diff options
Diffstat (limited to 'fs/btrfs/scrub.c')
-rw-r--r-- | fs/btrfs/scrub.c | 235 |
1 files changed, 175 insertions, 60 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index a2d91d9f8a10..3fcc7c092c5e 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -16,7 +16,6 @@ #include "backref.h" #include "extent_io.h" #include "dev-replace.h" -#include "check-integrity.h" #include "raid56.h" #include "block-group.h" #include "zoned.h" @@ -24,6 +23,7 @@ #include "accessors.h" #include "file-item.h" #include "scrub.h" +#include "raid-stripe-tree.h" /* * This is only the first step towards a full-features scrub. It reads all @@ -43,7 +43,7 @@ struct scrub_ctx; /* * The following value only influences the performance. * - * This detemines how many stripes would be submitted in one go, + * This determines how many stripes would be submitted in one go, * which is 512KiB (BTRFS_STRIPE_LEN * SCRUB_STRIPES_PER_GROUP). */ #define SCRUB_STRIPES_PER_GROUP 8 @@ -153,12 +153,14 @@ struct scrub_stripe { unsigned int init_nr_io_errors; unsigned int init_nr_csum_errors; unsigned int init_nr_meta_errors; + unsigned int init_nr_meta_gen_errors; /* * The following error bitmaps are all for the current status. * Every time we submit a new read, these bitmaps may be updated. * - * error_bitmap = io_error_bitmap | csum_error_bitmap | meta_error_bitmap; + * error_bitmap = io_error_bitmap | csum_error_bitmap | + * meta_error_bitmap | meta_generation_bitmap; * * IO and csum errors can happen for both metadata and data. */ @@ -166,6 +168,7 @@ struct scrub_stripe { unsigned long io_error_bitmap; unsigned long csum_error_bitmap; unsigned long meta_error_bitmap; + unsigned long meta_gen_error_bitmap; /* For writeback (repair or replace) error reporting. */ unsigned long write_error_bitmap; @@ -192,7 +195,6 @@ struct scrub_ctx { int cur_stripe; atomic_t cancel_req; int readonly; - int sectors_per_bio; /* State of IO submission throttling affecting the associated device */ ktime_t throttle_deadline; @@ -262,7 +264,7 @@ static int init_scrub_stripe(struct btrfs_fs_info *fs_info, atomic_set(&stripe->pending_io, 0); spin_lock_init(&stripe->write_error_lock); - ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages); + ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages, false); if (ret < 0) goto error; @@ -617,7 +619,7 @@ static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr memcpy(on_disk_csum, header->csum, fs_info->csum_size); if (logical != btrfs_stack_header_bytenr(header)) { - bitmap_set(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); btrfs_warn_rl(fs_info, "tree block %llu mirror %u has bad bytenr, has %llu want %llu", @@ -673,7 +675,7 @@ static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr } if (stripe->sectors[sector_nr].generation != btrfs_stack_header_generation(header)) { - bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->meta_gen_error_bitmap, sector_nr, sectors_per_tree); bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); btrfs_warn_rl(fs_info, "tree block %llu mirror %u has bad generation, has %llu want %llu", @@ -685,6 +687,7 @@ static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr bitmap_clear(&stripe->error_bitmap, sector_nr, sectors_per_tree); bitmap_clear(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree); bitmap_clear(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); + bitmap_clear(&stripe->meta_gen_error_bitmap, sector_nr, sectors_per_tree); } static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr) @@ -710,7 +713,7 @@ static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr) /* Metadata, verify the full tree block. */ if (sector->is_metadata) { /* - * Check if the tree block crosses the stripe boudary. If + * Check if the tree block crosses the stripe boundary. If * crossed the boundary, we cannot verify it but only give a * warning. * @@ -839,7 +842,7 @@ static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe, bbio->bio.bi_iter.bi_size >= blocksize)) { ASSERT(bbio->bio.bi_iter.bi_size); atomic_inc(&stripe->pending_io); - btrfs_submit_bio(bbio, mirror); + btrfs_submit_bbio(bbio, mirror); if (wait) wait_scrub_stripe_io(stripe); bbio = NULL; @@ -858,7 +861,7 @@ static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe, if (bbio) { ASSERT(bbio->bio.bi_iter.bi_size); atomic_inc(&stripe->pending_io); - btrfs_submit_bio(bbio, mirror); + btrfs_submit_bbio(bbio, mirror); if (wait) wait_scrub_stripe_io(stripe); } @@ -884,7 +887,7 @@ static void scrub_stripe_report_errors(struct scrub_ctx *sctx, /* * Init needed infos for error reporting. * - * Although our scrub_stripe infrastucture is mostly based on btrfs_submit_bio() + * Although our scrub_stripe infrastructure is mostly based on btrfs_submit_bio() * thus no need for dev/physical, error reporting still needs dev and physical. */ if (!bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) { @@ -897,7 +900,7 @@ static void scrub_stripe_report_errors(struct scrub_ctx *sctx, ASSERT(stripe->mirror_num >= 1); ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, stripe->logical, &mapped_len, &bioc, - NULL, NULL, 1); + NULL, NULL); /* * If we failed, dev will be NULL, and later detailed reports * will just be skipped. @@ -973,8 +976,22 @@ skip: if (__ratelimit(&rs) && dev) scrub_print_common_warning("header error", dev, false, stripe->logical, physical); + if (test_bit(sector_nr, &stripe->meta_gen_error_bitmap)) + if (__ratelimit(&rs) && dev) + scrub_print_common_warning("generation error", dev, false, + stripe->logical, physical); } + /* Update the device stats. */ + for (int i = 0; i < stripe->init_nr_io_errors; i++) + btrfs_dev_stat_inc_and_print(stripe->dev, BTRFS_DEV_STAT_READ_ERRS); + for (int i = 0; i < stripe->init_nr_csum_errors; i++) + btrfs_dev_stat_inc_and_print(stripe->dev, BTRFS_DEV_STAT_CORRUPTION_ERRS); + /* Generation mismatch error is based on each metadata, not each block. */ + for (int i = 0; i < stripe->init_nr_meta_gen_errors; + i += (fs_info->nodesize >> fs_info->sectorsize_bits)) + btrfs_dev_stat_inc_and_print(stripe->dev, BTRFS_DEV_STAT_GENERATION_ERRS); + spin_lock(&sctx->stat_lock); sctx->stat.data_extents_scrubbed += stripe->nr_data_extents; sctx->stat.tree_extents_scrubbed += stripe->nr_meta_extents; @@ -983,7 +1000,8 @@ skip: sctx->stat.no_csum += nr_nodatacsum_sectors; sctx->stat.read_errors += stripe->init_nr_io_errors; sctx->stat.csum_errors += stripe->init_nr_csum_errors; - sctx->stat.verify_errors += stripe->init_nr_meta_errors; + sctx->stat.verify_errors += stripe->init_nr_meta_errors + + stripe->init_nr_meta_gen_errors; sctx->stat.uncorrectable_errors += bitmap_weight(&stripe->error_bitmap, stripe->nr_sectors); sctx->stat.corrected_errors += nr_repaired_sectors; @@ -1029,6 +1047,8 @@ static void scrub_stripe_read_repair_worker(struct work_struct *work) stripe->nr_sectors); stripe->init_nr_meta_errors = bitmap_weight(&stripe->meta_error_bitmap, stripe->nr_sectors); + stripe->init_nr_meta_gen_errors = bitmap_weight(&stripe->meta_gen_error_bitmap, + stripe->nr_sectors); if (bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) goto out; @@ -1143,6 +1163,9 @@ static void scrub_write_endio(struct btrfs_bio *bbio) bitmap_set(&stripe->write_error_bitmap, sector_nr, bio_size >> fs_info->sectorsize_bits); spin_unlock_irqrestore(&stripe->write_error_lock, flags); + for (int i = 0; i < (bio_size >> fs_info->sectorsize_bits); i++) + btrfs_dev_stat_inc_and_print(stripe->dev, + BTRFS_DEV_STAT_WRITE_ERRS); } bio_put(&bbio->bio); @@ -1290,7 +1313,7 @@ static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *d * return 0 if it is a data stripe, 1 means parity stripe. */ static int get_raid56_logic_offset(u64 physical, int num, - struct map_lookup *map, u64 *offset, + struct btrfs_chunk_map *map, u64 *offset, u64 *stripe_start) { int i; @@ -1391,8 +1414,15 @@ static int find_first_extent_item(struct btrfs_root *extent_root, ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) return ret; + if (ret == 0) { + /* + * Key with offset -1 found, there would have to exist an extent + * item with such offset, but this is out of the valid range. + */ + btrfs_release_path(path); + return -EUCLEAN; + } - ASSERT(ret > 0); /* * Here we intentionally pass 0 as @min_objectid, as there could be * an extent item starting before @search_start. @@ -1419,14 +1449,11 @@ search_forward: if (ret > 0) break; next: - path->slots[0]++; - if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { - ret = btrfs_next_leaf(extent_root, path); - if (ret) { - /* Either no more item or fatal error */ - btrfs_release_path(path); - return ret; - } + ret = btrfs_next_item(extent_root, path); + if (ret) { + /* Either no more items or a fatal error. */ + btrfs_release_path(path); + return ret; } } btrfs_release_path(path); @@ -1505,10 +1532,12 @@ static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe) stripe->init_nr_io_errors = 0; stripe->init_nr_csum_errors = 0; stripe->init_nr_meta_errors = 0; + stripe->init_nr_meta_gen_errors = 0; stripe->error_bitmap = 0; stripe->io_error_bitmap = 0; stripe->csum_error_bitmap = 0; stripe->meta_error_bitmap = 0; + stripe->meta_gen_error_bitmap = 0; } /* @@ -1538,6 +1567,10 @@ static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg, u64 extent_gen; int ret; + if (unlikely(!extent_root || !csum_root)) { + btrfs_err(fs_info, "no valid extent or csum root for scrub"); + return -EUCLEAN; + } memset(stripe->sectors, 0, sizeof(struct scrub_sector_verification) * stripe->nr_sectors); scrub_stripe_reset_bitmaps(stripe); @@ -1645,20 +1678,105 @@ static void scrub_reset_stripe(struct scrub_stripe *stripe) } } +static u32 stripe_length(const struct scrub_stripe *stripe) +{ + ASSERT(stripe->bg); + + return min(BTRFS_STRIPE_LEN, + stripe->bg->start + stripe->bg->length - stripe->logical); +} + +static void scrub_submit_extent_sector_read(struct scrub_ctx *sctx, + struct scrub_stripe *stripe) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + struct btrfs_bio *bbio = NULL; + unsigned int nr_sectors = stripe_length(stripe) >> fs_info->sectorsize_bits; + u64 stripe_len = BTRFS_STRIPE_LEN; + int mirror = stripe->mirror_num; + int i; + + atomic_inc(&stripe->pending_io); + + for_each_set_bit(i, &stripe->extent_sector_bitmap, stripe->nr_sectors) { + struct page *page = scrub_stripe_get_page(stripe, i); + unsigned int pgoff = scrub_stripe_get_page_offset(stripe, i); + + /* We're beyond the chunk boundary, no need to read anymore. */ + if (i >= nr_sectors) + break; + + /* The current sector cannot be merged, submit the bio. */ + if (bbio && + ((i > 0 && + !test_bit(i - 1, &stripe->extent_sector_bitmap)) || + bbio->bio.bi_iter.bi_size >= stripe_len)) { + ASSERT(bbio->bio.bi_iter.bi_size); + atomic_inc(&stripe->pending_io); + btrfs_submit_bbio(bbio, mirror); + bbio = NULL; + } + + if (!bbio) { + struct btrfs_io_stripe io_stripe = {}; + struct btrfs_io_context *bioc = NULL; + const u64 logical = stripe->logical + + (i << fs_info->sectorsize_bits); + int err; + + io_stripe.rst_search_commit_root = true; + stripe_len = (nr_sectors - i) << fs_info->sectorsize_bits; + /* + * For RST cases, we need to manually split the bbio to + * follow the RST boundary. + */ + err = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical, + &stripe_len, &bioc, &io_stripe, &mirror); + btrfs_put_bioc(bioc); + if (err < 0) { + set_bit(i, &stripe->io_error_bitmap); + set_bit(i, &stripe->error_bitmap); + continue; + } + + bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ, + fs_info, scrub_read_endio, stripe); + bbio->bio.bi_iter.bi_sector = logical >> SECTOR_SHIFT; + } + + __bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); + } + + if (bbio) { + ASSERT(bbio->bio.bi_iter.bi_size); + atomic_inc(&stripe->pending_io); + btrfs_submit_bbio(bbio, mirror); + } + + if (atomic_dec_and_test(&stripe->pending_io)) { + wake_up(&stripe->io_wait); + INIT_WORK(&stripe->work, scrub_stripe_read_repair_worker); + queue_work(stripe->bg->fs_info->scrub_workers, &stripe->work); + } +} + static void scrub_submit_initial_read(struct scrub_ctx *sctx, struct scrub_stripe *stripe) { struct btrfs_fs_info *fs_info = sctx->fs_info; struct btrfs_bio *bbio; - unsigned int nr_sectors = min_t(u64, BTRFS_STRIPE_LEN, stripe->bg->start + - stripe->bg->length - stripe->logical) >> - fs_info->sectorsize_bits; + unsigned int nr_sectors = stripe_length(stripe) >> fs_info->sectorsize_bits; int mirror = stripe->mirror_num; ASSERT(stripe->bg); ASSERT(stripe->mirror_num > 0); ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state)); + if (btrfs_need_stripe_tree_update(fs_info, stripe->bg->flags)) { + scrub_submit_extent_sector_read(sctx, stripe); + return; + } + bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info, scrub_read_endio, stripe); @@ -1688,7 +1806,7 @@ static void scrub_submit_initial_read(struct scrub_ctx *sctx, mirror = calc_next_mirror(mirror, num_copies); } - btrfs_submit_bio(bbio, mirror); + btrfs_submit_bbio(bbio, mirror); } static bool stripe_has_metadata_error(struct scrub_stripe *stripe) @@ -1761,7 +1879,7 @@ static int flush_scrub_stripes(struct scrub_ctx *sctx) if (sctx->is_dev_replace) { /* * For dev-replace, if we know there is something wrong with - * metadata, we should immedately abort. + * metadata, we should immediately abort. */ for (int i = 0; i < nr_stripes; i++) { if (stripe_has_metadata_error(&sctx->stripes[i])) { @@ -1787,6 +1905,9 @@ static int flush_scrub_stripes(struct scrub_ctx *sctx) stripe = &sctx->stripes[i]; wait_scrub_stripe_io(stripe); + spin_lock(&sctx->stat_lock); + sctx->stat.last_physical = stripe->physical + stripe_length(stripe); + spin_unlock(&sctx->stat_lock); scrub_reset_stripe(stripe); } out: @@ -1843,7 +1964,7 @@ static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group * static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx, struct btrfs_device *scrub_dev, struct btrfs_block_group *bg, - struct map_lookup *map, + struct btrfs_chunk_map *map, u64 full_stripe_start) { DECLARE_COMPLETION_ONSTACK(io_done); @@ -1969,7 +2090,7 @@ static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx, btrfs_bio_counter_inc_blocked(fs_info); ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, full_stripe_start, - &length, &bioc, NULL, NULL, 1); + &length, &bioc, NULL, NULL); if (ret < 0) { btrfs_put_bioc(bioc); btrfs_bio_counter_dec(fs_info); @@ -2012,7 +2133,7 @@ out: */ static int scrub_simple_mirror(struct scrub_ctx *sctx, struct btrfs_block_group *bg, - struct map_lookup *map, + struct btrfs_chunk_map *map, u64 logical_start, u64 logical_length, struct btrfs_device *device, u64 physical, int mirror_num) @@ -2055,7 +2176,9 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, cur_physical, &found_logical); if (ret > 0) { /* No more extent, just update the accounting */ + spin_lock(&sctx->stat_lock); sctx->stat.last_physical = physical + logical_length; + spin_unlock(&sctx->stat_lock); ret = 0; break; } @@ -2073,7 +2196,7 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, } /* Calculate the full stripe length for simple stripe based profiles */ -static u64 simple_stripe_full_stripe_len(const struct map_lookup *map) +static u64 simple_stripe_full_stripe_len(const struct btrfs_chunk_map *map) { ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)); @@ -2082,7 +2205,7 @@ static u64 simple_stripe_full_stripe_len(const struct map_lookup *map) } /* Get the logical bytenr for the stripe */ -static u64 simple_stripe_get_logical(struct map_lookup *map, +static u64 simple_stripe_get_logical(struct btrfs_chunk_map *map, struct btrfs_block_group *bg, int stripe_index) { @@ -2099,7 +2222,7 @@ static u64 simple_stripe_get_logical(struct map_lookup *map, } /* Get the mirror number for the stripe */ -static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index) +static int simple_stripe_mirror_num(struct