[PATCH -next 1/6] blk-wbt: fix that wbt can't be disabled by default

[Yu Kuai]

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