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) 1996-2025, 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 : :
44 : : /*
45 : : * The magnetic disk storage manager keeps track of open file
46 : : * descriptors in its own descriptor pool. This is done to make it
47 : : * easier to support relations that are larger than the operating
48 : : * system's file size limit (often 2GBytes). In order to do that,
49 : : * we break relations up into "segment" files that are each shorter than
50 : : * the OS file size limit. The segment size is set by the RELSEG_SIZE
51 : : * configuration constant in pg_config.h.
52 : : *
53 : : * On disk, a relation must consist of consecutively numbered segment
54 : : * files in the pattern
55 : : * -- Zero or more full segments of exactly RELSEG_SIZE blocks each
56 : : * -- Exactly one partial segment of size 0 <= size < RELSEG_SIZE blocks
57 : : * -- Optionally, any number of inactive segments of size 0 blocks.
58 : : * The full and partial segments are collectively the "active" segments.
59 : : * Inactive segments are those that once contained data but are currently
60 : : * not needed because of an mdtruncate() operation. The reason for leaving
61 : : * them present at size zero, rather than unlinking them, is that other
62 : : * backends and/or the checkpointer might be holding open file references to
63 : : * such segments. If the relation expands again after mdtruncate(), such
64 : : * that a deactivated segment becomes active again, it is important that
65 : : * such file references still be valid --- else data might get written
66 : : * out to an unlinked old copy of a segment file that will eventually
67 : : * disappear.
68 : : *
69 : : * RELSEG_SIZE must fit into BlockNumber; but since we expose its value
70 : : * as an integer GUC, it actually needs to fit in signed int. It's worth
71 : : * having a cross-check for this since configure's --with-segsize options
72 : : * could let people select insane values.
73 : : */
74 : : StaticAssertDecl(RELSEG_SIZE > 0 && RELSEG_SIZE <= INT_MAX,
75 : : "RELSEG_SIZE must fit in an integer");
76 : :
77 : : /*
78 : : * File descriptors are stored in the per-fork md_seg_fds arrays inside
79 : : * SMgrRelation. The length of these arrays is stored in md_num_open_segs.
80 : : * Note that a fork's md_num_open_segs having a specific value does not
81 : : * necessarily mean the relation doesn't have additional segments; we may
82 : : * just not have opened the next segment yet. (We could not have "all
83 : : * segments are in the array" as an invariant anyway, since another backend
84 : : * could extend the relation while we aren't looking.) We do not have
85 : : * entries for inactive segments, however; as soon as we find a partial
86 : : * segment, we assume that any subsequent segments are inactive.
87 : : *
88 : : * The entire MdfdVec array is palloc'd in the MdCxt memory context.
89 : : */
90 : :
91 : : typedef struct _MdfdVec
92 : : {
93 : : File mdfd_vfd; /* fd number in fd.c's pool */
94 : : BlockNumber mdfd_segno; /* segment number, from 0 */
95 : : } MdfdVec;
96 : :
97 : : static MemoryContext MdCxt; /* context for all MdfdVec objects */
98 : :
99 : :
100 : : /* Populate a file tag describing an md.c segment file. */
101 : : #define INIT_MD_FILETAG(a,xx_rlocator,xx_forknum,xx_segno) \
102 : : ( \
103 : : memset(&(a), 0, sizeof(FileTag)), \
104 : : (a).handler = SYNC_HANDLER_MD, \
105 : : (a).rlocator = (xx_rlocator), \
106 : : (a).forknum = (xx_forknum), \
107 : : (a).segno = (xx_segno) \
108 : : )
109 : :
110 : :
111 : : /*** behavior for mdopen & _mdfd_getseg ***/
112 : : /* ereport if segment not present */
113 : : #define EXTENSION_FAIL (1 << 0)
114 : : /* return NULL if segment not present */
115 : : #define EXTENSION_RETURN_NULL (1 << 1)
116 : : /* create new segments as needed */
117 : : #define EXTENSION_CREATE (1 << 2)
118 : : /* create new segments if needed during recovery */
119 : : #define EXTENSION_CREATE_RECOVERY (1 << 3)
120 : : /* don't try to open a segment, if not already open */
121 : : #define EXTENSION_DONT_OPEN (1 << 5)
122 : :
123 : :
124 : : /*
125 : : * Fixed-length string to represent paths to files that need to be built by
126 : : * md.c.
127 : : *
128 : : * The maximum number of segments is MaxBlockNumber / RELSEG_SIZE, where
129 : : * RELSEG_SIZE can be set to 1 (for testing only).
130 : : */
131 : : #define SEGMENT_CHARS OIDCHARS
132 : : #define MD_PATH_STR_MAXLEN \
133 : : (\
134 : : REL_PATH_STR_MAXLEN \
135 : : + sizeof((char)'.') \
136 : : + SEGMENT_CHARS \
137 : : )
138 : : typedef struct MdPathStr
139 : : {
140 : : char str[MD_PATH_STR_MAXLEN + 1];
141 : : } MdPathStr;
142 : :
143 : :
144 : : /* local routines */
145 : : static void mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum,
146 : : bool isRedo);
147 : : static MdfdVec *mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior);
148 : : static void register_dirty_segment(SMgrRelation reln, ForkNumber forknum,
149 : : MdfdVec *seg);
150 : : static void register_unlink_segment(RelFileLocatorBackend rlocator, ForkNumber forknum,
151 : : BlockNumber segno);
152 : : static void register_forget_request(RelFileLocatorBackend rlocator, ForkNumber forknum,
153 : : BlockNumber segno);
154 : : static void _fdvec_resize(SMgrRelation reln,
155 : : ForkNumber forknum,
156 : : int nseg);
157 : : static MdPathStr _mdfd_segpath(SMgrRelation reln, ForkNumber forknum,
158 : : BlockNumber segno);
159 : : static MdfdVec *_mdfd_openseg(SMgrRelation reln, ForkNumber forknum,
160 : : BlockNumber segno, int oflags);
161 : : static MdfdVec *_mdfd_getseg(SMgrRelation reln, ForkNumber forknum,
162 : : BlockNumber blkno, bool skipFsync, int behavior);
163 : : static BlockNumber _mdnblocks(SMgrRelation reln, ForkNumber forknum,
164 : : MdfdVec *seg);
165 : :
166 : : static PgAioResult md_readv_complete(PgAioHandle *ioh, PgAioResult prior_result, uint8 cb_data);
167 : : static void md_readv_report(PgAioResult result, const PgAioTargetData *td, int elevel);
168 : :
169 : : const PgAioHandleCallbacks aio_md_readv_cb = {
170 : : .complete_shared = md_readv_complete,
171 : : .report = md_readv_report,
172 : : };
173 : :
174 : :
175 : : static inline int
934 tmunro@postgresql.or 176 :CBC 1281086 : _mdfd_open_flags(void)
177 : : {
178 : 1281086 : int flags = O_RDWR | PG_BINARY;
179 : :
180 [ + + ]: 1281086 : if (io_direct_flags & IO_DIRECT_DATA)
181 : 305 : flags |= PG_O_DIRECT;
182 : :
183 : 1281086 : return flags;
184 : : }
185 : :
186 : : /*
187 : : * mdinit() -- Initialize private state for magnetic disk storage manager.
188 : : */
189 : : void
8889 tgl@sss.pgh.pa.us 190 : 19092 : mdinit(void)
191 : : {
9253 192 : 19092 : MdCxt = AllocSetContextCreate(TopMemoryContext,
193 : : "MdSmgr",
194 : : ALLOCSET_DEFAULT_SIZES);
5969 heikki.linnakangas@i 195 : 19092 : }
196 : :
197 : : /*
198 : : * mdexists() -- Does the physical file exist?
199 : : *
200 : : * Note: this will return true for lingering files, with pending deletions
201 : : */
202 : : bool
1135 pg@bowt.ie 203 : 503134 : mdexists(SMgrRelation reln, ForkNumber forknum)
204 : : {
205 : : /*
206 : : * Close it first, to ensure that we notice if the fork has been unlinked
207 : : * since we opened it. As an optimization, we can skip that in recovery,
208 : : * which already closes relations when dropping them.
209 : : */
1300 tmunro@postgresql.or 210 [ + + ]: 503134 : if (!InRecovery)
1135 pg@bowt.ie 211 : 483219 : mdclose(reln, forknum);
212 : :
213 : 503134 : return (mdopenfork(reln, forknum, EXTENSION_RETURN_NULL) != NULL);
214 : : }
215 : :
216 : : /*
217 : : * mdcreate() -- Create a new relation on magnetic disk.
218 : : *
219 : : * If isRedo is true, it's okay for the relation to exist already.
220 : : */
221 : : void
222 : 5652251 : mdcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
223 : : {
224 : : MdfdVec *mdfd;
225 : : RelPathStr path;
226 : : File fd;
227 : :
228 [ + + + + ]: 5652251 : if (isRedo && reln->md_num_open_segs[forknum] > 0)
6873 tgl@sss.pgh.pa.us 229 : 5486651 : return; /* created and opened already... */
230 : :
1135 pg@bowt.ie 231 [ - + ]: 165600 : Assert(reln->md_num_open_segs[forknum] == 0);
232 : :
233 : : /*
234 : : * We may be using the target table space for the first time in this
235 : : * database, so create a per-database subdirectory if needed.
236 : : *
237 : : * XXX this is a fairly ugly violation of module layering, but this seems
238 : : * to be the best place to put the check. Maybe TablespaceCreateDbspace
239 : : * should be here and not in commands/tablespace.c? But that would imply
240 : : * importing a lot of stuff that smgr.c oughtn't know, either.
241 : : */
1210 rhaas@postgresql.org 242 : 165600 : TablespaceCreateDbspace(reln->smgr_rlocator.locator.spcOid,
243 : : reln->smgr_rlocator.locator.dbOid,
244 : : isRedo);
245 : :
1135 pg@bowt.ie 246 : 165600 : path = relpath(reln->smgr_rlocator, forknum);
247 : :
245 andres@anarazel.de 248 : 165600 : fd = PathNameOpenFile(path.str, _mdfd_open_flags() | O_CREAT | O_EXCL);
249 : :
10278 bruce@momjian.us 250 [ + + ]: 165600 : if (fd < 0)
251 : : {
8986 252 : 12133 : int save_errno = errno;
253 : :
2465 akapila@postgresql.o 254 [ + - ]: 12133 : if (isRedo)
245 andres@anarazel.de 255 : 12133 : fd = PathNameOpenFile(path.str, _mdfd_open_flags());
10278 bruce@momjian.us 256 [ - + ]: 12133 : if (fd < 0)
257 : : {
258 : : /* be sure to report the error reported by create, not open */
9262 tgl@sss.pgh.pa.us 259 :UBC 0 : errno = save_errno;
6873 260 [ # # ]: 0 : ereport(ERROR,
261 : : (errcode_for_file_access(),
262 : : errmsg("could not create file \"%s\": %m", path.str)));
263 : : }
264 : : }
265 : :
1135 pg@bowt.ie 266 :CBC 165600 : _fdvec_resize(reln, forknum, 1);
267 : 165600 : mdfd = &reln->md_seg_fds[forknum][0];
3337 andres@anarazel.de 268 : 165600 : mdfd->mdfd_vfd = fd;
269 : 165600 : mdfd->mdfd_segno = 0;
270 : :
847 heikki.linnakangas@i 271 [ + + ]: 165600 : if (!SmgrIsTemp(reln))
272 : 162238 : register_dirty_segment(reln, forknum, mdfd);
273 : : }
274 : :
275 : : /*
276 : : * mdunlink() -- Unlink a relation.
277 : : *
278 : : * Note that we're passed a RelFileLocatorBackend --- by the time this is called,
279 : : * there won't be an SMgrRelation hashtable entry anymore.
280 : : *
281 : : * forknum can be a fork number to delete a specific fork, or InvalidForkNumber
282 : : * to delete all forks.
283 : : *
284 : : * For regular relations, we don't unlink the first segment file of the rel,
285 : : * but just truncate it to zero length, and record a request to unlink it after
286 : : * the next checkpoint. Additional segments can be unlinked immediately,
287 : : * however. Leaving the empty file in place prevents that relfilenumber
288 : : * from being reused. The scenario this protects us from is:
289 : : * 1. We delete a relation (and commit, and actually remove its file).
290 : : * 2. We create a new relation, which by chance gets the same relfilenumber as
291 : : * the just-deleted one (OIDs must've wrapped around for that to happen).
292 : : * 3. We crash before another checkpoint occurs.
293 : : * During replay, we would delete the file and then recreate it, which is fine
294 : : * if the contents of the file were repopulated by subsequent WAL entries.
295 : : * But if we didn't WAL-log insertions, but instead relied on fsyncing the
296 : : * file after populating it (as we do at wal_level=minimal), the contents of
297 : : * the file would be lost forever. By leaving the empty file until after the
298 : : * next checkpoint, we prevent reassignment of the relfilenumber until it's
299 : : * safe, because relfilenumber assignment skips over any existing file.
