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Fix some more bugs in GIN's WAL replay logic.

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In commit 4016bdef8aded77b4903c457050622a5a1815c16 I fixed a bunch of
ginxlog.c bugs having to do with not handling XLogReadBuffer failures
correctly.  However, in ginRedoUpdateMetapage and ginRedoDeleteListPages,
I unaccountably thought that failure to read the metapage would be
impossible and just put in an elog(PANIC) call.  This is of course wrong:
failure is exactly what will happen if the index got dropped (or rebuilt)
between creation of the WAL record and the crash we're trying to recover
from.  I believe this explains Nicholas Wilson's recent report of these
errors getting reached.

Also, fix memory leak in forgetIncompleteSplit.  This wasn't of much
concern when the code was written, but in a long-running standby server
page split records could be expected to accumulate indefinitely.

Back-patch to 8.4 --- before that, GIN didn't have a metapage.
This commit is contained in:
Tom Lane 2012-02-26 15:12:17 -05:00
parent b5c077c368
commit 1b630751d0
1 changed files with 6 additions and 3 deletions
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9
src/backend/access/gin/ginxlog.c
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@ -58,9 +58,12 @@ forgetIncompleteSplit(RelFileNode node, BlockNumber leftBlkno, BlockNumber updat
{ {
ginIncompleteSplit *split = (ginIncompleteSplit *) lfirst(l); ginIncompleteSplit *split = (ginIncompleteSplit *) lfirst(l);
if (RelFileNodeEquals(node, split->node) && leftBlkno == split->leftBlkno && updateBlkno == split->rightBlkno) if (RelFileNodeEquals(node, split->node) &&
leftBlkno == split->leftBlkno &&
updateBlkno == split->rightBlkno)
{ {
incomplete_splits = list_delete_ptr(incomplete_splits, split); incomplete_splits = list_delete_ptr(incomplete_splits, split);
pfree(split);
break; break;
} }
} }
@ -486,7 +489,7 @@ ginRedoUpdateMetapage(XLogRecPtr lsn, XLogRecord *record)
metabuffer = XLogReadBuffer(data->node, GIN_METAPAGE_BLKNO, false); metabuffer = XLogReadBuffer(data->node, GIN_METAPAGE_BLKNO, false);
if (!BufferIsValid(metabuffer)) if (!BufferIsValid(metabuffer))
elog(PANIC, "GIN metapage disappeared"); return; /* assume index was deleted, nothing to do */
metapage = BufferGetPage(metabuffer); metapage = BufferGetPage(metabuffer);
if (!XLByteLE(lsn, PageGetLSN(metapage))) if (!XLByteLE(lsn, PageGetLSN(metapage)))
@ -631,7 +634,7 @@ ginRedoDeleteListPages(XLogRecPtr lsn, XLogRecord *record)
metabuffer = XLogReadBuffer(data->node, GIN_METAPAGE_BLKNO, false); metabuffer = XLogReadBuffer(data->node, GIN_METAPAGE_BLKNO, false);
if (!BufferIsValid(metabuffer)) if (!BufferIsValid(metabuffer))
elog(PANIC, "GIN metapage disappeared"); return; /* assume index was deleted, nothing to do */
metapage = BufferGetPage(metabuffer); metapage = BufferGetPage(metabuffer);
if (!XLByteLE(lsn, PageGetLSN(metapage))) if (!XLByteLE(lsn, PageGetLSN(metapage)))