| /* |
| * Copyright (C) 2011 STRATO. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <linux/blkdev.h> |
| #include <linux/ratelimit.h> |
| #include "ctree.h" |
| #include "volumes.h" |
| #include "disk-io.h" |
| #include "ordered-data.h" |
| #include "transaction.h" |
| #include "backref.h" |
| #include "extent_io.h" |
| #include "check-integrity.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_dev; |
| |
| #define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */ |
| #define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */ |
| #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */ |
| |
| struct scrub_page { |
| struct scrub_block *sblock; |
| struct page *page; |
| struct block_device *bdev; |
| u64 flags; /* extent flags */ |
| u64 generation; |
| u64 logical; |
| u64 physical; |
| struct { |
| unsigned int mirror_num:8; |
| unsigned int have_csum:1; |
| unsigned int io_error:1; |
| }; |
| u8 csum[BTRFS_CSUM_SIZE]; |
| }; |
| |
| struct scrub_bio { |
| int index; |
| struct scrub_dev *sdev; |
| struct bio *bio; |
| int err; |
| u64 logical; |
| u64 physical; |
| struct scrub_page *pagev[SCRUB_PAGES_PER_BIO]; |
| 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; |
| atomic_t ref_count; /* free mem on transition to zero */ |
| struct scrub_dev *sdev; |
| struct { |
| unsigned int header_error:1; |
| unsigned int checksum_error:1; |
| unsigned int no_io_error_seen:1; |
| }; |
| }; |
| |
| struct scrub_dev { |
| struct scrub_bio *bios[SCRUB_BIOS_PER_DEV]; |
| struct btrfs_device *dev; |
| int first_free; |
| int curr; |
| atomic_t in_flight; |
| atomic_t fixup_cnt; |
| spinlock_t list_lock; |
| wait_queue_head_t list_wait; |
| u16 csum_size; |
| struct list_head csum_list; |
| atomic_t cancel_req; |
| int readonly; |
| int pages_per_bio; /* <= SCRUB_PAGES_PER_BIO */ |
| u32 sectorsize; |
| u32 nodesize; |
| u32 leafsize; |
| /* |
| * statistics |
| */ |
| struct btrfs_scrub_progress stat; |
| spinlock_t stat_lock; |
| }; |
| |
| struct scrub_fixup_nodatasum { |
| struct scrub_dev *sdev; |
| u64 logical; |
| struct btrfs_root *root; |
| struct btrfs_work work; |
| int mirror_num; |
| }; |
| |
| struct scrub_warning { |
| struct btrfs_path *path; |
| u64 extent_item_size; |
| char *scratch_buf; |
| char *msg_buf; |
| const char *errstr; |
| sector_t sector; |
| u64 logical; |
| struct btrfs_device *dev; |
| int msg_bufsize; |
| int scratch_bufsize; |
| }; |
| |
| |
| static int scrub_handle_errored_block(struct scrub_block *sblock_to_check); |
| static int scrub_setup_recheck_block(struct scrub_dev *sdev, |
| struct btrfs_mapping_tree *map_tree, |
| u64 length, u64 logical, |
| struct scrub_block *sblock); |
| static int scrub_recheck_block(struct btrfs_fs_info *fs_info, |
| struct scrub_block *sblock, int is_metadata, |
| int have_csum, u8 *csum, u64 generation, |
| u16 csum_size); |
| static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, |
| struct scrub_block *sblock, |
| int is_metadata, int have_csum, |
| const u8 *csum, u64 generation, |
| u16 csum_size); |
| static void scrub_complete_bio_end_io(struct bio *bio, int err); |
| static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, |
| struct scrub_block *sblock_good, |
| int force_write); |
| 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 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 int scrub_add_page_to_bio(struct scrub_dev *sdev, |
| struct scrub_page *spage); |
| static int scrub_pages(struct scrub_dev *sdev, u64 logical, u64 len, |
| u64 physical, u64 flags, u64 gen, int mirror_num, |
| u8 *csum, int force); |
| static void scrub_bio_end_io(struct bio *bio, int err); |
| static void scrub_bio_end_io_worker(struct btrfs_work *work); |
| static void scrub_block_complete(struct scrub_block *sblock); |
| |
| |
| static void scrub_free_csums(struct scrub_dev *sdev) |
| { |
| while (!list_empty(&sdev->csum_list)) { |
| struct btrfs_ordered_sum *sum; |
| sum = list_first_entry(&sdev->csum_list, |
| struct btrfs_ordered_sum, list); |
| list_del(&sum->list); |
| kfree(sum); |
| } |
| } |
| |
| static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev) |
| { |
| int i; |
| |
| if (!sdev) |
| return; |
| |
| /* this can happen when scrub is cancelled */ |
| if (sdev->curr != -1) { |
| struct scrub_bio *sbio = sdev->bios[sdev->curr]; |
| |
| for (i = 0; i < sbio->page_count; i++) { |
| BUG_ON(!sbio->pagev[i]); |
| BUG_ON(!sbio->pagev[i]->page); |
| scrub_block_put(sbio->pagev[i]->sblock); |
| } |
| bio_put(sbio->bio); |
| } |
| |
| for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) { |
| struct scrub_bio *sbio = sdev->bios[i]; |
| |
| if (!sbio) |
| break; |
| kfree(sbio); |
| } |
| |
| scrub_free_csums(sdev); |
| kfree(sdev); |
| } |
| |
| static noinline_for_stack |
| struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev) |
| { |
| struct scrub_dev *sdev; |
| int i; |
| struct btrfs_fs_info *fs_info = dev->dev_root->fs_info; |
| int pages_per_bio; |
| |
| pages_per_bio = min_t(int, SCRUB_PAGES_PER_BIO, |
| bio_get_nr_vecs(dev->bdev)); |
| sdev = kzalloc(sizeof(*sdev), GFP_NOFS); |
| if (!sdev) |
| goto nomem; |
| sdev->dev = dev; |
| sdev->pages_per_bio = pages_per_bio; |
| sdev->curr = -1; |
| for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) { |
| struct scrub_bio *sbio; |
| |
| sbio = kzalloc(sizeof(*sbio), GFP_NOFS); |
| if (!sbio) |
| goto nomem; |
| sdev->bios[i] = sbio; |
| |
| sbio->index = i; |
| sbio->sdev = sdev; |
| sbio->page_count = 0; |
| sbio->work.func = scrub_bio_end_io_worker; |
| |
| if (i != SCRUB_BIOS_PER_DEV-1) |
| sdev->bios[i]->next_free = i + 1; |
| else |
| sdev->bios[i]->next_free = -1; |
| } |
| sdev->first_free = 0; |
| sdev->nodesize = dev->dev_root->nodesize; |
| sdev->leafsize = dev->dev_root->leafsize; |
| sdev->sectorsize = dev->dev_root->sectorsize; |
| atomic_set(&sdev->in_flight, 0); |
| atomic_set(&sdev->fixup_cnt, 0); |
| atomic_set(&sdev->cancel_req, 0); |
| sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy); |
| INIT_LIST_HEAD(&sdev->csum_list); |
| |
| spin_lock_init(&sdev->list_lock); |
| spin_lock_init(&sdev->stat_lock); |
| init_waitqueue_head(&sdev->list_wait); |
| return sdev; |
| |
| nomem: |
| scrub_free_dev(sdev); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx) |
| { |
| u64 isize; |
| u32 nlink; |
| int ret; |
| int i; |
| struct extent_buffer *eb; |
| struct btrfs_inode_item *inode_item; |
| struct scrub_warning *swarn = ctx; |
| struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info; |
| struct inode_fs_paths *ipath = NULL; |
| struct btrfs_root *local_root; |
| struct btrfs_key root_key; |
| |
| root_key.objectid = root; |
| root_key.type = BTRFS_ROOT_ITEM_KEY; |
| root_key.offset = (u64)-1; |
| local_root = btrfs_read_fs_root_no_name(fs_info, &root_key); |
| if (IS_ERR(local_root)) { |
| ret = PTR_ERR(local_root); |
| goto err; |
| } |
| |
| ret = inode_item_info(inum, 0, local_root, swarn->path); |
| if (ret) { |
| 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); |
| |
