Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * md.c
4 : : * This code manages relations that reside on magnetic disk.
5 : : *
6 : : * Or at least, that was what the Berkeley folk had in mind when they named
7 : : * this file. In reality, what this code provides is an interface from
8 : : * the smgr API to Unix-like filesystem APIs, so it will work with any type
9 : : * of device for which the operating system provides filesystem support.
10 : : * It doesn't matter whether the bits are on spinning rust or some other
11 : : * storage technology.
12 : : *
13 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
14 : : * Portions Copyright (c) 1994, Regents of the University of California
15 : : *
16 : : *
17 : : * IDENTIFICATION
18 : : * src/backend/storage/smgr/md.c
19 : : *
20 : : *-------------------------------------------------------------------------
21 : : */
22 : : #include "postgres.h"
23 : :
24 : : #include <limits.h>
25 : : #include <unistd.h>
26 : : #include <fcntl.h>
27 : : #include <sys/file.h>
28 : :
29 : : #include "access/xlogutils.h"
30 : : #include "commands/tablespace.h"
31 : : #include "common/file_utils.h"
32 : : #include "miscadmin.h"
33 : : #include "pg_trace.h"
34 : : #include "pgstat.h"
35 : : #include "storage/aio.h"
36 : : #include "storage/bufmgr.h"
37 : : #include "storage/fd.h"
38 : : #include "storage/md.h"
39 : : #include "storage/relfilelocator.h"
40 : : #include "storage/smgr.h"
41 : : #include "storage/sync.h"
42 : : #include "utils/memutils.h"
43 : : #include "utils/wait_event.h"
44 : :
45 : : /*
46 : : * The magnetic disk storage manager keeps track of open file
47 : : * descriptors in its own descriptor pool. This is done to make it
48 : : * easier to support relations that are larger than the operating
49 : : * system's file size limit (often 2GBytes). In order to do that,
50 : : * we break relations up into "segment" files that are each shorter than
51 : : * the OS file size limit. The segment size is set by the RELSEG_SIZE
52 : : * configuration constant in pg_config.h.
53 : : *
54 : : * On disk, a relation must consist of consecutively numbered segment
55 : : * files in the pattern
56 : : * -- Zero or more full segments of exactly RELSEG_SIZE blocks each
57 : : * -- Exactly one partial segment of size 0 <= size < RELSEG_SIZE blocks
58 : : * -- Optionally, any number of inactive segments of size 0 blocks.
59 : : * The full and partial segments are collectively the "active" segments.
60 : : * Inactive segments are those that once contained data but are currently
61 : : * not needed because of an mdtruncate() operation. The reason for leaving
62 : : * them present at size zero, rather than unlinking them, is that other
63 : : * backends and/or the checkpointer might be holding open file references to
64 : : * such segments. If the relation expands again after mdtruncate(), such
65 : : * that a deactivated segment becomes active again, it is important that
66 : : * such file references still be valid --- else data might get written
67 : : * out to an unlinked old copy of a segment file that will eventually
68 : : * disappear.
69 : : *
70 : : * RELSEG_SIZE must fit into BlockNumber; but since we expose its value
71 : : * as an integer GUC, it actually needs to fit in signed int. It's worth
72 : : * having a cross-check for this since configure's --with-segsize options
73 : : * could let people select insane values.
74 : : */
75 : : StaticAssertDecl(RELSEG_SIZE > 0 && RELSEG_SIZE <= INT_MAX,
76 : : "RELSEG_SIZE must fit in an integer");
77 : :
78 : : /*
79 : : * File descriptors are stored in the per-fork md_seg_fds arrays inside
80 : : * SMgrRelation. The length of these arrays is stored in md_num_open_segs.
81 : : * Note that a fork's md_num_open_segs having a specific value does not
82 : : * necessarily mean the relation doesn't have additional segments; we may
83 : : * just not have opened the next segment yet. (We could not have "all
84 : : * segments are in the array" as an invariant anyway, since another backend
85 : : * could extend the relation while we aren't looking.) We do not have
86 : : * entries for inactive segments, however; as soon as we find a partial
87 : : * segment, we assume that any subsequent segments are inactive.
88 : : *
89 : : * The entire MdfdVec array is palloc'd in the MdCxt memory context.
90 : : */
91 : :
92 : : typedef struct _MdfdVec
93 : : {
94 : : File mdfd_vfd; /* fd number in fd.c's pool */
95 : : BlockNumber mdfd_segno; /* segment number, from 0 */
96 : : } MdfdVec;
97 : :
98 : : static MemoryContext MdCxt; /* context for all MdfdVec objects */
99 : :
100 : :
101 : : /* Populate a file tag describing an md.c segment file. */
102 : : #define INIT_MD_FILETAG(a,xx_rlocator,xx_forknum,xx_segno) \
103 : : ( \
104 : : memset(&(a), 0, sizeof(FileTag)), \
105 : : (a).handler = SYNC_HANDLER_MD, \
106 : : (a).rlocator = (xx_rlocator), \
107 : : (a).forknum = (xx_forknum), \
108 : : (a).segno = (xx_segno) \
109 : : )
110 : :
111 : :
112 : : /*** behavior for mdopen & _mdfd_getseg ***/
113 : : /* ereport if segment not present */
114 : : #define EXTENSION_FAIL (1 << 0)
115 : : /* return NULL if segment not present */
116 : : #define EXTENSION_RETURN_NULL (1 << 1)
117 : : /* create new segments as needed */
118 : : #define EXTENSION_CREATE (1 << 2)
119 : : /* create new segments if needed during recovery */
120 : : #define EXTENSION_CREATE_RECOVERY (1 << 3)
121 : : /* don't try to open a segment, if not already open */
122 : : #define EXTENSION_DONT_OPEN (1 << 5)
123 : :
124 : :
125 : : /*
126 : : * Fixed-length string to represent paths to files that need to be built by
127 : : * md.c.
128 : : *
129 : : * The maximum number of segments is MaxBlockNumber / RELSEG_SIZE, where
130 : : * RELSEG_SIZE can be set to 1 (for testing only).
131 : : */
132 : : #define SEGMENT_CHARS OIDCHARS
133 : : #define MD_PATH_STR_MAXLEN \
134 : : (\
135 : : REL_PATH_STR_MAXLEN \
136 : : + sizeof((char)'.') \
137 : : + SEGMENT_CHARS \
138 : : )
139 : : typedef struct MdPathStr
140 : : {
141 : : char str[MD_PATH_STR_MAXLEN + 1];
142 : : } MdPathStr;
143 : :
144 : :
145 : : /* local routines */
146 : : static void mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum,
147 : : bool isRedo);
148 : : static MdfdVec *mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior);
149 : : static void register_dirty_segment(SMgrRelation reln, ForkNumber forknum,
150 : : MdfdVec *seg);
151 : : static void register_unlink_segment(RelFileLocatorBackend rlocator, ForkNumber forknum,
152 : : BlockNumber segno);
153 : : static void register_forget_request(RelFileLocatorBackend rlocator, ForkNumber forknum,
154 : : BlockNumber segno);
155 : : static void _fdvec_resize(SMgrRelation reln,
156 : : ForkNumber forknum,
157 : : int nseg);
158 : : static MdPathStr _mdfd_segpath(SMgrRelation reln, ForkNumber forknum,
159 : : BlockNumber segno);
160 : : static MdfdVec *_mdfd_openseg(SMgrRelation reln, ForkNumber forknum,
161 : : BlockNumber segno, int oflags);
162 : : static MdfdVec *_mdfd_getseg(SMgrRelation reln, ForkNumber forknum,
163 : : BlockNumber blkno, bool skipFsync, int behavior);
164 : : static BlockNumber _mdnblocks(SMgrRelation reln, ForkNumber forknum,
165 : : MdfdVec *seg);
166 : :
167 : : static PgAioResult md_readv_complete(PgAioHandle *ioh, PgAioResult prior_result, uint8 cb_data);
168 : : static void md_readv_report(PgAioResult result, const PgAioTargetData *td, int elevel);
169 : :
170 : : const PgAioHandleCallbacks aio_md_readv_cb = {
171 : : .complete_shared = md_readv_complete,
172 : : .report = md_readv_report,
173 : : };
174 : :
175 : :
176 : : static inline int
1072 tmunro@postgresql.or 177 :CBC 1332338 : _mdfd_open_flags(void)
178 : : {
179 : 1332338 : int flags = O_RDWR | PG_BINARY;
180 : :
181 [ + + ]: 1332338 : if (io_direct_flags & IO_DIRECT_DATA)
182 : 314 : flags |= PG_O_DIRECT;
183 : :
184 : 1332338 : return flags;
185 : : }
186 : :
187 : : /*
188 : : * mdinit() -- Initialize private state for magnetic disk storage manager.
189 : : */
190 : : void
9027 tgl@sss.pgh.pa.us 191 : 21566 : mdinit(void)
192 : : {
9391 193 : 21566 : MdCxt = AllocSetContextCreate(TopMemoryContext,
194 : : "MdSmgr",
195 : : ALLOCSET_DEFAULT_SIZES);
6107 heikki.linnakangas@i 196 : 21566 : }
197 : :
198 : : /*
199 : : * mdexists() -- Does the physical file exist?
200 : : *
201 : : * Note: this will return true for lingering files, with pending deletions
202 : : */
203 : : bool
1273 pg@bowt.ie 204 : 491939 : mdexists(SMgrRelation reln, ForkNumber forknum)
205 : : {
206 : : /*
207 : : * Close it first, to ensure that we notice if the fork has been unlinked
208 : : * since we opened it. As an optimization, we can skip that in recovery,
209 : : * which already closes relations when dropping them.
210 : : */
1438 tmunro@postgresql.or 211 [ + + ]: 491939 : if (!InRecovery)
1273 pg@bowt.ie 212 : 470347 : mdclose(reln, forknum);
213 : :
214 : 491939 : return (mdopenfork(reln, forknum, EXTENSION_RETURN_NULL) != NULL);
215 : : }
216 : :
217 : : /*
218 : : * mdcreate() -- Create a new relation on magnetic disk.
219 : : *
220 : : * If isRedo is true, it's okay for the relation to exist already.
221 : : */
222 : : void
223 : 5758333 : mdcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
224 : : {
225 : : MdfdVec *mdfd;
226 : : RelPathStr path;
227 : : File fd;
228 : :
229 [ + + + + ]: 5758333 : if (isRedo && reln->md_num_open_segs[forknum] > 0)
7011 tgl@sss.pgh.pa.us 230 : 5582697 : return; /* created and opened already... */
231 : :
1273 pg@bowt.ie 232 [ - + ]: 175636 : Assert(reln->md_num_open_segs[forknum] == 0);
233 : :
234 : : /*
235 : : * We may be using the target table space for the first time in this
236 : : * database, so create a per-database subdirectory if needed.
237 : : *
238 : : * XXX this is a fairly ugly violation of module layering, but this seems
239 : : * to be the best place to put the check. Maybe TablespaceCreateDbspace
240 : : * should be here and not in commands/tablespace.c? But that would imply
241 : : * importing a lot of stuff that smgr.c oughtn't know, either.
242 : : */
1348 rhaas@postgresql.org 243 : 175636 : TablespaceCreateDbspace(reln->smgr_rlocator.locator.spcOid,
244 : : reln->smgr_rlocator.locator.dbOid,
245 : : isRedo);
246 : :
1273 pg@bowt.ie 247 : 175636 : path = relpath(reln->smgr_rlocator, forknum);
248 : :
383 andres@anarazel.de 249 : 175636 : fd = PathNameOpenFile(path.str, _mdfd_open_flags() | O_CREAT | O_EXCL);
250 : :
10416 bruce@momjian.us 251 [ + + ]: 175636 : if (fd < 0)
252 : : {
9124 253 : 12999 : int save_errno = errno;
254 : :
2603 akapila@postgresql.o 255 [ + - ]: 12999 : if (isRedo)
383 andres@anarazel.de 256 : 12999 : fd = PathNameOpenFile(path.str, _mdfd_open_flags());
10416 bruce@momjian.us 257 [ - + ]: 12999 : if (fd < 0)
258 : : {
259 : : /* be sure to report the error reported by create, not open */
9400 tgl@sss.pgh.pa.us 260 :UBC 0 : errno = save_errno;
7011 261 [ # # ]: 0 : ereport(ERROR,
262 : : (errcode_for_file_access(),
263 : : errmsg("could not create file \"%s\": %m", path.str)));
264 : : }
265 : : }
266 : :
1273 pg@bowt.ie 267 :CBC 175636 : _fdvec_resize(reln, forknum, 1);
268 : 175636 : mdfd = &reln->md_seg_fds[forknum][0];
3475 andres@anarazel.de 269 : 175636 : mdfd->mdfd_vfd = fd;
270 : 175636 : mdfd->mdfd_segno = 0;
271 : :
985 heikki.linnakangas@i 272 [ + + ]: 175636 : if (!SmgrIsTemp(reln))
273 : 172147 : register_dirty_segment(reln, forknum, mdfd);
274 : : }
275 : :
276 : : /*
277 : : * mdunlink() -- Unlink a relation.
278 : : *
279 : : * Note that we're passed a RelFileLocatorBackend --- by the time this is called,
280 : : * there won't be an SMgrRelation hashtable entry anymore.
281 : : *
282 : : * forknum can be a fork number to delete a specific fork, or InvalidForkNumber
283 : : * to delete all forks.
