[PATCH v2 7/7] pmem, dax: have direct_access use __pmem annotation

[Dan Williams]

On Fri, Aug 14, 2015 at 9:55 AM, Ross Zwisler
<ross.zwisler at linux.intel.com> wrote:
> On Thu, 2015-08-13 at 14:20 -0700, Dan Williams wrote:
>> On Thu, Aug 13, 2015 at 9:51 AM, Ross Zwisler
>> <ross.zwisler at linux.intel.com> wrote:
>> > Update the annotation for the kaddr pointer returned by direct_access()
>> > so that it is a __pmem pointer.  This is consistent with the PMEM driver
>> > and with how this direct_access() pointer is used in the DAX code.
>> >
>> > Signed-off-by: Ross Zwisler <ross.zwisler at linux.intel.com>
>> > ---
>> >  Documentation/filesystems/Locking |  3 ++-
>> >  arch/powerpc/sysdev/axonram.c     |  7 ++++---
>> >  drivers/block/brd.c               |  4 ++--
>> >  drivers/nvdimm/pmem.c             |  4 ++--
>> >  drivers/s390/block/dcssblk.c      | 10 +++++----
>> >  fs/block_dev.c                    |  2 +-
>> >  fs/dax.c                          | 44 +++++++++++++++++++++------------------
>> >  include/linux/blkdev.h            |  8 +++----
>> >  8 files changed, 45 insertions(+), 37 deletions(-)
>> >
>> > diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
>> > index 6a34a0f..06d4434 100644
>> > --- a/Documentation/filesystems/Locking
>> > +++ b/Documentation/filesystems/Locking
>> > @@ -397,7 +397,8 @@ prototypes:
>> >         int (*release) (struct gendisk *, fmode_t);
>> >         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
>> >         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
>> > -       int (*direct_access) (struct block_device *, sector_t, void **, unsigned long *);
>> > +       int (*direct_access) (struct block_device *, sector_t, void __pmem **,
>> > +                               unsigned long *);
>>
>> So this collides with the __pfn_t work.  I think the we have a
>> reasonable chance of getting that in to 4.3, so I'd wait to see if we
>> hit any major roadblocks with that set [1] before merging these.
>>
>> [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-August/001803.html
>
> Fair enough.  Yea, I hadn't merged with that series yet a) because I didn't
> know when its review cycle would settle down and b) because that series hadn't
> pulled in changes from Matthew for PMD support, which I was originally using
> as a baseline.
>
> I'll merge with your code for v3.

Sounds, let me go rebase the __pfn_t patches on -mm so we'all lined up
and collision free.