2 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/blkdev.h>
20 #include <linux/ratelimit.h>
24 #include "ordered-data.h"
25 #include "transaction.h"
27 #include "extent_io.h"
28 #include "dev-replace.h"
29 #include "check-integrity.h"
30 #include "rcu-string.h"
34 * This is only the first step towards a full-features scrub. It reads all
35 * extent and super block and verifies the checksums. In case a bad checksum
36 * is found or the extent cannot be read, good data will be written back if
39 * Future enhancements:
40 * - In case an unrepairable extent is encountered, track which files are
41 * affected and report them
42 * - track and record media errors, throw out bad devices
43 * - add a mode to also read unallocated space
50 * the following three values only influence the performance.
51 * The last one configures the number of parallel and outstanding I/O
52 * operations. The first two values configure an upper limit for the number
53 * of (dynamically allocated) pages that are added to a bio.
55 #define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
56 #define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
57 #define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
60 * the following value times PAGE_SIZE needs to be large enough to match the
61 * largest node/leaf/sector size that shall be supported.
62 * Values larger than BTRFS_STRIPE_LEN are not supported.
64 #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
67 struct scrub_block *sblock;
69 struct btrfs_device *dev;
70 u64 flags; /* extent flags */
74 u64 physical_for_dev_replace;
77 unsigned int mirror_num:8;
78 unsigned int have_csum:1;
79 unsigned int io_error:1;
81 u8 csum[BTRFS_CSUM_SIZE];
86 struct scrub_ctx *sctx;
87 struct btrfs_device *dev;
92 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
93 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
95 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
99 struct btrfs_work work;
103 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
105 atomic_t outstanding_pages;
106 atomic_t ref_count; /* free mem on transition to zero */
107 struct scrub_ctx *sctx;
109 unsigned int header_error:1;
110 unsigned int checksum_error:1;
111 unsigned int no_io_error_seen:1;
112 unsigned int generation_error:1; /* also sets header_error */
116 struct scrub_wr_ctx {
117 struct scrub_bio *wr_curr_bio;
118 struct btrfs_device *tgtdev;
119 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
120 atomic_t flush_all_writes;
121 struct mutex wr_lock;
125 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
126 struct btrfs_root *dev_root;
129 atomic_t bios_in_flight;
130 atomic_t workers_pending;
131 spinlock_t list_lock;
132 wait_queue_head_t list_wait;
134 struct list_head csum_list;
137 int pages_per_rd_bio;
143 struct scrub_wr_ctx wr_ctx;
148 struct btrfs_scrub_progress stat;
149 spinlock_t stat_lock;
152 struct scrub_fixup_nodatasum {
153 struct scrub_ctx *sctx;
154 struct btrfs_device *dev;
156 struct btrfs_root *root;
157 struct btrfs_work work;
161 struct scrub_nocow_inode {
165 struct list_head list;
168 struct scrub_copy_nocow_ctx {
169 struct scrub_ctx *sctx;
173 u64 physical_for_dev_replace;
174 struct list_head inodes;
175 struct btrfs_work work;
178 struct scrub_warning {
179 struct btrfs_path *path;
180 u64 extent_item_size;
186 struct btrfs_device *dev;
192 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
193 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
194 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
195 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
196 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
197 static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
198 struct btrfs_fs_info *fs_info,
199 struct scrub_block *original_sblock,
200 u64 length, u64 logical,
201 struct scrub_block *sblocks_for_recheck);
202 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
203 struct scrub_block *sblock, int is_metadata,
204 int have_csum, u8 *csum, u64 generation,
206 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
207 struct scrub_block *sblock,
208 int is_metadata, int have_csum,
209 const u8 *csum, u64 generation,
211 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
212 struct scrub_block *sblock_good,
214 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
215 struct scrub_block *sblock_good,
216 int page_num, int force_write);
217 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
218 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
220 static int scrub_checksum_data(struct scrub_block *sblock);
221 static int scrub_checksum_tree_block(struct scrub_block *sblock);
222 static int scrub_checksum_super(struct scrub_block *sblock);
223 static void scrub_block_get(struct scrub_block *sblock);
224 static void scrub_block_put(struct scrub_block *sblock);
225 static void scrub_page_get(struct scrub_page *spage);
226 static void scrub_page_put(struct scrub_page *spage);
227 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
228 struct scrub_page *spage);
229 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
230 u64 physical, struct btrfs_device *dev, u64 flags,
231 u64 gen, int mirror_num, u8 *csum, int force,
232 u64 physical_for_dev_replace);
233 static void scrub_bio_end_io(struct bio *bio, int err);
234 static void scrub_bio_end_io_worker(struct btrfs_work *work);
235 static void scrub_block_complete(struct scrub_block *sblock);
236 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
237 u64 extent_logical, u64 extent_len,
238 u64 *extent_physical,
239 struct btrfs_device **extent_dev,
240 int *extent_mirror_num);
241 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
242 struct scrub_wr_ctx *wr_ctx,
243 struct btrfs_fs_info *fs_info,
244 struct btrfs_device *dev,
246 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
247 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
248 struct scrub_page *spage);
249 static void scrub_wr_submit(struct scrub_ctx *sctx);
250 static void scrub_wr_bio_end_io(struct bio *bio, int err);
251 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
252 static int write_page_nocow(struct scrub_ctx *sctx,
253 u64 physical_for_dev_replace, struct page *page);
254 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
255 struct scrub_copy_nocow_ctx *ctx);
256 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
257 int mirror_num, u64 physical_for_dev_replace);
258 static void copy_nocow_pages_worker(struct btrfs_work *work);
259 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
260 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
263 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
265 atomic_inc(&sctx->bios_in_flight);
268 static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
270 atomic_dec(&sctx->bios_in_flight);
271 wake_up(&sctx->list_wait);
274 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
276 while (atomic_read(&fs_info->scrub_pause_req)) {
277 mutex_unlock(&fs_info->scrub_lock);
278 wait_event(fs_info->scrub_pause_wait,
279 atomic_read(&fs_info->scrub_pause_req) == 0);
280 mutex_lock(&fs_info->scrub_lock);
284 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
286 atomic_inc(&fs_info->scrubs_paused);
287 wake_up(&fs_info->scrub_pause_wait);
289 mutex_lock(&fs_info->scrub_lock);
290 __scrub_blocked_if_needed(fs_info);
291 atomic_dec(&fs_info->scrubs_paused);
292 mutex_unlock(&fs_info->scrub_lock);
294 wake_up(&fs_info->scrub_pause_wait);
298 * used for workers that require transaction commits (i.e., for the
301 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
303 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
306 * increment scrubs_running to prevent cancel requests from
307 * completing as long as a worker is running. we must also
308 * increment scrubs_paused to prevent deadlocking on pause
309 * requests used for transactions commits (as the worker uses a
310 * transaction context). it is safe to regard the worker
311 * as paused for all matters practical. effectively, we only
312 * avoid cancellation requests from completing.
314 mutex_lock(&fs_info->scrub_lock);
315 atomic_inc(&fs_info->scrubs_running);
316 atomic_inc(&fs_info->scrubs_paused);
317 mutex_unlock(&fs_info->scrub_lock);
318 atomic_inc(&sctx->workers_pending);
321 /* used for workers that require transaction commits */
322 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
324 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
327 * see scrub_pending_trans_workers_inc() why we're pretending
328 * to be paused in the scrub counters
330 mutex_lock(&fs_info->scrub_lock);
331 atomic_dec(&fs_info->scrubs_running);
332 atomic_dec(&fs_info->scrubs_paused);
333 mutex_unlock(&fs_info->scrub_lock);
334 atomic_dec(&sctx->workers_pending);
335 wake_up(&fs_info->scrub_pause_wait);
336 wake_up(&sctx->list_wait);
339 static void scrub_free_csums(struct scrub_ctx *sctx)
341 while (!list_empty(&sctx->csum_list)) {
342 struct btrfs_ordered_sum *sum;
343 sum = list_first_entry(&sctx->csum_list,
344 struct btrfs_ordered_sum, list);
345 list_del(&sum->list);
350 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
357 scrub_free_wr_ctx(&sctx->wr_ctx);
359 /* this can happen when scrub is cancelled */
360 if (sctx->curr != -1) {
361 struct scrub_bio *sbio = sctx->bios[sctx->curr];
363 for (i = 0; i < sbio->page_count; i++) {
364 WARN_ON(!sbio->pagev[i]->page);
365 scrub_block_put(sbio->pagev[i]->sblock);
370 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
371 struct scrub_bio *sbio = sctx->bios[i];
378 scrub_free_csums(sctx);
382 static noinline_for_stack
383 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
385 struct scrub_ctx *sctx;
387 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
388 int pages_per_rd_bio;
392 * the setting of pages_per_rd_bio is correct for scrub but might
393 * be wrong for the dev_replace code where we might read from
394 * different devices in the initial huge bios. However, that
395 * code is able to correctly handle the case when adding a page
399 pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO,
400 bio_get_nr_vecs(dev->bdev));
402 pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
403 sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
406 sctx->is_dev_replace = is_dev_replace;
407 sctx->pages_per_rd_bio = pages_per_rd_bio;
409 sctx->dev_root = dev->dev_root;
410 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
411 struct scrub_bio *sbio;
413 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
416 sctx->bios[i] = sbio;
420 sbio->page_count = 0;
421 sbio->work.func = scrub_bio_end_io_worker;
423 if (i != SCRUB_BIOS_PER_SCTX - 1)
424 sctx->bios[i]->next_free = i + 1;
426 sctx->bios[i]->next_free = -1;
428 sctx->first_free = 0;
429 sctx->nodesize = dev->dev_root->nodesize;
430 sctx->leafsize = dev->dev_root->leafsize;
431 sctx->sectorsize = dev->dev_root->sectorsize;
432 atomic_set(&sctx->bios_in_flight, 0);
433 atomic_set(&sctx->workers_pending, 0);
434 atomic_set(&sctx->cancel_req, 0);
435 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
