PostgreSQL Source Code git master
Data Structures | Macros | Functions | Variables
freespace.c File Reference
#include "postgres.h"
#include "access/htup_details.h"
#include "access/xloginsert.h"
#include "access/xlogutils.h"
#include "miscadmin.h"
#include "storage/freespace.h"
#include "storage/fsm_internals.h"
#include "storage/smgr.h"
#include "utils/rel.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 Buffer  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_p)
 
static bool  fsm_does_block_exist (Relation rel, BlockNumber blknumber)
 
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 (RelFileLocator rlocator, 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

Definition at line 78 of file freespace.c.

◆ FSM_CAT_STEP

#define FSM_CAT_STEP   (BLCKSZ / FSM_CATEGORIES)

Definition at line 65 of file freespace.c.

◆ FSM_CATEGORIES

#define FSM_CATEGORIES   256

Definition at line 64 of file freespace.c.

◆ FSM_ROOT_LEVEL

#define FSM_ROOT_LEVEL   (FSM_TREE_DEPTH - 1)

Definition at line 77 of file freespace.c.

◆ FSM_TREE_DEPTH

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

Definition at line 75 of file freespace.c.

◆ MaxFSMRequestSize

#define MaxFSMRequestSize   MaxHeapTupleSize

Definition at line 66 of file freespace.c.

Function Documentation

◆ FreeSpaceMapPrepareTruncateRel()

BlockNumber FreeSpaceMapPrepareTruncateRel ( Relation  rel,
BlockNumber  nblocks 
)

Definition at line 275 of file freespace.c.

276{
277 BlockNumber new_nfsmblocks;
278 FSMAddress first_removed_address;
279 uint16 first_removed_slot;
280 Buffer buf;
281
282 /*
283 * If no FSM has been created yet for this relation, there's nothing to
284 * truncate.
285 */
287 return InvalidBlockNumber;
288
289 /* Get the location in the FSM of the first removed heap block */
290 first_removed_address = fsm_get_location(nblocks, &first_removed_slot);
291
292 /*
293 * Zero out the tail of the last remaining FSM page. If the slot
294 * representing the first removed heap block is at a page boundary, as the
295 * first slot on the FSM page that first_removed_address points to, we can
296 * just truncate that page altogether.
297 */
298 if (first_removed_slot > 0)
299 {
300 buf = fsm_readbuf(rel, first_removed_address, false);
301 if (!BufferIsValid(buf))
302 return InvalidBlockNumber; /* nothing to do; the FSM was already
303 * smaller */
305
306 /* NO EREPORT(ERROR) from here till changes are logged */
308
309 fsm_truncate_avail(BufferGetPage(buf), first_removed_slot);
310
311 /*
312 * This change is non-critical, because fsm_does_block_exist() would
313 * stop us from returning a truncated-away block. However, since this
314 * may remove up to SlotsPerFSMPage slots, it's nice to avoid the cost
315 * of that many fsm_does_block_exist() rejections. Use a full
316 * MarkBufferDirty(), not MarkBufferDirtyHint().
317 */
319
320 /*
321 * WAL-log like MarkBufferDirtyHint() might have done, just to avoid
322 * differing from the rest of the file in this respect. This is
323 * optional; see README mention of full page images. XXX consider
324 * XLogSaveBufferForHint() for even closer similarity.
325 *
326 * A higher-level operation calls us at WAL replay. If we crash
327 * before the XLOG_SMGR_TRUNCATE flushes to disk, main fork length has
328 * not changed, and our fork remains valid. If we crash after that
329 * flush, redo will return here.
330 */
332 log_newpage_buffer(buf, false);
333
335
337
338 new_nfsmblocks = fsm_logical_to_physical(first_removed_address) + 1;
339 }
340 else
341 {
342 new_nfsmblocks = fsm_logical_to_physical(first_removed_address);
343 if (smgrnblocks(RelationGetSmgr(rel), FSM_FORKNUM) <= new_nfsmblocks)
344 return InvalidBlockNumber; /* nothing to do; the FSM was already
345 * smaller */
346 }
347
348 return new_nfsmblocks;
349}
uint32 BlockNumber
Definition: block.h:31
#define InvalidBlockNumber
Definition: block.h:33
int Buffer
Definition: buf.h:23
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:5355
void MarkBufferDirty(Buffer buffer)
Definition: bufmgr.c:2921
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:5572
static Page BufferGetPage(Buffer buffer)
Definition: bufmgr.h:417
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:198
static bool BufferIsValid(Buffer bufnum)
Definition: bufmgr.h:368
uint16_t uint16
Definition: c.h:537
static BlockNumber fsm_logical_to_physical(FSMAddress addr)
Definition: freespace.c:455
static FSMAddress fsm_get_location(BlockNumber heapblk, uint16 *slot)
Definition: freespace.c:491
static Buffer fsm_readbuf(Relation rel, FSMAddress addr, bool extend)
Definition: freespace.c:554
bool fsm_truncate_avail(Page page, int nslots)
Definition: fsmpage.c:313
#define START_CRIT_SECTION()
Definition: miscadmin.h:149
#define END_CRIT_SECTION()
Definition: miscadmin.h:151
static char * buf
Definition: pg_test_fsync.c:72
static SMgrRelation RelationGetSmgr(Relation rel)
Definition: rel.h:576
#define RelationNeedsWAL(relation)
Definition: rel.h:637
@ FSM_FORKNUM
Definition: relpath.h:59
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:819
bool smgrexists(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:462
#define XLogHintBitIsNeeded()
Definition: xlog.h:120
XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std)
Definition: xloginsert.c:1249
bool InRecovery
Definition: xlogutils.c:50