| ipath = init_ipath(4096, local_root, swarn->path); |
| if (IS_ERR(ipath)) { |
| 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) |
| printk(KERN_WARNING "btrfs: %s at logical %llu on dev " |
| "%s, sector %llu, root %llu, inode %llu, offset %llu, " |
| "length %llu, links %u (path: %s)\n", swarn->errstr, |
| swarn->logical, swarn->dev->name, |
| (unsigned long long)swarn->sector, root, inum, offset, |
| min(isize - offset, (u64)PAGE_SIZE), nlink, |
| (char *)(unsigned long)ipath->fspath->val[i]); |
| |
| free_ipath(ipath); |
| return 0; |
| |
| err: |
| printk(KERN_WARNING "btrfs: %s at logical %llu on dev " |
| "%s, sector %llu, root %llu, inode %llu, offset %llu: path " |
| "resolving failed with ret=%d\n", swarn->errstr, |
| swarn->logical, swarn->dev->name, |
| (unsigned long long)swarn->sector, 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 = sblock->sdev->dev; |
| struct btrfs_fs_info *fs_info = dev->dev_root->fs_info; |
| struct btrfs_path *path; |
| struct btrfs_key found_key; |
| struct extent_buffer *eb; |
| struct btrfs_extent_item *ei; |
| struct scrub_warning swarn; |
| u32 item_size; |
| int ret; |
| u64 ref_root; |
| u8 ref_level; |
| unsigned long ptr = 0; |
| const int bufsize = 4096; |
| u64 extent_item_pos; |
| |
| path = btrfs_alloc_path(); |
| |
| swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS); |
| swarn.msg_buf = kmalloc(bufsize, GFP_NOFS); |
| BUG_ON(sblock->page_count < 1); |
| swarn.sector = (sblock->pagev[0].physical) >> 9; |
| swarn.logical = sblock->pagev[0].logical; |
| swarn.errstr = errstr; |
| swarn.dev = dev; |
| swarn.msg_bufsize = bufsize; |
| swarn.scratch_bufsize = bufsize; |
| |
| if (!path || !swarn.scratch_buf || !swarn.msg_buf) |
| goto out; |
| |
| ret = extent_from_logical(fs_info, swarn.logical, path, &found_key); |
| 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]); |
| btrfs_release_path(path); |
| |
| if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
| do { |
| ret = tree_backref_for_extent(&ptr, eb, ei, item_size, |
| &ref_root, &ref_level); |
| printk(KERN_WARNING |
| "btrfs: %s at logical %llu on dev %s, " |
| "sector %llu: metadata %s (level %d) in tree " |
| "%llu\n", errstr, swarn.logical, dev->name, |
| (unsigned long long)swarn.sector, |
| ref_level ? "node" : "leaf", |
| ret < 0 ? -1 : ref_level, |
| ret < 0 ? -1 : ref_root); |
| } while (ret != 1); |
| } else { |
| swarn.path = path; |
| iterate_extent_inodes(fs_info, found_key.objectid, |
| extent_item_pos, 1, |
| scrub_print_warning_inode, &swarn); |
| } |
| |
| out: |
| btrfs_free_path(path); |
| kfree(swarn.scratch_buf); |
| kfree(swarn.msg_buf); |
| } |
| |
| static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx) |
| { |
| struct page *page = NULL; |
| unsigned long index; |
| struct scrub_fixup_nodatasum *fixup = ctx; |
| int ret; |
| int corrected = 0; |
| struct btrfs_key key; |
| struct inode *inode = NULL; |
| u64 end = offset + PAGE_SIZE - 1; |
| struct btrfs_root *local_root; |
| |
| key.objectid = root; |
| key.type = BTRFS_ROOT_ITEM_KEY; |
| key.offset = (u64)-1; |
| local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key); |
| if (IS_ERR(local_root)) |
| return PTR_ERR(local_root); |
| |
| key.type = BTRFS_INODE_ITEM_KEY; |
| key.objectid = inum; |
| key.offset = 0; |
| inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL); |
| if (IS_ERR(inode)) |
| return PTR_ERR(inode); |
| |
| index = offset >> PAGE_CACHE_SHIFT; |
| |
| page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); |
| if (!page) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| if (PageUptodate(page)) { |
| struct btrfs_mapping_tree *map_tree; |
| if (PageDirty(page)) { |
| /* |
| * we need to write the data to the defect sector. the |
| * data that was in that sector is not in memory, |
| * because the page was modified. we must not write the |
| * modified page to that sector. |
| * |
| * TODO: what could be done here: wait for the delalloc |
| * runner to write out that page (might involve |
| * COW) and see whether the sector is still |
| * referenced afterwards. |
| * |
| * For the meantime, we'll treat this error |
| * incorrectable, although there is a chance that a |
| * later scrub will find the bad sector again and that |
| * there's no dirty page in memory, then. |
| */ |
| ret = -EIO; |
| goto out; |
| } |
| map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree; |
| ret = repair_io_failure(map_tree, offset, PAGE_SIZE, |
| fixup->logical, page, |
| fixup->mirror_num); |
| unlock_page(page); |
| corrected = !ret; |
| } else { |
| /* |
| * we need to get good data first. the general readpage path |
| * will call repair_io_failure for us, we just have to make |
| * sure we read the bad mirror. |
| */ |
| ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, |
| EXTENT_DAMAGED, GFP_NOFS); |
| if (ret) { |
| /* set_extent_bits should give proper error */ |
| WARN_ON(ret > 0); |
| if (ret > 0) |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page, |
| btrfs_get_extent, |
| fixup->mirror_num); |
| wait_on_page_locked(page); |
| |
| corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset, |
| end, EXTENT_DAMAGED, 0, NULL); |
| if (!corrected) |
| clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, |
| EXTENT_DAMAGED, GFP_NOFS); |
| } |
| |
| out: |
| if (page) |
| put_page(page); |
| if (inode) |
| iput(inode); |
| |
| if (ret < 0) |
| return ret; |
| |
| if (ret == 0 && corrected) { |
| /* |
| * we only need to call readpage for one of the inodes belonging |
| * to this extent. so make iterate_extent_inodes stop |
| */ |
| return 1; |
| } |
| |
| return -EIO; |
| } |
| |
| static void scrub_fixup_nodatasum(struct btrfs_work *work) |
| { |
| int ret; |
| struct scrub_fixup_nodatasum *fixup; |
| struct scrub_dev *sdev; |
| struct btrfs_trans_handle *trans = NULL; |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_path *path; |
| int uncorrectable = 0; |
| |
| fixup = container_of(work, struct scrub_fixup_nodatasum, work); |
| sdev = fixup->sdev; |
| fs_info = fixup->root->fs_info; |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| spin_lock(&sdev->stat_lock); |
| ++sdev->stat.malloc_errors; |
| spin_unlock(&sdev->stat_lock); |
| uncorrectable = 1; |
| goto out; |
| } |
| |
| trans = btrfs_join_transaction(fixup->root); |
| if (IS_ERR(trans)) { |
| uncorrectable = 1; |
| goto out; |
| } |
| |
| /* |
| * the idea is to trigger a regular read through the standard path. we |
| * read a page from the (failed) logical address by specifying the |
| * corresponding copynum of the failed sector. thus, that readpage is |
| * expected to fail. |
| * that is the point where on-the-fly error correction will kick in |
| * (once it's finished) and rewrite the failed sector if a good copy |
| * can be found. |
| */ |
| ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info, |
| path, scrub_fixup_readpage, |
| fixup); |
| if (ret < 0) { |
| uncorrectable = 1; |
| goto out; |
| } |
| WARN_ON(ret != 1); |
| |
| spin_lock(&sdev->stat_lock); |
