From: Tejun Heo <tj@kernel.org>
Date: Tue, 6 Nov 2012 20:26:23 +0000 (-0800)
Subject: Merge branch 'cgroup/for-3.7-fixes' into cgroup/for-3.8
X-Git-Tag: firefly_0821_release~3680^2~1492^2~46
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5b805f2a7675634fbdf9ac1c9b2256905ab2ea68;p=firefly-linux-kernel-4.4.55.git

Merge branch 'cgroup/for-3.7-fixes' into cgroup/for-3.8

This is to receive device_cgroup fixes so that further device_cgroup
changes can be made in cgroup/for-3.8.

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

5b805f2a7675634fbdf9ac1c9b2256905ab2ea68
diff --cc kernel/cgroup.c
index e3045ad4267a,f24f724620dd..3070164e2036
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@@ -4736,45 -4883,13 +4724,36 @@@ void cgroup_post_fork(struct task_struc
  	 */
  	if (use_task_css_set_links) {
  		write_lock(&css_set_lock);
- 		if (list_empty(&child->cg_list)) {
- 			/*
- 			 * It's safe to use child->cgroups without task_lock()
- 			 * here because we are protected through
- 			 * threadgroup_change_begin() against concurrent
- 			 * css_set change in cgroup_task_migrate(). Also
- 			 * the task can't exit at that point until
- 			 * wake_up_new_task() is called, so we are protected
- 			 * against cgroup_exit() setting child->cgroup to
- 			 * init_css_set.
- 			 */
+ 		task_lock(child);
+ 		if (list_empty(&child->cg_list))
  			list_add(&child->cg_list, &child->cgroups->tasks);
- 		}
+ 		task_unlock(child);
  		write_unlock(&css_set_lock);
  	}
 +
 +	/*
 +	 * Call ss->fork().  This must happen after @child is linked on
 +	 * css_set; otherwise, @child might change state between ->fork()
 +	 * and addition to css_set.
 +	 */
 +	if (need_forkexit_callback) {
 +		for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
 +			struct cgroup_subsys *ss = subsys[i];
 +
 +			/*
 +			 * fork/exit callbacks are supported only for
 +			 * builtin subsystems and we don't need further
 +			 * synchronization as they never go away.
 +			 */
 +			if (!ss || ss->module)
 +				continue;
 +
 +			if (ss->fork)
 +				ss->fork(child);
 +		}
 +	}
  }
 +
  /**
   * cgroup_exit - detach cgroup from exiting task
   * @tsk: pointer to task_struct of exiting process