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(), RelationGetSmgr(), RelationNeedsWAL, smgrexists(), smgrnblocks(), START_CRIT_SECTION, UnlockReleaseBuffer(), and XLogHintBitIsNeeded.

Referenced by RelationTruncate(), and smgr_redo().

◆ FreeSpaceMapVacuum()

void FreeSpaceMapVacuum ( Relation  rel )

Definition at line 358 of file freespace.c.

359{
360 bool dummy;
361
362 /* Recursively scan the tree, starting at the root */
365 &dummy);
366}
static uint8 fsm_vacuum_page(Relation rel, FSMAddress addr, BlockNumber start, BlockNumber end, bool *eof_p)
Definition: freespace.c:812
static const FSMAddress FSM_ROOT_ADDRESS
Definition: freespace.c:91

References FSM_ROOT_ADDRESS, fsm_vacuum_page(), and InvalidBlockNumber.

Referenced by brin_vacuum_scan(), and IndexFreeSpaceMapVacuum().

◆ FreeSpaceMapVacuumRange()

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

Definition at line 377 of file freespace.c.

378{
379 bool dummy;
380
381 /* Recursively scan the tree, starting at the root */
382 if (end > start)
383 (void) fsm_vacuum_page(rel, FSM_ROOT_ADDRESS, start, end, &dummy);
384}
return str start

References FSM_ROOT_ADDRESS, fsm_vacuum_page(), and start.

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

◆ fsm_does_block_exist()

static bool fsm_does_block_exist ( Relation  rel,
BlockNumber  blknumber 
)
static

Definition at line 926 of file freespace.c.

927{
928 SMgrRelation smgr = RelationGetSmgr(rel);
929
930 /*
931 * If below the cached nblocks, the block surely exists. Otherwise, we
932 * face a trade-off. We opt to compare to a fresh nblocks, incurring
933 * lseek() overhead. The alternative would be to assume the block does
934 * not exist, but that would cause FSM to set zero space available for
935 * blocks that main fork extension just recorded.
936 */
938 blknumber < smgr->smgr_cached_nblocks[MAIN_FORKNUM]) ||
939 blknumber < RelationGetNumberOfBlocks(rel));
940}
static bool BlockNumberIsValid(BlockNumber blockNumber)
Definition: block.h:71
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:283
@ MAIN_FORKNUM
Definition: relpath.h:58
BlockNumber smgr_cached_nblocks[MAX_FORKNUM+1]
Definition: smgr.h:47

References BlockNumberIsValid(), MAIN_FORKNUM, RelationGetNumberOfBlocks, RelationGetSmgr(), and SMgrRelationData::smgr_cached_nblocks.

