1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index cd67e90003c..60d82e1e498 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -593,6 +593,15 @@ there are not tasks in the cgroup. If pre_destroy() returns error code,
 rmdir() will fail with it. From this behavior, pre_destroy() can be
 called multiple times against a cgroup.
 
+int allow_attach(struct cgroup *cgrp, struct task_struct *task)
+(cgroup_mutex held by caller)
+
+Called prior to moving a task into a cgroup; if the subsystem
+returns an error, this will abort the attach operation.  Used
+to extend the permission checks - if all subsystems in a cgroup
+return 0, the attach will be allowed to proceed, even if the
+default permission check (root or same user) fails.
+
 int can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
                struct task_struct *task)
 (cgroup_mutex held by caller)