net/ncsi: Avoid channel_monitor hrtimer deadlock
Calling ncsi_stop_channel_monitor from channel_monitor is a guaranteed deadlock on SMP because stop calls del_timer_sync on the timer that invoked channel_monitor as its timer function. Recognise the inherent race of marking the monitor disabled before deleting the timer by just returning if enable was cleared. After a timeout (the default case -- reset to START when response received) just mark the monitor.enabled false. If the channel has an entry on the channel_queue list, or if the state is not ACTIVE or INACTIVE, then warn and mark the timer stopped and don't restart, as the locking is broken somehow. Fixes: 0795fb20 ("net/ncsi: Stop monitor if channel times out or is inactive") Signed-off-by:Milton Miller <miltonm@us.ibm.com> Signed-off-by:
Eddie James <eajames@linux.ibm.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
6e5a03bc