diff options
Diffstat (limited to 'src/backend/access/heap/heapam_xlog.c')
| -rw-r--r-- | src/backend/access/heap/heapam_xlog.c | 1339 |
1 files changed, 1339 insertions, 0 deletions
diff --git a/src/backend/access/heap/heapam_xlog.c b/src/backend/access/heap/heapam_xlog.c new file mode 100644 index 00000000000..6dae7233ecb --- /dev/null +++ b/src/backend/access/heap/heapam_xlog.c @@ -0,0 +1,1339 @@ +/*------------------------------------------------------------------------- + * + * heapam_xlog.c + * WAL replay logic for heap access method. + * + * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/access/heap/heapam_xlog.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/bufmask.h" +#include "access/heapam.h" +#include "access/visibilitymap.h" +#include "access/xlog.h" +#include "access/xlogutils.h" +#include "storage/freespace.h" +#include "storage/standby.h" + + +/* + * Replay XLOG_HEAP2_PRUNE_* records. + */ +static void +heap_xlog_prune_freeze(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + char *maindataptr = XLogRecGetData(record); + xl_heap_prune xlrec; + Buffer buffer; + RelFileLocator rlocator; + BlockNumber blkno; + XLogRedoAction action; + + XLogRecGetBlockTag(record, 0, &rlocator, NULL, &blkno); + memcpy(&xlrec, maindataptr, SizeOfHeapPrune); + maindataptr += SizeOfHeapPrune; + + /* + * We will take an ordinary exclusive lock or a cleanup lock depending on + * whether the XLHP_CLEANUP_LOCK flag is set. With an ordinary exclusive + * lock, we better not be doing anything that requires moving existing + * tuple data. + */ + Assert((xlrec.flags & XLHP_CLEANUP_LOCK) != 0 || + (xlrec.flags & (XLHP_HAS_REDIRECTIONS | XLHP_HAS_DEAD_ITEMS)) == 0); + + /* + * We are about to remove and/or freeze tuples. In Hot Standby mode, + * ensure that there are no queries running for which the removed tuples + * are still visible or which still consider the frozen xids as running. + * The conflict horizon XID comes after xl_heap_prune. + */ + if ((xlrec.flags & XLHP_HAS_CONFLICT_HORIZON) != 0) + { + TransactionId snapshot_conflict_horizon; + + /* memcpy() because snapshot_conflict_horizon is stored unaligned */ + memcpy(&snapshot_conflict_horizon, maindataptr, sizeof(TransactionId)); + maindataptr += sizeof(TransactionId); + + if (InHotStandby) + ResolveRecoveryConflictWithSnapshot(snapshot_conflict_horizon, + (xlrec.flags & XLHP_IS_CATALOG_REL) != 0, + rlocator); + } + + /* + * If we have a full-page image, restore it and we're done. + */ + action = XLogReadBufferForRedoExtended(record, 0, RBM_NORMAL, + (xlrec.flags & XLHP_CLEANUP_LOCK) != 0, + &buffer); + if (action == BLK_NEEDS_REDO) + { + Page page = (Page) BufferGetPage(buffer); + OffsetNumber *redirected; + OffsetNumber *nowdead; + OffsetNumber *nowunused; + int nredirected; + int ndead; + int nunused; + int nplans; + Size datalen; + xlhp_freeze_plan *plans; + OffsetNumber *frz_offsets; + char *dataptr = XLogRecGetBlockData(record, 0, &datalen); + + heap_xlog_deserialize_prune_and_freeze(dataptr, xlrec.flags, + &nplans, &plans, &frz_offsets, + &nredirected, &redirected, + &ndead, &nowdead, + &nunused, &nowunused); + + /* + * Update all line pointers per the record, and repair fragmentation + * if needed. + */ + if (nredirected > 0 || ndead > 0 || nunused > 0) + heap_page_prune_execute(buffer, + (xlrec.flags & XLHP_CLEANUP_LOCK) == 0, + redirected, nredirected, + nowdead, ndead, + nowunused, nunused); + + /* Freeze tuples */ + for (int p = 0; p < nplans; p++) + { + HeapTupleFreeze frz; + + /* + * Convert freeze plan representation from WAL record into + * per-tuple format used by heap_execute_freeze_tuple + */ + frz.xmax = plans[p].xmax; + frz.t_infomask2 = plans[p].t_infomask2; + frz.t_infomask = plans[p].t_infomask; + frz.frzflags = plans[p].frzflags; + frz.offset = InvalidOffsetNumber; /* unused, but be tidy */ + + for (int i = 0; i < plans[p].ntuples; i++) + { + OffsetNumber offset = *(frz_offsets++); + ItemId lp; + HeapTupleHeader tuple; + + lp = PageGetItemId(page, offset); + tuple = (HeapTupleHeader) PageGetItem(page, lp); + heap_execute_freeze_tuple(tuple, &frz); + } + } + + /* There should be no more data */ + Assert((char *) frz_offsets == dataptr + datalen); + + /* + * Note: we don't worry about updating the page's prunability hints. + * At worst this will cause an extra prune cycle to occur soon. + */ + + PageSetLSN(page, lsn); + MarkBufferDirty(buffer); + } + + /* + * If we released any space or line pointers, update the free space map. + * + * Do this regardless of a full-page image being