Referenced by fsm_search(), and RecordAndGetPageWithFreeSpace().

◆ fsm_extend()

static Buffer fsm_extend ( Relation  rel,
BlockNumber  fsm_nblocks 
)
static

Definition at line 629 of file freespace.c.

630{
631 return ExtendBufferedRelTo(BMR_REL(rel), FSM_FORKNUM, NULL,
634 fsm_nblocks,
636}
Buffer ExtendBufferedRelTo(BufferManagerRelation bmr, ForkNumber fork, BufferAccessStrategy strategy, uint32 flags, BlockNumber extend_to, ReadBufferMode mode)
Definition: bufmgr.c:922
@ EB_CLEAR_SIZE_CACHE
Definition: bufmgr.h:90
@ EB_CREATE_FORK_IF_NEEDED
Definition: bufmgr.h:84
@ RBM_ZERO_ON_ERROR
Definition: bufmgr.h:51
#define BMR_REL(p_rel)
Definition: bufmgr.h:111

References BMR_REL, EB_CLEAR_SIZE_CACHE, EB_CREATE_FORK_IF_NEEDED, ExtendBufferedRelTo(), FSM_FORKNUM, and RBM_ZERO_ON_ERROR.

Referenced by fsm_readbuf().

◆ fsm_get_child()

static FSMAddress fsm_get_child ( FSMAddress  parent,
uint16  slot 
)
static

Definition at line 535 of file freespace.c.

536{
537 FSMAddress child;
538
539 Assert(parent.level > FSM_BOTTOM_LEVEL);
540
541 child.level = parent.level - 1;
542 child.logpageno = parent.logpageno * SlotsPerFSMPage + slot;
543
544 return child;
545}
#define FSM_BOTTOM_LEVEL
Definition: freespace.c:78
#define SlotsPerFSMPage
Definition: fsm_internals.h:61
Assert(PointerIsAligned(start, uint64))
int logpageno
Definition: freespace.c:87
int level
Definition: freespace.c:86

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

Referenced by fsm_search(), and fsm_vacuum_page().

◆ fsm_get_heap_blk()

static BlockNumber fsm_get_heap_blk ( FSMAddress  addr,
uint16  slot 
)
static

Definition at line 506 of file freespace.c.

507{
509 return ((unsigned int) addr.logpageno) * SlotsPerFSMPage + slot;
510}

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

Referenced by fsm_search(), and RecordAndGetPageWithFreeSpace().

◆ fsm_get_location()

static FSMAddress fsm_get_location ( BlockNumber  heapblk,
uint16 *  slot 
)
static

Definition at line 491 of file freespace.c.

492{
493 FSMAddress addr;
494
495 addr.level = FSM_BOTTOM_LEVEL;
496 addr.logpageno = heapblk / SlotsPerFSMPage;
497 *slot = heapblk % SlotsPerFSMPage;
498
499 return addr;
500}

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

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

◆ fsm_get_parent()

static FSMAddress fsm_get_parent ( FSMAddress  child,
uint16 *  slot 
)
static

Definition at line 517 of file freespace.c.

518{
519 FSMAddress parent;
520
521 Assert(child.level < FSM_ROOT_LEVEL);
522
523 parent.level = child.level + 1;
524 parent.logpageno = child.logpageno / SlotsPerFSMPage;
525 *slot = child.logpageno % SlotsPerFSMPage;
526
527 return parent;
528}
#define FSM_ROOT_LEVEL
Definition: freespace.c:77

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

Referenced by fsm_search(), and fsm_vacuum_page().

◆ fsm_logical_to_physical()

static BlockNumber fsm_logical_to_physical ( FSMAddress  addr )
static

Definition at line 455 of file freespace.c.

