diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/scrub.c | 3062 |
1 files changed, 3062 insertions, 0 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c new file mode 100644 index 0000000000..1e3ff87d04 --- /dev/null +++ b/fs/btrfs/scrub.c @@ -0,0 +1,3062 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2011, 2012 STRATO. All rights reserved. + */ + +#include <linux/blkdev.h> +#include <linux/ratelimit.h> +#include <linux/sched/mm.h> +#include <crypto/hash.h> +#include "ctree.h" +#include "discard.h" +#include "volumes.h" +#include "disk-io.h" +#include "ordered-data.h" +#include "transaction.h" +#include "backref.h" +#include "extent_io.h" +#include "dev-replace.h" +#include "check-integrity.h" +#include "raid56.h" +#include "block-group.h" +#include "zoned.h" +#include "fs.h" +#include "accessors.h" +#include "file-item.h" +#include "scrub.h" + +/* + * This is only the first step towards a full-features scrub. It reads all + * extent and super block and verifies the checksums. In case a bad checksum + * is found or the extent cannot be read, good data will be written back if + * any can be found. + * + * Future enhancements: + * - In case an unrepairable extent is encountered, track which files are + * affected and report them + * - track and record media errors, throw out bad devices + * - add a mode to also read unallocated space + */ + +struct scrub_ctx; + +/* + * The following value only influences the performance. + * + * This detemines how many stripes would be submitted in one go, + * which is 512KiB (BTRFS_STRIPE_LEN * SCRUB_STRIPES_PER_GROUP). + */ +#define SCRUB_STRIPES_PER_GROUP 8 + +/* + * How many groups we have for each sctx. + * + * This would be 8M per device, the same value as the old scrub in-flight bios + * size limit. + */ +#define SCRUB_GROUPS_PER_SCTX 16 + +#define SCRUB_TOTAL_STRIPES (SCRUB_GROUPS_PER_SCTX * SCRUB_STRIPES_PER_GROUP) + +/* + * The following value times PAGE_SIZE needs to be large enough to match the + * largest node/leaf/sector size that shall be supported. + */ +#define SCRUB_MAX_SECTORS_PER_BLOCK (BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K) + +/* Represent one sector and its needed info to verify the content. */ +struct scrub_sector_verification { + bool is_metadata; + + union { + /* + * Csum pointer for data csum verification. Should point to a + * sector csum inside scrub_stripe::csums. + * + * NULL if this data sector has no csum. + */ + u8 *csum; + + /* + * Extra info for metadata verification. All sectors inside a + * tree block share the same generation. + */ + u64 generation; + }; +}; + +enum scrub_stripe_flags { + /* Set when @mirror_num, @dev, @physical and @logical are set. */ + SCRUB_STRIPE_FLAG_INITIALIZED, + + /* Set when the read-repair is finished. */ + SCRUB_STRIPE_FLAG_REPAIR_DONE, + + /* + * Set for data stripes if it's triggered from P/Q stripe. + * During such scrub, we should not report errors in data stripes, nor + * update the accounting. + */ + SCRUB_STRIPE_FLAG_NO_REPORT, +}; + +#define SCRUB_STRIPE_PAGES (BTRFS_STRIPE_LEN / PAGE_SIZE) + +/* + * Represent one contiguous range with a length of BTRFS_STRIPE_LEN. + */ +struct scrub_stripe { + struct scrub_ctx *sctx; + struct btrfs_block_group *bg; + + struct page *pages[SCRUB_STRIPE_PAGES]; + struct scrub_sector_verification *sectors; + + struct btrfs_device *dev; + u64 logical; + u64 physical; + + u16 mirror_num; + + /* Should be BTRFS_STRIPE_LEN / sectorsize. */ + u16 nr_sectors; + + /* + * How many data/meta extents are in this stripe. Only for scrub status + * reporting purposes. + */ + u16 nr_data_extents; + u16 nr_meta_extents; + + atomic_t pending_io; + wait_queue_head_t io_wait; + wait_queue_head_t repair_wait; + + /* + * Indicate the states of the stripe. Bits are defined in + * scrub_stripe_flags enum. + */ + unsigned long state; + + /* Indicate which sectors are covered by extent items. */ + unsigned long extent_sector_bitmap; + + /* + * The errors hit during the initial read of the stripe. + * + * Would be utilized for error reporting and repair. + * + * The remaining init_nr_* records the number of errors hit, only used + * by error reporting. + */ + unsigned long init_error_bitmap; + unsigned int init_nr_io_errors; + unsigned int init_nr_csum_errors; + unsigned int init_nr_meta_errors; + + /* + * The following error bitmaps are all for the current status. + * Every time we submit a new read, these bitmaps may be updated. + * + * error_bitmap = io_error_bitmap | csum_error_bitmap | meta_error_bitmap; + * + * IO and csum errors can happen for both metadata and data. + */ + unsigned long error_bitmap; + unsigned long io_error_bitmap; + unsigned long csum_error_bitmap; + unsigned long meta_error_bitmap; + + /* For writeback (repair or replace) error reporting. */ + unsigned long write_error_bitmap; + + /* Writeback can be concurrent, thus we need to protect the bitmap. */ + spinlock_t write_error_lock; + + /* + * Checksum for the whole stripe if this stripe is inside a data block + * group. + */ + u8 *csums; + + struct work_struct work; +}; + +struct scrub_ctx { + struct scrub_stripe stripes[SCRUB_TOTAL_STRIPES]; + struct scrub_stripe *raid56_data_stripes; + struct btrfs_fs_info *fs_info; + struct btrfs_path extent_path; + struct btrfs_path csum_path; + int first_free; + int cur_stripe; + atomic_t cancel_req; + int readonly; + int sectors_per_bio; + + /* State of IO submission throttling affecting the associated device */ + ktime_t throttle_deadline; + u64 throttle_sent; + + int is_dev_replace; + u64 write_pointer; + + struct mutex wr_lock; + struct btrfs_device *wr_tgtdev; + + /* + * statistics + */ + struct btrfs_scrub_progress stat; + spinlock_t stat_lock; + + /* + * Use a ref counter to avoid use-after-free issues. Scrub workers + * decrement bios_in_flight and workers_pending and then do a wakeup + * on the list_wait wait queue. We must ensure the main scrub task + * doesn't free the scrub context before or while the workers are + * doing the wakeup() call. + */ + refcount_t refs; +}; + +struct scrub_warning { + struct btrfs_path *path; + u64 extent_item_size; + const char *errstr; + u64 physical; + u64 logical; + struct btrfs_device *dev; +}; + +static void release_scrub_stripe(struct scrub_stripe *stripe) +{ + if (!stripe) + return; + + for (int i = 0; i < SCRUB_STRIPE_PAGES; i++) { + if (stripe->pages[i]) + __free_page(stripe->pages[i]); + stripe->pages[i] = NULL; + } + kfree(stripe->sectors); + kfree(stripe->csums); + stripe->sectors = NULL; + stripe->csums = NULL; + stripe->sctx = NULL; + stripe->state = 0; +} + +static int init_scrub_stripe(struct btrfs_fs_info *fs_info, + struct scrub_stripe *stripe) +{ + int ret; + + memset(stripe, 0, sizeof(*stripe)); + + stripe->nr_sectors = BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits; + stripe->state = 0; + + init_waitqueue_head(&stripe->io_wait); + init_waitqueue_head(&stripe->repair_wait); + atomic_set(&stripe->pending_io, 0); + spin_lock_init(&stripe->write_error_lock); + + ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages); + if (ret < 0) + goto error; + + stripe->sectors = kcalloc(stripe->nr_sectors, + sizeof(struct scrub_sector_verification), + GFP_KERNEL); + if (!stripe->sectors) + goto error; + + stripe->csums = kcalloc(BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits, + fs_info->csum_size, GFP_KERNEL); + if (!stripe->csums) + goto error; + return 0; +error: + release_scrub_stripe(stripe); + return -ENOMEM; +} + +static void wait_scrub_stripe_io(struct scrub_stripe *stripe) +{ + wait_event(stripe->io_wait, atomic_read(&stripe->pending_io) == 0); +} + +static void scrub_put_ctx(struct scrub_ctx *sctx); + +static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) +{ + while (atomic_read(&fs_info->scrub_pause_req)) { + mutex_unlock(&fs_info->scrub_lock); + wait_event(fs_info->scrub_pause_wait, + atomic_read(&fs_info->scrub_pause_req) == 0); + mutex_lock(&fs_info->scrub_lock); + } +} + +static void scrub_pause_on(struct btrfs_fs_info *fs_info) +{ + atomic_inc(&fs_info->scrubs_paused); + wake_up(&fs_info->scrub_pause_wait); +} + +static void scrub_pause_off(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->scrub_lock); + __scrub_blocked_if_needed(fs_info); + atomic_dec(&fs_info->scrubs_paused); + mutex_unlock(&fs_info->scrub_lock); + + wake_up(&fs_info->scrub_pause_wait); +} + +static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) +{ + scrub_pause_on(fs_info); + scrub_pause_off(fs_info); +} + +static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) +{ + int i; + + if (!sctx) + return; + + for (i = 0; i < SCRUB_TOTAL_STRIPES; i++) + release_scrub_stripe(&sctx->stripes[i]); + + kvfree(sctx); +} + +static void scrub_put_ctx(struct scrub_ctx *sctx) +{ + if (refcount_dec_and_test(&sctx->refs)) + scrub_free_ctx(sctx); +} + +static noinline_for_stack struct scrub_ctx *scrub_setup_ctx( + struct btrfs_fs_info *fs_info, int is_dev_replace) +{ + struct scrub_ctx *sctx; + int i; + + /* Since sctx has inline 128 stripes, it can go beyond 64K easily. Use + * kvzalloc(). + */ + sctx = kvzalloc(sizeof(*sctx), GFP_KERNEL); + if (!sctx) + goto nomem; + refcount_set(&sctx->refs, 1); + sctx->is_dev_replace = is_dev_replace; + sctx->fs_info = fs_info; + sctx->extent_path.search_commit_root = 1; + sctx->extent_path.skip_locking = 1; + sctx->csum_path.search_commit_root = 1; + sctx->csum_path.skip_locking = 1; + for (i = 0; i < SCRUB_TOTAL_STRIPES; i++) { + int ret; + + ret = init_scrub_stripe(fs_info, &sctx->stripes[i]); + if (ret < 0) + goto nomem; + sctx->stripes[i].sctx = sctx; + } + sctx->first_free = 0; + atomic_set(&sctx->cancel_req, 0); + + spin_lock_init(&sctx->stat_lock); + sctx->throttle_deadline = 0; + + mutex_init(&sctx->wr_lock); + if (is_dev_replace) { + WARN_ON(!fs_info->dev_replace.tgtdev); + sctx->wr_tgtdev = fs_info->dev_replace.tgtdev; + } + + return sctx; + +nomem: + scrub_free_ctx(sctx); + return ERR_PTR(-ENOMEM); +} + +static int scrub_print_warning_inode(u64 inum, u64 offset, u64 num_bytes, + u64 root, void *warn_ctx) +{ + u32 nlink; + int ret; + int i; + unsigned nofs_flag; + struct extent_buffer *eb; + struct btrfs_inode_item *inode_item; + struct scrub_warning *swarn = warn_ctx; + struct btrfs_fs_info *fs_info = swarn->dev->fs_info; + struct inode_fs_paths *ipath = NULL; + struct btrfs_root *local_root; + struct btrfs_key key; + + local_root = btrfs_get_fs_root(fs_info, root, true); + if (IS_ERR(local_root)) { + ret = PTR_ERR(local_root); + goto err; + } + + /* + * this makes the path point to (inum INODE_ITEM ioff) + */ + key.objectid = inum; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0); + if (ret) { + btrfs_put_root(local_root); + btrfs_release_path(swarn->path); + goto err; + } + + eb = swarn->path->nodes[0]; + inode_item = btrfs_item_ptr(eb, swarn->path->slots[0], + struct btrfs_inode_item); + nlink = btrfs_inode_nlink(eb, inode_item); + btrfs_release_path(swarn->path); + + /* + * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub + * uses GFP_NOFS in this context, so we keep it consistent but it does + * not seem to be strictly necessary. + */ + nofs_flag = memalloc_nofs_save(); + ipath = init_ipath(4096, local_root, swarn->path); + memalloc_nofs_restore(nofs_flag); + if (IS_ERR(ipath)) { + btrfs_put_root(local_root); + ret = PTR_ERR(ipath); + ipath = NULL; + goto err; + } + ret = paths_from_inode(inum, ipath); + + if (ret < 0) + goto err; + + /* + * we deliberately ignore the bit ipath might have been too small to + * hold all of the paths here + */ + for (i = 0; i < ipath->fspath->elem_cnt; ++i) + btrfs_warn_in_rcu(fs_info, +"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %u, links %u (path: %s)", + swarn->errstr, swarn->logical, + btrfs_dev_name(swarn->dev), + swarn->physical, + root, inum, offset, + fs_info->sectorsize, nlink, + (char *)(unsigned long)ipath->fspath->val[i]); + + btrfs_put_root(local_root); + free_ipath(ipath); + return 0; + +err: + btrfs_warn_in_rcu(fs_info, + "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d", + swarn->errstr, swarn->logical, + btrfs_dev_name(swarn->dev), + swarn->physical, + root, inum, offset, ret); + + free_ipath(ipath); + return 0; +} + +static void scrub_print_common_warning(const char *errstr, struct btrfs_device *dev, + bool is_super, u64 logical, u64 physical) +{ + struct btrfs_fs_info *fs_info = dev->fs_info; + struct btrfs_path *path; + struct btrfs_key found_key; + struct extent_buffer *eb; + struct btrfs_extent_item *ei; + struct scrub_warning swarn; + u64 flags = 0; + u32 item_size; + int ret; + + /* Super block error, no need to search extent tree. */ + if (is_super) { + btrfs_warn_in_rcu(fs_info, "%s on device %s, physical %llu", + errstr, btrfs_dev_name(dev), physical); + return; + } + path = btrfs_alloc_path(); + if (!path) + return; + + swarn.physical = physical; + swarn.logical = logical; + swarn.errstr = errstr; + swarn.dev = NULL; + + ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, + &flags); + if (ret < 0) + goto out; + + swarn.extent_item_size = found_key.offset; + + eb = path->nodes[0]; + ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); + item_size = btrfs_item_size(eb, path->slots[0]); + + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + unsigned long ptr = 0; + u8 ref_level; + u64 ref_root; + + while (true) { + ret = tree_backref_for_extent(&ptr, eb, &found_key, ei, + item_size, &ref_root, + &ref_level); + if (ret < 0) { + btrfs_warn(fs_info, + "failed to resolve tree backref for logical %llu: %d", + swarn.logical, ret); + break; + } + if (ret > 0) + break; + btrfs_warn_in_rcu(fs_info, +"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu", + errstr, swarn.logical, btrfs_dev_name(dev), + swarn.physical, (ref_level ? "node" : "leaf"), + ref_level, ref_root); + } + btrfs_release_path(path); + } else { + struct btrfs_backref_walk_ctx ctx = { 0 }; + + btrfs_release_path(path); + + ctx.bytenr = found_key.objectid; + ctx.extent_item_pos = swarn.logical - found_key.objectid; + ctx.fs_info = fs_info; + + swarn.path = path; + swarn.dev = dev; + + iterate_extent_inodes(&ctx, true, scrub_print_warning_inode, &swarn); + } + +out: + btrfs_free_path(path); +} + +static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical) +{ + int ret = 0; + u64 length; + + if (!btrfs_is_zoned(sctx->fs_info)) + return 0; + + if (!btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) + return 0; + + if (sctx->write_pointer < physical) { + length = physical - sctx->write_pointer; + + ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev, + sctx->write_pointer, length); + if (!ret) + sctx->write_pointer = physical; + } + return ret; +} + +static struct page *scrub_stripe_get_page(struct scrub_stripe *stripe, int sector_nr) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + int page_index = (sector_nr << fs_info->sectorsize_bits) >> PAGE_SHIFT; + + return stripe->pages[page_index]; +} + +static unsigned int scrub_stripe_get_page_offset(struct scrub_stripe *stripe, + int sector_nr) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + + return offset_in_page(sector_nr << fs_info->sectorsize_bits); +} + +static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits; + const u64 logical = stripe->logical + (sector_nr << fs_info->sectorsize_bits); + const struct page *first_page = scrub_stripe_get_page(stripe, sector_nr); + const unsigned int first_off = scrub_stripe_get_page_offset(stripe, sector_nr); + SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); + u8 on_disk_csum[BTRFS_CSUM_SIZE]; + u8 calculated_csum[BTRFS_CSUM_SIZE]; + struct btrfs_header *header; + + /* + * Here we don't have a good way to attach the pages (and subpages) + * to a dummy extent buffer, thus we have to directly grab the members + * from pages. + */ + header = (struct btrfs_header *)(page_address(first_page) + first_off); + memcpy(on_disk_csum, header->csum, fs_info->csum_size); + + if (logical != btrfs_stack_header_bytenr(header)) { + bitmap_set(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); + btrfs_warn_rl(fs_info, + "tree block %llu mirror %u has bad bytenr, has %llu want %llu", + logical, stripe->mirror_num, + btrfs_stack_header_bytenr(header), logical); + return; + } + if (memcmp(header->fsid, fs_info->fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) != 0) { + bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); + btrfs_warn_rl(fs_info, + "tree block %llu mirror %u has bad fsid, has %pU want %pU", + logical, stripe->mirror_num, + header->fsid, fs_info->fs_devices->fsid); + return; + } + if (memcmp(header->chunk_tree_uuid, fs_info->chunk_tree_uuid, + BTRFS_UUID_SIZE) != 0) { + bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); + btrfs_warn_rl(fs_info, + "tree block %llu mirror %u has bad chunk tree uuid, has %pU want %pU", + logical, stripe->mirror_num, + header->chunk_tree_uuid, fs_info->chunk_tree_uuid); + return; + } + + /* Now check tree block csum. */ + shash->tfm = fs_info->csum_shash; + crypto_shash_init(shash); + crypto_shash_update(shash, page_address(first_page) + first_off + + BTRFS_CSUM_SIZE, fs_info->sectorsize - BTRFS_CSUM_SIZE); + + for (int i = sector_nr + 1; i < sector_nr + sectors_per_tree; i++) { + struct page *page = scrub_stripe_get_page(stripe, i); + unsigned int page_off = scrub_stripe_get_page_offset(stripe, i); + + crypto_shash_update(shash, page_address(page) + page_off, + fs_info->sectorsize); + } + + crypto_shash_final(shash, calculated_csum); + if (memcmp(calculated_csum, on_disk_csum, fs_info->csum_size) != 0) { + bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); + btrfs_warn_rl(fs_info, + "tree block %llu mirror %u has bad csum, has " CSUM_FMT " want " CSUM_FMT, + logical, stripe->mirror_num, + CSUM_FMT_VALUE(fs_info->csum_size, on_disk_csum), + CSUM_FMT_VALUE(fs_info->csum_size, calculated_csum)); + return; + } + if (stripe->sectors[sector_nr].generation != + btrfs_stack_header_generation(header)) { + bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); + bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree); + btrfs_warn_rl(fs_info, + "tree block %llu mirror %u has bad generation, has %llu want %llu", + logical, stripe->mirror_num, + btrfs_stack_header_generation(header), + stripe->sectors[sector_nr].generation); + return; + } + bitmap_clear(&stripe->error_bitmap, sector_nr, sectors_per_tree); + bitmap_clear(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree); + bitmap_clear(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree); +} + +static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + struct scrub_sector_verification *sector = &stripe->sectors[sector_nr]; + const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits; + struct page *page = scrub_stripe_get_page(stripe, sector_nr); + unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr); + u8 csum_buf[BTRFS_CSUM_SIZE]; + int ret; + + ASSERT(sector_nr >= 0 && sector_nr < stripe->nr_sectors); + + /* Sector not utilized, skip it. */ + if (!test_bit(sector_nr, &stripe->extent_sector_bitmap)) + return; + + /* IO error, no need to check. */ + if (test_bit(sector_nr, &stripe->io_error_bitmap)) + return; + + /* Metadata, verify the full tree block. */ + if (sector->is_metadata) { + /* + * Check if the tree block crosses the stripe boudary. If + * crossed the boundary, we cannot verify it but only give a + * warning. + * + * This can only happen on a very old filesystem where chunks + * are not ensured to be stripe aligned. + */ + if (unlikely(sector_nr + sectors_per_tree > stripe->nr_sectors)) { + btrfs_warn_rl(fs_info, + "tree block at %llu crosses stripe boundary %llu", + stripe->logical + + (sector_nr << fs_info->sectorsize_bits), + stripe->logical); + return; + } + scrub_verify_one_metadata(stripe, sector_nr); + return; + } + + /* + * Data is easier, we just verify the data csum (if we have it). For + * cases without csum, we have no other choice but to trust it. + */ + if (!sector->csum) { + clear_bit(sector_nr, &stripe->error_bitmap); + return; + } + + ret = btrfs_check_sector_csum(fs_info, page, pgoff, csum_buf, sector->csum); + if (ret < 0) { + set_bit(sector_nr, &stripe->csum_error_bitmap); + set_bit(sector_nr, &stripe->error_bitmap); + } else { + clear_bit(sector_nr, &stripe->csum_error_bitmap); + clear_bit(sector_nr, &stripe->error_bitmap); + } +} + +/* Verify specified sectors of a stripe. */ +static void scrub_verify_one_stripe(struct scrub_stripe *stripe, unsigned long bitmap) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits; + int sector_nr; + + for_each_set_bit(sector_nr, &bitmap, stripe->nr_sectors) { + scrub_verify_one_sector(stripe, sector_nr); + if (stripe->sectors[sector_nr].is_metadata) + sector_nr += sectors_per_tree - 1; + } +} + +static int calc_sector_number(struct scrub_stripe *stripe, struct bio_vec *first_bvec) +{ + int i; + + for (i = 0; i < stripe->nr_sectors; i++) { + if (scrub_stripe_get_page(stripe, i) == first_bvec->bv_page && + scrub_stripe_get_page_offset(stripe, i) == first_bvec->bv_offset) + break; + } + ASSERT(i < stripe->nr_sectors); + return i; +} + +/* + * Repair read is different to the regular read: + * + * - Only reads the failed sectors + * - May have extra blocksize limits + */ +static void scrub_repair_read_endio(struct btrfs_bio *bbio) +{ + struct scrub_stripe *stripe = bbio->private; + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + struct bio_vec *bvec; + int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio)); + u32 bio_size = 0; + int i; + + ASSERT(sector_nr < stripe->nr_sectors); + + bio_for_each_bvec_all(bvec, &bbio->bio, i) + bio_size += bvec->bv_len; + + if (bbio->bio.bi_status) { + bitmap_set(&stripe->io_error_bitmap, sector_nr, + bio_size >> fs_info->sectorsize_bits); + bitmap_set(&stripe->error_bitmap, sector_nr, + bio_size >> fs_info->sectorsize_bits); + } else { + bitmap_clear(&stripe->io_error_bitmap, sector_nr, + bio_size >> fs_info->sectorsize_bits); + } + bio_put(&bbio->bio); + if (atomic_dec_and_test(&stripe->pending_io)) + wake_up(&stripe->io_wait); +} + +static int calc_next_mirror(int mirror, int num_copies) +{ + ASSERT(mirror <= num_copies); + return (mirror + 1 > num_copies) ? 