From: Yu Kuai <[email protected]>
commit b11d31ae01e6 ("blk-wbt: remove unnecessary check in
wbt_enable_default()") removes the checking of CONFIG_BLK_WBT_MQ by
mistake, which is used to control enable or disable wbt by default.
Fix the problem by adding back the checking. This patch also do a litter
cleanup to make related code more readable.
Fixes: b11d31ae01e6 ("blk-wbt: remove unnecessary check in wbt_enable_default()")
Reported-by: Lukas Bulwahn <[email protected]>
Link: https://lore.kernel.org/lkml/CAKXUXMzfKq_J9nKHGyr5P5rvUETY4B-fxoQD4sO+NYjFOfVtZA@mail.gmail.com/t/
Signed-off-by: Yu Kuai <[email protected]>
---
block/blk-wbt.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index e49a48684532..9ec2a2f1eda3 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -730,14 +730,16 @@ void wbt_enable_default(struct gendisk *disk)
{
struct request_queue *q = disk->queue;
struct rq_qos *rqos;
- bool disable_flag = q->elevator &&
- test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
+ bool enable = IS_ENABLED(CONFIG_BLK_WBT_MQ);
+
+ if (q->elevator &&
+ test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags))
+ enable = false;
/* Throttling already enabled? */
rqos = wbt_rq_qos(q);
if (rqos) {
- if (!disable_flag &&
- RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
+ if (enable && RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT;
return;
}
@@ -746,7 +748,7 @@ void wbt_enable_default(struct gendisk *disk)
if (!blk_queue_registered(q))
return;
- if (queue_is_mq(q) && !disable_flag)
+ if (queue_is_mq(q) && enable)
wbt_init(disk);
}
EXPORT_SYMBOL_GPL(wbt_enable_default);
--
2.39.2
On 2023/5/12 17:35, Yu Kuai wrote:
> From: Yu Kuai <[email protected]>
>
> commit b11d31ae01e6 ("blk-wbt: remove unnecessary check in
> wbt_enable_default()") removes the checking of CONFIG_BLK_WBT_MQ by
> mistake, which is used to control enable or disable wbt by default.
>
> Fix the problem by adding back the checking. This patch also do a litter
> cleanup to make related code more readable.
>
> Fixes: b11d31ae01e6 ("blk-wbt: remove unnecessary check in wbt_enable_default()")
> Reported-by: Lukas Bulwahn <[email protected]>
> Link: https://lore.kernel.org/lkml/CAKXUXMzfKq_J9nKHGyr5P5rvUETY4B-fxoQD4sO+NYjFOfVtZA@mail.gmail.com/t/
> Signed-off-by: Yu Kuai <[email protected]>
> ---
> block/blk-wbt.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index e49a48684532..9ec2a2f1eda3 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -730,14 +730,16 @@ void wbt_enable_default(struct gendisk *disk)
> {
> struct request_queue *q = disk->queue;
> struct rq_qos *rqos;
> - bool disable_flag = q->elevator &&
> - test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
> + bool enable = IS_ENABLED(CONFIG_BLK_WBT_MQ);
> +
> + if (q->elevator &&
> + test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags))
> + enable = false;
Why not just early return, so "enable" is not needed at all?
I have another question that CONFIG_BLK_WBT_MQ is not much flexible, can we
just get rid of it? (I'm not sure when to disable it in the config)
Thanks.
>
> /* Throttling already enabled? */
> rqos = wbt_rq_qos(q);
> if (rqos) {
> - if (!disable_flag &&
> - RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
> + if (enable && RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
> RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT;
> return;
> }
> @@ -746,7 +748,7 @@ void wbt_enable_default(struct gendisk *disk)
> if (!blk_queue_registered(q))
> return;
>
> - if (queue_is_mq(q) && !disable_flag)
> + if (queue_is_mq(q) && enable)
> wbt_init(disk);
> }
> EXPORT_SYMBOL_GPL(wbt_enable_default);
Looks good:
Reviewed-by: Christoph Hellwig <[email protected]>