284 : : *
285 : : * For regular relations, we don't unlink the first segment file of the rel,
286 : : * but just truncate it to zero length, and record a request to unlink it after
287 : : * the next checkpoint. Additional segments can be unlinked immediately,
288 : : * however. Leaving the empty file in place prevents that relfilenumber
289 : : * from being reused. The scenario this protects us from is:
290 : : * 1. We delete a relation (and commit, and actually remove its file).
291 : : * 2. We create a new relation, which by chance gets the same relfilenumber as
292 : : * the just-deleted one (OIDs must've wrapped around for that to happen).
293 : : * 3. We crash before another checkpoint occurs.
294 : : * During replay, we would delete the file and then recreate it, which is fine
295 : : * if the contents of the file were repopulated by subsequent WAL entries.
296 : : * But if we didn't WAL-log insertions, but instead relied on fsyncing the
297 : : * file after populating it (as we do at wal_level=minimal), the contents of
298 : : * the file would be lost forever. By leaving the empty file until after the
299 : : * next checkpoint, we prevent reassignment of the relfilenumber until it's
300 : : * safe, because relfilenumber assignment skips over any existing file.
301 : : *
302 : : * Additional segments, if any, are truncated and then unlinked. The reason
303 : : * for truncating is that other backends may still hold open FDs for these at
304 : : * the smgr level, so that the kernel can't remove the file yet. We want to
305 : : * reclaim the disk space right away despite that.
306 : : *
307 : : * We do not need to go through this dance for temp relations, though, because
308 : : * we never make WAL entries for temp rels, and so a temp rel poses no threat
309 : : * to the health of a regular rel that has taken over its relfilenumber.
310 : : * The fact that temp rels and regular rels have different file naming
311 : : * patterns provides additional safety. Other backends shouldn't have open
312 : : * FDs for them, either.
313 : : *
314 : : * We also don't do it while performing a binary upgrade. There is no reuse
315 : : * hazard in that case, since after a crash or even a simple ERROR, the
316 : : * upgrade fails and the whole cluster must be recreated from scratch.
317 : : * Furthermore, it is important to remove the files from disk immediately,
318 : : * because we may be about to reuse the same relfilenumber.
319 : : *
320 : : * All the above applies only to the relation's main fork; other forks can
321 : : * just be removed immediately, since they are not needed to prevent the
322 : : * relfilenumber from being recycled. Also, we do not carefully
323 : : * track whether other forks have been created or not, but just attempt to
324 : : * unlink them unconditionally; so we should never complain about ENOENT.
325 : : *
326 : : * If isRedo is true, it's unsurprising for the relation to be already gone.
327 : : * Also, we should remove the file immediately instead of queuing a request
328 : : * for later, since during redo there's no possibility of creating a
329 : : * conflicting relation.
330 : : *
331 : : * Note: we currently just never warn about ENOENT at all. We could warn in
332 : : * the main-fork, non-isRedo case, but it doesn't seem worth the trouble.
333 : : *
334 : : * Note: any failure should be reported as WARNING not ERROR, because
335 : : * we are usually not in a transaction anymore when this is called.
336 : : */
337 : : void
1273 pg@bowt.ie 338 : 194476 : mdunlink(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
339 : : {
340 : : /* Now do the per-fork work */
341 [ - + ]: 194476 : if (forknum == InvalidForkNumber)
342 : : {
1273 pg@bowt.ie 343 [ # # ]:UBC 0 : for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
344 : 0 : mdunlinkfork(rlocator, forknum, isRedo);
345 : : }
346 : : else
1273 pg@bowt.ie 347 :CBC 194476 : mdunlinkfork(rlocator, forknum, isRedo);
4987 tgl@sss.pgh.pa.us 348 : 194476 : }
349 : :
350 : : /*
351 : : * Truncate a file to release disk space.
352 : : */
353 : : static int
1930 tmunro@postgresql.or 354 : 228497 : do_truncate(const char *path)
355 : : {
356 : : int save_errno;
357 : : int ret;
358 : :
359 : 228497 : ret = pg_truncate(path, 0);
360 : :
361 : : /* Log a warning here to avoid repetition in callers. */
362 [ + + - + ]: 228497 : if (ret < 0 && errno != ENOENT)
363 : : {
1930 tmunro@postgresql.or 364 :UBC 0 : save_errno = errno;
365 [ # # ]: 0 : ereport(WARNING,
366 : : (errcode_for_file_access(),
367 : : errmsg("could not truncate file \"%s\": %m", path)));
368 : 0 : errno = save_errno;
369 : : }
370 : :
1930 tmunro@postgresql.or 371 :CBC 228497 : return ret;
372 : : }
373 : :
374 : : static void
1273 pg@bowt.ie 375 : 194476 : mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
376 : : {
377 : : RelPathStr path;
378 : : int ret;
379 : : int save_errno;
380 : :
381 : 194476 : path = relpath(rlocator, forknum);
382 : :
383 : : /*
384 : : * Truncate and then unlink the first segment, or just register a request
385 : : * to unlink it later, as described in the comments for mdunlink().
386 : : */
1222 tgl@sss.pgh.pa.us 387 [ + + + + : 194476 : if (isRedo || IsBinaryUpgrade || forknum != MAIN_FORKNUM ||
+ + ]
388 [ + + ]: 40403 : RelFileLocatorBackendIsTemp(rlocator))
389 : : {
1348 rhaas@postgresql.org 390 [ + + ]: 157384 : if (!RelFileLocatorBackendIsTemp(rlocator))
391 : : {
392 : : /* Prevent other backends' fds from holding on to the disk space */
383 andres@anarazel.de 393 : 144140 : ret = do_truncate(path.str);
394 : :
395 : : /* Forget any pending sync requests for the first segment */
1224 tgl@sss.pgh.pa.us 396 : 144140 : save_errno = errno;
1273 pg@bowt.ie 397 : 144140 : register_forget_request(rlocator, forknum, 0 /* first seg */ );
1224 tgl@sss.pgh.pa.us 398 : 144140 : errno = save_errno;
399 : : }
400 : : else
1930 tmunro@postgresql.or 401 : 13244 : ret = 0;
402 : :
403 : : /* Next unlink the file, unless it was already found to be missing */
1222 tgl@sss.pgh.pa.us 404 [ + + - + ]: 157384 : if (ret >= 0 || errno != ENOENT)
405 : : {
383 andres@anarazel.de 406 : 23421 : ret = unlink(path.str);
1930 tmunro@postgresql.or 407 [ + + - + ]: 23421 : if (ret < 0 && errno != ENOENT)
408 : : {
1222 tgl@sss.pgh.pa.us 409 :UBC 0 : save_errno = errno;
1930 tmunro@postgresql.or 410 [ # # ]: 0 : ereport(WARNING,
411 : : (errcode_for_file_access(),
412 : : errmsg("could not remove file \"%s\": %m", path.str)));
1222 tgl@sss.pgh.pa.us 413 : 0 : errno = save_errno;
414 : : }
415 : : }
416 : : }
417 : : else
418 : : {
419 : : /* Prevent other backends' fds from holding on to the disk space */
383 andres@anarazel.de 420 :CBC 37092 : ret = do_truncate(path.str);
421 : :
422 : : /* Register request to unlink first segment later */
1222 tgl@sss.pgh.pa.us 423 : 37092 : save_errno = errno;
424 : 37092 : register_unlink_segment(rlocator, forknum, 0 /* first seg */ );
425 : 37092 : errno = save_errno;
426 : : }
427 : :
428 : : /*
429 : : * Delete any additional segments.
430 : : *
431 : : * Note that because we loop until getting ENOENT, we will correctly
432 : : * remove all inactive segments as well as active ones. Ideally we'd
433 : : * continue the loop until getting exactly that errno, but that risks an
434 : : * infinite loop if the problem is directory-wide (for instance, if we
435 : : * suddenly can't read the data directory itself). We compromise by
436 : : * continuing after a non-ENOENT truncate error, but stopping after any
437 : : * unlink error. If there is indeed a directory-wide problem, additional
438 : : * unlink attempts wouldn't work anyway.
439 : : */
440 [ + + - + ]: 194476 : if (ret >= 0 || errno != ENOENT)
441 : : {
442 : : MdPathStr segpath;
443 : : BlockNumber segno;
444 : :
445 : 50754 : for (segno = 1;; segno++)
446 : : {
383 andres@anarazel.de 447 : 50754 : sprintf(segpath.str, "%s.%u", path.str, segno);
448 : :
1348 rhaas@postgresql.org 449 [ + + ]: 50754 : if (!RelFileLocatorBackendIsTemp(rlocator))
450 : : {
451 : : /*
452 : : * Prevent other backends' fds from holding on to the disk
453 : : * space. We're done if we see ENOENT, though.
454 : : */
383 andres@anarazel.de 455 [ + - + - ]: 47265 : if (do_truncate(segpath.str) < 0 && errno == ENOENT)
1930 tmunro@postgresql.or 456 : 47265 : break;
457 : :
458 : : /*
459 : : * Forget any pending sync requests for this segment before we
460 : : * try to unlink.
461 : : */
1273 pg@bowt.ie 462 :UBC 0 : register_forget_request(rlocator, forknum, segno);
463 : : }
464 : :
383 andres@anarazel.de 465 [ + - ]:CBC 3489 : if (unlink(segpath.str) < 0)
466 : : {
467 : : /* ENOENT is expected after the last segment... */
9258 tgl@sss.pgh.pa.us 468 [ - + ]: 3489 : if (errno != ENOENT)
7011 tgl@sss.pgh.pa.us 469 [ # # ]:UBC 0 : ereport(WARNING,
470 : : (errcode_for_file_access(),
471 : : errmsg("could not remove file \"%s\": %m", segpath.str)));
9258 tgl@sss.pgh.pa.us 472 :CBC 3489 : break;
473 : : }
474 : : }
475 : : }
10841 scrappy@hub.org 476 : 194476 : }
477 : :
478 : : /*
479 : : * mdextend() -- Add a block to the specified relation.
480 : : *
481 : : * The semantics are nearly the same as mdwrite(): write at the
482 : : * specified position. However, this is to be used for the case of
483 : : * extending a relation (i.e., blocknum is at or beyond the current
484 : : * EOF). Note that we assume writing a block beyond current EOF
485 : : * causes intervening file space to become filled with zeroes.
486 : : */
487 : : void
6425 heikki.linnakangas@i 488 : 124979 : mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
489 : : const void *buffer, bool skipFsync)
490 : : {
491 : : pgoff_t seekpos;
492 : : int nbytes;
493 : : MdfdVec *v;
494 : :
495 : : /* If this build supports direct I/O, the buffer must be I/O aligned. */
496 : : if (PG_O_DIRECT != 0 && PG_IO_ALIGN_SIZE <= BLCKSZ)
1072 tmunro@postgresql.or 497 [ - + ]: 124979 : Assert((uintptr_t) buffer == TYPEALIGN(PG_IO_ALIGN_SIZE, buffer));
498 : :
499 : : /* This assert is too expensive to have on normally ... */
500 : : #ifdef CHECK_WRITE_VS_EXTEND
501 : : Assert(blocknum >= mdnblocks(reln, forknum));
502 : : #endif
503 : :
504 : : /*
505 : : * If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
506 : : * more --- we mustn't create a block whose number actually is
507 : : * InvalidBlockNumber. (Note that this failure should be unreachable
508 : : * because of upstream checks in bufmgr.c.)
509 : : */
7011 tgl@sss.pgh.pa.us 510 [ - + ]: 124979 : if (blocknum == InvalidBlockNumber)
7011 tgl@sss.pgh.pa.us 511 [ # # ]:UBC 0 : ereport(ERROR,
512 : : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
513 : : errmsg("cannot extend file \"%s\" beyond %u blocks",
514 : : relpath(reln->smgr_rlocator, forknum).str,
515 : : InvalidBlockNumber)));
516 : :
5693 rhaas@postgresql.org 517 :CBC 124979 : v = _mdfd_getseg(reln, forknum, blocknum, skipFsync, EXTENSION_CREATE);
518 : :
122 michael@paquier.xyz 519 :GNC 124979 : seekpos = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
520 : :
521 [ - + ]: 124979 : Assert(seekpos < (pgoff_t) BLCKSZ * RELSEG_SIZE);
522 : :
2685 tmunro@postgresql.or 523 [ - + ]:CBC 124979 : if ((nbytes = FileWrite(v->mdfd_vfd, buffer, BLCKSZ, seekpos, WAIT_EVENT_DATA_FILE_EXTEND)) != BLCKSZ)
524 : : {
7011 tgl@sss.pgh.pa.us 525 [ # # ]:UBC 0 : if (nbytes < 0)
526 [ # # ]: 0 : ereport(ERROR,
527 : : (errcode_for_file_access(),
528 : : errmsg("could not extend file \"%s\": %m",
529 : : FilePathName(v->mdfd_vfd)),
530 : : errhint("Check free disk space.")));
531 : : /* short write: complain appropriately */
532 [ # # ]: 0 : ereport(ERROR,
533 : : (errcode(ERRCODE_DISK_FULL),
534 : : errmsg("could not extend file \"%s\": wrote only %d of %d bytes at block %u",
535 : : FilePathName(v->mdfd_vfd),
536 : : nbytes, BLCKSZ, blocknum),
537 : : errhint("Check free disk space.")));
538 : : }
539 : :
5693 rhaas@postgresql.org 540 [ + + + - ]:CBC 124979 : if (!skipFsync && !SmgrIsTemp(reln))
6425 heikki.linnakangas@i 541 : 29 : register_dirty_segment(reln, forknum, v);
542 : :
543 [ - + ]: 124979 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
10841 scrappy@hub.org 544 : 124979 : }
545 : :
546 : : /*
547 : : * mdzeroextend() -- Add new zeroed out blocks to the specified relation.