456{
457 BlockNumber pages;
458 int leafno;
459 int l;
460
461 /*
462 * Calculate the logical page number of the first leaf page below the
463 * given page.
464 */
465 leafno = addr.logpageno;
466 for (l = 0; l < addr.level; l++)
467 leafno *= SlotsPerFSMPage;
468
469 /* Count upper level nodes required to address the leaf page */
470 pages = 0;
471 for (l = 0; l < FSM_TREE_DEPTH; l++)
472 {
473 pages += leafno + 1;
474 leafno /= SlotsPerFSMPage;
475 }
476
477 /*
478 * If the page we were asked for wasn't at the bottom level, subtract the
479 * additional lower level pages we counted above.
480 */
481 pages -= addr.level;
482
483 /* Turn the page count into 0-based block number */
484 return pages - 1;
485}
#define FSM_TREE_DEPTH
Definition: freespace.c:75

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

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

◆ fsm_readbuf()

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

Definition at line 554 of file freespace.c.

555{
557 Buffer buf;
558 SMgrRelation reln = RelationGetSmgr(rel);
559
560 /*
561 * If we haven't cached the size of the FSM yet, check it first. Also
562 * recheck if the requested block seems to be past end, since our cached
563 * value might be stale. (We send smgr inval messages on truncation, but
564 * not on extension.)
565 */
567 blkno >= reln->smgr_cached_nblocks[FSM_FORKNUM])
568 {
569 /* Invalidate the cache so smgrnblocks asks the kernel. */
571 if (smgrexists(reln, FSM_FORKNUM))
573 else
575 }
576
577 /*
578 * For reading we use ZERO_ON_ERROR mode, and initialize the page if
579 * necessary. The FSM information is not accurate anyway, so it's better
580 * to clear corrupt pages than error out. Since the FSM changes are not
581 * WAL-logged, the so-called torn page problem on crash can lead to pages
582 * with corrupt headers, for example.
583 *
584 * We use the same path below to initialize pages when extending the
585 * relation, as a concurrent extension can end up with vm_extend()
586 * returning an already-initialized page.
587 */
588 if (blkno >= reln->smgr_cached_nblocks[FSM_FORKNUM])
589 {
590 if (extend)
591 buf = fsm_extend(rel, blkno + 1);
592 else
593 return InvalidBuffer;
594 }
595 else
597
598 /*
599 * Initializing the page when needed is trickier than it looks, because of
600 * the possibility of multiple backends doing this concurrently, and our
601 * desire to not uselessly take the buffer lock in the normal path where
602 * the page is OK. We must take the lock to initialize the page, so
603 * recheck page newness after we have the lock, in case someone else
604 * already did it. Also, because we initially check PageIsNew with no
605 * lock, it's possible to fall through and return the buffer while someone
606 * else is still initializing the page (i.e., we might see pd_upper as set
607 * but other page header fields are still zeroes). This is harmless for
608 * callers that will take a buffer lock themselves, but some callers
609 * inspect the page without any lock at all. The latter is OK only so
610 * long as it doesn't depend on the page header having correct contents.
611 * Current usage is safe because PageGetContents() does not require that.
612 */
614 {
617 PageInit(BufferGetPage(buf), BLCKSZ, 0);
619 }
620 return buf;
621}
#define InvalidBuffer
Definition: buf.h:25
Buffer ReadBufferExtended(Relation reln, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
Definition: bufmgr.c:805
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:196
void PageInit(Page page, Size pageSize, Size specialSize)
Definition: bufpage.c:42
static bool PageIsNew(const PageData *page)
Definition: bufpage.h:234
static Buffer fsm_extend(Relation rel, BlockNumber fsm_nblocks)
Definition: freespace.c:629

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, ReadBufferExtended(), RelationGetSmgr(), SMgrRelationData::smgr_cached_nblocks, smgrexists(), and smgrnblocks().

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

◆ fsm_search()

static BlockNumber fsm_search ( Relation  rel,
uint8  min_cat 
)
static

Definition at line 678 of file freespace.c.

