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, &found_key, ei,
581 item_size, &ref_root,
583 printk_in_rcu(KERN_WARNING
584 "BTRFS: %s at logical %llu on dev %s, "
585 "sector %llu: metadata %s (level %d) in tree "
586 "%llu\n", errstr, swarn.logical,
587 rcu_str_deref(dev->name),
588 (unsigned long long)swarn.sector,
589 ref_level ? "node" : "leaf",
590 ret < 0 ? -1 : ref_level,
591 ret < 0 ? -1 : ref_root);
593 btrfs_release_path(path);
595 btrfs_release_path(path);
598 iterate_extent_inodes(fs_info, found_key.objectid,
600 scrub_print_warning_inode, &swarn);
604 btrfs_free_path(path);
605 kfree(swarn.scratch_buf);
606 kfree(swarn.msg_buf);
609 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
611 struct page *page = NULL;
613 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
616 struct btrfs_key key;
617 struct inode *inode = NULL;
618 struct btrfs_fs_info *fs_info;
619 u64 end = offset + PAGE_SIZE - 1;
620 struct btrfs_root *local_root;
624 key.type = BTRFS_ROOT_ITEM_KEY;
625 key.offset = (u64)-1;
627 fs_info = fixup->root->fs_info;
628 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
630 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
631 if (IS_ERR(local_root)) {
632 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
633 return PTR_ERR(local_root);
636 key.type = BTRFS_INODE_ITEM_KEY;
639 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
640 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
642 return PTR_ERR(inode);
644 index = offset >> PAGE_CACHE_SHIFT;
646 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
652 if (PageUptodate(page)) {
653 if (PageDirty(page)) {
655 * we need to write the data to the defect sector. the
656 * data that was in that sector is not in memory,
657 * because the page was modified. we must not write the
658 * modified page to that sector.
660 * TODO: what could be done here: wait for the delalloc
661 * runner to write out that page (might involve
662 * COW) and see whether the sector is still
663 * referenced afterwards.
665 * For the meantime, we'll treat this error
666 * incorrectable, although there is a chance that a
667 * later scrub will find the bad sector again and that
668 * there's no dirty page in memory, then.
673 fs_info = BTRFS_I(inode)->root->fs_info;
674 ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
675 fixup->logical, page,
681 * we need to get good data first. the general readpage path
682 * will call repair_io_failure for us, we just have to make
683 * sure we read the bad mirror.
685 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
686 EXTENT_DAMAGED, GFP_NOFS);
688 /* set_extent_bits should give proper error */
695 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
698 wait_on_page_locked(page);
700 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
701 end, EXTENT_DAMAGED, 0, NULL);
703 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
704 EXTENT_DAMAGED, GFP_NOFS);
716 if (ret == 0 && corrected) {
718 * we only need to call readpage for one of the inodes belonging
719 * to this extent. so make iterate_extent_inodes stop
727 static void scrub_fixup_nodatasum(struct btrfs_work *work)
730 struct scrub_fixup_nodatasum *fixup;
731 struct scrub_ctx *sctx;
732 struct btrfs_trans_handle *trans = NULL;
733 struct btrfs_path *path;
734 int uncorrectable = 0;
736 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
739 path = btrfs_alloc_path();
741 spin_lock(&sctx->stat_lock);
742 ++sctx->stat.malloc_errors;
743 spin_unlock(&sctx->stat_lock);
748 trans = btrfs_join_transaction(fixup->root);
755 * the idea is to trigger a regular read through the standard path. we
756 * read a page from the (failed) logical address by specifying the
757 * corresponding copynum of the failed sector. thus, that readpage is
759 * that is the point where on-the-fly error correction will kick in
760 * (once it's finished) and rewrite the failed sector if a good copy
763 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
764 path, scrub_fixup_readpage,
772 spin_lock(&sctx->stat_lock);
773 ++sctx->stat.corrected_errors;
774 spin_unlock(&sctx->stat_lock);
777 if (trans && !IS_ERR(trans))
778 btrfs_end_transaction(trans, fixup->root);
780 spin_lock(&sctx->stat_lock);
781 ++sctx->stat.uncorrectable_errors;
782 spin_unlock(&sctx->stat_lock);
783 btrfs_dev_replace_stats_inc(
784 &sctx->dev_root->fs_info->dev_replace.
785 num_uncorrectable_read_errors);
786 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
787 "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
788 fixup->logical, rcu_str_deref(fixup->dev->name));
791 btrfs_free_path(path);
794 scrub_pending_trans_workers_dec(sctx);
798 * scrub_handle_errored_block gets called when either verification of the
799 * pages failed or the bio failed to read, e.g. with EIO. In the latter
800 * case, this function handles all pages in the bio, even though only one
802 * The goal of this function is to repair the errored block by using the
803 * contents of one of the mirrors.
805 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
807 struct scrub_ctx *sctx = sblock_to_check->sctx;
808 struct btrfs_device *dev;
809 struct btrfs_fs_info *fs_info;
813 unsigned int failed_mirror_index;
814 unsigned int is_metadata;
815 unsigned int have_csum;
817 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
818 struct scrub_block *sblock_bad;
823 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
824 DEFAULT_RATELIMIT_BURST);
826 BUG_ON(sblock_to_check->page_count < 1);
827 fs_info = sctx->dev_root->fs_info;
828 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
830 * if we find an error in a super block, we just report it.
831 * They will get written with the next transaction commit
834 spin_lock(&sctx->stat_lock);
835 ++sctx->stat.super_errors;
836 spin_unlock(&sctx->stat_lock);
839 length = sblock_to_check->page_count * PAGE_SIZE;
840 logical = sblock_to_check->pagev[0]->logical;
841 generation = sblock_to_check->pagev[0]->generation;
842 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
843 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
844 is_metadata = !(sblock_to_check->pagev[0]->flags &
845 BTRFS_EXTENT_FLAG_DATA);
846 have_csum = sblock_to_check->pagev[0]->have_csum;
847 csum = sblock_to_check->pagev[0]->csum;
848 dev = sblock_to_check->pagev[0]->dev;
850 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
851 sblocks_for_recheck = NULL;
856 * read all mirrors one after the other. This includes to
857 * re-read the extent or metadata block that failed (that was
858 * the cause that this fixup code is called) another time,
859 * page by page this time in order to know which pages
860 * caused I/O errors and which ones are good (for all mirrors).
861 * It is the goal to handle the situation when more than one
862 * mirror contains I/O errors, but the errors do not
863 * overlap, i.e. the data can be repaired by selecting the
864 * pages from those mirrors without I/O error on the
865 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
866 * would be that mirror #1 has an I/O error on the first page,
867 * the second page is good, and mirror #2 has an I/O error on
868 * the second page, but the first page is good.
869 * Then the first page of the first mirror can be repaired by
870 * taking the first page of the second mirror, and the
871 * second page of the second mirror can be repaired by
872 * copying the contents of the 2nd page of the 1st mirror.
873 * One more note: if the pages of one mirror contain I/O
874 * errors, the checksum cannot be verified. In order to get
875 * the best data for repairing, the first attempt is to find
876 * a mirror without I/O errors and with a validated checksum.
877 * Only if this is not possible, the pages are picked from
878 * mirrors with I/O errors without considering the checksum.