548 : : *
549 : : * Similar to mdextend(), except the relation can be extended by multiple
550 : : * blocks at once and the added blocks will be filled with zeroes.
551 : : */
552 : : void
1075 andres@anarazel.de 553 : 221176 : mdzeroextend(SMgrRelation reln, ForkNumber forknum,
554 : : BlockNumber blocknum, int nblocks, bool skipFsync)
555 : : {
556 : : MdfdVec *v;
557 : 221176 : BlockNumber curblocknum = blocknum;
558 : 221176 : int remblocks = nblocks;
559 : :
560 [ - + ]: 221176 : Assert(nblocks > 0);
561 : :
562 : : /* This assert is too expensive to have on normally ... */
563 : : #ifdef CHECK_WRITE_VS_EXTEND
564 : : Assert(blocknum >= mdnblocks(reln, forknum));
565 : : #endif
566 : :
567 : : /*
568 : : * If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
569 : : * more --- we mustn't create a block whose number actually is
570 : : * InvalidBlockNumber or larger.
571 : : */
572 [ - + ]: 221176 : if ((uint64) blocknum + nblocks >= (uint64) InvalidBlockNumber)
1075 andres@anarazel.de 573 [ # # ]:UBC 0 : ereport(ERROR,
574 : : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
575 : : errmsg("cannot extend file \"%s\" beyond %u blocks",
576 : : relpath(reln->smgr_rlocator, forknum).str,
577 : : InvalidBlockNumber)));
578 : :
1075 andres@anarazel.de 579 [ + + ]:CBC 442352 : while (remblocks > 0)
580 : : {
1031 tgl@sss.pgh.pa.us 581 : 221176 : BlockNumber segstartblock = curblocknum % ((BlockNumber) RELSEG_SIZE);
122 michael@paquier.xyz 582 :GNC 221176 : pgoff_t seekpos = (pgoff_t) BLCKSZ * segstartblock;
583 : : int numblocks;
584 : :
1075 andres@anarazel.de 585 [ - + ]:CBC 221176 : if (segstartblock + remblocks > RELSEG_SIZE)
1075 andres@anarazel.de 586 :UBC 0 : numblocks = RELSEG_SIZE - segstartblock;
587 : : else
1075 andres@anarazel.de 588 :CBC 221176 : numblocks = remblocks;
589 : :
590 : 221176 : v = _mdfd_getseg(reln, forknum, curblocknum, skipFsync, EXTENSION_CREATE);
591 : :
592 [ - + ]: 221176 : Assert(segstartblock < RELSEG_SIZE);
593 [ - + ]: 221176 : Assert(segstartblock + numblocks <= RELSEG_SIZE);
594 : :
595 : : /*
596 : : * If available and useful, use posix_fallocate() (via
597 : : * FileFallocate()) to extend the relation. That's often more
598 : : * efficient than using write(), as it commonly won't cause the kernel
599 : : * to allocate page cache space for the extended pages.
600 : : *
601 : : * However, we don't use FileFallocate() for small extensions, as it
602 : : * defeats delayed allocation on some filesystems. Not clear where
603 : : * that decision should be made though? For now just use a cutoff of
604 : : * 8, anything between 4 and 8 worked OK in some local testing.
605 : : */
288 tmunro@postgresql.or 606 [ + + ]: 221176 : if (numblocks > 8 &&
607 [ + - ]: 524 : file_extend_method != FILE_EXTEND_METHOD_WRITE_ZEROS)
1075 andres@anarazel.de 608 : 524 : {
288 tmunro@postgresql.or 609 : 524 : int ret = 0;
610 : :
611 : : #ifdef HAVE_POSIX_FALLOCATE
612 [ + - ]: 524 : if (file_extend_method == FILE_EXTEND_METHOD_POSIX_FALLOCATE)
613 : : {
614 : 524 : ret = FileFallocate(v->mdfd_vfd,
615 : : seekpos, (pgoff_t) BLCKSZ * numblocks,
616 : : WAIT_EVENT_DATA_FILE_EXTEND);
617 : : }
618 : : else
619 : : #endif
620 : : {
288 tmunro@postgresql.or 621 [ # # ]:UBC 0 : elog(ERROR, "unsupported file_extend_method: %d",
622 : : file_extend_method);
623 : : }
1075 andres@anarazel.de 624 [ - + ]:CBC 524 : if (ret != 0)
625 : : {
1075 andres@anarazel.de 626 [ # # ]:UBC 0 : ereport(ERROR,
627 : : errcode_for_file_access(),
628 : : errmsg("could not extend file \"%s\" with FileFallocate(): %m",
629 : : FilePathName(v->mdfd_vfd)),
630 : : errhint("Check free disk space."));
631 : : }
632 : : }
633 : : else
634 : : {
635 : : int ret;
636 : :
637 : : /*
638 : : * Even if we don't want to use fallocate, we can still extend a
639 : : * bit more efficiently than writing each 8kB block individually.
640 : : * pg_pwrite_zeros() (via FileZero()) uses pg_pwritev_with_retry()
641 : : * to avoid multiple writes or needing a zeroed buffer for the
642 : : * whole length of the extension.
643 : : */
1075 andres@anarazel.de 644 :CBC 220652 : ret = FileZero(v->mdfd_vfd,
645 : : seekpos, (pgoff_t) BLCKSZ * numblocks,
646 : : WAIT_EVENT_DATA_FILE_EXTEND);
647 [ - + ]: 220652 : if (ret < 0)
1075 andres@anarazel.de 648 [ # # ]:UBC 0 : ereport(ERROR,
649 : : errcode_for_file_access(),
650 : : errmsg("could not extend file \"%s\": %m",
651 : : FilePathName(v->mdfd_vfd)),
652 : : errhint("Check free disk space."));
653 : : }
654 : :
1075 andres@anarazel.de 655 [ + - + + ]:CBC 221176 : if (!skipFsync && !SmgrIsTemp(reln))
656 : 208621 : register_dirty_segment(reln, forknum, v);
657 : :
658 [ - + ]: 221176 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
659 : :
660 : 221176 : remblocks -= numblocks;
661 : 221176 : curblocknum += numblocks;
662 : : }
663 : 221176 : }
664 : :
665 : : /*
666 : : * mdopenfork() -- Open one fork of the specified relation.
667 : : *
668 : : * Note we only open the first segment, when there are multiple segments.
669 : : *
670 : : * If first segment is not present, either ereport or return NULL according
671 : : * to "behavior". We treat EXTENSION_CREATE the same as EXTENSION_FAIL;
672 : : * EXTENSION_CREATE means it's OK to extend an existing relation, not to
673 : : * invent one out of whole cloth.
674 : : */
675 : : static MdfdVec *
2433 tmunro@postgresql.or 676 : 4071124 : mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
677 : : {
678 : : MdfdVec *mdfd;
679 : : RelPathStr path;
680 : : File fd;
681 : :
682 : : /* No work if already open */
3475 andres@anarazel.de 683 [ + + ]: 4071124 : if (reln->md_num_open_segs[forknum] > 0)
684 : 2953319 : return &reln->md_seg_fds[forknum][0];
685 : :
1348 rhaas@postgresql.org 686 : 1117805 : path = relpath(reln->smgr_rlocator, forknum);
687 : :
383 andres@anarazel.de 688 : 1117805 : fd = PathNameOpenFile(path.str, _mdfd_open_flags());
689 : :
10416 bruce@momjian.us 690 [ + + ]: 1117805 : if (fd < 0)
691 : : {
2603 akapila@postgresql.o 692 [ + + ]: 344525 : if ((behavior & EXTENSION_RETURN_NULL) &&
693 [ + - ]: 344503 : FILE_POSSIBLY_DELETED(errno))
694 : 344503 : return NULL;
695 [ + - ]: 22 : ereport(ERROR,
696 : : (errcode_for_file_access(),
697 : : errmsg("could not open file \"%s\": %m", path.str)));
698 : : }
699 : :
3475 andres@anarazel.de 700 : 773280 : _fdvec_resize(reln, forknum, 1);
701 : 773280 : mdfd = &reln->md_seg_fds[forknum][0];
7958 tgl@sss.pgh.pa.us 702 : 773280 : mdfd->mdfd_vfd = fd;
703 : 773280 : mdfd->mdfd_segno = 0;
704 : :
6425 heikki.linnakangas@i 705 [ - + ]: 773280 : Assert(_mdnblocks(reln, forknum, mdfd) <= ((BlockNumber) RELSEG_SIZE));
706 : :
7958 tgl@sss.pgh.pa.us 707 : 773280 : return mdfd;
708 : : }
709 : :
710 : : /*
711 : : * mdopen() -- Initialize newly-opened relation.
712 : : */
713 : : void
2433 tmunro@postgresql.or 714 : 1065525 : mdopen(SMgrRelation reln)
715 : : {
716 : : /* mark it not open */
717 [ + + ]: 5327625 : for (int forknum = 0; forknum <= MAX_FORKNUM; forknum++)
718 : 4262100 : reln->md_num_open_segs[forknum] = 0;
719 : 1065525 : }
720 : :
721 : : /*
722 : : * mdclose() -- Close the specified relation, if it isn't closed already.
723 : : */
724 : : void
6425 heikki.linnakangas@i 725 : 3625439 : mdclose(SMgrRelation reln, ForkNumber forknum)
726 : : {
3475 andres@anarazel.de 727 : 3625439 : int nopensegs = reln->md_num_open_segs[forknum];
728 : :
729 : : /* No work if already closed */
730 [ + + ]: 3625439 : if (nopensegs == 0)
7011 tgl@sss.pgh.pa.us 731 : 3081040 : return;
732 : :
733 : : /* close segments starting from the end */
3475 andres@anarazel.de 734 [ + + ]: 1088798 : while (nopensegs > 0)
735 : : {
736 : 544399 : MdfdVec *v = &reln->md_seg_fds[forknum][nopensegs - 1];
737 : :
2256 noah@leadboat.com 738 : 544399 : FileClose(v->mdfd_vfd);
739 : 544399 : _fdvec_resize(reln, forknum, nopensegs - 1);
3475 andres@anarazel.de 740 : 544399 : nopensegs--;
741 : : }
742 : : }
743 : :
744 : : /*
745 : : * mdprefetch() -- Initiate asynchronous read of the specified blocks of a relation
746 : : */
747 : : bool
820 tmunro@postgresql.or 748 : 8678 : mdprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
749 : : int nblocks)
750 : : {
751 : : #ifdef USE_PREFETCH
752 : :
1072 753 [ - + ]: 8678 : Assert((io_direct_flags & IO_DIRECT_DATA) == 0);
754 : :
820 755 [ - + ]: 8678 : if ((uint64) blocknum + nblocks > (uint64) MaxBlockNumber + 1)
2167 tmunro@postgresql.or 756 :UBC 0 : return false;
757 : :
820 tmunro@postgresql.or 758 [ + + ]:CBC 17356 : while (nblocks > 0)
759 : : {
760 : : pgoff_t seekpos;
761 : : MdfdVec *v;
762 : : int nblocks_this_segment;
763 : :
764 : 8678 : v = _mdfd_getseg(reln, forknum, blocknum, false,
765 [ + + ]: 8678 : InRecovery ? EXTENSION_RETURN_NULL : EXTENSION_FAIL);
766 [ - + ]: 8678 : if (v == NULL)
820 tmunro@postgresql.or 767 :UBC 0 : return false;
768 : :
122 michael@paquier.xyz 769 :GNC 8678 : seekpos = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
770 : :
771 [ - + ]: 8678 : Assert(seekpos < (pgoff_t) BLCKSZ * RELSEG_SIZE);
772 : :
820 tmunro@postgresql.or 773 :CBC 8678 : nblocks_this_segment =
774 : 8678 : Min(nblocks,
775 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
776 : :
777 : 8678 : (void) FilePrefetch(v->mdfd_vfd, seekpos, BLCKSZ * nblocks_this_segment,
778 : : WAIT_EVENT_DATA_FILE_PREFETCH);
779 : :
780 : 8678 : blocknum += nblocks_this_segment;
781 : 8678 : nblocks -= nblocks_this_segment;
782 : : }
783 : : #endif /* USE_PREFETCH */
784 : :
2167 785 : 8678 : return true;
786 : : }
787 : :
788 : : /*
789 : : * Convert an array of buffer address into an array of iovec objects, and
790 : : * return the number that were required. 'iov' must have enough space for up
791 : : * to 'nblocks' elements, but the number used may be less depending on
792 : : * merging. In the case of a run of fully contiguous buffers, a single iovec
793 : : * will be populated that can be handled as a plain non-vectored I/O.
