From cf78408f937a67f59f5e90ee8e6cadeed7c128a8 Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Thu, 4 Feb 2021 15:50:43 +0800 Subject: [PATCH 1/6] md: add md_submit_discard_bio() for submitting discard bio Move these logic from raid0.c to md.c, so that we can also use it in raid10.c. Reviewed-by: Coly Li Reviewed-by: Guoqing Jiang Tested-by: Adrian Huang Signed-off-by: Xiao Ni Signed-off-by: Song Liu --- drivers/md/md.c | 20 ++++++++++++++++++++ drivers/md/md.h | 2 ++ drivers/md/raid0.c | 14 ++------------ 3 files changed, 24 insertions(+), 12 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 21da0c48f6c21..498a1c2e95e9d 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8575,6 +8575,26 @@ void md_write_end(struct mddev *mddev) EXPORT_SYMBOL(md_write_end); +/* This is used by raid0 and raid10 */ +void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev, + struct bio *bio, sector_t start, sector_t size) +{ + struct bio *discard_bio = NULL; + + if (__blkdev_issue_discard(rdev->bdev, start, size, GFP_NOIO, 0, + &discard_bio) || !discard_bio) + return; + + bio_chain(discard_bio, bio); + bio_clone_blkg_association(discard_bio, bio); + if (mddev->gendisk) + trace_block_bio_remap(discard_bio, + disk_devt(mddev->gendisk), + bio->bi_iter.bi_sector); + submit_bio_noacct(discard_bio); +} +EXPORT_SYMBOL_GPL(md_submit_discard_bio); + /* md_allow_write(mddev) * Calling this ensures that the array is marked 'active' so that writes * may proceed without blocking. It is important to call this before diff --git a/drivers/md/md.h b/drivers/md/md.h index bcbba1b5ec4a7..fb7eab58cfd51 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -713,6 +713,8 @@ extern void md_write_end(struct mddev *mddev); extern void md_done_sync(struct mddev *mddev, int blocks, int ok); extern void md_error(struct mddev *mddev, struct md_rdev *rdev); extern void md_finish_reshape(struct mddev *mddev); +void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev, + struct bio *bio, sector_t start, sector_t size); extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio); extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev, diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 67f157f2525d4..e5d7411cba9b4 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -477,7 +477,6 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) for (disk = 0; disk < zone->nb_dev; disk++) { sector_t dev_start, dev_end; - struct bio *discard_bio = NULL; struct md_rdev *rdev; if (disk < start_disk_index) @@ -500,18 +499,9 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) rdev = conf->devlist[(zone - conf->strip_zone) * conf->strip_zone[0].nb_dev + disk]; - if (__blkdev_issue_discard(rdev->bdev, + md_submit_discard_bio(mddev, rdev, bio, dev_start + zone->dev_start + rdev->data_offset, - dev_end - dev_start, GFP_NOIO, 0, &discard_bio) || - !discard_bio) - continue; - bio_chain(discard_bio, bio); - bio_clone_blkg_association(discard_bio, bio); - if (mddev->gendisk) - trace_block_bio_remap(discard_bio, - disk_devt(mddev->gendisk), - bio->bi_iter.bi_sector); - submit_bio_noacct(discard_bio); + dev_end - dev_start); } bio_endio(bio); } From c2968285925adb97b9aa4ede94c1f1ab61ce0925 Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Thu, 4 Feb 2021 15:50:44 +0800 Subject: [PATCH 2/6] md/raid10: extend r10bio devs to raid disks Now it allocs r10bio->devs[conf->copies]. Discard bio needs to submit to all member disks and it needs to use r10bio. So extend to r10bio->devs[geo.raid_disks]. Reviewed-by: Coly Li Tested-by: Adrian Huang Signed-off-by: Xiao Ni Signed-off-by: Song Liu --- drivers/md/raid10.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index a9ae7d113492c..5fa390880f85f 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -91,7 +91,7 @@ static inline struct r10bio *get_resync_r10bio(struct bio *bio) static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) { struct r10conf *conf = data; - int size = offsetof(struct r10bio, devs[conf->copies]); + int size = offsetof(struct r10bio, devs[conf->geo.raid_disks]); /* allocate a r10bio with room for raid_disks entries in the * bios array */ @@ -238,7 +238,7 @@ static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio) { int i; - for (i = 0; i < conf->copies; i++) { + for (i = 0; i < conf->geo.raid_disks; i++) { struct bio **bio = & r10_bio->devs[i].bio; if (!BIO_SPECIAL(*bio)) bio_put(*bio); @@ -327,7 +327,7 @@ static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio, int slot; int repl = 0; - for (slot = 0; slot < conf->copies; slot++) { + for (slot = 0; slot < conf->geo.raid_disks; slot++) { if (r10_bio->devs[slot].bio == bio) break; if (r10_bio->devs[slot].repl_bio == bio) { @@ -336,7 +336,6 @@ static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio, } } - BUG_ON(slot == conf->copies); update_head_pos(slot, r10_bio); if (slotp) @@ -1492,7 +1491,8 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors) r10_bio->sector = bio->bi_iter.bi_sector; r10_bio->state = 0; r10_bio->read_slot = -1; - memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * conf->copies); + memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * + conf->geo.raid_disks); if (bio_data_dir(bio) == READ) raid10_read_request(mddev, bio, r10_bio); From f2e7e269a7525317752d472bb48a549780e87d22 Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Thu, 4 Feb 2021 15:50:45 +0800 Subject: [PATCH 3/6] md/raid10: pull the code that wait for blocked dev into one function The following patch will reuse these logics, so pull the same codes into one function. Tested-by: Adrian Huang Signed-off-by: Xiao Ni Signed-off-by: Song Liu --- drivers/md/raid10.c | 120 +++++++++++++++++++++++++------------------- 1 file changed, 69 insertions(+), 51 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 5fa390880f85f..16ddf41b56ef5 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1273,12 +1273,77 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, } } +static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio) +{ + int i; + struct r10conf *conf = mddev->private; + struct md_rdev *blocked_rdev; + +retry_wait: + blocked_rdev = NULL; + rcu_read_lock(); + for (i = 0; i < conf->copies; i++) { + struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + struct md_rdev *rrdev = rcu_dereference( + conf->mirrors[i].replacement); + if (rdev == rrdev) + rrdev = NULL; + if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { + atomic_inc(&rdev->nr_pending); + blocked_rdev = rdev; + break; + } + if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) { + atomic_inc(&rrdev->nr_pending); + blocked_rdev = rrdev; + break; + } + + if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) { + sector_t first_bad; + sector_t dev_sector = r10_bio->devs[i].addr; + int bad_sectors; + int is_bad; + + /* + * Discard request doesn't care the write result + * so it doesn't need to wait blocked disk here. + */ + if (!r10_bio->sectors) + continue; + + is_bad = is_badblock(rdev, dev_sector, r10_bio->sectors, + &first_bad, &bad_sectors); + if (is_bad < 0) { + /* + * Mustn't write here until the bad block + * is acknowledged + */ + atomic_inc(&rdev->nr_pending); + set_bit(BlockedBadBlocks, &rdev->flags); + blocked_rdev = rdev; + break; + } + } + } + rcu_read_unlock(); + + if (unlikely(blocked_rdev)) { + /* Have to wait for this device to get unblocked, then retry */ + allow_barrier(conf); + raid10_log(conf->mddev, "%s wait rdev %d blocked", + __func__, blocked_rdev->raid_disk); + md_wait_for_blocked_rdev(blocked_rdev, mddev); + wait_barrier(conf); + goto retry_wait; + } +} + static void raid10_write_request(struct mddev *mddev, struct bio *bio, struct r10bio *r10_bio) { struct r10conf *conf = mddev->private; int i; - struct md_rdev *blocked_rdev; sector_t sectors; int max_sectors; @@ -1336,8 +1401,9 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, r10_bio->read_slot = -1; /* make sure repl_bio gets freed */ raid10_find_phys(conf, r10_bio); -retry_write: - blocked_rdev = NULL; + + wait_blocked_dev(mddev, r10_bio); + rcu_read_lock(); max_sectors = r10_bio->sectors; @@ -1348,16 +1414,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, conf->mirrors[d].replacement); if (rdev == rrdev) rrdev = NULL; - if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { - atomic_inc(&rdev->nr_pending); - blocked_rdev = rdev; - break; - } - if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) { - atomic_inc(&rrdev->nr_pending); - blocked_rdev = rrdev; - break; - } if (rdev && (test_bit(Faulty, &rdev->flags))) rdev = NULL; if (rrdev && (test_bit(Faulty, &rrdev->flags))) @@ -1378,15 +1434,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, is_bad = is_badblock(rdev, dev_sector, max_sectors, &first_bad, &bad_sectors); - if (is_bad < 0) { - /* Mustn't write here until the bad block - * is acknowledged - */ - atomic_inc(&rdev->nr_pending); - set_bit(BlockedBadBlocks, &rdev->flags); - blocked_rdev = rdev; - break; - } if (is_bad && first_bad <= dev_sector) { /* Cannot write here at all */ bad_sectors -= (dev_sector - first_bad); @@ -1422,35 +1469,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, } rcu_read_unlock(); - if (unlikely(blocked_rdev)) { - /* Have to wait for this device to get unblocked, then retry */ - int j; - int d; - - for (j = 0; j < i; j++) { - if (r10_bio->devs[j].bio) { - d = r10_bio->devs[j].devnum; - rdev_dec_pending(conf->mirrors[d].rdev, mddev); - } - if (r10_bio->devs[j].repl_bio) { - struct md_rdev *rdev; - d = r10_bio->devs[j].devnum; - rdev = conf->mirrors[d].replacement; - if (!rdev) { - /* Race with remove_disk */ - smp_mb(); - rdev = conf->mirrors[d].rdev; - } - rdev_dec_pending(rdev, mddev); - } - } - allow_barrier(conf); - raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk); - md_wait_for_blocked_rdev(blocked_rdev, mddev); - wait_barrier(conf); - goto retry_write; - } - if (max_sectors < r10_bio->sectors) r10_bio->sectors = max_sectors; From d30588b2731fb01e1616cf16c3fe79a1443e29aa Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Thu, 4 Feb 2021 15:50:46 +0800 Subject: [PATCH 4/6] md/raid10: improve raid10 discard request MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now the discard request is split by chunk size. So it takes a long time to finish mkfs on disks which support discard function. This patch improve handling raid10 discard request. It uses the similar way with patch 29efc390b (md/md0: optimize raid0 discard handling). But it's a little complex than raid0. Because raid10 has different layout. If raid10 is offset layout and the discard request is smaller than stripe size. There are some holes when we submit discard bio to underlayer disks. For example: five disks (disk1 - disk5) D01 D02 D03 D04 D05 D05 D01 D02 D03 D04 D06 D07 D08 D09 D10 D10 D06 D07 D08 D09 The discard bio just wants to discard from D03 to D10. For disk3, there is a hole between D03 and D08. For disk4, there is a hole between D04 and D09. D03 is a chunk, raid10_write_request can handle one chunk perfectly. So the part that is not aligned with stripe size is still handled by raid10_write_request. If reshape is running when discard bio comes and the discard bio spans the reshape position, raid10_write_request is responsible to handle this discard bio. I did a test with this patch set. Without patch: time mkfs.xfs /dev/md0 real4m39.775s user0m0.000s sys0m0.298s With patch: time mkfs.xfs /dev/md0 real0m0.105s user0m0.000s sys0m0.007s nvme3n1 259:1 0 477G 0 disk └─nvme3n1p1 259:10 0 50G 0 part nvme4n1 259:2 0 477G 0 disk └─nvme4n1p1 259:11 0 50G 0 part nvme5n1 259:6 0 477G 0 disk └─nvme5n1p1 259:12 0 50G 0 part nvme2n1 259:9 0 477G 0 disk └─nvme2n1p1 259:15 0 50G 0 part nvme0n1 259:13 0 477G 0 disk └─nvme0n1p1 259:14 0 50G 0 part Reviewed-by: Coly Li Reviewed-by: Guoqing Jiang Tested-by: Adrian Huang Signed-off-by: Xiao Ni Signed-off-by: Song Liu --- drivers/md/raid10.c | 263 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 262 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 16ddf41b56ef5..2a61700dfc722 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1518,6 +1518,263 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors) raid10_write_request(mddev, bio, r10_bio); } +static void raid10_end_discard_request(struct bio *bio) +{ + struct r10bio *r10_bio = bio->bi_private; + struct r10conf *conf = r10_bio->mddev->private; + struct md_rdev *rdev = NULL; + int dev; + int slot, repl; + + /* + * We don't care the return value of discard bio + */ + if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) + set_bit(R10BIO_Uptodate, &r10_bio->state); + + dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl); + if (repl) + rdev = conf->mirrors[dev].replacement; + if (!rdev) { + /* + * raid10_remove_disk uses smp_mb to make sure rdev is set to + * replacement before setting replacement to NULL. It can read + * rdev first without barrier protect even replacment is NULL + */ + smp_rmb(); + rdev = conf->mirrors[dev].rdev; + } + + 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); +} + +/* + * There are some limitations to handle discard bio + * 1st, the discard size is bigger than stripe_size*2. + * 2st, if the discard bio spans reshape progress, we use the old way to + * handle discard bio + */ +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; + struct bio *split; + int disk; + sector_t chunk; + unsigned int stripe_size; + unsigned int stripe_data_disks; + sector_t split_size; + sector_t bio_start, bio_end; + sector_t first_stripe_index, last_stripe_index; + sector_t start_disk_offset; + unsigned int start_disk_index; + sector_t end_disk_offset; + unsigned int end_disk_index; + unsigned int remainder; + + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + return -EAGAIN; + + wait_barrier(conf); + + /* + * Check reshape again to avoid reshape happens after checking + * MD_RECOVERY_RESHAPE and before wait_barrier + */ + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + goto out; + + if (geo->near_copies) + stripe_data_disks = geo->raid_disks / geo->near_copies + + geo->raid_disks % geo->near_copies; + else + stripe_data_disks = geo->raid_disks; + + stripe_size = stripe_data_disks << geo->chunk_shift; + + bio_start = bio->bi_iter.bi_sector; + bio_end = bio_end_sector(bio); + + /* + * Maybe one discard bio is smaller than strip size or across one + * stripe and discard region is larger than one stripe size. For far + * offset layout, if the discard region is not aligned with stripe + * size, there is hole when we submit discard bio to member disk. + * For simplicity, we only handle discard bio which discard region + * is bigger than stripe_size * 2 + */ + if (bio_sectors(bio) < stripe_size*2) + goto out; + + /* + * Keep bio aligned with strip size. + */ + div_u64_rem(bio_start, stripe_size, &remainder); + if (remainder) { + split_size = stripe_size - remainder; + split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split); + bio_chain(split, bio); + allow_barrier(conf); + /* Resend the fist split part */ + submit_bio_noacct(split); + wait_barrier(conf); + } + div_u64_rem(bio_end, stripe_size, &remainder); + if (remainder) { + split_size = bio_sectors(bio) - remainder; + split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split); + bio_chain(split, bio); + allow_barrier(conf); + /* Resend the second split part */ + submit_bio_noacct(bio); + bio = split; + wait_barrier(conf); + } + + 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); + + /* + * Raid10 uses chunk as the unit to store data. It's similar like raid0. + * One stripe contains the chunks from all member disk (one chunk from + * one disk at the same HBA address). For layout detail, see 'man md 4' + */ + chunk = bio_start >> geo->chunk_shift; + chunk *= geo->near_copies; + first_stripe_index = chunk; + start_disk_index = sector_div(first_stripe_index, geo->raid_disks); + if (geo->far_offset) + first_stripe_index *= geo->far_copies; + start_disk_offset = (bio_start & geo->chunk_mask) + + (first_stripe_index << geo->chunk_shift); + + chunk = bio_end >> geo->chunk_shift; + chunk *= geo->near_copies; + last_stripe_index = chunk; + end_disk_index = sector_div(last_stripe_index, geo->raid_disks); + if (geo->far_offset) + last_stripe_index *= geo->far_copies; + end_disk_offset = (bio_end & geo->chunk_mask) + + (last_stripe_index << geo->chunk_shift); + + rcu_read_lock(); + for (disk = 0; disk < geo->raid_disks; disk++) { + struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev); + struct md_rdev *rrdev = rcu_dereference( + conf->mirrors[disk].replacement); + + r10_bio->devs[disk].bio = NULL; + r10_bio->devs[disk].repl_bio = NULL; + + if (rdev && (test_bit(Faulty, &rdev->flags))) + rdev = NULL; + if (rrdev && (test_bit(Faulty, &rrdev->flags))) + rrdev = NULL; + if (!rdev && !rrdev) + continue; + + if (rdev) { + r10_bio->devs[disk].bio = bio; + atomic_inc(&rdev->nr_pending); + } + if (rrdev) { + r10_bio->devs[disk].repl_bio = bio; + atomic_inc(&rrdev->nr_pending); + } + } + rcu_read_unlock(); + + atomic_set(&r10_bio->remaining, 1); + for (disk = 0; disk < geo->raid_disks; disk++) { + sector_t dev_start, dev_end; + struct bio *mbio, *rbio = NULL; + struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev); + struct md_rdev *rrdev = rcu_dereference( + conf->mirrors[disk].replacement); + + /* + * Now start to calculate the start and end address for each disk. + * The space between dev_start and dev_end is the discard region. + * + * For dev_start, it needs to consider three conditions: + * 1st, the disk is before start_disk, you can imagine the disk in + * the next stripe. So the dev_start is the start address of next + * stripe. + * 2st, the disk is after start_disk, it means the disk is at the + * same stripe of first disk + * 3st, the first disk itself, we can use start_disk_offset directly + */ + if (disk < start_disk_index) + dev_start = (first_stripe_index + 1) * mddev->chunk_sectors; + else if (disk > start_disk_index) + dev_start = first_stripe_index * mddev->chunk_sectors; + else + dev_start = start_disk_offset; + + if (disk < end_disk_index) + dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; + else if (disk > end_disk_index) + dev_end = last_stripe_index * mddev->chunk_sectors; + else + dev_end = end_disk_offset; + + /* + * It only handles discard bio which size is >= stripe size, so + * dev_end > dev_start all the time + */ + if (r10_bio->devs[disk].bio) { + mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set); + mbio->bi_end_io = raid10_end_discard_request; + mbio->bi_private = r10_bio; + r10_bio->devs[disk].bio = mbio; + r10_bio->devs[disk].devnum = disk; + atomic_inc(&r10_bio->remaining); + md_submit_discard_bio(mddev, rdev, mbio, + dev_start + choose_data_offset(r10_bio, rdev), + dev_end - dev_start); + bio_endio(mbio); + } + if (r10_bio->devs[disk].repl_bio) { + rbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set); + rbio->bi_end_io = raid10_end_discard_request; + rbio->bi_private = r10_bio; + r10_bio->devs[disk].repl_bio = rbio; + r10_bio->devs[disk].devnum = disk; + atomic_inc(&r10_bio->remaining); + md_submit_discard_bio(mddev, rrdev, rbio, + dev_start + choose_data_offset(r10_bio, rrdev), + dev_end - dev_start); + bio_endio(rbio); + } + } + + if (atomic_dec_and_test(&r10_bio->remaining)) { + md_write_end(r10_bio->mddev); + raid_end_bio_io(r10_bio); + } + + return 0; +out: + allow_barrier(conf); + return -EAGAIN; +} + static bool raid10_make_request(struct mddev *mddev, struct bio *bio) { struct r10conf *conf = mddev->private; @@ -1532,6 +1789,10 @@ static bool raid10_make_request(struct mddev *mddev, struct bio *bio) if (!md_write_start(mddev, bio)) return