From 8ddc25481951f9115fecd6c8880f3bf14657e5eb Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Wed, 29 Apr 2026 12:53:49 -0400 Subject: [PATCH v4 2/4] Fix VM clear WAL logging by registering VM blocks Heap WAL records that clear bits on the visibility map (like inserts and deletes) did not register the visibility map blocks they modified. Because the WAL summarizer only records registered blocks, an incremental backup taken over such operations would omit the changed VM pages. On restore, the VM would retain stale all-visible/all-frozen bits, which can cause wrong results from index-only scans and incorrect relfrozenxid advancement due to vacuum page skipping. Not registering the VM buffer also meant we never emitted FPIs of VM pages when clearing bits. A torn VM page won't raise an error because the VM is read with ZERO_ON_ERROR; with checksums on, it would be detected and zeroed, but with checksums off, it is accepted as-is and can lead to data corruption. Fix this by registering the VM buffer in the WAL record when clearing VM bits. The VM buffer must now be locked throughout the critical section that modifies the VM and heap pages and emits the WAL record. This can slow down operations that clear the VM, since the VM lock is held longer and VM FPIs may be emitted, but it is required for correctness. Note that this fix does not repair existing incremental backups. Author: Melanie Plageman Author: Andres Freund Reviewed-by: Robert Haas Reviewed-by: Andrey Borodin Discussion: https://postgr.es/m/flat/CAAKRu_bn%2Be7F4yPFBgFbnP%2BsyJRKyNK092bjD2LKvZW7O4Svag> Backpatch-through: 17 --- contrib/pg_surgery/heap_surgery.c | 40 ++- src/backend/access/heap/heapam.c | 383 ++++++++++++++++++++---- src/backend/access/heap/heapam_xlog.c | 239 ++++++++++----- src/backend/access/heap/visibilitymap.c | 34 ++- src/bin/pg_walsummary/t/002_blocks.pl | 7 +- src/include/access/heapam_xlog.h | 17 +- src/include/access/visibilitymap.h | 2 + 7 files changed, 574 insertions(+), 148 deletions(-) diff --git a/contrib/pg_surgery/heap_surgery.c b/contrib/pg_surgery/heap_surgery.c index 602aca66c60..6a38ac577c6 100644 --- a/contrib/pg_surgery/heap_surgery.c +++ b/contrib/pg_surgery/heap_surgery.c @@ -17,6 +17,7 @@ #include "access/visibilitymap.h" #include "access/xloginsert.h" #include "catalog/pg_am_d.h" +#include "catalog/pg_control.h" #include "miscadmin.h" #include "storage/bufmgr.h" #include "utils/acl.h" @@ -146,6 +147,7 @@ heap_force_common(FunctionCallInfo fcinfo, HeapTupleForceOption heap_force_opt) { Buffer buf; Buffer vmbuf = InvalidBuffer; + bool unlock_vmbuf = false; Page page; BlockNumber blkno; OffsetNumber curoff; @@ -233,11 +235,15 @@ heap_force_common(FunctionCallInfo fcinfo, HeapTupleForceOption heap_force_opt) } /* - * Before entering the critical section, pin the visibility map page - * if it appears to be necessary. + * Before entering the critical section, pin and lock the visibility + * map page if it appears to be necessary. */ if (heap_force_opt == HEAP_FORCE_KILL && PageIsAllVisible(page)) + { visibilitymap_pin(rel, blkno, &vmbuf); + LockBuffer(vmbuf, BUFFER_LOCK_EXCLUSIVE); + unlock_vmbuf = true; + } /* No ereport(ERROR) from here until all the changes are logged. */ START_CRIT_SECTION(); @@ -266,10 +272,11 @@ heap_force_common(FunctionCallInfo fcinfo, HeapTupleForceOption heap_force_opt) */ if (PageIsAllVisible(page)) { + if (visibilitymap_clear_locked(rel, blkno, vmbuf, + VISIBILITYMAP_VALID_BITS)) + did_modify_vm = true; + PageClearAllVisible(page); - visibilitymap_clear(rel, blkno, vmbuf, - VISIBILITYMAP_VALID_BITS); - did_modify_vm = true; } } else @@ -320,18 +327,29 @@ heap_force_common(FunctionCallInfo fcinfo, HeapTupleForceOption heap_force_opt) /* XLOG stuff */ if (RelationNeedsWAL(rel)) - log_newpage_buffer(buf, true); + { + XLogRecPtr recptr; + + XLogBeginInsert(); + XLogRegisterBuffer(0, buf, REGBUF_STANDARD | REGBUF_FORCE_IMAGE); + /* Include the VM page if it was modified. */ + if (did_modify_vm) + XLogRegisterBuffer(1, vmbuf, REGBUF_FORCE_IMAGE); + recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI); + if (did_modify_vm) + PageSetLSN(BufferGetPage(vmbuf), recptr); + PageSetLSN(BufferGetPage(buf), recptr); + } } - /* WAL log the VM page if it was modified. */ - if (did_modify_vm && RelationNeedsWAL(rel)) - log_newpage_buffer(vmbuf, false); - END_CRIT_SECTION(); UnlockReleaseBuffer(buf); - if (vmbuf != InvalidBuffer) + if (unlock_vmbuf) + LockBuffer(vmbuf, BUFFER_LOCK_UNLOCK); + + if (BufferIsValid(vmbuf)) ReleaseBuffer(vmbuf); /* Update the current_start_ptr before moving to the next page. */ diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 96c25197788..c3f611a42ed 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -58,7 +58,8 @@ static HeapTuple heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid, CommandId cid, int options); static XLogRecPtr log_heap_update(Relation reln, Buffer oldbuf, - Buffer newbuf, HeapTuple oldtup, + Buffer vmbuffer_old, Buffer newbuf, + Buffer vmbuffer_new, HeapTuple oldtup, HeapTuple newtup, HeapTuple old_key_tuple, bool all_visible_cleared, bool new_all_visible_cleared); #ifdef USE_ASSERT_CHECKING @@ -2083,8 +2084,10 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, TransactionId xid = GetCurrentTransactionId(); HeapTuple heaptup; Buffer buffer; + Page page; Buffer vmbuffer = InvalidBuffer; - bool all_visible_cleared = false; + bool clear_all_visible = false; + bool