// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2011, 2012 STRATO. All rights reserved. */ #include #include #include #include #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 "rcu-string.h" #include "raid56.h" #include "block-group.h" #include "zoned.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_block; struct scrub_ctx; /* * the following three values only influence the performance. * The last one configures the number of parallel and outstanding I/O * operations. The first two values configure an upper limit for the number * of (dynamically allocated) pages that are added to a bio. */ #define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */ #define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */ #define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */ /* * the following value times PAGE_SIZE needs to be large enough to match the * largest node/leaf/sector size that shall be supported. * Values larger than BTRFS_STRIPE_LEN are not supported. */ #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */ struct scrub_recover { refcount_t refs; struct btrfs_bio *bbio; u64 map_length; }; struct scrub_page { struct scrub_block *sblock; struct page *page; struct btrfs_device *dev; struct list_head list; u64 flags; /* extent flags */ u64 generation; u64 logical; u64 physical; u64 physical_for_dev_replace; atomic_t refs; u8 mirror_num; int have_csum:1; int io_error:1; u8 csum[BTRFS_CSUM_SIZE]; struct scrub_recover *recover; }; struct scrub_bio { int index; struct scrub_ctx *sctx; struct btrfs_device *dev; struct bio *bio; blk_status_t status; u64 logical; u64 physical; #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO]; #else struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO]; #endif int page_count; int next_free; struct btrfs_work work; }; struct scrub_block { struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK]; int page_count; atomic_t outstanding_pages; refcount_t refs; /* free mem on transition to zero */ struct scrub_ctx *sctx; struct scrub_parity *sparity; struct { unsigned int header_error:1; unsigned int checksum_error:1; unsigned int no_io_error_seen:1; unsigned int generation_error:1; /* also sets header_error */ /* The following is for the data used to check parity */ /* It is for the data with checksum */ unsigned int data_corrected:1; }; struct btrfs_work work; }; /* Used for the chunks with parity stripe such RAID5/6 */ struct scrub_parity { struct scrub_ctx *sctx; struct btrfs_device *scrub_dev; u64 logic_start; u64 logic_end; int nsectors; u32 stripe_len; refcount_t refs; struct list_head spages; /* Work of parity check and repair */ struct btrfs_work work; /* Mark the parity blocks which have data */ unsigned long *dbitmap; /* * Mark the parity blocks which have data, but errors happen when * read data or check data */ unsigned long *ebitmap; unsigned long bitmap[]; }; struct scrub_ctx { struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX]; struct btrfs_fs_info *fs_info; int first_free; int curr; atomic_t bios_in_flight; atomic_t workers_pending; spinlock_t list_lock; wait_queue_head_t list_wait; struct list_head csum_list; atomic_t cancel_req; int readonly; int pages_per_rd_bio; int is_dev_replace; struct scrub_bio *wr_curr_bio; struct mutex wr_lock; int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */ struct btrfs_device *wr_tgtdev; bool flush_all_writes; /* * 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; }; struct full_stripe_lock { struct rb_node node; u64 logical; u64 refs; struct mutex mutex; }; static void scrub_pending_bio_inc(struct scrub_ctx *sctx); static void scrub_pending_bio_dec(struct scrub_ctx *sctx); static int scrub_handle_errored_block(struct scrub_block *sblock_to_check); static int scrub_setup_recheck_block(struct scrub_block *original_sblock, struct scrub_block *sblocks_for_recheck); static void scrub_recheck_block(struct btrfs_fs_info *fs_info, struct scrub_block *sblock, int retry_failed_mirror); static void scrub_recheck_block_checksum(struct scrub_block *sblock); static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, struct scrub_block *sblock_good); static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, struct scrub_block *sblock_good, int page_num, int force_write); static void scrub_write_block_to_dev_replace(struct scrub_block *sblock); static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, int page_num); static int scrub_checksum_data(struct scrub_block *sblock); static int scrub_checksum_tree_block(struct scrub_block *sblock); static int scrub_checksum_super(struct scrub_block *sblock); static void scrub_block_get(struct scrub_block *sblock); static void scrub_block_put(struct scrub_block *sblock); static void scrub_page_get(struct scrub_page *spage); static void scrub_page_put(struct scrub_page *spage); static void scrub_parity_get(struct scrub_parity *sparity); static void scrub_parity_put(struct scrub_parity *sparity); static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, struct scrub_page *spage); static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u32 len, u64 physical, struct btrfs_device *dev, u64 flags, u64 gen, int mirror_num, u8 *csum, u64 physical_for_dev_replace); static void scrub_bio_end_io(struct bio *bio); static void scrub_bio_end_io_worker(struct btrfs_work *work); static void scrub_block_complete(struct scrub_block *sblock); static void scrub_remap_extent(struct btrfs_fs_info *fs_info, u64 extent_logical, u32 extent_len, u64 *extent_physical, struct btrfs_device **extent_dev, int *extent_mirror_num); static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, struct scrub_page *spage); static void scrub_wr_submit(struct scrub_ctx *sctx); static void scrub_wr_bio_end_io(struct bio *bio); static void scrub_wr_bio_end_io_worker(struct btrfs_work *work); static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); static void scrub_put_ctx(struct scrub_ctx *sctx); static inline int scrub_is_page_on_raid56(struct scrub_page *spage) { return spage->recover && (spage->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK); } static void scrub_pending_bio_inc(struct scrub_ctx *sctx) { refcount_inc(&sctx->refs); atomic_inc(&sctx->bios_in_flight); } static void scrub_pending_bio_dec(struct scrub_ctx *sctx) { atomic_dec(&sctx->bios_in_flight); wake_up(&sctx->list_wait); scrub_put_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); } /* * Insert new full stripe lock into full stripe locks tree * * Return pointer to existing or newly inserted full_stripe_lock structure if * everything works well. * Return ERR_PTR(-ENOMEM) if we failed to allocate memory * * NOTE: caller must hold full_stripe_locks_root->lock before calling this * function */ static struct full_stripe_lock *insert_full_stripe_lock( struct btrfs_full_stripe_locks_tree *locks_root, u64 fstripe_logical) { struct rb_node **p; struct rb_node *parent = NULL; struct full_stripe_lock *entry; struct full_stripe_lock *ret; lockdep_assert_held(&locks_root->lock); p = &locks_root->root.rb_node; while (*p) { parent = *p; entry = rb_entry(parent, struct full_stripe_lock, node); if (fstripe_logical < entry->logical) { p = &(*p)->rb_left; } else if (fstripe_logical > entry->logical) { p = &(*p)->rb_right; } else { entry->refs++; return entry; } } /* * Insert new lock. */ ret = kmalloc(sizeof(*ret), GFP_KERNEL); if (!ret) return ERR_PTR(-ENOMEM); ret->logical = fstripe_logical; ret->refs = 1; mutex_init(&ret->mutex); rb_link_node(&ret->node, parent, p); rb_insert_color(&ret->node, &locks_root->root); return ret; } /* * Search for a full stripe lock of a block group * * Return pointer to existing full stripe lock if found * Return NULL if not found */ static struct full_stripe_lock *search_full_stripe_lock( struct btrfs_full_stripe_locks_tree *locks_root, u64 fstripe_logical) { struct rb_node *node; struct full_stripe_lock *entry; lockdep_assert_held(&locks_root->lock); node = locks_root->root.rb_node; while (node) { entry = rb_entry(node, struct full_stripe_lock, node); if (fstripe_logical < entry->logical) node = node->rb_left; else if (fstripe_logical > entry->logical) node = node->rb_right; else return entry; } return NULL; } /* * Helper to get full stripe logical from a normal bytenr. * * Caller must ensure @cache is a RAID56 block group. */ static u64 get_full_stripe_logical(struct btrfs_block_group *cache, u64 bytenr) { u64 ret; /* * Due to chunk item size limit, full stripe length should not be * larger than U32_MAX. Just a sanity check here. */ WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX); /* * round_down() can only handle power of 2, while RAID56 full * stripe length can be 64KiB * n, so we need to manually round down. */ ret = div64_u64(bytenr - cache->start, cache->full_stripe_len) * cache->full_stripe_len + cache->start; return ret; } /* * Lock a full stripe to avoid concurrency of recovery and read * * It's only used for profiles with parities (RAID5/6), for other profiles it * does nothing. * * Return 0 if we locked full stripe covering @bytenr, with a mutex held. * So caller must call unlock_full_stripe() at the same context. * * Return <0 if encounters error. */ static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr, bool *locked_ret) { struct btrfs_block_group *bg_cache; struct btrfs_full_stripe_locks_tree *locks_root; struct full_stripe_lock *existing; u64 fstripe_start; int ret = 0; *locked_ret = false; bg_cache = btrfs_lookup_block_group(fs_info, bytenr); if (!bg_cache) { ASSERT(0); return -ENOENT; } /* Profiles not based on parity don't need full stripe lock */ if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) goto out; locks_root = &bg_cache->full_stripe_locks_root; fstripe_start = get_full_stripe_logical(bg_cache, bytenr); /* Now insert the full stripe lock */ mutex_lock(&locks_root->lock); existing = insert_full_stripe_lock(locks_root, fstripe_start); mutex_unlock(&locks_root->lock); if (IS_ERR(existing)) { ret = PTR_ERR(existing); goto out; } mutex_lock(&existing->mutex); *locked_ret = true; out: btrfs_put_block_group(bg_cache); return ret; } /* * Unlock a full stripe. * * NOTE: Caller must ensure it's the same context calling corresponding * lock_full_stripe(). * * Return 0 if we unlock full stripe without problem. * Return <0 for error */ static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr, bool locked) { struct btrfs_block_group *bg_cache; struct btrfs_full_stripe_locks_tree *locks_root; struct full_stripe_lock *fstripe_lock; u64 fstripe_start; bool freeit = false; int ret = 0; /* If we didn't acquire full stripe lock, no need to continue */ if (!locked) return 0; bg_cache = btrfs_lookup_block_group(fs_info, bytenr); if (!bg_cache) { ASSERT(0); return -ENOENT; } if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) goto out; locks_root = &bg_cache->full_stripe_locks_root; fstripe_start = get_full_stripe_logical(bg_cache, bytenr); mutex_lock(&locks_root->lock); fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start); /* Unpaired unlock_full_stripe() detected */ if (!fstripe_lock) { WARN_ON(1); ret = -ENOENT; mutex_unlock(&locks_root->lock); goto out; } if (fstripe_lock->refs == 0) { WARN_ON(1); btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow", fstripe_lock->logical); } else { fstripe_lock->refs--; } if (fstripe_lock->refs == 0) { rb_erase(&fstripe_lock->node, &locks_root->root); freeit = true; } mutex_unlock(&locks_root->lock); mutex_unlock(&fstripe_lock->mutex); if (freeit) kfree(fstripe_lock); out: btrfs_put_block_group(bg_cache); return ret; } static void scrub_free_csums(struct scrub_ctx *sctx) { while (!list_empty(&sctx->csum_list)) { struct btrfs_ordered_sum *sum; sum = list_first_entry(&sctx->csum_list, struct btrfs_ordered_sum, list); list_del(&sum->list); kfree(sum); } } static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) { int i; if (!sctx) return; /* this can happen when scrub is cancelled */ if (sctx->curr != -1) { struct scrub_bio *sbio = sctx->bios[sctx->curr]; for (i = 0; i < sbio->page_count; i++) { WARN_ON(!sbio->pagev[i]->page); scrub_block_put(sbio->pagev[i]->sblock); } bio_put(sbio->bio); } for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { struct scrub_bio *sbio = sctx->bios[i]; if (!sbio) break; kfree(sbio); } kfree(sctx->wr_curr_bio); scrub_free_csums(sctx); kfree(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; sctx = kzalloc(sizeof(*sctx), GFP_KERNEL); if (!sctx) goto nomem; refcount_set(&sctx->refs, 1); sctx->is_dev_replace = is_dev_replace; sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO; sctx->curr = -1; sctx->fs_info = fs_info; INIT_LIST_HEAD(&sctx->csum_list); for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { struct scrub_bio *sbio; sbio = kzalloc(sizeof(*sbio), GFP_KERNEL); if (!sbio) goto nomem; sctx->bios[i] = sbio; sbio->index = i; sbio->sctx = sctx; sbio->page_count = 0; btrfs_init_work(&sbio->work, scrub_bio_end_io_worker, NULL, NULL); if (i != SCRUB_BIOS_PER_SCTX - 1) sctx->bios[i]->next_free = i + 1; else sctx->bios[i]->next_free = -1; } sctx->first_free = 0; atomic_set(&sctx->bios_in_flight, 0); atomic_set(&sctx->workers_pending, 0); atomic_set(&sctx->cancel_req, 0); spin_lock_init(&sctx->list_lock); spin_lock_init(&sctx->stat_lock); init_waitqueue_head(&sctx->list_wait); WARN_ON(sctx->wr_curr_bio != NULL); mutex_init(&sctx->wr_lock); sctx->wr_curr_bio = NULL; if (is_dev_replace) { WARN_ON(!fs_info->dev_replace.tgtdev); sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO; sctx->wr_tgtdev = fs_info->dev_replace.tgtdev; sctx->flush_all_writes = false; } return sctx; nomem: scrub_free_ctx(sctx); return ERR_PTR(-ENOMEM); } static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *warn_ctx) { u64 isize; 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); isize = btrfs_inode_size(eb, 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 %llu, links %u (path: %s)", swarn->errstr, swarn->logical, rcu_str_deref(swarn->dev->name), swarn->physical, root, inum, offset, min(isize - offset, (u64)PAGE_SIZE), 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, rcu_str_deref(swarn->dev->name), swarn->physical, root, inum, offset, ret); free_ipath(ipath); return 0; } static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) { struct btrfs_device *dev; struct btrfs_fs_info *fs_info; struct btrfs_path *path; struct btrfs_key found_key; struct extent_buffer *eb; struct btrfs_extent_item *ei; struct scrub_warning swarn; unsigned long ptr = 0; u64 extent_item_pos; u64 flags = 0; u64 ref_root; u32 item_size; u8 ref_level = 0; int ret; WARN_ON(sblock->page_count < 1); dev = sblock->pagev[0]->dev; fs_info = sblock->sctx->fs_info; path = btrfs_alloc_path(); if (!path) return; swarn.physical = sblock->pagev[0]->physical; swarn.logical = sblock->pagev[0]->logical; swarn.errstr = errstr; swarn.dev = NULL; ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, &flags); if (ret < 0) goto out; extent_item_pos = swarn.logical - found_key.objectid; 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_nr(eb, path->slots[0]); if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { do { ret = tree_backref_for_extent(&ptr, eb, &found_key, ei, item_size, &ref_root, &ref_level); 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, rcu_str_deref(dev->name), swarn.physical, ref_level ? "node" : "leaf", ret < 0 ? -1 : ref_level, ret < 0 ? -1 : ref_root); } while (ret != 1); btrfs_release_path(path); } else { btrfs_release_path(path); swarn.path = path; swarn.dev = dev; iterate_extent_inodes(fs_info, found_key.objectid, extent_item_pos, 1, scrub_print_warning_inode, &swarn, false); } out: btrfs_free_path(path); } static inline void scrub_get_recover(struct scrub_recover *recover) { refcount_inc(&recover->refs); } static inline void scrub_put_recover(struct btrfs_fs_info *fs_info, struct scrub_recover *recover) { if (refcount_dec_and_test(&recover->refs)) { btrfs_bio_counter_dec(fs_info); btrfs_put_bbio(recover->bbio); kfree(recover); } } /* * scrub_handle_errored_block gets called when either verification of the * pages failed or the bio failed to read, e.g. with EIO. In the latter * case, this function handles all pages in the bio, even though only one * may be bad. * The goal of this function is to repair the errored block by using the * contents of one of the mirrors. */ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) { struct scrub_ctx *sctx = sblock_to_check->sctx; struct btrfs_device *dev; struct btrfs_fs_info *fs_info; u64 logical; unsigned int failed_mirror_index; unsigned int is_metadata; unsigned int have_csum; struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */ struct scrub_block *sblock_bad; int ret; int mirror_index; int page_num; int success; bool full_stripe_locked; unsigned int nofs_flag; static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); BUG_ON(sblock_to_check->page_count < 1); fs_info = sctx->fs_info; if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) { /* * if we find an error in a super block, we just report it. * They will get written with the next transaction commit * anyway */ spin_lock(&sctx->stat_lock); ++sctx->stat.super_errors; spin_unlock(&sctx->stat_lock); return 0; } logical = sblock_to_check->pagev[0]->logical; BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1); failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1; is_metadata = !(sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA); have_csum = sblock_to_check->pagev[0]->have_csum; dev = sblock_to_check->pagev[0]->dev; /* * We must use GFP_NOFS because the scrub task might be waiting for a * worker task executing this function and in turn a transaction commit * might be waiting the scrub task to pause (which needs to wait for all * the worker tasks to complete before pausing). * We do allocations in the workers through insert_full_stripe_lock() * and scrub_add_page_to_wr_bio(), which happens down the call chain of * this function. */ nofs_flag = memalloc_nofs_save(); /* * For RAID5/6, race can happen for a different device scrub thread. * For data corruption, Parity and Data threads will both try * to recovery the data. * Race can lead to doubly added csum error, or even unrecoverable * error. */ ret = lock_full_stripe(fs_info, logical, &full_stripe_locked); if (ret < 0) { memalloc_nofs_restore(nofs_flag); spin_lock(&sctx->stat_lock); if (ret == -ENOMEM) sctx->stat.malloc_errors++; sctx->stat.read_errors++; sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); return ret; } /* * read all mirrors one after the other. This includes to * re-read the extent or metadata block that failed (that was * the cause that this fixup code is called) another time, * page by page this time in order to know which pages * caused I/O errors and which ones are good (for all mirrors). * It is the goal to handle the situation when more than one * mirror contains I/O errors, but the errors do not * overlap, i.e. the data can be repaired by selecting the * pages from those mirrors without I/O error on the * particular pages. One example (with blocks >= 2 * PAGE_SIZE) * would be that mirror #1 has an I/O error on the first page, * the second page is good, and mirror #2 has an I/O error on * the second page, but the first page is good. * Then the first page of the first mirror can be repaired by * taking the first page of the second mirror, and the * second page of the second mirror can be repaired by * copying the contents of the 2nd page of the 1st mirror. * One more note: if the pages of one mirror contain I/O * errors, the checksum cannot be verified. In order to get * the best data for repairing, the first attempt is to find * a mirror without I/O errors and with a validated checksum. * Only if this is not possible, the pages are picked from * mirrors with I/O errors without considering the checksum. * If the latter is the case, at the end, the checksum of the * repaired area is verified in order to correctly maintain * the statistics. */ sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS, sizeof(*sblocks_for_recheck), GFP_KERNEL); if (!sblocks_for_recheck) { spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; sctx->stat.read_errors++; sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); goto out; } /* setup the context, map the logical blocks and alloc the pages */ ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck); if (ret) { spin_lock(&sctx->stat_lock); sctx->stat.read_errors++; sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); goto out; } BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS); sblock_bad = sblocks_for_recheck + failed_mirror_index; /* build and submit the bios for the failed mirror, check checksums */ scrub_recheck_block(fs_info, sblock_bad, 1); if (!sblock_bad->header_error && !sblock_bad->checksum_error && sblock_bad->no_io_error_seen) { /* * the error disappeared after reading page by page, or * the area was part of a huge bio and other parts of the * bio caused I/O errors, or the block layer merged several * read requests into one and the error is caused by a * different bio (usually one of the two latter cases is * the cause) */ spin_lock(&sctx->stat_lock); sctx->stat.unverified_errors++; sblock_to_check->data_corrected = 1; spin_unlock(&sctx->stat_lock); if (sctx->is_dev_replace) scrub_write_block_to_dev_replace(sblock_bad); goto out; } if (!sblock_bad->no_io_error_seen) { spin_lock(&sctx->stat_lock); sctx->stat.read_errors++; spin_unlock(&sctx->stat_lock); if (__ratelimit(&rs)) scrub_print_warning("i/o error", sblock_to_check); btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); } else if (sblock_bad->checksum_error) { spin_lock(&sctx->stat_lock); sctx->stat.csum_errors++; spin_unlock(&sctx->stat_lock); if (__ratelimit(&rs)) scrub_print_warning("checksum error", sblock_to_check); btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS); } else if (sblock_bad->header_error) { spin_lock(&sctx->stat_lock); sctx->stat.verify_errors++; spin_unlock(&sctx->stat_lock); if (__ratelimit(&rs)) scrub_print_warning("checksum/header error", sblock_to_check); if (sblock_bad->generation_error) btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_GENERATION_ERRS); else btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS); } if (sctx->readonly) { ASSERT(!sctx->is_dev_replace); goto out; } /* * now build and submit the bios for the other mirrors, check * checksums. * First try to pick the mirror which is completely without I/O * errors and also does not have a checksum error. * If one is found, and if a checksum is present, the full block * that is known to contain an error is rewritten. Afterwards * the block is known to be corrected. * If a mirror is found which is completely correct, and no * checksum is present, only those pages are rewritten that had * an I/O error in the block to be repaired, since it cannot be * determined, which copy of the other pages is better (and it * could happen otherwise that a correct page would be * overwritten by a bad one). */ for (mirror_index = 0; ;mirror_index++) { struct scrub_block *sblock_other; if (mirror_index == failed_mirror_index) continue; /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */ if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) { if (mirror_index >= BTRFS_MAX_MIRRORS) break; if (!sblocks_for_recheck[mirror_index].page_count) break; sblock_other = sblocks_for_recheck + mirror_index; } else { struct scrub_recover *r = sblock_bad->pagev[0]->recover; int max_allowed = r->bbio->num_stripes - r->bbio->num_tgtdevs; if (mirror_index >= max_allowed) break; if (!sblocks_for_recheck[1].page_count) break; ASSERT(failed_mirror_index == 0); sblock_other = sblocks_for_recheck + 1; sblock_other->pagev[0]->mirror_num = 1 + mirror_index; } /* build and submit the bios, check checksums */ scrub_recheck_block(fs_info, sblock_other, 0); if (!sblock_other->header_error && !sblock_other->checksum_error && sblock_other->no_io_error_seen) { if (sctx->is_dev_replace) { scrub_write_block_to_dev_replace(sblock_other); goto corrected_error; } else { ret = scrub_repair_block_from_good_copy( sblock_bad, sblock_other); if (!ret) goto corrected_error; } } } if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace) goto did_not_correct_error; /* * In case of I/O errors in the area that is supposed to be * repaired, continue by picking good copies of those pages. * Select the good pages from mirrors to rewrite bad pages from * the area to fix. Afterwards verify the checksum of the block * that is supposed to be repaired. This verification step is * only done for the purpose of statistic counting and for the * final scrub report, whether errors remain. * A perfect algorithm could make use of the checksum and try * all possible combinations of pages from the different mirrors * until the checksum verification succeeds. For example, when * the 2nd page of mirror #1 faces I/O errors, and the 2nd page * of mirror #2 is readable but the final checksum test fails, * then the 2nd page of mirror #3 could be tried, whether now * the final checksum succeeds. But this would be a rare * exception and is therefore not implemented. At least it is * avoided that the good copy is overwritten. * A more useful improvement would be to pick the sectors * without I/O error based on sector sizes (512 bytes on legacy * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one * mirror could be repaired by taking 512 byte of a different * mirror, even if other 512 byte sectors in the same PAGE_SIZE * area are unreadable. */ success = 1; for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { struct scrub_page *spage_bad = sblock_bad->pagev[page_num]; struct scrub_block *sblock_other = NULL; /* skip no-io-error page in scrub */ if (!spage_bad->io_error && !sctx->is_dev_replace) continue; if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) { /* * In case of dev replace, if raid56 rebuild process * didn't work out correct data, then copy the content * in sblock_bad to make sure target device is identical * to source device, instead of writing garbage data in * sblock_for_recheck array to target device. */ sblock_other = NULL; } else if (spage_bad->io_error) { /* try to find no-io-error page in mirrors */ for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS && sblocks_for_recheck[mirror_index].page_count > 0; mirror_index++) { if (!sblocks_for_recheck[mirror_index]. pagev[page_num]->io_error) { sblock_other = sblocks_for_recheck + mirror_index; break; } } if (!sblock_other) success = 0; } if (sctx->is_dev_replace) { /* * did not find a mirror to fetch the page * from. scrub_write_page_to_dev_replace() * handles this case (page->io_error), by * filling the block with zeros before * submitting the write request */ if (!sblock_other) sblock_other = sblock_bad; if (scrub_write_page_to_dev_replace(sblock_other, page_num) != 0) { atomic64_inc( &fs_info->dev_replace.num_write_errors); success = 0; } } else if (sblock_other) { ret = scrub_repair_page_from_good_copy(sblock_bad, sblock_other, page_num, 0); if (0 == ret) spage_bad->io_error = 0; else success = 0; } } if (success && !sctx->is_dev_replace) { if (is_metadata || have_csum) { /* * need to verify the checksum now that all * sectors on disk are repaired (the write * request for data to be repaired is on its way). * Just be lazy and use scrub_recheck_block() * which re-reads the data before the checksum * is verified, but most likely the data comes out * of the page cache. */ scrub_recheck_block(fs_info, sblock_bad, 1); if (!sblock_bad->header_error && !sblock_bad->checksum_error && sblock_bad->no_io_error_seen) goto corrected_error; else goto did_not_correct_error; } else { corrected_error: spin_lock(&sctx->stat_lock); sctx->stat.corrected_errors++; sblock_to_check->data_corrected = 1; spin_unlock(&sctx->stat_lock); btrfs_err_rl_in_rcu(fs_info, "fixed up error at logical %llu on dev %s", logical, rcu_str_deref(dev->name)); } } else { did_not_correct_error: spin_lock(&sctx->stat_lock); sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); btrfs_err_rl_in_rcu(fs_info, "unable to fixup (regular) error at logical %llu on dev %s", logical, rcu_str_deref(dev->name)); } out: if (sblocks_for_recheck) { for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS; mirror_index++) { struct scrub_block *sblock = sblocks_for_recheck + mirror_index; struct scrub_recover *recover; int page_index; for (page_index = 0; page_index < sblock->page_count; page_index++) { sblock->pagev[page_index]->sblock = NULL; recover = sblock->pagev[page_index]->recover; if (recover) { scrub_put_recover(fs_info, recover); sblock->pagev[page_index]->recover = NULL; } scrub_page_put(sblock->pagev[page_index]); } } kfree(sblocks_for_recheck); } ret = unlock_full_stripe(fs_info, logical, full_stripe_locked); memalloc_nofs_restore(nofs_flag); if (ret < 0) return ret; return 0; } static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio) { if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5) return 2; else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) return 3; else return (int)bbio->num_stripes; } static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type, u64 *raid_map, u64 mapped_length, int nstripes, int mirror, int *stripe_index, u64 *stripe_offset) { int i; if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) { /* RAID5/6 */ for (i = 0; i < nstripes; i++) { if (raid_map[i] == RAID6_Q_STRIPE || raid_map[i] == RAID5_P_STRIPE) continue; if (logical >= raid_map[i] && logical < raid_map[i] + mapped_length) break; } *stripe_index = i; *stripe_offset = logical - raid_map[i]; } else { /* The other RAID type */ *stripe_index = mirror; *stripe_offset = 0; } } static int scrub_setup_recheck_block(struct scrub_block *original_sblock, struct scrub_block *sblocks_for_recheck) { struct scrub_ctx *sctx = original_sblock->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; u64 length = original_sblock->page_count * PAGE_SIZE; u64 logical = original_sblock->pagev[0]->logical; u64 generation = original_sblock->pagev[0]->generation; u64 flags = original_sblock->pagev[0]->flags; u64 have_csum = original_sblock->pagev[0]->have_csum; struct scrub_recover *recover; struct btrfs_bio *bbio; u64 sublen; u64 mapped_length; u64 stripe_offset; int stripe_index; int page_index = 0; int mirror_index; int nmirrors; int ret; /* * note: the two members refs and outstanding_pages * are not used (and not set) in the blocks that are used for * the recheck procedure */ while (length > 0) { sublen = min_t(u64, length, PAGE_SIZE); mapped_length = sublen; bbio = NULL; /* * with a length of PAGE_SIZE, each returned stripe * represents one mirror */ btrfs_bio_counter_inc_blocked(fs_info); ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical, &mapped_length, &bbio); if (ret || !bbio || mapped_length < sublen) { btrfs_put_bbio(bbio); btrfs_bio_counter_dec(fs_info); return -EIO; } recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS); if (!recover) { btrfs_put_bbio(bbio); btrfs_bio_counter_dec(fs_info); return -ENOMEM; } refcount_set(&recover->refs, 1); recover->bbio = bbio; recover->map_length = mapped_length; BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK); nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS); for (mirror_index = 0; mirror_index < nmirrors; mirror_index++) { struct scrub_block *sblock; struct scrub_page *spage; sblock = sblocks_for_recheck + mirror_index; sblock->sctx = sctx; spage = kzalloc(sizeof(*spage), GFP_NOFS); if (!spage) { leave_nomem: spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); scrub_put_recover(fs_info, recover); return -ENOMEM; } scrub_page_get(spage); sblock->pagev[page_index] = spage; spage->sblock = sblock; spage->flags = flags; spage->generation = generation; spage->logical = logical; spage->have_csum = have_csum; if (have_csum) memcpy(spage->csum, original_sblock->pagev[0]->csum, sctx->fs_info->csum_size); scrub_stripe_index_and_offset(logical, bbio->map_type, bbio->raid_map, mapped_length, bbio->num_stripes - bbio->num_tgtdevs, mirror_index, &stripe_index, &stripe_offset); spage->physical = bbio->stripes[stripe_index].physical + stripe_offset; spage->dev = bbio->stripes[stripe_index].dev; BUG_ON(page_index >= original_sblock->page_count); spage->physical_for_dev_replace = original_sblock->pagev[page_index]-> physical_for_dev_replace; /* for missing devices, dev->bdev is NULL */ spage->mirror_num = mirror_index + 1; sblock->page_count++; spage->page = alloc_page(GFP_NOFS); if (!spage->page) goto leave_nomem; scrub_get_recover(recover); spage->recover = recover; } scrub_put_recover(fs_info, recover); length -= sublen; logical += sublen; page_index++; } return 0; } static void scrub_bio_wait_endio(struct bio *bio) { complete(bio->bi_private); } static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info, struct bio *bio, struct scrub_page *spage) { DECLARE_COMPLETION_ONSTACK(done); int ret; int mirror_num; bio->bi_iter.bi_sector = spage->logical >> 9; bio->bi_private = &done; bio->bi_end_io = scrub_bio_wait_endio; mirror_num = spage->sblock->pagev[0]->mirror_num; ret = raid56_parity_recover(fs_info, bio, spage->recover->bbio, spage->recover->map_length, mirror_num, 0); if (ret) return ret; wait_for_completion_io(&done); return blk_status_to_errno(bio->bi_status); } static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info, struct scrub_block *sblock) { struct scrub_page *first_page = sblock->pagev[0]; struct bio *bio; int page_num; /* All pages in sblock belong to the same stripe on the same device. */ ASSERT(first_page->dev); if (!first_page->dev->bdev) goto out; bio = btrfs_io_bio_alloc(BIO_MAX_PAGES); bio_set_dev(bio, first_page->dev->bdev); for (page_num = 0; page_num < sblock->page_count; page_num++) { struct scrub_page *spage = sblock->pagev[page_num]; WARN_ON(!spage->page); bio_add_page(bio, spage->page, PAGE_SIZE, 0); } if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) { bio_put(bio); goto out; } bio_put(bio); scrub_recheck_block_checksum(sblock); return; out: for (page_num = 0; page_num < sblock->page_count; page_num++) sblock->pagev[page_num]->io_error = 1; sblock->no_io_error_seen = 0; } /* * this function will check the on disk data for checksum errors, header * errors and read I/O errors. If any I/O errors happen, the exact pages * which are errored are marked as being bad. The goal is to enable scrub * to take those pages that are not errored from all the mirrors so that * the pages that are errored in the just handled mirror can be repaired. */ static void scrub_recheck_block(struct btrfs_fs_info *fs_info, struct scrub_block *sblock, int retry_failed_mirror) { int page_num; sblock->no_io_error_seen = 1; /* short cut for raid56 */ if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0])) return scrub_recheck_block_on_raid56(fs_info, sblock); for (page_num = 0; page_num < sblock->page_count; page_num++) { struct bio *bio; struct scrub_page *spage = sblock->pagev[page_num]; if (spage->dev->bdev == NULL) { spage->io_error = 1; sblock->no_io_error_seen = 0; continue; } WARN_ON(!spage->page); bio = btrfs_io_bio_alloc(1); bio_set_dev(bio, spage->dev->bdev); bio_add_page(bio, spage->page, PAGE_SIZE, 0); bio->bi_iter.bi_sector = spage->physical >> 9; bio->bi_opf = REQ_OP_READ; if (btrfsic_submit_bio_wait(bio)) { spage->io_error = 1; sblock->no_io_error_seen = 0; } bio_put(bio); } if (sblock->no_io_error_seen) scrub_recheck_block_checksum(sblock); } static inline int scrub_check_fsid(u8 fsid[], struct scrub_page *spage) { struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices; int ret; ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE); return !ret; } static void scrub_recheck_block_checksum(struct scrub_block *sblock) { sblock->header_error = 0; sblock->checksum_error = 0; sblock->generation_error = 0; if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA) scrub_checksum_data(sblock); else scrub_checksum_tree_block(sblock); } static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, struct scrub_block *sblock_good) { int page_num; int ret = 0; for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { int ret_sub; ret_sub = scrub_repair_page_from_good_copy(sblock_bad, sblock_good, page_num, 1); if (ret_sub) ret = ret_sub; } return ret; } static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, struct scrub_block *sblock_good, int page_num, int force_write) { struct scrub_page *spage_bad = sblock_bad->pagev[page_num]; struct scrub_page *spage_good = sblock_good->pagev[page_num]; struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info; BUG_ON(spage_bad->page == NULL); BUG_ON(spage_good->page == NULL); if (force_write || sblock_bad->header_error || sblock_bad->checksum_error || spage_bad->io_error) { struct bio *bio; int ret; if (!spage_bad->dev->bdev) { btrfs_warn_rl(fs_info, "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected"); return -EIO; } bio = btrfs_io_bio_alloc(1); bio_set_dev(bio, spage_bad->dev->bdev); bio->bi_iter.bi_sector = spage_bad->physical >> 9; bio->bi_opf = REQ_OP_WRITE; ret = bio_add_page(bio, spage_good->page, PAGE_SIZE, 0); if (PAGE_SIZE != ret) { bio_put(bio); return -EIO; } if (btrfsic_submit_bio_wait(bio)) { btrfs_dev_stat_inc_and_print(spage_bad->dev, BTRFS_DEV_STAT_WRITE_ERRS); atomic64_inc(&fs_info->dev_replace.num_write_errors); bio_put(bio); return -EIO; } bio_put(bio); } return 0; } static void scrub_write_block_to_dev_replace(struct scrub_block *sblock) { struct btrfs_fs_info *fs_info = sblock->sctx->fs_info; int page_num; /* * This block is used for the check of the parity on the source device, * so the data needn't be written into the destination device. */ if (sblock->sparity) return; for (page_num = 0; page_num < sblock->page_count; page_num++) { int ret; ret = scrub_write_page_to_dev_replace(sblock, page_num); if (ret) atomic64_inc(&fs_info->dev_replace.num_write_errors); } } static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, int page_num) { struct scrub_page *spage = sblock->pagev[page_num]; BUG_ON(spage->page == NULL); if (spage->io_error) clear_page(page_address(spage->page)); return scrub_add_page_to_wr_bio(sblock->sctx, spage); } static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, struct scrub_page *spage) { struct scrub_bio *sbio; int ret; mutex_lock(&sctx->wr_lock); again: if (!sctx->wr_curr_bio) { sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio), GFP_KERNEL); if (!sctx->wr_curr_bio) { mutex_unlock(&sctx->wr_lock); return -ENOMEM; } sctx->wr_curr_bio->sctx = sctx; sctx->wr_curr_bio->page_count = 0; } sbio = sctx->wr_curr_bio; if (sbio->page_count == 0) { struct bio *bio; sbio->physical = spage->physical_for_dev_replace; sbio->logical = spage->logical; sbio->dev = sctx->wr_tgtdev; bio = sbio->bio; if (!bio) { bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio); sbio->bio = bio; } bio->bi_private = sbio; bio->bi_end_io = scrub_wr_bio_end_io; bio_set_dev(bio, sbio->dev->bdev); bio->bi_iter.bi_sector = sbio->physical >> 9; bio->bi_opf = REQ_OP_WRITE; sbio->status = 0; } else if (sbio->physical + sbio->page_count * PAGE_SIZE != spage->physical_for_dev_replace || sbio->logical + sbio->page_count * PAGE_SIZE != spage->logical) { scrub_wr_submit(sctx); goto again; } ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); if (ret != PAGE_SIZE) { if (sbio->page_count < 1) { bio_put(sbio->bio); sbio->bio = NULL; mutex_unlock(&sctx->wr_lock); return -EIO; } scrub_wr_submit(sctx); goto again; } sbio->pagev[sbio->page_count] = spage; scrub_page_get(spage); sbio->page_count++; if (sbio->page_count == sctx->pages_per_wr_bio) scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); return 0; } static void scrub_wr_submit(struct scrub_ctx *sctx) { struct scrub_bio *sbio; if (!sctx->wr_curr_bio) return; sbio = sctx->wr_curr_bio; sctx->wr_curr_bio = NULL; WARN_ON(!sbio->bio->bi_disk); scrub_pending_bio_inc(sctx); /* process all writes in a single worker thread. Then the block layer * orders the requests before sending them to the driver which * doubled the write performance on spinning disks when measured * with Linux 3.5 */ btrfsic_submit_bio(sbio->bio); } static void scrub_wr_bio_end_io(struct bio *bio) { struct scrub_bio *sbio = bio->bi_private; struct btrfs_fs_info *fs_info = sbio->dev->fs_info; sbio->status = bio->bi_status; sbio->bio = bio; btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL); btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work); } static void scrub_wr_bio_end_io_worker(struct btrfs_work *work) { struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); struct scrub_ctx *sctx = sbio->sctx; int i; WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO); if (sbio->status) { struct btrfs_dev_replace *dev_replace = &sbio->sctx->fs_info->dev_replace; for (i = 0; i < sbio->page_count; i++) { struct scrub_page *spage = sbio->pagev[i]; spage->io_error = 1; atomic64_inc(&dev_replace->num_write_errors); } } for (i = 0; i < sbio->page_count; i++) scrub_page_put(sbio->pagev[i]); bio_put(sbio->bio); kfree(sbio); scrub_pending_bio_dec(sctx); } static int scrub_checksum(struct scrub_block *sblock) { u64 flags; int ret; /* * No need to initialize these stats currently, * because this function only use return value * instead of these stats value. * * Todo: * always use stats */ sblock->header_error = 0; sblock->generation_error = 0; sblock->checksum_error = 0; WARN_ON(sblock->page_count < 1); flags = sblock->pagev[0]->flags; ret = 0; if (flags & BTRFS_EXTENT_FLAG_DATA) ret = scrub_checksum_data(sblock); else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) ret = scrub_checksum_tree_block(sblock); else if (flags & BTRFS_EXTENT_FLAG_SUPER) (void)scrub_checksum_super(sblock); else WARN_ON(1); if (ret) scrub_handle_errored_block(sblock); return ret; } static int scrub_checksum_data(struct scrub_block *sblock) { struct scrub_ctx *sctx = sblock->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); u8 csum[BTRFS_CSUM_SIZE]; struct scrub_page *spage; char *kaddr; BUG_ON(sblock->page_count < 1); spage = sblock->pagev[0]; if (!spage->have_csum) return 0; kaddr = page_address(spage->page); shash->tfm = fs_info->csum_shash; crypto_shash_init(shash); crypto_shash_digest(shash, kaddr, PAGE_SIZE, csum); if (memcmp(csum, spage->csum, sctx->fs_info->csum_size)) sblock->checksum_error = 1; return sblock->checksum_error; } static int scrub_checksum_tree_block(struct scrub_block *sblock) { struct scrub_ctx *sctx = sblock->sctx; struct btrfs_header *h; struct btrfs_fs_info *fs_info = sctx->fs_info; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); u8 calculated_csum[BTRFS_CSUM_SIZE]; u8 on_disk_csum[BTRFS_CSUM_SIZE]; const int num_pages = sctx->fs_info->nodesize >> PAGE_SHIFT; int i; struct scrub_page *spage; char *kaddr; BUG_ON(sblock->page_count < 1); spage = sblock->pagev[0]; kaddr = page_address(spage->page); h = (struct btrfs_header *)kaddr; memcpy(on_disk_csum, h->csum, sctx->fs_info->csum_size); /* * we don't use the getter functions here, as we * a) don't have an extent buffer and * b) the page is already kmapped */ if (spage->logical != btrfs_stack_header_bytenr(h)) sblock->header_error = 1; if (spage->generation != btrfs_stack_header_generation(h)) { sblock->header_error = 1; sblock->generation_error = 1; } if (!scrub_check_fsid(h->fsid, spage)) sblock->header_error = 1; if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, BTRFS_UUID_SIZE)) sblock->header_error = 1; shash->tfm = fs_info->csum_shash; crypto_shash_init(shash); crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE, PAGE_SIZE - BTRFS_CSUM_SIZE); for (i = 1; i < num_pages; i++) { kaddr = page_address(sblock->pagev[i]->page); crypto_shash_update(shash, kaddr, PAGE_SIZE); } crypto_shash_final(shash, calculated_csum); if (memcmp(calculated_csum, on_disk_csum, sctx->fs_info->csum_size)) sblock->checksum_error = 1; return sblock->header_error || sblock->checksum_error; } static int scrub_checksum_super(struct scrub_block *sblock) { struct btrfs_super_block *s; struct scrub_ctx *sctx = sblock->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); u8 calculated_csum[BTRFS_CSUM_SIZE]; struct scrub_page *spage; char *kaddr; int fail_gen = 0; int fail_cor = 0; BUG_ON(sblock->page_count < 1); spage = sblock->pagev[0]; kaddr = page_address(spage->page); s = (struct btrfs_super_block *)kaddr; if (spage->logical != btrfs_super_bytenr(s)) ++fail_cor; if (spage->generation != btrfs_super_generation(s)) ++fail_gen; if (!scrub_check_fsid(s->fsid, spage)) ++fail_cor; shash->tfm = fs_info->csum_shash; crypto_shash_init(shash); crypto_shash_digest(shash, kaddr + BTRFS_CSUM_SIZE, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, calculated_csum); if (memcmp(calculated_csum, s->csum, sctx->fs_info->csum_size)) ++fail_cor; if (fail_cor + fail_gen) { /* * if we find an error in a super block, we just report it. * They will get written with the next transaction commit * anyway */ spin_lock(&sctx->stat_lock); ++sctx->stat.super_errors; spin_unlock(&sctx->stat_lock); if (fail_cor) btrfs_dev_stat_inc_and_print(spage->dev, BTRFS_DEV_STAT_CORRUPTION_ERRS); else btrfs_dev_stat_inc_and_print(spage->dev, BTRFS_DEV_STAT_GENERATION_ERRS); } return fail_cor + fail_gen; } static void scrub_block_get(struct scrub_block *sblock) { refcount_inc(&sblock->refs); } static void scrub_block_put(struct scrub_block *sblock) { if (refcount_dec_and_test(&sblock->refs)) { int i; if (sblock->sparity) scrub_parity_put(sblock->sparity); for (i = 0; i < sblock->page_count; i++) scrub_page_put(sblock->pagev[i]); kfree(sblock); } } static void scrub_page_get(struct scrub_page *spage) { atomic_inc(&spage->refs); } static void scrub_page_put(struct scrub_page *spage) { if (atomic_dec_and_test(&spage->refs)) { if (spage->page) __free_page(spage->page); kfree(spage); } } static void scrub_submit(struct scrub_ctx *sctx) { struct scrub_bio *sbio; if (sctx->curr == -1) return; sbio = sctx->bios[sctx->curr]; sctx->curr = -1; scrub_pending_bio_inc(sctx); btrfsic_submit_bio(sbio->bio); } static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, struct scrub_page *spage) { struct scrub_block *sblock = spage->sblock; struct scrub_bio *sbio; int ret; again: /* * grab a fresh bio or wait for one to become available */ while (sctx->curr == -1) { spin_lock(&sctx->list_lock); sctx->curr = sctx->first_free; if (sctx->curr != -1) { sctx->first_free = sctx->bios[sctx->curr]->next_free; sctx->bios[sctx->curr]->next_free = -1; sctx->bios[sctx->curr]->page_count = 0; spin_unlock(&sctx->list_lock); } else { spin_unlock(&sctx->list_lock); wait_event(sctx->list_wait, sctx->first_free != -1); } } sbio = sctx->bios[sctx->curr]; if (sbio->page_count == 0) { struct bio *bio; sbio->physical = spage->physical; sbio->logical = spage->logical; sbio->dev = spage->dev; bio = sbio->bio; if (!bio) { bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio); sbio->bio = bio; } bio->bi_private = sbio; bio->bi_end_io = scrub_bio_end_io; bio_set_dev(bio, sbio->dev->bdev); bio->bi_iter.bi_sector = sbio->physical >> 9; bio->bi_opf = REQ_OP_READ; sbio->status = 0; } else if (sbio->physical + sbio->page_count * PAGE_SIZE != spage->physical || sbio->logical + sbio->page_count * PAGE_SIZE != spage->logical || sbio->dev != spage->dev) { scrub_submit(sctx); goto again; } sbio->pagev[sbio->page_count] = spage; ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); if (ret != PAGE_SIZE) { if (sbio->page_count < 1) { bio_put(sbio->bio); sbio->bio = NULL; return -EIO; } scrub_submit(sctx); goto again; } scrub_block_get(sblock); /* one for the page added to the bio */ atomic_inc(&sblock->outstanding_pages); sbio->page_count++; if (sbio->page_count == sctx->pages_per_rd_bio) scrub_submit(sctx); return 0; } static void scrub_missing_raid56_end_io(struct bio *bio) { struct scrub_block *sblock = bio->bi_private; struct btrfs_fs_info *fs_info = sblock->sctx->fs_info; if (bio->bi_status) sblock->no_io_error_seen = 0; bio_put(bio); btrfs_queue_work(fs_info->scrub_workers, &sblock->work); } static void scrub_missing_raid56_worker(struct btrfs_work *work) { struct scrub_block *sblock = container_of(work, struct scrub_block, work); struct scrub_ctx *sctx = sblock->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; u64 logical; struct btrfs_device *dev; logical = sblock->pagev[0]->logical; dev = sblock->pagev[0]->dev; if (sblock->no_io_error_seen) scrub_recheck_block_checksum(sblock); if (!sblock->no_io_error_seen) { spin_lock(&sctx->stat_lock); sctx->stat.read_errors++; spin_unlock(&sctx->stat_lock); btrfs_err_rl_in_rcu(fs_info, "IO error rebuilding logical %llu for dev %s", logical, rcu_str_deref(dev->name)); } else if (sblock->header_error || sblock->checksum_error) { spin_lock(&sctx->stat_lock); sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); btrfs_err_rl_in_rcu(fs_info, "failed to rebuild valid logical %llu for dev %s", logical, rcu_str_deref(dev->name)); } else { scrub_write_block_to_dev_replace(sblock); } if (sctx->is_dev_replace && sctx->flush_all_writes) { mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); } scrub_block_put(sblock); scrub_pending_bio_dec(sctx); } static void scrub_missing_raid56_pages(struct scrub_block *sblock) { struct scrub_ctx *sctx = sblock->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; u64 length = sblock->page_count * PAGE_SIZE; u64 logical = sblock->pagev[0]->logical; struct btrfs_bio *bbio = NULL; struct bio *bio; struct btrfs_raid_bio *rbio; int ret; int i; btrfs_bio_counter_inc_blocked(fs_info); ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical, &length, &bbio); if (ret || !bbio || !bbio->raid_map) goto bbio_out; if (WARN_ON(!sctx->is_dev_replace || !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) { /* * We shouldn't be scrubbing a missing device. Even for dev * replace, we should only get here for RAID 5/6. We either * managed to mount something with no mirrors remaining or * there's a bug in scrub_remap_extent()/btrfs_map_block(). */ goto bbio_out; } bio = btrfs_io_bio_alloc(0); bio->bi_iter.bi_sector = logical >> 9; bio->bi_private = sblock; bio->bi_end_io = scrub_missing_raid56_end_io; rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length); if (!rbio) goto rbio_out; for (i = 0; i < sblock->page_count; i++) { struct scrub_page *spage = sblock->pagev[i]; raid56_add_scrub_pages(rbio, spage->page, spage->logical); } btrfs_init_work(&sblock->work, scrub_missing_raid56_worker, NULL, NULL); scrub_block_get(sblock); scrub_pending_bio_inc(sctx); raid56_submit_missing_rbio(rbio); return; rbio_out: bio_put(bio); bbio_out: btrfs_bio_counter_dec(fs_info); btrfs_put_bbio(bbio); spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); } static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u32 len, u64 physical, struct btrfs_device *dev, u64 flags, u64 gen, int mirror_num, u8 *csum, u64 physical_for_dev_replace) { struct scrub_block *sblock; const u32 sectorsize = sctx->fs_info->sectorsize; int index; sblock = kzalloc(sizeof(*sblock), GFP_KERNEL); if (!sblock) { spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); return -ENOMEM; } /* one ref inside this function, plus one for each page added to * a bio later on */ refcount_set(&sblock->refs, 1); sblock->sctx = sctx; sblock->no_io_error_seen = 1; for (index = 0; len > 0; index++) { struct scrub_page *spage; /* * Here we will allocate one page for one sector to scrub. * This is fine if PAGE_SIZE == sectorsize, but will cost * more memory for PAGE_SIZE > sectorsize case. */ u32 l = min(sectorsize, len); spage = kzalloc(sizeof(*spage), GFP_KERNEL); if (!spage) { leave_nomem: spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); scrub_block_put(sblock); return -ENOMEM; } BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); scrub_page_get(spage); sblock->pagev[index] = spage; spage->sblock = sblock; spage->dev = dev; spage->flags = flags; spage->generation = gen; spage->logical = logical; spage->physical = physical; spage->physical_for_dev_replace = physical_for_dev_replace; spage->mirror_num = mirror_num; if (csum) { spage->have_csum = 1; memcpy(spage->csum, csum, sctx->fs_info->csum_size); } else { spage->have_csum = 0; } sblock->page_count++; spage->page = alloc_page(GFP_KERNEL); if (!spage->page) goto leave_nomem; len -= l; logical += l; physical += l; physical_for_dev_replace += l; } WARN_ON(sblock->page_count == 0); if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) { /* * This case should only be hit for RAID 5/6 device replace. See * the comment in scrub_missing_raid56_pages() for details. */ scrub_missing_raid56_pages(sblock); } else { for (index = 0; index < sblock->page_count; index++) { struct scrub_page *spage = sblock->pagev[index]; int ret; ret = scrub_add_page_to_rd_bio(sctx, spage); if (ret) { scrub_block_put(sblock); return ret; } } if (flags & BTRFS_EXTENT_FLAG_SUPER) scrub_submit(sctx); } /* last one frees, either here or in bio completion for last page */ scrub_block_put(sblock); return 0; } static void scrub_bio_end_io(struct bio *bio) { struct scrub_bio *sbio = bio->bi_private; struct btrfs_fs_info *fs_info = sbio->dev->fs_info; sbio->status = bio->bi_status; sbio->bio = bio; btrfs_queue_work(fs_info->scrub_workers, &sbio->work); } static void scrub_bio_end_io_worker(struct btrfs_work *work) { struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); struct scrub_ctx *sctx = sbio->sctx; int i; BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO); if (sbio->status) { for (i = 0; i < sbio->page_count; i++) { struct scrub_page *spage = sbio->pagev[i]; spage->io_error = 1; spage->sblock->no_io_error_seen = 0; } } /* now complete the scrub_block items that have all pages completed */ for (i = 0; i < sbio->page_count; i++) { struct scrub_page *spage = sbio->pagev[i]; struct scrub_block *sblock = spage->sblock; if (atomic_dec_and_test(&sblock->outstanding_pages)) scrub_block_complete(sblock); scrub_block_put(sblock); } bio_put(sbio->bio); sbio->bio = NULL; spin_lock(&sctx->list_lock); sbio->next_free = sctx->first_free; sctx->first_free = sbio->index; spin_unlock(&sctx->list_lock); if (sctx->is_dev_replace && sctx->flush_all_writes) { mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); } scrub_pending_bio_dec(sctx); } static inline void __scrub_mark_bitmap(struct scrub_parity *sparity, unsigned long *bitmap, u64 start, u32 len) { u64 offset; u32 