : * checkpoint_timeout is set to.
6936 : : */
6937 : 7 : PrevCheckPointDistance = nbytes;
6938 [ + + ]: 7 : if (CheckPointDistanceEstimate < nbytes)
6939 : 3 : CheckPointDistanceEstimate = nbytes;
6940 : : else
6941 : 4 : CheckPointDistanceEstimate =
6942 : 4 : (0.90 * CheckPointDistanceEstimate + 0.10 * (double) nbytes);
6943 : 7 : }
6944 : :
6945 : : /*
6946 : : * Update the ps display for a process running a checkpoint. Note that
6947 : : * this routine should not do any allocations so as it can be called
6948 : : * from a critical section.
6949 : : */
6950 : : static void
6951 : 14 : update_checkpoint_display(int flags, bool restartpoint, bool reset)
6952 : : {
6953 : : /*
6954 : : * The status is reported only for end-of-recovery and shutdown
6955 : : * checkpoints or shutdown restartpoints. Updating the ps display is
6956 : : * useful in those situations as it may not be possible to rely on
6957 : : * pg_stat_activity to see the status of the checkpointer or the startup
6958 : : * process.
6959 : : */
6960 [ + + ]: 14 : if ((flags & (CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IS_SHUTDOWN)) == 0)
6961 : 8 : return;
6962 : :
6963 [ + + ]: 6 : if (reset)
6964 : 3 : set_ps_display("");
6965 : : else
6966 : : {
6967 : 3 : char activitymsg[128];
6968 : :
6969 : 6 : snprintf(activitymsg, sizeof(activitymsg), "performing %s%s%s",
6970 : 3 : (flags & CHECKPOINT_END_OF_RECOVERY) ? "end-of-recovery " : "",
6971 : 3 : (flags & CHECKPOINT_IS_SHUTDOWN) ? "shutdown " : "",
6972 : 3 : restartpoint ? "restartpoint" : "checkpoint");
6973 : 3 : set_ps_display(activitymsg);
6974 : 3 : }
6975 : 14 : }
6976 : :
6977 : :
6978 : : /*
6979 : : * Perform a checkpoint --- either during shutdown, or on-the-fly
6980 : : *
6981 : : * flags is a bitwise OR of the following:
6982 : : * CHECKPOINT_IS_SHUTDOWN: checkpoint is for database shutdown.
6983 : : * CHECKPOINT_END_OF_RECOVERY: checkpoint is for end of WAL recovery.
6984 : : * CHECKPOINT_FAST: finish the checkpoint ASAP, ignoring
6985 : : * checkpoint_completion_target parameter.
6986 : : * CHECKPOINT_FORCE: force a checkpoint even if no XLOG activity has occurred
6987 : : * since the last one (implied by CHECKPOINT_IS_SHUTDOWN or
6988 : : * CHECKPOINT_END_OF_RECOVERY).
6989 : : * CHECKPOINT_FLUSH_UNLOGGED: also flush buffers of unlogged tables.
6990 : : *
6991 : : * Note: flags contains other bits, of interest here only for logging purposes.
6992 : : * In particular note that this routine is synchronous and does not pay
6993 : : * attention to CHECKPOINT_WAIT.
6994 : : *
6995 : : * If !shutdown then we are writing an online checkpoint. An XLOG_CHECKPOINT_REDO
6996 : : * record is inserted into WAL at the logical location of the checkpoint, before
6997 : : * flushing anything to disk, and when the checkpoint is eventually completed,
6998 : : * and it is from this point that WAL replay will begin in the case of a recovery
6999 : : * from this checkpoint. Once everything is written to disk, an
7000 : : * XLOG_CHECKPOINT_ONLINE record is written to complete the checkpoint, and
7001 : : * points back to the earlier XLOG_CHECKPOINT_REDO record. This mechanism allows
7002 : : * other write-ahead log records to be written while the checkpoint is in
7003 : : * progress, but we must be very careful about order of operations. This function
7004 : : * may take many minutes to execute on a busy system.
7005 : : *
7006 : : * On the other hand, when shutdown is true, concurrent insertion into the
7007 : : * write-ahead log is impossible, so there is no need for two separate records.
7008 : : * In this case, we only insert an XLOG_CHECKPOINT_SHUTDOWN record, and it's
7009 : : * both the record marking the completion of the checkpoint and the location
7010 : : * from which WAL replay would begin if needed.
7011 : : *
7012 : : * Returns true if a new checkpoint was performed, or false if it was skipped
7013 : : * because the system was idle.
7014 : : */
7015 : : bool
7016 : 7 : CreateCheckPoint(int flags)
7017 : : {
7018 : 7 : bool shutdown;
7019 : 7 : CheckPoint checkPoint;
7020 : 7 : XLogRecPtr recptr;
7021 : 7 : XLogSegNo _logSegNo;
7022 : 7 : XLogCtlInsert *Insert = &XLogCtl->Insert;
7023 : 7 : uint32 freespace;
7024 : 7 : XLogRecPtr PriorRedoPtr;
7025 : 7 : XLogRecPtr last_important_lsn;
7026 : 7 : VirtualTransactionId *vxids;
7027 : 7 : int nvxids;
7028 : 7 : int oldXLogAllowed = 0;
7029 : :
7030 : : /*
7031 : : * An end-of-recovery checkpoint is really a shutdown checkpoint, just
7032 : : * issued at a different time.
7033 : : */
7034 [ + + ]: 7 : if (flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY))
7035 : 3 : shutdown = true;
7036 : : else
7037 : 4 : shutdown = false;
7038 : :
7039 : : /* sanity check */
7040 [ - + # # ]: 7 : if (RecoveryInProgress() && (flags & CHECKPOINT_END_OF_RECOVERY) == 0)
7041 [ # # # # ]: 0 : elog(ERROR, "can't create a checkpoint during recovery");
7042 : :
7043 : : /*
7044 : : * Prepare to accumulate statistics.
7045 : : *
7046 : : * Note: because it is possible for log_checkpoints to change while a
7047 : : * checkpoint proceeds, we always accumulate stats, even if
7048 : : * log_checkpoints is currently off.
7049 : : */
7050 [ + - + - : 77 : MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
+ - - + +
+ ]
7051 : 7 : CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
7052 : :
7053 : : /*
7054 : : * Let smgr prepare for checkpoint; this has to happen outside the
7055 : : * critical section and before we determine the REDO pointer. Note that
7056 : : * smgr must not do anything that'd have to be undone if we decide no
7057 : : * checkpoint is needed.
7058 : : */
7059 : 7 : SyncPreCheckpoint();
7060 : :
7061 : : /* Run these points outside the critical section. */
7062 : : INJECTION_POINT("create-checkpoint-initial", NULL);
7063 : : INJECTION_POINT_LOAD("create-checkpoint-run");
7064 : :
7065 : : /*
7066 : : * Use a critical section to force system panic if we have trouble.
7067 : : */
7068 : 7 : START_CRIT_SECTION();
7069 : :
7070 [ + + ]: 7 : if (shutdown)
7071 : : {
7072 : 3 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7073 : 3 : ControlFile->state = DB_SHUTDOWNING;
7074 : 3 : UpdateControlFile();
7075 : 3 : LWLockRelease(ControlFileLock);
7076 : 3 : }
7077 : :
7078 : : /* Begin filling in the checkpoint WAL record */
7079 [ + - + - : 91 : MemSet(&checkPoint, 0, sizeof(checkPoint));
+ - - + +
+ ]
7080 : 7 : checkPoint.time = (pg_time_t) time(NULL);
7081 : :
7082 : : /*
7083 : : * For Hot Standby, derive the oldestActiveXid before we fix the redo
7084 : : * pointer. This allows us to begin accumulating changes to assemble our
7085 : : * starting snapshot of locks and transactions.
7086 : : */
7087 [ + + - + ]: 7 : if (!shutdown && XLogStandbyInfoActive())
7088 : 4 : checkPoint.oldestActiveXid = GetOldestActiveTransactionId(false, true);
7089 : : else
7090 : 3 : checkPoint.oldestActiveXid = InvalidTransactionId;
7091 : :
7092 : : /*
7093 : : * Get location of last important record before acquiring insert locks (as
7094 : : * GetLastImportantRecPtr() also locks WAL locks).
7095 : : */
7096 : 7 : last_important_lsn = GetLastImportantRecPtr();
7097 : :
7098 : : /*
7099 : : * If this isn't a shutdown or forced checkpoint, and if there has been no
7100 : : * WAL activity requiring a checkpoint, skip it. The idea here is to
7101 : : * avoid inserting duplicate checkpoints when the system is idle.
7102 : : */
7103 : 7 : if ((flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY |
7104 [ + - ]: 7 : CHECKPOINT_FORCE)) == 0)
7105 : : {
7106 [ # # ]: 0 : if (last_important_lsn == ControlFile->checkPoint)
7107 : : {
7108 [ # # ]: 0 : END_CRIT_SECTION();
7109 [ # # # # ]: 0 : ereport(DEBUG1,
7110 : : (errmsg_internal("checkpoint skipped because system is idle")));
7111 : 0 : return false;
7112 : : }
7113 : 0 : }
7114 : :
7115 : : /*
7116 : : * An end-of-recovery checkpoint is created before anyone is allowed to
7117 : : * write WAL. To allow us to write the checkpoint record, temporarily
7118 : : * enable XLogInsertAllowed.
7119 : : */
7120 [ + - ]: 7 : if (flags & CHECKPOINT_END_OF_RECOVERY)
7121 : 0 : oldXLogAllowed = LocalSetXLogInsertAllowed();
7122 : :
7123 : 7 : checkPoint.ThisTimeLineID = XLogCtl->InsertTimeLineID;
7124 [ - + ]: 7 : if (flags & CHECKPOINT_END_OF_RECOVERY)
7125 : 0 : checkPoint.PrevTimeLineID = XLogCtl->PrevTimeLineID;
7126 : : else
7127 : 7 : checkPoint.PrevTimeLineID = checkPoint.ThisTimeLineID;
7128 : :
7129 : : /*
7130 : : * We must block concurrent insertions while examining insert state.
7131 : : */
7132 : 7 : WALInsertLockAcquireExclusive();
7133 : :
7134 : 7 : checkPoint.fullPageWrites = Insert->fullPageWrites;
7135 : 7 : checkPoint.wal_level = wal_level;
7136 : :
7137 [ + + ]: 7 : if (shutdown)
7138 : : {
7139 : 3 : XLogRecPtr curInsert = XLogBytePosToRecPtr(Insert->CurrBytePos);
7140 : :
7141 : : /*
7142 : : * Compute new REDO record ptr = location of next XLOG record.
7143 : : *
7144 : : * Since this is a shutdown checkpoint, there can't be any concurrent
7145 : : * WAL insertion.
7146 : : */
7147 [ + - ]: 3 : freespace = INSERT_FREESPACE(curInsert);
7148 [ + - ]: 3 : if (freespace == 0)
7149 : : {
7150 [ # # ]: 0 : if (XLogSegmentOffset(curInsert, wal_segment_size) == 0)
7151 : 0 : curInsert += SizeOfXLogLongPHD;
7152 : : else
7153 : 0 : curInsert += SizeOfXLogShortPHD;
7154 : 0 : }
7155 : 3 : checkPoint.redo = curInsert;
7156 : :
7157 : : /*
7158 : : * Here we update the shared RedoRecPtr for future XLogInsert calls;
7159 : : * this must be done while holding all the insertion locks.
7160 : : *
7161 : : * Note: if we fail to complete the checkpoint, RedoRecPtr will be
7162 : : * left pointing past where it really needs to point. This is okay;
7163 : : * the only consequence is that XLogInsert might back up whole buffers
7164 : : * that it didn't really need to. We can't postpone advancing
7165 : : * RedoRecPtr because XLogInserts that happen while we are dumping
7166 : : * buffers must assume that their buffer changes are not included in
7167 : : * the checkpoint.
7168 : : */
7169 : 3 : RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
7170 : 3 : }
7171 : :
7172 : : /*
7173 : : * Now we can release the WAL insertion locks, allowing other xacts to
7174 : : * proceed while we are flushing disk buffers.
7175 : : */
7176 : 7 : WALInsertLockRelease();
7177 : :
7178 : : /*
7179 : : * If this is an online checkpoint, we have not yet determined the redo
7180 : : * point. We do so now by inserting the special XLOG_CHECKPOINT_REDO
7181 : : * record; the LSN at which it starts becomes the new redo pointer. We
7182 : : * don't do this for a shutdown checkpoint, because in that case no WAL
7183 : : * can be written between the redo point and the insertion of the
7184 : : * checkpoint record itself, so the checkpoint record itself serves to
7185 : : * mark the redo point.
7186 : : */
7187 [ + + ]: 7 : if (!shutdown)
7188 : : {
7189 : : /* Include WAL level in record for WAL summarizer's benefit. */
7190 : 4 : XLogBeginInsert();
7191 : 4 : XLogRegisterData(&wal_level, sizeof(wal_level));
7192 : 4 : (void) XLogInsert(RM_XLOG_ID, XLOG_CHECKPOINT_REDO);
7193 : :
7194 : : /*
7195 : : * XLogInsertRecord will have updated XLogCtl->Insert.RedoRecPtr in
7196 : : * shared memory and RedoRecPtr in backend-local memory, but we need
7197 : : * to copy that into the record that will be inserted when the
7198 : : * checkpoint is complete.
7199 : : */
7200 : 4 : checkPoint.redo = RedoRecPtr;
7201 : 4 : }
7202 : :
7203 : : /* Update the info_lck-protected copy of RedoRecPtr as well */
7204 [ - + ]: 7 : SpinLockAcquire(&XLogCtl->info_lck);
7205 : 7 : XLogCtl->RedoRecPtr = checkPoint.redo;
7206 : 7 : SpinLockRelease(&XLogCtl->info_lck);
7207 : :
7208 : : /*
7209 : : * If enabled, log checkpoint start. We postpone this until now so as not
7210 : : * to log anything if we decided to skip the checkpoint.
7211 : : */
7212 [ + + ]: 7 : if (log_checkpoints)
7213 : 1 : LogCheckpointStart(flags, false);
7214 : :
7215 : : INJECTION_POINT_CACHED("create-checkpoint-run", NULL);
7216 : :
7217 : : /* Update the process title */
7218 : 7 : update_checkpoint_display(flags, false, false);
7219 : :
7220 : 7 : TRACE_POSTGRESQL_CHECKPOINT_START(flags);
7221 : :
7222 : : /*
7223 : : * Get the other info we need for the checkpoint record.
7224 : : *
7225 : : * We don't need to save oldestClogXid in the checkpoint, it only matters
7226 : : * for the short period in which clog is being truncated, and if we crash
7227 : : * during that we'll redo the clog truncation and fix up oldestClogXid
7228 : : * there.
7229 : : */
7230 : 7 : LWLockAcquire(XidGenLock, LW_SHARED);
7231 : 7 : checkPoint.nextXid = TransamVariables->nextXid;
7232 : 7 : checkPoint.oldestXid = TransamVariables->oldestXid;
7233 : 7 : checkPoint.oldestXidDB = TransamVariables->oldestXidDB;
7234 : 7 : LWLockRelease(XidGenLock);
7235 : :
7236 : 7 : LWLockAcquire(CommitTsLock, LW_SHARED);
7237 : 7 : checkPoint.oldestCommitTsXid = TransamVariables->oldestCommitTsXid;
7238 : 7 : checkPoint.newestCommitTsXid = TransamVariables->newestCommitTsXid;
7239 : 7 : LWLockRelease(CommitTsLock);
7240 : :
7241 : 7 : LWLockAcquire(OidGenLock, LW_SHARED);
7242 : 7 : checkPoint.nextOid = TransamVariables->nextOid;
7243 [ + + ]: 7 : if (!shutdown)
7244 : 4 : checkPoint.nextOid += TransamVariables->oidCount;
7245 : 7 : LWLockRelease(OidGenLock);
7246 : :
7247 : 7 : checkPoint.logicalDecodingEnabled = IsLogicalDecodingEnabled();
7248 : :
7249 : 14 : MultiXactGetCheckptMulti(shutdown,
7250 : 7 : &checkPoint.nextMulti,
7251 : 7 : &checkPoint.nextMultiOffset,
7252 : 7 : &checkPoint.oldestMulti,
7253 : 7 : &checkPoint.oldestMultiDB);
7254 : :
7255 : : /*
7256 : : * Having constructed the checkpoint record, ensure all shmem disk buffers
7257 : : * and commit-log buffers are flushed to disk.
7258 : : *
7259 : : * This I/O could fail for various reasons. If so, we will fail to
7260 : : * complete the checkpoint, but there is no reason to force a system
7261 : : * panic. Accordingly, exit critical section while doing it.
