1 files changed, 22 insertions, 4 deletions

diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index c293e08b301f..68a774d7a7c9 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -27,6 +27,7 @@
 
 #include "blk-wbt.h"
 #include "blk-rq-qos.h"
+#include "elevator.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/wbt.h>
@@ -422,6 +423,14 @@ static void wbt_update_limits(struct rq_wb *rwb)
 	rwb_wake_all(rwb);
 }
 
+bool wbt_disabled(struct request_queue *q)
+{
+	struct rq_qos *rqos = wbt_rq_qos(q);
+
+	return !rqos || RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT ||
+	       RQWB(rqos)->enable_state == WBT_STATE_OFF_MANUAL;
+}
+
 u64 wbt_get_min_lat(struct request_queue *q)
 {
 	struct rq_qos *rqos = wbt_rq_qos(q);
@@ -435,8 +444,13 @@ void wbt_set_min_lat(struct request_queue *q, u64 val)
 	struct rq_qos *rqos = wbt_rq_qos(q);
 	if (!rqos)
 		return;
+
 	RQWB(rqos)->min_lat_nsec = val;
-	RQWB(rqos)->enable_state = WBT_STATE_ON_MANUAL;
+	if (val)
+		RQWB(rqos)->enable_state = WBT_STATE_ON_MANUAL;
+	else
+		RQWB(rqos)->enable_state = WBT_STATE_OFF_MANUAL;
+
 	wbt_update_limits(RQWB(rqos));
 }
 
@@ -638,11 +652,15 @@ void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
  */
 void wbt_enable_default(struct request_queue *q)
 {
-	struct rq_qos *rqos = wbt_rq_qos(q);
+	struct rq_qos *rqos;
+	bool disable_flag = q->elevator &&
+		    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
 
 	/* Throttling already enabled? */
+	rqos = wbt_rq_qos(q);
 	if (rqos) {
-		if (RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
+		if (!disable_flag &&
+		    RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
 			RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT;
 		return;
 	}
@@ -651,7 +669,7 @@ void wbt_enable_default(struct request_queue *q)
 	if (!blk_queue_registered(q))
 		return;
 
-	if (queue_is_mq(q) && IS_ENABLED(CONFIG_BLK_WBT_MQ))
+	if (queue_is_mq(q) && !disable_flag)
 		wbt_init(q);
 }
 EXPORT_SYMBOL_GPL(wbt_enable_default);