Revert "brd: remove unused brd_mutex"

This reverts commit 15f7b41f70ddcca3b555bd0fdc7c8da7466b517e.

To support brd flush to free ramdisk brd_mutex is required.

Change-Id: Ide75bcb73812c3c7e04bfe6ebaed0d6d511e01dd
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 79f18cf..047ae4f 100644 (file)
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -53,6 +53,7 @@ struct brd_device {
 /*
  * Look up and return a brd's page for a given sector.
  */
+static DEFINE_MUTEX(brd_mutex);
 static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector)
 {
        pgoff_t idx;