679{
680 int restarts = 0;
682
683 for (;;)
684 {
685 int slot;
686 Buffer buf;
687 uint8 max_avail = 0;
688
689 /* Read the FSM page. */
690 buf = fsm_readbuf(rel, addr, false);
691
692 /* Search within the page */
693 if (BufferIsValid(buf))
694 {
696 slot = fsm_search_avail(buf, min_cat,
697 (addr.level == FSM_BOTTOM_LEVEL),
698 false);
699 if (slot == -1)
700 {
701 max_avail = fsm_get_max_avail(BufferGetPage(buf));
703 }
704 else
705 {
706 /* Keep the pin for possible update below */
708 }
709 }
710 else
711 slot = -1;
712
713 if (slot != -1)
714 {
715 /*
716 * Descend the tree, or return the found block if we're at the
717 * bottom.
718 */
719 if (addr.level == FSM_BOTTOM_LEVEL)
720 {
721 BlockNumber blkno = fsm_get_heap_blk(addr, slot);
722 Page page;
723
724 if (fsm_does_block_exist(rel, blkno))
725 {
727 return blkno;
728 }
729
730 /*
731 * Block is past the end of the relation. Update FSM, and
732 * restart from root. The usual "advancenext" behavior is
733 * pessimal for this rare scenario, since every later slot is
734 * unusable in the same way. We could zero all affected slots
735 * on the same FSM page, but don't bet on the benefits of that
736 * optimization justifying its compiled code bulk.
737 */
738 page = BufferGetPage(buf);
740 fsm_set_avail(page, slot, 0);
741 MarkBufferDirtyHint(buf, false);
743 if (restarts++ > 10000) /* same rationale as below */
744 return InvalidBlockNumber;
745 addr = FSM_ROOT_ADDRESS;
746 }
747 else
748 {
750 }
751 addr = fsm_get_child(addr, slot);
752 }
753 else if (addr.level == FSM_ROOT_LEVEL)
754 {
755 /*
756 * At the root, failure means there's no page with enough free
757 * space in the FSM. Give up.
758 */
759 return InvalidBlockNumber;
760 }
761 else
762 {
763 uint16 parentslot;
764 FSMAddress parent;
765
766 /*
767 * At lower level, failure can happen if the value in the upper-
768 * level node didn't reflect the value on the lower page. Update
769 * the upper node, to avoid falling into the same trap again, and
770 * start over.
771 *
772 * There's a race condition here, if another backend updates this
773 * page right after we release it, and gets the lock on the parent
774 * page before us. We'll then update the parent page with the now
775 * stale information we had. It's OK, because it should happen
776 * rarely, and will be fixed by the next vacuum.
777 */
778 parent = fsm_get_parent(addr, &parentslot);
779 fsm_set_and_search(rel, parent, parentslot, max_avail, 0);
780
781 /*
782 * If the upper pages are badly out of date, we might need to loop
783 * quite a few times, updating them as we go. Any inconsistencies
784 * should eventually be corrected and the loop should end. Looping
785 * indefinitely is nevertheless scary, so provide an emergency
786 * valve.
787 */
788 if (restarts++ > 10000)
789 return InvalidBlockNumber;
790
791 /* Start search all over from the root */
792 addr = FSM_ROOT_ADDRESS;
793 }
794 }
795}
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:5338
void MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
Definition: bufmgr.c:5402
#define BUFFER_LOCK_SHARE
Definition: bufmgr.h:197
PageData * Page
Definition: bufpage.h:82
uint8_t uint8
Definition: c.h:536
static FSMAddress fsm_get_child(FSMAddress parent, uint16 slot)
Definition: freespace.c:535
static bool fsm_does_block_exist(Relation rel, BlockNumber blknumber)
Definition: freespace.c:926
static FSMAddress fsm_get_parent(FSMAddress child, uint16 *slot)
Definition: freespace.c:517
static int fsm_set_and_search(Relation rel, FSMAddress addr, uint16 slot, uint8 newValue, uint8 minValue)
Definition: freespace.c:646
static BlockNumber fsm_get_heap_blk(FSMAddress addr, uint16 slot)
Definition: freespace.c:506
uint8 fsm_get_max_avail(Page page)
Definition: fsmpage.c:138
bool fsm_set_avail(Page page, int slot, uint8 value)
Definition: fsmpage.c:63
int fsm_search_avail(Buffer buf, uint8 minvalue, bool advancenext, bool exclusive_lock_held)
Definition: fsmpage.c:158

References buf, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BufferGetPage(), BufferIsValid(), FSM_BOTTOM_LEVEL, fsm_does_block_exist(), 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(), fsm_set_avail(), InvalidBlockNumber, FSMAddress::level, LockBuffer(), MarkBufferDirtyHint(), ReleaseBuffer(), and UnlockReleaseBuffer().