7262 : : */
7263 [ + - ]: 7 : END_CRIT_SECTION();
7264 : :
7265 : : /*
7266 : : * In some cases there are groups of actions that must all occur on one
7267 : : * side or the other of a checkpoint record. Before flushing the
7268 : : * checkpoint record we must explicitly wait for any backend currently
7269 : : * performing those groups of actions.
7270 : : *
7271 : : * One example is end of transaction, so we must wait for any transactions
7272 : : * that are currently in commit critical sections. If an xact inserted
7273 : : * its commit record into XLOG just before the REDO point, then a crash
7274 : : * restart from the REDO point would not replay that record, which means
7275 : : * that our flushing had better include the xact's update of pg_xact. So
7276 : : * we wait till he's out of his commit critical section before proceeding.
7277 : : * See notes in RecordTransactionCommit().
7278 : : *
7279 : : * Because we've already released the insertion locks, this test is a bit
7280 : : * fuzzy: it is possible that we will wait for xacts we didn't really need
7281 : : * to wait for. But the delay should be short and it seems better to make
7282 : : * checkpoint take a bit longer than to hold off insertions longer than
7283 : : * necessary. (In fact, the whole reason we have this issue is that xact.c
7284 : : * does commit record XLOG insertion and clog update as two separate steps
7285 : : * protected by different locks, but again that seems best on grounds of
7286 : : * minimizing lock contention.)
7287 : : *
7288 : : * A transaction that has not yet set delayChkptFlags when we look cannot
7289 : : * be at risk, since it has not inserted its commit record yet; and one
7290 : : * that's already cleared it is not at risk either, since it's done fixing
7291 : : * clog and we will correctly flush the update below. So we cannot miss
7292 : : * any xacts we need to wait for.
7293 : : */
7294 : 7 : vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
7295 [ - + ]: 7 : if (nvxids > 0)
7296 : : {
7297 : 0 : do
7298 : : {
7299 : : /*
7300 : : * Keep absorbing fsync requests while we wait. There could even
7301 : : * be a deadlock if we don't, if the process that prevents the
7302 : : * checkpoint is trying to add a request to the queue.
7303 : : */
7304 : 0 : AbsorbSyncRequests();
7305 : :
7306 : 0 : pgstat_report_wait_start(WAIT_EVENT_CHECKPOINT_DELAY_START);
7307 : 0 : pg_usleep(10000L); /* wait for 10 msec */
7308 : 0 : pgstat_report_wait_end();
7309 [ # # ]: 0 : } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
7310 : : DELAY_CHKPT_START));
7311 : 0 : }
7312 : 7 : pfree(vxids);
7313 : :
7314 : 7 : CheckPointGuts(checkPoint.redo, flags);
7315 : :
7316 : 7 : vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
7317 [ - + ]: 7 : if (nvxids > 0)
7318 : : {
7319 : 0 : do
7320 : : {
7321 : 0 : AbsorbSyncRequests();
7322 : :
7323 : 0 : pgstat_report_wait_start(WAIT_EVENT_CHECKPOINT_DELAY_COMPLETE);
7324 : 0 : pg_usleep(10000L); /* wait for 10 msec */
7325 : 0 : pgstat_report_wait_end();
7326 [ # # ]: 0 : } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
7327 : : DELAY_CHKPT_COMPLETE));
7328 : 0 : }
7329 : 7 : pfree(vxids);
7330 : :
7331 : : /*
7332 : : * Take a snapshot of running transactions and write this to WAL. This
7333 : : * allows us to reconstruct the state of running transactions during
7334 : : * archive recovery, if required. Skip, if this info disabled.
7335 : : *
7336 : : * If we are shutting down, or Startup process is completing crash
7337 : : * recovery we don't need to write running xact data.
7338 : : */
7339 [ + + - + ]: 7 : if (!shutdown && XLogStandbyInfoActive())
7340 : 4 : LogStandbySnapshot();
7341 : :
7342 : 7 : START_CRIT_SECTION();
7343 : :
7344 : : /*
7345 : : * Now insert the checkpoint record into XLOG.
7346 : : */
7347 : 7 : XLogBeginInsert();
7348 : 7 : XLogRegisterData(&checkPoint, sizeof(checkPoint));
7349 : 7 : recptr = XLogInsert(RM_XLOG_ID,
7350 : 7 : shutdown ? XLOG_CHECKPOINT_SHUTDOWN :
7351 : : XLOG_CHECKPOINT_ONLINE);
7352 : :
7353 : 7 : XLogFlush(recptr);
7354 : :
7355 : : /*
7356 : : * We mustn't write any new WAL after a shutdown checkpoint, or it will be
7357 : : * overwritten at next startup. No-one should even try, this just allows
7358 : : * sanity-checking. In the case of an end-of-recovery checkpoint, we want
7359 : : * to just temporarily disable writing until the system has exited
7360 : : * recovery.
7361 : : */
7362 [ + + ]: 7 : if (shutdown)
7363 : : {
7364 [ - + ]: 3 : if (flags & CHECKPOINT_END_OF_RECOVERY)
7365 : 0 : LocalXLogInsertAllowed = oldXLogAllowed;
7366 : : else
7367 : 3 : LocalXLogInsertAllowed = 0; /* never again write WAL */
7368 : 3 : }
7369 : :
7370 : : /*
7371 : : * We now have ProcLastRecPtr = start of actual checkpoint record, recptr
7372 : : * = end of actual checkpoint record.
7373 : : */
7374 [ + + + - ]: 7 : if (shutdown && checkPoint.redo != ProcLastRecPtr)
7375 [ # # # # ]: 0 : ereport(PANIC,
7376 : : (errmsg("concurrent write-ahead log activity while database system is shutting down")));
7377 : :
7378 : : /*
7379 : : * Remember the prior checkpoint's redo ptr for
7380 : : * UpdateCheckPointDistanceEstimate()
7381 : : */
7382 : 7 : PriorRedoPtr = ControlFile->checkPointCopy.redo;
7383 : :
7384 : : /*
7385 : : * Update the control file.
7386 : : */
7387 : 7 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7388 [ + + ]: 7 : if (shutdown)
7389 : 3 : ControlFile->state = DB_SHUTDOWNED;
7390 : 7 : ControlFile->checkPoint = ProcLastRecPtr;
7391 : 7 : ControlFile->checkPointCopy = checkPoint;
7392 : : /* crash recovery should always recover to the end of WAL */
7393 : 7 : ControlFile->minRecoveryPoint = InvalidXLogRecPtr;
7394 : 7 : ControlFile->minRecoveryPointTLI = 0;
7395 : :
7396 : : /*
7397 : : * Persist unloggedLSN value. It's reset on crash recovery, so this goes
7398 : : * unused on non-shutdown checkpoints, but seems useful to store it always
7399 : : * for debugging purposes.
7400 : : */
7401 : 7 : ControlFile->unloggedLSN = pg_atomic_read_membarrier_u64(&XLogCtl->unloggedLSN);
7402 : :
7403 : 7 : UpdateControlFile();
7404 : 7 : LWLockRelease(ControlFileLock);
7405 : :
7406 : : /*
7407 : : * We are now done with critical updates; no need for system panic if we
7408 : : * have trouble while fooling with old log segments.
7409 : : */
7410 [ + - ]: 7 : END_CRIT_SECTION();
7411 : :
7412 : : /*
7413 : : * WAL summaries end when the next XLOG_CHECKPOINT_REDO or
7414 : : * XLOG_CHECKPOINT_SHUTDOWN record is reached. This is the first point
7415 : : * where (a) we're not inside of a critical section and (b) we can be
7416 : : * certain that the relevant record has been flushed to disk, which must
7417 : : * happen before it can be summarized.
7418 : : *
7419 : : * If this is a shutdown checkpoint, then this happens reasonably
7420 : : * promptly: we've only just inserted and flushed the
7421 : : * XLOG_CHECKPOINT_SHUTDOWN record. If this is not a shutdown checkpoint,
7422 : : * then this might not be very prompt at all: the XLOG_CHECKPOINT_REDO
7423 : : * record was written before we began flushing data to disk, and that
7424 : : * could be many minutes ago at this point. However, we don't XLogFlush()
7425 : : * after inserting that record, so we're not guaranteed that it's on disk
7426 : : * until after the above call that flushes the XLOG_CHECKPOINT_ONLINE
7427 : : * record.
7428 : : */
7429 : 7 : WakeupWalSummarizer();
7430 : :
7431 : : /*
7432 : : * Let smgr do post-checkpoint cleanup (eg, deleting old files).
7433 : : */
7434 : 7 : SyncPostCheckpoint();
7435 : :
7436 : : /*
7437 : : * Update the average distance between checkpoints if the prior checkpoint
7438 : : * exists.
7439 : : */
7440 [ - + ]: 7 : if (XLogRecPtrIsValid(PriorRedoPtr))
7441 : 7 : UpdateCheckPointDistanceEstimate(RedoRecPtr - PriorRedoPtr);
7442 : :
7443 : : INJECTION_POINT("checkpoint-before-old-wal-removal", NULL);
7444 : :
7445 : : /*
7446 : : * Delete old log files, those no longer needed for last checkpoint to
7447 : : * prevent the disk holding the xlog from growing full.
7448 : : */
7449 : 7 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
7450 : 7 : KeepLogSeg(recptr, &_logSegNo);
7451 [ + - ]: 7 : if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED | RS_INVAL_IDLE_TIMEOUT,
7452 : 7 : _logSegNo, InvalidOid,
7453 : : InvalidTransactionId))
7454 : : {
7455 : : /*
7456 : : * Some slots have been invalidated; recalculate the old-segment
7457 : : * horizon, starting again from RedoRecPtr.
7458 : : */
7459 : 0 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
7460 : 0 : KeepLogSeg(recptr, &_logSegNo);
7461 : 0 : }
7462 : 7 : _logSegNo--;
7463 : 14 : RemoveOldXlogFiles(_logSegNo, RedoRecPtr, recptr,
7464 : 7 : checkPoint.ThisTimeLineID);
7465 : :
7466 : : /*
7467 : : * Make more log segments if needed. (Do this after recycling old log
7468 : : * segments, since that may supply some of the needed files.)
7469 : : */
7470 [ + + ]: 7 : if (!shutdown)
7471 : 4 : PreallocXlogFiles(recptr, checkPoint.ThisTimeLineID);
7472 : :
7473 : : /*
7474 : : * Truncate pg_subtrans if possible. We can throw away all data before
7475 : : * the oldest XMIN of any running transaction. No future transaction will
7476 : : * attempt to reference any pg_subtrans entry older than that (see Asserts
7477 : : * in subtrans.c). During recovery, though, we mustn't do this because
7478 : : * StartupSUBTRANS hasn't been called yet.
7479 : : */
7480 [ - + ]: 7 : if (!RecoveryInProgress())
7481 : 7 : TruncateSUBTRANS(GetOldestTransactionIdConsideredRunning());
7482 : :
7483 : : /* Real work is done; log and update stats. */
7484 : 7 : LogCheckpointEnd(false);
7485 : :
7486 : : /* Reset the process title */
7487 : 7 : update_checkpoint_display(flags, false, true);
7488 : :
7489 : 7 : TRACE_POSTGRESQL_CHECKPOINT_DONE(CheckpointStats.ckpt_bufs_written,
7490 : : NBuffers,
7491 : : CheckpointStats.ckpt_segs_added,
7492 : : CheckpointStats.ckpt_segs_removed,
7493 : : CheckpointStats.ckpt_segs_recycled);
7494 : :
7495 : 7 : return true;
7496 : 7 : }
7497 : :
7498 : : /*
7499 : : * Mark the end of recovery in WAL though without running a full checkpoint.
7500 : : * We can expect that a restartpoint is likely to be in progress as we
7501 : : * do this, though we are unwilling to wait for it to complete.
7502 : : *
7503 : : * CreateRestartPoint() allows for the case where recovery may end before
7504 : : * the restartpoint completes so there is no concern of concurrent behaviour.
7505 : : */
7506 : : static void
7507 : 0 : CreateEndOfRecoveryRecord(void)
7508 : : {
7509 : 0 : xl_end_of_recovery xlrec;
7510 : 0 : XLogRecPtr recptr;
7511 : :
7512 : : /* sanity check */
7513 [ # # ]: 0 : if (!RecoveryInProgress())
7514 [ # # # # ]: 0 : elog(ERROR, "can only be used to end recovery");
7515 : :
7516 : 0 : xlrec.end_time = GetCurrentTimestamp();
7517 : 0 : xlrec.wal_level = wal_level;
7518 : :
7519 : 0 : WALInsertLockAcquireExclusive();
7520 : 0 : xlrec.ThisTimeLineID = XLogCtl->InsertTimeLineID;
7521 : 0 : xlrec.PrevTimeLineID = XLogCtl->PrevTimeLineID;
7522 : 0 : WALInsertLockRelease();
7523 : :
7524 : 0 : START_CRIT_SECTION();
7525 : :
7526 : 0 : XLogBeginInsert();
7527 : 0 : XLogRegisterData(&xlrec, sizeof(xl_end_of_recovery));
7528 : 0 : recptr = XLogInsert(RM_XLOG_ID, XLOG_END_OF_RECOVERY);
7529 : :
7530 : 0 : XLogFlush(recptr);
7531 : :
7532 : : /*
7533 : : * Update the control file so that crash recovery can follow the timeline
7534 : : * changes to this point.
7535 : : */
7536 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7537 : 0 : ControlFile->minRecoveryPoint = recptr;
7538 : 0 : ControlFile->minRecoveryPointTLI = xlrec.ThisTimeLineID;
7539 : 0 : UpdateControlFile();
7540 : 0 : LWLockRelease(ControlFileLock);
7541 : :
7542 [ # # ]: 0 : END_CRIT_SECTION();
7543 : 0 : }
7544 : :
7545 : : /*
7546 : : * Write an OVERWRITE_CONTRECORD message.
7547 : : *
7548 : : * When on WAL replay we expect a continuation record at the start of a page
7549 : : * that is not there, recovery ends and WAL writing resumes at that point.
7550 : : * But it's wrong to resume writing new WAL back at the start of the record
7551 : : * that was broken, because downstream consumers of that WAL (physical
7552 : : * replicas) are not prepared to "rewind". So the first action after
7553 : : * finishing replay of all valid WAL must be to write a record of this type
7554 : : * at the point where the contrecord was missing; to support xlogreader
7555 : : * detecting the special case, XLP_FIRST_IS_OVERWRITE_CONTRECORD is also added
7556 : : * to the page header where the record occurs. xlogreader has an ad-hoc
7557 : : * mechanism to report metadata about the broken record, which is what we
7558 : : * use here.
7559 : : *
7560 : : * At replay time, XLP_FIRST_IS_OVERWRITE_CONTRECORD instructs xlogreader to
7561 : : * skip the record it was reading, and pass back the LSN of the skipped
7562 : : * record, so that its caller can verify (on "replay" of that record) that the
7563 : : * XLOG_OVERWRITE_CONTRECORD matches what was effectively overwritten.
7564 : : *
7565 : : * 'aborted_lsn' is the beginning position of the record that was incomplete.
7566 : : * It is included in the WAL record. 'pagePtr' and 'newTLI' point to the
7567 : : * beginning of the XLOG page where the record is to be inserted. They must
7568 : : * match the current WAL insert position, they're passed here just so that we
7569 : : * can verify that.
7570 : : */
7571 : : static XLogRecPtr
7572 : 0 : CreateOverwriteContrecordRecord(XLogRecPtr aborted_lsn, XLogRecPtr pagePtr,
7573 : : TimeLineID newTLI)
7574 : : {
7575 : 0 : xl_overwrite_contrecord xlrec;
7576 : 0 : XLogRecPtr recptr;
7577 : 0 : XLogPageHeader pagehdr;
7578 : 0 : XLogRecPtr startPos;
7579 : :
7580 : : /* sanity checks */
7581 [ # # ]: 0 : if (!RecoveryInProgress())
7582 [ # # # # ]: 0 : elog(ERROR, "can only be used at end of recovery");
7583 [ # # ]: 0 : if (pagePtr % XLOG_BLCKSZ != 0)
7584 [ # # # # ]: 0 : elog(ERROR, "invalid position for missing continuation record %X/%08X",
7585 : : LSN_FORMAT_ARGS(pagePtr));
7586 : :
7587 : : /* The current WAL insert position should be right after the page header */
7588 : 0 : startPos = pagePtr;
7589 [ # # ]: 0 : if (XLogSegmentOffset(startPos, wal_segment_size) == 0)
7590 : 0 : startPos += SizeOfXLogLongPHD;
7591 : : else
7592 : 0 : startPos += SizeOfXLogShortPHD;
7593 : 0 : recptr = GetXLogInsertRecPtr();
7594 [ # # ]: 0 : if (recptr != startPos)
7595 [ # # # # ]: 0 : elog(ERROR, "invalid WAL insert position %X/%08X for OVERWRITE_CONTRECORD",
7596 : : LSN_FORMAT_ARGS(recptr));
7597 : :
7598 : 0 : START_CRIT_SECTION();
7599 : :
7600 : : /*
7601 : : * Initialize the XLOG page header (by GetXLogBuffer), and set the
7602 : : * XLP_FIRST_IS_OVERWRITE_CONTRECORD flag.
