dax/super: Do not request a pointer kaddr when not required

Function __bdev_dax_supported doesn't need to get local pointer kaddr
from direct_access. Using NULL instead of having to pass in a useless
local pointer that caller then just throw away.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 903d9c473749..c2f42b1f3363 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -88,7 +88,6 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
         bool dax_enabled = false;
         pgoff_t pgoff;
         int err, id;
-        void *kaddr;
         pfn_t pfn;
         long len;
         char buf[BDEVNAME_SIZE];
@@ -114,7 +113,7 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
         }
 
         id = dax_read_lock();
-        len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn);
+        len = dax_direct_access(dax_dev, pgoff, 1, NULL, &pfn);
         dax_read_unlock(id);
 
         put_dax(dax_dev);