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) 1996-2024, 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 <unistd.h>
25 : : #include <fcntl.h>
26 : : #include <sys/file.h>
27 : :
28 : : #include "access/xlogutils.h"
29 : : #include "commands/tablespace.h"
30 : : #include "common/file_utils.h"
31 : : #include "miscadmin.h"
32 : : #include "pg_trace.h"
33 : : #include "pgstat.h"
34 : : #include "storage/bufmgr.h"
35 : : #include "storage/fd.h"
36 : : #include "storage/md.h"
37 : : #include "storage/relfilelocator.h"
38 : : #include "storage/smgr.h"
39 : : #include "storage/sync.h"
40 : : #include "utils/memutils.h"
41 : :
42 : : /*
43 : : * The magnetic disk storage manager keeps track of open file
44 : : * descriptors in its own descriptor pool. This is done to make it
45 : : * easier to support relations that are larger than the operating
46 : : * system's file size limit (often 2GBytes). In order to do that,
47 : : * we break relations up into "segment" files that are each shorter than
48 : : * the OS file size limit. The segment size is set by the RELSEG_SIZE
49 : : * configuration constant in pg_config.h.
50 : : *
51 : : * On disk, a relation must consist of consecutively numbered segment
52 : : * files in the pattern
53 : : * -- Zero or more full segments of exactly RELSEG_SIZE blocks each
54 : : * -- Exactly one partial segment of size 0 <= size < RELSEG_SIZE blocks
55 : : * -- Optionally, any number of inactive segments of size 0 blocks.
56 : : * The full and partial segments are collectively the "active" segments.
57 : : * Inactive segments are those that once contained data but are currently
58 : : * not needed because of an mdtruncate() operation. The reason for leaving
59 : : * them present at size zero, rather than unlinking them, is that other
60 : : * backends and/or the checkpointer might be holding open file references to
61 : : * such segments. If the relation expands again after mdtruncate(), such
62 : : * that a deactivated segment becomes active again, it is important that
63 : : * such file references still be valid --- else data might get written
64 : : * out to an unlinked old copy of a segment file that will eventually
65 : : * disappear.
66 : : *
67 : : * File descriptors are stored in the per-fork md_seg_fds arrays inside
68 : : * SMgrRelation. The length of these arrays is stored in md_num_open_segs.
69 : : * Note that a fork's md_num_open_segs having a specific value does not
70 : : * necessarily mean the relation doesn't have additional segments; we may
71 : : * just not have opened the next segment yet. (We could not have "all
72 : : * segments are in the array" as an invariant anyway, since another backend
73 : : * could extend the relation while we aren't looking.) We do not have
74 : : * entries for inactive segments, however; as soon as we find a partial
75 : : * segment, we assume that any subsequent segments are inactive.
76 : : *
77 : : * The entire MdfdVec array is palloc'd in the MdCxt memory context.
78 : : */
79 : :
80 : : typedef struct _MdfdVec
81 : : {
82 : : File mdfd_vfd; /* fd number in fd.c's pool */
83 : : BlockNumber mdfd_segno; /* segment number, from 0 */
84 : : } MdfdVec;
85 : :
86 : : static MemoryContext MdCxt; /* context for all MdfdVec objects */
87 : :
88 : :
89 : : /* Populate a file tag describing an md.c segment file. */
90 : : #define INIT_MD_FILETAG(a,xx_rlocator,xx_forknum,xx_segno) \
91 : : ( \
92 : : memset(&(a), 0, sizeof(FileTag)), \
93 : : (a).handler = SYNC_HANDLER_MD, \
94 : : (a).rlocator = (xx_rlocator), \
95 : : (a).forknum = (xx_forknum), \
96 : : (a).segno = (xx_segno) \
97 : : )
98 : :
99 : :
100 : : /*** behavior for mdopen & _mdfd_getseg ***/
101 : : /* ereport if segment not present */
102 : : #define EXTENSION_FAIL (1 << 0)
103 : : /* return NULL if segment not present */
104 : : #define EXTENSION_RETURN_NULL (1 << 1)
105 : : /* create new segments as needed */
106 : : #define EXTENSION_CREATE (1 << 2)
107 : : /* create new segments if needed during recovery */
108 : : #define EXTENSION_CREATE_RECOVERY (1 << 3)
109 : : /*
110 : : * Allow opening segments which are preceded by segments smaller than
111 : : * RELSEG_SIZE, e.g. inactive segments (see above). Note that this breaks
112 : : * mdnblocks() and related functionality henceforth - which currently is ok,
113 : : * because this is only required in the checkpointer which never uses
114 : : * mdnblocks().
115 : : */
116 : : #define EXTENSION_DONT_CHECK_SIZE (1 << 4)
117 : : /* don't try to open a segment, if not already open */
118 : : #define EXTENSION_DONT_OPEN (1 << 5)
119 : :
120 : :
121 : : /* local routines */
122 : : static void mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum,
123 : : bool isRedo);
124 : : static MdfdVec *mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior);
125 : : static void register_dirty_segment(SMgrRelation reln, ForkNumber forknum,
126 : : MdfdVec *seg);
127 : : static void register_unlink_segment(RelFileLocatorBackend rlocator, ForkNumber forknum,
128 : : BlockNumber segno);
129 : : static void register_forget_request(RelFileLocatorBackend rlocator, ForkNumber forknum,
130 : : BlockNumber segno);
131 : : static void _fdvec_resize(SMgrRelation reln,
132 : : ForkNumber forknum,
133 : : int nseg);
134 : : static char *_mdfd_segpath(SMgrRelation reln, ForkNumber forknum,
135 : : BlockNumber segno);
136 : : static MdfdVec *_mdfd_openseg(SMgrRelation reln, ForkNumber forknum,
137 : : BlockNumber segno, int oflags);
138 : : static MdfdVec *_mdfd_getseg(SMgrRelation reln, ForkNumber forknum,
139 : : BlockNumber blkno, bool skipFsync, int behavior);
140 : : static BlockNumber _mdnblocks(SMgrRelation reln, ForkNumber forknum,
141 : : MdfdVec *seg);
142 : :
143 : : static inline int
372 tmunro@postgresql.or 144 :CBC 1237959 : _mdfd_open_flags(void)
145 : : {
146 : 1237959 : int flags = O_RDWR | PG_BINARY;
147 : :
148 [ + + ]: 1237959 : if (io_direct_flags & IO_DIRECT_DATA)
149 : 319 : flags |= PG_O_DIRECT;
150 : :
151 : 1237959 : return flags;
152 : : }
153 : :
154 : : /*
155 : : * mdinit() -- Initialize private state for magnetic disk storage manager.
156 : : */
157 : : void
8327 tgl@sss.pgh.pa.us 158 : 19578 : mdinit(void)
159 : : {
8691 160 : 19578 : MdCxt = AllocSetContextCreate(TopMemoryContext,
161 : : "MdSmgr",
162 : : ALLOCSET_DEFAULT_SIZES);
5407 heikki.linnakangas@i 163 : 19578 : }
164 : :
165 : : /*
166 : : * mdexists() -- Does the physical file exist?
167 : : *
168 : : * Note: this will return true for lingering files, with pending deletions
169 : : */
170 : : bool
573 pg@bowt.ie 171 : 1123745 : mdexists(SMgrRelation reln, ForkNumber forknum)
172 : : {
173 : : /*
174 : : * Close it first, to ensure that we notice if the fork has been unlinked
175 : : * since we opened it. As an optimization, we can skip that in recovery,
176 : : * which already closes relations when dropping them.
177 : : */
738 tmunro@postgresql.or 178 [ + + ]: 1123745 : if (!InRecovery)
573 pg@bowt.ie 179 : 526893 : mdclose(reln, forknum);
180 : :
181 : 1123745 : return (mdopenfork(reln, forknum, EXTENSION_RETURN_NULL) != NULL);
182 : : }
183 : :
184 : : /*
185 : : * mdcreate() -- Create a new relation on magnetic disk.
186 : : *
187 : : * If isRedo is true, it's okay for the relation to exist already.
188 : : */
189 : : void
190 : 3127289 : mdcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
191 : : {
192 : : MdfdVec *mdfd;
193 : : char *path;
194 : : File fd;
195 : :
196 [ + + + + ]: 3127289 : if (isRedo && reln->md_num_open_segs[forknum] > 0)
6311 tgl@sss.pgh.pa.us 197 : 2982072 : return; /* created and opened already... */
198 : :
573 pg@bowt.ie 199 [ - + ]: 145217 : Assert(reln->md_num_open_segs[forknum] == 0);
200 : :
201 : : /*
202 : : * We may be using the target table space for the first time in this
203 : : * database, so create a per-database subdirectory if needed.
204 : : *
205 : : * XXX this is a fairly ugly violation of module layering, but this seems
206 : : * to be the best place to put the check. Maybe TablespaceCreateDbspace
207 : : * should be here and not in commands/tablespace.c? But that would imply
208 : : * importing a lot of stuff that smgr.c oughtn't know, either.
209 : : */
648 rhaas@postgresql.org 210 : 145217 : TablespaceCreateDbspace(reln->smgr_rlocator.locator.spcOid,
211 : : reln->smgr_rlocator.locator.dbOid,
212 : : isRedo);
213 : :
573 pg@bowt.ie 214 : 145217 : path = relpath(reln->smgr_rlocator, forknum);
215 : :
372 tmunro@postgresql.or 216 : 145217 : fd = PathNameOpenFile(path, _mdfd_open_flags() | O_CREAT | O_EXCL);
217 : :
9716 bruce@momjian.us 218 [ + + ]: 145217 : if (fd < 0)
219 : : {
8424 220 : 6182 : int save_errno = errno;
221 : :
1903 akapila@postgresql.o 222 [ + - ]: 6182 : if (isRedo)
372 tmunro@postgresql.or 223 : 6182 : fd = PathNameOpenFile(path, _mdfd_open_flags());
9716 bruce@momjian.us 224 [ - + ]: 6182 : if (fd < 0)
225 : : {
226 : : /* be sure to report the error reported by create, not open */
8700 tgl@sss.pgh.pa.us 227 :UBC 0 : errno = save_errno;
6311 228 [ # # ]: 0 : ereport(ERROR,
229 : : (errcode_for_file_access(),
230 : : errmsg("could not create file \"%s\": %m", path)));
231 : : }
232 : : }
233 : :
8558 tgl@sss.pgh.pa.us 234 :CBC 145217 : pfree(path);
235 : :
573 pg@bowt.ie 236 : 145217 : _fdvec_resize(reln, forknum, 1);
237 : 145217 : mdfd = &reln->md_seg_fds[forknum][0];
2775 andres@anarazel.de 238 : 145217 : mdfd->mdfd_vfd = fd;
239 : 145217 : mdfd->mdfd_segno = 0;
240 : :
285 heikki.linnakangas@i 241 [ + + ]: 145217 : if (!SmgrIsTemp(reln))
242 : 142168 : register_dirty_segment(reln, forknum, mdfd);
243 : : }
244 : :
245 : : /*
246 : : * mdunlink() -- Unlink a relation.
247 : : *
248 : : * Note that we're passed a RelFileLocatorBackend --- by the time this is called,
249 : : * there won't be an SMgrRelation hashtable entry anymore.
250 : : *
251 : : * forknum can be a fork number to delete a specific fork, or InvalidForkNumber
252 : : * to delete all forks.
