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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
4 */
5
6#include <linux/blkdev.h>
7#include <linux/ratelimit.h>
8#include <linux/sched/mm.h>
9#include <crypto/hash.h>
10#include "ctree.h"
11#include "discard.h"
12#include "volumes.h"
13#include "disk-io.h"
14#include "ordered-data.h"
15#include "transaction.h"
16#include "backref.h"
17#include "extent_io.h"
18#include "dev-replace.h"
19#include "raid56.h"
20#include "block-group.h"
21#include "zoned.h"
22#include "fs.h"
23#include "accessors.h"
24#include "file-item.h"
25#include "scrub.h"
26#include "raid-stripe-tree.h"
27
28/*
29 * This is only the first step towards a full-features scrub. It reads all
30 * extent and super block and verifies the checksums. In case a bad checksum
31 * is found or the extent cannot be read, good data will be written back if
32 * any can be found.
33 *
34 * Future enhancements:
35 * - In case an unrepairable extent is encountered, track which files are
36 * affected and report them
37 * - track and record media errors, throw out bad devices
38 * - add a mode to also read unallocated space
39 */
40
41struct scrub_ctx;
42
43/*
44 * The following value only influences the performance.
45 *
46 * This determines how many stripes would be submitted in one go,
47 * which is 512KiB (BTRFS_STRIPE_LEN * SCRUB_STRIPES_PER_GROUP).
48 */
49#define SCRUB_STRIPES_PER_GROUP 8
50
51/*
52 * How many groups we have for each sctx.
53 *
54 * This would be 8M per device, the same value as the old scrub in-flight bios
55 * size limit.
56 */
57#define SCRUB_GROUPS_PER_SCTX 16
58
59#define SCRUB_TOTAL_STRIPES (SCRUB_GROUPS_PER_SCTX * SCRUB_STRIPES_PER_GROUP)
60
61/*
62 * The following value times PAGE_SIZE needs to be large enough to match the
63 * largest node/leaf/sector size that shall be supported.
64 */
65#define SCRUB_MAX_SECTORS_PER_BLOCK (BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K)
66
67/* Represent one sector and its needed info to verify the content. */
68struct scrub_sector_verification {
69 bool is_metadata;
70
71 union {
72 /*
73 * Csum pointer for data csum verification. Should point to a
74 * sector csum inside scrub_stripe::csums.
75 *
76 * NULL if this data sector has no csum.
77 */
78 u8 *csum;
79
80 /*
81 * Extra info for metadata verification. All sectors inside a
82 * tree block share the same generation.
83 */
84 u64 generation;
85 };
86};
87
88enum scrub_stripe_flags {
89 /* Set when @mirror_num, @dev, @physical and @logical are set. */
90 SCRUB_STRIPE_FLAG_INITIALIZED,
91
92 /* Set when the read-repair is finished. */
93 SCRUB_STRIPE_FLAG_REPAIR_DONE,
94
95 /*
96 * Set for data stripes if it's triggered from P/Q stripe.
97 * During such scrub, we should not report errors in data stripes, nor
98 * update the accounting.
99 */
100 SCRUB_STRIPE_FLAG_NO_REPORT,
101};
102
103#define SCRUB_STRIPE_PAGES (BTRFS_STRIPE_LEN / PAGE_SIZE)
104
105/*
106 * Represent one contiguous range with a length of BTRFS_STRIPE_LEN.
107 */
108struct scrub_stripe {
109 struct scrub_ctx *sctx;
110 struct btrfs_block_group *bg;
111
112 struct page *pages[SCRUB_STRIPE_PAGES];
113 struct scrub_sector_verification *sectors;
114
115 struct btrfs_device *dev;
116 u64 logical;
117 u64 physical;
118
119 u16 mirror_num;
120
121 /* Should be BTRFS_STRIPE_LEN / sectorsize. */
122 u16 nr_sectors;
123
124 /*
125 * How many data/meta extents are in this stripe. Only for scrub status
126 * reporting purposes.
127 */
128 u16 nr_data_extents;
129 u16 nr_meta_extents;
130
131 atomic_t pending_io;
132 wait_queue_head_t io_wait;
133 wait_queue_head_t repair_wait;
134
135 /*
136 * Indicate the states of the stripe. Bits are defined in
137 * scrub_stripe_flags enum.
138 */
139 unsigned long state;
140
141 /* Indicate which sectors are covered by extent items. */
142 unsigned long extent_sector_bitmap;
143
144 /*
145 * The errors hit during the initial read of the stripe.
146 *
147 * Would be utilized for error reporting and repair.
148 *
149 * The remaining init_nr_* records the number of errors hit, only used
150 * by error reporting.
151 */
152 unsigned long init_error_bitmap;
153 unsigned int init_nr_io_errors;
154 unsigned int init_nr_csum_errors;
155 unsigned int init_nr_meta_errors;
156
157 /*
158 * The following error bitmaps are all for the current status.
159 * Every time we submit a new read, these bitmaps may be updated.
160 *
161 * error_bitmap = io_error_bitmap | csum_error_bitmap | meta_error_bitmap;
162 *
163 * IO and csum errors can happen for both metadata and data.
164 */
165 unsigned long error_bitmap;
166 unsigned long io_error_bitmap;
167 unsigned long csum_error_bitmap;
168 unsigned long meta_error_bitmap;
169
170 /* For writeback (repair or replace) error reporting. */
171 unsigned long write_error_bitmap;
172
173 /* Writeback can be concurrent, thus we need to protect the bitmap. */
174 spinlock_t write_error_lock;
175
176 /*
177 * Checksum for the whole stripe if this stripe is inside a data block
178 * group.
179 */
180 u8 *csums;
181
182 struct work_struct work;
183};
184
185struct scrub_ctx {
186 struct scrub_stripe stripes[SCRUB_TOTAL_STRIPES];
187 struct scrub_stripe *raid56_data_stripes;
188 struct btrfs_fs_info *fs_info;
189 struct btrfs_path extent_path;
190 struct btrfs_path csum_path;
191 int first_free;
192 int cur_stripe;
193 atomic_t cancel_req;
194 int readonly;
195
196 /* State of IO submission throttling affecting the associated device */
197 ktime_t throttle_deadline;
198 u64 throttle_sent;
199
200 int is_dev_replace;
201 u64 write_pointer;
202
203 struct mutex wr_lock;
204 struct btrfs_device *wr_tgtdev;
205
206 /*
207 * statistics
208 */
209 struct btrfs_scrub_progress stat;
210 spinlock_t stat_lock;
211
212 /*
213 * Use a ref counter to avoid use-after-free issues. Scrub workers
214 * decrement bios_in_flight and workers_pending and then do a wakeup
215 * on the list_wait wait queue. We must ensure the main scrub task
216 * doesn't free the scrub context before or while the workers are
217 * doing the wakeup() call.
