diff --git a/block/bdev.c b/block/bdev.c
index 13de871fa816..5dced478f190 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -487,9 +487,11 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
 	bdev = I_BDEV(inode);
 	mutex_init(&bdev->bd_fsfreeze_mutex);
 	spin_lock_init(&bdev->bd_size_lock);
+	spin_lock_init(&bdev->bd_stat_lock);
 	bdev->bd_partno = partno;
 	bdev->bd_inode = inode;
 	bdev->bd_queue = disk->queue;
+	bdev->stat_time = 0;
 	bdev->bd_stats = alloc_percpu(struct disk_stats);
 	if (!bdev->bd_stats) {
 		iput(inode);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c33fb378b168..7a14d4058b14 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -149,6 +149,48 @@ unsigned int blk_mq_in_flight(struct request_queue *q,
 	return mi.inflight[0] + mi.inflight[1];
 }
 
+static bool blk_mq_check_inflight_stat(struct request *rq, void *priv,
+				       bool reserved)
+{
+	struct mq_inflight *mi = priv;
+
+	if ((!mi->part->bd_partno || rq->part == mi->part) &&
+	    blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) {
+		u64 stat_time;
+
+		mi->inflight[rq_data_dir(rq)]++;
+		if (!rq->part)
+			return true;
+
+		stat_time = READ_ONCE(rq->stat_time_ns);
+		/*
+		 * This might fail if 'req->stat_time_ns' happen to be updated
+		 * in blk_account_io_done().
+		 */
+		if (likely(cmpxchg(&rq->stat_time_ns, stat_time,
+			    rq->part->stat_time) == stat_time)) {
+			int sgrp = op_stat_group(req_op(rq));
+			u64 duation = stat_time ?
+				rq->part->stat_time - stat_time :
+				rq->part->stat_time - rq->start_time_ns;
+
+			part_stat_add(rq->part, nsecs[sgrp], duation);
+		}
+	}
+
+	return true;
+}
+
+unsigned int blk_mq_in_flight_stat(struct request_queue *q,
+		struct block_device *part)
+{
+	struct mq_inflight mi = { .part = part };
+
+	blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_stat, &mi);
+
+	return mi.inflight[0] + mi.inflight[1];
+}
+
 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
 		unsigned int inflight[2])
 {
@@ -368,6 +410,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 		rq->start_time_ns = ktime_get_ns();
 	else
 		rq->start_time_ns = 0;
+	rq->stat_time_ns = 0;
 	rq->part = NULL;
 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
 	rq->alloc_time_ns = alloc_time_ns;
@@ -874,7 +917,25 @@ static void __blk_account_io_done(struct request *req, u64 now)
 	part_stat_lock();
 	update_io_ticks(req->part, jiffies, true);
 	part_stat_inc(req->part, ios[sgrp]);
-	part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns);
+
+	if (queue_is_mq(req->q)) {
+		u64 stat_time = READ_ONCE(req->stat_time_ns);
+
+		/*
+		 * This might fail if 'req->stat_time_ns' happen to be updated
+		 * in part_get_stat().
+		 */
+		if (likely(cmpxchg(&req->stat_time_ns, stat_time, now) ==
+			   stat_time)) {
+			u64 duation = stat_time ? now - stat_time :
+						  now - req->start_time_ns;
+
+			part_stat_add(req->part, nsecs[sgrp], duation);
+		}
+	} else {
+		part_stat_add(req->part, nsecs[sgrp],
+			      now - req->part->stat_time);
+	}
 	part_stat_unlock();
 }
 
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 7d1acf8e1e51..37941f5f1d08 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -189,6 +189,8 @@ static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 
 unsigned int blk_mq_in_flight(struct request_queue *q,
 		struct block_device *part);
+unsigned int blk_mq_in_flight_stat(struct request_queue *q,
+		struct block_device *part);
 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
 		unsigned int inflight[2]);
 
diff --git a/block/genhd.c b/block/genhd.c
index f2c7de2e7ca9..31603c7aff49 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -953,6 +953,19 @@ ssize_t part_size_show(struct device *dev,
 	return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
 }
 
+static void part_set_stat_time(struct block_device *part)
+{
+	u64 now = ktime_get_ns();
+
+again:
+	part->stat_time = now;
+
+	if (part->bd_partno) {
+		part = bdev_whole(part);
+		goto again;
+	}
+}
+
 static unsigned int part_get_stat(struct block_device *bdev,
 				  struct disk_stats *stat)
 
@@ -960,10 +973,16 @@ static unsigned int part_get_stat(struct block_device *bdev,
 	struct request_queue *q = bdev_get_queue(bdev);
 	unsigned int inflight;
 
-	if (queue_is_mq(q))
-		inflight = blk_mq_in_flight(q, bdev);
-	else
+	if (queue_is_mq(q)) {
+		spin_lock(&bdev->bd_stat_lock);
+		part_stat_lock();
+		part_set_stat_time(bdev);
+		inflight = blk_mq_in_flight_stat(q, bdev);
+		part_stat_unlock();
+		spin_unlock(&bdev->bd_stat_lock);
+	} else {
 		inflight = part_in_flight(bdev);
+	}
 
 	if (inflight) {
 		part_stat_lock();
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e512da636e0f..e98f07d1741c 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -108,6 +108,8 @@ struct request {
 	u64 start_time_ns;
 	/* Time that I/O was submitted to the device. */
 	u64 io_start_time_ns;
+	/* Time that I/O was accounted in part_get_stat() */
+	u64 stat_time_ns;
 
 #ifdef CONFIG_BLK_WBT
 	unsigned short wbt_flags;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index c6ed4a559e6a..5cd399b5670d 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -65,6 +65,11 @@ struct block_device {
 	struct super_block	*bd_fsfreeze_sb;
 
 	struct partition_meta_info *bd_meta_info;
+
+	/* Prevent part_get_stat() to be called concurrently */
+	spinlock_t		bd_stat_lock;
+	/* Will be set when part_stat_show() or diskstats_show() is called */
+	u64			stat_time;
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 	bool			bd_make_it_fail;
 #endif
