PostgreSQL Source Code  git master
freespace.c File Reference
#include "postgres.h"
#include "access/htup_details.h"
#include "access/xlogutils.h"
#include "miscadmin.h"
#include "storage/freespace.h"
#include "storage/fsm_internals.h"
#include "storage/lmgr.h"
#include "storage/smgr.h"
Include dependency graph for freespace.c:

Go to the source code of this file.

Data Structures

struct  FSMAddress
 

Macros

#define FSM_CATEGORIES   256
 
#define FSM_CAT_STEP   (BLCKSZ / FSM_CATEGORIES)
 
#define MaxFSMRequestSize   MaxHeapTupleSize
 
#define FSM_TREE_DEPTH   ((SlotsPerFSMPage >= 1626) ? 3 : 4)
 
#define FSM_ROOT_LEVEL   (FSM_TREE_DEPTH - 1)
 
#define FSM_BOTTOM_LEVEL   0
 

Functions

static FSMAddress fsm_get_child (FSMAddress parent, uint16 slot)
 
static FSMAddress fsm_get_parent (FSMAddress child, uint16 *slot)
 
static FSMAddress fsm_get_location (BlockNumber heapblk, uint16 *slot)
 
static BlockNumber fsm_get_heap_blk (FSMAddress addr, uint16 slot)
 
static BlockNumber fsm_logical_to_physical (FSMAddress addr)
 
static Buffer fsm_readbuf (Relation rel, FSMAddress addr, bool extend)
 
static void fsm_extend (Relation rel, BlockNumber fsm_nblocks)
 
static uint8 fsm_space_avail_to_cat (Size avail)
 
static uint8 fsm_space_needed_to_cat (Size needed)
 
static Size fsm_space_cat_to_avail (uint8 cat)
 
static int fsm_set_and_search (Relation rel, FSMAddress addr, uint16 slot, uint8 newValue, uint8 minValue)
 
static BlockNumber fsm_search (Relation rel, uint8 min_cat)
 
static uint8 fsm_vacuum_page (Relation rel, FSMAddress addr, BlockNumber start, BlockNumber end, bool *eof)
 
BlockNumber GetPageWithFreeSpace (Relation rel, Size spaceNeeded)
 
BlockNumber RecordAndGetPageWithFreeSpace (Relation rel, BlockNumber oldPage, Size oldSpaceAvail, Size spaceNeeded)
 
void RecordPageWithFreeSpace (Relation rel, BlockNumber heapBlk, Size spaceAvail)
 
void XLogRecordPageWithFreeSpace (RelFileNode rnode, BlockNumber heapBlk, Size spaceAvail)
 
Size GetRecordedFreeSpace (Relation rel, BlockNumber heapBlk)
 
BlockNumber FreeSpaceMapPrepareTruncateRel (Relation rel, BlockNumber nblocks)
 
void FreeSpaceMapVacuum (Relation rel)
 
void FreeSpaceMapVacuumRange (Relation rel, BlockNumber start, BlockNumber end)
 

Variables

static const FSMAddress FSM_ROOT_ADDRESS = {FSM_ROOT_LEVEL, 0}
 

Macro Definition Documentation

◆ FSM_BOTTOM_LEVEL

#define FSM_BOTTOM_LEVEL   0

◆ FSM_CAT_STEP

#define FSM_CAT_STEP   (BLCKSZ / FSM_CATEGORIES)

◆ FSM_CATEGORIES

#define FSM_CATEGORIES   256

Definition at line 63 of file freespace.c.

◆ FSM_ROOT_LEVEL

#define FSM_ROOT_LEVEL   (FSM_TREE_DEPTH - 1)

Definition at line 76 of file freespace.c.

Referenced by fsm_get_parent(), and fsm_search().

◆ FSM_TREE_DEPTH

#define FSM_TREE_DEPTH   ((SlotsPerFSMPage >= 1626) ? 3 : 4)

Definition at line 74 of file freespace.c.

Referenced by fsm_logical_to_physical().

◆ MaxFSMRequestSize

#define MaxFSMRequestSize   MaxHeapTupleSize

Function Documentation

◆ FreeSpaceMapPrepareTruncateRel()

BlockNumber FreeSpaceMapPrepareTruncateRel ( Relation  rel,
BlockNumber  nblocks 
)

Definition at line 261 of file freespace.c.

References buf, BUFFER_LOCK_EXCLUSIVE, BufferGetPage, BufferIsValid, END_CRIT_SECTION, FSM_FORKNUM, fsm_get_location(), fsm_logical_to_physical(), fsm_readbuf(), fsm_truncate_avail(), InRecovery, InvalidBlockNumber, LockBuffer(), log_newpage_buffer(), MarkBufferDirty(), RelationData::rd_smgr, RelationNeedsWAL, RelationOpenSmgr, smgrexists(), smgrnblocks(), START_CRIT_SECTION, UnlockReleaseBuffer(), and XLogHintBitIsNeeded.

Referenced by RelationTruncate(), and smgr_redo().

