• Joe Eykholt's avatar
    [SCSI] fcoe: flush per-cpu thread work when destroying interface · 061e7be2
    Joe Eykholt authored
    This fixes one cause of an occational problem when unloading
    libfc where the exchange manager pool doesn't have all items freed.
    
    The existing WARN_ON(mp->total_exches <= 0) isn't hit.
    However, note that total_exches is decremented when the
    exchange is completed, and it can be held with a refcnt
    for a while after that.
    
    I'm not sure what the offending exchange is, but I suspect
    it is an incoming request, because outgoing state machines
    should be all stopped at this point.
    
    Note that although receive is stopped before the exchange
    manager is freed, there could still be active threads
    handling received frames.
    
    This patch flushes the queues by allocating a new skb
    and sending it through, and have the thread handle
    this new skb specially.  This is similar to the way the work
    queues are flushed now by putting work items in them and waiting
    until they make it through the queue.
    
    An skb->destructor function is used to inform us of
    the completion of the flush, and the fr_dev() is left
    NULL to indicate to fcoe_percpu_receive_thread() that
    the skb should be just freed.  There's already a check
    for the lp being NULL which prints a message.
    We skip printing the message if the destructor is for flushing.
    Signed-off-by: default avatarJoe Eykholt <jeykholt@cisco.com>
    Signed-off-by: default avatarRobert Love <robert.w.love@intel.com>
    Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
    061e7be2
fcoe.c 51.5 KB