vmbuffer_modified = false; /* Cheap, simplistic check that the tuple matches the rel's rowtype. */ Assert(HeapTupleHeaderGetNatts(tup->t_data) <= @@ -2108,6 +2111,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, InvalidBuffer, options, bistate, &vmbuffer, NULL, 0); + page = BufferGetPage(buffer); /* * We're about to do the actual insert -- but check for conflict first, to @@ -2126,19 +2130,28 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, */ CheckForSerializableConflictIn(relation, NULL, InvalidBlockNumber); + /* Lock the vmbuffer before the critical section */ + if (PageIsAllVisible(page)) + { + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + clear_all_visible = true; + } + /* NO EREPORT(ERROR) from here till changes are logged */ START_CRIT_SECTION(); RelationPutHeapTuple(relation, buffer, heaptup, (options & HEAP_INSERT_SPECULATIVE) != 0); - if (PageIsAllVisible(BufferGetPage(buffer))) + if (clear_all_visible) { - all_visible_cleared = true; - PageClearAllVisible(BufferGetPage(buffer)); - visibilitymap_clear(relation, - ItemPointerGetBlockNumber(&(heaptup->t_self)), - vmbuffer, VISIBILITYMAP_VALID_BITS); + /* It's possible the VM bits were already clear */ + if (visibilitymap_clear_locked(relation, + ItemPointerGetBlockNumber(&(heaptup->t_self)), + vmbuffer, VISIBILITYMAP_VALID_BITS)) + vmbuffer_modified = true; + + PageClearAllVisible(page); } /* @@ -2160,7 +2173,6 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, xl_heap_insert xlrec; xl_heap_header xlhdr; XLogRecPtr recptr; - Page page = BufferGetPage(buffer); uint8 info = XLOG_HEAP_INSERT; int bufflags = 0; @@ -2185,7 +2197,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, xlrec.offnum = ItemPointerGetOffsetNumber(&heaptup->t_self); xlrec.flags = 0; - if (all_visible_cleared) + if (clear_all_visible) xlrec.flags |= XLH_INSERT_ALL_VISIBLE_CLEARED; if (options & HEAP_INSERT_SPECULATIVE) xlrec.flags |= XLH_INSERT_IS_SPECULATIVE; @@ -2230,15 +2242,28 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, /* filtering by origin on a row level is much more efficient */ XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN); + if (vmbuffer_modified) + XLogRegisterBuffer(HEAP_INSERT_BLKREF_VM, vmbuffer, 0); + recptr = XLogInsert(RM_HEAP_ID, info); PageSetLSN(page, recptr); + + if (vmbuffer_modified) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); UnlockReleaseBuffer(buffer); - if (vmbuffer != InvalidBuffer) + + /* + * We locked vmbuffer if clear_all_visible was true regardless of whether + * or not we ended up modifying the vmbuffer. + */ + if (clear_all_visible) + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + if (BufferIsValid(vmbuffer)) ReleaseBuffer(vmbuffer); /* @@ -2419,8 +2444,9 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, while (ndone < ntuples) { Buffer buffer; - bool all_visible_cleared = false; + bool clear_all_visible = false; bool all_frozen_set = false; + bool vmbuffer_modified = false; int nthispage; CHECK_FOR_INTERRUPTS(); @@ -2462,6 +2488,17 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, if (starting_with_empty_page && (options & HEAP_INSERT_FROZEN)) all_frozen_set = true; + /* + * If clearing all-visible, take the VM buffer lock before entering + * the critical section where that action will be WAL-logged. Setting + * the VM all-frozen is done and WAL-logged separately. + */ + if (PageIsAllVisible(page) && !(options & HEAP_INSERT_FROZEN)) + { + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + clear_all_visible = true; + } + /* NO EREPORT(ERROR) from here till changes are logged */ START_CRIT_SECTION(); @@ -2502,13 +2539,15 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, * If we're only adding already frozen rows to a previously empty * page, mark it as all-visible. */ - if (PageIsAllVisible(page) && !(options & HEAP_INSERT_FROZEN)) + if (clear_all_visible) { - all_visible_cleared = true; + /* It's possible the VM bits were already clear */ + if (visibilitymap_clear_locked(relation, + BufferGetBlockNumber(buffer), + vmbuffer, VISIBILITYMAP_VALID_BITS)) + vmbuffer_modified = true; + PageClearAllVisible(page); - visibilitymap_clear(relation, - BufferGetBlockNumber(buffer), - vmbuffer, VISIBILITYMAP_VALID_BITS); } else if (all_frozen_set) PageSetAllVisible(page); @@ -2554,10 +2593,10 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, tupledata = scratchptr; /* check that the mutually exclusive flags are not both set */ - Assert(!(all_visible_cleared && all_frozen_set)); + Assert(!(clear_all_visible && all_frozen_set)); xlrec->flags = 0; - if (all_visible_cleared) + if (clear_all_visible) xlrec->flags = XLH_INSERT_ALL_VISIBLE_CLEARED; if (all_frozen_set) xlrec->flags = XLH_INSERT_ALL_FROZEN_SET; @@ -2623,6 +2662,8 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, XLogRegisterData(xlrec, tupledata - scratch.data); XLogRegisterBuffer(HEAP_MULTI_INSERT_BLKREF_HEAP, buffer, REGBUF_STANDARD | bufflags); + if (vmbuffer_modified) + XLogRegisterBuffer(HEAP_MULTI_INSERT_BLKREF_VM, vmbuffer, 0); XLogRegisterBufData(HEAP_MULTI_INSERT_BLKREF_HEAP, tupledata, totaldatalen); @@ -2633,10 +2674,19 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, recptr = XLogInsert(RM_HEAP2_ID, info); PageSetLSN(page, recptr); + if (vmbuffer_modified) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); + /* + * We locked vmbuffer if clear_all_visible was true regardless of + * whether or not we ended up