262 {
263  BlockNumber new_nfsmblocks;
264  FSMAddress first_removed_address;
265  uint16 first_removed_slot;
266  Buffer buf;
267 
268  RelationOpenSmgr(rel);
269 
270  /*
271  * If no FSM has been created yet for this relation, there's nothing to
272  * truncate.
273  */
274  if (!smgrexists(rel->rd_smgr, FSM_FORKNUM))
275  return InvalidBlockNumber;
276 
277  /* Get the location in the FSM of the first removed heap block */
278  first_removed_address = fsm_get_location(nblocks, &first_removed_slot);
279 
280  /*
281  * Zero out the tail of the last remaining FSM page. If the slot
282  * representing the first removed heap block is at a page boundary, as the
283  * first slot on the FSM page that first_removed_address points to, we can
284  * just truncate that page altogether.
285  */
286  if (first_removed_slot > 0)
287  {
288  buf = fsm_readbuf(rel, first_removed_address, false);
289  if (!BufferIsValid(buf))
290  return InvalidBlockNumber; /* nothing to do; the FSM was already smaller */
292 
293  /* NO EREPORT(ERROR) from here till changes are logged */
295 
296  fsm_truncate_avail(BufferGetPage(buf), first_removed_slot);
297 
298  /*
299  * Truncation of a relation is WAL-logged at a higher-level, and we
300  * will be called at WAL replay. But if checksums are enabled, we need
301  * to still write a WAL record to protect against a torn page, if the
302  * page is flushed to disk before the truncation WAL record. We cannot
303  * use MarkBufferDirtyHint here, because that will not dirty the page
304  * during recovery.
305  */
306  MarkBufferDirty(buf);
308  log_newpage_buffer(buf, false);
309 
311 
312  UnlockReleaseBuffer(buf);
313 
314  new_nfsmblocks = fsm_logical_to_physical(first_removed_address) + 1;
315  }
316  else
317  {
318  new_nfsmblocks = fsm_logical_to_physical(first_removed_address);
319  if (smgrnblocks(rel->rd_smgr, FSM_FORKNUM) <= new_nfsmblocks)
320  return InvalidBlockNumber; /* nothing to do; the FSM was already smaller */
321  }
322 
323  return new_nfsmblocks;
324 }
bool fsm_truncate_avail(Page page, int nslots)
Definition: fsmpage.c:313
XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std)
Definition: xloginsert.c:1009
void MarkBufferDirty(Buffer buffer)
Definition: bufmgr.c:1458
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
bool InRecovery
Definition: xlog.c:200
#define END_CRIT_SECTION()
Definition: miscadmin.h:134
#define START_CRIT_SECTION()
Definition: miscadmin.h:132
uint32 BlockNumber
Definition: block.h:31
bool smgrexists(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:247
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
#define RelationOpenSmgr(relation)
Definition: rel.h:476
unsigned short uint16
Definition: c.h:357
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3388
static char * buf
Definition: pg_test_fsync.c:68
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:466
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:555
#define InvalidBlockNumber
Definition: block.h:33
static BlockNumber fsm_logical_to_physical(FSMAddress addr)
Definition: freespace.c:430
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define RelationNeedsWAL(relation)
Definition: rel.h:521
static Buffer fsm_readbuf(Relation rel, FSMAddress addr, bool extend)
Definition: freespace.c:529
int Buffer
Definition: buf.h:23
#define XLogHintBitIsNeeded()
Definition: xlog.h:192

◆ FreeSpaceMapVacuum()

void FreeSpaceMapVacuum ( Relation  rel)

Definition at line 333 of file freespace.c.

References fsm_vacuum_page(), and InvalidBlockNumber.

Referenced by brin_vacuum_scan(), and IndexFreeSpaceMapVacuum().

334 {
335  bool dummy;
336 
337  /* Recursively scan the tree, starting at the root */
338  (void) fsm_vacuum_page(rel, FSM_ROOT_ADDRESS,
340  &dummy);
341 }
uint32 BlockNumber
Definition: block.h:31
static uint8 fsm_vacuum_page(Relation rel, FSMAddress addr, BlockNumber start, BlockNumber end, bool *eof)
Definition: freespace.c:785
static const FSMAddress FSM_ROOT_ADDRESS
Definition: freespace.c:90
#define InvalidBlockNumber
Definition: block.h:33

◆ FreeSpaceMapVacuumRange()

void FreeSpaceMapVacuumRange ( Relation  rel,
BlockNumber  start,
BlockNumber  end 
)

Definition at line 352 of file freespace.c.

References fsm_vacuum_page().

Referenced by brin_doinsert(), brin_doupdate(), brin_getinsertbuffer(), lazy_scan_heap(), RelationAddExtraBlocks(), RelationTruncate(), smgr_redo(), and terminate_brin_buildstate().

353 {
354  bool dummy;
355 
356  /* Recursively scan the tree, starting at the root */
357  if (end > start)
358  (void) fsm_vacuum_page(rel, FSM_ROOT_ADDRESS, start, end, &dummy);
359 }
static uint8 fsm_vacuum_page(Relation rel, FSMAddress addr, BlockNumber start, BlockNumber end, bool *eof)
Definition: freespace.c:785
static const FSMAddress FSM_ROOT_ADDRESS
Definition: freespace.c:90

◆ fsm_extend()

static void fsm_extend ( Relation  rel,
BlockNumber  fsm_nblocks 
)
static

Definition at line 599 of file freespace.c.

References PGAlignedBlock::data, ExclusiveLock, FSM_FORKNUM, InvalidBlockNumber, LockRelationForExtension(), PageInit(), PageSetChecksumInplace(), RelationData::rd_smgr, RelationOpenSmgr, SMgrRelationData::smgr_fsm_nblocks, smgrcreate(), smgrexists(), smgrextend(), smgrnblocks(), and UnlockRelationForExtension().

Referenced by fsm_readbuf().