879 * If the latter is the case, at the end, the checksum of the
880 * repaired area is verified in order to correctly maintain
884 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
885 sizeof(*sblocks_for_recheck),
887 if (!sblocks_for_recheck) {
888 spin_lock(&sctx->stat_lock);
889 sctx->stat.malloc_errors++;
890 sctx->stat.read_errors++;
891 sctx->stat.uncorrectable_errors++;
892 spin_unlock(&sctx->stat_lock);
893 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
897 /* setup the context, map the logical blocks and alloc the pages */
898 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
899 logical, sblocks_for_recheck);
901 spin_lock(&sctx->stat_lock);
902 sctx->stat.read_errors++;
903 sctx->stat.uncorrectable_errors++;
904 spin_unlock(&sctx->stat_lock);
905 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
908 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
909 sblock_bad = sblocks_for_recheck + failed_mirror_index;
911 /* build and submit the bios for the failed mirror, check checksums */
912 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
913 csum, generation, sctx->csum_size);
915 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
916 sblock_bad->no_io_error_seen) {
918 * the error disappeared after reading page by page, or
919 * the area was part of a huge bio and other parts of the
920 * bio caused I/O errors, or the block layer merged several
921 * read requests into one and the error is caused by a
922 * different bio (usually one of the two latter cases is
925 spin_lock(&sctx->stat_lock);
926 sctx->stat.unverified_errors++;
927 spin_unlock(&sctx->stat_lock);
929 if (sctx->is_dev_replace)
930 scrub_write_block_to_dev_replace(sblock_bad);
934 if (!sblock_bad->no_io_error_seen) {
935 spin_lock(&sctx->stat_lock);
936 sctx->stat.read_errors++;
937 spin_unlock(&sctx->stat_lock);
938 if (__ratelimit(&_rs))
939 scrub_print_warning("i/o error", sblock_to_check);
940 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
941 } else if (sblock_bad->checksum_error) {
942 spin_lock(&sctx->stat_lock);
943 sctx->stat.csum_errors++;
944 spin_unlock(&sctx->stat_lock);
945 if (__ratelimit(&_rs))
946 scrub_print_warning("checksum error", sblock_to_check);
947 btrfs_dev_stat_inc_and_print(dev,
948 BTRFS_DEV_STAT_CORRUPTION_ERRS);
949 } else if (sblock_bad->header_error) {
950 spin_lock(&sctx->stat_lock);
951 sctx->stat.verify_errors++;
952 spin_unlock(&sctx->stat_lock);
953 if (__ratelimit(&_rs))
954 scrub_print_warning("checksum/header error",
956 if (sblock_bad->generation_error)
957 btrfs_dev_stat_inc_and_print(dev,
958 BTRFS_DEV_STAT_GENERATION_ERRS);
960 btrfs_dev_stat_inc_and_print(dev,
961 BTRFS_DEV_STAT_CORRUPTION_ERRS);
964 if (sctx->readonly) {
965 ASSERT(!sctx->is_dev_replace);
969 if (!is_metadata && !have_csum) {
970 struct scrub_fixup_nodatasum *fixup_nodatasum;
973 WARN_ON(sctx->is_dev_replace);
976 * !is_metadata and !have_csum, this means that the data
977 * might not be COW'ed, that it might be modified
978 * concurrently. The general strategy to work on the
979 * commit root does not help in the case when COW is not
982 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
983 if (!fixup_nodatasum)
984 goto did_not_correct_error;
985 fixup_nodatasum->sctx = sctx;
986 fixup_nodatasum->dev = dev;
987 fixup_nodatasum->logical = logical;
988 fixup_nodatasum->root = fs_info->extent_root;
989 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
990 scrub_pending_trans_workers_inc(sctx);
991 fixup_nodatasum->work.func = scrub_fixup_nodatasum;
992 btrfs_queue_worker(&fs_info->scrub_workers,
993 &fixup_nodatasum->work);
998 * now build and submit the bios for the other mirrors, check
1000 * First try to pick the mirror which is completely without I/O
1001 * errors and also does not have a checksum error.
1002 * If one is found, and if a checksum is present, the full block
1003 * that is known to contain an error is rewritten. Afterwards
1004 * the block is known to be corrected.
1005 * If a mirror is found which is completely correct, and no
1006 * checksum is present, only those pages are rewritten that had
1007 * an I/O error in the block to be repaired, since it cannot be
1008 * determined, which copy of the other pages is better (and it
1009 * could happen otherwise that a correct page would be
1010 * overwritten by a bad one).
1012 for (mirror_index = 0;
1013 mirror_index < BTRFS_MAX_MIRRORS &&
1014 sblocks_for_recheck[mirror_index].page_count > 0;
1016 struct scrub_block *sblock_other;
1018 if (mirror_index == failed_mirror_index)
1020 sblock_other = sblocks_for_recheck + mirror_index;
1022 /* build and submit the bios, check checksums */
1023 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1024 have_csum, csum, generation,
1027 if (!sblock_other->header_error &&
1028 !sblock_other->checksum_error &&
1029 sblock_other->no_io_error_seen) {
1030 if (sctx->is_dev_replace) {
1031 scrub_write_block_to_dev_replace(sblock_other);
1033 int force_write = is_metadata || have_csum;
1035 ret = scrub_repair_block_from_good_copy(
1036 sblock_bad, sblock_other,
1040 goto corrected_error;
1045 * for dev_replace, pick good pages and write to the target device.
1047 if (sctx->is_dev_replace) {
1049 for (page_num = 0; page_num < sblock_bad->page_count;
1054 for (mirror_index = 0;
1055 mirror_index < BTRFS_MAX_MIRRORS &&
1056 sblocks_for_recheck[mirror_index].page_count > 0;
1058 struct scrub_block *sblock_other =
1059 sblocks_for_recheck + mirror_index;
1060 struct scrub_page *page_other =
1061 sblock_other->pagev[page_num];
1063 if (!page_other->io_error) {
1064 ret = scrub_write_page_to_dev_replace(
1065 sblock_other, page_num);
1067 /* succeeded for this page */
1071 btrfs_dev_replace_stats_inc(
1073 fs_info->dev_replace.
1081 * did not find a mirror to fetch the page
1082 * from. scrub_write_page_to_dev_replace()
1083 * handles this case (page->io_error), by
1084 * filling the block with zeros before
1085 * submitting the write request
1088 ret = scrub_write_page_to_dev_replace(
1089 sblock_bad, page_num);
1091 btrfs_dev_replace_stats_inc(
1092 &sctx->dev_root->fs_info->
1093 dev_replace.num_write_errors);
1101 * for regular scrub, repair those pages that are errored.
1102 * In case of I/O errors in the area that is supposed to be
1103 * repaired, continue by picking good copies of those pages.
1104 * Select the good pages from mirrors to rewrite bad pages from
1105 * the area to fix. Afterwards verify the checksum of the block
1106 * that is supposed to be repaired. This verification step is
1107 * only done for the purpose of statistic counting and for the
1108 * final scrub report, whether errors remain.
1109 * A perfect algorithm could make use of the checksum and try
1110 * all possible combinations of pages from the different mirrors
1111 * until the checksum verification succeeds. For example, when
1112 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1113 * of mirror #2 is readable but the final checksum test fails,
1114 * then the 2nd page of mirror #3 could be tried, whether now
1115 * the final checksum succeedes. But this would be a rare
1116 * exception and is therefore not implemented. At least it is
1117 * avoided that the good copy is overwritten.
1118 * A more useful improvement would be to pick the sectors
1119 * without I/O error based on sector sizes (512 bytes on legacy
1120 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1121 * mirror could be repaired by taking 512 byte of a different
1122 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1123 * area are unreadable.
1126 /* can only fix I/O errors from here on */
1127 if (sblock_bad->no_io_error_seen)
1128 goto did_not_correct_error;
1131 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1132 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1134 if (!page_bad->io_error)
1137 for (mirror_index = 0;
1138 mirror_index < BTRFS_MAX_MIRRORS &&
1139 sblocks_for_recheck[mirror_index].page_count > 0;
1141 struct scrub_block *sblock_other = sblocks_for_recheck +
1143 struct scrub_page *page_other = sblock_other->pagev[
1146 if (!page_other->io_error) {
1147 ret = scrub_repair_page_from_good_copy(
1148 sblock_bad, sblock_other, page_num, 0);
1150 page_bad->io_error = 0;
1151 break; /* succeeded for this page */
1156 if (page_bad->io_error) {
1157 /* did not find a mirror to copy the page from */
1163 if (is_metadata || have_csum) {
1165 * need to verify the checksum now that all
1166 * sectors on disk are repaired (the write
1167 * request for data to be repaired is on its way).
1168 * Just be lazy and use scrub_recheck_block()
1169 * which re-reads the data before the checksum
1170 * is verified, but most likely the data comes out
1171 * of the page cache.
