dax: introduce dax_direct_access()
Replace bdev_direct_access() with dax_direct_access() that uses
dax_device and dax_operations instead of a block_device and
block_device_operations for dax. Once all consumers of the old api have
been converted bdev_direct_access() will be deleted.
Given that block device partitioning decisions can cause dax page
alignment constraints to be violated this also introduces the
bdev_dax_pgoff() helper. It handles calculating a logical pgoff relative
to the dax_device and also checks for page alignment.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 39a0312..7e62e28 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -27,6 +27,8 @@
bool dax_alive(struct dax_device *dax_dev);
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);
/*
* We use lowest available bit in exceptional entry for locking, one bit for