600 {
601  BlockNumber fsm_nblocks_now;
602  PGAlignedBlock pg;
603 
604  PageInit((Page) pg.data, BLCKSZ, 0);
605 
606  /*
607  * We use the relation extension lock to lock out other backends trying to
608  * extend the FSM at the same time. It also locks out extension of the
609  * main fork, unnecessarily, but extending the FSM happens seldom enough
610  * that it doesn't seem worthwhile to have a separate lock tag type for
611  * it.
612  *
613  * Note that another backend might have extended or created the relation
614  * by the time we get the lock.
615  */
617 
618  /* Might have to re-open if a cache flush happened */
619  RelationOpenSmgr(rel);
620 
621  /*
622  * Create the FSM file first if it doesn't exist. If smgr_fsm_nblocks is
623  * positive then it must exist, no need for an smgrexists call.
624  */
625  if ((rel->rd_smgr->smgr_fsm_nblocks == 0 ||
628  smgrcreate(rel->rd_smgr, FSM_FORKNUM, false);
629 
630  fsm_nblocks_now = smgrnblocks(rel->rd_smgr, FSM_FORKNUM);
631 
632  while (fsm_nblocks_now < fsm_nblocks)
633  {
634  PageSetChecksumInplace((Page) pg.data, fsm_nblocks_now);
635 
636  smgrextend(rel->rd_smgr, FSM_FORKNUM, fsm_nblocks_now,
637  pg.data, false);
638  fsm_nblocks_now++;
639  }
640 
641  /* Update local cache with the up-to-date size */
642  rel->rd_smgr->smgr_fsm_nblocks = fsm_nblocks_now;
643 
645 }
void smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
Definition: smgr.c:333
#define ExclusiveLock
Definition: lockdefs.h:44
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
uint32 BlockNumber
Definition: block.h:31
BlockNumber smgr_fsm_nblocks
Definition: smgr.h:55
bool smgrexists(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:247
#define RelationOpenSmgr(relation)
Definition: rel.h:476
char data[BLCKSZ]
Definition: c.h:1060
void LockRelationForExtension(Relation relation, LOCKMODE lockmode)
Definition: lmgr.c:402
void UnlockRelationForExtension(Relation relation, LOCKMODE lockmode)
Definition: lmgr.c:452
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:555
#define InvalidBlockNumber
Definition: block.h:33
void PageSetChecksumInplace(Page page, BlockNumber blkno)
Definition: bufpage.c:1198
void smgrextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, char *buffer, bool skipFsync)
Definition: smgr.c:483
Pointer Page
Definition: bufpage.h:78
void PageInit(Page page, Size pageSize, Size specialSize)
Definition: bufpage.c:42

◆ fsm_get_child()

static FSMAddress fsm_get_child ( FSMAddress  parent,
uint16  slot 
)
static

Definition at line 510 of file freespace.c.

References Assert, FSM_BOTTOM_LEVEL, FSMAddress::level, FSMAddress::logpageno, and SlotsPerFSMPage.

Referenced by fsm_search(), and fsm_vacuum_page().

511 {
512  FSMAddress child;
513 
514  Assert(parent.level > FSM_BOTTOM_LEVEL);
515 
516  child.level = parent.level - 1;
517  child.logpageno = parent.logpageno * SlotsPerFSMPage + slot;
518 
519  return child;
520 }
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
int logpageno
Definition: freespace.c:86
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:77
int level
Definition: freespace.c:85
#define Assert(condition)
Definition: c.h:732

◆ fsm_get_heap_blk()

static BlockNumber fsm_get_heap_blk ( FSMAddress  addr,
uint16  slot 
)
static

Definition at line 481 of file freespace.c.

References Assert, FSM_BOTTOM_LEVEL, FSMAddress::level, FSMAddress::logpageno, and SlotsPerFSMPage.

Referenced by fsm_search(), and RecordAndGetPageWithFreeSpace().

482 {
483  Assert(addr.level == FSM_BOTTOM_LEVEL);
484  return ((unsigned int) addr.logpageno) * SlotsPerFSMPage + slot;
485 }
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
int logpageno
Definition: freespace.c:86
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:77
int level
Definition: freespace.c:85
#define Assert(condition)
Definition: c.h:732

◆ fsm_get_location()

static FSMAddress fsm_get_location ( BlockNumber  heapblk,
uint16 slot 
)
static

Definition at line 466 of file freespace.c.

References FSM_BOTTOM_LEVEL, FSMAddress::level, FSMAddress::logpageno, and SlotsPerFSMPage.

Referenced by FreeSpaceMapPrepareTruncateRel(), fsm_vacuum_page(), GetRecordedFreeSpace(), RecordAndGetPageWithFreeSpace(), RecordPageWithFreeSpace(), and XLogRecordPageWithFreeSpace().

467 {
468  FSMAddress addr;
469 
470  addr.level = FSM_BOTTOM_LEVEL;
471  addr.logpageno = heapblk / SlotsPerFSMPage;
472  *slot = heapblk % SlotsPerFSMPage;
473 
474  return addr;
475 }
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
int logpageno
Definition: freespace.c:86
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:77
int level
Definition: freespace.c:85

◆ fsm_get_parent()

static FSMAddress fsm_get_parent ( FSMAddress  child,
uint16 slot 
)
static

Definition at line 492 of file freespace.c.

References Assert, FSM_ROOT_LEVEL, FSMAddress::level, FSMAddress::logpageno, and SlotsPerFSMPage.

Referenced by fsm_search(), and fsm_vacuum_page().

493 {
494  FSMAddress parent;
495 
496  Assert(child.level < FSM_ROOT_LEVEL);
497 
498  parent.level = child.level + 1;
499  parent.logpageno = child.logpageno / SlotsPerFSMPage;
500  *slot = child.logpageno % SlotsPerFSMPage;
501 
502  return parent;
503 }
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
int logpageno
Definition: freespace.c:86
#define FSM_ROOT_LEVEL
Definition: freespace.c:76
int level
Definition: freespace.c:85
#define Assert(condition)
Definition: c.h:732

◆ fsm_logical_to_physical()

static BlockNumber fsm_logical_to_physical ( FSMAddress  addr)
static

Definition at line 430 of file freespace.c.

