leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

xfs: fix iclog release error check race with shutdown

Browse Source 
Prior to commit df732b29c8 ("xfs: call xlog_state_release_iclog with
l_icloglock held"), xlog_state_release_iclog() always performed a
locked check of the iclog error state before proceeding into the
sync state processing code. As of this commit, part of
xlog_state_release_iclog() was open-coded into
xfs_log_release_iclog() and as a result the locked error state check
was lost.

The lockless check still exists, but this doesn't account for the
possibility of a race with a shutdown being performed by another
task causing the iclog state to change while the original task waits
on ->l_icloglock. This has reproduced very rarely via generic/475
and manifests as an assert failure in __xlog_state_release_iclog()
due to an unexpected iclog state.

Restore the locked error state check in xlog_state_release_iclog()
to ensure that an iclog state update via shutdown doesn't race with
the iclog release state processing code.

Fixes: df732b29c8 ("xfs: call xlog_state_release_iclog with l_icloglock held")
Reported-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Brian Foster 2020-02-21 07:36:24 -08:00 committed by Darrick J. Wong
parent 98d54f81e3
commit 6b789c337a
1 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
fs/xfs/xfs_log.c
View File

@ -605,18 +605,23 @@ xfs_log_release_iclog(
struct xlog *log = mp->m_log;
bool sync;
if (iclog->ic_state == XLOG_STATE_IOERROR) {
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
return -EIO;
}
if (iclog->ic_state == XLOG_STATE_IOERROR)
goto error;
if (atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock)) {
if (iclog->ic_state == XLOG_STATE_IOERROR) {
spin_unlock(&log->l_icloglock);
goto error;
}
sync = __xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
if (sync)
xlog_sync(log, iclog);
}
return 0;
error:
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
return -EIO;
}
/*