follow_dotdot{,_rcu}(): change calling conventions

Instead of returning NULL when we are in root, just make it return
the current position (and set *seqp and *inodep accordingly).
That collapses the calls of step_into() in handle_dots()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index e4a58d5975ca3f31403423ec90796603eef5fbe7..9c50facb97699d74615ff71fe7cd24edd544ba12 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1909,7 +1909,9 @@ in_root:
                return ERR_PTR(-ECHILD);
        if (unlikely(nd->flags & LOOKUP_BENEATH))
                return ERR_PTR(-ECHILD);
-       return NULL;
+       *seqp = nd->seq;
+       *inodep = nd->path.dentry->d_inode;
+       return nd->path.dentry;
 }
 
 static struct dentry *follow_dotdot(struct nameidata *nd,
@@ -1945,8 +1947,9 @@ static struct dentry *follow_dotdot(struct nameidata *nd,
 in_root:
        if (unlikely(nd->flags & LOOKUP_BENEATH))
                return ERR_PTR(-EXDEV);
-       dget(nd->path.dentry);
-       return NULL;
+       *seqp = 0;
+       *inodep = nd->path.dentry->d_inode;
+       return dget(nd->path.dentry);
 }
 
 static const char *handle_dots(struct nameidata *nd, int type)
@@ -1968,12 +1971,7 @@ static const char *handle_dots(struct nameidata *nd, int type)
                        parent = follow_dotdot(nd, &inode, &seq);
                if (IS_ERR(parent))
                        return ERR_CAST(parent);
-               if (unlikely(!parent))
-                       error = step_into(nd, WALK_NOFOLLOW,
-                                        nd->path.dentry, nd->inode, nd->seq);
-               else
-                       error = step_into(nd, WALK_NOFOLLOW,
-                                        parent, inode, seq);
+               error = step_into(nd, WALK_NOFOLLOW, parent, inode, seq);
                if (unlikely(error))
                        return error;