nsectors; u32 sectorsize_bits = sparity->sctx->fs_info->sectorsize_bits; if (len >= sparity->stripe_len) { bitmap_set(bitmap, 0, sparity->nsectors); return; } start -= sparity->logic_start; start = div64_u64_rem(start, sparity->stripe_len, &offset); offset = offset >> sectorsize_bits; nsectors = len >> sectorsize_bits; if (offset + nsectors <= sparity->nsectors) { bitmap_set(bitmap, offset, nsectors); return; } bitmap_set(bitmap, offset, sparity->nsectors - offset); bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset)); } static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity, u64 start, u32 len) { __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len); } static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity, u64 start, u32 len) { __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len); } static void scrub_block_complete(struct scrub_block *sblock) { int corrupted = 0; if (!sblock->no_io_error_seen) { corrupted = 1; scrub_handle_errored_block(sblock); } else { /* * if has checksum error, write via repair mechanism in * dev replace case, otherwise write here in dev replace * case. */ corrupted = scrub_checksum(sblock); if (!corrupted && sblock->sctx->is_dev_replace) scrub_write_block_to_dev_replace(sblock); } if (sblock->sparity && corrupted && !sblock->data_corrected) { u64 start = sblock->pagev[0]->logical; u64 end = sblock->pagev[sblock->page_count - 1]->logical + PAGE_SIZE; ASSERT(end - start <= U32_MAX); scrub_parity_mark_sectors_error(sblock->sparity, start, end - start); } } static void drop_csum_range(struct scrub_ctx *sctx, struct btrfs_ordered_sum *sum) { sctx->stat.csum_discards += sum->len >> sctx->fs_info->sectorsize_bits; list_del(&sum->list); kfree(sum); } /* * Find the desired csum for range [logical, logical + sectorsize), and store * the csum into @csum. * * The search source is sctx->csum_list, which is a pre-populated list * storing bytenr ordered csum ranges. We're reponsible to cleanup any range * that is before @logical. * * Return 0 if there is no csum for the range. * Return 1 if there is csum for the range and copied to @csum. */ static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum) { bool found = false; while (!list_empty(&sctx->csum_list)) { struct btrfs_ordered_sum *sum = NULL; unsigned long index; unsigned long num_sectors; sum = list_first_entry(&sctx->csum_list, struct btrfs_ordered_sum, list); /* The current csum range is beyond our range, no csum found */ if (sum->bytenr > logical) break; /* * The current sum is before our bytenr, since scrub is always * done in bytenr order, the csum will never be used anymore, * clean it up so that later calls won't bother with the range, * and continue search the next range. */ if (sum->bytenr + sum->len <= logical) { drop_csum_range(sctx, sum); continue; } /* Now the csum range covers our bytenr, copy the csum */ found = true; index = (logical - sum->bytenr) >> sctx->fs_info->sectorsize_bits; num_sectors = sum->len >> sctx->fs_info->sectorsize_bits; memcpy(csum, sum->sums + index * sctx->fs_info->csum_size, sctx->fs_info->csum_size); /* Cleanup the range if we're at the end of the csum range */ if (index == num_sectors - 1) drop_csum_range(sctx, sum); break; } if (!found) return 0; return 1; } /* scrub extent tries to collect up to 64 kB for each bio */ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map, u64 logical, u32 len, u64 physical, struct btrfs_device *dev, u64 flags, u64 gen, int mirror_num, u64 physical_for_dev_replace) { int ret; u8 csum[BTRFS_CSUM_SIZE]; u32 blocksize; if (flags & BTRFS_EXTENT_FLAG_DATA) { if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) blocksize = map->stripe_len; else blocksize = sctx->fs_info->sectorsize; spin_lock(&sctx->stat_lock); sctx->stat.data_extents_scrubbed++; sctx->stat.data_bytes_scrubbed += len; spin_unlock(&sctx->stat_lock); } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) blocksize = map->stripe_len; else blocksize = sctx->fs_info->nodesize; spin_lock(&sctx->stat_lock); sctx->stat.tree_extents_scrubbed++; sctx->stat.tree_bytes_scrubbed += len; spin_unlock(&sctx->stat_lock); } else { blocksize = sctx->fs_info->sectorsize; WARN_ON(1); } while (len) { u32 l = min(len, blocksize); int have_csum = 0; if (flags & BTRFS_EXTENT_FLAG_DATA) { /* push csums to sbio */ have_csum = scrub_find_csum(sctx, logical, csum); if (have_csum == 0) ++sctx->stat.no_csum; } ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen, mirror_num, have_csum ? csum : NULL, physical_for_dev_replace); if (ret) return ret; len -= l; logical += l; physical += l; physical_for_dev_replace += l; } return 0; } static int scrub_pages_for_parity(struct scrub_parity *sparity, u64 logical, u32 len, u64 physical, struct btrfs_device *dev, u64 flags, u64 gen, int mirror_num, u8 *csum) { struct scrub_ctx *sctx = sparity->sctx; struct scrub_block *sblock; const u32 sectorsize = sctx->fs_info->sectorsize; int index; ASSERT(IS_ALIGNED(len, sectorsize)); sblock = kzalloc(sizeof(*sblock), GFP_KERNEL); if (!sblock) { spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); return -ENOMEM; } /* one ref inside this function, plus one for each page added to * a bio later on */ refcount_set(&sblock->refs, 1); sblock->sctx = sctx; sblock->no_io_error_seen = 1; sblock->sparity = sparity; scrub_parity_get(sparity); for (index = 0; len > 0; index++) { struct scrub_page *spage; spage = kzalloc(sizeof(*spage), GFP_KERNEL); if (!spage) { leave_nomem: spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); scrub_block_put(sblock); return -ENOMEM; } BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); /* For scrub block */ scrub_page_get(spage); sblock->pagev[index] = spage; /* For scrub parity */ scrub_page_get(spage); list_add_tail(&spage->list, &sparity->spages); spage->sblock = sblock; spage->dev = dev; spage->flags = flags; spage->generation = gen; spage->logical = logical; spage->physical = physical; spage->mirror_num = mirror_num; if (csum) { spage->have_csum = 1; memcpy(spage->csum, csum, sctx->fs_info->csum_size); } else { spage->have_csum = 0; } sblock->page_count++; spage->page = alloc_page(GFP_KERNEL); if (!spage->page) goto leave_nomem; /* Iterate over the stripe range in sectorsize steps */ len -= sectorsize; logical += sectorsize; physical += sectorsize; } WARN_ON(sblock->page_count == 0); for (index = 0; index < sblock->page_count; index++) { struct scrub_page *spage = sblock->pagev[index]; int ret; ret = scrub_add_page_to_rd_bio(sctx, spage); if (ret) { scrub_block_put(sblock); return ret; } } /* last one frees, either here or in bio completion for last page */ scrub_block_put(sblock); return 0; } static int scrub_extent_for_parity(struct scrub_parity *sparity, u64 logical, u32 len, u64 physical, struct btrfs_device *dev, u64 flags, u64 gen, int mirror_num) { struct scrub_ctx *sctx = sparity->sctx; int ret; u8 csum[BTRFS_CSUM_SIZE]; u32 blocksize; if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) { scrub_parity_mark_sectors_error(sparity, logical, len); return 0; } if (flags & BTRFS_EXTENT_FLAG_DATA) { blocksize = sparity->stripe_len; } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { blocksize = sparity->stripe_len; } else { blocksize = sctx->fs_info->sectorsize; WARN_ON(1); } while (len) { u32 l = min(len, blocksize); int have_csum = 0; if (flags & BTRFS_EXTENT_FLAG_DATA) { /* push csums to sbio */ have_csum = scrub_find_csum(sctx, logical, csum); if (have_csum == 0) goto skip; } ret = scrub_pages_for_parity(sparity, logical, l, physical, dev, flags, gen, mirror_num, have_csum ? csum : NULL); if (ret) return ret; skip: len -= l; logical += l; physical += l; } return 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 stripe_nr; u64 last_offset; u32 stripe_index; u32 rot; 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++) { *offset = last_offset + i * map->stripe_len; stripe_nr = div64_u64(*offset, map->stripe_len); stripe_nr = div_u64(stripe_nr, data_stripes); /* Work out the disk rotation on this stripe-set */ stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot); /* 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 + j * map->stripe_len; return 1; } static void scrub_free_parity(struct scrub_parity *sparity) { struct scrub_ctx *sctx = sparity->sctx; struct scrub_page *curr, *next; int nbits; nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors); if (nbits) { spin_lock(&sctx->stat_lock); sctx->stat.read_errors += nbits; sctx->stat.uncorrectable_errors += nbits; spin_unlock(&sctx->stat_lock); } list_for_each_entry_safe(curr, next, &sparity->spages, list) { list_del_init(&curr->list); scrub_page_put(curr); } kfree(sparity); } static void scrub_parity_bio_endio_worker(struct btrfs_work *work) { struct scrub_parity *sparity = container_of(work, struct scrub_parity, work); struct scrub_ctx *sctx = sparity->sctx; scrub_free_parity(sparity); scrub_pending_bio_dec(sctx); } static void scrub_parity_bio_endio(struct bio *bio) { struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private; struct btrfs_fs_info *fs_info = sparity->sctx->fs_info; if (bio->bi_status) bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap, sparity->nsectors); bio_put(bio); btrfs_init_work(&sparity->work, scrub_parity_bio_endio_worker, NULL, NULL); btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work); } static void scrub_parity_check_and_repair(struct scrub_parity *sparity) { struct scrub_ctx *sctx = sparity->sctx; struct btrfs_fs_info *fs_info = sctx->fs_info; struct bio *bio; struct btrfs_raid_bio *rbio; struct btrfs_bio *bbio = NULL; u64 length; int ret; if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap, sparity->nsectors)) goto out; length = sparity->logic_end - sparity->logic_start; btrfs_bio_counter_inc_blocked(fs_info); ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start, &length, &bbio); if (ret || !bbio || !bbio->raid_map) goto bbio_out; bio = btrfs_io_bio_alloc(0); bio->bi_iter.bi_sector = sparity->logic_start >> 9; bio->bi_private = sparity; bio->bi_end_io = scrub_parity_bio_endio; rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio, length, sparity->scrub_dev, sparity->dbitmap, sparity->nsectors); if (!rbio) goto rbio_out; scrub_pending_bio_inc(sctx); raid56_parity_submit_scrub_rbio(rbio); return; rbio_out: bio_put(bio); bbio_out: btrfs_bio_counter_dec(fs_info); btrfs_put_bbio(bbio); bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap, sparity->nsectors); spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); out: scrub_free_parity(sparity); } static inline int scrub_calc_parity_bitmap_len(int nsectors) { return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long); } static void scrub_parity_get(struct scrub_parity *sparity) { refcount_inc(&sparity->refs); } static void scrub_parity_put(struct scrub_parity *sparity) { if (!refcount_dec_and_test(&sparity->refs)) return; scrub_parity_check_and_repair(sparity); } static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, struct map_lookup *map, struct btrfs_device *sdev, struct btrfs_path *path, u64 logic_start, u64 logic_end) { struct btrfs_fs_info *fs_info = sctx->fs_info; struct btrfs_root *root = fs_info->extent_root; struct btrfs_root *csum_root = fs_info->csum_root; struct btrfs_extent_item *extent; struct btrfs_bio *bbio = NULL; u64 flags; int ret; int slot; struct extent_buffer *l; struct btrfs_key key; u64 generation; u64 extent_logical; u64 extent_physical; /* Check the comment in scrub_stripe() for why u32 is enough here */ u32 extent_len; u64 mapped_length; struct btrfs_device *extent_dev; struct scrub_parity *sparity; int nsectors; int bitmap_len; int extent_mirror_num; int stop_loop = 0; ASSERT(map->stripe_len <= U32_MAX); nsectors = map->stripe_len >> fs_info->sectorsize_bits; bitmap_len = scrub_calc_parity_bitmap_len(nsectors); sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len, GFP_NOFS); if (!sparity) { spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); return -ENOMEM; } ASSERT(map->stripe_len <= U32_MAX); sparity->stripe_len = map->stripe_len; sparity->nsectors = nsectors; sparity->sctx = sctx; sparity->scrub_dev = sdev; sparity->logic_start = logic_start; sparity->logic_end = logic_end; refcount_set(&sparity->refs, 1); INIT_LIST_HEAD(&sparity->spages); sparity->dbitmap = sparity->bitmap; sparity->ebitmap = (void *)sparity->bitmap + bitmap_len; ret = 0; while (logic_start < logic_end) { if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) key.type = BTRFS_METADATA_ITEM_KEY; else key.type = BTRFS_EXTENT_ITEM_KEY; key.objectid = logic_start; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; if (ret > 0) { ret = btrfs_previous_extent_item(root, path, 0); if (ret < 0) goto out; if (ret > 0) { btrfs_release_path(path); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; } } stop_loop = 0; while (1) { u64 bytes; l = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(l)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto out; stop_loop = 1; break; } btrfs_item_key_to_cpu(l, &key, slot); if (key.type != BTRFS_EXTENT_ITEM_KEY && key.type != BTRFS_METADATA_ITEM_KEY) goto next; if (key.type == BTRFS_METADATA_ITEM_KEY) bytes = fs_info->nodesize; else bytes = key.offset; if (key.objectid + bytes <= logic_start) goto next; if (key.objectid >= logic_end) { stop_loop = 1; break; } while (key.objectid >= logic_start + map->stripe_len) logic_start += map->stripe_len; extent = btrfs_item_ptr(l, slot, struct btrfs_extent_item); flags = btrfs_extent_flags(l, extent); generation = btrfs_extent_generation(l, extent); if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) && (key.objectid < logic_start || key.objectid + bytes > logic_start + map->stripe_len)) { btrfs_err(fs_info, "scrub: tree block %llu spanning stripes, ignored. logical=%llu", key.objectid, logic_start); spin_lock(&sctx->stat_lock); sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); goto next; } again: extent_logical = key.objectid; ASSERT(bytes <= U32_MAX); extent_len = bytes; if (extent_logical < logic_start) { extent_len -= logic_start - extent_logical; extent_logical = logic_start; } if (extent_logical + extent_len > logic_start + map->stripe_len) extent_len = logic_start + map->stripe_len - extent_logical; scrub_parity_mark_sectors_data(sparity, extent_logical, extent_len); mapped_length = extent_len; bbio = NULL; ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical, &mapped_length, &bbio, 0); if (!ret) { if (!bbio || mapped_length < extent_len) ret = -EIO; } if (ret) { btrfs_put_bbio(bbio); goto out; } extent_physical = bbio->stripes[0].physical; extent_mirror_num = bbio->mirror_num; extent_dev = bbio->stripes[0].dev; btrfs_put_bbio(bbio); ret = btrfs_lookup_csums_range(csum_root, extent_logical, extent_logical + extent_len - 1, &sctx->csum_list, 1); if (ret) goto out; ret = scrub_extent_for_parity(sparity, extent_logical, extent_len, extent_physical, extent_dev, flags, generation, extent_mirror_num); scrub_free_csums(sctx); if (ret) goto out; if (extent_logical + extent_len < key.objectid + bytes) { logic_start += map->stripe_len; if (logic_start >= logic_end) { stop_loop = 1; break; } if (logic_start < key.objectid + bytes) { cond_resched(); goto again; } } next: path->slots[0]++; } btrfs_release_path(path); if (stop_loop) break; logic_start += map->stripe_len; } out: if (ret < 0) { ASSERT(logic_end - logic_start <= U32_MAX); scrub_parity_mark_sectors_error(sparity, logic_start, logic_end - logic_start); } scrub_parity_put(sparity); scrub_submit(sctx); mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); btrfs_release_path(path); return ret < 0 ? ret : 0; } static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, struct map_lookup *map, struct btrfs_device *scrub_dev, int num, u64 base, u64 length, struct btrfs_block_group *cache) { struct btrfs_path *path, *ppath; struct btrfs_fs_info *fs_info = sctx->fs_info; struct btrfs_root *root = fs_info->extent_root; struct btrfs_root *csum_root = fs_info->csum_root; struct btrfs_extent_item *extent; struct blk_plug plug; u64 flags; int ret; int slot; u64 nstripes; struct extent_buffer *l; u64 physical; u64 logical; u64 logic_end; u64 physical_end; u64 generation; int mirror_num; struct reada_control *reada1; struct reada_control *reada2; struct btrfs_key key; struct btrfs_key key_end; u64 increment = map->stripe_len; u64 offset; u64 extent_logical; u64 extent_physical; /* * Unlike chunk length, extent length should never go beyond * BTRFS_MAX_EXTENT_SIZE, thus u32 is enough here. */ u32 extent_len; u64 stripe_logical; u64 stripe_end; struct btrfs_device *extent_dev; int extent_mirror_num; int stop_loop = 0; physical = map->stripes[num].physical; offset = 0; nstripes = div64_u64(length, map->stripe_len); if (map->type & BTRFS_BLOCK_GROUP_RAID0) { offset = map->stripe_len * num; increment = map->stripe_len * map->num_stripes; mirror_num = 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { int factor = map->num_stripes / map->sub_stripes; offset = map->stripe_len * (num / map->sub_stripes); increment = map->stripe_len * factor; mirror_num = num % map->sub_stripes + 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) { increment = map->stripe_len; mirror_num = num % map->num_stripes + 1; } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { increment = map->stripe_len; mirror_num = num % map->num_stripes + 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { get_raid56_logic_offset(physical, num, map, &offset, NULL); increment = map->stripe_len * nr_data_stripes(map); mirror_num = 1; } else { increment = map->stripe_len; mirror_num = 1; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; ppath = btrfs_alloc_path(); if (!ppath) { btrfs_free_path(path); return -ENOMEM; } /* * work on commit root. The related disk blocks are static as * long as COW is applied. This means, it is save to rewrite * them to repair disk errors without any race conditions */ path->search_commit_root = 1; path->skip_locking = 1; ppath->search_commit_root = 1; ppath->skip_locking = 1; /* * trigger the readahead for extent tree csum tree and wait for * completion. During readahead, the scrub is officially paused * to not hold off transaction commits */ logical = base + offset; physical_end = physical + nstripes * map->stripe_len; if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { get_raid56_logic_offset(physical_end, num, map, &logic_end, NULL); logic_end += base; } else { logic_end = logical + increment * nstripes; } wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); scrub_blocked_if_needed(fs_info); /* FIXME it might be better to start readahead at commit root */ key.objectid = logical; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = (u64)0; key_end.objectid = logic_end; key_end.type = BTRFS_METADATA_ITEM_KEY; key_end.offset = (u64)-1; reada1 = btrfs_reada_add(root, &key, &key_end); if (cache->flags & BTRFS_BLOCK_GROUP_DATA) { key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; key.type = BTRFS_EXTENT_CSUM_KEY; key.offset = logical; key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID; key_end.type = BTRFS_EXTENT_CSUM_KEY; key_end.offset = logic_end; reada2 = btrfs_reada_add(csum_root, &key, &key_end); } else { reada2 = NULL; } if (!IS_ERR(reada1)) btrfs_reada_wait(reada1); if (!IS_ERR_OR_NULL(reada2)) btrfs_reada_wait(reada2); /* * collect all data csums for the stripe to avoid seeking during * the scrub. This might currently (crc32) end up to be about 1MB */ blk_start_plug(&plug); /* * now find all extents for each stripe and scrub them */ ret = 0; while (physical < physical_end) { /* * canceled? */ if (atomic_read(&fs_info->scrub_cancel_req) || atomic_read(&sctx->cancel_req)) { ret = -ECANCELED; goto out; } /* * check to see if we have to pause */ if (atomic_read(&fs_info->scrub_pause_req)) { /* push queued extents */ sctx->flush_all_writes = true; scrub_submit(sctx); mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); sctx->flush_all_writes = false; scrub_blocked_if_needed(fs_info); } if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { ret = get_raid56_logic_offset(physical, num, map, &logical, &stripe_logical); logical += base; if (ret) { /* it is parity strip */ stripe_logical += base; stripe_end = stripe_logical + increment; ret = scrub_raid56_parity(sctx, map, scrub_dev, ppath, stripe_logical, stripe_end); if (ret) goto out; goto skip; } } if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) key.type = BTRFS_METADATA_ITEM_KEY; else key.type = BTRFS_EXTENT_ITEM_KEY; key.objectid = logical; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; if (ret > 0) { ret = btrfs_previous_extent_item(root, path, 0); if (ret < 0) goto out; if (ret > 0) { /* there's no smaller item, so stick with the * larger one */ btrfs_release_path(path); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; } } stop_loop = 0; while (1) { u64 bytes; l = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(l)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto out; stop_loop = 1; break; } btrfs_item_key_to_cpu(l, &key, slot); if (key.type != BTRFS_EXTENT_ITEM_KEY && key.type != BTRFS_METADATA_ITEM_KEY) goto next; if (key.type == BTRFS_METADATA_ITEM_KEY) bytes = fs_info->nodesize; else bytes = key.offset; if (key.objectid + bytes <= logical) goto next; if (key.objectid >= logical + map->stripe_len) { /* out of this device extent */ if (key.objectid >= logic_end) stop_loop = 1; break; } /* * If our block group was removed in the meanwhile, just * stop scrubbing since there is no point in continuing. * Continuing would prevent reusing its device extents * for new block groups for a long time. */ spin_lock(&cache->lock); if (cache->removed) { spin_unlock(&cache->lock); ret = 0; goto out; } spin_unlock(&cache->lock); extent = btrfs_item_ptr(l, slot, struct btrfs_extent_item); flags = btrfs_extent_flags(l, extent); generation = btrfs_extent_generation(l, extent); if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) && (key.objectid < logical || key.objectid + bytes > logical + map->stripe_len)) { btrfs_err(fs_info, "scrub: tree block %llu spanning stripes, ignored. logical=%llu", key.objectid, logical); spin_lock(&sctx->stat_lock); sctx->stat.uncorrectable_errors++; spin_unlock(&sctx->stat_lock); goto next; } again: extent_logical = key.objectid; ASSERT(bytes <= U32_MAX); extent_len = bytes; /* * trim extent to this stripe */ if (extent_logical < logical) { extent_len -= logical - extent_logical; extent_logical = logical; } if (extent_logical + extent_len > logical + map->stripe_len) { extent_len = logical + map->stripe_len - extent_logical; } extent_physical = extent_logical - logical + physical; extent_dev = scrub_dev; extent_mirror_num = mirror_num; if (sctx->is_dev_replace) scrub_remap_extent(fs_info, extent_logical, extent_len, &extent_physical, &extent_dev, &extent_mirror_num); if (flags & BTRFS_EXTENT_FLAG_DATA) { ret = btrfs_lookup_csums_range(csum_root, extent_logical, extent_logical + extent_len - 1, &sctx->csum_list, 1); if (ret) goto out; } ret = scrub_extent(sctx, map, extent_logical, extent_len, extent_physical, extent_dev, flags, generation, extent_mirror_num, extent_logical - logical + physical); scrub_free_csums(sctx); if (ret) goto out; if (extent_logical + extent_len < key.objectid + bytes) { if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { /* * loop until we find next data stripe * or we have finished all stripes. */ loop: physical += map->stripe_len; ret = get_raid56_logic_offset(physical, num, map, &logical, &stripe_logical); logical += base; if (ret && physical < physical_end) { stripe_logical += base; stripe_end = stripe_logical + increment; ret = scrub_raid56_parity(sctx, map, scrub_dev, ppath, stripe_logical, stripe_end); if (ret) goto out; goto loop; } } else { physical += map->stripe_len; logical += increment; } if (logical < key.objectid + bytes) { cond_resched(); goto again; } if (physical >= physical_end) { stop_loop = 1; break; } } next: path->slots[0]++; } btrfs_release_path(path); skip: logical += increment; physical += map->stripe_len; spin_lock(&sctx->stat_lock); if (stop_loop) sctx->stat.last_physical = map->stripes[num].physical + length; else sctx->stat.last_physical = physical; spin_unlock(&sctx->stat_lock); if (stop_loop) break; } out: /* push queued extents */ scrub_submit(sctx); mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); blk_finish_plug(&plug); btrfs_free_path(path); btrfs_free_path(ppath); return ret < 0 ? ret : 0; } static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, struct btrfs_device *scrub_dev, u64 chunk_offset, u64 length, u64 dev_offset, struct btrfs_block_group *cache) { 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, chunk_offset, 1); read_unlock(&map_tree->lock); if (!em) { /* * Might have been an unused block group deleted by the cleaner * kthread or relocation. */ spin_lock(&cache->lock); if (!cache->removed) ret = -EINVAL; spin_unlock(&cache->lock); return ret; } map = em->map_lookup; if (em->start != chunk_offset) goto out; if (em->len < length) goto out; 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, map, scrub_dev, i, chunk_offset, length, cache); if (ret) goto out; } } out: free_extent_map(em); return ret; } 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 length; 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) { 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); length = btrfs_dev_extent_length(l, dev_extent); if (found_key.offset + length <= 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; /* * 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 (cache->removed) { 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 == 0) { ro_set = 1; } else if (ret == -ENOSPC && !sctx->is_dev_replace) { /* * 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. */ ro_set = 0; } 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 + length; dev_replace->cursor_left = found_key.offset; dev_replace->item_needs_writeback = 1; up_write(&dev_replace->rwsem); ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length, found_key.offset, cache); /* * flush, submit all pending read and write bios, afterwards * wait for them. * Note that in the dev replace case, a read request causes * write requests that are submitted in the read completion * worker. Therefore in the current situation, it is required * that all write requests are flushed, so that all read and * write requests are really completed when bios_in_flight * changes to 0. */ sctx->flush_all_writes = true; scrub_submit(sctx); mutex_lock(&sctx->wr_lock); scrub_wr_submit(sctx); mutex_unlock(&sctx->wr_lock); wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); scrub_pause_on(fs_info); /* * must be called before we decrease @scrub_paused. * make sure we don't block transaction commit while * we are waiting pending workers finished. */ wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0); sctx->flush_all_writes = false; scrub_pause_off(fs_info); 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 (!cache->removed && !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); } 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 + length; btrfs_release_path(path); } btrfs_free_path(path); return ret; } static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, struct btrfs_device *scrub_dev) { int i; u64 bytenr; u64 gen; int ret; struct btrfs_fs_info *fs_info = sctx->fs_info; if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) return -EROFS; /* 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++) { bytenr = btrfs_sb_offset(i); if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->commit_total_bytes) break; if (!btrfs_check_super_location(scrub_dev, bytenr)) continue; ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr, scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, bytenr); if (ret) return ret; } wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 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 btrfs_workqueue *scrub_workers = NULL; struct btrfs_workqueue *scrub_wr_comp = NULL; struct btrfs_workqueue *scrub_parity = NULL; scrub_workers = fs_info->scrub_workers; scrub_wr_comp = fs_info->scrub_wr_completion_workers; scrub_parity = fs_info->scrub_parity_workers; fs_info->scrub_workers = NULL; fs_info->scrub_wr_completion_workers = NULL; fs_info->scrub_parity_workers = NULL; mutex_unlock(&fs_info->scrub_lock); btrfs_destroy_workqueue(scrub_workers); btrfs_destroy_workqueue(scrub_wr_comp); btrfs_destroy_workqueue(scrub_parity); } } /* * 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, int is_dev_replace) { struct btrfs_workqueue *scrub_workers = NULL; struct btrfs_workqueue *scrub_wr_comp = NULL; struct btrfs_workqueue *scrub_parity = 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 = btrfs_alloc_workqueue(fs_info, "scrub", flags, is_dev_replace ? 1 : max_active, 4); if (!scrub_workers) goto fail_scrub_workers; scrub_wr_comp = btrfs_alloc_workqueue(fs_info, "scrubwrc", flags, max_active, 2); if (!scrub_wr_comp) goto fail_scrub_wr_completion_workers; scrub_parity = btrfs_alloc_workqueue(fs_info, "scrubparity", flags, max_active, 2); if (!scrub_parity) goto fail_scrub_parity_workers; mutex_lock(&fs_info->scrub_lock); if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) { ASSERT(fs_info->scrub_workers == NULL && fs_info->scrub_wr_completion_workers == NULL && fs_info->scrub_parity_workers == NULL); fs_info->scrub_workers = scrub_workers; fs_info->scrub_wr_completion_workers = scrub_wr_comp; fs_info->scrub_parity_workers = scrub_parity; 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; btrfs_destroy_workqueue(scrub_parity); fail_scrub_parity_workers: btrfs_destroy_workqueue(scrub_wr_comp); fail_scrub_wr_completion_workers: btrfs_destroy_workqueue(scrub_workers); fail_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 scrub_ctx *sctx; int ret; struct btrfs_device *dev; unsigned int nofs_flag; if (btrfs_fs_closing(fs_info)) return -EAGAIN; if (fs_info->nodesize > BTRFS_STRIPE_LEN) { /* * in this case scrub is unable to calculate the checksum * the way scrub is implemented. Do not handle this * situation at all because it won't ever happen. */ btrfs_err(fs_info, "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails", fs_info->nodesize, BTRFS_STRIPE_LEN); return -EINVAL; } if (fs_info->sectorsize != PAGE_SIZE) { /* not supported for data w/o checksums */ btrfs_err_rl(fs_info, "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails", fs_info->sectorsize, PAGE_SIZE); return -EINVAL; } if (fs_info->nodesize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK || fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) { /* * would exhaust the array bounds of pagev member in * struct scrub_block */ btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails", fs_info->nodesize, SCRUB_MAX_PAGES_PER_BLOCK, fs_info->sectorsize, SCRUB_MAX_PAGES_PER_BLOCK); return -EINVAL; } /* 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, is_dev_replace); if (ret) goto out_free_ctx; mutex_lock(&fs_info->fs_devices->device_list_mutex); dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL); 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, rcu_str_deref(dev->name)); 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_pages() and scrub_pages_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) { 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); } if (!ret) ret = scrub_enumerate_chunks(sctx, dev, start, end); memalloc_nofs_restore(nofs_flag); wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); atomic_dec(&fs_info->scrubs_running); wake_up(&fs_info->scrub_pause_wait); wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0); 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); 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_device *dev; struct scrub_ctx *sctx = NULL; mutex_lock(&fs_info->fs_devices->device_list_mutex); dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL); 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; } static void scrub_remap_extent(struct btrfs_fs_info *fs_info, u64 extent_logical, u32 extent_len, u64 *extent_physical, struct btrfs_device **extent_dev, int *extent_mirror_num) { u64 mapped_length; struct btrfs_bio *bbio = NULL; int ret; mapped_length = extent_len; ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical, &mapped_length, &bbio, 0); if (ret || !bbio || mapped_length < extent_len || !bbio->stripes[0].dev->bdev) { btrfs_put_bbio(bbio); return; } *extent_physical = bbio->stripes[0].physical; *extent_mirror_num = bbio->mirror_num; *extent_dev = bbio->stripes[0].dev; btrfs_put_bbio(bbio); }