794 : : */
795 : : static int
818 796 : 1940897 : buffers_to_iovec(struct iovec *iov, void **buffers, int nblocks)
797 : : {
798 : : struct iovec *iovp;
799 : : int iovcnt;
800 : :
801 [ - + ]: 1940897 : Assert(nblocks >= 1);
802 : :
803 : : /* If this build supports direct I/O, buffers must be I/O aligned. */
804 [ + + ]: 4055954 : for (int i = 0; i < nblocks; ++i)
805 : : {
806 : : if (PG_O_DIRECT != 0 && PG_IO_ALIGN_SIZE <= BLCKSZ)
807 [ - + ]: 2115057 : Assert((uintptr_t) buffers[i] ==
808 : : TYPEALIGN(PG_IO_ALIGN_SIZE, buffers[i]));
809 : : }
810 : :
811 : : /* Start the first iovec off with the first buffer. */
812 : 1940897 : iovp = &iov[0];
813 : 1940897 : iovp->iov_base = buffers[0];
814 : 1940897 : iovp->iov_len = BLCKSZ;
815 : 1940897 : iovcnt = 1;
816 : :
817 : : /* Try to merge the rest. */
818 [ + + ]: 2115057 : for (int i = 1; i < nblocks; ++i)
819 : : {
820 : 174160 : void *buffer = buffers[i];
821 : :
822 [ + + ]: 174160 : if (((char *) iovp->iov_base + iovp->iov_len) == buffer)
823 : : {
824 : : /* Contiguous with the last iovec. */
825 : 173263 : iovp->iov_len += BLCKSZ;
826 : : }
827 : : else
828 : : {
829 : : /* Need a new iovec. */
830 : 897 : iovp++;
831 : 897 : iovp->iov_base = buffer;
832 : 897 : iovp->iov_len = BLCKSZ;
833 : 897 : iovcnt++;
834 : : }
835 : : }
836 : :
837 : 1940897 : return iovcnt;
838 : : }
839 : :
840 : : /*
841 : : * mdmaxcombine() -- Return the maximum number of total blocks that can be
842 : : * combined with an IO starting at blocknum.
843 : : */
844 : : uint32
523 andres@anarazel.de 845 : 35405 : mdmaxcombine(SMgrRelation reln, ForkNumber forknum,
846 : : BlockNumber blocknum)
847 : : {
848 : : BlockNumber segoff;
849 : :
850 : 35405 : segoff = blocknum % ((BlockNumber) RELSEG_SIZE);
851 : :
852 : 35405 : return RELSEG_SIZE - segoff;
853 : : }
854 : :
855 : : /*
856 : : * mdreadv() -- Read the specified blocks from a relation.
857 : : */
858 : : void
818 tmunro@postgresql.or 859 : 598 : mdreadv(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
860 : : void **buffers, BlockNumber nblocks)
861 : : {
862 [ + + ]: 1196 : while (nblocks > 0)
863 : : {
864 : : struct iovec iov[PG_IOV_MAX];
865 : : int iovcnt;
866 : : pgoff_t seekpos;
867 : : int nbytes;
868 : : MdfdVec *v;
869 : : BlockNumber nblocks_this_segment;
870 : : size_t transferred_this_segment;
871 : : size_t size_this_segment;
872 : :
873 : 598 : v = _mdfd_getseg(reln, forknum, blocknum, false,
874 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
875 : :
122 michael@paquier.xyz 876 :GNC 598 : seekpos = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
877 : :
878 [ - + ]: 598 : Assert(seekpos < (pgoff_t) BLCKSZ * RELSEG_SIZE);
879 : :
818 tmunro@postgresql.or 880 :CBC 598 : nblocks_this_segment =
881 : 598 : Min(nblocks,
882 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
883 : 598 : nblocks_this_segment = Min(nblocks_this_segment, lengthof(iov));
884 : :
523 andres@anarazel.de 885 [ - + ]: 598 : if (nblocks_this_segment != nblocks)
523 andres@anarazel.de 886 [ # # ]:UBC 0 : elog(ERROR, "read crosses segment boundary");
887 : :
818 tmunro@postgresql.or 888 :CBC 598 : iovcnt = buffers_to_iovec(iov, buffers, nblocks_this_segment);
889 : 598 : size_this_segment = nblocks_this_segment * BLCKSZ;
890 : 598 : transferred_this_segment = 0;
891 : :
892 : : /*
893 : : * Inner loop to continue after a short read. We'll keep going until
894 : : * we hit EOF rather than assuming that a short read means we hit the
895 : : * end.
896 : : */
897 : : for (;;)
898 : : {
818 tmunro@postgresql.or 899 :UBC 0 : TRACE_POSTGRESQL_SMGR_MD_READ_START(forknum, blocknum,
900 : : reln->smgr_rlocator.locator.spcOid,
901 : : reln->smgr_rlocator.locator.dbOid,
902 : : reln->smgr_rlocator.locator.relNumber,
903 : : reln->smgr_rlocator.backend);
818 tmunro@postgresql.or 904 :CBC 598 : nbytes = FileReadV(v->mdfd_vfd, iov, iovcnt, seekpos,
905 : : WAIT_EVENT_DATA_FILE_READ);
906 : : TRACE_POSTGRESQL_SMGR_MD_READ_DONE(forknum, blocknum,
907 : : reln->smgr_rlocator.locator.spcOid,
908 : : reln->smgr_rlocator.locator.dbOid,
909 : : reln->smgr_rlocator.locator.relNumber,
910 : : reln->smgr_rlocator.backend,
911 : : nbytes,
912 : : size_this_segment - transferred_this_segment);
913 : :
914 : : #ifdef SIMULATE_SHORT_READ
915 : : nbytes = Min(nbytes, 4096);
916 : : #endif
917 : :
918 [ - + ]: 598 : if (nbytes < 0)
818 tmunro@postgresql.or 919 [ # # ]:UBC 0 : ereport(ERROR,
920 : : (errcode_for_file_access(),
921 : : errmsg("could not read blocks %u..%u in file \"%s\": %m",
922 : : blocknum,
923 : : blocknum + nblocks_this_segment - 1,
924 : : FilePathName(v->mdfd_vfd))));
925 : :
818 tmunro@postgresql.or 926 [ - + ]:CBC 598 : if (nbytes == 0)
927 : : {
928 : : /*
929 : : * We are at or past EOF, or we read a partial block at EOF.
930 : : * Normally this is an error; upper levels should never try to
931 : : * read a nonexistent block. However, if zero_damaged_pages
932 : : * is ON or we are InRecovery, we should instead return zeroes
933 : : * without complaining. This allows, for example, the case of
934 : : * trying to update a block that was later truncated away.
935 : : *
936 : : * NB: We think that this codepath is unreachable in recovery
937 : : * and incomplete with zero_damaged_pages, as missing segments
938 : : * are not created. Putting blocks into the buffer-pool that
939 : : * do not exist on disk is rather problematic, as it will not
940 : : * be found by scans that rely on smgrnblocks(), as they are
941 : : * beyond EOF. It also can cause weird problems with relation
942 : : * extension, as relation extension does not expect blocks
943 : : * beyond EOF to exist.
944 : : *
945 : : * Therefore we do not want to copy the logic into
946 : : * mdstartreadv(), where it would have to be more complicated
947 : : * due to potential differences in the zero_damaged_pages
948 : : * setting between the definer and completor of IO.
949 : : *
950 : : * For PG 18, we are putting an Assert(false) in mdreadv()
951 : : * (triggering failures in assertion-enabled builds, but
952 : : * continuing to work in production builds). Afterwards we
953 : : * plan to remove this code entirely.
954 : : */
818 tmunro@postgresql.or 955 [ # # # # ]:UBC 0 : if (zero_damaged_pages || InRecovery)
956 : : {
348 andres@anarazel.de 957 : 0 : Assert(false); /* see comment above */
958 : :
959 : : for (BlockNumber i = transferred_this_segment / BLCKSZ;
960 : : i < nblocks_this_segment;
961 : : ++i)
962 : : memset(buffers[i], 0, BLCKSZ);
963 : : break;
964 : : }
965 : : else
818 tmunro@postgresql.or 966 [ # # ]: 0 : ereport(ERROR,
967 : : (errcode(ERRCODE_DATA_CORRUPTED),
968 : : errmsg("could not read blocks %u..%u in file \"%s\": read only %zu of %zu bytes",
969 : : blocknum,
970 : : blocknum + nblocks_this_segment - 1,
971 : : FilePathName(v->mdfd_vfd),
972 : : transferred_this_segment,
973 : : size_this_segment)));
974 : : }
975 : :
976 : : /* One loop should usually be enough. */
818 tmunro@postgresql.or 977 :CBC 598 : transferred_this_segment += nbytes;
978 [ - + ]: 598 : Assert(transferred_this_segment <= size_this_segment);
979 [ + - ]: 598 : if (transferred_this_segment == size_this_segment)
980 : 598 : break;
981 : :
982 : : /* Adjust position and vectors after a short read. */
818 tmunro@postgresql.or 983 :UBC 0 : seekpos += nbytes;
984 : 0 : iovcnt = compute_remaining_iovec(iov, iov, iovcnt, nbytes);
985 : : }
986 : :
818 tmunro@postgresql.or 987 :CBC 598 : nblocks -= nblocks_this_segment;
988 : 598 : buffers += nblocks_this_segment;
989 : 598 : blocknum += nblocks_this_segment;
990 : : }
10841 scrappy@hub.org 991 : 598 : }
992 : :
993 : : /*
994 : : * mdstartreadv() -- Asynchronous version of mdreadv().
995 : : */
996 : : void
351 andres@anarazel.de 997 : 1336926 : mdstartreadv(PgAioHandle *ioh,
998 : : SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
999 : : void **buffers, BlockNumber nblocks)
1000 : : {
1001 : : pgoff_t seekpos;
1002 : : MdfdVec *v;
1003 : : BlockNumber nblocks_this_segment;
1004 : : struct iovec *iov;
1005 : : int iovcnt;
1006 : : int ret;
1007 : :
1008 : 1336926 : v = _mdfd_getseg(reln, forknum, blocknum, false,
1009 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
1010 : :
122 michael@paquier.xyz 1011 :GNC 1336911 : seekpos = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1012 : :
1013 [ - + ]: 1336911 : Assert(seekpos < (pgoff_t) BLCKSZ * RELSEG_SIZE);
1014 : :
351 andres@anarazel.de 1015 :CBC 1336911 : nblocks_this_segment =
1016 : 1336911 : Min(nblocks,
1017 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
1018 : :
1019 [ - + ]: 1336911 : if (nblocks_this_segment != nblocks)
351 andres@anarazel.de 1020 [ # # ]:UBC 0 : elog(ERROR, "read crossing segment boundary");
1021 : :
351 andres@anarazel.de 1022 :CBC 1336911 : iovcnt = pgaio_io_get_iovec(ioh, &iov);
1023 : :
1024 [ - + ]: 1336911 : Assert(nblocks <= iovcnt);
1025 : :
1026 : 1336911 : iovcnt = buffers_to_iovec(iov, buffers, nblocks_this_segment);
1027 : :
1028 [ - + ]: 1336911 : Assert(iovcnt <= nblocks_this_segment);
1029 : :
1030 [ + + ]: 1336911 : if (!(io_direct_flags & IO_DIRECT_DATA))
1031 : 1335530 : pgaio_io_set_flag(ioh, PGAIO_HF_BUFFERED);
1032 : :
1033 : 1336911 : pgaio_io_set_target_smgr(ioh,
1034 : : reln,
1035 : : forknum,
1036 : : blocknum,
1037 : : nblocks,
1038 : : false);
1039 : 1336911 : pgaio_io_register_callbacks(ioh, PGAIO_HCB_MD_READV, 0);
1040 : :
1041 : 1336911 : ret = FileStartReadV(ioh, v->mdfd_vfd, iovcnt, seekpos, WAIT_EVENT_DATA_FILE_READ);
1042 [ - + ]: 1336911 : if (ret != 0)
351 andres@anarazel.de 1043 [ # # ]:UBC 0 : ereport(ERROR,
1044 : : (errcode_for_file_access(),
1045 : : errmsg("could not start reading blocks %u..%u in file \"%s\": %m",
1046 : : blocknum,
1047 : : blocknum + nblocks_this_segment - 1,
1048 : : FilePathName(v->mdfd_vfd))));
1049 : :
1050 : : /*
1051 : : * The error checks corresponding to the post-read checks in mdreadv() are
1052 : : * in md_readv_complete().
1053 : : *
1054 : : * However we chose, at least for now, to not implement the
1055 : : * zero_damaged_pages logic present in mdreadv(). As outlined in mdreadv()
1056 : : * that logic is rather problematic, and we want to get rid of it. Here
1057 : : * equivalent logic would have to be more complicated due to potential
1058 : : * differences in the zero_damaged_pages setting between the definer and
1059 : : * completor of IO.
1060 : : */
351 andres@anarazel.de 1061 :CBC 1336911 : }
1062 : :
1063 : : /*
1064 : : * mdwritev() -- Write the supplied blocks at the appropriate location.
1065 : : *
1066 : : * This is to be used only for updating already-existing blocks of a
1067 : : * relation (ie, those before the current EOF). To extend a relation,
1068 : : * use mdextend().
