From e02ee89baa66c40e1002cf8b09141fce7265e0f5 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 20 Mar 2023 10:12:58 +0800 Subject: [PATCH] btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure Switch scrub_simple_mirror() to the new scrub_stripe infrastructure. Since scrub_simple_mirror() is the core part of scrub (only RAID56 P/Q stripes don't utilize it), we can get rid of a big chunk of code, mostly scrub_extent(), scrub_sectors() and directly called functions. There is a functionality change: - Scrub speed throttle now only affects read on the scrubbing device Writes (for repair and replace), and reads from other mirrors won't be limited by the set limits. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/scrub.c | 493 +++-------------------------------------------- fs/btrfs/scrub.h | 10 - 2 files changed, 29 insertions(+), 474 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index d5d5cd68ac2e94..c0dd9828849b9b 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -582,10 +582,6 @@ static void scrub_sector_get(struct scrub_sector *sector); static void scrub_sector_put(struct scrub_sector *sector); static void scrub_parity_get(struct scrub_parity *sparity); static void scrub_parity_put(struct scrub_parity *sparity); -static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len, - u64 physical, struct btrfs_device *dev, u64 flags, - u64 gen, int mirror_num, u8 *csum, - u64 physical_for_dev_replace); static void scrub_bio_end_io(struct bio *bio); static void scrub_bio_end_io_worker(struct work_struct *work); static void scrub_block_complete(struct scrub_block *sblock); @@ -2952,22 +2948,15 @@ static void scrub_sector_put(struct scrub_sector *sector) kfree(sector); } -/* - * Throttling of IO submission, bandwidth-limit based, the timeslice is 1 - * second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max. - */ -static void scrub_throttle(struct scrub_ctx *sctx) +static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *device, + unsigned int bio_size) { const int time_slice = 1000; - struct scrub_bio *sbio; - struct btrfs_device *device; s64 delta; ktime_t now; u32 div; u64 bwlimit; - sbio = sctx->bios[sctx->curr]; - device = sbio->dev; bwlimit = READ_ONCE(device->scrub_speed_max); if (bwlimit == 0) return; @@ -2989,7 +2978,7 @@ static void scrub_throttle(struct scrub_ctx *sctx) /* Still in the time to send? */ if (ktime_before(now, sctx->throttle_deadline)) { /* If current bio is within the limit, send it */ - sctx->throttle_sent += sbio->bio->bi_iter.bi_size; + sctx->throttle_sent += bio_size; if (sctx->throttle_sent <= div_u64(bwlimit, div)) return; @@ -3011,6 +3000,17 @@ static void scrub_throttle(struct scrub_ctx *sctx) sctx->throttle_deadline = 0; } +/* + * Throttling of IO submission, bandwidth-limit based, the timeslice is 1 + * second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max. + */ +static void scrub_throttle(struct scrub_ctx *sctx) +{ + struct scrub_bio *sbio = sctx->bios[sctx->curr]; + + scrub_throttle_dev_io(sctx, sbio->dev, sbio->bio->bi_iter.bi_size); +} + static void scrub_submit(struct scrub_ctx *sctx) { struct scrub_bio *sbio; @@ -3095,202 +3095,6 @@ static int scrub_add_sector_to_rd_bio(struct scrub_ctx *sctx, return 0; } -static void scrub_missing_raid56_end_io(struct bio *bio) -{ - struct scrub_block *sblock = bio->bi_private; - struct btrfs_fs_info *fs_info = sblock->sctx->fs_info; - - btrfs_bio_counter_dec(fs_info); - if (bio->bi_status) - sblock->no_io_error_seen = 0; - - bio_put(bio); - - queue_work(fs_info->scrub_workers, &sblock->work); -} - -static void scrub_missing_raid56_worker(struct work_struct *work) -{ - struct scrub_block *sblock = container_of(work, struct scrub_block, work); - struct scrub_ctx *sctx = sblock->sctx; - struct btrfs_fs_info *fs_info = sctx->fs_info; - u64 logical; - struct btrfs_device *dev; - - logical = sblock->logical; - dev = sblock->dev; - - if (sblock->no_io_error_seen) - scrub_recheck_block_checksum(sblock); - - if (!sblock->no_io_error_seen) { - spin_lock(&sctx->stat_lock); - sctx->stat.read_errors++; - spin_unlock(&sctx->stat_lock); - btrfs_err_rl_in_rcu(fs_info, - "IO error rebuilding logical %llu for dev %s", - logical, btrfs_dev_name(dev)); - } else if (sblock->header_error || sblock->checksum_error) { - spin_lock(&sctx->stat_lock); - sctx->stat.uncorrectable_errors++; - spin_unlock(&sctx->stat_lock); - btrfs_err_rl_in_rcu(fs_info, - "failed to rebuild valid logical %llu for dev %s", - logical, btrfs_dev_name(dev)); - } else { - scrub_write_block_to_dev_replace(sblock); - } - - if (sctx->is_dev_replace && sctx->flush_all_writes) { - mutex_lock(&sctx->wr_lock); - scrub_wr_submit(sctx); - mutex_unlock(&sctx->wr_lock); - } - - scrub_block_put(sblock); - scrub_pending_bio_dec(sctx); -} - -static void scrub_missing_raid56_pages(struct scrub_block *sblock) -{ - struct scrub_ctx *sctx = sblock->sctx; - struct btrfs_fs_info *fs_info = sctx->fs_info; - u64 length = sblock->sector_count << fs_info->sectorsize_bits; - u64 logical = sblock->logical; - struct btrfs_io_context *bioc = NULL; - struct bio *bio; - struct btrfs_raid_bio *rbio; - int ret; - int i; - - btrfs_bio_counter_inc_blocked(fs_info); - ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical, - &length, &bioc); - if (ret || !bioc) - goto bioc_out; - - if (WARN_ON(!sctx->is_dev_replace || - !(bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) { - /* - * We shouldn't be scrubbing a missing device. Even for dev - * replace, we should only get here for RAID 5/6. We either - * managed to mount something with no mirrors remaining or - * there's a bug in scrub_find_good_copy()/btrfs_map_block(). - */ - goto bioc_out; - } - - bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS); - bio->bi_iter.bi_sector = logical >> 9; - bio->bi_private = sblock; - bio->bi_end_io = scrub_missing_raid56_end_io; - - rbio = raid56_alloc_missing_rbio(bio, bioc); - if (!rbio) - goto rbio_out; - - for (i = 0; i < sblock->sector_count; i++) { - struct scrub_sector *sector = sblock->sectors[i]; - - raid56_add_scrub_pages(rbio, scrub_sector_get_page(sector), - scrub_sector_get_page_offset(sector), - sector->offset + sector->sblock->logical); - } - - INIT_WORK(&sblock->work, scrub_missing_raid56_worker); - scrub_block_get(sblock); - scrub_pending_bio_inc(sctx); - raid56_submit_missing_rbio(rbio); - btrfs_put_bioc(bioc); - return; - -rbio_out: - bio_put(bio); -bioc_out: - btrfs_bio_counter_dec(fs_info); - btrfs_put_bioc(bioc); - spin_lock(&sctx->stat_lock); - sctx->stat.malloc_errors++; - spin_unlock(&sctx->stat_lock); -} - -static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len, - u64 physical, struct btrfs_device *dev, u64 flags, - u64 gen, int mirror_num, u8 *csum, - u64 physical_for_dev_replace) -{ - struct scrub_block *sblock; - const u32 sectorsize = sctx->fs_info->sectorsize; - int index; - - sblock = alloc_scrub_block(sctx, dev, logical, physical, - physical_for_dev_replace, mirror_num); - if (!sblock) { - spin_lock(&sctx->stat_lock); - sctx->stat.malloc_errors++; - spin_unlock(&sctx->stat_lock); - return -ENOMEM; - } - - for (index = 0; len > 0; index++) { - struct scrub_sector *sector; - /* - * Here we will allocate one page for one sector to scrub. - * This is fine if PAGE_SIZE == sectorsize, but will cost - * more memory for PAGE_SIZE > sectorsize case. - */ - u32 l = min(sectorsize, len); - - sector = alloc_scrub_sector(sblock, logical); - if (!sector) { - spin_lock(&sctx->stat_lock); - sctx->stat.malloc_errors++; - spin_unlock(&sctx->stat_lock); - scrub_block_put(sblock); - return -ENOMEM; - } - sector->flags = flags; - sector->generation = gen; - if (csum) { - sector->have_csum = 1; - memcpy(sector->csum, csum, sctx->fs_info->csum_size); - } else { - sector->have_csum = 0; - } - len -= l; - logical += l; - physical += l; - physical_for_dev_replace += l; - } - - WARN_ON(sblock->sector_count == 