Add HOLD_INTERRUPTS section into FinishPreparedTransaction.

If an interrupt arrives in the middle of FinishPreparedTransaction
and any callback decide to call CHECK_FOR_INTERRUPTS (e.g.
RemoveTwoPhaseFile can write a warning with ereport, which checks for
interrupts) then it's possible to leave current GXact undeleted.

Backpatch to all supported branches

Stas Kelvich

Discussion: ihttps://www.postgresql.org/message-id/3AD85097-A3F3-4EBA-99BD-C38EDF8D2949@postgrespro.ru

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index cdd8156ce4d3cb53f7bb3b9d5414dfafa8eebe15..65194db70e33a24690c3c4a32bb83e2b4c346541 100644 (file)
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1487,6 +1487,9 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
        /* compute latestXid among all children */
        latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
 
+       /* Prevent cancel/die interrupt while cleaning up */
+       HOLD_INTERRUPTS();
+
        /*
         * The order of operations here is critical: make the XLOG entry for
         * commit or abort, then mark the transaction committed or aborted in
@@ -1578,6 +1581,8 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
        LWLockRelease(TwoPhaseStateLock);
        MyLockedGxact = NULL;
 
+       RESUME_INTERRUPTS();
+
        pfree(buf);
 }