From bbace5697df12398e87ffd9879171c39d27f5b33 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 24 Mar 2022 14:32:24 -0400 Subject: Fix possible recovery trouble if TRUNCATE overlaps a checkpoint. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If TRUNCATE causes some buffers to be invalidated and thus the checkpoint does not flush them, TRUNCATE must also ensure that the corresponding files are truncated on disk. Otherwise, a replay from the checkpoint might find that the buffers exist but have the wrong contents, which may cause replay to fail. Report by Teja Mupparti. Patch by Kyotaro Horiguchi, per a design suggestion from Heikki Linnakangas, with some changes to the comments by me. Review of this and a prior patch that approached the issue differently by Heikki Linnakangas, Andres Freund, Álvaro Herrera, Masahiko Sawada, and Tom Lane. Discussion: http://postgr.es/m/BYAPR06MB6373BF50B469CA393C614257ABF00@BYAPR06MB6373.namprd06.prod.outlook.com --- src/backend/access/transam/twophase.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'src/backend/access/transam/twophase.c') diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 7cc76c1db73..dea3f485f7a 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -474,7 +474,7 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, } proc->xid = xid; Assert(proc->xmin == InvalidTransactionId); - proc->delayChkpt = false; + proc->delayChkpt = 0; proc->statusFlags = 0; proc->pid = 0; proc->databaseId = databaseid; @@ -1165,7 +1165,8 @@ EndPrepare(GlobalTransaction gxact) START_CRIT_SECTION(); - MyProc->delayChkpt = true; + Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); + MyProc->delayChkpt |= DELAY_CHKPT_START; XLogBeginInsert(); for (record = records.head; record != NULL; record = record->next) @@ -1208,7 +1209,7 @@ EndPrepare(GlobalTransaction gxact) * checkpoint starting after this will certainly see the gxact as a * candidate for fsyncing. */ - MyProc->delayChkpt = false; + MyProc->delayChkpt &= ~DELAY_CHKPT_START; /* * Remember that we have this GlobalTransaction entry locked for us. If @@ -2275,7 +2276,8 @@ RecordTransactionCommitPrepared(TransactionId xid, START_CRIT_SECTION(); /* See notes in RecordTransactionCommit */ - MyProc->delayChkpt = true; + Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); + MyProc->delayChkpt |= DELAY_CHKPT_START; /* * Emit the XLOG commit record. Note that we mark 2PC commits as @@ -2323,7 +2325,7 @@ RecordTransactionCommitPrepared(TransactionId xid, TransactionIdCommitTree(xid, nchildren, children); /* Checkpoint can proceed now */ - MyProc->delayChkpt = false; + MyProc->delayChkpt &= ~DELAY_CHKPT_START; END_CRIT_SECTION(); -- cgit v1.2.3