diff options
| author | Jiang Biao <jiang.biao2@zte.com.cn> | 2018-04-18 08:37:18 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-06-21 04:02:43 +0900 |
| commit | 9d5e2d69705fed4ab527f5a283b90ae602f4e0fd (patch) | |
| tree | df8ad81c0c97af93dc023b144de70b0820debc50 /block | |
| parent | c5b6316c3f5139cbc1d9a37cd6b86bb7be3802bf (diff) | |
blkcg: don't hold blkcg lock when deactivating policy
[ Upstream commit 946b81da114b8ba5c74bb01e57c0c6eca2bdc801 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -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 d3f56baee936..00b133c44474 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1374,17 +1374,12 @@ 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 (pol->pd_offline_fn) pol->pd_offline_fn(blkg->pd[pol->plid]); pol->pd_free_fn(blkg->pd[pol->plid]); blkg->pd[pol->plid] = NULL; } - - spin_unlock(&blkg->blkcg->lock); } spin_unlock_irq(q->queue_lock); |