Hello,
On Mon, Sep 26, 2016 at 03:36:25PM -0700, Bart Van Assche wrote:
> 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 <bart.vanassche@xxxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> 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;
> + }
Wouldn't it be better to drop explicit mutx_unlock(&blkcg_pol_mutex)
on "if (!cpd)"?
Thanks.
--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