0); - if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) { - /* - * This case should only be hit for RAID 5/6 device replace. See - * the comment in scrub_missing_raid56_pages() for details. - */ - scrub_missing_raid56_pages(sblock); - } else { - for (index = 0; index < sblock->sector_count; index++) { - struct scrub_sector *sector = sblock->sectors[index]; - int ret; - - ret = scrub_add_sector_to_rd_bio(sctx, sector); - if (ret) { - scrub_block_put(sblock); - return ret; - } - } - - if (flags & BTRFS_EXTENT_FLAG_SUPER) - scrub_submit(sctx); - } - - /* last one frees, either here or in bio completion for last page */ - scrub_block_put(sblock); - return 0; -} - static void scrub_bio_end_io(struct bio *bio) { struct scrub_bio *sbio = bio->bi_private; @@ -3475,179 +3279,6 @@ static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum) return 1; } -static bool should_use_device(struct btrfs_fs_info *fs_info, - struct btrfs_device *dev, - bool follow_replace_read_mode) -{ - struct btrfs_device *replace_srcdev = fs_info->dev_replace.srcdev; - struct btrfs_device *replace_tgtdev = fs_info->dev_replace.tgtdev; - - if (!dev->bdev) - return false; - - /* - * We're doing scrub/replace, if it's pure scrub, no tgtdev should be - * here. If it's replace, we're going to write data to tgtdev, thus - * the current data of the tgtdev is all garbage, thus we can not use - * it at all. - */ - if (dev == replace_tgtdev) - return false; - - /* No need to follow replace read mode, any existing device is fine. */ - if (!follow_replace_read_mode) - return true; - - /* Need to follow the mode. */ - if (fs_info->dev_replace.cont_reading_from_srcdev_mode == - BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID) - return dev != replace_srcdev; - return true; -} -static int scrub_find_good_copy(struct btrfs_fs_info *fs_info, - u64 extent_logical, u32 extent_len, - u64 *extent_physical, - struct btrfs_device **extent_dev, - int *extent_mirror_num) -{ - u64 mapped_length; - struct btrfs_io_context *bioc = NULL; - int ret; - int i; - - mapped_length = extent_len; - ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, - extent_logical, &mapped_length, &bioc, 0); - if (ret || !bioc || mapped_length < extent_len) { - btrfs_put_bioc(bioc); - btrfs_err_rl(fs_info, "btrfs_map_block() failed for logical %llu: %d", - extent_logical, ret); - return -EIO; - } - - /* - * First loop to exclude all missing devices and the source device if - * needed. And we don't want to use target device as mirror either, as - * we're doing the replace, the target device range contains nothing. - */ - for (i = 0; i < bioc->num_stripes - bioc->replace_nr_stripes; i++) { - struct btrfs_io_stripe *stripe = &bioc->stripes[i]; - - if (!should_use_device(fs_info, stripe->dev, true)) - continue; - goto found; - } - /* - * We didn't find any alternative mirrors, we have to break our replace - * read mode, or we can not read at all. - */ - for (i = 0; i < bioc->num_stripes - bioc->replace_nr_stripes; i++) { - struct btrfs_io_stripe *stripe = &bioc->stripes[i]; - - if (!should_use_device(fs_info, stripe->dev, false)) - continue; - goto found; - } - - btrfs_err_rl(fs_info, "failed to find any live mirror for logical %llu", - extent_logical); - return -EIO; - -found: - *extent_physical = bioc->stripes[i].physical; - *extent_mirror_num = i + 1; - *extent_dev = bioc->stripes[i].dev; - btrfs_put_bioc(bioc); - return 0; -} - -static bool scrub_need_different_mirror(struct scrub_ctx *sctx, - struct map_lookup *map, - struct btrfs_device *dev) -{ - /* - * For RAID56, all the extra mirrors are rebuilt from other P/Q, - * cannot utilize other mirrors directly. - */ - if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) - return false; - - if (!dev->bdev) - return true; - - return sctx->fs_info->dev_replace.cont_reading_from_srcdev_mode == - BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID; -} - -/* scrub extent tries to collect up to 64 kB for