436 INIT_LIST_HEAD(&sctx->csum_list);
438 spin_lock_init(&sctx->list_lock);
439 spin_lock_init(&sctx->stat_lock);
440 init_waitqueue_head(&sctx->list_wait);
442 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
443 fs_info->dev_replace.tgtdev, is_dev_replace);
445 scrub_free_ctx(sctx);
451 scrub_free_ctx(sctx);
452 return ERR_PTR(-ENOMEM);
455 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
462 struct extent_buffer *eb;
463 struct btrfs_inode_item *inode_item;
464 struct scrub_warning *swarn = warn_ctx;
465 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
466 struct inode_fs_paths *ipath = NULL;
467 struct btrfs_root *local_root;
468 struct btrfs_key root_key;
470 root_key.objectid = root;
471 root_key.type = BTRFS_ROOT_ITEM_KEY;
472 root_key.offset = (u64)-1;
473 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
474 if (IS_ERR(local_root)) {
475 ret = PTR_ERR(local_root);
479 ret = inode_item_info(inum, 0, local_root, swarn->path);
481 btrfs_release_path(swarn->path);
485 eb = swarn->path->nodes[0];
486 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
487 struct btrfs_inode_item);
488 isize = btrfs_inode_size(eb, inode_item);
489 nlink = btrfs_inode_nlink(eb, inode_item);
490 btrfs_release_path(swarn->path);
492 ipath = init_ipath(4096, local_root, swarn->path);
494 ret = PTR_ERR(ipath);
498 ret = paths_from_inode(inum, ipath);
504 * we deliberately ignore the bit ipath might have been too small to
505 * hold all of the paths here
507 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
508 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
509 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
510 "length %llu, links %u (path: %s)\n", swarn->errstr,
511 swarn->logical, rcu_str_deref(swarn->dev->name),
512 (unsigned long long)swarn->sector, root, inum, offset,
513 min(isize - offset, (u64)PAGE_SIZE), nlink,
514 (char *)(unsigned long)ipath->fspath->val[i]);
520 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
521 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
522 "resolving failed with ret=%d\n", swarn->errstr,
523 swarn->logical, rcu_str_deref(swarn->dev->name),
524 (unsigned long long)swarn->sector, root, inum, offset, ret);
530 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
532 struct btrfs_device *dev;
533 struct btrfs_fs_info *fs_info;
534 struct btrfs_path *path;
535 struct btrfs_key found_key;
536 struct extent_buffer *eb;
537 struct btrfs_extent_item *ei;
538 struct scrub_warning swarn;
539 unsigned long ptr = 0;
545 const int bufsize = 4096;
548 WARN_ON(sblock->page_count < 1);
549 dev = sblock->pagev[0]->dev;
550 fs_info = sblock->sctx->dev_root->fs_info;
552 path = btrfs_alloc_path();
554 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
555 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
556 swarn.sector = (sblock->pagev[0]->physical) >> 9;
557 swarn.logical = sblock->pagev[0]->logical;
558 swarn.errstr = errstr;
560 swarn.msg_bufsize = bufsize;
561 swarn.scratch_bufsize = bufsize;
563 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
566 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
571 extent_item_pos = swarn.logical - found_key.objectid;
572 swarn.extent_item_size = found_key.offset;
575 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
576 item_size = btrfs_item_size_nr(eb, path->slots[0]);
578 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
580 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
581 &ref_root, &ref_level);
582 printk_in_rcu(KERN_WARNING
583 "BTRFS: %s at logical %llu on dev %s, "
584 "sector %llu: metadata %s (level %d) in tree "
585 "%llu\n", errstr, swarn.logical,
586 rcu_str_deref(dev->name),
587 (unsigned long long)swarn.sector,
588 ref_level ? "node" : "leaf",
589 ret < 0 ? -1 : ref_level,
590 ret < 0 ? -1 : ref_root);
592 btrfs_release_path(path);
594 btrfs_release_path(path);
597 iterate_extent_inodes(fs_info, found_key.objectid,
599 scrub_print_warning_inode, &swarn);
603 btrfs_free_path(path);
604 kfree(swarn.scratch_buf);
605 kfree(swarn.msg_buf);
608 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
610 struct page *page = NULL;
612 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
615 struct btrfs_key key;
616 struct inode *inode = NULL;
617 struct btrfs_fs_info *fs_info;
618 u64 end = offset + PAGE_SIZE - 1;
619 struct btrfs_root *local_root;
623 key.type = BTRFS_ROOT_ITEM_KEY;
624 key.offset = (u64)-1;
626 fs_info = fixup->root->fs_info;
627 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
629 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
630 if (IS_ERR(local_root)) {
631 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
632 return PTR_ERR(local_root);
635 key.type = BTRFS_INODE_ITEM_KEY;
638 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
639 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
641 return PTR_ERR(inode);
643 index = offset >> PAGE_CACHE_SHIFT;
645 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
651 if (PageUptodate(page)) {
652 if (PageDirty(page)) {
654 * we need to write the data to the defect sector. the
655 * data that was in that sector is not in memory,
656 * because the page was modified. we must not write the
657 * modified page to that sector.
659 * TODO: what could be done here: wait for the delalloc
660 * runner to write out that page (might involve
661 * COW) and see whether the sector is still
662 * referenced afterwards.
664 * For the meantime, we'll treat this error
665 * incorrectable, although there is a chance that a
666 * later scrub will find the bad sector again and that
667 * there's no dirty page in memory, then.
672 fs_info = BTRFS_I(inode)->root->fs_info;
673 ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
674 fixup->logical, page,
680 * we need to get good data first. the general readpage path
681 * will call repair_io_failure for us, we just have to make
682 * sure we read the bad mirror.
684 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
685 EXTENT_DAMAGED, GFP_NOFS);
687 /* set_extent_bits should give proper error */
694 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
697 wait_on_page_locked(page);
699 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
700 end, EXTENT_DAMAGED, 0, NULL);
702 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
703 EXTENT_DAMAGED, GFP_NOFS);
715 if (ret == 0 && corrected) {
717 * we only need to call readpage for one of the inodes belonging
718 * to this extent. so make iterate_extent_inodes stop
726 static void scrub_fixup_nodatasum(struct btrfs_work *work)
729 struct scrub_fixup_nodatasum *fixup;
730 struct scrub_ctx *sctx;
731 struct btrfs_trans_handle *trans = NULL;
732 struct btrfs_path *path;
733 int uncorrectable = 0;
735 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
738 path = btrfs_alloc_path();
740 spin_lock(&sctx->stat_lock);
741 ++sctx->stat.malloc_errors;
742 spin_unlock(&sctx->stat_lock);
747 trans = btrfs_join_transaction(fixup->root);
754 * the idea is to trigger a regular read through the standard path. we
755 * read a page from the (failed) logical address by specifying the
756 * corresponding copynum of the failed sector. thus, that readpage is
758 * that is the point where on-the-fly error correction will kick in
759 * (once it's finished) and rewrite the failed sector if a good copy
762 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
763 path, scrub_fixup_readpage,
771 spin_lock(&sctx->stat_lock);
772 ++sctx->stat.corrected_errors;
773 spin_unlock(&sctx->stat_lock);
776 if (trans && !IS_ERR(trans))
777 btrfs_end_transaction(trans, fixup->root);
779 spin_lock(&sctx->stat_lock);
780 ++sctx->stat.uncorrectable_errors;
781 spin_unlock(&sctx->stat_lock);
782 btrfs_dev_replace_stats_inc(
783 &sctx->dev_root->fs_info->dev_replace.
784 num_uncorrectable_read_errors);
785 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
786 "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
787 fixup->logical, rcu_str_deref(fixup->dev->name));
790 btrfs_free_path(path);
793 scrub_pending_trans_workers_dec(sctx);
797 * scrub_handle_errored_block gets called when either verification of the
798 * pages failed or the bio failed to read, e.g. with EIO. In the latter
799 * case, this function handles all pages in the bio, even though only one
801 * The goal of this function is to repair the errored block by using the
802 * contents of one of the mirrors.
804 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
806 struct scrub_ctx *sctx = sblock_to_check->sctx;
807 struct btrfs_device *dev;
808 struct btrfs_fs_info *fs_info;
812 unsigned int failed_mirror_index;
813 unsigned int is_metadata;
814 unsigned int have_csum;
816 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
817 struct scrub_block *sblock_bad;
822 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
823 DEFAULT_RATELIMIT_BURST);
825 BUG_ON(sblock_to_check->page_count < 1);
826 fs_info = sctx->dev_root->fs_info;
827 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
829 * if we find an error in a super block, we just report it.
830 * They will get written with the next transaction commit
833 spin_lock(&sctx->stat_lock);
834 ++sctx->stat.super_errors;
835 spin_unlock(&sctx->stat_lock);
838 length = sblock_to_check->page_count * PAGE_SIZE;
839 logical = sblock_to_check->pagev[0]->logical;
840 generation = sblock_to_check->pagev[0]->generation;
841 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
842 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
843 is_metadata = !(sblock_to_check->pagev[0]->flags &
844 BTRFS_EXTENT_FLAG_DATA);
845 have_csum = sblock_to_check->pagev[0]->have_csum;
846 csum = sblock_to_check->pagev[0]->csum;
847 dev = sblock_to_check->pagev[0]->dev;
849 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
850 sblocks_for_recheck = NULL;
855 * read all mirrors one after the other. This includes to
856 * re-read the extent or metadata block that failed (that was
857 * the cause that this fixup code is called) another time,
858 * page by page this time in order to know which pages
859 * caused I/O errors and which ones are good (for all mirrors).
860 * It is the goal to handle the situation when more than one
861 * mirror contains I/O errors, but the errors do not
862 * overlap, i.e. the data can be repaired by selecting the
863 * pages from those mirrors without I/O error on the
864 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
865 * would be that mirror #1 has an I/O error on the first page,
866 * the second page is good, and mirror #2 has an I/O error on
867 * the second page, but the first page is good.
868 * Then the first page of the first mirror can be repaired by
869 * taking the first page of the second mirror, and the
870 * second page of the second mirror can be repaired by
871 * copying the contents of the 2nd page of the 1st mirror.
872 * One more note: if the pages of one mirror contain I/O
873 * errors, the checksum cannot be verified. In order to get
874 * the best data for repairing, the first attempt is to find
875 * a mirror without I/O errors and with a validated checksum.