1 : mirror + 1; +} + +static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe, + int mirror, int blocksize, bool wait) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + struct btrfs_bio *bbio = NULL; + const unsigned long old_error_bitmap = stripe->error_bitmap; + int i; + + ASSERT(stripe->mirror_num >= 1); + ASSERT(atomic_read(&stripe->pending_io) == 0); + + for_each_set_bit(i, &old_error_bitmap, stripe->nr_sectors) { + struct page *page; + int pgoff; + int ret; + + page = scrub_stripe_get_page(stripe, i); + pgoff = scrub_stripe_get_page_offset(stripe, i); + + /* The current sector cannot be merged, submit the bio. */ + if (bbio && ((i > 0 && !test_bit(i - 1, &stripe->error_bitmap)) || + bbio->bio.bi_iter.bi_size >= blocksize)) { + ASSERT(bbio->bio.bi_iter.bi_size); + atomic_inc(&stripe->pending_io); + btrfs_submit_bio(bbio, mirror); + if (wait) + wait_scrub_stripe_io(stripe); + bbio = NULL; + } + + if (!bbio) { + bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ, + fs_info, scrub_repair_read_endio, stripe); + bbio->bio.bi_iter.bi_sector = (stripe->logical + + (i << fs_info->sectorsize_bits)) >> SECTOR_SHIFT; + } + + ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); + ASSERT(ret == fs_info->sectorsize); + } + if (bbio) { + ASSERT(bbio->bio.bi_iter.bi_size); + atomic_inc(&stripe->pending_io); + btrfs_submit_bio(bbio, mirror); + if (wait) + wait_scrub_stripe_io(stripe); + } +} + +static void scrub_stripe_report_errors(struct scrub_ctx *sctx, + struct scrub_stripe *stripe) +{ + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct btrfs_device *dev = NULL; + u64 physical = 0; + int nr_data_sectors = 0; + int nr_meta_sectors = 0; + int nr_nodatacsum_sectors = 0; + int nr_repaired_sectors = 0; + int sector_nr; + + if (test_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state)) + return; + + /* + * Init needed infos for error reporting. + * + * Although our scrub_stripe infrastucture is mostly based on btrfs_submit_bio() + * thus no need for dev/physical, error reporting still needs dev and physical. + */ + if (!bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) { + u64 mapped_len = fs_info->sectorsize; + struct btrfs_io_context *bioc = NULL; + int stripe_index = stripe->mirror_num - 1; + int ret; + + /* For scrub, our mirror_num should always start at 1. */ + ASSERT(stripe->mirror_num >= 1); + ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, + stripe->logical, &mapped_len, &bioc, + NULL, NULL, 1); + /* + * If we failed, dev will be NULL, and later detailed reports + * will just be skipped. + */ + if (ret < 0) + goto skip; + physical = bioc->stripes[stripe_index].physical; + dev = bioc->stripes[stripe_index].dev; + btrfs_put_bioc(bioc); + } + +skip: + for_each_set_bit(sector_nr, &stripe->extent_sector_bitmap, stripe->nr_sectors) { + bool repaired = false; + + if (stripe->sectors[sector_nr].is_metadata) { + nr_meta_sectors++; + } else { + nr_data_sectors++; + if (!stripe->sectors[sector_nr].csum) + nr_nodatacsum_sectors++; + } + + if (test_bit(sector_nr, &stripe->init_error_bitmap) && + !test_bit(sector_nr, &stripe->error_bitmap)) { + nr_repaired_sectors++; + repaired = true; + } + + /* Good sector from the beginning, nothing need to be done. */ + if (!test_bit(sector_nr, &stripe->init_error_bitmap)) + continue; + + /* + * Report error for the corrupted sectors. If repaired, just + * output the message of repaired message. + */ + if (repaired) { + if (dev) { + btrfs_err_rl_in_rcu(fs_info, + "fixed up error at logical %llu on dev %s physical %llu", + stripe->logical, btrfs_dev_name(dev), + physical); + } else { + btrfs_err_rl_in_rcu(fs_info, + "fixed up error at logical %llu on mirror %u", + stripe->logical, stripe->mirror_num); + } + continue; + } + + /* The remaining are all for unrepaired. */ + if (dev) { + btrfs_err_rl_in_rcu(fs_info, + "unable to fixup (regular) error at logical %llu on dev %s physical %llu", + stripe->logical, btrfs_dev_name(dev), + physical); + } else { + btrfs_err_rl_in_rcu(fs_info, + "unable to fixup (regular) error at logical %llu on mirror %u", + stripe->logical, stripe->mirror_num); + } + + if (test_bit(sector_nr, &stripe->io_error_bitmap)) + if (__ratelimit(&rs) && dev) + scrub_print_common_warning("i/o error", dev, false, + stripe->logical, physical); + if (test_bit(sector_nr, &stripe->csum_error_bitmap)) + if (__ratelimit(&rs) && dev) + scrub_print_common_warning("checksum error", dev, false, + stripe->logical, physical); + if (test_bit(sector_nr, &stripe->meta_error_bitmap)) + if (__ratelimit(&rs) && dev) + scrub_print_common_warning("header error", dev, false, + stripe->logical, physical); + } + + spin_lock(&sctx->stat_lock); + sctx->stat.data_extents_scrubbed += stripe->nr_data_extents; + sctx->stat.tree_extents_scrubbed += stripe->nr_meta_extents; + sctx->stat.data_bytes_scrubbed += nr_data_sectors << fs_info->sectorsize_bits; + sctx->stat.tree_bytes_scrubbed += nr_meta_sectors << fs_info->sectorsize_bits; + sctx->stat.no_csum += nr_nodatacsum_sectors; + sctx->stat.read_errors += stripe->init_nr_io_errors; + sctx->stat.csum_errors += stripe->init_nr_csum_errors; + sctx->stat.verify_errors += stripe->init_nr_meta_errors; + sctx->stat.uncorrectable_errors += + bitmap_weight(&stripe->error_bitmap, stripe->nr_sectors); + sctx->stat.corrected_errors += nr_repaired_sectors; + spin_unlock(&sctx->stat_lock); +} + +static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe, + unsigned long write_bitmap, bool dev_replace); + +/* + * The main entrance for all read related scrub work, including: + * + * - Wait for the initial read to finish + * - Verify and locate any bad sectors + * - Go through the remaining mirrors and try to read as large blocksize as + * possible + * - Go through all mirrors (including the failed mirror) sector-by-sector + * - Submit writeback for repaired sectors + * + * Writeback for dev-replace does not happen here, it needs extra + * synchronization for zoned devices. + */ +static void scrub_stripe_read_repair_worker(struct work_struct *work) +{ + struct scrub_stripe *stripe = container_of(work, struct scrub_stripe, work); + struct scrub_ctx *sctx = stripe->sctx; + struct btrfs_fs_info *fs_info = sctx->fs_info; + int num_copies = btrfs_num_copies(fs_info, stripe->bg->start, + stripe->bg->length); + int mirror; + int i; + + ASSERT(stripe->mirror_num > 0); + + wait_scrub_stripe_io(stripe); + scrub_verify_one_stripe(stripe, stripe->extent_sector_bitmap); + /* Save the initial failed bitmap for later repair and report usage. */ + stripe->init_error_bitmap = stripe->error_bitmap; + stripe->init_nr_io_errors = bitmap_weight(&stripe->io_error_bitmap, + stripe->nr_sectors); + stripe->init_nr_csum_errors = bitmap_weight(&stripe->csum_error_bitmap, + stripe->nr_sectors); + stripe->init_nr_meta_errors = bitmap_weight(&stripe->meta_error_bitmap, + stripe->nr_sectors); + + if (bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) + goto out; + + /* + * Try all remaining mirrors. + * + * Here we still try to read as large block as possible, as this is + * faster and we have extra safety nets to rely on. + */ + for (mirror = calc_next_mirror(stripe->mirror_num, num_copies); + mirror != stripe->mirror_num; + mirror = calc_next_mirror(mirror, num_copies)) { + const unsigned long old_error_bitmap = stripe->error_bitmap; + + scrub_stripe_submit_repair_read(stripe, mirror, + BTRFS_STRIPE_LEN, false); + wait_scrub_stripe_io(stripe); + scrub_verify_one_stripe(stripe, old_error_bitmap); + if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors)) + goto out; + } + + /* + * Last safety net, try re-checking all mirrors, including the failed + * one, sector-by-sector. + * + * As if one sector failed the drive's internal csum, the whole read + * containing the offending sector would be marked as error. + * Thus here we do sector-by-sector read. + * + * This can be slow, thus we only try it as the last resort. + */ + + for (i = 0, mirror = stripe->mirror_num; + i < num_copies; + i++, mirror = calc_next_mirror(mirror, num_copies)) { + const unsigned long old_error_bitmap = stripe->error_bitmap; + + scrub_stripe_submit_repair_read(stripe, mirror, + fs_info->sectorsize, true); + wait_scrub_stripe_io(stripe); + scrub_verify_one_stripe(stripe, old_error_bitmap); + if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors)) + goto out; + } +out: + /* + * Submit the repaired sectors. For zoned case, we cannot do repair + * in-place, but queue the bg to be relocated. + */ + if (btrfs_is_zoned(fs_info)) { + if (!bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors)) + btrfs_repair_one_zone(fs_info, sctx->stripes[0].bg->start); + } else if (!sctx->readonly) { + unsigned long repaired; + + bitmap_andnot(&repaired, &stripe->init_error_bitmap, + &stripe->error_bitmap, stripe->nr_sectors); + scrub_write_sectors(sctx, stripe, repaired, false); + wait_scrub_stripe_io(stripe); + } + + scrub_stripe_report_errors(sctx, stripe); + set_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state); + wake_up(&stripe->repair_wait); +} + +static void scrub_read_endio(struct btrfs_bio *bbio) +{ + struct scrub_stripe *stripe = bbio->private; + struct bio_vec *bvec; + int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio)); + int num_sectors; + u32 bio_size = 0; + int i; + + ASSERT(sector_nr < stripe->nr_sectors); + bio_for_each_bvec_all(bvec, &bbio->bio, i) + bio_size += bvec->bv_len; + num_sectors = bio_size >> stripe->bg->fs_info->sectorsize_bits; + + if (bbio->bio.bi_status) { + bitmap_set(&stripe->io_error_bitmap, sector_nr, num_sectors); + bitmap_set(&stripe->error_bitmap, sector_nr, num_sectors); + } else { + bitmap_clear(&stripe->io_error_bitmap, sector_nr, num_sectors); + } + bio_put(&bbio->bio); + if (atomic_dec_and_test(&stripe->pending_io)) { + wake_up(&stripe->io_wait); + INIT_WORK(&stripe->work, scrub_stripe_read_repair_worker); + queue_work(stripe->bg->fs_info->scrub_workers, &stripe->work); + } +} + +static void scrub_write_endio(struct btrfs_bio *bbio) +{ + struct scrub_stripe *stripe = bbio->private; + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + struct bio_vec *bvec; + int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio)); + u32 bio_size = 0; + int i; + + bio_for_each_bvec_all(bvec, &bbio->bio, i) + bio_size += bvec->bv_len; + + if (bbio->bio.bi_status) { + unsigned long flags; + + spin_lock_irqsave(&stripe->write_error_lock, flags); + bitmap_set(&stripe->write_error_bitmap, sector_nr, + bio_size >> fs_info->sectorsize_bits); + spin_unlock_irqrestore(&stripe->write_error_lock, flags); + } + bio_put(&bbio->bio); + + if (atomic_dec_and_test(&stripe->pending_io)) + wake_up(&stripe->io_wait); +} + +static void scrub_submit_write_bio(struct scrub_ctx *sctx, + struct scrub_stripe *stripe, + struct btrfs_bio *bbio, bool dev_replace) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + u32 bio_len = bbio->bio.bi_iter.bi_size; + u32 bio_off = (bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT) - + stripe->logical; + + fill_writer_pointer_gap(sctx, stripe->physical + bio_off); + atomic_inc(&stripe->pending_io); + btrfs_submit_repair_write(bbio, stripe->mirror_num, dev_replace); + if (!btrfs_is_zoned(fs_info)) + return; + /* + * For zoned writeback, queue depth must be 1, thus we must wait for + * the write to finish before the next write. + */ + wait_scrub_stripe_io(stripe); + + /* + * And also need to update the write pointer if write finished + * successfully. + */ + if (!test_bit(bio_off >> fs_info->sectorsize_bits, + &stripe->write_error_bitmap)) + sctx->write_pointer += bio_len; +} + +/* + * Submit the write bio(s) for the sectors specified by @write_bitmap. + * + * Here we utilize btrfs_submit_repair_write(), which has some extra benefits: + * + * - Only needs logical bytenr and mirror_num + * Just like the scrub read path + * + * - Would only result in writes to the specified mirror + * Unlike the regular writeback path, which would write back to all stripes + * + * - Handle dev-replace and read-repair writeback differently + */ +static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe, + unsigned long write_bitmap, bool dev_replace) +{ + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + struct btrfs_bio *bbio = NULL; + int sector_nr; + + for_each_set_bit(sector_nr, &write_bitmap, stripe->nr_sectors) { + struct page *page = scrub_stripe_get_page(stripe, sector_nr); + unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr); + int ret; + + /* We should only writeback sectors covered by an extent. */ + ASSERT(test_bit(sector_nr, &stripe->extent_sector_bitmap)); + + /* Cannot merge with previous sector, submit the current one. */ + if (bbio && sector_nr && !test_bit(sector_nr - 1, &write_bitmap)) { + scrub_submit_write_bio(sctx, stripe, bbio, dev_replace); + bbio = NULL; + } + if (!bbio) { + bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_WRITE, + fs_info, scrub_write_endio, stripe); + bbio->bio.bi_iter.bi_sector = (stripe->logical + + (sector_nr << fs_info->sectorsize_bits)) >> + SECTOR_SHIFT; + } + ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); + ASSERT(ret == fs_info->sectorsize); + } + if (bbio) + scrub_submit_write_bio(sctx, stripe, bbio, dev_replace); +} + +/* + * Throttling of IO submission, bandwidth-limit based, the timeslice is 1 + * second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max. + */ +static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *device, + unsigned int bio_size) +{ + const int time_slice = 1000; + s64 delta; + ktime_t now; + u32 div; + u64 bwlimit; + + bwlimit = READ_ONCE(device->scrub_speed_max); + if (bwlimit == 0) + return; + + /* + * Slice is divided into intervals when the IO is submitted, adjust by + * bwlimit and maximum of 64 intervals. + */ + div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024))); + div = min_t(u32, 64, div); + + /* Start new epoch, set deadline */ + now = ktime_get(); + if (sctx->throttle_deadline == 0) { + sctx->throttle_deadline = ktime_add_ms(now, time_slice / div); + sctx->throttle_sent = 0; + } + + /* Still in the time to send? */ + if (ktime_before(now, sctx->throttle_deadline)) { + /* If current bio is within the limit, send it */ + sctx->throttle_sent += bio_size; + if (sctx->throttle_sent <= div_u64(bwlimit, div)) + return; + + /* We're over the limit, sleep until the rest of the slice */ + delta = ktime_ms_delta(sctx->throttle_deadline, now); + } else { + /* New request after deadline, start new epoch */ + delta = 0; + } + + if (delta) { + long timeout; + + timeout = div_u64(delta * HZ, 1000); + schedule_timeout_interruptible(timeout); + } + + /* Next call will start the deadline period */ + sctx->throttle_deadline = 0; +} + +/* + * Given a physical address, this will calculate it's + * logical offset. if this is a parity stripe, it will return + * the most left data stripe's logical offset. + * + * return 0 if it is a data stripe, 1 means parity stripe. + */ +static int get_raid56_logic_offset(u64 physical, int num, + struct map_lookup *map, u64 *offset, + u64 *stripe_start) +{ + int i; + int j = 0; + u64 last_offset; + const int data_stripes = nr_data_stripes(map); + + last_offset = (physical - map->stripes[num].physical) * data_stripes; + if (stripe_start) + *stripe_start = last_offset; + + *offset = last_offset; + for (i = 0; i < data_stripes; i++) { + u32 stripe_nr; + u32 stripe_index; + u32 rot; + + *offset = last_offset + btrfs_stripe_nr_to_offset(i); + + stripe_nr = (u32)(*offset >> BTRFS_STRIPE_LEN_SHIFT) / data_stripes; + + /* Work out the disk rotation on this stripe-set */ + rot = stripe_nr % map->num_stripes; + /* calculate which stripe this data locates */ + rot += i; + stripe_index = rot % map->num_stripes; + if (stripe_index == num) + return 0; + if (stripe_index < num) + j++; + } + *offset = last_offset + btrfs_stripe_nr_to_offset(j); + return 1; +} + +/* + * Return 0 if the extent item range covers any byte of the range. + * Return <0 if the extent item is before @search_start. + * Return >0 if the extent item is after @start_start + @search_len. + */ +static int compare_extent_item_range(struct btrfs_path *path, + u64 search_start, u64 search_len) +{ + struct btrfs_fs_info *fs_info = path->nodes[0]->fs_info; + u64 len; + struct btrfs_key key; + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + ASSERT(key.type == BTRFS_EXTENT_ITEM_KEY || + key.type == BTRFS_METADATA_ITEM_KEY); + if (key.type == BTRFS_METADATA_ITEM_KEY) + len = fs_info->nodesize; + else + len = key.offset; + + if (key.objectid + len <= search_start) + return -1; + if (key.objectid >= search_start + search_len) + return 1; + return 0; +} + +/* + * Locate one extent item which covers any byte in range + * [@search_start, @search_start + @search_length) + * + * If the path is not initialized, we will initialize the search by doing + * a btrfs_search_slot(). + * If the path is already initialized, we will use the path as the initial + * slot, to avoid duplicated btrfs_search_slot() calls. + * + * NOTE: If an extent item starts before @search_start, we will still + * return the extent item. This is for data extent crossing stripe boundary. + * + * Return 0 if we found such extent item, and @path will point to the extent item. + * Return >0 if no such extent item can be found, and @path will be released. + * Return <0 if hit fatal error, and @path will be released. + */ +static int find_first_extent_item(struct btrfs_root *extent_root, + struct btrfs_path *path, + u64 search_start, u64 search_len) +{ + struct btrfs_fs_info *fs_info = extent_root->fs_info; + struct btrfs_key key; + int ret; + + /* Continue using the existing path */ + if (path->nodes[0]) + goto search_forward; + + if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) + key.type = BTRFS_METADATA_ITEM_KEY; + else + key.type = BTRFS_EXTENT_ITEM_KEY; + key.objectid = search_start; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); + if (ret < 0) + return ret; + + ASSERT(ret > 0); + /* + * Here we intentionally pass 0 as @min_objectid, as there could be + * an extent item starting before @search_start. + */ + ret = btrfs_previous_extent_item(extent_root, path, 0); + if (ret < 0) + return ret; + /* + * No matter whether we have found an extent item, the next loop will + * properly do every check on the key. + */ +search_forward: + while (true) { + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid >= search_start + search_len) + break; + if (key.type != BTRFS_METADATA_ITEM_KEY && + key.type != BTRFS_EXTENT_ITEM_KEY) + goto next; + + ret = compare_extent_item_range(path, search_start, search_len); + if (ret == 0) + return ret; + if (ret > 0) + break; +next: + path->slots[0]++; + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(extent_root, path); + if (ret) { + /* Either no more item or fatal error */ + btrfs_release_path(path); + return ret; + } + } + } + btrfs_release_path(path); + return 1; +} + +static void get_extent_info(struct btrfs_path *path, u64 *extent_start_ret, + u64 *size_ret, u64 *flags_ret, u64 *generation_ret) +{ + struct btrfs_key key; + struct btrfs_extent_item *ei; + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + ASSERT(key.type == BTRFS_METADATA_ITEM_KEY || + key.type == BTRFS_EXTENT_ITEM_KEY); + *extent_start_ret = key.objectid; + if (key.type == BTRFS_METADATA_ITEM_KEY) + *size_ret = path->nodes[0]->fs_info->nodesize; + else + *size_ret = key.offset; + ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item); + *flags_ret = btrfs_extent_flags(path->nodes[0], ei); + *generation_ret = btrfs_extent_generation(path->nodes[0], ei); +} + +static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical, + u64 physical, u64 physical_end) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + int ret = 0; + + if (!btrfs_is_zoned(fs_info)) + return 0; + + mutex_lock(&sctx->wr_lock); + if (sctx->write_pointer < physical_end) { + ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical, + physical, + sctx->write_pointer); + if (ret) + btrfs_err(fs_info, + "zoned: failed to recover write pointer"); + } + mutex_unlock(&sctx->wr_lock); + btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical); + + return ret; +} + +static void fill_one_extent_info(struct btrfs_fs_info *fs_info, + struct scrub_stripe *stripe, + u64 extent_start, u64 extent_len, + u64 extent_flags, u64 extent_gen) +{ + for (u64 cur_logical = max(stripe->logical, extent_start); + cur_logical < min(stripe->logical + BTRFS_STRIPE_LEN, + extent_start + extent_len); + cur_logical += fs_info->sectorsize) { + const int nr_sector = (cur_logical - stripe->logical) >> + fs_info->sectorsize_bits; + struct scrub_sector_verification *sector = + &stripe->sectors[nr_sector]; + + set_bit(nr_sector, &stripe->extent_sector_bitmap); + if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + sector->is_metadata = true; + sector->generation = extent_gen; + } + } +} + +static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe) +{ + stripe->extent_sector_bitmap = 0; + stripe->init_error_bitmap = 0; + stripe->init_nr_io_errors = 0; + stripe->init_nr_csum_errors = 0; + stripe->init_nr_meta_errors = 0; + stripe->error_bitmap = 0; + stripe->io_error_bitmap = 0; + stripe->csum_error_bitmap = 0; + stripe->meta_error_bitmap = 0; +} + +/* + * Locate one stripe which has at least one extent in its range. + * + * Return 0 if found such stripe, and store its info into @stripe. + * Return >0 if there is no such stripe in the specified range. + * Return <0 for error. + */ +static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg, + struct btrfs_path *extent_path, + struct btrfs_path *csum_path, + struct btrfs_device *dev, u64 physical, + int mirror_num, u64 logical_start, + u32 logical_len, + struct