| ++sdev->stat.corrected_errors; |
| spin_unlock(&sdev->stat_lock); |
| |
| out: |
| if (trans && !IS_ERR(trans)) |
| btrfs_end_transaction(trans, fixup->root); |
| if (uncorrectable) { |
| spin_lock(&sdev->stat_lock); |
| ++sdev->stat.uncorrectable_errors; |
| spin_unlock(&sdev->stat_lock); |
| printk_ratelimited(KERN_ERR |
| "btrfs: unable to fixup (nodatasum) error at logical %llu on dev %s\n", |
| (unsigned long long)fixup->logical, sdev->dev->name); |
| } |
| |
| btrfs_free_path(path); |
| kfree(fixup); |
| |
| /* see caller why we're pretending to be paused in the scrub counters */ |
| mutex_lock(&fs_info->scrub_lock); |
| atomic_dec(&fs_info->scrubs_running); |
| atomic_dec(&fs_info->scrubs_paused); |
| mutex_unlock(&fs_info->scrub_lock); |
| atomic_dec(&sdev->fixup_cnt); |
| wake_up(&fs_info->scrub_pause_wait); |
| wake_up(&sdev->list_wait); |
| } |
| |
| /* |
| * 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_dev *sdev = sblock_to_check->sdev; |
| struct btrfs_fs_info *fs_info; |
| u64 length; |
| u64 logical; |
| u64 generation; |
| unsigned int failed_mirror_index; |
| unsigned int is_metadata; |
| unsigned int have_csum; |
| u8 *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; |
| static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, |
| DEFAULT_RATELIMIT_BURST); |
| |
| BUG_ON(sblock_to_check->page_count < 1); |
| fs_info = sdev->dev->dev_root->fs_info; |
| length = sblock_to_check->page_count * PAGE_SIZE; |
| logical = sblock_to_check->pagev[0].logical; |
| generation = sblock_to_check->pagev[0].generation; |
| 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; |
| csum = sblock_to_check->pagev[0].csum; |
| |
| /* |
| * 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 = kzalloc(BTRFS_MAX_MIRRORS * |
| sizeof(*sblocks_for_recheck), |
| GFP_NOFS); |
| if (!sblocks_for_recheck) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.malloc_errors++; |
| sdev->stat.read_errors++; |
| sdev->stat.uncorrectable_errors++; |
| spin_unlock(&sdev->stat_lock); |
| goto out; |
| } |
| |
| /* setup the context, map the logical blocks and alloc the pages */ |
| ret = scrub_setup_recheck_block(sdev, &fs_info->mapping_tree, length, |
| logical, sblocks_for_recheck); |
| if (ret) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.read_errors++; |
| sdev->stat.uncorrectable_errors++; |
| spin_unlock(&sdev->stat_lock); |
| 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 */ |
| ret = scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum, |
| csum, generation, sdev->csum_size); |
| if (ret) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.read_errors++; |
| sdev->stat.uncorrectable_errors++; |
| spin_unlock(&sdev->stat_lock); |
| goto out; |
| } |
| |
| 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(&sdev->stat_lock); |
| sdev->stat.unverified_errors++; |
| spin_unlock(&sdev->stat_lock); |
| |
| goto out; |
| } |
| |
| if (!sblock_bad->no_io_error_seen) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.read_errors++; |
| spin_unlock(&sdev->stat_lock); |
| if (__ratelimit(&_rs)) |
| scrub_print_warning("i/o error", sblock_to_check); |
| } else if (sblock_bad->checksum_error) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.csum_errors++; |
| spin_unlock(&sdev->stat_lock); |
| if (__ratelimit(&_rs)) |
| scrub_print_warning("checksum error", sblock_to_check); |
| } else if (sblock_bad->header_error) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.verify_errors++; |
| spin_unlock(&sdev->stat_lock); |
| if (__ratelimit(&_rs)) |
| scrub_print_warning("checksum/header error", |
| sblock_to_check); |
| } |
| |
| if (sdev->readonly) |
| goto did_not_correct_error; |
| |
| if (!is_metadata && !have_csum) { |
| struct scrub_fixup_nodatasum *fixup_nodatasum; |
| |
| /* |
| * !is_metadata and !have_csum, this means that the data |
| * might not be COW'ed, that it might be modified |
| * concurrently. The general strategy to work on the |
| * commit root does not help in the case when COW is not |
| * used. |
| */ |
| fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS); |
| if (!fixup_nodatasum) |
| goto did_not_correct_error; |
| fixup_nodatasum->sdev = sdev; |
| fixup_nodatasum->logical = logical; |
| fixup_nodatasum->root = fs_info->extent_root; |
| fixup_nodatasum->mirror_num = failed_mirror_index + 1; |
| /* |
| * increment scrubs_running to prevent cancel requests from |
| * completing as long as a fixup worker is running. we must also |
| * increment scrubs_paused to prevent deadlocking on pause |
| * requests used for transactions commits (as the worker uses a |
| * transaction context). it is safe to regard the fixup worker |
| * as paused for all matters practical. effectively, we only |
| * avoid cancellation requests from completing. |
| */ |
| mutex_lock(&fs_info->scrub_lock); |
| atomic_inc(&fs_info->scrubs_running); |
| atomic_inc(&fs_info->scrubs_paused); |
| mutex_unlock(&fs_info->scrub_lock); |
| atomic_inc(&sdev->fixup_cnt); |
| fixup_nodatasum->work.func = scrub_fixup_nodatasum; |
| btrfs_queue_worker(&fs_info->scrub_workers, |
| &fixup_nodatasum->work); |
| goto out; |
| } |
| |
| /* |
| * now build and submit the bios for the other mirrors, check |
| * checksums |
| */ |
| for (mirror_index = 0; |
| mirror_index < BTRFS_MAX_MIRRORS && |
| sblocks_for_recheck[mirror_index].page_count > 0; |
| mirror_index++) { |
| if (mirror_index == failed_mirror_index) |
| continue; |
| |
| /* build and submit the bios, check checksums */ |
| ret = scrub_recheck_block(fs_info, |
| sblocks_for_recheck + mirror_index, |
| is_metadata, have_csum, csum, |
| generation, sdev->csum_size); |
| if (ret) |
| goto did_not_correct_error; |
| } |
| |
| /* |
| * 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 < BTRFS_MAX_MIRRORS && |
| sblocks_for_recheck[mirror_index].page_count > 0; |
| mirror_index++) { |
| struct scrub_block *sblock_other = sblocks_for_recheck + |
| mirror_index; |
| |
| if (!sblock_other->header_error && |
| !sblock_other->checksum_error && |
| sblock_other->no_io_error_seen) { |
| int force_write = is_metadata || have_csum; |
| |
| ret = scrub_repair_block_from_good_copy(sblock_bad, |
| sblock_other, |
| force_write); |
| if (0 == ret) |
| goto corrected_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 succeedes. 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. |
| */ |
| |
| /* can only fix I/O errors from here on */ |
| if (sblock_bad->no_io_error_seen) |
| goto did_not_correct_error; |
| |
| success = 1; |
| for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { |
| struct scrub_page *page_bad = sblock_bad->pagev + page_num; |
| |
| if (!page_bad->io_error) |
| continue; |
| |
| for (mirror_index = 0; |
| mirror_index < BTRFS_MAX_MIRRORS && |
| sblocks_for_recheck[mirror_index].page_count > 0; |
| mirror_index++) { |
| struct scrub_block *sblock_other = sblocks_for_recheck + |
| mirror_index; |
| struct scrub_page *page_other = sblock_other->pagev + |
| page_num; |
| |
| if (!page_other->io_error) { |