876 * Only if this is not possible, the pages are picked from
877 * mirrors with I/O errors without considering the checksum.
878 * If the latter is the case, at the end, the checksum of the
879 * repaired area is verified in order to correctly maintain
883 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
884 sizeof(*sblocks_for_recheck),
886 if (!sblocks_for_recheck) {
887 spin_lock(&sctx->stat_lock);
888 sctx->stat.malloc_errors++;
889 sctx->stat.read_errors++;
890 sctx->stat.uncorrectable_errors++;
891 spin_unlock(&sctx->stat_lock);
892 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
896 /* setup the context, map the logical blocks and alloc the pages */
897 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
898 logical, sblocks_for_recheck);
900 spin_lock(&sctx->stat_lock);
901 sctx->stat.read_errors++;
902 sctx->stat.uncorrectable_errors++;
903 spin_unlock(&sctx->stat_lock);
904 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
907 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
908 sblock_bad = sblocks_for_recheck + failed_mirror_index;
910 /* build and submit the bios for the failed mirror, check checksums */
911 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
912 csum, generation, sctx->csum_size);
914 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
915 sblock_bad->no_io_error_seen) {
917 * the error disappeared after reading page by page, or
918 * the area was part of a huge bio and other parts of the
919 * bio caused I/O errors, or the block layer merged several
920 * read requests into one and the error is caused by a
921 * different bio (usually one of the two latter cases is
924 spin_lock(&sctx->stat_lock);
925 sctx->stat.unverified_errors++;
926 spin_unlock(&sctx->stat_lock);
928 if (sctx->is_dev_replace)
929 scrub_write_block_to_dev_replace(sblock_bad);
933 if (!sblock_bad->no_io_error_seen) {
934 spin_lock(&sctx->stat_lock);
935 sctx->stat.read_errors++;
936 spin_unlock(&sctx->stat_lock);
937 if (__ratelimit(&_rs))
938 scrub_print_warning("i/o error", sblock_to_check);
939 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
940 } else if (sblock_bad->checksum_error) {
941 spin_lock(&sctx->stat_lock);
942 sctx->stat.csum_errors++;
943 spin_unlock(&sctx->stat_lock);
944 if (__ratelimit(&_rs))
945 scrub_print_warning("checksum error", sblock_to_check);
946 btrfs_dev_stat_inc_and_print(dev,
947 BTRFS_DEV_STAT_CORRUPTION_ERRS);
948 } else if (sblock_bad->header_error) {
949 spin_lock(&sctx->stat_lock);
950 sctx->stat.verify_errors++;
951 spin_unlock(&sctx->stat_lock);
952 if (__ratelimit(&_rs))
953 scrub_print_warning("checksum/header error",
955 if (sblock_bad->generation_error)
956 btrfs_dev_stat_inc_and_print(dev,
957 BTRFS_DEV_STAT_GENERATION_ERRS);
959 btrfs_dev_stat_inc_and_print(dev,
960 BTRFS_DEV_STAT_CORRUPTION_ERRS);
963 if (sctx->readonly) {
964 ASSERT(!sctx->is_dev_replace);
968 if (!is_metadata && !have_csum) {
969 struct scrub_fixup_nodatasum *fixup_nodatasum;
972 WARN_ON(sctx->is_dev_replace);
975 * !is_metadata and !have_csum, this means that the data
976 * might not be COW'ed, that it might be modified
977 * concurrently. The general strategy to work on the
978 * commit root does not help in the case when COW is not
981 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
982 if (!fixup_nodatasum)
983 goto did_not_correct_error;
984 fixup_nodatasum->sctx = sctx;
985 fixup_nodatasum->dev = dev;
986 fixup_nodatasum->logical = logical;
987 fixup_nodatasum->root = fs_info->extent_root;
988 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
989 scrub_pending_trans_workers_inc(sctx);
990 fixup_nodatasum->work.func = scrub_fixup_nodatasum;
991 btrfs_queue_worker(&fs_info->scrub_workers,
992 &fixup_nodatasum->work);
997 * now build and submit the bios for the other mirrors, check
999 * First try to pick the mirror which is completely without I/O
1000 * errors and also does not have a checksum error.
1001 * If one is found, and if a checksum is present, the full block
1002 * that is known to contain an error is rewritten. Afterwards
1003 * the block is known to be corrected.
1004 * If a mirror is found which is completely correct, and no
1005 * checksum is present, only those pages are rewritten that had
1006 * an I/O error in the block to be repaired, since it cannot be
1007 * determined, which copy of the other pages is better (and it
1008 * could happen otherwise that a correct page would be
1009 * overwritten by a bad one).
1011 for (mirror_index = 0;
1012 mirror_index < BTRFS_MAX_MIRRORS &&
1013 sblocks_for_recheck[mirror_index].page_count > 0;
1015 struct scrub_block *sblock_other;
1017 if (mirror_index == failed_mirror_index)
1019 sblock_other = sblocks_for_recheck + mirror_index;
1021 /* build and submit the bios, check checksums */
1022 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1023 have_csum, csum, generation,
1026 if (!sblock_other->header_error &&
1027 !sblock_other->checksum_error &&
1028 sblock_other->no_io_error_seen) {
1029 if (sctx->is_dev_replace) {
1030 scrub_write_block_to_dev_replace(sblock_other);
1032 int force_write = is_metadata || have_csum;
1034 ret = scrub_repair_block_from_good_copy(
1035 sblock_bad, sblock_other,
1039 goto corrected_error;
1044 * for dev_replace, pick good pages and write to the target device.
1046 if (sctx->is_dev_replace) {
1048 for (page_num = 0; page_num < sblock_bad->page_count;
1053 for (mirror_index = 0;
1054 mirror_index < BTRFS_MAX_MIRRORS &&
1055 sblocks_for_recheck[mirror_index].page_count > 0;
1057 struct scrub_block *sblock_other =
1058 sblocks_for_recheck + mirror_index;
1059 struct scrub_page *page_other =
1060 sblock_other->pagev[page_num];
1062 if (!page_other->io_error) {
1063 ret = scrub_write_page_to_dev_replace(
1064 sblock_other, page_num);
1066 /* succeeded for this page */
1070 btrfs_dev_replace_stats_inc(
1072 fs_info->dev_replace.
1080 * did not find a mirror to fetch the page
1081 * from. scrub_write_page_to_dev_replace()
1082 * handles this case (page->io_error), by
1083 * filling the block with zeros before
1084 * submitting the write request
1087 ret = scrub_write_page_to_dev_replace(
1088 sblock_bad, page_num);
1090 btrfs_dev_replace_stats_inc(
1091 &sctx->dev_root->fs_info->
1092 dev_replace.num_write_errors);
1100 * for regular scrub, repair those pages that are errored.
1101 * In case of I/O errors in the area that is supposed to be
1102 * repaired, continue by picking good copies of those pages.
1103 * Select the good pages from mirrors to rewrite bad pages from
1104 * the area to fix. Afterwards verify the checksum of the block
1105 * that is supposed to be repaired. This verification step is
1106 * only done for the purpose of statistic counting and for the
1107 * final scrub report, whether errors remain.
1108 * A perfect algorithm could make use of the checksum and try
1109 * all possible combinations of pages from the different mirrors
1110 * until the checksum verification succeeds. For example, when
1111 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1112 * of mirror #2 is readable but the final checksum test fails,
1113 * then the 2nd page of mirror #3 could be tried, whether now
1114 * the final checksum succeedes. But this would be a rare
1115 * exception and is therefore not implemented. At least it is
1116 * avoided that the good copy is overwritten.
1117 * A more useful improvement would be to pick the sectors
1118 * without I/O error based on sector sizes (512 bytes on legacy
1119 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1120 * mirror could be repaired by taking 512 byte of a different
1121 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1122 * area are unreadable.
1125 /* can only fix I/O errors from here on */
1126 if (sblock_bad->no_io_error_seen)
1127 goto did_not_correct_error;
1130 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1131 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1133 if (!page_bad->io_error)
1136 for (mirror_index = 0;
1137 mirror_index < BTRFS_MAX_MIRRORS &&
1138 sblocks_for_recheck[mirror_index].page_count > 0;
1140 struct scrub_block *sblock_other = sblocks_for_recheck +
1142 struct scrub_page *page_other = sblock_other->pagev[
1145 if (!page_other->io_error) {
1146 ret = scrub_repair_page_from_good_copy(
1147 sblock_bad, sblock_other, page_num, 0);
1149 page_bad->io_error = 0;
1150 break; /* succeeded for this page */
1155 if (page_bad->io_error) {
1156 /* did not find a mirror to copy the page from */
1162 if (is_metadata || have_csum) {
1164 * need to verify the checksum now that all
1165 * sectors on disk are repaired (the write
1166 * request for data to be repaired is on its way).
1167 * Just be lazy and use scrub_recheck_block()
1168 * which re-reads the data before the checksum
1169 * is verified, but most likely the data comes out
1170 * of the page cache.
