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-rw-r--r--src/backend/access/transam/xact.c1
-rw-r--r--src/backend/commands/portalcmds.c6
-rw-r--r--src/backend/tcop/pquery.c12
-rw-r--r--src/backend/utils/cache/relcache.c35
-rw-r--r--src/backend/utils/mmgr/portalmem.c82
5 files changed, 110 insertions, 26 deletions
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 9f989f87d6c..7af17d1f77b 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -4352,6 +4352,7 @@ AbortSubTransaction(void)
AfterTriggerEndSubXact(false);
AtSubAbort_Portals(s->subTransactionId,
s->parent->subTransactionId,
+ s->curTransactionOwner,
s->parent->curTransactionOwner);
AtEOSubXact_LargeObject(false, s->subTransactionId,
s->parent->subTransactionId);
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c
index 28e785afb84..69f89a26040 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -335,11 +335,7 @@ PersistHoldablePortal(Portal portal)
/*
* Check for improper portal use, and mark portal active.
*/
- if (portal->status != PORTAL_READY)
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("portal \"%s\" cannot be run", portal->name)));
- portal->status = PORTAL_ACTIVE;
+ MarkPortalActive(portal);
/*
* Set up global portal context pointers.
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index f9ed266c1ad..0446564f033 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -734,11 +734,7 @@ PortalRun(Portal portal, long count, bool isTopLevel,
/*
* Check for improper portal use, and mark portal active.
*/
- if (portal->status != PORTAL_READY)
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("portal \"%s\" cannot be run", portal->name)));
- portal->status = PORTAL_ACTIVE;
+ MarkPortalActive(portal);
/*
* Set up global portal context pointers.
@@ -1398,11 +1394,7 @@ PortalRunFetch(Portal portal,
/*
* Check for improper portal use, and mark portal active.
*/
- if (portal->status != PORTAL_READY)
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("portal \"%s\" cannot be run", portal->name)));
- portal->status = PORTAL_ACTIVE;
+ MarkPortalActive(portal);
/*
* Set up global portal context pointers.
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 42b500ac2b2..bbbb609d2e9 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -1957,7 +1957,9 @@ RelationClearRelation(Relation relation, bool rebuild)
{
/*
* As per notes above, a rel to be rebuilt MUST have refcnt > 0; while of
- * course it would be a bad idea to blow away one with nonzero refcnt.
+ * course it would be an equally bad idea to blow away one with nonzero
+ * refcnt, since that would leave someone somewhere with a dangling
+ * pointer. All callers are expected to have verified that this holds.
*/
Assert(rebuild ?
!RelationHasReferenceCountZero(relation) :
@@ -2559,11 +2561,25 @@ AtEOXact_cleanup(Relation relation, bool isCommit)
{
if (isCommit)
relation->rd_createSubid = InvalidSubTransactionId;
- else
+ else if (RelationHasReferenceCountZero(relation))
{
RelationClearRelation(relation, false);
return;
}
+ else
+ {
+ /*
+ * Hmm, somewhere there's a (leaked?) reference to the relation.
+ * We daren't remove the entry for fear of dereferencing a
+ * dangling pointer later. Bleat, and mark it as not belonging to
+ * the current transaction. Hopefully it'll get cleaned up
+ * eventually. This must be just a WARNING to avoid
+ * error-during-error-recovery loops.
+ */
+ relation->rd_createSubid = InvalidSubTransactionId;
+ elog(WARNING, "cannot remove relcache entry for \"%s\" because it has nonzero refcount",
+ RelationGetRelationName(relation));
+ }
}
/*
@@ -2652,11 +2668,24 @@ AtEOSubXact_cleanup(Relation relation, bool isCommit,
{
if (isCommit)
relation->rd_createSubid = parentSubid;
- else
+ else if (RelationHasReferenceCountZero(relation))
{
RelationClearRelation(relation, false);
return;
}
+ else
+ {
+ /*
+ * Hmm, somewhere there's a (leaked?) reference to the relation.
+ * We daren't remove the entry for fear of dereferencing a
+ * dangling pointer later. Bleat, and transfer it to the parent
+ * subtransaction so we can try again later. This must be just a
+ * WARNING to avoid error-during-error-recovery loops.
+ */
+ relation->rd_createSubid = parentSubid;
+ elog(WARNING, "cannot remove relcache entry for \"%s\" because it has nonzero refcount",
+ RelationGetRelationName(relation));
+ }
}
/*
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index c1b13c360f3..88b7908310f 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -232,6 +232,7 @@ CreatePortal(const char *name, bool allowDup, bool dupSilent)
portal->status = PORTAL_NEW;
portal->cleanup = PortalCleanup;
portal->createSubid = GetCurrentSubTransactionId();
+ portal->activeSubid = portal->createSubid;
portal->strategy = PORTAL_MULTI_QUERY;
portal->cursorOptions = CURSOR_OPT_NO_SCROLL;
portal->atStart = true;
@@ -403,6 +404,25 @@ UnpinPortal(Portal portal)
}
/*
+ * MarkPortalActive
+ * Transition a portal from READY to ACTIVE state.