218 */
219 refcount_t refs;
220};
221
222struct scrub_warning {
223 struct btrfs_path *path;
224 u64 extent_item_size;
225 const char *errstr;
226 u64 physical;
227 u64 logical;
228 struct btrfs_device *dev;
229};
230
231static void release_scrub_stripe(struct scrub_stripe *stripe)
232{
233 if (!stripe)
234 return;
235
236 for (int i = 0; i < SCRUB_STRIPE_PAGES; i++) {
237 if (stripe->pages[i])
238 __free_page(stripe->pages[i]);
239 stripe->pages[i] = NULL;
240 }
241 kfree(stripe->sectors);
242 kfree(stripe->csums);
243 stripe->sectors = NULL;
244 stripe->csums = NULL;
245 stripe->sctx = NULL;
246 stripe->state = 0;
247}
248
249static int init_scrub_stripe(struct btrfs_fs_info *fs_info,
250 struct scrub_stripe *stripe)
251{
252 int ret;
253
254 memset(stripe, 0, sizeof(*stripe));
255
256 stripe->nr_sectors = BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits;
257 stripe->state = 0;
258
259 init_waitqueue_head(&stripe->io_wait);
260 init_waitqueue_head(&stripe->repair_wait);
261 atomic_set(&stripe->pending_io, 0);
262 spin_lock_init(&stripe->write_error_lock);
263
264 ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages, 0);
265 if (ret < 0)
266 goto error;
267
268 stripe->sectors = kcalloc(stripe->nr_sectors,
269 sizeof(struct scrub_sector_verification),
270 GFP_KERNEL);
271 if (!stripe->sectors)
272 goto error;
273
274 stripe->csums = kcalloc(BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits,
275 fs_info->csum_size, GFP_KERNEL);
276 if (!stripe->csums)
277 goto error;
278 return 0;
279error:
280 release_scrub_stripe(stripe);
281 return -ENOMEM;
282}
283
284static void wait_scrub_stripe_io(struct scrub_stripe *stripe)
285{
286 wait_event(stripe->io_wait, atomic_read(&stripe->pending_io) == 0);
287}
288
289static void scrub_put_ctx(struct scrub_ctx *sctx);
290
291static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
292{
293 while (atomic_read(&fs_info->scrub_pause_req)) {
294 mutex_unlock(&fs_info->scrub_lock);
295 wait_event(fs_info->scrub_pause_wait,
296 atomic_read(&fs_info->scrub_pause_req) == 0);
297 mutex_lock(&fs_info->scrub_lock);
298 }
299}
300
301static void scrub_pause_on(struct btrfs_fs_info *fs_info)
302{
303 atomic_inc(&fs_info->scrubs_paused);
304 wake_up(&fs_info->scrub_pause_wait);
305}
306
307static void scrub_pause_off(struct btrfs_fs_info *fs_info)
308{
309 mutex_lock(&fs_info->scrub_lock);
310 __scrub_blocked_if_needed(fs_info);
311 atomic_dec(&fs_info->scrubs_paused);
312 mutex_unlock(&fs_info->scrub_lock);
313
314 wake_up(&fs_info->scrub_pause_wait);
315}
316
317static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
318{
319 scrub_pause_on(fs_info);
320 scrub_pause_off(fs_info);
321}
322
323static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
324{
325 int i;
326
327 if (!sctx)
328 return;
329
330 for (i = 0; i < SCRUB_TOTAL_STRIPES; i++)
331 release_scrub_stripe(&sctx->stripes[i]);
332
333 kvfree(sctx);
334}
335
336static void scrub_put_ctx(struct scrub_ctx *sctx)
337{
338 if (refcount_dec_and_test(&sctx->refs))
339 scrub_free_ctx(sctx);
340}
341
342static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
343 struct btrfs_fs_info *fs_info, int is_dev_replace)
344{
345 struct scrub_ctx *sctx;
346 int i;
347
348 /* Since sctx has inline 128 stripes, it can go beyond 64K easily. Use
349 * kvzalloc().
350 */
351 sctx = kvzalloc(sizeof(*sctx), GFP_KERNEL);
352 if (!sctx)
353 goto nomem;
354 refcount_set(&sctx->refs, 1);
355 sctx->is_dev_replace = is_dev_replace;
356 sctx->fs_info = fs_info;
357 sctx->extent_path.search_commit_root = 1;
358 sctx->extent_path.skip_locking = 1;
359 sctx->csum_path.search_commit_root = 1;
360 sctx->csum_path.skip_locking = 1;
361 for (i = 0; i < SCRUB_TOTAL_STRIPES; i++) {
362 int ret;
363
364 ret = init_scrub_stripe(fs_info, &sctx->stripes[i]);
365 if (ret < 0)
366 goto nomem;
367 sctx->stripes[i].sctx = sctx;
368 }
369 sctx->first_free = 0;
370 atomic_set(&sctx->cancel_req, 0);
371
372 spin_lock_init(&sctx->stat_lock);
373 sctx->throttle_deadline = 0;
374
375 mutex_init(&sctx->wr_lock);
376 if (is_dev_replace) {
377 WARN_ON(!fs_info->dev_replace.tgtdev);
378 sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
379 }
380
381 return sctx;
382
383nomem:
384 scrub_free_ctx(sctx);
385 return ERR_PTR(-ENOMEM);
386}
387
388static int scrub_print_warning_inode(u64 inum, u64 offset, u64 num_bytes,
389 u64 root, void *warn_ctx)
390{
391 u32 nlink;
392 int ret;
393 int i;
394 unsigned nofs_flag;
395 struct extent_buffer *eb;
396 struct btrfs_inode_item *inode_item;
397 struct scrub_warning *swarn = warn_ctx;
398 struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
399 struct inode_fs_paths *ipath = NULL;
400 struct btrfs_root *local_root;
401 struct btrfs_key key;
402
403 local_root = btrfs_get_fs_root(fs_info, root, true);
404 if (IS_ERR(local_root)) {
405 ret = PTR_ERR(local_root);
406 goto err;
407 }
408
409 /*
410 * this makes the path point to (inum INODE_ITEM ioff)
411 */
412 key.objectid = inum;
413 key.type = BTRFS_INODE_ITEM_KEY;
414 key.offset = 0;
415
416 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
417 if (ret) {
418 btrfs_put_root(local_root);
419 btrfs_release_path(swarn->path);
420 goto err;
421 }
422
423 eb = swarn->path->nodes[0];
424 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
425 struct btrfs_inode_item);
426 nlink = btrfs_inode_nlink(eb, inode_item);
427 btrfs_release_path(swarn->path);
428
429 /*
430 * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
431 * uses GFP_NOFS in this context, so we keep it consistent but it does
432 * not seem to be strictly necessary.
433 */
434 nofs_flag = memalloc_nofs_save();
435 ipath = init_ipath(4096, local_root, swarn->path);
436 memalloc_nofs_restore(nofs_flag);
437 if (IS_ERR(ipath)) {
438 btrfs_put_root(local_root);
439 ret = PTR_ERR(ipath);
440 ipath = NULL;
441 goto err;
442 }
443 ret = paths_from_inode(inum, ipath);
444
445 if (ret < 0)
446 goto err;
447
448 /*
449 * we deliberately ignore the bit ipath might have been too small to
450 * hold all of the paths here
451 */
452 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
453 btrfs_warn_in_rcu(fs_info,
454"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %u, links %u (path: %s)",
455 swarn->errstr, swarn->logical,
456 btrfs_dev_name(swarn->dev),
457 swarn->physical,
458 root, inum, offset,
459 fs_info->sectorsize, nlink,
460 (char *)(unsigned long)ipath->fspath->val[i]);
461
462 btrfs_put_root(local_root);
463 free_ipath(ipath);
464 return 0;
465
466err:
467 btrfs_warn_in_rcu(fs_info,
468 "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
469 swarn->errstr, swarn->logical,
470 btrfs_dev_name(swarn->dev),
471 swarn->physical,
472 root, inum, offset, ret);
473
474 free_ipath(ipath);
475 return 0;
476}
477
478static void scrub_print_common_warning(const char *errstr, struct btrfs_device *dev,
479 bool is_super, u64 logical, u64 physical)
480{
481 struct btrfs_fs_info *fs_info = dev->fs_info;
482 struct btrfs_path *path;
483 struct btrfs_key found_key;
484 struct extent_buffer *eb;
485 struct btrfs_extent_item *ei;
486 struct scrub_warning swarn;
487 u64 flags = 0;
488 u32 item_size;
489 int ret;
490
491 /* Super block error, no need to search extent tree. */
492 if (is_super) {
493 btrfs_warn_in_rcu(fs_info, "%s on device %s, physical %llu",
494 errstr, btrfs_dev_name(dev), physical);
495 return;
496 }
497 path = btrfs_alloc_path();
498 if (!path)
499 return;
500
501 swarn.physical = physical;
502 swarn.logical = logical;
503 swarn.errstr = errstr;
504 swarn.dev = NULL;
505
506 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
507 &flags);
508 if (ret < 0)
509 goto out;
510
511 swarn.extent_item_size = found_key.offset;