300 : : *
301 : : * Additional segments, if any, are truncated and then unlinked. The reason
302 : : * for truncating is that other backends may still hold open FDs for these at
303 : : * the smgr level, so that the kernel can't remove the file yet. We want to
304 : : * reclaim the disk space right away despite that.
305 : : *
306 : : * We do not need to go through this dance for temp relations, though, because
307 : : * we never make WAL entries for temp rels, and so a temp rel poses no threat
308 : : * to the health of a regular rel that has taken over its relfilenumber.
309 : : * The fact that temp rels and regular rels have different file naming
310 : : * patterns provides additional safety. Other backends shouldn't have open
311 : : * FDs for them, either.
312 : : *
313 : : * We also don't do it while performing a binary upgrade. There is no reuse
314 : : * hazard in that case, since after a crash or even a simple ERROR, the
315 : : * upgrade fails and the whole cluster must be recreated from scratch.
316 : : * Furthermore, it is important to remove the files from disk immediately,
317 : : * because we may be about to reuse the same relfilenumber.
318 : : *
319 : : * All the above applies only to the relation's main fork; other forks can
320 : : * just be removed immediately, since they are not needed to prevent the
321 : : * relfilenumber from being recycled. Also, we do not carefully
322 : : * track whether other forks have been created or not, but just attempt to
323 : : * unlink them unconditionally; so we should never complain about ENOENT.
324 : : *
325 : : * If isRedo is true, it's unsurprising for the relation to be already gone.
326 : : * Also, we should remove the file immediately instead of queuing a request
327 : : * for later, since during redo there's no possibility of creating a
328 : : * conflicting relation.
329 : : *
330 : : * Note: we currently just never warn about ENOENT at all. We could warn in
331 : : * the main-fork, non-isRedo case, but it doesn't seem worth the trouble.
332 : : *
333 : : * Note: any failure should be reported as WARNING not ERROR, because
334 : : * we are usually not in a transaction anymore when this is called.
335 : : */
336 : : void
1135 pg@bowt.ie 337 : 183352 : mdunlink(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
338 : : {
339 : : /* Now do the per-fork work */
340 [ - + ]: 183352 : if (forknum == InvalidForkNumber)
341 : : {
1135 pg@bowt.ie 342 [ # # ]:UBC 0 : for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
343 : 0 : mdunlinkfork(rlocator, forknum, isRedo);
344 : : }
345 : : else
1135 pg@bowt.ie 346 :CBC 183352 : mdunlinkfork(rlocator, forknum, isRedo);
4849 tgl@sss.pgh.pa.us 347 : 183352 : }
348 : :
349 : : /*
350 : : * Truncate a file to release disk space.
351 : : */
352 : : static int
1792 tmunro@postgresql.or 353 : 215158 : do_truncate(const char *path)
354 : : {
355 : : int save_errno;
356 : : int ret;
357 : :
358 : 215158 : ret = pg_truncate(path, 0);
359 : :
360 : : /* Log a warning here to avoid repetition in callers. */
361 [ + + - + ]: 215158 : if (ret < 0 && errno != ENOENT)
362 : : {
1792 tmunro@postgresql.or 363 :UBC 0 : save_errno = errno;
364 [ # # ]: 0 : ereport(WARNING,
365 : : (errcode_for_file_access(),
366 : : errmsg("could not truncate file \"%s\": %m", path)));
367 : 0 : errno = save_errno;
368 : : }
369 : :
1792 tmunro@postgresql.or 370 :CBC 215158 : return ret;
371 : : }
372 : :
373 : : static void
1135 pg@bowt.ie 374 : 183352 : mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
375 : : {
376 : : RelPathStr path;
377 : : int ret;
378 : : int save_errno;
379 : :
380 : 183352 : path = relpath(rlocator, forknum);
381 : :
382 : : /*
383 : : * Truncate and then unlink the first segment, or just register a request
384 : : * to unlink it later, as described in the comments for mdunlink().
385 : : */
1084 tgl@sss.pgh.pa.us 386 [ + + + + : 183352 : if (isRedo || IsBinaryUpgrade || forknum != MAIN_FORKNUM ||
+ + ]
387 [ + + ]: 38162 : RelFileLocatorBackendIsTemp(rlocator))
388 : : {
1210 rhaas@postgresql.org 389 [ + + ]: 148376 : if (!RelFileLocatorBackendIsTemp(rlocator))
390 : : {
391 : : /* Prevent other backends' fds from holding on to the disk space */
245 andres@anarazel.de 392 : 135632 : ret = do_truncate(path.str);
393 : :
394 : : /* Forget any pending sync requests for the first segment */
1086 tgl@sss.pgh.pa.us 395 : 135632 : save_errno = errno;
1135 pg@bowt.ie 396 : 135632 : register_forget_request(rlocator, forknum, 0 /* first seg */ );
1086 tgl@sss.pgh.pa.us 397 : 135632 : errno = save_errno;
398 : : }
399 : : else
1792 tmunro@postgresql.or 400 : 12744 : ret = 0;
401 : :
402 : : /* Next unlink the file, unless it was already found to be missing */
1084 tgl@sss.pgh.pa.us 403 [ + + - + ]: 148376 : if (ret >= 0 || errno != ENOENT)
404 : : {
245 andres@anarazel.de 405 : 22322 : ret = unlink(path.str);
1792 tmunro@postgresql.or 406 [ + + - + ]: 22322 : if (ret < 0 && errno != ENOENT)
407 : : {
1084 tgl@sss.pgh.pa.us 408 :UBC 0 : save_errno = errno;
1792 tmunro@postgresql.or 409 [ # # ]: 0 : ereport(WARNING,
410 : : (errcode_for_file_access(),
411 : : errmsg("could not remove file \"%s\": %m", path.str)));
1084 tgl@sss.pgh.pa.us 412 : 0 : errno = save_errno;
413 : : }
414 : : }
415 : : }
416 : : else
417 : : {
418 : : /* Prevent other backends' fds from holding on to the disk space */
245 andres@anarazel.de 419 :CBC 34976 : ret = do_truncate(path.str);
420 : :
421 : : /* Register request to unlink first segment later */
1084 tgl@sss.pgh.pa.us 422 : 34976 : save_errno = errno;
423 : 34976 : register_unlink_segment(rlocator, forknum, 0 /* first seg */ );
424 : 34976 : errno = save_errno;
425 : : }
426 : :
427 : : /*
428 : : * Delete any additional segments.
429 : : *
430 : : * Note that because we loop until getting ENOENT, we will correctly
431 : : * remove all inactive segments as well as active ones. Ideally we'd
432 : : * continue the loop until getting exactly that errno, but that risks an
433 : : * infinite loop if the problem is directory-wide (for instance, if we
434 : : * suddenly can't read the data directory itself). We compromise by
435 : : * continuing after a non-ENOENT truncate error, but stopping after any
436 : : * unlink error. If there is indeed a directory-wide problem, additional
437 : : * unlink attempts wouldn't work anyway.
438 : : */
439 [ + + - + ]: 183352 : if (ret >= 0 || errno != ENOENT)
440 : : {
441 : : MdPathStr segpath;
442 : : BlockNumber segno;
443 : :
444 : 47912 : for (segno = 1;; segno++)
445 : : {
245 andres@anarazel.de 446 : 47912 : sprintf(segpath.str, "%s.%u", path.str, segno);
447 : :
1210 rhaas@postgresql.org 448 [ + + ]: 47912 : if (!RelFileLocatorBackendIsTemp(rlocator))
449 : : {
450 : : /*
451 : : * Prevent other backends' fds from holding on to the disk
452 : : * space. We're done if we see ENOENT, though.
453 : : */
245 andres@anarazel.de 454 [ + - + - ]: 44550 : if (do_truncate(segpath.str) < 0 && errno == ENOENT)
1792 tmunro@postgresql.or 455 : 44550 : break;
456 : :
457 : : /*
458 : : * Forget any pending sync requests for this segment before we
459 : : * try to unlink.
460 : : */
1135 pg@bowt.ie 461 :UBC 0 : register_forget_request(rlocator, forknum, segno);
462 : : }
463 : :
245 andres@anarazel.de 464 [ + - ]:CBC 3362 : if (unlink(segpath.str) < 0)
465 : : {
466 : : /* ENOENT is expected after the last segment... */
9120 tgl@sss.pgh.pa.us 467 [ - + ]: 3362 : if (errno != ENOENT)
6873 tgl@sss.pgh.pa.us 468 [ # # ]:UBC 0 : ereport(WARNING,
469 : : (errcode_for_file_access(),
470 : : errmsg("could not remove file \"%s\": %m", segpath.str)));
9120 tgl@sss.pgh.pa.us 471 :CBC 3362 : break;
472 : : }
473 : : }
474 : : }
10703 scrappy@hub.org 475 : 183352 : }
476 : :
477 : : /*
478 : : * mdextend() -- Add a block to the specified relation.
479 : : *
480 : : * The semantics are nearly the same as mdwrite(): write at the
481 : : * specified position. However, this is to be used for the case of
482 : : * extending a relation (i.e., blocknum is at or beyond the current
483 : : * EOF). Note that we assume writing a block beyond current EOF
484 : : * causes intervening file space to become filled with zeroes.
485 : : */
486 : : void
6287 heikki.linnakangas@i 487 : 118546 : mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
488 : : const void *buffer, bool skipFsync)
489 : : {
490 : : off_t seekpos;
491 : : int nbytes;
492 : : MdfdVec *v;
493 : :
494 : : /* If this build supports direct I/O, the buffer must be I/O aligned. */
495 : : if (PG_O_DIRECT != 0 && PG_IO_ALIGN_SIZE <= BLCKSZ)
934 tmunro@postgresql.or 496 [ - + ]: 118546 : Assert((uintptr_t) buffer == TYPEALIGN(PG_IO_ALIGN_SIZE, buffer));
497 : :
498 : : /* This assert is too expensive to have on normally ... */
499 : : #ifdef CHECK_WRITE_VS_EXTEND
500 : : Assert(blocknum >= mdnblocks(reln, forknum));
501 : : #endif
502 : :
503 : : /*
504 : : * If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
505 : : * more --- we mustn't create a block whose number actually is
506 : : * InvalidBlockNumber. (Note that this failure should be unreachable
507 : : * because of upstream checks in bufmgr.c.)
508 : : */
6873 tgl@sss.pgh.pa.us 509 [ - + ]: 118546 : if (blocknum == InvalidBlockNumber)
6873 tgl@sss.pgh.pa.us 510 [ # # ]:UBC 0 : ereport(ERROR,
511 : : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
512 : : errmsg("cannot extend file \"%s\" beyond %u blocks",
513 : : relpath(reln->smgr_rlocator, forknum).str,
514 : : InvalidBlockNumber)));
515 : :
5555 rhaas@postgresql.org 516 :CBC 118546 : v = _mdfd_getseg(reln, forknum, blocknum, skipFsync, EXTENSION_CREATE);
517 : :
3051 tgl@sss.pgh.pa.us 518 : 118546 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
519 : :
6441 520 [ - + ]: 118546 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
521 : :
2547 tmunro@postgresql.or 522 [ - + ]: 118546 : if ((nbytes = FileWrite(v->mdfd_vfd, buffer, BLCKSZ, seekpos, WAIT_EVENT_DATA_FILE_EXTEND)) != BLCKSZ)
523 : : {
6873 tgl@sss.pgh.pa.us 524 [ # # ]:UBC 0 : if (nbytes < 0)
525 [ # # ]: 0 : ereport(ERROR,
526 : : (errcode_for_file_access(),
527 : : errmsg("could not extend file \"%s\": %m",
528 : : FilePathName(v->mdfd_vfd)),
529 : : errhint("Check free disk space.")));
530 : : /* short write: complain appropriately */
531 [ # # ]: 0 : ereport(ERROR,
532 : : (errcode(ERRCODE_DISK_FULL),
533 : : errmsg("could not extend file \"%s\": wrote only %d of %d bytes at block %u",
534 : : FilePathName(v->mdfd_vfd),
535 : : nbytes, BLCKSZ, blocknum),
536 : : errhint("Check free disk space.")));
537 : : }
538 : :
5555 rhaas@postgresql.org 539 [ + + + - ]:CBC 118546 : if (!skipFsync && !SmgrIsTemp(reln))
6287 heikki.linnakangas@i 540 : 29 : register_dirty_segment(reln, forknum, v);
541 : :
542 [ - + ]: 118546 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
10703 scrappy@hub.org 543 : 118546 : }
544 : :
545 : : /*
546 : : * mdzeroextend() -- Add new zeroed out blocks to the specified relation.
547 : : *
548 : : * Similar to mdextend(), except the relation can be extended by multiple
549 : : * blocks at once and the added blocks will be filled with zeroes.
