VFS: fs/cachefiles: d_backing_inode() annotations

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c
index fbb08e9..6af790f 100644
--- a/fs/cachefiles/bind.c
+++ b/fs/cachefiles/bind.c
@@ -123,11 +123,11 @@
 
 	/* check parameters */
 	ret = -EOPNOTSUPP;
-	if (!root->d_inode ||
-	    !root->d_inode->i_op->lookup ||
-	    !root->d_inode->i_op->mkdir ||
-	    !root->d_inode->i_op->setxattr ||
-	    !root->d_inode->i_op->getxattr ||
+	if (d_is_negative(root) ||
+	    !d_backing_inode(root)->i_op->lookup ||
+	    !d_backing_inode(root)->i_op->mkdir ||
+	    !d_backing_inode(root)->i_op->setxattr ||
+	    !d_backing_inode(root)->i_op->getxattr ||
 	    !root->d_sb->s_op->statfs ||
 	    !root->d_sb->s_op->sync_fs)
 		goto error_unsupported;