rbd: rename __rbd_add_snap_dev()

Rename __rbd_add_snap_dev() to be rbd_snap_create().  We no longer
have devices for non-mapped snapshots, and we're not actually
"adding" it to the list in this function, just creating it.

Rename rbd_remove_snap_dev() to be rbd_snap_destroy() for reasons
similar to the above.  Stop having this function delete the snapshot
from its list (to be symmetrical with its create counterpart) and do
that in the caller instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

drivers/block/rbd.c

@@ -359,7 +359,7 @@ static int rbd_img_request_submit(struct rbd_img_request *img_request);
 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev);
 
 static void rbd_dev_release(struct device *dev);
-static void rbd_remove_snap_dev(struct rbd_snap *snap);
+static void rbd_snap_destroy(struct rbd_snap *snap);
 
 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
 		       size_t count);
@@ -3010,8 +3010,10 @@ static void rbd_remove_all_snaps(struct rbd_device *rbd_dev)
 	struct rbd_snap *snap;
 	struct rbd_snap *next;
 
-	list_for_each_entry_safe(snap, next, &rbd_dev->snaps, node)
-		rbd_remove_snap_dev(snap);
+	list_for_each_entry_safe(snap, next, &rbd_dev->snaps, node) {
+		list_del(&snap->node);
+		rbd_snap_destroy(snap);
+	}
 }
 
 static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
@@ -3413,14 +3415,13 @@ static void rbd_dev_destroy(struct rbd_device *rbd_dev)
 	kfree(rbd_dev);
 }
 
-static void rbd_remove_snap_dev(struct rbd_snap *snap)
+static void rbd_snap_destroy(struct rbd_snap *snap)
 {
-	list_del(&snap->node);
 	kfree(snap->name);
 	kfree(snap);
 }
 
-static struct rbd_snap *__rbd_add_snap_dev(struct rbd_device *rbd_dev,
+static struct rbd_snap *rbd_snap_create(struct rbd_device *rbd_dev,
 						const char *snap_name,
 						u64 snap_id, u64 snap_size,
 						u64 snap_features)
@@ -4070,7 +4071,9 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
 				rbd_dev->spec->snap_id == snap->id ?
 							"mapped " : "",
 				(unsigned long long)snap->id);
-			rbd_remove_snap_dev(snap);
+
+			list_del(&snap->node);
+			rbd_snap_destroy(snap);
 
 			/* Done with this list entry; advance */
 
@@ -4093,7 +4096,7 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
 
 			/* We haven't seen this snapshot before */
 
-			new_snap = __rbd_add_snap_dev(rbd_dev, snap_name,
+			new_snap = rbd_snap_create(rbd_dev, snap_name,
 					snap_id, snap_size, snap_features);
 			if (IS_ERR(new_snap)) {
 				ret = PTR_ERR(new_snap);