namei: move link count check and stack allocation into pick_link()
authorAl Viro <viro@zeniv.linux.org.uk>
Mon, 4 May 2015 22:26:59 +0000 (18:26 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Mon, 11 May 2015 02:20:13 +0000 (22:20 -0400)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/namei.c

index 1b4bc1b..046a703 100644 (file)
@@ -891,16 +891,10 @@ const char *get_link(struct nameidata *nd)
        if (nd->link.mnt == nd->path.mnt)
                mntget(nd->link.mnt);
 
-       if (unlikely(current->total_link_count >= MAXSYMLINKS)) {
-               path_put(&nd->link);
-               return ERR_PTR(-ELOOP);
-       }
-
        last->link = nd->link;
        last->cookie = NULL;
 
        cond_resched();
-       current->total_link_count++;
 
        touch_atime(&last->link);
 
@@ -1568,12 +1562,23 @@ static void terminate_walk(struct nameidata *nd)
 
 static int pick_link(struct nameidata *nd, struct path *link)
 {
+       int error;
+       if (unlikely(current->total_link_count++ >= MAXSYMLINKS)) {
+               path_to_nameidata(link, nd);
+               return -ELOOP;
+       }
        if (nd->flags & LOOKUP_RCU) {
                if (unlikely(nd->path.mnt != link->mnt ||
                             unlazy_walk(nd, link->dentry))) {
                        return -ECHILD;
                }
        }
+       error = nd_alloc_stack(nd);
+       if (unlikely(error)) {
+               path_to_nameidata(link, nd);
+               return error;
+       }
+
        nd->link = *link;
        return 1;
 }
@@ -1840,15 +1845,7 @@ OK:
                        break;
 
                if (err) {
-                       const char *s;
-
-                       err = nd_alloc_stack(nd);
-                       if (unlikely(err)) {
-                               path_to_nameidata(&nd->link, nd);
-                               break;
-                       }
-
-                       s = get_link(nd);
+                       const char *s = get_link(nd);
 
                        if (unlikely(IS_ERR(s))) {
                                err = PTR_ERR(s);