From 2afd044c9491c484d0b2b6910b17896a64a08c01 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 11 Oct 2010 19:04:59 -0400 Subject: [PATCH] Fix assorted bugs in GIN's WAL replay logic. The original coding was quite sloppy about handling the case where XLogReadBuffer fails (because the page has since been deleted). This would result in either "bad buffer id: 0" or an Assert failure during replay, if indeed the page were no longer there. In a couple of places it also neglected to check whether the change had already been applied, which would probably result in corrupted index contents. I believe that bug #5703 is an instance of the first problem. These issues could show up without replication, but only if you were unfortunate enough to crash between modification of a GIN index and the next checkpoint. Back-patch to 8.2, which is as far back as GIN has WAL support. --- src/backend/access/gin/ginxlog.c | 198 ++++++++++++++++++------------- 1 file changed, 118 insertions(+), 80 deletions(-) diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c index 37d04cfb7e..b7b89e4e49 100644 --- a/src/backend/access/gin/ginxlog.c +++ b/src/backend/access/gin/ginxlog.c @@ -121,22 +121,49 @@ ginRedoInsert(XLogRecPtr lsn, XLogRecord *record) Buffer buffer; Page page; + /* first, forget any incomplete split this insertion completes */ + if (data->isData) + { + Assert(data->isDelete == FALSE); + if (!data->isLeaf && data->updateBlkno != InvalidBlockNumber) + { + PostingItem *pitem; + + pitem = (PostingItem *) (XLogRecGetData(record) + sizeof(ginxlogInsert)); + forgetIncompleteSplit(data->node, + PostingItemGetBlockNumber(pitem), + data->updateBlkno); + } + } + else + { + if (!data->isLeaf && data->updateBlkno != InvalidBlockNumber) + { + IndexTuple itup; + + itup = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogInsert)); + forgetIncompleteSplit(data->node, + GinItemPointerGetBlockNumber(&itup->t_tid), + data->updateBlkno); + } + } + /* nothing else to do if page was backed up */ if (record->xl_info & XLR_BKP_BLOCK_1) return; reln = XLogOpenRelation(data->node); buffer = XLogReadBuffer(reln, data->blkno, false); - Assert(BufferIsValid(buffer)); + if (!BufferIsValid(buffer)) + return; page = (Page) BufferGetPage(buffer); - if (data->isData) + if (!XLByteLE(lsn, PageGetLSN(page))) { - Assert(data->isDelete == FALSE); - Assert(GinPageIsData(page)); - - if (!XLByteLE(lsn, PageGetLSN(page))) + if (data->isData) { + Assert(GinPageIsData(page)); + if (data->isLeaf) { OffsetNumber i; @@ -166,23 +193,12 @@ ginRedoInsert(XLogRecPtr lsn, XLogRecord *record) GinDataPageAddItem(page, pitem, data->offset); } } - - if (!data->isLeaf && data->updateBlkno != InvalidBlockNumber) + else { - PostingItem *pitem = (PostingItem *) (XLogRecGetData(record) + sizeof(ginxlogInsert)); - - forgetIncompleteSplit(data->node, PostingItemGetBlockNumber(pitem), data->updateBlkno); - } + IndexTuple itup; - } - else - { - IndexTuple itup; + Assert(!GinPageIsData(page)); - Assert(!GinPageIsData(page)); - - if (!XLByteLE(lsn, PageGetLSN(page))) - { if (data->updateBlkno != InvalidBlockNumber) { /* update link to right page after split */ @@ -203,23 +219,15 @@ ginRedoInsert(XLogRecPtr lsn, XLogRecord *record) if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), data->offset, false, false) == InvalidOffsetNumber) elog(ERROR, "failed to add item to index page in %u/%u/%u", - data->node.spcNode, data->node.dbNode, data->node.relNode); + data->node.spcNode, data->node.dbNode, data->node.relNode); } - if (!data->isLeaf && data->updateBlkno != InvalidBlockNumber) - { - itup = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogInsert)); - forgetIncompleteSplit(data->node, GinItemPointerGetBlockNumber(&itup->t_tid), data->updateBlkno); - } - } - - if (!XLByteLE(lsn, PageGetLSN(page))) - { PageSetLSN(page, lsn); PageSetTLI(page, ThisTimeLineID); MarkBufferDirty(buffer); } + UnlockReleaseBuffer(buffer); } @@ -241,7 +249,7 @@ ginRedoSplit(XLogRecPtr lsn, XLogRecord *record) if (data->isData) flags |= GIN_DATA; - lbuffer = XLogReadBuffer(reln, data->lblkno, data->isRootSplit); + lbuffer = XLogReadBuffer(reln, data->lblkno, true); Assert(BufferIsValid(lbuffer)); lpage = (Page) BufferGetPage(lbuffer); GinInitBuffer(lbuffer, flags); @@ -318,7 +326,7 @@ ginRedoSplit(XLogRecPtr lsn, XLogRecord *record) if (data->isRootSplit) { - Buffer rootBuf = XLogReadBuffer(reln, data->rootBlkno, false); + Buffer rootBuf = XLogReadBuffer(reln, data->rootBlkno, true); Page rootPage = BufferGetPage(rootBuf); GinInitBuffer(rootBuf, flags & ~GIN_LEAF); @@ -355,46 +363,51 @@ ginRedoVacuumPage(XLogRecPtr lsn, XLogRecord *record) Buffer buffer; Page page; - /* nothing else to do if page was backed up (and no info to do it with) */ + /* nothing to do if page was backed up (and no info to do it with) */ if (record->xl_info & XLR_BKP_BLOCK_1) return; reln = XLogOpenRelation(data->node); buffer = XLogReadBuffer(reln, data->blkno, false); - Assert(BufferIsValid(buffer)); + if (!BufferIsValid(buffer)) + return; page = (Page) BufferGetPage(buffer); - if (GinPageIsData(page)) - { - memcpy(GinDataPageGetData(page), XLogRecGetData(record) + sizeof(ginxlogVacuumPage), - GinSizeOfItem(page) *data->nitem); - GinPageGetOpaque(page)->maxoff = data->nitem; - } - else + if (!XLByteLE(lsn, PageGetLSN(page))) { - OffsetNumber i, - *tod; - IndexTuple itup = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogVacuumPage)); + if (GinPageIsData(page)) + { + memcpy(GinDataPageGetData(page), XLogRecGetData(record) + sizeof(ginxlogVacuumPage), + GinSizeOfItem(page) *data->nitem); + GinPageGetOpaque(page)->maxoff = data->nitem; + } + else + { + OffsetNumber i, + *tod; + IndexTuple itup = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogVacuumPage)); - tod = (OffsetNumber *) palloc(sizeof(OffsetNumber) * PageGetMaxOffsetNumber(page)); - for (i = FirstOffsetNumber; i <= PageGetMaxOffsetNumber(page); i++) - tod[i - 1] = i; + tod = (OffsetNumber *) palloc(sizeof(OffsetNumber) * PageGetMaxOffsetNumber(page)); + for (i = FirstOffsetNumber; i <= PageGetMaxOffsetNumber(page); i++) + tod[i - 1] = i; - PageIndexMultiDelete(page, tod, PageGetMaxOffsetNumber(page)); + PageIndexMultiDelete(page, tod, PageGetMaxOffsetNumber(page)); - for (i = 0; i < data->nitem; i++) - { - if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false, false) == InvalidOffsetNumber) - elog(ERROR, "failed to add item to index page in %u/%u/%u", - data->node.spcNode, data->node.dbNode, data->node.relNode); - itup = (IndexTuple) (((char *) itup) + MAXALIGN(IndexTupleSize(itup))); + for (i = 0; i < data->nitem; i++) + { + if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false, false) == InvalidOffsetNumber) + elog(ERROR, "failed to add item to index page in %u/%u/%u", + data->node.spcNode, data->node.dbNode, data->node.relNode); + itup = (IndexTuple) (((char *) itup) + MAXALIGN(IndexTupleSize(itup))); + } } - } - PageSetLSN(page, lsn); - PageSetTLI(page, ThisTimeLineID); + PageSetLSN(page, lsn); + PageSetTLI(page, ThisTimeLineID); + + MarkBufferDirty(buffer); + } - MarkBufferDirty(buffer); UnlockReleaseBuffer(buffer); } @@ -411,38 +424,56 @@ ginRedoDeletePage(XLogRecPtr lsn, XLogRecord *record) if (!(record->xl_info & XLR_BKP_BLOCK_1)) { buffer = XLogReadBuffer(reln, data->blkno, false); - page = BufferGetPage(buffer); - Assert(GinPageIsData(page)); - GinPageGetOpaque(page)->flags = GIN_DELETED; - PageSetLSN(page, lsn); - PageSetTLI(page, ThisTimeLineID); - MarkBufferDirty(buffer); - UnlockReleaseBuffer(buffer); + if (BufferIsValid(buffer)) + { + page = BufferGetPage(buffer); + if (!XLByteLE(lsn, PageGetLSN(page))) + { + Assert(GinPageIsData(page)); + GinPageGetOpaque(page)->flags = GIN_DELETED; + PageSetLSN(page, lsn); + PageSetTLI(page, ThisTimeLineID); + MarkBufferDirty(buffer); + } + UnlockReleaseBuffer(buffer); + } } if (!(record->xl_info & XLR_BKP_BLOCK_2)) { buffer = XLogReadBuffer(reln, data->parentBlkno, false); - page = BufferGetPage(buffer); - Assert(GinPageIsData(page)); - Assert(!GinPageIsLeaf(page)); - PageDeletePostingItem(page, data->parentOffset); - PageSetLSN(page, lsn); - PageSetTLI(page, ThisTimeLineID); - MarkBufferDirty(buffer); - UnlockReleaseBuffer(buffer); + if (BufferIsValid(buffer)) + { + page = BufferGetPage(buffer); + if (!XLByteLE(lsn, PageGetLSN(page))) + { + Assert(GinPageIsData(page)); + Assert(!GinPageIsLeaf(page)); + PageDeletePostingItem(page, data->parentOffset); + PageSetLSN(page, lsn); + PageSetTLI(page, ThisTimeLineID); + MarkBufferDirty(buffer); + } + UnlockReleaseBuffer(buffer); + } } if (!(record->xl_info & XLR_BKP_BLOCK_3) && data->leftBlkno != InvalidBlockNumber) { buffer = XLogReadBuffer(reln, data->leftBlkno, false); - page = BufferGetPage(buffer); - Assert(GinPageIsData(page)); - GinPageGetOpaque(page)->rightlink = data->rightLink; - PageSetLSN(page, lsn); - PageSetTLI(page, ThisTimeLineID); - MarkBufferDirty(buffer); - UnlockReleaseBuffer(buffer); + if (BufferIsValid(buffer)) + { + page = BufferGetPage(buffer); + if (!XLByteLE(lsn, PageGetLSN(page))) + { + Assert(GinPageIsData(page)); + GinPageGetOpaque(page)->rightlink = data->rightLink; + PageSetLSN(page, lsn); + PageSetTLI(page, ThisTimeLineID); + MarkBufferDirty(buffer); + } + UnlockReleaseBuffer(buffer); + } } } @@ -560,6 +591,13 @@ ginContinueSplit(ginIncompleteSplit *split) buffer = XLogReadBuffer(reln, split->leftBlkno, false); + /* + * Failure should be impossible here, because we wrote the page earlier. + */ + if (!BufferIsValid(buffer)) + elog(PANIC, "ginContinueSplit: left block %u not found", + split->leftBlkno); + if (split->rootBlkno == GIN_ROOT_BLKNO) { prepareEntryScan(&btree, reln, (Datum) 0, NULL); -- GitLab