Age Owner TLA Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * xloginsert.c
4 : * Functions for constructing WAL records
5 : *
6 : * Constructing a WAL record begins with a call to XLogBeginInsert,
7 : * followed by a number of XLogRegister* calls. The registered data is
8 : * collected in private working memory, and finally assembled into a chain
9 : * of XLogRecData structs by a call to XLogRecordAssemble(). See
10 : * access/transam/README for details.
11 : *
12 : * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
13 : * Portions Copyright (c) 1994, Regents of the University of California
14 : *
15 : * src/backend/access/transam/xloginsert.c
16 : *
17 : *-------------------------------------------------------------------------
18 : */
19 :
20 : #include "postgres.h"
21 :
22 : #ifdef USE_LZ4
23 : #include <lz4.h>
24 : #endif
25 :
26 : #ifdef USE_ZSTD
27 : #include <zstd.h>
28 : #endif
29 :
30 : #include "access/xact.h"
31 : #include "access/xlog.h"
32 : #include "access/xlog_internal.h"
33 : #include "access/xloginsert.h"
34 : #include "catalog/pg_control.h"
35 : #include "common/pg_lzcompress.h"
36 : #include "executor/instrument.h"
37 : #include "miscadmin.h"
38 : #include "pg_trace.h"
39 : #include "replication/origin.h"
40 : #include "storage/bufmgr.h"
41 : #include "storage/proc.h"
42 : #include "utils/memutils.h"
43 :
44 : /*
45 : * Guess the maximum buffer size required to store a compressed version of
46 : * backup block image.
47 : */
48 : #ifdef USE_LZ4
49 : #define LZ4_MAX_BLCKSZ LZ4_COMPRESSBOUND(BLCKSZ)
50 : #else
51 : #define LZ4_MAX_BLCKSZ 0
52 : #endif
53 :
54 : #ifdef USE_ZSTD
55 : #define ZSTD_MAX_BLCKSZ ZSTD_COMPRESSBOUND(BLCKSZ)
56 : #else
57 : #define ZSTD_MAX_BLCKSZ 0
58 : #endif
59 :
60 : #define PGLZ_MAX_BLCKSZ PGLZ_MAX_OUTPUT(BLCKSZ)
61 :
62 : /* Buffer size required to store a compressed version of backup block image */
63 : #define COMPRESS_BUFSIZE Max(Max(PGLZ_MAX_BLCKSZ, LZ4_MAX_BLCKSZ), ZSTD_MAX_BLCKSZ)
64 :
65 : /*
66 : * For each block reference registered with XLogRegisterBuffer, we fill in
67 : * a registered_buffer struct.
68 : */
69 : typedef struct
70 : {
71 : bool in_use; /* is this slot in use? */
72 : uint8 flags; /* REGBUF_* flags */
73 : RelFileLocator rlocator; /* identifies the relation and block */
74 : ForkNumber forkno;
75 : BlockNumber block;
76 : Page page; /* page content */
77 : uint32 rdata_len; /* total length of data in rdata chain */
78 : XLogRecData *rdata_head; /* head of the chain of data registered with
79 : * this block */
80 : XLogRecData *rdata_tail; /* last entry in the chain, or &rdata_head if
81 : * empty */
82 :
83 : XLogRecData bkp_rdatas[2]; /* temporary rdatas used to hold references to
84 : * backup block data in XLogRecordAssemble() */
85 :
86 : /* buffer to store a compressed version of backup block image */
87 : char compressed_page[COMPRESS_BUFSIZE];
88 : } registered_buffer;
89 :
90 : static registered_buffer *registered_buffers;
91 : static int max_registered_buffers; /* allocated size */
92 : static int max_registered_block_id = 0; /* highest block_id + 1 currently
93 : * registered */
94 :
95 : /*
96 : * A chain of XLogRecDatas to hold the "main data" of a WAL record, registered
97 : * with XLogRegisterData(...).
98 : */
99 : static XLogRecData *mainrdata_head;
100 : static XLogRecData *mainrdata_last = (XLogRecData *) &mainrdata_head;
101 : static uint64 mainrdata_len; /* total # of bytes in chain */
102 :
103 : /* flags for the in-progress insertion */
104 : static uint8 curinsert_flags = 0;
105 :
106 : /*
107 : * These are used to hold the record header while constructing a record.
108 : * 'hdr_scratch' is not a plain variable, but is palloc'd at initialization,
109 : * because we want it to be MAXALIGNed and padding bytes zeroed.
110 : *
111 : * For simplicity, it's allocated large enough to hold the headers for any
112 : * WAL record.
113 : */
114 : static XLogRecData hdr_rdt;
115 : static char *hdr_scratch = NULL;
116 :
117 : #define SizeOfXlogOrigin (sizeof(RepOriginId) + sizeof(char))
118 : #define SizeOfXLogTransactionId (sizeof(TransactionId) + sizeof(char))
119 :
120 : #define HEADER_SCRATCH_SIZE \
121 : (SizeOfXLogRecord + \
122 : MaxSizeOfXLogRecordBlockHeader * (XLR_MAX_BLOCK_ID + 1) + \
123 : SizeOfXLogRecordDataHeaderLong + SizeOfXlogOrigin + \
124 : SizeOfXLogTransactionId)
125 :
126 : /*
127 : * An array of XLogRecData structs, to hold registered data.
128 : */
129 : static XLogRecData *rdatas;
130 : static int num_rdatas; /* entries currently used */
131 : static int max_rdatas; /* allocated size */
132 :
133 : static bool begininsert_called = false;
134 :
135 : /* Memory context to hold the registered buffer and data references. */
136 : static MemoryContext xloginsert_cxt;
137 :
138 : static XLogRecData *XLogRecordAssemble(RmgrId rmid, uint8 info,
139 : XLogRecPtr RedoRecPtr, bool doPageWrites,
140 : XLogRecPtr *fpw_lsn, int *num_fpi,
141 : bool *topxid_included);
142 : static bool XLogCompressBackupBlock(char *page, uint16 hole_offset,
143 : uint16 hole_length, char *dest, uint16 *dlen);
144 :
145 : /*
146 : * Begin constructing a WAL record. This must be called before the
147 : * XLogRegister* functions and XLogInsert().
148 : */
149 : void
3062 heikki.linnakangas 150 CBC 23120097 : XLogBeginInsert(void)
151 : {
152 23120097 : Assert(max_registered_block_id == 0);
153 23120097 : Assert(mainrdata_last == (XLogRecData *) &mainrdata_head);
154 23120097 : Assert(mainrdata_len == 0);
155 :
156 : /* cross-check on whether we should be here or not */
157 23120097 : if (!XLogInsertAllowed())
3062 heikki.linnakangas 158 UBC 0 : elog(ERROR, "cannot make new WAL entries during recovery");
159 :
2842 heikki.linnakangas 160 CBC 23120097 : if (begininsert_called)
2842 heikki.linnakangas 161 UBC 0 : elog(ERROR, "XLogBeginInsert was already called");
162 :
3062 heikki.linnakangas 163 CBC 23120097 : begininsert_called = true;
164 23120097 : }
165 :
166 : /*
167 : * Ensure that there are enough buffer and data slots in the working area,
168 : * for subsequent XLogRegisterBuffer, XLogRegisterData and XLogRegisterBufData
169 : * calls.
170 : *
171 : * There is always space for a small number of buffers and data chunks, enough
172 : * for most record types. This function is for the exceptional cases that need
173 : * more.
174 : */
175 : void
176 33860 : XLogEnsureRecordSpace(int max_block_id, int ndatas)
177 : {
178 : int nbuffers;
179 :
180 : /*
181 : * This must be called before entering a critical section, because
182 : * allocating memory inside a critical section can fail. repalloc() will
183 : * check the same, but better to check it here too so that we fail
184 : * consistently even if the arrays happen to be large enough already.
185 : */
186 33860 : Assert(CritSectionCount == 0);
187 :
188 : /* the minimum values can't be decreased */
189 33860 : if (max_block_id < XLR_NORMAL_MAX_BLOCK_ID)
190 2084 : max_block_id = XLR_NORMAL_MAX_BLOCK_ID;
191 33860 : if (ndatas < XLR_NORMAL_RDATAS)
192 33846 : ndatas = XLR_NORMAL_RDATAS;
193 :
194 33860 : if (max_block_id > XLR_MAX_BLOCK_ID)
3062 heikki.linnakangas 195 UBC 0 : elog(ERROR, "maximum number of WAL record block references exceeded");
3062 heikki.linnakangas 196 CBC 33860 : nbuffers = max_block_id + 1;
197 :
198 33860 : if (nbuffers > max_registered_buffers)
199 : {
200 500 : registered_buffers = (registered_buffer *)
201 500 : repalloc(registered_buffers, sizeof(registered_buffer) * nbuffers);
202 :
203 : /*
204 : * At least the padding bytes in the structs must be zeroed, because
205 : * they are included in WAL data, but initialize it all for tidiness.