btrfs_chunk_map *map, int stripe_index) { ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)); @@ -2111,7 +2234,7 @@ static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index) static int scrub_simple_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, - struct map_lookup *map, + struct btrfs_chunk_map *map, struct btrfs_device *device, int stripe_index) { @@ -2144,18 +2267,17 @@ static int scrub_simple_stripe(struct scrub_ctx *sctx, static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, - struct extent_map *em, + struct btrfs_chunk_map *map, struct btrfs_device *scrub_dev, int stripe_index) { struct btrfs_fs_info *fs_info = sctx->fs_info; - struct map_lookup *map = em->map_lookup; const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK; const u64 chunk_logical = bg->start; int ret; int ret2; u64 physical = map->stripes[stripe_index].physical; - const u64 dev_stripe_len = btrfs_calc_stripe_length(em); + const u64 dev_stripe_len = btrfs_calc_stripe_length(map); const u64 physical_end = physical + dev_stripe_len; u64 logical; u64 logic_end; @@ -2253,6 +2375,10 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, stripe_logical += chunk_logical; ret = scrub_raid56_parity_stripe(sctx, scrub_dev, bg, map, stripe_logical); + spin_lock(&sctx->stat_lock); + sctx->stat.last_physical = min(physical + BTRFS_STRIPE_LEN, + physical_end); + spin_unlock(&sctx->stat_lock); if (ret) goto out; goto next; @@ -2318,17 +2444,12 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, u64 dev_extent_len) { struct btrfs_fs_info *fs_info = sctx->fs_info; - struct extent_map_tree *map_tree = &fs_info->mapping_tree; - struct map_lookup *map; - struct extent_map *em; + struct btrfs_chunk_map *map; int i; int ret = 0; - read_lock(&map_tree->lock); - em = lookup_extent_mapping(map_tree, bg->start, bg->length); - read_unlock(&map_tree->lock); - - if (!em) { + map = btrfs_find_chunk_map(fs_info, bg->start, bg->length); + if (!map) { /* * Might have been an unused block group deleted by the cleaner * kthread or relocation. @@ -2340,22 +2461,21 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, return ret; } - if (em->start != bg->start) + if (map->start != bg->start) goto out; - if (em->len < dev_extent_len) + if (map->chunk_len < dev_extent_len) goto out; - map = em->map_lookup; for (i = 0; i < map->num_stripes; ++i) { if (map->stripes[i].dev->bdev == scrub_dev->bdev && map->stripes[i].physical == dev_offset) { - ret = scrub_stripe(sctx, bg, em, scrub_dev, i); + ret = scrub_stripe(sctx, bg, map, scrub_dev, i); if (ret) goto out; } } out: - free_extent_map(em); + btrfs_free_chunk_map(map); return ret; } @@ -2364,19 +2484,15 @@ static int finish_extent_writes_for_zoned(struct btrfs_root *root, struct btrfs_block_group *cache) { struct btrfs_fs_info *fs_info = cache->fs_info; - struct btrfs_trans_handle *trans; if (!btrfs_is_zoned(fs_info)) return 0; btrfs_wait_block_group_reservations(cache); btrfs_wait_nocow_writers(cache); - btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length); + btrfs_wait_ordered_roots(fs_info, U64_MAX, cache); - trans = btrfs_join_transaction(root); - if (IS_ERR(trans)) - return PTR_ERR(trans); - return btrfs_commit_transaction(trans); + return btrfs_commit_current_transaction(root); } static noinline_for_stack @@ -2607,8 +2723,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, */ if (sctx->is_dev_replace) { btrfs_wait_nocow_writers(cache); - btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, - cache->length); + btrfs_wait_ordered_roots(fs_info, U64_MAX, cache); } scrub_pause_off(fs_info); @@ -2736,7 +2851,7 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, if (scrub_dev->fs_devices != fs_info->fs_devices) gen = scrub_dev->generation; else - gen = fs_info->last_trans_committed; + gen = btrfs_get_last_trans_committed(fs_info); for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { ret = btrfs_sb_log_location(scrub_dev, i, 0, &bytenr); |