dm: add ->copy_from_iter() dax operation support
authorDan Williams <dan.j.williams@intel.com>
Mon, 29 May 2017 19:57:56 +0000 (12:57 -0700)
committerDan Williams <dan.j.williams@intel.com>
Fri, 9 Jun 2017 16:22:21 +0000 (09:22 -0700)
commit7e026c8c0a4200da86bc51edeaad79dcdccf78ca
treeb1e30796161a6b1696ce75c2098d2fb980cb6a44
parent0aed55af88345b5d673240f90e671d79662fb01e
dm: add ->copy_from_iter() dax operation support

Allow device-mapper to route copy_from_iter operations to the
per-target implementation. In order for the device stacking to work we
need a dax_dev and a pgoff relative to that device. This gives each
layer of the stack the information it needs to look up the operation
pointer for the next level.

This conceptually allows for an array of mixed device drivers with
varying copy_from_iter implementations.

Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/dax/super.c
drivers/md/dm-linear.c
drivers/md/dm-stripe.c
drivers/md/dm.c
include/linux/dax.h
include/linux/device-mapper.h