7603 : : *
7604 : : * No other backend is allowed to write WAL yet, so acquiring the WAL
7605 : : * insertion lock is just pro forma.
7606 : : */
7607 : 0 : WALInsertLockAcquire();
7608 : 0 : pagehdr = (XLogPageHeader) GetXLogBuffer(pagePtr, newTLI);
7609 : 0 : pagehdr->xlp_info |= XLP_FIRST_IS_OVERWRITE_CONTRECORD;
7610 : 0 : WALInsertLockRelease();
7611 : :
7612 : : /*
7613 : : * Insert the XLOG_OVERWRITE_CONTRECORD record as the first record on the
7614 : : * page. We know it becomes the first record, because no other backend is
7615 : : * allowed to write WAL yet.
7616 : : */
7617 : 0 : XLogBeginInsert();
7618 : 0 : xlrec.overwritten_lsn = aborted_lsn;
7619 : 0 : xlrec.overwrite_time = GetCurrentTimestamp();
7620 : 0 : XLogRegisterData(&xlrec, sizeof(xl_overwrite_contrecord));
7621 : 0 : recptr = XLogInsert(RM_XLOG_ID, XLOG_OVERWRITE_CONTRECORD);
7622 : :
7623 : : /* check that the record was inserted to the right place */
7624 [ # # ]: 0 : if (ProcLastRecPtr != startPos)
7625 [ # # # # ]: 0 : elog(ERROR, "OVERWRITE_CONTRECORD was inserted to unexpected position %X/%08X",
7626 : : LSN_FORMAT_ARGS(ProcLastRecPtr));
7627 : :
7628 : 0 : XLogFlush(recptr);
7629 : :
7630 [ # # ]: 0 : END_CRIT_SECTION();
7631 : :
7632 : 0 : return recptr;
7633 : 0 : }
7634 : :
7635 : : /*
7636 : : * Flush all data in shared memory to disk, and fsync
7637 : : *
7638 : : * This is the common code shared between regular checkpoints and
7639 : : * recovery restartpoints.
7640 : : */
7641 : : static void
7642 : 7 : CheckPointGuts(XLogRecPtr checkPointRedo, int flags)
7643 : : {
7644 : 7 : CheckPointRelationMap();
7645 : 7 : CheckPointReplicationSlots(flags & CHECKPOINT_IS_SHUTDOWN);
7646 : 7 : CheckPointSnapBuild();
7647 : 7 : CheckPointLogicalRewriteHeap();
7648 : 7 : CheckPointReplicationOrigin();
7649 : :
7650 : : /* Write out all dirty data in SLRUs and the main buffer pool */
7651 : 7 : TRACE_POSTGRESQL_BUFFER_CHECKPOINT_START(flags);
7652 : 7 : CheckpointStats.ckpt_write_t = GetCurrentTimestamp();
7653 : 7 : CheckPointCLOG();
7654 : 7 : CheckPointCommitTs();
7655 : 7 : CheckPointSUBTRANS();
7656 : 7 : CheckPointMultiXact();
7657 : 7 : CheckPointPredicate();
7658 : 7 : CheckPointBuffers(flags);
7659 : :
7660 : : /* Perform all queued up fsyncs */
7661 : 7 : TRACE_POSTGRESQL_BUFFER_CHECKPOINT_SYNC_START();
7662 : 7 : CheckpointStats.ckpt_sync_t = GetCurrentTimestamp();
7663 : 7 : ProcessSyncRequests();
7664 : 7 : CheckpointStats.ckpt_sync_end_t = GetCurrentTimestamp();
7665 : 7 : TRACE_POSTGRESQL_BUFFER_CHECKPOINT_DONE();
7666 : :
7667 : : /* We deliberately delay 2PC checkpointing as long as possible */
7668 : 7 : CheckPointTwoPhase(checkPointRedo);
7669 : 7 : }
7670 : :
7671 : : /*
7672 : : * Save a checkpoint for recovery restart if appropriate
7673 : : *
7674 : : * This function is called each time a checkpoint record is read from XLOG.
7675 : : * It must determine whether the checkpoint represents a safe restartpoint or
7676 : : * not. If so, the checkpoint record is stashed in shared memory so that
7677 : : * CreateRestartPoint can consult it. (Note that the latter function is
7678 : : * executed by the checkpointer, while this one will be executed by the
7679 : : * startup process.)
7680 : : */
7681 : : static void
7682 : 0 : RecoveryRestartPoint(const CheckPoint *checkPoint, XLogReaderState *record)
7683 : : {
7684 : : /*
7685 : : * Also refrain from creating a restartpoint if we have seen any
7686 : : * references to non-existent pages. Restarting recovery from the
7687 : : * restartpoint would not see the references, so we would lose the
7688 : : * cross-check that the pages belonged to a relation that was dropped
7689 : : * later.
7690 : : */
7691 [ # # ]: 0 : if (XLogHaveInvalidPages())
7692 : : {
7693 [ # # # # ]: 0 : elog(DEBUG2,
7694 : : "could not record restart point at %X/%08X because there are unresolved references to invalid pages",
7695 : : LSN_FORMAT_ARGS(checkPoint->redo));
7696 : 0 : return;
7697 : : }
7698 : :
7699 : : /*
7700 : : * Copy the checkpoint record to shared memory, so that checkpointer can
7701 : : * work out the next time it wants to perform a restartpoint.
7702 : : */
7703 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
7704 : 0 : XLogCtl->lastCheckPointRecPtr = record->ReadRecPtr;
7705 : 0 : XLogCtl->lastCheckPointEndPtr = record->EndRecPtr;
7706 : 0 : XLogCtl->lastCheckPoint = *checkPoint;
7707 : 0 : SpinLockRelease(&XLogCtl->info_lck);
7708 : 0 : }
7709 : :
7710 : : /*
7711 : : * Establish a restartpoint if possible.
7712 : : *
7713 : : * This is similar to CreateCheckPoint, but is used during WAL recovery
7714 : : * to establish a point from which recovery can roll forward without
7715 : : * replaying the entire recovery log.
7716 : : *
7717 : : * Returns true if a new restartpoint was established. We can only establish
7718 : : * a restartpoint if we have replayed a safe checkpoint record since last
7719 : : * restartpoint.
7720 : : */
7721 : : bool
7722 : 0 : CreateRestartPoint(int flags)
7723 : : {
7724 : 0 : XLogRecPtr lastCheckPointRecPtr;
7725 : 0 : XLogRecPtr lastCheckPointEndPtr;
7726 : 0 : CheckPoint lastCheckPoint;
7727 : 0 : XLogRecPtr PriorRedoPtr;
7728 : 0 : XLogRecPtr receivePtr;
7729 : 0 : XLogRecPtr replayPtr;
7730 : 0 : TimeLineID replayTLI;
7731 : 0 : XLogRecPtr endptr;
7732 : 0 : XLogSegNo _logSegNo;
7733 : 0 : TimestampTz xtime;
7734 : :
7735 : : /* Concurrent checkpoint/restartpoint cannot happen */
7736 [ # # # # ]: 0 : Assert(!IsUnderPostmaster || MyBackendType == B_CHECKPOINTER);
7737 : :
7738 : : /* Get a local copy of the last safe checkpoint record. */
7739 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
7740 : 0 : lastCheckPointRecPtr = XLogCtl->lastCheckPointRecPtr;
7741 : 0 : lastCheckPointEndPtr = XLogCtl->lastCheckPointEndPtr;
7742 : 0 : lastCheckPoint = XLogCtl->lastCheckPoint;
7743 : 0 : SpinLockRelease(&XLogCtl->info_lck);
7744 : :
7745 : : /*
7746 : : * Check that we're still in recovery mode. It's ok if we exit recovery
7747 : : * mode after this check, the restart point is valid anyway.
7748 : : */
7749 [ # # ]: 0 : if (!RecoveryInProgress())
7750 : : {
7751 [ # # # # ]: 0 : ereport(DEBUG2,
7752 : : (errmsg_internal("skipping restartpoint, recovery has already ended")));
7753 : 0 : return false;
7754 : : }
7755 : :
7756 : : /*
7757 : : * If the last checkpoint record we've replayed is already our last
7758 : : * restartpoint, we can't perform a new restart point. We still update
7759 : : * minRecoveryPoint in that case, so that if this is a shutdown restart
7760 : : * point, we won't start up earlier than before. That's not strictly
7761 : : * necessary, but when hot standby is enabled, it would be rather weird if
7762 : : * the database opened up for read-only connections at a point-in-time
7763 : : * before the last shutdown. Such time travel is still possible in case of
7764 : : * immediate shutdown, though.
7765 : : *
7766 : : * We don't explicitly advance minRecoveryPoint when we do create a
7767 : : * restartpoint. It's assumed that flushing the buffers will do that as a
7768 : : * side-effect.
7769 : : */
7770 [ # # # # ]: 0 : if (!XLogRecPtrIsValid(lastCheckPointRecPtr) ||
7771 : 0 : lastCheckPoint.redo <= ControlFile->checkPointCopy.redo)
7772 : : {
7773 [ # # # # ]: 0 : ereport(DEBUG2,
7774 : : errmsg_internal("skipping restartpoint, already performed at %X/%08X",
7775 : : LSN_FORMAT_ARGS(lastCheckPoint.redo)));
7776 : :
7777 : 0 : UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
7778 [ # # ]: 0 : if (flags & CHECKPOINT_IS_SHUTDOWN)
7779 : : {
7780 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7781 : 0 : ControlFile->state = DB_SHUTDOWNED_IN_RECOVERY;
7782 : 0 : UpdateControlFile();
7783 : 0 : LWLockRelease(ControlFileLock);
7784 : 0 : }
7785 : 0 : return false;
7786 : : }
7787 : :
7788 : : /*
7789 : : * Update the shared RedoRecPtr so that the startup process can calculate
7790 : : * the number of segments replayed since last restartpoint, and request a
7791 : : * restartpoint if it exceeds CheckPointSegments.
7792 : : *
7793 : : * Like in CreateCheckPoint(), hold off insertions to update it, although
7794 : : * during recovery this is just pro forma, because no WAL insertions are
7795 : : * happening.
7796 : : */
7797 : 0 : WALInsertLockAcquireExclusive();
7798 : 0 : RedoRecPtr = XLogCtl->Insert.RedoRecPtr = lastCheckPoint.redo;
7799 : 0 : WALInsertLockRelease();
7800 : :
7801 : : /* Also update the info_lck-protected copy */
7802 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
7803 : 0 : XLogCtl->RedoRecPtr = lastCheckPoint.redo;
7804 : 0 : SpinLockRelease(&XLogCtl->info_lck);
7805 : :
7806 : : /*
7807 : : * Prepare to accumulate statistics.
7808 : : *
7809 : : * Note: because it is possible for log_checkpoints to change while a
7810 : : * checkpoint proceeds, we always accumulate stats, even if
7811 : : * log_checkpoints is currently off.
7812 : : */
7813 [ # # # # : 0 : MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
# # # # #
# ]
7814 : 0 : CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
7815 : :
7816 [ # # ]: 0 : if (log_checkpoints)
7817 : 0 : LogCheckpointStart(flags, true);
7818 : :
7819 : : /* Update the process title */
7820 : 0 : update_checkpoint_display(flags, true, false);
7821 : :
7822 : 0 : CheckPointGuts(lastCheckPoint.redo, flags);
7823 : :
7824 : : /*
7825 : : * This location needs to be after CheckPointGuts() to ensure that some
7826 : : * work has already happened during this checkpoint.
7827 : : */
7828 : : INJECTION_POINT("create-restart-point", NULL);
7829 : :
7830 : : /*
7831 : : * Remember the prior checkpoint's redo ptr for
7832 : : * UpdateCheckPointDistanceEstimate()
7833 : : */
7834 : 0 : PriorRedoPtr = ControlFile->checkPointCopy.redo;
7835 : :
7836 : : /*
7837 : : * Update pg_control, using current time. Check that it still shows an
7838 : : * older checkpoint, else do nothing; this is a quick hack to make sure
7839 : : * nothing really bad happens if somehow we get here after the
7840 : : * end-of-recovery checkpoint.
7841 : : */
7842 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7843 [ # # ]: 0 : if (ControlFile->checkPointCopy.redo < lastCheckPoint.redo)
7844 : : {
7845 : : /*
7846 : : * Update the checkpoint information. We do this even if the cluster
7847 : : * does not show DB_IN_ARCHIVE_RECOVERY to match with the set of WAL
7848 : : * segments recycled below.
7849 : : */
7850 : 0 : ControlFile->checkPoint = lastCheckPointRecPtr;
7851 : 0 : ControlFile->checkPointCopy = lastCheckPoint;
7852 : :
7853 : : /*
7854 : : * Ensure minRecoveryPoint is past the checkpoint record and update it
7855 : : * if the control file still shows DB_IN_ARCHIVE_RECOVERY. Normally,
7856 : : * this will have happened already while writing out dirty buffers,
7857 : : * but not necessarily - e.g. because no buffers were dirtied. We do
7858 : : * this because a backup performed in recovery uses minRecoveryPoint
7859 : : * to determine which WAL files must be included in the backup, and
7860 : : * the file (or files) containing the checkpoint record must be
7861 : : * included, at a minimum. Note that for an ordinary restart of
7862 : : * recovery there's no value in having the minimum recovery point any
7863 : : * earlier than this anyway, because redo will begin just after the
7864 : : * checkpoint record.
7865 : : */
7866 [ # # ]: 0 : if (ControlFile->state == DB_IN_ARCHIVE_RECOVERY)
7867 : : {
7868 [ # # ]: 0 : if (ControlFile->minRecoveryPoint < lastCheckPointEndPtr)
7869 : : {
7870 : 0 : ControlFile->minRecoveryPoint = lastCheckPointEndPtr;
7871 : 0 : ControlFile->minRecoveryPointTLI = lastCheckPoint.ThisTimeLineID;
7872 : :
7873 : : /* update local copy */
7874 : 0 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
7875 : 0 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
7876 : 0 : }
7877 [ # # ]: 0 : if (flags & CHECKPOINT_IS_SHUTDOWN)
7878 : 0 : ControlFile->state = DB_SHUTDOWNED_IN_RECOVERY;
7879 : 0 : }
7880 : 0 : UpdateControlFile();
7881 : 0 : }
7882 : 0 : LWLockRelease(ControlFileLock);
7883 : :
7884 : : /*
7885 : : * Update the average distance between checkpoints/restartpoints if the
7886 : : * prior checkpoint exists.
7887 : : */
7888 [ # # ]: 0 : if (XLogRecPtrIsValid(PriorRedoPtr))
7889 : 0 : UpdateCheckPointDistanceEstimate(RedoRecPtr - PriorRedoPtr);
7890 : :
7891 : : /*
7892 : : * Delete old log files, those no longer needed for last restartpoint to
7893 : : * prevent the disk holding the xlog from growing full.
7894 : : */
7895 : 0 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
7896 : :
7897 : : /*
7898 : : * Retreat _logSegNo using the current end of xlog replayed or received,
7899 : : * whichever is later.
7900 : : */
7901 : 0 : receivePtr = GetWalRcvFlushRecPtr(NULL, NULL);
7902 : 0 : replayPtr = GetXLogReplayRecPtr(&replayTLI);
7903 [ # # ]: 0 : endptr = (receivePtr < replayPtr) ? replayPtr : receivePtr;
7904 : 0 : KeepLogSeg(endptr, &_logSegNo);
7905 [ # # ]: 0 : if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED | RS_INVAL_IDLE_TIMEOUT,
7906 : 0 : _logSegNo, InvalidOid,
7907 : : InvalidTransactionId))
7908 : : {
7909 : : /*
7910 : : * Some slots have been invalidated; recalculate the old-segment
7911 : : * horizon, starting again from RedoRecPtr.
7912 : : */
7913 : 0 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
7914 : 0 : KeepLogSeg(endptr, &_logSegNo);
7915 : 0 : }
7916 : 0 : _logSegNo--;
7917 : :
7918 : : /*
7919 : : * Try to recycle segments on a useful timeline. If we've been promoted
7920 : : * since the beginning of this restartpoint, use the new timeline chosen
7921 : : * at end of recovery. If we're still in recovery, use the timeline we're
7922 : : * currently replaying.
7923 : : *
7924 : : * There is no guarantee that the WAL segments will be useful on the
7925 : : * current timeline; if recovery proceeds to a new timeline right after
7926 : : * this, the pre-allocated WAL segments on this timeline will not be used,
7927 : : * and will go wasted until recycled on the next restartpoint. We'll live
7928 : : * with that.
