From 6568b08b77816cda2a95919c7494108d983d5941 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 24 Jan 2017 18:44:18 -0800 Subject: 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 Signed-off-by: Dan Williams --- include/linux/dax.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/linux/dax.h b/include/linux/dax.h index 9b2d5ba10d7d..74ebb92b625a 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -7,6 +7,16 @@ #include struct iomap_ops; +struct dax_device; +struct dax_operations { + /* + * direct_access: translate a device-relative + * logical-page-offset into an absolute physical pfn. Return the + * number of pages available for DAX at that pfn. + */ + long (*direct_access)(struct dax_device *, pgoff_t, long, + void **, pfn_t *); +}; int dax_read_lock(void); void dax_read_unlock(int id); -- cgit v1.2.3