206 : */
207 500 : MemSet(®istered_buffers[max_registered_buffers], 0,
208 : (nbuffers - max_registered_buffers) * sizeof(registered_buffer));
209 500 : max_registered_buffers = nbuffers;
210 : }
211 :
212 33860 : if (ndatas > max_rdatas)
213 : {
214 12 : rdatas = (XLogRecData *) repalloc(rdatas, sizeof(XLogRecData) * ndatas);
215 12 : max_rdatas = ndatas;
216 : }
217 33860 : }
218 :
219 : /*
220 : * Reset WAL record construction buffers.
221 : */
222 : void
223 23144663 : XLogResetInsertion(void)
224 : {
225 : int i;
226 :
227 46358906 : for (i = 0; i < max_registered_block_id; i++)
228 23214243 : registered_buffers[i].in_use = false;
229 :
230 23144663 : num_rdatas = 0;
231 23144663 : max_registered_block_id = 0;
232 23144663 : mainrdata_len = 0;
233 23144663 : mainrdata_last = (XLogRecData *) &mainrdata_head;
2299 andres 234 23144663 : curinsert_flags = 0;
3062 heikki.linnakangas 235 23144663 : begininsert_called = false;
236 23144663 : }
237 :
238 : /*
239 : * Register a reference to a buffer with the WAL record being constructed.
240 : * This must be called for every page that the WAL-logged operation modifies.
241 : */
242 : void
243 22971600 : XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
244 : {
245 : registered_buffer *regbuf;
246 :
247 : /* NO_IMAGE doesn't make sense with FORCE_IMAGE */
248 22971600 : Assert(!((flags & REGBUF_FORCE_IMAGE) && (flags & (REGBUF_NO_IMAGE))));
249 22971600 : Assert(begininsert_called);
250 :
251 22971600 : if (block_id >= max_registered_block_id)
252 : {
253 22616494 : if (block_id >= max_registered_buffers)
3062 heikki.linnakangas 254 UBC 0 : elog(ERROR, "too many registered buffers");
3062 heikki.linnakangas 255 CBC 22616494 : max_registered_block_id = block_id + 1;
256 : }
257 :
258 22971600 : regbuf = ®istered_buffers[block_id];
259 :
277 rhaas 260 GNC 22971600 : BufferGetTag(buffer, ®buf->rlocator, ®buf->forkno, ®buf->block);
2545 kgrittn 261 CBC 22971600 : regbuf->page = BufferGetPage(buffer);
3062 heikki.linnakangas 262 22971600 : regbuf->flags = flags;
263 22971600 : regbuf->rdata_tail = (XLogRecData *) ®buf->rdata_head;
264 22971600 : regbuf->rdata_len = 0;
265 :
266 : /*
267 : * Check that this page hasn't already been registered with some other
268 : * block_id.
269 : */
270 : #ifdef USE_ASSERT_CHECKING
271 : {
272 : int i;
273 :
274 47799162 : for (i = 0; i < max_registered_block_id; i++)
275 : {
276 24827562 : registered_buffer *regbuf_old = ®istered_buffers[i];
277 :
278 24827562 : if (i == block_id || !regbuf_old->in_use)
279 23344453 : continue;
280 :
277 rhaas 281 GNC 1483109 : Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
282 : regbuf_old->forkno != regbuf->forkno ||
283 : regbuf_old->block != regbuf->block);
284 : }
285 : }
286 : #endif
287 :
3062 heikki.linnakangas 288 CBC 22971600 : regbuf->in_use = true;
289 22971600 : }
290 :
291 : /*
292 : * Like XLogRegisterBuffer, but for registering a block that's not in the
293 : * shared buffer pool (i.e. when you don't have a Buffer for it).
294 : */
295 : void
277 rhaas 296 GNC 227106 : XLogRegisterBlock(uint8 block_id, RelFileLocator *rlocator, ForkNumber forknum,
297 : BlockNumber blknum, Page page, uint8 flags)
298 : {
299 : registered_buffer *regbuf;
300 :
3062 heikki.linnakangas 301 CBC 227106 : Assert(begininsert_called);
302 :
303 227106 : if (block_id >= max_registered_block_id)
304 227106 : max_registered_block_id = block_id + 1;
305 :
306 227106 : if (block_id >= max_registered_buffers)
3062 heikki.linnakangas 307 UBC 0 : elog(ERROR, "too many registered buffers");
308 :
3062 heikki.linnakangas 309 CBC 227106 : regbuf = ®istered_buffers[block_id];
310 :
277 rhaas 311 GNC 227106 : regbuf->rlocator = *rlocator;
3062 heikki.linnakangas 312 CBC 227106 : regbuf->forkno = forknum;
313 227106 : regbuf->block = blknum;
314 227106 : regbuf->page = page;
315 227106 : regbuf->flags = flags;
316 227106 : regbuf->rdata_tail = (XLogRecData *) ®buf->rdata_head;
317 227106 : regbuf->rdata_len = 0;
318 :
319 : /*
320 : * Check that this page hasn't already been registered with some other
321 : * block_id.
322 : */
323 : #ifdef USE_ASSERT_CHECKING
324 : {
325 : int i;
326 :
327 460767 : for (i = 0; i < max_registered_block_id; i++)
328 : {
329 233661 : registered_buffer *regbuf_old = ®istered_buffers[i];
330 :
331 233661 : if (i == block_id || !regbuf_old->in_use)
332 227106 : continue;
333 :
277 rhaas 334 GNC 6555 : Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
335 : regbuf_old->forkno != regbuf->forkno ||
336 : regbuf_old->block != regbuf->block);
337 : }
338 : }
339 : #endif
340 :
3062 heikki.linnakangas 341 CBC 227106 : regbuf->in_use = true;
342 227106 : }
343 :
344 : /*
345 : * Add data to the WAL record that's being constructed.
346 : *
347 : * The data is appended to the "main chunk", available at replay with
348 : * XLogRecGetData().
349 : */
350 : void
256 michael 351 GNC 24364384 : XLogRegisterData(char *data, uint32 len)
352 : {
353 : XLogRecData *rdata;
354 :
3062 heikki.linnakangas 355 CBC 24364384 : Assert(begininsert_called);
356 :
357 24364384 : if (num_rdatas >= max_rdatas)
2 michael 358 UNC 0 : ereport(ERROR,
359 : (errmsg_internal("too much WAL data"),
360 : errdetail_internal("%u out of %u data segments are already in use.",
361 : num_rdatas, max_rdatas)));
3062 heikki.linnakangas 362 GIC 24364384 : rdata = &rdatas[num_rdatas++];
363 :
364 24364384 : rdata->data = data;
3062 heikki.linnakangas 365 CBC 24364384 : rdata->len = len;
366 :
3062 heikki.linnakangas 367 ECB : /*
368 : * we use the mainrdata_last pointer to track the end of the chain, so no
369 : * need to clear 'next' here.
370 : */
371 :
3062 heikki.linnakangas 372 GIC 24364384 : mainrdata_last->next = rdata;
373 24364384 : mainrdata_last = rdata;
374 :
3062 heikki.linnakangas 375 CBC 24364384 : mainrdata_len += len;
376 24364384 : }
377 :
3062 heikki.linnakangas 378 ECB : /*
379 : * Add buffer-specific data to the WAL record that's being constructed.
380 : *
381 : * Block_id must reference a block previously registered with
382 : * XLogRegisterBuffer(). If this is called more than once for the same
383 : * block_id, the data is appended.
384 : *
385 : * The maximum amount of data that can be registered per block is 65535
386 : * bytes. That should be plenty; if you need more than BLCKSZ bytes to
387 : * reconstruct the changes to the page, you might as well just log a full
388 : * copy of it. (the "main data" that's not associated with a block is not
389 : * limited)
390 : */
391 : void
256 michael 392 GNC 32267949 : XLogRegisterBufData(uint8 block_id, char *data, uint32 len)
393 : {
394 : registered_buffer *regbuf;
3062 heikki.linnakangas 395 ECB : XLogRecData *rdata;
396 :
3062 heikki.linnakangas 397 GIC 32267949 : Assert(begininsert_called);
398 :
399 : /* find the registered buffer struct */
3062 heikki.linnakangas 400 CBC 32267949 : regbuf = ®istered_buffers[block_id];
3062 heikki.linnakangas 401 GIC 32267949 : if (!regbuf->in_use)
3062 heikki.linnakangas 402 UIC 0 : elog(ERROR, "no block with id %d registered with WAL insertion",
3062 heikki.linnakangas 403 ECB : block_id);
404 :
405 : /*
406 : * Check against max_rdatas and ensure we do not register more data per
407 : * buffer than can be handled by the physical data format; i.e. that
408 : * regbuf->rdata_len does not grow beyond what
409 : * XLogRecordBlockHeader->data_length can hold.