1069 : : */
1070 : : void
818 tmunro@postgresql.or 1071 : 603388 : mdwritev(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
1072 : : const void **buffers, BlockNumber nblocks, bool skipFsync)
1073 : : {
1074 : : /* This assert is too expensive to have on normally ... */
1075 : : #ifdef CHECK_WRITE_VS_EXTEND
1076 : : Assert((uint64) blocknum + (uint64) nblocks <= (uint64) mdnblocks(reln, forknum));
1077 : : #endif
1078 : :
1079 [ + + ]: 1206776 : while (nblocks > 0)
1080 : : {
1081 : : struct iovec iov[PG_IOV_MAX];
1082 : : int iovcnt;
1083 : : pgoff_t seekpos;
1084 : : int nbytes;
1085 : : MdfdVec *v;
1086 : : BlockNumber nblocks_this_segment;
1087 : : size_t transferred_this_segment;
1088 : : size_t size_this_segment;
1089 : :
1090 : 603388 : v = _mdfd_getseg(reln, forknum, blocknum, skipFsync,
1091 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
1092 : :
122 michael@paquier.xyz 1093 :GNC 603388 : seekpos = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1094 : :
1095 [ - + ]: 603388 : Assert(seekpos < (pgoff_t) BLCKSZ * RELSEG_SIZE);
1096 : :
818 tmunro@postgresql.or 1097 :CBC 603388 : nblocks_this_segment =
1098 : 603388 : Min(nblocks,
1099 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
1100 : 603388 : nblocks_this_segment = Min(nblocks_this_segment, lengthof(iov));
1101 : :
523 andres@anarazel.de 1102 [ - + ]: 603388 : if (nblocks_this_segment != nblocks)
523 andres@anarazel.de 1103 [ # # ]:UBC 0 : elog(ERROR, "write crosses segment boundary");
1104 : :
818 tmunro@postgresql.or 1105 :CBC 603388 : iovcnt = buffers_to_iovec(iov, (void **) buffers, nblocks_this_segment);
1106 : 603388 : size_this_segment = nblocks_this_segment * BLCKSZ;
1107 : 603388 : transferred_this_segment = 0;
1108 : :
1109 : : /*
1110 : : * Inner loop to continue after a short write. If the reason is that
1111 : : * we're out of disk space, a future attempt should get an ENOSPC
1112 : : * error from the kernel.
1113 : : */
1114 : : for (;;)
1115 : : {
818 tmunro@postgresql.or 1116 :UBC 0 : TRACE_POSTGRESQL_SMGR_MD_WRITE_START(forknum, blocknum,
1117 : : reln->smgr_rlocator.locator.spcOid,
1118 : : reln->smgr_rlocator.locator.dbOid,
1119 : : reln->smgr_rlocator.locator.relNumber,
1120 : : reln->smgr_rlocator.backend);
818 tmunro@postgresql.or 1121 :CBC 603388 : nbytes = FileWriteV(v->mdfd_vfd, iov, iovcnt, seekpos,
1122 : : WAIT_EVENT_DATA_FILE_WRITE);
1123 : : TRACE_POSTGRESQL_SMGR_MD_WRITE_DONE(forknum, blocknum,
1124 : : reln->smgr_rlocator.locator.spcOid,
1125 : : reln->smgr_rlocator.locator.dbOid,
1126 : : reln->smgr_rlocator.locator.relNumber,
1127 : : reln->smgr_rlocator.backend,
1128 : : nbytes,
1129 : : size_this_segment - transferred_this_segment);
1130 : :
1131 : : #ifdef SIMULATE_SHORT_WRITE
1132 : : nbytes = Min(nbytes, 4096);
1133 : : #endif
1134 : :
1135 [ - + ]: 603388 : if (nbytes < 0)
1136 : : {
818 tmunro@postgresql.or 1137 :UBC 0 : bool enospc = errno == ENOSPC;
1138 : :
1139 [ # # # # ]: 0 : ereport(ERROR,
1140 : : (errcode_for_file_access(),
1141 : : errmsg("could not write blocks %u..%u in file \"%s\": %m",
1142 : : blocknum,
1143 : : blocknum + nblocks_this_segment - 1,
1144 : : FilePathName(v->mdfd_vfd)),
1145 : : enospc ? errhint("Check free disk space.") : 0));
1146 : : }
1147 : :
1148 : : /* One loop should usually be enough. */
818 tmunro@postgresql.or 1149 :CBC 603388 : transferred_this_segment += nbytes;
1150 [ - + ]: 603388 : Assert(transferred_this_segment <= size_this_segment);
1151 [ + - ]: 603388 : if (transferred_this_segment == size_this_segment)
1152 : 603388 : break;
1153 : :
1154 : : /* Adjust position and iovecs after a short write. */
818 tmunro@postgresql.or 1155 :UBC 0 : seekpos += nbytes;
1156 : 0 : iovcnt = compute_remaining_iovec(iov, iov, iovcnt, nbytes);
1157 : : }
1158 : :
818 tmunro@postgresql.or 1159 [ + + + + ]:CBC 603388 : if (!skipFsync && !SmgrIsTemp(reln))
1160 : 598961 : register_dirty_segment(reln, forknum, v);
1161 : :
1162 : 603388 : nblocks -= nblocks_this_segment;
1163 : 603388 : buffers += nblocks_this_segment;
1164 : 603388 : blocknum += nblocks_this_segment;
1165 : : }
9471 tgl@sss.pgh.pa.us 1166 : 603388 : }
1167 : :
1168 : :
1169 : : /*
1170 : : * mdwriteback() -- Tell the kernel to write pages back to storage.
1171 : : *
1172 : : * This accepts a range of blocks because flushing several pages at once is
1173 : : * considerably more efficient than doing so individually.
1174 : : */
1175 : : void
1031 peter@eisentraut.org 1176 :UBC 0 : mdwriteback(SMgrRelation reln, ForkNumber forknum,
1177 : : BlockNumber blocknum, BlockNumber nblocks)
1178 : : {
1179 [ # # ]: 0 : Assert((io_direct_flags & IO_DIRECT_DATA) == 0);
1180 : :
1181 : : /*
1182 : : * Issue flush requests in as few requests as possible; have to split at
1183 : : * segment boundaries though, since those are actually separate files.
1184 : : */
1185 [ # # ]: 0 : while (nblocks > 0)
1186 : : {
1187 : 0 : BlockNumber nflush = nblocks;
1188 : : pgoff_t seekpos;
1189 : : MdfdVec *v;
1190 : : int segnum_start,
1191 : : segnum_end;
1192 : :
1193 : 0 : v = _mdfd_getseg(reln, forknum, blocknum, true /* not used */ ,
1194 : : EXTENSION_DONT_OPEN);
1195 : :
1196 : : /*
1197 : : * We might be flushing buffers of already removed relations, that's
1198 : : * ok, just ignore that case. If the segment file wasn't open already
1199 : : * (ie from a recent mdwrite()), then we don't want to re-open it, to
1200 : : * avoid a race with PROCSIGNAL_BARRIER_SMGRRELEASE that might leave
1201 : : * us with a descriptor to a file that is about to be unlinked.
1202 : : */
1203 [ # # ]: 0 : if (!v)
1204 : 0 : return;
1205 : :
1206 : : /* compute offset inside the current segment */
1207 : 0 : segnum_start = blocknum / RELSEG_SIZE;
1208 : :
1209 : : /* compute number of desired writes within the current segment */
1210 : 0 : segnum_end = (blocknum + nblocks - 1) / RELSEG_SIZE;
1211 [ # # ]: 0 : if (segnum_start != segnum_end)
1212 : 0 : nflush = RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE));
1213 : :
1214 [ # # ]: 0 : Assert(nflush >= 1);
1215 [ # # ]: 0 : Assert(nflush <= nblocks);
1216 : :
122 michael@paquier.xyz 1217 :UNC 0 : seekpos = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1218 : :
1219 : 0 : FileWriteback(v->mdfd_vfd, seekpos, (pgoff_t) BLCKSZ * nflush, WAIT_EVENT_DATA_FILE_FLUSH);
1220 : :
1031 peter@eisentraut.org 1221 :UBC 0 : nblocks -= nflush;
1222 : 0 : blocknum += nflush;
1223 : : }
1224 : : }
1225 : :
1226 : : /*
1227 : : * mdnblocks() -- Get the number of blocks stored in a relation.
1228 : : *
1229 : : * Important side effect: all active segments of the relation are opened
1230 : : * and added to the md_seg_fds array. If this routine has not been
1231 : : * called, then only segments up to the last one actually touched
1232 : : * are present in the array.
1233 : : */
1234 : : BlockNumber
6425 heikki.linnakangas@i 1235 :CBC 2844710 : mdnblocks(SMgrRelation reln, ForkNumber forknum)
1236 : : {
1237 : : MdfdVec *v;
1238 : : BlockNumber nblocks;
1239 : : BlockNumber segno;
1240 : :
2019 bruce@momjian.us 1241 : 2844710 : mdopenfork(reln, forknum, EXTENSION_FAIL);
1242 : :
1243 : : /* mdopen has opened the first segment */
3475 andres@anarazel.de 1244 [ - + ]: 2844691 : Assert(reln->md_num_open_segs[forknum] > 0);
1245 : :
1246 : : /*
1247 : : * Start from the last open segments, to avoid redundant seeks. We have
1248 : : * previously verified that these segments are exactly RELSEG_SIZE long,
1249 : : * and it's useless to recheck that each time.
1250 : : *
1251 : : * NOTE: this assumption could only be wrong if another backend has
1252 : : * truncated the relation. We rely on higher code levels to handle that
1253 : : * scenario by closing and re-opening the md fd, which is handled via
1254 : : * relcache flush. (Since the checkpointer doesn't participate in
1255 : : * relcache flush, it could have segment entries for inactive segments;
1256 : : * that's OK because the checkpointer never needs to compute relation
1257 : : * size.)
1258 : : */
1259 : 2844691 : segno = reln->md_num_open_segs[forknum] - 1;
1260 : 2844691 : v = &reln->md_seg_fds[forknum][segno];
1261 : :
1262 : : for (;;)
1263 : : {
6425 heikki.linnakangas@i 1264 : 2844691 : nblocks = _mdnblocks(reln, forknum, v);
9027 tgl@sss.pgh.pa.us 1265 [ - + ]: 2844691 : if (nblocks > ((BlockNumber) RELSEG_SIZE))
8270 tgl@sss.pgh.pa.us 1266 [ # # ]:UBC 0 : elog(FATAL, "segment too big");
9027 tgl@sss.pgh.pa.us 1267 [ + - ]:CBC 2844691 : if (nblocks < ((BlockNumber) RELSEG_SIZE))
1268 : 2844691 : return (segno * ((BlockNumber) RELSEG_SIZE)) + nblocks;
1269 : :
1270 : : /*
1271 : : * If segment is exactly RELSEG_SIZE, advance to next one.
1272 : : */
9075 tgl@sss.pgh.pa.us 1273 :UBC 0 : segno++;
1274 : :
1275 : : /*
1276 : : * We used to pass O_CREAT here, but that has the disadvantage that it
1277 : : * might create a segment which has vanished through some operating
1278 : : * system misadventure. In such a case, creating the segment here
1279 : : * undermines _mdfd_getseg's attempts to notice and report an error
1280 : : * upon access to a missing segment.
1281 : : */
3475 andres@anarazel.de 1282 : 0 : v = _mdfd_openseg(reln, forknum, segno, 0);
1283 [ # # ]: 0 : if (v == NULL)
1284 : 0 : return segno * ((BlockNumber) RELSEG_SIZE);
1285 : : }
1286 : : }
1287 : :
1288 : : /*
1289 : : * mdtruncate() -- Truncate relation to specified number of blocks.
1290 : : *
1291 : : * Guaranteed not to allocate memory, so it can be used in a critical section.
1292 : : * Caller must have called smgrnblocks() to obtain curnblk while holding a
1293 : : * sufficient lock to prevent a change in relation size, and not used any smgr
1294 : : * functions for this relation or handled interrupts in between. This makes
1295 : : * sure we have opened all active segments, so that truncate loop will get
1296 : : * them all!
1297 : : *
1298 : : * If nblocks > curnblk, the request is ignored when we are InRecovery,
1299 : : * otherwise, an error is raised.
1300 : : */
1301 : : void
450 tmunro@postgresql.or 1302 :CBC 905 : mdtruncate(SMgrRelation reln, ForkNumber forknum,
1303 : : BlockNumber curnblk, BlockNumber nblocks)
1304 : : {
1305 : : BlockNumber priorblocks;
1306 : : int curopensegs;
1307 : :
9027 tgl@sss.pgh.pa.us 1308 [ - + ]: 905 : if (nblocks > curnblk)
1309 : : {
1310 : : /* Bogus request ... but no complaint if InRecovery */
7011 tgl@sss.pgh.pa.us 1311 [ # # ]:UBC 0 : if (InRecovery)
1312 : 0 : return;
1313 [ # # ]: 0 : ereport(ERROR,
1314 : : (errmsg("could not truncate file \"%s\" to %u blocks: it's only %u blocks now",
1315 : : relpath(reln->smgr_rlocator, forknum).str,
1316 : : nblocks, curnblk)));
1317 : : }
9691 tgl@sss.pgh.pa.us 1318 [ + + ]:CBC 905 : if (nblocks == curnblk)
7011 1319 : 368 : return; /* no work */
1320 : :
1321 : : /*
1322 : : * Truncate segments, starting at the last one. Starting at the end makes
1323 : : * managing the memory for the fd array easier, should there be errors.