7929 : : */
7930 [ # # ]: 0 : if (!RecoveryInProgress())
7931 : 0 : replayTLI = XLogCtl->InsertTimeLineID;
7932 : :
7933 : 0 : RemoveOldXlogFiles(_logSegNo, RedoRecPtr, endptr, replayTLI);
7934 : :
7935 : : /*
7936 : : * Make more log segments if needed. (Do this after recycling old log
7937 : : * segments, since that may supply some of the needed files.)
7938 : : */
7939 : 0 : PreallocXlogFiles(endptr, replayTLI);
7940 : :
7941 : : /*
7942 : : * Truncate pg_subtrans if possible. We can throw away all data before
7943 : : * the oldest XMIN of any running transaction. No future transaction will
7944 : : * attempt to reference any pg_subtrans entry older than that (see Asserts
7945 : : * in subtrans.c). When hot standby is disabled, though, we mustn't do
7946 : : * this because StartupSUBTRANS hasn't been called yet.
7947 : : */
7948 [ # # ]: 0 : if (EnableHotStandby)
7949 : 0 : TruncateSUBTRANS(GetOldestTransactionIdConsideredRunning());
7950 : :
7951 : : /* Real work is done; log and update stats. */
7952 : 0 : LogCheckpointEnd(true);
7953 : :
7954 : : /* Reset the process title */
7955 : 0 : update_checkpoint_display(flags, true, true);
7956 : :
7957 : 0 : xtime = GetLatestXTime();
7958 [ # # # # : 0 : ereport((log_checkpoints ? LOG : DEBUG2),
# # # # #
# # # ]
7959 : : errmsg("recovery restart point at %X/%08X",
7960 : : LSN_FORMAT_ARGS(lastCheckPoint.redo)),
7961 : : xtime ? errdetail("Last completed transaction was at log time %s.",
7962 : : timestamptz_to_str(xtime)) : 0);
7963 : :
7964 : : /*
7965 : : * Finally, execute archive_cleanup_command, if any.
7966 : : */
7967 [ # # # # ]: 0 : if (archiveCleanupCommand && strcmp(archiveCleanupCommand, "") != 0)
7968 : 0 : ExecuteRecoveryCommand(archiveCleanupCommand,
7969 : : "archive_cleanup_command",
7970 : : false,
7971 : : WAIT_EVENT_ARCHIVE_CLEANUP_COMMAND);
7972 : :
7973 : 0 : return true;
7974 : 0 : }
7975 : :
7976 : : /*
7977 : : * Report availability of WAL for the given target LSN
7978 : : * (typically a slot's restart_lsn)
7979 : : *
7980 : : * Returns one of the following enum values:
7981 : : *
7982 : : * * WALAVAIL_RESERVED means targetLSN is available and it is in the range of
7983 : : * max_wal_size.
7984 : : *
7985 : : * * WALAVAIL_EXTENDED means it is still available by preserving extra
7986 : : * segments beyond max_wal_size. If max_slot_wal_keep_size is smaller
7987 : : * than max_wal_size, this state is not returned.
7988 : : *
7989 : : * * WALAVAIL_UNRESERVED means it is being lost and the next checkpoint will
7990 : : * remove reserved segments. The walsender using this slot may return to the
7991 : : * above.
7992 : : *
7993 : : * * WALAVAIL_REMOVED means it has been removed. A replication stream on
7994 : : * a slot with this LSN cannot continue. (Any associated walsender
7995 : : * processes should have been terminated already.)
7996 : : *
7997 : : * * WALAVAIL_INVALID_LSN means the slot hasn't been set to reserve WAL.
7998 : : */
7999 : : WALAvailability
8000 : 0 : GetWALAvailability(XLogRecPtr targetLSN)
8001 : : {
8002 : 0 : XLogRecPtr currpos; /* current write LSN */
8003 : 0 : XLogSegNo currSeg; /* segid of currpos */
8004 : 0 : XLogSegNo targetSeg; /* segid of targetLSN */
8005 : 0 : XLogSegNo oldestSeg; /* actual oldest segid */
8006 : 0 : XLogSegNo oldestSegMaxWalSize; /* oldest segid kept by max_wal_size */
8007 : 0 : XLogSegNo oldestSlotSeg; /* oldest segid kept by slot */
8008 : 0 : uint64 keepSegs;
8009 : :
8010 : : /*
8011 : : * slot does not reserve WAL. Either deactivated, or has never been active
8012 : : */
8013 [ # # ]: 0 : if (!XLogRecPtrIsValid(targetLSN))
8014 : 0 : return WALAVAIL_INVALID_LSN;
8015 : :
8016 : : /*
8017 : : * Calculate the oldest segment currently reserved by all slots,
8018 : : * considering wal_keep_size and max_slot_wal_keep_size. Initialize
8019 : : * oldestSlotSeg to the current segment.
8020 : : */
8021 : 0 : currpos = GetXLogWriteRecPtr();
8022 : 0 : XLByteToSeg(currpos, oldestSlotSeg, wal_segment_size);
8023 : 0 : KeepLogSeg(currpos, &oldestSlotSeg);
8024 : :
8025 : : /*
8026 : : * Find the oldest extant segment file. We get 1 until checkpoint removes
8027 : : * the first WAL segment file since startup, which causes the status being
8028 : : * wrong under certain abnormal conditions but that doesn't actually harm.
8029 : : */
8030 : 0 : oldestSeg = XLogGetLastRemovedSegno() + 1;
8031 : :
8032 : : /* calculate oldest segment by max_wal_size */
8033 : 0 : XLByteToSeg(currpos, currSeg, wal_segment_size);
8034 : 0 : keepSegs = ConvertToXSegs(max_wal_size_mb, wal_segment_size) + 1;
8035 : :
8036 [ # # ]: 0 : if (currSeg > keepSegs)
8037 : 0 : oldestSegMaxWalSize = currSeg - keepSegs;
8038 : : else
8039 : 0 : oldestSegMaxWalSize = 1;
8040 : :
8041 : : /* the segment we care about */
8042 : 0 : XLByteToSeg(targetLSN, targetSeg, wal_segment_size);
8043 : :
8044 : : /*
8045 : : * No point in returning reserved or extended status values if the
8046 : : * targetSeg is known to be lost.
8047 : : */
8048 [ # # ]: 0 : if (targetSeg >= oldestSlotSeg)
8049 : : {
8050 : : /* show "reserved" when targetSeg is within max_wal_size */
8051 [ # # ]: 0 : if (targetSeg >= oldestSegMaxWalSize)
8052 : 0 : return WALAVAIL_RESERVED;
8053 : :
8054 : : /* being retained by slots exceeding max_wal_size */
8055 : 0 : return WALAVAIL_EXTENDED;
8056 : : }
8057 : :
8058 : : /* WAL segments are no longer retained but haven't been removed yet */
8059 [ # # ]: 0 : if (targetSeg >= oldestSeg)
8060 : 0 : return WALAVAIL_UNRESERVED;
8061 : :
8062 : : /* Definitely lost */
8063 : 0 : return WALAVAIL_REMOVED;
8064 : 0 : }
8065 : :
8066 : :
8067 : : /*
8068 : : * Retreat *logSegNo to the last segment that we need to retain because of
8069 : : * either wal_keep_size or replication slots.
8070 : : *
8071 : : * This is calculated by subtracting wal_keep_size from the given xlog
8072 : : * location, recptr and by making sure that that result is below the
8073 : : * requirement of replication slots. For the latter criterion we do consider
8074 : : * the effects of max_slot_wal_keep_size: reserve at most that much space back
8075 : : * from recptr.
8076 : : *
8077 : : * Note about replication slots: if this function calculates a value
8078 : : * that's further ahead than what slots need reserved, then affected
8079 : : * slots need to be invalidated and this function invoked again.
8080 : : * XXX it might be a good idea to rewrite this function so that
8081 : : * invalidation is optionally done here, instead.
8082 : : */
8083 : : static void
8084 : 7 : KeepLogSeg(XLogRecPtr recptr, XLogSegNo *logSegNo)
8085 : : {
8086 : 7 : XLogSegNo currSegNo;
8087 : 7 : XLogSegNo segno;
8088 : 7 : XLogRecPtr keep;
8089 : :
8090 : 7 : XLByteToSeg(recptr, currSegNo, wal_segment_size);
8091 : 7 : segno = currSegNo;
8092 : :
8093 : : /* Calculate how many segments are kept by slots. */
8094 : 7 : keep = XLogGetReplicationSlotMinimumLSN();
8095 [ - + # # ]: 7 : if (XLogRecPtrIsValid(keep) && keep < recptr)
8096 : : {
8097 : 0 : XLByteToSeg(keep, segno, wal_segment_size);
8098 : :
8099 : : /*
8100 : : * Account for max_slot_wal_keep_size to avoid keeping more than
8101 : : * configured. However, don't do that during a binary upgrade: if
8102 : : * slots were to be invalidated because of this, it would not be
8103 : : * possible to preserve logical ones during the upgrade.
8104 : : */
8105 [ # # # # ]: 0 : if (max_slot_wal_keep_size_mb >= 0 && !IsBinaryUpgrade)
8106 : : {
8107 : 0 : uint64 slot_keep_segs;
8108 : :
8109 : 0 : slot_keep_segs =
8110 : 0 : ConvertToXSegs(max_slot_wal_keep_size_mb, wal_segment_size);
8111 : :
8112 [ # # ]: 0 : if (currSegNo - segno > slot_keep_segs)
8113 : 0 : segno = currSegNo - slot_keep_segs;
8114 : 0 : }
8115 : 0 : }
8116 : :
8117 : : /*
8118 : : * If WAL summarization is in use, don't remove WAL that has yet to be
8119 : : * summarized.
8120 : : */
8121 : 7 : keep = GetOldestUnsummarizedLSN(NULL, NULL);
8122 [ + - ]: 7 : if (XLogRecPtrIsValid(keep))
8123 : : {
8124 : 0 : XLogSegNo unsummarized_segno;
8125 : :
8126 : 0 : XLByteToSeg(keep, unsummarized_segno, wal_segment_size);
8127 [ # # ]: 0 : if (unsummarized_segno < segno)
8128 : 0 : segno = unsummarized_segno;
8129 : 0 : }
8130 : :
8131 : : /* but, keep at least wal_keep_size if that's set */
8132 [ + - ]: 7 : if (wal_keep_size_mb > 0)
8133 : : {
8134 : 0 : uint64 keep_segs;
8135 : :
8136 : 0 : keep_segs = ConvertToXSegs(wal_keep_size_mb, wal_segment_size);
8137 [ # # ]: 0 : if (currSegNo - segno < keep_segs)
8138 : : {
8139 : : /* avoid underflow, don't go below 1 */
8140 [ # # ]: 0 : if (currSegNo <= keep_segs)
8141 : 0 : segno = 1;
8142 : : else
8143 : 0 : segno = currSegNo - keep_segs;
8144 : 0 : }
8145 : 0 : }
8146 : :
8147 : : /* don't delete WAL segments newer than the calculated segment */
8148 [ + - ]: 7 : if (segno < *logSegNo)
8149 : 0 : *logSegNo = segno;
8150 : 7 : }
8151 : :
8152 : : /*
8153 : : * Write a NEXTOID log record
8154 : : */
8155 : : void
8156 : 9 : XLogPutNextOid(Oid nextOid)
8157 : : {
8158 : 9 : XLogBeginInsert();
8159 : 9 : XLogRegisterData(&nextOid, sizeof(Oid));
8160 : 9 : (void) XLogInsert(RM_XLOG_ID, XLOG_NEXTOID);
8161 : :
8162 : : /*
8163 : : * We need not flush the NEXTOID record immediately, because any of the
8164 : : * just-allocated OIDs could only reach disk as part of a tuple insert or
8165 : : * update that would have its own XLOG record that must follow the NEXTOID
8166 : : * record. Therefore, the standard buffer LSN interlock applied to those
8167 : : * records will ensure no such OID reaches disk before the NEXTOID record
8168 : : * does.
8169 : : *
8170 : : * Note, however, that the above statement only covers state "within" the
8171 : : * database. When we use a generated OID as a file or directory name, we
8172 : : * are in a sense violating the basic WAL rule, because that filesystem
8173 : : * change may reach disk before the NEXTOID WAL record does. The impact
8174 : : * of this is that if a database crash occurs immediately afterward, we
8175 : : * might after restart re-generate the same OID and find that it conflicts
8176 : : * with the leftover file or directory. But since for safety's sake we
8177 : : * always loop until finding a nonconflicting filename, this poses no real
8178 : : * problem in practice. See pgsql-hackers discussion 27-Sep-2006.
8179 : : */
8180 : 9 : }
8181 : :
8182 : : /*
8183 : : * Write an XLOG SWITCH record.
8184 : : *
8185 : : * Here we just blindly issue an XLogInsert request for the record.
8186 : : * All the magic happens inside XLogInsert.
8187 : : *
8188 : : * The return value is either the end+1 address of the switch record,
8189 : : * or the end+1 address of the prior segment if we did not need to
8190 : : * write a switch record because we are already at segment start.
8191 : : */
8192 : : XLogRecPtr
8193 : 0 : RequestXLogSwitch(bool mark_unimportant)
8194 : : {
8195 : 0 : XLogRecPtr RecPtr;
8196 : :
8197 : : /* XLOG SWITCH has no data */
8198 : 0 : XLogBeginInsert();
8199 : :
8200 [ # # ]: 0 : if (mark_unimportant)
8201 : 0 : XLogSetRecordFlags(XLOG_MARK_UNIMPORTANT);
8202 : 0 : RecPtr = XLogInsert(RM_XLOG_ID, XLOG_SWITCH);
8203 : :
8204 : 0 : return RecPtr;
8205 : 0 : }
8206 : :
8207 : : /*
8208 : : * Write a RESTORE POINT record
8209 : : */
8210 : : XLogRecPtr
8211 : 0 : XLogRestorePoint(const char *rpName)
8212 : : {
8213 : 0 : XLogRecPtr RecPtr;
8214 : 0 : xl_restore_point xlrec;
8215 : :
8216 : 0 : xlrec.rp_time = GetCurrentTimestamp();
8217 : 0 : strlcpy(xlrec.rp_name, rpName, MAXFNAMELEN);
8218 : :
8219 : 0 : XLogBeginInsert();
8220 : 0 : XLogRegisterData(&xlrec, sizeof(xl_restore_point));
8221 : :
8222 : 0 : RecPtr = XLogInsert(RM_XLOG_ID, XLOG_RESTORE_POINT);
8223 : :
8224 [ # # # # ]: 0 : ereport(LOG,
8225 : : errmsg("restore point \"%s\" created at %X/%08X",
8226 : : rpName, LSN_FORMAT_ARGS(RecPtr)));
8227 : :
8228 : 0 : return RecPtr;
8229 : 0 : }
8230 : :
8231 : : /*
8232 : : * Check if any of the GUC parameters that are critical for hot standby
8233 : : * have changed, and update the value in pg_control file if necessary.
8234 : : */
8235 : : static void
8236 : 4 : XLogReportParameters(void)
8237 : : {
8238 [ + + ]: 4 : if (wal_level != ControlFile->wal_level ||
8239 [ + - ]: 3 : wal_log_hints != ControlFile->wal_log_hints ||
8240 [ + - ]: 3 : MaxConnections != ControlFile->MaxConnections ||
8241 [ + - ]: 3 : max_worker_processes != ControlFile->max_worker_processes ||
8242 [ + - ]: 3 : max_wal_senders != ControlFile->max_wal_senders ||
8243 [ + + ]: 3 : max_prepared_xacts != ControlFile->max_prepared_xacts ||
8244 [ + - - + ]: 2 : max_locks_per_xact != ControlFile->max_locks_per_xact ||
8245 : 2 : track_commit_timestamp != ControlFile->track_commit_timestamp)
8246 : : {
8247 : : /*
8248 : : * The change in number of backend slots doesn't need to be WAL-logged
8249 : : * if archiving is not enabled, as you can't start archive recovery
8250 : : * with wal_level=minimal anyway. We don't really care about the
8251 : : * values in pg_control either if wal_level=minimal, but seems better
8252 : : * to keep them up-to-date to avoid confusion.