| ret = scrub_repair_page_from_good_copy( |
| sblock_bad, sblock_other, page_num, 0); |
| if (0 == ret) { |
| page_bad->io_error = 0; |
| break; /* succeeded for this page */ |
| } |
| } |
| } |
| |
| if (page_bad->io_error) { |
| /* did not find a mirror to copy the page from */ |
| success = 0; |
| } |
| } |
| |
| if (success) { |
| 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. |
| */ |
| ret = scrub_recheck_block(fs_info, sblock_bad, |
| is_metadata, have_csum, csum, |
| generation, sdev->csum_size); |
| if (!ret && !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(&sdev->stat_lock); |
| sdev->stat.corrected_errors++; |
| spin_unlock(&sdev->stat_lock); |
| printk_ratelimited(KERN_ERR |
| "btrfs: fixed up error at logical %llu on dev %s\n", |
| (unsigned long long)logical, sdev->dev->name); |
| } |
| } else { |
| did_not_correct_error: |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.uncorrectable_errors++; |
| spin_unlock(&sdev->stat_lock); |
| printk_ratelimited(KERN_ERR |
| "btrfs: unable to fixup (regular) error at logical %llu on dev %s\n", |
| (unsigned long long)logical, sdev->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; |
| int page_index; |
| |
| for (page_index = 0; page_index < SCRUB_PAGES_PER_BIO; |
| page_index++) |
| if (sblock->pagev[page_index].page) |
| __free_page( |
| sblock->pagev[page_index].page); |
| } |
| kfree(sblocks_for_recheck); |
| } |
| |
| return 0; |
| } |
| |
| static int scrub_setup_recheck_block(struct scrub_dev *sdev, |
| struct btrfs_mapping_tree *map_tree, |
| u64 length, u64 logical, |
| struct scrub_block *sblocks_for_recheck) |
| { |
| int page_index; |
| int mirror_index; |
| int ret; |
| |
| /* |
| * note: the three members sdev, ref_count and outstanding_pages |
| * are not used (and not set) in the blocks that are used for |
| * the recheck procedure |
| */ |
| |
| page_index = 0; |
| while (length > 0) { |
| u64 sublen = min_t(u64, length, PAGE_SIZE); |
| u64 mapped_length = sublen; |
| struct btrfs_bio *bbio = NULL; |
| |
| /* |
| * with a length of PAGE_SIZE, each returned stripe |
| * represents one mirror |
| */ |
| ret = btrfs_map_block(map_tree, WRITE, logical, &mapped_length, |
| &bbio, 0); |
| if (ret || !bbio || mapped_length < sublen) { |
| kfree(bbio); |
| return -EIO; |
| } |
| |
| BUG_ON(page_index >= SCRUB_PAGES_PER_BIO); |
| for (mirror_index = 0; mirror_index < (int)bbio->num_stripes; |
| mirror_index++) { |
| struct scrub_block *sblock; |
| struct scrub_page *page; |
| |
| if (mirror_index >= BTRFS_MAX_MIRRORS) |
| continue; |
| |
| sblock = sblocks_for_recheck + mirror_index; |
| page = sblock->pagev + page_index; |
| page->logical = logical; |
| page->physical = bbio->stripes[mirror_index].physical; |
| page->bdev = bbio->stripes[mirror_index].dev->bdev; |
| page->mirror_num = mirror_index + 1; |
| page->page = alloc_page(GFP_NOFS); |
| if (!page->page) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.malloc_errors++; |
| spin_unlock(&sdev->stat_lock); |
| return -ENOMEM; |
| } |
| sblock->page_count++; |
| } |
| kfree(bbio); |
| length -= sublen; |
| logical += sublen; |
| page_index++; |
| } |
| |
| return 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 int scrub_recheck_block(struct btrfs_fs_info *fs_info, |
| struct scrub_block *sblock, int is_metadata, |
| int have_csum, u8 *csum, u64 generation, |
| u16 csum_size) |
| { |
| int page_num; |
| |
| sblock->no_io_error_seen = 1; |
| sblock->header_error = 0; |
| sblock->checksum_error = 0; |
| |
| for (page_num = 0; page_num < sblock->page_count; page_num++) { |
| struct bio *bio; |
| int ret; |
| struct scrub_page *page = sblock->pagev + page_num; |
| DECLARE_COMPLETION_ONSTACK(complete); |
| |
| BUG_ON(!page->page); |
| bio = bio_alloc(GFP_NOFS, 1); |
| if (!bio) |
| return -EIO; |
| bio->bi_bdev = page->bdev; |
| bio->bi_sector = page->physical >> 9; |
| bio->bi_end_io = scrub_complete_bio_end_io; |
| bio->bi_private = &complete; |
| |
| ret = bio_add_page(bio, page->page, PAGE_SIZE, 0); |
| if (PAGE_SIZE != ret) { |
| bio_put(bio); |
| return -EIO; |
| } |
| btrfsic_submit_bio(READ, bio); |
| |
| /* this will also unplug the queue */ |
| wait_for_completion(&complete); |
| |
| page->io_error = !test_bit(BIO_UPTODATE, &bio->bi_flags); |
| if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| sblock->no_io_error_seen = 0; |
| bio_put(bio); |
| } |
| |
| if (sblock->no_io_error_seen) |
| scrub_recheck_block_checksum(fs_info, sblock, is_metadata, |
| have_csum, csum, generation, |
| csum_size); |
| |
| return 0; |
| } |
| |
| static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, |
| struct scrub_block *sblock, |
| int is_metadata, int have_csum, |
| const u8 *csum, u64 generation, |
| u16 csum_size) |
| { |
| int page_num; |
| u8 calculated_csum[BTRFS_CSUM_SIZE]; |
| u32 crc = ~(u32)0; |
| struct btrfs_root *root = fs_info->extent_root; |
| void *mapped_buffer; |
| |
| BUG_ON(!sblock->pagev[0].page); |
| if (is_metadata) { |
| struct btrfs_header *h; |
| |
| mapped_buffer = kmap_atomic(sblock->pagev[0].page, KM_USER0); |
| h = (struct btrfs_header *)mapped_buffer; |
| |
| if (sblock->pagev[0].logical != le64_to_cpu(h->bytenr) || |
| generation != le64_to_cpu(h->generation) || |
| memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) || |
| memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, |
| BTRFS_UUID_SIZE)) |
| sblock->header_error = 1; |
| csum = h->csum; |
| } else { |
| if (!have_csum) |
| return; |
| |
| mapped_buffer = kmap_atomic(sblock->pagev[0].page, KM_USER0); |
| } |
| |
| for (page_num = 0;;) { |
| if (page_num == 0 && is_metadata) |
| crc = btrfs_csum_data(root, |
| ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE, |
| crc, PAGE_SIZE - BTRFS_CSUM_SIZE); |
| else |
| crc = btrfs_csum_data(root, mapped_buffer, crc, |
| PAGE_SIZE); |
| |
| kunmap_atomic(mapped_buffer, KM_USER0); |
| page_num++; |
| if (page_num >= sblock->page_count) |
| break; |
| BUG_ON(!sblock->pagev[page_num].page); |
| |
| mapped_buffer = kmap_atomic(sblock->pagev[page_num].page, |
| KM_USER0); |
| } |
| |
| btrfs_csum_final(crc, calculated_csum); |
| if (memcmp(calculated_csum, csum, csum_size)) |
| sblock->checksum_error = 1; |
| } |
| |
| static void scrub_complete_bio_end_io(struct bio *bio, int err) |
| { |
| complete((struct completion *)bio->bi_private); |
| } |
| |
| static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, |
| struct scrub_block *sblock_good, |
| int force_write) |
| { |
| 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, |
| force_write); |
| 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 *page_bad = sblock_bad->pagev + page_num; |
| struct scrub_page *page_good = sblock_good->pagev + page_num; |
| |
| BUG_ON(sblock_bad->pagev[page_num].page == NULL); |
| BUG_ON(sblock_good->pagev[page_num].page == NULL); |
| if (force_write || sblock_bad->header_error || |
| sblock_bad->checksum_error || page_bad->io_error) { |
| struct bio *bio; |
| int ret; |
| DECLARE_COMPLETION_ONSTACK(complete); |
