diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 068e59bec0..669ba958e8 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -86,6 +86,7 @@ #include "access/xlog.h" #include "access/xloginsert.h" #include "access/xlogreader.h" +#include "access/xlogrecovery.h" #include "access/xlogutils.h" #include "catalog/pg_type.h" #include "catalog/storage.h" @@ -2477,6 +2478,38 @@ PrepareRedoAdd(char *buf, XLogRecPtr start_lsn, * that it got added in the redo phase */ + /* + * In the event of a crash while a checkpoint was running, it may be + * possible that some two-phase data found its way to disk while its + * corresponding record needs to be replayed in the follow-up recovery. + * As the 2PC data was on disk, it has already been restored at the + * beginning of recovery with restoreTwoPhaseData(), so skip this record + * to avoid duplicates in TwoPhaseState. If a consistent state has been + * reached, the record is added to TwoPhaseState and it should have no + * corresponding file in pg_twophase. + */ + if (!XLogRecPtrIsInvalid(start_lsn)) + { + char path[MAXPGPATH]; + + TwoPhaseFilePath(path, hdr->xid); + + if (access(path, F_OK) == 0) + { + ereport(reachedConsistency ? ERROR : WARNING, + (errmsg("could not recover two-phase state file for transaction %u", + hdr->xid), + errdetail("Two-phase state file has been found in WAL record %X/%X, but this transaction has already been restored from disk.", + LSN_FORMAT_ARGS(start_lsn)))); + return; + } + + if (errno != ENOENT) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not access file \"%s\": %m", path))); + } + /* Get a free gxact from the freelist */ if (TwoPhaseState->freeGXacts == NULL) ereport(ERROR,