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author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2014-05-08 14:43:04 +0300 |
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committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2014-05-08 14:46:43 +0300 |
commit | be7830596f333b70243661b70e09a783ed57b497 (patch) | |
tree | 14309b2c5d7cf401fb538de4661550b9ad09b361 | |
parent | 664ac3de7f50e3a16b9c96fa73c4f6e733500ade (diff) | |
download | postgresql-be7830596f333b70243661b70e09a783ed57b497.tar.gz |
Protect against torn pages when deleting GIN list pages.
To-be-deleted list pages contain no useful information, as they are being
deleted, but we must still protect the writes from being torn by a crash
after a partial write. To do that, re-initialize the pages on WAL replay.
Jeff Janes caught this with a test program to test partial writes.
Backpatch to all supported versions.
-rw-r--r-- | src/backend/access/gin/ginxlog.c | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c index 2344ec25bc..de0a2ed796 100644 --- a/src/backend/access/gin/ginxlog.c +++ b/src/backend/access/gin/ginxlog.c @@ -650,25 +650,24 @@ ginRedoDeleteListPages(XLogRecPtr lsn, XLogRecord *record) PageSetTLI(metapage, ThisTimeLineID); MarkBufferDirty(metabuffer); + /* + * No full-page images are taken of the deleted pages. Instead, they are + * re-initialized as empty, deleted pages. + */ for (i = 0; i < data->ndeleted; i++) { - Buffer buffer = XLogReadBuffer(data->node, data->toDelete[i], false); + Buffer buffer; + Page page; - if (BufferIsValid(buffer)) - { - Page page = BufferGetPage(buffer); - - if (!XLByteLE(lsn, PageGetLSN(page))) - { - GinPageGetOpaque(page)->flags = GIN_DELETED; + buffer = XLogReadBuffer(data->node, data->toDelete[i], true); + page = BufferGetPage(buffer); + GinInitBuffer(buffer, GIN_DELETED); - PageSetLSN(page, lsn); - PageSetTLI(page, ThisTimeLineID); - MarkBufferDirty(buffer); - } + PageSetLSN(page, lsn); + PageSetTLI(page, ThisTimeLineID); + MarkBufferDirty(buffer); - UnlockReleaseBuffer(buffer); - } + UnlockReleaseBuffer(buffer); } UnlockReleaseBuffer(metabuffer); } |