410 : */
2 michael 411 GBC 32267949 : if (num_rdatas >= max_rdatas)
2 michael 412 UNC 0 : ereport(ERROR,
413 : (errmsg_internal("too much WAL data"),
414 : errdetail_internal("%u out of %u data segments are already in use.",
415 : num_rdatas, max_rdatas)));
2 michael 416 GNC 32267949 : if (regbuf->rdata_len + len > UINT16_MAX || len > UINT16_MAX)
2 michael 417 UNC 0 : ereport(ERROR,
418 : (errmsg_internal("too much WAL data"),
419 : errdetail_internal("Registering more than maximum %u bytes allowed to block %u: current %u bytes, adding %u bytes.",
420 : UINT16_MAX, block_id, regbuf->rdata_len, len)));
421 :
3062 heikki.linnakangas 422 GIC 32267949 : rdata = &rdatas[num_rdatas++];
423 :
424 32267949 : rdata->data = data;
425 32267949 : rdata->len = len;
426 :
427 32267949 : regbuf->rdata_tail->next = rdata;
428 32267949 : regbuf->rdata_tail = rdata;
3062 heikki.linnakangas 429 CBC 32267949 : regbuf->rdata_len += len;
3062 heikki.linnakangas 430 GBC 32267949 : }
431 :
432 : /*
433 : * Set insert status flags for the upcoming WAL record.
2299 andres 434 ECB : *
2299 andres 435 EUB : * The flags that can be used here are:
436 : * - XLOG_INCLUDE_ORIGIN, to determine if the replication origin should be
437 : * included in the record.
438 : * - XLOG_MARK_UNIMPORTANT, to signal that the record is not important for
439 : * durability, which allows to avoid triggering WAL archiving and other
2153 bruce 440 ECB : * background activity.
441 : */
2902 andres 442 : void
2299 andres 443 CBC 13933043 : XLogSetRecordFlags(uint8 flags)
444 : {
2902 445 13933043 : Assert(begininsert_called);
993 akapila 446 13933043 : curinsert_flags |= flags;
2902 andres 447 13933043 : }
2902 andres 448 ECB :
449 : /*
450 : * Insert an XLOG record having the specified RMID and info bytes, with the
451 : * body of the record being the data and buffer references registered earlier
452 : * with XLogRegister* calls.
453 : *
454 : * Returns XLOG pointer to end of record (beginning of next record).
455 : * This can be used as LSN for data pages affected by the logged action.
456 : * (LSN is the XLOG point up to which the XLOG must be flushed to disk
457 : * before the data page can be written out. This implements the basic
458 : * WAL rule "write the log before the data".)
459 : */
460 : XLogRecPtr
3062 heikki.linnakangas 461 CBC 23120097 : XLogInsert(RmgrId rmid, uint8 info)
462 : {
3076 heikki.linnakangas 463 ECB : XLogRecPtr EndPos;
464 :
3062 465 : /* XLogBeginInsert() must have been called. */
3062 heikki.linnakangas 466 GIC 23120097 : if (!begininsert_called)
3062 heikki.linnakangas 467 UIC 0 : elog(ERROR, "XLogBeginInsert was not called");
468 :
469 : /*
470 : * The caller can set rmgr bits, XLR_SPECIAL_REL_UPDATE and
471 : * XLR_CHECK_CONSISTENCY; the rest are reserved for use by me.
472 : */
2251 rhaas 473 GIC 23120097 : if ((info & ~(XLR_RMGR_INFO_MASK |
474 : XLR_SPECIAL_REL_UPDATE |
475 : XLR_CHECK_CONSISTENCY)) != 0)
3076 heikki.linnakangas 476 UIC 0 : elog(PANIC, "invalid xlog info mask %02X", info);
477 :
478 : TRACE_POSTGRESQL_WAL_INSERT(rmid, info);
3076 heikki.linnakangas 479 ECB :
480 : /*
481 : * In bootstrap mode, we don't actually log anything but XLOG resources;
482 : * return a phony record pointer.
483 : */
3076 heikki.linnakangas 484 CBC 23120097 : if (IsBootstrapProcessingMode() && rmid != RM_XLOG_ID)
3076 heikki.linnakangas 485 EUB : {
3062 heikki.linnakangas 486 GIC 3720695 : XLogResetInsertion();
2118 tgl 487 3720695 : EndPos = SizeOfXLogLongPHD; /* start of 1st chkpt record */
3076 heikki.linnakangas 488 3720695 : return EndPos;
489 : }
490 :
3062 heikki.linnakangas 491 ECB : do
492 : {
493 : XLogRecPtr RedoRecPtr;
3062 heikki.linnakangas 494 EUB : bool doPageWrites;
523 akapila 495 GIC 19404394 : bool topxid_included = false;
496 : XLogRecPtr fpw_lsn;
497 : XLogRecData *rdt;
1069 498 19404394 : int num_fpi = 0;
499 :
500 : /*
501 : * Get values needed to decide whether to do full-page writes. Since
3062 heikki.linnakangas 502 ECB : * we don't yet have an insertion lock, these could change under us,
503 : * but XLogInsertRecord will recheck them once it has a lock.
3076 504 : */
3062 heikki.linnakangas 505 CBC 19404394 : GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
3076 heikki.linnakangas 506 ECB :
3062 heikki.linnakangas 507 GIC 19404394 : rdt = XLogRecordAssemble(rmid, info, RedoRecPtr, doPageWrites,
508 : &fpw_lsn, &num_fpi, &topxid_included);
509 :
523 akapila 510 19404394 : EndPos = XLogInsertRecord(rdt, fpw_lsn, curinsert_flags, num_fpi,
511 : topxid_included);
3062 heikki.linnakangas 512 19404394 : } while (EndPos == InvalidXLogRecPtr);
3062 heikki.linnakangas 513 ECB :
3062 heikki.linnakangas 514 GIC 19399402 : XLogResetInsertion();
515 :
3076 heikki.linnakangas 516 CBC 19399402 : return EndPos;
517 : }
518 :
519 : /*
520 : * Assemble a WAL record from the registered data and buffers into an
521 : * XLogRecData chain, ready for insertion with XLogInsertRecord().
522 : *
3062 heikki.linnakangas 523 ECB : * The record header fields are filled in, except for the xl_prev field. The
524 : * calculated CRC does not include the record header yet.
3076 525 : *
526 : * If there are any registered buffers, and a full-page image was not taken
527 : * of all of them, *fpw_lsn is set to the lowest LSN among such pages. This
3061 528 : * signals that the assembled record is only good for insertion on the
529 : * assumption that the RedoRecPtr and doPageWrites values were up-to-date.
523 akapila 530 : *
531 : * *topxid_included is set if the topmost transaction ID is logged with the
532 : * current subtransaction.
533 : */
3076 heikki.linnakangas 534 : static XLogRecData *
3062 heikki.linnakangas 535 GIC 19404394 : XLogRecordAssemble(RmgrId rmid, uint8 info,
536 : XLogRecPtr RedoRecPtr, bool doPageWrites,
537 : XLogRecPtr *fpw_lsn, int *num_fpi, bool *topxid_included)
538 : {
539 : XLogRecData *rdt;
2 michael 540 GNC 19404394 : uint64 total_len = 0;
541 : int block_id;
542 : pg_crc32c rdata_crc;
3062 heikki.linnakangas 543 GIC 19404394 : registered_buffer *prev_regbuf = NULL;
544 : XLogRecData *rdt_datas_last;
545 : XLogRecord *rechdr;
546 19404394 : char *scratch = hdr_scratch;
547 :
548 : /*
549 : * Note: this function can be called multiple times for the same record.
550 : * All the modifications we do to the rdata chains below must handle that.
551 : */
552 :
3062 heikki.linnakangas 553 ECB : /* The record begins with the fixed-size header */
3062 heikki.linnakangas 554 GIC 19404394 : rechdr = (XLogRecord *) scratch;
555 19404394 : scratch += SizeOfXLogRecord;
556 :
557 19404394 : hdr_rdt.next = NULL;
3062 heikki.linnakangas 558 CBC 19404394 : rdt_datas_last = &hdr_rdt;
3062 heikki.linnakangas 559 GIC 19404394 : hdr_rdt.data = hdr_scratch;
560 :
2251 rhaas 561 ECB : /*
562 : * Enforce consistency checks for this record if user is looking for it.
563 : * Do this before at the beginning of this routine to give the possibility
2153 bruce 564 : * for callers of XLogInsert() to pass XLR_CHECK_CONSISTENCY directly for
565 : * a record.