8253 : : */
8254 [ + + + - ]: 2 : if (wal_level != ControlFile->wal_level || XLogIsNeeded())
8255 : : {
8256 : 2 : xl_parameter_change xlrec;
8257 : 2 : XLogRecPtr recptr;
8258 : :
8259 : 2 : xlrec.MaxConnections = MaxConnections;
8260 : 2 : xlrec.max_worker_processes = max_worker_processes;
8261 : 2 : xlrec.max_wal_senders = max_wal_senders;
8262 : 2 : xlrec.max_prepared_xacts = max_prepared_xacts;
8263 : 2 : xlrec.max_locks_per_xact = max_locks_per_xact;
8264 : 2 : xlrec.wal_level = wal_level;
8265 : 2 : xlrec.wal_log_hints = wal_log_hints;
8266 : 2 : xlrec.track_commit_timestamp = track_commit_timestamp;
8267 : :
8268 : 2 : XLogBeginInsert();
8269 : 2 : XLogRegisterData(&xlrec, sizeof(xlrec));
8270 : :
8271 : 2 : recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE);
8272 : 2 : XLogFlush(recptr);
8273 : 2 : }
8274 : :
8275 : 2 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8276 : :
8277 : 2 : ControlFile->MaxConnections = MaxConnections;
8278 : 2 : ControlFile->max_worker_processes = max_worker_processes;
8279 : 2 : ControlFile->max_wal_senders = max_wal_senders;
8280 : 2 : ControlFile->max_prepared_xacts = max_prepared_xacts;
8281 : 2 : ControlFile->max_locks_per_xact = max_locks_per_xact;
8282 : 2 : ControlFile->wal_level = wal_level;
8283 : 2 : ControlFile->wal_log_hints = wal_log_hints;
8284 : 2 : ControlFile->track_commit_timestamp = track_commit_timestamp;
8285 : 2 : UpdateControlFile();
8286 : :
8287 : 2 : LWLockRelease(ControlFileLock);
8288 : 2 : }
8289 : 4 : }
8290 : :
8291 : : /*
8292 : : * Update full_page_writes in shared memory, and write an
8293 : : * XLOG_FPW_CHANGE record if necessary.
8294 : : *
8295 : : * Note: this function assumes there is no other process running
8296 : : * concurrently that could update it.
8297 : : */
8298 : : void
8299 : 5 : UpdateFullPageWrites(void)
8300 : : {
8301 : 5 : XLogCtlInsert *Insert = &XLogCtl->Insert;
8302 : 5 : bool recoveryInProgress;
8303 : :
8304 : : /*
8305 : : * Do nothing if full_page_writes has not been changed.
8306 : : *
8307 : : * It's safe to check the shared full_page_writes without the lock,
8308 : : * because we assume that there is no concurrently running process which
8309 : : * can update it.
8310 : : */
8311 [ + + ]: 5 : if (fullPageWrites == Insert->fullPageWrites)
8312 : 4 : return;
8313 : :
8314 : : /*
8315 : : * Perform this outside critical section so that the WAL insert
8316 : : * initialization done by RecoveryInProgress() doesn't trigger an
8317 : : * assertion failure.
8318 : : */
8319 : 1 : recoveryInProgress = RecoveryInProgress();
8320 : :
8321 : 1 : START_CRIT_SECTION();
8322 : :
8323 : : /*
8324 : : * It's always safe to take full page images, even when not strictly
8325 : : * required, but not the other round. So if we're setting full_page_writes
8326 : : * to true, first set it true and then write the WAL record. If we're
8327 : : * setting it to false, first write the WAL record and then set the global
8328 : : * flag.
8329 : : */
8330 [ - + ]: 1 : if (fullPageWrites)
8331 : : {
8332 : 1 : WALInsertLockAcquireExclusive();
8333 : 1 : Insert->fullPageWrites = true;
8334 : 1 : WALInsertLockRelease();
8335 : 1 : }
8336 : :
8337 : : /*
8338 : : * Write an XLOG_FPW_CHANGE record. This allows us to keep track of
8339 : : * full_page_writes during archive recovery, if required.
8340 : : */
8341 [ + - + - ]: 1 : if (XLogStandbyInfoActive() && !recoveryInProgress)
8342 : : {
8343 : 0 : XLogBeginInsert();
8344 : 0 : XLogRegisterData(&fullPageWrites, sizeof(bool));
8345 : :
8346 : 0 : XLogInsert(RM_XLOG_ID, XLOG_FPW_CHANGE);
8347 : 0 : }
8348 : :
8349 [ + - ]: 1 : if (!fullPageWrites)
8350 : : {
8351 : 0 : WALInsertLockAcquireExclusive();
8352 : 0 : Insert->fullPageWrites = false;
8353 : 0 : WALInsertLockRelease();
8354 : 0 : }
8355 [ + - ]: 1 : END_CRIT_SECTION();
8356 [ - + ]: 5 : }
8357 : :
8358 : : /*
8359 : : * XLOG resource manager's routines
8360 : : *
8361 : : * Definitions of info values are in include/catalog/pg_control.h, though
8362 : : * not all record types are related to control file updates.
8363 : : *
8364 : : * NOTE: Some XLOG record types that are directly related to WAL recovery
8365 : : * are handled in xlogrecovery_redo().
8366 : : */
8367 : : void
8368 : 0 : xlog_redo(XLogReaderState *record)
8369 : : {
8370 : 0 : uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
8371 : 0 : XLogRecPtr lsn = record->EndRecPtr;
8372 : :
8373 : : /*
8374 : : * In XLOG rmgr, backup blocks are only used by XLOG_FPI and
8375 : : * XLOG_FPI_FOR_HINT records.
8376 : : */
8377 [ # # # # : 0 : Assert(info == XLOG_FPI || info == XLOG_FPI_FOR_HINT ||
# # ]
8378 : : !XLogRecHasAnyBlockRefs(record));
8379 : :
8380 [ # # ]: 0 : if (info == XLOG_NEXTOID)
8381 : : {
8382 : 0 : Oid nextOid;
8383 : :
8384 : : /*
8385 : : * We used to try to take the maximum of TransamVariables->nextOid and
8386 : : * the recorded nextOid, but that fails if the OID counter wraps
8387 : : * around. Since no OID allocation should be happening during replay
8388 : : * anyway, better to just believe the record exactly. We still take
8389 : : * OidGenLock while setting the variable, just in case.
8390 : : */
8391 : 0 : memcpy(&nextOid, XLogRecGetData(record), sizeof(Oid));
8392 : 0 : LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
8393 : 0 : TransamVariables->nextOid = nextOid;
8394 : 0 : TransamVariables->oidCount = 0;
8395 : 0 : LWLockRelease(OidGenLock);
8396 : 0 : }
8397 [ # # ]: 0 : else if (info == XLOG_CHECKPOINT_SHUTDOWN)
8398 : : {
8399 : 0 : CheckPoint checkPoint;
8400 : 0 : TimeLineID replayTLI;
8401 : :
8402 : 0 : memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
8403 : : /* In a SHUTDOWN checkpoint, believe the counters exactly */
8404 : 0 : LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
8405 : 0 : TransamVariables->nextXid = checkPoint.nextXid;
8406 : 0 : LWLockRelease(XidGenLock);
8407 : 0 : LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
8408 : 0 : TransamVariables->nextOid = checkPoint.nextOid;
8409 : 0 : TransamVariables->oidCount = 0;
8410 : 0 : LWLockRelease(OidGenLock);
8411 : 0 : MultiXactSetNextMXact(checkPoint.nextMulti,
8412 : 0 : checkPoint.nextMultiOffset);
8413 : :
8414 : 0 : MultiXactAdvanceOldest(checkPoint.oldestMulti,
8415 : 0 : checkPoint.oldestMultiDB);
8416 : :
8417 : : /*
8418 : : * No need to set oldestClogXid here as well; it'll be set when we
8419 : : * redo an xl_clog_truncate if it changed since initialization.
8420 : : */
8421 : 0 : SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
8422 : :
8423 : : /*
8424 : : * If we see a shutdown checkpoint while waiting for an end-of-backup
8425 : : * record, the backup was canceled and the end-of-backup record will
8426 : : * never arrive.
8427 : : */
8428 [ # # ]: 0 : if (ArchiveRecoveryRequested &&
8429 [ # # # # ]: 0 : XLogRecPtrIsValid(ControlFile->backupStartPoint) &&
8430 : 0 : !XLogRecPtrIsValid(ControlFile->backupEndPoint))
8431 [ # # # # ]: 0 : ereport(PANIC,
8432 : : (errmsg("online backup was canceled, recovery cannot continue")));
8433 : :
8434 : : /*
8435 : : * If we see a shutdown checkpoint, we know that nothing was running
8436 : : * on the primary at this point. So fake-up an empty running-xacts
8437 : : * record and use that here and now. Recover additional standby state
8438 : : * for prepared transactions.
8439 : : */
8440 [ # # ]: 0 : if (standbyState >= STANDBY_INITIALIZED)
8441 : : {
8442 : 0 : TransactionId *xids;
8443 : 0 : int nxids;
8444 : 0 : TransactionId oldestActiveXID;
8445 : 0 : TransactionId latestCompletedXid;
8446 : 0 : RunningTransactionsData running;
8447 : :
8448 : 0 : oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
8449 : :
8450 : : /* Update pg_subtrans entries for any prepared transactions */
8451 : 0 : StandbyRecoverPreparedTransactions();
8452 : :
8453 : : /*
8454 : : * Construct a RunningTransactions snapshot representing a shut
8455 : : * down server, with only prepared transactions still alive. We're
8456 : : * never overflowed at this point because all subxids are listed
8457 : : * with their parent prepared transactions.
8458 : : */
8459 : 0 : running.xcnt = nxids;
8460 : 0 : running.subxcnt = 0;
8461 : 0 : running.subxid_status = SUBXIDS_IN_SUBTRANS;
8462 : 0 : running.nextXid = XidFromFullTransactionId(checkPoint.nextXid);
8463 : 0 : running.oldestRunningXid = oldestActiveXID;
8464 : 0 : latestCompletedXid = XidFromFullTransactionId(checkPoint.nextXid);
8465 [ # # ]: 0 : TransactionIdRetreat(latestCompletedXid);
8466 [ # # ]: 0 : Assert(TransactionIdIsNormal(latestCompletedXid));
8467 : 0 : running.latestCompletedXid = latestCompletedXid;
8468 : 0 : running.xids = xids;
8469 : :
8470 : 0 : ProcArrayApplyRecoveryInfo(&running);
8471 : 0 : }
8472 : :
8473 : : /* ControlFile->checkPointCopy always tracks the latest ckpt XID */
8474 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8475 : 0 : ControlFile->checkPointCopy.nextXid = checkPoint.nextXid;
8476 : 0 : LWLockRelease(ControlFileLock);
8477 : :
8478 : : /*
8479 : : * We should've already switched to the new TLI before replaying this
8480 : : * record.
8481 : : */
8482 : 0 : (void) GetCurrentReplayRecPtr(&replayTLI);
8483 [ # # ]: 0 : if (checkPoint.ThisTimeLineID != replayTLI)
8484 [ # # # # ]: 0 : ereport(PANIC,
8485 : : (errmsg("unexpected timeline ID %u (should be %u) in shutdown checkpoint record",
8486 : : checkPoint.ThisTimeLineID, replayTLI)));
8487 : :
8488 : 0 : RecoveryRestartPoint(&checkPoint, record);
8489 : :
8490 : : /*
8491 : : * After replaying a checkpoint record, free all smgr objects.
8492 : : * Otherwise we would never do so for dropped relations, as the
8493 : : * startup does not process shared invalidation messages or call
8494 : : * AtEOXact_SMgr().
8495 : : */
8496 : 0 : smgrdestroyall();
8497 : 0 : }
8498 [ # # ]: 0 : else if (info == XLOG_CHECKPOINT_ONLINE)
8499 : : {
8500 : 0 : CheckPoint checkPoint;
8501 : 0 : TimeLineID replayTLI;
8502 : :
8503 : 0 : memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
8504 : : /* In an ONLINE checkpoint, treat the XID counter as a minimum */
8505 : 0 : LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
8506 [ # # ]: 0 : if (FullTransactionIdPrecedes(TransamVariables->nextXid,
8507 : : checkPoint.nextXid))
8508 : 0 : TransamVariables->nextXid = checkPoint.nextXid;
8509 : 0 : LWLockRelease(XidGenLock);
8510 : :
8511 : : /*
8512 : : * We ignore the nextOid counter in an ONLINE checkpoint, preferring
8513 : : * to track OID assignment through XLOG_NEXTOID records. The nextOid
8514 : : * counter is from the start of the checkpoint and might well be stale
8515 : : * compared to later XLOG_NEXTOID records. We could try to take the
8516 : : * maximum of the nextOid counter and our latest value, but since
8517 : : * there's no particular guarantee about the speed with which the OID
8518 : : * counter wraps around, that's a risky thing to do. In any case,
8519 : : * users of the nextOid counter are required to avoid assignment of
8520 : : * duplicates, so that a somewhat out-of-date value should be safe.
8521 : : */
8522 : :
8523 : : /* Handle multixact */
8524 : 0 : MultiXactAdvanceNextMXact(checkPoint.nextMulti,
8525 : 0 : checkPoint.nextMultiOffset);
8526 : :
8527 : : /*
8528 : : * NB: This may perform multixact truncation when replaying WAL
8529 : : * generated by an older primary.
8530 : : */
8531 : 0 : MultiXactAdvanceOldest(checkPoint.oldestMulti,
8532 : 0 : checkPoint.oldestMultiDB);
8533 [ # # # # ]: 0 : if (TransactionIdPrecedes(TransamVariables->oldestXid,
8534 : 0 : checkPoint.oldestXid))
8535 : 0 : SetTransactionIdLimit(checkPoint.oldestXid,
8536 : 0 : checkPoint.oldestXidDB);
8537 : : /* ControlFile->checkPointCopy always tracks the latest ckpt XID */
8538 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8539 : 0 : ControlFile->checkPointCopy.nextXid = checkPoint.nextXid;
8540 : 0 : LWLockRelease(ControlFileLock);
8541 : :
8542 : : /* TLI should not change in an on-line checkpoint */
8543 : 0 : (void) GetCurrentReplayRecPtr(&replayTLI);
8544 [ # # ]: 0 : if (checkPoint.ThisTimeLineID != replayTLI)
8545 [ # # # # ]: 0 : ereport(PANIC,
8546 : : (errmsg("unexpected timeline ID %u (should be %u) in online checkpoint record",
8547 : : checkPoint.ThisTimeLineID, replayTLI)));
8548 : :
8549 : 0 : RecoveryRestartPoint(&checkPoint, record);
8550 : :
8551 : : /*
8552 : : * After replaying a checkpoint record, free all smgr objects.
8553 : : * Otherwise we would never do so for dropped relations, as the
8554 : : * startup does not process shared invalidation messages or call
8555 : : * AtEOXact_SMgr().
8556 : : */
8557 : 0 : smgrdestroyall();
8558 : 0 : }
8559 [ # # ]: 0 : else if (info == XLOG_OVERWRITE_CONTRECORD)
8560 : : {
8561 : : /* nothing to do here, handled in xlogrecovery_redo() */
8562 : 0 : }
8563 [ # # ]: 0 : else if (info == XLOG_END_OF_RECOVERY)
8564 : : {
8565 : 0 : xl_end_of_recovery xlrec;
8566 : 0 : TimeLineID replayTLI;
8567 : :
8568 : 0 : memcpy(&xlrec, XLogRecGetData(record), sizeof(xl_end_of_recovery));
8569 : :
8570 : : /*
8571 : : * For Hot Standby, we could treat this like a Shutdown Checkpoint,
8572 : : * but this case is rarer and harder to test, so the benefit doesn't
8573 : : * outweigh the potential extra cost of maintenance.
8574 : : */
8575 : :
8576 : : /*
8577 : : * We should've already switched to the new TLI before replaying this
8578 : : * record.
8579 : : */
8580 : 0 : (void) GetCurrentReplayRecPtr(&replayTLI);
8581 [ # # ]: 0 : if (xlrec.ThisTimeLineID != replayTLI)
8582 [ # # # # ]: 0 : ereport(PANIC,
8583 : : (errmsg("unexpected timeline ID %u (should be %u) in end-of-recovery record",
8584 : : xlrec.ThisTimeLineID, replayTLI)));
8585 : 0 : }
8586 [ # # ]: 0 : else if (info == XLOG_NOOP)
8587 : : {
8588 : : /* nothing to do here */
8589 : 0 : }
8590 [ # # ]: 0 : else if (info == XLOG_SWITCH)
8591 : : {
8592 : : /* nothing to do here */
8593 : 0 : }
8594 [ # # ]: 0 : else if (info == XLOG_RESTORE_POINT)
8595 : : {
8596 : : /* nothing to do here, handled in xlogrecovery.c */
8597 : 0 : }
8598 [ # # # # ]: 0 : else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT)
8599 : : {
8600 : : /*
8601 : : * XLOG_FPI records contain nothing else but one or more block
8602 : : * references. Every block reference must include a full-page image
8603 : : * even if full_page_writes was disabled when the record was generated
8604 : : * - otherwise there would be no point in this record.
8605 : : *
8606 : : * XLOG_FPI_FOR_HINT records are generated when a page needs to be
8607 : : * WAL-logged because of a hint bit update. They are only generated
8608 : : * when checksums and/or wal_log_hints are enabled. They may include
8609 : : * no full-page images if full_page_writes was disabled when they were
8610 : : * generated. In this case there is nothing to do here.
