// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2011, 2012 STRATO. All rights reserved. */ #include <linux/blkdev.h> #include <linux/ratelimit.h> #include <linux/sched/mm.h> #include <crypto/hash.h> #include "ctree.h" #include "discard.h" #include "volumes.h" #include "disk-io.h" #include "ordered-data.h" #include "transaction.h" #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" #include "fs.h" #include "accessors.h" #include "file-item.h" #include "scrub.h" /* * This is only the first step towards a full-features scrub. It reads all * extent and super block and verifies the checksums. In case a bad checksum * is found or the extent cannot be read, good data will be written back if * any can be found. * * Future enhancements: * - In case an unrepairable extent is encountered, track which files are * affected and report them * - track and record media errors, throw out bad devices * - add a mode to also read unallocated space */ struct scrub_ctx; /* * The following value only influences the performance. * * This detemines 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 /* * How many groups we have for each sctx. * * This would be 8M per device, the same value as the old scrub in-flight bios * size limit. */ #define SCRUB_GROUPS_PER_SCTX 16 #define SCRUB_TOTAL_STRIPES (SCRUB_GROUPS_PER_SCTX * SCRUB_STRIPES_PER_GROUP) /* * The following value times PAGE_SIZE needs to be large enough to match the * largest node/leaf/sector size that shall be supported. */ #define SCRUB_MAX_SECTORS_PER_BLOCK (BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K) /* Represent one sector and its needed info to verify the content. */ struct scrub_sector_verification { bool is_metadata; union { /* * Csum pointer for data csum verification. Should point to a * sector csum inside scrub_stripe::csums. * * NULL if this data sector has no csum. */ u8 *csum; /* * Extra info for metadata verification. All sectors inside a * tree block share the same generation. */ u64 generation; }; }; enum scrub_stripe_flags { /* Set when @mirror_num, @dev, @physical and @logical are set. */ SCRUB_STRIPE_FLAG_INITIALIZED, /* Set when the read-repair is finished. */ SCRUB_STRIPE_FLAG_REPAIR_DONE, /* * Set for data stripes if it's triggered from P/Q stripe. * During such scrub, we should not report errors in data stripes, nor * update the accounting. */ SCRUB_STRIPE_FLAG_NO_REPORT, }; #define SCRUB_STRIPE_PAGES (BTRFS_STRIPE_LEN / PAGE_SIZE) /* * Represent one contiguous range with a length of BTRFS_STRIPE_LEN. */ struct scrub_stripe { struct scrub_ctx *sctx; struct btrfs_block_group *bg; struct page *pages[SCRUB_STRIPE_PAGES]; struct scrub_sector_verification *sectors; struct btrfs_device *dev; u64 logical; u64 physical; u16 mirror_num; /* Should be BTRFS_STRIPE_LEN / sectorsize. */ u16 nr_sectors; /* * How many data/meta extents are in this stripe. Only for scrub status * reporting purposes. */ u16 nr_data_extents; u16 nr_meta_extents; atomic_t pending_io; wait_queue_head_t io_wait; wait_queue_head_t repair_wait; /* * Indicate the states of the stripe. Bits are defined in * scrub_stripe_flags enum. */ unsigned long state; /* Indicate which sectors are covered by extent items. */ unsigned long extent_sector_bitmap; /* * The errors hit during the initial read of the stripe. * * Would be utilized for error reporting and repair. * * The remaining init_nr_* records the number of errors hit, only used * by error reporting. */ unsigned long init_error_bitmap; unsigned int init_nr_io_errors; unsigned int init_nr_csum_errors; unsigned int init_nr_meta_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; * * IO and csum errors can happen for both metadata and data. */ unsigned long error_bitmap; unsigned long io_error_bitmap; unsigned long csum_error_bitmap; unsigned long meta_error_bitmap; /* For writeback (repair or replace) error reporting. */ unsigned long write_error_bitmap; /* Writeback can be concurrent, thus we need to protect the bitmap. */ spinlock_t write_error_lock; /* * Checksum for the whole stripe if this stripe is inside a data block * group. */ u8 *csums; struct work_struct work; }; struct scrub_ctx { struct scrub_stripe stripes[SCRUB_TOTAL_STRIPES]; struct scrub_stripe *raid56_data_stripes; struct btrfs_fs_info *fs_info; struct btrfs_path extent_path; struct btrfs_path csum_path; int first_free; 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; u64 throttle_sent; int is_dev_replace; u64 write_pointer; struct mutex wr_lock; struct btrfs_device *wr_tgtdev; /* * statistics */ struct btrfs_scrub_progress stat; spinlock_t stat_lock; /* * Use a ref counter to avoid use-after-free issues. Scrub workers * decrement bios_in_flight and workers_pending and then do a wakeup * on the list_wait wait queue. We must ensure the main scrub task * doesn't free the scrub context before or while the workers are * doing the wakeup() call. */ refcount_t refs; }; struct scrub_warning { struct btrfs_path *path; u64 extent_item_size; const char *errstr; u64 physical; u64 logical; struct btrfs_device *dev; }; static void release_scrub_stripe(struct scrub_stripe *stripe) { if (!stripe) return; for (int i = 0; i < SCRUB_STRIPE_PAGES; i++) { if (stripe->pages[i]) __free_page(stripe->pages[i]); stripe->pages[i] = NULL; } kfree(stripe->sectors); kfree(stripe->csums); stripe->sectors = NULL; stripe->csums = NULL; stripe->sctx = NULL; stripe->state = 0; } static int init_scrub_stripe(struct btrfs_fs_info *fs_info, struct scrub_stripe *stripe) { int ret; memset(stripe, 0, sizeof(*stripe)); stripe->nr_sectors = BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits; stripe->state = 0; init_waitqueue_head(&stripe->io_wait); init_waitqueue_head(&stripe->repair_wait); atomic_set(&stripe->pending_io, 0); spin_lock_init(&stripe->write_error_lock); ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages); if (ret < 0) goto error; stripe->sectors = kcalloc(stripe->nr_sectors, sizeof(struct scrub_sector_verification), GFP_KERNEL); if (!stripe->sectors) goto error; stripe->csums = kcalloc(BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits, fs_info->csum_size, GFP_KERNEL); if (!stripe->csums) goto error; return 0; error: release_scrub_stripe(stripe); return -ENOMEM; } static void wait_scrub_stripe_io(struct scrub_stripe *stripe) { wait_event(stripe->io_wait, atomic_read(&stripe->pending_io) == 0); } static void scrub_put_ctx(struct scrub_ctx *sctx); static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) { while (atomic_read(&fs_info->scrub_pause_req)) { mutex_unlock(&fs_info->scrub_lock); wait_event(fs_info->scrub_pause_wait, atomic_read(&fs_info->scrub_pause_req) == 0); mutex_lock(&fs_info->scrub_lock); } } static void scrub_pause_on(struct btrfs_fs_info *fs_info) { atomic_inc(&fs_info->scrubs_paused); wake_up(&fs_info->scrub_pause_wait); } static void scrub_pause_off(struct btrfs_fs_info *fs_info) { mutex_lock(&fs_info->scrub_lock); __scrub_blocked_if_needed(fs_info); atomic_dec(&fs_info->scrubs_paused); mutex_unlock(&fs_info->scrub_lock); wake_up(&fs_info->scrub_pause_wait); } static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) { scrub_pause_on(fs_info); scrub_pause_off(fs_info); } static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) { int i; if (!sctx) return; for (i = 0; i < SCRUB_TOTAL_STRIPES; i++) release_scrub_stripe(&sctx->stripes[i]); kvfree(sctx); } static void scrub_put_ctx(struct scrub_ctx *sctx) { if (refcount_dec_and_test(&sctx->refs)) scrub_free_ctx(sctx); } static noinline_for_stack struct scrub_ctx *scrub_setup_ctx( struct btrfs_fs_info *fs_info, int is_dev_replace) { struct scrub_ctx *sctx; int i; /* Since sctx has inline 128 stripes, it can go beyond 64K easily. Use * kvzalloc(). */ sctx = kvzalloc(sizeof(*sctx), GFP_KERNEL); if (!sctx) goto nomem; refcount_set(&sctx->refs, 1); sctx->is_dev_replace = is_dev_replace; sctx->fs_info = fs_info; sctx->extent_path.search_commit_root = 1; sctx->extent_path.skip_locking = 1; sctx->csum_path.search_commit_root = 1; sctx->csum_path.skip_locking = 1; for (i = 0; i < SCRUB_TOTAL_STRIPES; i++) { int ret; ret = init_scrub_stripe(fs_info, &sctx->stripes[i]); if (ret < 0) goto nomem; sctx->stripes[i].sctx = sctx; } sctx->first_free = 0; atomic_set(&sctx->cancel_req, 0); spin_lock_init(&sctx->stat_lock); sctx->throttle_deadline = 0; mutex_init(&sctx->wr_lock); if (is_dev_replace) { WARN_ON(!fs_info->dev_replace.tgtdev); sctx->wr_tgtdev = fs_info->dev_replace.tgtdev; } return sctx; nomem: scrub_free_ctx(sctx); return ERR_PTR(-ENOMEM); } static int scrub_print_warning_inode(u64 inum, u64 offset, u64 num_bytes, u64 root, void *warn_ctx) { u32 nlink; int ret; int i; unsigned nofs_flag; struct extent_buffer *eb; struct btrfs_inode_item *inode_item; struct scrub_warning *swarn = warn_ctx; struct btrfs_fs_info *fs_info = swarn->dev->fs_info; struct inode_fs_paths *ipath = NULL; struct btrfs_root *local_root; struct btrfs_key key; local_root = btrfs_get_fs_root(fs_info, root, true); if (IS_ERR(local_root)) { ret = PTR_ERR(local_root); goto err; } /* * this makes the path point to (inum INODE_ITEM ioff) */ key.objectid = inum; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0); if (ret) { btrfs_put_root(local_root); btrfs_release_path(swarn->path); goto err; } eb = swarn->path->nodes[0]; inode_item = btrfs_item_ptr(eb, swarn->path->slots[0], struct btrfs_inode_item); nlink = btrfs_inode_nlink(eb, inode_item); btrfs_release_path(swarn->path); /* * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub * uses GFP_NOFS in this context, so we keep it consistent but it does * not seem to be strictly necessary. */ nofs_flag = memalloc_nofs_save(); ipath = init_ipath(4096, local_root, swarn->path); memalloc_nofs_restore(nofs_flag); if (IS_ERR(ipath)) { btrfs_put_root(local_root); ret = PTR_ERR(ipath); ipath = NULL; goto err; } ret = paths_from_inode(inum, ipath); if (ret < 0) goto err; /* * we deliberately ignore the bit ipath might have been too small to * hold all of the paths here */ for (i = 0; i < ipath->fspath->elem_cnt; ++i) btrfs_warn_in_rcu(fs_info, "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %u, links %u (path: %s)", swarn->errstr, swarn->logical, btrfs_dev_name(swarn->dev), swarn->physical, root, inum, offset, fs_info->sectorsize, nlink, (char *)(unsigned long)ipath->fspath->val[i]); btrfs_put_root(local_root); free_ipath(ipath); return 0; err: btrfs_warn_in_rcu(fs_info, "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d", swarn->errstr, swarn->logical, btrfs_dev_name(swarn->dev), swarn->physical, root, inum, offset, ret); free_ipath(ipath); return 0; } static void scrub_print_common_warning(const char *errstr, struct btrfs_device *dev, bool is_super, u64 logical, u64 physical) { struct btrfs_fs_info *fs_info = dev->fs_info; struct btrfs_path *path; struct btrfs_key found_key; struct extent_buffer *eb; struct btrfs_extent_item *ei; struct scrub_warning swarn; u64 flags = 0; u32 item_size; int ret; /* Super block error, no need to search extent tree. */ if (is_super) { btrfs_warn_in_rcu(fs_info, "%s on device %s, physical %llu", errstr, btrfs_dev_name(dev), physical); return; } path = btrfs_alloc_path(); if (!path) return; swarn.physical = physical; swarn.logical = logical; swarn.errstr = errstr; swarn.dev = NULL; ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, &flags); if (ret < 0) goto out; swarn.extent_item_size = found_key.offset; eb = path->nodes[0]; ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); item_size = btrfs_item_size(eb, path->slots[0]); if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { unsigned long ptr = 0; u8 ref_level; u64 ref_root; while (true) { ret = tree_backref_for_extent(&ptr, eb, &found_key, ei, item_size, &ref_root, &ref_level); if (ret < 0) { btrfs_warn(fs_info, "failed to resolve tree backref for logical %llu: %d", swarn.logical, ret); break; } if (ret > 0) break; btrfs_warn_in_rcu(fs_info, "%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu", errstr, swarn.logical, btrfs_dev_name(dev), swarn.physical, (ref_level ? "node" : "leaf"), ref_level, ref_root); } btrfs_release_path(path); } else { struct btrfs_backref_walk_ctx ctx = { 0 }; btrfs_release_path(path); ctx.bytenr = found_key.objectid; ctx.extent_item_pos = swarn.logical - found_key.objectid; ctx.fs_info = fs_info; swarn.path = path; swarn.dev = dev; iterate_extent_inodes(&ctx, true, scrub_print_warning_inode, &swarn); } out: btrfs_free_path(path); } static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical) { int ret = 0; u64 length; if (!btrfs_is_zoned(sctx->fs_info)) return 0; if (!btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) return 0; if (sctx->write_pointer < physical) { length = physical - sctx->write_pointer; ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev, sctx->write_pointer, length); if (!ret) sctx->write_pointer = physical; } return ret; } static struct page *scrub_stripe_get_page(struct scrub_stripe *stripe, int sector_nr) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; int page_index = (sector_nr << fs_info->sectorsize_bits) >> PAGE_SHIFT; return stripe->pages[page_index]; } static unsigned int scrub_stripe_get_page_offset(struct scrub_stripe *stripe, int sector_nr) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; return offset_in_page(sector_nr << fs_info->sectorsize_bits); } static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits; const u64 logical = stripe->logical + (sector_nr << fs_info->sectorsize_bits); const struct page *first_page = scrub_stripe_get_page(stripe, sector_nr); const unsigned int first_off = scrub_stripe_get_page_offset(stripe, sector_nr); SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); u8 on_disk_csum[BTRFS_CSUM_SIZE]; u8 calculated_csum[BTRFS_CSUM_SIZE]; struct btrfs_header *header; /* * Here we don't have a good way to attach the pages (and subpages) * to a dummy extent buffer, thus we have to directly grab the members * from pages. */ header = (struct btrfs_header *)(page_address(first_page) + first_off); 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->error_bitmap, sector_nr, sectors_per_tree); btrfs_warn_rl(fs_info, "tree block %llu mirror %u has bad bytenr, has %llu want %llu", logical, stripe->mirror_num, btrfs_stack_header_bytenr(header), logical); return; } if (memcmp(header->fsid, fs_info->fs_devices->metadata_uuid, BTRFS_FSID_SIZE) != 0) { 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 fsid, has %pU want %pU", logical, stripe->mirror_num, header->fsid, fs_info->fs_devices->fsid); return; } if (memcmp(header->chunk_tree_uuid, fs_info->chunk_tree_uuid, BTRFS_UUID_SIZE) != 0) { 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 chunk tree uuid, has %pU want %pU", logical, stripe->mirror_num, header->chunk_tree_uuid, fs_info->chunk_tree_uuid); return; } /* Now check tree block csum. */ shash->tfm = fs_info->csum_shash; crypto_shash_init(shash); crypto_shash_update(shash, page_address(first_page) + first_off + BTRFS_CSUM_SIZE, fs_info->sectorsize - BTRFS_CSUM_SIZE); for (int i = sector_nr + 1; i < sector_nr + sectors_per_tree; i++) { struct page *page = scrub_stripe_get_page(stripe, i); unsigned int page_off = scrub_stripe_get_page_offset(stripe, i); crypto_shash_update(shash, page_address(page) + page_off, fs_info->sectorsize); } crypto_shash_final(shash, calculated_csum); if (memcmp(calculated_csum, on_disk_csum, fs_info->csum_size) != 0) { 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 csum, has " CSUM_FMT " want " CSUM_FMT, logical, stripe->mirror_num, CSUM_FMT_VALUE(fs_info->csum_size, on_disk_csum), CSUM_FMT_VALUE(fs_info->csum_size, calculated_csum)); return; } 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->error_bitmap, sector_nr, sectors_per_tree); btrfs_warn_rl(fs_info, "tree block %llu mirror %u has bad generation, has %llu want %llu", logical, stripe->mirror_num, btrfs_stack_header_generation(header), stripe->sectors[sector_nr].generation); return; } 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); } static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; struct scrub_sector_verification *sector = &stripe->sectors[sector_nr]; const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits; struct page *page = scrub_stripe_get_page(stripe, sector_nr); unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr); u8 csum_buf[BTRFS_CSUM_SIZE]; int ret; ASSERT(sector_nr >= 0 && sector_nr < stripe->nr_sectors); /* Sector not utilized, skip it. */ if (!test_bit(sector_nr, &stripe->extent_sector_bitmap)) return; /* IO error, no need to check. */ if (test_bit(sector_nr, &stripe->io_error_bitmap)) return; /* Metadata, verify the full tree block. */ if (sector->is_metadata) { /* * Check if the tree block crosses the stripe boudary. If * crossed the boundary, we cannot verify it but only give a * warning. * * This can only happen on a very old filesystem where chunks * are not ensured to be stripe aligned. */ if (unlikely(sector_nr + sectors_per_tree > stripe->nr_sectors)) { btrfs_warn_rl(fs_info, "tree block at %llu crosses stripe boundary %llu", stripe->logical + (sector_nr << fs_info->sectorsize_bits), stripe->logical); return; } scrub_verify_one_metadata(stripe, sector_nr); return; } /* * Data is easier, we just verify the data csum (if we have it). For * cases without csum, we have no other choice but to trust it. */ if (!sector->csum) { clear_bit(sector_nr, &stripe->error_bitmap); return; } ret = btrfs_check_sector_csum(fs_info, page, pgoff, csum_buf, sector->csum); if (ret < 0) { set_bit(sector_nr, &stripe->csum_error_bitmap); set_bit(sector_nr, &stripe->error_bitmap); } else { clear_bit(sector_nr, &stripe->csum_error_bitmap); clear_bit(sector_nr, &stripe->error_bitmap); } } /* Verify specified sectors of a stripe. */ static void scrub_verify_one_stripe(struct scrub_stripe *stripe, unsigned long bitmap) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits; int sector_nr; for_each_set_bit(sector_nr, &bitmap, stripe->nr_sectors) { scrub_verify_one_sector(stripe, sector_nr); if (stripe->sectors[sector_nr].is_metadata) sector_nr += sectors_per_tree - 1; } } static int calc_sector_number(struct scrub_stripe *stripe, struct bio_vec *first_bvec) { int i; for (i = 0; i < stripe->nr_sectors; i++) { if (scrub_stripe_get_page(stripe, i) == first_bvec->bv_page && scrub_stripe_get_page_offset(stripe, i) == first_bvec->bv_offset) break; } ASSERT(i < stripe->nr_sectors); return i; } /* * Repair read is different to the regular read: * * - Only reads the failed sectors * - May have extra blocksize limits */ static void scrub_repair_read_endio(struct btrfs_bio *bbio) { struct scrub_stripe *stripe = bbio->private; struct btrfs_fs_info *fs_info = stripe->bg->fs_info; struct bio_vec *bvec; int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio)); u32 bio_size = 0; int i; ASSERT(sector_nr < stripe->nr_sectors); bio_for_each_bvec_all(bvec, &bbio->bio, i) bio_size += bvec->bv_len; if (bbio->bio.bi_status) { bitmap_set(&stripe->io_error_bitmap, sector_nr, bio_size >> fs_info->sectorsize_bits); bitmap_set(&stripe->error_bitmap, sector_nr, bio_size >> fs_info->sectorsize_bits); } else { bitmap_clear(&stripe->io_error_bitmap, sector_nr, bio_size >> fs_info->sectorsize_bits); } bio_put(&bbio->bio); if (atomic_dec_and_test(&stripe->pending_io)) wake_up(&stripe->io_wait); } static int calc_next_mirror(int mirror, int num_copies) { ASSERT(mirror <= num_copies); return (mirror + 1 > num_copies) ? 