566 : */
2251 rhaas 567 GIC 19404394 : if (wal_consistency_checking[rmid])
568 3225 : info |= XLR_CHECK_CONSISTENCY;
569 :
570 : /*
571 : * Make an rdata chain containing all the data portions of all block
3062 heikki.linnakangas 572 ECB : * references. This includes the data for full-page images. Also append
573 : * the headers for the block references in the scratch buffer.
574 : */
3076 heikki.linnakangas 575 CBC 19404394 : *fpw_lsn = InvalidXLogRecPtr;
3062 576 39039459 : for (block_id = 0; block_id < max_registered_block_id; block_id++)
3076 heikki.linnakangas 577 ECB : {
3062 heikki.linnakangas 578 GIC 19635065 : registered_buffer *regbuf = ®istered_buffers[block_id];
579 : bool needs_backup;
580 : bool needs_data;
581 : XLogRecordBlockHeader bkpb;
582 : XLogRecordBlockImageHeader bimg;
2947 fujii 583 19635065 : XLogRecordBlockCompressHeader cbimg = {0};
584 : bool samerel;
2951 fujii 585 CBC 19635065 : bool is_compressed = false;
2251 rhaas 586 ECB : bool include_image;
587 :
3062 heikki.linnakangas 588 GIC 19635065 : if (!regbuf->in_use)
589 15537 : continue;
590 :
591 : /* Determine if this block needs to be backed up */
592 19619528 : if (regbuf->flags & REGBUF_FORCE_IMAGE)
3062 heikki.linnakangas 593 CBC 314590 : needs_backup = true;
594 19304938 : else if (regbuf->flags & REGBUF_NO_IMAGE)
3062 heikki.linnakangas 595 GIC 423687 : needs_backup = false;
3062 heikki.linnakangas 596 CBC 18881251 : else if (!doPageWrites)
3062 heikki.linnakangas 597 GIC 208913 : needs_backup = false;
598 : else
599 : {
600 : /*
3062 heikki.linnakangas 601 ECB : * We assume page LSN is first data on *every* page that can be
602 : * passed to XLogInsert, whether it has the standard page layout
603 : * or not.
604 : */
3062 heikki.linnakangas 605 GIC 18672338 : XLogRecPtr page_lsn = PageGetLSN(regbuf->page);
3062 heikki.linnakangas 606 ECB :
3062 heikki.linnakangas 607 CBC 18672338 : needs_backup = (page_lsn <= RedoRecPtr);
3062 heikki.linnakangas 608 GIC 18672338 : if (!needs_backup)
609 : {
3062 heikki.linnakangas 610 CBC 18592651 : if (*fpw_lsn == InvalidXLogRecPtr || page_lsn < *fpw_lsn)
611 18150756 : *fpw_lsn = page_lsn;
3062 heikki.linnakangas 612 ECB : }
3076 613 : }
3062 614 :
615 : /* Determine if the buffer data needs to included */
3062 heikki.linnakangas 616 GIC 19619528 : if (regbuf->rdata_len == 0)
617 2972249 : needs_data = false;
618 16647279 : else if ((regbuf->flags & REGBUF_KEEP_DATA) != 0)
619 389871 : needs_data = true;
620 : else
621 16257408 : needs_data = !needs_backup;
622 :
3062 heikki.linnakangas 623 CBC 19619528 : bkpb.id = block_id;
3062 heikki.linnakangas 624 GIC 19619528 : bkpb.fork_flags = regbuf->forkno;
3062 heikki.linnakangas 625 CBC 19619528 : bkpb.data_length = 0;
3062 heikki.linnakangas 626 ECB :
3062 heikki.linnakangas 627 GIC 19619528 : if ((regbuf->flags & REGBUF_WILL_INIT) == REGBUF_WILL_INIT)
3062 heikki.linnakangas 628 CBC 277915 : bkpb.fork_flags |= BKPBLOCK_WILL_INIT;
3062 heikki.linnakangas 629 ECB :
630 : /*
631 : * If needs_backup is true or WAL checking is enabled for current
632 : * resource manager, log a full-page write for the current block.
633 : */
2251 rhaas 634 CBC 19619528 : include_image = needs_backup || (info & XLR_CHECK_CONSISTENCY) != 0;
2251 rhaas 635 ECB :
2251 rhaas 636 CBC 19619528 : if (include_image)
3076 heikki.linnakangas 637 ECB : {
3062 heikki.linnakangas 638 GIC 399497 : Page page = regbuf->page;
1880 tgl 639 CBC 399497 : uint16 compressed_len = 0;
640 :
3062 heikki.linnakangas 641 ECB : /*
2951 fujii 642 : * The page needs to be backed up, so calculate its hole length
643 : * and offset.
644 : */
3062 heikki.linnakangas 645 CBC 399497 : if (regbuf->flags & REGBUF_STANDARD)
3076 heikki.linnakangas 646 ECB : {
647 : /* Assume we can omit data between pd_lower and pd_upper */
3062 heikki.linnakangas 648 GIC 302981 : uint16 lower = ((PageHeader) page)->pd_lower;
649 302981 : uint16 upper = ((PageHeader) page)->pd_upper;
650 :
651 302981 : if (lower >= SizeOfPageHeaderData &&
3062 heikki.linnakangas 652 CBC 301878 : upper > lower &&
653 : upper <= BLCKSZ)
3076 heikki.linnakangas 654 ECB : {
2947 fujii 655 GIC 301878 : bimg.hole_offset = lower;
2947 fujii 656 CBC 301878 : cbimg.hole_length = upper - lower;
3076 heikki.linnakangas 657 ECB : }
658 : else
659 : {
660 : /* No "hole" to remove */
2947 fujii 661 GIC 1103 : bimg.hole_offset = 0;
662 1103 : cbimg.hole_length = 0;
3076 heikki.linnakangas 663 ECB : }
664 : }
665 : else
3062 666 : {
667 : /* Not a standard page header, don't try to eliminate "hole" */
2947 fujii 668 GIC 96516 : bimg.hole_offset = 0;
2947 fujii 669 CBC 96516 : cbimg.hole_length = 0;
2951 fujii 670 ECB : }
671 :
672 : /*
673 : * Try to compress a block image if wal_compression is enabled
674 : */
649 michael 675 GIC 399497 : if (wal_compression != WAL_COMPRESSION_NONE)
676 : {
677 : is_compressed =
2947 fujii 678 UIC 0 : XLogCompressBackupBlock(page, bimg.hole_offset,
2947 fujii 679 LBC 0 : cbimg.hole_length,
2951 680 0 : regbuf->compressed_page,
681 : &compressed_len);
682 : }
683 :
684 : /*
685 : * Fill in the remaining fields in the XLogRecordBlockHeader
2878 bruce 686 ECB : * struct
687 : */
3062 heikki.linnakangas 688 GIC 399497 : bkpb.fork_flags |= BKPBLOCK_HAS_IMAGE;
689 :
690 : /* Report a full page image constructed for the WAL record */
1069 akapila 691 399497 : *num_fpi += 1;
692 :
3062 heikki.linnakangas 693 ECB : /*
694 : * Construct XLogRecData entries for the page content.
695 : */
3062 heikki.linnakangas 696 GBC 399497 : rdt_datas_last->next = ®buf->bkp_rdatas[0];
697 399497 : rdt_datas_last = rdt_datas_last->next;
2951 fujii 698 EUB :
2947 fujii 699 GIC 399497 : bimg.bimg_info = (cbimg.hole_length == 0) ? 0 : BKPIMAGE_HAS_HOLE;
700 :
701 : /*
702 : * If WAL consistency checking is enabled for the resource manager
703 : * of this WAL record, a full-page image is included in the record
704 : * for the block modified. During redo, the full-page is replayed
705 : * only if BKPIMAGE_APPLY is set.