8611 : : *
8612 : : * No recovery conflicts are generated by these generic records - if a
8613 : : * resource manager needs to generate conflicts, it has to define a
8614 : : * separate WAL record type and redo routine.
8615 : : */
8616 [ # # ]: 0 : for (uint8 block_id = 0; block_id <= XLogRecMaxBlockId(record); block_id++)
8617 : : {
8618 : 0 : Buffer buffer;
8619 : :
8620 [ # # ]: 0 : if (!XLogRecHasBlockImage(record, block_id))
8621 : : {
8622 [ # # ]: 0 : if (info == XLOG_FPI)
8623 [ # # # # ]: 0 : elog(ERROR, "XLOG_FPI record did not contain a full-page image");
8624 : 0 : continue;
8625 : : }
8626 : :
8627 [ # # ]: 0 : if (XLogReadBufferForRedo(record, block_id, &buffer) != BLK_RESTORED)
8628 [ # # # # ]: 0 : elog(ERROR, "unexpected XLogReadBufferForRedo result when restoring backup block");
8629 : 0 : UnlockReleaseBuffer(buffer);
8630 [ # # # ]: 0 : }
8631 : 0 : }
8632 [ # # ]: 0 : else if (info == XLOG_BACKUP_END)
8633 : : {
8634 : : /* nothing to do here, handled in xlogrecovery_redo() */
8635 : 0 : }
8636 [ # # ]: 0 : else if (info == XLOG_PARAMETER_CHANGE)
8637 : : {
8638 : 0 : xl_parameter_change xlrec;
8639 : :
8640 : : /* Update our copy of the parameters in pg_control */
8641 : 0 : memcpy(&xlrec, XLogRecGetData(record), sizeof(xl_parameter_change));
8642 : :
8643 : 0 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8644 : 0 : ControlFile->MaxConnections = xlrec.MaxConnections;
8645 : 0 : ControlFile->max_worker_processes = xlrec.max_worker_processes;
8646 : 0 : ControlFile->max_wal_senders = xlrec.max_wal_senders;
8647 : 0 : ControlFile->max_prepared_xacts = xlrec.max_prepared_xacts;
8648 : 0 : ControlFile->max_locks_per_xact = xlrec.max_locks_per_xact;
8649 : 0 : ControlFile->wal_level = xlrec.wal_level;
8650 : 0 : ControlFile->wal_log_hints = xlrec.wal_log_hints;
8651 : :
8652 : : /*
8653 : : * Update minRecoveryPoint to ensure that if recovery is aborted, we
8654 : : * recover back up to this point before allowing hot standby again.
8655 : : * This is important if the max_* settings are decreased, to ensure
8656 : : * you don't run queries against the WAL preceding the change. The
8657 : : * local copies cannot be updated as long as crash recovery is
8658 : : * happening and we expect all the WAL to be replayed.
8659 : : */
8660 [ # # ]: 0 : if (InArchiveRecovery)
8661 : : {
8662 : 0 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
8663 : 0 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
8664 : 0 : }
8665 [ # # # # ]: 0 : if (XLogRecPtrIsValid(LocalMinRecoveryPoint) && LocalMinRecoveryPoint < lsn)
8666 : : {
8667 : 0 : TimeLineID replayTLI;
8668 : :
8669 : 0 : (void) GetCurrentReplayRecPtr(&replayTLI);
8670 : 0 : ControlFile->minRecoveryPoint = lsn;
8671 : 0 : ControlFile->minRecoveryPointTLI = replayTLI;
8672 : 0 : }
8673 : :
8674 : 0 : CommitTsParameterChange(xlrec.track_commit_timestamp,
8675 : 0 : ControlFile->track_commit_timestamp);
8676 : 0 : ControlFile->track_commit_timestamp = xlrec.track_commit_timestamp;
8677 : :
8678 : 0 : UpdateControlFile();
8679 : 0 : LWLockRelease(ControlFileLock);
8680 : :
8681 : : /* Check to see if any parameter change gives a problem on recovery */
8682 : 0 : CheckRequiredParameterValues();
8683 : 0 : }
8684 [ # # ]: 0 : else if (info == XLOG_FPW_CHANGE)
8685 : : {
8686 : 0 : bool fpw;
8687 : :
8688 : 0 : memcpy(&fpw, XLogRecGetData(record), sizeof(bool));
8689 : :
8690 : : /*
8691 : : * Update the LSN of the last replayed XLOG_FPW_CHANGE record so that
8692 : : * do_pg_backup_start() and do_pg_backup_stop() can check whether
8693 : : * full_page_writes has been disabled during online backup.
8694 : : */
8695 [ # # ]: 0 : if (!fpw)
8696 : : {
8697 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
8698 [ # # ]: 0 : if (XLogCtl->lastFpwDisableRecPtr < record->ReadRecPtr)
8699 : 0 : XLogCtl->lastFpwDisableRecPtr = record->ReadRecPtr;
8700 : 0 : SpinLockRelease(&XLogCtl->info_lck);
8701 : 0 : }
8702 : :
8703 : : /* Keep track of full_page_writes */
8704 : 0 : lastFullPageWrites = fpw;
8705 : 0 : }
8706 [ # # ]: 0 : else if (info == XLOG_CHECKPOINT_REDO)
8707 : : {
8708 : : /* nothing to do here, just for informational purposes */
8709 : 0 : }
8710 [ # # ]: 0 : else if (info == XLOG_LOGICAL_DECODING_STATUS_CHANGE)
8711 : : {
8712 : 0 : bool status;
8713 : :
8714 : 0 : memcpy(&status, XLogRecGetData(record), sizeof(bool));
8715 : :
8716 : : /*
8717 : : * We need to toggle the logical decoding status and update the
8718 : : * XLogLogicalInfo cache of processes synchronously because
8719 : : * XLogLogicalInfoActive() is used even during read-only queries
8720 : : * (e.g., via RelationIsAccessibleInLogicalDecoding()). In the
8721 : : * 'disable' case, it is safe to invalidate existing slots after
8722 : : * disabling logical decoding because logical decoding cannot process
8723 : : * subsequent WAL records, which may not contain logical information.
8724 : : */
8725 [ # # ]: 0 : if (status)
8726 : 0 : EnableLogicalDecoding();
8727 : : else
8728 : 0 : DisableLogicalDecoding();
8729 : :
8730 [ # # # # ]: 0 : elog(DEBUG1, "update logical decoding status to %d during recovery",
8731 : : status);
8732 : :
8733 [ # # # # ]: 0 : if (InRecovery && InHotStandby)
8734 : : {
8735 [ # # ]: 0 : if (!status)
8736 : : {
8737 : : /*
8738 : : * Invalidate logical slots if we are in hot standby and the
8739 : : * primary disabled logical decoding.
8740 : : */
8741 : 0 : InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_LEVEL,
8742 : : 0, InvalidOid,
8743 : : InvalidTransactionId);
8744 : 0 : }
8745 [ # # ]: 0 : else if (sync_replication_slots)
8746 : : {
8747 : : /*
8748 : : * Signal the postmaster to launch the slotsync worker.
8749 : : *
8750 : : * XXX: For simplicity, we keep the slotsync worker running
8751 : : * even after logical decoding is disabled. A future
8752 : : * improvement can consider starting and stopping the worker
8753 : : * based on logical decoding status change.
8754 : : */
8755 : 0 : kill(PostmasterPid, SIGUSR1);
8756 : 0 : }
8757 : 0 : }
8758 : 0 : }
8759 : 0 : }
8760 : :
8761 : : /*
8762 : : * Return the extra open flags used for opening a file, depending on the
8763 : : * value of the GUCs wal_sync_method, fsync and debug_io_direct.
8764 : : */
8765 : : static int
8766 : 396 : get_sync_bit(int method)
8767 : : {
8768 : 396 : int o_direct_flag = 0;
8769 : :
8770 : : /*
8771 : : * Use O_DIRECT if requested, except in walreceiver process. The WAL
8772 : : * written by walreceiver is normally read by the startup process soon
8773 : : * after it's written. Also, walreceiver performs unaligned writes, which
8774 : : * don't work with O_DIRECT, so it is required for correctness too.
8775 : : */
8776 [ - + # # ]: 396 : if ((io_direct_flags & IO_DIRECT_WAL) && !AmWalReceiverProcess())
8777 : 0 : o_direct_flag = PG_O_DIRECT;
8778 : :
8779 : : /* If fsync is disabled, never open in sync mode */
8780 [ - + ]: 396 : if (!enableFsync)
8781 : 396 : return o_direct_flag;
8782 : :
8783 [ # # # # ]: 0 : switch (method)
8784 : : {
8785 : : /*
8786 : : * enum values for all sync options are defined even if they are
8787 : : * not supported on the current platform. But if not, they are
8788 : : * not included in the enum option array, and therefore will never
8789 : : * be seen here.
8790 : : */
8791 : : case WAL_SYNC_METHOD_FSYNC:
8792 : : case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
8793 : : case WAL_SYNC_METHOD_FDATASYNC:
8794 : 0 : return o_direct_flag;
8795 : : #ifdef O_SYNC
8796 : : case WAL_SYNC_METHOD_OPEN:
8797 : 0 : return O_SYNC | o_direct_flag;
8798 : : #endif
8799 : : #ifdef O_DSYNC
8800 : : case WAL_SYNC_METHOD_OPEN_DSYNC:
8801 : 0 : return O_DSYNC | o_direct_flag;
8802 : : #endif
8803 : : default:
8804 : : /* can't happen (unless we are out of sync with option array) */
8805 [ # # # # ]: 0 : elog(ERROR, "unrecognized \"wal_sync_method\": %d", method);
8806 : 0 : return 0; /* silence warning */
8807 : : }
8808 : 396 : }
8809 : :
8810 : : /*
8811 : : * GUC support
8812 : : */
8813 : : void
8814 : 6 : assign_wal_sync_method(int new_wal_sync_method, void *extra)
8815 : : {
8816 [ + - ]: 6 : if (wal_sync_method != new_wal_sync_method)
8817 : : {
8818 : : /*
8819 : : * To ensure that no blocks escape unsynced, force an fsync on the
8820 : : * currently open log segment (if any). Also, if the open flag is
8821 : : * changing, close the log file so it will be reopened (with new flag
8822 : : * bit) at next use.
8823 : : */
8824 [ # # ]: 0 : if (openLogFile >= 0)
8825 : : {
8826 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC_METHOD_ASSIGN);
8827 [ # # ]: 0 : if (pg_fsync(openLogFile) != 0)
8828 : : {
8829 : 0 : char xlogfname[MAXFNAMELEN];
8830 : 0 : int save_errno;
8831 : :
8832 : 0 : save_errno = errno;
8833 : 0 : XLogFileName(xlogfname, openLogTLI, openLogSegNo,
8834 : 0 : wal_segment_size);
8835 : 0 : errno = save_errno;
8836 [ # # # # ]: 0 : ereport(PANIC,
8837 : : (errcode_for_file_access(),
8838 : : errmsg("could not fsync file \"%s\": %m", xlogfname)));
8839 : 0 : }
8840 : :
8841 : 0 : pgstat_report_wait_end();
8842 [ # # ]: 0 : if (get_sync_bit(wal_sync_method) != get_sync_bit(new_wal_sync_method))
8843 : 0 : XLogFileClose();
8844 : 0 : }
8845 : 0 : }
8846 : 6 : }
8847 : :
8848 : :
8849 : : /*
8850 : : * Issue appropriate kind of fsync (if any) for an XLOG output file.
8851 : : *
8852 : : * 'fd' is a file descriptor for the XLOG file to be fsync'd.
8853 : : * 'segno' is for error reporting purposes.
8854 : : */
8855 : : void
8856 : 21 : issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
8857 : : {
8858 : 21 : char *msg = NULL;
8859 : 21 : instr_time start;
8860 : :
8861 [ + - ]: 21 : Assert(tli != 0);
8862 : :
8863 : : /*
8864 : : * Quick exit if fsync is disabled or write() has already synced the WAL
8865 : : * file.
8866 : : */
8867 [ - + ]: 21 : if (!enableFsync ||
8868 [ # # # # ]: 0 : wal_sync_method == WAL_SYNC_METHOD_OPEN ||
8869 : 0 : wal_sync_method == WAL_SYNC_METHOD_OPEN_DSYNC)
8870 : 21 : return;
8871 : :
8872 : : /*
8873 : : * Measure I/O timing to sync the WAL file for pg_stat_io.
8874 : : */
8875 : 0 : start = pgstat_prepare_io_time(track_wal_io_timing);
8876 : :
8877 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
8878 [ # # # # : 0 : switch (wal_sync_method)
# ]
8879 : : {
8880 : : case WAL_SYNC_METHOD_FSYNC:
8881 [ # # ]: 0 : if (pg_fsync_no_writethrough(fd) != 0)
8882 : 0 : msg = _("could not fsync file \"%s\": %m");
8883 : 0 : break;
8884 : : #ifdef HAVE_FSYNC_WRITETHROUGH
8885 : : case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
8886 [ # # ]: 0 : if (pg_fsync_writethrough(fd) != 0)
8887 : 0 : msg = _("could not fsync write-through file \"%s\": %m");
8888 : 0 : break;
8889 : : #endif
8890 : : case WAL_SYNC_METHOD_FDATASYNC:
8891 [ # # ]: 0 : if (pg_fdatasync(fd) != 0)
8892 : 0 : msg = _("could not fdatasync file \"%s\": %m");
8893 : 0 : break;
8894 : : case WAL_SYNC_METHOD_OPEN:
8895 : : case WAL_SYNC_METHOD_OPEN_DSYNC:
8896 : : /* not reachable */
8897 : 0 : Assert(false);
8898 : 0 : break;
8899 : : default:
8900 [ # # # # ]: 0 : ereport(PANIC,
8901 : : errcode(ERRCODE_INVALID_PARAMETER_VALUE),
8902 : : errmsg_internal("unrecognized \"wal_sync_method\": %d", wal_sync_method));
8903 : 0 : break;
8904 : : }
8905 : :
8906 : : /* PANIC if failed to fsync */
8907 [ # # ]: 0 : if (msg)
8908 : : {
8909 : 0 : char xlogfname[MAXFNAMELEN];
8910 : 0 : int save_errno = errno;
8911 : :
8912 : 0 : XLogFileName(xlogfname, tli, segno, wal_segment_size);
8913 : 0 : errno = save_errno;
8914 [ # # # # ]: 0 : ereport(PANIC,
8915 : : (errcode_for_file_access(),
8916 : : errmsg(msg, xlogfname)));
8917 : 0 : }
8918 : :
8919 : 0 : pgstat_report_wait_end();
8920 : :
8921 : 0 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_NORMAL, IOOP_FSYNC,
8922 : : start, 1, 0);
8923 [ - + ]: 21 : }
8924 : :
8925 : : /*
8926 : : * do_pg_backup_start is the workhorse of the user-visible pg_backup_start()
8927 : : * function. It creates the necessary starting checkpoint and constructs the
8928 : : * backup state and tablespace map.
8929 : : *
8930 : : * Input parameters are "state" (the backup state), "fast" (if true, we do
8931 : : * the checkpoint in fast mode), and "tablespaces" (if non-NULL, indicates a
8932 : : * list of tablespaceinfo structs describing the cluster's tablespaces.).
8933 : : *
8934 : : * The tablespace map contents are appended to passed-in parameter
8935 : : * tablespace_map and the caller is responsible for including it in the backup
8936 : : * archive as 'tablespace_map'. The tablespace_map file is required mainly for
8937 : : * tar format in windows as native windows utilities are not able to create
8938 : : * symlinks while extracting files from tar. However for consistency and
8939 : : * platform-independence, we do it the same way everywhere.
8940 : : *
8941 : : * It fills in "state" with the information required for the backup, such
8942 : : * as the minimum WAL location that must be present to restore from this
8943 : : * backup (starttli) and the corresponding timeline ID (starttli).
8944 : : *
8945 : : * Every successfully started backup must be stopped by calling
8946 : : * do_pg_backup_stop() or do_pg_abort_backup(). There can be many
8947 : : * backups active at the same time.
8948 : : *
8949 : : * It is the responsibility of the caller of this function to verify the
8950 : : * permissions of the calling user!
8951 : : */
8952 : : void
8953 : 0 : do_pg_backup_start(const char *backupidstr, bool fast, List **tablespaces,
8954 : : BackupState *state, StringInfo tblspcmapfile)
8955 : : {
8956 : 0 : bool backup_started_in_recovery;
8957 : :
8958 [ # # ]: 0 : Assert(state != NULL);
8959 : 0 : backup_started_in_recovery = RecoveryInProgress();
8960 : :
8961 : : /*
8962 : : * During recovery, we don't need to check WAL level. Because, if WAL
8963 : : * level is not sufficient, it's impossible to get here during recovery.
