[dm-devel] Revert "dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks"

[Bart Van Assche]

On Mon, 2018-03-12 at 17:23 -0400, Mike Snitzer wrote:
> Could you provide more details on your setup?
> 
> Obviously you're using "queue_mode mq", what are your underlying paths?
> 
> Given the trace it would seem you're hitting multipath_clone_and_map()'s
> blk_queue_dying(q) error path that calls activate_or_offline_path().

Hello Mike,

The reported kernel crash was triggered by running the following command:

srp-test/run_tests -c -d -r 10 -t 02-mq

The srp-test software is available at https://github.com/bvanassche/srp-test.
All patches necessary to run that script in a virtual machine (RoCE support
for the SRP initiator and target drivers) will be sent to Linus during the
kernel v4.17 merge window. These patches are already available in linux-next
today. Although I have not tried this myself, I expect that if you run the
above command against a kernel built from the linux-next code that that will
allow you to reproduce what I reported.

Thanks,

Bart.