1173 scrub_recheck_block(fs_info, sblock_bad,
1174 is_metadata, have_csum, csum,
1175 generation, sctx->csum_size);
1176 if (!sblock_bad->header_error &&
1177 !sblock_bad->checksum_error &&
1178 sblock_bad->no_io_error_seen)
1179 goto corrected_error;
1181 goto did_not_correct_error;
1184 spin_lock(&sctx->stat_lock);
1185 sctx->stat.corrected_errors++;
1186 spin_unlock(&sctx->stat_lock);
1187 printk_ratelimited_in_rcu(KERN_ERR
1188 "BTRFS: fixed up error at logical %llu on dev %s\n",
1189 logical, rcu_str_deref(dev->name));
1192 did_not_correct_error:
1193 spin_lock(&sctx->stat_lock);
1194 sctx->stat.uncorrectable_errors++;
1195 spin_unlock(&sctx->stat_lock);
1196 printk_ratelimited_in_rcu(KERN_ERR
1197 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
1198 logical, rcu_str_deref(dev->name));
1202 if (sblocks_for_recheck) {
1203 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1205 struct scrub_block *sblock = sblocks_for_recheck +
1209 for (page_index = 0; page_index < sblock->page_count;
1211 sblock->pagev[page_index]->sblock = NULL;
1212 scrub_page_put(sblock->pagev[page_index]);
1215 kfree(sblocks_for_recheck);
1221 static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
1222 struct btrfs_fs_info *fs_info,
1223 struct scrub_block *original_sblock,
1224 u64 length, u64 logical,
1225 struct scrub_block *sblocks_for_recheck)
1232 * note: the two members ref_count and outstanding_pages
1233 * are not used (and not set) in the blocks that are used for
1234 * the recheck procedure
1238 while (length > 0) {
1239 u64 sublen = min_t(u64, length, PAGE_SIZE);
1240 u64 mapped_length = sublen;
1241 struct btrfs_bio *bbio = NULL;
1244 * with a length of PAGE_SIZE, each returned stripe
1245 * represents one mirror
1247 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
1248 &mapped_length, &bbio, 0);
1249 if (ret || !bbio || mapped_length < sublen) {
1254 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
1255 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1257 struct scrub_block *sblock;
1258 struct scrub_page *page;
1260 if (mirror_index >= BTRFS_MAX_MIRRORS)
1263 sblock = sblocks_for_recheck + mirror_index;
1264 sblock->sctx = sctx;
1265 page = kzalloc(sizeof(*page), GFP_NOFS);
1268 spin_lock(&sctx->stat_lock);
1269 sctx->stat.malloc_errors++;
1270 spin_unlock(&sctx->stat_lock);
1274 scrub_page_get(page);
1275 sblock->pagev[page_index] = page;
1276 page->logical = logical;
1277 page->physical = bbio->stripes[mirror_index].physical;
1278 BUG_ON(page_index >= original_sblock->page_count);
1279 page->physical_for_dev_replace =
1280 original_sblock->pagev[page_index]->
1281 physical_for_dev_replace;
1282 /* for missing devices, dev->bdev is NULL */
1283 page->dev = bbio->stripes[mirror_index].dev;
1284 page->mirror_num = mirror_index + 1;
1285 sblock->page_count++;
1286 page->page = alloc_page(GFP_NOFS);
1300 * this function will check the on disk data for checksum errors, header
1301 * errors and read I/O errors. If any I/O errors happen, the exact pages
1302 * which are errored are marked as being bad. The goal is to enable scrub
1303 * to take those pages that are not errored from all the mirrors so that
1304 * the pages that are errored in the just handled mirror can be repaired.
1306 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1307 struct scrub_block *sblock, int is_metadata,
1308 int have_csum, u8 *csum, u64 generation,
1313 sblock->no_io_error_seen = 1;
1314 sblock->header_error = 0;
1315 sblock->checksum_error = 0;
1317 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1319 struct scrub_page *page = sblock->pagev[page_num];
1321 if (page->dev->bdev == NULL) {
1323 sblock->no_io_error_seen = 0;
1327 WARN_ON(!page->page);
1328 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1331 sblock->no_io_error_seen = 0;
1334 bio->bi_bdev = page->dev->bdev;
1335 bio->bi_iter.bi_sector = page->physical >> 9;
1337 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1338 if (btrfsic_submit_bio_wait(READ, bio))
1339 sblock->no_io_error_seen = 0;
1344 if (sblock->no_io_error_seen)
1345 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1346 have_csum, csum, generation,
1352 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1353 struct scrub_block *sblock,
1354 int is_metadata, int have_csum,
1355 const u8 *csum, u64 generation,
1359 u8 calculated_csum[BTRFS_CSUM_SIZE];
1361 void *mapped_buffer;
1363 WARN_ON(!sblock->pagev[0]->page);
1365 struct btrfs_header *h;
1367 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1368 h = (struct btrfs_header *)mapped_buffer;
1370 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
1371 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1372 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1374 sblock->header_error = 1;
1375 } else if (generation != btrfs_stack_header_generation(h)) {
1376 sblock->header_error = 1;
1377 sblock->generation_error = 1;
1384 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1387 for (page_num = 0;;) {
1388 if (page_num == 0 && is_metadata)
1389 crc = btrfs_csum_data(
1390 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1391 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1393 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
1395 kunmap_atomic(mapped_buffer);
1397 if (page_num >= sblock->page_count)
1399 WARN_ON(!sblock->pagev[page_num]->page);
1401 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
1404 btrfs_csum_final(crc, calculated_csum);
1405 if (memcmp(calculated_csum, csum, csum_size))
1406 sblock->checksum_error = 1;
1409 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1410 struct scrub_block *sblock_good,
1416 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1419 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1430 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1431 struct scrub_block *sblock_good,
1432 int page_num, int force_write)
1434 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1435 struct scrub_page *page_good = sblock_good->pagev[page_num];
1437 BUG_ON(page_bad->page == NULL);
1438 BUG_ON(page_good->page == NULL);
1439 if (force_write || sblock_bad->header_error ||
1440 sblock_bad->checksum_error || page_bad->io_error) {
1444 if (!page_bad->dev->bdev) {
1445 printk_ratelimited(KERN_WARNING "BTRFS: "
1446 "scrub_repair_page_from_good_copy(bdev == NULL) "
1447 "is unexpected!\n");
1451 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1454 bio->bi_bdev = page_bad->dev->bdev;
1455 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1457 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1458 if (PAGE_SIZE != ret) {
1463 if (btrfsic_submit_bio_wait(WRITE, bio)) {
1464 btrfs_dev_stat_inc_and_print(page_bad->dev,
1465 BTRFS_DEV_STAT_WRITE_ERRS);
1466 btrfs_dev_replace_stats_inc(
1467 &sblock_bad->sctx->dev_root->fs_info->
1468 dev_replace.num_write_errors);
1478 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1482 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1485 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1487 btrfs_dev_replace_stats_inc(
1488 &sblock->sctx->dev_root->fs_info->dev_replace.