Referenced by GetPageWithFreeSpace(), and RecordAndGetPageWithFreeSpace().

◆ fsm_set_and_search()

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

Definition at line 646 of file freespace.c.

648{
649 Buffer buf;
650 Page page;
651 int newslot = -1;
652
653 buf = fsm_readbuf(rel, addr, true);
655
656 page = BufferGetPage(buf);
657
658 if (fsm_set_avail(page, slot, newValue))
659 MarkBufferDirtyHint(buf, false);
660
661 if (minValue != 0)
662 {
663 /* Search while we still hold the lock */
664 newslot = fsm_search_avail(buf, minValue,
665 addr.level == FSM_BOTTOM_LEVEL,
666 true);
667 }
668
670
671 return newslot;
672}

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().

◆ fsm_space_avail_to_cat()

static uint8 fsm_space_avail_to_cat ( Size  avail )
static

Definition at line 392 of file freespace.c.

393{
394 int cat;
395
396 Assert(avail < BLCKSZ);
397
398 if (avail >= MaxFSMRequestSize)
399 return 255;
400
401 cat = avail / FSM_CAT_STEP;
402
403 /*
404 * The highest category, 255, is reserved for MaxFSMRequestSize bytes or
405 * more.
406 */
407 if (cat > 254)
408 cat = 254;
409
410 return (uint8) cat;
411}
#define MaxFSMRequestSize
Definition: freespace.c:66
#define FSM_CAT_STEP
Definition: freespace.c:65

References Assert(), FSM_CAT_STEP, and MaxFSMRequestSize.

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

◆ fsm_space_cat_to_avail()

static Size fsm_space_cat_to_avail ( uint8  cat )
static

Definition at line 418 of file freespace.c.

419{
420 /* The highest category represents exactly MaxFSMRequestSize bytes. */
421 if (cat == 255)
422 return MaxFSMRequestSize;
423 else
424 return cat * FSM_CAT_STEP;
425}

References FSM_CAT_STEP, and MaxFSMRequestSize.

Referenced by GetRecordedFreeSpace().

◆ fsm_space_needed_to_cat()

static uint8 fsm_space_needed_to_cat ( Size  needed )
static

Definition at line 432 of file freespace.c.

433{
434 int cat;
435
436 /* Can't ask for more space than the highest category represents */
437 if (needed > MaxFSMRequestSize)
438 elog(ERROR, "invalid FSM request size %zu", needed);
439
440 if (needed == 0)
441 return 1;
442
443 cat = (needed + FSM_CAT_STEP - 1) / FSM_CAT_STEP;
444
445 if (cat > 255)
446 cat = 255;
447
448 return (uint8) cat;
449}
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:226

References elog, ERROR, FSM_CAT_STEP, and MaxFSMRequestSize.

Referenced by GetPageWithFreeSpace(), and RecordAndGetPageWithFreeSpace().

◆ fsm_vacuum_page()

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

Definition at line 812 of file freespace.c.