550 : : */
551 : : void
937 andres@anarazel.de 552 : 208857 : mdzeroextend(SMgrRelation reln, ForkNumber forknum,
553 : : BlockNumber blocknum, int nblocks, bool skipFsync)
554 : : {
555 : : MdfdVec *v;
556 : 208857 : BlockNumber curblocknum = blocknum;
557 : 208857 : int remblocks = nblocks;
558 : :
559 [ - + ]: 208857 : Assert(nblocks > 0);
560 : :
561 : : /* This assert is too expensive to have on normally ... */
562 : : #ifdef CHECK_WRITE_VS_EXTEND
563 : : Assert(blocknum >= mdnblocks(reln, forknum));
564 : : #endif
565 : :
566 : : /*
567 : : * If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
568 : : * more --- we mustn't create a block whose number actually is
569 : : * InvalidBlockNumber or larger.
570 : : */
571 [ - + ]: 208857 : if ((uint64) blocknum + nblocks >= (uint64) InvalidBlockNumber)
937 andres@anarazel.de 572 [ # # ]:UBC 0 : ereport(ERROR,
573 : : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
574 : : errmsg("cannot extend file \"%s\" beyond %u blocks",
575 : : relpath(reln->smgr_rlocator, forknum).str,
576 : : InvalidBlockNumber)));
577 : :
937 andres@anarazel.de 578 [ + + ]:CBC 417714 : while (remblocks > 0)
579 : : {
893 tgl@sss.pgh.pa.us 580 : 208857 : BlockNumber segstartblock = curblocknum % ((BlockNumber) RELSEG_SIZE);
937 andres@anarazel.de 581 : 208857 : off_t seekpos = (off_t) BLCKSZ * segstartblock;
582 : : int numblocks;
583 : :
584 [ - + ]: 208857 : if (segstartblock + remblocks > RELSEG_SIZE)
937 andres@anarazel.de 585 :UBC 0 : numblocks = RELSEG_SIZE - segstartblock;
586 : : else
937 andres@anarazel.de 587 :CBC 208857 : numblocks = remblocks;
588 : :
589 : 208857 : v = _mdfd_getseg(reln, forknum, curblocknum, skipFsync, EXTENSION_CREATE);
590 : :
591 [ - + ]: 208857 : Assert(segstartblock < RELSEG_SIZE);
592 [ - + ]: 208857 : Assert(segstartblock + numblocks <= RELSEG_SIZE);
593 : :
594 : : /*
595 : : * If available and useful, use posix_fallocate() (via
596 : : * FileFallocate()) to extend the relation. That's often more
597 : : * efficient than using write(), as it commonly won't cause the kernel
598 : : * to allocate page cache space for the extended pages.
599 : : *
600 : : * However, we don't use FileFallocate() for small extensions, as it
601 : : * defeats delayed allocation on some filesystems. Not clear where
602 : : * that decision should be made though? For now just use a cutoff of
603 : : * 8, anything between 4 and 8 worked OK in some local testing.
604 : : */
605 [ + + ]: 208857 : if (numblocks > 8)
606 : : {
607 : : int ret;
608 : :
609 : 525 : ret = FileFallocate(v->mdfd_vfd,
610 : : seekpos, (off_t) BLCKSZ * numblocks,
611 : : WAIT_EVENT_DATA_FILE_EXTEND);
612 [ - + ]: 525 : if (ret != 0)
613 : : {
937 andres@anarazel.de 614 [ # # ]:UBC 0 : ereport(ERROR,
615 : : errcode_for_file_access(),
616 : : errmsg("could not extend file \"%s\" with FileFallocate(): %m",
617 : : FilePathName(v->mdfd_vfd)),
618 : : errhint("Check free disk space."));
619 : : }
620 : : }
621 : : else
622 : : {
623 : : int ret;
624 : :
625 : : /*
626 : : * Even if we don't want to use fallocate, we can still extend a
627 : : * bit more efficiently than writing each 8kB block individually.
628 : : * pg_pwrite_zeros() (via FileZero()) uses pg_pwritev_with_retry()
629 : : * to avoid multiple writes or needing a zeroed buffer for the
630 : : * whole length of the extension.
631 : : */
937 andres@anarazel.de 632 :CBC 208332 : ret = FileZero(v->mdfd_vfd,
633 : : seekpos, (off_t) BLCKSZ * numblocks,
634 : : WAIT_EVENT_DATA_FILE_EXTEND);
635 [ - + ]: 208332 : if (ret < 0)
937 andres@anarazel.de 636 [ # # ]:UBC 0 : ereport(ERROR,
637 : : errcode_for_file_access(),
638 : : errmsg("could not extend file \"%s\": %m",
639 : : FilePathName(v->mdfd_vfd)),
640 : : errhint("Check free disk space."));
641 : : }
642 : :
937 andres@anarazel.de 643 [ + - + + ]:CBC 208857 : if (!skipFsync && !SmgrIsTemp(reln))
644 : 196416 : register_dirty_segment(reln, forknum, v);
645 : :
646 [ - + ]: 208857 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
647 : :
648 : 208857 : remblocks -= numblocks;
649 : 208857 : curblocknum += numblocks;
650 : : }
651 : 208857 : }
652 : :
653 : : /*
654 : : * mdopenfork() -- Open one fork of the specified relation.
655 : : *
656 : : * Note we only open the first segment, when there are multiple segments.
657 : : *
658 : : * If first segment is not present, either ereport or return NULL according
659 : : * to "behavior". We treat EXTENSION_CREATE the same as EXTENSION_FAIL;
660 : : * EXTENSION_CREATE means it's OK to extend an existing relation, not to
661 : : * invent one out of whole cloth.
662 : : */
663 : : static MdfdVec *
2295 tmunro@postgresql.or 664 : 3365108 : mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
665 : : {
666 : : MdfdVec *mdfd;
667 : : RelPathStr path;
668 : : File fd;
669 : :
670 : : /* No work if already open */
3337 andres@anarazel.de 671 [ + + ]: 3365108 : if (reln->md_num_open_segs[forknum] > 0)
672 : 2286641 : return &reln->md_seg_fds[forknum][0];
673 : :
1210 rhaas@postgresql.org 674 : 1078467 : path = relpath(reln->smgr_rlocator, forknum);
675 : :
245 andres@anarazel.de 676 : 1078467 : fd = PathNameOpenFile(path.str, _mdfd_open_flags());
677 : :
10278 bruce@momjian.us 678 [ + + ]: 1078467 : if (fd < 0)
679 : : {
2465 akapila@postgresql.o 680 [ + + ]: 353777 : if ((behavior & EXTENSION_RETURN_NULL) &&
681 [ + - ]: 353755 : FILE_POSSIBLY_DELETED(errno))
682 : 353755 : return NULL;
683 [ + - ]: 22 : ereport(ERROR,
684 : : (errcode_for_file_access(),
685 : : errmsg("could not open file \"%s\": %m", path.str)));
686 : : }
687 : :
3337 andres@anarazel.de 688 : 724690 : _fdvec_resize(reln, forknum, 1);
689 : 724690 : mdfd = &reln->md_seg_fds[forknum][0];
7820 tgl@sss.pgh.pa.us 690 : 724690 : mdfd->mdfd_vfd = fd;
691 : 724690 : mdfd->mdfd_segno = 0;
692 : :
6287 heikki.linnakangas@i 693 [ - + ]: 724690 : Assert(_mdnblocks(reln, forknum, mdfd) <= ((BlockNumber) RELSEG_SIZE));
694 : :
7820 tgl@sss.pgh.pa.us 695 : 724690 : return mdfd;
696 : : }
697 : :
698 : : /*
699 : : * mdopen() -- Initialize newly-opened relation.
700 : : */
701 : : void
2295 tmunro@postgresql.or 702 : 970365 : mdopen(SMgrRelation reln)
703 : : {
704 : : /* mark it not open */
705 [ + + ]: 4851825 : for (int forknum = 0; forknum <= MAX_FORKNUM; forknum++)
706 : 3881460 : reln->md_num_open_segs[forknum] = 0;
707 : 970365 : }
708 : :
709 : : /*
710 : : * mdclose() -- Close the specified relation, if it isn't closed already.
711 : : */
712 : : void
6287 heikki.linnakangas@i 713 : 3454547 : mdclose(SMgrRelation reln, ForkNumber forknum)
714 : : {
3337 andres@anarazel.de 715 : 3454547 : int nopensegs = reln->md_num_open_segs[forknum];
716 : :
717 : : /* No work if already closed */
718 [ + + ]: 3454547 : if (nopensegs == 0)
6873 tgl@sss.pgh.pa.us 719 : 2927755 : return;
720 : :
721 : : /* close segments starting from the end */
3337 andres@anarazel.de 722 [ + + ]: 1053584 : while (nopensegs > 0)
723 : : {
724 : 526792 : MdfdVec *v = &reln->md_seg_fds[forknum][nopensegs - 1];
725 : :
2118 noah@leadboat.com 726 : 526792 : FileClose(v->mdfd_vfd);
727 : 526792 : _fdvec_resize(reln, forknum, nopensegs - 1);
3337 andres@anarazel.de 728 : 526792 : nopensegs--;
729 : : }
730 : : }
731 : :
732 : : /*
733 : : * mdprefetch() -- Initiate asynchronous read of the specified blocks of a relation
734 : : */
735 : : bool
682 tmunro@postgresql.or 736 : 8058 : mdprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
737 : : int nblocks)
738 : : {
739 : : #ifdef USE_PREFETCH
740 : :
934 741 [ - + ]: 8058 : Assert((io_direct_flags & IO_DIRECT_DATA) == 0);
742 : :
682 743 [ - + ]: 8058 : if ((uint64) blocknum + nblocks > (uint64) MaxBlockNumber + 1)
2029 tmunro@postgresql.or 744 :UBC 0 : return false;
745 : :
682 tmunro@postgresql.or 746 [ + + ]:CBC 16116 : while (nblocks > 0)
747 : : {
748 : : off_t seekpos;
749 : : MdfdVec *v;
750 : : int nblocks_this_segment;
751 : :
752 : 8058 : v = _mdfd_getseg(reln, forknum, blocknum, false,
753 [ + + ]: 8058 : InRecovery ? EXTENSION_RETURN_NULL : EXTENSION_FAIL);
754 [ - + ]: 8058 : if (v == NULL)
682 tmunro@postgresql.or 755 :UBC 0 : return false;
756 : :
682 tmunro@postgresql.or 757 :CBC 8058 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
758 : :
759 [ - + ]: 8058 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
760 : :
761 : 8058 : nblocks_this_segment =
762 : 8058 : Min(nblocks,
763 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
764 : :
765 : 8058 : (void) FilePrefetch(v->mdfd_vfd, seekpos, BLCKSZ * nblocks_this_segment,
766 : : WAIT_EVENT_DATA_FILE_PREFETCH);
767 : :
768 : 8058 : blocknum += nblocks_this_segment;
769 : 8058 : nblocks -= nblocks_this_segment;
770 : : }
771 : : #endif /* USE_PREFETCH */
772 : :
2029 773 : 8058 : return true;
774 : : }
775 : :
776 : : /*
777 : : * Convert an array of buffer address into an array of iovec objects, and
778 : : * return the number that were required. 'iov' must have enough space for up
779 : : * to 'nblocks' elements, but the number used may be less depending on
780 : : * merging. In the case of a run of fully contiguous buffers, a single iovec
781 : : * will be populated that can be handled as a plain non-vectored I/O.
782 : : */
783 : : static int
680 784 : 1829442 : buffers_to_iovec(struct iovec *iov, void **buffers, int nblocks)
785 : : {
786 : : struct iovec *iovp;
787 : : int iovcnt;
788 : :
789 [ - + ]: 1829442 : Assert(nblocks >= 1);
790 : :
791 : : /* If this build supports direct I/O, buffers must be I/O aligned. */
792 [ + + ]: 3822166 : for (int i = 0; i < nblocks; ++i)
793 : : {
794 : : if (PG_O_DIRECT != 0 && PG_IO_ALIGN_SIZE <= BLCKSZ)
795 [ - + ]: 1992724 : Assert((uintptr_t) buffers[i] ==
796 : : TYPEALIGN(PG_IO_ALIGN_SIZE, buffers[i]));
797 : : }
798 : :
799 : : /* Start the first iovec off with the first buffer. */
800 : 1829442 : iovp = &iov[0];
801 : 1829442 : iovp->iov_base = buffers[0];
802 : 1829442 : iovp->iov_len = BLCKSZ;
803 : 1829442 : iovcnt = 1;
804 : :
805 : : /* Try to merge the rest. */
806 [ + + ]: 1992724 : for (int i = 1; i < nblocks; ++i)
807 : : {
808 : 163282 : void *buffer = buffers[i];
809 : :
810 [ + + ]: 163282 : if (((char *) iovp->iov_base + iovp->iov_len) == buffer)
811 : : {
812 : : /* Contiguous with the last iovec. */
813 : 162055 : iovp->iov_len += BLCKSZ;
814 : : }
815 : : else
816 : : {
817 : : /* Need a new iovec. */
818 : 1227 : iovp++;
819 : 1227 : iovp->iov_base = buffer;
820 : 1227 : iovp->iov_len = BLCKSZ;
821 : 1227 : iovcnt++;
822 : : }
823 : : }
824 : :
825 : 1829442 : return iovcnt;
826 : : }
827 : :
828 : : /*
829 : : * mdmaxcombine() -- Return the maximum number of total blocks that can be
830 : : * combined with an IO starting at blocknum.
