ceph: remove call to bdi_unregister

bdi_destroy already does all the work, and if we delay freeing the
anon bdev we can get away with just that single call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

fs/ceph/super.c

@@ -40,17 +40,6 @@ static void ceph_put_super(struct super_block *s)
 
 	dout("put_super\n");
 	ceph_mdsc_close_sessions(fsc->mdsc);
-
-	/*
-	 * ensure we release the bdi before put_anon_super releases
-	 * the device name.
-	 */
-	if (s->s_bdi == &fsc->backing_dev_info) {
-		bdi_unregister(&fsc->backing_dev_info);
-		s->s_bdi = NULL;
-	}
-
-	return;
 }
 
 static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
@@ -1002,11 +991,16 @@ static struct dentry *ceph_mount(struct file_system_type *fs_type,
 static void ceph_kill_sb(struct super_block *s)
 {
 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
+	dev_t dev = s->s_dev;
+
 	dout("kill_sb %p\n", s);
+
 	ceph_mdsc_pre_umount(fsc->mdsc);
-	kill_anon_super(s);    /* will call put_super after sb is r/o */
+	generic_shutdown_super(s);
 	ceph_mdsc_destroy(fsc);
+
 	destroy_fs_client(fsc);
+	free_anon_bdev(dev);
 }
 
 static struct file_system_type ceph_fs_type = {