[dm-devel] [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq

[Christoph Hellwig]

On Tue, Jan 11, 2022 at 01:23:53PM -0500, Jeff Moyer wrote:
> Maybe I have bad taste, but the patches didn't look like cruft to me.
> :)

They do to me.  The extend the corner case of request on request
stacking that already is a bit of mess even more by adding yet another
special case in the block layer.

> 
> I'm not sure why we'd prevent users from using dm-mpath on nvmeof.  I
> think there's agreement that the nvme native multipath implementation is
> the preferred way (that's the default in rhel9, even), but I don't think
> that's a reason to nack this patch set.
> 
> Or have I missed your point entirely?

No you have not missed the point.  nvme-multipath exists longer than
the nvme-tcp driver and is the only supported one for it upstream for
a good reason.  If RedHat wants to do their own weirdo setups they can
patch their kernels, but please leave the upstrem code alone.