diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/btrfs/scrub.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/btrfs/scrub.c | 2440 |
1 files changed, 2440 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/btrfs/scrub.c b/ANDROID_3.4.5/fs/btrfs/scrub.c new file mode 100644 index 00000000..2f3d6f91 --- /dev/null +++ b/ANDROID_3.4.5/fs/btrfs/scrub.c @@ -0,0 +1,2440 @@ +/* + * 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; + /* for missing devices, bdev is NULL */ + 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); + + if (page->bdev == NULL) { + page->io_error = 1; + sblock->no_io_error_seen = 0; + continue; + } + + 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); + 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); + } + + 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); + 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); + } + + 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); + + 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); + 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); + } + + btrfs_csum_final(crc, csum); + if (memcmp(csum, on_disk_csum, sdev->csum_size)) + fail = 1; + + 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); + 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); + 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); + 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; + + 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); + 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); + 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); + 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; +} |