253 : : *
254 : : * For regular relations, we don't unlink the first segment file of the rel,
255 : : * but just truncate it to zero length, and record a request to unlink it after
256 : : * the next checkpoint. Additional segments can be unlinked immediately,
257 : : * however. Leaving the empty file in place prevents that relfilenumber
258 : : * from being reused. The scenario this protects us from is:
259 : : * 1. We delete a relation (and commit, and actually remove its file).
260 : : * 2. We create a new relation, which by chance gets the same relfilenumber as
261 : : * the just-deleted one (OIDs must've wrapped around for that to happen).
262 : : * 3. We crash before another checkpoint occurs.
263 : : * During replay, we would delete the file and then recreate it, which is fine
264 : : * if the contents of the file were repopulated by subsequent WAL entries.
265 : : * But if we didn't WAL-log insertions, but instead relied on fsyncing the
266 : : * file after populating it (as we do at wal_level=minimal), the contents of
267 : : * the file would be lost forever. By leaving the empty file until after the
268 : : * next checkpoint, we prevent reassignment of the relfilenumber until it's
269 : : * safe, because relfilenumber assignment skips over any existing file.
270 : : *
271 : : * Additional segments, if any, are truncated and then unlinked. The reason
272 : : * for truncating is that other backends may still hold open FDs for these at
273 : : * the smgr level, so that the kernel can't remove the file yet. We want to
274 : : * reclaim the disk space right away despite that.
275 : : *
276 : : * We do not need to go through this dance for temp relations, though, because
277 : : * we never make WAL entries for temp rels, and so a temp rel poses no threat
278 : : * to the health of a regular rel that has taken over its relfilenumber.
279 : : * The fact that temp rels and regular rels have different file naming
280 : : * patterns provides additional safety. Other backends shouldn't have open
281 : : * FDs for them, either.
282 : : *
283 : : * We also don't do it while performing a binary upgrade. There is no reuse
284 : : * hazard in that case, since after a crash or even a simple ERROR, the
285 : : * upgrade fails and the whole cluster must be recreated from scratch.
286 : : * Furthermore, it is important to remove the files from disk immediately,
287 : : * because we may be about to reuse the same relfilenumber.
288 : : *
289 : : * All the above applies only to the relation's main fork; other forks can
290 : : * just be removed immediately, since they are not needed to prevent the
291 : : * relfilenumber from being recycled. Also, we do not carefully
292 : : * track whether other forks have been created or not, but just attempt to
293 : : * unlink them unconditionally; so we should never complain about ENOENT.
294 : : *
295 : : * If isRedo is true, it's unsurprising for the relation to be already gone.
296 : : * Also, we should remove the file immediately instead of queuing a request
297 : : * for later, since during redo there's no possibility of creating a
298 : : * conflicting relation.
299 : : *
300 : : * Note: we currently just never warn about ENOENT at all. We could warn in
301 : : * the main-fork, non-isRedo case, but it doesn't seem worth the trouble.
302 : : *
303 : : * Note: any failure should be reported as WARNING not ERROR, because
304 : : * we are usually not in a transaction anymore when this is called.
305 : : */
306 : : void
573 pg@bowt.ie 307 : 169924 : mdunlink(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
308 : : {
309 : : /* Now do the per-fork work */
310 [ - + ]: 169924 : if (forknum == InvalidForkNumber)
311 : : {
573 pg@bowt.ie 312 [ # # ]:UBC 0 : for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
313 : 0 : mdunlinkfork(rlocator, forknum, isRedo);
314 : : }
315 : : else
573 pg@bowt.ie 316 :CBC 169924 : mdunlinkfork(rlocator, forknum, isRedo);
4287 tgl@sss.pgh.pa.us 317 : 169924 : }
318 : :
319 : : /*
320 : : * Truncate a file to release disk space.
321 : : */
322 : : static int
1230 tmunro@postgresql.or 323 : 199495 : do_truncate(const char *path)
324 : : {
325 : : int save_errno;
326 : : int ret;
327 : :
328 : 199495 : ret = pg_truncate(path, 0);
329 : :
330 : : /* Log a warning here to avoid repetition in callers. */
331 [ + + - + ]: 199495 : if (ret < 0 && errno != ENOENT)
332 : : {
1230 tmunro@postgresql.or 333 :UBC 0 : save_errno = errno;
334 [ # # ]: 0 : ereport(WARNING,
335 : : (errcode_for_file_access(),
336 : : errmsg("could not truncate file \"%s\": %m", path)));
337 : 0 : errno = save_errno;
338 : : }
339 : :
1230 tmunro@postgresql.or 340 :CBC 199495 : return ret;
341 : : }
342 : :
343 : : static void
573 pg@bowt.ie 344 : 169924 : mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
345 : : {
346 : : char *path;
347 : : int ret;
348 : : int save_errno;
349 : :
350 : 169924 : path = relpath(rlocator, forknum);
351 : :
352 : : /*
353 : : * Truncate and then unlink the first segment, or just register a request
354 : : * to unlink it later, as described in the comments for mdunlink().
355 : : */
522 tgl@sss.pgh.pa.us 356 [ + + + + : 169924 : if (isRedo || IsBinaryUpgrade || forknum != MAIN_FORKNUM ||
+ + ]
357 [ + + ]: 35454 : RelFileLocatorBackendIsTemp(rlocator))
358 : : {
648 rhaas@postgresql.org 359 [ + + ]: 137373 : if (!RelFileLocatorBackendIsTemp(rlocator))
360 : : {
361 : : /* Prevent other backends' fds from holding on to the disk space */
1230 tmunro@postgresql.or 362 : 125761 : ret = do_truncate(path);
363 : :
364 : : /* Forget any pending sync requests for the first segment */
524 tgl@sss.pgh.pa.us 365 : 125761 : save_errno = errno;
573 pg@bowt.ie 366 : 125761 : register_forget_request(rlocator, forknum, 0 /* first seg */ );
524 tgl@sss.pgh.pa.us 367 : 125761 : errno = save_errno;
368 : : }
369 : : else
1230 tmunro@postgresql.or 370 : 11612 : ret = 0;
371 : :
372 : : /* Next unlink the file, unless it was already found to be missing */
522 tgl@sss.pgh.pa.us 373 [ + + - + ]: 137373 : if (ret >= 0 || errno != ENOENT)
374 : : {
1230 tmunro@postgresql.or 375 : 20248 : ret = unlink(path);
376 [ + + - + ]: 20248 : if (ret < 0 && errno != ENOENT)
377 : : {
522 tgl@sss.pgh.pa.us 378 :UBC 0 : save_errno = errno;
1230 tmunro@postgresql.or 379 [ # # ]: 0 : ereport(WARNING,
380 : : (errcode_for_file_access(),
381 : : errmsg("could not remove file \"%s\": %m", path)));
522 tgl@sss.pgh.pa.us 382 : 0 : errno = save_errno;
383 : : }
384 : : }
385 : : }
386 : : else
387 : : {
388 : : /* Prevent other backends' fds from holding on to the disk space */
1230 tmunro@postgresql.or 389 :CBC 32551 : ret = do_truncate(path);
390 : :
391 : : /* Register request to unlink first segment later */
522 tgl@sss.pgh.pa.us 392 : 32551 : save_errno = errno;
393 : 32551 : register_unlink_segment(rlocator, forknum, 0 /* first seg */ );
394 : 32551 : errno = save_errno;
395 : : }
396 : :
397 : : /*
398 : : * Delete any additional segments.
399 : : *
400 : : * Note that because we loop until getting ENOENT, we will correctly
401 : : * remove all inactive segments as well as active ones. Ideally we'd
402 : : * continue the loop until getting exactly that errno, but that risks an
403 : : * infinite loop if the problem is directory-wide (for instance, if we
404 : : * suddenly can't read the data directory itself). We compromise by
405 : : * continuing after a non-ENOENT truncate error, but stopping after any
406 : : * unlink error. If there is indeed a directory-wide problem, additional
407 : : * unlink attempts wouldn't work anyway.
408 : : */
409 [ + + - + ]: 169924 : if (ret >= 0 || errno != ENOENT)
410 : : {
8558 411 : 44222 : char *segpath = (char *) palloc(strlen(path) + 12);
412 : : BlockNumber segno;
413 : :
522 tgl@sss.pgh.pa.us 414 :UBC 0 : for (segno = 1;; segno++)
415 : : {
522 tgl@sss.pgh.pa.us 416 :CBC 44222 : sprintf(segpath, "%s.%u", path, segno);
417 : :
648 rhaas@postgresql.org 418 [ + + ]: 44222 : if (!RelFileLocatorBackendIsTemp(rlocator))
419 : : {
420 : : /*
421 : : * Prevent other backends' fds from holding on to the disk
422 : : * space. We're done if we see ENOENT, though.
423 : : */
1230 tmunro@postgresql.or 424 [ + - + - ]: 41183 : if (do_truncate(segpath) < 0 && errno == ENOENT)
425 : 41183 : break;
426 : :
427 : : /*
428 : : * Forget any pending sync requests for this segment before we
429 : : * try to unlink.
430 : : */
573 pg@bowt.ie 431 :UBC 0 : register_forget_request(rlocator, forknum, segno);
432 : : }
433 : :
8558 tgl@sss.pgh.pa.us 434 [ + - ]:CBC 3039 : if (unlink(segpath) < 0)
435 : : {
436 : : /* ENOENT is expected after the last segment... */
437 [ - + ]: 3039 : if (errno != ENOENT)
6311 tgl@sss.pgh.pa.us 438 [ # # ]:UBC 0 : ereport(WARNING,
439 : : (errcode_for_file_access(),
440 : : errmsg("could not remove file \"%s\": %m", segpath)));
8558 tgl@sss.pgh.pa.us 441 :CBC 3039 : break;
442 : : }
443 : : }
444 : 44222 : pfree(segpath);
445 : : }
446 : :
447 : 169924 : pfree(path);
10141 scrappy@hub.org 448 : 169924 : }
449 : :
450 : : /*
451 : : * mdextend() -- Add a block to the specified relation.
452 : : *
453 : : * The semantics are nearly the same as mdwrite(): write at the
454 : : * specified position. However, this is to be used for the case of
455 : : * extending a relation (i.e., blocknum is at or beyond the current
456 : : * EOF). Note that we assume writing a block beyond current EOF
457 : : * causes intervening file space to become filled with zeroes.
458 : : */
459 : : void
5725 heikki.linnakangas@i 460 : 106809 : mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
461 : : const void *buffer, bool skipFsync)
462 : : {
463 : : off_t seekpos;
464 : : int nbytes;
465 : : MdfdVec *v;
466 : :
467 : : /* If this build supports direct I/O, the buffer must be I/O aligned. */
468 : : if (PG_O_DIRECT != 0 && PG_IO_ALIGN_SIZE <= BLCKSZ)
372 tmunro@postgresql.or 469 [ - + ]: 106809 : Assert((uintptr_t) buffer == TYPEALIGN(PG_IO_ALIGN_SIZE, buffer));
470 : :
471 : : /* This assert is too expensive to have on normally ... */
472 : : #ifdef CHECK_WRITE_VS_EXTEND
473 : : Assert(blocknum >= mdnblocks(reln, forknum));
474 : : #endif
475 : :
476 : : /*
477 : : * If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
478 : : * more --- we mustn't create a block whose number actually is
479 : : * InvalidBlockNumber. (Note that this failure should be unreachable
480 : : * because of upstream checks in bufmgr.c.)