1172 scrub_recheck_block(fs_info, sblock_bad,
1173 is_metadata, have_csum, csum,
1174 generation, sctx->csum_size);
1175 if (!sblock_bad->header_error &&
1176 !sblock_bad->checksum_error &&
1177 sblock_bad->no_io_error_seen)
1178 goto corrected_error;
1180 goto did_not_correct_error;
1183 spin_lock(&sctx->stat_lock);
1184 sctx->stat.corrected_errors++;
1185 spin_unlock(&sctx->stat_lock);
1186 printk_ratelimited_in_rcu(KERN_ERR
1187 "BTRFS: fixed up error at logical %llu on dev %s\n",
1188 logical, rcu_str_deref(dev->name));
1191 did_not_correct_error:
1192 spin_lock(&sctx->stat_lock);
1193 sctx->stat.uncorrectable_errors++;
1194 spin_unlock(&sctx->stat_lock);
1195 printk_ratelimited_in_rcu(KERN_ERR
1196 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
1197 logical, rcu_str_deref(dev->name));
1201 if (sblocks_for_recheck) {
1202 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1204 struct scrub_block *sblock = sblocks_for_recheck +
1208 for (page_index = 0; page_index < sblock->page_count;
1210 sblock->pagev[page_index]->sblock = NULL;
1211 scrub_page_put(sblock->pagev[page_index]);
1214 kfree(sblocks_for_recheck);
1220 static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
1221 struct btrfs_fs_info *fs_info,
1222 struct scrub_block *original_sblock,
1223 u64 length, u64 logical,
1224 struct scrub_block *sblocks_for_recheck)
1231 * note: the two members ref_count and outstanding_pages
1232 * are not used (and not set) in the blocks that are used for
1233 * the recheck procedure
1237 while (length > 0) {
1238 u64 sublen = min_t(u64, length, PAGE_SIZE);
1239 u64 mapped_length = sublen;
1240 struct btrfs_bio *bbio = NULL;
1243 * with a length of PAGE_SIZE, each returned stripe
1244 * represents one mirror
1246 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
1247 &mapped_length, &bbio, 0);
1248 if (ret || !bbio || mapped_length < sublen) {
1253 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
1254 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1256 struct scrub_block *sblock;
1257 struct scrub_page *page;
1259 if (mirror_index >= BTRFS_MAX_MIRRORS)
1262 sblock = sblocks_for_recheck + mirror_index;
1263 sblock->sctx = sctx;
1264 page = kzalloc(sizeof(*page), GFP_NOFS);
1267 spin_lock(&sctx->stat_lock);
1268 sctx->stat.malloc_errors++;
1269 spin_unlock(&sctx->stat_lock);
1273 scrub_page_get(page);
1274 sblock->pagev[page_index] = page;
1275 page->logical = logical;
1276 page->physical = bbio->stripes[mirror_index].physical;
1277 BUG_ON(page_index >= original_sblock->page_count);
1278 page->physical_for_dev_replace =
1279 original_sblock->pagev[page_index]->
1280 physical_for_dev_replace;
1281 /* for missing devices, dev->bdev is NULL */
1282 page->dev = bbio->stripes[mirror_index].dev;
1283 page->mirror_num = mirror_index + 1;
1284 sblock->page_count++;
1285 page->page = alloc_page(GFP_NOFS);
1299 * this function will check the on disk data for checksum errors, header
1300 * errors and read I/O errors. If any I/O errors happen, the exact pages
1301 * which are errored are marked as being bad. The goal is to enable scrub
1302 * to take those pages that are not errored from all the mirrors so that
1303 * the pages that are errored in the just handled mirror can be repaired.
1305 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1306 struct scrub_block *sblock, int is_metadata,
1307 int have_csum, u8 *csum, u64 generation,
1312 sblock->no_io_error_seen = 1;
1313 sblock->header_error = 0;
1314 sblock->checksum_error = 0;
1316 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1318 struct scrub_page *page = sblock->pagev[page_num];
1320 if (page->dev->bdev == NULL) {
1322 sblock->no_io_error_seen = 0;
1326 WARN_ON(!page->page);
1327 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1330 sblock->no_io_error_seen = 0;
1333 bio->bi_bdev = page->dev->bdev;
1334 bio->bi_iter.bi_sector = page->physical >> 9;
1336 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1337 if (btrfsic_submit_bio_wait(READ, bio))
1338 sblock->no_io_error_seen = 0;
1343 if (sblock->no_io_error_seen)
1344 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1345 have_csum, csum, generation,
1351 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1352 struct scrub_block *sblock,
1353 int is_metadata, int have_csum,
1354 const u8 *csum, u64 generation,
1358 u8 calculated_csum[BTRFS_CSUM_SIZE];
1360 void *mapped_buffer;
1362 WARN_ON(!sblock->pagev[0]->page);
1364 struct btrfs_header *h;
1366 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1367 h = (struct btrfs_header *)mapped_buffer;
1369 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
1370 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1371 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1373 sblock->header_error = 1;
1374 } else if (generation != btrfs_stack_header_generation(h)) {
1375 sblock->header_error = 1;
1376 sblock->generation_error = 1;
1383 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1386 for (page_num = 0;;) {
1387 if (page_num == 0 && is_metadata)
1388 crc = btrfs_csum_data(
1389 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1390 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1392 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
1394 kunmap_atomic(mapped_buffer);
1396 if (page_num >= sblock->page_count)
1398 WARN_ON(!sblock->pagev[page_num]->page);
1400 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
1403 btrfs_csum_final(crc, calculated_csum);
1404 if (memcmp(calculated_csum, csum, csum_size))
1405 sblock->checksum_error = 1;
1408 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1409 struct scrub_block *sblock_good,
1415 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1418 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1429 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1430 struct scrub_block *sblock_good,
1431 int page_num, int force_write)
1433 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1434 struct scrub_page *page_good = sblock_good->pagev[page_num];
1436 BUG_ON(page_bad->page == NULL);
1437 BUG_ON(page_good->page == NULL);
1438 if (force_write || sblock_bad->header_error ||
1439 sblock_bad->checksum_error || page_bad->io_error) {
1443 if (!page_bad->dev->bdev) {
1444 printk_ratelimited(KERN_WARNING "BTRFS: "
1445 "scrub_repair_page_from_good_copy(bdev == NULL) "
1446 "is unexpected!\n");
1450 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1453 bio->bi_bdev = page_bad->dev->bdev;
1454 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1456 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1457 if (PAGE_SIZE != ret) {
1462 if (btrfsic_submit_bio_wait(WRITE, bio)) {
1463 btrfs_dev_stat_inc_and_print(page_bad->dev,
1464 BTRFS_DEV_STAT_WRITE_ERRS);
1465 btrfs_dev_replace_stats_inc(
1466 &sblock_bad->sctx->dev_root->fs_info->
1467 dev_replace.num_write_errors);
1477 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1481 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1484 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1486 btrfs_dev_replace_stats_inc(
1487 &sblock->sctx->dev_root->fs_info->dev_replace.
1492 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1495 struct scrub_page *spage = sblock->pagev[page_num];
1497 BUG_ON(spage->page == NULL);
1498 if (spage->io_error) {
1499 void *mapped_buffer = kmap_atomic(spage->page);
1501 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1502 flush_dcache_page(spage->page);
1503 kunmap_atomic(mapped_buffer);
1505 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1508 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1509 struct scrub_page *spage)
1511 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1512 struct scrub_bio *sbio;
1515 mutex_lock(&wr_ctx->wr_lock);
1517 if (!wr_ctx->wr_curr_bio) {
1518 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1520 if (!wr_ctx->wr_curr_bio) {
1521 mutex_unlock(&wr_ctx->wr_lock);
1524 wr_ctx->wr_curr_bio->sctx = sctx;
1525 wr_ctx->wr_curr_bio->page_count = 0;
1527 sbio = wr_ctx->wr_curr_bio;
1528 if (sbio->page_count == 0) {
1531 sbio->physical = spage->physical_for_dev_replace;
1532 sbio->logical = spage->logical;
1533 sbio->dev = wr_ctx->tgtdev;
1536 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
1538 mutex_unlock(&wr_ctx->wr_lock);
1544 bio->bi_private = sbio;
1545 bio->bi_end_io = scrub_wr_bio_end_io;
1546 bio->bi_bdev = sbio->dev->bdev;
1547 bio->bi_iter.bi_sector = sbio->physical >> 9;
1549 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1550 spage->physical_for_dev_replace ||
1551 sbio->logical + sbio->page_count * PAGE_SIZE !=
1553 scrub_wr_submit(sctx);
1557 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1558 if (ret != PAGE_SIZE) {
1559 if (sbio->page_count < 1) {
1562 mutex_unlock(&wr_ctx->wr_lock);
1565 scrub_wr_submit(sctx);
1569 sbio->pagev[sbio->page_count] = spage;
1570 scrub_page_get(spage);
1572 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1573 scrub_wr_submit(sctx);
1574 mutex_unlock(&wr_ctx->wr_lock);
1579 static void scrub_wr_submit(struct scrub_ctx *sctx)
1581 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1582 struct scrub_bio *sbio;
1584 if (!wr_ctx->wr_curr_bio)
1587 sbio = wr_ctx->wr_curr_bio;
1588 wr_ctx->wr_curr_bio = NULL;
1589 WARN_ON(!sbio->bio->bi_bdev);
1590 scrub_pending_bio_inc(sctx);
1591 /* process all writes in a single worker thread. Then the block layer
1592 * orders the requests before sending them to the driver which
1593 * doubled the write performance on spinning disks when measured
1595 btrfsic_submit_bio(WRITE, sbio->bio);
1598 static void scrub_wr_bio_end_io(struct bio *bio, int err)
1600 struct scrub_bio *sbio = bio->bi_private;
1601 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1606 sbio->work.func = scrub_wr_bio_end_io_worker;
1607 btrfs_queue_worker(&fs_info->scrub_wr_completion_workers, &sbio->work);