| |
| bio = bio_alloc(GFP_NOFS, 1); |
| if (!bio) |
| return -EIO; |
| bio->bi_bdev = page_bad->bdev; |
| bio->bi_sector = page_bad->physical >> 9; |
| bio->bi_end_io = scrub_complete_bio_end_io; |
| bio->bi_private = &complete; |
| |
| ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0); |
| if (PAGE_SIZE != ret) { |
| bio_put(bio); |
| return -EIO; |
| } |
| btrfsic_submit_bio(WRITE, bio); |
| |
| /* this will also unplug the queue */ |
| wait_for_completion(&complete); |
| bio_put(bio); |
| } |
| |
| return 0; |
| } |
| |
| static void scrub_checksum(struct scrub_block *sblock) |
| { |
| u64 flags; |
| int ret; |
| |
| BUG_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); |
| } |
| |
| static int scrub_checksum_data(struct scrub_block *sblock) |
| { |
| struct scrub_dev *sdev = sblock->sdev; |
| u8 csum[BTRFS_CSUM_SIZE]; |
| u8 *on_disk_csum; |
| struct page *page; |
| void *buffer; |
| u32 crc = ~(u32)0; |
| int fail = 0; |
| struct btrfs_root *root = sdev->dev->dev_root; |
| u64 len; |
| int index; |
| |
| BUG_ON(sblock->page_count < 1); |
| if (!sblock->pagev[0].have_csum) |
| return 0; |
| |
| on_disk_csum = sblock->pagev[0].csum; |
| page = sblock->pagev[0].page; |
| buffer = kmap_atomic(page, KM_USER0); |
| |
| len = sdev->sectorsize; |
| index = 0; |
| for (;;) { |
| u64 l = min_t(u64, len, PAGE_SIZE); |
| |
| crc = btrfs_csum_data(root, buffer, crc, l); |
| kunmap_atomic(buffer, KM_USER0); |
| len -= l; |
| if (len == 0) |
| break; |
| index++; |
| BUG_ON(index >= sblock->page_count); |
| BUG_ON(!sblock->pagev[index].page); |
| page = sblock->pagev[index].page; |
| buffer = kmap_atomic(page, KM_USER0); |
| } |
| |
| btrfs_csum_final(crc, csum); |
| if (memcmp(csum, on_disk_csum, sdev->csum_size)) |
| fail = 1; |
| |
| if (fail) { |
| spin_lock(&sdev->stat_lock); |
| ++sdev->stat.csum_errors; |
| spin_unlock(&sdev->stat_lock); |
| } |
| |
| return fail; |
| } |
| |
| static int scrub_checksum_tree_block(struct scrub_block *sblock) |
| { |
| struct scrub_dev *sdev = sblock->sdev; |
| struct btrfs_header *h; |
| struct btrfs_root *root = sdev->dev->dev_root; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| u8 calculated_csum[BTRFS_CSUM_SIZE]; |
| u8 on_disk_csum[BTRFS_CSUM_SIZE]; |
| struct page *page; |
| void *mapped_buffer; |
| u64 mapped_size; |
| void *p; |
| u32 crc = ~(u32)0; |
| int fail = 0; |
| int crc_fail = 0; |
| u64 len; |
| int index; |
| |
| BUG_ON(sblock->page_count < 1); |
| page = sblock->pagev[0].page; |
| mapped_buffer = kmap_atomic(page, KM_USER0); |
| h = (struct btrfs_header *)mapped_buffer; |
| memcpy(on_disk_csum, h->csum, sdev->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 (sblock->pagev[0].logical != le64_to_cpu(h->bytenr)) |
| ++fail; |
| |
| if (sblock->pagev[0].generation != le64_to_cpu(h->generation)) |
| ++fail; |
| |
| if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) |
| ++fail; |
| |
| if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, |
| BTRFS_UUID_SIZE)) |
| ++fail; |
| |
| BUG_ON(sdev->nodesize != sdev->leafsize); |
| len = sdev->nodesize - BTRFS_CSUM_SIZE; |
| mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; |
| p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; |
| index = 0; |
| for (;;) { |
| u64 l = min_t(u64, len, mapped_size); |
| |
| crc = btrfs_csum_data(root, p, crc, l); |
| kunmap_atomic(mapped_buffer, KM_USER0); |
| len -= l; |
| if (len == 0) |
| break; |
| index++; |
| BUG_ON(index >= sblock->page_count); |
| BUG_ON(!sblock->pagev[index].page); |
| page = sblock->pagev[index].page; |
| mapped_buffer = kmap_atomic(page, KM_USER0); |
| mapped_size = PAGE_SIZE; |
| p = mapped_buffer; |
| } |
| |
| btrfs_csum_final(crc, calculated_csum); |
| if (memcmp(calculated_csum, on_disk_csum, sdev->csum_size)) |
| ++crc_fail; |
| |
| if (crc_fail || fail) { |
| spin_lock(&sdev->stat_lock); |
| if (crc_fail) |
| ++sdev->stat.csum_errors; |
| if (fail) |
| ++sdev->stat.verify_errors; |
| spin_unlock(&sdev->stat_lock); |
| } |
| |
| return fail || crc_fail; |
| } |
| |
| static int scrub_checksum_super(struct scrub_block *sblock) |
| { |
| struct btrfs_super_block *s; |
| struct scrub_dev *sdev = sblock->sdev; |
| struct btrfs_root *root = sdev->dev->dev_root; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| u8 calculated_csum[BTRFS_CSUM_SIZE]; |
| u8 on_disk_csum[BTRFS_CSUM_SIZE]; |
| struct page *page; |
| void *mapped_buffer; |
| u64 mapped_size; |
| void *p; |
| u32 crc = ~(u32)0; |
| int fail = 0; |
| u64 len; |
| int index; |
| |
| BUG_ON(sblock->page_count < 1); |
| page = sblock->pagev[0].page; |
| mapped_buffer = kmap_atomic(page, KM_USER0); |
| s = (struct btrfs_super_block *)mapped_buffer; |
| memcpy(on_disk_csum, s->csum, sdev->csum_size); |
| |
| if (sblock->pagev[0].logical != le64_to_cpu(s->bytenr)) |
| ++fail; |
| |
| if (sblock->pagev[0].generation != le64_to_cpu(s->generation)) |
| ++fail; |
| |
| if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) |
| ++fail; |
| |
| len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE; |
| mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; |
| p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; |
| index = 0; |
| for (;;) { |
| u64 l = min_t(u64, len, mapped_size); |
| |
| crc = btrfs_csum_data(root, p, crc, l); |
| kunmap_atomic(mapped_buffer, KM_USER0); |
| len -= l; |
| if (len == 0) |
| break; |
| index++; |
| BUG_ON(index >= sblock->page_count); |
| BUG_ON(!sblock->pagev[index].page); |
| page = sblock->pagev[index].page; |
| mapped_buffer = kmap_atomic(page, KM_USER0); |
| mapped_size = PAGE_SIZE; |
| p = mapped_buffer; |
| } |
| |
| btrfs_csum_final(crc, calculated_csum); |
| if (memcmp(calculated_csum, on_disk_csum, sdev->csum_size)) |
| ++fail; |
| |
| if (fail) { |
| /* |
| * 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(&sdev->stat_lock); |
| ++sdev->stat.super_errors; |
| spin_unlock(&sdev->stat_lock); |
| } |
| |
| return fail; |
| } |
| |
| static void scrub_block_get(struct scrub_block *sblock) |
| { |
| atomic_inc(&sblock->ref_count); |
| } |
| |
| static void scrub_block_put(struct scrub_block *sblock) |
| { |
| if (atomic_dec_and_test(&sblock->ref_count)) { |
| int i; |
| |
| for (i = 0; i < sblock->page_count; i++) |
| if (sblock->pagev[i].page) |
| __free_page(sblock->pagev[i].page); |
| kfree(sblock); |
| } |
| } |
| |
| static void scrub_submit(struct scrub_dev *sdev) |
| { |
| struct scrub_bio *sbio; |
| |
| if (sdev->curr == -1) |
| return; |
| |
| sbio = sdev->bios[sdev->curr]; |
| sdev->curr = -1; |
| atomic_inc(&sdev->in_flight); |
| |
| btrfsic_submit_bio(READ, sbio->bio); |
| } |
| |
| static int scrub_add_page_to_bio(struct scrub_dev *sdev, |
| 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 (sdev->curr == -1) { |
| spin_lock(&sdev->list_lock); |
| sdev->curr = sdev->first_free; |
| if (sdev->curr != -1) { |
| sdev->first_free = sdev->bios[sdev->curr]->next_free; |
| sdev->bios[sdev->curr]->next_free = -1; |
| sdev->bios[sdev->curr]->page_count = 0; |
