follow_dotdot{,_rcu}(): switch to use of step_into()

gets the regular mount crossing on result of ..

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

diff --git a/fs/namei.c b/fs/namei.c
index 1749e43..9c77501 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1722,33 +1722,18 @@ static const char *follow_dotdot_rcu(struct nameidata *nd)
                        /* we know that mountpoint was pinned */
                        nd->path.dentry = mountpoint;
                        nd->path.mnt = &mparent->mnt;
-                       inode = inode2;
+                       inode = nd->inode = inode2;
                        nd->seq = seq;
                }
        }
        if (unlikely(!parent)) {
                if (unlikely(nd->flags & LOOKUP_BENEATH))
                        return ERR_PTR(-ECHILD);
+               return step_into(nd, WALK_NOFOLLOW,
+                                nd->path.dentry, nd->inode, nd->seq);
        } else {
-               nd->path.dentry = parent;
-               nd->seq = seq;
+               return step_into(nd, WALK_NOFOLLOW, parent, inode, seq);
        }
-       while (unlikely(d_mountpoint(nd->path.dentry))) {
-               struct mount *mounted;
-               mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
-               if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
-                       return ERR_PTR(-ECHILD);
-               if (!mounted)
-                       break;
-               if (unlikely(nd->flags & LOOKUP_NO_XDEV))
-                       return ERR_PTR(-ECHILD);
-               nd->path.mnt = &mounted->mnt;
-               nd->path.dentry = mounted->mnt.mnt_root;
-               inode = nd->path.dentry->d_inode;
-               nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
-       }
-       nd->inode = inode;
-       return NULL;
 }
 
 static const char *follow_dotdot(struct nameidata *nd)
@@ -1774,13 +1759,11 @@ static const char *follow_dotdot(struct nameidata *nd)
        if (unlikely(!parent)) {
                if (unlikely(nd->flags & LOOKUP_BENEATH))
                        return ERR_PTR(-EXDEV);
+               return step_into(nd, WALK_NOFOLLOW,
+                                dget(nd->path.dentry), nd->inode, nd->seq);
        } else {
-               dput(nd->path.dentry);
-               nd->path.dentry = parent;
+               return step_into(nd, WALK_NOFOLLOW, parent, parent->d_inode, 0);
        }
-       follow_mount(&nd->path);
-       nd->inode = nd->path.dentry->d_inode;
-       return NULL;
 }
 
 static const char *handle_dots(struct nameidata *nd, int type)