1610 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1612 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1613 struct scrub_ctx *sctx = sbio->sctx;
1616 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1618 struct btrfs_dev_replace *dev_replace =
1619 &sbio->sctx->dev_root->fs_info->dev_replace;
1621 for (i = 0; i < sbio->page_count; i++) {
1622 struct scrub_page *spage = sbio->pagev[i];
1624 spage->io_error = 1;
1625 btrfs_dev_replace_stats_inc(&dev_replace->
1630 for (i = 0; i < sbio->page_count; i++)
1631 scrub_page_put(sbio->pagev[i]);
1635 scrub_pending_bio_dec(sctx);
1638 static int scrub_checksum(struct scrub_block *sblock)
1643 WARN_ON(sblock->page_count < 1);
1644 flags = sblock->pagev[0]->flags;
1646 if (flags & BTRFS_EXTENT_FLAG_DATA)
1647 ret = scrub_checksum_data(sblock);
1648 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1649 ret = scrub_checksum_tree_block(sblock);
1650 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1651 (void)scrub_checksum_super(sblock);
1655 scrub_handle_errored_block(sblock);
1660 static int scrub_checksum_data(struct scrub_block *sblock)
1662 struct scrub_ctx *sctx = sblock->sctx;
1663 u8 csum[BTRFS_CSUM_SIZE];
1672 BUG_ON(sblock->page_count < 1);
1673 if (!sblock->pagev[0]->have_csum)
1676 on_disk_csum = sblock->pagev[0]->csum;
1677 page = sblock->pagev[0]->page;
1678 buffer = kmap_atomic(page);
1680 len = sctx->sectorsize;
1683 u64 l = min_t(u64, len, PAGE_SIZE);
1685 crc = btrfs_csum_data(buffer, crc, l);
1686 kunmap_atomic(buffer);
1691 BUG_ON(index >= sblock->page_count);
1692 BUG_ON(!sblock->pagev[index]->page);
1693 page = sblock->pagev[index]->page;
1694 buffer = kmap_atomic(page);
1697 btrfs_csum_final(crc, csum);
1698 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1704 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1706 struct scrub_ctx *sctx = sblock->sctx;
1707 struct btrfs_header *h;
1708 struct btrfs_root *root = sctx->dev_root;
1709 struct btrfs_fs_info *fs_info = root->fs_info;
1710 u8 calculated_csum[BTRFS_CSUM_SIZE];
1711 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1713 void *mapped_buffer;
1722 BUG_ON(sblock->page_count < 1);
1723 page = sblock->pagev[0]->page;
1724 mapped_buffer = kmap_atomic(page);
1725 h = (struct btrfs_header *)mapped_buffer;
1726 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1729 * we don't use the getter functions here, as we
1730 * a) don't have an extent buffer and
1731 * b) the page is already kmapped
1734 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1737 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
1740 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1743 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1747 WARN_ON(sctx->nodesize != sctx->leafsize);
1748 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1749 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1750 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1753 u64 l = min_t(u64, len, mapped_size);
1755 crc = btrfs_csum_data(p, crc, l);
1756 kunmap_atomic(mapped_buffer);
1761 BUG_ON(index >= sblock->page_count);
1762 BUG_ON(!sblock->pagev[index]->page);
1763 page = sblock->pagev[index]->page;
1764 mapped_buffer = kmap_atomic(page);
1765 mapped_size = PAGE_SIZE;
1769 btrfs_csum_final(crc, calculated_csum);
1770 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1773 return fail || crc_fail;
1776 static int scrub_checksum_super(struct scrub_block *sblock)
1778 struct btrfs_super_block *s;
1779 struct scrub_ctx *sctx = sblock->sctx;
1780 struct btrfs_root *root = sctx->dev_root;
1781 struct btrfs_fs_info *fs_info = root->fs_info;
1782 u8 calculated_csum[BTRFS_CSUM_SIZE];
1783 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1785 void *mapped_buffer;
1794 BUG_ON(sblock->page_count < 1);
1795 page = sblock->pagev[0]->page;
1796 mapped_buffer = kmap_atomic(page);
1797 s = (struct btrfs_super_block *)mapped_buffer;
1798 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1800 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1803 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1806 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1809 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1810 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1811 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1814 u64 l = min_t(u64, len, mapped_size);
1816 crc = btrfs_csum_data(p, crc, l);
1817 kunmap_atomic(mapped_buffer);
1822 BUG_ON(index >= sblock->page_count);
1823 BUG_ON(!sblock->pagev[index]->page);
1824 page = sblock->pagev[index]->page;
1825 mapped_buffer = kmap_atomic(page);
1826 mapped_size = PAGE_SIZE;
1830 btrfs_csum_final(crc, calculated_csum);
1831 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1834 if (fail_cor + fail_gen) {
1836 * if we find an error in a super block, we just report it.
1837 * They will get written with the next transaction commit
1840 spin_lock(&sctx->stat_lock);
1841 ++sctx->stat.super_errors;
1842 spin_unlock(&sctx->stat_lock);
1844 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1845 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1847 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1848 BTRFS_DEV_STAT_GENERATION_ERRS);
1851 return fail_cor + fail_gen;
1854 static void scrub_block_get(struct scrub_block *sblock)
1856 atomic_inc(&sblock->ref_count);
1859 static void scrub_block_put(struct scrub_block *sblock)
1861 if (atomic_dec_and_test(&sblock->ref_count)) {
1864 for (i = 0; i < sblock->page_count; i++)
1865 scrub_page_put(sblock->pagev[i]);
1870 static void scrub_page_get(struct scrub_page *spage)
1872 atomic_inc(&spage->ref_count);
1875 static void scrub_page_put(struct scrub_page *spage)
1877 if (atomic_dec_and_test(&spage->ref_count)) {
1879 __free_page(spage->page);
1884 static void scrub_submit(struct scrub_ctx *sctx)
1886 struct scrub_bio *sbio;
1888 if (sctx->curr == -1)
1891 sbio = sctx->bios[sctx->curr];
1893 scrub_pending_bio_inc(sctx);
1895 if (!sbio->bio->bi_bdev) {
1897 * this case should not happen. If btrfs_map_block() is
1898 * wrong, it could happen for dev-replace operations on
1899 * missing devices when no mirrors are available, but in
1900 * this case it should already fail the mount.
1901 * This case is handled correctly (but _very_ slowly).
1903 printk_ratelimited(KERN_WARNING
1904 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
1905 bio_endio(sbio->bio, -EIO);
1907 btrfsic_submit_bio(READ, sbio->bio);
1911 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
1912 struct scrub_page *spage)
1914 struct scrub_block *sblock = spage->sblock;
1915 struct scrub_bio *sbio;
1920 * grab a fresh bio or wait for one to become available
1922 while (sctx->curr == -1) {
1923 spin_lock(&sctx->list_lock);
1924 sctx->curr = sctx->first_free;
1925 if (sctx->curr != -1) {
1926 sctx->first_free = sctx->bios[sctx->curr]->next_free;
1927 sctx->bios[sctx->curr]->next_free = -1;
1928 sctx->bios[sctx->curr]->page_count = 0;
1929 spin_unlock(&sctx->list_lock);
1931 spin_unlock(&sctx->list_lock);
1932 wait_event(sctx->list_wait, sctx->first_free != -1);
1935 sbio = sctx->bios[sctx->curr];
1936 if (sbio->page_count == 0) {
1939 sbio->physical = spage->physical;
1940 sbio->logical = spage->logical;
1941 sbio->dev = spage->dev;
1944 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
1950 bio->bi_private = sbio;
1951 bio->bi_end_io = scrub_bio_end_io;
1952 bio->bi_bdev = sbio->dev->bdev;
1953 bio->bi_iter.bi_sector = sbio->physical >> 9;
1955 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1957 sbio->logical + sbio->page_count * PAGE_SIZE !=
1959 sbio->dev != spage->dev) {
1964 sbio->pagev[sbio->page_count] = spage;
1965 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1966 if (ret != PAGE_SIZE) {
1967 if (sbio->page_count < 1) {
1976 scrub_block_get(sblock); /* one for the page added to the bio */
1977 atomic_inc(&sblock->outstanding_pages);
1979 if (sbio->page_count == sctx->pages_per_rd_bio)
1985 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
1986 u64 physical, struct btrfs_device *dev, u64 flags,
1987 u64 gen, int mirror_num, u8 *csum, int force,
1988 u64 physical_for_dev_replace)
1990 struct scrub_block *sblock;
1993 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
1995 spin_lock(&sctx->stat_lock);
1996 sctx->stat.malloc_errors++;
1997 spin_unlock(&sctx->stat_lock);
2001 /* one ref inside this function, plus one for each page added to
2003 atomic_set(&sblock->ref_count, 1);
2004 sblock->sctx = sctx;
2005 sblock->no_io_error_seen = 1;
2007 for (index = 0; len > 0; index++) {
2008 struct scrub_page *spage;
2009 u64 l = min_t(u64, len, PAGE_SIZE);
2011 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2014 spin_lock(&sctx->stat_lock);
2015 sctx->stat.malloc_errors++;
2016 spin_unlock(&sctx->stat_lock);
2017 scrub_block_put(sblock);
2020 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2021 scrub_page_get(spage);
2022 sblock->pagev[index] = spage;
2023 spage->sblock = sblock;
2025 spage->flags = flags;
2026 spage->generation = gen;
2027 spage->logical = logical;
2028 spage->physical = physical;
2029 spage->physical_for_dev_replace = physical_for_dev_replace;
2030 spage->mirror_num = mirror_num;
2032 spage->have_csum = 1;
2033 memcpy(spage->csum, csum, sctx->csum_size);
2035 spage->have_csum = 0;
2037 sblock->page_count++;
2038 spage->page = alloc_page(GFP_NOFS);
2044 physical_for_dev_replace += l;
2047 WARN_ON(sblock->page_count == 0);
2048 for (index = 0; index < sblock->page_count; index++) {
2049 struct scrub_page *spage = sblock->pagev[index];
2052 ret = scrub_add_page_to_rd_bio(sctx, spage);
2054 scrub_block_put(sblock);
2062 /* last one frees, either here or in bio completion for last page */
2063 scrub_block_put(sblock);
2067 static void scrub_bio_end_io(struct bio *bio, int err)
2069 struct scrub_bio *sbio = bio->bi_private;
2070 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