1493 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1496 struct scrub_page *spage = sblock->pagev[page_num];
1498 BUG_ON(spage->page == NULL);
1499 if (spage->io_error) {
1500 void *mapped_buffer = kmap_atomic(spage->page);
1502 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1503 flush_dcache_page(spage->page);
1504 kunmap_atomic(mapped_buffer);
1506 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1509 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1510 struct scrub_page *spage)
1512 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1513 struct scrub_bio *sbio;
1516 mutex_lock(&wr_ctx->wr_lock);
1518 if (!wr_ctx->wr_curr_bio) {
1519 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1521 if (!wr_ctx->wr_curr_bio) {
1522 mutex_unlock(&wr_ctx->wr_lock);
1525 wr_ctx->wr_curr_bio->sctx = sctx;
1526 wr_ctx->wr_curr_bio->page_count = 0;
1528 sbio = wr_ctx->wr_curr_bio;
1529 if (sbio->page_count == 0) {
1532 sbio->physical = spage->physical_for_dev_replace;
1533 sbio->logical = spage->logical;
1534 sbio->dev = wr_ctx->tgtdev;
1537 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
1539 mutex_unlock(&wr_ctx->wr_lock);
1545 bio->bi_private = sbio;
1546 bio->bi_end_io = scrub_wr_bio_end_io;
1547 bio->bi_bdev = sbio->dev->bdev;
1548 bio->bi_iter.bi_sector = sbio->physical >> 9;
1550 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1551 spage->physical_for_dev_replace ||
1552 sbio->logical + sbio->page_count * PAGE_SIZE !=
1554 scrub_wr_submit(sctx);
1558 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1559 if (ret != PAGE_SIZE) {
1560 if (sbio->page_count < 1) {
1563 mutex_unlock(&wr_ctx->wr_lock);
1566 scrub_wr_submit(sctx);
1570 sbio->pagev[sbio->page_count] = spage;
1571 scrub_page_get(spage);
1573 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1574 scrub_wr_submit(sctx);
1575 mutex_unlock(&wr_ctx->wr_lock);
1580 static void scrub_wr_submit(struct scrub_ctx *sctx)
1582 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1583 struct scrub_bio *sbio;
1585 if (!wr_ctx->wr_curr_bio)
1588 sbio = wr_ctx->wr_curr_bio;
1589 wr_ctx->wr_curr_bio = NULL;
1590 WARN_ON(!sbio->bio->bi_bdev);
1591 scrub_pending_bio_inc(sctx);
1592 /* process all writes in a single worker thread. Then the block layer
1593 * orders the requests before sending them to the driver which
1594 * doubled the write performance on spinning disks when measured
1596 btrfsic_submit_bio(WRITE, sbio->bio);
1599 static void scrub_wr_bio_end_io(struct bio *bio, int err)
1601 struct scrub_bio *sbio = bio->bi_private;
1602 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1607 sbio->work.func = scrub_wr_bio_end_io_worker;
1608 btrfs_queue_worker(&fs_info->scrub_wr_completion_workers, &sbio->work);
1611 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1613 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1614 struct scrub_ctx *sctx = sbio->sctx;
1617 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1619 struct btrfs_dev_replace *dev_replace =
1620 &sbio->sctx->dev_root->fs_info->dev_replace;
1622 for (i = 0; i < sbio->page_count; i++) {
1623 struct scrub_page *spage = sbio->pagev[i];
1625 spage->io_error = 1;
1626 btrfs_dev_replace_stats_inc(&dev_replace->
1631 for (i = 0; i < sbio->page_count; i++)
1632 scrub_page_put(sbio->pagev[i]);
1636 scrub_pending_bio_dec(sctx);
1639 static int scrub_checksum(struct scrub_block *sblock)
1644 WARN_ON(sblock->page_count < 1);
1645 flags = sblock->pagev[0]->flags;
1647 if (flags & BTRFS_EXTENT_FLAG_DATA)
1648 ret = scrub_checksum_data(sblock);
1649 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1650 ret = scrub_checksum_tree_block(sblock);
1651 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1652 (void)scrub_checksum_super(sblock);
1656 scrub_handle_errored_block(sblock);
1661 static int scrub_checksum_data(struct scrub_block *sblock)
1663 struct scrub_ctx *sctx = sblock->sctx;
1664 u8 csum[BTRFS_CSUM_SIZE];
1673 BUG_ON(sblock->page_count < 1);
1674 if (!sblock->pagev[0]->have_csum)
1677 on_disk_csum = sblock->pagev[0]->csum;
1678 page = sblock->pagev[0]->page;
1679 buffer = kmap_atomic(page);
1681 len = sctx->sectorsize;
1684 u64 l = min_t(u64, len, PAGE_SIZE);
1686 crc = btrfs_csum_data(buffer, crc, l);
1687 kunmap_atomic(buffer);
1692 BUG_ON(index >= sblock->page_count);
1693 BUG_ON(!sblock->pagev[index]->page);
1694 page = sblock->pagev[index]->page;
1695 buffer = kmap_atomic(page);
1698 btrfs_csum_final(crc, csum);
1699 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1705 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1707 struct scrub_ctx *sctx = sblock->sctx;
1708 struct btrfs_header *h;
1709 struct btrfs_root *root = sctx->dev_root;
1710 struct btrfs_fs_info *fs_info = root->fs_info;
1711 u8 calculated_csum[BTRFS_CSUM_SIZE];
1712 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1714 void *mapped_buffer;
1723 BUG_ON(sblock->page_count < 1);
1724 page = sblock->pagev[0]->page;
1725 mapped_buffer = kmap_atomic(page);
1726 h = (struct btrfs_header *)mapped_buffer;
1727 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1730 * we don't use the getter functions here, as we
1731 * a) don't have an extent buffer and
1732 * b) the page is already kmapped
1735 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1738 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
1741 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1744 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1748 WARN_ON(sctx->nodesize != sctx->leafsize);
1749 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1750 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1751 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1754 u64 l = min_t(u64, len, mapped_size);
1756 crc = btrfs_csum_data(p, crc, l);
1757 kunmap_atomic(mapped_buffer);
1762 BUG_ON(index >= sblock->page_count);
1763 BUG_ON(!sblock->pagev[index]->page);
1764 page = sblock->pagev[index]->page;
1765 mapped_buffer = kmap_atomic(page);
1766 mapped_size = PAGE_SIZE;
1770 btrfs_csum_final(crc, calculated_csum);
1771 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1774 return fail || crc_fail;
1777 static int scrub_checksum_super(struct scrub_block *sblock)
1779 struct btrfs_super_block *s;
1780 struct scrub_ctx *sctx = sblock->sctx;
1781 struct btrfs_root *root = sctx->dev_root;
1782 struct btrfs_fs_info *fs_info = root->fs_info;
1783 u8 calculated_csum[BTRFS_CSUM_SIZE];
1784 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1786 void *mapped_buffer;
1795 BUG_ON(sblock->page_count < 1);
1796 page = sblock->pagev[0]->page;
1797 mapped_buffer = kmap_atomic(page);
1798 s = (struct btrfs_super_block *)mapped_buffer;
1799 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1801 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1804 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1807 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1810 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1811 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1812 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1815 u64 l = min_t(u64, len, mapped_size);
1817 crc = btrfs_csum_data(p, crc, l);
1818 kunmap_atomic(mapped_buffer);
1823 BUG_ON(index >= sblock->page_count);
1824 BUG_ON(!sblock->pagev[index]->page);
1825 page = sblock->pagev[index]->page;
1826 mapped_buffer = kmap_atomic(page);
1827 mapped_size = PAGE_SIZE;
1831 btrfs_csum_final(crc, calculated_csum);
1832 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1835 if (fail_cor + fail_gen) {
1837 * if we find an error in a super block, we just report it.
1838 * They will get written with the next transaction commit
1841 spin_lock(&sctx->stat_lock);
1842 ++sctx->stat.super_errors;
1843 spin_unlock(&sctx->stat_lock);
1845 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1846 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1848 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1849 BTRFS_DEV_STAT_GENERATION_ERRS);
1852 return fail_cor + fail_gen;
1855 static void scrub_block_get(struct scrub_block *sblock)
1857 atomic_inc(&sblock->ref_count);
1860 static void scrub_block_put(struct scrub_block *sblock)
1862 if (atomic_dec_and_test(&sblock->ref_count)) {
1865 for (i = 0; i < sblock->page_count; i++)
1866 scrub_page_put(sblock->pagev[i]);
1871 static void scrub_page_get(struct scrub_page *spage)
1873 atomic_inc(&spage->ref_count);
1876 static void scrub_page_put(struct scrub_page *spage)
1878 if (atomic_dec_and_test(&spage->ref_count)) {
1880 __free_page(spage->page);
1885 static void scrub_submit(struct scrub_ctx *sctx)
1887 struct scrub_bio *sbio;
1889 if (sctx->curr == -1)
1892 sbio = sctx->bios[sctx->curr];
1894 scrub_pending_bio_inc(sctx);
1896 if (!sbio->bio->bi_bdev) {
1898 * this case should not happen. If btrfs_map_block() is
1899 * wrong, it could happen for dev-replace operations on
1900 * missing devices when no mirrors are available, but in
1901 * this case it should already fail the mount.
1902 * This case is handled correctly (but _very_ slowly).
