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Description of problem:

    The problem is that for the case of priority queues, we
    have to assume that __rpc_remove_wait_queue_priority will move new
    elements from the tk_wait.links lists into the queue->tasks[] list.
    We therefore cannot use list_for_each_entry_safe() on queue->tasks[],
    since that will skip these new tasks that __rpc_remove_wait_queue_priority
    is adding.
    
    Without this fix, rpc_wake_up and rpc_wake_up_status will both fail
    to wake up all functions on priority wait queues, which can result
    in some nasty hangs.


Version-Release number of selected component (if applicable):


How reproducible:
Sometimes 

Additional info:

Upstream commit:

commit 540a0f7584169651f485e8ab67461fcb06934e38
Author: Trond Myklebust <Trond.Myklebust>
Date:   Mon Mar 19 13:39:35 2012 -0400

    SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up()

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

*** This bug has been marked as a duplicate of bug 809928 ***