applied, since the FSM + * data is not in the page anyway. + */ + if (BufferIsValid(buffer)) + { + if (xlrec.flags & (XLHP_HAS_REDIRECTIONS | + XLHP_HAS_DEAD_ITEMS | + XLHP_HAS_NOW_UNUSED_ITEMS)) + { + Size freespace = PageGetHeapFreeSpace(BufferGetPage(buffer)); + + UnlockReleaseBuffer(buffer); + + XLogRecordPageWithFreeSpace(rlocator, blkno, freespace); + } + else + UnlockReleaseBuffer(buffer); + } +} + +/* + * Replay XLOG_HEAP2_VISIBLE records. + * + * The critical integrity requirement here is that we must never end up with + * a situation where the visibility map bit is set, and the page-level + * PD_ALL_VISIBLE bit is clear. If that were to occur, then a subsequent + * page modification would fail to clear the visibility map bit. + */ +static void +heap_xlog_visible(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_visible *xlrec = (xl_heap_visible *) XLogRecGetData(record); + Buffer vmbuffer = InvalidBuffer; + Buffer buffer; + Page page; + RelFileLocator rlocator; + BlockNumber blkno; + XLogRedoAction action; + + Assert((xlrec->flags & VISIBILITYMAP_XLOG_VALID_BITS) == xlrec->flags); + + XLogRecGetBlockTag(record, 1, &rlocator, NULL, &blkno); + + /* + * If there are any Hot Standby transactions running that have an xmin + * horizon old enough that this page isn't all-visible for them, they + * might incorrectly decide that an index-only scan can skip a heap fetch. + * + * NB: It might be better to throw some kind of "soft" conflict here that + * forces any index-only scan that is in flight to perform heap fetches, + * rather than killing the transaction outright. + */ + if (InHotStandby) + ResolveRecoveryConflictWithSnapshot(xlrec->snapshotConflictHorizon, + xlrec->flags & VISIBILITYMAP_XLOG_CATALOG_REL, + rlocator); + + /* + * Read the heap page, if it still exists. If the heap file has dropped or + * truncated later in recovery, we don't need to update the page, but we'd + * better still update the visibility map. + */ + action = XLogReadBufferForRedo(record, 1, &buffer); + if (action == BLK_NEEDS_REDO) + { + /* + * We don't bump the LSN of the heap page when setting the visibility + * map bit (unless checksums or wal_hint_bits is enabled, in which + * case we must). This exposes us to torn page hazards, but since + * we're not inspecting the existing page contents in any way, we + * don't care. + */ + page = BufferGetPage(buffer); + + PageSetAllVisible(page); + + if (XLogHintBitIsNeeded()) + PageSetLSN(page, lsn); + + MarkBufferDirty(buffer); + } + else if (action == BLK_RESTORED) + { + /* + * If heap block was backed up, we already restored it and there's + * nothing more to do. (This can only happen with checksums or + * wal_log_hints enabled.) + */ + } + + if (BufferIsValid(buffer)) + { + Size space = PageGetFreeSpace(BufferGetPage(buffer)); + + UnlockReleaseBuffer(buffer); + + /* + * Since FSM is not WAL-logged and only updated heuristically, it + * easily becomes stale in standbys. If the standby is later promoted + * and runs VACUUM, it will skip updating individual free space + * figures for pages that became all-visible (or all-frozen, depending + * on the vacuum mode,) which is troublesome when FreeSpaceMapVacuum + * propagates too optimistic free space values to upper FSM layers; + * later inserters try to use such pages only to find out that they + * are unusable. This can cause long stalls when there are many such + * pages. + * + * Forestall those problems by updating FSM's idea about a page that + * is becoming all-visible or all-frozen. + * + * Do this regardless of a full-page image being applied, since the + * FSM data is not in the page anyway. + */ + if (xlrec->flags & VISIBILITYMAP_VALID_BITS) + XLogRecordPageWithFreeSpace(rlocator, blkno, space); + } + + /* + * Even if we skipped the heap page update due to the LSN interlock, it's + * still safe to update the visibility map. Any WAL record that clears + * the visibility map bit does so before checking the page LSN, so any + * bits that need to be cleared will still be cleared. + */ + if (XLogReadBufferForRedoExtended(record, 0, RBM_ZERO_ON_ERROR, false, + &vmbuffer) == BLK_NEEDS_REDO) + { + Page vmpage = BufferGetPage(vmbuffer); + Relation reln; + uint8 vmbits; + + /* initialize the page if it was read as zeros */ + if (PageIsNew(vmpage)) + PageInit(vmpage, BLCKSZ, 0); + + /* remove VISIBILITYMAP_XLOG_* */ + vmbits = xlrec->flags & VISIBILITYMAP_VALID_BITS; + + /* + * XLogReadBufferForRedoExtended locked the buffer. But + * visibilitymap_set will handle locking itself. + */ + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + + reln = CreateFakeRelcacheEntry(rlocator); + visibilitymap_pin(reln, blkno, &vmbuffer); + + visibilitymap_set(reln, blkno, InvalidBuffer, lsn, vmbuffer, + xlrec->snapshotConflictHorizon, vmbits); + + ReleaseBuffer(vmbuffer); + FreeFakeRelcacheEntry(reln); + } + else if (BufferIsValid(vmbuffer)) + UnlockReleaseBuffer(vmbuffer); +} + +/* + * Given an "infobits" field from an XLog record, set the correct bits in the + * given infomask and infomask2 for the tuple touched by the record. + * + * (This is the reverse of compute_infobits). + */ +static void +fix_infomask_from_infobits(uint8 infobits, uint16 *infomask, uint16 *infomask2) +{ + *infomask &= ~(HEAP_XMAX_IS_MULTI | HEAP_XMAX_LOCK_ONLY | + HEAP_XMAX_KEYSHR_LOCK | HEAP_XMAX_EXCL_LOCK); + *infomask2 &= ~HEAP_KEYS_UPDATED; + + if (infobits & XLHL_XMAX_IS_MULTI) + *infomask |= HEAP_XMAX_IS_MULTI; + if (infobits & XLHL_XMAX_LOCK_ONLY) + *infomask |= HEAP_XMAX_LOCK_ONLY; + if (infobits & XLHL_XMAX_EXCL_LOCK) + *infomask |= HEAP_XMAX_EXCL_LOCK; + /* note HEAP_XMAX_SHR_LOCK isn't considered here */ + if (infobits & XLHL_XMAX_KEYSHR_LOCK) + *infomask |= HEAP_XMAX_KEYSHR_LOCK; + + if (infobits & XLHL_KEYS_UPDATED) + *infomask2 |= HEAP_KEYS_UPDATED; +} + +/* + * Replay XLOG_HEAP_DELETE records. + */ +static void +heap_xlog_delete(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_delete *xlrec = (xl_heap_delete *) XLogRecGetData(record); + Buffer buffer; + Page page; + ItemId lp = NULL; + HeapTupleHeader htup; + BlockNumber blkno; + RelFileLocator target_locator; + ItemPointerData target_tid; + + XLogRecGetBlockTag(record, 0, &target_locator, NULL, &blkno); + ItemPointerSetBlockNumber(&target_tid, blkno); + ItemPointerSetOffsetNumber(&target_tid, xlrec->offnum); + + /* + * The visibility map may need to be fixed even if the heap page is + * 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); + } + + if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO) + { + page = BufferGetPage(buffer); + + if (PageGetMaxOffsetNumber(page) >= xlrec->offnum) + lp = PageGetItemId(page, xlrec->offnum); + + if (PageGetMaxOffsetNumber(page) < xlrec->offnum || !ItemIdIsNormal(lp)) + elog(PANIC, "invalid lp"); + + htup = (HeapTupleHeader) PageGetItem(page, lp); + + htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED); + htup->t_infomask2 &= ~HEAP_KEYS_UPDATED; + HeapTupleHeaderClearHotUpdated(htup); + fix_infomask_from_infobits(xlrec->infobits_set, + &htup->t_infomask, &htup->t_infomask2); + if (!(xlrec->flags & XLH_DELETE_IS_SUPER)) + HeapTupleHeaderSetXmax(htup, xlrec->xmax); + else + HeapTupleHeaderSetXmin(htup, InvalidTransactionId); + HeapTupleHeaderSetCmax(htup, FirstCommandId, false); + + /* Mark the page as a candidate for pruning */ + PageSetPrunable(page, XLogRecGetXid(record)); + + if (xlrec->flags & XLH_DELETE_ALL_VISIBLE_CLEARED) + PageClearAllVisible(page); + + /* Make sure t_ctid is set correctly */ + if (xlrec->flags & XLH_DELETE_IS_PARTITION_MOVE) + HeapTupleHeaderSetMovedPartitions(htup); + else + htup->t_ctid = target_tid; + PageSetLSN(page, lsn); + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); +} + +/* + * Replay XLOG_HEAP_INSERT records. + */ +static void +heap_xlog_insert(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_insert *xlrec = (xl_heap_insert *) XLogRecGetData(record); + Buffer buffer; + Page page; + union + { + HeapTupleHeaderData hdr; + char data[MaxHeapTupleSize]; + } tbuf; + HeapTupleHeader htup; + xl_heap_header xlhdr; + uint32 newlen; + Size freespace = 0; + RelFileLocator target_locator; + BlockNumber blkno; + ItemPointerData target_tid; + XLogRedoAction action; + + XLogRecGetBlockTag(record, 0, &target_locator, NULL, &blkno); + ItemPointerSetBlockNumber(&target_tid, blkno); + ItemPointerSetOffsetNumber(&target_tid, xlrec->offnum); + + /* + * The visibility map may need to be fixed even if the heap page is + * 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); + } + + /* + * If we inserted the first and only tuple on the page, re-initialize the + * page from scratch. + */ + if (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE) + { + buffer = XLogInitBufferForRedo(record, 0); + page = BufferGetPage(buffer); + PageInit(page, BufferGetPageSize(buffer), 0); + action = BLK_NEEDS_REDO; + } + else + action = XLogReadBufferForRedo(record, 0, &buffer); + if (action == BLK_NEEDS_REDO) + { + Size datalen; + char *data; + + page = BufferGetPage(buffer); + + if (PageGetMaxOffsetNumber(page) + 1 < xlrec->offnum) + elog(PANIC, "invalid