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: 06b285bd11 ("blkcg: fix blkcg_policy_data allocation bug")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Bart Van Assche 2016-09-29 08:33:30 -07:00 committed by Tejun Heo
parent e0223003e6
commit bbb427e342
1 changed files with 1 additions and 3 deletions

View File

@ -1340,10 +1340,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
struct blkcg_policy_data *cpd; struct blkcg_policy_data *cpd;
cpd = pol->cpd_alloc_fn(GFP_KERNEL); cpd = pol->cpd_alloc_fn(GFP_KERNEL);
if (!cpd) { if (!cpd)
mutex_unlock(&blkcg_pol_mutex);
goto err_free_cpds; goto err_free_cpds;
}
blkcg->cpd[pol->plid] = cpd; blkcg->cpd[pol->plid] = cpd;
cpd->blkcg = blkcg; cpd->blkcg = blkcg;