[XFS] Fix lock inversion in forced shutdown.

Recent changes to xlog_state_release_iclog() placed the grant_lock inside
the icloglock. forced unmount of the log does this the opposite way
around, but does not depend on the order for correct working. Fix the
inversion by changing the order locks are gained in
xfs_log_force_umount().

SGI-PV: 979661
SGI-Modid: xfs-linux-melb:xfs-kern:30773a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 319b98eb410c5809b9ea7c1727c78451588642df..4a6f7c5d145933c2781bf18d7971368545f3bcc7 100644 (file)
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3499,8 +3499,8 @@ xfs_log_force_umount(
         * before we mark the filesystem SHUTDOWN and wake
         * everybody up to tell the bad news.
         */
-       spin_lock(&log->l_grant_lock);
        spin_lock(&log->l_icloglock);
+       spin_lock(&log->l_grant_lock);
        mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
        XFS_BUF_DONE(mp->m_sb_bp);
        /*