On Sat, Dec 17, 2016 at 10:58:00AM -0500, Mike Snitzer wrote:

The time for 4.10 inclusion has passed.  This needs to wait until 4.11.

It also needs more review, testing and possible re-working.  Each DM
target shouldn't have to worry about these details (though I do grant
that dm-crypt.c:clone_init call to bio_set_prio makes sense).

A more generic solution is needed (likely in DM core).

A while ago, Vivek floated a patch that spoke to the need for iocontext
(for the purposes of cgroups):
 https://patchwork.kernel.org/patch/8485451/

I don't consider your patch too dissimilar.  But it just needs to be
worked on during a development window.  On to 4.11 ;)

Mike, this current patch is a pure bugfix, and you can't fault Eric for not
wanting to do work on dm-cache too when all he's trying to do is solve a
particular real world problem. He should be able to do that without having to
dive into dm-cache code too.

Furthermore, pretty much every filesystem has private ioctls and interfaces -
this is no different.

If you dm guys want to standardize something, that's awesome - and in hindsight,
it wouldn't have been a bad idea to CC you guys on the original patches. But
please keep in mind Eric's not a full time kernel developer, and don't crap on
his work just becausue he's not working on dm-cache too.