From: Yu Kuai <yukuai3@xxxxxxxxxx> 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. Fixes: b11d31ae01e6 ("blk-wbt: remove unnecessary check in wbt_enable_default()") Reported-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx> Link: https://lore.kernel.org/lkml/CAKXUXMzfKq_J9nKHGyr5P5rvUETY4B-fxoQD4sO+NYjFOfVtZA@xxxxxxxxxxxxxx/t/ Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> --- block/blk-wbt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/block/blk-wbt.c b/block/blk-wbt.c index e49a48684532..b1ab4688eb5c 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -730,8 +730,9 @@ 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 disable_flag = (q->elevator && + test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags)) || + !IS_ENABLED(CONFIG_BLK_WBT_MQ); /* Throttling already enabled? */ rqos = wbt_rq_qos(q); -- 2.39.2