2251 rhaas 706 ECB : */
2251 rhaas 707 GIC 399497 : if (needs_backup)
708 394277 : bimg.bimg_info |= BKPIMAGE_APPLY;
2251 rhaas 709 ECB :
2951 fujii 710 GIC 399497 : if (is_compressed)
711 : {
712 : /* The current compression is stored in the WAL record */
2951 fujii 713 UIC 0 : bimg.length = compressed_len;
649 michael 714 ECB :
715 : /* Set the compression method used for this block */
649 michael 716 UIC 0 : switch ((WalCompression) wal_compression)
649 michael 717 ECB : {
649 michael 718 UIC 0 : case WAL_COMPRESSION_PGLZ:
719 0 : bimg.bimg_info |= BKPIMAGE_COMPRESS_PGLZ;
720 0 : break;
721 :
722 0 : case WAL_COMPRESSION_LZ4:
723 : #ifdef USE_LZ4
724 0 : bimg.bimg_info |= BKPIMAGE_COMPRESS_LZ4;
649 michael 725 ECB : #else
726 : elog(ERROR, "LZ4 is not supported by this build");
727 : #endif
649 michael 728 LBC 0 : break;
729 :
394 michael 730 UIC 0 : case WAL_COMPRESSION_ZSTD:
394 michael 731 EUB : #ifdef USE_ZSTD
394 michael 732 UIC 0 : bimg.bimg_info |= BKPIMAGE_COMPRESS_ZSTD;
733 : #else
394 michael 734 EUB : elog(ERROR, "zstd is not supported by this build");
735 : #endif
394 michael 736 UBC 0 : break;
394 michael 737 EUB :
649 michael 738 UBC 0 : case WAL_COMPRESSION_NONE:
649 michael 739 UIC 0 : Assert(false); /* cannot happen */
649 michael 740 EUB : break;
741 : /* no default case, so that compiler will warn */
742 : }
743 :
2951 fujii 744 UIC 0 : rdt_datas_last->data = regbuf->compressed_page;
745 0 : rdt_datas_last->len = compressed_len;
3062 heikki.linnakangas 746 EUB : }
747 : else
748 : {
2947 fujii 749 GIC 399497 : bimg.length = BLCKSZ - cbimg.hole_length;
3076 heikki.linnakangas 750 EUB :
2947 fujii 751 GIC 399497 : if (cbimg.hole_length == 0)
752 : {
2951 753 97619 : rdt_datas_last->data = page;
2951 fujii 754 GBC 97619 : rdt_datas_last->len = BLCKSZ;
755 : }
2951 fujii 756 EUB : else
757 : {
758 : /* must skip the hole */
2951 fujii 759 GIC 301878 : rdt_datas_last->data = page;
2947 760 301878 : rdt_datas_last->len = bimg.hole_offset;
761 :
2951 fujii 762 GBC 301878 : rdt_datas_last->next = ®buf->bkp_rdatas[1];
763 301878 : rdt_datas_last = rdt_datas_last->next;
764 :
2947 fujii 765 GIC 301878 : rdt_datas_last->data =
766 301878 : page + (bimg.hole_offset + cbimg.hole_length);
2947 fujii 767 CBC 301878 : rdt_datas_last->len =
2947 fujii 768 GIC 301878 : BLCKSZ - (bimg.hole_offset + cbimg.hole_length);
2951 fujii 769 ECB : }
770 : }
771 :
2951 fujii 772 CBC 399497 : total_len += bimg.length;
773 : }
774 :
3062 heikki.linnakangas 775 GIC 19619528 : if (needs_data)
776 : {
777 : /*
778 : * When copying to XLogRecordBlockHeader, the length is narrowed
779 : * to an uint16. Double-check that it is still correct.
780 : */
256 michael 781 GNC 16602152 : Assert(regbuf->rdata_len <= UINT16_MAX);
782 :
3062 heikki.linnakangas 783 ECB : /*
784 : * Link the caller-supplied rdata chain for this buffer to the
785 : * overall list.
786 : */
3062 heikki.linnakangas 787 CBC 16602152 : bkpb.fork_flags |= BKPBLOCK_HAS_DATA;
256 michael 788 GNC 16602152 : bkpb.data_length = (uint16) regbuf->rdata_len;
3062 heikki.linnakangas 789 CBC 16602152 : total_len += regbuf->rdata_len;
3062 heikki.linnakangas 790 ECB :
3062 heikki.linnakangas 791 CBC 16602152 : rdt_datas_last->next = regbuf->rdata_head;
792 16602152 : rdt_datas_last = regbuf->rdata_tail;
793 : }
794 :
277 rhaas 795 GNC 19619528 : if (prev_regbuf && RelFileLocatorEquals(regbuf->rlocator, prev_regbuf->rlocator))
3062 heikki.linnakangas 796 ECB : {
3062 heikki.linnakangas 797 GIC 832420 : samerel = true;
798 832420 : bkpb.fork_flags |= BKPBLOCK_SAME_REL;
3062 heikki.linnakangas 799 ECB : }
800 : else
3062 heikki.linnakangas 801 GIC 18787108 : samerel = false;
2897 802 19619528 : prev_regbuf = regbuf;
803 :
804 : /* Ok, copy the header to the scratch buffer */
3062 heikki.linnakangas 805 CBC 19619528 : memcpy(scratch, &bkpb, SizeOfXLogRecordBlockHeader);
3062 heikki.linnakangas 806 GIC 19619528 : scratch += SizeOfXLogRecordBlockHeader;
2251 rhaas 807 19619528 : if (include_image)
808 : {
3062 heikki.linnakangas 809 399497 : memcpy(scratch, &bimg, SizeOfXLogRecordBlockImageHeader);
810 399497 : scratch += SizeOfXLogRecordBlockImageHeader;
2947 fujii 811 CBC 399497 : if (cbimg.hole_length != 0 && is_compressed)
2951 fujii 812 ECB : {
2951 fujii 813 LBC 0 : memcpy(scratch, &cbimg,
814 : SizeOfXLogRecordBlockCompressHeader);
815 0 : scratch += SizeOfXLogRecordBlockCompressHeader;
2951 fujii 816 ECB : }
817 : }
3062 heikki.linnakangas 818 GIC 19619528 : if (!samerel)
3062 heikki.linnakangas 819 ECB : {
277 rhaas 820 GNC 18787108 : memcpy(scratch, ®buf->rlocator, sizeof(RelFileLocator));
821 18787108 : scratch += sizeof(RelFileLocator);
3062 heikki.linnakangas 822 ECB : }
3062 heikki.linnakangas 823 GIC 19619528 : memcpy(scratch, ®buf->block, sizeof(BlockNumber));
824 19619528 : scratch += sizeof(BlockNumber);
3062 heikki.linnakangas 825 ECB : }
3076 826 :
827 : /* followed by the record's origin, if any */
2299 andres 828 GIC 19404394 : if ((curinsert_flags & XLOG_INCLUDE_ORIGIN) &&
2299 andres 829 CBC 10244095 : replorigin_session_origin != InvalidRepOriginId)
2902 andres 830 ECB : {
2203 tgl 831 CBC 149492 : *(scratch++) = (char) XLR_BLOCK_ID_ORIGIN;
2750 alvherre 832 GIC 149492 : memcpy(scratch, &replorigin_session_origin, sizeof(replorigin_session_origin));
2750 alvherre 833 CBC 149492 : scratch += sizeof(replorigin_session_origin);
2902 andres 834 ECB : }
835 :
836 : /* followed by toplevel XID, if not already included in previous record */
523 akapila 837 GBC 19404394 : if (IsSubxactTopXidLogPending())
838 : {
993 839 236 : TransactionId xid = GetTopTransactionIdIfAny();
840 :
841 : /* Set the flag that the top xid is included in the WAL */
523 akapila 842 CBC 236 : *topxid_included = true;
843 :
993 844 236 : *(scratch++) = (char) XLR_BLOCK_ID_TOPLEVEL_XID;
845 236 : memcpy(scratch, &xid, sizeof(TransactionId));
993 akapila 846 GIC 236 : scratch += sizeof(TransactionId);
993 akapila 847 ECB : }
848 :
849 : /* followed by main data, if any */
3062 heikki.linnakangas 850 GIC 19404394 : if (mainrdata_len > 0)
851 : {
3062 heikki.linnakangas 852 CBC 19046256 : if (mainrdata_len > 255)
3076 heikki.linnakangas 853 ECB : {
854 : uint32 mainrdata_len_4b;
855 :
2 michael 856 GNC 69184 : if (mainrdata_len > PG_UINT32_MAX)
2 michael 857 UNC 0 : ereport(ERROR,
858 : (errmsg_internal("too much WAL data"),
859 : errdetail_internal("Main data length is %llu bytes for a maximum of %u bytes.",
860 : (unsigned long long) mainrdata_len,
861 : PG_UINT32_MAX)));
862 :
2 michael 863 GNC 69184 : mainrdata_len_4b = (uint32) mainrdata_len;
2203 tgl 864 GIC 69184 : *(scratch++) = (char) XLR_BLOCK_ID_DATA_LONG;
2 michael 865 GNC 69184 : memcpy(scratch, &mainrdata_len_4b, sizeof(uint32));
3062 heikki.linnakangas 866 CBC 69184 : scratch += sizeof(uint32);
3076 heikki.linnakangas 867 ECB : }
868 : else
869 : {
2203 tgl 870 GIC 18977072 : *(scratch++) = (char) XLR_BLOCK_ID_DATA_SHORT;
3062 heikki.linnakangas 871 CBC 18977072 : *(scratch++) = (uint8) mainrdata_len;
872 : }
873 19046256 : rdt_datas_last->next = mainrdata_head;
3062 heikki.linnakangas 874 GIC 19046256 : rdt_datas_last = mainrdata_last;
875 19046256 : total_len += mainrdata_len;
3076 heikki.linnakangas 876 ECB : }
3062 heikki.linnakangas 877 GIC 19404394 : rdt_datas_last->next = NULL;
3062 heikki.linnakangas 878 ECB :
3062 heikki.linnakangas 879 CBC 19404394 : hdr_rdt.len = (scratch - hdr_scratch);
880 19404394 : total_len += hdr_rdt.len;
881 :
882 : /*
883 : * Calculate CRC of the data
3062 heikki.linnakangas 884 ECB : *
885 : * Note that the record header isn't added into the CRC initially since we
886 : * don't know the prev-link yet. Thus, the CRC will represent the CRC of
887 : * the whole record in the order: rdata, then backup blocks, then record
888 : * header.
