[PATCH v2 4/6] dax/super: Do not request a pointer kaddr when not required

From: Huaisheng Ye
Date: Wed Jul 25 2018 - 12:30:15 EST


From: Huaisheng Ye <yehs1@xxxxxxxxxx>

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@xxxxxxxxxx>
---
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