1324 : : */
3475 andres@anarazel.de 1325 : 537 : curopensegs = reln->md_num_open_segs[forknum];
1326 [ + + ]: 1074 : while (curopensegs > 0)
1327 : : {
1328 : : MdfdVec *v;
1329 : :
1330 : 537 : priorblocks = (curopensegs - 1) * RELSEG_SIZE;
1331 : :
1332 : 537 : v = &reln->md_seg_fds[forknum][curopensegs - 1];
1333 : :
9691 tgl@sss.pgh.pa.us 1334 [ - + ]: 537 : if (priorblocks > nblocks)
1335 : : {
1336 : : /*
1337 : : * This segment is no longer active. We truncate the file, but do
1338 : : * not delete it, for reasons explained in the header comments.
1339 : : */
3284 rhaas@postgresql.org 1340 [ # # ]:UBC 0 : if (FileTruncate(v->mdfd_vfd, 0, WAIT_EVENT_DATA_FILE_TRUNCATE) < 0)
7011 tgl@sss.pgh.pa.us 1341 [ # # ]: 0 : ereport(ERROR,
1342 : : (errcode_for_file_access(),
1343 : : errmsg("could not truncate file \"%s\": %m",
1344 : : FilePathName(v->mdfd_vfd))));
1345 : :
5693 rhaas@postgresql.org 1346 [ # # ]: 0 : if (!SmgrIsTemp(reln))
6425 heikki.linnakangas@i 1347 : 0 : register_dirty_segment(reln, forknum, v);
1348 : :
1349 : : /* we never drop the 1st segment */
3475 andres@anarazel.de 1350 [ # # ]: 0 : Assert(v != &reln->md_seg_fds[forknum][0]);
1351 : :
1352 : 0 : FileClose(v->mdfd_vfd);
1353 : 0 : _fdvec_resize(reln, forknum, curopensegs - 1);
1354 : : }
9027 tgl@sss.pgh.pa.us 1355 [ + - ]:CBC 537 : else if (priorblocks + ((BlockNumber) RELSEG_SIZE) > nblocks)
1356 : : {
1357 : : /*
1358 : : * This is the last segment we want to keep. Truncate the file to
1359 : : * the right length. NOTE: if nblocks is exactly a multiple K of
1360 : : * RELSEG_SIZE, we will truncate the K+1st segment to 0 length but
1361 : : * keep it. This adheres to the invariant given in the header
1362 : : * comments.
1363 : : */
8907 bruce@momjian.us 1364 : 537 : BlockNumber lastsegblocks = nblocks - priorblocks;
1365 : :
122 michael@paquier.xyz 1366 [ - + ]:GNC 537 : if (FileTruncate(v->mdfd_vfd, (pgoff_t) lastsegblocks * BLCKSZ, WAIT_EVENT_DATA_FILE_TRUNCATE) < 0)
7011 tgl@sss.pgh.pa.us 1367 [ # # ]:UBC 0 : ereport(ERROR,
1368 : : (errcode_for_file_access(),
1369 : : errmsg("could not truncate file \"%s\" to %u blocks: %m",
1370 : : FilePathName(v->mdfd_vfd),
1371 : : nblocks)));
5693 rhaas@postgresql.org 1372 [ + + ]:CBC 537 : if (!SmgrIsTemp(reln))
6425 heikki.linnakangas@i 1373 : 372 : register_dirty_segment(reln, forknum, v);
1374 : : }
1375 : : else
1376 : : {
1377 : : /*
1378 : : * We still need this segment, so nothing to do for this and any
1379 : : * earlier segment.
1380 : : */
3475 andres@anarazel.de 1381 :UBC 0 : break;
1382 : : }
3475 andres@anarazel.de 1383 :CBC 537 : curopensegs--;
1384 : : }
1385 : : }
1386 : :
1387 : : /*
1388 : : * mdregistersync() -- Mark whole relation as needing fsync
1389 : : */
1390 : : void
751 heikki.linnakangas@i 1391 : 25888 : mdregistersync(SMgrRelation reln, ForkNumber forknum)
1392 : : {
1393 : : int segno;
1394 : : int min_inactive_seg;
1395 : :
1396 : : /*
1397 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1398 : : * the loop below will get them all!
1399 : : */
1400 : 25888 : mdnblocks(reln, forknum);
1401 : :
1402 : 25888 : min_inactive_seg = segno = reln->md_num_open_segs[forknum];
1403 : :
1404 : : /*
1405 : : * Temporarily open inactive segments, then close them after sync. There
1406 : : * may be some inactive segments left opened after error, but that is
1407 : : * harmless. We don't bother to clean them up and take a risk of further
1408 : : * trouble. The next mdclose() will soon close them.
1409 : : */
1410 [ - + ]: 25888 : while (_mdfd_openseg(reln, forknum, segno, 0) != NULL)
751 heikki.linnakangas@i 1411 :UBC 0 : segno++;
1412 : :
751 heikki.linnakangas@i 1413 [ + + ]:CBC 51776 : while (segno > 0)
1414 : : {
1415 : 25888 : MdfdVec *v = &reln->md_seg_fds[forknum][segno - 1];
1416 : :
1417 : 25888 : register_dirty_segment(reln, forknum, v);
1418 : :
1419 : : /* Close inactive segments immediately */
1420 [ - + ]: 25888 : if (segno > min_inactive_seg)
1421 : : {
751 heikki.linnakangas@i 1422 :UBC 0 : FileClose(v->mdfd_vfd);
1423 : 0 : _fdvec_resize(reln, forknum, segno - 1);
1424 : : }
1425 : :
751 heikki.linnakangas@i 1426 :CBC 25888 : segno--;
1427 : : }
1428 : 25888 : }
1429 : :
1430 : : /*
1431 : : * mdimmedsync() -- Immediately sync a relation to stable storage.
1432 : : *
1433 : : * Note that only writes already issued are synced; this routine knows
1434 : : * nothing of dirty buffers that may exist inside the buffer manager. We
1435 : : * sync active and inactive segments; smgrDoPendingSyncs() relies on this.
1436 : : * Consider a relation skipping WAL. Suppose a checkpoint syncs blocks of
1437 : : * some segment, then mdtruncate() renders that segment inactive. If we
1438 : : * crash before the next checkpoint syncs the newly-inactive segment, that
1439 : : * segment may survive recovery, reintroducing unwanted data into the table.
1440 : : */
1441 : : void
6425 1442 : 10 : mdimmedsync(SMgrRelation reln, ForkNumber forknum)
1443 : : {
1444 : : int segno;
1445 : : int min_inactive_seg;
1446 : :
1447 : : /*
1448 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1449 : : * the loop below will get them all!
1450 : : */
5452 peter_e@gmx.net 1451 : 10 : mdnblocks(reln, forknum);
1452 : :
2171 noah@leadboat.com 1453 : 10 : min_inactive_seg = segno = reln->md_num_open_segs[forknum];
1454 : :
1455 : : /*
1456 : : * Temporarily open inactive segments, then close them after sync. There
1457 : : * may be some inactive segments left opened after fsync() error, but that
1458 : : * is harmless. We don't bother to clean them up and take a risk of
1459 : : * further trouble. The next mdclose() will soon close them.
1460 : : */
1461 [ - + ]: 10 : while (_mdfd_openseg(reln, forknum, segno, 0) != NULL)
2171 noah@leadboat.com 1462 :UBC 0 : segno++;
1463 : :
3475 andres@anarazel.de 1464 [ + + ]:CBC 20 : while (segno > 0)
1465 : : {
1466 : 10 : MdfdVec *v = &reln->md_seg_fds[forknum][segno - 1];
1467 : :
1468 : : /*
1469 : : * fsyncs done through mdimmedsync() should be tracked in a separate
1470 : : * IOContext than those done through mdsyncfiletag() to differentiate
1471 : : * between unavoidable client backend fsyncs (e.g. those done during
1472 : : * index build) and those which ideally would have been done by the
1473 : : * checkpointer. Since other IO operations bypassing the buffer
1474 : : * manager could also be tracked in such an IOContext, wait until
1475 : : * these are also tracked to track immediate fsyncs.
1476 : : */
3284 rhaas@postgresql.org 1477 [ - + ]: 10 : if (FileSync(v->mdfd_vfd, WAIT_EVENT_DATA_FILE_IMMEDIATE_SYNC) < 0)
2673 tmunro@postgresql.or 1478 [ # # ]:UBC 0 : ereport(data_sync_elevel(ERROR),
1479 : : (errcode_for_file_access(),
1480 : : errmsg("could not fsync file \"%s\": %m",
1481 : : FilePathName(v->mdfd_vfd))));
1482 : :
1483 : : /* Close inactive segments immediately */
2171 noah@leadboat.com 1484 [ - + ]:CBC 10 : if (segno > min_inactive_seg)
1485 : : {
2171 noah@leadboat.com 1486 :UBC 0 : FileClose(v->mdfd_vfd);
1487 : 0 : _fdvec_resize(reln, forknum, segno - 1);
1488 : : }
1489 : :
3475 andres@anarazel.de 1490 :CBC 10 : segno--;
1491 : : }
7956 tgl@sss.pgh.pa.us 1492 : 10 : }
1493 : :
1494 : : int
351 andres@anarazel.de 1495 : 487023 : mdfd(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, uint32 *off)
1496 : : {
1497 : 487023 : MdfdVec *v = mdopenfork(reln, forknum, EXTENSION_FAIL);
1498 : :
1499 : 487023 : v = _mdfd_getseg(reln, forknum, blocknum, false,
1500 : : EXTENSION_FAIL);
1501 : :
122 michael@paquier.xyz 1502 :GNC 487023 : *off = (pgoff_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1503 : :
1504 [ - + ]: 487023 : Assert(*off < (pgoff_t) BLCKSZ * RELSEG_SIZE);
1505 : :
351 andres@anarazel.de 1506 :CBC 487023 : return FileGetRawDesc(v->mdfd_vfd);
1507 : : }
1508 : :
1509 : : /*
1510 : : * register_dirty_segment() -- Mark a relation segment as needing fsync
1511 : : *
1512 : : * If there is a local pending-ops table, just make an entry in it for
1513 : : * ProcessSyncRequests to process later. Otherwise, try to pass off the
1514 : : * fsync request to the checkpointer process. If that fails, just do the
1515 : : * fsync locally before returning (we hope this will not happen often
1516 : : * enough to be a performance problem).
1517 : : */
1518 : : static void
6425 heikki.linnakangas@i 1519 : 1006018 : register_dirty_segment(SMgrRelation reln, ForkNumber forknum, MdfdVec *seg)
1520 : : {
1521 : : FileTag tag;
1522 : :
1348 rhaas@postgresql.org 1523 : 1006018 : INIT_MD_FILETAG(tag, reln->smgr_rlocator.locator, forknum, seg->mdfd_segno);
1524 : :
1525 : : /* Temp relations should never be fsync'd */
4989 tgl@sss.pgh.pa.us 1526 [ - + ]: 1006018 : Assert(!SmgrIsTemp(reln));
1527 : :
2537 tmunro@postgresql.or 1528 [ + + ]: 1006018 : if (!RegisterSyncRequest(&tag, SYNC_REQUEST, false /* retryOnError */ ))
1529 : : {
1530 : : instr_time io_start;
1531 : :
1073 andres@anarazel.de 1532 [ - + ]: 170 : ereport(DEBUG1,
1533 : : (errmsg_internal("could not forward fsync request because request queue is full")));
1534 : :
382 michael@paquier.xyz 1535 : 170 : io_start = pgstat_prepare_io_time(track_io_timing);
1536 : :
1073 andres@anarazel.de 1537 [ - + ]: 170 : if (FileSync(seg->mdfd_vfd, WAIT_EVENT_DATA_FILE_SYNC) < 0)
1073 andres@anarazel.de 1538 [ # # ]:UBC 0 : ereport(data_sync_elevel(ERROR),
1539 : : (errcode_for_file_access(),
1540 : : errmsg("could not fsync file \"%s\": %m",
1541 : : FilePathName(seg->mdfd_vfd))));
1542 : :
1543 : : /*
1544 : : * We have no way of knowing if the current IOContext is
1545 : : * IOCONTEXT_NORMAL or IOCONTEXT_[BULKREAD, BULKWRITE, VACUUM] at this
1546 : : * point, so count the fsync as being in the IOCONTEXT_NORMAL
1547 : : * IOContext. This is probably okay, because the number of backend
1548 : : * fsyncs doesn't say anything about the efficacy of the
1549 : : * BufferAccessStrategy. And counting both fsyncs done in
1550 : : * IOCONTEXT_NORMAL and IOCONTEXT_[BULKREAD, BULKWRITE, VACUUM] under
1551 : : * IOCONTEXT_NORMAL is likely clearer when investigating the number of
1552 : : * backend fsyncs.