References FSM_TREE_DEPTH, FSMAddress::level, FSMAddress::logpageno, and SlotsPerFSMPage.

Referenced by FreeSpaceMapPrepareTruncateRel(), fsm_readbuf(), and XLogRecordPageWithFreeSpace().

431 {
432  BlockNumber pages;
433  int leafno;
434  int l;
435 
436  /*
437  * Calculate the logical page number of the first leaf page below the
438  * given page.
439  */
440  leafno = addr.logpageno;
441  for (l = 0; l < addr.level; l++)
442  leafno *= SlotsPerFSMPage;
443 
444  /* Count upper level nodes required to address the leaf page */
445  pages = 0;
446  for (l = 0; l < FSM_TREE_DEPTH; l++)
447  {
448  pages += leafno + 1;
449  leafno /= SlotsPerFSMPage;
450  }
451 
452  /*
453  * If the page we were asked for wasn't at the bottom level, subtract the
454  * additional lower level pages we counted above.
455  */
456  pages -= addr.level;
457 
458  /* Turn the page count into 0-based block number */
459  return pages - 1;
460 }
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
int logpageno
Definition: freespace.c:86
uint32 BlockNumber
Definition: block.h:31
int level
Definition: freespace.c:85
#define FSM_TREE_DEPTH
Definition: freespace.c:74

◆ fsm_readbuf()

static Buffer fsm_readbuf ( Relation  rel,
FSMAddress  addr,
bool  extend 
)
static

Definition at line 529 of file freespace.c.

References buf, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferGetPage, fsm_extend(), FSM_FORKNUM, fsm_logical_to_physical(), InvalidBlockNumber, InvalidBuffer, LockBuffer(), PageInit(), PageIsNew, RBM_ZERO_ON_ERROR, RelationData::rd_smgr, ReadBufferExtended(), RelationOpenSmgr, SMgrRelationData::smgr_fsm_nblocks, smgrexists(), and smgrnblocks().

Referenced by FreeSpaceMapPrepareTruncateRel(), fsm_search(), fsm_set_and_search(), fsm_vacuum_page(), and GetRecordedFreeSpace().

530 {
531  BlockNumber blkno = fsm_logical_to_physical(addr);
532  Buffer buf;
533 
534  RelationOpenSmgr(rel);
535 
536  /*
537  * If we haven't cached the size of the FSM yet, check it first. Also
538  * recheck if the requested block seems to be past end, since our cached
539  * value might be stale. (We send smgr inval messages on truncation, but
540  * not on extension.)
541  */
543  blkno >= rel->rd_smgr->smgr_fsm_nblocks)
544  {
545  if (smgrexists(rel->rd_smgr, FSM_FORKNUM))
547  FSM_FORKNUM);
548  else
549  rel->rd_smgr->smgr_fsm_nblocks = 0;
550  }
551 
552  /* Handle requests beyond EOF */
553  if (blkno >= rel->rd_smgr->smgr_fsm_nblocks)
554  {
555  if (extend)
556  fsm_extend(rel, blkno + 1);
557  else
558  return InvalidBuffer;
559  }
560 
561  /*
562  * Use ZERO_ON_ERROR mode, and initialize the page if necessary. The FSM
563  * information is not accurate anyway, so it's better to clear corrupt
564  * pages than error out. Since the FSM changes are not WAL-logged, the
565  * so-called torn page problem on crash can lead to pages with corrupt
566  * headers, for example.
567  *
568  * The initialize-the-page part is trickier than it looks, because of the
569  * possibility of multiple backends doing this concurrently, and our
570  * desire to not uselessly take the buffer lock in the normal path where
571  * the page is OK. We must take the lock to initialize the page, so
572  * recheck page newness after we have the lock, in case someone else
573  * already did it. Also, because we initially check PageIsNew with no
574  * lock, it's possible to fall through and return the buffer while someone
575  * else is still initializing the page (i.e., we might see pd_upper as set
576  * but other page header fields are still zeroes). This is harmless for
577  * callers that will take a buffer lock themselves, but some callers
578  * inspect the page without any lock at all. The latter is OK only so
579  * long as it doesn't depend on the page header having correct contents.
580  * Current usage is safe because PageGetContents() does not require that.
581  */
582  buf = ReadBufferExtended(rel, FSM_FORKNUM, blkno, RBM_ZERO_ON_ERROR, NULL);
583  if (PageIsNew(BufferGetPage(buf)))
584  {
586  if (PageIsNew(BufferGetPage(buf)))
587  PageInit(BufferGetPage(buf), BLCKSZ, 0);
589  }
590  return buf;
591 }
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:86
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
Buffer ReadBufferExtended(Relation reln, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
Definition: bufmgr.c:642
#define InvalidBuffer
Definition: buf.h:25
uint32 BlockNumber
Definition: block.h:31
BlockNumber smgr_fsm_nblocks
Definition: smgr.h:55
bool smgrexists(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:247
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
#define RelationOpenSmgr(relation)
Definition: rel.h:476
static char * buf
Definition: pg_test_fsync.c:68
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
static void fsm_extend(Relation rel, BlockNumber fsm_nblocks)
Definition: freespace.c:599
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:555
#define InvalidBlockNumber
Definition: block.h:33
static BlockNumber fsm_logical_to_physical(FSMAddress addr)
Definition: freespace.c:430
#define PageIsNew(page)
Definition: bufpage.h:229
int Buffer
Definition: buf.h:23
void PageInit(Page page, Size pageSize, Size specialSize)
Definition: bufpage.c:42

◆ fsm_search()

static BlockNumber fsm_search ( Relation  rel,
uint8  min_cat 
)
static

Definition at line 687 of file freespace.c.

