[PATCH] blkcg: Unlock blkcg_pol_mutex once if cpd == NULL
flat view
STALE3663d
From: Bart Van Assche <hidden>
Date: 2016-09-26 22:36:35
Subsystem:
block layer, control group - block io controller (blkio), the rest · Maintainers:
Jens Axboe, Tejun Heo, Josef Bacik, Linus Torvalds
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' Signed-off-by: Bart Van Assche <redacted> Cc: Tejun Heo <tj@kernel.org> Cc: <redacted> --- block/blk-cgroup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index dd38e5c..cdbca1c 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c@@ -1327,8 +1327,10 @@ int blkcg_policy_register(struct blkcg_policy *pol) for (i = 0; i < BLKCG_MAX_POLS; i++) if (!blkcg_policy[i]) break; - if (i >= BLKCG_MAX_POLS) + if (i >= BLKCG_MAX_POLS) { + mutex_unlock(&blkcg_pol_mutex); goto err_unlock; + } /* register @pol */ pol->plid = i;
@@ -1374,8 +1376,8 @@ err_free_cpds: } } blkcg_policy[pol->plid] = NULL; + err_unlock: - mutex_unlock(&blkcg_pol_mutex); mutex_unlock(&blkcg_pol_register_mutex); return ret; }
--
2.10.0