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 f3d239de6e12b6da2b7952ab475455283678acc1..4e0756059e850f428c341740c91e93c1de1fb873 100644 (file)
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1390,6 +1390,9 @@ 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
@@ -1477,6 +1480,8 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
        RemoveGXact(gxact);
        MyLockedGxact = NULL;
 
+       RESUME_INTERRUPTS();
+
        pfree(buf);
 }