If you encounter any errors in bch_cached_dev_attach it will return a negative
error code.  The variable 'v' which stores the result is unsigned, thus user
space sees a very large value returned for bytes written which can cause
incorrect user space behavior.  Utilize 1 signed variable to use throughout
the function to preserve error return capability.

Signed-off-by: Tony Asleson <redacted>
Acked-by: Coly Li <redacted>
Cc: stable@vger.kernel.org
---
 drivers/md/bcache/sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index cc0076d..7579ca6 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c

@@ -206,7 +206,7 @@ STORE(__cached_dev)
 {
 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 					     disk.kobj);
-	unsigned v = size;
+	ssize_t v = size;
 	struct cache_set *c;
 	struct kobj_uevent_env *env;
 	unsigned ioprio_class = 0; /* invalid initial ioprio values */

@@ -245,7 +245,7 @@ STORE(__cached_dev)
 		bch_cached_dev_run(dc);
 
 	if (attr == &sysfs_cache_mode) {
-		ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1);
+		v = bch_read_string_list(buf, bch_cache_modes + 1);
 
 		if (v < 0)
 			return v;

-- 
1.8.3.1