scrub_stripe *stripe) +{ + struct btrfs_fs_info *fs_info = bg->fs_info; + struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start); + struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bg->start); + const u64 logical_end = logical_start + logical_len; + u64 cur_logical = logical_start; + u64 stripe_end; + u64 extent_start; + u64 extent_len; + u64 extent_flags; + u64 extent_gen; + int ret; + + memset(stripe->sectors, 0, sizeof(struct scrub_sector_verification) * + stripe->nr_sectors); + scrub_stripe_reset_bitmaps(stripe); + + /* The range must be inside the bg. */ + ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length); + + ret = find_first_extent_item(extent_root, extent_path, logical_start, + logical_len); + /* Either error or not found. */ + if (ret) + goto out; + get_extent_info(extent_path, &extent_start, &extent_len, &extent_flags, + &extent_gen); + if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) + stripe->nr_meta_extents++; + if (extent_flags & BTRFS_EXTENT_FLAG_DATA) + stripe->nr_data_extents++; + cur_logical = max(extent_start, cur_logical); + + /* + * Round down to stripe boundary. + * + * The extra calculation against bg->start is to handle block groups + * whose logical bytenr is not BTRFS_STRIPE_LEN aligned. + */ + stripe->logical = round_down(cur_logical - bg->start, BTRFS_STRIPE_LEN) + + bg->start; + stripe->physical = physical + stripe->logical - logical_start; + stripe->dev = dev; + stripe->bg = bg; + stripe->mirror_num = mirror_num; + stripe_end = stripe->logical + BTRFS_STRIPE_LEN - 1; + + /* Fill the first extent info into stripe->sectors[] array. */ + fill_one_extent_info(fs_info, stripe, extent_start, extent_len, + extent_flags, extent_gen); + cur_logical = extent_start + extent_len; + + /* Fill the extent info for the remaining sectors. */ + while (cur_logical <= stripe_end) { + ret = find_first_extent_item(extent_root, extent_path, cur_logical, + stripe_end - cur_logical + 1); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + get_extent_info(extent_path, &extent_start, &extent_len, + &extent_flags, &extent_gen); + if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) + stripe->nr_meta_extents++; + if (extent_flags & BTRFS_EXTENT_FLAG_DATA) + stripe->nr_data_extents++; + fill_one_extent_info(fs_info, stripe, extent_start, extent_len, + extent_flags, extent_gen); + cur_logical = extent_start + extent_len; + } + + /* Now fill the data csum. */ + if (bg->flags & BTRFS_BLOCK_GROUP_DATA) { + int sector_nr; + unsigned long csum_bitmap = 0; + + /* Csum space should have already been allocated. */ + ASSERT(stripe->csums); + + /* + * Our csum bitmap should be large enough, as BTRFS_STRIPE_LEN + * should contain at most 16 sectors. + */ + ASSERT(BITS_PER_LONG >= BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits); + + ret = btrfs_lookup_csums_bitmap(csum_root, csum_path, + stripe->logical, stripe_end, + stripe->csums, &csum_bitmap); + if (ret < 0) + goto out; + if (ret > 0) + ret = 0; + + for_each_set_bit(sector_nr, &csum_bitmap, stripe->nr_sectors) { + stripe->sectors[sector_nr].csum = stripe->csums + + sector_nr * fs_info->csum_size; + } + } + set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state); +out: + return ret; +} + +static void scrub_reset_stripe(struct scrub_stripe *stripe) +{ + scrub_stripe_reset_bitmaps(stripe); + + stripe->nr_meta_extents = 0; + stripe->nr_data_extents = 0; + stripe->state = 0; + + for (int i = 0; i < stripe->nr_sectors; i++) { + stripe->sectors[i].is_metadata = false; + stripe->sectors[i].csum = NULL; + stripe->sectors[i].generation = 0; + } +} + +static void scrub_submit_initial_read(struct scrub_ctx *sctx, + struct scrub_stripe *stripe) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct btrfs_bio *bbio; + unsigned int nr_sectors = min_t(u64, BTRFS_STRIPE_LEN, stripe->bg->start + + stripe->bg->length - stripe->logical) >> + fs_info->sectorsize_bits; + int mirror = stripe->mirror_num; + + ASSERT(stripe->bg); + ASSERT(stripe->mirror_num > 0); + ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state)); + + bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info, + scrub_read_endio, stripe); + + bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT; + /* Read the whole range inside the chunk boundary. */ + for (unsigned int cur = 0; cur < nr_sectors; cur++) { + struct page *page = scrub_stripe_get_page(stripe, cur); + unsigned int pgoff = scrub_stripe_get_page_offset(stripe, cur); + int ret; + + ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); + /* We should have allocated enough bio vectors. */ + ASSERT(ret == fs_info->sectorsize); + } + atomic_inc(&stripe->pending_io); + + /* + * For dev-replace, either user asks to avoid the source dev, or + * the device is missing, we try the next mirror instead. + */ + if (sctx->is_dev_replace && + (fs_info->dev_replace.cont_reading_from_srcdev_mode == + BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID || + !stripe->dev->bdev)) { + int num_copies = btrfs_num_copies(fs_info, stripe->bg->start, + stripe->bg->length); + + mirror = calc_next_mirror(mirror, num_copies); + } + btrfs_submit_bio(bbio, mirror); +} + +static bool stripe_has_metadata_error(struct scrub_stripe *stripe) +{ + int i; + + for_each_set_bit(i, &stripe->error_bitmap, stripe->nr_sectors) { + if (stripe->sectors[i].is_metadata) { + struct btrfs_fs_info *fs_info = stripe->bg->fs_info; + + btrfs_err(fs_info, + "stripe %llu has unrepaired metadata sector at %llu", + stripe->logical, + stripe->logical + (i << fs_info->sectorsize_bits)); + return true; + } + } + return false; +} + +static void submit_initial_group_read(struct scrub_ctx *sctx, + unsigned int first_slot, + unsigned int nr_stripes) +{ + struct blk_plug plug; + + ASSERT(first_slot < SCRUB_TOTAL_STRIPES); + ASSERT(first_slot + nr_stripes <= SCRUB_TOTAL_STRIPES); + + scrub_throttle_dev_io(sctx, sctx->stripes[0].dev, + btrfs_stripe_nr_to_offset(nr_stripes)); + blk_start_plug(&plug); + for (int i = 0; i < nr_stripes; i++) { + struct scrub_stripe *stripe = &sctx->stripes[first_slot + i]; + + /* Those stripes should be initialized. */ + ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state)); + scrub_submit_initial_read(sctx, stripe); + } + blk_finish_plug(&plug); +} + +static int flush_scrub_stripes(struct scrub_ctx *sctx) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct scrub_stripe *stripe; + const int nr_stripes = sctx->cur_stripe; + int ret = 0; + + if (!nr_stripes) + return 0; + + ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state)); + + /* Submit the stripes which are populated but not submitted. */ + if (nr_stripes % SCRUB_STRIPES_PER_GROUP) { + const int first_slot = round_down(nr_stripes, SCRUB_STRIPES_PER_GROUP); + + submit_initial_group_read(sctx, first_slot, nr_stripes - first_slot); + } + + for (int i = 0; i < nr_stripes; i++) { + stripe = &sctx->stripes[i]; + + wait_event(stripe->repair_wait, + test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state)); + } + + /* Submit for dev-replace. */ + if (sctx->is_dev_replace) { + /* + * For dev-replace, if we know there is something wrong with + * metadata, we should immedately abort. + */ + for (int i = 0; i < nr_stripes; i++) { + if (stripe_has_metadata_error(&sctx->stripes[i])) { + ret = -EIO; + goto out; + } + } + for (int i = 0; i < nr_stripes; i++) { + unsigned long good; + + stripe = &sctx->stripes[i]; + + ASSERT(stripe->dev == fs_info->dev_replace.srcdev); + + bitmap_andnot(&good, &stripe->extent_sector_bitmap, + &stripe->error_bitmap, stripe->nr_sectors); + scrub_write_sectors(sctx, stripe, good, true); + } + } + + /* Wait for the above writebacks to finish. */ + for (int i = 0; i < nr_stripes; i++) { + stripe = &sctx->stripes[i]; + + wait_scrub_stripe_io(stripe); + scrub_reset_stripe(stripe); + } +out: + sctx->cur_stripe = 0; + return ret; +} + +static void raid56_scrub_wait_endio(struct bio *bio) +{ + complete(bio->bi_private); +} + +static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg, + struct btrfs_device *dev, int mirror_num, + u64 logical, u32 length, u64 physical, + u64 *found_logical_ret) +{ + struct scrub_stripe *stripe; + int ret; + + /* + * There should always be one slot left, as caller filling the last + * slot should flush them all. + */ + ASSERT(sctx->cur_stripe < SCRUB_TOTAL_STRIPES); + + /* @found_logical_ret must be specified. */ + ASSERT(found_logical_ret); + + stripe = &sctx->stripes[sctx->cur_stripe]; + scrub_reset_stripe(stripe); + ret = scrub_find_fill_first_stripe(bg, &sctx->extent_path, + &sctx->csum_path, dev, physical, + mirror_num, logical, length, stripe); + /* Either >0 as no more extents or <0 for error. */ + if (ret) + return ret; + *found_logical_ret = stripe->logical; + sctx->cur_stripe++; + + /* We filled one group, submit it. */ + if (sctx->cur_stripe % SCRUB_STRIPES_PER_GROUP == 0) { + const int first_slot = sctx->cur_stripe - SCRUB_STRIPES_PER_GROUP; + + submit_initial_group_read(sctx, first_slot, SCRUB_STRIPES_PER_GROUP); + } + + /* Last slot used, flush them all. */ + if (sctx->cur_stripe == SCRUB_TOTAL_STRIPES) + return flush_scrub_stripes(sctx); + return 0; +} + +static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx, + struct btrfs_device *scrub_dev, + struct btrfs_block_group *bg, + struct map_lookup *map, + u64 full_stripe_start) +{ + DECLARE_COMPLETION_ONSTACK(io_done); + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct btrfs_raid_bio *rbio; + struct btrfs_io_context *bioc = NULL; + struct btrfs_path extent_path = { 0 }; + struct btrfs_path csum_path = { 0 }; + struct bio *bio; + struct scrub_stripe *stripe; + bool all_empty = true; + const int data_stripes = nr_data_stripes(map); + unsigned long extent_bitmap = 0; + u64 length = btrfs_stripe_nr_to_offset(data_stripes); + int ret; + + ASSERT(sctx->raid56_data_stripes); + + /* + * For data stripe search, we cannot re-use the same extent/csum paths, + * as the data stripe bytenr may be smaller than previous extent. Thus + * we have to use our own extent/csum paths. + */ + extent_path.search_commit_root = 1; + extent_path.skip_locking = 1; + csum_path.search_commit_root = 1; + csum_path.skip_locking = 1; + + for (int i = 0; i < data_stripes; i++) { + int stripe_index; + int rot; + u64 physical; + + stripe = &sctx->raid56_data_stripes[i]; + rot = div_u64(full_stripe_start - bg->start, + data_stripes) >> BTRFS_STRIPE_LEN_SHIFT; + stripe_index = (i + rot) % map->num_stripes; + physical = map->stripes[stripe_index].physical + + btrfs_stripe_nr_to_offset(rot); + + scrub_reset_stripe(stripe); + set_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state); + ret = scrub_find_fill_first_stripe(bg, &extent_path, &csum_path, + map->stripes[stripe_index].dev, physical, 1, + full_stripe_start + btrfs_stripe_nr_to_offset(i), + BTRFS_STRIPE_LEN, stripe); + if (ret < 0) + goto out; + /* + * No extent in this data stripe, need to manually mark them + * initialized to make later read submission happy. + */ + if (ret > 0) { + stripe->logical = full_stripe_start + + btrfs_stripe_nr_to_offset(i); + stripe->dev = map->stripes[stripe_index].dev; + stripe->mirror_num = 1; + set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state); + } + } + + /* Check if all data stripes are empty. */ + for (int i = 0; i < data_stripes; i++) { + stripe = &sctx->raid56_data_stripes[i]; + if (!bitmap_empty(&stripe->extent_sector_bitmap, stripe->nr_sectors)) { + all_empty = false; + break; + } + } + if (all_empty) { + ret = 0; + goto out; + } + + for (int i = 0; i < data_stripes; i++) { + stripe = &sctx->raid56_data_stripes[i]; + scrub_submit_initial_read(sctx, stripe); + } + for (int i = 0; i < data_stripes; i++) { + stripe = &sctx->raid56_data_stripes[i]; + + wait_event(stripe->repair_wait, + test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state)); + } + /* For now, no zoned support for RAID56. */ + ASSERT(!btrfs_is_zoned(sctx->fs_info)); + + /* + * Now all data stripes are properly verified. Check if we have any + * unrepaired, if so abort immediately or we could further corrupt the + * P/Q stripes. + * + * During the loop, also populate extent_bitmap. + */ + for (int i = 0; i < data_stripes; i++) { + unsigned long error; + + stripe = &sctx->raid56_data_stripes[i]; + + /* + * We should only check the errors where there is an extent. + * As we may hit an empty data stripe while it's missing. + */ + bitmap_and(&error, &stripe->error_bitmap, + &stripe->extent_sector_bitmap, stripe->nr_sectors); + if (!bitmap_empty(&error, stripe->nr_sectors)) { + btrfs_err(fs_info, +"unrepaired sectors detected, full stripe %llu data stripe %u errors %*pbl", + full_stripe_start, i, stripe->nr_sectors, + &error); + ret = -EIO; + goto out; + } + bitmap_or(&extent_bitmap, &extent_bitmap, + &stripe->extent_sector_bitmap, stripe->nr_sectors); + } + + /* Now we can check and regenerate the P/Q stripe. */ + bio = bio_alloc(NULL, 1, REQ_OP_READ, GFP_NOFS); + bio->bi_iter.bi_sector = full_stripe_start >> SECTOR_SHIFT; + bio->bi_private = &io_done; + bio->bi_end_io = raid56_scrub_wait_endio; + + btrfs_bio_counter_inc_blocked(fs_info); + ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, full_stripe_start, + &length, &bioc, NULL, NULL, 1); + if (ret < 0) { + btrfs_put_bioc(bioc); + btrfs_bio_counter_dec(fs_info); + goto out; + } + rbio = raid56_parity_alloc_scrub_rbio(bio, bioc, scrub_dev, &extent_bitmap, + BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits); + btrfs_put_bioc(bioc); + if (!rbio) { + ret = -ENOMEM; + btrfs_bio_counter_dec(fs_info); + goto out; + } + /* Use the recovered stripes as cache to avoid read them from disk again. */ + for (int i = 0; i < data_stripes; i++) { + stripe = &sctx->raid56_data_stripes[i]; + + raid56_parity_cache_data_pages(rbio, stripe->pages, + full_stripe_start + (i << BTRFS_STRIPE_LEN_SHIFT)); + } + raid56_parity_submit_scrub_rbio(rbio); + wait_for_completion_io(&io_done); + ret = blk_status_to_errno(bio->bi_status); + bio_put(bio); + btrfs_bio_counter_dec(fs_info); + + btrfs_release_path(&extent_path); + btrfs_release_path(&csum_path); +out: + return ret; +} + +/* + * Scrub one range which can only has simple mirror based profile. + * (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in + * RAID0/RAID10). + * + * Since we may need to handle a subset of block group, we need @logical_start + * and @logical_length parameter. + */ +static int scrub_simple_mirror(struct scrub_ctx *sctx, + struct btrfs_block_group *bg, + struct map_lookup *map, + u64 logical_start, u64 logical_length, + struct btrfs_device *device, + u64 physical, int mirror_num) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + const u64 logical_end = logical_start + logical_length; + u64 cur_logical = logical_start; + int ret; + + /* The range must be inside the bg */ + ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length); + + /* Go through each extent items inside the logical range */ + while (cur_logical < logical_end) { + u64 found_logical = U64_MAX; + u64 cur_physical = physical + cur_logical - logical_start; + + /* Canceled? */ + if (atomic_read(&fs_info->scrub_cancel_req) || + atomic_read(&sctx->cancel_req)) { + ret = -ECANCELED; + break; + } + /* Paused? */ + if (atomic_read(&fs_info->scrub_pause_req)) { + /* Push queued extents */ + scrub_blocked_if_needed(fs_info); + } + /* Block group removed? */ + spin_lock(&bg->lock); + if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) { + spin_unlock(&bg->lock); + ret = 0; + break; + } + spin_unlock(&bg->lock); + + ret = queue_scrub_stripe(sctx, bg, device, mirror_num, + cur_logical, logical_end - cur_logical, + cur_physical, &found_logical); + if (ret > 0) { + /* No more extent, just update the accounting */ + sctx->stat.last_physical = physical + logical_length; + ret = 0; + break; + } + if (ret < 0) + break; + + /* queue_scrub_stripe() returned 0, @found_logical must be updated. */ + ASSERT(found_logical != U64_MAX); + cur_logical = found_logical + BTRFS_STRIPE_LEN; + + /* Don't hold CPU for too long time */ + cond_resched(); + } + return ret; +} + +/* Calculate the full stripe length for simple stripe based profiles */ +static u64 simple_stripe_full_stripe_len(const struct map_lookup *map) +{ + ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)); + + return btrfs_stripe_nr_to_offset(map->num_stripes / map->sub_stripes); +} + +/* Get the logical bytenr for the stripe */ +static u64 simple_stripe_get_logical(struct map_lookup *map, + struct btrfs_block_group *bg, + int stripe_index) +{ + ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)); + ASSERT(stripe_index < map->num_stripes); + + /* + * (stripe_index / sub_stripes) gives how many data stripes we need to + * skip. + */ + return btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes) + + bg->start; +} + +/* Get the mirror number for the stripe */ +static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index) +{ + ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)); + ASSERT(stripe_index < map->num_stripes); + + /* For RAID0, it's fixed to 1, for RAID10 it's 0,1,0,1... */ + return stripe_index % map->sub_stripes + 1; +} + +static int scrub_simple_stripe(struct scrub_ctx *sctx, + struct btrfs_block_group *bg, + struct map_lookup *map, + struct btrfs_device *device, + int stripe_index) +{ + const u64 logical_increment = simple_stripe_full_stripe_len(map); + const u64 orig_logical = simple_stripe_get_logical(map, bg, stripe_index); + const u64 orig_physical = map->stripes[stripe_index].physical; + const int mirror_num = simple_stripe_mirror_num(map, stripe_index); + u64 cur_logical = orig_logical; + u64 cur_physical = orig_physical; + int ret = 0; + + while (cur_logical < bg->start + bg->length) { + /* + * Inside each stripe, RAID0 is just SINGLE, and RAID10 is + * just RAID1, so we can reuse scrub_simple_mirror() to scrub + * this stripe. + */ + ret = scrub_simple_mirror(sctx, bg, map, cur_logical, + BTRFS_STRIPE_LEN, device, cur_physical, + mirror_num); + if (ret) + return ret; + /* Skip to next stripe which belongs to the target device */ + cur_logical += logical_increment; + /* For physical offset, we just go to next stripe */ + cur_physical += BTRFS_STRIPE_LEN; + } + return ret; +} + +static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, + struct btrfs_block_group *bg, + struct extent_map *em, + struct btrfs_device *scrub_dev, + int stripe_index) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct map_lookup *map = em->map_lookup; + const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK; + const u64 chunk_logical = bg->start; + int ret; + int ret2; + u64 physical = map->stripes[stripe_index].physical; + const u64 dev_stripe_len = btrfs_calc_stripe_length(em); + const u64 physical_end = physical + dev_stripe_len; + u64 logical; + u64 logic_end; + /* The logical increment after finishing one stripe */ + u64 increment; + /* Offset inside the chunk */ + u64 offset; + u64 stripe_logical; + int stop_loop = 0; + + /* Extent_path should be released by now. */ + ASSERT(sctx->extent_path.nodes[0] == NULL); + + scrub_blocked_if_needed(fs_info); + + if (sctx->is_dev_replace && + btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) { + mutex_lock(&sctx->wr_lock); + sctx->write_pointer = physical; + mutex_unlock(&sctx->wr_lock); + } + + /* Prepare the extra data stripes used by RAID56. */ + if (profile & BTRFS_BLOCK_GROUP_RAID56_MASK) { + ASSERT(sctx->raid56_data_stripes == NULL); + + sctx->raid56_data_stripes = kcalloc(nr_data_stripes(map), + sizeof(struct scrub_stripe), + GFP_KERNEL); + if (!sctx->raid56_data_stripes) { + ret = -ENOMEM; + goto out; + } + for (int i = 0; i < nr_data_stripes(map); i++) { + ret = init_scrub_stripe(fs_info, + &sctx->raid56_data_stripes[i]); + if (ret < 0) + goto out; + sctx->raid56_data_stripes[i].bg = bg; + sctx->raid56_data_stripes[i].sctx = sctx; + } + } + /* + * There used to be a big double loop to handle all profiles using the + * same routine, which grows larger and more gross over time. + * + * So here we handle each profile differently, so simpler profiles + * have simpler scrubbing function. + */ + if (!(profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_RAID56_MASK))) { + /* + * Above check rules out all complex profile, the remaining + * profiles are SINGLE|DUP|RAID1|RAID1C*, which is simple + * mirrored duplication without stripe. + * + * Only @physical and @mirror_num needs to calculated using + * @stripe_index. + */ + ret = scrub_simple_mirror(sctx, bg, map, bg->start, bg->length, + scrub_dev, map->stripes[stripe_index].physical, + stripe_index + 1); + offset = 0; + goto out; + } + if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) { + ret = scrub_simple_stripe(sctx, bg, map, scrub_dev, stripe_index); + offset = btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes); + goto out; + } + + /* Only RAID56 goes through the old code */ + ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK); + ret = 0; + + /* Calculate the logical end of the stripe */ + get_raid56_logic_offset(physical_end, stripe_index, + map, &logic_end, NULL); + logic_end += chunk_logical; + + /* Initialize @offset in case we need to go to out: label */ + get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL); + increment = btrfs_stripe_nr_to_offset(nr_data_stripes(map)); + + /* + * Due to the rotation, for RAID56 it's better to iterate each stripe + * using their physical offset. + */ + while (physical < physical_end) { + ret = get_raid56_logic_offset(physical, stripe_index, map, + &logical, &stripe_logical); + logical += chunk_logical; + if (ret) { + /* it is parity strip */ + stripe_logical += chunk_logical; + ret = scrub_raid56_parity_stripe(sctx, scrub_dev, bg, + map, stripe_logical); + if (ret) + goto out; + goto next; + } + + /* + * Now we're at a data stripe, scrub each extents in the range. + * + * At this stage, if we ignore the repair part, inside each data + * stripe it is no different than