Re: [PATCH] memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem()
From: Andrew Morton <hidden>
Date: 2016-05-26 21:02:04
Also in:
linux-mm
On Thu, 26 May 2016 16:30:18 -0400 Tejun Heo [off-list ref] wrote:
memcg_offline_kmem() may be called from memcg_free_kmem() after a css init failure. memcg_free_kmem() is a ->css_free callback which is called without cgroup_mutex and memcg_offline_kmem() ends up using css_for_each_descendant_pre() without any locking. Fix it by adding rcu read locking around it. mkdir: cannot create directory ___65530___: No space left on device [ 527.241361] =============================== [ 527.241845] [ INFO: suspicious RCU usage. ] [ 527.242367] 4.6.0-work+ #321 Not tainted [ 527.242730] ------------------------------- [ 527.243220] kernel/cgroup.c:4008 cgroup_mutex or RCU read lock required!
cc:stable?