References buf, BUFFER_LOCK_SHARE, BufferGetPage, BufferIsValid, FSM_BOTTOM_LEVEL, fsm_get_child(), fsm_get_heap_blk(), fsm_get_max_avail(), fsm_get_parent(), fsm_readbuf(), FSM_ROOT_ADDRESS, FSM_ROOT_LEVEL, fsm_search_avail(), fsm_set_and_search(), InvalidBlockNumber, FSMAddress::level, LockBuffer(), and UnlockReleaseBuffer().

Referenced by GetPageWithFreeSpace(), and RecordAndGetPageWithFreeSpace().

688 {
689  int restarts = 0;
691 
692  for (;;)
693  {
694  int slot;
695  Buffer buf;
696  uint8 max_avail = 0;
697 
698  /* Read the FSM page. */
699  buf = fsm_readbuf(rel, addr, false);
700 
701  /* Search within the page */
702  if (BufferIsValid(buf))
703  {
705  slot = fsm_search_avail(buf, min_cat,
706  (addr.level == FSM_BOTTOM_LEVEL),
707  false);
708  if (slot == -1)
709  max_avail = fsm_get_max_avail(BufferGetPage(buf));
710  UnlockReleaseBuffer(buf);
711  }
712  else
713  slot = -1;
714 
715  if (slot != -1)
716  {
717  /*
718  * Descend the tree, or return the found block if we're at the
719  * bottom.
720  */
721  if (addr.level == FSM_BOTTOM_LEVEL)
722  return fsm_get_heap_blk(addr, slot);
723 
724  addr = fsm_get_child(addr, slot);
725  }
726  else if (addr.level == FSM_ROOT_LEVEL)
727  {
728  /*
729  * At the root, failure means there's no page with enough free
730  * space in the FSM. Give up.
731  */
732  return InvalidBlockNumber;
733  }
734  else
735  {
736  uint16 parentslot;
737  FSMAddress parent;
738 
739  /*
740  * At lower level, failure can happen if the value in the upper-
741  * level node didn't reflect the value on the lower page. Update
742  * the upper node, to avoid falling into the same trap again, and
743  * start over.
744  *
745  * There's a race condition here, if another backend updates this
746  * page right after we release it, and gets the lock on the parent
747  * page before us. We'll then update the parent page with the now
748  * stale information we had. It's OK, because it should happen
749  * rarely, and will be fixed by the next vacuum.
750  */
751  parent = fsm_get_parent(addr, &parentslot);
752  fsm_set_and_search(rel, parent, parentslot, max_avail, 0);
753 
754  /*
755  * If the upper pages are badly out of date, we might need to loop
756  * quite a few times, updating them as we go. Any inconsistencies
757  * should eventually be corrected and the loop should end. Looping
758  * indefinitely is nevertheless scary, so provide an emergency
759  * valve.
760  */
761  if (restarts++ > 10000)
762  return InvalidBlockNumber;
763 
764  /* Start search all over from the root */
765  addr = FSM_ROOT_ADDRESS;
766  }
767  }
768 }
uint8 fsm_get_max_avail(Page page)
Definition: fsmpage.c:138
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:77
static FSMAddress fsm_get_parent(FSMAddress child, uint16 *slot)
Definition: freespace.c:492
unsigned char uint8
Definition: c.h:356
static BlockNumber fsm_get_heap_blk(FSMAddress addr, uint16 slot)
Definition: freespace.c:481
static FSMAddress fsm_get_child(FSMAddress parent, uint16 slot)
Definition: freespace.c:510
static const FSMAddress FSM_ROOT_ADDRESS
Definition: freespace.c:90
unsigned short uint16
Definition: c.h:357
#define FSM_ROOT_LEVEL
Definition: freespace.c:76
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3388
int level
Definition: freespace.c:85
static char * buf
Definition: pg_test_fsync.c:68
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
static int fsm_set_and_search(Relation rel, FSMAddress addr, uint16 slot, uint8 newValue, uint8 minValue)
Definition: freespace.c:655
#define InvalidBlockNumber
Definition: block.h:33
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
static Buffer fsm_readbuf(Relation rel, FSMAddress addr, bool extend)
Definition: freespace.c:529
#define BUFFER_LOCK_SHARE
Definition: bufmgr.h:87
int Buffer
Definition: buf.h:23
int fsm_search_avail(Buffer buf, uint8 minvalue, bool advancenext, bool exclusive_lock_held)
Definition: fsmpage.c:158

◆ fsm_set_and_search()

static int fsm_set_and_search ( Relation  rel,
FSMAddress  addr,
uint16  slot,
uint8  newValue,
uint8  minValue 
)
static

Definition at line 655 of file freespace.c.

References buf, BUFFER_LOCK_EXCLUSIVE, BufferGetPage, FSM_BOTTOM_LEVEL, fsm_readbuf(), fsm_search_avail(), fsm_set_avail(), FSMAddress::level, LockBuffer(), MarkBufferDirtyHint(), and UnlockReleaseBuffer().

Referenced by fsm_search(), RecordAndGetPageWithFreeSpace(), and RecordPageWithFreeSpace().

657 {
658  Buffer buf;
659  Page page;
660  int newslot = -1;
661 
662  buf = fsm_readbuf(rel, addr, true);
664 
665  page = BufferGetPage(buf);
666 
667  if (fsm_set_avail(page, slot, newValue))
668  MarkBufferDirtyHint(buf, false);
669 
670  if (minValue != 0)
671  {
672  /* Search while we still hold the lock */
673  newslot = fsm_search_avail(buf, minValue,
674  addr.level == FSM_BOTTOM_LEVEL,
675  true);
676  }
677 
678  UnlockReleaseBuffer(buf);
679 
680  return newslot;
681 }
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:77
void MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
Definition: bufmgr.c:3435
bool fsm_set_avail(Page page, int slot, uint8 value)
Definition: fsmpage.c:63
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3388
int level
Definition: freespace.c:85
static char * buf
Definition: pg_test_fsync.c:68
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
static Buffer fsm_readbuf(Relation rel, FSMAddress addr, bool extend)
Definition: freespace.c:529
int Buffer
Definition: buf.h:23
Pointer Page
Definition: bufpage.h:78
int fsm_search_avail(Buffer buf, uint8 minvalue, bool advancenext, bool exclusive_lock_held)
Definition: fsmpage.c:158

◆ fsm_space_avail_to_cat()

static uint8 fsm_space_avail_to_cat ( Size  avail)
static

Definition at line 367 of file freespace.c.

