From 82fe9af77cd11ea7bdc133ceed1f7f5fc08f7d25 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 9 Dec 2020 11:38:11 -0800 Subject: [PATCH] Revert "md/raid10: improve discard request for far layout" This reverts commit d3ee2d8415a6256c1c41e1be36e80e640c3e6359. Matthew Ruffell reported data corruption in raid10 due to the changes in discard handling [1]. Revert these changes before we find a proper fix. [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1907262/ Cc: Matthew Ruffell Cc: Xiao Ni Signed-off-by: Song Liu --- drivers/md/raid10.c | 86 ++++++++++++--------------------------------- drivers/md/raid10.h | 1 - 2 files changed, 23 insertions(+), 64 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index b7bca6703df8..05773ee1b5ba 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1534,28 +1534,6 @@ static struct bio *raid10_split_bio(struct r10conf *conf, return bio; } -static void raid_end_discard_bio(struct r10bio *r10bio) -{ - struct r10conf *conf = r10bio->mddev->private; - struct r10bio *first_r10bio; - - while (atomic_dec_and_test(&r10bio->remaining)) { - - allow_barrier(conf); - - if (!test_bit(R10BIO_Discard, &r10bio->state)) { - first_r10bio = (struct r10bio *)r10bio->master_bio; - free_r10bio(r10bio); - r10bio = first_r10bio; - } else { - md_write_end(r10bio->mddev); - bio_endio(r10bio->master_bio); - free_r10bio(r10bio); - break; - } - } -} - static void raid10_end_discard_request(struct bio *bio) { struct r10bio *r10_bio = bio->bi_private; @@ -1582,7 +1560,11 @@ static void raid10_end_discard_request(struct bio *bio) rdev = conf->mirrors[dev].rdev; } - raid_end_discard_bio(r10_bio); + if (atomic_dec_and_test(&r10_bio->remaining)) { + md_write_end(r10_bio->mddev); + raid_end_bio_io(r10_bio); + } + rdev_dec_pending(rdev, conf->mddev); } @@ -1595,9 +1577,7 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) { struct r10conf *conf = mddev->private; struct geom *geo = &conf->geo; - struct r10bio *r10_bio, *first_r10bio; - int far_copies = geo->far_copies; - bool first_copy = true; + struct r10bio *r10_bio; int disk; sector_t chunk; @@ -1636,20 +1616,30 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) if (bio_sectors(bio) < stripe_size*2) goto out; - /* For far and far offset layout, if bio is not aligned with stripe size, - * it splits the part that is not aligned with strip size. + /* For far offset layout, if bio is not aligned with stripe size, it splits + * the part that is not aligned with strip size. */ div_u64_rem(bio_start, stripe_size, &remainder); - if ((far_copies > 1) && remainder) { + if (geo->far_offset && remainder) { split_size = stripe_size - remainder; bio = raid10_split_bio(conf, bio, split_size, false); } div_u64_rem(bio_end, stripe_size, &remainder); - if ((far_copies > 1) && remainder) { + if (geo->far_offset && remainder) { split_size = bio_sectors(bio) - remainder; bio = raid10_split_bio(conf, bio, split_size, true); } + r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO); + r10_bio->mddev = mddev; + r10_bio->state = 0; + r10_bio->sectors = 0; + memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks); + + wait_blocked_dev(mddev, r10_bio); + + r10_bio->master_bio = bio; + bio_start = bio->bi_iter.bi_sector; bio_end = bio_end_sector(bio); @@ -1675,28 +1665,6 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) end_disk_offset = (bio_end & geo->chunk_mask) + (last_stripe_index << geo->chunk_shift); -retry_discard: - r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO); - r10_bio->mddev = mddev; - r10_bio->state = 0; - r10_bio->sectors = 0; - memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks); - wait_blocked_dev(mddev, r10_bio); - - /* For far layout it needs more than one r10bio to cover all regions. - * Inspired by raid10_sync_request, we can use the first r10bio->master_bio - * to record the discard bio. Other r10bio->master_bio record the first - * r10bio. The first r10bio only release after all other r10bios finish. - * The discard bio returns only first r10bio finishes - */ - if (first_copy) { - r10_bio->master_bio = bio; - set_bit(R10BIO_Discard, &r10_bio->state); - first_copy = false; - first_r10bio = r10_bio; - } else - r10_bio->master_bio = (struct bio *)first_r10bio; - rcu_read_lock(); for (disk = 0; disk < geo->raid_disks; disk++) { struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev); @@ -1787,19 +1755,11 @@ retry_discard: } } - if (!geo->far_offset && --far_copies) { - first_stripe_index += geo->stride >> geo->chunk_shift; - start_disk_offset += geo->stride; - last_stripe_index += geo->stride >> geo->chunk_shift; - end_disk_offset += geo->stride; - atomic_inc(&first_r10bio->remaining); - raid_end_discard_bio(r10_bio); - wait_barrier(conf); - goto retry_discard; + if (atomic_dec_and_test(&r10_bio->remaining)) { + md_write_end(r10_bio->mddev); + raid_end_bio_io(r10_bio); } - raid_end_discard_bio(r10_bio); - return 0; out: allow_barrier(conf); diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h index 1461fd55311b..79cd2b7d3128 100644 --- a/drivers/md/raid10.h +++ b/drivers/md/raid10.h @@ -179,6 +179,5 @@ enum r10bio_state { R10BIO_Previous, /* failfast devices did receive failfast requests. */ R10BIO_FailFast, - R10BIO_Discard, }; #endif