rbd: remove snapshots on error in rbd_add()

(cherry picked from commit 41f38c2b2f8b66b176a0e548ef06294343a7bfa2)

If rbd_dev_snaps_update() has ever been called for an rbd device
structure there could be snapshot structures on its snaps list.
In rbd_add(), this function is called but a subsequent error
path neglected to clean up any of these snapshots.

Add a call to rbd_remove_all_snaps() in the appropriate spot to
remedy this.  Change a couple of error labels to be a little
clearer while there.

Drop the leading underscores from the function name; there's nothing
special about that function that they might signify.  As suggested
in review, the leading underscores in __rbd_remove_snap_dev() have
been removed as well.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index cd75b4d38e2760dbae89a4ce4faad631ab062015..7bfe894cc9983dbaaf06ae8a6ceb26ea8426f191 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -221,7 +221,7 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev);
 static int rbd_dev_snaps_register(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_remove_snap_dev(struct rbd_snap *snap);
 
 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
                       size_t count);
@@ -1710,13 +1710,13 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
        return ret;
 }
 
-static void __rbd_remove_all_snaps(struct rbd_device *rbd_dev)
+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);
+               rbd_remove_snap_dev(snap);
 }
 
 /*
@@ -2060,7 +2060,7 @@ static bool rbd_snap_registered(struct rbd_snap *snap)
        return ret;
 }
 
-static void __rbd_remove_snap_dev(struct rbd_snap *snap)
+static void rbd_remove_snap_dev(struct rbd_snap *snap)
 {
        list_del(&snap->node);
        if (device_is_registered(&snap->dev))
@@ -2442,7 +2442,7 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
 
                        if (rbd_dev->mapping.snap_id == snap->id)
                                rbd_dev->mapping.snap_exists = false;
-                       __rbd_remove_snap_dev(snap);
+                       rbd_remove_snap_dev(snap);
                        dout("%ssnap id %llu has been removed\n",
                                rbd_dev->mapping.snap_id == snap->id ?
                                                                "mapped " : "",
@@ -3053,11 +3053,11 @@ static ssize_t rbd_add(struct bus_type *bus,
        /* no need to lock here, as rbd_dev is not registered yet */
        rc = rbd_dev_snaps_update(rbd_dev);
        if (rc)
-               goto err_out_header;
+               goto err_out_probe;
 
        rc = rbd_dev_set_mapping(rbd_dev, snap_name);
        if (rc)
-               goto err_out_header;
+               goto err_out_snaps;
 
        /* generate unique id: find highest unique id, add one */
        rbd_dev_id_get(rbd_dev);
@@ -3121,7 +3121,9 @@ err_out_blkdev:
        unregister_blkdev(rbd_dev->major, rbd_dev->name);
 err_out_id:
        rbd_dev_id_put(rbd_dev);
-err_out_header:
+err_out_snaps:
+       rbd_remove_all_snaps(rbd_dev);
+err_out_probe:
        rbd_header_free(&rbd_dev->header);
 err_out_client:
        kfree(rbd_dev->header_name);
@@ -3219,7 +3221,7 @@ static ssize_t rbd_remove(struct bus_type *bus,
                goto done;
        }
 
-       __rbd_remove_all_snaps(rbd_dev);
+       rbd_remove_all_snaps(rbd_dev);
        rbd_bus_del_dev(rbd_dev);
 
 done: