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| author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2013-10-23 14:03:54 +0300 |
|---|---|---|
| committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2013-10-23 14:25:50 +0300 |
| commit | 4da24f12e63313b7dbb6b3e3d0317e04045df636 (patch) | |
| tree | 8f5cd7cb613cf476376b2856bf94be4dda817870 /src/backend/commands/vacuumlazy.c | |
| parent | b89cedeffb9e5a4a4c9ac501c245ee92cf85aa5f (diff) | |
Fix two bugs in setting the vm bit of empty pages.
Use a critical section when setting the all-visible flag on an empty page,
and WAL-logging it. log_newpage_buffer() contains an assertion that it
must be called inside a critical section, and it's the right thing to do
when modifying a buffer anyway.
Also, the page should be marked dirty before calling log_newpage_buffer(),
per the comment in log_newpage_buffer() and src/backend/access/transam/README.
Patch by Andres Freund, in response to my report. Backpatch to 9.2, like
the patch that introduced these bugs (a6370fd9).
Diffstat (limited to 'src/backend/commands/vacuumlazy.c')
| -rw-r--r-- | src/backend/commands/vacuumlazy.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index 402e76e72bf..28f169e59c5 100644 --- a/src/backend/commands/vacuumlazy.c +++ b/src/backend/commands/vacuumlazy.c @@ -650,6 +650,11 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats, /* empty pages are always all-visible */ if (!PageIsAllVisible(page)) { + START_CRIT_SECTION(); + + /* mark buffer dirty before writing a WAL record */ + MarkBufferDirty(buf); + /* * It's possible that another backend has extended the heap, * initialized the page, and then failed to WAL-log the page @@ -669,9 +674,9 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats, log_newpage_buffer(buf); PageSetAllVisible(page); - MarkBufferDirty(buf); visibilitymap_set(onerel, blkno, InvalidXLogRecPtr, vmbuffer, InvalidTransactionId); + END_CRIT_SECTION(); } UnlockReleaseBuffer(buf); |