From 7e026c8c0a4200da86bc51edeaad79dcdccf78ca Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 29 May 2017 12:57:56 -0700 Subject: 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 Reviewed-by: Mike Snitzer Signed-off-by: Dan Williams --- include/linux/dax.h | 2 ++ include/linux/device-mapper.h | 3 +++ 2 files changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dax.h b/include/linux/dax.h index bbe79ed90e2b..28e398f8c59e 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -78,6 +78,8 @@ void kill_dax(struct dax_device *dax_dev); void *dax_get_private(struct dax_device *dax_dev); long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn); +size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, + size_t bytes, struct iov_iter *i); /* * We use lowest available bit in exceptional entry for locking, one bit for diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index f4c639c0c362..11c8a0a92f9c 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -132,6 +132,8 @@ typedef int (*dm_busy_fn) (struct dm_target *ti); */ typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn); +typedef size_t (*dm_dax_copy_from_iter_fn)(struct dm_target *ti, pgoff_t pgoff, + void *addr, size_t bytes, struct iov_iter *i); #define PAGE_SECTORS (PAGE_SIZE / 512) void dm_error(const char *message); @@ -181,6 +183,7 @@ struct target_type { dm_iterate_devices_fn iterate_devices; dm_io_hints_fn io_hints; dm_dax_direct_access_fn direct_access; + dm_dax_copy_from_iter_fn dax_copy_from_iter; /* For internal device-mapper use. */ struct list_head list; -- cgit v1.2.3