815{
816 Buffer buf;
817 Page page;
818 uint8 max_avail;
819
820 /* Read the page if it exists, or return EOF */
821 buf = fsm_readbuf(rel, addr, false);
822 if (!BufferIsValid(buf))
823 {
824 *eof_p = true;
825 return 0;
826 }
827 else
828 *eof_p = false;
829
830 page = BufferGetPage(buf);
831
832 /*
833 * If we're above the bottom level, recurse into children, and fix the
834 * information stored about them at this level.
835 */
836 if (addr.level > FSM_BOTTOM_LEVEL)
837 {
838 FSMAddress fsm_start,
839 fsm_end;
840 uint16 fsm_start_slot,
841 fsm_end_slot;
842 int slot,
843 start_slot,
844 end_slot;
845 bool eof = false;
846
847 /*
848 * Compute the range of slots we need to update on this page, given
849 * the requested range of heap blocks to consider. The first slot to
850 * update is the one covering the "start" block, and the last slot is
851 * the one covering "end - 1". (Some of this work will be duplicated
852 * in each recursive call, but it's cheap enough to not worry about.)
853 */
854 fsm_start = fsm_get_location(start, &fsm_start_slot);
855 fsm_end = fsm_get_location(end - 1, &fsm_end_slot);
856
857 while (fsm_start.level < addr.level)
858 {
859 fsm_start = fsm_get_parent(fsm_start, &fsm_start_slot);
860 fsm_end = fsm_get_parent(fsm_end, &fsm_end_slot);
861 }
862 Assert(fsm_start.level == addr.level);
863
864 if (fsm_start.logpageno == addr.logpageno)
865 start_slot = fsm_start_slot;
866 else if (fsm_start.logpageno > addr.logpageno)
867 start_slot = SlotsPerFSMPage; /* shouldn't get here... */
868 else
869 start_slot = 0;
870
871 if (fsm_end.logpageno == addr.logpageno)
872 end_slot = fsm_end_slot;
873 else if (fsm_end.logpageno > addr.logpageno)
874 end_slot = SlotsPerFSMPage - 1;
875 else
876 end_slot = -1; /* shouldn't get here... */
877
878 for (slot = start_slot; slot <= end_slot; slot++)
879 {
880 int child_avail;
881
883
884 /* After we hit end-of-file, just clear the rest of the slots */
885 if (!eof)
886 child_avail = fsm_vacuum_page(rel, fsm_get_child(addr, slot),
887 start, end,
888 &eof);
889 else
890 child_avail = 0;
891
892 /* Update information about the child */
893 if (fsm_get_avail(page, slot) != child_avail)
894 {
896 fsm_set_avail(page, slot, child_avail);
897 MarkBufferDirtyHint(buf, false);
899 }
900 }
901 }
902
903 /* Now get the maximum value on the page, to return to caller */
904 max_avail = fsm_get_max_avail(page);
905
906 /*
907 * Reset the next slot pointer. This encourages the use of low-numbered
908 * pages, increasing the chances that a later vacuum can truncate the
909 * relation. We don't bother with a lock here, nor with marking the page
910 * dirty if it wasn't already, since this is just a hint.
911 */
912 ((FSMPage) PageGetContents(page))->fp_next_slot = 0;
913
915
916 return max_avail;
917}
static char * PageGetContents(Page page)
Definition: bufpage.h:258
FSMPageData * FSMPage
Definition: fsm_internals.h:45
uint8 fsm_get_avail(Page page, int slot)
Definition: fsmpage.c:122
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:122

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(), fsm_vacuum_page(), FSMAddress::level, LockBuffer(), FSMAddress::logpageno, MarkBufferDirtyHint(), PageGetContents(), ReleaseBuffer(), SlotsPerFSMPage, and start.

Referenced by FreeSpaceMapVacuum(), FreeSpaceMapVacuumRange(), and fsm_vacuum_page().

◆ GetPageWithFreeSpace()

BlockNumber GetPageWithFreeSpace ( Relation  rel,
Size  spaceNeeded 
)

Definition at line 137 of file freespace.c.

138{
139 uint8 min_cat = fsm_space_needed_to_cat(spaceNeeded);
140
141 return fsm_search(rel, min_cat);
142}
static uint8 fsm_space_needed_to_cat(Size needed)
Definition: freespace.c:432
static BlockNumber fsm_search(Relation rel, uint8 min_cat)
Definition: freespace.c:678

References fsm_search(), and fsm_space_needed_to_cat().

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

◆ GetRecordedFreeSpace()

Size GetRecordedFreeSpace ( Relation  rel,
BlockNumber  heapBlk 
)

Definition at line 244 of file freespace.c.