2075 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
2078 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2080 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2081 struct scrub_ctx *sctx = sbio->sctx;
2084 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2086 for (i = 0; i < sbio->page_count; i++) {
2087 struct scrub_page *spage = sbio->pagev[i];
2089 spage->io_error = 1;
2090 spage->sblock->no_io_error_seen = 0;
2094 /* now complete the scrub_block items that have all pages completed */
2095 for (i = 0; i < sbio->page_count; i++) {
2096 struct scrub_page *spage = sbio->pagev[i];
2097 struct scrub_block *sblock = spage->sblock;
2099 if (atomic_dec_and_test(&sblock->outstanding_pages))
2100 scrub_block_complete(sblock);
2101 scrub_block_put(sblock);
2106 spin_lock(&sctx->list_lock);
2107 sbio->next_free = sctx->first_free;
2108 sctx->first_free = sbio->index;
2109 spin_unlock(&sctx->list_lock);
2111 if (sctx->is_dev_replace &&
2112 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2113 mutex_lock(&sctx->wr_ctx.wr_lock);
2114 scrub_wr_submit(sctx);
2115 mutex_unlock(&sctx->wr_ctx.wr_lock);
2118 scrub_pending_bio_dec(sctx);
2121 static void scrub_block_complete(struct scrub_block *sblock)
2123 if (!sblock->no_io_error_seen) {
2124 scrub_handle_errored_block(sblock);
2127 * if has checksum error, write via repair mechanism in
2128 * dev replace case, otherwise write here in dev replace
2131 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
2132 scrub_write_block_to_dev_replace(sblock);
2136 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
2139 struct btrfs_ordered_sum *sum = NULL;
2140 unsigned long index;
2141 unsigned long num_sectors;
2143 while (!list_empty(&sctx->csum_list)) {
2144 sum = list_first_entry(&sctx->csum_list,
2145 struct btrfs_ordered_sum, list);
2146 if (sum->bytenr > logical)
2148 if (sum->bytenr + sum->len > logical)
2151 ++sctx->stat.csum_discards;
2152 list_del(&sum->list);
2159 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2160 num_sectors = sum->len / sctx->sectorsize;
2161 memcpy(csum, sum->sums + index, sctx->csum_size);
2162 if (index == num_sectors - 1) {
2163 list_del(&sum->list);
2169 /* scrub extent tries to collect up to 64 kB for each bio */
2170 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2171 u64 physical, struct btrfs_device *dev, u64 flags,
2172 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2175 u8 csum[BTRFS_CSUM_SIZE];
2178 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2179 blocksize = sctx->sectorsize;
2180 spin_lock(&sctx->stat_lock);
2181 sctx->stat.data_extents_scrubbed++;
2182 sctx->stat.data_bytes_scrubbed += len;
2183 spin_unlock(&sctx->stat_lock);
2184 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2185 WARN_ON(sctx->nodesize != sctx->leafsize);
2186 blocksize = sctx->nodesize;
2187 spin_lock(&sctx->stat_lock);
2188 sctx->stat.tree_extents_scrubbed++;
2189 sctx->stat.tree_bytes_scrubbed += len;
2190 spin_unlock(&sctx->stat_lock);
2192 blocksize = sctx->sectorsize;
2197 u64 l = min_t(u64, len, blocksize);
2200 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2201 /* push csums to sbio */
2202 have_csum = scrub_find_csum(sctx, logical, l, csum);
2204 ++sctx->stat.no_csum;
2205 if (sctx->is_dev_replace && !have_csum) {
2206 ret = copy_nocow_pages(sctx, logical, l,
2208 physical_for_dev_replace);
2209 goto behind_scrub_pages;
2212 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2213 mirror_num, have_csum ? csum : NULL, 0,
2214 physical_for_dev_replace);
2221 physical_for_dev_replace += l;
2226 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
2227 struct map_lookup *map,
2228 struct btrfs_device *scrub_dev,
2229 int num, u64 base, u64 length,
2232 struct btrfs_path *path;
2233 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2234 struct btrfs_root *root = fs_info->extent_root;
2235 struct btrfs_root *csum_root = fs_info->csum_root;
2236 struct btrfs_extent_item *extent;
2237 struct blk_plug plug;
2242 struct extent_buffer *l;
2243 struct btrfs_key key;
2249 struct reada_control *reada1;
2250 struct reada_control *reada2;
2251 struct btrfs_key key_start;
2252 struct btrfs_key key_end;
2253 u64 increment = map->stripe_len;
2256 u64 extent_physical;
2258 struct btrfs_device *extent_dev;
2259 int extent_mirror_num;
2262 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2263 BTRFS_BLOCK_GROUP_RAID6)) {
2264 if (num >= nr_data_stripes(map)) {
2271 do_div(nstripes, map->stripe_len);
2272 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2273 offset = map->stripe_len * num;
2274 increment = map->stripe_len * map->num_stripes;
2276 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2277 int factor = map->num_stripes / map->sub_stripes;
2278 offset = map->stripe_len * (num / map->sub_stripes);
2279 increment = map->stripe_len * factor;
2280 mirror_num = num % map->sub_stripes + 1;
2281 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2282 increment = map->stripe_len;
2283 mirror_num = num % map->num_stripes + 1;
2284 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2285 increment = map->stripe_len;
2286 mirror_num = num % map->num_stripes + 1;
2288 increment = map->stripe_len;
2292 path = btrfs_alloc_path();
2297 * work on commit root. The related disk blocks are static as
2298 * long as COW is applied. This means, it is save to rewrite
2299 * them to repair disk errors without any race conditions
2301 path->search_commit_root = 1;
2302 path->skip_locking = 1;
2305 * trigger the readahead for extent tree csum tree and wait for
2306 * completion. During readahead, the scrub is officially paused
2307 * to not hold off transaction commits
2309 logical = base + offset;
2311 wait_event(sctx->list_wait,
2312 atomic_read(&sctx->bios_in_flight) == 0);
2313 scrub_blocked_if_needed(fs_info);
2315 /* FIXME it might be better to start readahead at commit root */
2316 key_start.objectid = logical;
2317 key_start.type = BTRFS_EXTENT_ITEM_KEY;
2318 key_start.offset = (u64)0;
2319 key_end.objectid = base + offset + nstripes * increment;
2320 key_end.type = BTRFS_METADATA_ITEM_KEY;
2321 key_end.offset = (u64)-1;
2322 reada1 = btrfs_reada_add(root, &key_start, &key_end);
2324 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2325 key_start.type = BTRFS_EXTENT_CSUM_KEY;
2326 key_start.offset = logical;
2327 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2328 key_end.type = BTRFS_EXTENT_CSUM_KEY;
2329 key_end.offset = base + offset + nstripes * increment;
2330 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
2332 if (!IS_ERR(reada1))
2333 btrfs_reada_wait(reada1);
2334 if (!IS_ERR(reada2))
2335 btrfs_reada_wait(reada2);
2339 * collect all data csums for the stripe to avoid seeking during
2340 * the scrub. This might currently (crc32) end up to be about 1MB
2342 blk_start_plug(&plug);
2345 * now find all extents for each stripe and scrub them
2347 logical = base + offset;
2348 physical = map->stripes[num].physical;
2349 logic_end = logical + increment * nstripes;
2351 while (logical < logic_end) {
2355 if (atomic_read(&fs_info->scrub_cancel_req) ||
2356 atomic_read(&sctx->cancel_req)) {
2361 * check to see if we have to pause
2363 if (atomic_read(&fs_info->scrub_pause_req)) {
2364 /* push queued extents */
2365 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2367 mutex_lock(&sctx->wr_ctx.wr_lock);
2368 scrub_wr_submit(sctx);
2369 mutex_unlock(&sctx->wr_ctx.wr_lock);
2370 wait_event(sctx->list_wait,
2371 atomic_read(&sctx->bios_in_flight) == 0);
2372 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2373 scrub_blocked_if_needed(fs_info);
2376 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2377 key.type = BTRFS_METADATA_ITEM_KEY;
2379 key.type = BTRFS_EXTENT_ITEM_KEY;
2380 key.objectid = logical;
2381 key.offset = (u64)-1;
2383 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2388 ret = btrfs_previous_extent_item(root, path, 0);
2392 /* there's no smaller item, so stick with the
2394 btrfs_release_path(path);
2395 ret = btrfs_search_slot(NULL, root, &key,
2407 slot = path->slots[0];
2408 if (slot >= btrfs_header_nritems(l)) {
2409 ret = btrfs_next_leaf(root, path);
2418 btrfs_item_key_to_cpu(l, &key, slot);
2420 if (key.type == BTRFS_METADATA_ITEM_KEY)
2421 bytes = root->leafsize;
2425 if (key.objectid + bytes <= logical)
2428 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2429 key.type != BTRFS_METADATA_ITEM_KEY)
2432 if (key.objectid >= logical + map->stripe_len) {
2433 /* out of this device extent */
2434 if (key.objectid >= logic_end)
2439 extent = btrfs_item_ptr(l, slot,
2440 struct btrfs_extent_item);
2441 flags = btrfs_extent_flags(l, extent);
2442 generation = btrfs_extent_generation(l, extent);
2444 if (key.objectid < logical &&
2445 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
2447 "scrub: tree block %llu spanning "
2448 "stripes, ignored. logical=%llu",
2449 key.objectid, logical);
2454 extent_logical = key.objectid;
2458 * trim extent to this stripe
2460 if (extent_logical < logical) {
2461 extent_len -= logical - extent_logical;
2462 extent_logical = logical;
2464 if (extent_logical + extent_len >
2465 logical + map->stripe_len) {
2466 extent_len = logical + map->stripe_len -
2470 extent_physical = extent_logical - logical + physical;
2471 extent_dev = scrub_dev;
2472 extent_mirror_num = mirror_num;
2474 scrub_remap_extent(fs_info, extent_logical,
2475 extent_len, &extent_physical,
2477 &extent_mirror_num);
2479 ret = btrfs_lookup_csums_range(csum_root, logical,
2480 logical + map->stripe_len - 1,
2481 &sctx->csum_list, 1);
2485 ret = scrub_extent(sctx, extent_logical, extent_len,
2486 extent_physical, extent_dev, flags,
2487 generation, extent_mirror_num,
2488 extent_logical - logical + physical);
2492 scrub_free_csums(sctx);
2493 if (extent_logical + extent_len <
2494 key.objectid + bytes) {