References Assert, FSM_CAT_STEP, and MaxFSMRequestSize.

Referenced by RecordAndGetPageWithFreeSpace(), RecordPageWithFreeSpace(), and XLogRecordPageWithFreeSpace().

368 {
369  int cat;
370 
371  Assert(avail < BLCKSZ);
372 
373  if (avail >= MaxFSMRequestSize)
374  return 255;
375 
376  cat = avail / FSM_CAT_STEP;
377 
378  /*
379  * The highest category, 255, is reserved for MaxFSMRequestSize bytes or
380  * more.
381  */
382  if (cat > 254)
383  cat = 254;
384 
385  return (uint8) cat;
386 }
unsigned char uint8
Definition: c.h:356
#define FSM_CAT_STEP
Definition: freespace.c:64
#define Assert(condition)
Definition: c.h:732
#define MaxFSMRequestSize
Definition: freespace.c:65

◆ fsm_space_cat_to_avail()

static Size fsm_space_cat_to_avail ( uint8  cat)
static

Definition at line 393 of file freespace.c.

References FSM_CAT_STEP, and MaxFSMRequestSize.

Referenced by GetRecordedFreeSpace().

394 {
395  /* The highest category represents exactly MaxFSMRequestSize bytes. */
396  if (cat == 255)
397  return MaxFSMRequestSize;
398  else
399  return cat * FSM_CAT_STEP;
400 }
#define FSM_CAT_STEP
Definition: freespace.c:64
#define MaxFSMRequestSize
Definition: freespace.c:65

◆ fsm_space_needed_to_cat()

static uint8 fsm_space_needed_to_cat ( Size  needed)
static

Definition at line 407 of file freespace.c.

References elog, ERROR, FSM_CAT_STEP, and MaxFSMRequestSize.

Referenced by GetPageWithFreeSpace(), and RecordAndGetPageWithFreeSpace().

408 {
409  int cat;
410 
411  /* Can't ask for more space than the highest category represents */
412  if (needed > MaxFSMRequestSize)
413  elog(ERROR, "invalid FSM request size %zu", needed);
414 
415  if (needed == 0)
416  return 1;
417 
418  cat = (needed + FSM_CAT_STEP - 1) / FSM_CAT_STEP;
419 
420  if (cat > 255)
421  cat = 255;
422 
423  return (uint8) cat;
424 }
unsigned char uint8
Definition: c.h:356
#define FSM_CAT_STEP
Definition: freespace.c:64
#define ERROR
Definition: elog.h:43
#define elog(elevel,...)
Definition: elog.h:226
#define MaxFSMRequestSize
Definition: freespace.c:65

◆ fsm_vacuum_page()

static uint8 fsm_vacuum_page ( Relation  rel,
FSMAddress  addr,
BlockNumber  start,
BlockNumber  end,
bool eof 
)
static

Definition at line 785 of file freespace.c.

References Assert, buf, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferGetPage, BufferIsValid, CHECK_FOR_INTERRUPTS, FSM_BOTTOM_LEVEL, fsm_get_avail(), fsm_get_child(), fsm_get_location(), fsm_get_max_avail(), fsm_get_parent(), fsm_readbuf(), fsm_set_avail(), FSMAddress::level, LockBuffer(), FSMAddress::logpageno, MarkBufferDirtyHint(), PageGetContents, ReleaseBuffer(), and SlotsPerFSMPage.

Referenced by FreeSpaceMapVacuum(), and FreeSpaceMapVacuumRange().

