[PATCH 4/4] rbd: use a single value of snap_name to mean no snap

[Alex Elder <elder@dreamhost.com>]

 From Josh Durgin <josh.durgin@dreamhost.com>

There's already a constant for this anyway.

(I changed Josh's code to use memcmp() and memcpy() instead. -Alex)

Signed-off-by: Alex Elder <elder@dreamhost.com>
---
  drivers/block/rbd.c |    8 +++-----
  1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 3d0f8cf..25ed3c0 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -563,10 +563,7 @@ static int rbd_header_set_snap(struct rbd_device *dev,

  	down_write(&header->snap_rwsem);

-	if (!snap_name ||
-	    !*snap_name ||
-	    strcmp(snap_name, "-") == 0 ||
-	    strcmp(snap_name, RBD_SNAP_HEAD_NAME) == 0) {
+	if (!memcmp(snap_name, RBD_SNAP_HEAD_NAME, sizeof RBD_SNAP_HEAD_NAME)) {
  		if (header->total_snaps)
  			snapc->seq = header->snap_seq;
  		else
@@ -2213,7 +2210,8 @@ static ssize_t rbd_add(struct bus_type *bus,
  	}

  	if (rbd_dev->snap_name[0] == 0)
-		rbd_dev->snap_name[0] = '-';
+		memcpy(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME,
+			sizeof RBD_SNAP_HEAD_NAME);

  	rbd_dev->obj_len = strlen(rbd_dev->obj);
  	snprintf(rbd_dev->obj_md_name, sizeof(rbd_dev->obj_md_name), "%s%s",
-- 
1.7.5.4