512
513 eb = path->nodes[0];
514 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
515 item_size = btrfs_item_size(eb, path->slots[0]);
516
517 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
518 unsigned long ptr = 0;
519 u8 ref_level;
520 u64 ref_root;
521
522 while (true) {
523 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
524 item_size, &ref_root,
525 &ref_level);
526 if (ret < 0) {
527 btrfs_warn(fs_info,
528 "failed to resolve tree backref for logical %llu: %d",
529 swarn.logical, ret);
530 break;
531 }
532 if (ret > 0)
533 break;
534 btrfs_warn_in_rcu(fs_info,
535"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
536 errstr, swarn.logical, btrfs_dev_name(dev),
537 swarn.physical, (ref_level ? "node" : "leaf"),
538 ref_level, ref_root);
539 }
540 btrfs_release_path(path);
541 } else {
542 struct btrfs_backref_walk_ctx ctx = { 0 };
543
544 btrfs_release_path(path);
545
546 ctx.bytenr = found_key.objectid;
547 ctx.extent_item_pos = swarn.logical - found_key.objectid;
548 ctx.fs_info = fs_info;
549
550 swarn.path = path;
551 swarn.dev = dev;
552
553 iterate_extent_inodes(&ctx, true, scrub_print_warning_inode, &swarn);
554 }
555
556out:
557 btrfs_free_path(path);
558}
559
560static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
561{
562 int ret = 0;
563 u64 length;
564
565 if (!btrfs_is_zoned(sctx->fs_info))
566 return 0;
567
568 if (!btrfs_dev_is_sequential(sctx->wr_tgtdev, physical))
569 return 0;
570
571 if (sctx->write_pointer < physical) {
572 length = physical - sctx->write_pointer;
573
574 ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
575 sctx->write_pointer, length);
576 if (!ret)
577 sctx->write_pointer = physical;
578 }
579 return ret;
580}
581
582static struct page *scrub_stripe_get_page(struct scrub_stripe *stripe, int sector_nr)
583{
584 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
585 int page_index = (sector_nr << fs_info->sectorsize_bits) >> PAGE_SHIFT;
586
587 return stripe->pages[page_index];
588}
589
590static unsigned int scrub_stripe_get_page_offset(struct scrub_stripe *stripe,
591 int sector_nr)
592{
593 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
594
595 return offset_in_page(sector_nr << fs_info->sectorsize_bits);
596}
597
598static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr)
599{
600 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
601 const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
602 const u64 logical = stripe->logical + (sector_nr << fs_info->sectorsize_bits);
603 const struct page *first_page = scrub_stripe_get_page(stripe, sector_nr);
604 const unsigned int first_off = scrub_stripe_get_page_offset(stripe, sector_nr);
605 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
606 u8 on_disk_csum[BTRFS_CSUM_SIZE];
607 u8 calculated_csum[BTRFS_CSUM_SIZE];
608 struct btrfs_header *header;
609
610 /*
611 * Here we don't have a good way to attach the pages (and subpages)
612 * to a dummy extent buffer, thus we have to directly grab the members
613 * from pages.
614 */
615 header = (struct btrfs_header *)(page_address(first_page) + first_off);
616 memcpy(on_disk_csum, header->csum, fs_info->csum_size);
617
618 if (logical != btrfs_stack_header_bytenr(header)) {
619 bitmap_set(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree);
620 bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
621 btrfs_warn_rl(fs_info,
622 "tree block %llu mirror %u has bad bytenr, has %llu want %llu",
623 logical, stripe->mirror_num,
624 btrfs_stack_header_bytenr(header), logical);
625 return;
626 }
627 if (memcmp(header->fsid, fs_info->fs_devices->metadata_uuid,
628 BTRFS_FSID_SIZE) != 0) {
629 bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
630 bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
631 btrfs_warn_rl(fs_info,
632 "tree block %llu mirror %u has bad fsid, has %pU want %pU",
633 logical, stripe->mirror_num,
634 header->fsid, fs_info->fs_devices->fsid);
635 return;
636 }
637 if (memcmp(header->chunk_tree_uuid, fs_info->chunk_tree_uuid,
638 BTRFS_UUID_SIZE) != 0) {
639 bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
640 bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
641 btrfs_warn_rl(fs_info,
642 "tree block %llu mirror %u has bad chunk tree uuid, has %pU want %pU",
643 logical, stripe->mirror_num,
644 header->chunk_tree_uuid, fs_info->chunk_tree_uuid);
645 return;
646 }
647
648 /* Now check tree block csum. */
649 shash->tfm = fs_info->csum_shash;
650 crypto_shash_init(shash);
651 crypto_shash_update(shash, page_address(first_page) + first_off +
652 BTRFS_CSUM_SIZE, fs_info->sectorsize - BTRFS_CSUM_SIZE);
653
654 for (int i = sector_nr + 1; i < sector_nr + sectors_per_tree; i++) {
655 struct page *page = scrub_stripe_get_page(stripe, i);
656 unsigned int page_off = scrub_stripe_get_page_offset(stripe, i);
657
658 crypto_shash_update(shash, page_address(page) + page_off,
659 fs_info->sectorsize);
660 }
661
662 crypto_shash_final(shash, calculated_csum);
663 if (memcmp(calculated_csum, on_disk_csum, fs_info->csum_size) != 0) {
664 bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
665 bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
666 btrfs_warn_rl(fs_info,
667 "tree block %llu mirror %u has bad csum, has " CSUM_FMT " want " CSUM_FMT,
668 logical, stripe->mirror_num,
669 CSUM_FMT_VALUE(fs_info->csum_size, on_disk_csum),
670 CSUM_FMT_VALUE(fs_info->csum_size, calculated_csum));
671 return;
672 }
673 if (stripe->sectors[sector_nr].generation !=
674 btrfs_stack_header_generation(header)) {
675 bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
676 bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
677 btrfs_warn_rl(fs_info,
678 "tree block %llu mirror %u has bad generation, has %llu want %llu",
679 logical, stripe->mirror_num,
680 btrfs_stack_header_generation(header),
681 stripe->sectors[sector_nr].generation);
682 return;
683 }
684 bitmap_clear(&stripe->error_bitmap, sector_nr, sectors_per_tree);
685 bitmap_clear(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree);
686 bitmap_clear(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
687}
688
689static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr)
690{
691 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
692 struct scrub_sector_verification *sector = &stripe->sectors[sector_nr];
693 const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
694 struct page *page = scrub_stripe_get_page(stripe, sector_nr);
695 unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr);
696 u8 csum_buf[BTRFS_CSUM_SIZE];
697 int ret;
698
699 ASSERT(sector_nr >= 0 && sector_nr < stripe->nr_sectors);
700
701 /* Sector not utilized, skip it. */
702 if (!test_bit(sector_nr, &stripe->extent_sector_bitmap))
703 return;
704
705 /* IO error, no need to check. */
706 if (test_bit(sector_nr, &stripe->io_error_bitmap))
707 return;
708
709 /* Metadata, verify the full tree block. */
710 if (sector->is_metadata) {
711 /*
712 * Check if the tree block crosses the stripe boundary. If
713 * crossed the boundary, we cannot verify it but only give a
714 * warning.
715 *
716 * This can only happen on a very old filesystem where chunks
717 * are not ensured to be stripe aligned.
718 */
719 if (unlikely(sector_nr + sectors_per_tree > stripe->nr_sectors)) {
720 btrfs_warn_rl(fs_info,
721 "tree block at %llu crosses stripe boundary %llu",
722 stripe->logical +
723 (sector_nr << fs_info->sectorsize_bits),
724 stripe->logical);
725 return;
726 }
727 scrub_verify_one_metadata(stripe, sector_nr);
728 return;
729 }
730
731 /*
732 * Data is easier, we just verify the data csum (if we have it). For
733 * cases without csum, we have no other choice but to trust it.
