Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6

[mv-sheeva.git] / include / linux / cgroup.h

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index e0aa067d1b11689b89989d3392ab0d0e6da7f4f6..ed3e92e41c6e5683ad3dbb823e48259f5150ac33 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -525,13 +525,21 @@ static inline struct cgroup_subsys_state *cgroup_subsys_state(
        return cgrp->subsys[subsys_id];
 }
 
-static inline struct cgroup_subsys_state *task_subsys_state(
-       struct task_struct *task, int subsys_id)
+/*
+ * function to get the cgroup_subsys_state which allows for extra
+ * rcu_dereference_check() conditions, such as locks used during the
+ * cgroup_subsys::attach() methods.
+ */
+#define task_subsys_state_check(task, subsys_id, __c)                  \
+       rcu_dereference_check(task->cgroups->subsys[subsys_id],         \
+                             rcu_read_lock_held() ||                   \
+                             lockdep_is_held(&task->alloc_lock) ||     \
+                             cgroup_lock_is_held() || (__c))
+
+static inline struct cgroup_subsys_state *
+task_subsys_state(struct task_struct *task, int subsys_id)
 {
-       return rcu_dereference_check(task->cgroups->subsys[subsys_id],
-                                    rcu_read_lock_held() ||
-                                    lockdep_is_held(&task->alloc_lock) ||
-                                    cgroup_lock_is_held());
+       return task_subsys_state_check(task, subsys_id, false);
 }
 
 static inline struct cgroup* task_cgroup(struct task_struct *task,