2495 logical += increment;
2496 physical += map->stripe_len;
2498 if (logical < key.objectid + bytes) {
2503 if (logical >= logic_end) {
2511 btrfs_release_path(path);
2512 logical += increment;
2513 physical += map->stripe_len;
2514 spin_lock(&sctx->stat_lock);
2516 sctx->stat.last_physical = map->stripes[num].physical +
2519 sctx->stat.last_physical = physical;
2520 spin_unlock(&sctx->stat_lock);
2525 /* push queued extents */
2527 mutex_lock(&sctx->wr_ctx.wr_lock);
2528 scrub_wr_submit(sctx);
2529 mutex_unlock(&sctx->wr_ctx.wr_lock);
2531 blk_finish_plug(&plug);
2532 btrfs_free_path(path);
2533 return ret < 0 ? ret : 0;
2536 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
2537 struct btrfs_device *scrub_dev,
2538 u64 chunk_tree, u64 chunk_objectid,
2539 u64 chunk_offset, u64 length,
2540 u64 dev_offset, int is_dev_replace)
2542 struct btrfs_mapping_tree *map_tree =
2543 &sctx->dev_root->fs_info->mapping_tree;
2544 struct map_lookup *map;
2545 struct extent_map *em;
2549 read_lock(&map_tree->map_tree.lock);
2550 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2551 read_unlock(&map_tree->map_tree.lock);
2556 map = (struct map_lookup *)em->bdev;
2557 if (em->start != chunk_offset)
2560 if (em->len < length)
2563 for (i = 0; i < map->num_stripes; ++i) {
2564 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
2565 map->stripes[i].physical == dev_offset) {
2566 ret = scrub_stripe(sctx, map, scrub_dev, i,
2567 chunk_offset, length,
2574 free_extent_map(em);
2579 static noinline_for_stack
2580 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
2581 struct btrfs_device *scrub_dev, u64 start, u64 end,
2584 struct btrfs_dev_extent *dev_extent = NULL;
2585 struct btrfs_path *path;
2586 struct btrfs_root *root = sctx->dev_root;
2587 struct btrfs_fs_info *fs_info = root->fs_info;
2594 struct extent_buffer *l;
2595 struct btrfs_key key;
2596 struct btrfs_key found_key;
2597 struct btrfs_block_group_cache *cache;
2598 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
2600 path = btrfs_alloc_path();
2605 path->search_commit_root = 1;
2606 path->skip_locking = 1;
2608 key.objectid = scrub_dev->devid;
2610 key.type = BTRFS_DEV_EXTENT_KEY;
2613 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2617 if (path->slots[0] >=
2618 btrfs_header_nritems(path->nodes[0])) {
2619 ret = btrfs_next_leaf(root, path);
2626 slot = path->slots[0];
2628 btrfs_item_key_to_cpu(l, &found_key, slot);
2630 if (found_key.objectid != scrub_dev->devid)
2633 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
2636 if (found_key.offset >= end)
2639 if (found_key.offset < key.offset)
2642 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2643 length = btrfs_dev_extent_length(l, dev_extent);
2645 if (found_key.offset + length <= start) {
2646 key.offset = found_key.offset + length;
2647 btrfs_release_path(path);
2651 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2652 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2653 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2656 * get a reference on the corresponding block group to prevent
2657 * the chunk from going away while we scrub it
2659 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2664 dev_replace->cursor_right = found_key.offset + length;
2665 dev_replace->cursor_left = found_key.offset;
2666 dev_replace->item_needs_writeback = 1;
2667 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
2668 chunk_offset, length, found_key.offset,
2672 * flush, submit all pending read and write bios, afterwards
2674 * Note that in the dev replace case, a read request causes
2675 * write requests that are submitted in the read completion
2676 * worker. Therefore in the current situation, it is required
2677 * that all write requests are flushed, so that all read and
2678 * write requests are really completed when bios_in_flight
2681 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2683 mutex_lock(&sctx->wr_ctx.wr_lock);
2684 scrub_wr_submit(sctx);
2685 mutex_unlock(&sctx->wr_ctx.wr_lock);
2687 wait_event(sctx->list_wait,
2688 atomic_read(&sctx->bios_in_flight) == 0);
2689 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2690 wait_event(sctx->list_wait,
2691 atomic_read(&sctx->workers_pending) == 0);
2692 scrub_blocked_if_needed(fs_info);
2694 btrfs_put_block_group(cache);
2697 if (is_dev_replace &&
2698 atomic64_read(&dev_replace->num_write_errors) > 0) {
2702 if (sctx->stat.malloc_errors > 0) {
2707 dev_replace->cursor_left = dev_replace->cursor_right;
2708 dev_replace->item_needs_writeback = 1;
2710 key.offset = found_key.offset + length;
2711 btrfs_release_path(path);
2714 btrfs_free_path(path);
2717 * ret can still be 1 from search_slot or next_leaf,
2718 * that's not an error
2720 return ret < 0 ? ret : 0;
2723 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2724 struct btrfs_device *scrub_dev)
2730 struct btrfs_root *root = sctx->dev_root;
2732 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
2735 gen = root->fs_info->last_trans_committed;
2737 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2738 bytenr = btrfs_sb_offset(i);
2739 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
2742 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
2743 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
2748 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
2754 * get a reference count on fs_info->scrub_workers. start worker if necessary
2756 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
2761 if (fs_info->scrub_workers_refcnt == 0) {
2763 btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1,
2764 &fs_info->generic_worker);
2766 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
2767 fs_info->thread_pool_size,
2768 &fs_info->generic_worker);
2769 fs_info->scrub_workers.idle_thresh = 4;
2770 ret = btrfs_start_workers(&fs_info->scrub_workers);
2773 btrfs_init_workers(&fs_info->scrub_wr_completion_workers,
2775 fs_info->thread_pool_size,
2776 &fs_info->generic_worker);
2777 fs_info->scrub_wr_completion_workers.idle_thresh = 2;
2778 ret = btrfs_start_workers(
2779 &fs_info->scrub_wr_completion_workers);
2782 btrfs_init_workers(&fs_info->scrub_nocow_workers, "scrubnc", 1,
2783 &fs_info->generic_worker);
2784 ret = btrfs_start_workers(&fs_info->scrub_nocow_workers);
2788 ++fs_info->scrub_workers_refcnt;
2793 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
2795 if (--fs_info->scrub_workers_refcnt == 0) {
2796 btrfs_stop_workers(&fs_info->scrub_workers);
2797 btrfs_stop_workers(&fs_info->scrub_wr_completion_workers);
2798 btrfs_stop_workers(&fs_info->scrub_nocow_workers);
2800 WARN_ON(fs_info->scrub_workers_refcnt < 0);
2803 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2804 u64 end, struct btrfs_scrub_progress *progress,
2805 int readonly, int is_dev_replace)
2807 struct scrub_ctx *sctx;
2809 struct btrfs_device *dev;
2811 if (btrfs_fs_closing(fs_info))
2815 * check some assumptions
2817 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
2819 "scrub: size assumption nodesize == leafsize (%d == %d) fails",
2820 fs_info->chunk_root->nodesize,
2821 fs_info->chunk_root->leafsize);
2825 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
2827 * in this case scrub is unable to calculate the checksum
2828 * the way scrub is implemented. Do not handle this
2829 * situation at all because it won't ever happen.
2832 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
2833 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
2837 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
2838 /* not supported for data w/o checksums */
2840 "scrub: size assumption sectorsize != PAGE_SIZE "
2841 "(%d != %lu) fails",
2842 fs_info->chunk_root->sectorsize, PAGE_SIZE);
2846 if (fs_info->chunk_root->nodesize >
2847 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
2848 fs_info->chunk_root->sectorsize >
2849 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
2851 * would exhaust the array bounds of pagev member in
2852 * struct scrub_block
2854 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
2855 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
2856 fs_info->chunk_root->nodesize,
2857 SCRUB_MAX_PAGES_PER_BLOCK,
2858 fs_info->chunk_root->sectorsize,
2859 SCRUB_MAX_PAGES_PER_BLOCK);
2864 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2865 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
2866 if (!dev || (dev->missing && !is_dev_replace)) {
2867 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2871 mutex_lock(&fs_info->scrub_lock);
2872 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
2873 mutex_unlock(&fs_info->scrub_lock);
2874 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2878 btrfs_dev_replace_lock(&fs_info->dev_replace);
2879 if (dev->scrub_device ||
2881 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2882 btrfs_dev_replace_unlock(&fs_info->dev_replace);
2883 mutex_unlock(&fs_info->scrub_lock);
2884 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2885 return -EINPROGRESS;
2887 btrfs_dev_replace_unlock(&fs_info->dev_replace);
2889 ret = scrub_workers_get(fs_info, is_dev_replace);
2891 mutex_unlock(&fs_info->scrub_lock);
2892 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2896 sctx = scrub_setup_ctx(dev, is_dev_replace);
2898 mutex_unlock(&fs_info->scrub_lock);
2899 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2900 scrub_workers_put(fs_info);
2901 return PTR_ERR(sctx);
2903 sctx->readonly = readonly;
2904 dev->scrub_device = sctx;
2905 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2908 * checking @scrub_pause_req here, we can avoid
2909 * race between committing transaction and scrubbing.
2911 __scrub_blocked_if_needed(fs_info);
2912 atomic_inc(&fs_info->scrubs_running);
2913 mutex_unlock(&fs_info->scrub_lock);
2915 if (!is_dev_replace) {
2917 * by holding device list mutex, we can
2918 * kick off writing super in log tree sync.