734 */
735 if (!sector->csum) {
736 clear_bit(sector_nr, &stripe->error_bitmap);
737 return;
738 }
739
740 ret = btrfs_check_sector_csum(fs_info, page, pgoff, csum_buf, sector->csum);
741 if (ret < 0) {
742 set_bit(sector_nr, &stripe->csum_error_bitmap);
743 set_bit(sector_nr, &stripe->error_bitmap);
744 } else {
745 clear_bit(sector_nr, &stripe->csum_error_bitmap);
746 clear_bit(sector_nr, &stripe->error_bitmap);
747 }
748}
749
750/* Verify specified sectors of a stripe. */
751static void scrub_verify_one_stripe(struct scrub_stripe *stripe, unsigned long bitmap)
752{
753 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
754 const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
755 int sector_nr;
756
757 for_each_set_bit(sector_nr, &bitmap, stripe->nr_sectors) {
758 scrub_verify_one_sector(stripe, sector_nr);
759 if (stripe->sectors[sector_nr].is_metadata)
760 sector_nr += sectors_per_tree - 1;
761 }
762}
763
764static int calc_sector_number(struct scrub_stripe *stripe, struct bio_vec *first_bvec)
765{
766 int i;
767
768 for (i = 0; i < stripe->nr_sectors; i++) {
769 if (scrub_stripe_get_page(stripe, i) == first_bvec->bv_page &&
770 scrub_stripe_get_page_offset(stripe, i) == first_bvec->bv_offset)
771 break;
772 }
773 ASSERT(i < stripe->nr_sectors);
774 return i;
775}
776
777/*
778 * Repair read is different to the regular read:
779 *
780 * - Only reads the failed sectors
781 * - May have extra blocksize limits
782 */
783static void scrub_repair_read_endio(struct btrfs_bio *bbio)
784{
785 struct scrub_stripe *stripe = bbio->private;
786 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
787 struct bio_vec *bvec;
788 int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio));
789 u32 bio_size = 0;
790 int i;
791
792 ASSERT(sector_nr < stripe->nr_sectors);
793
794 bio_for_each_bvec_all(bvec, &bbio->bio, i)
795 bio_size += bvec->bv_len;
796
797 if (bbio->bio.bi_status) {
798 bitmap_set(&stripe->io_error_bitmap, sector_nr,
799 bio_size >> fs_info->sectorsize_bits);
800 bitmap_set(&stripe->error_bitmap, sector_nr,
801 bio_size >> fs_info->sectorsize_bits);
802 } else {
803 bitmap_clear(&stripe->io_error_bitmap, sector_nr,
804 bio_size >> fs_info->sectorsize_bits);
805 }
806 bio_put(&bbio->bio);
807 if (atomic_dec_and_test(&stripe->pending_io))
808 wake_up(&stripe->io_wait);
809}
810
811static int calc_next_mirror(int mirror, int num_copies)
812{
813 ASSERT(mirror <= num_copies);
814 return (mirror + 1 > num_copies) ? 1 : mirror + 1;
815}
816
817static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe,
818 int mirror, int blocksize, bool wait)
819{
820 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
821 struct btrfs_bio *bbio = NULL;
822 const unsigned long old_error_bitmap = stripe->error_bitmap;
823 int i;
824
825 ASSERT(stripe->mirror_num >= 1);
826 ASSERT(atomic_read(&stripe->pending_io) == 0);
827
828 for_each_set_bit(i, &old_error_bitmap, stripe->nr_sectors) {
829 struct page *page;
830 int pgoff;
831 int ret;
832
833 page = scrub_stripe_get_page(stripe, i);
834 pgoff = scrub_stripe_get_page_offset(stripe, i);
835
836 /* The current sector cannot be merged, submit the bio. */
837 if (bbio && ((i > 0 && !test_bit(i - 1, &stripe->error_bitmap)) ||
838 bbio->bio.bi_iter.bi_size >= blocksize)) {
839 ASSERT(bbio->bio.bi_iter.bi_size);
840 atomic_inc(&stripe->pending_io);
841 btrfs_submit_bio(bbio, mirror);
842 if (wait)
843 wait_scrub_stripe_io(stripe);
844 bbio = NULL;
845 }
846
847 if (!bbio) {
848 bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ,
849 fs_info, scrub_repair_read_endio, stripe);
850 bbio->bio.bi_iter.bi_sector = (stripe->logical +
851 (i << fs_info->sectorsize_bits)) >> SECTOR_SHIFT;
852 }
853
854 ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
855 ASSERT(ret == fs_info->sectorsize);
856 }
857 if (bbio) {
858 ASSERT(bbio->bio.bi_iter.bi_size);
859 atomic_inc(&stripe->pending_io);
860 btrfs_submit_bio(bbio, mirror);
861 if (wait)
862 wait_scrub_stripe_io(stripe);
863 }
864}
865
866static void scrub_stripe_report_errors(struct scrub_ctx *sctx,
867 struct scrub_stripe *stripe)
868{
869 static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
870 DEFAULT_RATELIMIT_BURST);
871 struct btrfs_fs_info *fs_info = sctx->fs_info;
872 struct btrfs_device *dev = NULL;
873 u64 physical = 0;
874 int nr_data_sectors = 0;
875 int nr_meta_sectors = 0;
876 int nr_nodatacsum_sectors = 0;
877 int nr_repaired_sectors = 0;
878 int sector_nr;
879
880 if (test_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state))
881 return;
882
883 /*
884 * Init needed infos for error reporting.
885 *
886 * Although our scrub_stripe infrastructure is mostly based on btrfs_submit_bio()
887 * thus no need for dev/physical, error reporting still needs dev and physical.
888 */
889 if (!bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) {
890 u64 mapped_len = fs_info->sectorsize;
891 struct btrfs_io_context *bioc = NULL;
892 int stripe_index = stripe->mirror_num - 1;
893 int ret;
894
895 /* For scrub, our mirror_num should always start at 1. */
896 ASSERT(stripe->mirror_num >= 1);
897 ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
898 stripe->logical, &mapped_len, &bioc,
899 NULL, NULL);
900 /*
901 * If we failed, dev will be NULL, and later detailed reports
902 * will just be skipped.
903 */
904 if (ret < 0)
905 goto skip;
906 physical = bioc->stripes[stripe_index].physical;
907 dev = bioc->stripes[stripe_index].dev;
908 btrfs_put_bioc(bioc);
909 }
910
911skip:
912 for_each_set_bit(sector_nr, &stripe->extent_sector_bitmap, stripe->nr_sectors) {
913 bool repaired = false;
914
915 if (stripe->sectors[sector_nr].is_metadata) {
916 nr_meta_sectors++;
917 } else {
918 nr_data_sectors++;
919 if (!stripe->sectors[sector_nr].csum)
920 nr_nodatacsum_sectors++;
921 }
922
923 if (test_bit(sector_nr, &stripe->init_error_bitmap) &&
924 !test_bit(sector_nr, &stripe->error_bitmap)) {
925 nr_repaired_sectors++;
926 repaired = true;
927 }
928
929 /* Good sector from the beginning, nothing need to be done. */
930 if (!test_bit(sector_nr, &stripe->init_error_bitmap))
931 continue;
932
933 /*
934 * Report error for the corrupted sectors. If repaired, just
935 * output the message of repaired message.
936 */
937 if (repaired) {
938 if (dev) {
939 btrfs_err_rl_in_rcu(fs_info,
940 "fixed up error at logical %llu on dev %s physical %llu",
941 stripe->logical, btrfs_dev_name(dev),
942 physical);
943 } else {
944 btrfs_err_rl_in_rcu(fs_info,
945 "fixed up error at logical %llu on mirror %u",
946 stripe->logical, stripe->mirror_num);
947 }
948 continue;
949 }
950
951 /* The remaining are all for unrepaired. */
952 if (dev) {
953 btrfs_err_rl_in_rcu(fs_info,
954 "unable to fixup (regular) error at logical %llu on dev %s physical %llu",
955 stripe->logical, btrfs_dev_name(dev),
956 physical);
957 } else {
958 btrfs_err_rl_in_rcu(fs_info,
959 "unable to fixup (regular) error at logical %llu on mirror %u",
960 stripe->logical, stripe->mirror_num);
961 }
962
963 if (test_bit(sector_nr, &stripe->io_error_bitmap))
964 if (__ratelimit(&rs) && dev)
965 scrub_print_common_warning("i/o error", dev, false,
966 stripe->logical, physical);
967 if (test_bit(sector_nr, &stripe->csum_error_bitmap))
968 if (__ratelimit(&rs) && dev)
969 scrub_print_common_warning("checksum error", dev, false,
970 stripe->logical, physical);
971 if (test_bit(sector_nr, &stripe->meta_error_bitmap))
972 if (__ratelimit(&rs) && dev)
973 scrub_print_common_warning("header error", dev, false,
974 stripe->logical, physical);
975 }
976
977 spin_lock(&sctx->stat_lock);
978 sctx->stat.data_extents_scrubbed += stripe->nr_data_extents;
979 sctx->stat.tree_extents_scrubbed += stripe->nr_meta_extents;
980 sctx->stat.data_bytes_scrubbed += nr_data_sectors << fs_info->sectorsize_bits;
981 sctx->stat.tree_bytes_scrubbed += nr_meta_sectors << fs_info->sectorsize_bits;
982 sctx->stat.no_csum += nr_nodatacsum_sectors;
983 sctx->stat.read_errors += stripe->init_nr_io_errors;
984 sctx->stat.csum_errors += stripe->init_nr_csum_errors;
985 sctx->stat.verify_errors += stripe->init_nr_meta_errors;
986 sctx->stat.uncorrectable_errors +=
987 bitmap_weight(&stripe->error_bitmap, stripe->nr_sectors);
988 sctx->stat.corrected_errors += nr_repaired_sectors;
989 spin_unlock(&sctx->stat_lock);
990}
991
992static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe,
993 unsigned long write_bitmap, bool dev_replace);
994
995/*
996 * The main entrance for all read related scrub work, including:
997 *
998 * - Wait for the initial read to finish
999 * - Verify and locate any bad sectors
1000 * - Go through the remaining mirrors and try to read as large blocksize as
1001 * possible
1002 * - Go through all mirrors (including the failed mirror) sector-by-sector
1003 * - Submit writeback for repaired sectors
1004 *
1005 * Writeback for dev-replace does not happen here, it needs extra
1006 * synchronization for zoned devices.