8964 : : */
8965 [ # # # # ]: 0 : if (!backup_started_in_recovery && !XLogIsNeeded())
8966 [ # # # # ]: 0 : ereport(ERROR,
8967 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
8968 : : errmsg("WAL level not sufficient for making an online backup"),
8969 : : errhint("\"wal_level\" must be set to \"replica\" or \"logical\" at server start.")));
8970 : :
8971 [ # # ]: 0 : if (strlen(backupidstr) > MAXPGPATH)
8972 [ # # # # ]: 0 : ereport(ERROR,
8973 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
8974 : : errmsg("backup label too long (max %d bytes)",
8975 : : MAXPGPATH)));
8976 : :
8977 : 0 : strlcpy(state->name, backupidstr, sizeof(state->name));
8978 : :
8979 : : /*
8980 : : * Mark backup active in shared memory. We must do full-page WAL writes
8981 : : * during an on-line backup even if not doing so at other times, because
8982 : : * it's quite possible for the backup dump to obtain a "torn" (partially
8983 : : * written) copy of a database page if it reads the page concurrently with
8984 : : * our write to the same page. This can be fixed as long as the first
8985 : : * write to the page in the WAL sequence is a full-page write. Hence, we
8986 : : * increment runningBackups then force a CHECKPOINT, to ensure there are
8987 : : * no dirty pages in shared memory that might get dumped while the backup
8988 : : * is in progress without having a corresponding WAL record. (Once the
8989 : : * backup is complete, we need not force full-page writes anymore, since
8990 : : * we expect that any pages not modified during the backup interval must
8991 : : * have been correctly captured by the backup.)
8992 : : *
8993 : : * Note that forcing full-page writes has no effect during an online
8994 : : * backup from the standby.
8995 : : *
8996 : : * We must hold all the insertion locks to change the value of
8997 : : * runningBackups, to ensure adequate interlocking against
8998 : : * XLogInsertRecord().
8999 : : */
9000 : 0 : WALInsertLockAcquireExclusive();
9001 : 0 : XLogCtl->Insert.runningBackups++;
9002 : 0 : WALInsertLockRelease();
9003 : :
9004 : : /*
9005 : : * Ensure we decrement runningBackups if we fail below. NB -- for this to
9006 : : * work correctly, it is critical that sessionBackupState is only updated
9007 : : * after this block is over.
9008 : : */
9009 [ # # ]: 0 : PG_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(true));
9010 : : {
9011 : 0 : bool gotUniqueStartpoint = false;
9012 : 0 : DIR *tblspcdir;
9013 : 0 : struct dirent *de;
9014 : 0 : tablespaceinfo *ti;
9015 : 0 : int datadirpathlen;
9016 : :
9017 : : /*
9018 : : * Force an XLOG file switch before the checkpoint, to ensure that the
9019 : : * WAL segment the checkpoint is written to doesn't contain pages with
9020 : : * old timeline IDs. That would otherwise happen if you called
9021 : : * pg_backup_start() right after restoring from a PITR archive: the
9022 : : * first WAL segment containing the startup checkpoint has pages in
9023 : : * the beginning with the old timeline ID. That can cause trouble at
9024 : : * recovery: we won't have a history file covering the old timeline if
9025 : : * pg_wal directory was not included in the base backup and the WAL
9026 : : * archive was cleared too before starting the backup.
9027 : : *
9028 : : * This also ensures that we have emitted a WAL page header that has
9029 : : * XLP_BKP_REMOVABLE off before we emit the checkpoint record.
9030 : : * Therefore, if a WAL archiver (such as pglesslog) is trying to
9031 : : * compress out removable backup blocks, it won't remove any that
9032 : : * occur after this point.
9033 : : *
9034 : : * During recovery, we skip forcing XLOG file switch, which means that
9035 : : * the backup taken during recovery is not available for the special
9036 : : * recovery case described above.
9037 : : */
9038 [ # # ]: 0 : if (!backup_started_in_recovery)
9039 : 0 : RequestXLogSwitch(false);
9040 : :
9041 : 0 : do
9042 : : {
9043 : 0 : bool checkpointfpw;
9044 : :
9045 : : /*
9046 : : * Force a CHECKPOINT. Aside from being necessary to prevent torn
9047 : : * page problems, this guarantees that two successive backup runs
9048 : : * will have different checkpoint positions and hence different
9049 : : * history file names, even if nothing happened in between.
9050 : : *
9051 : : * During recovery, establish a restartpoint if possible. We use
9052 : : * the last restartpoint as the backup starting checkpoint. This
9053 : : * means that two successive backup runs can have same checkpoint
9054 : : * positions.
9055 : : *
9056 : : * Since the fact that we are executing do_pg_backup_start()
9057 : : * during recovery means that checkpointer is running, we can use
9058 : : * RequestCheckpoint() to establish a restartpoint.
9059 : : *
9060 : : * We use CHECKPOINT_FAST only if requested by user (via passing
9061 : : * fast = true). Otherwise this can take awhile.
9062 : : */
9063 : 0 : RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT |
9064 : 0 : (fast ? CHECKPOINT_FAST : 0));
9065 : :
9066 : : /*
9067 : : * Now we need to fetch the checkpoint record location, and also
9068 : : * its REDO pointer. The oldest point in WAL that would be needed
9069 : : * to restore starting from the checkpoint is precisely the REDO
9070 : : * pointer.
9071 : : */
9072 : 0 : LWLockAcquire(ControlFileLock, LW_SHARED);
9073 : 0 : state->checkpointloc = ControlFile->checkPoint;
9074 : 0 : state->startpoint = ControlFile->checkPointCopy.redo;
9075 : 0 : state->starttli = ControlFile->checkPointCopy.ThisTimeLineID;
9076 : 0 : checkpointfpw = ControlFile->checkPointCopy.fullPageWrites;
9077 : 0 : LWLockRelease(ControlFileLock);
9078 : :
9079 [ # # ]: 0 : if (backup_started_in_recovery)
9080 : : {
9081 : 0 : XLogRecPtr recptr;
9082 : :
9083 : : /*
9084 : : * Check to see if all WAL replayed during online backup
9085 : : * (i.e., since last restartpoint used as backup starting
9086 : : * checkpoint) contain full-page writes.
9087 : : */
9088 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
9089 : 0 : recptr = XLogCtl->lastFpwDisableRecPtr;
9090 : 0 : SpinLockRelease(&XLogCtl->info_lck);
9091 : :
9092 [ # # ]: 0 : if (!checkpointfpw || state->startpoint <= recptr)
9093 [ # # # # ]: 0 : ereport(ERROR,
9094 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9095 : : errmsg("WAL generated with \"full_page_writes=off\" was replayed "
9096 : : "since last restartpoint"),
9097 : : errhint("This means that the backup being taken on the standby "
9098 : : "is corrupt and should not be used. "
9099 : : "Enable \"full_page_writes\" and run CHECKPOINT on the primary, "
9100 : : "and then try an online backup again.")));
9101 : :
9102 : : /*
9103 : : * During recovery, since we don't use the end-of-backup WAL
9104 : : * record and don't write the backup history file, the
9105 : : * starting WAL location doesn't need to be unique. This means
9106 : : * that two base backups started at the same time might use
9107 : : * the same checkpoint as starting locations.
9108 : : */
9109 : 0 : gotUniqueStartpoint = true;
9110 : 0 : }
9111 : :
9112 : : /*
9113 : : * If two base backups are started at the same time (in WAL sender
9114 : : * processes), we need to make sure that they use different
9115 : : * checkpoints as starting locations, because we use the starting
9116 : : * WAL location as a unique identifier for the base backup in the
9117 : : * end-of-backup WAL record and when we write the backup history
9118 : : * file. Perhaps it would be better generate a separate unique ID
9119 : : * for each backup instead of forcing another checkpoint, but
9120 : : * taking a checkpoint right after another is not that expensive
9121 : : * either because only few buffers have been dirtied yet.
9122 : : */
9123 : 0 : WALInsertLockAcquireExclusive();
9124 [ # # ]: 0 : if (XLogCtl->Insert.lastBackupStart < state->startpoint)
9125 : : {
9126 : 0 : XLogCtl->Insert.lastBackupStart = state->startpoint;
9127 : 0 : gotUniqueStartpoint = true;
9128 : 0 : }
9129 : 0 : WALInsertLockRelease();
9130 [ # # ]: 0 : } while (!gotUniqueStartpoint);
9131 : :
9132 : : /*
9133 : : * Construct tablespace_map file.
9134 : : */
9135 : 0 : datadirpathlen = strlen(DataDir);
9136 : :
9137 : : /* Collect information about all tablespaces */
9138 : 0 : tblspcdir = AllocateDir(PG_TBLSPC_DIR);
9139 [ # # ]: 0 : while ((de = ReadDir(tblspcdir, PG_TBLSPC_DIR)) != NULL)
9140 : : {
9141 : 0 : char fullpath[MAXPGPATH + sizeof(PG_TBLSPC_DIR)];
9142 : 0 : char linkpath[MAXPGPATH];
9143 : 0 : char *relpath = NULL;
9144 : 0 : char *s;
9145 : 0 : PGFileType de_type;
9146 : 0 : char *badp;
9147 : 0 : Oid tsoid;
9148 : :
9149 : : /*
9150 : : * Try to parse the directory name as an unsigned integer.
9151 : : *
9152 : : * Tablespace directories should be positive integers that can be
9153 : : * represented in 32 bits, with no leading zeroes or trailing
9154 : : * garbage. If we come across a name that doesn't meet those
9155 : : * criteria, skip it.
9156 : : */
9157 [ # # # # ]: 0 : if (de->d_name[0] < '1' || de->d_name[1] > '9')
9158 : 0 : continue;
9159 : 0 : errno = 0;
9160 : 0 : tsoid = strtoul(de->d_name, &badp, 10);
9161 [ # # # # : 0 : if (*badp != '\0' || errno == EINVAL || errno == ERANGE)
# # ]
9162 : 0 : continue;
9163 : :
9164 : 0 : snprintf(fullpath, sizeof(fullpath), "%s/%s", PG_TBLSPC_DIR, de->d_name);
9165 : :
9166 : 0 : de_type = get_dirent_type(fullpath, de, false, ERROR);
9167 : :
9168 [ # # ]: 0 : if (de_type == PGFILETYPE_LNK)
9169 : : {
9170 : 0 : StringInfoData escapedpath;
9171 : 0 : int rllen;
9172 : :
9173 : 0 : rllen = readlink(fullpath, linkpath, sizeof(linkpath));
9174 [ # # ]: 0 : if (rllen < 0)
9175 : : {
9176 [ # # # # ]: 0 : ereport(WARNING,
9177 : : (errmsg("could not read symbolic link \"%s\": %m",
9178 : : fullpath)));
9179 : 0 : continue;
9180 : : }
9181 [ # # ]: 0 : else if (rllen >= sizeof(linkpath))
9182 : : {
9183 [ # # # # ]: 0 : ereport(WARNING,
9184 : : (errmsg("symbolic link \"%s\" target is too long",
9185 : : fullpath)));
9186 : 0 : continue;
9187 : : }
9188 : 0 : linkpath[rllen] = '\0';
9189 : :
9190 : : /*
9191 : : * Relpath holds the relative path of the tablespace directory
9192 : : * when it's located within PGDATA, or NULL if it's located
9193 : : * elsewhere.
9194 : : */
9195 [ # # ]: 0 : if (rllen > datadirpathlen &&
9196 [ # # # # ]: 0 : strncmp(linkpath, DataDir, datadirpathlen) == 0 &&
9197 : 0 : IS_DIR_SEP(linkpath[datadirpathlen]))
9198 : 0 : relpath = pstrdup(linkpath + datadirpathlen + 1);
9199 : :
9200 : : /*
9201 : : * Add a backslash-escaped version of the link path to the
9202 : : * tablespace map file.
9203 : : */
9204 : 0 : initStringInfo(&escapedpath);
9205 [ # # ]: 0 : for (s = linkpath; *s; s++)
9206 : : {
9207 [ # # # # : 0 : if (*s == '\n' || *s == '\r' || *s == '\\')
# # ]
9208 : 0 : appendStringInfoChar(&escapedpath, '\\');
9209 : 0 : appendStringInfoChar(&escapedpath, *s);
9210 : 0 : }
9211 : 0 : appendStringInfo(tblspcmapfile, "%s %s\n",
9212 : 0 : de->d_name, escapedpath.data);
9213 : 0 : pfree(escapedpath.data);
9214 [ # # ]: 0 : }
9215 [ # # ]: 0 : else if (de_type == PGFILETYPE_DIR)
9216 : : {
9217 : : /*
9218 : : * It's possible to use allow_in_place_tablespaces to create
9219 : : * directories directly under pg_tblspc, for testing purposes
9220 : : * only.
9221 : : *
9222 : : * In this case, we store a relative path rather than an
9223 : : * absolute path into the tablespaceinfo.
9224 : : */
9225 : 0 : snprintf(linkpath, sizeof(linkpath), "%s/%s",
9226 : 0 : PG_TBLSPC_DIR, de->d_name);
9227 : 0 : relpath = pstrdup(linkpath);
9228 : 0 : }
9229 : : else
9230 : : {
9231 : : /* Skip any other file type that appears here. */
9232 : 0 : continue;
9233 : : }
9234 : :
9235 : 0 : ti = palloc_object(tablespaceinfo);
9236 : 0 : ti->oid = tsoid;
9237 : 0 : ti->path = pstrdup(linkpath);
9238 : 0 : ti->rpath = relpath;
9239 : 0 : ti->size = -1;
9240 : :
9241 [ # # ]: 0 : if (tablespaces)
9242 : 0 : *tablespaces = lappend(*tablespaces, ti);
9243 [ # # # ]: 0 : }
9244 : 0 : FreeDir(tblspcdir);
9245 : :
9246 : 0 : state->starttime = (pg_time_t) time(NULL);
9247 : 0 : }
9248 [ # # ]: 0 : PG_END_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(true));
9249 : :
9250 : 0 : state->started_in_recovery = backup_started_in_recovery;
9251 : :
9252 : : /*
9253 : : * Mark that the start phase has correctly finished for the backup.
9254 : : */
9255 : 0 : sessionBackupState = SESSION_BACKUP_RUNNING;
9256 : 0 : }
9257 : :
9258 : : /*
9259 : : * Utility routine to fetch the session-level status of a backup running.
9260 : : */
9261 : : SessionBackupState
9262 : 0 : get_backup_status(void)
9263 : : {
9264 : 0 : return sessionBackupState;
9265 : : }
9266 : :
9267 : : /*
9268 : : * do_pg_backup_stop
9269 : : *
9270 : : * Utility function called at the end of an online backup. It creates history
9271 : : * file (if required), resets sessionBackupState and so on. It can optionally
9272 : : * wait for WAL segments to be archived.
9273 : : *
9274 : : * "state" is filled with the information necessary to restore from this
9275 : : * backup with its stop LSN (stoppoint), its timeline ID (stoptli), etc.
9276 : : *
9277 : : * It is the responsibility of the caller of this function to verify the
9278 : : * permissions of the calling user!
9279 : : */
9280 : : void
9281 : 0 : do_pg_backup_stop(BackupState *state, bool waitforarchive)
9282 : : {
9283 : 0 : bool backup_stopped_in_recovery = false;
9284 : 0 : char histfilepath[MAXPGPATH];
9285 : 0 : char lastxlogfilename[MAXFNAMELEN];
9286 : 0 : char histfilename[MAXFNAMELEN];
9287 : 0 : XLogSegNo _logSegNo;
9288 : 0 : FILE *fp;
9289 : 0 : int seconds_before_warning;
9290 : 0 : int waits = 0;
9291 : 0 : bool reported_waiting = false;
9292 : :
9293 [ # # ]: 0 : Assert(state != NULL);
9294 : :
9295 : 0 : backup_stopped_in_recovery = RecoveryInProgress();
9296 : :
9297 : : /*
9298 : : * During recovery, we don't need to check WAL level. Because, if WAL
9299 : : * level is not sufficient, it's impossible to get here during recovery.
9300 : : */
9301 [ # # # # ]: 0 : if (!backup_stopped_in_recovery && !XLogIsNeeded())
9302 [ # # # # ]: 0 : ereport(ERROR,
9303 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9304 : : errmsg("WAL level not sufficient for making an online backup"),
9305 : : errhint("\"wal_level\" must be set to \"replica\" or \"logical\" at server start.")));
9306 : :
9307 : : /*
9308 : : * OK to update backup counter and session-level lock.
9309 : : *
9310 : : * Note that CHECK_FOR_INTERRUPTS() must not occur while updating them,
9311 : : * otherwise they can be updated inconsistently, which might cause
9312 : : * do_pg_abort_backup() to fail.
9313 : : */
9314 : 0 : WALInsertLockAcquireExclusive();
9315 : :
9316 : : /*
9317 : : * It is expected that each do_pg_backup_start() call is matched by
9318 : : * exactly one do_pg_backup_stop() call.
