Fix subscriber invalid memory access on DDL.

This patch allows building the local relmap cache for a subscribed
relation after processing pending invalidation messages and potential
relcache updates.  Without this, the attributes in the local cache don't
tally with the updated relcache entry leading to invalid memory access.

Reported-by Jehan-Guillaume de Rorthais
Author: Jehan-Guillaume de Rorthais and Vignesh C
Reviewed-by: Amit Kapila
Backpatch-through: 10
Discussion: https://postgr.es/m/20191025175929.7e90dbf5@firost
This commit is contained in:
Amit Kapila 2019-12-16 15:23:46 +05:30
parent 52dcfda487
commit 04c8a69c0c
1 changed files with 25 additions and 13 deletions

View File

@ -220,6 +220,8 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
{
LogicalRepRelMapEntry *entry;
bool found;
Oid relid = InvalidOid;
LogicalRepRelation *remoterel;
if (LogicalRepRelMap == NULL)
logicalrep_relmap_init();
@ -232,19 +234,16 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
elog(ERROR, "no relation map entry for remote relation ID %u",
remoteid);
/* Need to update the local cache? */
remoterel = &entry->remoterel;
/*
* When opening and locking a relation, pending invalidation messages are
* processed which can invalidate the relation. We need to update the
* local cache both when we are first time accessing the relation and when
* the relation is invalidated (aka entry->localreloid is set InvalidOid).
*/
if (!OidIsValid(entry->localreloid))
{
Oid relid;
int i;
int found;
Bitmapset *idkey;
TupleDesc desc;
LogicalRepRelation *remoterel;
MemoryContext oldctx;
remoterel = &entry->remoterel;
/* Try to find and lock the relation by name. */
relid = RangeVarGetRelid(makeRangeVar(remoterel->nspname,
remoterel->relname, -1),
@ -256,6 +255,21 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
remoterel->nspname, remoterel->relname)));
entry->localrel = table_open(relid, NoLock);
}
else
{
relid = entry->localreloid;
entry->localrel = table_open(entry->localreloid, lockmode);
}
if (!OidIsValid(entry->localreloid))
{
int found;
Bitmapset *idkey;
TupleDesc desc;
MemoryContext oldctx;
int i;
/* Check for supported relkind. */
CheckSubscriptionRelkind(entry->localrel->rd_rel->relkind,
remoterel->nspname, remoterel->relname);
@ -350,8 +364,6 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
entry->localreloid = relid;
}
else
entry->localrel = table_open(entry->localreloid, lockmode);
if (entry->state != SUBREL_STATE_READY)
entry->state = GetSubscriptionRelState(MySubscription->oid,