1553 : : */
1073 andres@anarazel.de 1554 :CBC 170 : pgstat_count_io_op_time(IOOBJECT_RELATION, IOCONTEXT_NORMAL,
1555 : : IOOP_FSYNC, io_start, 1, 0);
1556 : : }
10841 scrappy@hub.org 1557 : 1006018 : }
1558 : :
1559 : : /*
1560 : : * register_unlink_segment() -- Schedule a file to be deleted after next checkpoint
1561 : : */
1562 : : static void
1348 rhaas@postgresql.org 1563 : 37092 : register_unlink_segment(RelFileLocatorBackend rlocator, ForkNumber forknum,
1564 : : BlockNumber segno)
1565 : : {
1566 : : FileTag tag;
1567 : :
1568 : 37092 : INIT_MD_FILETAG(tag, rlocator.locator, forknum, segno);
1569 : :
1570 : : /* Should never be used with temp relations */
1571 [ - + ]: 37092 : Assert(!RelFileLocatorBackendIsTemp(rlocator));
1572 : :
2537 tmunro@postgresql.or 1573 : 37092 : RegisterSyncRequest(&tag, SYNC_UNLINK_REQUEST, true /* retryOnError */ );
6695 tgl@sss.pgh.pa.us 1574 : 37092 : }
1575 : :
1576 : : /*
1577 : : * register_forget_request() -- forget any fsyncs for a relation fork's segment
1578 : : */
1579 : : static void
1348 rhaas@postgresql.org 1580 : 144140 : register_forget_request(RelFileLocatorBackend rlocator, ForkNumber forknum,
1581 : : BlockNumber segno)
1582 : : {
1583 : : FileTag tag;
1584 : :
1585 : 144140 : INIT_MD_FILETAG(tag, rlocator.locator, forknum, segno);
1586 : :
2537 tmunro@postgresql.or 1587 : 144140 : RegisterSyncRequest(&tag, SYNC_FORGET_REQUEST, true /* retryOnError */ );
6997 tgl@sss.pgh.pa.us 1588 : 144140 : }
1589 : :
1590 : : /*
1591 : : * ForgetDatabaseSyncRequests -- forget any fsyncs and unlinks for a DB
1592 : : */
1593 : : void
2537 tmunro@postgresql.or 1594 : 64 : ForgetDatabaseSyncRequests(Oid dbid)
1595 : : {
1596 : : FileTag tag;
1597 : : RelFileLocator rlocator;
1598 : :
1348 rhaas@postgresql.org 1599 : 64 : rlocator.dbOid = dbid;
1600 : 64 : rlocator.spcOid = 0;
1601 : 64 : rlocator.relNumber = 0;
1602 : :
1603 : 64 : INIT_MD_FILETAG(tag, rlocator, InvalidForkNumber, InvalidBlockNumber);
1604 : :
2537 tmunro@postgresql.or 1605 : 64 : RegisterSyncRequest(&tag, SYNC_FILTER_REQUEST, true /* retryOnError */ );
9269 vadim4o@yahoo.com 1606 : 64 : }
1607 : :
1608 : : /*
1609 : : * DropRelationFiles -- drop files of all given relations
1610 : : */
1611 : : void
1348 rhaas@postgresql.org 1612 : 2851 : DropRelationFiles(RelFileLocator *delrels, int ndelrels, bool isRedo)
1613 : : {
1614 : : SMgrRelation *srels;
1615 : : int i;
1616 : :
95 michael@paquier.xyz 1617 :GNC 2851 : srels = palloc_array(SMgrRelation, ndelrels);
2810 fujii@postgresql.org 1618 [ + + ]:CBC 10985 : for (i = 0; i < ndelrels; i++)
1619 : : {
742 heikki.linnakangas@i 1620 : 8134 : SMgrRelation srel = smgropen(delrels[i], INVALID_PROC_NUMBER);
1621 : :
2810 fujii@postgresql.org 1622 [ + + ]: 8134 : if (isRedo)
1623 : : {
1624 : : ForkNumber fork;
1625 : :
1626 [ + + ]: 40480 : for (fork = 0; fork <= MAX_FORKNUM; fork++)
1627 : 32384 : XLogDropRelation(delrels[i], fork);
1628 : : }
1629 : 8134 : srels[i] = srel;
1630 : : }
1631 : :
1632 : 2851 : smgrdounlinkall(srels, ndelrels, isRedo);
1633 : :
2545 tomas.vondra@postgre 1634 [ + + ]: 10985 : for (i = 0; i < ndelrels; i++)
2810 fujii@postgresql.org 1635 : 8134 : smgrclose(srels[i]);
1636 : 2851 : pfree(srels);
1637 : 2851 : }
1638 : :
1639 : :
1640 : : /*
1641 : : * _fdvec_resize() -- Resize the fork's open segments array
1642 : : */
1643 : : static void
3475 andres@anarazel.de 1644 : 1493315 : _fdvec_resize(SMgrRelation reln,
1645 : : ForkNumber forknum,
1646 : : int nseg)
1647 : : {
1648 [ + + ]: 1493315 : if (nseg == 0)
1649 : : {
1650 [ + - ]: 544399 : if (reln->md_num_open_segs[forknum] > 0)
1651 : : {
1652 : 544399 : pfree(reln->md_seg_fds[forknum]);
1653 : 544399 : reln->md_seg_fds[forknum] = NULL;
1654 : : }
1655 : : }
1656 [ + - ]: 948916 : else if (reln->md_num_open_segs[forknum] == 0)
1657 : : {
1658 : 948916 : reln->md_seg_fds[forknum] =
1659 : 948916 : MemoryContextAlloc(MdCxt, sizeof(MdfdVec) * nseg);
1660 : : }
450 tmunro@postgresql.or 1661 [ # # ]:UBC 0 : else if (nseg > reln->md_num_open_segs[forknum])
1662 : : {
1663 : : /*
1664 : : * It doesn't seem worthwhile complicating the code to amortize
1665 : : * repalloc() calls. Those are far faster than PathNameOpenFile() or
1666 : : * FileClose(), and the memory context internally will sometimes avoid
1667 : : * doing an actual reallocation.
1668 : : */
3475 andres@anarazel.de 1669 : 0 : reln->md_seg_fds[forknum] =
1670 : 0 : repalloc(reln->md_seg_fds[forknum],
1671 : : sizeof(MdfdVec) * nseg);
1672 : : }
1673 : : else
1674 : : {
1675 : : /*
1676 : : * We don't reallocate a smaller array, because we want mdtruncate()
1677 : : * to be able to promise that it won't allocate memory, so that it is
1678 : : * allowed in a critical section. This means that a bit of space in
1679 : : * the array is now wasted, until the next time we add a segment and
1680 : : * reallocate.
1681 : : */
1682 : : }
1683 : :
3475 andres@anarazel.de 1684 :CBC 1493315 : reln->md_num_open_segs[forknum] = nseg;
10524 vadim4o@yahoo.com 1685 : 1493315 : }
1686 : :
1687 : : /*
1688 : : * Return the filename for the specified segment of the relation. The
1689 : : * returned string is palloc'd.
1690 : : */
1691 : : static MdPathStr
6066 heikki.linnakangas@i 1692 : 25910 : _mdfd_segpath(SMgrRelation reln, ForkNumber forknum, BlockNumber segno)
1693 : : {
1694 : : RelPathStr path;
1695 : : MdPathStr fullpath;
1696 : :
1348 rhaas@postgresql.org 1697 : 25910 : path = relpath(reln->smgr_rlocator, forknum);
1698 : :
10416 bruce@momjian.us 1699 [ + - ]: 25910 : if (segno > 0)
383 andres@anarazel.de 1700 : 25910 : sprintf(fullpath.str, "%s.%u", path.str, segno);
1701 : : else
383 andres@anarazel.de 1702 :UBC 0 : strcpy(fullpath.str, path.str);
1703 : :
6066 heikki.linnakangas@i 1704 :CBC 25910 : return fullpath;
1705 : : }
1706 : :
1707 : : /*
1708 : : * Open the specified segment of the relation,
1709 : : * and make a MdfdVec object for it. Returns NULL on failure.
1710 : : */
1711 : : static MdfdVec *
1712 : 25898 : _mdfd_openseg(SMgrRelation reln, ForkNumber forknum, BlockNumber segno,
1713 : : int oflags)
1714 : : {
1715 : : MdfdVec *v;
1716 : : File fd;
1717 : : MdPathStr fullpath;
1718 : :
1719 : 25898 : fullpath = _mdfd_segpath(reln, forknum, segno);
1720 : :
1721 : : /* open the file */
383 andres@anarazel.de 1722 : 25898 : fd = PathNameOpenFile(fullpath.str, _mdfd_open_flags() | oflags);
1723 : :
10416 bruce@momjian.us 1724 [ + - ]: 25898 : if (fd < 0)
8103 neilc@samurai.com 1725 : 25898 : return NULL;
1726 : :
1727 : : /*
1728 : : * Segments are always opened in order from lowest to highest, so we must
1729 : : * be adding a new one at the end.
1730 : : */
2239 tmunro@postgresql.or 1731 [ # # ]:UBC 0 : Assert(segno == reln->md_num_open_segs[forknum]);
1732 : :
1733 : 0 : _fdvec_resize(reln, forknum, segno + 1);
1734 : :
1735 : : /* fill the entry */
3475 andres@anarazel.de 1736 : 0 : v = &reln->md_seg_fds[forknum][segno];
10416 bruce@momjian.us 1737 : 0 : v->mdfd_vfd = fd;
7958 tgl@sss.pgh.pa.us 1738 : 0 : v->mdfd_segno = segno;
1739 : :
6425 heikki.linnakangas@i 1740 [ # # ]: 0 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
1741 : :
1742 : : /* all done */
10057 bruce@momjian.us 1743 : 0 : return v;
1744 : : }
1745 : :
1746 : : /*
1747 : : * _mdfd_getseg() -- Find the segment of the relation holding the
1748 : : * specified block.
1749 : : *
1750 : : * If the segment doesn't exist, we ereport, return NULL, or create the
1751 : : * segment, according to "behavior". Note: skipFsync is only used in the
1752 : : * EXTENSION_CREATE case.
1753 : : */
1754 : : static MdfdVec *
6425 heikki.linnakangas@i 1755 :CBC 2782768 : _mdfd_getseg(SMgrRelation reln, ForkNumber forknum, BlockNumber blkno,
1756 : : bool skipFsync, int behavior)
1757 : : {
1758 : : MdfdVec *v;
1759 : : BlockNumber targetseg;
1760 : : BlockNumber nextsegno;
1761 : :
1762 : : /* some way to handle non-existent segments needs to be specified */
3602 andres@anarazel.de 1763 [ - + ]: 2782768 : Assert(behavior &
1764 : : (EXTENSION_FAIL | EXTENSION_CREATE | EXTENSION_RETURN_NULL |
1765 : : EXTENSION_DONT_OPEN));
1766 : :
7011 tgl@sss.pgh.pa.us 1767 : 2782768 : targetseg = blkno / ((BlockNumber) RELSEG_SIZE);
1768 : :
1769 : : /* if an existing and opened segment, we're done */
3475 andres@anarazel.de 1770 [ + + ]: 2782768 : if (targetseg < reln->md_num_open_segs[forknum])
1771 : : {
1772 : 2535304 : v = &reln->md_seg_fds[forknum][targetseg];
1773 : 2535304 : return v;
1774 : : }
1775 : :
1776 : : /* The caller only wants the segment if we already had it open. */
1408 tmunro@postgresql.or 1777 [ - + ]: 247464 : if (behavior & EXTENSION_DONT_OPEN)
1408 tmunro@postgresql.or 1778 :UBC 0 : return NULL;
1779 : :
1780 : : /*
1781 : : * The target segment is not yet open. Iterate over all the segments
1782 : : * between the last opened and the target segment. This way missing
1783 : : * segments either raise an error, or get created (according to
1784 : : * 'behavior'). Start with either the last opened, or the first segment if
1785 : : * none was opened before.
1786 : : */
3475 andres@anarazel.de 1787 [ + + ]:CBC 247464 : if (reln->md_num_open_segs[forknum] > 0)
1788 : 12 : v = &reln->md_seg_fds[forknum][reln->md_num_open_segs[forknum] - 1];
1789 : : else
1790 : : {
2433 tmunro@postgresql.or 1791 : 247452 : v = mdopenfork(reln, forknum, behavior);
3475 andres@anarazel.de 1792 [ - + ]: 247449 : if (!v)
3475 andres@anarazel.de 1793 :UBC 0 : return NULL; /* if behavior & EXTENSION_RETURN_NULL */
1794 : : }
1795 : :
3475 andres@anarazel.de 1796 :CBC 247461 : for (nextsegno = reln->md_num_open_segs[forknum];
1797 [ + + ]: 247461 : nextsegno <= targetseg; nextsegno++)
1798 : : {
1799 : 12 : BlockNumber nblocks = _mdnblocks(reln, forknum, v);
1800 : 12 : int flags = 0;
1801 : :
1802 [ - + ]: 12 : Assert(nextsegno == v->mdfd_segno + 1);
1803 : :
1804 [ - + ]: 12 : if (nblocks > ((BlockNumber) RELSEG_SIZE))
3475 andres@anarazel.de 1805 [ # # ]:UBC 0 : elog(FATAL, "segment too big");
1806 : :
3475 andres@anarazel.de 1807 [ + - ]:CBC 12 : if ((behavior & EXTENSION_CREATE) ||
1808 [ - + - - ]: 12 : (InRecovery && (behavior & EXTENSION_CREATE_RECOVERY)))
1809 : : {
1810 : : /*
1811 : : * Normally we will create new segments only if authorized by the
1812 : : * caller (i.e., we are doing mdextend()). But when doing WAL
1813 : : * recovery, create segments anyway; this allows cases such as
1814 : : * replaying WAL data that has a write into a high-numbered
1815 : : * segment of a relation that was later deleted. We want to go
1816 : : * ahead and create the segments so we can finish out the replay.
1817 : : *
1818 : : * We have to maintain the invariant that segments before the last
1819 : : * active segment are of size RELSEG_SIZE; therefore, if
1820 : : * extending, pad them out with zeroes if needed. (This only
1821 : : * matters if in recovery, or if the caller is extending the
1822 : : * relation discontiguously, but that can happen in hash indexes.)
