Commit f54d03a3 authored by Guoqing Jiang's avatar Guoqing Jiang Committed by Zheng Zengkai
Browse files

md/raid5: avoid redundant bio clone in raid5_read_one_chunk 

mainline inclusion
from mainline-v5.14-rc1
commit 1147f58e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I587H6
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1147f58e1010b8688bac1fd3bbab753b1379291d



-------------------------------

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>
Conflict:
	drivers/md/raid5.c
Signed-off-by: default avatarZhang Wensheng <zhangwensheng5@huawei.com>
Reviewed-by: default avatarJason Yan <yanaijie@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent c46da1e4

drivers/md/raid5.c

+14 −12
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_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 bio* align_bi;

	struct md_rdev *rdev;

	sector_t end_sector;

	struct md_io_acct *md_io_acct;



	if (!in_chunk_boundary(mddev, raid_bio)) {

		pr_debug("%s: non aligned\n", __func__);
@@ -5406,15 +5411,20 @@ static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio) 
	/*

	 * use bio_clone_fast to make a copy of the bio

	 */

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

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

	if (!align_bi)

		return 0;

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

	raid_bio->bi_next = (void *)rdev;

	if (blk_queue_io_stat(raid_bio->bi_disk->queue))

		md_io_acct->start_time = bio_start_io_acct(raid_bio);

	md_io_acct->orig_bio = raid_bio;

	/*

	 *   set bi_end_io to a new function, and set bi_private to the

	 *     original bio.

	 */

	align_bi->bi_end_io  = raid5_align_endio;

	align_bi->bi_private = raid_bio;

	align_bi->bi_private = md_io_acct;

	/*

	 *	compute position

	 */
@@ -5487,7 +5497,6 @@ 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;
@@ -5497,9 +5506,6 @@ 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;
@@ -5779,7 +5785,6 @@ 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);
@@ -5808,7 +5813,6 @@ 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;

	}
@@ -5823,9 +5827,7 @@ 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;