Take the completion of automount into new helper

[linux-2.6-block.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 9f544f35ed34ef8db7913c94904f1a25b5b4650c..bec51e4e0549d917ceb72af5d5b1346475ca5a2d 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1895,6 +1895,39 @@ static int do_new_mount(struct path *path, char *type, int flags,
        return do_add_mount(mnt, path, mnt_flags);
 }
 
+int finish_automount(struct vfsmount *m, struct path *path)
+{
+       int err;
+       /* The new mount record should have at least 2 refs to prevent it being
+        * expired before we get a chance to add it
+        */
+       BUG_ON(mnt_get_count(m) < 2);
+
+       if (m->mnt_sb == path->mnt->mnt_sb &&
+           m->mnt_root == path->dentry) {
+               mnt_clear_expiry(m);
+               mntput(m);
+               mntput(m);
+               return -ELOOP;
+       }
+
+       /* We need to add the mountpoint to the parent.  The filesystem may
+        * have placed it on an expiry list, and so we need to make sure it
+        * won't be expired under us if do_add_mount() fails (do_add_mount()
+        * will eat a reference unconditionally).
+        */
+       mntget(m);
+       err = do_add_mount(m, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
+       if (err) {
+               mnt_clear_expiry(m);
+               mntput(m);
+               mntput(m);
+       } else {
+               mntput(m);
+       }
+       return err;
+}
+
 /*
  * add a mount into a namespace's mount tree
  * - this unconditionally eats one of the caller's references to newmnt.