[dm-devel] dm-crypt: fix lost ioprio when queuing crypto bios from task with ioprio

[Kent Overstreet]

On Sun, Dec 18, 2016 at 06:17:55PM -0500, Mike Snitzer wrote:
> Spinning it as a pure bugfix is a reach (as Eric's header documents the
> patch, the case is weak for cc'ing stable).  Reality is the change is
> needed to enable a new bcache feature.  I'm not going to rush
> feature-enabling change that arrived in the last minute.

I do agree that it can wait for 4.11 and isn't a candidate for stable, I
should've said that earlier.

> 
> > 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.
> 
> You're completely misreading my having raised dm-cache.  I was poinitng
> out that Eric's patch to enable a new bcache feature ontop of dm-crypt
> was too late.  Had Eric known of this limitation sooner or thought to
> engage me or the rest of dm-devel then DM could've been fixed with
> precision during the 4.10 development window.
> 
> I wasn't saying Eric should've worked on dm-cache.  But had he raised
> this bcache feature to my attention, in the context of missing ioprio
> and why dm-cache would/could use it in the future too, then it'd have
> been all the better.  Simple as that.  I was trying to be helpful.  Not
> trying to be a PITA in any way.

I took your email to mean that the original patches shouldn't have gone in
without involving dm-cache. If that wasn't what you meant, let's just chalk this
up to a miscommunication.