max offset number"); + + data = XLogRecGetBlockData(record, 0, &datalen); + + newlen = datalen - SizeOfHeapHeader; + Assert(datalen > SizeOfHeapHeader && newlen <= MaxHeapTupleSize); + memcpy((char *) &xlhdr, data, SizeOfHeapHeader); + data += SizeOfHeapHeader; + + htup = &tbuf.hdr; + MemSet((char *) htup, 0, SizeofHeapTupleHeader); + /* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */ + memcpy((char *) htup + SizeofHeapTupleHeader, + data, + newlen); + newlen += SizeofHeapTupleHeader; + htup->t_infomask2 = xlhdr.t_infomask2; + htup->t_infomask = xlhdr.t_infomask; + htup->t_hoff = xlhdr.t_hoff; + HeapTupleHeaderSetXmin(htup, XLogRecGetXid(record)); + HeapTupleHeaderSetCmin(htup, FirstCommandId); + htup->t_ctid = target_tid; + + if (PageAddItem(page, (Item) htup, newlen, xlrec->offnum, + true, true) == InvalidOffsetNumber) + elog(PANIC, "failed to add tuple"); + + freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */ + + PageSetLSN(page, lsn); + + if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) + PageClearAllVisible(page); + + /* XLH_INSERT_ALL_FROZEN_SET implies that all tuples are visible */ + if (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET) + PageSetAllVisible(page); + + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); + + /* + * If the page is running low on free space, update the FSM as well. + * Arbitrarily, our definition of "low" is less than 20%. We can't do much + * better than that without knowing the fill-factor for the table. + * + * XXX: Don't do this if the page was restored from full page image. We + * don't bother to update the FSM in that case, it doesn't need to be + * totally accurate anyway. + */ + if (action == BLK_NEEDS_REDO && freespace < BLCKSZ / 5) + XLogRecordPageWithFreeSpace(target_locator, blkno, freespace); +} + +/* + * Replay XLOG_HEAP2_MULTI_INSERT records. + */ +static void +heap_xlog_multi_insert(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_multi_insert *xlrec; + RelFileLocator rlocator; + BlockNumber blkno; + Buffer buffer; + Page page; + union + { + HeapTupleHeaderData hdr; + char data[MaxHeapTupleSize]; + } tbuf; + HeapTupleHeader htup; + uint32 newlen; + Size freespace = 0; + int i; + bool isinit = (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE) != 0; + XLogRedoAction action; + + /* + * Insertion doesn't overwrite MVCC data, so no conflict processing is + * required. + */ + xlrec = (xl_heap_multi_insert *) XLogRecGetData(record); + + XLogRecGetBlockTag(record, 0, &rlocator, NULL, &blkno); + + /* check that the mutually exclusive flags are not both set */ + Assert(!((xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) && + (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET))); + + /* + * The visibility map may need to be fixed even if the heap page is + * already up-to-date. + */ + 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); + } + + if (isinit) + { + buffer = XLogInitBufferForRedo(record, 0); + page = BufferGetPage(buffer); + PageInit(page, BufferGetPageSize(buffer), 0); + action = BLK_NEEDS_REDO; + } + else + action = XLogReadBufferForRedo(record, 0, &buffer); + if (action == BLK_NEEDS_REDO) + { + char *tupdata; + char *endptr; + Size len; + + /* Tuples are stored as block data */ + tupdata = XLogRecGetBlockData(record, 0, &len); + endptr = tupdata + len; + + page = (Page) BufferGetPage(buffer); + + for (i = 0; i < xlrec->ntuples; i++) + { + OffsetNumber offnum; + xl_multi_insert_tuple *xlhdr; + + /* + * If we're reinitializing the page, the tuples are stored in + * order from FirstOffsetNumber. Otherwise there's an array of + * offsets in the WAL record, and the tuples come after that. + */ + if (isinit) + offnum = FirstOffsetNumber + i; + else + offnum = xlrec->offsets[i]; + if (PageGetMaxOffsetNumber(page) + 1 < offnum) + elog(PANIC, "invalid max offset number"); + + xlhdr = (xl_multi_insert_tuple *) SHORTALIGN(tupdata); + tupdata = ((char *) xlhdr) + SizeOfMultiInsertTuple; + + newlen = xlhdr->datalen; + Assert(newlen <= MaxHeapTupleSize); + htup = &tbuf.hdr; + MemSet((char *) htup, 0, SizeofHeapTupleHeader); + /* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */ + memcpy((char *) htup + SizeofHeapTupleHeader, + (char *) tupdata, + newlen); + tupdata += newlen; + + newlen += SizeofHeapTupleHeader; + htup->t_infomask2 = xlhdr->t_infomask2; + htup->t_infomask = xlhdr->t_infomask; + htup->t_hoff = xlhdr->t_hoff; + HeapTupleHeaderSetXmin(htup, XLogRecGetXid(record)); + HeapTupleHeaderSetCmin(htup, FirstCommandId); + ItemPointerSetBlockNumber(&htup->t_ctid, blkno); + ItemPointerSetOffsetNumber(&htup->t_ctid, offnum); + + offnum = PageAddItem(page, (Item) htup, newlen, offnum, true, true); + if (offnum == InvalidOffsetNumber) + elog(PANIC, "failed to add tuple"); + } + if (tupdata != endptr) + elog(PANIC, "total tuple length mismatch"); + + freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */ + + PageSetLSN(page, lsn); + + if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) + PageClearAllVisible(page); + + /* XLH_INSERT_ALL_FROZEN_SET implies that all tuples are visible */ + if (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET) + PageSetAllVisible(page); + + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); + + /* + * If the page is running low on free space, update the FSM as well. + * Arbitrarily, our definition of "low" is less than 20%. We can't do much + * better than that without knowing the fill-factor for the table. + * + * XXX: Don't do this if the page was restored from full page image. We + * don't bother to update the FSM in that case, it doesn't need to be + * totally accurate anyway. + */ + if (action == BLK_NEEDS_REDO && freespace < BLCKSZ / 5) + XLogRecordPageWithFreeSpace(rlocator, blkno, freespace); +} + +/* + * Replay XLOG_HEAP_UPDATE and XLOG_HEAP_HOT_UPDATE records. + */ +static void +heap_xlog_update(XLogReaderState *record, bool hot_update) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_update *xlrec = (xl_heap_update *) XLogRecGetData(record); + RelFileLocator rlocator; + BlockNumber oldblk; + BlockNumber newblk; + ItemPointerData newtid; + Buffer obuffer, + nbuffer; + Page page; + OffsetNumber offnum; + ItemId lp = NULL; + HeapTupleData oldtup; + HeapTupleHeader htup; + uint16 prefixlen = 0, + suffixlen = 0; + char *newp; + union + { + HeapTupleHeaderData hdr; + char data[MaxHeapTupleSize]; + } tbuf; + xl_heap_header xlhdr; + uint32 newlen; + Size freespace = 0; + XLogRedoAction oldaction; + XLogRedoAction newaction; + + /* initialize to keep the compiler quiet */ + oldtup.t_data = NULL; + oldtup.t_len = 0; + + XLogRecGetBlockTag(record, 0, &rlocator, NULL, &newblk); + if (XLogRecGetBlockTagExtended(record, 1, NULL, NULL, &oldblk, NULL)) + { + /* HOT updates are never done across pages */ + Assert(!hot_update); + } + else + oldblk = newblk; + + ItemPointerSet(&newtid, newblk, xlrec->new_offnum); + + /* + * 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) + { + Relation reln = CreateFakeRelcacheEntry(rlocator); + Buffer vmbuffer = InvalidBuffer; + + visibilitymap_pin(reln, oldblk, &vmbuffer); + visibilitymap_clear(reln, oldblk, vmbuffer, VISIBILITYMAP_VALID_BITS); + ReleaseBuffer(vmbuffer); + FreeFakeRelcacheEntry(reln); + } + + /* + * In normal operation, it is important to lock the two pages in + * page-number order, to avoid possible deadlocks against other update + * operations going the other way. However, during WAL replay there can + * be no other update happening, so we don't need to worry about that. But + * we *do* need to worry that we don't expose an inconsistent state to Hot + * Standby queries --- so the original page can't be unlocked before we've + * added the new tuple to the new page. + */ + + /* Deal with old tuple version */ + oldaction = XLogReadBufferForRedo(record, (oldblk == newblk) ? 0 : 1, + &obuffer); + if (oldaction == BLK_NEEDS_REDO) + { + page = BufferGetPage(obuffer); + offnum = xlrec->old_offnum; + if (PageGetMaxOffsetNumber(page) >= offnum) + lp = PageGetItemId(page, offnum); + + if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp)) + elog(PANIC, "invalid lp"); + + htup = (HeapTupleHeader) PageGetItem(page, lp); + + oldtup.t_data = htup; + oldtup.t_len = ItemIdGetLength(lp); + + htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED); + htup->t_infomask2 &= ~HEAP_KEYS_UPDATED; + if (hot_update) + HeapTupleHeaderSetHotUpdated(htup); + else + HeapTupleHeaderClearHotUpdated(htup); + fix_infomask_from_infobits(xlrec->old_infobits_set, &htup->t_infomask, + &htup->t_infomask2); + HeapTupleHeaderSetXmax(htup, xlrec->old_xmax); + HeapTupleHeaderSetCmax(htup, FirstCommandId, false); + /* Set forward chain link in t_ctid */ + htup->t_ctid = newtid; + + /* Mark the page as a candidate for pruning */ + PageSetPrunable(page, XLogRecGetXid(record)); + + if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED) + PageClearAllVisible(page); + + PageSetLSN(page, lsn); + MarkBufferDirty(obuffer); + } + + /* + * Read the page the new tuple goes into, if different from old. + */ + if (oldblk == newblk) + { + nbuffer = obuffer; + newaction = oldaction; + } + else if (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE) + { + nbuffer = XLogInitBufferForRedo(record, 0); + page = (Page) BufferGetPage(nbuffer); + PageInit(page, BufferGetPageSize(nbuffer), 0); + newaction = BLK_NEEDS_REDO; + } + else + newaction = XLogReadBufferForRedo(record, 0, &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) + { + char *recdata; + char *recdata_end; + Size datalen; + Size tuplen; + + recdata = XLogRecGetBlockData(record, 0, &datalen); + recdata_end = recdata + datalen; + + page = BufferGetPage(nbuffer); + + offnum = xlrec->new_offnum; + if (PageGetMaxOffsetNumber(page) + 1 < offnum) + elog(PANIC, "invalid max offset number"); + + if (xlrec->flags & XLH_UPDATE_PREFIX_FROM_OLD) + { + Assert(newblk == oldblk); + memcpy(&prefixlen, recdata, sizeof(uint16)); + recdata += sizeof(uint16); + } + if (xlrec->flags & XLH_UPDATE_SUFFIX_FROM_OLD) + { + Assert(newblk == oldblk); + memcpy(&suffixlen, recdata, sizeof(uint16)); + recdata += sizeof(uint16); + } + + memcpy((char *) &xlhdr, recdata, SizeOfHeapHeader); + recdata += SizeOfHeapHeader; + + tuplen = recdata_end - recdata; + Assert(tuplen <= MaxHeapTupleSize); + + htup = &tbuf.hdr; + MemSet((char *) htup, 0, SizeofHeapTupleHeader); + + /* + * Reconstruct the new tuple using the prefix and/or suffix from the + * old tuple, and the data stored in the WAL record. + */ + newp = (char *) htup + SizeofHeapTupleHeader; + if (prefixlen > 0) + { + int len; + + /* copy bitmap [+ padding] [+ oid] from WAL record */ + len = xlhdr.t_hoff - SizeofHeapTupleHeader; + memcpy(newp, recdata, len); + recdata += len; + newp += len; + + /* copy prefix from old tuple */ + memcpy(newp, (char *) oldtup.t_data + oldtup.t_data->t_hoff, prefixlen); + newp += prefixlen; + + /* copy new tuple data from WAL record */ + len = tuplen - (xlhdr.t_hoff - SizeofHeapTupleHeader); + memcpy(newp, recdata, len); + recdata += len; + newp += len; + } + else + { + /* + * copy bitmap [+ padding] [+ oid] + data from record, all in one + * go + */ + memcpy(newp, recdata, tuplen); + recdata += tuplen; + newp += tuplen; + } + Assert(recdata == recdata_end); + + /* copy suffix from old tuple */ + if (suffixlen > 0) + memcpy(newp, (char *) oldtup.t_data + oldtup.t_len - suffixlen, suffixlen); + + newlen = SizeofHeapTupleHeader + tuplen + prefixlen + suffixlen; + htup->t_infomask2 = xlhdr.t_infomask2; + htup->t_infomask = xlhdr.t_infomask; + htup->t_hoff = xlhdr.t_hoff; + + HeapTupleHeaderSetXmin(htup, XLogRecGetXid(record)); + HeapTupleHeaderSetCmin(htup, FirstCommandId); + HeapTupleHeaderSetXmax(htup, xlrec->new_xmax); + /* Make sure there is no forward chain link in t_ctid */ + htup->t_ctid = newtid; + + offnum = PageAddItem(page, (Item) htup, newlen, offnum, true, true); + if (offnum == InvalidOffsetNumber) + elog(PANIC, "failed to add tuple"); + + if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED) + PageClearAllVisible(page); + + freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */ + + PageSetLSN(page, lsn); + MarkBufferDirty(nbuffer); + } + + if (BufferIsValid(nbuffer) && nbuffer != obuffer) + UnlockReleaseBuffer(nbuffer); + if (BufferIsValid(obuffer)) + UnlockReleaseBuffer(obuffer); + + /* + * If the new page is running low on free space, update the FSM as well. + * Arbitrarily, our definition of "low" is less than 20%. We can't do much + * better than that without knowing the fill-factor for the table. + * + * However, don't update the FSM on HOT updates, because after crash + * recovery, either the old or the new tuple will certainly be dead and + * prunable. After pruning, the page will have roughly as much free space + * as it did before the update, assuming the new tuple is about the same + * size as the old one. + * + * XXX: Don't do this if the page was restored from full page image. We + * don't bother to update the FSM in that case, it doesn't need to be + * totally accurate anyway. + */ + if (newaction == BLK_NEEDS_REDO && !hot_update && freespace < BLCKSZ / 5) + XLogRecordPageWithFreeSpace(rlocator, newblk, freespace); +} + +/* + * Replay XLOG_HEAP_CONFIRM records. + */ +static void +heap_xlog_confirm(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_confirm *xlrec = (xl_heap_confirm *) XLogRecGetData(record); + Buffer buffer; + Page page; + OffsetNumber offnum; + ItemId lp = NULL; + HeapTupleHeader htup; + + if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO) + { + page = BufferGetPage(buffer); + + offnum = xlrec->offnum; + if (PageGetMaxOffsetNumber(page) >= offnum) + lp = PageGetItemId(page, offnum); + + if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp)) + elog(PANIC, "invalid lp"); + + htup = (HeapTupleHeader) PageGetItem(page, lp); + + /* + * Confirm tuple as actually inserted + */ + ItemPointerSet(&htup->t_ctid, BufferGetBlockNumber(buffer), offnum); + + PageSetLSN(page, lsn); + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); +} + +/* + * Replay XLOG_HEAP_LOCK records. + */ +static void +heap_xlog_lock(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_lock *xlrec = (xl_heap_lock *) XLogRecGetData(record); + Buffer buffer; + Page page; + OffsetNumber offnum; + ItemId lp = NULL; + HeapTupleHeader htup; + + /* + * The visibility map may need to be fixed even if the heap page is + * already up-to-date. + */ + if (xlrec->flags & XLH_LOCK_ALL_FROZEN_CLEARED) + { + RelFileLocator rlocator; + Buffer vmbuffer = InvalidBuffer; + BlockNumber block; + Relation reln; + + XLogRecGetBlockTag(record, 0, &rlocator, NULL, &block); + reln = CreateFakeRelcacheEntry(rlocator); + + visibilitymap_pin(reln, block, &vmbuffer); + visibilitymap_clear(reln, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN); + + ReleaseBuffer(vmbuffer); + FreeFakeRelcacheEntry(reln); + } + + if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO) + { + page = (Page) BufferGetPage(buffer); + + offnum = xlrec->offnum; + if (PageGetMaxOffsetNumber(page) >= offnum) + lp = PageGetItemId(page, offnum); + + if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp)) + elog(PANIC, "invalid lp"); + + htup = (HeapTupleHeader) PageGetItem(page, lp); + + htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED); + htup->t_infomask2 &= ~HEAP_KEYS_UPDATED; + fix_infomask_from_infobits(xlrec->infobits_set, &htup->t_infomask, + &htup->t_infomask2); + + /* + * Clear relevant update flags, but only if the modified infomask says + * there's no update. + */ + if (HEAP_XMAX_IS_LOCKED_ONLY(htup->t_infomask)) + { + HeapTupleHeaderClearHotUpdated(htup); + /* Make sure there is no forward chain link in t_ctid */ + ItemPointerSet(&htup->t_ctid, + BufferGetBlockNumber(buffer), + offnum); + } + HeapTupleHeaderSetXmax(htup, xlrec->xmax); + HeapTupleHeaderSetCmax(htup, FirstCommandId, false); + PageSetLSN(page, lsn); + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); +} + +/* + * Replay XLOG_HEAP2_LOCK_UPDATED records. + */ +static void +heap_xlog_lock_updated(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_lock_updated *xlrec; + Buffer buffer; + Page page; + OffsetNumber offnum; + ItemId lp = NULL; + HeapTupleHeader htup; + + xlrec = (xl_heap_lock_updated *) XLogRecGetData(record); + + /* + * The visibility map may need to be fixed even if the heap page is + * already up-to-date. + */ + if (xlrec->flags & XLH_LOCK_ALL_FROZEN_CLEARED) + { + RelFileLocator rlocator; + Buffer vmbuffer = InvalidBuffer; + BlockNumber block; + Relation reln; + + XLogRecGetBlockTag(record, 0, &rlocator, NULL, &block); + reln = CreateFakeRelcacheEntry(rlocator); + + visibilitymap_pin(reln, block, &vmbuffer); + visibilitymap_clear(reln, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN); + + ReleaseBuffer(vmbuffer); + FreeFakeRelcacheEntry(reln); + } + + if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO) + { + page = BufferGetPage(buffer); + + offnum = xlrec->offnum; + if (PageGetMaxOffsetNumber(page) >= offnum) + lp = PageGetItemId(page, offnum); + + if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp)) + elog(PANIC, "invalid lp"); + + htup = (HeapTupleHeader) PageGetItem(page, lp); + + htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED); + htup->t_infomask2 &= ~HEAP_KEYS_UPDATED; + fix_infomask_from_infobits(xlrec->infobits_set, &htup->t_infomask, + &htup->t_infomask2); + HeapTupleHeaderSetXmax(htup, xlrec->xmax); + + PageSetLSN(page, lsn); + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); +} + +/* + * Replay XLOG_HEAP_INPLACE records. + */ +static void +heap_xlog_inplace(XLogReaderState *record) +{ + XLogRecPtr lsn = record->EndRecPtr; + xl_heap_inplace *xlrec = (xl_heap_inplace *) XLogRecGetData(record); + Buffer buffer; + Page page; + OffsetNumber offnum; + ItemId lp = NULL; + HeapTupleHeader htup; + uint32 oldlen; + Size newlen; + + if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO) + { + char *newtup = XLogRecGetBlockData(record, 0, &newlen); + + page = BufferGetPage(buffer); + + offnum = xlrec->offnum; + if (PageGetMaxOffsetNumber(page) >= offnum) + lp = PageGetItemId(page, offnum); + + if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp)) + elog(PANIC, "invalid lp"); + + htup = (HeapTupleHeader) PageGetItem(page, lp); + + oldlen = ItemIdGetLength(lp) - htup->t_hoff; + if (oldlen != newlen) + elog(PANIC, "wrong tuple length"); + + memcpy((char *) htup + htup->t_hoff, newtup, newlen); + + PageSetLSN(page, lsn); + MarkBufferDirty(buffer); + } + if (BufferIsValid(buffer)) + UnlockReleaseBuffer(buffer); +} + +void +heap_redo(XLogReaderState *record) +{ + uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK; + + /* + * These operations don't overwrite MVCC data so no conflict processing is + * required. The ones in heap2 rmgr do. + */ + + switch (info & XLOG_HEAP_OPMASK) + { + case XLOG_HEAP_INSERT: + heap_xlog_insert(record); + break; + case XLOG_HEAP_DELETE: + heap_xlog_delete(record); + break; + case XLOG_HEAP_UPDATE: + heap_xlog_update(record, false); + break; + case XLOG_HEAP_TRUNCATE: + + /* + * TRUNCATE is a no-op because the actions are already logged as + * SMGR WAL records. TRUNCATE WAL record only exists for logical + * decoding. + */ + break; + case XLOG_HEAP_HOT_UPDATE: + heap_xlog_update(record, true); + break; + case XLOG_HEAP_CONFIRM: + heap_xlog_confirm(record); + break; + case XLOG_HEAP_LOCK: + heap_xlog_lock(record); + break; + case XLOG_HEAP_INPLACE: + heap_xlog_inplace(record); + break; + default: + elog(PANIC, "heap_redo: unknown op code %u", info); + } +} + +void +heap2_redo(XLogReaderState *record) +{ + uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK; + + switch (info & XLOG_HEAP_OPMASK) + { + case XLOG_HEAP2_PRUNE_ON_ACCESS: + case XLOG_HEAP2_PRUNE_VACUUM_SCAN: + case XLOG_HEAP2_PRUNE_VACUUM_CLEANUP: + heap_xlog_prune_freeze(record); + break; + case XLOG_HEAP2_VISIBLE: + heap_xlog_visible(record); + break; + case XLOG_HEAP2_MULTI_INSERT: + heap_xlog_multi_insert(record); + break; + case XLOG_HEAP2_LOCK_UPDATED: + heap_xlog_lock_updated(record); + break; + case XLOG_HEAP2_NEW_CID: + + /* + * Nothing to do on a real replay, only used during logical + * decoding. + */ + break; + case XLOG_HEAP2_REWRITE: + heap_xlog_logical_rewrite(record); + break; + default: + elog(PANIC, "heap2_redo: unknown op code %u", info); + } +} + +/* + * Mask a heap page before performing consistency checks on it. + */ +void +heap_mask(char *pagedata, BlockNumber blkno) +{ + Page page = (Page) pagedata; + OffsetNumber off; + + mask_page_lsn_and_checksum(page); + + mask_page_hint_bits(page); + mask_unused_space(page); + + for (off = 1; off <= PageGetMaxOffsetNumber(page); off++) + { + ItemId iid = PageGetItemId(page, off); + char *page_item; + + page_item = (char *) (page + ItemIdGetOffset(iid)); + + if (ItemIdIsNormal(iid)) + { + HeapTupleHeader page_htup = (HeapTupleHeader) page_item; + + /* + * If xmin of a tuple is not yet frozen, we should ignore + * differences in hint bits, since they can be set without + * emitting WAL. + */ + if (!HeapTupleHeaderXminFrozen(page_htup)) + page_htup->t_infomask &= ~HEAP_XACT_MASK; + else + { + /* Still we need to mask xmax hint bits. */ + page_htup->t_infomask &= ~HEAP_XMAX_INVALID; + page_htup->t_infomask &= ~HEAP_XMAX_COMMITTED; + } + + /* + * During replay, we set Command Id to FirstCommandId. Hence, mask + * it. See heap_xlog_insert() for details. + */ + page_htup->t_choice.t_heap.t_field3.t_cid = MASK_MARKER; + + /* + * For a speculative tuple, heap_insert() does not set ctid in the + * caller-passed heap tuple itself, leaving the ctid field to + * contain a speculative token value - a per-backend monotonically + * increasing identifier. Besides, it does not WAL-log ctid under + * any circumstances. + * + * During redo, heap_xlog_insert() sets t_ctid to current block + * number and self offset number. It doesn't care about any + * speculative insertions on the primary. Hence, we set t_ctid to + * current block number and self offset number to ignore any + * inconsistency. + */ + if (HeapTupleHeaderIsSpeculative(page_htup)) + ItemPointerSet(&page_htup->t_ctid, blkno, off); + + /* + * NB: Not ignoring ctid changes due to the tuple having moved + * (i.e. HeapTupleHeaderIndicatesMovedPartitions), because that's + * important information that needs to be in-sync between primary + * and standby, and thus is WAL logged. + */ + } + + /* + * Ignore any padding bytes after the tuple, when the length of the + * item is not MAXALIGNed. + */ + if (ItemIdHasStorage(iid)) + { + int len = ItemIdGetLength(iid); + int padlen = MAXALIGN(len) - len; + + if (padlen > 0) + memset(page_item + len, MASK_MARKER, padlen); + } + } +} |