[PATCH 6.1 69/71] blk-wbt: fix that wbt can't be disabled by default

Sasha Levin
2024-03-13T16:41:21Z

From: Yu Kuai <yukuai3@huawei.com>

[ Upstream commit 8a2b20a997a3779ae9fcae268f2959eb82ec05a1 ]

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 <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/lkml/CAKXUXMzfKq_J9nKHGyr5P5rvUETY4B-fxoQD4sO+NYjFOfVtZA@mail.gmail.com/t/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230522121854.2928880-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 fcacdff8af93b..526fb12c3e4cf 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -640,14 +640,16 @@ 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;
}
@@ -656,7 +658,7 @@ 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);
--
2.43.0