1904 printk_ratelimited(KERN_WARNING
1905 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
1906 bio_endio(sbio->bio, -EIO);
1908 btrfsic_submit_bio(READ, sbio->bio);
1912 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
1913 struct scrub_page *spage)
1915 struct scrub_block *sblock = spage->sblock;
1916 struct scrub_bio *sbio;
1921 * grab a fresh bio or wait for one to become available
1923 while (sctx->curr == -1) {
1924 spin_lock(&sctx->list_lock);
1925 sctx->curr = sctx->first_free;
1926 if (sctx->curr != -1) {
1927 sctx->first_free = sctx->bios[sctx->curr]->next_free;
1928 sctx->bios[sctx->curr]->next_free = -1;
1929 sctx->bios[sctx->curr]->page_count = 0;
1930 spin_unlock(&sctx->list_lock);
1932 spin_unlock(&sctx->list_lock);
1933 wait_event(sctx->list_wait, sctx->first_free != -1);
1936 sbio = sctx->bios[sctx->curr];
1937 if (sbio->page_count == 0) {
1940 sbio->physical = spage->physical;
1941 sbio->logical = spage->logical;
1942 sbio->dev = spage->dev;
1945 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
1951 bio->bi_private = sbio;
1952 bio->bi_end_io = scrub_bio_end_io;
1953 bio->bi_bdev = sbio->dev->bdev;
1954 bio->bi_iter.bi_sector = sbio->physical >> 9;
1956 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1958 sbio->logical + sbio->page_count * PAGE_SIZE !=
1960 sbio->dev != spage->dev) {
1965 sbio->pagev[sbio->page_count] = spage;
1966 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1967 if (ret != PAGE_SIZE) {
1968 if (sbio->page_count < 1) {
1977 scrub_block_get(sblock); /* one for the page added to the bio */
1978 atomic_inc(&sblock->outstanding_pages);
1980 if (sbio->page_count == sctx->pages_per_rd_bio)
1986 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
1987 u64 physical, struct btrfs_device *dev, u64 flags,
1988 u64 gen, int mirror_num, u8 *csum, int force,
1989 u64 physical_for_dev_replace)
1991 struct scrub_block *sblock;
1994 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
1996 spin_lock(&sctx->stat_lock);
1997 sctx->stat.malloc_errors++;
1998 spin_unlock(&sctx->stat_lock);
2002 /* one ref inside this function, plus one for each page added to
2004 atomic_set(&sblock->ref_count, 1);
2005 sblock->sctx = sctx;
2006 sblock->no_io_error_seen = 1;
2008 for (index = 0; len > 0; index++) {
2009 struct scrub_page *spage;
2010 u64 l = min_t(u64, len, PAGE_SIZE);
2012 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2015 spin_lock(&sctx->stat_lock);
2016 sctx->stat.malloc_errors++;
2017 spin_unlock(&sctx->stat_lock);
2018 scrub_block_put(sblock);
2021 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2022 scrub_page_get(spage);
2023 sblock->pagev[index] = spage;
2024 spage->sblock = sblock;
2026 spage->flags = flags;
2027 spage->generation = gen;
2028 spage->logical = logical;
2029 spage->physical = physical;
2030 spage->physical_for_dev_replace = physical_for_dev_replace;
2031 spage->mirror_num = mirror_num;
2033 spage->have_csum = 1;
2034 memcpy(spage->csum, csum, sctx->csum_size);
2036 spage->have_csum = 0;
2038 sblock->page_count++;
2039 spage->page = alloc_page(GFP_NOFS);
2045 physical_for_dev_replace += l;
2048 WARN_ON(sblock->page_count == 0);
2049 for (index = 0; index < sblock->page_count; index++) {
2050 struct scrub_page *spage = sblock->pagev[index];
2053 ret = scrub_add_page_to_rd_bio(sctx, spage);
2055 scrub_block_put(sblock);
2063 /* last one frees, either here or in bio completion for last page */
2064 scrub_block_put(sblock);
2068 static void scrub_bio_end_io(struct bio *bio, int err)
2070 struct scrub_bio *sbio = bio->bi_private;
2071 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
2076 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
2079 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2081 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2082 struct scrub_ctx *sctx = sbio->sctx;
2085 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2087 for (i = 0; i < sbio->page_count; i++) {
2088 struct scrub_page *spage = sbio->pagev[i];
2090 spage->io_error = 1;
2091 spage->sblock->no_io_error_seen = 0;
2095 /* now complete the scrub_block items that have all pages completed */
2096 for (i = 0; i < sbio->page_count; i++) {
2097 struct scrub_page *spage = sbio->pagev[i];
2098 struct scrub_block *sblock = spage->sblock;
2100 if (atomic_dec_and_test(&sblock->outstanding_pages))
2101 scrub_block_complete(sblock);
2102 scrub_block_put(sblock);
2107 spin_lock(&sctx->list_lock);
2108 sbio->next_free = sctx->first_free;
2109 sctx->first_free = sbio->index;
2110 spin_unlock(&sctx->list_lock);
2112 if (sctx->is_dev_replace &&
2113 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2114 mutex_lock(&sctx->wr_ctx.wr_lock);
2115 scrub_wr_submit(sctx);
2116 mutex_unlock(&sctx->wr_ctx.wr_lock);
2119 scrub_pending_bio_dec(sctx);
2122 static void scrub_block_complete(struct scrub_block *sblock)
2124 if (!sblock->no_io_error_seen) {
2125 scrub_handle_errored_block(sblock);
2128 * if has checksum error, write via repair mechanism in
2129 * dev replace case, otherwise write here in dev replace
2132 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
2133 scrub_write_block_to_dev_replace(sblock);
2137 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
2140 struct btrfs_ordered_sum *sum = NULL;
2141 unsigned long index;
2142 unsigned long num_sectors;
2144 while (!list_empty(&sctx->csum_list)) {
2145 sum = list_first_entry(&sctx->csum_list,
2146 struct btrfs_ordered_sum, list);
2147 if (sum->bytenr > logical)
2149 if (sum->bytenr + sum->len > logical)
2152 ++sctx->stat.csum_discards;
2153 list_del(&sum->list);
2160 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2161 num_sectors = sum->len / sctx->sectorsize;
2162 memcpy(csum, sum->sums + index, sctx->csum_size);
2163 if (index == num_sectors - 1) {
2164 list_del(&sum->list);
2170 /* scrub extent tries to collect up to 64 kB for each bio */
2171 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2172 u64 physical, struct btrfs_device *dev, u64 flags,
2173 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2176 u8 csum[BTRFS_CSUM_SIZE];
2179 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2180 blocksize = sctx->sectorsize;
2181 spin_lock(&sctx->stat_lock);
2182 sctx->stat.data_extents_scrubbed++;
2183 sctx->stat.data_bytes_scrubbed += len;
2184 spin_unlock(&sctx->stat_lock);
2185 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2186 WARN_ON(sctx->nodesize != sctx->leafsize);
2187 blocksize = sctx->nodesize;
2188 spin_lock(&sctx->stat_lock);
2189 sctx->stat.tree_extents_scrubbed++;
2190 sctx->stat.tree_bytes_scrubbed += len;
2191 spin_unlock(&sctx->stat_lock);
2193 blocksize = sctx->sectorsize;
2198 u64 l = min_t(u64, len, blocksize);
2201 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2202 /* push csums to sbio */
2203 have_csum = scrub_find_csum(sctx, logical, l, csum);
2205 ++sctx->stat.no_csum;
2206 if (sctx->is_dev_replace && !have_csum) {
2207 ret = copy_nocow_pages(sctx, logical, l,
2209 physical_for_dev_replace);
2210 goto behind_scrub_pages;
2213 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2214 mirror_num, have_csum ? csum : NULL, 0,
2215 physical_for_dev_replace);
2222 physical_for_dev_replace += l;
2227 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
2228 struct map_lookup *map,
2229 struct btrfs_device *scrub_dev,
2230 int num, u64 base, u64 length,
2233 struct btrfs_path *path;
2234 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2235 struct btrfs_root *root = fs_info->extent_root;
2236 struct btrfs_root *csum_root = fs_info->csum_root;
2237 struct btrfs_extent_item *extent;
2238 struct blk_plug plug;
2243 struct extent_buffer *l;
2244 struct btrfs_key key;
2250 struct reada_control *reada1;
2251 struct reada_control *reada2;
2252 struct btrfs_key key_start;
2253 struct btrfs_key key_end;
2254 u64 increment = map->stripe_len;
2257 u64 extent_physical;
2259 struct btrfs_device *extent_dev;
2260 int extent_mirror_num;
2263 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2264 BTRFS_BLOCK_GROUP_RAID6)) {
2265 if (num >= nr_data_stripes(map)) {
2272 do_div(nstripes, map->stripe_len);
2273 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2274 offset = map->stripe_len * num;
2275 increment = map->stripe_len * map->num_stripes;
2277 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2278 int factor = map->num_stripes / map->sub_stripes;
2279 offset = map->stripe_len * (num / map->sub_stripes);
2280 increment = map->stripe_len * factor;
2281 mirror_num = num % map->sub_stripes + 1;
