From bbb427e342495df1cda10051d0566388697499c0 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 29 Sep 2016 08:33:30 -0700 Subject: blkcg: Unlock blkcg_pol_mutex only once when cpd == NULL Unlocking a mutex twice is wrong. Hence modify blkcg_policy_register() such that blkcg_pol_mutex is unlocked once if cpd == NULL. This patch avoids that smatch reports the following error: block/blk-cgroup.c:1378: blkcg_policy_register() error: double unlock 'mutex:&blkcg_pol_mutex' Fixes: 06b285bd1125 ("blkcg: fix blkcg_policy_data allocation bug") Signed-off-by: Bart Van Assche Cc: Tejun Heo Cc: # v4.2+ Signed-off-by: Tejun Heo --- block/blk-cgroup.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'block/blk-cgroup.c') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index dd38e5ced4a3..b08ccbb9393a 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1340,10 +1340,8 @@ int blkcg_policy_register(struct blkcg_policy *pol) struct blkcg_policy_data *cpd; cpd = pol->cpd_alloc_fn(GFP_KERNEL); - if (!cpd) { - mutex_unlock(&blkcg_pol_mutex); + if (!cpd) goto err_free_cpds; - } blkcg->cpd[pol->plid] = cpd; cpd->blkcg = blkcg; -- cgit v1.2.1