fs/namei.c: new helper - legitimize_root()

identical logics in unlazy_walk() and unlazy_child()

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

diff --git a/fs/namei.c b/fs/namei.c
index 3fca26398bc2d7dab7bbfcf7bfbe06a86b310be4..2af485ddc507a2f0166f5363ea864b056762ce29 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -641,6 +641,13 @@ static bool legitimize_links(struct nameidata *nd)
        return true;
 }
 
+static bool legitimize_root(struct nameidata *nd)
+{
+       if (!nd->root.mnt || (nd->flags & LOOKUP_ROOT))
+               return true;
+       return legitimize_path(nd, &nd->root, nd->root_seq);
+}
+
 /*
  * Path walking has 2 modes, rcu-walk and ref-walk (see
  * Documentation/filesystems/path-lookup.txt).  In situations when we can't
@@ -674,10 +681,8 @@ static int unlazy_walk(struct nameidata *nd)
                goto out2;
        if (unlikely(!legitimize_path(nd, &nd->path, nd->seq)))
                goto out1;
-       if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
-               if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq)))
-                       goto out;
-       }
+       if (unlikely(!legitimize_root(nd)))
+               goto out;
        rcu_read_unlock();
        BUG_ON(nd->inode != parent->d_inode);
        return 0;
@@ -736,12 +741,10 @@ static int unlazy_child(struct nameidata *nd, struct dentry *dentry, unsigned se
         * Sequence counts matched. Now make sure that the root is
         * still valid and get it if required.
         */
-       if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
-               if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq))) {
-                       rcu_read_unlock();
-                       dput(dentry);
-                       return -ECHILD;
-               }
+       if (unlikely(!legitimize_root(nd))) {
+               rcu_read_unlock();
+               dput(dentry);
+               return -ECHILD;
        }
 
        rcu_read_unlock();