[PATCH 1/5] scsi_transport_srp: Fix fast_io_fail_tmo=dev_loss_tmo=off behavior

[Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org>]

If scsi_remove_host() is called while an rport is in the blocked
state then scsi_remove_host() will only finish if the rport is
unblocked from inside a timer function. Make sure that an rport
only enters the blocked state if a timer will be started that
will unblock it. This avoids that unloading the ib_srp kernel
module after having disconnected the initiator from the target
system results in a deadlock if both the fast_io_fail_tmo and
dev_loss_tmo parameters have been set to "off".

Signed-off-by: Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org>
Cc: James Bottomley <jbottomley-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
Cc: David Dillow <dave-i1Mk8JYDVaaSihdK6806/g@public.gmane.org>
Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
---
 drivers/scsi/scsi_transport_srp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index 13e8983..a0c5bfd 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -473,7 +473,8 @@ static void __srp_start_tl_fail_timers(struct srp_rport *rport)
 	if (delay > 0)
 		queue_delayed_work(system_long_wq, &rport->reconnect_work,
 				   1UL * delay * HZ);
-	if (srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
+	if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
+	    srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
 		pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
 			 rport->state);
 		scsi_target_block(&shost->shost_gendev);
-- 
1.8.4.5

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