[bug report] NVMe/IB: reset_controller need more than 1min

[Sagi Grimberg]

> Hello
> 
> Gentle ping here, this issue still exists on latest 5.13-rc7
> 
> # time nvme reset /dev/nvme0
> 
> real 0m12.636s
> user 0m0.002s
> sys 0m0.005s
> # time nvme reset /dev/nvme0
> 
> real 0m12.641s
> user 0m0.000s
> sys 0m0.007s

Strange that even normal resets take so long...
What device are you using?

> # time nvme reset /dev/nvme0
> 
> real 1m16.133s
> user 0m0.000s
> sys 0m0.007s

There seems to be a spurious command timeout here, but maybe this
is due to the fact that the queues take so long to connect and
the target expires the keep-alive timer.

Does this patch help?
--
diff --git a/drivers/nvme/target/fabrics-cmd.c 
b/drivers/nvme/target/fabrics-cmd.c
index 7d0f3523fdab..f4a7db1ab3e5 100644
--- a/drivers/nvme/target/fabrics-cmd.c
+++ b/drivers/nvme/target/fabrics-cmd.c
@@ -142,6 +142,14 @@ static u16 nvmet_install_queue(struct nvmet_ctrl 
*ctrl, struct nvmet_req *req)
                 }
         }

+       /*
+        * Controller establishment flow may take some time, and the 
host may not
+        * send us keep-alive during this period, hence reset the
+        * traffic based keep-alive timer so we don't trigger a
+        * controller teardown as a result of a keep-alive expiration.
+        */
+       ctrl->reset_tbkas = true;
+
         return 0;

  err:
--

>> target:
>> [  934.306016] nvmet: creating controller 1 for subsystem testnqn for
>> NQN nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4c10-8058-b7c04f383432.
>> [  944.875021] nvmet: ctrl 1 keep-alive timer (5 seconds) expired!
>> [  944.900051] nvmet: ctrl 1 fatal error occurred!
>> [ 1005.628340] nvmet: creating controller 1 for subsystem testnqn for
>> NQN nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4c10-8058-b7c04f383432.
>>
>> client:
>> [  857.264029] nvme nvme0: resetting controller
>> [  864.115369] nvme nvme0: creating 40 I/O queues.
>> [  867.996746] nvme nvme0: mapped 40/0/0 default/read/poll queues.
>> [  868.001673] nvme nvme0: resetting controller
>> [  935.396789] nvme nvme0: I/O 9 QID 0 timeout
>> [  935.402036] nvme nvme0: Property Set error: 881, offset 0x14
>> [  935.438080] nvme nvme0: creating 40 I/O queues.
>> [  939.332125] nvme nvme0: mapped 40/0/0 default/read/poll queues.