md/raid1: enable io accounting

For raid1, we record the start time between split bio and clone bio,
and finish the accounting in the final endio.

Also introduce start_time in r1bio accordingly.

Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>

drivers/md/raid1.c

@@ -300,6 +300,8 @@ static void call_bio_endio(struct r1bio *r1_bio)
 	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
 		bio->bi_status = BLK_STS_IOERR;
 
+	if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
+		bio_end_io_acct(bio, r1_bio->start_time);
 	bio_endio(bio);
 }
 
@@ -1292,6 +1294,9 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 
 	r1_bio->read_disk = rdisk;
 
+	if (!r1bio_existed && blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
+		r1_bio->start_time = bio_start_io_acct(bio);
+
 	read_bio = bio_clone_fast(bio, gfp, &mddev->bio_set);
 
 	r1_bio->bios[rdisk] = read_bio;
@@ -1461,6 +1466,8 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 		r1_bio->sectors = max_sectors;
 	}
 
+	if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
+		r1_bio->start_time = bio_start_io_acct(bio);
 	atomic_set(&r1_bio->remaining, 1);
 	atomic_set(&r1_bio->behind_remaining, 0);
 

drivers/md/raid1.h

@@ -158,6 +158,7 @@ struct r1bio {
 	sector_t		sector;
 	int			sectors;
 	unsigned long		state;
+	unsigned long		start_time;
 	struct mddev		*mddev;
 	/*
 	 * original bio going to /dev/mdx