| spin_unlock(&sdev->list_lock); |
| } else { |
| spin_unlock(&sdev->list_lock); |
| wait_event(sdev->list_wait, sdev->first_free != -1); |
| } |
| } |
| sbio = sdev->bios[sdev->curr]; |
| if (sbio->page_count == 0) { |
| struct bio *bio; |
| |
| sbio->physical = spage->physical; |
| sbio->logical = spage->logical; |
| bio = sbio->bio; |
| if (!bio) { |
| bio = bio_alloc(GFP_NOFS, sdev->pages_per_bio); |
| if (!bio) |
| return -ENOMEM; |
| sbio->bio = bio; |
| } |
| |
| bio->bi_private = sbio; |
| bio->bi_end_io = scrub_bio_end_io; |
| bio->bi_bdev = sdev->dev->bdev; |
| bio->bi_sector = spage->physical >> 9; |
| sbio->err = 0; |
| } else if (sbio->physical + sbio->page_count * PAGE_SIZE != |
| spage->physical || |
| sbio->logical + sbio->page_count * PAGE_SIZE != |
| spage->logical) { |
| scrub_submit(sdev); |
| 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(sdev); |
| goto again; |
| } |
| |
| scrub_block_get(sblock); /* one for the added page */ |
| atomic_inc(&sblock->outstanding_pages); |
| sbio->page_count++; |
| if (sbio->page_count == sdev->pages_per_bio) |
| scrub_submit(sdev); |
| |
| return 0; |
| } |
| |
| static int scrub_pages(struct scrub_dev *sdev, u64 logical, u64 len, |
| u64 physical, u64 flags, u64 gen, int mirror_num, |
| u8 *csum, int force) |
| { |
| struct scrub_block *sblock; |
| int index; |
| |
| sblock = kzalloc(sizeof(*sblock), GFP_NOFS); |
| if (!sblock) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.malloc_errors++; |
| spin_unlock(&sdev->stat_lock); |
| return -ENOMEM; |
| } |
| |
| /* one ref inside this function, plus one for each page later on */ |
| atomic_set(&sblock->ref_count, 1); |
| sblock->sdev = sdev; |
| sblock->no_io_error_seen = 1; |
| |
| for (index = 0; len > 0; index++) { |
| struct scrub_page *spage = sblock->pagev + index; |
| u64 l = min_t(u64, len, PAGE_SIZE); |
| |
| BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); |
| spage->page = alloc_page(GFP_NOFS); |
| if (!spage->page) { |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.malloc_errors++; |
| spin_unlock(&sdev->stat_lock); |
| while (index > 0) { |
| index--; |
| __free_page(sblock->pagev[index].page); |
| } |
| kfree(sblock); |
| return -ENOMEM; |
| } |
| spage->sblock = sblock; |
| spage->bdev = sdev->dev->bdev; |
| 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, sdev->csum_size); |
| } else { |
| spage->have_csum = 0; |
| } |
| sblock->page_count++; |
| len -= l; |
| logical += l; |
| physical += l; |
| } |
| |
| BUG_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_bio(sdev, spage); |
| if (ret) { |
| scrub_block_put(sblock); |
| return ret; |
| } |
| } |
| |
| if (force) |
| scrub_submit(sdev); |
| |
| /* 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, int err) |
| { |
| struct scrub_bio *sbio = bio->bi_private; |
| struct scrub_dev *sdev = sbio->sdev; |
| struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info; |
| |
| sbio->err = err; |
| sbio->bio = bio; |
| |
| btrfs_queue_worker(&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_dev *sdev = sbio->sdev; |
| int i; |
| |
| BUG_ON(sbio->page_count > SCRUB_PAGES_PER_BIO); |
| if (sbio->err) { |
| 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); |
| } |
| |
| if (sbio->err) { |
| /* what is this good for??? */ |
| sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1); |
| sbio->bio->bi_flags |= 1 << BIO_UPTODATE; |
| sbio->bio->bi_phys_segments = 0; |
| sbio->bio->bi_idx = 0; |
| |
| for (i = 0; i < sbio->page_count; i++) { |
| struct bio_vec *bi; |
| bi = &sbio->bio->bi_io_vec[i]; |
| bi->bv_offset = 0; |
| bi->bv_len = PAGE_SIZE; |
| } |
| } |
| |
| bio_put(sbio->bio); |
| sbio->bio = NULL; |
| spin_lock(&sdev->list_lock); |
| sbio->next_free = sdev->first_free; |
| sdev->first_free = sbio->index; |
| spin_unlock(&sdev->list_lock); |
| atomic_dec(&sdev->in_flight); |
| wake_up(&sdev->list_wait); |
| } |
| |
| static void scrub_block_complete(struct scrub_block *sblock) |
| { |
| if (!sblock->no_io_error_seen) |
| scrub_handle_errored_block(sblock); |
| else |
| scrub_checksum(sblock); |
| } |
| |
| static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len, |
| u8 *csum) |
| { |
| struct btrfs_ordered_sum *sum = NULL; |
| int ret = 0; |
| unsigned long i; |
| unsigned long num_sectors; |
| |
| while (!list_empty(&sdev->csum_list)) { |
| sum = list_first_entry(&sdev->csum_list, |
| struct btrfs_ordered_sum, list); |
| if (sum->bytenr > logical) |
| return 0; |
| if (sum->bytenr + sum->len > logical) |
| break; |
| |
| ++sdev->stat.csum_discards; |
| list_del(&sum->list); |
| kfree(sum); |
| sum = NULL; |
| } |
| if (!sum) |
| return 0; |
| |
| num_sectors = sum->len / sdev->sectorsize; |
| for (i = 0; i < num_sectors; ++i) { |
| if (sum->sums[i].bytenr == logical) { |
| memcpy(csum, &sum->sums[i].sum, sdev->csum_size); |
| ret = 1; |
| break; |
| } |
| } |
| if (ret && i == num_sectors - 1) { |
| list_del(&sum->list); |
| kfree(sum); |
| } |
| return ret; |
| } |
| |
| /* scrub extent tries to collect up to 64 kB for each bio */ |
| static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len, |
| u64 physical, u64 flags, u64 gen, int mirror_num) |
| { |
| int ret; |
| u8 csum[BTRFS_CSUM_SIZE]; |
| u32 blocksize; |
| |
| if (flags & BTRFS_EXTENT_FLAG_DATA) { |
| blocksize = sdev->sectorsize; |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.data_extents_scrubbed++; |
| sdev->stat.data_bytes_scrubbed += len; |
| spin_unlock(&sdev->stat_lock); |
| } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
| BUG_ON(sdev->nodesize != sdev->leafsize); |
| blocksize = sdev->nodesize; |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.tree_extents_scrubbed++; |
| sdev->stat.tree_bytes_scrubbed += len; |
| spin_unlock(&sdev->stat_lock); |
| } else { |
| blocksize = sdev->sectorsize; |
| BUG_ON(1); |
| } |
| |
| while (len) { |
| u64 l = min_t(u64, len, blocksize); |
| int have_csum = 0; |
| |
| if (flags & BTRFS_EXTENT_FLAG_DATA) { |
| /* push csums to sbio */ |
| have_csum = scrub_find_csum(sdev, logical, l, csum); |
| if (have_csum == 0) |
| ++sdev->stat.no_csum; |
| } |
| ret = scrub_pages(sdev, logical, l, physical, flags, gen, |
| mirror_num, have_csum ? csum : NULL, 0); |
| if (ret) |
| return ret; |
| len -= l; |
| logical += l; |
| physical += l; |
| } |
| return 0; |
| } |
| |
| static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev, |
| struct map_lookup *map, int num, u64 base, u64 length) |
| { |
| struct btrfs_path *path; |
| struct btrfs_fs_info *fs_info = sdev->dev->dev_root->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; |
| int i; |
| u64 nstripes; |
| struct extent_buffer *l; |
| struct btrfs_key key; |
| u64 physical; |
| u64 logical; |
| u64 generation; |
| int mirror_num; |
| struct reada_control *reada1; |
| struct reada_control *reada2; |
| struct btrfs_key key_start; |
| struct btrfs_key key_end; |
| |
| u64 increment = map->stripe_len; |
| u64 offset; |
| |
| nstripes = length; |
| offset = 0; |