1 : mirror + 1; } static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe, int mirror, int blocksize, bool wait) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; struct btrfs_bio *bbio = NULL; const unsigned long old_error_bitmap = stripe->error_bitmap; int i; ASSERT(stripe->mirror_num >= 1); ASSERT(atomic_read(&stripe->pending_io) == 0); for_each_set_bit(i, &old_error_bitmap, stripe->nr_sectors) { struct page *page; int pgoff; int ret; page = scrub_stripe_get_page(stripe, i); pgoff = scrub_stripe_get_page_offset(stripe, i); /* The current sector cannot be merged, submit the bio. */ if (bbio && ((i > 0 && !test_bit(i - 1, &stripe->error_bitmap)) || bbio->bio.bi_iter.bi_size >= blocksize)) { ASSERT(bbio->bio.bi_iter.bi_size); atomic_inc(&stripe->pending_io); btrfs_submit_bio(bbio, mirror); if (wait) wait_scrub_stripe_io(stripe); bbio = NULL; } if (!bbio) { bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ, fs_info, scrub_repair_read_endio, stripe); bbio->bio.bi_iter.bi_sector = (stripe->logical + (i << fs_info->sectorsize_bits)) >> SECTOR_SHIFT; } ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); ASSERT(ret == fs_info->sectorsize); } if (bbio) { ASSERT(bbio->bio.bi_iter.bi_size); atomic_inc(&stripe->pending_io); btrfs_submit_bio(bbio, mirror); if (wait) wait_scrub_stripe_io(stripe); } } static void scrub_stripe_report_errors(struct scrub_ctx *sctx, struct scrub_stripe *stripe) { static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); struct btrfs_fs_info *fs_info = sctx->fs_info; struct btrfs_device *dev = NULL; u64 physical = 0; int nr_data_sectors = 0; int nr_meta_sectors = 0; int nr_nodatacsum_sectors = 0; int nr_repaired_sectors = 0; int sector_nr; if (test_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state)) return; /* * Init needed infos for error reporting. * * Although our scrub_stripe infrastucture 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)) { u64 mapped_len = fs_info->sectorsize; struct btrfs_io_context *bioc = NULL; int stripe_index = stripe->mirror_num - 1; int ret; /* For scrub, our mirror_num should always start at 1. */ ASSERT(stripe->mirror_num >= 1); ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, stripe->logical, &mapped_len, &bioc, NULL, NULL, 1); /* * If we failed, dev will be NULL, and later detailed reports * will just be skipped. */ if (ret < 0) goto skip; physical = bioc->stripes[stripe_index].physical; dev = bioc->stripes[stripe_index].dev; btrfs_put_bioc(bioc); } skip: for_each_set_bit(sector_nr, &stripe->extent_sector_bitmap, stripe->nr_sectors) { bool repaired = false; if (stripe->sectors[sector_nr].is_metadata) { nr_meta_sectors++; } else { nr_data_sectors++; if (!stripe->sectors[sector_nr].csum) nr_nodatacsum_sectors++; } if (test_bit(sector_nr, &stripe->init_error_bitmap) && !test_bit(sector_nr, &stripe->error_bitmap)) { nr_repaired_sectors++; repaired = true; } /* Good sector from the beginning, nothing need to be done. */ if (!test_bit(sector_nr, &stripe->init_error_bitmap)) continue; /* * Report error for the corrupted sectors. If repaired, just * output the message of repaired message. */ if (repaired) { if (dev) { btrfs_err_rl_in_rcu(fs_info, "fixed up error at logical %llu on dev %s physical %llu", stripe->logical, btrfs_dev_name(dev), physical); } else { btrfs_err_rl_in_rcu(fs_info, "fixed up error at logical %llu on mirror %u", stripe->logical, stripe->mirror_num); } continue; } /* The remaining are all for unrepaired. */ if (dev) { btrfs_err_rl_in_rcu(fs_info, "unable to fixup (regular) error at logical %llu on dev %s physical %llu", stripe->logical, btrfs_dev_name(dev), physical); } else { btrfs_err_rl_in_rcu(fs_info, "unable to fixup (regular) error at logical %llu on mirror %u", stripe->logical, stripe->mirror_num); } if (test_bit(sector_nr, &stripe->io_error_bitmap)) if (__ratelimit(&rs) && dev) scrub_print_common_warning("i/o error", dev, false, stripe->logical, physical); if (test_bit(sector_nr, &stripe->csum_error_bitmap)) if (__ratelimit(&rs) && dev) scrub_print_common_warning("checksum error", dev, false, stripe->logical, physical); if (test_bit(sector_nr, &stripe->meta_error_bitmap)) if (__ratelimit(&rs) && dev) scrub_print_common_warning("header error", dev, false, stripe->logical, physical); } spin_lock(&sctx->stat_lock); sctx->stat.data_extents_scrubbed += stripe->nr_data_extents; sctx->stat.tree_extents_scrubbed += stripe->nr_meta_extents; sctx->stat.data_bytes_scrubbed += nr_data_sectors << fs_info->sectorsize_bits; sctx->stat.tree_bytes_scrubbed += nr_meta_sectors << fs_info->sectorsize_bits; 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.uncorrectable_errors += bitmap_weight(&stripe->error_bitmap, stripe->nr_sectors); sctx->stat.corrected_errors += nr_repaired_sectors; spin_unlock(&sctx->stat_lock); } static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe, unsigned long write_bitmap, bool dev_replace); /* * The main entrance for all read related scrub work, including: * * - Wait for the initial read to finish * - Verify and locate any bad sectors * - Go through the remaining mirrors and try to read as large blocksize as * possible * - Go through all mirrors (including the failed mirror) sector-by-sector * - Submit writeback for repaired sectors * * Writeback for dev-replace does not happen here, it needs extra * synchronization for zoned devices. */ static void scrub_stripe_read_repair_worker(struct work_struct *work) { struct scrub_stripe *stripe = container_of(work, struct scrub_stripe, work); struct scrub_ctx *sctx = stripe->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; int num_copies = btrfs_num_copies(fs_info, stripe->bg->start, stripe->bg->length); unsigned long repaired; int mirror; int i; ASSERT(stripe->mirror_num > 0); wait_scrub_stripe_io(stripe); scrub_verify_one_stripe(stripe, stripe->extent_sector_bitmap); /* Save the initial failed bitmap for later repair and report usage. */ stripe->init_error_bitmap = stripe->error_bitmap; stripe->init_nr_io_errors = bitmap_weight(&stripe->io_error_bitmap, stripe->nr_sectors); stripe->init_nr_csum_errors = bitmap_weight(&stripe->csum_error_bitmap, stripe->nr_sectors); stripe->init_nr_meta_errors = bitmap_weight(&stripe->meta_error_bitmap, stripe->nr_sectors); if (bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) goto out; /* * Try all remaining mirrors. * * Here we still try to read as large block as possible, as this is * faster and we have extra safety nets to rely on. */ for (mirror = calc_next_mirror(stripe->mirror_num, num_copies); mirror != stripe->mirror_num; mirror = calc_next_mirror(mirror, num_copies)) { const unsigned long old_error_bitmap = stripe->error_bitmap; scrub_stripe_submit_repair_read(stripe, mirror, BTRFS_STRIPE_LEN, false); wait_scrub_stripe_io(stripe); scrub_verify_one_stripe(stripe, old_error_bitmap); if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors)) goto out; } /* * Last safety net, try re-checking all mirrors, including the failed * one, sector-by-sector. * * As if one sector failed the drive's internal csum, the whole read * containing the offending sector would be marked as error. * Thus here we do sector-by-sector read. * * This can be slow, thus we only try it as the last resort. */ for (i = 0, mirror = stripe->mirror_num; i < num_copies; i++, mirror = calc_next_mirror(mirror, num_copies)) { const unsigned long old_error_bitmap = stripe->error_bitmap; scrub_stripe_submit_repair_read(stripe, mirror, fs_info->sectorsize, true); wait_scrub_stripe_io(stripe); scrub_verify_one_stripe(stripe, old_error_bitmap); if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors)) goto out; } out: /* * Submit the repaired sectors. For zoned case, we cannot do repair * in-place, but queue the bg to be relocated. */ bitmap_andnot(&repaired, &stripe->init_error_bitmap, &stripe->error_bitmap, stripe->nr_sectors); if (!sctx->readonly && !bitmap_empty(&repaired, stripe->nr_sectors)) { if (btrfs_is_zoned(fs_info)) { btrfs_repair_one_zone(fs_info, sctx->stripes[0].bg->start); } else { scrub_write_sectors(sctx, stripe, repaired, false); wait_scrub_stripe_io(stripe); } } scrub_stripe_report_errors(sctx, stripe); set_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state); wake_up(&stripe->repair_wait); } static void scrub_read_endio(struct btrfs_bio *bbio) { struct scrub_stripe *stripe = bbio->private; struct bio_vec *bvec; int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio)); int num_sectors; u32 bio_size = 0; int i; ASSERT(sector_nr < stripe->nr_sectors); bio_for_each_bvec_all(bvec, &bbio->bio, i) bio_size += bvec->bv_len; num_sectors = bio_size >> stripe->bg->fs_info->sectorsize_bits; if (bbio->bio.bi_status) { bitmap_set(&stripe->io_error_bitmap, sector_nr, num_sectors); bitmap_set(&stripe->error_bitmap, sector_nr, num_sectors); } else { bitmap_clear(&stripe->io_error_bitmap, sector_nr, num_sectors); } bio_put(&bbio->bio); 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_write_endio(struct btrfs_bio *bbio) { struct scrub_stripe *stripe = bbio->private; struct btrfs_fs_info *fs_info = stripe->bg->fs_info; struct bio_vec *bvec; int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio)); u32 bio_size = 0; int i; bio_for_each_bvec_all(bvec, &bbio->bio, i) bio_size += bvec->bv_len; if (bbio->bio.bi_status) { unsigned long flags; spin_lock_irqsave(&stripe->write_error_lock, flags); bitmap_set(&stripe->write_error_bitmap, sector_nr, bio_size >> fs_info->sectorsize_bits); spin_unlock_irqrestore(&stripe->write_error_lock, flags); } bio_put(&bbio->bio); if (atomic_dec_and_test(&stripe->pending_io)) wake_up(&stripe->io_wait); } static void scrub_submit_write_bio(struct scrub_ctx *sctx, struct scrub_stripe *stripe, struct btrfs_bio *bbio, bool dev_replace) { struct btrfs_fs_info *fs_info = sctx->fs_info; u32 bio_len = bbio->bio.bi_iter.bi_size; u32 bio_off = (bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT) - stripe->logical; fill_writer_pointer_gap(sctx, stripe->physical + bio_off); atomic_inc(&stripe->pending_io); btrfs_submit_repair_write(bbio, stripe->mirror_num, dev_replace); if (!btrfs_is_zoned(fs_info)) return; /* * For zoned writeback, queue depth must be 1, thus we must wait for * the write to finish before the next write. */ wait_scrub_stripe_io(stripe); /* * And also need to update the write pointer if write finished * successfully. */ if (!test_bit(bio_off >> fs_info->sectorsize_bits, &stripe->write_error_bitmap)) sctx->write_pointer += bio_len; } /* * Submit the write bio(s) for the sectors specified by @write_bitmap. * * Here we utilize btrfs_submit_repair_write(), which has some extra benefits: * * - Only needs logical bytenr and mirror_num * Just like the scrub read path * * - Would only result in writes to the specified mirror * Unlike the regular writeback path, which would write back to all stripes * * - Handle dev-replace and read-repair writeback differently */ static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe, unsigned long write_bitmap, bool dev_replace) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; struct btrfs_bio *bbio = NULL; int sector_nr; for_each_set_bit(sector_nr, &write_bitmap, stripe->nr_sectors) { struct page *page = scrub_stripe_get_page(stripe, sector_nr); unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr); int ret; /* We should only writeback sectors covered by an extent. */ ASSERT(test_bit(sector_nr, &stripe->extent_sector_bitmap)); /* Cannot merge with previous sector, submit the current one. */ if (bbio && sector_nr && !test_bit(sector_nr - 1, &write_bitmap)) { scrub_submit_write_bio(sctx, stripe, bbio, dev_replace); bbio = NULL; } if (!bbio) { bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_WRITE, fs_info, scrub_write_endio, stripe); bbio->bio.bi_iter.bi_sector = (stripe->logical + (sector_nr << fs_info->sectorsize_bits)) >> SECTOR_SHIFT; } ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); ASSERT(ret == fs_info->sectorsize); } if (bbio) scrub_submit_write_bio(sctx, stripe, bbio, dev_replace); } /* * 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_dev_io(struct scrub_ctx *sctx, struct btrfs_device *device, unsigned int bio_size) { const int time_slice = 1000; s64 delta; ktime_t now; u32 div; u64 bwlimit; bwlimit = READ_ONCE(device->scrub_speed_max); if (bwlimit == 0) return; /* * Slice is divided into intervals when the IO is submitted, adjust by * bwlimit and maximum of 64 intervals. */ div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024))); div = min_t(u32, 64, div); /* Start new epoch, set deadline */ now = ktime_get(); if (sctx->throttle_deadline == 0) { sctx->throttle_deadline = ktime_add_ms(now, time_slice / div); sctx->throttle_sent = 0; } /* 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 += bio_size; if (sctx->throttle_sent <= div_u64(bwlimit, div)) return; /* We're over the limit, sleep until the rest of the slice */ delta = ktime_ms_delta(sctx->throttle_deadline, now); } else { /* New request after deadline, start new epoch */ delta = 0; } if (delta) { long timeout; timeout = div_u64(delta * HZ, 1000); schedule_timeout_interruptible(timeout); } /* Next call will start the deadline period */ sctx->throttle_deadline = 0; } /* * Given a physical address, this will calculate it's * logical offset. if this is a parity stripe, it will return * the most left data stripe's logical offset. * * 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, u64 *stripe_start) { int i; int j = 0; u64 last_offset; const int data_stripes = nr_data_stripes(map); last_offset = (physical - map->stripes[num].physical) * data_stripes; if (stripe_start) *stripe_start = last_offset; *offset = last_offset; for (i = 0; i < data_stripes; i++) { u32 stripe_nr; u32 stripe_index; u32 rot; *offset = last_offset + btrfs_stripe_nr_to_offset(i); stripe_nr = (u32)(*offset >> BTRFS_STRIPE_LEN_SHIFT) / data_stripes; /* Work out the disk rotation on this stripe-set */ rot = stripe_nr % map->num_stripes; /* calculate which stripe this data locates */ rot += i; stripe_index = rot % map->num_stripes; if (stripe_index == num) return 0; if (stripe_index < num) j++; } *offset = last_offset + btrfs_stripe_nr_to_offset(j); return 1; } /* * Return 0 if the extent item range covers any byte of the range. * Return <0 if the extent item is before @search_start. * Return >0 if the extent item is after @start_start + @search_len. */ static int compare_extent_item_range(struct btrfs_path *path, u64 search_start, u64 search_len) { struct btrfs_fs_info *fs_info = path->nodes[0]->fs_info; u64 len; struct btrfs_key key; btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); ASSERT(key.type == BTRFS_EXTENT_ITEM_KEY || key.type == BTRFS_METADATA_ITEM_KEY); if (key.type == BTRFS_METADATA_ITEM_KEY) len = fs_info->nodesize; else len = key.offset; if (key.objectid + len <= search_start) return -1; if (key.objectid >= search_start + search_len) return 1; return 0; } /* * Locate one extent item which covers any byte in range * [@search_start, @search_start + @search_length) * * If the path is not initialized, we will initialize the search by doing * a btrfs_search_slot(). * If the path is already initialized, we will use the path as the initial * slot, to avoid duplicated btrfs_search_slot() calls. * * NOTE: If an extent item starts before @search_start, we will still * return the extent item. This is for data extent crossing stripe boundary. * * Return 0 if we found such extent item, and @path will point to the extent item. * Return >0 if no such extent item can be found, and @path will be released. * Return <0 if hit fatal error, and @path will be released. */ static int find_first_extent_item(struct btrfs_root *extent_root, struct btrfs_path *path, u64 search_start, u64 search_len) { struct btrfs_fs_info *fs_info = extent_root->fs_info; struct btrfs_key key; int ret; /* Continue using the existing path */ if (path->nodes[0]) goto search_forward; if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) key.type = BTRFS_METADATA_ITEM_KEY; else key.type = BTRFS_EXTENT_ITEM_KEY; key.objectid = search_start; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) return ret; ASSERT(ret > 0); /* * Here we intentionally pass 0 as @min_objectid, as there could be * an extent item starting before @search_start. */ ret = btrfs_previous_extent_item(extent_root, path, 0); if (ret < 0) return ret; /* * No matter whether we have found an extent item, the next loop will * properly do every check on the key. */ search_forward: while (true) { btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid >= search_start + search_len) break; if (key.type != BTRFS_METADATA_ITEM_KEY && key.type != BTRFS_EXTENT_ITEM_KEY) goto next; ret = compare_extent_item_range(path, search_start, search_len); if (ret == 0) return ret; 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; } } } btrfs_release_path(path); return 1; } static void get_extent_info(struct btrfs_path *path, u64 *extent_start_ret, u64 *size_ret, u64 *flags_ret, u64 *generation_ret) { struct btrfs_key key; struct btrfs_extent_item *ei; btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); ASSERT(key.type == BTRFS_METADATA_ITEM_KEY || key.type == BTRFS_EXTENT_ITEM_KEY); *extent_start_ret = key.objectid; if (key.type == BTRFS_METADATA_ITEM_KEY) *size_ret = path->nodes[0]->fs_info->nodesize; else *size_ret = key.offset; ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item); *flags_ret = btrfs_extent_flags(path->nodes[0], ei); *generation_ret = btrfs_extent_generation(path->nodes[0], ei); } static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical, u64 physical, u64 physical_end) { struct btrfs_fs_info *fs_info = sctx->fs_info; int ret = 0; if (!btrfs_is_zoned(fs_info)) return 0; mutex_lock(&sctx->wr_lock); if (sctx->write_pointer < physical_end) { ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical, physical, sctx->write_pointer); if (ret) btrfs_err(fs_info, "zoned: failed to recover write pointer"); } mutex_unlock(&sctx->wr_lock); btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical); return ret; } static void fill_one_extent_info(struct btrfs_fs_info *fs_info, struct scrub_stripe *stripe, u64 extent_start, u64 extent_len, u64 extent_flags, u64 extent_gen) { for (u64 cur_logical = max(stripe->logical, extent_start); cur_logical < min(stripe->logical + BTRFS_STRIPE_LEN, extent_start + extent_len); cur_logical += fs_info->sectorsize) { const int nr_sector = (cur_logical - stripe->logical) >> fs_info->sectorsize_bits; struct scrub_sector_verification *sector = &stripe->sectors[nr_sector]; set_bit(nr_sector, &stripe->extent_sector_bitmap); if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { sector->is_metadata = true; sector->generation = extent_gen; } } } static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe) { stripe->extent_sector_bitmap = 0; stripe->init_error_bitmap = 0; stripe->init_nr_io_errors = 0; stripe->init_nr_csum_errors = 0; stripe->init_nr_meta_errors = 0; stripe->error_bitmap = 0; stripe->io_error_bitmap = 0; stripe->csum_error_bitmap = 0; stripe->meta_error_bitmap = 0; } /* * Locate one stripe which has at least one extent in its range. * * Return 0 if found such stripe, and store its info into @stripe. * Return >0 if there is no such stripe in the specified range. * Return <0 for error. */ static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg, struct btrfs_path *extent_path, struct btrfs_path *csum_path, struct btrfs_device *dev, u64 physical, int mirror_num, u64 logical_start, u32 logical_len, struct scrub_stripe *stripe) { struct btrfs_fs_info *fs_info = bg->fs_info; struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start); struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bg->start); const u64 logical_end = logical_start + logical_len; u64 cur_logical = logical_start; u64 stripe_end; u64 extent_start; u64 extent_len; u64 extent_flags; u64 extent_gen; int ret; memset(stripe->sectors, 0, sizeof(struct scrub_sector_verification) * stripe->nr_sectors); scrub_stripe_reset_bitmaps(stripe); /* The range must be inside the bg. */ ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length); ret = find_first_extent_item(extent_root, extent_path, logical_start, logical_len); /* Either error or not found. */ if (ret) goto out; get_extent_info(extent_path, &extent_start, &extent_len, &extent_flags, &extent_gen); if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) stripe->nr_meta_extents++; if (extent_flags & BTRFS_EXTENT_FLAG_DATA) stripe->nr_data_extents++; cur_logical = max(extent_start, cur_logical); /* * Round down to stripe boundary. * * The extra calculation against bg->start is to handle block groups * whose logical bytenr is not BTRFS_STRIPE_LEN aligned. */ stripe->logical = round_down(cur_logical - bg->start, BTRFS_STRIPE_LEN) + bg->start; stripe->physical = physical + stripe->logical - logical_start; stripe->dev = dev; stripe->bg = bg; stripe->mirror_num = mirror_num; stripe_end = stripe->logical + BTRFS_STRIPE_LEN - 1; /* Fill the first extent info into stripe->sectors[] array. */ fill_one_extent_info(fs_info, stripe, extent_start, extent_len, extent_flags, extent_gen); cur_logical = extent_start + extent_len; /* Fill the extent info for the remaining sectors. */ while (cur_logical <= stripe_end) { ret = find_first_extent_item(extent_root, extent_path, cur_logical, stripe_end - cur_logical + 1); if (ret < 0) goto out; if (ret > 0) { ret = 0; break; } get_extent_info(extent_path, &extent_start, &extent_len, &extent_flags, &extent_gen); if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) stripe->nr_meta_extents++; if (extent_flags & BTRFS_EXTENT_FLAG_DATA) stripe->nr_data_extents++; fill_one_extent_info(fs_info, stripe, extent_start, extent_len, extent_flags, extent_gen); cur_logical = extent_start + extent_len; } /* Now fill the data csum. */ if (bg->flags & BTRFS_BLOCK_GROUP_DATA) { int sector_nr; unsigned long csum_bitmap = 0; /* Csum space should have already been allocated. */ ASSERT(stripe->csums); /* * Our csum bitmap should be large enough, as BTRFS_STRIPE_LEN * should contain at most 16 sectors. */ ASSERT(BITS_PER_LONG >= BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits); ret = btrfs_lookup_csums_bitmap(csum_root, csum_path, stripe->logical, stripe_end, stripe->csums, &csum_bitmap); if (ret < 0) goto out; if (ret > 0) ret = 0; for_each_set_bit(sector_nr, &csum_bitmap, stripe->nr_sectors) { stripe->sectors[sector_nr].csum = stripe->csums + sector_nr * fs_info->csum_size; } } set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state); out: return ret; } static void scrub_reset_stripe(struct scrub_stripe *stripe) { scrub_stripe_reset_bitmaps(stripe); stripe->nr_meta_extents = 0; stripe->nr_data_extents = 0; stripe->state = 0; for (int i = 0; i < stripe->nr_sectors; i++) { stripe->sectors[i].is_metadata = false; stripe->sectors[i].csum = NULL; stripe->sectors[i].generation = 0; } } 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; int mirror = stripe->mirror_num; ASSERT(stripe->bg); ASSERT(stripe->mirror_num > 0); ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state)); bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info, scrub_read_endio, stripe); bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT; /* Read the whole range inside the chunk boundary. */ for (unsigned int cur = 0; cur < nr_sectors; cur++) { struct page *page = scrub_stripe_get_page(stripe, cur); unsigned int pgoff = scrub_stripe_get_page_offset(stripe, cur); int ret; ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); /* We should have allocated enough bio vectors. */ ASSERT(ret == fs_info->sectorsize); } atomic_inc(&stripe->pending_io); /* * For dev-replace, either user asks to avoid the source dev, or * the device is missing, we try the next mirror instead. */ if (sctx->is_dev_replace && (fs_info->dev_replace.cont_reading_from_srcdev_mode == BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID || !stripe->dev->bdev)) { int num_copies = btrfs_num_copies(fs_info, stripe->bg->start, stripe->bg->length); mirror = calc_next_mirror(mirror, num_copies); } btrfs_submit_bio(bbio, mirror); } static bool stripe_has_metadata_error(struct scrub_stripe *stripe) { int i; for_each_set_bit(i, &stripe->error_bitmap, stripe->nr_sectors) { if (stripe->sectors[i].is_metadata) { struct btrfs_fs_info *fs_info = stripe->bg->fs_info; btrfs_err(fs_info, "stripe %llu has unrepaired metadata sector at %llu", stripe->logical, stripe->logical + (i << fs_info->sectorsize_bits)); return true; } } return false; } static void submit_initial_group_read(struct scrub_ctx *sctx, unsigned int first_slot, unsigned int nr_stripes) { struct blk_plug plug; ASSERT(first_slot < SCRUB_TOTAL_STRIPES); ASSERT(first_slot + nr_stripes <= SCRUB_TOTAL_STRIPES); scrub_throttle_dev_io(sctx, sctx->stripes[0].dev, btrfs_stripe_nr_to_offset(nr_stripes)); blk_start_plug(&plug); for (int i = 0; i < nr_stripes; i++) { struct scrub_stripe *stripe = &sctx->stripes[first_slot + i]; /* Those stripes should be initialized. */ ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state)); scrub_submit_initial_read(sctx, stripe); } blk_finish_plug(&plug); } static int flush_scrub_stripes(struct scrub_ctx *sctx) { struct btrfs_fs_info *fs_info = sctx->fs_info; struct scrub_stripe *stripe; const int nr_stripes = sctx->cur_stripe; int ret = 0; if (!nr_stripes) return 0; ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state)); /* Submit the stripes which are populated but not submitted. */ if (nr_stripes % SCRUB_STRIPES_PER_GROUP) { const int first_slot = round_down(nr_stripes, SCRUB_STRIPES_PER_GROUP); submit_initial_group_read(sctx, first_slot, nr_stripes - first_slot); } for (int i = 0; i < nr_stripes; i++) { stripe = &sctx->stripes[i]; wait_event(stripe->repair_wait, test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state)); } /* Submit for dev-replace. */ if (sctx->is_dev_replace) { /* * For dev-replace, if we know there is something wrong with * metadata, we should immedately abort. */ for (int i = 0; i < nr_stripes; i++) { if (stripe_has_metadata_error(&sctx->stripes[i])) { ret = -EIO; goto out; } } for (int i = 0; i < nr_stripes; i++) { unsigned long good; stripe = &sctx->stripes[i]; ASSERT(stripe->dev == fs_info->dev_replace.srcdev); bitmap_andnot(&good, &stripe->extent_sector_bitmap, &stripe->error_bitmap, stripe->nr_sectors); scrub_write_sectors(sctx, stripe, good, true); } } /* Wait for the above writebacks to finish. */ for (int i = 0; i < nr_stripes; i++) { stripe = &sctx->stripes[i]; wait_scrub_stripe_io(stripe); scrub_reset_stripe(stripe); } out: sctx->cur_stripe = 0; return ret; } static void raid56_scrub_wait_endio(struct bio *bio) { complete(bio->bi_private); } 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, u64 *found_logical_ret) { struct scrub_stripe *stripe; int ret; /* * There should always be one slot left, as caller filling the last * slot should flush them all. */ ASSERT(sctx->cur_stripe < SCRUB_TOTAL_STRIPES); /* @found_logical_ret must be specified. */ ASSERT(found_logical_ret); stripe = &sctx->stripes[sctx->cur_stripe]; scrub_reset_stripe(stripe); ret = scrub_find_fill_first_stripe(bg, &sctx->extent_path, &sctx->csum_path, dev, physical, mirror_num, logical, length, stripe); /* Either >0 as no more extents or <0 for error. */ if (ret) return ret; *found_logical_ret = stripe->logical; sctx->cur_stripe++; /* We filled one group, submit it. */ if (sctx->cur_stripe % SCRUB_STRIPES_PER_GROUP == 0) { const int first_slot = sctx->cur_stripe - SCRUB_STRIPES_PER_GROUP; submit_initial_group_read(sctx, first_slot, SCRUB_STRIPES_PER_GROUP); } /* Last slot used, flush them all. */ if (sctx->cur_stripe == SCRUB_TOTAL_STRIPES) return flush_scrub_stripes(sctx); return 0; } static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx, struct btrfs_device *scrub_dev, struct btrfs_block_group *bg, struct map_lookup *map, u64 full_stripe_start) { DECLARE_COMPLETION_ONSTACK(io_done); struct btrfs_fs_info *fs_info = sctx->fs_info; struct btrfs_raid_bio *rbio; struct btrfs_io_context *bioc = NULL; struct btrfs_path extent_path = { 0 }; struct btrfs_path csum_path = { 0 }; struct bio *bio; struct scrub_stripe *stripe; bool all_empty = true; const int data_stripes = nr_data_stripes(map); unsigned long extent_bitmap = 0; u64 length = btrfs_stripe_nr_to_offset(data_stripes); int ret; ASSERT(sctx->raid56_data_stripes); /* * For data stripe search, we cannot re-use the same extent/csum paths, * as the data stripe bytenr may be smaller than previous extent. Thus * we have to use our own extent/csum paths. */ extent_path.search_commit_root = 1; extent_path.skip_locking = 1; csum_path.search_commit_root = 1; csum_path.skip_locking = 1; for (int i = 0; i < data_stripes; i++) { int stripe_index; int rot; u64 physical; stripe = &sctx->raid56_data_stripes[i]; rot = div_u64(full_stripe_start - bg->start, data_stripes) >> BTRFS_STRIPE_LEN_SHIFT; stripe_index = (i + rot) % map->num_stripes; physical = map->stripes[stripe_index].physical + btrfs_stripe_nr_to_offset(rot); scrub_reset_stripe(stripe); set_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state); ret = scrub_find_fill_first_stripe(bg, &extent_path, &csum_path, map->stripes[stripe_index].dev, physical, 1, full_stripe_start + btrfs_stripe_nr_to_offset(i), BTRFS_STRIPE_LEN, stripe); if (ret < 0) goto out; /* * No extent in this data stripe, need to manually mark them * initialized to make later read submission happy. */ if (ret > 0) { stripe->logical = full_stripe_start + btrfs_stripe_nr_to_offset(i); stripe->dev = map->stripes[stripe_index].dev; stripe->mirror_num = 1; set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state); } } /* Check if all data stripes are empty. */ for (int i = 0; i < data_stripes; i++) { stripe = &sctx->raid56_data_stripes[i]; if (!bitmap_empty(&stripe->extent_sector_bitmap, stripe->nr_sectors)) { all_empty = false; break; } } if (all_empty) { ret = 0; goto