831 : : */
832 : : uint32
385 andres@anarazel.de 833 : 32639 : mdmaxcombine(SMgrRelation reln, ForkNumber forknum,
834 : : BlockNumber blocknum)
835 : : {
836 : : BlockNumber segoff;
837 : :
838 : 32639 : segoff = blocknum % ((BlockNumber) RELSEG_SIZE);
839 : :
840 : 32639 : return RELSEG_SIZE - segoff;
841 : : }
842 : :
843 : : /*
844 : : * mdreadv() -- Read the specified blocks from a relation.
845 : : */
846 : : void
680 tmunro@postgresql.or 847 : 598 : mdreadv(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
848 : : void **buffers, BlockNumber nblocks)
849 : : {
850 [ + + ]: 1196 : while (nblocks > 0)
851 : : {
852 : : struct iovec iov[PG_IOV_MAX];
853 : : int iovcnt;
854 : : off_t seekpos;
855 : : int nbytes;
856 : : MdfdVec *v;
857 : : BlockNumber nblocks_this_segment;
858 : : size_t transferred_this_segment;
859 : : size_t size_this_segment;
860 : :
861 : 598 : v = _mdfd_getseg(reln, forknum, blocknum, false,
862 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
863 : :
864 : 598 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
865 : :
866 [ - + ]: 598 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
867 : :
868 : 598 : nblocks_this_segment =
869 : 598 : Min(nblocks,
870 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
871 : 598 : nblocks_this_segment = Min(nblocks_this_segment, lengthof(iov));
872 : :
385 andres@anarazel.de 873 [ - + ]: 598 : if (nblocks_this_segment != nblocks)
385 andres@anarazel.de 874 [ # # ]:UBC 0 : elog(ERROR, "read crosses segment boundary");
875 : :
680 tmunro@postgresql.or 876 :CBC 598 : iovcnt = buffers_to_iovec(iov, buffers, nblocks_this_segment);
877 : 598 : size_this_segment = nblocks_this_segment * BLCKSZ;
878 : 598 : transferred_this_segment = 0;
879 : :
880 : : /*
881 : : * Inner loop to continue after a short read. We'll keep going until
882 : : * we hit EOF rather than assuming that a short read means we hit the
883 : : * end.
884 : : */
885 : : for (;;)
886 : : {
680 tmunro@postgresql.or 887 :UBC 0 : TRACE_POSTGRESQL_SMGR_MD_READ_START(forknum, blocknum,
888 : : reln->smgr_rlocator.locator.spcOid,
889 : : reln->smgr_rlocator.locator.dbOid,
890 : : reln->smgr_rlocator.locator.relNumber,
891 : : reln->smgr_rlocator.backend);
680 tmunro@postgresql.or 892 :CBC 598 : nbytes = FileReadV(v->mdfd_vfd, iov, iovcnt, seekpos,
893 : : WAIT_EVENT_DATA_FILE_READ);
894 : : TRACE_POSTGRESQL_SMGR_MD_READ_DONE(forknum, blocknum,
895 : : reln->smgr_rlocator.locator.spcOid,
896 : : reln->smgr_rlocator.locator.dbOid,
897 : : reln->smgr_rlocator.locator.relNumber,
898 : : reln->smgr_rlocator.backend,
899 : : nbytes,
900 : : size_this_segment - transferred_this_segment);
901 : :
902 : : #ifdef SIMULATE_SHORT_READ
903 : : nbytes = Min(nbytes, 4096);
904 : : #endif
905 : :
906 [ - + ]: 598 : if (nbytes < 0)
680 tmunro@postgresql.or 907 [ # # ]:UBC 0 : ereport(ERROR,
908 : : (errcode_for_file_access(),
909 : : errmsg("could not read blocks %u..%u in file \"%s\": %m",
910 : : blocknum,
911 : : blocknum + nblocks_this_segment - 1,
912 : : FilePathName(v->mdfd_vfd))));
913 : :
680 tmunro@postgresql.or 914 [ - + ]:CBC 598 : if (nbytes == 0)
915 : : {
916 : : /*
917 : : * We are at or past EOF, or we read a partial block at EOF.
918 : : * Normally this is an error; upper levels should never try to
919 : : * read a nonexistent block. However, if zero_damaged_pages
920 : : * is ON or we are InRecovery, we should instead return zeroes
921 : : * without complaining. This allows, for example, the case of
922 : : * trying to update a block that was later truncated away.
923 : : *
924 : : * NB: We think that this codepath is unreachable in recovery
925 : : * and incomplete with zero_damaged_pages, as missing segments
926 : : * are not created. Putting blocks into the buffer-pool that
927 : : * do not exist on disk is rather problematic, as it will not
928 : : * be found by scans that rely on smgrnblocks(), as they are
929 : : * beyond EOF. It also can cause weird problems with relation
930 : : * extension, as relation extension does not expect blocks
931 : : * beyond EOF to exist.
932 : : *
933 : : * Therefore we do not want to copy the logic into
934 : : * mdstartreadv(), where it would have to be more complicated
935 : : * due to potential differences in the zero_damaged_pages
936 : : * setting between the definer and completor of IO.
937 : : *
938 : : * For PG 18, we are putting an Assert(false) in mdreadv()
939 : : * (triggering failures in assertion-enabled builds, but
940 : : * continuing to work in production builds). Afterwards we
941 : : * plan to remove this code entirely.
942 : : */
680 tmunro@postgresql.or 943 [ # # # # ]:UBC 0 : if (zero_damaged_pages || InRecovery)
944 : : {
210 andres@anarazel.de 945 : 0 : Assert(false); /* see comment above */
946 : :
947 : : for (BlockNumber i = transferred_this_segment / BLCKSZ;
948 : : i < nblocks_this_segment;
949 : : ++i)
950 : : memset(buffers[i], 0, BLCKSZ);
951 : : break;
952 : : }
953 : : else
680 tmunro@postgresql.or 954 [ # # ]: 0 : ereport(ERROR,
955 : : (errcode(ERRCODE_DATA_CORRUPTED),
956 : : errmsg("could not read blocks %u..%u in file \"%s\": read only %zu of %zu bytes",
957 : : blocknum,
958 : : blocknum + nblocks_this_segment - 1,
959 : : FilePathName(v->mdfd_vfd),
960 : : transferred_this_segment,
961 : : size_this_segment)));
962 : : }
963 : :
964 : : /* One loop should usually be enough. */
680 tmunro@postgresql.or 965 :CBC 598 : transferred_this_segment += nbytes;
966 [ - + ]: 598 : Assert(transferred_this_segment <= size_this_segment);
967 [ + - ]: 598 : if (transferred_this_segment == size_this_segment)
968 : 598 : break;
969 : :
970 : : /* Adjust position and vectors after a short read. */
680 tmunro@postgresql.or 971 :UBC 0 : seekpos += nbytes;
972 : 0 : iovcnt = compute_remaining_iovec(iov, iov, iovcnt, nbytes);
973 : : }
974 : :
680 tmunro@postgresql.or 975 :CBC 598 : nblocks -= nblocks_this_segment;
976 : 598 : buffers += nblocks_this_segment;
977 : 598 : blocknum += nblocks_this_segment;
978 : : }
10703 scrappy@hub.org 979 : 598 : }
980 : :
981 : : /*
982 : : * mdstartreadv() -- Asynchronous version of mdreadv().
983 : : */
984 : : void
213 andres@anarazel.de 985 : 1267713 : mdstartreadv(PgAioHandle *ioh,
986 : : SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
987 : : void **buffers, BlockNumber nblocks)
988 : : {
989 : : off_t seekpos;
990 : : MdfdVec *v;
991 : : BlockNumber nblocks_this_segment;
992 : : struct iovec *iov;
993 : : int iovcnt;
994 : : int ret;
995 : :
996 : 1267713 : v = _mdfd_getseg(reln, forknum, blocknum, false,
997 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
998 : :
999 : 1267698 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1000 : :
1001 [ - + ]: 1267698 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
1002 : :
1003 : 1267698 : nblocks_this_segment =
1004 : 1267698 : Min(nblocks,
1005 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
1006 : :
1007 [ - + ]: 1267698 : if (nblocks_this_segment != nblocks)
213 andres@anarazel.de 1008 [ # # ]:UBC 0 : elog(ERROR, "read crossing segment boundary");
1009 : :
213 andres@anarazel.de 1010 :CBC 1267698 : iovcnt = pgaio_io_get_iovec(ioh, &iov);
1011 : :
1012 [ - + ]: 1267698 : Assert(nblocks <= iovcnt);
1013 : :
1014 : 1267698 : iovcnt = buffers_to_iovec(iov, buffers, nblocks_this_segment);
1015 : :
1016 [ - + ]: 1267698 : Assert(iovcnt <= nblocks_this_segment);
1017 : :
1018 [ + + ]: 1267698 : if (!(io_direct_flags & IO_DIRECT_DATA))
1019 : 1266302 : pgaio_io_set_flag(ioh, PGAIO_HF_BUFFERED);
1020 : :
1021 : 1267698 : pgaio_io_set_target_smgr(ioh,
1022 : : reln,
1023 : : forknum,
1024 : : blocknum,
1025 : : nblocks,
1026 : : false);
1027 : 1267698 : pgaio_io_register_callbacks(ioh, PGAIO_HCB_MD_READV, 0);
1028 : :
1029 : 1267698 : ret = FileStartReadV(ioh, v->mdfd_vfd, iovcnt, seekpos, WAIT_EVENT_DATA_FILE_READ);
1030 [ - + ]: 1267698 : if (ret != 0)
213 andres@anarazel.de 1031 [ # # ]:UBC 0 : ereport(ERROR,
1032 : : (errcode_for_file_access(),
1033 : : errmsg("could not start reading blocks %u..%u in file \"%s\": %m",
1034 : : blocknum,
1035 : : blocknum + nblocks_this_segment - 1,
1036 : : FilePathName(v->mdfd_vfd))));
1037 : :
1038 : : /*
1039 : : * The error checks corresponding to the post-read checks in mdreadv() are
1040 : : * in md_readv_complete().
1041 : : *
1042 : : * However we chose, at least for now, to not implement the
1043 : : * zero_damaged_pages logic present in mdreadv(). As outlined in mdreadv()
1044 : : * that logic is rather problematic, and we want to get rid of it. Here
1045 : : * equivalent logic would have to be more complicated due to potential
1046 : : * differences in the zero_damaged_pages setting between the definer and
1047 : : * completor of IO.
1048 : : */
213 andres@anarazel.de 1049 :CBC 1267698 : }
1050 : :
1051 : : /*
1052 : : * mdwritev() -- Write the supplied blocks at the appropriate location.
1053 : : *
1054 : : * This is to be used only for updating already-existing blocks of a
1055 : : * relation (ie, those before the current EOF). To extend a relation,
1056 : : * use mdextend().
1057 : : */
1058 : : void
680 tmunro@postgresql.or 1059 : 561146 : mdwritev(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
1060 : : const void **buffers, BlockNumber nblocks, bool skipFsync)
1061 : : {
1062 : : /* This assert is too expensive to have on normally ... */
1063 : : #ifdef CHECK_WRITE_VS_EXTEND
1064 : : Assert((uint64) blocknum + (uint64) nblocks <= (uint64) mdnblocks(reln, forknum));
1065 : : #endif
1066 : :
1067 [ + + ]: 1122292 : while (nblocks > 0)
1068 : : {
1069 : : struct iovec iov[PG_IOV_MAX];
1070 : : int iovcnt;
1071 : : off_t seekpos;
1072 : : int nbytes;
1073 : : MdfdVec *v;
1074 : : BlockNumber nblocks_this_segment;
1075 : : size_t transferred_this_segment;
1076 : : size_t size_this_segment;
1077 : :
1078 : 561146 : v = _mdfd_getseg(reln, forknum, blocknum, skipFsync,
1079 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
1080 : :
1081 : 561146 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1082 : :
1083 [ - + ]: 561146 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
1084 : :
1085 : 561146 : nblocks_this_segment =
1086 : 561146 : Min(nblocks,
1087 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
1088 : 561146 : nblocks_this_segment = Min(nblocks_this_segment, lengthof(iov));
1089 : :
385 andres@anarazel.de 1090 [ - + ]: 561146 : if (nblocks_this_segment != nblocks)
385 andres@anarazel.de 1091 [ # # ]:UBC 0 : elog(ERROR, "write crosses segment boundary");
1092 : :
680 tmunro@postgresql.or 1093 :CBC 561146 : iovcnt = buffers_to_iovec(iov, (void **) buffers, nblocks_this_segment);
1094 : 561146 : size_this_segment = nblocks_this_segment * BLCKSZ;
1095 : 561146 : transferred_this_segment = 0;
1096 : :
1097 : : /*
1098 : : * Inner loop to continue after a short write. If the reason is that
1099 : : * we're out of disk space, a future attempt should get an ENOSPC
1100 : : * error from the kernel.