+ *
+ * NOTE: never set portal->status = PORTAL_ACTIVE directly; call this instead.
+ */
+void
+MarkPortalActive(Portal portal)
+{
+ /* For safety, this is a runtime test not just an Assert */
+ if (portal->status != PORTAL_READY)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("portal \"%s\" cannot be run", portal->name)));
+ /* Perform the state transition */
+ portal->status = PORTAL_ACTIVE;
+ portal->activeSubid = GetCurrentSubTransactionId();
+}
+
+/*
* MarkPortalDone
* Transition a portal from ACTIVE to DONE state.
*
@@ -690,6 +710,7 @@ PreCommit_Portals(bool isPrepare)
* not belonging to this transaction.
*/
portal->createSubid = InvalidSubTransactionId;
+ portal->activeSubid = InvalidSubTransactionId;
/* Report we changed state */
result = true;
@@ -836,8 +857,8 @@ AtCleanup_Portals(void)
/*
* Pre-subcommit processing for portals.
*
- * Reassign the portals created in the current subtransaction to the parent
- * subtransaction.
+ * Reassign portals created or used in the current subtransaction to the
+ * parent subtransaction.
*/
void
AtSubCommit_Portals(SubTransactionId mySubid,
@@ -859,14 +880,16 @@ AtSubCommit_Portals(SubTransactionId mySubid,
if (portal->resowner)
ResourceOwnerNewParent(portal->resowner, parentXactOwner);
}
+ if (portal->activeSubid == mySubid)
+ portal->activeSubid = parentSubid;
}
}
/*
* Subtransaction abort handling for portals.
*
- * Deactivate portals created during the failed subtransaction.
- * Note that per AtSubCommit_Portals, this will catch portals created
+ * Deactivate portals created or used during the failed subtransaction.
+ * Note that per AtSubCommit_Portals, this will catch portals created/used
* in descendants of the subtransaction too.
*
* We don't destroy any portals here; that's done in AtSubCleanup_Portals.
@@ -874,6 +897,7 @@ AtSubCommit_Portals(SubTransactionId mySubid,
void
AtSubAbort_Portals(SubTransactionId mySubid,
SubTransactionId parentSubid,
+ ResourceOwner myXactOwner,
ResourceOwner parentXactOwner)
{
HASH_SEQ_STATUS status;
@@ -885,16 +909,58 @@ AtSubAbort_Portals(SubTransactionId mySubid,
{
Portal portal = hentry->portal;
+ /* Was it created in this subtransaction? */
if (portal->createSubid != mySubid)
+ {
+ /* No, but maybe it was used in this subtransaction? */
+ if (portal->activeSubid == mySubid)
+ {
+ /* Maintain activeSubid until the portal is removed */
+ portal->activeSubid = parentSubid;
+
+ /*
+ * Upper-level portals that failed while running in this
+ * subtransaction must be forced into FAILED state, for the
+ * same reasons discussed below.
+ *
+ * We assume we can get away without forcing upper-level READY
+ * portals to fail, even if they were run and then suspended.
+ * In theory a suspended upper-level portal could have
+ * acquired some references to objects that are about to be
+ * destroyed, but there should be sufficient defenses against
+ * such cases: the portal's original query cannot contain such
+ * references, and any references within, say, cached plans of
+ * PL/pgSQL functions are not from active queries and should
+ * be protected by revalidation logic.
+ */
+ if (portal->status == PORTAL_ACTIVE)
+ MarkPortalFailed(portal);
+
+ /*
+ * Also, if we failed it during the current subtransaction
+ * (either just above, or earlier), reattach its resource
+ * owner to the current subtransaction's resource owner, so
+ * that any resources it still holds will be released while
+ * cleaning up this subtransaction. This prevents some corner
+ * cases wherein we might get Asserts or worse while cleaning
+ * up objects created during the current subtransaction
+ * (because they're still referenced within this portal).
+ */
+ if (portal->status == PORTAL_FAILED && portal->resowner)
+ {
+ ResourceOwnerNewParent(portal->resowner, myXactOwner);
+ portal->resowner = NULL;
+ }
+ }
+ /* Done if it wasn't created in this subtransaction */
continue;
+ }
/*
* Force any live portals of my own subtransaction into FAILED state.
* We have to do this because they might refer to objects created or
- * changed in the failed subtransaction, leading to crashes if
- * execution is resumed, or even if we just try to run ExecutorEnd.
- * (Note we do NOT do this to upper-level portals, since they cannot
- * have such references and hence may be able to continue.)
+ * changed in the failed subtransaction, leading to crashes within
+ * ExecutorEnd when portalcmds.c tries to close down the portal.
*/
if (portal->status == PORTAL_READY ||
portal->status == PORTAL_ACTIVE)
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-16 22:23:23 +0000