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| author | Andres Freund <andres@anarazel.de> | 2023-03-22 09:26:23 -0700 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2023-03-22 09:26:23 -0700 |
| commit | 560bb56c6eba5da7917e67783d46f0d5ca30e89a (patch) | |
| tree | 1636c19449a402440e31ffb111a116395a5c44fd /src/backend/storage/buffer/bufmgr.c | |
| parent | a70e6e430628fe5ee802f47f4b043d33a0d41dda (diff) | |
| download | postgresql-560bb56c6eba5da7917e67783d46f0d5ca30e89a.tar.gz postgresql-560bb56c6eba5da7917e67783d46f0d5ca30e89a.zip | |
Fix memory leak and inefficiency in CREATE DATABASE ... STRATEGY WAL_LOG
RelationCopyStorageUsingBuffer() did not free the strategies used to access
the source / target relation. They memory was released at the end of the
transaction, but when using a template database with a lot of relations, the
temporary leak can become big prohibitively big.
RelationCopyStorageUsingBuffer() acquired the buffer for the target relation
with RBM_NORMAL, therefore requiring a read of a block guaranteed to be
zero. Use RBM_ZERO_AND_LOCK instead.
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/20230321070113.o2vqqxogjykwgfrr@awork3.anarazel.de
Backpatch: 15-, where STRATEGY WAL_LOG was introduced
Diffstat (limited to 'src/backend/storage/buffer/bufmgr.c')
| -rw-r--r-- | src/backend/storage/buffer/bufmgr.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 8727a50d949..9fcb3d6e194 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -3756,11 +3756,9 @@ RelationCopyStorageUsingBuffer(RelFileNode srcnode, LockBuffer(srcBuf, BUFFER_LOCK_SHARE); srcPage = BufferGetPage(srcBuf); - /* Use P_NEW to extend the destination relation. */ dstBuf = ReadBufferWithoutRelcache(dstnode, forkNum, blkno, - RBM_NORMAL, bstrategy_dst, + RBM_ZERO_AND_LOCK, bstrategy_dst, permanent); - LockBuffer(dstBuf, BUFFER_LOCK_EXCLUSIVE); dstPage = BufferGetPage(dstBuf); START_CRIT_SECTION(); @@ -3778,6 +3776,9 @@ RelationCopyStorageUsingBuffer(RelFileNode srcnode, UnlockReleaseBuffer(dstBuf); UnlockReleaseBuffer(srcBuf); } + + FreeAccessStrategy(bstrategy_src); + FreeAccessStrategy(bstrategy_dst); } /* --------------------------------------------------------------------- |