1101 : : */
1102 : : for (;;)
1103 : : {
680 tmunro@postgresql.or 1104 :UBC 0 : TRACE_POSTGRESQL_SMGR_MD_WRITE_START(forknum, blocknum,
1105 : : reln->smgr_rlocator.locator.spcOid,
1106 : : reln->smgr_rlocator.locator.dbOid,
1107 : : reln->smgr_rlocator.locator.relNumber,
1108 : : reln->smgr_rlocator.backend);
680 tmunro@postgresql.or 1109 :CBC 561146 : nbytes = FileWriteV(v->mdfd_vfd, iov, iovcnt, seekpos,
1110 : : WAIT_EVENT_DATA_FILE_WRITE);
1111 : : TRACE_POSTGRESQL_SMGR_MD_WRITE_DONE(forknum, blocknum,
1112 : : reln->smgr_rlocator.locator.spcOid,
1113 : : reln->smgr_rlocator.locator.dbOid,
1114 : : reln->smgr_rlocator.locator.relNumber,
1115 : : reln->smgr_rlocator.backend,
1116 : : nbytes,
1117 : : size_this_segment - transferred_this_segment);
1118 : :
1119 : : #ifdef SIMULATE_SHORT_WRITE
1120 : : nbytes = Min(nbytes, 4096);
1121 : : #endif
1122 : :
1123 [ - + ]: 561146 : if (nbytes < 0)
1124 : : {
680 tmunro@postgresql.or 1125 :UBC 0 : bool enospc = errno == ENOSPC;
1126 : :
1127 [ # # # # ]: 0 : ereport(ERROR,
1128 : : (errcode_for_file_access(),
1129 : : errmsg("could not write blocks %u..%u in file \"%s\": %m",
1130 : : blocknum,
1131 : : blocknum + nblocks_this_segment - 1,
1132 : : FilePathName(v->mdfd_vfd)),
1133 : : enospc ? errhint("Check free disk space.") : 0));
1134 : : }
1135 : :
1136 : : /* One loop should usually be enough. */
680 tmunro@postgresql.or 1137 :CBC 561146 : transferred_this_segment += nbytes;
1138 [ - + ]: 561146 : Assert(transferred_this_segment <= size_this_segment);
1139 [ + - ]: 561146 : if (transferred_this_segment == size_this_segment)
1140 : 561146 : break;
1141 : :
1142 : : /* Adjust position and iovecs after a short write. */
680 tmunro@postgresql.or 1143 :UBC 0 : seekpos += nbytes;
1144 : 0 : iovcnt = compute_remaining_iovec(iov, iov, iovcnt, nbytes);
1145 : : }
1146 : :
680 tmunro@postgresql.or 1147 [ + + + + ]:CBC 561146 : if (!skipFsync && !SmgrIsTemp(reln))
1148 : 556726 : register_dirty_segment(reln, forknum, v);
1149 : :
1150 : 561146 : nblocks -= nblocks_this_segment;
1151 : 561146 : buffers += nblocks_this_segment;
1152 : 561146 : blocknum += nblocks_this_segment;
1153 : : }
9333 tgl@sss.pgh.pa.us 1154 : 561146 : }
1155 : :
1156 : :
1157 : : /*
1158 : : * mdwriteback() -- Tell the kernel to write pages back to storage.
1159 : : *
1160 : : * This accepts a range of blocks because flushing several pages at once is
1161 : : * considerably more efficient than doing so individually.
1162 : : */
1163 : : void
893 peter@eisentraut.org 1164 :UBC 0 : mdwriteback(SMgrRelation reln, ForkNumber forknum,
1165 : : BlockNumber blocknum, BlockNumber nblocks)
1166 : : {
1167 [ # # ]: 0 : Assert((io_direct_flags & IO_DIRECT_DATA) == 0);
1168 : :
1169 : : /*
1170 : : * Issue flush requests in as few requests as possible; have to split at
1171 : : * segment boundaries though, since those are actually separate files.
1172 : : */
1173 [ # # ]: 0 : while (nblocks > 0)
1174 : : {
1175 : 0 : BlockNumber nflush = nblocks;
1176 : : off_t seekpos;
1177 : : MdfdVec *v;
1178 : : int segnum_start,
1179 : : segnum_end;
1180 : :
1181 : 0 : v = _mdfd_getseg(reln, forknum, blocknum, true /* not used */ ,
1182 : : EXTENSION_DONT_OPEN);
1183 : :
1184 : : /*
1185 : : * We might be flushing buffers of already removed relations, that's
1186 : : * ok, just ignore that case. If the segment file wasn't open already
1187 : : * (ie from a recent mdwrite()), then we don't want to re-open it, to
1188 : : * avoid a race with PROCSIGNAL_BARRIER_SMGRRELEASE that might leave
1189 : : * us with a descriptor to a file that is about to be unlinked.
1190 : : */
1191 [ # # ]: 0 : if (!v)
1192 : 0 : return;
1193 : :
1194 : : /* compute offset inside the current segment */
1195 : 0 : segnum_start = blocknum / RELSEG_SIZE;
1196 : :
1197 : : /* compute number of desired writes within the current segment */
1198 : 0 : segnum_end = (blocknum + nblocks - 1) / RELSEG_SIZE;
1199 [ # # ]: 0 : if (segnum_start != segnum_end)
1200 : 0 : nflush = RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE));
1201 : :
1202 [ # # ]: 0 : Assert(nflush >= 1);
1203 [ # # ]: 0 : Assert(nflush <= nblocks);
1204 : :
1205 : 0 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1206 : :
1207 : 0 : FileWriteback(v->mdfd_vfd, seekpos, (off_t) BLCKSZ * nflush, WAIT_EVENT_DATA_FILE_FLUSH);
1208 : :
1209 : 0 : nblocks -= nflush;
1210 : 0 : blocknum += nflush;
1211 : : }
1212 : : }
1213 : :
1214 : : /*
1215 : : * mdnblocks() -- Get the number of blocks stored in a relation.
1216 : : *
1217 : : * Important side effect: all active segments of the relation are opened
1218 : : * and added to the md_seg_fds array. If this routine has not been
1219 : : * called, then only segments up to the last one actually touched
1220 : : * are present in the array.
1221 : : */
1222 : : BlockNumber
6287 heikki.linnakangas@i 1223 :CBC 2176236 : mdnblocks(SMgrRelation reln, ForkNumber forknum)
1224 : : {
1225 : : MdfdVec *v;
1226 : : BlockNumber nblocks;
1227 : : BlockNumber segno;
1228 : :
1881 bruce@momjian.us 1229 : 2176236 : mdopenfork(reln, forknum, EXTENSION_FAIL);
1230 : :
1231 : : /* mdopen has opened the first segment */
3337 andres@anarazel.de 1232 [ - + ]: 2176217 : Assert(reln->md_num_open_segs[forknum] > 0);
1233 : :
1234 : : /*
1235 : : * Start from the last open segments, to avoid redundant seeks. We have
1236 : : * previously verified that these segments are exactly RELSEG_SIZE long,
1237 : : * and it's useless to recheck that each time.
1238 : : *
1239 : : * NOTE: this assumption could only be wrong if another backend has
1240 : : * truncated the relation. We rely on higher code levels to handle that
1241 : : * scenario by closing and re-opening the md fd, which is handled via
1242 : : * relcache flush. (Since the checkpointer doesn't participate in
1243 : : * relcache flush, it could have segment entries for inactive segments;
1244 : : * that's OK because the checkpointer never needs to compute relation
1245 : : * size.)
1246 : : */
1247 : 2176217 : segno = reln->md_num_open_segs[forknum] - 1;
1248 : 2176217 : v = &reln->md_seg_fds[forknum][segno];
1249 : :
1250 : : for (;;)
1251 : : {
6287 heikki.linnakangas@i 1252 : 2176217 : nblocks = _mdnblocks(reln, forknum, v);
8889 tgl@sss.pgh.pa.us 1253 [ - + ]: 2176217 : if (nblocks > ((BlockNumber) RELSEG_SIZE))
8132 tgl@sss.pgh.pa.us 1254 [ # # ]:UBC 0 : elog(FATAL, "segment too big");
8889 tgl@sss.pgh.pa.us 1255 [ + - ]:CBC 2176217 : if (nblocks < ((BlockNumber) RELSEG_SIZE))
1256 : 2176217 : return (segno * ((BlockNumber) RELSEG_SIZE)) + nblocks;
1257 : :
1258 : : /*
1259 : : * If segment is exactly RELSEG_SIZE, advance to next one.
1260 : : */
8937 tgl@sss.pgh.pa.us 1261 :UBC 0 : segno++;
1262 : :
1263 : : /*
1264 : : * We used to pass O_CREAT here, but that has the disadvantage that it
1265 : : * might create a segment which has vanished through some operating
1266 : : * system misadventure. In such a case, creating the segment here
1267 : : * undermines _mdfd_getseg's attempts to notice and report an error
1268 : : * upon access to a missing segment.
1269 : : */
3337 andres@anarazel.de 1270 : 0 : v = _mdfd_openseg(reln, forknum, segno, 0);
1271 [ # # ]: 0 : if (v == NULL)
1272 : 0 : return segno * ((BlockNumber) RELSEG_SIZE);
1273 : : }
1274 : : }
1275 : :
1276 : : /*
1277 : : * mdtruncate() -- Truncate relation to specified number of blocks.
1278 : : *
1279 : : * Guaranteed not to allocate memory, so it can be used in a critical section.
1280 : : * Caller must have called smgrnblocks() to obtain curnblk while holding a
1281 : : * sufficient lock to prevent a change in relation size, and not used any smgr
1282 : : * functions for this relation or handled interrupts in between. This makes
1283 : : * sure we have opened all active segments, so that truncate loop will get
1284 : : * them all!
1285 : : */
1286 : : void
312 tmunro@postgresql.or 1287 :CBC 901 : mdtruncate(SMgrRelation reln, ForkNumber forknum,
1288 : : BlockNumber curnblk, BlockNumber nblocks)
1289 : : {
1290 : : BlockNumber priorblocks;
1291 : : int curopensegs;
1292 : :
8889 tgl@sss.pgh.pa.us 1293 [ - + ]: 901 : if (nblocks > curnblk)
1294 : : {
1295 : : /* Bogus request ... but no complaint if InRecovery */
6873 tgl@sss.pgh.pa.us 1296 [ # # ]:UBC 0 : if (InRecovery)
1297 : 0 : return;
1298 [ # # ]: 0 : ereport(ERROR,
1299 : : (errmsg("could not truncate file \"%s\" to %u blocks: it's only %u blocks now",
1300 : : relpath(reln->smgr_rlocator, forknum).str,
1301 : : nblocks, curnblk)));
1302 : : }
9553 tgl@sss.pgh.pa.us 1303 [ + + ]:CBC 901 : if (nblocks == curnblk)
6873 1304 : 374 : return; /* no work */
1305 : :
1306 : : /*
1307 : : * Truncate segments, starting at the last one. Starting at the end makes
1308 : : * managing the memory for the fd array easier, should there be errors.
1309 : : */
3337 andres@anarazel.de 1310 : 527 : curopensegs = reln->md_num_open_segs[forknum];
1311 [ + + ]: 1054 : while (curopensegs > 0)
1312 : : {
1313 : : MdfdVec *v;
1314 : :
1315 : 527 : priorblocks = (curopensegs - 1) * RELSEG_SIZE;
1316 : :
1317 : 527 : v = &reln->md_seg_fds[forknum][curopensegs - 1];
1318 : :
9553 tgl@sss.pgh.pa.us 1319 [ - + ]: 527 : if (priorblocks > nblocks)
1320 : : {
1321 : : /*
1322 : : * This segment is no longer active. We truncate the file, but do
1323 : : * not delete it, for reasons explained in the header comments.
1324 : : */
3146 rhaas@postgresql.org 1325 [ # # ]:UBC 0 : if (FileTruncate(v->mdfd_vfd, 0, WAIT_EVENT_DATA_FILE_TRUNCATE) < 0)
6873 tgl@sss.pgh.pa.us 1326 [ # # ]: 0 : ereport(ERROR,
1327 : : (errcode_for_file_access(),
1328 : : errmsg("could not truncate file \"%s\": %m",
1329 : : FilePathName(v->mdfd_vfd))));
1330 : :
5555 rhaas@postgresql.org 1331 [ # # ]: 0 : if (!SmgrIsTemp(reln))
6287 heikki.linnakangas@i 1332 : 0 : register_dirty_segment(reln, forknum, v);
1333 : :
1334 : : /* we never drop the 1st segment */
3337 andres@anarazel.de 1335 [ # # ]: 0 : Assert(v != &reln->md_seg_fds[forknum][0]);
1336 : :
1337 : 0 : FileClose(v->mdfd_vfd);
1338 : 0 : _fdvec_resize(reln, forknum, curopensegs - 1);
1339 : : }
8889 tgl@sss.pgh.pa.us 1340 [ + - ]:CBC 527 : else if (priorblocks + ((BlockNumber) RELSEG_SIZE) > nblocks)
1341 : : {
1342 : : /*
1343 : : * This is the last segment we want to keep. Truncate the file to
1344 : : * the right length. NOTE: if nblocks is exactly a multiple K of
1345 : : * RELSEG_SIZE, we will truncate the K+1st segment to 0 length but
1346 : : * keep it. This adheres to the invariant given in the header
1347 : : * comments.
