Fix an assertion failure related to an exclusive backup.
Previously multiple sessions could execute pg_start_backup() and
pg_stop_backup() to start and stop an exclusive backup at the same time.
This could trigger the assertion failure of
"FailedAssertion("!(XLogCtl->Insert.exclusiveBackup)".
This happend because, even while pg_start_backup() was starting
an exclusive backup, other session could run pg_stop_backup()
concurrently and mark the backup as not-in-progress unconditionally.
This patch introduces ExclusiveBackupState indicating the state of
an exclusive backup. This state is used to ensure that there is only
one session running pg_start_backup() or pg_stop_backup() at
the same time, to avoid the assertion failure.
Back-patch to all supported versions.
Author: Michael Paquier
Reviewed-By: Kyotaro Horiguchi and me
Reported-By: Andreas Seltenreich
Discussion: <87mvktojme.fsf@credativ.de>
Branch
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REL9_5_STABLE
Details
-------
http://git.postgresql.org/pg/commitdiff/dfe348c1b1ca5327cf2ff058b795ac188d442715
Modified Files
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src/backend/access/transam/xlog.c | 223 ++++++++++++++++++++++++++------------
1 file changed, 155 insertions(+), 68 deletions(-)
