alex chen 2f2eca20a0 ocfs2: check if the ocfs2 lock resource has been initialized before calling ocfs2_dlm_lock
If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
the lock won't be dropped and then will lead umount hung.  The case is
described below:

ocfs2_mknod
    ocfs2_mknod_locked
        __ocfs2_mknod_locked
            ocfs2_journal_access_di
            Failed because of -ENOMEM or other reasons, the inode lockres
            has not been initialized yet.

    iput(inode)
        ocfs2_evict_inode
            ocfs2_delete_inode
                ocfs2_inode_lock
                    ocfs2_inode_lock_full_nested
                        __ocfs2_cluster_lock
                        Succeeds and allocates a new dlm lockres.
            ocfs2_clear_inode
                ocfs2_open_unlock
                    ocfs2_drop_inode_locks
                        ocfs2_drop_lock
                        Since lockres has not been initialized, the lock
                        can't be dropped and the lockres can't be
                        migrated, thus umount will hang forever.

Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: joyce.xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:58 -07:00
..
2015-04-01 00:01:47 -05:00
2015-02-16 17:56:03 -08:00
2015-03-18 10:29:48 +01:00
2015-02-05 16:34:25 +01:00
2014-11-19 13:01:20 -05:00
2015-02-20 04:56:44 -05:00
2015-02-16 17:56:04 -08:00
2015-01-29 00:13:13 -05:00
2014-11-19 13:01:26 -05:00