Re: Revert "dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks"

[Bart Van Assche <Bart.VanAssche@wdc.com>]

On Tue, 2018-03-13 at 17:41 -0400, Mike Snitzer wrote:
> On Tue, Mar 13 2018 at  1:10pm -0400,
> Bart Van Assche <Bart.VanAssche@wdc.com> wrote:
> > Even if that would be the case, that can't have been the cause of what I
> > reported. Before I run any dm tests I merge the block layer, SCSI and RDMA
> > changes that are scheduled for the next kernel version into the dm tree.
> 
> Well I've rebased dm-4.16 ontop of v4.15-rc5.  If you udate to latest
> dm-4.16 and look at the following diff it is pretty clear that these
> changes will not compromise dm-mpath's "mq" mode (which you're using):
> 
> git diff 8d47e65948ddea4398892946d9e50778a316b397^..e8f74a0f00113d74ac18d6de13096f9e2f95618a -- drivers/md/dm-mpath.c
> 
> I see no reason why you'd hit hangs with requests lingering on the requeue_list

Hello Mike,

I agree with you that the hanging requests shouldn't be related to the most recent
dm changes. I will try to find some time to root-cause this myself.

Bart.