In case (a) scsi_eh_inc_host_failed() will wake up the error handler. And in
case (b) scsi_dec_host_busy() will wake up the error handler. So it's not
clear to me why you think that there is a scenario in which the EH won't be
woken up?
So in case (b), in my understanding, scsi_dec_host_busy can skip wakeups
as it does not see host_failed change yet.
That's not correct. If scsi_dec_host_busy() obtains the SCSI host lock before
scsi_eh_inc_host_failed() obtains it then the latter function will trigger a
SCSI EH wakeup.
You are right! Thanks a lot for pointing that out! Now when I understand
it, your patch looks good for me:
Reviewed-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com>
By the way, I very much like your idea of using rcu for these case.
Thanks, Pavel.
Bart.