1348 : : */
8769 bruce@momjian.us 1349 : 527 : BlockNumber lastsegblocks = nblocks - priorblocks;
1350 : :
3146 rhaas@postgresql.org 1351 [ - + ]: 527 : if (FileTruncate(v->mdfd_vfd, (off_t) lastsegblocks * BLCKSZ, WAIT_EVENT_DATA_FILE_TRUNCATE) < 0)
6873 tgl@sss.pgh.pa.us 1352 [ # # ]:UBC 0 : ereport(ERROR,
1353 : : (errcode_for_file_access(),
1354 : : errmsg("could not truncate file \"%s\" to %u blocks: %m",
1355 : : FilePathName(v->mdfd_vfd),
1356 : : nblocks)));
5555 rhaas@postgresql.org 1357 [ + + ]:CBC 527 : if (!SmgrIsTemp(reln))
6287 heikki.linnakangas@i 1358 : 363 : register_dirty_segment(reln, forknum, v);
1359 : : }
1360 : : else
1361 : : {
1362 : : /*
1363 : : * We still need this segment, so nothing to do for this and any
1364 : : * earlier segment.
1365 : : */
3337 andres@anarazel.de 1366 :UBC 0 : break;
1367 : : }
3337 andres@anarazel.de 1368 :CBC 527 : curopensegs--;
1369 : : }
1370 : : }
1371 : :
1372 : : /*
1373 : : * mdregistersync() -- Mark whole relation as needing fsync
1374 : : */
1375 : : void
613 heikki.linnakangas@i 1376 : 24868 : mdregistersync(SMgrRelation reln, ForkNumber forknum)
1377 : : {
1378 : : int segno;
1379 : : int min_inactive_seg;
1380 : :
1381 : : /*
1382 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1383 : : * the loop below will get them all!
1384 : : */
1385 : 24868 : mdnblocks(reln, forknum);
1386 : :
1387 : 24868 : min_inactive_seg = segno = reln->md_num_open_segs[forknum];
1388 : :
1389 : : /*
1390 : : * Temporarily open inactive segments, then close them after sync. There
1391 : : * may be some inactive segments left opened after error, but that is
1392 : : * harmless. We don't bother to clean them up and take a risk of further
1393 : : * trouble. The next mdclose() will soon close them.
1394 : : */
1395 [ - + ]: 24868 : while (_mdfd_openseg(reln, forknum, segno, 0) != NULL)
613 heikki.linnakangas@i 1396 :UBC 0 : segno++;
1397 : :
613 heikki.linnakangas@i 1398 [ + + ]:CBC 49736 : while (segno > 0)
1399 : : {
1400 : 24868 : MdfdVec *v = &reln->md_seg_fds[forknum][segno - 1];
1401 : :
1402 : 24868 : register_dirty_segment(reln, forknum, v);
1403 : :
1404 : : /* Close inactive segments immediately */
1405 [ - + ]: 24868 : if (segno > min_inactive_seg)
1406 : : {
613 heikki.linnakangas@i 1407 :UBC 0 : FileClose(v->mdfd_vfd);
1408 : 0 : _fdvec_resize(reln, forknum, segno - 1);
1409 : : }
1410 : :
613 heikki.linnakangas@i 1411 :CBC 24868 : segno--;
1412 : : }
1413 : 24868 : }
1414 : :
1415 : : /*
1416 : : * mdimmedsync() -- Immediately sync a relation to stable storage.
1417 : : *
1418 : : * Note that only writes already issued are synced; this routine knows
1419 : : * nothing of dirty buffers that may exist inside the buffer manager. We
1420 : : * sync active and inactive segments; smgrDoPendingSyncs() relies on this.
1421 : : * Consider a relation skipping WAL. Suppose a checkpoint syncs blocks of
1422 : : * some segment, then mdtruncate() renders that segment inactive. If we
1423 : : * crash before the next checkpoint syncs the newly-inactive segment, that
1424 : : * segment may survive recovery, reintroducing unwanted data into the table.
1425 : : */
1426 : : void
6287 1427 : 18 : mdimmedsync(SMgrRelation reln, ForkNumber forknum)
1428 : : {
1429 : : int segno;
1430 : : int min_inactive_seg;
1431 : :
1432 : : /*
1433 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1434 : : * the loop below will get them all!
1435 : : */
5314 peter_e@gmx.net 1436 : 18 : mdnblocks(reln, forknum);
1437 : :
2033 noah@leadboat.com 1438 : 18 : min_inactive_seg = segno = reln->md_num_open_segs[forknum];
1439 : :
1440 : : /*
1441 : : * Temporarily open inactive segments, then close them after sync. There
1442 : : * may be some inactive segments left opened after fsync() error, but that
1443 : : * is harmless. We don't bother to clean them up and take a risk of
1444 : : * further trouble. The next mdclose() will soon close them.
1445 : : */
1446 [ - + ]: 18 : while (_mdfd_openseg(reln, forknum, segno, 0) != NULL)
2033 noah@leadboat.com 1447 :UBC 0 : segno++;
1448 : :
3337 andres@anarazel.de 1449 [ + + ]:CBC 36 : while (segno > 0)
1450 : : {
1451 : 18 : MdfdVec *v = &reln->md_seg_fds[forknum][segno - 1];
1452 : :
1453 : : /*
1454 : : * fsyncs done through mdimmedsync() should be tracked in a separate
1455 : : * IOContext than those done through mdsyncfiletag() to differentiate
1456 : : * between unavoidable client backend fsyncs (e.g. those done during
1457 : : * index build) and those which ideally would have been done by the
1458 : : * checkpointer. Since other IO operations bypassing the buffer
1459 : : * manager could also be tracked in such an IOContext, wait until
1460 : : * these are also tracked to track immediate fsyncs.
1461 : : */
3146 rhaas@postgresql.org 1462 [ - + ]: 18 : if (FileSync(v->mdfd_vfd, WAIT_EVENT_DATA_FILE_IMMEDIATE_SYNC) < 0)
2535 tmunro@postgresql.or 1463 [ # # ]:UBC 0 : ereport(data_sync_elevel(ERROR),
1464 : : (errcode_for_file_access(),
1465 : : errmsg("could not fsync file \"%s\": %m",
1466 : : FilePathName(v->mdfd_vfd))));
1467 : :
1468 : : /* Close inactive segments immediately */
2033 noah@leadboat.com 1469 [ - + ]:CBC 18 : if (segno > min_inactive_seg)
1470 : : {
2033 noah@leadboat.com 1471 :UBC 0 : FileClose(v->mdfd_vfd);
1472 : 0 : _fdvec_resize(reln, forknum, segno - 1);
1473 : : }
1474 : :
3337 andres@anarazel.de 1475 :CBC 18 : segno--;
1476 : : }
7818 tgl@sss.pgh.pa.us 1477 : 18 : }
1478 : :
1479 : : int
213 andres@anarazel.de 1480 : 457879 : mdfd(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, uint32 *off)
1481 : : {
1482 : 457879 : MdfdVec *v = mdopenfork(reln, forknum, EXTENSION_FAIL);
1483 : :
1484 : 457879 : v = _mdfd_getseg(reln, forknum, blocknum, false,
1485 : : EXTENSION_FAIL);
1486 : :
1487 : 457879 : *off = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1488 : :
1489 [ - + ]: 457879 : Assert(*off < (off_t) BLCKSZ * RELSEG_SIZE);
1490 : :
1491 : 457879 : return FileGetRawDesc(v->mdfd_vfd);
1492 : : }
1493 : :
1494 : : /*
1495 : : * register_dirty_segment() -- Mark a relation segment as needing fsync
1496 : : *
1497 : : * If there is a local pending-ops table, just make an entry in it for
1498 : : * ProcessSyncRequests to process later. Otherwise, try to pass off the
1499 : : * fsync request to the checkpointer process. If that fails, just do the
1500 : : * fsync locally before returning (we hope this will not happen often
1501 : : * enough to be a performance problem).
1502 : : */
1503 : : static void
6287 heikki.linnakangas@i 1504 : 940640 : register_dirty_segment(SMgrRelation reln, ForkNumber forknum, MdfdVec *seg)
1505 : : {
1506 : : FileTag tag;
1507 : :
1210 rhaas@postgresql.org 1508 : 940640 : INIT_MD_FILETAG(tag, reln->smgr_rlocator.locator, forknum, seg->mdfd_segno);
1509 : :
1510 : : /* Temp relations should never be fsync'd */
4851 tgl@sss.pgh.pa.us 1511 [ - + ]: 940640 : Assert(!SmgrIsTemp(reln));
1512 : :
2399 tmunro@postgresql.or 1513 [ + + ]: 940640 : if (!RegisterSyncRequest(&tag, SYNC_REQUEST, false /* retryOnError */ ))
1514 : : {
1515 : : instr_time io_start;
1516 : :
935 andres@anarazel.de 1517 [ - + ]: 81 : ereport(DEBUG1,
1518 : : (errmsg_internal("could not forward fsync request because request queue is full")));
1519 : :
244 michael@paquier.xyz 1520 : 81 : io_start = pgstat_prepare_io_time(track_io_timing);
1521 : :
935 andres@anarazel.de 1522 [ - + ]: 81 : if (FileSync(seg->mdfd_vfd, WAIT_EVENT_DATA_FILE_SYNC) < 0)
935 andres@anarazel.de 1523 [ # # ]:UBC 0 : ereport(data_sync_elevel(ERROR),
1524 : : (errcode_for_file_access(),
1525 : : errmsg("could not fsync file \"%s\": %m",
1526 : : FilePathName(seg->mdfd_vfd))));
1527 : :
1528 : : /*
1529 : : * We have no way of knowing if the current IOContext is
1530 : : * IOCONTEXT_NORMAL or IOCONTEXT_[BULKREAD, BULKWRITE, VACUUM] at this
1531 : : * point, so count the fsync as being in the IOCONTEXT_NORMAL
1532 : : * IOContext. This is probably okay, because the number of backend
1533 : : * fsyncs doesn't say anything about the efficacy of the
1534 : : * BufferAccessStrategy. And counting both fsyncs done in
1535 : : * IOCONTEXT_NORMAL and IOCONTEXT_[BULKREAD, BULKWRITE, VACUUM] under
1536 : : * IOCONTEXT_NORMAL is likely clearer when investigating the number of
1537 : : * backend fsyncs.