788 {
789  Buffer buf;
790  Page page;
791  uint8 max_avail;
792 
793  /* Read the page if it exists, or return EOF */
794  buf = fsm_readbuf(rel, addr, false);
795  if (!BufferIsValid(buf))
796  {
797  *eof_p = true;
798  return 0;
799  }
800  else
801  *eof_p = false;
802 
803  page = BufferGetPage(buf);
804 
805  /*
806  * If we're above the bottom level, recurse into children, and fix the
807  * information stored about them at this level.
808  */
809  if (addr.level > FSM_BOTTOM_LEVEL)
810  {
811  FSMAddress fsm_start,
812  fsm_end;
813  uint16 fsm_start_slot,
814  fsm_end_slot;
815  int slot,
816  start_slot,
817  end_slot;
818  bool eof = false;
819 
820  /*
821  * Compute the range of slots we need to update on this page, given
822  * the requested range of heap blocks to consider. The first slot to
823  * update is the one covering the "start" block, and the last slot is
824  * the one covering "end - 1". (Some of this work will be duplicated
825  * in each recursive call, but it's cheap enough to not worry about.)
826  */
827  fsm_start = fsm_get_location(start, &fsm_start_slot);
828  fsm_end = fsm_get_location(end - 1, &fsm_end_slot);
829 
830  while (fsm_start.level < addr.level)
831  {
832  fsm_start = fsm_get_parent(fsm_start, &fsm_start_slot);
833  fsm_end = fsm_get_parent(fsm_end, &fsm_end_slot);
834  }
835  Assert(fsm_start.level == addr.level);
836 
837  if (fsm_start.logpageno == addr.logpageno)
838  start_slot = fsm_start_slot;
839  else if (fsm_start.logpageno > addr.logpageno)
840  start_slot = SlotsPerFSMPage; /* shouldn't get here... */
841  else
842  start_slot = 0;
843 
844  if (fsm_end.logpageno == addr.logpageno)
845  end_slot = fsm_end_slot;
846  else if (fsm_end.logpageno > addr.logpageno)
847  end_slot = SlotsPerFSMPage - 1;
848  else
849  end_slot = -1; /* shouldn't get here... */
850 
851  for (slot = start_slot; slot <= end_slot; slot++)
852  {
853  int child_avail;
854 
856 
857  /* After we hit end-of-file, just clear the rest of the slots */
858  if (!eof)
859  child_avail = fsm_vacuum_page(rel, fsm_get_child(addr, slot),
860  start, end,
861  &eof);
862  else
863  child_avail = 0;
864 
865  /* Update information about the child */
866  if (fsm_get_avail(page, slot) != child_avail)
867  {
869  fsm_set_avail(page, slot, child_avail);
870  MarkBufferDirtyHint(buf, false);
872  }
873  }
874  }
875 
876  /* Now get the maximum value on the page, to return to caller */
877  max_avail = fsm_get_max_avail(page);
878 
879  /*
880  * Reset the next slot pointer. This encourages the use of low-numbered
881  * pages, increasing the chances that a later vacuum can truncate the
882  * relation. We don't bother with a lock here, nor with marking the page
883  * dirty if it wasn't already, since this is just a hint.
884  */
885  ((FSMPage) PageGetContents(page))->fp_next_slot = 0;
886 
887  ReleaseBuffer(buf);
888 
889  return max_avail;
890 }
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
int logpageno
Definition: freespace.c:86
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:86
uint8 fsm_get_max_avail(Page page)
Definition: fsmpage.c:138
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:77
void MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
Definition: bufmgr.c:3435
static FSMAddress fsm_get_parent(FSMAddress child, uint16 *slot)
Definition: freespace.c:492
bool fsm_set_avail(Page page, int slot, uint8 value)
Definition: fsmpage.c:63
unsigned char uint8
Definition: c.h:356
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3365
static uint8 fsm_vacuum_page(Relation rel, FSMAddress addr, BlockNumber start, BlockNumber end, bool *eof)
Definition: freespace.c:785
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
static FSMAddress fsm_get_child(FSMAddress parent, uint16 slot)
Definition: freespace.c:510
unsigned short uint16
Definition: c.h:357
int level
Definition: freespace.c:85
FSMPageData * FSMPage
Definition: fsm_internals.h:45
static char * buf
Definition: pg_test_fsync.c:68
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:466
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
#define PageGetContents(page)
Definition: bufpage.h:246
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
#define Assert(condition)
Definition: c.h:732
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
uint8 fsm_get_avail(Page page, int slot)
Definition: fsmpage.c:122
static Buffer fsm_readbuf(Relation rel, FSMAddress addr, bool extend)
Definition: freespace.c:529
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:99
int Buffer
Definition: buf.h:23
Pointer Page
Definition: bufpage.h:78

◆ GetPageWithFreeSpace()

BlockNumber GetPageWithFreeSpace ( Relation  rel,
Size  spaceNeeded 
)

Definition at line 132 of file freespace.c.

References fsm_search(), and fsm_space_needed_to_cat().

Referenced by brin_getinsertbuffer(), GetFreeIndexPage(), and RelationGetBufferForTuple().

133 {
134  uint8 min_cat = fsm_space_needed_to_cat(spaceNeeded);
135 
136  return fsm_search(rel, min_cat);
137 }
unsigned char uint8
Definition: c.h:356
static uint8 fsm_space_needed_to_cat(Size needed)
Definition: freespace.c:407
static BlockNumber fsm_search(Relation rel, uint8 min_cat)
Definition: freespace.c:687

◆ GetRecordedFreeSpace()

Size GetRecordedFreeSpace ( Relation  rel,
BlockNumber  heapBlk 
)

Definition at line 230 of file freespace.c.

References buf, BufferGetPage, BufferIsValid, fsm_get_avail(), fsm_get_location(), fsm_readbuf(), fsm_space_cat_to_avail(), and ReleaseBuffer().

Referenced by lazy_scan_heap(), pg_freespace(), and statapprox_heap().

231 {
232  FSMAddress addr;
233  uint16 slot;
234  Buffer buf;
235  uint8 cat;
236 
237  /* Get the location of the FSM byte representing the heap block */
238  addr = fsm_get_location(heapBlk, &slot);
239 
240  buf = fsm_readbuf(rel, addr, false);
241  if (!BufferIsValid(buf))
242  return 0;
243  cat = fsm_get_avail(BufferGetPage(buf), slot);
244  ReleaseBuffer(buf);
245 
246  return fsm_space_cat_to_avail(cat);
247 }
unsigned char uint8
Definition: c.h:356
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3365
unsigned short uint16
Definition: c.h:357
static Size fsm_space_cat_to_avail(uint8 cat)
Definition: freespace.c:393
static char * buf
Definition: pg_test_fsync.c:68
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:466
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
uint8 fsm_get_avail(Page page, int slot)
Definition: fsmpage.c:122
static Buffer fsm_readbuf(Relation rel, FSMAddress addr, bool extend)
Definition: freespace.c:529
int Buffer
Definition: buf.h:23

◆ RecordAndGetPageWithFreeSpace()

BlockNumber RecordAndGetPageWithFreeSpace ( Relation  rel,
BlockNumber  oldPage,
Size  oldSpaceAvail,
Size  spaceNeeded 
)

Definition at line 149 of file freespace.c.

