Fix assorted syscache lookup sloppiness in partition-related code.

heap_drop_with_catalog and ATExecDetachPartition neglected to check for
SearchSysCache failures, as noted in bugs #14927 and #14928 from Pan Bian.
Such failures are pretty unlikely, since we should already have some sort
of lock on the rel at these points, but it's neither a good idea nor
per project style to omit a check for failure.

Also, StorePartitionKey contained a syscache lookup that it never did
anything with, including never releasing the result.  Presumably the
reason why we don't see refcount-leak complaints is that the lookup
always fails; but in any case it's pretty useless, so remove it.

All of these errors were evidently introduced by the relation
partitioning feature.  Back-patch to v10 where that came in.

Amit Langote and Tom Lane

Discussion: https://postgr.es/m/20171127090105.1463.3962@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20171127091341.1468.72696@wrigleys.postgresql.org

diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index a376b99f1ed49f21f6d0e03a8de0cdf288e8cad9..bb21e58a454b16de0a0a30ebc2134cb333be5439 100644 (file)
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -1769,6 +1769,8 @@ heap_drop_with_catalog(Oid relid)
     * shared-cache-inval notice that will make them update their index lists.
     */
    tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+   if (!HeapTupleIsValid(tuple))
+       elog(ERROR, "cache lookup failed for relation %u", relid);
    if (((Form_pg_class) GETSTRUCT(tuple))->relispartition)
    {
        parentOid = get_partition_parent(relid);
@@ -3105,9 +3107,6 @@ StorePartitionKey(Relation rel,
 
    Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
 
-   tuple = SearchSysCache1(PARTRELID,
-                           ObjectIdGetDatum(RelationGetRelid(rel)));
-
    /* Copy the partition attribute numbers, opclass OIDs into arrays */
    partattrs_vec = buildint2vector(partattrs, partnatts);
    partopclass_vec = buildoidvector(partopclass, partnatts);

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 33c99b3777e485e0df68a98f02d852508e61878a..18c9f21617d5ed8750601a3d8ee0c43c1ec4239d 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -13815,6 +13815,9 @@ ATExecDetachPartition(Relation rel, RangeVar *name)
    classRel = heap_open(RelationRelationId, RowExclusiveLock);
    tuple = SearchSysCacheCopy1(RELOID,
                                ObjectIdGetDatum(RelationGetRelid(partRel)));
+   if (!HeapTupleIsValid(tuple))
+       elog(ERROR, "cache lookup failed for relation %u",
+            RelationGetRelid(partRel));
    Assert(((Form_pg_class) GETSTRUCT(tuple))->relispartition);
 
    (void) SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relpartbound,