889 : */
3062 heikki.linnakangas 890 CBC 19404394 : INIT_CRC32C(rdata_crc);
3062 heikki.linnakangas 891 GBC 19404394 : COMP_CRC32C(rdata_crc, hdr_scratch + SizeOfXLogRecord, hdr_rdt.len - SizeOfXLogRecord);
3062 heikki.linnakangas 892 GIC 65952150 : for (rdt = hdr_rdt.next; rdt != NULL; rdt = rdt->next)
893 46547756 : COMP_CRC32C(rdata_crc, rdt->data, rdt->len);
894 :
895 : /*
896 : * Ensure that the XLogRecord is not too large.
897 : *
898 : * XLogReader machinery is only able to handle records up to a certain
899 : * size (ignoring machine resource limitations), so make sure that we will
900 : * not emit records larger than the sizes advertised to be supported.
901 : * This cap is based on DecodeXLogRecordRequiredSpace().
902 : */
2 michael 903 GNC 19404394 : if (total_len >= XLogRecordMaxSize)
2 michael 904 UNC 0 : ereport(ERROR,
905 : (errmsg_internal("oversized WAL record"),
906 : errdetail_internal("WAL record would be %llu bytes (of maximum %u bytes); rmid %u flags %u.",
907 : (unsigned long long) total_len, XLogRecordMaxSize, rmid, info)));
908 :
909 : /*
910 : * Fill in the fields in the record header. Prev-link is filled in later,
3062 heikki.linnakangas 911 ECB : * once we know where in the WAL the record will be inserted. The CRC does
912 : * not include the record header yet.
3076 913 : */
3076 heikki.linnakangas 914 CBC 19404394 : rechdr->xl_xid = GetCurrentTransactionIdIfAny();
2 michael 915 GNC 19404394 : rechdr->xl_tot_len = (uint32) total_len;
3076 heikki.linnakangas 916 GIC 19404394 : rechdr->xl_info = info;
917 19404394 : rechdr->xl_rmid = rmid;
3076 heikki.linnakangas 918 CBC 19404394 : rechdr->xl_prev = InvalidXLogRecPtr;
3062 919 19404394 : rechdr->xl_crc = rdata_crc;
920 :
3076 921 19404394 : return &hdr_rdt;
3076 heikki.linnakangas 922 ECB : }
923 :
924 : /*
2951 fujii 925 : * Create a compressed version of a backup block image.
926 : *
2062 peter_e 927 : * Returns false if compression fails (i.e., compressed result is actually
928 : * bigger than original). Otherwise, returns true and sets 'dlen' to
929 : * the length of compressed block image.
930 : */
931 : static bool
2878 bruce 932 UIC 0 : XLogCompressBackupBlock(char *page, uint16 hole_offset, uint16 hole_length,
933 : char *dest, uint16 *dlen)
934 : {
2951 fujii 935 0 : int32 orig_len = BLCKSZ - hole_length;
649 michael 936 0 : int32 len = -1;
2951 fujii 937 0 : int32 extra_bytes = 0;
2951 fujii 938 ECB : char *source;
1681 tgl 939 : PGAlignedBlock tmp;
2951 fujii 940 :
2951 fujii 941 LBC 0 : if (hole_length != 0)
942 : {
943 : /* must skip the hole */
1681 tgl 944 UIC 0 : source = tmp.data;
2951 fujii 945 0 : memcpy(source, page, hole_offset);
946 0 : memcpy(source + hole_offset,
947 0 : page + (hole_offset + hole_length),
948 0 : BLCKSZ - (hole_length + hole_offset));
949 :
950 : /*
2951 fujii 951 ECB : * Extra data needs to be stored in WAL record for the compressed
2951 fujii 952 EUB : * version of block image if the hole exists.
953 : */
2951 fujii 954 UIC 0 : extra_bytes = SizeOfXLogRecordBlockCompressHeader;
955 : }
956 : else
957 0 : source = page;
958 :
649 michael 959 0 : switch ((WalCompression) wal_compression)
960 : {
961 0 : case WAL_COMPRESSION_PGLZ:
649 michael 962 LBC 0 : len = pglz_compress(source, orig_len, dest, PGLZ_strategy_default);
963 0 : break;
649 michael 964 ECB :
649 michael 965 LBC 0 : case WAL_COMPRESSION_LZ4:
649 michael 966 ECB : #ifdef USE_LZ4
649 michael 967 LBC 0 : len = LZ4_compress_default(source, dest, orig_len,
968 : COMPRESS_BUFSIZE);
969 0 : if (len <= 0)
649 michael 970 UIC 0 : len = -1; /* failure */
971 : #else
972 : elog(ERROR, "LZ4 is not supported by this build");
973 : #endif
974 0 : break;
975 :
394 976 0 : case WAL_COMPRESSION_ZSTD:
977 : #ifdef USE_ZSTD
978 0 : len = ZSTD_compress(dest, COMPRESS_BUFSIZE, source, orig_len,
979 : ZSTD_CLEVEL_DEFAULT);
394 michael 980 UBC 0 : if (ZSTD_isError(len))
394 michael 981 UIC 0 : len = -1; /* failure */
982 : #else
394 michael 983 EUB : elog(ERROR, "zstd is not supported by this build");
984 : #endif
394 michael 985 UBC 0 : break;
986 :
649 michael 987 UIC 0 : case WAL_COMPRESSION_NONE:
988 0 : Assert(false); /* cannot happen */
649 michael 989 EUB : break;
990 : /* no default case, so that compiler will warn */
991 : }
992 :
2951 fujii 993 : /*
649 michael 994 : * We recheck the actual size even if compression reports success and see
995 : * if the number of bytes saved by compression is larger than the length
996 : * of extra data needed for the compressed version of block image.
997 : */
2951 fujii 998 UIC 0 : if (len >= 0 &&
999 0 : len + extra_bytes < orig_len)
1000 : {
2878 bruce 1001 0 : *dlen = (uint16) len; /* successful compression */
2951 fujii 1002 UBC 0 : return true;
1003 : }
2951 fujii 1004 UIC 0 : return false;
2951 fujii 1005 EUB : }
1006 :
3076 heikki.linnakangas 1007 : /*
1008 : * Determine whether the buffer referenced has to be backed up.
1009 : *
1010 : * Since we don't yet have the insert lock, fullPageWrites and runningBackups
1011 : * (which forces full-page writes) could change later, so the result should
1012 : * be used for optimization purposes only.
1013 : */
1014 : bool
3076 heikki.linnakangas 1015 GBC 188010 : XLogCheckBufferNeedsBackup(Buffer buffer)
1016 : {
3076 heikki.linnakangas 1017 EUB : XLogRecPtr RedoRecPtr;
1018 : bool doPageWrites;
1019 : Page page;
1020 :
3076 heikki.linnakangas 1021 GIC 188010 : GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
3076 heikki.linnakangas 1022 EUB :
2545 kgrittn 1023 GIC 188010 : page = BufferGetPage(buffer);
3076 heikki.linnakangas 1024 EUB :
3076 heikki.linnakangas 1025 GIC 188010 : if (doPageWrites && PageGetLSN(page) <= RedoRecPtr)
3076 heikki.linnakangas 1026 GBC 808 : return true; /* buffer requires backup */
1027 :
1028 187202 : return false; /* buffer does not need to be backed up */
3076 heikki.linnakangas 1029 EUB : }
1030 :
1031 : /*
1032 : * Write a backup block if needed when we are setting a hint. Note that
1033 : * this may be called for a variety of page types, not just heaps.
1034 : *
1035 : * Callable while holding just share lock on the buffer content.
1036 : *
1037 : * We can't use the plain backup block mechanism since that relies on the
1038 : * Buffer being exclusively locked. Since some modifications (setting LSN, hint
1039 : * bits) are allowed in a sharelocked buffer that can lead to wal checksum
1040 : * failures. So instead we copy the page and insert the copied data as normal
1041 : * record data.