each bio */ -static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map, - u64 logical, u32 len, - u64 physical, struct btrfs_device *dev, u64 flags, - u64 gen, int mirror_num) -{ - struct btrfs_device *src_dev = dev; - u64 src_physical = physical; - int src_mirror = mirror_num; - int ret; - u8 csum[BTRFS_CSUM_SIZE]; - u32 blocksize; - - if (flags & BTRFS_EXTENT_FLAG_DATA) { - if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) - blocksize = BTRFS_STRIPE_LEN; - else - blocksize = sctx->fs_info->sectorsize; - spin_lock(&sctx->stat_lock); - sctx->stat.data_extents_scrubbed++; - sctx->stat.data_bytes_scrubbed += len; - spin_unlock(&sctx->stat_lock); - } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { - if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) - blocksize = BTRFS_STRIPE_LEN; - else - blocksize = sctx->fs_info->nodesize; - spin_lock(&sctx->stat_lock); - sctx->stat.tree_extents_scrubbed++; - sctx->stat.tree_bytes_scrubbed += len; - spin_unlock(&sctx->stat_lock); - } else { - blocksize = sctx->fs_info->sectorsize; - WARN_ON(1); - } - - /* - * For dev-replace case, we can have @dev being a missing device, or - * we want to avoid reading from the source device if possible. - */ - if (sctx->is_dev_replace && scrub_need_different_mirror(sctx, map, dev)) { - ret = scrub_find_good_copy(sctx->fs_info, logical, len, - &src_physical, &src_dev, &src_mirror); - if (ret < 0) - return ret; - } - while (len) { - u32 l = min(len, blocksize); - int have_csum = 0; - - if (flags & BTRFS_EXTENT_FLAG_DATA) { - /* push csums to sbio */ - have_csum = scrub_find_csum(sctx, logical, csum); - if (have_csum == 0) - ++sctx->stat.no_csum; - } - ret = scrub_sectors(sctx, logical, l, src_physical, src_dev, - flags, gen, src_mirror, - have_csum ? csum : NULL, physical); - if (ret) - return ret; - len -= l; - logical += l; - physical += l; - src_physical += l; - } - return 0; -} - static int scrub_sectors_for_parity(struct scrub_parity *sparity, u64 logical, u32 len, u64 physical, struct btrfs_device *dev, @@ -4230,20 +3861,6 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, return ret < 0 ? ret : 0; } -static void sync_replace_for_zoned(struct scrub_ctx *sctx) -{ - if (!btrfs_is_zoned(sctx->fs_info)) - return; - - sctx->flush_all_writes = true; - scrub_submit(sctx); - mutex_lock(&sctx->wr_lock); - scrub_wr_submit(sctx); - mutex_unlock(&sctx->wr_lock); - - wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); -} - static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical, u64 physical, u64 physical_end) { @@ -4488,6 +4105,9 @@ static void flush_scrub_stripes(struct scrub_ctx *sctx) return; ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state)); + + scrub_throttle_dev_io(sctx, sctx->stripes[0].dev, + nr_stripes << BTRFS_STRIPE_LEN_SHIFT); for (int i = 0; i < nr_stripes; i++) { stripe = &sctx->stripes[i]; scrub_submit_initial_read(sctx, stripe); @@ -4551,9 +4171,9 @@ static void flush_scrub_stripes(struct scrub_ctx *sctx) sctx->cur_stripe = 0; } -int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, - struct btrfs_device *dev, int mirror_num, - u64 logical, u32 length, u64 physical) +static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, + struct btrfs_device *dev, int mirror_num, + u64 logical, u32 length, u64 physical) { struct scrub_stripe *stripe; int ret; @@ -4591,11 +4211,8 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, u64 physical, int mirror_num) { struct btrfs_fs_info *fs_info = sctx->fs_info; - struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bg->start); - struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start); const u64 logical_end = logical_start + logical_length; /* An artificial limit, inherit from old scrub behavior */ - const u32 max_length = SZ_64K; struct btrfs_path path = { 0 }; u64 cur_logical = logical_start; int ret; @@ -4607,11 +4224,7 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, path.skip_locking = 