2282 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2283 increment = map->stripe_len;
2284 mirror_num = num % map->num_stripes + 1;
2285 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2286 increment = map->stripe_len;
2287 mirror_num = num % map->num_stripes + 1;
2289 increment = map->stripe_len;
2293 path = btrfs_alloc_path();
2298 * work on commit root. The related disk blocks are static as
2299 * long as COW is applied. This means, it is save to rewrite
2300 * them to repair disk errors without any race conditions
2302 path->search_commit_root = 1;
2303 path->skip_locking = 1;
2306 * trigger the readahead for extent tree csum tree and wait for
2307 * completion. During readahead, the scrub is officially paused
2308 * to not hold off transaction commits
2310 logical = base + offset;
2312 wait_event(sctx->list_wait,
2313 atomic_read(&sctx->bios_in_flight) == 0);
2314 scrub_blocked_if_needed(fs_info);
2316 /* FIXME it might be better to start readahead at commit root */
2317 key_start.objectid = logical;
2318 key_start.type = BTRFS_EXTENT_ITEM_KEY;
2319 key_start.offset = (u64)0;
2320 key_end.objectid = base + offset + nstripes * increment;
2321 key_end.type = BTRFS_METADATA_ITEM_KEY;
2322 key_end.offset = (u64)-1;
2323 reada1 = btrfs_reada_add(root, &key_start, &key_end);
2325 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2326 key_start.type = BTRFS_EXTENT_CSUM_KEY;
2327 key_start.offset = logical;
2328 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2329 key_end.type = BTRFS_EXTENT_CSUM_KEY;
2330 key_end.offset = base + offset + nstripes * increment;
2331 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
2333 if (!IS_ERR(reada1))
2334 btrfs_reada_wait(reada1);
2335 if (!IS_ERR(reada2))
2336 btrfs_reada_wait(reada2);
2340 * collect all data csums for the stripe to avoid seeking during
2341 * the scrub. This might currently (crc32) end up to be about 1MB
2343 blk_start_plug(&plug);
2346 * now find all extents for each stripe and scrub them
2348 logical = base + offset;
2349 physical = map->stripes[num].physical;
2350 logic_end = logical + increment * nstripes;
2352 while (logical < logic_end) {
2356 if (atomic_read(&fs_info->scrub_cancel_req) ||
2357 atomic_read(&sctx->cancel_req)) {
2362 * check to see if we have to pause
2364 if (atomic_read(&fs_info->scrub_pause_req)) {
2365 /* push queued extents */
2366 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2368 mutex_lock(&sctx->wr_ctx.wr_lock);
2369 scrub_wr_submit(sctx);
2370 mutex_unlock(&sctx->wr_ctx.wr_lock);
2371 wait_event(sctx->list_wait,
2372 atomic_read(&sctx->bios_in_flight) == 0);
2373 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2374 scrub_blocked_if_needed(fs_info);
2377 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2378 key.type = BTRFS_METADATA_ITEM_KEY;
2380 key.type = BTRFS_EXTENT_ITEM_KEY;
2381 key.objectid = logical;
2382 key.offset = (u64)-1;
2384 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2389 ret = btrfs_previous_extent_item(root, path, 0);
2393 /* there's no smaller item, so stick with the
2395 btrfs_release_path(path);
2396 ret = btrfs_search_slot(NULL, root, &key,
2408 slot = path->slots[0];
2409 if (slot >= btrfs_header_nritems(l)) {
2410 ret = btrfs_next_leaf(root, path);
2419 btrfs_item_key_to_cpu(l, &key, slot);
2421 if (key.type == BTRFS_METADATA_ITEM_KEY)
2422 bytes = root->leafsize;
2426 if (key.objectid + bytes <= logical)
2429 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2430 key.type != BTRFS_METADATA_ITEM_KEY)
2433 if (key.objectid >= logical + map->stripe_len) {
2434 /* out of this device extent */
2435 if (key.objectid >= logic_end)
2440 extent = btrfs_item_ptr(l, slot,
2441 struct btrfs_extent_item);
2442 flags = btrfs_extent_flags(l, extent);
2443 generation = btrfs_extent_generation(l, extent);
2445 if (key.objectid < logical &&
2446 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
2448 "scrub: tree block %llu spanning "
2449 "stripes, ignored. logical=%llu",
2450 key.objectid, logical);
2455 extent_logical = key.objectid;
2459 * trim extent to this stripe
2461 if (extent_logical < logical) {
2462 extent_len -= logical - extent_logical;
2463 extent_logical = logical;
2465 if (extent_logical + extent_len >
2466 logical + map->stripe_len) {
2467 extent_len = logical + map->stripe_len -
2471 extent_physical = extent_logical - logical + physical;
2472 extent_dev = scrub_dev;
2473 extent_mirror_num = mirror_num;
2475 scrub_remap_extent(fs_info, extent_logical,
2476 extent_len, &extent_physical,
2478 &extent_mirror_num);
2480 ret = btrfs_lookup_csums_range(csum_root, logical,
2481 logical + map->stripe_len - 1,
2482 &sctx->csum_list, 1);
2486 ret = scrub_extent(sctx, extent_logical, extent_len,
2487 extent_physical, extent_dev, flags,
2488 generation, extent_mirror_num,
2489 extent_logical - logical + physical);
2493 scrub_free_csums(sctx);
2494 if (extent_logical + extent_len <
2495 key.objectid + bytes) {
2496 logical += increment;
2497 physical += map->stripe_len;
2499 if (logical < key.objectid + bytes) {
2504 if (logical >= logic_end) {
2512 btrfs_release_path(path);
2513 logical += increment;
2514 physical += map->stripe_len;
2515 spin_lock(&sctx->stat_lock);
2517 sctx->stat.last_physical = map->stripes[num].physical +
2520 sctx->stat.last_physical = physical;
2521 spin_unlock(&sctx->stat_lock);
2526 /* push queued extents */
2528 mutex_lock(&sctx->wr_ctx.wr_lock);
2529 scrub_wr_submit(sctx);
2530 mutex_unlock(&sctx->wr_ctx.wr_lock);
2532 blk_finish_plug(&plug);
2533 btrfs_free_path(path);
2534 return ret < 0 ? ret : 0;
2537 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
2538 struct btrfs_device *scrub_dev,
2539 u64 chunk_tree, u64 chunk_objectid,
2540 u64 chunk_offset, u64 length,
2541 u64 dev_offset, int is_dev_replace)
2543 struct btrfs_mapping_tree *map_tree =
2544 &sctx->dev_root->fs_info->mapping_tree;
2545 struct map_lookup *map;
2546 struct extent_map *em;
2550 read_lock(&map_tree->map_tree.lock);
2551 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2552 read_unlock(&map_tree->map_tree.lock);
2557 map = (struct map_lookup *)em->bdev;
2558 if (em->start != chunk_offset)
2561 if (em->len < length)
2564 for (i = 0; i < map->num_stripes; ++i) {
2565 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
2566 map->stripes[i].physical == dev_offset) {
2567 ret = scrub_stripe(sctx, map, scrub_dev, i,
2568 chunk_offset, length,
2575 free_extent_map(em);
2580 static noinline_for_stack
2581 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
2582 struct btrfs_device *scrub_dev, u64 start, u64 end,
2585 struct btrfs_dev_extent *dev_extent = NULL;
2586 struct btrfs_path *path;
2587 struct btrfs_root *root = sctx->dev_root;
2588 struct btrfs_fs_info *fs_info = root->fs_info;
2595 struct extent_buffer *l;
2596 struct btrfs_key key;
2597 struct btrfs_key found_key;
2598 struct btrfs_block_group_cache *cache;
2599 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
2601 path = btrfs_alloc_path();
2606 path->search_commit_root = 1;
2607 path->skip_locking = 1;
2609 key.objectid = scrub_dev->devid;
2611 key.type = BTRFS_DEV_EXTENT_KEY;
2614 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2618 if (path->slots[0] >=
2619 btrfs_header_nritems(path->nodes[0])) {
2620 ret = btrfs_next_leaf(root, path);
2627 slot = path->slots[0];
2629 btrfs_item_key_to_cpu(l, &found_key, slot);
2631 if (found_key.objectid != scrub_dev->devid)
2634 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
2637 if (found_key.offset >= end)
2640 if (found_key.offset < key.offset)
2643 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2644 length = btrfs_dev_extent_length(l, dev_extent);
2646 if (found_key.offset + length <= start) {
2647 key.offset = found_key.offset + length;
2648 btrfs_release_path(path);
2652 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2653 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2654 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2657 * get a reference on the corresponding block group to prevent
2658 * the chunk from going away while we scrub it
2660 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2665 dev_replace->cursor_right = found_key.offset + length;
2666 dev_replace->cursor_left = found_key.offset;
2667 dev_replace->item_needs_writeback = 1;
2668 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
2669 chunk_offset, length, found_key.offset,
2673 * flush, submit all pending read and write bios, afterwards
2675 * Note that in the dev replace case, a read request causes
2676 * write requests that are submitted in the read completion