out; } for (int i = 0; i < data_stripes; i++) { stripe = &sctx->raid56_data_stripes[i]; scrub_submit_initial_read(sctx, stripe); } for (int i = 0; i < data_stripes; i++) { stripe = &sctx->raid56_data_stripes[i]; wait_event(stripe->repair_wait, test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state)); } /* For now, no zoned support for RAID56. */ ASSERT(!btrfs_is_zoned(sctx->fs_info)); /* * Now all data stripes are properly verified. Check if we have any * unrepaired, if so abort immediately or we could further corrupt the * P/Q stripes. * * During the loop, also populate extent_bitmap. */ for (int i = 0; i < data_stripes; i++) { unsigned long error; stripe = &sctx->raid56_data_stripes[i]; /* * We should only check the errors where there is an extent. * As we may hit an empty data stripe while it's missing. */ bitmap_and(&error, &stripe->error_bitmap, &stripe->extent_sector_bitmap, stripe->nr_sectors); if (!bitmap_empty(&error, stripe->nr_sectors)) { btrfs_err(fs_info, "unrepaired sectors detected, full stripe %llu data stripe %u errors %*pbl", full_stripe_start, i, stripe->nr_sectors, &error); ret = -EIO; goto out; } bitmap_or(&extent_bitmap, &extent_bitmap, &stripe->extent_sector_bitmap, stripe->nr_sectors); } /* Now we can check and regenerate the P/Q stripe. */ bio = bio_alloc(NULL, 1, REQ_OP_READ, GFP_NOFS); bio->bi_iter.bi_sector = full_stripe_start >> SECTOR_SHIFT; bio->bi_private = &io_done; bio->bi_end_io = raid56_scrub_wait_endio; btrfs_bio_counter_inc_blocked(fs_info); ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, full_stripe_start, &length, &bioc, NULL, NULL, 1); if (ret < 0) { btrfs_put_bioc(bioc); btrfs_bio_counter_dec(fs_info); goto out; } rbio = raid56_parity_alloc_scrub_rbio(bio, bioc, scrub_dev, &extent_bitmap, BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits); btrfs_put_bioc(bioc); if (!rbio) { ret = -ENOMEM; btrfs_bio_counter_dec(fs_info); goto out; } /* Use the recovered stripes as cache to avoid read them from disk again. */ for (int i = 0; i < data_stripes; i++) { stripe = &sctx->raid56_data_stripes[i]; raid56_parity_cache_data_pages(rbio, stripe->pages, full_stripe_start + (i << BTRFS_STRIPE_LEN_SHIFT)); } raid56_parity_submit_scrub_rbio(rbio); wait_for_completion_io(&io_done); ret = blk_status_to_errno(bio->bi_status); bio_put(bio); btrfs_bio_counter_dec(fs_info); btrfs_release_path(&extent_path); btrfs_release_path(&csum_path); out: return ret; } /* * Scrub one range which can only has simple mirror based profile. * (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in * RAID0/RAID10). * * Since we may need to handle a subset of block group, we need @logical_start * and @logical_length parameter. */ static int scrub_simple_mirror(struct scrub_ctx *sctx, struct btrfs_block_group *bg, struct map_lookup *map, u64 logical_start, u64 logical_length, struct btrfs_device *device, u64 physical, int mirror_num) { struct btrfs_fs_info *fs_info = sctx->fs_info; const u64 logical_end = logical_start + logical_length; u64 cur_logical = logical_start; int ret = 0; /* The range must be inside the bg */ ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length); /* Go through each extent items inside the logical range */ while (cur_logical < logical_end) { u64 found_logical = U64_MAX; u64 cur_physical = physical + cur_logical - logical_start; /* Canceled? */ if (atomic_read(&fs_info->scrub_cancel_req) || atomic_read(&sctx->cancel_req)) { ret = -ECANCELED; break; } /* Paused? */ if (atomic_read(&fs_info->scrub_pause_req)) { /* Push queued extents */ scrub_blocked_if_needed(fs_info); } /* Block group removed? */ spin_lock(&bg->lock); if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) { spin_unlock(&bg->lock); ret = 0; break; } spin_unlock(&bg->lock); ret = queue_scrub_stripe(sctx, bg, device, mirror_num, cur_logical, logical_end - cur_logical, cur_physical, &found_logical); if (ret > 0) { /* No more extent, just update the accounting */ sctx->stat.last_physical = physical + logical_length; ret = 0; break; } if (ret < 0) break; /* queue_scrub_stripe() returned 0, @found_logical must be updated. */ ASSERT(found_logical != U64_MAX); cur_logical = found_logical + BTRFS_STRIPE_LEN; /* Don't hold CPU for too long time */ cond_resched(); } return ret; } /* Calculate the full stripe length for simple stripe based profiles */ static u64 simple_stripe_full_stripe_len(const struct map_lookup *map) { ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)); return btrfs_stripe_nr_to_offset(map->num_stripes / map->sub_stripes); } /* Get the logical bytenr for the stripe */ static u64 simple_stripe_get_logical(struct map_lookup *map, struct btrfs_block_group *bg, int stripe_index) { ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)); ASSERT(stripe_index < map->num_stripes); /* * (stripe_index / sub_stripes) gives how many data stripes we need to * skip. */ return btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes) + bg->start; } /* Get the mirror number for the stripe */ static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index) { ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)); ASSERT(stripe_index < map->num_stripes); /* For RAID0, it's fixed to 1, for RAID10 it's 0,1,0,1... */ return stripe_index % map->sub_stripes + 1; } static int scrub_simple_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, struct map_lookup *map, struct btrfs_device *device, int stripe_index) { const u64 logical_increment = simple_stripe_full_stripe_len(map); const u64 orig_logical = simple_stripe_get_logical(map, bg, stripe_index); const u64 orig_physical = map->stripes[stripe_index].physical; const int mirror_num = simple_stripe_mirror_num(map, stripe_index); u64 cur_logical = orig_logical; u64 cur_physical = orig_physical; int ret = 0; while (cur_logical < bg->start + bg->length) { /* * Inside each stripe, RAID0 is just SINGLE, and RAID10 is * just RAID1, so we can reuse scrub_simple_mirror() to scrub * this stripe. */ ret = scrub_simple_mirror(sctx, bg, map, cur_logical, BTRFS_STRIPE_LEN, device, cur_physical, mirror_num); if (ret) return ret; /* Skip to next stripe which belongs to the target device */ cur_logical += logical_increment; /* For physical offset, we just go to next stripe */ cur_physical += BTRFS_STRIPE_LEN; } return ret; } static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, struct extent_map *em, 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 physical_end = physical + dev_stripe_len; u64 logical; u64 logic_end; /* The logical increment after finishing one stripe */ u64 increment; /* Offset inside the chunk */ u64 offset; u64 stripe_logical; int stop_loop = 0; /* Extent_path should be released by now. */ ASSERT(sctx->extent_path.nodes[0] == NULL); scrub_blocked_if_needed(fs_info); if (sctx->is_dev_replace && btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) { mutex_lock(&sctx->wr_lock); sctx->write_pointer = physical; mutex_unlock(&sctx->wr_lock); } /* Prepare the extra data stripes used by RAID56. */ if (profile & BTRFS_BLOCK_GROUP_RAID56_MASK) { ASSERT(sctx->raid56_data_stripes == NULL); sctx->raid56_data_stripes = kcalloc(nr_data_stripes(map), sizeof(struct scrub_stripe), GFP_KERNEL); if (!sctx->raid56_data_stripes) { ret = -ENOMEM; goto out; } for (int i = 0; i < nr_data_stripes(map); i++) { ret = init_scrub_stripe(fs_info, &sctx->raid56_data_stripes[i]); if (ret < 0) goto out; sctx->raid56_data_stripes[i].bg = bg; sctx->raid56_data_stripes[i].sctx = sctx; } } /* * There used to be a big double loop to handle all profiles using the * same routine, which grows larger and more gross over time. * * So here we handle each profile differently, so simpler profiles * have simpler scrubbing function. */ if (!(profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_RAID56_MASK))) { /* * Above check rules out all complex profile, the remaining * profiles are SINGLE|DUP|RAID1|RAID1C*, which is simple * mirrored duplication without stripe. * * Only @physical and @mirror_num needs to calculated using * @stripe_index. */ ret = scrub_simple_mirror(sctx, bg, map, bg->start, bg->length, scrub_dev, map->stripes[stripe_index].physical, stripe_index + 1); offset = 0; goto out; } if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) { ret = scrub_simple_stripe(sctx, bg, map, scrub_dev, stripe_index); offset = btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes); goto out; } /* Only RAID56 goes through the old code */ ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK); ret = 0; /* Calculate the logical end of the stripe */ get_raid56_logic_offset(physical_end, stripe_index, map, &logic_end, NULL); logic_end += chunk_logical; /* Initialize @offset in case we need to go to out: label */ get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL); increment = btrfs_stripe_nr_to_offset(nr_data_stripes(map)); /* * Due to the rotation, for RAID56 it's better to iterate each stripe * using their physical offset. */ while (physical < physical_end) { ret = get_raid56_logic_offset(physical, stripe_index, map, &logical, &stripe_logical); logical += chunk_logical; if (ret) { /* it is parity strip */ stripe_logical += chunk_logical; ret = scrub_raid56_parity_stripe(sctx, scrub_dev, bg, map, stripe_logical); if (ret) goto out; goto next; } /* * Now we're at a data stripe, scrub each extents in the range. * * At this stage, if we ignore the repair part, inside each data * stripe it is no different than SINGLE profile. * We can reuse scrub_simple_mirror() here, as the repair part * is still based on @mirror_num. */ ret = scrub_simple_mirror(sctx, bg, map, logical, BTRFS_STRIPE_LEN, scrub_dev, physical, 1); if (ret < 0) goto out; next: logical += increment; physical += BTRFS_STRIPE_LEN; spin_lock(&sctx->stat_lock); if (stop_loop) sctx->stat.last_physical = map->stripes[stripe_index].physical + dev_stripe_len; else sctx->stat.last_physical = physical; spin_unlock(&sctx->stat_lock); if (stop_loop) break; } out: ret2 = flush_scrub_stripes(sctx); if (!ret) ret = ret2; btrfs_release_path(&sctx->extent_path); btrfs_release_path(&sctx->csum_path); if (sctx->raid56_data_stripes) { for (int i = 0; i < nr_data_stripes(map); i++) release_scrub_stripe(&sctx->raid56_data_stripes[i]); kfree(sctx->raid56_data_stripes); sctx->raid56_data_stripes = NULL; } if (sctx->is_dev_replace && ret >= 0) { int ret2; ret2 = sync_write_pointer_for_zoned(sctx, chunk_logical + offset, map->stripes[stripe_index].physical, physical_end); if (ret2) ret = ret2; } return ret < 0 ? ret : 0; } static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, struct btrfs_block_group *bg, struct btrfs_device *scrub_dev, u64 dev_offset, 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; 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) { /* * Might have been an unused block group deleted by the cleaner * kthread or relocation. */ spin_lock(&bg->lock); if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) ret = -EINVAL; spin_unlock(&bg->lock); return ret; } if (em->start != bg->start) goto out; if (em->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); if (ret) goto out; } } out: free_extent_map(em); return ret; } 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); trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return PTR_ERR(trans); return btrfs_commit_transaction(trans); } static noinline_for_stack int scrub_enumerate_chunks(struct scrub_ctx *sctx, struct btrfs_device *scrub_dev, u64 start, u64 end) { struct btrfs_dev_extent *dev_extent = NULL; struct btrfs_path *path; struct btrfs_fs_info *fs_info = sctx->fs_info; struct btrfs_root *root = fs_info->dev_root; u64 chunk_offset; int ret = 0; int ro_set; int slot; struct extent_buffer *l; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_block_group *cache; struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; path->search_commit_root = 1; path->skip_locking = 1; key.objectid = scrub_dev->devid; key.offset = 0ull; key.type = BTRFS_DEV_EXTENT_KEY; while (1) { u64 dev_extent_len; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) break; if (ret > 0) { if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { ret = btrfs_next_leaf(root, path); if (ret < 0) break; if (ret > 0) { ret = 0; break; } } else { ret = 0; } } l = path->nodes[0]; slot = path->slots[0]; btrfs_item_key_to_cpu(l, &found_key, slot); if (found_key.objectid != scrub_dev->devid) break; if (found_key.type != BTRFS_DEV_EXTENT_KEY) break; if (found_key.offset >= end) break; if (found_key.offset < key.offset) break; dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); dev_extent_len = btrfs_dev_extent_length(l, dev_extent); if (found_key.offset + dev_extent_len <= start) goto skip; chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); /* * get a reference on the corresponding block group to prevent * the chunk from going away while we scrub it */ cache = btrfs_lookup_block_group(fs_info, chunk_offset); /* some chunks are removed but not committed to disk yet, * continue scrubbing */ if (!cache) goto skip; ASSERT(cache->start <= chunk_offset); /* * We are using the commit root to search for device extents, so * that means we could have found a device extent item from a * block group that was deleted in the current transaction. The * logical start offset of the deleted block group, stored at * @chunk_offset, might be part of the logical address range of * a new block group (which uses different physical extents). * In this case btrfs_lookup_block_group() has returned the new * block group, and its start address is less than @chunk_offset. * * We skip such new block groups, because it's pointless to * process them, as we won't find their extents because we search * for them using the commit root of the extent tree. For a device * replace it's also fine to skip it, we won't miss copying them * to the target device because we have the write duplication * setup through the regular write path (by btrfs_map_block()), * and we have committed a transaction when we started the device * replace, right after setting up the device replace state. */ if (cache->start < chunk_offset) { btrfs_put_block_group(cache); goto skip; } if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) { if (!test_bit(BLOCK_GROUP_FLAG_TO_COPY, &cache->runtime_flags)) { btrfs_put_block_group(cache); goto skip; } } /* * Make sure that while we are scrubbing the corresponding block * group doesn't get its logical address and its device extents * reused for another block group, which can possibly be of a * different type and different profile. We do this to prevent * false error detections and crashes due to bogus attempts to * repair extents. */ spin_lock(&cache->lock); if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags)) { spin_unlock(&cache->lock); btrfs_put_block_group(cache); goto skip; } btrfs_freeze_block_group(cache); spin_unlock(&cache->lock); /* * we need call btrfs_inc_block_group_ro() with scrubs_paused, * to avoid deadlock caused by: * btrfs_inc_block_group_ro() * -> btrfs_wait_for_commit() * -> btrfs_commit_transaction() * -> btrfs_scrub_pause() */ scrub_pause_on(fs_info); /* * Don't do chunk preallocation for scrub. * * This is especially important for SYSTEM bgs, or we can hit * -EFBIG from btrfs_finish_chunk_alloc() like: * 1. The only SYSTEM bg is marked RO. * Since SYSTEM bg is small, that's pretty common. * 2. New SYSTEM bg will be allocated * Due to regular version will allocate new chunk. * 3. New SYSTEM bg is empty and will get cleaned up * Before cleanup really happens, it's marked RO again. * 4. Empty SYSTEM bg get scrubbed * We go back to 2. * * This can easily boost the amount of SYSTEM chunks if cleaner * thread can't be triggered fast enough, and use up all space * of btrfs_super_block::sys_chunk_array * * While for dev replace, we need to try our best to mark block * group RO, to prevent race between: * - Write duplication * Contains latest data * - Scrub copy * Contains data from commit tree * * If target block group is not marked RO, nocow writes can * be overwritten by scrub copy, causing data corruption. * So for dev-replace, it's not allowed to continue if a block * group is not RO. */ ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace); if (!ret && sctx->is_dev_replace) { ret = finish_extent_writes_for_zoned(root, cache); if (ret) { btrfs_dec_block_group_ro(cache); scrub_pause_off(fs_info); btrfs_put_block_group(cache); break; } } if (ret == 0) { ro_set = 1; } else if (ret == -ENOSPC && !sctx->is_dev_replace && !(cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) { /* * btrfs_inc_block_group_ro return -ENOSPC when it * failed in creating new chunk for metadata. * It is not a problem for scrub, because * metadata are always cowed, and our scrub paused * commit_transactions. * * For RAID56 chunks, we have to mark them read-only * for scrub, as later we would use our own cache * out of RAID56 realm. * Thus we want the RAID56 bg to be marked RO to * prevent RMW from screwing up out cache. */ ro_set = 0; } else if (ret == -ETXTBSY) { btrfs_warn(fs_info, "skipping scrub of block group %llu due to active swapfile", cache->start); scrub_pause_off(fs_info); ret = 0; goto skip_unfreeze; } else { btrfs_warn(fs_info, "failed setting block group ro: %d", ret); btrfs_unfreeze_block_group(cache); btrfs_put_block_group(cache); scrub_pause_off(fs_info); break; } /* * Now the target block is marked RO, wait for nocow writes to * finish before dev-replace. * COW is fine, as COW never overwrites extents in commit tree. */ if (sctx->is_dev_replace) { btrfs_wait_nocow_writers(cache); btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length); } scrub_pause_off(fs_info); down_write(&dev_replace->rwsem); dev_replace->cursor_right = found_key.offset + dev_extent_len; dev_replace->cursor_left = found_key.offset; dev_replace->item_needs_writeback = 1; up_write(&dev_replace->rwsem); ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset, dev_extent_len); if (sctx->is_dev_replace && !btrfs_finish_block_group_to_copy(dev_replace->srcdev, cache, found_key.offset)) ro_set = 0; down_write(&dev_replace->rwsem); dev_replace->cursor_left = dev_replace->cursor_right; dev_replace->item_needs_writeback = 1; up_write(&dev_replace->rwsem); if (ro_set) btrfs_dec_block_group_ro(cache); /* * We might have prevented the cleaner kthread from deleting * this block group if it was already unused because we raced * and set it to RO mode first. So add it back to the unused * list, otherwise it might not ever be deleted unless a manual * balance is triggered or it becomes used and unused again. */ spin_lock(&cache->lock); if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags) && !cache->ro && cache->reserved == 0 && cache->used == 0) { spin_unlock(&cache->lock); if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) btrfs_discard_queue_work(&fs_info->discard_ctl, cache); else btrfs_mark_bg_unused(cache); } else { spin_unlock(&cache->lock); } skip_unfreeze: btrfs_unfreeze_block_group(cache); btrfs_put_block_group(cache); if (ret) break; if (sctx->is_dev_replace && atomic64_read(&dev_replace->num_write_errors) > 0) { ret = -EIO; break; } if (sctx->stat.malloc_errors > 0) { ret = -ENOMEM; break; } skip: key.offset = found_key.offset + dev_extent_len; btrfs_release_path(path); } btrfs_free_path(path); return ret; } static int scrub_one_super(struct scrub_ctx *sctx, struct btrfs_device *dev, struct page *page, u64 physical, u64 generation) { struct btrfs_fs_info *fs_info = sctx->fs_info; struct bio_vec bvec; struct bio bio; struct btrfs_super_block *sb = page_address(page); int ret; bio_init(&bio, dev->bdev, &bvec, 1, REQ_OP_READ); bio.bi_iter.bi_sector = physical >> SECTOR_SHIFT; __bio_add_page(&bio, page, BTRFS_SUPER_INFO_SIZE, 0); ret = submit_bio_wait(&bio); bio_uninit(&bio); if (ret < 0) return ret; ret = btrfs_check_super_csum(fs_info, sb); if (ret != 0) { btrfs_err_rl(fs_info, "super block at physical %llu devid %llu has bad csum", physical, dev->devid); return -EIO; } if (btrfs_super_generation(sb) != generation) { btrfs_err_rl(fs_info, "super block at physical %llu devid %llu has bad generation %llu expect %llu", physical, dev->devid, btrfs_super_generation(sb), generation); return -EUCLEAN; } return btrfs_validate_super(fs_info, sb, -1); } static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, struct btrfs_device *scrub_dev) { int i; u64 bytenr; u64 gen; int ret = 0; struct page *page; struct btrfs_fs_info *fs_info = sctx->fs_info; if (BTRFS_FS_ERROR(fs_info)) return -EROFS; page = alloc_page(GFP_KERNEL); if (!page) { spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); return -ENOMEM; } /* Seed devices of a new filesystem has their own generation. */ if (scrub_dev->fs_devices != fs_info->fs_devices) gen = scrub_dev->generation; else gen = fs_info->last_trans_committed; for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { ret = btrfs_sb_log_location(scrub_dev, i, 0, &bytenr); if (ret == -ENOENT) break; if (ret) { spin_lock(&sctx->stat_lock); sctx->stat.super_errors++; spin_unlock(&sctx->stat_lock); continue; } if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->commit_total_bytes) break; if (!btrfs_check_super_location(scrub_dev, bytenr)) continue; ret = scrub_one_super(sctx, scrub_dev, page, bytenr, gen); if (ret) { spin_lock(&sctx->stat_lock); sctx->stat.super_errors++; spin_unlock(&sctx->stat_lock); } } __free_page(page); return 0; } static void scrub_workers_put(struct btrfs_fs_info *fs_info) { if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt, &fs_info->scrub_lock)) { struct workqueue_struct *scrub_workers = fs_info->scrub_workers; fs_info->scrub_workers = NULL; mutex_unlock(&fs_info->scrub_lock); if (scrub_workers) destroy_workqueue(scrub_workers); } } /* * get a reference count on fs_info->scrub_workers. start worker if necessary */ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info) { struct workqueue_struct *scrub_workers = NULL; unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND; int max_active = fs_info->thread_pool_size; int ret = -ENOMEM; if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt)) return 0; scrub_workers = alloc_workqueue("btrfs-scrub", flags, max_active); if (!scrub_workers) return -ENOMEM; mutex_lock(&fs_info->scrub_lock); if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) { ASSERT(fs_info->scrub_workers == NULL); fs_info->scrub_workers = scrub_workers; refcount_set(&fs_info->scrub_workers_refcnt, 1); mutex_unlock(&fs_info->scrub_lock); return 0; } /* Other thread raced in and created the workers for us */ refcount_inc(&fs_info->scrub_workers_refcnt); mutex_unlock(&fs_info->scrub_lock); ret = 0; destroy_workqueue(scrub_workers); return ret; } int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, u64 end, struct btrfs_scrub_progress *progress, int readonly, int is_dev_replace) { struct btrfs_dev_lookup_args args = { .devid = devid }; struct scrub_ctx *sctx; int ret; struct btrfs_device *dev; unsigned int nofs_flag; bool need_commit = false; if (btrfs_fs_closing(fs_info)) return -EAGAIN; /* At mount time we have ensured nodesize is in the range of [4K, 64K]. */ ASSERT(fs_info->nodesize <= BTRFS_STRIPE_LEN); /* * SCRUB_MAX_SECTORS_PER_BLOCK is calculated using the largest possible * value (max nodesize / min sectorsize), thus nodesize should always * be fine. */ ASSERT(fs_info->nodesize <= SCRUB_MAX_SECTORS_PER_BLOCK << fs_info->sectorsize_bits); /* Allocate outside of device_list_mutex */ sctx = scrub_setup_ctx(fs_info, is_dev_replace); if (IS_ERR(sctx)) return PTR_ERR(sctx); ret = scrub_workers_get(fs_info); if (ret) goto out_free_ctx; mutex_lock(&fs_info->fs_devices->device_list_mutex); dev = btrfs_find_device(fs_info->fs_devices, &args); if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) && !is_dev_replace)) { mutex_unlock(&fs_info->fs_devices->device_list_mutex); ret = -ENODEV; goto out; } if (!is_dev_replace && !readonly && !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) { mutex_unlock(&fs_info->fs_devices->device_list_mutex); btrfs_err_in_rcu(fs_info, "scrub on devid %llu: filesystem on %s is not writable", devid, btrfs_dev_name(dev)); ret = -EROFS; goto out; } mutex_lock(&fs_info->scrub_lock); if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) || test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) { mutex_unlock(&fs_info->scrub_lock); mutex_unlock(&fs_info->fs_devices->device_list_mutex); ret = -EIO; goto out; } down_read(&fs_info->dev_replace.rwsem); if (dev->scrub_ctx || (!is_dev_replace && btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) { up_read(&fs_info->dev_replace.rwsem); mutex_unlock(&fs_info->scrub_lock); mutex_unlock(&fs_info->fs_devices->device_list_mutex); ret = -EINPROGRESS; goto out; } up_read(&fs_info->dev_replace.rwsem); sctx->readonly = readonly; dev->scrub_ctx = sctx; mutex_unlock(&fs_info->fs_devices->device_list_mutex); /* * checking @scrub_pause_req here, we can avoid * race between committing transaction and scrubbing. */ __scrub_blocked_if_needed(fs_info); atomic_inc(&fs_info->scrubs_running); mutex_unlock(&fs_info->scrub_lock); /* * In order to avoid deadlock with reclaim when there is a transaction * trying to pause scrub, make sure we use GFP_NOFS for all the * allocations done at btrfs_scrub_sectors() and scrub_sectors_for_parity() * invoked by our callees. The pausing request is done when the * transaction commit starts, and it blocks the transaction until scrub * is paused (done at specific points at scrub_stripe() or right above * before incrementing fs_info->scrubs_running). */ nofs_flag = memalloc_nofs_save(); if (!is_dev_replace) { u64 old_super_errors; spin_lock(&sctx->stat_lock); old_super_errors = sctx->stat.super_errors; spin_unlock(&sctx->stat_lock); btrfs_info(fs_info, "scrub: started on devid %llu", devid); /* * by holding device list mutex, we can * kick off writing super in log tree sync. */ mutex_lock(&fs_info->fs_devices->device_list_mutex); ret = scrub_supers(sctx, dev); mutex_unlock(&fs_info->fs_devices->device_list_mutex); spin_lock(&sctx->stat_lock); /* * Super block errors found, but we can not commit transaction * at current context, since btrfs_commit_transaction() needs * to pause the current running scrub (hold by ourselves). */ if (sctx->stat.super_errors > old_super_errors && !sctx->readonly) need_commit = true; spin_unlock(&sctx->stat_lock); } if (!ret) ret = scrub_enumerate_chunks(sctx, dev, start, end); memalloc_nofs_restore(nofs_flag); atomic_dec(&fs_info->scrubs_running); wake_up(&fs_info->scrub_pause_wait); if (progress) memcpy(progress, &sctx->stat, sizeof(*progress)); if (!is_dev_replace) btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d", ret ? "not finished" : "finished", devid, ret); mutex_lock(&fs_info->scrub_lock); dev->scrub_ctx = NULL; mutex_unlock(&fs_info->scrub_lock); scrub_workers_put(fs_info); scrub_put_ctx(sctx); /* * We found some super block errors before, now try to force a * transaction commit, as scrub has finished. */ if (need_commit) { struct btrfs_trans_handle *trans; trans = btrfs_start_transaction(fs_info->tree_root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); btrfs_err(fs_info, "scrub: failed to start transaction to fix super block errors: %d", ret); return ret; } ret = btrfs_commit_transaction(trans); if (ret < 0) btrfs_err(fs_info, "scrub: failed to commit transaction to fix super block errors: %d", ret); } return ret; out: scrub_workers_put(fs_info); out_free_ctx: scrub_free_ctx(sctx); return ret; } void btrfs_scrub_pause(struct btrfs_fs_info *fs_info) { mutex_lock(&fs_info->scrub_lock); atomic_inc(&fs_info->scrub_pause_req); while (atomic_read(&fs_info->scrubs_paused) != atomic_read(&fs_info->scrubs_running)) { mutex_unlock(&fs_info->scrub_lock); wait_event(fs_info->scrub_pause_wait, atomic_read(&fs_info->scrubs_paused) == atomic_read(&fs_info->scrubs_running)); mutex_lock(&fs_info->scrub_lock); } mutex_unlock(&fs_info->scrub_lock); } void btrfs_scrub_continue(struct btrfs_fs_info *fs_info) { atomic_dec(&fs_info->scrub_pause_req); wake_up(&fs_info->scrub_pause_wait); } int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info) { mutex_lock(&fs_info->scrub_lock); if (!atomic_read(&fs_info->scrubs_running)) { mutex_unlock(&fs_info->scrub_lock); return -ENOTCONN; } atomic_inc(&fs_info->scrub_cancel_req); while (atomic_read(&fs_info->scrubs_running)) { mutex_unlock(&fs_info->scrub_lock); wait_event(fs_info->scrub_pause_wait, atomic_read(&fs_info->scrubs_running) == 0); mutex_lock(&fs_info->scrub_lock); } atomic_dec(&fs_info->scrub_cancel_req); mutex_unlock(&fs_info->scrub_lock); return 0; } int btrfs_scrub_cancel_dev(struct btrfs_device *dev) { struct btrfs_fs_info *fs_info = dev->fs_info; struct scrub_ctx *sctx; mutex_lock(&fs_info->scrub_lock); sctx = dev->scrub_ctx; if (!sctx) { mutex_unlock(&fs_info->scrub_lock); return -ENOTCONN; } atomic_inc(&sctx->cancel_req); while (dev->scrub_ctx) { mutex_unlock(&fs_info->scrub_lock); wait_event(fs_info->scrub_pause_wait, dev->scrub_ctx == NULL); mutex_lock(&fs_info->scrub_lock); } mutex_unlock(&fs_info->scrub_lock); return 0; } int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid, struct btrfs_scrub_progress *progress) { struct btrfs_dev_lookup_args args = { .devid = devid }; struct btrfs_device *dev; struct scrub_ctx *sctx = NULL; mutex_lock(&fs_info->fs_devices->device_list_mutex); dev = btrfs_find_device(fs_info->fs_devices, &args); if (dev) sctx = dev->scrub_ctx; if (sctx) memcpy(progress, &sctx->stat, sizeof(*progress)); mutex_unlock(&fs_info->fs_devices->device_list_mutex); return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV; }