releases/3.16.3/scsi_transport_srp-fix-fast_io_fail_tmo-dev_loss_tmo-off-behavior.patch

   1 From cd53eb686d2418eda938aad3c9da42b7dfa9351f Mon Sep 17 00:00:00 2001
   2 From: Bart Van Assche <bvanassche@acm.org>
   3 Date: Wed, 9 Jul 2014 15:56:43 +0200
   4 Subject: scsi_transport_srp: Fix fast_io_fail_tmo=dev_loss_tmo=off behavior
   5
   6 From: Bart Van Assche <bvanassche@acm.org>
   7
   8 commit cd53eb686d2418eda938aad3c9da42b7dfa9351f upstream.
   9
  10 If scsi_remove_host() is called while an rport is in the blocked state
  11 then scsi_remove_host() will only finish if the rport is unblocked
  12 from inside a timer function. Make sure that an rport only enters the
  13 blocked state if a timer will be started that will unblock it. This
  14 avoids that unloading the ib_srp kernel module after having
  15 disconnected the initiator from the target system results in a
  16 deadlock if both the fast_io_fail_tmo and dev_loss_tmo parameters have
  17 been set to "off".
  18
  19 Signed-off-by: Bart Van Assche <bvanassche@acm.org>
  20 Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
  21 Reviewed-by: David Dillow <dave@thedillows.org>
  22 Signed-off-by: Roland Dreier <roland@purestorage.com>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24
  25 ---
  26  drivers/scsi/scsi_transport_srp.c |    3 ++-
  27  1 file changed, 2 insertions(+), 1 deletion(-)
  28
  29 --- a/drivers/scsi/scsi_transport_srp.c
  30 +++ b/drivers/scsi/scsi_transport_srp.c
  31 @@ -473,7 +473,8 @@ static void __srp_start_tl_fail_timers(s
  32         if (delay > 0)
  33                 queue_delayed_work(system_long_wq, &rport->reconnect_work,
  34                                    1UL * delay * HZ);
  35 -       if (srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
  36 +       if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
  37 +           srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
  38                 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
  39                          rport->state);
  40                 scsi_target_block(&shost->shost_gendev);