2677 * worker. Therefore in the current situation, it is required
2678 * that all write requests are flushed, so that all read and
2679 * write requests are really completed when bios_in_flight
2682 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2684 mutex_lock(&sctx->wr_ctx.wr_lock);
2685 scrub_wr_submit(sctx);
2686 mutex_unlock(&sctx->wr_ctx.wr_lock);
2688 wait_event(sctx->list_wait,
2689 atomic_read(&sctx->bios_in_flight) == 0);
2690 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2691 wait_event(sctx->list_wait,
2692 atomic_read(&sctx->workers_pending) == 0);
2693 scrub_blocked_if_needed(fs_info);
2695 btrfs_put_block_group(cache);
2698 if (is_dev_replace &&
2699 atomic64_read(&dev_replace->num_write_errors) > 0) {
2703 if (sctx->stat.malloc_errors > 0) {
2708 dev_replace->cursor_left = dev_replace->cursor_right;
2709 dev_replace->item_needs_writeback = 1;
2711 key.offset = found_key.offset + length;
2712 btrfs_release_path(path);
2715 btrfs_free_path(path);
2718 * ret can still be 1 from search_slot or next_leaf,
2719 * that's not an error
2721 return ret < 0 ? ret : 0;
2724 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2725 struct btrfs_device *scrub_dev)
2731 struct btrfs_root *root = sctx->dev_root;
2733 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
2736 gen = root->fs_info->last_trans_committed;
2738 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2739 bytenr = btrfs_sb_offset(i);
2740 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
2743 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
2744 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
2749 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
2755 * get a reference count on fs_info->scrub_workers. start worker if necessary
2757 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
2762 if (fs_info->scrub_workers_refcnt == 0) {
2764 btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1,
2765 &fs_info->generic_worker);
2767 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
2768 fs_info->thread_pool_size,
2769 &fs_info->generic_worker);
2770 fs_info->scrub_workers.idle_thresh = 4;
2771 ret = btrfs_start_workers(&fs_info->scrub_workers);
2774 btrfs_init_workers(&fs_info->scrub_wr_completion_workers,
2776 fs_info->thread_pool_size,
2777 &fs_info->generic_worker);
2778 fs_info->scrub_wr_completion_workers.idle_thresh = 2;
2779 ret = btrfs_start_workers(
2780 &fs_info->scrub_wr_completion_workers);
2783 btrfs_init_workers(&fs_info->scrub_nocow_workers, "scrubnc", 1,
2784 &fs_info->generic_worker);
2785 ret = btrfs_start_workers(&fs_info->scrub_nocow_workers);
2789 ++fs_info->scrub_workers_refcnt;
2794 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
2796 if (--fs_info->scrub_workers_refcnt == 0) {
2797 btrfs_stop_workers(&fs_info->scrub_workers);
2798 btrfs_stop_workers(&fs_info->scrub_wr_completion_workers);
2799 btrfs_stop_workers(&fs_info->scrub_nocow_workers);
2801 WARN_ON(fs_info->scrub_workers_refcnt < 0);
2804 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2805 u64 end, struct btrfs_scrub_progress *progress,
2806 int readonly, int is_dev_replace)
2808 struct scrub_ctx *sctx;
2810 struct btrfs_device *dev;
2812 if (btrfs_fs_closing(fs_info))
2816 * check some assumptions
2818 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
2820 "scrub: size assumption nodesize == leafsize (%d == %d) fails",
2821 fs_info->chunk_root->nodesize,
2822 fs_info->chunk_root->leafsize);
2826 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
2828 * in this case scrub is unable to calculate the checksum
2829 * the way scrub is implemented. Do not handle this
2830 * situation at all because it won't ever happen.
2833 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
2834 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
2838 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
2839 /* not supported for data w/o checksums */
2841 "scrub: size assumption sectorsize != PAGE_SIZE "
2842 "(%d != %lu) fails",
2843 fs_info->chunk_root->sectorsize, PAGE_SIZE);
2847 if (fs_info->chunk_root->nodesize >
2848 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
2849 fs_info->chunk_root->sectorsize >
2850 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
2852 * would exhaust the array bounds of pagev member in
2853 * struct scrub_block
2855 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
2856 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
2857 fs_info->chunk_root->nodesize,
2858 SCRUB_MAX_PAGES_PER_BLOCK,
2859 fs_info->chunk_root->sectorsize,
2860 SCRUB_MAX_PAGES_PER_BLOCK);
2865 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2866 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
2867 if (!dev || (dev->missing && !is_dev_replace)) {
2868 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2872 mutex_lock(&fs_info->scrub_lock);
2873 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
2874 mutex_unlock(&fs_info->scrub_lock);
2875 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2879 btrfs_dev_replace_lock(&fs_info->dev_replace);
2880 if (dev->scrub_device ||
2882 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2883 btrfs_dev_replace_unlock(&fs_info->dev_replace);
2884 mutex_unlock(&fs_info->scrub_lock);
2885 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2886 return -EINPROGRESS;
2888 btrfs_dev_replace_unlock(&fs_info->dev_replace);
2890 ret = scrub_workers_get(fs_info, is_dev_replace);
2892 mutex_unlock(&fs_info->scrub_lock);
2893 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2897 sctx = scrub_setup_ctx(dev, is_dev_replace);
2899 mutex_unlock(&fs_info->scrub_lock);
2900 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2901 scrub_workers_put(fs_info);
2902 return PTR_ERR(sctx);
2904 sctx->readonly = readonly;
2905 dev->scrub_device = sctx;
2906 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2909 * checking @scrub_pause_req here, we can avoid
2910 * race between committing transaction and scrubbing.
2912 __scrub_blocked_if_needed(fs_info);
2913 atomic_inc(&fs_info->scrubs_running);
2914 mutex_unlock(&fs_info->scrub_lock);
2916 if (!is_dev_replace) {
2918 * by holding device list mutex, we can
2919 * kick off writing super in log tree sync.
2921 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2922 ret = scrub_supers(sctx, dev);
2923 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2927 ret = scrub_enumerate_chunks(sctx, dev, start, end,
2930 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
2931 atomic_dec(&fs_info->scrubs_running);
2932 wake_up(&fs_info->scrub_pause_wait);
2934 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
2937 memcpy(progress, &sctx->stat, sizeof(*progress));
2939 mutex_lock(&fs_info->scrub_lock);
2940 dev->scrub_device = NULL;
2941 scrub_workers_put(fs_info);
2942 mutex_unlock(&fs_info->scrub_lock);
2944 scrub_free_ctx(sctx);
2949 void btrfs_scrub_pause(struct btrfs_root *root)
2951 struct btrfs_fs_info *fs_info = root->fs_info;
2953 mutex_lock(&fs_info->scrub_lock);
2954 atomic_inc(&fs_info->scrub_pause_req);
2955 while (atomic_read(&fs_info->scrubs_paused) !=
2956 atomic_read(&fs_info->scrubs_running)) {
2957 mutex_unlock(&fs_info->scrub_lock);
2958 wait_event(fs_info->scrub_pause_wait,
2959 atomic_read(&fs_info->scrubs_paused) ==
2960 atomic_read(&fs_info->scrubs_running));
2961 mutex_lock(&fs_info->scrub_lock);
2963 mutex_unlock(&fs_info->scrub_lock);
2966 void btrfs_scrub_continue(struct btrfs_root *root)
2968 struct btrfs_fs_info *fs_info = root->fs_info;
2970 atomic_dec(&fs_info->scrub_pause_req);
2971 wake_up(&fs_info->scrub_pause_wait);
2974 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
2976 mutex_lock(&fs_info->scrub_lock);
2977 if (!atomic_read(&fs_info->scrubs_running)) {
2978 mutex_unlock(&fs_info->scrub_lock);
2982 atomic_inc(&fs_info->scrub_cancel_req);
2983 while (atomic_read(&fs_info->scrubs_running)) {
2984 mutex_unlock(&fs_info->scrub_lock);
2985 wait_event(fs_info->scrub_pause_wait,
2986 atomic_read(&fs_info->scrubs_running) == 0);
2987 mutex_lock(&fs_info->scrub_lock);
2989 atomic_dec(&fs_info->scrub_cancel_req);
2990 mutex_unlock(&fs_info->scrub_lock);
2995 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
2996 struct btrfs_device *dev)
2998 struct scrub_ctx *sctx;
3000 mutex_lock(&fs_info->scrub_lock);
3001 sctx = dev->scrub_device;
3003 mutex_unlock(&fs_info->scrub_lock);
3006 atomic_inc(&sctx->cancel_req);
3007 while (dev->scrub_device) {
3008 mutex_unlock(&fs_info->scrub_lock);
3009 wait_event(fs_info->scrub_pause_wait,
3010 dev->scrub_device == NULL);