1007 */
1008static void scrub_stripe_read_repair_worker(struct work_struct *work)
1009{
1010 struct scrub_stripe *stripe = container_of(work, struct scrub_stripe, work);
1011 struct scrub_ctx *sctx = stripe->sctx;
1012 struct btrfs_fs_info *fs_info = sctx->fs_info;
1013 int num_copies = btrfs_num_copies(fs_info, stripe->bg->start,
1014 stripe->bg->length);
1015 unsigned long repaired;
1016 int mirror;
1017 int i;
1018
1019 ASSERT(stripe->mirror_num > 0);
1020
1021 wait_scrub_stripe_io(stripe);
1022 scrub_verify_one_stripe(stripe, stripe->extent_sector_bitmap);
1023 /* Save the initial failed bitmap for later repair and report usage. */
1024 stripe->init_error_bitmap = stripe->error_bitmap;
1025 stripe->init_nr_io_errors = bitmap_weight(&stripe->io_error_bitmap,
1026 stripe->nr_sectors);
1027 stripe->init_nr_csum_errors = bitmap_weight(&stripe->csum_error_bitmap,
1028 stripe->nr_sectors);
1029 stripe->init_nr_meta_errors = bitmap_weight(&stripe->meta_error_bitmap,
1030 stripe->nr_sectors);
1031
1032 if (bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors))
1033 goto out;
1034
1035 /*
1036 * Try all remaining mirrors.
1037 *
1038 * Here we still try to read as large block as possible, as this is
1039 * faster and we have extra safety nets to rely on.
1040 */
1041 for (mirror = calc_next_mirror(stripe->mirror_num, num_copies);
1042 mirror != stripe->mirror_num;
1043 mirror = calc_next_mirror(mirror, num_copies)) {
1044 const unsigned long old_error_bitmap = stripe->error_bitmap;
1045
1046 scrub_stripe_submit_repair_read(stripe, mirror,
1047 BTRFS_STRIPE_LEN, false);
1048 wait_scrub_stripe_io(stripe);
1049 scrub_verify_one_stripe(stripe, old_error_bitmap);
1050 if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors))
1051 goto out;
1052 }
1053
1054 /*
1055 * Last safety net, try re-checking all mirrors, including the failed
1056 * one, sector-by-sector.
1057 *
1058 * As if one sector failed the drive's internal csum, the whole read
1059 * containing the offending sector would be marked as error.
1060 * Thus here we do sector-by-sector read.
1061 *
1062 * This can be slow, thus we only try it as the last resort.
1063 */
1064
1065 for (i = 0, mirror = stripe->mirror_num;
1066 i < num_copies;
1067 i++, mirror = calc_next_mirror(mirror, num_copies)) {
1068 const unsigned long old_error_bitmap = stripe->error_bitmap;
1069
1070 scrub_stripe_submit_repair_read(stripe, mirror,
1071 fs_info->sectorsize, true);
1072 wait_scrub_stripe_io(stripe);
1073 scrub_verify_one_stripe(stripe, old_error_bitmap);
1074 if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors))
1075 goto out;
1076 }
1077out:
1078 /*
1079 * Submit the repaired sectors. For zoned case, we cannot do repair
1080 * in-place, but queue the bg to be relocated.
1081 */
1082 bitmap_andnot(&repaired, &stripe->init_error_bitmap, &stripe->error_bitmap,
1083 stripe->nr_sectors);
1084 if (!sctx->readonly && !bitmap_empty(&repaired, stripe->nr_sectors)) {
1085 if (btrfs_is_zoned(fs_info)) {
1086 btrfs_repair_one_zone(fs_info, sctx->stripes[0].bg->start);
1087 } else {
1088 scrub_write_sectors(sctx, stripe, repaired, false);
1089 wait_scrub_stripe_io(stripe);
1090 }
1091 }
1092
1093 scrub_stripe_report_errors(sctx, stripe);
1094 set_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state);
1095 wake_up(&stripe->repair_wait);
1096}
1097
1098static void scrub_read_endio(struct btrfs_bio *bbio)
1099{
1100 struct scrub_stripe *stripe = bbio->private;
1101 struct bio_vec *bvec;
1102 int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio));
1103 int num_sectors;
1104 u32 bio_size = 0;
1105 int i;
1106
1107 ASSERT(sector_nr < stripe->nr_sectors);
1108 bio_for_each_bvec_all(bvec, &bbio->bio, i)
1109 bio_size += bvec->bv_len;
1110 num_sectors = bio_size >> stripe->bg->fs_info->sectorsize_bits;
1111
1112 if (bbio->bio.bi_status) {
1113 bitmap_set(&stripe->io_error_bitmap, sector_nr, num_sectors);
1114 bitmap_set(&stripe->error_bitmap, sector_nr, num_sectors);
1115 } else {
1116 bitmap_clear(&stripe->io_error_bitmap, sector_nr, num_sectors);
1117 }
1118 bio_put(&bbio->bio);
1119 if (atomic_dec_and_test(&stripe->pending_io)) {
1120 wake_up(&stripe->io_wait);
1121 INIT_WORK(&stripe->work, scrub_stripe_read_repair_worker);
1122 queue_work(stripe->bg->fs_info->scrub_workers, &stripe->work);
1123 }
1124}
1125
1126static void scrub_write_endio(struct btrfs_bio *bbio)
1127{
1128 struct scrub_stripe *stripe = bbio->private;
1129 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
1130 struct bio_vec *bvec;
1131 int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio));
1132 u32 bio_size = 0;
1133 int i;
1134
1135 bio_for_each_bvec_all(bvec, &bbio->bio, i)
1136 bio_size += bvec->bv_len;
1137
1138 if (bbio->bio.bi_status) {
1139 unsigned long flags;
1140
1141 spin_lock_irqsave(&stripe->write_error_lock, flags);
1142 bitmap_set(&stripe->write_error_bitmap, sector_nr,
1143 bio_size >> fs_info->sectorsize_bits);
1144 spin_unlock_irqrestore(&stripe->write_error_lock, flags);
1145 }
1146 bio_put(&bbio->bio);
1147
1148 if (atomic_dec_and_test(&stripe->pending_io))
1149 wake_up(&stripe->io_wait);
1150}
1151
1152static void scrub_submit_write_bio(struct scrub_ctx *sctx,
1153 struct scrub_stripe *stripe,
1154 struct btrfs_bio *bbio, bool dev_replace)
1155{
1156 struct btrfs_fs_info *fs_info = sctx->fs_info;
1157 u32 bio_len = bbio->bio.bi_iter.bi_size;
1158 u32 bio_off = (bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT) -
1159 stripe->logical;
1160
1161 fill_writer_pointer_gap(sctx, stripe->physical + bio_off);
1162 atomic_inc(&stripe->pending_io);
1163 btrfs_submit_repair_write(bbio, stripe->mirror_num, dev_replace);
1164 if (!btrfs_is_zoned(fs_info))
1165 return;
1166 /*
1167 * For zoned writeback, queue depth must be 1, thus we must wait for
1168 * the write to finish before the next write.