modifying the vmbuffer. + */ + if (clear_all_visible) + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + /* * If we've frozen everything on the page, update the visibilitymap. * We're already holding pin on the vmbuffer. @@ -2786,12 +2836,13 @@ heap_delete(Relation relation, ItemPointer tid, BlockNumber block; Buffer buffer; Buffer vmbuffer = InvalidBuffer; + bool vmbuffer_modified = false; TransactionId new_xmax; uint16 new_infomask, new_infomask2; bool have_tuple_lock = false; bool iscombo; - bool all_visible_cleared = false; + bool clear_all_visible = false; HeapTuple old_key_tuple = NULL; /* replica identity of the tuple */ bool old_key_copied = false; @@ -3040,6 +3091,13 @@ l1: xid, LockTupleExclusive, true, &new_xmax, &new_infomask, &new_infomask2); + /* Lock the VM before entering the critical section */ + if (PageIsAllVisible(page)) + { + clear_all_visible = true; + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + } + START_CRIT_SECTION(); /* @@ -3051,12 +3109,14 @@ l1: */ PageSetPrunable(page, xid); - if (PageIsAllVisible(page)) + if (clear_all_visible) { - all_visible_cleared = true; + /* It's possible the VM bits were already clear */ + if (visibilitymap_clear_locked(relation, BufferGetBlockNumber(buffer), + vmbuffer, VISIBILITYMAP_VALID_BITS)) + vmbuffer_modified = true; + PageClearAllVisible(page); - visibilitymap_clear(relation, BufferGetBlockNumber(buffer), - vmbuffer, VISIBILITYMAP_VALID_BITS); } /* store transaction information of xact deleting the tuple */ @@ -3096,7 +3156,7 @@ l1: log_heap_new_cid(relation, &tp); xlrec.flags = 0; - if (all_visible_cleared) + if (clear_all_visible) xlrec.flags |= XLH_DELETE_ALL_VISIBLE_CLEARED; if (changingPart) xlrec.flags |= XLH_DELETE_IS_PARTITION_MOVE; @@ -3137,13 +3197,27 @@ l1: /* filtering by origin on a row level is much more efficient */ XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN); + if (vmbuffer_modified) + XLogRegisterBuffer(HEAP_DELETE_BLKREF_VM, vmbuffer, 0); + recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_DELETE); PageSetLSN(page, recptr); + + if (vmbuffer_modified) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); + /* + * Release VM lock first, since it covers many heap blocks. We locked + * vmbuffer if clear_all_visible was true regardless of whether or not we + * ended up modifying the vmbuffer. + */ + if (clear_all_visible) + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + LockBuffer(buffer, BUFFER_LOCK_UNLOCK); if (vmbuffer != InvalidBuffer) @@ -3261,13 +3335,16 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup, HeapTuple heaptup; HeapTuple old_key_tuple = NULL; bool old_key_copied = false; - Page page; + Page page, + newpage; BlockNumber block; MultiXactStatus mxact_status; Buffer buffer, newbuf, vmbuffer = InvalidBuffer, vmbuffer_new = InvalidBuffer; + bool unlock_vmbuffer = false; + bool unlock_vmbuffer_new = false; bool need_toast; Size newtupsize, pagefree; @@ -3276,8 +3353,10 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup, bool use_hot_update = false; bool summarized_update = false; bool key_intact; - bool all_visible_cleared = false; - bool all_visible_cleared_new = false; + bool clear_all_visible = false; + bool clear_all_visible_new = false; + bool vmbuffer_modified = false; + bool vmbuffer_new_modified = false; bool checked_lockers; bool locker_remains; bool id_has_external = false; @@ -3852,6 +3931,12 @@ l2: Assert(HEAP_XMAX_IS_LOCKED_ONLY(infomask_lock_old_tuple)); + if (PageIsAllVisible(page)) + { + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + unlock_vmbuffer = true; + } + START_CRIT_SECTION(); /* Clear obsolete visibility flags ... */ @@ -3874,10 +3959,13 @@ l2: * overhead would be unchanged, that doesn't seem necessarily * worthwhile. */ - if (PageIsAllVisible(page) && - visibilitymap_clear(relation, block, vmbuffer, - VISIBILITYMAP_ALL_FROZEN)) - cleared_all_frozen = true; + if (PageIsAllVisible(page)) + { + /* It's possible all-frozen was already clear */ + if (visibilitymap_clear_locked(relation, block, vmbuffer, + VISIBILITYMAP_ALL_FROZEN)) + cleared_all_frozen = true; + } MarkBufferDirty(buffer); @@ -3896,12 +3984,24 @@ l2: xlrec.flags = cleared_all_frozen ? XLH_LOCK_ALL_FROZEN_CLEARED : 0; XLogRegisterData(&xlrec, SizeOfHeapLock); + + if (cleared_all_frozen) + XLogRegisterBuffer(HEAP_LOCK_BLKREF_VM, vmbuffer, 0); + recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_LOCK); PageSetLSN(page, recptr); + + if (cleared_all_frozen) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); + /* release VM lock first, since it covers many heap blocks */ + if (unlock_vmbuffer) + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + unlock_vmbuffer = false; + LockBuffer(buffer, BUFFER_LOCK_UNLOCK); /* @@ -3987,6 +4087,8 @@ l2: heaptup = newtup; } + newpage = BufferGetPage(newbuf); + /* * We're about to do the actual update -- check for conflict first, to * avoid possibly having to roll back work we've just done. @@ -4050,6 +4152,69 @@ l2: id_has_external, &old_key_copied); + clear_all_visible = PageIsAllVisible(page); + clear_all_visible_new = newbuf != buffer && PageIsAllVisible(newpage); + + /* + * Clear PD_ALL_VISIBLE flags and reset visibility map bits for any heap + * pages that were all-visible. If there are two heap pages, we may need + * to clear VM bits for both. + */ + if (clear_all_visible && clear_all_visible_new && + vmbuffer_new == vmbuffer) + { + /* + * This is the