1; /* Go through each extent items inside the logical range */ while (cur_logical < logical_end) { - u64 extent_start; - u64 extent_len; - u64 extent_flags; - u64 extent_gen; - u64 scrub_len; + u64 cur_physical = physical + cur_logical - logical_start; /* Canceled? */ if (atomic_read(&fs_info->scrub_cancel_req) || @@ -4641,8 +4254,9 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, } spin_unlock(&bg->lock); - ret = find_first_extent_item(extent_root, &path, cur_logical, - logical_end - cur_logical); + ret = queue_scrub_stripe(sctx, bg, device, mirror_num, + cur_logical, logical_end - cur_logical, + cur_physical); if (ret > 0) { /* No more extent, just update the accounting */ sctx->stat.last_physical = physical + logical_length; @@ -4651,52 +4265,11 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, } if (ret < 0) break; - get_extent_info(&path, &extent_start, &extent_len, - &extent_flags, &extent_gen); - /* Skip hole range which doesn't have any extent */ - cur_logical = max(extent_start, cur_logical); - /* - * Scrub len has three limits: - * - Extent size limit - * - Scrub range limit - * This is especially imporatant for RAID0/RAID10 to reuse - * this function - * - Max scrub size limit - */ - scrub_len = min(min(extent_start + extent_len, - logical_end), cur_logical + max_length) - - cur_logical; - - if (extent_flags & BTRFS_EXTENT_FLAG_DATA) { - ret = btrfs_lookup_csums_list(csum_root, cur_logical, - cur_logical + scrub_len - 1, - &sctx->csum_list, 1, false); - if (ret) - break; - } - if ((extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) && - does_range_cross_boundary(extent_start, extent_len, - logical_start, logical_length)) { - btrfs_err(fs_info, -"scrub: tree block %llu spanning boundaries, ignored. boundary=[%llu, %llu)", - extent_start, logical_start, logical_end); - spin_lock(&sctx->stat_lock); - sctx->stat.uncorrectable_errors++; - spin_unlock(&sctx->stat_lock); - cur_logical += scrub_len; - continue; - } - ret = scrub_extent(sctx, map, cur_logical, scrub_len, - cur_logical - logical_start + physical, - device, extent_flags, extent_gen, - mirror_num); - scrub_free_csums(sctx); - if (ret) - break; - if (sctx->is_dev_replace) - sync_replace_for_zoned(sctx); - cur_logical += scrub_len; + ASSERT(sctx->cur_stripe > 0); + cur_logical = sctx->stripes[sctx->cur_stripe - 1].logical + + BTRFS_STRIPE_LEN; + /* Don't hold CPU for too long time */ cond_resched(); } @@ -4781,7 +4354,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, int stripe_index) { struct btrfs_fs_info *fs_info = sctx->fs_info; - struct blk_plug plug; struct map_lookup *map = em->map_lookup; const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK; const u64 chunk_logical = bg->start; @@ -4803,12 +4375,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, atomic_read(&sctx->bios_in_flight) == 0); scrub_blocked_if_needed(fs_info); - /* - * collect all data csums for the stripe to avoid seeking during - * the scrub. This might currently (crc32) end up to be about 1MB - */ - blk_start_plug(&plug); - if (sctx->is_dev_replace && btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) { mutex_lock(&sctx->wr_lock); @@ -4910,8 +4476,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); - - blk_finish_plug(&plug); + flush_scrub_stripes(sctx); if (sctx->is_dev_replace && ret >= 0) { int ret2; diff --git a/fs/btrfs/scrub.h b/fs/btrfs/scrub.h index fb9d906f5a1708..7639103ebf9df3 100644 --- a/fs/btrfs/scrub.h +++ b/fs/btrfs/scrub.h @@ -13,14 +13,4 @@ int btrfs_scrub_cancel_dev(struct btrfs_device *dev); int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid, struct btrfs_scrub_progress *progress); -/* - * The following functions are temporary exports to avoid warning on unused - * static functions. - */ -struct scrub_stripe; -int queue_scrub_stripe(struct scrub_ctx *sctx, - struct btrfs_block_group *bg, - struct btrfs_device *dev, int mirror_num, - u64 logical, u32 length, u64 physical); - #endif