Re: [PATCH v3 1/3] pmem: only set QUEUE_FLAG_DAX for fsdax mode

[Kani, Toshi]

On Thu, 2018-06-28 at 13:04 -0600, Ross Zwisler wrote:
> On Thu, Jun 28, 2018 at 05:42:34PM +0000, Kani, Toshi wrote:
> > On Tue, 2018-06-26 at 16:04 -0600, Ross Zwisler wrote:
> > > On Tue, Jun 26, 2018 at 02:51:52PM -0700, Dan Williams wrote:
> > > > On Tue, Jun 26, 2018 at 2:31 PM, Kani, Toshi <toshi.kani@xxxxxxx> wrote:
 :
> > Your patches look good.  But I am still not clear about the Fixes &
> > stable handling.  Talking about user visible behavior, I do not think we
> > had any issue until dax support was dropped from raw mode.  Until then,
> > the pmem driver supported dax for all modes, and the check for
> > direct_access worked.    
> 
> I agree that the fsdax + raw mode failure mode I mentioned in my cover letter
> only started when we restricted filesystem DAX to having struct page, but I
> think that the other failure mode, fsdax + some random block driver (I used
> brd) was present in DM from the beginning.

Ah, I see.

> In any case, I think both are fixed with the patches, and I think it's fine
> that all 3 get thrown at stable.  Thanks, Mike, for the help.

Yup, agreed. 

Thanks!
-Toshi