diff options
| author | Jiang Biao <jiang.biao2@zte.com.cn> | 2018-04-18 08:37:18 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-04-18 08:37:18 -0600 |
| commit | 946b81da114b8ba5c74bb01e57c0c6eca2bdc801 (patch) | |
| tree | 5f4adb9a9a46eaee2c142dfc7f76d60abaea07da | |
| parent | 0ce9144471de9ee09306ca0127e7cd27521ccc3f (diff) | |
blkcg: don't hold blkcg lock when deactivating policy
As described in the comment of blkcg_activate_policy(),
*Update of each blkg is protected by both queue and blkcg locks so
that holding either lock and testing blkcg_policy_enabled() is
always enough for dereferencing policy data.*
with queue lock held, there is no need to hold blkcg lock in
blkcg_deactivate_policy(). Similar case is in
blkcg_activate_policy(), which has removed holding of blkcg lock in
commit 4c55f4f9ad3001ac1fefdd8d8ca7641d18558e23.
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
CC: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-cgroup.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 1c16694ae145..21bc449d01c0 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1410,9 +1410,6 @@ void blkcg_deactivate_policy(struct request_queue *q, __clear_bit(pol->plid, q->blkcg_pols); list_for_each_entry(blkg, &q->blkg_list, q_node) { - /* grab blkcg lock too while removing @pd from @blkg */ - spin_lock(&blkg->blkcg->lock); - if (blkg->pd[pol->plid]) { if (!blkg->pd[pol->plid]->offline && pol->pd_offline_fn) { @@ -1422,8 +1419,6 @@ void blkcg_deactivate_policy(struct request_queue *q, pol->pd_free_fn(blkg->pd[pol->plid]); blkg->pd[pol->plid] = NULL; } - - spin_unlock(&blkg->blkcg->lock); } spin_unlock_irq(q->queue_lock); |