Merge branch 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu...

This is to receive percpu_refcount which will replace atomic_t
reference count in cgroup_subsys_state.

Signed-off-by: Tejun Heo <tj@kernel.org>

diff --cc kernel/cgroup.c
index df6814706cca03d2af1ac68bf453aece8f4bf8da,a7c9e6ddb9797a886e96bbff7c75fb8ed9670c68..ebbfc043153f6a7520da5c9f1a1ac8326c8f84b4
--- 1/kernel/cgroup.c
--- 2/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@@ -1686,13 -1684,16 +1686,16 @@@ static struct dentry *cgroup_mount(stru
                 * We re-used an existing hierarchy - the new root (if
                 * any) is not needed
                 */
 -              cgroup_drop_root(opts.new_root);
 +              cgroup_free_root(opts.new_root);
  
-               if (((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) &&
-                   root->flags != opts.flags) {
-                       pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n");
-                       ret = -EINVAL;
-                       goto drop_new_super;
+               if (root->flags != opts.flags) {
+                       if ((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) {
+                               pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n");
+                               ret = -EINVAL;
+                               goto drop_new_super;
+                       } else {
+                               pr_warning("cgroup: new mount options do not match the existing superblock, will be ignored\n");
+                       }
                }
  
                /* no subsys rebinding, so refcounts don't change */