dax: introduce dax_operations
authorDan Williams <dan.j.williams@intel.com>
Wed, 25 Jan 2017 02:44:18 +0000 (18:44 -0800)
committerDan Williams <dan.j.williams@intel.com>
Wed, 19 Apr 2017 22:14:35 +0000 (15:14 -0700)
commit6568b08b77816cda2a95919c7494108d983d5941
treecdc776afdf8dd6c583155d169017eb78ab94a8bf
parent72058005411ffddcae6c06f7b691d635489132af
dax: introduce dax_operations

Track a set of dax_operations per dax_device that can be set at
alloc_dax() time. These operations will be used to stop the abuse of
block_device_operations for communicating dax capabilities to
filesystems. It will also be used to replace the "pmem api" and move
pmem-specific cache maintenance, and other dax-driver-specific
filesystem-dax operations, to dax device methods. In particular this
allows us to stop abusing __copy_user_nocache(), via memcpy_to_pmem(),
with a driver specific replacement.

This is a standalone introduction of the operations. Follow on patches
convert each dax-driver and teach fs/dax.c to use ->direct_access() from
dax_operations instead of block_device_operations.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/dax/dax.h
drivers/dax/device.c
drivers/dax/super.c
include/linux/dax.h