References fsm_get_heap_blk(), fsm_get_location(), fsm_search(), fsm_set_and_search(), fsm_space_avail_to_cat(), and fsm_space_needed_to_cat().

Referenced by brin_getinsertbuffer(), and RelationGetBufferForTuple().

151 {
152  int old_cat = fsm_space_avail_to_cat(oldSpaceAvail);
153  int search_cat = fsm_space_needed_to_cat(spaceNeeded);
154  FSMAddress addr;
155  uint16 slot;
156  int search_slot;
157 
158  /* Get the location of the FSM byte representing the heap block */
159  addr = fsm_get_location(oldPage, &slot);
160 
161  search_slot = fsm_set_and_search(rel, addr, slot, old_cat, search_cat);
162 
163  /*
164  * If fsm_set_and_search found a suitable new block, return that.
165  * Otherwise, search as usual.
166  */
167  if (search_slot != -1)
168  return fsm_get_heap_blk(addr, search_slot);
169  else
170  return fsm_search(rel, search_cat);
171 }
static BlockNumber fsm_get_heap_blk(FSMAddress addr, uint16 slot)
Definition: freespace.c:481
unsigned short uint16
Definition: c.h:357
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:466
static uint8 fsm_space_avail_to_cat(Size avail)
Definition: freespace.c:367
static uint8 fsm_space_needed_to_cat(Size needed)
Definition: freespace.c:407
static int fsm_set_and_search(Relation rel, FSMAddress addr, uint16 slot, uint8 newValue, uint8 minValue)
Definition: freespace.c:655
static BlockNumber fsm_search(Relation rel, uint8 min_cat)
Definition: freespace.c:687

◆ RecordPageWithFreeSpace()

void RecordPageWithFreeSpace ( Relation  rel,
BlockNumber  heapBlk,
Size  spaceAvail 
)

Definition at line 181 of file freespace.c.

References fsm_get_location(), fsm_set_and_search(), and fsm_space_avail_to_cat().

Referenced by brin_doinsert(), brin_doupdate(), brin_initialize_empty_new_buffer(), brin_page_cleanup(), lazy_scan_heap(), lazy_vacuum_heap(), RecordFreeIndexPage(), RecordUsedIndexPage(), RelationAddExtraBlocks(), and terminate_brin_buildstate().

182 {
183  int new_cat = fsm_space_avail_to_cat(spaceAvail);
184  FSMAddress addr;
185  uint16 slot;
186 
187  /* Get the location of the FSM byte representing the heap block */
188  addr = fsm_get_location(heapBlk, &slot);
189 
190  fsm_set_and_search(rel, addr, slot, new_cat, 0);
191 }
unsigned short uint16
Definition: c.h:357
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:466
static uint8 fsm_space_avail_to_cat(Size avail)
Definition: freespace.c:367
static int fsm_set_and_search(Relation rel, FSMAddress addr, uint16 slot, uint8 newValue, uint8 minValue)
Definition: freespace.c:655

◆ XLogRecordPageWithFreeSpace()

void XLogRecordPageWithFreeSpace ( RelFileNode  rnode,
BlockNumber  heapBlk,
Size  spaceAvail 
)

Definition at line 198 of file freespace.c.

References buf, BUFFER_LOCK_EXCLUSIVE, BufferGetPage, FSM_FORKNUM, fsm_get_location(), fsm_logical_to_physical(), fsm_set_avail(), fsm_space_avail_to_cat(), LockBuffer(), MarkBufferDirtyHint(), PageInit(), PageIsNew, RBM_ZERO_ON_ERROR, UnlockReleaseBuffer(), and XLogReadBufferExtended().

Referenced by heap_xlog_clean(), heap_xlog_insert(), heap_xlog_multi_insert(), heap_xlog_update(), and heap_xlog_visible().

200 {
201  int new_cat = fsm_space_avail_to_cat(spaceAvail);
202  FSMAddress addr;
203  uint16 slot;
204  BlockNumber blkno;
205  Buffer buf;
206  Page page;
207 
208  /* Get the location of the FSM byte representing the heap block */
209  addr = fsm_get_location(heapBlk, &slot);
210  blkno = fsm_logical_to_physical(addr);
211 
212  /* If the page doesn't exist already, extend */
215 
216  page = BufferGetPage(buf);
217  if (PageIsNew(page))
218  PageInit(page, BLCKSZ, 0);
219 
220  if (fsm_set_avail(page, slot, new_cat))
221  MarkBufferDirtyHint(buf, false);
222  UnlockReleaseBuffer(buf);
223 }
void MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
Definition: bufmgr.c:3435
bool fsm_set_avail(Page page, int slot, uint8 value)
Definition: fsmpage.c:63
Buffer XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum, BlockNumber blkno, ReadBufferMode mode)
Definition: xlogutils.c:437
uint32 BlockNumber
Definition: block.h:31
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
unsigned short uint16
Definition: c.h:357
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3388
static char * buf
Definition: pg_test_fsync.c:68
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:466
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
static uint8 fsm_space_avail_to_cat(Size avail)
Definition: freespace.c:367
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
static BlockNumber fsm_logical_to_physical(FSMAddress addr)
Definition: freespace.c:430
#define PageIsNew(page)
Definition: bufpage.h:229
int Buffer
Definition: buf.h:23
Pointer Page
Definition: bufpage.h:78
void PageInit(Page page, Size pageSize, Size specialSize)
Definition: bufpage.c:42

Variable Documentation

◆ FSM_ROOT_ADDRESS

const FSMAddress FSM_ROOT_ADDRESS = {FSM_ROOT_LEVEL, 0}
static

Definition at line 90 of file freespace.c.

Referenced by fsm_search().