Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices

From	"Kani, Toshimitsu" <toshi.kani@hpe.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices
Date	2016-06-21 18:10 +0200
Message-ID	<rMwfM-7MM-31@gated-at.bofh.it> (permalink)
References	(5 earlier) <rMfeV-5bZ-7@gated-at.bofh.it> <rMfyi-5y7-29@gated-at.bofh.it> <rMfyi-5y7-27@gated-at.bofh.it> <rMg1j-5KE-5@gated-at.bofh.it> <rMudX-6uM-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, 2016-06-21 at 09:41 -0400, Mike Snitzer wrote:
> On Mon, Jun 20 2016 at  6:22pm -0400,
> Mike Snitzer <snitzer@redhat.com> wrote:
> > 
> > On Mon, Jun 20 2016 at  5:28pm -0400,
> > Kani, Toshimitsu <toshi.kani@hpe.com> wrote:
> > 
 :
> > Looks good, I folded it in and tested it to work.  Pushed to my 'wip'
> > branch.
> > 
> > No longer seeing any corruption in my test that was using partitions to
> > span pmem devices with a dm-linear device.
> > 
> > Jens, any chance you'd be open to picking up the first 2 patches in this
> > series?  Or would you like to see them folded or something different?
>
> I'm now wondering if we'd be better off setting a new QUEUE_FLAG_DAX
> rather than establish GENHD_FL_DAX on the genhd?
> 
> It'd be quite a bit easier to allow upper layers (e.g. XFS and ext4) to
> check for a queue flag.

I think GENHD_FL_DAX is more appropriate since DAX does not use a request
queue, except for protecting the underlining device being disabled while
direct_access() is called (b2e0d1625e19).  

About protecting direct_access, this patch assumes that the underlining
device cannot be disabled until dtr() is called.  Is this correct?  If not,
I will need to call dax_map_atomic().

Thanks,
-Toshi

Thread

[PATCH 0/6] Support DAX for device-mapper dm-linear devices Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  [PATCH 1/6] genhd: Add GENHD_FL_DAX to gendisk flags Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  [PATCH 4/6] dm-linear: Add linear_direct_access() Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  [PATCH 6/6] dm: Enable DAX support for mapper device Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  [PATCH 3/6] dm: Add dm_blk_direct_access() for mapped device Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  [PATCH 2/6] block: Check GENHD_FL_DAX for DAX capability Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  [PATCH 5/6] dm, dm-linear: Add dax_supported to dm_target Toshi Kani <toshi.kani@hpe.com> - 2016-06-14 00:40 +0200
  Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-14 01:00 +0200
    Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-20 20:30 +0200
      Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-20 21:50 +0200
        Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-20 23:50 +0200
          Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-21 00:10 +0200
            Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-21 00:40 +0200
              Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-21 15:50 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-21 18:00 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-21 18:10 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-21 18:30 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-21 18:50 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-21 19:20 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-21 19:00 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-21 20:30 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-22 19:50 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-22 21:20 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-22 22:20 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-23 00:40 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-23 01:20 +0200
          Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-21 00:50 +0200
      Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-20 23:10 +0200
  Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-14 01:20 +0200
    Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-14 02:00 +0200
      Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-14 02:10 +0200
        Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-14 09:40 +0200
      Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Jeff Moyer <jmoyer@redhat.com> - 2016-06-14 16:00 +0200
        Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-14 17:50 +0200
          Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-14 20:10 +0200
          Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Jeff Moyer <jmoyer@redhat.com> - 2016-06-14 22:20 +0200
            Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-15 03:50 +0200
              Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Dan Williams <dan.j.williams@intel.com> - 2016-06-15 04:10 +0200
                Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Mike Snitzer <snitzer@redhat.com> - 2016-06-15 04:40 +0200
        Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-06-14 18:00 +0200

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