1169 */
1170 wait_scrub_stripe_io(stripe);
1171
1172 /*
1173 * And also need to update the write pointer if write finished
1174 * successfully.
1175 */
1176 if (!test_bit(bio_off >> fs_info->sectorsize_bits,
1177 &stripe->write_error_bitmap))
1178 sctx->write_pointer += bio_len;
1179}
1180
1181/*
1182 * Submit the write bio(s) for the sectors specified by @write_bitmap.
1183 *
1184 * Here we utilize btrfs_submit_repair_write(), which has some extra benefits:
1185 *
1186 * - Only needs logical bytenr and mirror_num
1187 * Just like the scrub read path
1188 *
1189 * - Would only result in writes to the specified mirror
1190 * Unlike the regular writeback path, which would write back to all stripes
1191 *
1192 * - Handle dev-replace and read-repair writeback differently
1193 */
1194static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe,
1195 unsigned long write_bitmap, bool dev_replace)
1196{
1197 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
1198 struct btrfs_bio *bbio = NULL;
1199 int sector_nr;
1200
1201 for_each_set_bit(sector_nr, &write_bitmap, stripe->nr_sectors) {
1202 struct page *page = scrub_stripe_get_page(stripe, sector_nr);
1203 unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr);
1204 int ret;
1205
1206 /* We should only writeback sectors covered by an extent. */
1207 ASSERT(test_bit(sector_nr, &stripe->extent_sector_bitmap));
1208
1209 /* Cannot merge with previous sector, submit the current one. */
1210 if (bbio && sector_nr && !test_bit(sector_nr - 1, &write_bitmap)) {
1211 scrub_submit_write_bio(sctx, stripe, bbio, dev_replace);
1212 bbio = NULL;
1213 }
1214 if (!bbio) {
1215 bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_WRITE,
1216 fs_info, scrub_write_endio, stripe);
1217 bbio->bio.bi_iter.bi_sector = (stripe->logical +
1218 (sector_nr << fs_info->sectorsize_bits)) >>
1219 SECTOR_SHIFT;
1220 }
1221 ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
1222 ASSERT(ret == fs_info->sectorsize);
1223 }
1224 if (bbio)
1225 scrub_submit_write_bio(sctx, stripe, bbio, dev_replace);
1226}
1227
1228/*
1229 * Throttling of IO submission, bandwidth-limit based, the timeslice is 1
1230 * second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max.
1231 */
1232static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *device,
1233 unsigned int bio_size)
1234{
1235 const int time_slice = 1000;
1236 s64 delta;
1237 ktime_t now;
1238 u32 div;
1239 u64 bwlimit;
1240
1241 bwlimit = READ_ONCE(device->scrub_speed_max);
1242 if (bwlimit == 0)
1243 return;
1244
1245 /*
1246 * Slice is divided into intervals when the IO is submitted, adjust by
1247 * bwlimit and maximum of 64 intervals.
1248 */
1249 div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024)));
1250 div = min_t(u32, 64, div);
1251
1252 /* Start new epoch, set deadline */
1253 now = ktime_get();
1254 if (sctx->throttle_deadline == 0) {
1255 sctx->throttle_deadline = ktime_add_ms(now, time_slice / div);
1256 sctx->throttle_sent = 0;
1257 }
1258
1259 /* Still in the time to send? */
1260 if (ktime_before(now, sctx->throttle_deadline)) {
1261 /* If current bio is within the limit, send it */
1262 sctx->throttle_sent += bio_size;
1263 if (sctx->throttle_sent <= div_u64(bwlimit, div))
1264 return;
1265
1266 /* We're over the limit, sleep until the rest of the slice */
1267 delta = ktime_ms_delta(sctx->throttle_deadline, now);
1268 } else {
1269 /* New request after deadline, start new epoch */
1270 delta = 0;
1271 }
1272
1273 if (delta) {
1274 long timeout;
1275
1276 timeout = div_u64(delta * HZ, 1000);
1277 schedule_timeout_interruptible(timeout);
1278 }
1279
1280 /* Next call will start the deadline period */
1281 sctx->throttle_deadline = 0;
1282}
1283
1284/*
1285 * Given a physical address, this will calculate it's
1286 * logical offset. if this is a parity stripe, it will return
1287 * the most left data stripe's logical offset.
1288 *
1289 * return 0 if it is a data stripe, 1 means parity stripe.
1290 */
1291static int get_raid56_logic_offset(u64 physical, int num,
1292 struct btrfs_chunk_map *map, u64 *offset,
1293 u64 *stripe_start)
1294{
1295 int i;
1296 int j = 0;
1297 u64 last_offset;
1298 const int data_stripes = nr_data_stripes(map);
1299
1300 last_offset = (physical - map->stripes[num].physical) * data_stripes;
1301 if (stripe_start)
1302 *stripe_start = last_offset;
1303
1304 *offset = last_offset;
1305 for (i = 0; i < data_stripes; i++) {
1306 u32 stripe_nr;
1307 u32 stripe_index;
1308 u32 rot;
1309
1310 *offset = last_offset + btrfs_stripe_nr_to_offset(i);
1311
1312 stripe_nr = (u32)(*offset >> BTRFS_STRIPE_LEN_SHIFT) / data_stripes;
1313
1314 /* Work out the disk rotation on this stripe-set */
1315 rot = stripe_nr % map->num_stripes;
1316 /* calculate which stripe this data locates */
1317 rot += i;
1318 stripe_index = rot % map->num_stripes;
1319 if (stripe_index == num)
1320 return 0;
1321 if (stripe_index < num)
1322 j++;
1323 }
1324 *offset = last_offset + btrfs_stripe_nr_to_offset(j);
1325 return 1;
1326}
1327
1328/*
1329 * Return 0 if the extent item range covers any byte of the range.
1330 * Return <0 if the extent item is before @search_start.
1331 * Return >0 if the extent item is after @start_start + @search_len.
1332 */
1333static int compare_extent_item_range(struct btrfs_path *path,
1334 u64 search_start, u64 search_len)
1335{
1336 struct btrfs_fs_info *fs_info = path->nodes[0]->fs_info;
1337 u64 len;
1338 struct btrfs_key key;
1339
1340 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1341 ASSERT(key.type == BTRFS_EXTENT_ITEM_KEY ||
1342 key.type == BTRFS_METADATA_ITEM_KEY);
1343 if (key.type == BTRFS_METADATA_ITEM_KEY)
1344 len = fs_info->nodesize;
1345 else
1346 len = key.offset;
1347
1348 if (key.objectid + len <= search_start)
1349 return -1;
1350 if (key.objectid >= search_start + search_len)
1351 return 1;
1352 return 0;
1353}
1354
1355/*
1356 * Locate one extent item which covers any byte in range
1357 * [@search_start, @search_start + @search_length)
1358 *
1359 * If the path is not initialized, we will initialize the search by doing
1360 * a btrfs_search_slot().
1361 * If the path is already initialized, we will use the path as the initial
1362 * slot, to avoid duplicated btrfs_search_slot() calls.
1363 *
1364 * NOTE: If an extent item starts before @search_start, we will still
1365 * return the extent item. This is for data extent crossing stripe boundary.
1366 *
1367 * Return 0 if we found such extent item, and @path will point to the extent item.
1368 * Return >0 if no such extent item can be found, and @path will be released.
1369 * Return <0 if hit fatal error, and @path will be released.
1370 */
1371static int find_first_extent_item(struct btrfs_root *extent_root,
1372 struct btrfs_path *path,
1373 u64 search_start, u64 search_len)
1374{
1375 struct btrfs_fs_info *fs_info = extent_root->fs_info;
1376 struct btrfs_key key;
1377 int ret;
1378
1379 /* Continue using the existing path */
1380 if (path->nodes[0])
1381 goto search_forward;
1382
1383 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
1384 key.type = BTRFS_METADATA_ITEM_KEY;
1385 else
1386 key.type = BTRFS_EXTENT_ITEM_KEY;
1387 key.objectid = search_start;
1388 key.offset = (u64)-1;
1389
1390 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
1391 if (ret < 0)
1392 return ret;
1393 if (ret == 0) {
1394 /*
1395 * Key with offset -1 found, there would have to exist an extent
1396 * item with such offset, but this is out of the valid range.
