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authorDan Williams <dan.j.williams@intel.com>2017-01-25 05:44:18 +0300
committerDan Williams <dan.j.williams@intel.com>2017-04-20 01:14:35 +0300
commit6568b08b77816cda2a95919c7494108d983d5941 (patch)
treecdc776afdf8dd6c583155d169017eb78ab94a8bf /include/linux/dax.h
parent72058005411ffddcae6c06f7b691d635489132af (diff)
downloadlinux-6568b08b77816cda2a95919c7494108d983d5941.tar.xz
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>
Diffstat (limited to 'include/linux/dax.h')
-rw-r--r--include/linux/dax.h10
1 files changed, 10 insertions, 0 deletions
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 <asm/pgtable.h>
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);