| do_div(nstripes, 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) { |
| 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 { |
| increment = map->stripe_len; |
| mirror_num = 1; |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!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; |
| |
| /* |
| * 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; |
| |
| wait_event(sdev->list_wait, |
| atomic_read(&sdev->in_flight) == 0); |
| atomic_inc(&fs_info->scrubs_paused); |
| wake_up(&fs_info->scrub_pause_wait); |
| |
| /* FIXME it might be better to start readahead at commit root */ |
| key_start.objectid = logical; |
| key_start.type = BTRFS_EXTENT_ITEM_KEY; |
| key_start.offset = (u64)0; |
| key_end.objectid = base + offset + nstripes * increment; |
| key_end.type = BTRFS_EXTENT_ITEM_KEY; |
| key_end.offset = (u64)0; |
| reada1 = btrfs_reada_add(root, &key_start, &key_end); |
| |
| key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
| key_start.type = BTRFS_EXTENT_CSUM_KEY; |
| key_start.offset = logical; |
| key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
| key_end.type = BTRFS_EXTENT_CSUM_KEY; |
| key_end.offset = base + offset + nstripes * increment; |
| reada2 = btrfs_reada_add(csum_root, &key_start, &key_end); |
| |
| if (!IS_ERR(reada1)) |
| btrfs_reada_wait(reada1); |
| if (!IS_ERR(reada2)) |
| btrfs_reada_wait(reada2); |
| |
| mutex_lock(&fs_info->scrub_lock); |
| 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); |
| } |
| atomic_dec(&fs_info->scrubs_paused); |
| mutex_unlock(&fs_info->scrub_lock); |
| wake_up(&fs_info->scrub_pause_wait); |
| |
| /* |
| * 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 |
| */ |
| logical = base + offset; |
| physical = map->stripes[num].physical; |
| ret = 0; |
| for (i = 0; i < nstripes; ++i) { |
| /* |
| * canceled? |
| */ |
| if (atomic_read(&fs_info->scrub_cancel_req) || |
| atomic_read(&sdev->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 */ |
| scrub_submit(sdev); |
| wait_event(sdev->list_wait, |
| atomic_read(&sdev->in_flight) == 0); |
| atomic_inc(&fs_info->scrubs_paused); |
| wake_up(&fs_info->scrub_pause_wait); |
| mutex_lock(&fs_info->scrub_lock); |
| 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); |
| } |
| atomic_dec(&fs_info->scrubs_paused); |
| mutex_unlock(&fs_info->scrub_lock); |
| wake_up(&fs_info->scrub_pause_wait); |
| } |
| |
| ret = btrfs_lookup_csums_range(csum_root, logical, |
| logical + map->stripe_len - 1, |
| &sdev->csum_list, 1); |
| if (ret) |
| goto out; |
| |
| key.objectid = logical; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = (u64)0; |
| |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| if (ret > 0) { |
| ret = btrfs_previous_item(root, path, 0, |
| BTRFS_EXTENT_ITEM_KEY); |
| 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; |
| } |
| } |
| |
| while (1) { |
| 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; |
| |
| break; |
| } |
| btrfs_item_key_to_cpu(l, &key, slot); |
| |
| if (key.objectid + key.offset <= logical) |
| goto next; |
| |
| if (key.objectid >= logical + map->stripe_len) |
| break; |
| |
| if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) |
| goto next; |
| |
| extent = btrfs_item_ptr(l, slot, |
| struct btrfs_extent_item); |
| flags = btrfs_extent_flags(l, extent); |
| generation = btrfs_extent_generation(l, extent); |
| |
| if (key.objectid < logical && |
| (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) { |
| printk(KERN_ERR |
| "btrfs scrub: tree block %llu spanning " |
| "stripes, ignored. logical=%llu\n", |
| (unsigned long long)key.objectid, |
| (unsigned long long)logical); |
| goto next; |
| } |
| |
| /* |
| * trim extent to this stripe |
| */ |
| if (key.objectid < logical) { |
| key.offset -= logical - key.objectid; |
| key.objectid = logical; |
| } |
| if (key.objectid + key.offset > |
| logical + map->stripe_len) { |
| key.offset = logical + map->stripe_len - |
| key.objectid; |
| } |
| |
| ret = scrub_extent(sdev, key.objectid, key.offset, |
| key.objectid - logical + physical, |
| flags, generation, mirror_num); |
| if (ret) |
| goto out; |
| |
| next: |
| path->slots[0]++; |
| } |
| btrfs_release_path(path); |
| logical += increment; |
| physical += map->stripe_len; |
| spin_lock(&sdev->stat_lock); |
| sdev->stat.last_physical = physical; |
| spin_unlock(&sdev->stat_lock); |
| } |
| /* push queued extents */ |
| scrub_submit(sdev); |
| |
| out: |
| blk_finish_plug(&plug); |
| btrfs_free_path(path); |
| return ret < 0 ? ret : 0; |
| } |
| |
| static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev, |
| u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length, |
| u64 dev_offset) |
| { |
| struct btrfs_mapping_tree *map_tree = |
| &sdev->dev->dev_root->fs_info->mapping_tree; |
| struct map_lookup *map; |
| struct extent_map *em; |
| int i; |
| int ret = -EINVAL; |
| |
| read_lock(&map_tree->map_tree.lock); |
| em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); |
| read_unlock(&map_tree->map_tree.lock); |
| |
| if (!em) |
| return -EINVAL; |
| |
| map = (struct map_lookup *)em->bdev; |
| 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 == sdev->dev && |
| map->stripes[i].physical == dev_offset) { |
| ret = scrub_stripe(sdev, map, i, chunk_offset, length); |
| if (ret) |
| goto out; |
| } |
| } |
| out: |
| free_extent_map(em); |
| |
| return ret; |
| } |
| |
| static noinline_for_stack |
| int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end) |
| { |
| struct btrfs_dev_extent *dev_extent = NULL; |
| struct btrfs_path *path; |
| struct btrfs_root *root = sdev->dev->dev_root; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| u64 length; |
| u64 chunk_tree; |
| u64 chunk_objectid; |
| u64 chunk_offset; |
| int ret; |
| int slot; |
| struct extent_buffer *l; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct btrfs_block_group_cache *cache; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->reada = 2; |
| path->search_commit_root = 1; |
| path->skip_locking = 1; |
| |
| key.objectid = sdev->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) |
| break; |
| } |
| } |
| |
| l = path->nodes[0]; |
| slot = path->slots[0]; |
| |
| btrfs_item_key_to_cpu(l, &found_key, slot); |
| |
| if (found_key.objectid != sdev->dev->devid) |
| break; |
| |
| if (btrfs_key_type(&found_key) != 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) { |
| key.offset = found_key.offset + length; |
| btrfs_release_path(path); |
| continue; |
| } |
| |
| chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); |
| chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); |
| 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); |
| if (!cache) { |
| ret = -ENOENT; |
| break; |
| } |
| ret = scrub_chunk(sdev, chunk_tree, chunk_objectid, |
| chunk_offset, length, found_key.offset); |
| btrfs_put_block_group(cache); |
| if (ret) |
| break; |
| |
| key.offset = found_key.offset + length; |
| btrfs_release_path(path); |
| } |
| |
| btrfs_free_path(path); |
| |
| /* |
| * ret can still be 1 from search_slot or next_leaf, |