1397 */
1398 btrfs_release_path(path);
1399 return -EUCLEAN;
1400 }
1401
1402 /*
1403 * Here we intentionally pass 0 as @min_objectid, as there could be
1404 * an extent item starting before @search_start.
1405 */
1406 ret = btrfs_previous_extent_item(extent_root, path, 0);
1407 if (ret < 0)
1408 return ret;
1409 /*
1410 * No matter whether we have found an extent item, the next loop will
1411 * properly do every check on the key.
1412 */
1413search_forward:
1414 while (true) {
1415 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1416 if (key.objectid >= search_start + search_len)
1417 break;
1418 if (key.type != BTRFS_METADATA_ITEM_KEY &&
1419 key.type != BTRFS_EXTENT_ITEM_KEY)
1420 goto next;
1421
1422 ret = compare_extent_item_range(path, search_start, search_len);
1423 if (ret == 0)
1424 return ret;
1425 if (ret > 0)
1426 break;
1427next:
1428 ret = btrfs_next_item(extent_root, path);
1429 if (ret) {
1430 /* Either no more items or a fatal error. */
1431 btrfs_release_path(path);
1432 return ret;
1433 }
1434 }
1435 btrfs_release_path(path);
1436 return 1;
1437}
1438
1439static void get_extent_info(struct btrfs_path *path, u64 *extent_start_ret,
1440 u64 *size_ret, u64 *flags_ret, u64 *generation_ret)
1441{
1442 struct btrfs_key key;
1443 struct btrfs_extent_item *ei;
1444
1445 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1446 ASSERT(key.type == BTRFS_METADATA_ITEM_KEY ||
1447 key.type == BTRFS_EXTENT_ITEM_KEY);
1448 *extent_start_ret = key.objectid;
1449 if (key.type == BTRFS_METADATA_ITEM_KEY)
1450 *size_ret = path->nodes[0]->fs_info->nodesize;
1451 else
1452 *size_ret = key.offset;
1453 ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item);
1454 *flags_ret = btrfs_extent_flags(path->nodes[0], ei);
1455 *generation_ret = btrfs_extent_generation(path->nodes[0], ei);
1456}
1457
1458static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
1459 u64 physical, u64 physical_end)
1460{
1461 struct btrfs_fs_info *fs_info = sctx->fs_info;
1462 int ret = 0;
1463
1464 if (!btrfs_is_zoned(fs_info))
1465 return 0;
1466
1467 mutex_lock(&sctx->wr_lock);
1468 if (sctx->write_pointer < physical_end) {
1469 ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical,
1470 physical,
1471 sctx->write_pointer);
1472 if (ret)
1473 btrfs_err(fs_info,
1474 "zoned: failed to recover write pointer");
1475 }
1476 mutex_unlock(&sctx->wr_lock);
1477 btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical);
1478
1479 return ret;
1480}
1481
1482static void fill_one_extent_info(struct btrfs_fs_info *fs_info,
1483 struct scrub_stripe *stripe,
1484 u64 extent_start, u64 extent_len,
1485 u64 extent_flags, u64 extent_gen)
1486{
1487 for (u64 cur_logical = max(stripe->logical, extent_start);
1488 cur_logical < min(stripe->logical + BTRFS_STRIPE_LEN,
1489 extent_start + extent_len);
1490 cur_logical += fs_info->sectorsize) {
1491 const int nr_sector = (cur_logical - stripe->logical) >>
1492 fs_info->sectorsize_bits;
1493 struct scrub_sector_verification *sector =
1494 &stripe->sectors[nr_sector];
1495
1496 set_bit(nr_sector, &stripe->extent_sector_bitmap);
1497 if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1498 sector->is_metadata = true;
1499 sector->generation = extent_gen;
1500 }
1501 }
1502}
1503
1504static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe)
1505{
1506 stripe->extent_sector_bitmap = 0;
1507 stripe->init_error_bitmap = 0;
1508 stripe->init_nr_io_errors = 0;
1509 stripe->init_nr_csum_errors = 0;
1510 stripe->init_nr_meta_errors = 0;
1511 stripe->error_bitmap = 0;
1512 stripe->io_error_bitmap = 0;
1513 stripe->csum_error_bitmap = 0;
1514 stripe->meta_error_bitmap = 0;
1515}
1516
1517/*
1518 * Locate one stripe which has at least one extent in its range.
1519 *
1520 * Return 0 if found such stripe, and store its info into @stripe.
1521 * Return >0 if there is no such stripe in the specified range.
1522 * Return <0 for error.
1523 */
1524static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
1525 struct btrfs_path *extent_path,
1526 struct btrfs_path *csum_path,
1527 struct btrfs_device *dev, u64 physical,
1528 int mirror_num, u64 logical_start,
1529 u32 logical_len,
1530 struct scrub_stripe *stripe)
1531{
1532 struct btrfs_fs_info *fs_info = bg->fs_info;
1533 struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start);
1534 struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bg->start);
1535 const u64 logical_end = logical_start + logical_len;
1536 u64 cur_logical = logical_start;
1537 u64 stripe_end;
1538 u64 extent_start;
1539 u64 extent_len;
1540 u64 extent_flags;
1541 u64 extent_gen;
1542 int ret;
1543
1544 memset(stripe->sectors, 0, sizeof(struct scrub_sector_verification) *
1545 stripe->nr_sectors);
1546 scrub_stripe_reset_bitmaps(stripe);
1547
1548 /* The range must be inside the bg. */
1549 ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
1550
1551 ret = find_first_extent_item(extent_root, extent_path, logical_start,
1552 logical_len);
1553 /* Either error or not found. */
1554 if (ret)
1555 goto out;
1556 get_extent_info(extent_path, &extent_start, &extent_len, &extent_flags,
1557 &extent_gen);
1558 if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1559 stripe->nr_meta_extents++;
1560 if (extent_flags & BTRFS_EXTENT_FLAG_DATA)
1561 stripe->nr_data_extents++;
1562 cur_logical = max(extent_start, cur_logical);
1563
1564 /*
1565 * Round down to stripe boundary.
1566 *
1567 * The extra calculation against bg->start is to handle block groups
1568 * whose logical bytenr is not BTRFS_STRIPE_LEN aligned.
1569 */
1570 stripe->logical = round_down(cur_logical - bg->start, BTRFS_STRIPE_LEN) +
1571 bg->start;
1572 stripe->physical = physical + stripe->logical - logical_start;
1573 stripe->dev = dev;
1574 stripe->bg = bg;
1575 stripe->mirror_num = mirror_num;
1576 stripe_end = stripe->logical + BTRFS_STRIPE_LEN - 1;
1577
1578 /* Fill the first extent info into stripe->sectors[] array. */
1579 fill_one_extent_info(fs_info, stripe, extent_start, extent_len,
1580 extent_flags, extent_gen);
1581 cur_logical = extent_start + extent_len;
1582
1583 /* Fill the extent info for the remaining sectors. */
1584 while (cur_logical <= stripe_end) {
1585 ret = find_first_extent_item(extent_root, extent_path, cur_logical,
1586 stripe_end - cur_logical + 1);
1587 if (ret < 0)
1588 goto out;
1589 if (ret > 0) {
1590 ret = 0;
1591 break;
1592 }
1593 get_extent_info(extent_path, &extent_start, &extent_len,
1594 &extent_flags, &extent_gen);
1595 if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1596 stripe->nr_meta_extents++;
1597 if (extent_flags & BTRFS_EXTENT_FLAG_DATA)
1598 stripe->nr_data_extents++;
1599 fill_one_extent_info(fs_info, stripe, extent_start, extent_len,
1600 extent_flags, extent_gen);
1601 cur_logical = extent_start + extent_len;
1602 }
1603
1604 /* Now fill the data csum. */
1605 if (bg->flags & BTRFS_BLOCK_GROUP_DATA) {
1606 int sector_nr;
1607 unsigned long csum_bitmap = 0;
1608
1609 /* Csum space should have already been allocated. */
1610 ASSERT(stripe->csums);
1611
1612 /*
1613 * Our csum bitmap should be large enough, as BTRFS_STRIPE_LEN
1614 * should contain at most 16 sectors.
