[dm-devel] [PATCH v3 4/6] dax/super: Do not request a pointer kaddr when not required

[Huaisheng Ye]

From: Huaisheng Ye <yehs1 at lenovo.com>

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 at lenovo.com>
Reviewed-by: Ross Zwisler <ross.zwisler at linux.intel.com>
---
 drivers/dax/super.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 45276ab..6e928f3 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -89,7 +89,6 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
 	struct request_queue *q;
 	pgoff_t pgoff;
 	int err, id;
-	void *kaddr;
 	pfn_t pfn;
 	long len;
 	char buf[BDEVNAME_SIZE];
@@ -122,7 +121,7 @@ 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);
-- 
1.8.3.1