[PATCH 1/4] rbd: move locking out of rbd_header_set_snap()

[Alex Elder <elder@inktank.com>]

Move the calls to get the header semaphore out of
rbd_header_set_snap() and into its caller.

Signed-off-by: Alex Elder <elder@inktank.com>
---
 drivers/block/rbd.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 634a16c..214c937 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -647,8 +647,6 @@ static int rbd_header_set_snap(struct rbd_device
*rbd_dev, char *snap_name)
 {
 	int ret;

-	down_write(&rbd_dev->header_rwsem);
-
 	if (!memcmp(snap_name, RBD_SNAP_HEAD_NAME,
 		    sizeof (RBD_SNAP_HEAD_NAME))) {
 		rbd_dev->mapping.snap_id = CEPH_NOSNAP;
@@ -666,7 +664,6 @@ static int rbd_header_set_snap(struct rbd_device
*rbd_dev, char *snap_name)

 	ret = 0;
 done:
-	up_write(&rbd_dev->header_rwsem);
 	return ret;
 }

@@ -2608,7 +2605,9 @@ static ssize_t rbd_add(struct bus_type *bus,
 	if (rc)
 		goto err_out_bus;

+	down_write(&rbd_dev->header_rwsem);
 	rc = rbd_header_set_snap(rbd_dev, snap_name);
+	up_write(&rbd_dev->header_rwsem);
 	if (rc)
 		goto err_out_bus;

-- 
1.7.9.5