481 : : */
6311 tgl@sss.pgh.pa.us 482 [ - + ]: 106809 : if (blocknum == InvalidBlockNumber)
6311 tgl@sss.pgh.pa.us 483 [ # # ]:UBC 0 : ereport(ERROR,
484 : : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
485 : : errmsg("cannot extend file \"%s\" beyond %u blocks",
486 : : relpath(reln->smgr_rlocator, forknum),
487 : : InvalidBlockNumber)));
488 : :
4993 rhaas@postgresql.org 489 :CBC 106809 : v = _mdfd_getseg(reln, forknum, blocknum, skipFsync, EXTENSION_CREATE);
490 : :
2489 tgl@sss.pgh.pa.us 491 : 106809 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
492 : :
5879 493 [ - + ]: 106809 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
494 : :
1985 tmunro@postgresql.or 495 [ - + ]: 106809 : if ((nbytes = FileWrite(v->mdfd_vfd, buffer, BLCKSZ, seekpos, WAIT_EVENT_DATA_FILE_EXTEND)) != BLCKSZ)
496 : : {
6311 tgl@sss.pgh.pa.us 497 [ # # ]:UBC 0 : if (nbytes < 0)
498 [ # # ]: 0 : ereport(ERROR,
499 : : (errcode_for_file_access(),
500 : : errmsg("could not extend file \"%s\": %m",
501 : : FilePathName(v->mdfd_vfd)),
502 : : errhint("Check free disk space.")));
503 : : /* short write: complain appropriately */
504 [ # # ]: 0 : ereport(ERROR,
505 : : (errcode(ERRCODE_DISK_FULL),
506 : : errmsg("could not extend file \"%s\": wrote only %d of %d bytes at block %u",
507 : : FilePathName(v->mdfd_vfd),
508 : : nbytes, BLCKSZ, blocknum),
509 : : errhint("Check free disk space.")));
510 : : }
511 : :
4993 rhaas@postgresql.org 512 [ + + + - ]:CBC 106809 : if (!skipFsync && !SmgrIsTemp(reln))
5725 heikki.linnakangas@i 513 : 29 : register_dirty_segment(reln, forknum, v);
514 : :
515 [ - + ]: 106809 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
10141 scrappy@hub.org 516 : 106809 : }
517 : :
518 : : /*
519 : : * mdzeroextend() -- Add new zeroed out blocks to the specified relation.
520 : : *
521 : : * Similar to mdextend(), except the relation can be extended by multiple
522 : : * blocks at once and the added blocks will be filled with zeroes.
523 : : */
524 : : void
375 andres@anarazel.de 525 : 195784 : mdzeroextend(SMgrRelation reln, ForkNumber forknum,
526 : : BlockNumber blocknum, int nblocks, bool skipFsync)
527 : : {
528 : : MdfdVec *v;
529 : 195784 : BlockNumber curblocknum = blocknum;
530 : 195784 : int remblocks = nblocks;
531 : :
532 [ - + ]: 195784 : Assert(nblocks > 0);
533 : :
534 : : /* This assert is too expensive to have on normally ... */
535 : : #ifdef CHECK_WRITE_VS_EXTEND
536 : : Assert(blocknum >= mdnblocks(reln, forknum));
537 : : #endif
538 : :
539 : : /*
540 : : * If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
541 : : * more --- we mustn't create a block whose number actually is
542 : : * InvalidBlockNumber or larger.
543 : : */
544 [ - + ]: 195784 : if ((uint64) blocknum + nblocks >= (uint64) InvalidBlockNumber)
375 andres@anarazel.de 545 [ # # ]:UBC 0 : ereport(ERROR,
546 : : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
547 : : errmsg("cannot extend file \"%s\" beyond %u blocks",
548 : : relpath(reln->smgr_rlocator, forknum),
549 : : InvalidBlockNumber)));
550 : :
375 andres@anarazel.de 551 [ + + ]:CBC 391568 : while (remblocks > 0)
552 : : {
331 tgl@sss.pgh.pa.us 553 : 195784 : BlockNumber segstartblock = curblocknum % ((BlockNumber) RELSEG_SIZE);
375 andres@anarazel.de 554 : 195784 : off_t seekpos = (off_t) BLCKSZ * segstartblock;
555 : : int numblocks;
556 : :
557 [ - + ]: 195784 : if (segstartblock + remblocks > RELSEG_SIZE)
375 andres@anarazel.de 558 :UBC 0 : numblocks = RELSEG_SIZE - segstartblock;
559 : : else
375 andres@anarazel.de 560 :CBC 195784 : numblocks = remblocks;
561 : :
562 : 195784 : v = _mdfd_getseg(reln, forknum, curblocknum, skipFsync, EXTENSION_CREATE);
563 : :
564 [ - + ]: 195784 : Assert(segstartblock < RELSEG_SIZE);
565 [ - + ]: 195784 : Assert(segstartblock + numblocks <= RELSEG_SIZE);
566 : :
567 : : /*
568 : : * If available and useful, use posix_fallocate() (via
569 : : * FileFallocate()) to extend the relation. That's often more
570 : : * efficient than using write(), as it commonly won't cause the kernel
571 : : * to allocate page cache space for the extended pages.
572 : : *
573 : : * However, we don't use FileFallocate() for small extensions, as it
574 : : * defeats delayed allocation on some filesystems. Not clear where
575 : : * that decision should be made though? For now just use a cutoff of
576 : : * 8, anything between 4 and 8 worked OK in some local testing.
577 : : */
578 [ + + ]: 195784 : if (numblocks > 8)
579 : : {
580 : : int ret;
581 : :
582 : 509 : ret = FileFallocate(v->mdfd_vfd,
583 : : seekpos, (off_t) BLCKSZ * numblocks,
584 : : WAIT_EVENT_DATA_FILE_EXTEND);
585 [ - + ]: 509 : if (ret != 0)
586 : : {
375 andres@anarazel.de 587 [ # # ]:UBC 0 : ereport(ERROR,
588 : : errcode_for_file_access(),
589 : : errmsg("could not extend file \"%s\" with FileFallocate(): %m",
590 : : FilePathName(v->mdfd_vfd)),
591 : : errhint("Check free disk space."));
592 : : }
593 : : }
594 : : else
595 : : {
596 : : int ret;
597 : :
598 : : /*
599 : : * Even if we don't want to use fallocate, we can still extend a
600 : : * bit more efficiently than writing each 8kB block individually.
601 : : * pg_pwrite_zeros() (via FileZero()) uses pg_pwritev_with_retry()
602 : : * to avoid multiple writes or needing a zeroed buffer for the
603 : : * whole length of the extension.
604 : : */
375 andres@anarazel.de 605 :CBC 195275 : ret = FileZero(v->mdfd_vfd,
606 : : seekpos, (off_t) BLCKSZ * numblocks,
607 : : WAIT_EVENT_DATA_FILE_EXTEND);
608 [ - + ]: 195275 : if (ret < 0)
375 andres@anarazel.de 609 [ # # ]:UBC 0 : ereport(ERROR,
610 : : errcode_for_file_access(),
611 : : errmsg("could not extend file \"%s\": %m",
612 : : FilePathName(v->mdfd_vfd)),
613 : : errhint("Check free disk space."));
614 : : }
615 : :
375 andres@anarazel.de 616 [ + - + + ]:CBC 195784 : if (!skipFsync && !SmgrIsTemp(reln))
617 : 186740 : register_dirty_segment(reln, forknum, v);
618 : :
619 [ - + ]: 195784 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
620 : :
621 : 195784 : remblocks -= numblocks;
622 : 195784 : curblocknum += numblocks;
623 : : }
624 : 195784 : }
625 : :
626 : : /*
627 : : * mdopenfork() -- Open one fork of the specified relation.
628 : : *
629 : : * Note we only open the first segment, when there are multiple segments.
630 : : *
631 : : * If first segment is not present, either ereport or return NULL according
632 : : * to "behavior". We treat EXTENSION_CREATE the same as EXTENSION_FAIL;
633 : : * EXTENSION_CREATE means it's OK to extend an existing relation, not to
634 : : * invent one out of whole cloth.
635 : : */
636 : : static MdfdVec *
1733 tmunro@postgresql.or 637 : 3245026 : mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
638 : : {
639 : : MdfdVec *mdfd;
640 : : char *path;
641 : : File fd;
642 : :
643 : : /* No work if already open */
2775 andres@anarazel.de 644 [ + + ]: 3245026 : if (reln->md_num_open_segs[forknum] > 0)
645 : 2180455 : return &reln->md_seg_fds[forknum][0];
646 : :
648 rhaas@postgresql.org 647 : 1064571 : path = relpath(reln->smgr_rlocator, forknum);
648 : :
372 tmunro@postgresql.or 649 : 1064571 : fd = PathNameOpenFile(path, _mdfd_open_flags());
650 : :
9716 bruce@momjian.us 651 [ + + ]: 1064571 : if (fd < 0)
652 : : {
1903 akapila@postgresql.o 653 [ + + ]: 359003 : if ((behavior & EXTENSION_RETURN_NULL) &&
654 [ + - ]: 358981 : FILE_POSSIBLY_DELETED(errno))
655 : : {
656 : 358981 : pfree(path);
657 : 358981 : return NULL;
658 : : }
659 [ + - ]: 22 : ereport(ERROR,
660 : : (errcode_for_file_access(),
661 : : errmsg("could not open file \"%s\": %m", path)));
662 : : }
663 : :
8558 tgl@sss.pgh.pa.us 664 : 705568 : pfree(path);
665 : :
2775 andres@anarazel.de 666 : 705568 : _fdvec_resize(reln, forknum, 1);
667 : 705568 : mdfd = &reln->md_seg_fds[forknum][0];
7258 tgl@sss.pgh.pa.us 668 : 705568 : mdfd->mdfd_vfd = fd;
669 : 705568 : mdfd->mdfd_segno = 0;
670 : :
5725 heikki.linnakangas@i 671 [ - + ]: 705568 : Assert(_mdnblocks(reln, forknum, mdfd) <= ((BlockNumber) RELSEG_SIZE));
672 : :
7258 tgl@sss.pgh.pa.us 673 : 705568 : return mdfd;
674 : : }
675 : :
676 : : /*
677 : : * mdopen() -- Initialize newly-opened relation.
678 : : */
679 : : void
1733 tmunro@postgresql.or 680 : 976733 : mdopen(SMgrRelation reln)
681 : : {
682 : : /* mark it not open */
683 [ + + ]: 4883665 : for (int forknum = 0; forknum <= MAX_FORKNUM; forknum++)
684 : 3906932 : reln->md_num_open_segs[forknum] = 0;
685 : 976733 : }
686 : :
687 : : /*
688 : : * mdclose() -- Close the specified relation, if it isn't closed already.
