If the call to udisk_LogEnd() fails (probably due to an I/O error)
don't leak the UBIK_VERSION_LOCK.
This is the possible cause of a vlserver deadlock, which had
approximately 4800 threads blocked. Analysis of backtrace of all
of these threads showed that all blocked threads were waiting in
ubik.c:555 (blocked on DBHOLD) with the exception of:
One in beacon.c:388 (blocked on UBIK_VERSION_LOCK)
One in recovery.c:503 (blocked on DBHOLD)
One in ubik.c:125 (blocked on DBHOLD)
One in ubik.c:585 (blocked on UBIK_VERSION_LOCK)
The last of these is the critical one, because it already holds
the lock that DBHOLD waits on - so despite the vast majority of
threads being blocked in DBHOLD, it's actually UBIK_VERSION_LOCK
that we're waiting on.
There is no sign of a thread which is still active which currently
holds UBIK_VERSION_LOCK.
Change-Id: I1627b448d359152237912d4d78c9fa52c7149aa0
Reviewed-on: http://gerrit.openafs.org/11427
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
code = udisk_LogEnd(dbase, &dbase->version);
if (code) {
dbase->version.counter--;
- return (code);
+ UBIK_VERSION_UNLOCK;
+ return code;
}
UBIK_VERSION_UNLOCK;