Commit 1147f58e authored by Guoqing Jiang's avatar Guoqing Jiang Committed by Song Liu
Browse files

md/raid5: avoid redundant bio clone in raid5_read_one_chunk 



After enable io accounting, chunk read bio could be cloned twice which
is not good. To avoid such inefficiency, let's clone align_bio from
io_acct_set too, then we need only call md_account_bio in make_request
unconditionally.

Signed-off-by: default avatarGuoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: default avatarSong Liu <song@kernel.org>
parent c82aa1b7

drivers/md/raid5.c

+15 −14
Original line number Diff line number Diff line
@@ -5364,11 +5364,13 @@ static struct bio *remove_bio_from_retry(struct r5conf *conf, 
 */

static void raid5_align_endio(struct bio *bi)

{

	struct bio* raid_bi  = bi->bi_private;

	struct md_io_acct *md_io_acct = bi->bi_private;

	struct bio *raid_bi = md_io_acct->orig_bio;

	struct mddev *mddev;

	struct r5conf *conf;

	struct md_rdev *rdev;

	blk_status_t error = bi->bi_status;

	unsigned long start_time = md_io_acct->start_time;



	bio_put(bi);
@@ -5380,6 +5382,8 @@ static void raid5_align_endio(struct bio *bi) 
	rdev_dec_pending(rdev, conf->mddev);



	if (!error) {

		if (blk_queue_io_stat(raid_bi->bi_bdev->bd_disk->queue))

			bio_end_io_acct(raid_bi, start_time);

		bio_endio(raid_bi);

		if (atomic_dec_and_test(&conf->active_aligned_reads))

			wake_up(&conf->wait_for_quiescent);
@@ -5398,6 +5402,7 @@ static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio) 
	struct md_rdev *rdev;

	sector_t sector, end_sector, first_bad;

	int bad_sectors, dd_idx;

	struct md_io_acct *md_io_acct;



	if (!in_chunk_boundary(mddev, raid_bio)) {

		pr_debug("%s: non aligned\n", __func__);
@@ -5434,14 +5439,18 @@ static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio) 
		return 0;

	}



	align_bio = bio_clone_fast(raid_bio, GFP_NOIO, &mddev->bio_set);

	align_bio = bio_clone_fast(raid_bio, GFP_NOIO, &mddev->io_acct_set);

	md_io_acct = container_of(align_bio, struct md_io_acct, bio_clone);

	raid_bio->bi_next = (void *)rdev;

	if (blk_queue_io_stat(raid_bio->bi_bdev->bd_disk->queue))

		md_io_acct->start_time = bio_start_io_acct(raid_bio);

	md_io_acct->orig_bio = raid_bio;



	bio_set_dev(align_bio, rdev->bdev);

	align_bio->bi_end_io = raid5_align_endio;

	align_bio->bi_private = raid_bio;

	align_bio->bi_private = md_io_acct;

	align_bio->bi_iter.bi_sector = sector;



	raid_bio->bi_next = (void *)rdev;



	/* No reshape active, so we can trust rdev->data_offset */

	align_bio->bi_iter.bi_sector += rdev->data_offset;
@@ -5468,7 +5477,6 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio) 
	sector_t sector = raid_bio->bi_iter.bi_sector;

	unsigned chunk_sects = mddev->chunk_sectors;

	unsigned sectors = chunk_sects - (sector & (chunk_sects-1));

	struct r5conf *conf = mddev->private;



	if (sectors < bio_sectors(raid_bio)) {

		struct r5conf *conf = mddev->private;
@@ -5478,9 +5486,6 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio) 
		raid_bio = split;

	}



	if (raid_bio->bi_pool != &conf->bio_split)

		md_account_bio(mddev, &raid_bio);



	if (!raid5_read_one_chunk(mddev, raid_bio))

		return raid_bio;
@@ -5760,7 +5765,6 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) 
	DEFINE_WAIT(w);

	bool do_prepare;

	bool do_flush = false;

	bool do_clone = false;



	if (unlikely(bi->bi_opf & REQ_PREFLUSH)) {

		int ret = log_handle_flush_request(conf, bi);
@@ -5789,7 +5793,6 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) 
	if (rw == READ && mddev->degraded == 0 &&

	    mddev->reshape_position == MaxSector) {

		bi = chunk_aligned_read(mddev, bi);

		do_clone = true;

		if (!bi)

			return true;

	}
@@ -5804,9 +5807,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) 
	last_sector = bio_end_sector(bi);

	bi->bi_next = NULL;



	if (!do_clone)

	md_account_bio(mddev, &bi);



	prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);

	for (; logical_sector < last_sector; logical_sector += RAID5_STRIPE_SECTORS(conf)) {

		int previous;