689 : : */
690 : : void
5725 heikki.linnakangas@i 691 : 3357189 : mdclose(SMgrRelation reln, ForkNumber forknum)
692 : : {
2775 andres@anarazel.de 693 : 3357189 : int nopensegs = reln->md_num_open_segs[forknum];
694 : :
695 : : /* No work if already closed */
696 [ + + ]: 3357189 : if (nopensegs == 0)
6311 tgl@sss.pgh.pa.us 697 : 2882951 : return;
698 : :
699 : : /* close segments starting from the end */
2775 andres@anarazel.de 700 [ + + ]: 948476 : while (nopensegs > 0)
701 : : {
702 : 474238 : MdfdVec *v = &reln->md_seg_fds[forknum][nopensegs - 1];
703 : :
1556 noah@leadboat.com 704 : 474238 : FileClose(v->mdfd_vfd);
705 : 474238 : _fdvec_resize(reln, forknum, nopensegs - 1);
2775 andres@anarazel.de 706 : 474238 : nopensegs--;
707 : : }
708 : : }
709 : :
710 : : /*
711 : : * mdprefetch() -- Initiate asynchronous read of the specified blocks of a relation
712 : : */
713 : : bool
120 tmunro@postgresql.or 714 :GNC 137257 : mdprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
715 : : int nblocks)
716 : : {
717 : : #ifdef USE_PREFETCH
718 : :
372 tmunro@postgresql.or 719 [ - + ]:CBC 137257 : Assert((io_direct_flags & IO_DIRECT_DATA) == 0);
720 : :
120 tmunro@postgresql.or 721 [ - + ]:GNC 137257 : if ((uint64) blocknum + nblocks > (uint64) MaxBlockNumber + 1)
1467 tmunro@postgresql.or 722 :UBC 0 : return false;
723 : :
120 tmunro@postgresql.or 724 [ + + ]:GNC 274514 : while (nblocks > 0)
725 : : {
726 : : off_t seekpos;
727 : : MdfdVec *v;
728 : : int nblocks_this_segment;
729 : :
730 : 137257 : v = _mdfd_getseg(reln, forknum, blocknum, false,
731 [ + + ]: 137257 : InRecovery ? EXTENSION_RETURN_NULL : EXTENSION_FAIL);
732 [ - + ]: 137257 : if (v == NULL)
120 tmunro@postgresql.or 733 :UNC 0 : return false;
734 : :
120 tmunro@postgresql.or 735 :GNC 137257 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
736 : :
737 [ - + ]: 137257 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
738 : :
739 : 137257 : nblocks_this_segment =
740 : 137257 : Min(nblocks,
741 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
742 : :
743 : 137257 : (void) FilePrefetch(v->mdfd_vfd, seekpos, BLCKSZ * nblocks_this_segment,
744 : : WAIT_EVENT_DATA_FILE_PREFETCH);
745 : :
746 : 137257 : blocknum += nblocks_this_segment;
747 : 137257 : nblocks -= nblocks_this_segment;
748 : : }
749 : : #endif /* USE_PREFETCH */
750 : :
1467 tmunro@postgresql.or 751 :CBC 137257 : return true;
752 : : }
753 : :
754 : : /*
755 : : * Convert an array of buffer address into an array of iovec objects, and
756 : : * return the number that were required. 'iov' must have enough space for up
757 : : * to 'nblocks' elements, but the number used may be less depending on
758 : : * merging. In the case of a run of fully contiguous buffers, a single iovec
759 : : * will be populated that can be handled as a plain non-vectored I/O.
760 : : */
761 : : static int
118 tmunro@postgresql.or 762 :GNC 1636798 : buffers_to_iovec(struct iovec *iov, void **buffers, int nblocks)
763 : : {
764 : : struct iovec *iovp;
765 : : int iovcnt;
766 : :
767 [ - + ]: 1636798 : Assert(nblocks >= 1);
768 : :
769 : : /* If this build supports direct I/O, buffers must be I/O aligned. */
770 [ + + ]: 3311021 : for (int i = 0; i < nblocks; ++i)
771 : : {
772 : : if (PG_O_DIRECT != 0 && PG_IO_ALIGN_SIZE <= BLCKSZ)
773 [ - + ]: 1674223 : Assert((uintptr_t) buffers[i] ==
774 : : TYPEALIGN(PG_IO_ALIGN_SIZE, buffers[i]));
775 : : }
776 : :
777 : : /* Start the first iovec off with the first buffer. */
778 : 1636798 : iovp = &iov[0];
779 : 1636798 : iovp->iov_base = buffers[0];
780 : 1636798 : iovp->iov_len = BLCKSZ;
781 : 1636798 : iovcnt = 1;
782 : :
783 : : /* Try to merge the rest. */
784 [ + + ]: 1674223 : for (int i = 1; i < nblocks; ++i)
785 : : {
786 : 37425 : void *buffer = buffers[i];
787 : :
788 [ + + ]: 37425 : if (((char *) iovp->iov_base + iovp->iov_len) == buffer)
789 : : {
790 : : /* Contiguous with the last iovec. */
791 : 35683 : iovp->iov_len += BLCKSZ;
792 : : }
793 : : else
794 : : {
795 : : /* Need a new iovec. */
796 : 1742 : iovp++;
797 : 1742 : iovp->iov_base = buffer;
798 : 1742 : iovp->iov_len = BLCKSZ;
799 : 1742 : iovcnt++;
800 : : }
801 : : }
802 : :
803 : 1636798 : return iovcnt;
804 : : }
805 : :
806 : : /*
807 : : * mdreadv() -- Read the specified blocks from a relation.
808 : : */
809 : : void
810 : 1105525 : mdreadv(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
811 : : void **buffers, BlockNumber nblocks)
812 : : {
813 [ + + ]: 2211035 : while (nblocks > 0)
814 : : {
815 : : struct iovec iov[PG_IOV_MAX];
816 : : int iovcnt;
817 : : off_t seekpos;
818 : : int nbytes;
819 : : MdfdVec *v;
820 : : BlockNumber nblocks_this_segment;
821 : : size_t transferred_this_segment;
822 : : size_t size_this_segment;
823 : :
824 : 1105525 : v = _mdfd_getseg(reln, forknum, blocknum, false,
825 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
826 : :
827 : 1105510 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
828 : :
829 [ - + ]: 1105510 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
830 : :
831 : 1105510 : nblocks_this_segment =
832 : 1105510 : Min(nblocks,
833 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
834 : 1105510 : nblocks_this_segment = Min(nblocks_this_segment, lengthof(iov));
835 : :
836 : 1105510 : iovcnt = buffers_to_iovec(iov, buffers, nblocks_this_segment);
837 : 1105510 : size_this_segment = nblocks_this_segment * BLCKSZ;
838 : 1105510 : transferred_this_segment = 0;
839 : :
840 : : /*
841 : : * Inner loop to continue after a short read. We'll keep going until
842 : : * we hit EOF rather than assuming that a short read means we hit the
843 : : * end.
844 : : */
845 : : for (;;)
846 : : {
118 tmunro@postgresql.or 847 :UNC 0 : TRACE_POSTGRESQL_SMGR_MD_READ_START(forknum, blocknum,
848 : : reln->smgr_rlocator.locator.spcOid,
849 : : reln->smgr_rlocator.locator.dbOid,
850 : : reln->smgr_rlocator.locator.relNumber,
851 : : reln->smgr_rlocator.backend);
118 tmunro@postgresql.or 852 :GNC 1105510 : nbytes = FileReadV(v->mdfd_vfd, iov, iovcnt, seekpos,
853 : : WAIT_EVENT_DATA_FILE_READ);
854 : : TRACE_POSTGRESQL_SMGR_MD_READ_DONE(forknum, blocknum,
855 : : reln->smgr_rlocator.locator.spcOid,
856 : : reln->smgr_rlocator.locator.dbOid,
857 : : reln->smgr_rlocator.locator.relNumber,
858 : : reln->smgr_rlocator.backend,
859 : : nbytes,
860 : : size_this_segment - transferred_this_segment);
861 : :
862 : : #ifdef SIMULATE_SHORT_READ
863 : : nbytes = Min(nbytes, 4096);
864 : : #endif
865 : :
866 [ - + ]: 1105510 : if (nbytes < 0)
118 tmunro@postgresql.or 867 [ # # ]:UNC 0 : ereport(ERROR,
868 : : (errcode_for_file_access(),
869 : : errmsg("could not read blocks %u..%u in file \"%s\": %m",
870 : : blocknum,
871 : : blocknum + nblocks_this_segment - 1,
872 : : FilePathName(v->mdfd_vfd))));
873 : :
118 tmunro@postgresql.or 874 [ - + ]:GNC 1105510 : if (nbytes == 0)
875 : : {
876 : : /*
877 : : * We are at or past EOF, or we read a partial block at EOF.
878 : : * Normally this is an error; upper levels should never try to
879 : : * read a nonexistent block. However, if zero_damaged_pages
880 : : * is ON or we are InRecovery, we should instead return zeroes
881 : : * without complaining. This allows, for example, the case of
882 : : * trying to update a block that was later truncated away.
883 : : */
118 tmunro@postgresql.or 884 [ # # # # ]:UNC 0 : if (zero_damaged_pages || InRecovery)
885 : : {
886 : 0 : for (BlockNumber i = transferred_this_segment / BLCKSZ;
887 [ # # ]: 0 : i < nblocks_this_segment;
888 : 0 : ++i)
889 : 0 : memset(buffers[i], 0, BLCKSZ);
890 : 0 : break;
891 : : }
892 : : else
893 [ # # ]: 0 : ereport(ERROR,
894 : : (errcode(ERRCODE_DATA_CORRUPTED),
895 : : errmsg("could not read blocks %u..%u in file \"%s\": read only %zu of %zu bytes",
896 : : blocknum,
897 : : blocknum + nblocks_this_segment - 1,
898 : : FilePathName(v->mdfd_vfd),
899 : : transferred_this_segment,
900 : : size_this_segment)));
901 : : }
902 : :
903 : : /* One loop should usually be enough. */
118 tmunro@postgresql.or 904 :GNC 1105510 : transferred_this_segment += nbytes;
905 [ - + ]: 1105510 : Assert(transferred_this_segment <= size_this_segment);
906 [ + - ]: 1105510 : if (transferred_this_segment == size_this_segment)
907 : 1105510 : break;
908 : :
909 : : /* Adjust position and vectors after a short read. */
118 tmunro@postgresql.or 910 :UNC 0 : seekpos += nbytes;
911 : 0 : iovcnt = compute_remaining_iovec(iov, iov, iovcnt, nbytes);
912 : : }
913 : :
118 tmunro@postgresql.or 914 :GNC 1105510 : nblocks -= nblocks_this_segment;
915 : 1105510 : buffers += nblocks_this_segment;
916 : 1105510 : blocknum += nblocks_this_segment;
917 : : }
10141 scrappy@hub.org 918 :CBC 1105510 : }
919 : :
920 : : /*
921 : : * mdwritev() -- Write the supplied blocks at the appropriate location.
922 : : *
923 : : * This is to be used only for updating already-existing blocks of a
924 : : * relation (ie, those before the current EOF). To extend a relation,
925 : : * use mdextend().
926 : : */
927 : : void
118 tmunro@postgresql.or 928 :GNC 531288 : mdwritev(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
929 : : const void **buffers, BlockNumber nblocks, bool skipFsync)
930 : : {
931 : : /* This assert is too expensive to have on normally ... */
932 : : #ifdef CHECK_WRITE_VS_EXTEND
933 : : Assert(blocknum < mdnblocks(reln, forknum));
934 : : #endif
935 : :
936 [ + + ]: 1062576 : while (nblocks > 0)
937 : : {
938 : : struct iovec iov[PG_IOV_MAX];
939 : : int iovcnt;
940 : : off_t seekpos;
941 : : int nbytes;
942 : : MdfdVec *v;
943 : : BlockNumber nblocks_this_segment;
944 : : size_t transferred_this_segment;
945 : : size_t size_this_segment;
946 : :
947 : 531288 : v = _mdfd_getseg(reln, forknum, blocknum, skipFsync,
948 : : EXTENSION_FAIL | EXTENSION_CREATE_RECOVERY);
949 : :
950 : 531288 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
951 : :
952 [ - + ]: 531288 : Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
953 : :
954 : 531288 : nblocks_this_segment =
955 : 531288 : Min(nblocks,
956 : : RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE)));
957 : 531288 : nblocks_this_segment = Min(nblocks_this_segment, lengthof(iov));
958 : :
959 : 531288 : iovcnt = buffers_to_iovec(iov, (void **) buffers, nblocks_this_segment);
960 : 531288 : size_this_segment = nblocks_this_segment * BLCKSZ;
961 : 531288 : transferred_this_segment = 0;
962 : :
963 : : /*
964 : : * Inner loop to continue after a short write. If the reason is that
965 : : * we're out of disk space, a future attempt should get an ENOSPC
966 : : * error from the kernel.