1823 : : */
3475 andres@anarazel.de 1824 [ # # ]:UBC 0 : if (nblocks < ((BlockNumber) RELSEG_SIZE))
1825 : : {
1072 tmunro@postgresql.or 1826 : 0 : char *zerobuf = palloc_aligned(BLCKSZ, PG_IO_ALIGN_SIZE,
1827 : : MCXT_ALLOC_ZERO);
1828 : :
3475 andres@anarazel.de 1829 : 0 : mdextend(reln, forknum,
1830 : 0 : nextsegno * ((BlockNumber) RELSEG_SIZE) - 1,
1831 : : zerobuf, skipFsync);
1832 : 0 : pfree(zerobuf);
1833 : : }
1834 : 0 : flags = O_CREAT;
1835 : : }
456 tmunro@postgresql.or 1836 [ + - ]:CBC 12 : else if (nblocks < ((BlockNumber) RELSEG_SIZE))
1837 : : {
1838 : : /*
1839 : : * When not extending, only open the next segment if the current
1840 : : * one is exactly RELSEG_SIZE. If not (this branch), either
1841 : : * return NULL or fail.
1842 : : */
3475 andres@anarazel.de 1843 [ - + ]: 12 : if (behavior & EXTENSION_RETURN_NULL)
1844 : : {
1845 : : /*
1846 : : * Some callers discern between reasons for _mdfd_getseg()
1847 : : * returning NULL based on errno. As there's no failing
1848 : : * syscall involved in this case, explicitly set errno to
1849 : : * ENOENT, as that seems the closest interpretation.
1850 : : */
3475 andres@anarazel.de 1851 :UBC 0 : errno = ENOENT;
1852 : 0 : return NULL;
1853 : : }
1854 : :
3475 andres@anarazel.de 1855 [ + - ]:CBC 12 : ereport(ERROR,
1856 : : (errcode_for_file_access(),
1857 : : errmsg("could not open file \"%s\" (target block %u): previous segment is only %u blocks",
1858 : : _mdfd_segpath(reln, forknum, nextsegno).str,
1859 : : blkno, nblocks)));
1860 : : }
1861 : :
3475 andres@anarazel.de 1862 :UBC 0 : v = _mdfd_openseg(reln, forknum, nextsegno, flags);
1863 : :
1864 [ # # ]: 0 : if (v == NULL)
1865 : : {
1866 [ # # ]: 0 : if ((behavior & EXTENSION_RETURN_NULL) &&
1867 [ # # ]: 0 : FILE_POSSIBLY_DELETED(errno))
1868 : 0 : return NULL;
1869 [ # # ]: 0 : ereport(ERROR,
1870 : : (errcode_for_file_access(),
1871 : : errmsg("could not open file \"%s\" (target block %u): %m",
1872 : : _mdfd_segpath(reln, forknum, nextsegno).str,
1873 : : blkno)));
1874 : : }
1875 : : }
1876 : :
10057 bruce@momjian.us 1877 :CBC 247449 : return v;
1878 : : }
1879 : :
1880 : : /*
1881 : : * Get number of blocks present in a single disk file
1882 : : */
1883 : : static BlockNumber
6425 heikki.linnakangas@i 1884 : 3964138 : _mdnblocks(SMgrRelation reln, ForkNumber forknum, MdfdVec *seg)
1885 : : {
1886 : : pgoff_t len;
1887 : :
2685 tmunro@postgresql.or 1888 : 3964138 : len = FileSize(seg->mdfd_vfd);
9468 bruce@momjian.us 1889 [ - + ]: 3964138 : if (len < 0)
7011 tgl@sss.pgh.pa.us 1890 [ # # ]:UBC 0 : ereport(ERROR,
1891 : : (errcode_for_file_access(),
1892 : : errmsg("could not seek to end of file \"%s\": %m",
1893 : : FilePathName(seg->mdfd_vfd))));
1894 : : /* note that this calculation will ignore any partial block at EOF */
7011 tgl@sss.pgh.pa.us 1895 :CBC 3964138 : return (BlockNumber) (len / BLCKSZ);
1896 : : }
1897 : :
1898 : : /*
1899 : : * Sync a file to disk, given a file tag. Write the path into an output
1900 : : * buffer so the caller can use it in error messages.
1901 : : *
1902 : : * Return 0 on success, -1 on failure, with errno set.
1903 : : */
1904 : : int
2537 tmunro@postgresql.or 1905 :UBC 0 : mdsyncfiletag(const FileTag *ftag, char *path)
1906 : : {
742 heikki.linnakangas@i 1907 : 0 : SMgrRelation reln = smgropen(ftag->rlocator, INVALID_PROC_NUMBER);
1908 : : File file;
1909 : : instr_time io_start;
1910 : : bool need_to_close;
1911 : : int result,
1912 : : save_errno;
1913 : :
1914 : : /* See if we already have the file open, or need to open it. */
2283 tmunro@postgresql.or 1915 [ # # ]: 0 : if (ftag->segno < reln->md_num_open_segs[ftag->forknum])
1916 : : {
1917 : 0 : file = reln->md_seg_fds[ftag->forknum][ftag->segno].mdfd_vfd;
1918 : 0 : strlcpy(path, FilePathName(file), MAXPGPATH);
1919 : 0 : need_to_close = false;
1920 : : }
1921 : : else
1922 : : {
1923 : : MdPathStr p;
1924 : :
1925 : 0 : p = _mdfd_segpath(reln, ftag->forknum, ftag->segno);
383 andres@anarazel.de 1926 : 0 : strlcpy(path, p.str, MD_PATH_STR_MAXLEN);
1927 : :
1072 tmunro@postgresql.or 1928 : 0 : file = PathNameOpenFile(path, _mdfd_open_flags());
2283 1929 [ # # ]: 0 : if (file < 0)
1930 : 0 : return -1;
1931 : 0 : need_to_close = true;
1932 : : }
1933 : :
382 michael@paquier.xyz 1934 : 0 : io_start = pgstat_prepare_io_time(track_io_timing);
1935 : :
1936 : : /* Sync the file. */
2283 tmunro@postgresql.or 1937 : 0 : result = FileSync(file, WAIT_EVENT_DATA_FILE_SYNC);
1938 : 0 : save_errno = errno;
1939 : :
1940 [ # # ]: 0 : if (need_to_close)
1941 : 0 : FileClose(file);
1942 : :
1073 andres@anarazel.de 1943 : 0 : pgstat_count_io_op_time(IOOBJECT_RELATION, IOCONTEXT_NORMAL,
1944 : : IOOP_FSYNC, io_start, 1, 0);
1945 : :
2283 tmunro@postgresql.or 1946 : 0 : errno = save_errno;
1947 : 0 : return result;
1948 : : }
1949 : :
1950 : : /*
1951 : : * Unlink a file, given a file tag. Write the path into an output
1952 : : * buffer so the caller can use it in error messages.
1953 : : *
1954 : : * Return 0 on success, -1 on failure, with errno set.
1955 : : */
1956 : : int
2537 tmunro@postgresql.or 1957 :CBC 35116 : mdunlinkfiletag(const FileTag *ftag, char *path)
1958 : : {
1959 : : RelPathStr p;
1960 : :
1961 : : /* Compute the path. */
1348 rhaas@postgresql.org 1962 : 35116 : p = relpathperm(ftag->rlocator, MAIN_FORKNUM);
383 andres@anarazel.de 1963 : 35116 : strlcpy(path, p.str, MAXPGPATH);
1964 : :
1965 : : /* Try to unlink the file. */
2537 tmunro@postgresql.or 1966 : 35116 : return unlink(path);
1967 : : }
1968 : :
1969 : : /*
1970 : : * Check if a given candidate request matches a given tag, when processing
1971 : : * a SYNC_FILTER_REQUEST request. This will be called for all pending
1972 : : * requests to find out whether to forget them.
1973 : : */
1974 : : bool
1975 : 7382 : mdfiletagmatches(const FileTag *ftag, const FileTag *candidate)
1976 : : {
1977 : : /*
1978 : : * For now we only use filter requests as a way to drop all scheduled
1979 : : * callbacks relating to a given database, when dropping the database.
1980 : : * We'll return true for all candidates that have the same database OID as
1981 : : * the ftag from the SYNC_FILTER_REQUEST request, so they're forgotten.
1982 : : */
1348 rhaas@postgresql.org 1983 : 7382 : return ftag->rlocator.dbOid == candidate->rlocator.dbOid;
1984 : : }
1985 : :
1986 : : /*
1987 : : * AIO completion callback for mdstartreadv().
1988 : : */
1989 : : static PgAioResult
351 andres@anarazel.de 1990 : 1202811 : md_readv_complete(PgAioHandle *ioh, PgAioResult prior_result, uint8 cb_data)
1991 : : {
1992 : 1202811 : PgAioTargetData *td = pgaio_io_get_target_data(ioh);
1993 : 1202811 : PgAioResult result = prior_result;
1994 : :
1995 [ + + ]: 1202811 : if (prior_result.result < 0)
1996 : : {
1997 : 10 : result.status = PGAIO_RS_ERROR;
1998 : 10 : result.id = PGAIO_HCB_MD_READV;
1999 : : /* For "hard" errors, track the error number in error_data */
2000 : 10 : result.error_data = -prior_result.result;
2001 : 10 : result.result = 0;
2002 : :
2003 : : /*
2004 : : * Immediately log a message about the IO error, but only to the
2005 : : * server log. The reason to do so immediately is that the originator
2006 : : * might not process the query result immediately (because it is busy
2007 : : * doing another part of query processing) or at all (e.g. if it was
2008 : : * cancelled or errored out due to another IO also failing). The
2009 : : * definer of the IO will emit an ERROR when processing the IO's
2010 : : * results
2011 : : */
2012 : 10 : pgaio_result_report(result, td, LOG_SERVER_ONLY);
2013 : :
2014 : 10 : return result;
2015 : : }
2016 : :
2017 : : /*
2018 : : * As explained above smgrstartreadv(), the smgr API operates on the level
2019 : : * of blocks, rather than bytes. Convert.
2020 : : */
2021 : 1202801 : result.result /= BLCKSZ;
2022 : :
2023 [ - + ]: 1202801 : Assert(result.result <= td->smgr.nblocks);
2024 : :
2025 [ + + ]: 1202801 : if (result.result == 0)
2026 : : {
2027 : : /* consider 0 blocks read a failure */
2028 : 3 : result.status = PGAIO_RS_ERROR;
2029 : 3 : result.id = PGAIO_HCB_MD_READV;
2030 : 3 : result.error_data = 0;
2031 : :
2032 : : /* see comment above the "hard error" case */
2033 : 3 : pgaio_result_report(result, td, LOG_SERVER_ONLY);
2034 : :
2035 : 3 : return result;
2036 : : }
2037 : :
2038 [ + - ]: 1202798 : if (result.status != PGAIO_RS_ERROR &&
2039 [ + + ]: 1202798 : result.result < td->smgr.nblocks)
2040 : : {
2041 : : /* partial reads should be retried at upper level */
2042 : 18 : result.status = PGAIO_RS_PARTIAL;
2043 : 18 : result.id = PGAIO_HCB_MD_READV;
2044 : : }
2045 : :
2046 : 1202798 : return result;
2047 : : }
2048 : :
2049 : : /*
2050 : : * AIO error reporting callback for mdstartreadv().
2051 : : *
2052 : : * Errors are encoded as follows:
2053 : : * - PgAioResult.error_data != 0 encodes IO that failed with that errno
2054 : : * - PgAioResult.error_data == 0 encodes IO that didn't read all data
2055 : : */
2056 : : static void
2057 : 41 : md_readv_report(PgAioResult result, const PgAioTargetData *td, int elevel)
2058 : : {
2059 : : RelPathStr path;
2060 : :
2061 [ - + ]: 41 : path = relpathbackend(td->smgr.rlocator,
2062 : : td->smgr.is_temp ? MyProcNumber : INVALID_PROC_NUMBER,
2063 : : td->smgr.forkNum);
2064 : :
2065 [ + + ]: 41 : if (result.error_data != 0)
2066 : : {
2067 : : /* for errcode_for_file_access() and %m */
2068 : 20 : errno = result.error_data;
2069 : :
2070 [ + - ]: 20 : ereport(elevel,
2071 : : errcode_for_file_access(),
2072 : : errmsg("could not read blocks %u..%u in file \"%s\": %m",
2073 : : td->smgr.blockNum,
2074 : : td->smgr.blockNum + td->smgr.nblocks - 1,
2075 : : path.str));
2076 : : }
2077 : : else
2078 : : {
2079 : : /*
2080 : : * NB: This will typically only be output in debug messages, while
2081 : : * retrying a partial IO.
2082 : : */
2083 [ + - ]: 21 : ereport(elevel,
2084 : : errcode(ERRCODE_DATA_CORRUPTED),
2085 : : errmsg("could not read blocks %u..%u in file \"%s\": read only %zu of %zu bytes",
2086 : : td->smgr.blockNum,
2087 : : td->smgr.blockNum + td->smgr.nblocks - 1,
2088 : : path.str,
2089 : : result.result * (size_t) BLCKSZ,
2090 : : td->smgr.nblocks * (size_t) BLCKSZ));
2091 : : }
2092 : 28 : }
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