From 0c6293dd0361a0d3c72c94ced389c509019713a7 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Tue, 26 Oct 2010 21:15:42 +0300 Subject: [PATCH] Before removing backup_label and irrevocably changing pg_control file, check that WAL file containing the checkpoint redo-location can be found. This avoids making the cluster irrecoverable if the redo location is in an earlie WAL file than the checkpoint record. Report, analysis and patch by Jeff Davis, with small changes by me. --- src/backend/access/transam/xlog.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 22fd578056..6f1fedd114 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -5839,14 +5839,29 @@ StartupXLOG(void) record = ReadCheckpointRecord(checkPointLoc, 0); if (record != NULL) { + memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint)); ereport(DEBUG1, (errmsg("checkpoint record is at %X/%X", checkPointLoc.xlogid, checkPointLoc.xrecoff))); InRecovery = true; /* force recovery even if SHUTDOWNED */ + + /* + * Make sure that REDO location exists. This may not be + * the case if there was a crash during an online backup, + * which left a backup_label around that references a WAL + * segment that's already been archived. + */ + if (XLByteLT(checkPoint.redo, checkPointLoc)) + { + if (!ReadRecord(&(checkPoint.redo), LOG, false)) + ereport(FATAL, + (errmsg("could not find redo location referenced by checkpoint record"), + errhint("If you are not restoring from a backup, try removing the file \"%s/backup_label\".", DataDir))); + } } else { - ereport(PANIC, + ereport(FATAL, (errmsg("could not locate required checkpoint record"), errhint("If you are not restoring from a backup, try removing the file \"%s/backup_label\".", DataDir))); } @@ -5892,10 +5907,10 @@ StartupXLOG(void) ereport(PANIC, (errmsg("could not locate a valid checkpoint record"))); } + memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint)); } LastRec = RecPtr = checkPointLoc; - memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint)); wasShutdown = (record->xl_info == XLOG_CHECKPOINT_SHUTDOWN); ereport(DEBUG1, -- 2.40.0