From: Tejun Heo <tj@kernel.org>
Date: Wed, 23 May 2012 10:16:21 +0000 (+0200)
Subject: blkcg: tg_stats_alloc_lock is an irq lock
X-Git-Tag: v3.5-rc1~42^2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ff26eaadf4d914e397872b99885d45756104e9ae;p=pandora-kernel.git

blkcg: tg_stats_alloc_lock is an irq lock

tg_stats_alloc_lock nests inside queue lock and should always be held
with irq disabled.  throtl_pd_{init|exit}() were using non-irqsafe
spinlock ops which triggered inverse lock ordering via irq warning via
RCU freeing of blkg invoking throtl_pd_exit() w/o disabling IRQ.

Update both functions to use irq safe operations.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
LKML-Reference: <1335339396.16988.80.camel@lappy>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

Reading git-diff-tree failed