1538 : : */
935 andres@anarazel.de 1539 :CBC 81 : pgstat_count_io_op_time(IOOBJECT_RELATION, IOCONTEXT_NORMAL,
1540 : : IOOP_FSYNC, io_start, 1, 0);
1541 : : }
10703 scrappy@hub.org 1542 : 940640 : }
1543 : :
1544 : : /*
1545 : : * register_unlink_segment() -- Schedule a file to be deleted after next checkpoint
1546 : : */
1547 : : static void
1210 rhaas@postgresql.org 1548 : 34976 : register_unlink_segment(RelFileLocatorBackend rlocator, ForkNumber forknum,
1549 : : BlockNumber segno)
1550 : : {
1551 : : FileTag tag;
1552 : :
1553 : 34976 : INIT_MD_FILETAG(tag, rlocator.locator, forknum, segno);
1554 : :
1555 : : /* Should never be used with temp relations */
1556 [ - + ]: 34976 : Assert(!RelFileLocatorBackendIsTemp(rlocator));
1557 : :
2399 tmunro@postgresql.or 1558 : 34976 : RegisterSyncRequest(&tag, SYNC_UNLINK_REQUEST, true /* retryOnError */ );
6557 tgl@sss.pgh.pa.us 1559 : 34976 : }
1560 : :
1561 : : /*
1562 : : * register_forget_request() -- forget any fsyncs for a relation fork's segment
1563 : : */
1564 : : static void
1210 rhaas@postgresql.org 1565 : 135632 : register_forget_request(RelFileLocatorBackend rlocator, ForkNumber forknum,
1566 : : BlockNumber segno)
1567 : : {
1568 : : FileTag tag;
1569 : :
1570 : 135632 : INIT_MD_FILETAG(tag, rlocator.locator, forknum, segno);
1571 : :
2399 tmunro@postgresql.or 1572 : 135632 : RegisterSyncRequest(&tag, SYNC_FORGET_REQUEST, true /* retryOnError */ );
6859 tgl@sss.pgh.pa.us 1573 : 135632 : }
1574 : :
1575 : : /*
1576 : : * ForgetDatabaseSyncRequests -- forget any fsyncs and unlinks for a DB
1577 : : */
1578 : : void
2399 tmunro@postgresql.or 1579 : 60 : ForgetDatabaseSyncRequests(Oid dbid)
1580 : : {
1581 : : FileTag tag;
1582 : : RelFileLocator rlocator;
1583 : :
1210 rhaas@postgresql.org 1584 : 60 : rlocator.dbOid = dbid;
1585 : 60 : rlocator.spcOid = 0;
1586 : 60 : rlocator.relNumber = 0;
1587 : :
1588 : 60 : INIT_MD_FILETAG(tag, rlocator, InvalidForkNumber, InvalidBlockNumber);
1589 : :
2399 tmunro@postgresql.or 1590 : 60 : RegisterSyncRequest(&tag, SYNC_FILTER_REQUEST, true /* retryOnError */ );
9131 vadim4o@yahoo.com 1591 : 60 : }
1592 : :
1593 : : /*
1594 : : * DropRelationFiles -- drop files of all given relations
1595 : : */
1596 : : void
1210 rhaas@postgresql.org 1597 : 2644 : DropRelationFiles(RelFileLocator *delrels, int ndelrels, bool isRedo)
1598 : : {
1599 : : SMgrRelation *srels;
1600 : : int i;
1601 : :
2672 fujii@postgresql.org 1602 : 2644 : srels = palloc(sizeof(SMgrRelation) * ndelrels);
1603 [ + + ]: 10232 : for (i = 0; i < ndelrels; i++)
1604 : : {
604 heikki.linnakangas@i 1605 : 7588 : SMgrRelation srel = smgropen(delrels[i], INVALID_PROC_NUMBER);
1606 : :
2672 fujii@postgresql.org 1607 [ + + ]: 7588 : if (isRedo)
1608 : : {
1609 : : ForkNumber fork;
1610 : :
1611 [ + + ]: 37820 : for (fork = 0; fork <= MAX_FORKNUM; fork++)
1612 : 30256 : XLogDropRelation(delrels[i], fork);
1613 : : }
1614 : 7588 : srels[i] = srel;
1615 : : }
1616 : :
1617 : 2644 : smgrdounlinkall(srels, ndelrels, isRedo);
1618 : :
2407 tomas.vondra@postgre 1619 [ + + ]: 10232 : for (i = 0; i < ndelrels; i++)
2672 fujii@postgresql.org 1620 : 7588 : smgrclose(srels[i]);
1621 : 2644 : pfree(srels);
1622 : 2644 : }
1623 : :
1624 : :
1625 : : /*
1626 : : * _fdvec_resize() -- Resize the fork's open segments array
1627 : : */
1628 : : static void
3337 andres@anarazel.de 1629 : 1417082 : _fdvec_resize(SMgrRelation reln,
1630 : : ForkNumber forknum,
1631 : : int nseg)
1632 : : {
1633 [ + + ]: 1417082 : if (nseg == 0)
1634 : : {
1635 [ + - ]: 526792 : if (reln->md_num_open_segs[forknum] > 0)
1636 : : {
1637 : 526792 : pfree(reln->md_seg_fds[forknum]);
1638 : 526792 : reln->md_seg_fds[forknum] = NULL;
1639 : : }
1640 : : }
1641 [ + - ]: 890290 : else if (reln->md_num_open_segs[forknum] == 0)
1642 : : {
1643 : 890290 : reln->md_seg_fds[forknum] =
1644 : 890290 : MemoryContextAlloc(MdCxt, sizeof(MdfdVec) * nseg);
1645 : : }
312 tmunro@postgresql.or 1646 [ # # ]:UBC 0 : else if (nseg > reln->md_num_open_segs[forknum])
1647 : : {
1648 : : /*
1649 : : * It doesn't seem worthwhile complicating the code to amortize
1650 : : * repalloc() calls. Those are far faster than PathNameOpenFile() or
1651 : : * FileClose(), and the memory context internally will sometimes avoid
1652 : : * doing an actual reallocation.
1653 : : */
3337 andres@anarazel.de 1654 : 0 : reln->md_seg_fds[forknum] =
1655 : 0 : repalloc(reln->md_seg_fds[forknum],
1656 : : sizeof(MdfdVec) * nseg);
1657 : : }
1658 : : else
1659 : : {
1660 : : /*
1661 : : * We don't reallocate a smaller array, because we want mdtruncate()
1662 : : * to be able to promise that it won't allocate memory, so that it is
1663 : : * allowed in a critical section. This means that a bit of space in
1664 : : * the array is now wasted, until the next time we add a segment and
1665 : : * reallocate.
1666 : : */
1667 : : }
1668 : :
3337 andres@anarazel.de 1669 :CBC 1417082 : reln->md_num_open_segs[forknum] = nseg;
10386 vadim4o@yahoo.com 1670 : 1417082 : }
1671 : :
1672 : : /*
1673 : : * Return the filename for the specified segment of the relation. The
1674 : : * returned string is palloc'd.
1675 : : */
1676 : : static MdPathStr
5928 heikki.linnakangas@i 1677 : 24898 : _mdfd_segpath(SMgrRelation reln, ForkNumber forknum, BlockNumber segno)
1678 : : {
1679 : : RelPathStr path;
1680 : : MdPathStr fullpath;
1681 : :
1210 rhaas@postgresql.org 1682 : 24898 : path = relpath(reln->smgr_rlocator, forknum);
1683 : :
10278 bruce@momjian.us 1684 [ + - ]: 24898 : if (segno > 0)
245 andres@anarazel.de 1685 : 24898 : sprintf(fullpath.str, "%s.%u", path.str, segno);
1686 : : else
245 andres@anarazel.de 1687 :UBC 0 : strcpy(fullpath.str, path.str);
1688 : :
5928 heikki.linnakangas@i 1689 :CBC 24898 : return fullpath;
1690 : : }
1691 : :
1692 : : /*
1693 : : * Open the specified segment of the relation,
1694 : : * and make a MdfdVec object for it. Returns NULL on failure.
1695 : : */
1696 : : static MdfdVec *
1697 : 24886 : _mdfd_openseg(SMgrRelation reln, ForkNumber forknum, BlockNumber segno,
1698 : : int oflags)
1699 : : {
1700 : : MdfdVec *v;
1701 : : File fd;
1702 : : MdPathStr fullpath;
1703 : :
1704 : 24886 : fullpath = _mdfd_segpath(reln, forknum, segno);
1705 : :
1706 : : /* open the file */
245 andres@anarazel.de 1707 : 24886 : fd = PathNameOpenFile(fullpath.str, _mdfd_open_flags() | oflags);
1708 : :
10278 bruce@momjian.us 1709 [ + - ]: 24886 : if (fd < 0)
7965 neilc@samurai.com 1710 : 24886 : return NULL;
1711 : :
1712 : : /*
1713 : : * Segments are always opened in order from lowest to highest, so we must
1714 : : * be adding a new one at the end.
1715 : : */
2101 tmunro@postgresql.or 1716 [ # # ]:UBC 0 : Assert(segno == reln->md_num_open_segs[forknum]);
1717 : :
1718 : 0 : _fdvec_resize(reln, forknum, segno + 1);
1719 : :
1720 : : /* fill the entry */
3337 andres@anarazel.de 1721 : 0 : v = &reln->md_seg_fds[forknum][segno];
10278 bruce@momjian.us 1722 : 0 : v->mdfd_vfd = fd;
7820 tgl@sss.pgh.pa.us 1723 : 0 : v->mdfd_segno = segno;
1724 : :
6287 heikki.linnakangas@i 1725 [ # # ]: 0 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
1726 : :
1727 : : /* all done */
9919 bruce@momjian.us 1728 : 0 : return v;
1729 : : }
1730 : :
1731 : : /*
1732 : : * _mdfd_getseg() -- Find the segment of the relation holding the
1733 : : * specified block.
1734 : : *
1735 : : * If the segment doesn't exist, we ereport, return NULL, or create the
1736 : : * segment, according to "behavior". Note: skipFsync is only used in the
1737 : : * EXTENSION_CREATE case.
1738 : : */
1739 : : static MdfdVec *
6287 heikki.linnakangas@i 1740 :CBC 2622797 : _mdfd_getseg(SMgrRelation reln, ForkNumber forknum, BlockNumber blkno,
1741 : : bool skipFsync, int behavior)
1742 : : {
1743 : : MdfdVec *v;
1744 : : BlockNumber targetseg;
1745 : : BlockNumber nextsegno;
1746 : :
1747 : : /* some way to handle non-existent segments needs to be specified */
3464 andres@anarazel.de 1748 [ - + ]: 2622797 : Assert(behavior &
1749 : : (EXTENSION_FAIL | EXTENSION_CREATE | EXTENSION_RETURN_NULL |
1750 : : EXTENSION_DONT_OPEN));
1751 : :
6873 tgl@sss.pgh.pa.us 1752 : 2622797 : targetseg = blkno / ((BlockNumber) RELSEG_SIZE);
1753 : :
1754 : : /* if an existing and opened segment, we're done */
3337 andres@anarazel.de 1755 [ + + ]: 2622797 : if (targetseg < reln->md_num_open_segs[forknum])
1756 : : {
1757 : 2394926 : v = &reln->md_seg_fds[forknum][targetseg];
1758 : 2394926 : return v;
1759 : : }
1760 : :
1761 : : /* The caller only wants the segment if we already had it open. */
1270 tmunro@postgresql.or 1762 [ - + ]: 227871 : if (behavior & EXTENSION_DONT_OPEN)
1270 tmunro@postgresql.or 1763 :UBC 0 : return NULL;
1764 : :
1765 : : /*
1766 : : * The target segment is not yet open. Iterate over all the segments
1767 : : * between the last opened and the target segment. This way missing
1768 : : * segments either raise an error, or get created (according to
1769 : : * 'behavior'). Start with either the last opened, or the first segment if
1770 : : * none was opened before.
1771 : : */
3337 andres@anarazel.de 1772 [ + + ]:CBC 227871 : if (reln->md_num_open_segs[forknum] > 0)
1773 : 12 : v = &reln->md_seg_fds[forknum][reln->md_num_open_segs[forknum] - 1];
1774 : : else
1775 : : {
2295 tmunro@postgresql.or 1776 : 227859 : v = mdopenfork(reln, forknum, behavior);
3337 andres@anarazel.de 1777 [ - + ]: 227856 : if (!v)
3337 andres@anarazel.de 1778 :UBC 0 : return NULL; /* if behavior & EXTENSION_RETURN_NULL */
1779 : : }
1780 : :
3337 andres@anarazel.de 1781 :CBC 227868 : for (nextsegno = reln->md_num_open_segs[forknum];
1782 [ + + ]: 227868 : nextsegno <= targetseg; nextsegno++)
1783 : : {
1784 : 12 : BlockNumber nblocks = _mdnblocks(reln, forknum, v);
1785 : 12 : int flags = 0;
1786 : :
1787 [ - + ]: 12 : Assert(nextsegno == v->mdfd_segno + 1);
1788 : :
1789 [ - + ]: 12 : if (nblocks > ((BlockNumber) RELSEG_SIZE))
3337 andres@anarazel.de 1790 [ # # ]:UBC 0 : elog(FATAL, "segment too big");
1791 : :
3337 andres@anarazel.de 1792 [ + - ]:CBC 12 : if ((behavior & EXTENSION_CREATE) ||
1793 [ - + - - ]: 12 : (InRecovery && (behavior & EXTENSION_CREATE_RECOVERY)))
1794 : : {
1795 : : /*
1796 : : * Normally we will create new segments only if authorized by the
1797 : : * caller (i.e., we are doing mdextend()). But when doing WAL
1798 : : * recovery, create segments anyway; this allows cases such as
1799 : : * replaying WAL data that has a write into a high-numbered
1800 : : * segment of a relation that was later deleted. We want to go
1801 : : * ahead and create the segments so we can finish out the replay.
1802 : : *
1803 : : * We have to maintain the invariant that segments before the last
1804 : : * active segment are of size RELSEG_SIZE; therefore, if
1805 : : * extending, pad them out with zeroes if needed. (This only
1806 : : * matters if in recovery, or if the caller is extending the
1807 : : * relation discontiguously, but that can happen in hash indexes.)