| * that's not an error |
| */ |
| return ret < 0 ? ret : 0; |
| } |
| |
| static noinline_for_stack int scrub_supers(struct scrub_dev *sdev) |
| { |
| int i; |
| u64 bytenr; |
| u64 gen; |
| int ret; |
| struct btrfs_device *device = sdev->dev; |
| struct btrfs_root *root = device->dev_root; |
| |
| if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) |
| return -EIO; |
| |
| gen = root->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 > device->total_bytes) |
| break; |
| |
| ret = scrub_pages(sdev, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr, |
| BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1); |
| if (ret) |
| return ret; |
| } |
| wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0); |
| |
| return 0; |
| } |
| |
| /* |
| * get a reference count on fs_info->scrub_workers. start worker if necessary |
| */ |
| static noinline_for_stack int scrub_workers_get(struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| int ret = 0; |
| |
| mutex_lock(&fs_info->scrub_lock); |
| if (fs_info->scrub_workers_refcnt == 0) { |
| btrfs_init_workers(&fs_info->scrub_workers, "scrub", |
| fs_info->thread_pool_size, &fs_info->generic_worker); |
| fs_info->scrub_workers.idle_thresh = 4; |
| ret = btrfs_start_workers(&fs_info->scrub_workers); |
| if (ret) |
| goto out; |
| } |
| ++fs_info->scrub_workers_refcnt; |
| out: |
| mutex_unlock(&fs_info->scrub_lock); |
| |
| return ret; |
| } |
| |
| static noinline_for_stack void scrub_workers_put(struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| mutex_lock(&fs_info->scrub_lock); |
| if (--fs_info->scrub_workers_refcnt == 0) |
| btrfs_stop_workers(&fs_info->scrub_workers); |
| WARN_ON(fs_info->scrub_workers_refcnt < 0); |
| mutex_unlock(&fs_info->scrub_lock); |
| } |
| |
| |
| int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end, |
| struct btrfs_scrub_progress *progress, int readonly) |
| { |
| struct scrub_dev *sdev; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| int ret; |
| struct btrfs_device *dev; |
| |
| if (btrfs_fs_closing(root->fs_info)) |
| return -EINVAL; |
| |
| /* |
| * check some assumptions |
| */ |
| if (root->nodesize != root->leafsize) { |
| printk(KERN_ERR |
| "btrfs_scrub: size assumption nodesize == leafsize (%d == %d) fails\n", |
| root->nodesize, root->leafsize); |
| return -EINVAL; |
| } |
| |
| if (root->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. |
| */ |
| printk(KERN_ERR |
| "btrfs_scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails\n", |
| root->nodesize, BTRFS_STRIPE_LEN); |
| return -EINVAL; |
| } |
| |
| if (root->sectorsize != PAGE_SIZE) { |
| /* not supported for data w/o checksums */ |
| printk(KERN_ERR |
| "btrfs_scrub: size assumption sectorsize != PAGE_SIZE (%d != %lld) fails\n", |
| root->sectorsize, (unsigned long long)PAGE_SIZE); |
| return -EINVAL; |
| } |
| |
| ret = scrub_workers_get(root); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&root->fs_info->fs_devices->device_list_mutex); |
| dev = btrfs_find_device(root, devid, NULL, NULL); |
| if (!dev || dev->missing) { |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| scrub_workers_put(root); |
| return -ENODEV; |
| } |
| mutex_lock(&fs_info->scrub_lock); |
| |
| if (!dev->in_fs_metadata) { |
| mutex_unlock(&fs_info->scrub_lock); |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| scrub_workers_put(root); |
| return -ENODEV; |
| } |
| |
| if (dev->scrub_device) { |
| mutex_unlock(&fs_info->scrub_lock); |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| scrub_workers_put(root); |
| return -EINPROGRESS; |
| } |
| sdev = scrub_setup_dev(dev); |
| if (IS_ERR(sdev)) { |
| mutex_unlock(&fs_info->scrub_lock); |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| scrub_workers_put(root); |
| return PTR_ERR(sdev); |
| } |
| sdev->readonly = readonly; |
| dev->scrub_device = sdev; |
| |
| atomic_inc(&fs_info->scrubs_running); |
| mutex_unlock(&fs_info->scrub_lock); |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| |
| down_read(&fs_info->scrub_super_lock); |
| ret = scrub_supers(sdev); |
| up_read(&fs_info->scrub_super_lock); |
| |
| if (!ret) |
| ret = scrub_enumerate_chunks(sdev, start, end); |
| |
| wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0); |
| atomic_dec(&fs_info->scrubs_running); |
| wake_up(&fs_info->scrub_pause_wait); |
| |
| wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0); |
| |
| if (progress) |
| memcpy(progress, &sdev->stat, sizeof(*progress)); |
| |
| mutex_lock(&fs_info->scrub_lock); |
| dev->scrub_device = NULL; |
| mutex_unlock(&fs_info->scrub_lock); |
| |
| scrub_free_dev(sdev); |
| scrub_workers_put(root); |
| |
| return ret; |
| } |
| |
| void btrfs_scrub_pause(struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->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_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| atomic_dec(&fs_info->scrub_pause_req); |
| wake_up(&fs_info->scrub_pause_wait); |
| } |
| |
| void btrfs_scrub_pause_super(struct btrfs_root *root) |
| { |
| down_write(&root->fs_info->scrub_super_lock); |
| } |
| |
| void btrfs_scrub_continue_super(struct btrfs_root *root) |
| { |
| up_write(&root->fs_info->scrub_super_lock); |
| } |
| |
| 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(struct btrfs_root *root) |
| { |
| return __btrfs_scrub_cancel(root->fs_info); |
| } |
| |
| int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct scrub_dev *sdev; |
| |
| mutex_lock(&fs_info->scrub_lock); |
| sdev = dev->scrub_device; |
| if (!sdev) { |
| mutex_unlock(&fs_info->scrub_lock); |
| return -ENOTCONN; |
| } |
| atomic_inc(&sdev->cancel_req); |
| while (dev->scrub_device) { |
| mutex_unlock(&fs_info->scrub_lock); |
| wait_event(fs_info->scrub_pause_wait, |
| dev->scrub_device == NULL); |
| mutex_lock(&fs_info->scrub_lock); |
| } |
| mutex_unlock(&fs_info->scrub_lock); |
| |
| return 0; |
| } |
| |
| int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_device *dev; |
| int ret; |
| |
| /* |
| * we have to hold the device_list_mutex here so the device |
| * does not go away in cancel_dev. FIXME: find a better solution |
| */ |
| mutex_lock(&fs_info->fs_devices->device_list_mutex); |
| dev = btrfs_find_device(root, devid, NULL, NULL); |
| if (!dev) { |
| mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| return -ENODEV; |
| } |
| ret = btrfs_scrub_cancel_dev(root, dev); |
| mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| |
| return ret; |
| } |
| |
| int btrfs_scrub_progress(struct btrfs_root *root, u64 devid, |
| struct btrfs_scrub_progress *progress) |
| { |
| struct btrfs_device *dev; |
| struct scrub_dev *sdev = NULL; |
| |
| mutex_lock(&root->fs_info->fs_devices->device_list_mutex); |
| dev = btrfs_find_device(root, devid, NULL, NULL); |
| if (dev) |
| sdev = dev->scrub_device; |
| if (sdev) |
| memcpy(progress, &sdev->stat, sizeof(*progress)); |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| |
| return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV; |
| } |