new helper: mount_subtree()

[pandora-kernel.git] / fs / btrfs / super.c

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8bd9d6d..17ee7fc 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -825,13 +825,9 @@ static char *setup_root_args(char *args)
 static struct dentry *mount_subvol(const char *subvol_name, int flags,
                                   const char *device_name, char *data)
 {
-       struct super_block *s;
        struct dentry *root;
        struct vfsmount *mnt;
-       struct mnt_namespace *ns_private;
        char *newargs;
-       struct path path;
-       int error;
 
        newargs = setup_root_args(data);
        if (!newargs)
@@ -842,39 +838,17 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags,
        if (IS_ERR(mnt))
                return ERR_CAST(mnt);
 
-       ns_private = create_mnt_ns(mnt);
-       if (IS_ERR(ns_private)) {
-               mntput(mnt);
-               return ERR_CAST(ns_private);
-       }
+       root = mount_subtree(mnt, subvol_name);
 
-       /*
-        * This will trigger the automount of the subvol so we can just
-        * drop the mnt we have here and return the dentry that we
-        * found.
-        */
-       error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name,
-                               LOOKUP_FOLLOW, &path);
-       put_mnt_ns(ns_private);
-       if (error)
-               return ERR_PTR(error);
-
-       if (!is_subvolume_inode(path.dentry->d_inode)) {
-               path_put(&path);
-               mntput(mnt);
-               error = -EINVAL;
+       if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
+               struct super_block *s = root->d_sb;
+               dput(root);
+               root = ERR_PTR(-EINVAL);
+               deactivate_locked_super(s);
                printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
                                subvol_name);
-               return ERR_PTR(-EINVAL);
        }
 
-       /* Get a ref to the sb and the dentry we found and return it */
-       s = path.mnt->mnt_sb;
-       atomic_inc(&s->s_active);
-       root = dget(path.dentry);
-       path_put(&path);
-       down_write(&s->s_umount);
-
        return root;
 }