967 : : */
968 : : for (;;)
969 : : {
118 tmunro@postgresql.or 970 :UNC 0 : TRACE_POSTGRESQL_SMGR_MD_WRITE_START(forknum, blocknum,
971 : : reln->smgr_rlocator.locator.spcOid,
972 : : reln->smgr_rlocator.locator.dbOid,
973 : : reln->smgr_rlocator.locator.relNumber,
974 : : reln->smgr_rlocator.backend);
118 tmunro@postgresql.or 975 :GNC 531288 : nbytes = FileWriteV(v->mdfd_vfd, iov, iovcnt, seekpos,
976 : : WAIT_EVENT_DATA_FILE_WRITE);
977 : : TRACE_POSTGRESQL_SMGR_MD_WRITE_DONE(forknum, blocknum,
978 : : reln->smgr_rlocator.locator.spcOid,
979 : : reln->smgr_rlocator.locator.dbOid,
980 : : reln->smgr_rlocator.locator.relNumber,
981 : : reln->smgr_rlocator.backend,
982 : : nbytes,
983 : : size_this_segment - transferred_this_segment);
984 : :
985 : : #ifdef SIMULATE_SHORT_WRITE
986 : : nbytes = Min(nbytes, 4096);
987 : : #endif
988 : :
989 [ - + ]: 531288 : if (nbytes < 0)
990 : : {
118 tmunro@postgresql.or 991 :UNC 0 : bool enospc = errno == ENOSPC;
992 : :
993 [ # # # # ]: 0 : ereport(ERROR,
994 : : (errcode_for_file_access(),
995 : : errmsg("could not write blocks %u..%u in file \"%s\": %m",
996 : : blocknum,
997 : : blocknum + nblocks_this_segment - 1,
998 : : FilePathName(v->mdfd_vfd)),
999 : : enospc ? errhint("Check free disk space.") : 0));
1000 : : }
1001 : :
1002 : : /* One loop should usually be enough. */
118 tmunro@postgresql.or 1003 :GNC 531288 : transferred_this_segment += nbytes;
1004 [ - + ]: 531288 : Assert(transferred_this_segment <= size_this_segment);
1005 [ + - ]: 531288 : if (transferred_this_segment == size_this_segment)
1006 : 531288 : break;
1007 : :
1008 : : /* Adjust position and iovecs after a short write. */
118 tmunro@postgresql.or 1009 :UNC 0 : seekpos += nbytes;
1010 : 0 : iovcnt = compute_remaining_iovec(iov, iov, iovcnt, nbytes);
1011 : : }
1012 : :
118 tmunro@postgresql.or 1013 [ + + + + ]:GNC 531288 : if (!skipFsync && !SmgrIsTemp(reln))
1014 : 530338 : register_dirty_segment(reln, forknum, v);
1015 : :
1016 : 531288 : nblocks -= nblocks_this_segment;
1017 : 531288 : buffers += nblocks_this_segment;
1018 : 531288 : blocknum += nblocks_this_segment;
1019 : : }
8771 tgl@sss.pgh.pa.us 1020 :CBC 531288 : }
1021 : :
1022 : :
1023 : : /*
1024 : : * mdwriteback() -- Tell the kernel to write pages back to storage.
1025 : : *
1026 : : * This accepts a range of blocks because flushing several pages at once is
1027 : : * considerably more efficient than doing so individually.
1028 : : */
1029 : : void
331 peter@eisentraut.org 1030 : 85655 : mdwriteback(SMgrRelation reln, ForkNumber forknum,
1031 : : BlockNumber blocknum, BlockNumber nblocks)
1032 : : {
1033 [ - + ]: 85655 : Assert((io_direct_flags & IO_DIRECT_DATA) == 0);
1034 : :
1035 : : /*
1036 : : * Issue flush requests in as few requests as possible; have to split at
1037 : : * segment boundaries though, since those are actually separate files.
1038 : : */
1039 [ + + ]: 170842 : while (nblocks > 0)
1040 : : {
1041 : 85655 : BlockNumber nflush = nblocks;
1042 : : off_t seekpos;
1043 : : MdfdVec *v;
1044 : : int segnum_start,
1045 : : segnum_end;
1046 : :
1047 : 85655 : v = _mdfd_getseg(reln, forknum, blocknum, true /* not used */ ,
1048 : : EXTENSION_DONT_OPEN);
1049 : :
1050 : : /*
1051 : : * We might be flushing buffers of already removed relations, that's
1052 : : * ok, just ignore that case. If the segment file wasn't open already
1053 : : * (ie from a recent mdwrite()), then we don't want to re-open it, to
1054 : : * avoid a race with PROCSIGNAL_BARRIER_SMGRRELEASE that might leave
1055 : : * us with a descriptor to a file that is about to be unlinked.
1056 : : */
1057 [ + + ]: 85655 : if (!v)
1058 : 468 : return;
1059 : :
1060 : : /* compute offset inside the current segment */
1061 : 85187 : segnum_start = blocknum / RELSEG_SIZE;
1062 : :
1063 : : /* compute number of desired writes within the current segment */
1064 : 85187 : segnum_end = (blocknum + nblocks - 1) / RELSEG_SIZE;
1065 [ - + ]: 85187 : if (segnum_start != segnum_end)
331 peter@eisentraut.org 1066 :UBC 0 : nflush = RELSEG_SIZE - (blocknum % ((BlockNumber) RELSEG_SIZE));
1067 : :
331 peter@eisentraut.org 1068 [ - + ]:CBC 85187 : Assert(nflush >= 1);
1069 [ - + ]: 85187 : Assert(nflush <= nblocks);
1070 : :
1071 : 85187 : seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
1072 : :
1073 : 85187 : FileWriteback(v->mdfd_vfd, seekpos, (off_t) BLCKSZ * nflush, WAIT_EVENT_DATA_FILE_FLUSH);
1074 : :
1075 : 85187 : nblocks -= nflush;
1076 : 85187 : blocknum += nflush;
1077 : : }
1078 : : }
1079 : :
1080 : : /*
1081 : : * mdnblocks() -- Get the number of blocks stored in a relation.
1082 : : *
1083 : : * Important side effect: all active segments of the relation are opened
1084 : : * and added to the md_seg_fds array. If this routine has not been
1085 : : * called, then only segments up to the last one actually touched
1086 : : * are present in the array.
1087 : : */
1088 : : BlockNumber
5725 heikki.linnakangas@i 1089 : 1937888 : mdnblocks(SMgrRelation reln, ForkNumber forknum)
1090 : : {
1091 : : MdfdVec *v;
1092 : : BlockNumber nblocks;
1093 : : BlockNumber segno;
1094 : :
1319 bruce@momjian.us 1095 : 1937888 : mdopenfork(reln, forknum, EXTENSION_FAIL);
1096 : :
1097 : : /* mdopen has opened the first segment */
2775 andres@anarazel.de 1098 [ - + ]: 1937869 : Assert(reln->md_num_open_segs[forknum] > 0);
1099 : :
1100 : : /*
1101 : : * Start from the last open segments, to avoid redundant seeks. We have
1102 : : * previously verified that these segments are exactly RELSEG_SIZE long,
1103 : : * and it's useless to recheck that each time.
1104 : : *
1105 : : * NOTE: this assumption could only be wrong if another backend has
1106 : : * truncated the relation. We rely on higher code levels to handle that
1107 : : * scenario by closing and re-opening the md fd, which is handled via
1108 : : * relcache flush. (Since the checkpointer doesn't participate in
1109 : : * relcache flush, it could have segment entries for inactive segments;
1110 : : * that's OK because the checkpointer never needs to compute relation
1111 : : * size.)
1112 : : */
1113 : 1937869 : segno = reln->md_num_open_segs[forknum] - 1;
1114 : 1937869 : v = &reln->md_seg_fds[forknum][segno];
1115 : :
1116 : : for (;;)
1117 : : {
5725 heikki.linnakangas@i 1118 :UBC 0 : nblocks = _mdnblocks(reln, forknum, v);
8327 tgl@sss.pgh.pa.us 1119 [ - + ]:CBC 1937869 : if (nblocks > ((BlockNumber) RELSEG_SIZE))
7570 tgl@sss.pgh.pa.us 1120 [ # # ]:UBC 0 : elog(FATAL, "segment too big");
8327 tgl@sss.pgh.pa.us 1121 [ + - ]:CBC 1937869 : if (nblocks < ((BlockNumber) RELSEG_SIZE))
1122 : 1937869 : return (segno * ((BlockNumber) RELSEG_SIZE)) + nblocks;
1123 : :
1124 : : /*
1125 : : * If segment is exactly RELSEG_SIZE, advance to next one.
1126 : : */
8375 tgl@sss.pgh.pa.us 1127 :UBC 0 : segno++;
1128 : :
1129 : : /*
1130 : : * We used to pass O_CREAT here, but that has the disadvantage that it
1131 : : * might create a segment which has vanished through some operating
1132 : : * system misadventure. In such a case, creating the segment here
1133 : : * undermines _mdfd_getseg's attempts to notice and report an error
1134 : : * upon access to a missing segment.
1135 : : */
2775 andres@anarazel.de 1136 : 0 : v = _mdfd_openseg(reln, forknum, segno, 0);
1137 [ # # ]: 0 : if (v == NULL)
1138 : 0 : return segno * ((BlockNumber) RELSEG_SIZE);
1139 : : }
1140 : : }
1141 : :
1142 : : /*
1143 : : * mdtruncate() -- Truncate relation to specified number of blocks.
1144 : : */
1145 : : void
4993 rhaas@postgresql.org 1146 :CBC 851 : mdtruncate(SMgrRelation reln, ForkNumber forknum, BlockNumber nblocks)
1147 : : {
1148 : : BlockNumber curnblk;
1149 : : BlockNumber priorblocks;
1150 : : int curopensegs;
1151 : :
1152 : : /*
1153 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1154 : : * truncation loop will get them all!
1155 : : */
5725 heikki.linnakangas@i 1156 : 851 : curnblk = mdnblocks(reln, forknum);
8327 tgl@sss.pgh.pa.us 1157 [ - + ]: 851 : if (nblocks > curnblk)
1158 : : {
1159 : : /* Bogus request ... but no complaint if InRecovery */
6311 tgl@sss.pgh.pa.us 1160 [ # # ]:UBC 0 : if (InRecovery)
1161 : 0 : return;
1162 [ # # ]: 0 : ereport(ERROR,
1163 : : (errmsg("could not truncate file \"%s\" to %u blocks: it's only %u blocks now",
1164 : : relpath(reln->smgr_rlocator, forknum),
1165 : : nblocks, curnblk)));
1166 : : }
8991 tgl@sss.pgh.pa.us 1167 [ + + ]:CBC 851 : if (nblocks == curnblk)
6311 1168 : 340 : return; /* no work */
1169 : :
1170 : : /*
1171 : : * Truncate segments, starting at the last one. Starting at the end makes
1172 : : * managing the memory for the fd array easier, should there be errors.