3011 mutex_lock(&fs_info->scrub_lock);
3013 mutex_unlock(&fs_info->scrub_lock);
3018 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3019 struct btrfs_scrub_progress *progress)
3021 struct btrfs_device *dev;
3022 struct scrub_ctx *sctx = NULL;
3024 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3025 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
3027 sctx = dev->scrub_device;
3029 memcpy(progress, &sctx->stat, sizeof(*progress));
3030 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3032 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
3035 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3036 u64 extent_logical, u64 extent_len,
3037 u64 *extent_physical,
3038 struct btrfs_device **extent_dev,
3039 int *extent_mirror_num)
3042 struct btrfs_bio *bbio = NULL;
3045 mapped_length = extent_len;
3046 ret = btrfs_map_block(fs_info, READ, extent_logical,
3047 &mapped_length, &bbio, 0);
3048 if (ret || !bbio || mapped_length < extent_len ||
3049 !bbio->stripes[0].dev->bdev) {
3054 *extent_physical = bbio->stripes[0].physical;
3055 *extent_mirror_num = bbio->mirror_num;
3056 *extent_dev = bbio->stripes[0].dev;
3060 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3061 struct scrub_wr_ctx *wr_ctx,
3062 struct btrfs_fs_info *fs_info,
3063 struct btrfs_device *dev,
3066 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3068 mutex_init(&wr_ctx->wr_lock);
3069 wr_ctx->wr_curr_bio = NULL;
3070 if (!is_dev_replace)
3073 WARN_ON(!dev->bdev);
3074 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
3075 bio_get_nr_vecs(dev->bdev));
3076 wr_ctx->tgtdev = dev;
3077 atomic_set(&wr_ctx->flush_all_writes, 0);
3081 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3083 mutex_lock(&wr_ctx->wr_lock);
3084 kfree(wr_ctx->wr_curr_bio);
3085 wr_ctx->wr_curr_bio = NULL;
3086 mutex_unlock(&wr_ctx->wr_lock);
3089 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3090 int mirror_num, u64 physical_for_dev_replace)
3092 struct scrub_copy_nocow_ctx *nocow_ctx;
3093 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3095 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3097 spin_lock(&sctx->stat_lock);
3098 sctx->stat.malloc_errors++;
3099 spin_unlock(&sctx->stat_lock);
3103 scrub_pending_trans_workers_inc(sctx);
3105 nocow_ctx->sctx = sctx;
3106 nocow_ctx->logical = logical;
3107 nocow_ctx->len = len;
3108 nocow_ctx->mirror_num = mirror_num;
3109 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
3110 nocow_ctx->work.func = copy_nocow_pages_worker;
3111 INIT_LIST_HEAD(&nocow_ctx->inodes);
3112 btrfs_queue_worker(&fs_info->scrub_nocow_workers,
3118 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
3120 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3121 struct scrub_nocow_inode *nocow_inode;
3123 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
3126 nocow_inode->inum = inum;
3127 nocow_inode->offset = offset;
3128 nocow_inode->root = root;
3129 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
3133 #define COPY_COMPLETE 1
3135 static void copy_nocow_pages_worker(struct btrfs_work *work)
3137 struct scrub_copy_nocow_ctx *nocow_ctx =
3138 container_of(work, struct scrub_copy_nocow_ctx, work);
3139 struct scrub_ctx *sctx = nocow_ctx->sctx;
3140 u64 logical = nocow_ctx->logical;
3141 u64 len = nocow_ctx->len;
3142 int mirror_num = nocow_ctx->mirror_num;
3143 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3145 struct btrfs_trans_handle *trans = NULL;
3146 struct btrfs_fs_info *fs_info;
3147 struct btrfs_path *path;
3148 struct btrfs_root *root;
3149 int not_written = 0;
3151 fs_info = sctx->dev_root->fs_info;
3152 root = fs_info->extent_root;
3154 path = btrfs_alloc_path();
3156 spin_lock(&sctx->stat_lock);
3157 sctx->stat.malloc_errors++;
3158 spin_unlock(&sctx->stat_lock);
3163 trans = btrfs_join_transaction(root);
3164 if (IS_ERR(trans)) {
3169 ret = iterate_inodes_from_logical(logical, fs_info, path,
3170 record_inode_for_nocow, nocow_ctx);
3171 if (ret != 0 && ret != -ENOENT) {
3172 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
3173 "phys %llu, len %llu, mir %u, ret %d",
3174 logical, physical_for_dev_replace, len, mirror_num,
3180 btrfs_end_transaction(trans, root);
3182 while (!list_empty(&nocow_ctx->inodes)) {
3183 struct scrub_nocow_inode *entry;
3184 entry = list_first_entry(&nocow_ctx->inodes,
3185 struct scrub_nocow_inode,
3187 list_del_init(&entry->list);
3188 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
3189 entry->root, nocow_ctx);
3191 if (ret == COPY_COMPLETE) {
3199 while (!list_empty(&nocow_ctx->inodes)) {
3200 struct scrub_nocow_inode *entry;
3201 entry = list_first_entry(&nocow_ctx->inodes,
3202 struct scrub_nocow_inode,
3204 list_del_init(&entry->list);
3207 if (trans && !IS_ERR(trans))
3208 btrfs_end_transaction(trans, root);
3210 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
3211 num_uncorrectable_read_errors);
3213 btrfs_free_path(path);
3216 scrub_pending_trans_workers_dec(sctx);
3219 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
3220 struct scrub_copy_nocow_ctx *nocow_ctx)
3222 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
3223 struct btrfs_key key;
3224 struct inode *inode;
3226 struct btrfs_root *local_root;
3227 struct btrfs_ordered_extent *ordered;
3228 struct extent_map *em;
3229 struct extent_state *cached_state = NULL;
3230 struct extent_io_tree *io_tree;
3231 u64 physical_for_dev_replace;
3232 u64 len = nocow_ctx->len;
3233 u64 lockstart = offset, lockend = offset + len - 1;
3234 unsigned long index;
3239 key.objectid = root;
3240 key.type = BTRFS_ROOT_ITEM_KEY;
3241 key.offset = (u64)-1;
3243 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
3245 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
3246 if (IS_ERR(local_root)) {
3247 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
3248 return PTR_ERR(local_root);
3251 key.type = BTRFS_INODE_ITEM_KEY;
3252 key.objectid = inum;
3254 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
3255 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
3257 return PTR_ERR(inode);
3259 /* Avoid truncate/dio/punch hole.. */
3260 mutex_lock(&inode->i_mutex);
3261 inode_dio_wait(inode);
3263 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3264 io_tree = &BTRFS_I(inode)->io_tree;
3266 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
3267 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
3269 btrfs_put_ordered_extent(ordered);
3273 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0);
3280 * This extent does not actually cover the logical extent anymore,
3281 * move on to the next inode.
3283 if (em->block_start > nocow_ctx->logical ||
3284 em->block_start + em->block_len < nocow_ctx->logical + len) {
3285 free_extent_map(em);
3288 free_extent_map(em);
3290 while (len >= PAGE_CACHE_SIZE) {
3291 index = offset >> PAGE_CACHE_SHIFT;
3293 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3295 btrfs_err(fs_info, "find_or_create_page() failed");
3300 if (PageUptodate(page)) {
3301 if (PageDirty(page))
3304 ClearPageError(page);
3305 err = extent_read_full_page_nolock(io_tree, page,
3307 nocow_ctx->mirror_num);
3315 * If the page has been remove from the page cache,
3316 * the data on it is meaningless, because it may be
3317 * old one, the new data may be written into the new
3318 * page in the page cache.
3320 if (page->mapping != inode->i_mapping) {
3322 page_cache_release(page);
3325 if (!PageUptodate(page)) {
3330 err = write_page_nocow(nocow_ctx->sctx,
3331 physical_for_dev_replace, page);
3336 page_cache_release(page);
3341 offset += PAGE_CACHE_SIZE;
3342 physical_for_dev_replace += PAGE_CACHE_SIZE;
3343 len -= PAGE_CACHE_SIZE;
3345 ret = COPY_COMPLETE;
3347 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
3350 mutex_unlock(&inode->i_mutex);
3355 static int write_page_nocow(struct scrub_ctx *sctx,
3356 u64 physical_for_dev_replace, struct page *page)
3359 struct btrfs_device *dev;
3362 dev = sctx->wr_ctx.tgtdev;
3366 printk_ratelimited(KERN_WARNING
3367 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
3370 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
3372 spin_lock(&sctx->stat_lock);
3373 sctx->stat.malloc_errors++;
3374 spin_unlock(&sctx->stat_lock);
3377 bio->bi_iter.bi_size = 0;
3378 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
3379 bio->bi_bdev = dev->bdev;
3380 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
3381 if (ret != PAGE_CACHE_SIZE) {
3384 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
3388 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
3389 goto leave_with_eio;