btrfs: create sprout should rename fsid on the sysfs as well

Creating sprout will change the fsid of the mounted root.
do the same on the sysfs as well.

reproducer:
 mount /dev/sdb /btrfs (seed disk)
 btrfs dev add /dev/sdc /btrfs
 mount -o rw,remount /btrfs
 btrfs dev del /dev/sdb /btrfs
 mount /dev/sdb /btrfs

Error:
kobject_add_internal failed for fe350492-dc28-4051-a601-e017b17e6145 with -EEXIST, don't try to register things with the same name in the same directory.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 19b67e969b52..6ca0d9cc46f9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2154,6 +2154,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
         if (seeding_dev) {
+                char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
                 ret = init_first_rw_device(trans, root, device);
                 if (ret) {
                         btrfs_abort_transaction(trans, root, ret);
@@ -2164,6 +2165,14 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
                         btrfs_abort_transaction(trans, root, ret);
                         goto error_trans;
                 }
+
+                /* Sprouting would change fsid of the mounted root,
+                 * so rename the fsid on the sysfs
+                 */
+                snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
+                                                root->fs_info->fsid);
+                if (kobject_rename(&root->fs_info->super_kobj, fsid_buf))
+                        goto error_trans;
         } else {
                 ret = btrfs_add_device(trans, root, device);
                 if (ret) {