9319 : : */
9320 [ # # ]: 0 : Assert(XLogCtl->Insert.runningBackups > 0);
9321 : 0 : XLogCtl->Insert.runningBackups--;
9322 : :
9323 : : /*
9324 : : * Clean up session-level lock.
9325 : : *
9326 : : * You might think that WALInsertLockRelease() can be called before
9327 : : * cleaning up session-level lock because session-level lock doesn't need
9328 : : * to be protected with WAL insertion lock. But since
9329 : : * CHECK_FOR_INTERRUPTS() can occur in it, session-level lock must be
9330 : : * cleaned up before it.
9331 : : */
9332 : 0 : sessionBackupState = SESSION_BACKUP_NONE;
9333 : :
9334 : 0 : WALInsertLockRelease();
9335 : :
9336 : : /*
9337 : : * If we are taking an online backup from the standby, we confirm that the
9338 : : * standby has not been promoted during the backup.
9339 : : */
9340 [ # # # # ]: 0 : if (state->started_in_recovery && !backup_stopped_in_recovery)
9341 [ # # # # ]: 0 : ereport(ERROR,
9342 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9343 : : errmsg("the standby was promoted during online backup"),
9344 : : errhint("This means that the backup being taken is corrupt "
9345 : : "and should not be used. "
9346 : : "Try taking another online backup.")));
9347 : :
9348 : : /*
9349 : : * During recovery, we don't write an end-of-backup record. We assume that
9350 : : * pg_control was backed up last and its minimum recovery point can be
9351 : : * available as the backup end location. Since we don't have an
9352 : : * end-of-backup record, we use the pg_control value to check whether
9353 : : * we've reached the end of backup when starting recovery from this
9354 : : * backup. We have no way of checking if pg_control wasn't backed up last
9355 : : * however.
9356 : : *
9357 : : * We don't force a switch to new WAL file but it is still possible to
9358 : : * wait for all the required files to be archived if waitforarchive is
9359 : : * true. This is okay if we use the backup to start a standby and fetch
9360 : : * the missing WAL using streaming replication. But in the case of an
9361 : : * archive recovery, a user should set waitforarchive to true and wait for
9362 : : * them to be archived to ensure that all the required files are
9363 : : * available.
9364 : : *
9365 : : * We return the current minimum recovery point as the backup end
9366 : : * location. Note that it can be greater than the exact backup end
9367 : : * location if the minimum recovery point is updated after the backup of
9368 : : * pg_control. This is harmless for current uses.
9369 : : *
9370 : : * XXX currently a backup history file is for informational and debug
9371 : : * purposes only. It's not essential for an online backup. Furthermore,
9372 : : * even if it's created, it will not be archived during recovery because
9373 : : * an archiver is not invoked. So it doesn't seem worthwhile to write a
9374 : : * backup history file during recovery.
9375 : : */
9376 [ # # ]: 0 : if (backup_stopped_in_recovery)
9377 : : {
9378 : 0 : XLogRecPtr recptr;
9379 : :
9380 : : /*
9381 : : * Check to see if all WAL replayed during online backup contain
9382 : : * full-page writes.
9383 : : */
9384 [ # # ]: 0 : SpinLockAcquire(&XLogCtl->info_lck);
9385 : 0 : recptr = XLogCtl->lastFpwDisableRecPtr;
9386 : 0 : SpinLockRelease(&XLogCtl->info_lck);
9387 : :
9388 [ # # ]: 0 : if (state->startpoint <= recptr)
9389 [ # # # # ]: 0 : ereport(ERROR,
9390 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9391 : : errmsg("WAL generated with \"full_page_writes=off\" was replayed "
9392 : : "during online backup"),
9393 : : errhint("This means that the backup being taken on the standby "
9394 : : "is corrupt and should not be used. "
9395 : : "Enable \"full_page_writes\" and run CHECKPOINT on the primary, "
9396 : : "and then try an online backup again.")));
9397 : :
9398 : :
9399 : 0 : LWLockAcquire(ControlFileLock, LW_SHARED);
9400 : 0 : state->stoppoint = ControlFile->minRecoveryPoint;
9401 : 0 : state->stoptli = ControlFile->minRecoveryPointTLI;
9402 : 0 : LWLockRelease(ControlFileLock);
9403 : 0 : }
9404 : : else
9405 : : {
9406 : 0 : char *history_file;
9407 : :
9408 : : /*
9409 : : * Write the backup-end xlog record
9410 : : */
9411 : 0 : XLogBeginInsert();
9412 : 0 : XLogRegisterData(&state->startpoint,
9413 : : sizeof(state->startpoint));
9414 : 0 : state->stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END);
9415 : :
9416 : : /*
9417 : : * Given that we're not in recovery, InsertTimeLineID is set and can't
9418 : : * change, so we can read it without a lock.
9419 : : */
9420 : 0 : state->stoptli = XLogCtl->InsertTimeLineID;
9421 : :
9422 : : /*
9423 : : * Force a switch to a new xlog segment file, so that the backup is
9424 : : * valid as soon as archiver moves out the current segment file.
9425 : : */
9426 : 0 : RequestXLogSwitch(false);
9427 : :
9428 : 0 : state->stoptime = (pg_time_t) time(NULL);
9429 : :
9430 : : /*
9431 : : * Write the backup history file
9432 : : */
9433 : 0 : XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
9434 : 0 : BackupHistoryFilePath(histfilepath, state->stoptli, _logSegNo,
9435 : 0 : state->startpoint, wal_segment_size);
9436 : 0 : fp = AllocateFile(histfilepath, "w");
9437 [ # # ]: 0 : if (!fp)
9438 [ # # # # ]: 0 : ereport(ERROR,
9439 : : (errcode_for_file_access(),
9440 : : errmsg("could not create file \"%s\": %m",
9441 : : histfilepath)));
9442 : :
9443 : : /* Build and save the contents of the backup history file */
9444 : 0 : history_file = build_backup_content(state, true);
9445 : 0 : fprintf(fp, "%s", history_file);
9446 : 0 : pfree(history_file);
9447 : :
9448 [ # # ]: 0 : if (fflush(fp) || ferror(fp) || FreeFile(fp))
9449 [ # # # # ]: 0 : ereport(ERROR,
9450 : : (errcode_for_file_access(),
9451 : : errmsg("could not write file \"%s\": %m",
9452 : : histfilepath)));
9453 : :
9454 : : /*
9455 : : * Clean out any no-longer-needed history files. As a side effect,
9456 : : * this will post a .ready file for the newly created history file,
9457 : : * notifying the archiver that history file may be archived
9458 : : * immediately.
9459 : : */
9460 : 0 : CleanupBackupHistory();
9461 : 0 : }
9462 : :
9463 : : /*
9464 : : * If archiving is enabled, wait for all the required WAL files to be
9465 : : * archived before returning. If archiving isn't enabled, the required WAL
9466 : : * needs to be transported via streaming replication (hopefully with
9467 : : * wal_keep_size set high enough), or some more exotic mechanism like
9468 : : * polling and copying files from pg_wal with script. We have no knowledge
9469 : : * of those mechanisms, so it's up to the user to ensure that he gets all
9470 : : * the required WAL.
9471 : : *
9472 : : * We wait until both the last WAL file filled during backup and the
9473 : : * history file have been archived, and assume that the alphabetic sorting
9474 : : * property of the WAL files ensures any earlier WAL files are safely
9475 : : * archived as well.
9476 : : *
9477 : : * We wait forever, since archive_command is supposed to work and we
9478 : : * assume the admin wanted his backup to work completely. If you don't
9479 : : * wish to wait, then either waitforarchive should be passed in as false,
9480 : : * or you can set statement_timeout. Also, some notices are issued to
9481 : : * clue in anyone who might be doing this interactively.
9482 : : */
9483 : :
9484 [ # # ]: 0 : if (waitforarchive &&
9485 [ # # # # : 0 : ((!backup_stopped_in_recovery && XLogArchivingActive()) ||
# # # # ]
9486 [ # # # # : 0 : (backup_stopped_in_recovery && XLogArchivingAlways())))
# # ]
9487 : : {
9488 : 0 : XLByteToPrevSeg(state->stoppoint, _logSegNo, wal_segment_size);
9489 : 0 : XLogFileName(lastxlogfilename, state->stoptli, _logSegNo,
9490 : 0 : wal_segment_size);
9491 : :
9492 : 0 : XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
9493 : 0 : BackupHistoryFileName(histfilename, state->stoptli, _logSegNo,
9494 : 0 : state->startpoint, wal_segment_size);
9495 : :
9496 : 0 : seconds_before_warning = 60;
9497 : 0 : waits = 0;
9498 : :
9499 [ # # # # ]: 0 : while (XLogArchiveIsBusy(lastxlogfilename) ||
9500 : 0 : XLogArchiveIsBusy(histfilename))
9501 : : {
9502 [ # # ]: 0 : CHECK_FOR_INTERRUPTS();
9503 : :
9504 [ # # # # ]: 0 : if (!reported_waiting && waits > 5)
9505 : : {
9506 [ # # # # ]: 0 : ereport(NOTICE,
9507 : : (errmsg("base backup done, waiting for required WAL segments to be archived")));
9508 : 0 : reported_waiting = true;
9509 : 0 : }
9510 : :
9511 : 0 : (void) WaitLatch(MyLatch,
9512 : : WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
9513 : : 1000L,
9514 : : WAIT_EVENT_BACKUP_WAIT_WAL_ARCHIVE);
9515 : 0 : ResetLatch(MyLatch);
9516 : :
9517 [ # # ]: 0 : if (++waits >= seconds_before_warning)
9518 : : {
9519 : 0 : seconds_before_warning *= 2; /* This wraps in >10 years... */
9520 [ # # # # ]: 0 : ereport(WARNING,
9521 : : (errmsg("still waiting for all required WAL segments to be archived (%d seconds elapsed)",
9522 : : waits),
9523 : : errhint("Check that your \"archive_command\" is executing properly. "
9524 : : "You can safely cancel this backup, "
9525 : : "but the database backup will not be usable without all the WAL segments.")));
9526 : 0 : }
9527 : : }
9528 : :
9529 [ # # # # ]: 0 : ereport(NOTICE,
9530 : : (errmsg("all required WAL segments have been archived")));
9531 : 0 : }
9532 [ # # ]: 0 : else if (waitforarchive)
9533 [ # # # # ]: 0 : ereport(NOTICE,
9534 : : (errmsg("WAL archiving is not enabled; you must ensure that all required WAL segments are copied through other means to complete the backup")));
9535 : 0 : }
9536 : :
9537 : :
9538 : : /*
9539 : : * do_pg_abort_backup: abort a running backup
9540 : : *
9541 : : * This does just the most basic steps of do_pg_backup_stop(), by taking the
9542 : : * system out of backup mode, thus making it a lot more safe to call from
9543 : : * an error handler.
9544 : : *
9545 : : * 'arg' indicates that it's being called during backup setup; so
9546 : : * sessionBackupState has not been modified yet, but runningBackups has
9547 : : * already been incremented. When it's false, then it's invoked as a
9548 : : * before_shmem_exit handler, and therefore we must not change state
9549 : : * unless sessionBackupState indicates that a backup is actually running.
9550 : : *
9551 : : * NB: This gets used as a PG_ENSURE_ERROR_CLEANUP callback and
9552 : : * before_shmem_exit handler, hence the odd-looking signature.
9553 : : */
9554 : : void
9555 : 0 : do_pg_abort_backup(int code, Datum arg)
9556 : : {
9557 : 0 : bool during_backup_start = DatumGetBool(arg);
9558 : :
9559 : : /* If called during backup start, there shouldn't be one already running */
9560 [ # # # # ]: 0 : Assert(!during_backup_start || sessionBackupState == SESSION_BACKUP_NONE);
9561 : :
9562 [ # # # # ]: 0 : if (during_backup_start || sessionBackupState != SESSION_BACKUP_NONE)
9563 : : {
9564 : 0 : WALInsertLockAcquireExclusive();
9565 [ # # ]: 0 : Assert(XLogCtl->Insert.runningBackups > 0);
9566 : 0 : XLogCtl->Insert.runningBackups--;
9567 : :
9568 : 0 : sessionBackupState = SESSION_BACKUP_NONE;
9569 : 0 : WALInsertLockRelease();
9570 : :
9571 [ # # ]: 0 : if (!during_backup_start)
9572 [ # # # # ]: 0 : ereport(WARNING,
9573 : : errmsg("aborting backup due to backend exiting before pg_backup_stop was called"));
9574 : 0 : }
9575 : 0 : }
9576 : :
9577 : : /*
9578 : : * Register a handler that will warn about unterminated backups at end of
9579 : : * session, unless this has already been done.
9580 : : */
9581 : : void
9582 : 0 : register_persistent_abort_backup_handler(void)
9583 : : {
9584 : : static bool already_done = false;
9585 : :
9586 [ # # ]: 0 : if (already_done)
9587 : 0 : return;
9588 : 0 : before_shmem_exit(do_pg_abort_backup, BoolGetDatum(false));
9589 : 0 : already_done = true;
9590 : 0 : }
9591 : :
9592 : : /*
9593 : : * Get latest WAL insert pointer
9594 : : */
9595 : : XLogRecPtr
9596 : 0 : GetXLogInsertRecPtr(void)
9597 : : {
9598 : 0 : XLogCtlInsert *Insert = &XLogCtl->Insert;
9599 : 0 : uint64 current_bytepos;
9600 : :
9601 [ # # ]: 0 : SpinLockAcquire(&Insert->insertpos_lck);
9602 : 0 : current_bytepos = Insert->CurrBytePos;
9603 : 0 : SpinLockRelease(&Insert->insertpos_lck);
9604 : :
9605 : 0 : return XLogBytePosToRecPtr(current_bytepos);
9606 : 0 : }
9607 : :
9608 : : /*
9609 : : * Get latest WAL write pointer
9610 : : */
9611 : : XLogRecPtr
9612 : 1 : GetXLogWriteRecPtr(void)
9613 : : {
9614 : 1 : RefreshXLogWriteResult(LogwrtResult);
9615 : :
9616 : 1 : return LogwrtResult.Write;
9617 : : }
9618 : :
9619 : : /*
9620 : : * Returns the redo pointer of the last checkpoint or restartpoint. This is
9621 : : * the oldest point in WAL that we still need, if we have to restart recovery.
9622 : : */
9623 : : void
9624 : 0 : GetOldestRestartPoint(XLogRecPtr *oldrecptr, TimeLineID *oldtli)
9625 : : {
9626 : 0 : LWLockAcquire(ControlFileLock, LW_SHARED);
9627 : 0 : *oldrecptr = ControlFile->checkPointCopy.redo;
9628 : 0 : *oldtli = ControlFile->checkPointCopy.ThisTimeLineID;
9629 : 0 : LWLockRelease(ControlFileLock);
9630 : 0 : }
9631 : :
9632 : : /* Thin wrapper around ShutdownWalRcv(). */
9633 : : void
9634 : 4 : XLogShutdownWalRcv(void)
9635 : : {
9636 [ + + + - ]: 4 : Assert(AmStartupProcess() || !IsUnderPostmaster);
9637 : :
9638 : 4 : ShutdownWalRcv();
9639 : 4 : ResetInstallXLogFileSegmentActive();
9640 : 4 : }
9641 : :
9642 : : /* Enable WAL file recycling and preallocation. */
9643 : : void
9644 : 5 : SetInstallXLogFileSegmentActive(void)
9645 : : {
9646 : 5 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
9647 : 5 : XLogCtl->InstallXLogFileSegmentActive = true;
9648 : 5 : LWLockRelease(ControlFileLock);
9649 : 5 : }
9650 : :
9651 : : /* Disable WAL file recycling and preallocation. */
9652 : : void
9653 : 4 : ResetInstallXLogFileSegmentActive(void)
9654 : : {
9655 : 4 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
9656 : 4 : XLogCtl->InstallXLogFileSegmentActive = false;
9657 : 4 : LWLockRelease(ControlFileLock);
9658 : 4 : }
9659 : :
9660 : : bool
9661 : 0 : IsInstallXLogFileSegmentActive(void)
9662 : : {
9663 : 0 : bool result;
9664 : :
9665 : 0 : LWLockAcquire(ControlFileLock, LW_SHARED);
9666 : 0 : result = XLogCtl->InstallXLogFileSegmentActive;
9667 : 0 : LWLockRelease(ControlFileLock);
9668 : :
9669 : 0 : return result;
9670 : 0 : }
9671 : :
9672 : : /*
9673 : : * Update the WalWriterSleeping flag.
9674 : : */
9675 : : void
9676 : 1 : SetWalWriterSleeping(bool sleeping)
9677 : : {
9678 [ - + ]: 1 : SpinLockAcquire(&XLogCtl->info_lck);
9679 : 1 : XLogCtl->WalWriterSleeping = sleeping;
9680 : 1 : SpinLockRelease(&XLogCtl->info_lck);
9681 : 1 : }
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