1173 : : */
2775 andres@anarazel.de 1174 : 511 : curopensegs = reln->md_num_open_segs[forknum];
1175 [ + + ]: 1022 : while (curopensegs > 0)
1176 : : {
1177 : : MdfdVec *v;
1178 : :
1179 : 511 : priorblocks = (curopensegs - 1) * RELSEG_SIZE;
1180 : :
1181 : 511 : v = &reln->md_seg_fds[forknum][curopensegs - 1];
1182 : :
8991 tgl@sss.pgh.pa.us 1183 [ - + ]: 511 : if (priorblocks > nblocks)
1184 : : {
1185 : : /*
1186 : : * This segment is no longer active. We truncate the file, but do
1187 : : * not delete it, for reasons explained in the header comments.
1188 : : */
2584 rhaas@postgresql.org 1189 [ # # ]:UBC 0 : if (FileTruncate(v->mdfd_vfd, 0, WAIT_EVENT_DATA_FILE_TRUNCATE) < 0)
6311 tgl@sss.pgh.pa.us 1190 [ # # ]: 0 : ereport(ERROR,
1191 : : (errcode_for_file_access(),
1192 : : errmsg("could not truncate file \"%s\": %m",
1193 : : FilePathName(v->mdfd_vfd))));
1194 : :
4993 rhaas@postgresql.org 1195 [ # # ]: 0 : if (!SmgrIsTemp(reln))
5725 heikki.linnakangas@i 1196 : 0 : register_dirty_segment(reln, forknum, v);
1197 : :
1198 : : /* we never drop the 1st segment */
2775 andres@anarazel.de 1199 [ # # ]: 0 : Assert(v != &reln->md_seg_fds[forknum][0]);
1200 : :
1201 : 0 : FileClose(v->mdfd_vfd);
1202 : 0 : _fdvec_resize(reln, forknum, curopensegs - 1);
1203 : : }
8327 tgl@sss.pgh.pa.us 1204 [ + - ]:CBC 511 : else if (priorblocks + ((BlockNumber) RELSEG_SIZE) > nblocks)
1205 : : {
1206 : : /*
1207 : : * This is the last segment we want to keep. Truncate the file to
1208 : : * the right length. NOTE: if nblocks is exactly a multiple K of
1209 : : * RELSEG_SIZE, we will truncate the K+1st segment to 0 length but
1210 : : * keep it. This adheres to the invariant given in the header
1211 : : * comments.
1212 : : */
8207 bruce@momjian.us 1213 : 511 : BlockNumber lastsegblocks = nblocks - priorblocks;
1214 : :
2584 rhaas@postgresql.org 1215 [ - + ]: 511 : if (FileTruncate(v->mdfd_vfd, (off_t) lastsegblocks * BLCKSZ, WAIT_EVENT_DATA_FILE_TRUNCATE) < 0)
6311 tgl@sss.pgh.pa.us 1216 [ # # ]:UBC 0 : ereport(ERROR,
1217 : : (errcode_for_file_access(),
1218 : : errmsg("could not truncate file \"%s\" to %u blocks: %m",
1219 : : FilePathName(v->mdfd_vfd),
1220 : : nblocks)));
4993 rhaas@postgresql.org 1221 [ + + ]:CBC 511 : if (!SmgrIsTemp(reln))
5725 heikki.linnakangas@i 1222 : 374 : register_dirty_segment(reln, forknum, v);
1223 : : }
1224 : : else
1225 : : {
1226 : : /*
1227 : : * We still need this segment, so nothing to do for this and any
1228 : : * earlier segment.
1229 : : */
2775 andres@anarazel.de 1230 :UBC 0 : break;
1231 : : }
2775 andres@anarazel.de 1232 :CBC 511 : curopensegs--;
1233 : : }
1234 : : }
1235 : :
1236 : : /*
1237 : : * mdregistersync() -- Mark whole relation as needing fsync
1238 : : */
1239 : : void
51 heikki.linnakangas@i 1240 :GNC 21978 : mdregistersync(SMgrRelation reln, ForkNumber forknum)
1241 : : {
1242 : : int segno;
1243 : : int min_inactive_seg;
1244 : :
1245 : : /*
1246 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1247 : : * the loop below will get them all!
1248 : : */
1249 : 21978 : mdnblocks(reln, forknum);
1250 : :
1251 : 21978 : min_inactive_seg = segno = reln->md_num_open_segs[forknum];
1252 : :
1253 : : /*
1254 : : * Temporarily open inactive segments, then close them after sync. There
1255 : : * may be some inactive segments left opened after error, but that is
1256 : : * harmless. We don't bother to clean them up and take a risk of further
1257 : : * trouble. The next mdclose() will soon close them.
1258 : : */
1259 [ - + ]: 21978 : while (_mdfd_openseg(reln, forknum, segno, 0) != NULL)
51 heikki.linnakangas@i 1260 :UNC 0 : segno++;
1261 : :
51 heikki.linnakangas@i 1262 [ + + ]:GNC 43956 : while (segno > 0)
1263 : : {
1264 : 21978 : MdfdVec *v = &reln->md_seg_fds[forknum][segno - 1];
1265 : :
1266 : 21978 : register_dirty_segment(reln, forknum, v);
1267 : :
1268 : : /* Close inactive segments immediately */
1269 [ - + ]: 21978 : if (segno > min_inactive_seg)
1270 : : {
51 heikki.linnakangas@i 1271 :UNC 0 : FileClose(v->mdfd_vfd);
1272 : 0 : _fdvec_resize(reln, forknum, segno - 1);
1273 : : }
1274 : :
51 heikki.linnakangas@i 1275 :GNC 21978 : segno--;
1276 : : }
1277 : 21978 : }
1278 : :
1279 : : /*
1280 : : * mdimmedsync() -- Immediately sync a relation to stable storage.
1281 : : *
1282 : : * Note that only writes already issued are synced; this routine knows
1283 : : * nothing of dirty buffers that may exist inside the buffer manager. We
1284 : : * sync active and inactive segments; smgrDoPendingSyncs() relies on this.
1285 : : * Consider a relation skipping WAL. Suppose a checkpoint syncs blocks of
1286 : : * some segment, then mdtruncate() renders that segment inactive. If we
1287 : : * crash before the next checkpoint syncs the newly-inactive segment, that
1288 : : * segment may survive recovery, reintroducing unwanted data into the table.
1289 : : */
1290 : : void
5725 heikki.linnakangas@i 1291 :CBC 11 : mdimmedsync(SMgrRelation reln, ForkNumber forknum)
1292 : : {
1293 : : int segno;
1294 : : int min_inactive_seg;
1295 : :
1296 : : /*
1297 : : * NOTE: mdnblocks makes sure we have opened all active segments, so that
1298 : : * the loop below will get them all!
1299 : : */
4752 peter_e@gmx.net 1300 : 11 : mdnblocks(reln, forknum);
1301 : :
1471 noah@leadboat.com 1302 : 11 : min_inactive_seg = segno = reln->md_num_open_segs[forknum];
1303 : :
1304 : : /*
1305 : : * Temporarily open inactive segments, then close them after sync. There
1306 : : * may be some inactive segments left opened after fsync() error, but that
1307 : : * is harmless. We don't bother to clean them up and take a risk of
1308 : : * further trouble. The next mdclose() will soon close them.
1309 : : */
1310 [ - + ]: 11 : while (_mdfd_openseg(reln, forknum, segno, 0) != NULL)
1471 noah@leadboat.com 1311 :UBC 0 : segno++;
1312 : :
2775 andres@anarazel.de 1313 [ + + ]:CBC 22 : while (segno > 0)
1314 : : {
1315 : 11 : MdfdVec *v = &reln->md_seg_fds[forknum][segno - 1];
1316 : :
1317 : : /*
1318 : : * fsyncs done through mdimmedsync() should be tracked in a separate
1319 : : * IOContext than those done through mdsyncfiletag() to differentiate
1320 : : * between unavoidable client backend fsyncs (e.g. those done during
1321 : : * index build) and those which ideally would have been done by the
1322 : : * checkpointer. Since other IO operations bypassing the buffer
1323 : : * manager could also be tracked in such an IOContext, wait until
1324 : : * these are also tracked to track immediate fsyncs.
1325 : : */
2584 rhaas@postgresql.org 1326 [ - + ]: 11 : if (FileSync(v->mdfd_vfd, WAIT_EVENT_DATA_FILE_IMMEDIATE_SYNC) < 0)
1973 tmunro@postgresql.or 1327 [ # # ]:UBC 0 : ereport(data_sync_elevel(ERROR),
1328 : : (errcode_for_file_access(),
1329 : : errmsg("could not fsync file \"%s\": %m",
1330 : : FilePathName(v->mdfd_vfd))));
1331 : :
1332 : : /* Close inactive segments immediately */
1471 noah@leadboat.com 1333 [ - + ]:CBC 11 : if (segno > min_inactive_seg)
1334 : : {
1471 noah@leadboat.com 1335 :UBC 0 : FileClose(v->mdfd_vfd);
1336 : 0 : _fdvec_resize(reln, forknum, segno - 1);
1337 : : }
1338 : :
2775 andres@anarazel.de 1339 :CBC 11 : segno--;
1340 : : }
7256 tgl@sss.pgh.pa.us 1341 : 11 : }
1342 : :
1343 : : /*
1344 : : * register_dirty_segment() -- Mark a relation segment as needing fsync
1345 : : *
1346 : : * If there is a local pending-ops table, just make an entry in it for
1347 : : * ProcessSyncRequests to process later. Otherwise, try to pass off the
1348 : : * fsync request to the checkpointer process. If that fails, just do the
1349 : : * fsync locally before returning (we hope this will not happen often
1350 : : * enough to be a performance problem).
1351 : : */
1352 : : static void
5725 heikki.linnakangas@i 1353 : 881627 : register_dirty_segment(SMgrRelation reln, ForkNumber forknum, MdfdVec *seg)
1354 : : {
1355 : : FileTag tag;
1356 : :
648 rhaas@postgresql.org 1357 : 881627 : INIT_MD_FILETAG(tag, reln->smgr_rlocator.locator, forknum, seg->mdfd_segno);
1358 : :
1359 : : /* Temp relations should never be fsync'd */
4289 tgl@sss.pgh.pa.us 1360 [ - + ]: 881627 : Assert(!SmgrIsTemp(reln));
1361 : :
1837 tmunro@postgresql.or 1362 [ - + ]: 881627 : if (!RegisterSyncRequest(&tag, SYNC_REQUEST, false /* retryOnError */ ))
1363 : : {
1364 : : instr_time io_start;
1365 : :
373 andres@anarazel.de 1366 [ # # ]:LBC (454) : ereport(DEBUG1,
1367 : : (errmsg_internal("could not forward fsync request because request queue is full")));
1368 : :
120 michael@paquier.xyz 1369 :UNC 0 : io_start = pgstat_prepare_io_time(track_io_timing);
1370 : :
373 andres@anarazel.de 1371 [ # # ]:LBC (454) : if (FileSync(seg->mdfd_vfd, WAIT_EVENT_DATA_FILE_SYNC) < 0)
373 andres@anarazel.de 1372 [ # # ]:UBC 0 : ereport(data_sync_elevel(ERROR),
1373 : : (errcode_for_file_access(),
1374 : : errmsg("could not fsync file \"%s\": %m",
1375 : : FilePathName(seg->mdfd_vfd))));
1376 : :
1377 : : /*
1378 : : * We have no way of knowing if the current IOContext is
1379 : : * IOCONTEXT_NORMAL or IOCONTEXT_[BULKREAD, BULKWRITE, VACUUM] at this
1380 : : * point, so count the fsync as being in the IOCONTEXT_NORMAL
1381 : : * IOContext. This is probably okay, because the number of backend
1382 : : * fsyncs doesn't say anything about the efficacy of the
1383 : : * BufferAccessStrategy. And counting both fsyncs done in
1384 : : * IOCONTEXT_NORMAL and IOCONTEXT_[BULKREAD, BULKWRITE, VACUUM] under
1385 : : * IOCONTEXT_NORMAL is likely clearer when investigating the number of
1386 : : * backend fsyncs.