SINGLE profile. + * We can reuse scrub_simple_mirror() here, as the repair part + * is still based on @mirror_num. + */ + ret = scrub_simple_mirror(sctx, bg, map, logical, BTRFS_STRIPE_LEN, + scrub_dev, physical, 1); + if (ret < 0) + goto out; +next: + logical += increment; + physical += BTRFS_STRIPE_LEN; + spin_lock(&sctx->stat_lock); + if (stop_loop) + sctx->stat.last_physical = + map->stripes[stripe_index].physical + dev_stripe_len; + else + sctx->stat.last_physical = physical; + spin_unlock(&sctx->stat_lock); + if (stop_loop) + break; + } +out: + ret2 = flush_scrub_stripes(sctx); + if (!ret) + ret = ret2; + btrfs_release_path(&sctx->extent_path); + btrfs_release_path(&sctx->csum_path); + + if (sctx->raid56_data_stripes) { + for (int i = 0; i < nr_data_stripes(map); i++) + release_scrub_stripe(&sctx->raid56_data_stripes[i]); + kfree(sctx->raid56_data_stripes); + sctx->raid56_data_stripes = NULL; + } + + if (sctx->is_dev_replace && ret >= 0) { + int ret2; + + ret2 = sync_write_pointer_for_zoned(sctx, + chunk_logical + offset, + map->stripes[stripe_index].physical, + physical_end); + if (ret2) + ret = ret2; + } + + return ret < 0 ? ret : 0; +} + +static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, + struct btrfs_block_group *bg, + struct btrfs_device *scrub_dev, + u64 dev_offset, + u64 dev_extent_len) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct extent_map_tree *map_tree = &fs_info->mapping_tree; + struct map_lookup *map; + struct extent_map *em; + int i; + int ret = 0; + + read_lock(&map_tree->lock); + em = lookup_extent_mapping(map_tree, bg->start, bg->length); + read_unlock(&map_tree->lock); + + if (!em) { + /* + * Might have been an unused block group deleted by the cleaner + * kthread or relocation. + */ + spin_lock(&bg->lock); + if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) + ret = -EINVAL; + spin_unlock(&bg->lock); + + return ret; + } + if (em->start != bg->start) + goto out; + if (em->len < dev_extent_len) + goto out; + + map = em->map_lookup; + for (i = 0; i < map->num_stripes; ++i) { + if (map->stripes[i].dev->bdev == scrub_dev->bdev && + map->stripes[i].physical == dev_offset) { + ret = scrub_stripe(sctx, bg, em, scrub_dev, i); + if (ret) + goto out; + } + } +out: + free_extent_map(em); + + return ret; +} + +static int finish_extent_writes_for_zoned(struct btrfs_root *root, + struct btrfs_block_group *cache) +{ + struct btrfs_fs_info *fs_info = cache->fs_info; + struct btrfs_trans_handle *trans; + + if (!btrfs_is_zoned(fs_info)) + return 0; + + btrfs_wait_block_group_reservations(cache); + btrfs_wait_nocow_writers(cache); + btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length); + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + return btrfs_commit_transaction(trans); +} + +static noinline_for_stack +int scrub_enumerate_chunks(struct scrub_ctx *sctx, + struct btrfs_device *scrub_dev, u64 start, u64 end) +{ + struct btrfs_dev_extent *dev_extent = NULL; + struct btrfs_path *path; + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct btrfs_root *root = fs_info->dev_root; + u64 chunk_offset; + int ret = 0; + int ro_set; + int slot; + struct extent_buffer *l; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_block_group *cache; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = READA_FORWARD; + path->search_commit_root = 1; + path->skip_locking = 1; + + key.objectid = scrub_dev->devid; + key.offset = 0ull; + key.type = BTRFS_DEV_EXTENT_KEY; + + while (1) { + u64 dev_extent_len; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + break; + if (ret > 0) { + if (path->slots[0] >= + btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + break; + if (ret > 0) { + ret = 0; + break; + } + } else { + ret = 0; + } + } + + l = path->nodes[0]; + slot = path->slots[0]; + + btrfs_item_key_to_cpu(l, &found_key, slot); + + if (found_key.objectid != scrub_dev->devid) + break; + + if (found_key.type != BTRFS_DEV_EXTENT_KEY) + break; + + if (found_key.offset >= end) + break; + + if (found_key.offset < key.offset) + break; + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + dev_extent_len = btrfs_dev_extent_length(l, dev_extent); + + if (found_key.offset + dev_extent_len <= start) + goto skip; + + chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); + + /* + * get a reference on the corresponding block group to prevent + * the chunk from going away while we scrub it + */ + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + + /* some chunks are removed but not committed to disk yet, + * continue scrubbing */ + if (!cache) + goto skip; + + ASSERT(cache->start <= chunk_offset); + /* + * We are using the commit root to search for device extents, so + * that means we could have found a device extent item from a + * block group that was deleted in the current transaction. The + * logical start offset of the deleted block group, stored at + * @chunk_offset, might be part of the logical address range of + * a new block group (which uses different physical extents). + * In this case btrfs_lookup_block_group() has returned the new + * block group, and its start address is less than @chunk_offset. + * + * We skip such new block groups, because it's pointless to + * process them, as we won't find their extents because we search + * for them using the commit root of the extent tree. For a device + * replace it's also fine to skip it, we won't miss copying them + * to the target device because we have the write duplication + * setup through the regular write path (by btrfs_map_block()), + * and we have committed a transaction when we started the device + * replace, right after setting up the device replace state. + */ + if (cache->start < chunk_offset) { + btrfs_put_block_group(cache); + goto skip; + } + + if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) { + if (!test_bit(BLOCK_GROUP_FLAG_TO_COPY, &cache->runtime_flags)) { + btrfs_put_block_group(cache); + goto skip; + } + } + + /* + * Make sure that while we are scrubbing the corresponding block + * group doesn't get its logical address and its device extents + * reused for another block group, which can possibly be of a + * different type and different profile. We do this to prevent + * false error detections and crashes due to bogus attempts to + * repair extents. + */ + spin_lock(&cache->lock); + if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags)) { + spin_unlock(&cache->lock); + btrfs_put_block_group(cache); + goto skip; + } + btrfs_freeze_block_group(cache); + spin_unlock(&cache->lock); + + /* + * we need call btrfs_inc_block_group_ro() with scrubs_paused, + * to avoid deadlock caused by: + * btrfs_inc_block_group_ro() + * -> btrfs_wait_for_commit() + * -> btrfs_commit_transaction() + * -> btrfs_scrub_pause() + */ + scrub_pause_on(fs_info); + + /* + * Don't do chunk preallocation for scrub. + * + * This is especially important for SYSTEM bgs, or we can hit + * -EFBIG from btrfs_finish_chunk_alloc() like: + * 1. The only SYSTEM bg is marked RO. + * Since SYSTEM bg is small, that's pretty common. + * 2. New SYSTEM bg will be allocated + * Due to regular version will allocate new chunk. + * 3. New SYSTEM bg is empty and will get cleaned up + * Before cleanup really happens, it's marked RO again. + * 4. Empty SYSTEM bg get scrubbed + * We go back to 2. + * + * This can easily boost the amount of SYSTEM chunks if cleaner + * thread can't be triggered fast enough, and use up all space + * of btrfs_super_block::sys_chunk_array + * + * While for dev replace, we need to try our best to mark block + * group RO, to prevent race between: + * - Write duplication + * Contains latest data + * - Scrub copy + * Contains data from commit tree + * + * If target block group is not marked RO, nocow writes can + * be overwritten by scrub copy, causing data corruption. + * So for dev-replace, it's not allowed to continue if a block + * group is not RO. + */ + ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace); + if (!ret && sctx->is_dev_replace) { + ret = finish_extent_writes_for_zoned(root, cache); + if (ret) { + btrfs_dec_block_group_ro(cache); + scrub_pause_off(fs_info); + btrfs_put_block_group(cache); + break; + } + } + + if (ret == 0) { + ro_set = 1; + } else if (ret == -ENOSPC && !sctx->is_dev_replace && + !(cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) { + /* + * btrfs_inc_block_group_ro return -ENOSPC when it + * failed in creating new chunk for metadata. + * It is not a problem for scrub, because + * metadata are always cowed, and our scrub paused + * commit_transactions. + * + * For RAID56 chunks, we have to mark them read-only + * for scrub, as later we would use our own cache + * out of RAID56 realm. + * Thus we want the RAID56 bg to be marked RO to + * prevent RMW from screwing up out cache. + */ + ro_set = 0; + } else if (ret == -ETXTBSY) { + btrfs_warn(fs_info, + "skipping scrub of block group %llu due to active swapfile", + cache->start); + scrub_pause_off(fs_info); + ret = 0; + goto skip_unfreeze; + } else { + btrfs_warn(fs_info, + "failed setting block group ro: %d", ret); + btrfs_unfreeze_block_group(cache); + btrfs_put_block_group(cache); + scrub_pause_off(fs_info); + break; + } + + /* + * Now the target block is marked RO, wait for nocow writes to + * finish before dev-replace. + * COW is fine, as COW never overwrites extents in commit tree. + */ + if (sctx->is_dev_replace) { + btrfs_wait_nocow_writers(cache); + btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, + cache->length); + } + + scrub_pause_off(fs_info); + down_write(&dev_replace->rwsem); + dev_replace->cursor_right = found_key.offset + dev_extent_len; + dev_replace->cursor_left = found_key.offset; + dev_replace->item_needs_writeback = 1; + up_write(&dev_replace->rwsem); + + ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset, + dev_extent_len); + if (sctx->is_dev_replace && + !btrfs_finish_block_group_to_copy(dev_replace->srcdev, + cache, found_key.offset)) + ro_set = 0; + + down_write(&dev_replace->rwsem); + dev_replace->cursor_left = dev_replace->cursor_right; + dev_replace->item_needs_writeback = 1; + up_write(&dev_replace->rwsem); + + if (ro_set) + btrfs_dec_block_group_ro(cache); + + /* + * We might have prevented the cleaner kthread from deleting + * this block group if it was already unused because we raced + * and set it to RO mode first. So add it back to the unused + * list, otherwise it might not ever be deleted unless a manual + * balance is triggered or it becomes used and unused again. + */ + spin_lock(&cache->lock); + if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags) && + !cache->ro && cache->reserved == 0 && cache->used == 0) { + spin_unlock(&cache->lock); + if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) + btrfs_discard_queue_work(&fs_info->discard_ctl, + cache); + else + btrfs_mark_bg_unused(cache); + } else { + spin_unlock(&cache->lock); + } +skip_unfreeze: + btrfs_unfreeze_block_group(cache); + btrfs_put_block_group(cache); + if (ret) + break; + if (sctx->is_dev_replace && + atomic64_read(&dev_replace->num_write_errors) > 0) { + ret = -EIO; + break; + } + if (sctx->stat.malloc_errors > 0) { + ret = -ENOMEM; + break; + } +skip: + key.offset = found_key.offset + dev_extent_len; + btrfs_release_path(path); + } + + btrfs_free_path(path); + + return ret; +} + +static int scrub_one_super(struct scrub_ctx *sctx, struct btrfs_device *dev, + struct page *page, u64 physical, u64 generation) +{ + struct btrfs_fs_info *fs_info = sctx->fs_info; + struct bio_vec bvec; + struct bio bio; + struct btrfs_super_block *sb = page_address(page); + int ret; + + bio_init(&bio, dev->bdev, &bvec, 1, REQ_OP_READ); + bio.bi_iter.bi_sector = physical >> SECTOR_SHIFT; + __bio_add_page(&bio, page, BTRFS_SUPER_INFO_SIZE, 0); + ret = submit_bio_wait(&bio); + bio_uninit(&bio); + + if (ret < 0) + return ret; + ret = btrfs_check_super_csum(fs_info, sb); + if (ret != 0) { + btrfs_err_rl(fs_info, + "super block at physical %llu devid %llu has bad csum", + physical, dev->devid); + return -EIO; + } + if (btrfs_super_generation(sb) != generation) { + btrfs_err_rl(fs_info, +"super block at physical %llu devid %llu has bad generation %llu expect %llu", + physical, dev->devid, + btrfs_super_generation(sb), generation); + return -EUCLEAN; + } + + return btrfs_validate_super(fs_info, sb, -1); +} + +static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, + struct btrfs_device *scrub_dev) +{ + int i; + u64 bytenr; + u64 gen; + int ret = 0; + struct page *page; + struct btrfs_fs_info *fs_info = sctx->fs_info; + + if (BTRFS_FS_ERROR(fs_info)) + return -EROFS; + + page = alloc_page(GFP_KERNEL); + if (!page) { + spin_lock(&sctx->stat_lock); + sctx->stat.malloc_errors++; + spin_unlock(&sctx->stat_lock); + return -ENOMEM; + } + + /* Seed devices of a new filesystem has their own generation. */ + if (scrub_dev->fs_devices != fs_info->fs_devices) + gen = scrub_dev->generation; + else + gen = fs_info->last_trans_committed; + + for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { + 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_one_super(sctx, scrub_dev, page, bytenr, gen); + if (ret) { + spin_lock(&sctx->stat_lock); + sctx->stat.super_errors++; + spin_unlock(&sctx->stat_lock); + } + } + __free_page(page); + return 0; +} + +static void scrub_workers_put(struct btrfs_fs_info *fs_info) +{ + if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt, + &fs_info->scrub_lock)) { + struct workqueue_struct *scrub_workers = fs_info->scrub_workers; + + fs_info->scrub_workers = NULL; + mutex_unlock(&fs_info->scrub_lock); + + if (scrub_workers) + destroy_workqueue(scrub_workers); + } +} + +/* + * get a reference count on fs_info->scrub_workers. start worker if necessary + */ +static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info) +{ + struct workqueue_struct *scrub_workers = NULL; + unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND; + int max_active = fs_info->thread_pool_size; + int ret = -ENOMEM; + + if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt)) + return 0; + + scrub_workers = alloc_workqueue("btrfs-scrub", flags, max_active); + if (!scrub_workers) + return -ENOMEM; + + mutex_lock(&fs_info->scrub_lock); + if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) { + ASSERT(fs_info->scrub_workers == NULL); + fs_info->scrub_workers = scrub_workers; + refcount_set(&fs_info->scrub_workers_refcnt, 1); + mutex_unlock(&fs_info->scrub_lock); + return 0; + } + /* Other thread raced in and created the workers for us */ + refcount_inc(&fs_info->scrub_workers_refcnt); + mutex_unlock(&fs_info->scrub_lock); + + ret = 0; + + destroy_workqueue(scrub_workers); + return ret; +} + +int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, + u64 end, struct btrfs_scrub_progress *progress, + int readonly, int is_dev_replace) +{ + struct btrfs_dev_lookup_args args = { .devid = devid }; + struct scrub_ctx *sctx; + int ret; + struct btrfs_device *dev; + unsigned int nofs_flag; + bool need_commit = false; + + if (btrfs_fs_closing(fs_info)) + return -EAGAIN; + + /* At mount time we have ensured nodesize is in the range of [4K, 64K]. */ + ASSERT(fs_info->nodesize <= BTRFS_STRIPE_LEN); + + /* + * SCRUB_MAX_SECTORS_PER_BLOCK is calculated using the largest possible + * value (max nodesize / min sectorsize), thus nodesize should always + * be fine. + */ + ASSERT(fs_info->nodesize <= + SCRUB_MAX_SECTORS_PER_BLOCK << fs_info->sectorsize_bits); + + /* Allocate outside of device_list_mutex */ + sctx = scrub_setup_ctx(fs_info, is_dev_replace); + if (IS_ERR(sctx)) + return PTR_ERR(sctx); + + ret = scrub_workers_get(fs_info); + if (ret) + goto out_free_ctx; + + mutex_lock(&fs_info->fs_devices->device_list_mutex); + dev = btrfs_find_device(fs_info->fs_devices, &args); + if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) && + !is_dev_replace)) { + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + ret = -ENODEV; + goto out; + } + + if (!is_dev_replace && !readonly && + !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) { + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + btrfs_err_in_rcu(fs_info, + "scrub on devid %llu: filesystem on %s is not writable", + devid, btrfs_dev_name(dev)); + ret = -EROFS; + goto out; + } + + mutex_lock(&fs_info->scrub_lock); + if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) { + mutex_unlock(&fs_info->scrub_lock); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + ret = -EIO; + goto out; + } + + down_read(&fs_info->dev_replace.rwsem); + if (dev->scrub_ctx || + (!is_dev_replace && + btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) { + up_read(&fs_info->dev_replace.rwsem); + mutex_unlock(&fs_info->scrub_lock); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + ret = -EINPROGRESS; + goto out; + } + up_read(&fs_info->dev_replace.rwsem); + + sctx->readonly = readonly; + dev->scrub_ctx = sctx; + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + + /* + * checking @scrub_pause_req here, we can avoid + * race between committing transaction and scrubbing. + */ + __scrub_blocked_if_needed(fs_info); + atomic_inc(&fs_info->scrubs_running); + mutex_unlock(&fs_info->scrub_lock); + + /* + * In order to avoid deadlock with reclaim when there is a transaction + * trying to pause scrub, make sure we use GFP_NOFS for all the + * allocations done at btrfs_scrub_sectors() and scrub_sectors_for_parity() + * invoked by our callees. The pausing request is done when the + * transaction commit starts, and it blocks the transaction until scrub + * is paused (done at specific points at scrub_stripe() or right above + * before incrementing fs_info->scrubs_running). + */ + nofs_flag = memalloc_nofs_save(); + if (!is_dev_replace) { + u64 old_super_errors; + + spin_lock(&sctx->stat_lock); + old_super_errors = sctx->stat.super_errors; + spin_unlock(&sctx->stat_lock); + + btrfs_info(fs_info, "scrub: started on devid %llu", devid); + /* + * by holding device list mutex, we can + * kick off writing super in log tree sync. + */ + mutex_lock(&fs_info->fs_devices->device_list_mutex); + ret = scrub_supers(sctx, dev); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + + spin_lock(&sctx->stat_lock); + /* + * Super block errors found, but we can not commit transaction + * at current context, since btrfs_commit_transaction() needs + * to pause the current running scrub (hold by ourselves). + */ + if (sctx->stat.super_errors > old_super_errors && !sctx->readonly) + need_commit = true; + spin_unlock(&sctx->stat_lock); + } + + if (!ret) + ret = scrub_enumerate_chunks(sctx, dev, start, end); + memalloc_nofs_restore(nofs_flag); + + atomic_dec(&fs_info->scrubs_running); + wake_up(&fs_info->scrub_pause_wait); + + if (progress) + memcpy(progress, &sctx->stat, sizeof(*progress)); + + if (!is_dev_replace) + btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d", + ret ? "not finished" : "finished", devid, ret); + + mutex_lock(&fs_info->scrub_lock); + dev->scrub_ctx = NULL; + mutex_unlock(&fs_info->scrub_lock); + + scrub_workers_put(fs_info); + scrub_put_ctx(sctx); + + /* + * We found some super block errors before, now try to force a + * transaction commit, as scrub has finished. + */ + if (need_commit) { + struct btrfs_trans_handle *trans; + + trans = btrfs_start_transaction(fs_info->tree_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + btrfs_err(fs_info, + "scrub: failed to start transaction to fix super block errors: %d", ret); + return ret; + } + ret = btrfs_commit_transaction(trans); + if (ret < 0) + btrfs_err(fs_info, + "scrub: failed to commit transaction to fix super block errors: %d", ret); + } + return ret; +out: + scrub_workers_put(fs_info); +out_free_ctx: + scrub_free_ctx(sctx); + + return ret; +} + +void btrfs_scrub_pause(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->scrub_lock); + atomic_inc(&fs_info->scrub_pause_req); + while (atomic_read(&fs_info->scrubs_paused) != + atomic_read(&fs_info->scrubs_running)) { + mutex_unlock(&fs_info->scrub_lock); + wait_event(fs_info->scrub_pause_wait, + atomic_read(&fs_info->scrubs_paused) == + atomic_read(&fs_info->scrubs_running)); + mutex_lock(&fs_info->scrub_lock); + } + mutex_unlock(&fs_info->scrub_lock); +} + +void btrfs_scrub_continue(struct btrfs_fs_info *fs_info) +{ + atomic_dec(&fs_info->scrub_pause_req); + wake_up(&fs_info->scrub_pause_wait); +} + +int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->scrub_lock); + if (!atomic_read(&fs_info->scrubs_running)) { + mutex_unlock(&fs_info->scrub_lock); + return -ENOTCONN; + } + + atomic_inc(&fs_info->scrub_cancel_req); + while (atomic_read(&fs_info->scrubs_running)) { + mutex_unlock(&fs_info->scrub_lock); + wait_event(fs_info->scrub_pause_wait, + atomic_read(&fs_info->scrubs_running) == 0); + mutex_lock(&fs_info->scrub_lock); + } + atomic_dec(&fs_info->scrub_cancel_req); + mutex_unlock(&fs_info->scrub_lock); + + return 0; +} + +int btrfs_scrub_cancel_dev(struct btrfs_device *dev) +{ + struct btrfs_fs_info *fs_info = dev->fs_info; + struct scrub_ctx *sctx; + + mutex_lock(&fs_info->scrub_lock); + sctx = dev->scrub_ctx; + if (!sctx) { + mutex_unlock(&fs_info->scrub_lock); + return -ENOTCONN; + } + atomic_inc(&sctx->cancel_req); + while (dev->scrub_ctx) { + mutex_unlock(&fs_info->scrub_lock); + wait_event(fs_info->scrub_pause_wait, + dev->scrub_ctx == NULL); + mutex_lock(&fs_info->scrub_lock); + } + mutex_unlock(&fs_info->scrub_lock); + + return 0; +} + +int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid, + struct btrfs_scrub_progress *progress) +{ + struct btrfs_dev_lookup_args args = { .devid = devid }; + struct btrfs_device *dev; + struct scrub_ctx *sctx = NULL; + + mutex_lock(&fs_info->fs_devices->device_list_mutex); + dev = btrfs_find_device(fs_info->fs_devices, &args); + if (dev) + sctx = dev->scrub_ctx; + if (sctx) + memcpy(progress, &sctx->stat, sizeof(*progress)); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + + return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV; +} |