1808 : : */
3337 andres@anarazel.de 1809 [ # # ]:UBC 0 : if (nblocks < ((BlockNumber) RELSEG_SIZE))
1810 : : {
934 tmunro@postgresql.or 1811 : 0 : char *zerobuf = palloc_aligned(BLCKSZ, PG_IO_ALIGN_SIZE,
1812 : : MCXT_ALLOC_ZERO);
1813 : :
3337 andres@anarazel.de 1814 : 0 : mdextend(reln, forknum,
1815 : 0 : nextsegno * ((BlockNumber) RELSEG_SIZE) - 1,
1816 : : zerobuf, skipFsync);
1817 : 0 : pfree(zerobuf);
1818 : : }
1819 : 0 : flags = O_CREAT;
1820 : : }
318 tmunro@postgresql.or 1821 [ + - ]:CBC 12 : else if (nblocks < ((BlockNumber) RELSEG_SIZE))
1822 : : {
1823 : : /*
1824 : : * When not extending, only open the next segment if the current
1825 : : * one is exactly RELSEG_SIZE. If not (this branch), either
1826 : : * return NULL or fail.
1827 : : */
3337 andres@anarazel.de 1828 [ - + ]: 12 : if (behavior & EXTENSION_RETURN_NULL)
1829 : : {
1830 : : /*
1831 : : * Some callers discern between reasons for _mdfd_getseg()
1832 : : * returning NULL based on errno. As there's no failing
1833 : : * syscall involved in this case, explicitly set errno to
1834 : : * ENOENT, as that seems the closest interpretation.
1835 : : */
3337 andres@anarazel.de 1836 :UBC 0 : errno = ENOENT;
1837 : 0 : return NULL;
1838 : : }
1839 : :
3337 andres@anarazel.de 1840 [ + - ]:CBC 12 : ereport(ERROR,
1841 : : (errcode_for_file_access(),
1842 : : errmsg("could not open file \"%s\" (target block %u): previous segment is only %u blocks",
1843 : : _mdfd_segpath(reln, forknum, nextsegno).str,
1844 : : blkno, nblocks)));
1845 : : }
1846 : :
3337 andres@anarazel.de 1847 :UBC 0 : v = _mdfd_openseg(reln, forknum, nextsegno, flags);
1848 : :
1849 [ # # ]: 0 : if (v == NULL)
1850 : : {
1851 [ # # ]: 0 : if ((behavior & EXTENSION_RETURN_NULL) &&
1852 [ # # ]: 0 : FILE_POSSIBLY_DELETED(errno))
1853 : 0 : return NULL;
1854 [ # # ]: 0 : ereport(ERROR,
1855 : : (errcode_for_file_access(),
1856 : : errmsg("could not open file \"%s\" (target block %u): %m",
1857 : : _mdfd_segpath(reln, forknum, nextsegno).str,
1858 : : blkno)));
1859 : : }
1860 : : }
1861 : :
9919 bruce@momjian.us 1862 :CBC 227856 : return v;
1863 : : }
1864 : :
1865 : : /*
1866 : : * Get number of blocks present in a single disk file
1867 : : */
1868 : : static BlockNumber
6287 heikki.linnakangas@i 1869 : 3228322 : _mdnblocks(SMgrRelation reln, ForkNumber forknum, MdfdVec *seg)
1870 : : {
1871 : : off_t len;
1872 : :
2547 tmunro@postgresql.or 1873 : 3228322 : len = FileSize(seg->mdfd_vfd);
9330 bruce@momjian.us 1874 [ - + ]: 3228322 : if (len < 0)
6873 tgl@sss.pgh.pa.us 1875 [ # # ]:UBC 0 : ereport(ERROR,
1876 : : (errcode_for_file_access(),
1877 : : errmsg("could not seek to end of file \"%s\": %m",
1878 : : FilePathName(seg->mdfd_vfd))));
1879 : : /* note that this calculation will ignore any partial block at EOF */
6873 tgl@sss.pgh.pa.us 1880 :CBC 3228322 : return (BlockNumber) (len / BLCKSZ);
1881 : : }
1882 : :
1883 : : /*
1884 : : * Sync a file to disk, given a file tag. Write the path into an output
1885 : : * buffer so the caller can use it in error messages.
1886 : : *
1887 : : * Return 0 on success, -1 on failure, with errno set.
1888 : : */
1889 : : int
2399 tmunro@postgresql.or 1890 :UBC 0 : mdsyncfiletag(const FileTag *ftag, char *path)
1891 : : {
604 heikki.linnakangas@i 1892 : 0 : SMgrRelation reln = smgropen(ftag->rlocator, INVALID_PROC_NUMBER);
1893 : : File file;
1894 : : instr_time io_start;
1895 : : bool need_to_close;
1896 : : int result,
1897 : : save_errno;
1898 : :
1899 : : /* See if we already have the file open, or need to open it. */
2145 tmunro@postgresql.or 1900 [ # # ]: 0 : if (ftag->segno < reln->md_num_open_segs[ftag->forknum])
1901 : : {
1902 : 0 : file = reln->md_seg_fds[ftag->forknum][ftag->segno].mdfd_vfd;
1903 : 0 : strlcpy(path, FilePathName(file), MAXPGPATH);
1904 : 0 : need_to_close = false;
1905 : : }
1906 : : else
1907 : : {
1908 : : MdPathStr p;
1909 : :
1910 : 0 : p = _mdfd_segpath(reln, ftag->forknum, ftag->segno);
245 andres@anarazel.de 1911 : 0 : strlcpy(path, p.str, MD_PATH_STR_MAXLEN);
1912 : :
934 tmunro@postgresql.or 1913 : 0 : file = PathNameOpenFile(path, _mdfd_open_flags());
2145 1914 [ # # ]: 0 : if (file < 0)
1915 : 0 : return -1;
1916 : 0 : need_to_close = true;
1917 : : }
1918 : :
244 michael@paquier.xyz 1919 : 0 : io_start = pgstat_prepare_io_time(track_io_timing);
1920 : :
1921 : : /* Sync the file. */
2145 tmunro@postgresql.or 1922 : 0 : result = FileSync(file, WAIT_EVENT_DATA_FILE_SYNC);
1923 : 0 : save_errno = errno;
1924 : :
1925 [ # # ]: 0 : if (need_to_close)
1926 : 0 : FileClose(file);
1927 : :
935 andres@anarazel.de 1928 : 0 : pgstat_count_io_op_time(IOOBJECT_RELATION, IOCONTEXT_NORMAL,
1929 : : IOOP_FSYNC, io_start, 1, 0);
1930 : :
2145 tmunro@postgresql.or 1931 : 0 : errno = save_errno;
1932 : 0 : return result;
1933 : : }
1934 : :
1935 : : /*
1936 : : * Unlink a file, given a file tag. Write the path into an output
1937 : : * buffer so the caller can use it in error messages.
1938 : : *
1939 : : * Return 0 on success, -1 on failure, with errno set.
1940 : : */
1941 : : int
2399 tmunro@postgresql.or 1942 :CBC 33036 : mdunlinkfiletag(const FileTag *ftag, char *path)
1943 : : {
1944 : : RelPathStr p;
1945 : :
1946 : : /* Compute the path. */
1210 rhaas@postgresql.org 1947 : 33036 : p = relpathperm(ftag->rlocator, MAIN_FORKNUM);
245 andres@anarazel.de 1948 : 33036 : strlcpy(path, p.str, MAXPGPATH);
1949 : :
1950 : : /* Try to unlink the file. */
2399 tmunro@postgresql.or 1951 : 33036 : return unlink(path);
1952 : : }
1953 : :
1954 : : /*
1955 : : * Check if a given candidate request matches a given tag, when processing
1956 : : * a SYNC_FILTER_REQUEST request. This will be called for all pending
1957 : : * requests to find out whether to forget them.
1958 : : */
1959 : : bool
1960 : 7850 : mdfiletagmatches(const FileTag *ftag, const FileTag *candidate)
1961 : : {
1962 : : /*
1963 : : * For now we only use filter requests as a way to drop all scheduled
1964 : : * callbacks relating to a given database, when dropping the database.
1965 : : * We'll return true for all candidates that have the same database OID as
1966 : : * the ftag from the SYNC_FILTER_REQUEST request, so they're forgotten.
1967 : : */
1210 rhaas@postgresql.org 1968 : 7850 : return ftag->rlocator.dbOid == candidate->rlocator.dbOid;
1969 : : }
1970 : :
1971 : : /*
1972 : : * AIO completion callback for mdstartreadv().
1973 : : */
1974 : : static PgAioResult
213 andres@anarazel.de 1975 : 1164179 : md_readv_complete(PgAioHandle *ioh, PgAioResult prior_result, uint8 cb_data)
1976 : : {
1977 : 1164179 : PgAioTargetData *td = pgaio_io_get_target_data(ioh);
1978 : 1164179 : PgAioResult result = prior_result;
1979 : :
1980 [ - + ]: 1164179 : if (prior_result.result < 0)
1981 : : {
213 andres@anarazel.de 1982 :UBC 0 : result.status = PGAIO_RS_ERROR;
1983 : 0 : result.id = PGAIO_HCB_MD_READV;
1984 : : /* For "hard" errors, track the error number in error_data */
1985 : 0 : result.error_data = -prior_result.result;
1986 : 0 : result.result = 0;
1987 : :
1988 : : /*
1989 : : * Immediately log a message about the IO error, but only to the
1990 : : * server log. The reason to do so immediately is that the originator
1991 : : * might not process the query result immediately (because it is busy
1992 : : * doing another part of query processing) or at all (e.g. if it was
1993 : : * cancelled or errored out due to another IO also failing). The
1994 : : * definer of the IO will emit an ERROR when processing the IO's
1995 : : * results
1996 : : */
1997 : 0 : pgaio_result_report(result, td, LOG_SERVER_ONLY);
1998 : :
1999 : 0 : return result;
2000 : : }
2001 : :
2002 : : /*
2003 : : * As explained above smgrstartreadv(), the smgr API operates on the level
2004 : : * of blocks, rather than bytes. Convert.
2005 : : */
213 andres@anarazel.de 2006 :CBC 1164179 : result.result /= BLCKSZ;
2007 : :
2008 [ - + ]: 1164179 : Assert(result.result <= td->smgr.nblocks);
2009 : :
2010 [ - + ]: 1164179 : if (result.result == 0)
2011 : : {
2012 : : /* consider 0 blocks read a failure */
213 andres@anarazel.de 2013 :UBC 0 : result.status = PGAIO_RS_ERROR;
2014 : 0 : result.id = PGAIO_HCB_MD_READV;
2015 : 0 : result.error_data = 0;
2016 : :
2017 : : /* see comment above the "hard error" case */
2018 : 0 : pgaio_result_report(result, td, LOG_SERVER_ONLY);
2019 : :
2020 : 0 : return result;
2021 : : }
2022 : :
213 andres@anarazel.de 2023 [ + - ]:CBC 1164179 : if (result.status != PGAIO_RS_ERROR &&
2024 [ - + ]: 1164179 : result.result < td->smgr.nblocks)
2025 : : {
2026 : : /* partial reads should be retried at upper level */
213 andres@anarazel.de 2027 :UBC 0 : result.status = PGAIO_RS_PARTIAL;
2028 : 0 : result.id = PGAIO_HCB_MD_READV;
2029 : : }
2030 : :
213 andres@anarazel.de 2031 :CBC 1164179 : return result;
2032 : : }
2033 : :
2034 : : /*
2035 : : * AIO error reporting callback for mdstartreadv().
2036 : : *
2037 : : * Errors are encoded as follows:
2038 : : * - PgAioResult.error_data != 0 encodes IO that failed with that errno
2039 : : * - PgAioResult.error_data == 0 encodes IO that didn't read all data
2040 : : */
2041 : : static void
213 andres@anarazel.de 2042 :UBC 0 : md_readv_report(PgAioResult result, const PgAioTargetData *td, int elevel)
2043 : : {
2044 : : RelPathStr path;
2045 : :
2046 [ # # ]: 0 : path = relpathbackend(td->smgr.rlocator,
2047 : : td->smgr.is_temp ? MyProcNumber : INVALID_PROC_NUMBER,
2048 : : td->smgr.forkNum);
2049 : :
2050 [ # # ]: 0 : if (result.error_data != 0)
2051 : : {
2052 : : /* for errcode_for_file_access() and %m */
2053 : 0 : errno = result.error_data;
2054 : :
2055 [ # # ]: 0 : ereport(elevel,
2056 : : errcode_for_file_access(),
2057 : : errmsg("could not read blocks %u..%u in file \"%s\": %m",
2058 : : td->smgr.blockNum,
2059 : : td->smgr.blockNum + td->smgr.nblocks - 1,
2060 : : path.str));
2061 : : }
2062 : : else
2063 : : {
2064 : : /*
2065 : : * NB: This will typically only be output in debug messages, while
2066 : : * retrying a partial IO.
2067 : : */
2068 [ # # ]: 0 : ereport(elevel,
2069 : : errcode(ERRCODE_DATA_CORRUPTED),
2070 : : errmsg("could not read blocks %u..%u in file \"%s\": read only %zu of %zu bytes",
2071 : : td->smgr.blockNum,
2072 : : td->smgr.blockNum + td->smgr.nblocks - 1,
2073 : : path.str,
2074 : : result.result * (size_t) BLCKSZ,
2075 : : td->smgr.nblocks * (size_t) BLCKSZ));
2076 : : }
2077 : 0 : }
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