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authorBart Van Assche <bart.vanassche@sandisk.com>2016-09-29 08:33:30 -0700
committerTejun Heo <tj@kernel.org>2016-09-30 10:31:20 +0200
commitbbb427e342495df1cda10051d0566388697499c0 (patch)
treef52002457cef52dd9e3cdcb490b6342a81767d9f
parente0223003e6e141533446d01a92784592a97a8552 (diff)
downloadlinux-bbb427e342495df1cda10051d0566388697499c0.tar.bz2
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 <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>
-rw-r--r--block/blk-cgroup.c4
1 files changed, 1 insertions, 3 deletions
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;