245{
246 FSMAddress addr;
247 uint16 slot;
248 Buffer buf;
249 uint8 cat;
250
251 /* Get the location of the FSM byte representing the heap block */
252 addr = fsm_get_location(heapBlk, &slot);
253
254 buf = fsm_readbuf(rel, addr, false);
255 if (!BufferIsValid(buf))
256 return 0;
257 cat = fsm_get_avail(BufferGetPage(buf), slot);
259
260 return fsm_space_cat_to_avail(cat);
261}
static Size fsm_space_cat_to_avail(uint8 cat)
Definition: freespace.c:418

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

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

◆ RecordAndGetPageWithFreeSpace()

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

Definition at line 154 of file freespace.c.

156{
157 int old_cat = fsm_space_avail_to_cat(oldSpaceAvail);
158 int search_cat = fsm_space_needed_to_cat(spaceNeeded);
159 FSMAddress addr;
160 uint16 slot;
161 int search_slot;
162
163 /* Get the location of the FSM byte representing the heap block */
164 addr = fsm_get_location(oldPage, &slot);
165
166 search_slot = fsm_set_and_search(rel, addr, slot, old_cat, search_cat);
167
168 /*
169 * If fsm_set_and_search found a suitable new block, return that.
170 * Otherwise, search as usual.
171 */
172 if (search_slot != -1)
173 {
174 BlockNumber blknum = fsm_get_heap_blk(addr, search_slot);
175
176 /*
177 * Check that the blknum is actually in the relation. Don't try to
178 * update the FSM in that case, just fall back to the other case
179 */
180 if (fsm_does_block_exist(rel, blknum))
181 return blknum;
182 }
183 return fsm_search(rel, search_cat);
184}
static uint8 fsm_space_avail_to_cat(Size avail)
Definition: freespace.c:392

References fsm_does_block_exist(), 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().

◆ RecordPageWithFreeSpace()

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

Definition at line 194 of file freespace.c.

195{
196 int new_cat = fsm_space_avail_to_cat(spaceAvail);
197 FSMAddress addr;
198 uint16 slot;
199
200 /* Get the location of the FSM byte representing the heap block */
201 addr = fsm_get_location(heapBlk, &slot);
202
203 fsm_set_and_search(rel, addr, slot, new_cat, 0);
204}

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_scan_new_or_empty(), lazy_vacuum_heap_rel(), RecordFreeIndexPage(), RecordUsedIndexPage(), RelationAddBlocks(), RelationGetBufferForTuple(), and terminate_brin_buildstate().

◆ XLogRecordPageWithFreeSpace()

void XLogRecordPageWithFreeSpace ( RelFileLocator  rlocator,
BlockNumber  heapBlk,
Size  spaceAvail 
)

Definition at line 211 of file freespace.c.

213{
214 int new_cat = fsm_space_avail_to_cat(spaceAvail);
215 FSMAddress addr;
216 uint16 slot;
217 BlockNumber blkno;
218 Buffer buf;
219 Page page;
220
221 /* Get the location of the FSM byte representing the heap block */
222 addr = fsm_get_location(heapBlk, &slot);
223 blkno = fsm_logical_to_physical(addr);
224
225 /* If the page doesn't exist already, extend */
226 buf = XLogReadBufferExtended(rlocator, FSM_FORKNUM, blkno,
229
230 page = BufferGetPage(buf);
231 if (PageIsNew(page))
232 PageInit(page, BLCKSZ, 0);
233
234 if (fsm_set_avail(page, slot, new_cat))
235 MarkBufferDirtyHint(buf, false);
237}
Buffer XLogReadBufferExtended(RelFileLocator rlocator, ForkNumber forknum, BlockNumber blkno, ReadBufferMode mode, Buffer recent_buffer)
Definition: xlogutils.c:460

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

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

Variable Documentation

◆ FSM_ROOT_ADDRESS

const FSMAddress FSM_ROOT_ADDRESS = {FSM_ROOT_LEVEL, 0}
static

Definition at line 91 of file freespace.c.

Referenced by FreeSpaceMapVacuum(), FreeSpaceMapVacuumRange(), and fsm_search().

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