rbd: don't register snapshots in bus_add_dev()

When rbd_bus_add_dev() is called (one spot--in rbd_add()), the rbd
image header has not even been read yet.  This means that the list
of snapshots will be empty at the time of the call.  As a result,
there is no need for the code that calls rbd_register_snap_dev()
for each entry in that list--so get rid of it.

Once the header has been read (just after returning), a call will
be made to rbd_dev_snap_devs_update(), which will then find every
snapshot in the context to be new and will therefore call
rbd_register_snap_dev() via __rbd_add_snap_dev() accomplishing
the same thing.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 3 insertions, 11 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 214c937a6de5..144694ee03a5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2244,29 +2244,21 @@ static int rbd_dev_snap_devs_update(struct rbd_device *rbd_dev)
 
 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
 {
-        int ret;
         struct device *dev;
-        struct rbd_snap *snap;
+        int ret;
 
         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-        dev = &rbd_dev->dev;
 
+        dev = &rbd_dev->dev;
         dev->bus = &rbd_bus_type;
         dev->type = &rbd_device_type;
         dev->parent = &rbd_root_dev;
         dev->release = rbd_dev_release;
         dev_set_name(dev, "%d", rbd_dev->dev_id);
         ret = device_register(dev);
-        if (ret < 0)
-                goto out;
 
-        list_for_each_entry(snap, &rbd_dev->snaps, node) {
-                ret = rbd_register_snap_dev(snap, &rbd_dev->dev);
-                if (ret < 0)
-                        break;
-        }
-out:
         mutex_unlock(&ctl_mutex);
+
         return ret;
 }