more complicated case: both the new and old heap pages + * are all-visible and both their VM bits are on the same page of the + * VM, so we register a single VM buffer as HEAP_UPDATE_BLKREF_VM_NEW + * in the WAL record. We must be careful to only lock and register one + * buffer, even though we modify it twice -- once for each heap + * block's VM bits. + */ + LockBuffer(vmbuffer_new, BUFFER_LOCK_EXCLUSIVE); + unlock_vmbuffer_new = true; + + /* We will not lock or attempt to modify old VM buffer */ + } + else + { + /* + * In all the remaining cases, we will clear at most one heap block's + * VM bits per VM page. + */ + Buffer vmbuffers[2] = { + clear_all_visible ? vmbuffer : InvalidBuffer, + clear_all_visible_new ? vmbuffer_new : InvalidBuffer + }; + + /* + * When both pages need different VM pages cleared, acquire the VM + * buffer locks in VM block order to avoid deadlocks between backends + * updating tuples in opposite directions across VM pages. + */ + if (clear_all_visible && clear_all_visible_new && + BufferGetBlockNumber(vmbuffers[0]) > BufferGetBlockNumber(vmbuffers[1])) + { + Buffer swap = vmbuffers[0]; + + vmbuffers[0] = vmbuffers[1]; + vmbuffers[1] = swap; + } + + Assert((!BufferIsValid(vmbuffers[0]) && !BufferIsValid(vmbuffers[1])) || + vmbuffers[0] != vmbuffers[1]); + + if (BufferIsValid(vmbuffers[0])) + LockBuffer(vmbuffers[0], BUFFER_LOCK_EXCLUSIVE); + if (BufferIsValid(vmbuffers[1])) + LockBuffer(vmbuffers[1], BUFFER_LOCK_EXCLUSIVE); + + if (clear_all_visible) + unlock_vmbuffer = true; + if (clear_all_visible_new) + unlock_vmbuffer_new = true; + } + /* NO EREPORT(ERROR) from here till changes are logged */ START_CRIT_SECTION(); @@ -4086,7 +4251,6 @@ l2: RelationPutHeapTuple(relation, newbuf, heaptup, false); /* insert new tuple */ - /* Clear obsolete visibility flags, possibly set by ourselves above... */ oldtup.t_data->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED); oldtup.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED; @@ -4101,19 +4265,38 @@ l2: oldtup.t_data->t_ctid = heaptup->t_self; /* clear PD_ALL_VISIBLE flags, reset all visibilitymap bits */ - if (PageIsAllVisible(BufferGetPage(buffer))) + if (clear_all_visible) { - all_visible_cleared = true; - PageClearAllVisible(BufferGetPage(buffer)); - visibilitymap_clear(relation, BufferGetBlockNumber(buffer), - vmbuffer, VISIBILITYMAP_VALID_BITS); + /* It's possible the VM bits were already clear */ + if (visibilitymap_clear_locked(relation, block, + vmbuffer, VISIBILITYMAP_VALID_BITS)) + { + /* + * If both heap blocks' VM bits are on the same VM buffer, + * vmbuffer_new and vmbuffer will be equal. In that case only + * vmbuffer_new is registered in the WAL record (see + * log_heap_update), so attribute any change to the old heap + * block's VM bits to vmbuffer_new as well. + */ + if (vmbuffer == vmbuffer_new) + vmbuffer_new_modified = true; + else + vmbuffer_modified = true; + } + + PageClearAllVisible(page); } - if (newbuf != buffer && PageIsAllVisible(BufferGetPage(newbuf))) + if (clear_all_visible_new) { - all_visible_cleared_new = true; - PageClearAllVisible(BufferGetPage(newbuf)); - visibilitymap_clear(relation, BufferGetBlockNumber(newbuf), - vmbuffer_new, VISIBILITYMAP_VALID_BITS); + /* + * If both heap blocks' VM bits are on the same VM buffer, this will + * clear the new heap block's VM bits from the shared vmbuffer. + */ + if (visibilitymap_clear_locked(relation, BufferGetBlockNumber(newbuf), + vmbuffer_new, VISIBILITYMAP_VALID_BITS)) + vmbuffer_new_modified = true; + + PageClearAllVisible(newpage); } if (newbuf != buffer) @@ -4136,19 +4319,30 @@ l2: } recptr = log_heap_update(relation, buffer, - newbuf, &oldtup, heaptup, + vmbuffer_modified ? vmbuffer : InvalidBuffer, + newbuf, + vmbuffer_new_modified ? vmbuffer_new : InvalidBuffer, + &oldtup, heaptup, old_key_tuple, - all_visible_cleared, - all_visible_cleared_new); + clear_all_visible, + clear_all_visible_new); if (newbuf != buffer) - { - PageSetLSN(BufferGetPage(newbuf), recptr); - } + PageSetLSN(newpage, recptr); PageSetLSN(BufferGetPage(buffer), recptr); + + if (vmbuffer_modified) + PageSetLSN(BufferGetPage(vmbuffer), recptr); + if (vmbuffer_new_modified) + PageSetLSN(BufferGetPage(vmbuffer_new), recptr); } END_CRIT_SECTION(); + if (unlock_vmbuffer) + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + if (unlock_vmbuffer_new) + LockBuffer(vmbuffer_new, BUFFER_LOCK_UNLOCK); + if (newbuf != buffer) LockBuffer(newbuf, BUFFER_LOCK_UNLOCK); LockBuffer(buffer, BUFFER_LOCK_UNLOCK); @@ -4586,6 +4780,7 @@ heap_lock_tuple(Relation relation, HeapTuple tuple, ItemId lp; Page page; Buffer vmbuffer = InvalidBuffer; + bool unlock_vmbuffer = false; BlockNumber block; TransactionId xid, xmax; @@ -5166,6 +5361,13 @@ failed: GetCurrentTransactionId(), mode, false, &xid, &new_infomask, &new_infomask2); + /* Lock VM buffer before entering critical section */ + if (PageIsAllVisible(page)) + { + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + unlock_vmbuffer = true; + } + START_CRIT_SECTION(); /* @@ -5197,11 +5399,13 @@ failed: tuple->t_data->t_ctid = *tid; /* Clear only the all-frozen bit on visibility map if needed */ - if (PageIsAllVisible(page) && - visibilitymap_clear(relation, block, vmbuffer, - VISIBILITYMAP_ALL_FROZEN)) - cleared_all_frozen = true; - + if (PageIsAllVisible(page)) + { + /* It's possible all-frozen was already clear */ + if (visibilitymap_clear_locked(relation, block, vmbuffer, + VISIBILITYMAP_ALL_FROZEN)) + cleared_all_frozen = true; + } MarkBufferDirty(*buffer); @@ -5232,19 +5436,31 @@ failed: xlrec.flags = cleared_all_frozen ? XLH_LOCK_ALL_FROZEN_CLEARED : 0; XLogRegisterData(&xlrec, SizeOfHeapLock); + if (cleared_all_frozen) + XLogRegisterBuffer(HEAP_LOCK_BLKREF_VM, vmbuffer, 0); + /* we don't decode row locks atm, so no need to log the origin */ recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_LOCK); PageSetLSN(page, recptr); + + if (cleared_all_frozen) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); + /* release VM lock first, since it covers many heap blocks */ + if (unlock_vmbuffer) + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + unlock_vmbuffer = false; + result = TM_Ok; out_locked: LockBuffer(*buffer, BUFFER_LOCK_UNLOCK); + Assert(!unlock_vmbuffer); out_unlocked: if (BufferIsValid(vmbuffer)) @@ -5707,6 +5923,7 @@ heap_lock_updated_tuple_rec(Relation rel, TransactionId priorXmax, ItemPointerData tupid; HeapTupleData mytup; Buffer buf; + Page page; uint16 new_infomask, new_infomask2, old_infomask, @@ -5716,6 +5933,7 @@ heap_lock_updated_tuple_rec(Relation rel, TransactionId priorXmax, bool cleared_all_frozen = false; bool pinned_desired_page; Buffer vmbuffer = InvalidBuffer; + bool unlock_vmbuffer = false; BlockNumber block; ItemPointerCopy(tid, &tupid); @@ -5724,6 +5942,7 @@ heap_lock_updated_tuple_rec(Relation rel, TransactionId priorXmax, { new_infomask = 0; new_xmax = InvalidTransactionId; + cleared_all_frozen = false; block = ItemPointerGetBlockNumber(&tupid); ItemPointerCopy(&tupid, &(mytup.t_self)); @@ -5743,13 +5962,15 @@ heap_lock_updated_tuple_rec(Relation rel, TransactionId priorXmax, l4: CHECK_FOR_INTERRUPTS(); + page = BufferGetPage(buf); + /* * Before locking the buffer, pin the visibility map page if it * appears to be necessary. Since we haven't got the lock yet, * someone else might be in the middle of changing this, so we'll need * to recheck after we have the lock. */ - if (PageIsAllVisible(BufferGetPage(buf))) + if (PageIsAllVisible(page)) { visibilitymap_pin(rel, block, &vmbuffer); pinned_desired_page = true; @@ -5770,7 +5991,7 @@ l4: * this page. If this page isn't all-visible, we won't use the vm * page, but we hold onto such a pin till the end of the function. */ - if (!pinned_desired_page && PageIsAllVisible(BufferGetPage(buf))) + if (!pinned_desired_page && PageIsAllVisible(page)) { LockBuffer(buf, BUFFER_LOCK_UNLOCK); visibilitymap_pin(rel, block, &vmbuffer); @@ -5951,10 +6172,11 @@ l4: xid, mode, false, &new_xmax, &new_infomask, &new_infomask2); - if (PageIsAllVisible(BufferGetPage(buf)) && - visibilitymap_clear(rel, block, vmbuffer, - VISIBILITYMAP_ALL_FROZEN)) - cleared_all_frozen = true; + if (PageIsAllVisible(page)) + { + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + unlock_vmbuffer = true; + } START_CRIT_SECTION(); @@ -5967,12 +6189,19 @@ l4: MarkBufferDirty(buf); + if (PageIsAllVisible(page)) + { + /* It's possible all-frozen was already clear */ + if (visibilitymap_clear_locked(rel, block, vmbuffer, + VISIBILITYMAP_ALL_FROZEN)) + cleared_all_frozen = true; + } + /* XLOG stuff */ if (RelationNeedsWAL(rel)) { xl_heap_lock_updated xlrec; XLogRecPtr recptr; - Page page = BufferGetPage(buf); XLogBeginInsert(); XLogRegisterBuffer(HEAP_LOCK_BLKREF_HEAP, buf, REGBUF_STANDARD); @@ -5985,13 +6214,26 @@ l4: XLogRegisterData(&xlrec, SizeOfHeapLockUpdated); + if (cleared_all_frozen) + XLogRegisterBuffer(HEAP_LOCK_BLKREF_VM, vmbuffer, 0); + recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_LOCK_UPDATED); PageSetLSN(page, recptr); + + if (cleared_all_frozen) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); + /* release VM lock first, since it covers many heap blocks */ + if (unlock_vmbuffer) + { + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + unlock_vmbuffer = false; + } + next: /* if we find the end of update chain, we're done. */ if (mytup.t_data->t_infomask & HEAP_XMAX_INVALID || @@ -8848,8 +9090,9 @@ log_heap_visible(Relation rel, Buffer heap_buffer, Buffer vm_buffer, * have modified the buffer(s) and marked them dirty. */ static XLogRecPtr -log_heap_update(Relation reln, Buffer oldbuf, - Buffer newbuf, HeapTuple oldtup, HeapTuple newtup, +log_heap_update(Relation reln, Buffer oldbuf, Buffer vmbuffer_old, + Buffer newbuf, Buffer vmbuffer_new, + HeapTuple oldtup, HeapTuple newtup, HeapTuple old_key_tuple, bool all_visible_cleared, bool new_all_visible_cleared) { @@ -9058,6 +9301,20 @@ log_heap_update(Relation reln, Buffer oldbuf, old_key_tuple->t_len - SizeofHeapTupleHeader); } + /* + * Register VM buffers. If the old and new heap pages' VM bits are on the + * same VM page, the caller passes only vmbuffer_new (mirroring the heap + * page convention where block 0 = new is always registered). + */ + Assert((BufferIsInvalid(vmbuffer_old) && BufferIsInvalid(vmbuffer_new)) || + (vmbuffer_old != vmbuffer_new)); + + if (BufferIsValid(vmbuffer_new)) + XLogRegisterBuffer(HEAP_UPDATE_BLKREF_VM_NEW, vmbuffer_new, 0); + + if (BufferIsValid(vmbuffer_old)) + XLogRegisterBuffer(HEAP_UPDATE_BLKREF_VM_OLD, vmbuffer_old, 0); + /* filtering by origin on a row level is much more efficient */ XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN); diff --git a/src/backend/access/heap/heapam_xlog.c b/src/backend/access/heap/heapam_xlog.c index 87b5c44fd46..41bd03e80a0 100644 --- a/src/backend/access/heap/heapam_xlog.c +++ b/src/backend/access/heap/heapam_xlog.c @@ -22,6 +22,70 @@ #include "storage/freespace.h" #include "storage/standby.h" +/* + * Clear visibility map bits for a single heap block during heap redo. + * + * Used by records that modify one heap block and, at most, its corresponding + * VM block (insert, delete, multi_insert, lock). Records that can touch + * multiple heap or VM blocks (e.g. updates) replay the VM changes inline + * instead. + * + * 'record' is the WAL record being replayed + * 'target_locator' identifies the relation whose VM is being updated + * 'heap_blkno' is the heap block whose VM bits should be cleared + * 'wal_vm_block_id' is the WAL block reference id of the VM page + * 'flags' specifies which visibility map bits to clear + */ +static void +heap_xlog_vm_clear(XLogReaderState *record, + RelFileLocator target_locator, + BlockNumber heap_blkno, + uint8 wal_vm_block_id, uint8 flags) +{ + XLogRecPtr lsn = record->EndRecPtr; + Relation reln = CreateFakeRelcacheEntry(target_locator); + Buffer vmbuffer = InvalidBuffer; + + /* + * If the vmbuffer was registered, use the recovery-specific routines to + * read it. These will either apply an FPI or indicate that we should + * clear the requested bits ourselves. + * + * Originally, clearing the VM did not register the VM buffers, so since + * registering the VM buffer was a bug fix, we keep a fallback path to + * support replay of WAL generated from before the fix. + */ + if (XLogRecHasBlockRef(record, wal_vm_block_id)) + { + if (XLogReadBufferForRedo(record, wal_vm_block_id, + &vmbuffer) == BLK_NEEDS_REDO) + { + if (visibilitymap_clear_locked(reln, + heap_blkno, vmbuffer, + flags)) + PageSetLSN(BufferGetPage(vmbuffer), lsn); + } + if (BufferIsValid(vmbuffer)) + UnlockReleaseBuffer(vmbuffer); + } + else + { + /* + * This is the backwards compatibility path to clear VM bits for + * records predating VM buffer registration. It is also invoked if the + * heap page's PD_ALL_VISIBLE was cleared but the VM bits were already + * clear. The WAL record flags do not distinguish between these two + * situations. Though this is wasted effort, the behavior is + * historical and the situation should be rare. + */ + visibilitymap_pin(reln, heap_blkno, &vmbuffer); + visibilitymap_clear(reln, heap_blkno, vmbuffer, flags); + ReleaseBuffer(vmbuffer); + } + + FreeFakeRelcacheEntry(reln); +} + /* * Replay XLOG_HEAP2_PRUNE_* records. @@ -360,15 +424,9 @@ heap_xlog_delete(XLogReaderState *record) * already up-to-date. */ if (xlrec->flags & XLH_DELETE_ALL_VISIBLE_CLEARED) - { - Relation reln = CreateFakeRelcacheEntry(target_locator); - Buffer vmbuffer = InvalidBuffer; - - visibilitymap_pin(reln, blkno, &vmbuffer); - visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS); - ReleaseBuffer(vmbuffer); - FreeFakeRelcacheEntry(reln); - } + heap_xlog_vm_clear(record, target_locator, + blkno, HEAP_DELETE_BLKREF_VM, + VISIBILITYMAP_VALID_BITS); if (XLogReadBufferForRedo(record, HEAP_DELETE_BLKREF_HEAP, &buffer) == BLK_NEEDS_REDO) @@ -449,15 +507,9 @@ heap_xlog_insert(XLogReaderState *record) * already up-to-date. */ if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) - { - Relation reln = CreateFakeRelcacheEntry(target_locator); - Buffer vmbuffer = InvalidBuffer; - - visibilitymap_pin(reln, blkno, &vmbuffer); - visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS); - ReleaseBuffer(vmbuffer); - FreeFakeRelcacheEntry(reln); - } + heap_xlog_vm_clear(record, target_locator, + blkno, HEAP_INSERT_BLKREF_VM, + VISIBILITYMAP_VALID_BITS); /* * If we inserted the first and only tuple on the page, re-initialize the @@ -573,17 +625,15 @@ heap_xlog_multi_insert(XLogReaderState *record) /* * The visibility map may need to be fixed even if the heap page is * already up-to-date. + * + * Clear the VM (if needed) before clearing the heap page-level visibility + * flag (PD_ALL_VISIBLE) to prevent the heap page from being marked + * all-visible in the VM while its PD_ALL_VISIBLE is clear. */ if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) - { - Relation reln = CreateFakeRelcacheEntry(rlocator); - Buffer vmbuffer = InvalidBuffer; - - visibilitymap_pin(reln, blkno, &vmbuffer); - visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS); - ReleaseBuffer(vmbuffer); - FreeFakeRelcacheEntry(reln); - } + heap_xlog_vm_clear(record, rlocator, + blkno, HEAP_MULTI_INSERT_BLKREF_VM, + VISIBILITYMAP_VALID_BITS); if (isinit) { @@ -698,6 +748,8 @@ heap_xlog_update(XLogReaderState *record, bool hot_update) Buffer obuffer, nbuffer; Page page; + bool new_cleared, + old_cleared; OffsetNumber offnum; ItemId lp = NULL; HeapTupleData oldtup; @@ -737,14 +789,92 @@ heap_xlog_update(XLogReaderState *record, bool hot_update) * The visibility map may need to be fixed even if the heap page is * already up-to-date. */ - if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED) + new_cleared = (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED) != 0; + old_cleared = (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED) != 0; + if (new_cleared || old_cleared) { Relation reln = CreateFakeRelcacheEntry(rlocator); - Buffer vmbuffer = InvalidBuffer; + bool has_vm_old = XLogRecHasBlockRef(record, HEAP_UPDATE_BLKREF_VM_OLD); + bool has_vm_new = XLogRecHasBlockRef(record, HEAP_UPDATE_BLKREF_VM_NEW); + + if (has_vm_new) + { + Buffer vmbuffer_new = InvalidBuffer; + bool vmbuffer_new_modified = false; + + Assert(new_cleared); + if (XLogReadBufferForRedo(record, HEAP_UPDATE_BLKREF_VM_NEW, &vmbuffer_new) == + BLK_NEEDS_REDO) + { + /* + * If both the old and new heap pages were all-visible and + * their VM bits are on the same VM page, that single VM page + * is registered as HEAP_UPDATE_BLKREF_VM_NEW. Clear both heap + * blocks' VM bits from the single provided VM buffer. + * + * We must verify that oldblk's VM bits really are on this VM + * page, rather than relying on the absence of a separate + * VM_OLD block reference: VM_OLD is also omitted when oldblk + * is on a different VM page but its bit was already clear. + */ + if (old_cleared && visibilitymap_pin_ok(oldblk, vmbuffer_new)) + { + if (visibilitymap_clear_locked(reln, oldblk, vmbuffer_new, + VISIBILITYMAP_VALID_BITS)) + vmbuffer_new_modified = true; + } + if (visibilitymap_clear_locked(reln, newblk, vmbuffer_new, + VISIBILITYMAP_VALID_BITS)) + vmbuffer_new_modified = true; + + if (vmbuffer_new_modified) + PageSetLSN(BufferGetPage(vmbuffer_new), lsn); + } + if (BufferIsValid(vmbuffer_new)) + UnlockReleaseBuffer(vmbuffer_new); + } + if (has_vm_old) + { + Buffer vmbuffer_old = InvalidBuffer; + + Assert(old_cleared); + if (XLogReadBufferForRedo(record, HEAP_UPDATE_BLKREF_VM_OLD, &vmbuffer_old) == + BLK_NEEDS_REDO) + { + if (visibilitymap_clear_locked(reln, oldblk, vmbuffer_old, + VISIBILITYMAP_VALID_BITS)) + PageSetLSN(BufferGetPage(vmbuffer_old), lsn); + } + if (BufferIsValid(vmbuffer_old)) + UnlockReleaseBuffer(vmbuffer_old); + } + if (!has_vm_old && !has_vm_new) + { + /* + * Backwards compatibility path. Previously, the VM buffers were + * not registered in the WAL record. We need this path to replay + * WAL generated by a not-yet-patched primary during upgrade. + */ + if (old_cleared) + { + Buffer vmbuffer = InvalidBuffer; + + visibilitymap_pin(reln, oldblk, &vmbuffer); + visibilitymap_clear(reln, oldblk, vmbuffer, + VISIBILITYMAP_VALID_BITS); + ReleaseBuffer(vmbuffer); + } + if (new_cleared) + { + Buffer vmbuffer = InvalidBuffer; + + visibilitymap_pin(reln, newblk, &vmbuffer); + visibilitymap_clear(reln, newblk, vmbuffer, + VISIBILITYMAP_VALID_BITS); + ReleaseBuffer(vmbuffer); + } + } - visibilitymap_pin(reln, oldblk, &vmbuffer); - visibilitymap_clear(reln, oldblk, vmbuffer, VISIBILITYMAP_VALID_BITS); - ReleaseBuffer(vmbuffer); FreeFakeRelcacheEntry(reln); } @@ -793,7 +923,7 @@ heap_xlog_update(XLogReaderState *record, bool hot_update) /* Mark the page as a candidate for pruning */ PageSetPrunable(page, XLogRecGetXid(record)); - if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED) + if (old_cleared) PageClearAllVisible(page); PageSetLSN(page, lsn); @@ -819,21 +949,6 @@ heap_xlog_update(XLogReaderState *record, bool hot_update) newaction = XLogReadBufferForRedo(record, HEAP_UPDATE_BLKREF_HEAP_NEW, &nbuffer); - /* - * The visibility map may need to be fixed even if the heap page is - * already up-to-date. - */ - if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED) - { - Relation reln = CreateFakeRelcacheEntry(rlocator); - Buffer vmbuffer = InvalidBuffer; - - visibilitymap_pin(reln, newblk, &vmbuffer); - visibilitymap_clear(reln, newblk, vmbuffer, VISIBILITYMAP_VALID_BITS); - ReleaseBuffer(vmbuffer); - FreeFakeRelcacheEntry(reln); - } - /* Deal with new tuple */ if (newaction == BLK_NEEDS_REDO) { @@ -930,7 +1045,7 @@ heap_xlog_update(XLogReaderState *record, bool hot_update) if (offnum == InvalidOffsetNumber) elog(PANIC, "failed to add tuple"); - if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED) + if (new_cleared) PageClearAllVisible(page); freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */ @@ -1022,20 +1137,15 @@ heap_xlog_lock(XLogReaderState *record) */ if (xlrec->flags & XLH_LOCK_ALL_FROZEN_CLEARED) { - RelFileLocator rlocator; - Buffer vmbuffer = InvalidBuffer; BlockNumber block; - Relation reln; + RelFileLocator rlocator; XLogRecGetBlockTag(record, HEAP_LOCK_BLKREF_HEAP, &rlocator, NULL, &block); - reln = CreateFakeRelcacheEntry(rlocator); - - visibilitymap_pin(reln, block, &vmbuffer); - visibilitymap_clear(reln, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN); - ReleaseBuffer(vmbuffer); - FreeFakeRelcacheEntry(reln); + heap_xlog_vm_clear(record, rlocator, + block, HEAP_LOCK_BLKREF_VM, + VISIBILITYMAP_ALL_FROZEN); } if (XLogReadBufferForRedo(record, HEAP_LOCK_BLKREF_HEAP, @@ -1100,20 +1210,15 @@ heap_xlog_lock_updated(XLogReaderState *record) */ if (xlrec->flags & XLH_LOCK_ALL_FROZEN_CLEARED) { - RelFileLocator rlocator; - Buffer vmbuffer = InvalidBuffer; BlockNumber block; - Relation reln; + RelFileLocator rlocator; XLogRecGetBlockTag(record, HEAP_LOCK_BLKREF_HEAP, &rlocator, NULL, &block); - reln = CreateFakeRelcacheEntry(rlocator); - - visibilitymap_pin(reln, block, &vmbuffer); - visibilitymap_clear(reln, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN); - ReleaseBuffer(vmbuffer); - FreeFakeRelcacheEntry(reln); + heap_xlog_vm_clear(record, rlocator, + block, HEAP_LOCK_BLKREF_VM, + VISIBILITYMAP_ALL_FROZEN); } if (XLogReadBufferForRedo(record, HEAP_LOCK_BLKREF_HEAP, diff --git a/src/backend/access/heap/visibilitymap.c b/src/backend/access/heap/visibilitymap.c index 1874a3fda37..d44620eca7f 100644 --- a/src/backend/access/heap/visibilitymap.c +++ b/src/backend/access/heap/visibilitymap.c @@ -135,9 +135,38 @@ static Buffer vm_extend(Relation rel, BlockNumber vm_nblocks); * You must pass a buffer containing the correct map page to this function. * Call visibilitymap_pin first