2920 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2921 ret = scrub_supers(sctx, dev);
2922 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2926 ret = scrub_enumerate_chunks(sctx, dev, start, end,
2929 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
2930 atomic_dec(&fs_info->scrubs_running);
2931 wake_up(&fs_info->scrub_pause_wait);
2933 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
2936 memcpy(progress, &sctx->stat, sizeof(*progress));
2938 mutex_lock(&fs_info->scrub_lock);
2939 dev->scrub_device = NULL;
2940 scrub_workers_put(fs_info);
2941 mutex_unlock(&fs_info->scrub_lock);
2943 scrub_free_ctx(sctx);
2948 void btrfs_scrub_pause(struct btrfs_root *root)
2950 struct btrfs_fs_info *fs_info = root->fs_info;
2952 mutex_lock(&fs_info->scrub_lock);
2953 atomic_inc(&fs_info->scrub_pause_req);
2954 while (atomic_read(&fs_info->scrubs_paused) !=
2955 atomic_read(&fs_info->scrubs_running)) {
2956 mutex_unlock(&fs_info->scrub_lock);
2957 wait_event(fs_info->scrub_pause_wait,
2958 atomic_read(&fs_info->scrubs_paused) ==
2959 atomic_read(&fs_info->scrubs_running));
2960 mutex_lock(&fs_info->scrub_lock);
2962 mutex_unlock(&fs_info->scrub_lock);
2965 void btrfs_scrub_continue(struct btrfs_root *root)
2967 struct btrfs_fs_info *fs_info = root->fs_info;
2969 atomic_dec(&fs_info->scrub_pause_req);
2970 wake_up(&fs_info->scrub_pause_wait);
2973 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
2975 mutex_lock(&fs_info->scrub_lock);
2976 if (!atomic_read(&fs_info->scrubs_running)) {
2977 mutex_unlock(&fs_info->scrub_lock);
2981 atomic_inc(&fs_info->scrub_cancel_req);
2982 while (atomic_read(&fs_info->scrubs_running)) {
2983 mutex_unlock(&fs_info->scrub_lock);
2984 wait_event(fs_info->scrub_pause_wait,
2985 atomic_read(&fs_info->scrubs_running) == 0);
2986 mutex_lock(&fs_info->scrub_lock);
2988 atomic_dec(&fs_info->scrub_cancel_req);
2989 mutex_unlock(&fs_info->scrub_lock);
2994 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
2995 struct btrfs_device *dev)
2997 struct scrub_ctx *sctx;
2999 mutex_lock(&fs_info->scrub_lock);
3000 sctx = dev->scrub_device;
3002 mutex_unlock(&fs_info->scrub_lock);
3005 atomic_inc(&sctx->cancel_req);
3006 while (dev->scrub_device) {
3007 mutex_unlock(&fs_info->scrub_lock);
3008 wait_event(fs_info->scrub_pause_wait,
3009 dev->scrub_device == NULL);
3010 mutex_lock(&fs_info->scrub_lock);
3012 mutex_unlock(&fs_info->scrub_lock);
3017 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3018 struct btrfs_scrub_progress *progress)
3020 struct btrfs_device *dev;
3021 struct scrub_ctx *sctx = NULL;
3023 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3024 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
3026 sctx = dev->scrub_device;
3028 memcpy(progress, &sctx->stat, sizeof(*progress));
3029 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3031 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
3034 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3035 u64 extent_logical, u64 extent_len,
3036 u64 *extent_physical,
3037 struct btrfs_device **extent_dev,
3038 int *extent_mirror_num)
3041 struct btrfs_bio *bbio = NULL;
3044 mapped_length = extent_len;
3045 ret = btrfs_map_block(fs_info, READ, extent_logical,
3046 &mapped_length, &bbio, 0);
3047 if (ret || !bbio || mapped_length < extent_len ||
3048 !bbio->stripes[0].dev->bdev) {
3053 *extent_physical = bbio->stripes[0].physical;
3054 *extent_mirror_num = bbio->mirror_num;
3055 *extent_dev = bbio->stripes[0].dev;
3059 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3060 struct scrub_wr_ctx *wr_ctx,
3061 struct btrfs_fs_info *fs_info,
3062 struct btrfs_device *dev,
3065 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3067 mutex_init(&wr_ctx->wr_lock);
3068 wr_ctx->wr_curr_bio = NULL;
3069 if (!is_dev_replace)
3072 WARN_ON(!dev->bdev);
3073 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
3074 bio_get_nr_vecs(dev->bdev));
3075 wr_ctx->tgtdev = dev;
3076 atomic_set(&wr_ctx->flush_all_writes, 0);
3080 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3082 mutex_lock(&wr_ctx->wr_lock);
3083 kfree(wr_ctx->wr_curr_bio);
3084 wr_ctx->wr_curr_bio = NULL;
3085 mutex_unlock(&wr_ctx->wr_lock);
3088 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3089 int mirror_num, u64 physical_for_dev_replace)
3091 struct scrub_copy_nocow_ctx *nocow_ctx;
3092 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3094 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3096 spin_lock(&sctx->stat_lock);
3097 sctx->stat.malloc_errors++;
3098 spin_unlock(&sctx->stat_lock);
3102 scrub_pending_trans_workers_inc(sctx);
3104 nocow_ctx->sctx = sctx;
3105 nocow_ctx->logical = logical;
3106 nocow_ctx->len = len;
3107 nocow_ctx->mirror_num = mirror_num;
3108 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
3109 nocow_ctx->work.func = copy_nocow_pages_worker;
3110 INIT_LIST_HEAD(&nocow_ctx->inodes);
3111 btrfs_queue_worker(&fs_info->scrub_nocow_workers,
3117 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
3119 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3120 struct scrub_nocow_inode *nocow_inode;
3122 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
3125 nocow_inode->inum = inum;
3126 nocow_inode->offset = offset;
3127 nocow_inode->root = root;
3128 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
3132 #define COPY_COMPLETE 1
3134 static void copy_nocow_pages_worker(struct btrfs_work *work)
3136 struct scrub_copy_nocow_ctx *nocow_ctx =
3137 container_of(work, struct scrub_copy_nocow_ctx, work);
3138 struct scrub_ctx *sctx = nocow_ctx->sctx;
3139 u64 logical = nocow_ctx->logical;
3140 u64 len = nocow_ctx->len;
3141 int mirror_num = nocow_ctx->mirror_num;
3142 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3144 struct btrfs_trans_handle *trans = NULL;
3145 struct btrfs_fs_info *fs_info;
3146 struct btrfs_path *path;
3147 struct btrfs_root *root;
3148 int not_written = 0;
3150 fs_info = sctx->dev_root->fs_info;
3151 root = fs_info->extent_root;
3153 path = btrfs_alloc_path();
3155 spin_lock(&sctx->stat_lock);
3156 sctx->stat.malloc_errors++;
3157 spin_unlock(&sctx->stat_lock);
3162 trans = btrfs_join_transaction(root);
3163 if (IS_ERR(trans)) {
3168 ret = iterate_inodes_from_logical(logical, fs_info, path,
3169 record_inode_for_nocow, nocow_ctx);
3170 if (ret != 0 && ret != -ENOENT) {
3171 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
3172 "phys %llu, len %llu, mir %u, ret %d",
3173 logical, physical_for_dev_replace, len, mirror_num,
3179 btrfs_end_transaction(trans, root);
3181 while (!list_empty(&nocow_ctx->inodes)) {
3182 struct scrub_nocow_inode *entry;
3183 entry = list_first_entry(&nocow_ctx->inodes,
3184 struct scrub_nocow_inode,
3186 list_del_init(&entry->list);
3187 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
3188 entry->root, nocow_ctx);
3190 if (ret == COPY_COMPLETE) {
3198 while (!list_empty(&nocow_ctx->inodes)) {
3199 struct scrub_nocow_inode *entry;
3200 entry = list_first_entry(&nocow_ctx->inodes,
3201 struct scrub_nocow_inode,
3203 list_del_init(&entry->list);
3206 if (trans && !IS_ERR(trans))
3207 btrfs_end_transaction(trans, root);
3209 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
3210 num_uncorrectable_read_errors);
3212 btrfs_free_path(path);
3215 scrub_pending_trans_workers_dec(sctx);
3218 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
3219 struct scrub_copy_nocow_ctx *nocow_ctx)
3221 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
3222 struct btrfs_key key;
3223 struct inode *inode;
3225 struct btrfs_root *local_root;
3226 struct btrfs_ordered_extent *ordered;
3227 struct extent_map *em;
3228 struct extent_state *cached_state = NULL;
3229 struct extent_io_tree *io_tree;
3230 u64 physical_for_dev_replace;
3231 u64 len = nocow_ctx->len;
3232 u64 lockstart = offset, lockend = offset + len - 1;
3233 unsigned long index;
3238 key.objectid = root;
3239 key.type = BTRFS_ROOT_ITEM_KEY;
3240 key.offset = (u64)-1;
3242 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
3244 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
3245 if (IS_ERR(local_root)) {
3246 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
3247 return PTR_ERR(local_root);
3250 key.type = BTRFS_INODE_ITEM_KEY;
3251 key.objectid = inum;
3253 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
3254 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
3256 return PTR_ERR(inode);
3258 /* Avoid truncate/dio/punch hole.. */
3259 mutex_lock(&inode->i_mutex);
3260 inode_dio_wait(inode);
3262 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3263 io_tree = &BTRFS_I(inode)->io_tree;
3265 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
3266 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
3268 btrfs_put_ordered_extent(ordered);
3272 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0);
3279 * This extent does not actually cover the logical extent anymore,
3280 * move on to the next inode.
3282 if (em->block_start > nocow_ctx->logical ||
3283 em->block_start + em->block_len < nocow_ctx->logical + len) {
3284 free_extent_map(em);
3287 free_extent_map(em);
3289 while (len >= PAGE_CACHE_SIZE) {
3290 index = offset >> PAGE_CACHE_SHIFT;
3292 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3294 btrfs_err(fs_info, "find_or_create_page() failed");
3299 if (PageUptodate(page)) {
3300 if (PageDirty(page))
3303 ClearPageError(page);
3304 err = extent_read_full_page_nolock(io_tree, page,
3306 nocow_ctx->mirror_num);
3314 * If the page has been remove from the page cache,
3315 * the data on it is meaningless, because it may be
3316 * old one, the new data may be written into the new
3317 * page in the page cache.
3319 if (page->mapping != inode->i_mapping) {
3321 page_cache_release(page);
3324 if (!PageUptodate(page)) {
3329 err = write_page_nocow(nocow_ctx->sctx,
3330 physical_for_dev_replace, page);
3335 page_cache_release(page);
3340 offset += PAGE_CACHE_SIZE;
3341 physical_for_dev_replace += PAGE_CACHE_SIZE;
3342 len -= PAGE_CACHE_SIZE;
3344 ret = COPY_COMPLETE;
3346 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
3349 mutex_unlock(&inode->i_mutex);
3354 static int write_page_nocow(struct scrub_ctx *sctx,
3355 u64 physical_for_dev_replace, struct page *page)
3358 struct btrfs_device *dev;
3361 dev = sctx->wr_ctx.tgtdev;
3365 printk_ratelimited(KERN_WARNING
3366 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
3369 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
3371 spin_lock(&sctx->stat_lock);
3372 sctx->stat.malloc_errors++;
3373 spin_unlock(&sctx->stat_lock);
3376 bio->bi_iter.bi_size = 0;
3377 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
3378 bio->bi_bdev = dev->bdev;
3379 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
3380 if (ret != PAGE_CACHE_SIZE) {
3383 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
3387 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
3388 goto leave_with_eio;