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| author | Chandra Seetharaman <sekharan@us.ibm.com> | 2013-07-19 17:31:38 -0500 |
|---|---|---|
| committer | Ben Myers <bpm@sgi.com> | 2013-07-22 13:58:10 -0500 |
| commit | 297aa63769e6ae06b7db97eb76c9211beeb32c69 (patch) | |
| tree | 151526cae76c8c74d22024ff2ef02df37d9888f6 | |
| parent | 58e59854a3dfa9ab1fa1bcfc6324646cd77046a7 (diff) | |
| download | linux-297aa63769e6ae06b7db97eb76c9211beeb32c69.tar.bz2 | |
xfs: Fix a deadlock in xfs_log_commit_cil() code path
While testing and rearranging pquota/gquota code, I stumbled
on a xfs_shutdown() during a mount. But the mount just hung.
Debugged and found that there is a deadlock involving
&log->l_cilp->xc_ctx_lock.
It is in a code path where &log->l_cilp->xc_ctx_lock is first
acquired in read mode and some levels down the same semaphore
is being acquired in write mode causing a deadlock.
This is the stack:
xfs_log_commit_cil -> acquires &log->l_cilp->xc_ctx_lock in read mode
xlog_print_tic_res
xfs_force_shutdown
xfs_log_force_umount
xlog_cil_force
xlog_cil_force_lsn
xlog_cil_push_foreground
xlog_cil_push - tries to acquire same semaphore in write mode
This patch fixes the deadlock by changing the reason code for
xfs_force_shutdown in xlog_print_tic_res() to SHUTDOWN_LOG_IO_ERROR.
SHUTDOWN_LOG_IO_ERROR is the right reason code to be set since
we are in the log path.
Thanks to Dave for suggesting this solution.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
| -rw-r--r-- | fs/xfs/xfs_log.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index d852a2b3e1fd..bf89eb97fefd 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1941,7 +1941,7 @@ xlog_print_tic_res( xfs_alert_tag(mp, XFS_PTAG_LOGRES, "xlog_write: reservation ran out. Need to up reservation"); - xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); + xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); } /* |