1387 : : */
373 andres@anarazel.de 1388 :LBC (454) : pgstat_count_io_op_time(IOOBJECT_RELATION, IOCONTEXT_NORMAL,
1389 : : IOOP_FSYNC, io_start, 1);
1390 : : }
10141 scrappy@hub.org 1391 :CBC 881627 : }
1392 : :
1393 : : /*
1394 : : * register_unlink_segment() -- Schedule a file to be deleted after next checkpoint
1395 : : */
1396 : : static void
648 rhaas@postgresql.org 1397 : 32551 : register_unlink_segment(RelFileLocatorBackend rlocator, ForkNumber forknum,
1398 : : BlockNumber segno)
1399 : : {
1400 : : FileTag tag;
1401 : :
1402 : 32551 : INIT_MD_FILETAG(tag, rlocator.locator, forknum, segno);
1403 : :
1404 : : /* Should never be used with temp relations */
1405 [ - + ]: 32551 : Assert(!RelFileLocatorBackendIsTemp(rlocator));
1406 : :
1837 tmunro@postgresql.or 1407 : 32551 : RegisterSyncRequest(&tag, SYNC_UNLINK_REQUEST, true /* retryOnError */ );
5995 tgl@sss.pgh.pa.us 1408 : 32551 : }
1409 : :
1410 : : /*
1411 : : * register_forget_request() -- forget any fsyncs for a relation fork's segment
1412 : : */
1413 : : static void
648 rhaas@postgresql.org 1414 : 125761 : register_forget_request(RelFileLocatorBackend rlocator, ForkNumber forknum,
1415 : : BlockNumber segno)
1416 : : {
1417 : : FileTag tag;
1418 : :
1419 : 125761 : INIT_MD_FILETAG(tag, rlocator.locator, forknum, segno);
1420 : :
1837 tmunro@postgresql.or 1421 : 125761 : RegisterSyncRequest(&tag, SYNC_FORGET_REQUEST, true /* retryOnError */ );
6297 tgl@sss.pgh.pa.us 1422 : 125761 : }
1423 : :
1424 : : /*
1425 : : * ForgetDatabaseSyncRequests -- forget any fsyncs and unlinks for a DB
1426 : : */
1427 : : void
1837 tmunro@postgresql.or 1428 : 59 : ForgetDatabaseSyncRequests(Oid dbid)
1429 : : {
1430 : : FileTag tag;
1431 : : RelFileLocator rlocator;
1432 : :
648 rhaas@postgresql.org 1433 : 59 : rlocator.dbOid = dbid;
1434 : 59 : rlocator.spcOid = 0;
1435 : 59 : rlocator.relNumber = 0;
1436 : :
1437 : 59 : INIT_MD_FILETAG(tag, rlocator, InvalidForkNumber, InvalidBlockNumber);
1438 : :
1837 tmunro@postgresql.or 1439 : 59 : RegisterSyncRequest(&tag, SYNC_FILTER_REQUEST, true /* retryOnError */ );
8569 vadim4o@yahoo.com 1440 : 59 : }
1441 : :
1442 : : /*
1443 : : * DropRelationFiles -- drop files of all given relations
1444 : : */
1445 : : void
648 rhaas@postgresql.org 1446 : 2493 : DropRelationFiles(RelFileLocator *delrels, int ndelrels, bool isRedo)
1447 : : {
1448 : : SMgrRelation *srels;
1449 : : int i;
1450 : :
2110 fujii@postgresql.org 1451 : 2493 : srels = palloc(sizeof(SMgrRelation) * ndelrels);
1452 [ + + ]: 9524 : for (i = 0; i < ndelrels; i++)
1453 : : {
42 heikki.linnakangas@i 1454 :GNC 7031 : SMgrRelation srel = smgropen(delrels[i], INVALID_PROC_NUMBER);
1455 : :
2110 fujii@postgresql.org 1456 [ + + ]:CBC 7031 : if (isRedo)
1457 : : {
1458 : : ForkNumber fork;
1459 : :
1460 [ + + ]: 35035 : for (fork = 0; fork <= MAX_FORKNUM; fork++)
1461 : 28028 : XLogDropRelation(delrels[i], fork);
1462 : : }
1463 : 7031 : srels[i] = srel;
1464 : : }
1465 : :
1466 : 2493 : smgrdounlinkall(srels, ndelrels, isRedo);
1467 : :
1845 tomas.vondra@postgre 1468 [ + + ]: 9524 : for (i = 0; i < ndelrels; i++)
2110 fujii@postgresql.org 1469 : 7031 : smgrclose(srels[i]);
1470 : 2493 : pfree(srels);
1471 : 2493 : }
1472 : :
1473 : :
1474 : : /*
1475 : : * _fdvec_resize() -- Resize the fork's open segments array
1476 : : */
1477 : : static void
2775 andres@anarazel.de 1478 : 1325023 : _fdvec_resize(SMgrRelation reln,
1479 : : ForkNumber forknum,
1480 : : int nseg)
1481 : : {
1482 [ + + ]: 1325023 : if (nseg == 0)
1483 : : {
1484 [ + - ]: 474238 : if (reln->md_num_open_segs[forknum] > 0)
1485 : : {
1486 : 474238 : pfree(reln->md_seg_fds[forknum]);
1487 : 474238 : reln->md_seg_fds[forknum] = NULL;
1488 : : }
1489 : : }
1490 [ + - ]: 850785 : else if (reln->md_num_open_segs[forknum] == 0)
1491 : : {
1492 : 850785 : reln->md_seg_fds[forknum] =
1493 : 850785 : MemoryContextAlloc(MdCxt, sizeof(MdfdVec) * nseg);
1494 : : }
1495 : : else
1496 : : {
1497 : : /*
1498 : : * It doesn't seem worthwhile complicating the code to amortize
1499 : : * repalloc() calls. Those are far faster than PathNameOpenFile() or
1500 : : * FileClose(), and the memory context internally will sometimes avoid
1501 : : * doing an actual reallocation.
1502 : : */
2775 andres@anarazel.de 1503 :UBC 0 : reln->md_seg_fds[forknum] =
1504 : 0 : repalloc(reln->md_seg_fds[forknum],
1505 : : sizeof(MdfdVec) * nseg);
1506 : : }
1507 : :
2775 andres@anarazel.de 1508 :CBC 1325023 : reln->md_num_open_segs[forknum] = nseg;
9824 vadim4o@yahoo.com 1509 : 1325023 : }
1510 : :
1511 : : /*
1512 : : * Return the filename for the specified segment of the relation. The
1513 : : * returned string is palloc'd.
1514 : : */
1515 : : static char *
5366 heikki.linnakangas@i 1516 : 22001 : _mdfd_segpath(SMgrRelation reln, ForkNumber forknum, BlockNumber segno)
1517 : : {
1518 : : char *path,
1519 : : *fullpath;
1520 : :
648 rhaas@postgresql.org 1521 : 22001 : path = relpath(reln->smgr_rlocator, forknum);
1522 : :
9716 bruce@momjian.us 1523 [ + - ]: 22001 : if (segno > 0)
1524 : : {
3751 peter_e@gmx.net 1525 : 22001 : fullpath = psprintf("%s.%u", path, segno);
8771 tgl@sss.pgh.pa.us 1526 : 22001 : pfree(path);
1527 : : }
1528 : : else
9716 bruce@momjian.us 1529 :UBC 0 : fullpath = path;
1530 : :
5366 heikki.linnakangas@i 1531 :CBC 22001 : return fullpath;
1532 : : }
1533 : :
1534 : : /*
1535 : : * Open the specified segment of the relation,
1536 : : * and make a MdfdVec object for it. Returns NULL on failure.
1537 : : */
1538 : : static MdfdVec *
1539 : 21989 : _mdfd_openseg(SMgrRelation reln, ForkNumber forknum, BlockNumber segno,
1540 : : int oflags)
1541 : : {
1542 : : MdfdVec *v;
1543 : : File fd;
1544 : : char *fullpath;
1545 : :
1546 : 21989 : fullpath = _mdfd_segpath(reln, forknum, segno);
1547 : :
1548 : : /* open the file */
372 tmunro@postgresql.or 1549 : 21989 : fd = PathNameOpenFile(fullpath, _mdfd_open_flags() | oflags);
1550 : :
8771 tgl@sss.pgh.pa.us 1551 : 21989 : pfree(fullpath);
1552 : :
9716 bruce@momjian.us 1553 [ + - ]: 21989 : if (fd < 0)
7403 neilc@samurai.com 1554 : 21989 : return NULL;
1555 : :
1556 : : /*
1557 : : * Segments are always opened in order from lowest to highest, so we must
1558 : : * be adding a new one at the end.
1559 : : */
1539 tmunro@postgresql.or 1560 [ # # ]:UBC 0 : Assert(segno == reln->md_num_open_segs[forknum]);
1561 : :
1562 : 0 : _fdvec_resize(reln, forknum, segno + 1);
1563 : :
1564 : : /* fill the entry */
2775 andres@anarazel.de 1565 : 0 : v = &reln->md_seg_fds[forknum][segno];
9716 bruce@momjian.us 1566 : 0 : v->mdfd_vfd = fd;
7258 tgl@sss.pgh.pa.us 1567 : 0 : v->mdfd_segno = segno;
1568 : :
5725 heikki.linnakangas@i 1569 [ # # ]: 0 : Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
1570 : :
1571 : : /* all done */
9357 bruce@momjian.us 1572 : 0 : return v;
1573 : : }
1574 : :
1575 : : /*
1576 : : * _mdfd_getseg() -- Find the segment of the relation holding the
1577 : : * specified block.
1578 : : *
1579 : : * If the segment doesn't exist, we ereport, return NULL, or create the
1580 : : * segment, according to "behavior". Note: skipFsync is only used in the
1581 : : * EXTENSION_CREATE case.
1582 : : */
1583 : : static MdfdVec *
5725 heikki.linnakangas@i 1584 :CBC 2162318 : _mdfd_getseg(SMgrRelation reln, ForkNumber forknum, BlockNumber blkno,
1585 : : bool skipFsync, int behavior)
1586 : : {
1587 : : MdfdVec *v;
1588 : : BlockNumber targetseg;
1589 : : BlockNumber nextsegno;
1590 : :
1591 : : /* some way to handle non-existent segments needs to be specified */
2902 andres@anarazel.de 1592 [ - + ]: 2162318 : Assert(behavior &
1593 : : (EXTENSION_FAIL | EXTENSION_CREATE | EXTENSION_RETURN_NULL |
1594 : : EXTENSION_DONT_OPEN));
1595 : :
6311 tgl@sss.pgh.pa.us 1596 : 2162318 : targetseg = blkno / ((BlockNumber) RELSEG_SIZE);
1597 : :
1598 : : /* if an existing and opened segment, we're done */
2775 andres@anarazel.de 1599 [ + + ]: 2162318 : if (targetseg < reln->md_num_open_segs[forknum])
1600 : : {
1601 : 1978445 : v = &reln->md_seg_fds[forknum][targetseg];
1602 : 1978445 : return v;
1603 : : }
1604 : :
1605 : : /* The caller only wants the segment if we already had it open. */
708 tmunro@postgresql.or 1606 [ + + ]: 183873 : if (behavior & EXTENSION_DONT_OPEN)
1607 : 468 : return NULL;
1608 : :
1609 : : /*
1610 : : * The target segment is not yet open. Iterate over all the segments
1611 : : * between the last opened and the target segment. This way missing
1612 : : * segments either raise an error, or get created (according to
1613 : : * 'behavior'). Start with either the last opened, or the first segment if
1614 : : * none was opened before.