false; + if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) + if (!raid10_handle_discard(mddev, bio)) + return true; + /* * If this request crosses a chunk boundary, we need to split * it. @@ -3771,7 +4032,7 @@ static int raid10_run(struct mddev *mddev) if (mddev->queue) { blk_queue_max_discard_sectors(mddev->queue, - mddev->chunk_sectors); + UINT_MAX); blk_queue_max_write_same_sectors(mddev->queue, 0); blk_queue_max_write_zeroes_sectors(mddev->queue, 0); blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); From 254c271da0712ea8914f187588e0f81f7678ee2f Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Thu, 4 Feb 2021 15:50:47 +0800 Subject: [PATCH 5/6] md/raid10: improve discard request for far layout For far layout, the discard region is not continuous on disks. So it needs far copies r10bio to cover all regions. It needs a way to know all r10bios have finish or not. Similar with raid10_sync_request, only the first r10bio master_bio records the discard bio. Other r10bios master_bio record the first r10bio. The first r10bio can finish after other r10bios finish and then return the discard bio. Tested-by: Adrian Huang Signed-off-by: Xiao Ni Signed-off-by: Song Liu --- drivers/md/raid10.c | 79 ++++++++++++++++++++++++++++++++++----------- drivers/md/raid10.h | 1 + 2 files changed, 61 insertions(+), 19 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 2a61700dfc722..13f5e6b2a73d6 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1518,6 +1518,28 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors) raid10_write_request(mddev, bio, r10_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; @@ -1545,11 +1567,7 @@ static void raid10_end_discard_request(struct bio *bio) rdev = conf->mirrors[dev].rdev; } - 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); rdev_dec_pending(rdev, conf->mddev); } @@ -1563,7 +1581,9 @@ 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; + int far_copies = geo->far_copies; + bool first_copy = true; + struct r10bio *r10_bio, *first_r10bio; struct bio *split; int disk; sector_t chunk; @@ -1637,16 +1657,6 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) wait_barrier(conf); } - 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); @@ -1673,6 +1683,29 @@ 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); @@ -1764,11 +1797,19 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) } } - if (atomic_dec_and_test(&r10_bio->remaining)) { - md_write_end(r10_bio->mddev); - raid_end_bio_io(r10_bio); + 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; } + 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 79cd2b7d3128b..1461fd55311be 100644 --- a/drivers/md/raid10.h +++ b/drivers/md/raid10.h @@ -179,5 +179,6 @@ enum r10bio_state { R10BIO_Previous, /* failfast devices did receive failfast requests. */ R10BIO_FailFast, + R10BIO_Discard, }; #endif From 7abfabaf5f805f5171d133ce6af9b65ab766e76a Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Wed, 17 Mar 2021 15:04:39 +0100 Subject: [PATCH 6/6] md: Fix missing unused status line of /proc/mdstat Reading /proc/mdstat with a read buffer size that would not fit the unused status line in the first read will skip this line from the output. So 'dd if=/proc/mdstat bs=64 2>/dev/null' will not print something like: unused devices: Don't return NULL immediately in start() for v=2 but call show() once to print the status line also for multiple reads. Cc: stable@vger.kernel.org Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") Signed-off-by: Jan Glauber Signed-off-by: Song Liu --- drivers/md/md.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 498a1c2e95e9d..368cad6cd53a6 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8153,7 +8153,11 @@ static void *md_seq_start(struct seq_file *seq, loff_t *pos) loff_t l = *pos; struct mddev *mddev; - if (l >= 0x10000) + if (l == 0x10000) { + ++*pos; + return (void *)2; + } + if (l > 0x10000) return NULL; if (!l--) /* header */