1042 : *
1043 : * We only need to do something if page has not yet been full page written in
1044 : * this checkpoint round. The LSN of the inserted wal record is returned if we
1045 : * had to write, InvalidXLogRecPtr otherwise.
1046 : *
1047 : * It is possible that multiple concurrent backends could attempt to write WAL
1048 : * records. In that case, multiple copies of the same block would be recorded
1049 : * in separate WAL records by different backends, though that is still OK from
1050 : * a correctness perspective.
1051 : */
1052 : XLogRecPtr
3076 heikki.linnakangas 1053 GIC 49519 : XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
1054 : {
1055 49519 : XLogRecPtr recptr = InvalidXLogRecPtr;
1056 : XLogRecPtr lsn;
1057 : XLogRecPtr RedoRecPtr;
1058 :
1059 : /*
1060 : * Ensure no checkpoint can change our view of RedoRecPtr.
1061 : */
366 rhaas 1062 49519 : Assert((MyProc->delayChkptFlags & DELAY_CHKPT_START) != 0);
3076 heikki.linnakangas 1063 ECB :
1064 : /*
1065 : * Update RedoRecPtr so that we can make the right decision
1066 : */
3076 heikki.linnakangas 1067 GIC 49519 : RedoRecPtr = GetRedoRecPtr();
1068 :
3076 heikki.linnakangas 1069 ECB : /*
1070 : * We assume page LSN is first data on *every* page that can be passed to
1071 : * XLogInsert, whether it has the standard page layout or not. Since we're
1072 : * only holding a share-lock on the page, we must take the buffer header
1073 : * lock when we look at the LSN.
1074 : */
3076 heikki.linnakangas 1075 GIC 49519 : lsn = BufferGetLSNAtomic(buffer);
3076 heikki.linnakangas 1076 ECB :
3076 heikki.linnakangas 1077 GIC 49519 : if (lsn <= RedoRecPtr)
1078 : {
627 fujii 1079 5122 : int flags = 0;
1080 : PGAlignedBlock copied_buffer;
3076 heikki.linnakangas 1081 5122 : char *origdata = (char *) BufferGetBlock(buffer);
1082 : RelFileLocator rlocator;
1083 : ForkNumber forkno;
1084 : BlockNumber blkno;
1085 :
1086 : /*
1087 : * Copy buffer so we don't have to worry about concurrent hint bit or
1088 : * lsn updates. We assume pd_lower/upper cannot be changed without an
1089 : * exclusive lock, so the contents bkp are not racy.
1090 : */
3062 1091 5122 : if (buffer_std)
1092 : {
1093 : /* Assume we can omit data between pd_lower and pd_upper */
2545 kgrittn 1094 3722 : Page page = BufferGetPage(buffer);
3062 heikki.linnakangas 1095 3722 : uint16 lower = ((PageHeader) page)->pd_lower;
1096 3722 : uint16 upper = ((PageHeader) page)->pd_upper;
1097 :
1681 tgl 1098 3722 : memcpy(copied_buffer.data, origdata, lower);
1099 3722 : memcpy(copied_buffer.data + upper, origdata + upper, BLCKSZ - upper);
1100 : }
3062 heikki.linnakangas 1101 ECB : else
1681 tgl 1102 GIC 1400 : memcpy(copied_buffer.data, origdata, BLCKSZ);
3076 heikki.linnakangas 1103 ECB :
3062 heikki.linnakangas 1104 GIC 5122 : XLogBeginInsert();
1105 :
1106 5122 : if (buffer_std)
1107 3722 : flags |= REGBUF_STANDARD;
1108 :
277 rhaas 1109 GNC 5122 : BufferGetTag(buffer, &rlocator, &forkno, &blkno);
1110 5122 : XLogRegisterBlock(0, &rlocator, forkno, blkno, copied_buffer.data, flags);
1111 :
3058 heikki.linnakangas 1112 GIC 5122 : recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_FOR_HINT);
1113 : }
1114 :
3076 heikki.linnakangas 1115 CBC 49519 : return recptr;
1116 : }
1117 :
1118 : /*
1119 : * Write a WAL record containing a full image of a page. Caller is responsible
1120 : * for writing the page to disk after calling this routine.
1121 : *
1122 : * Note: If you're using this function, you should be building pages in private
3076 heikki.linnakangas 1123 ECB : * memory and writing them directly to smgr. If you're using buffers, call
1124 : * log_newpage_buffer instead.
1125 : *
1126 : * If the page follows the standard page layout, with a PageHeader and unused
2062 peter_e 1127 : * space between pd_lower and pd_upper, set 'page_std' to true. That allows
1128 : * the unused space to be left out from the WAL record, making it smaller.
3076 heikki.linnakangas 1129 : */
1130 : XLogRecPtr
202 pg 1131 GNC 221528 : log_newpage(RelFileLocator *rlocator, ForkNumber forknum, BlockNumber blkno,
1132 : Page page, bool page_std)
1133 : {
1134 : int flags;
1135 : XLogRecPtr recptr;
1136 :
3062 heikki.linnakangas 1137 GIC 221528 : flags = REGBUF_FORCE_IMAGE;
3076 1138 221528 : if (page_std)
3062 heikki.linnakangas 1139 CBC 221445 : flags |= REGBUF_STANDARD;
1140 :
3062 heikki.linnakangas 1141 GIC 221528 : XLogBeginInsert();
202 pg 1142 GNC 221528 : XLogRegisterBlock(0, rlocator, forknum, blkno, page, flags);
3062 heikki.linnakangas 1143 CBC 221528 : recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
3076 heikki.linnakangas 1144 ECB :
1145 : /*
1146 : * The page may be uninitialized. If so, we can't set the LSN because that
1147 : * would corrupt the page.
1148 : */
3076 heikki.linnakangas 1149 GIC 221528 : if (!PageIsNew(page))
3076 heikki.linnakangas 1150 ECB : {
3076 heikki.linnakangas 1151 GIC 221522 : PageSetLSN(page, recptr);
3076 heikki.linnakangas 1152 ECB : }
1153 :
3076 heikki.linnakangas 1154 CBC 221528 : return recptr;
3076 heikki.linnakangas 1155 ECB : }
1156 :
934 1157 : /*
1158 : * Like log_newpage(), but allows logging multiple pages in one operation.
1159 : * It is more efficient than calling log_newpage() for each page separately,
1160 : * because we can write multiple pages in a single WAL record.
1161 : */
1162 : void
202 pg 1163 GNC 19 : log_newpages(RelFileLocator *rlocator, ForkNumber forknum, int num_pages,
1164 : BlockNumber *blknos, Page *pages, bool page_std)
1165 : {
1166 : int flags;
1167 : XLogRecPtr recptr;
1168 : int i;
1169 : int j;
1170 :
934 heikki.linnakangas 1171 GIC 19 : flags = REGBUF_FORCE_IMAGE;
1172 19 : if (page_std)
1173 19 : flags |= REGBUF_STANDARD;
1174 :
1175 : /*
1176 : * Iterate over all the pages. They are collected into batches of
1177 : * XLR_MAX_BLOCK_ID pages, and a single WAL-record is written for each
1178 : * batch.
934 heikki.linnakangas 1179 ECB : */
934 heikki.linnakangas 1180 GIC 19 : XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
1181 :
1182 19 : i = 0;
1183 38 : while (i < num_pages)
1184 : {
934 heikki.linnakangas 1185 CBC 19 : int batch_start = i;
934 heikki.linnakangas 1186 ECB : int nbatch;
1187 :
934 heikki.linnakangas 1188 GIC 19 : XLogBeginInsert();
934 heikki.linnakangas 1189 ECB :
934 heikki.linnakangas 1190 CBC 19 : nbatch = 0;
1191 475 : while (nbatch < XLR_MAX_BLOCK_ID && i < num_pages)
1192 : {
202 pg 1193 GNC 456 : XLogRegisterBlock(nbatch, rlocator, forknum, blknos[i], pages[i], flags);
934 heikki.linnakangas 1194 GIC 456 : i++;
1195 456 : nbatch++;
1196 : }
934 heikki.linnakangas 1197 ECB :
934 heikki.linnakangas 1198 GIC 19 : recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
934 heikki.linnakangas 1199 ECB :
934 heikki.linnakangas 1200 GIC 475 : for (j = batch_start; j < i; j++)
1201 : {
934 heikki.linnakangas 1202 ECB : /*
1203 : * The page may be uninitialized. If so, we can't set the LSN
1204 : * because that would corrupt the page.