1615 : : */
2775 andres@anarazel.de 1616 [ + + ]: 183405 : if (reln->md_num_open_segs[forknum] > 0)
1617 : 12 : v = &reln->md_seg_fds[forknum][reln->md_num_open_segs[forknum] - 1];
1618 : : else
1619 : : {
1733 tmunro@postgresql.or 1620 : 183393 : v = mdopenfork(reln, forknum, behavior);
2775 andres@anarazel.de 1621 [ - + ]: 183390 : if (!v)
2775 andres@anarazel.de 1622 :UBC 0 : return NULL; /* if behavior & EXTENSION_RETURN_NULL */
1623 : : }
1624 : :
2775 andres@anarazel.de 1625 :CBC 183402 : for (nextsegno = reln->md_num_open_segs[forknum];
1626 [ + + ]: 183402 : nextsegno <= targetseg; nextsegno++)
1627 : : {
1628 : 12 : BlockNumber nblocks = _mdnblocks(reln, forknum, v);
1629 : 12 : int flags = 0;
1630 : :
1631 [ - + ]: 12 : Assert(nextsegno == v->mdfd_segno + 1);
1632 : :
1633 [ - + ]: 12 : if (nblocks > ((BlockNumber) RELSEG_SIZE))
2775 andres@anarazel.de 1634 [ # # ]:UBC 0 : elog(FATAL, "segment too big");
1635 : :
2775 andres@anarazel.de 1636 [ + - ]:CBC 12 : if ((behavior & EXTENSION_CREATE) ||
1637 [ - + - - ]: 12 : (InRecovery && (behavior & EXTENSION_CREATE_RECOVERY)))
1638 : : {
1639 : : /*
1640 : : * Normally we will create new segments only if authorized by the
1641 : : * caller (i.e., we are doing mdextend()). But when doing WAL
1642 : : * recovery, create segments anyway; this allows cases such as
1643 : : * replaying WAL data that has a write into a high-numbered
1644 : : * segment of a relation that was later deleted. We want to go
1645 : : * ahead and create the segments so we can finish out the replay.
1646 : : *
1647 : : * We have to maintain the invariant that segments before the last
1648 : : * active segment are of size RELSEG_SIZE; therefore, if
1649 : : * extending, pad them out with zeroes if needed. (This only
1650 : : * matters if in recovery, or if the caller is extending the
1651 : : * relation discontiguously, but that can happen in hash indexes.)
1652 : : */
2775 andres@anarazel.de 1653 [ # # ]:UBC 0 : if (nblocks < ((BlockNumber) RELSEG_SIZE))
1654 : : {
372 tmunro@postgresql.or 1655 : 0 : char *zerobuf = palloc_aligned(BLCKSZ, PG_IO_ALIGN_SIZE,
1656 : : MCXT_ALLOC_ZERO);
1657 : :
2775 andres@anarazel.de 1658 : 0 : mdextend(reln, forknum,
1659 : 0 : nextsegno * ((BlockNumber) RELSEG_SIZE) - 1,
1660 : : zerobuf, skipFsync);
1661 : 0 : pfree(zerobuf);
1662 : : }
1663 : 0 : flags = O_CREAT;
1664 : : }
2775 andres@anarazel.de 1665 [ + - + - ]:CBC 12 : else if (!(behavior & EXTENSION_DONT_CHECK_SIZE) &&
1666 : : nblocks < ((BlockNumber) RELSEG_SIZE))
1667 : : {
1668 : : /*
1669 : : * When not extending (or explicitly including truncated
1670 : : * segments), only open the next segment if the current one is
1671 : : * exactly RELSEG_SIZE. If not (this branch), either return NULL
1672 : : * or fail.
1673 : : */
1674 [ - + ]: 12 : if (behavior & EXTENSION_RETURN_NULL)
1675 : : {
1676 : : /*
1677 : : * Some callers discern between reasons for _mdfd_getseg()
1678 : : * returning NULL based on errno. As there's no failing
1679 : : * syscall involved in this case, explicitly set errno to
1680 : : * ENOENT, as that seems the closest interpretation.
1681 : : */
2775 andres@anarazel.de 1682 :UBC 0 : errno = ENOENT;
1683 : 0 : return NULL;
1684 : : }
1685 : :
2775 andres@anarazel.de 1686 [ + - ]:CBC 12 : ereport(ERROR,
1687 : : (errcode_for_file_access(),
1688 : : errmsg("could not open file \"%s\" (target block %u): previous segment is only %u blocks",
1689 : : _mdfd_segpath(reln, forknum, nextsegno),
1690 : : blkno, nblocks)));
1691 : : }
1692 : :
2775 andres@anarazel.de 1693 :UBC 0 : v = _mdfd_openseg(reln, forknum, nextsegno, flags);
1694 : :
1695 [ # # ]: 0 : if (v == NULL)
1696 : : {
1697 [ # # ]: 0 : if ((behavior & EXTENSION_RETURN_NULL) &&
1698 [ # # ]: 0 : FILE_POSSIBLY_DELETED(errno))
1699 : 0 : return NULL;
1700 [ # # ]: 0 : ereport(ERROR,
1701 : : (errcode_for_file_access(),
1702 : : errmsg("could not open file \"%s\" (target block %u): %m",
1703 : : _mdfd_segpath(reln, forknum, nextsegno),
1704 : : blkno)));
1705 : : }
1706 : : }
1707 : :
9357 bruce@momjian.us 1708 :CBC 183390 : return v;
1709 : : }
1710 : :
1711 : : /*
1712 : : * Get number of blocks present in a single disk file
1713 : : */
1714 : : static BlockNumber
5725 heikki.linnakangas@i 1715 : 2946042 : _mdnblocks(SMgrRelation reln, ForkNumber forknum, MdfdVec *seg)
1716 : : {
1717 : : off_t len;
1718 : :
1985 tmunro@postgresql.or 1719 : 2946042 : len = FileSize(seg->mdfd_vfd);
8768 bruce@momjian.us 1720 [ - + ]: 2946042 : if (len < 0)
6311 tgl@sss.pgh.pa.us 1721 [ # # ]:UBC 0 : ereport(ERROR,
1722 : : (errcode_for_file_access(),
1723 : : errmsg("could not seek to end of file \"%s\": %m",
1724 : : FilePathName(seg->mdfd_vfd))));
1725 : : /* note that this calculation will ignore any partial block at EOF */
6311 tgl@sss.pgh.pa.us 1726 :CBC 2946042 : return (BlockNumber) (len / BLCKSZ);
1727 : : }
1728 : :
1729 : : /*
1730 : : * Sync a file to disk, given a file tag. Write the path into an output
1731 : : * buffer so the caller can use it in error messages.
1732 : : *
1733 : : * Return 0 on success, -1 on failure, with errno set.
1734 : : */
1735 : : int
1837 tmunro@postgresql.or 1736 :UBC 0 : mdsyncfiletag(const FileTag *ftag, char *path)
1737 : : {
42 heikki.linnakangas@i 1738 :UNC 0 : SMgrRelation reln = smgropen(ftag->rlocator, INVALID_PROC_NUMBER);
1739 : : File file;
1740 : : instr_time io_start;
1741 : : bool need_to_close;
1742 : : int result,
1743 : : save_errno;
1744 : :
1745 : : /* See if we already have the file open, or need to open it. */
1583 tmunro@postgresql.or 1746 [ # # ]:UBC 0 : if (ftag->segno < reln->md_num_open_segs[ftag->forknum])
1747 : : {
1748 : 0 : file = reln->md_seg_fds[ftag->forknum][ftag->segno].mdfd_vfd;
1749 : 0 : strlcpy(path, FilePathName(file), MAXPGPATH);
1750 : 0 : need_to_close = false;
1751 : : }
1752 : : else
1753 : : {
1754 : : char *p;
1755 : :
1756 : 0 : p = _mdfd_segpath(reln, ftag->forknum, ftag->segno);
1757 : 0 : strlcpy(path, p, MAXPGPATH);
1758 : 0 : pfree(p);
1759 : :
372 1760 : 0 : file = PathNameOpenFile(path, _mdfd_open_flags());
1583 1761 [ # # ]: 0 : if (file < 0)
1762 : 0 : return -1;
1763 : 0 : need_to_close = true;
1764 : : }
1765 : :
120 michael@paquier.xyz 1766 :UNC 0 : io_start = pgstat_prepare_io_time(track_io_timing);
1767 : :
1768 : : /* Sync the file. */
1583 tmunro@postgresql.or 1769 :UBC 0 : result = FileSync(file, WAIT_EVENT_DATA_FILE_SYNC);
1770 : 0 : save_errno = errno;
1771 : :
1772 [ # # ]: 0 : if (need_to_close)
1773 : 0 : FileClose(file);
1774 : :
373 andres@anarazel.de 1775 : 0 : pgstat_count_io_op_time(IOOBJECT_RELATION, IOCONTEXT_NORMAL,
1776 : : IOOP_FSYNC, io_start, 1);
1777 : :
1583 tmunro@postgresql.or 1778 : 0 : errno = save_errno;
1779 : 0 : return result;
1780 : : }
1781 : :
1782 : : /*
1783 : : * Unlink a file, given a file tag. Write the path into an output
1784 : : * buffer so the caller can use it in error messages.
1785 : : *
1786 : : * Return 0 on success, -1 on failure, with errno set.
1787 : : */
1788 : : int
1837 tmunro@postgresql.or 1789 :CBC 30677 : mdunlinkfiletag(const FileTag *ftag, char *path)
1790 : : {
1791 : : char *p;
1792 : :
1793 : : /* Compute the path. */
648 rhaas@postgresql.org 1794 : 30677 : p = relpathperm(ftag->rlocator, MAIN_FORKNUM);
1837 tmunro@postgresql.or 1795 : 30677 : strlcpy(path, p, MAXPGPATH);
1796 : 30677 : pfree(p);
1797 : :
1798 : : /* Try to unlink the file. */
1799 : 30677 : return unlink(path);
1800 : : }
1801 : :
1802 : : /*
1803 : : * Check if a given candidate request matches a given tag, when processing
1804 : : * a SYNC_FILTER_REQUEST request. This will be called for all pending
1805 : : * requests to find out whether to forget them.
1806 : : */
1807 : : bool
1808 : 19329 : mdfiletagmatches(const FileTag *ftag, const FileTag *candidate)
1809 : : {
1810 : : /*
1811 : : * For now we only use filter requests as a way to drop all scheduled
1812 : : * callbacks relating to a given database, when dropping the database.
1813 : : * We'll return true for all candidates that have the same database OID as
1814 : : * the ftag from the SYNC_FILTER_REQUEST request, so they're forgotten.
1815 : : */
648 rhaas@postgresql.org 1816 : 19329 : return ftag->rlocator.dbOid == candidate->rlocator.dbOid;
1817 : : }
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