to pin the right one. This function doesn't do * any I/O. Returns true if any bits have been cleared and false otherwise. + * + * Most callers should use visibilitymap_clear_locked rather than this + * function. It is usually necessary to register the VM buffer in the WAL + * record, and this necessitates holding the lock for longer than it is held + * here. However, we retain this function for behavioral compatibility on the + * back branches (out-of-tree callers may expect it to take the lock). And, + * since we have it, we use it for in-tree callers that don't have to manage + * the VM buffer lock themselves. */ bool visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags) +{ + bool cleared = false; + + LockBuffer(vmbuf, BUFFER_LOCK_EXCLUSIVE); + + cleared = visibilitymap_clear_locked(rel, heapBlk, vmbuf, flags); + + LockBuffer(vmbuf, BUFFER_LOCK_UNLOCK); + + return cleared; +} + +/* + * Clear specified bits, caller holds VM lock + * + * Like visibilitymap_clear(), except the caller must already hold the VM + * buffer exclusive lock and is responsible for unlocking it. + * Returns true if any bits were actually cleared, false otherwise. + */ +bool +visibilitymap_clear_locked(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags) { BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(heapBlk); int mapByte = HEAPBLK_TO_MAPBYTE(heapBlk); @@ -157,7 +186,8 @@ visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags if (!BufferIsValid(vmbuf) || BufferGetBlockNumber(vmbuf) != mapBlock) elog(ERROR, "wrong buffer passed to visibilitymap_clear"); - LockBuffer(vmbuf, BUFFER_LOCK_EXCLUSIVE); + Assert(BufferIsExclusiveLocked(vmbuf)); + map = PageGetContents(BufferGetPage(vmbuf)); if (map[mapByte] & mask) @@ -168,8 +198,6 @@ visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags cleared = true; } - LockBuffer(vmbuf, BUFFER_LOCK_UNLOCK); - return cleared; } diff --git a/src/bin/pg_walsummary/t/002_blocks.pl b/src/bin/pg_walsummary/t/002_blocks.pl index 0f98c7df82e..fcb701e1b98 100644 --- a/src/bin/pg_walsummary/t/002_blocks.pl +++ b/src/bin/pg_walsummary/t/002_blocks.pl @@ -93,13 +93,14 @@ my $filename = sprintf "%s/pg_wal/summaries/%08s%08s%08s%08s%08s.summary", split(m@/@, $end_lsn); ok(-f $filename, "WAL summary file exists"); -# Run pg_walsummary on it. We expect exactly two blocks to be modified, -# block 0 and one other. +# Run pg_walsummary on it. We expect exactly three blocks to be modified, +# block 0 (old tuple), another block (new tuple), and the block for the VM. my ($stdout, $stderr) = run_command([ 'pg_walsummary', '-i', $filename ]); note($stdout); @lines = split(/\n/, $stdout); like($stdout, qr/FORK main: block 0$/m, "stdout shows block 0 modified"); +like($stdout, qr/FORK vm: block 0$/m, "stdout shows VM block 0 modified"); is($stderr, '', 'stderr is empty'); -is(0 + @lines, 2, "UPDATE modified 2 blocks"); +is(0 + @lines, 3, "UPDATE modified 3 blocks"); done_testing(); diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h index 92744c53899..c4c3c3f15fa 100644 --- a/src/include/access/heapam_xlog.h +++ b/src/include/access/heapam_xlog.h @@ -111,6 +111,7 @@ /* This is what we need to know about delete */ #define HEAP_DELETE_BLKREF_HEAP 0 +#define HEAP_DELETE_BLKREF_VM 1 typedef struct xl_heap_delete { @@ -160,6 +161,7 @@ typedef struct xl_heap_header /* This is what we need to know about insert */ #define HEAP_INSERT_BLKREF_HEAP 0 +#define HEAP_INSERT_BLKREF_VM 1 typedef struct xl_heap_insert { @@ -179,6 +181,7 @@ typedef struct xl_heap_insert * (XLOG_HEAP_INIT_PAGE). */ #define HEAP_MULTI_INSERT_BLKREF_HEAP 0 +#define HEAP_MULTI_INSERT_BLKREF_VM 1 /* * In HEAP_MULTI_INSERT_BLKREF_HEAP's data portion, there is an @@ -222,10 +225,21 @@ typedef struct xl_multi_insert_tuple * * HEAP_UPDATE_BLKREF_HEAP_OLD: old page, if different. (no data, just a reference * to the block) + * + * HEAP_UPDATE_BLKREF_VM_NEW: VM page covering the new heap page. Registered + * when XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED is set and the new heap page's VM + * bit was actually cleared. Also covers the old heap page's VM bits when both + * heap pages map to the same VM page. + * + * HEAP_UPDATE_BLKREF_VM_OLD: VM page covering the old heap page. Only + * registered when XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED is set, the old heap + * page's VM bits are on a different VM page from the new heap page's, and the + * old heap page's VM bit was actually cleared. */ - #define HEAP_UPDATE_BLKREF_HEAP_NEW 0 #define HEAP_UPDATE_BLKREF_HEAP_OLD 1 +#define HEAP_UPDATE_BLKREF_VM_NEW 2 +#define HEAP_UPDATE_BLKREF_VM_OLD 3 typedef struct xl_heap_update { @@ -406,6 +420,7 @@ typedef struct xlhp_prune_items /* This is what we need to know about lock */ #define HEAP_LOCK_BLKREF_HEAP 0 +#define HEAP_LOCK_BLKREF_VM 1 typedef struct xl_heap_lock { diff --git a/src/include/access/visibilitymap.h b/src/include/access/visibilitymap.h index ea889bf9ec7..1bc59c9ac33 100644 --- a/src/include/access/visibilitymap.h +++ b/src/include/access/visibilitymap.h @@ -26,6 +26,8 @@ #define VM_ALL_FROZEN(r, b, v) \ ((visibilitymap_get_status((r), (b), (v)) & VISIBILITYMAP_ALL_FROZEN) != 0) +extern bool visibilitymap_clear_locked(Relation rel, BlockNumber heapBlk, + Buffer vmbuf, uint8 flags); extern bool visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags); extern void visibilitymap_pin(Relation rel, BlockNumber heapBlk, -- 2.47.3