1205 : */
934 heikki.linnakangas 1206 GIC 456 : if (!PageIsNew(pages[j]))
1207 : {
1208 456 : PageSetLSN(pages[j], recptr);
1209 : }
1210 : }
934 heikki.linnakangas 1211 ECB : }
934 heikki.linnakangas 1212 GIC 19 : }
1213 :
1214 : /*
1215 : * Write a WAL record containing a full image of a page.
1216 : *
1217 : * Caller should initialize the buffer and mark it dirty before calling this
1218 : * function. This function will set the page LSN.
3076 heikki.linnakangas 1219 ECB : *
1220 : * If the page follows the standard page layout, with a PageHeader and unused
2062 peter_e 1221 : * space between pd_lower and pd_upper, set 'page_std' to true. That allows
1222 : * the unused space to be left out from the WAL record, making it smaller.
1223 : */
1224 : XLogRecPtr
3076 heikki.linnakangas 1225 GIC 104032 : log_newpage_buffer(Buffer buffer, bool page_std)
1226 : {
2545 kgrittn 1227 104032 : Page page = BufferGetPage(buffer);
1228 : RelFileLocator rlocator;
1229 : ForkNumber forknum;
3076 heikki.linnakangas 1230 ECB : BlockNumber blkno;
1231 :
1232 : /* Shared buffers should be modified in a critical section. */
3076 heikki.linnakangas 1233 CBC 104032 : Assert(CritSectionCount > 0);
1234 :
202 pg 1235 GNC 104032 : BufferGetTag(buffer, &rlocator, &forknum, &blkno);
3076 heikki.linnakangas 1236 ECB :
202 pg 1237 GNC 104032 : return log_newpage(&rlocator, forknum, blkno, page, page_std);
3076 heikki.linnakangas 1238 ECB : }
1239 :
1240 : /*
1467 1241 : * WAL-log a range of blocks in a relation.
1242 : *
1401 akapila 1243 : * An image of all pages with block numbers 'startblk' <= X < 'endblk' is
1244 : * written to the WAL. If the range is large, this is done in multiple WAL
1245 : * records.
1467 heikki.linnakangas 1246 : *
1247 : * If all page follows the standard page layout, with a PageHeader and unused
1248 : * space between pd_lower and pd_upper, set 'page_std' to true. That allows
1249 : * the unused space to be left out from the WAL records, making them smaller.
1250 : *
1251 : * NOTE: This function acquires exclusive-locks on the pages. Typically, this
1252 : * is used on a newly-built relation, and the caller is holding a
1253 : * AccessExclusiveLock on it, so no other backend can be accessing it at the
1254 : * same time. If that's not the case, you must ensure that this does not
1255 : * cause a deadlock through some other means.
1256 : */
1257 : void
202 pg 1258 GNC 31653 : log_newpage_range(Relation rel, ForkNumber forknum,
1259 : BlockNumber startblk, BlockNumber endblk,
1467 heikki.linnakangas 1260 ECB : bool page_std)
1261 : {
1262 : int flags;
1263 : BlockNumber blkno;
1264 :
1114 noah 1265 GIC 31653 : flags = REGBUF_FORCE_IMAGE;
1266 31653 : if (page_std)
1267 257 : flags |= REGBUF_STANDARD;
1268 :
1269 : /*
1270 : * Iterate over all the pages in the range. They are collected into
1271 : * batches of XLR_MAX_BLOCK_ID pages, and a single WAL-record is written
1272 : * for each batch.
1467 heikki.linnakangas 1273 ECB : */
1467 heikki.linnakangas 1274 GIC 31653 : XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
1467 heikki.linnakangas 1275 ECB :
1467 heikki.linnakangas 1276 GIC 31653 : blkno = startblk;
1277 55321 : while (blkno < endblk)
1278 : {
1279 : Buffer bufpack[XLR_MAX_BLOCK_ID];
1280 : XLogRecPtr recptr;
1467 heikki.linnakangas 1281 ECB : int nbufs;
1282 : int i;
1283 :
1467 heikki.linnakangas 1284 GIC 23668 : CHECK_FOR_INTERRUPTS();
1467 heikki.linnakangas 1285 ECB :
1286 : /* Collect a batch of blocks. */
1467 heikki.linnakangas 1287 GIC 23668 : nbufs = 0;
1288 114707 : while (nbufs < XLR_MAX_BLOCK_ID && blkno < endblk)
1289 : {
202 pg 1290 GNC 91039 : Buffer buf = ReadBufferExtended(rel, forknum, blkno,
1291 : RBM_NORMAL, NULL);
1292 :
1467 heikki.linnakangas 1293 GIC 91039 : LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
1294 :
1295 : /*
1296 : * Completely empty pages are not WAL-logged. Writing a WAL record
1297 : * would change the LSN, and we don't want that. We want the page
1298 : * to stay empty.
1299 : */
1300 91039 : if (!PageIsNew(BufferGetPage(buf)))
1301 90938 : bufpack[nbufs++] = buf;
1302 : else
1303 101 : UnlockReleaseBuffer(buf);
1304 91039 : blkno++;
1305 : }
1467 heikki.linnakangas 1306 ECB :
1307 : /* Write WAL record for this batch. */
1467 heikki.linnakangas 1308 GIC 23668 : XLogBeginInsert();
1309 :
1310 23668 : START_CRIT_SECTION();
1311 114606 : for (i = 0; i < nbufs; i++)
1312 : {
1114 noah 1313 CBC 90938 : XLogRegisterBuffer(i, bufpack[i], flags);
1467 heikki.linnakangas 1314 90938 : MarkBufferDirty(bufpack[i]);
1467 heikki.linnakangas 1315 ECB : }
1316 :
1467 heikki.linnakangas 1317 GIC 23668 : recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
1318 :
1319 114606 : for (i = 0; i < nbufs; i++)
1320 : {
1321 90938 : PageSetLSN(BufferGetPage(bufpack[i]), recptr);
1467 heikki.linnakangas 1322 CBC 90938 : UnlockReleaseBuffer(bufpack[i]);
1323 : }
1324 23668 : END_CRIT_SECTION();
1467 heikki.linnakangas 1325 ECB : }
1467 heikki.linnakangas 1326 GIC 31653 : }
1327 :
1328 : /*
1329 : * Allocate working buffers needed for WAL record construction.
1330 : */
1331 : void
3062 heikki.linnakangas 1332 CBC 13218 : InitXLogInsert(void)
1333 : {
1334 : #ifdef USE_ASSERT_CHECKING
1335 :
1336 : /*
1337 : * Check that any records assembled can be decoded. This is capped based
1338 : * on what XLogReader would require at its maximum bound. This code path
1339 : * is called once per backend, more than enough for this check.
1340 : */
2 michael 1341 GNC 13218 : size_t max_required = DecodeXLogRecordRequiredSpace(XLogRecordMaxSize);
1342 :
1343 13218 : Assert(AllocSizeIsValid(max_required));
1344 : #endif
1345 :
1346 : /* Initialize the working areas */
3062 heikki.linnakangas 1347 CBC 13218 : if (xloginsert_cxt == NULL)
3062 heikki.linnakangas 1348 ECB : {
3062 heikki.linnakangas 1349 GIC 13218 : xloginsert_cxt = AllocSetContextCreate(TopMemoryContext,
3062 heikki.linnakangas 1350 ECB : "WAL record construction",
1351 : ALLOCSET_DEFAULT_SIZES);
1352 : }
3076 1353 :
3062 heikki.linnakangas 1354 GIC 13218 : if (registered_buffers == NULL)
1355 : {
1356 13218 : registered_buffers = (registered_buffer *)
1357 13218 : MemoryContextAllocZero(xloginsert_cxt,
1358 : sizeof(registered_buffer) * (XLR_NORMAL_MAX_BLOCK_ID + 1));
1359 13218 : max_registered_buffers = XLR_NORMAL_MAX_BLOCK_ID + 1;
3076 heikki.linnakangas 1360 ECB : }
3062 heikki.linnakangas 1361 CBC 13218 : if (rdatas == NULL)
1362 : {
1363 13218 : rdatas = MemoryContextAlloc(xloginsert_cxt,
3062 heikki.linnakangas 1364 ECB : sizeof(XLogRecData) * XLR_NORMAL_RDATAS);
3062 heikki.linnakangas 1365 GIC 13218 : max_rdatas = XLR_NORMAL_RDATAS;
1366 : }
1367 :
3062 heikki.linnakangas 1368 ECB : /*
1369 : * Allocate a buffer to hold the header information for a WAL record.
1370 : */
3062 heikki.linnakangas 1371 CBC 13218 : if (hdr_scratch == NULL)
3054 heikki.linnakangas 1372 GIC 13218 : hdr_scratch = MemoryContextAllocZero(xloginsert_cxt,
3054 heikki.linnakangas 1373 ECB : HEADER_SCRATCH_SIZE);
3076 heikki.linnakangas 1374 CBC 13218 : }
|
