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authorTom Lane2018-10-31 21:04:43 +0000
committerTom Lane2018-10-31 21:04:43 +0000
commit82dd1c271492e7dc4d5b96825f7b29679c5dc33a (patch)
tree469ded2ad689f73c0d6ad7eccab2316a859997d4
parent7dd8b3ca829a033aa09ea8cbfd624ecb6c264c4b (diff)
Fix memory leak in repeated SPGIST index scans.
spgendscan neglected to pfree all the memory allocated by spgbeginscan. It's possible to get away with that in most normal queries, since the memory is allocated in the executor's per-query context which is about to get deleted anyway; but it causes severe memory leakage during creation or filling of large exclusion-constraint indexes. Also, document that amendscan is supposed to free what ambeginscan allocates. The docs' lack of clarity on that point probably caused this bug to begin with. (There is discussion of changing that API spec going forward, but I don't think it'd be appropriate for the back branches.) Per report from Bruno Wolff. It's been like this since the beginning, so back-patch to all active branches. In HEAD, also fix an independent leak caused by commit 2a6368343 (allocating memory during spgrescan instead of spgbeginscan, which might be all right if it got cleaned up, but it didn't). And do a bit of code beautification on that commit, too. Discussion: https://postgr.es/m/[email protected]
-rw-r--r--doc/src/sgml/indexam.sgml3
-rw-r--r--src/backend/access/spgist/spgscan.c8
2 files changed, 10 insertions, 1 deletions
diff --git a/doc/src/sgml/indexam.sgml b/doc/src/sgml/indexam.sgml
index 570ee90dcd..09ec0538c9 100644
--- a/doc/src/sgml/indexam.sgml
+++ b/doc/src/sgml/indexam.sgml
@@ -455,7 +455,8 @@ amendscan (IndexScanDesc scan);
</programlisting>
End a scan and release resources. The <literal>scan</> struct itself
should not be freed, but any locks or pins taken internally by the
- access method must be released.
+ access method must be released, as well as any other memory allocated
+ by <function>ambeginscan</function> and other scan-related functions.
</para>
<para>
diff --git a/src/backend/access/spgist/spgscan.c b/src/backend/access/spgist/spgscan.c
index eb049ede4e..ff6bf15806 100644
--- a/src/backend/access/spgist/spgscan.c
+++ b/src/backend/access/spgist/spgscan.c
@@ -236,6 +236,14 @@ spgendscan(PG_FUNCTION_ARGS)
MemoryContextDelete(so->tempCxt);
+ if (so->keyData)
+ pfree(so->keyData);
+
+ if (so->state.deadTupleStorage)
+ pfree(so->state.deadTupleStorage);
+
+ pfree(so);
+
PG_RETURN_VOID();
}