• Joseph Qi's avatar
    ocfs2/dlm: fix deadlock when dispatch assert master · 012572d4
    Joseph Qi authored
    The order of the following three spinlocks should be:
    dlm_domain_lock < dlm_ctxt->spinlock < dlm_lock_resource->spinlock
    But dlm_dispatch_assert_master() is called while holding
    dlm_ctxt->spinlock and dlm_lock_resource->spinlock, and then it calls
    dlm_grab() which will take dlm_domain_lock.
    Once another thread (for example, dlm_query_join_handler) has already
    taken dlm_domain_lock, and tries to take dlm_ctxt->spinlock deadlock
    Signed-off-by: default avatarJoseph Qi <joseph.qi@huawei.com>
    Cc: Joel Becker <jlbec@evilplan.org>
    Cc: Mark Fasheh <mfasheh@suse.com>
    Cc: "Junxiao Bi" <junxiao.bi@oracle.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
dlmmaster.c 95.9 KB