Update of blkg_stat and blkg_rwstat may happen in bh context. While u64_stats_fetch_r...
authorHong Zhiguo <zhiguohong@tencent.com>
Wed, 20 Nov 2013 17:35:05 +0000 (10:35 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 12 Dec 2013 06:36:27 +0000 (22:36 -0800)
commit950cda7f8e2bc6f182a2640817970166c55240db
treee770f6d656a19cb92fdb0e6ad0f9b669d03d3a97
parentc52348079702c2fa0fcc74e2ac5ba81c70a47fbc
Update of blkg_stat and blkg_rwstat may happen in bh context. While u64_stats_fetch_retry is only preempt_disable on 32bit UP system. This is not enough to avoid preemption by bh and may read strange 64 bit value.

commit 2c575026fae6e63771bd2a4c1d407214a8096a89 upstream.

Signed-off-by: Hong Zhiguo <zhiguohong@tencent.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
block/blk-cgroup.h