1615 */
1616 ASSERT(BITS_PER_LONG >= BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits);
1617
1618 ret = btrfs_lookup_csums_bitmap(csum_root, csum_path,
1619 stripe->logical, stripe_end,
1620 stripe->csums, &csum_bitmap);
1621 if (ret < 0)
1622 goto out;
1623 if (ret > 0)
1624 ret = 0;
1625
1626 for_each_set_bit(sector_nr, &csum_bitmap, stripe->nr_sectors) {
1627 stripe->sectors[sector_nr].csum = stripe->csums +
1628 sector_nr * fs_info->csum_size;
1629 }
1630 }
1631 set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state);
1632out:
1633 return ret;
1634}
1635
1636static void scrub_reset_stripe(struct scrub_stripe *stripe)
1637{
1638 scrub_stripe_reset_bitmaps(stripe);
1639
1640 stripe->nr_meta_extents = 0;
1641 stripe->nr_data_extents = 0;
1642 stripe->state = 0;
1643
1644 for (int i = 0; i < stripe->nr_sectors; i++) {
1645 stripe->sectors[i].is_metadata = false;
1646 stripe->sectors[i].csum = NULL;
1647 stripe->sectors[i].generation = 0;
1648 }
1649}
1650
1651static void scrub_submit_extent_sector_read(struct scrub_ctx *sctx,
1652 struct scrub_stripe *stripe)
1653{
1654 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
1655 struct btrfs_bio *bbio = NULL;
1656 unsigned int nr_sectors = min(BTRFS_STRIPE_LEN, stripe->bg->start +
1657 stripe->bg->length - stripe->logical) >>
1658 fs_info->sectorsize_bits;
1659 u64 stripe_len = BTRFS_STRIPE_LEN;
1660 int mirror = stripe->mirror_num;
1661 int i;
1662
1663 atomic_inc(&stripe->pending_io);
1664
1665 for_each_set_bit(i, &stripe->extent_sector_bitmap, stripe->nr_sectors) {
1666 struct page *page = scrub_stripe_get_page(stripe, i);
1667 unsigned int pgoff = scrub_stripe_get_page_offset(stripe, i);
1668
1669 /* We're beyond the chunk boundary, no need to read anymore. */
1670 if (i >= nr_sectors)
1671 break;
1672
1673 /* The current sector cannot be merged, submit the bio. */
1674 if (bbio &&
1675 ((i > 0 &&
1676 !test_bit(i - 1, &stripe->extent_sector_bitmap)) ||
1677 bbio->bio.bi_iter.bi_size >= stripe_len)) {
1678 ASSERT(bbio->bio.bi_iter.bi_size);
1679 atomic_inc(&stripe->pending_io);
1680 btrfs_submit_bio(bbio, mirror);
1681 bbio = NULL;
1682 }
1683
1684 if (!bbio) {
1685 struct btrfs_io_stripe io_stripe = {};
1686 struct btrfs_io_context *bioc = NULL;
1687 const u64 logical = stripe->logical +
1688 (i << fs_info->sectorsize_bits);
1689 int err;
1690
1691 bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ,
1692 fs_info, scrub_read_endio, stripe);
1693 bbio->bio.bi_iter.bi_sector = logical >> SECTOR_SHIFT;
1694
1695 io_stripe.is_scrub = true;
1696 err = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
1697 &stripe_len, &bioc, &io_stripe,
1698 &mirror);
1699 btrfs_put_bioc(bioc);
1700 if (err) {
1701 btrfs_bio_end_io(bbio,
1702 errno_to_blk_status(err));
1703 return;
1704 }
1705 }
1706
1707 __bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
1708 }
1709
1710 if (bbio) {
1711 ASSERT(bbio->bio.bi_iter.bi_size);
1712 atomic_inc(&stripe->pending_io);
1713 btrfs_submit_bio(bbio, mirror);
1714 }
1715
1716 if (atomic_dec_and_test(&stripe->pending_io)) {
1717 wake_up(&stripe->io_wait);
1718 INIT_WORK(&stripe->work, scrub_stripe_read_repair_worker);
1719 queue_work(stripe->bg->fs_info->scrub_workers, &stripe->work);
1720 }
1721}
1722
1723static void scrub_submit_initial_read(struct scrub_ctx *sctx,
1724 struct scrub_stripe *stripe)
1725{
1726 struct btrfs_fs_info *fs_info = sctx->fs_info;
1727 struct btrfs_bio *bbio;
1728 unsigned int nr_sectors = min(BTRFS_STRIPE_LEN, stripe->bg->start +
1729 stripe->bg->length - stripe->logical) >>
1730 fs_info->sectorsize_bits;
1731 int mirror = stripe->mirror_num;
1732
1733 ASSERT(stripe->bg);
1734 ASSERT(stripe->mirror_num > 0);
1735 ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state));
1736
1737 if (btrfs_need_stripe_tree_update(fs_info, stripe->bg->flags)) {
1738 scrub_submit_extent_sector_read(sctx, stripe);
1739 return;
1740 }
1741
1742 bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info,
1743 scrub_read_endio, stripe);
1744
1745 bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT;
1746 /* Read the whole range inside the chunk boundary. */
1747 for (unsigned int cur = 0; cur < nr_sectors; cur++) {
1748 struct page *page = scrub_stripe_get_page(stripe, cur);
1749 unsigned int pgoff = scrub_stripe_get_page_offset(stripe, cur);
1750 int ret;
1751
1752 ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
1753 /* We should have allocated enough bio vectors. */
1754 ASSERT(ret == fs_info->sectorsize);
1755 }
1756 atomic_inc(&stripe->pending_io);
1757
1758 /*
1759 * For dev-replace, either user asks to avoid the source dev, or
1760 * the device is missing, we try the next mirror instead.
1761 */
1762 if (sctx->is_dev_replace &&
1763 (fs_info->dev_replace.cont_reading_from_srcdev_mode ==
1764 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID ||
1765 !stripe->dev->bdev)) {
1766 int num_copies = btrfs_num_copies(fs_info, stripe->bg->start,
1767 stripe->bg->length);
1768
1769 mirror = calc_next_mirror(mirror, num_copies);
1770 }
1771 btrfs_submit_bio(bbio, mirror);
1772}
1773
1774static bool stripe_has_metadata_error(struct scrub_stripe *stripe)
1775{
1776 int i;
1777
1778 for_each_set_bit(i, &stripe->error_bitmap, stripe->nr_sectors) {
1779 if (stripe->sectors[i].is_metadata) {
1780 struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
1781
1782 btrfs_err(fs_info,
1783 "stripe %llu has unrepaired metadata sector at %llu",
1784 stripe->logical,
1785 stripe->logical + (i << fs_info->sectorsize_bits));
1786 return true;
1787 }
1788 }
1789 return false;
1790}
1791
1792static void submit_initial_group_read(struct scrub_ctx *sctx,
1793 unsigned int first_slot,
1794 unsigned int nr_stripes)
1795{
1796 struct blk_plug plug;
1797
1798 ASSERT(first_slot < SCRUB_TOTAL_STRIPES);
1799 ASSERT(first_slot + nr_stripes <= SCRUB_TOTAL_STRIPES);
1800
1801 scrub_throttle_dev_io(sctx, sctx->stripes[0].dev,
1802 btrfs_stripe_nr_to_offset(nr_stripes));
1803 blk_start_plug(&plug);
1804 for (int i = 0; i < nr_stripes; i++) {
1805 struct scrub_stripe *stripe = &sctx->stripes[first_slot + i];
1806
1807 /* Those stripes should be initialized. */
1808 ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state));
1809 scrub_submit_initial_read(sctx, stripe);
1810 }
1811 blk_finish_plug(&plug);
1812}
1813
1814static int flush_scrub_stripes(struct scrub_ctx *sctx)
1815{
1816 struct btrfs_fs_info *fs_info = sctx->fs_info;
1817 struct scrub_stripe *stripe;
1818 const int nr_stripes = sctx->cur_stripe;
1819 int ret = 0;
1820
1821 if (!nr_stripes)
1822 return 0;
1823
1824 ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state));
1825
1826 /* Submit the stripes which are populated but not submitted. */
1827 if (nr_stripes % SCRUB_STRIPES_PER_GROUP) {
1828 const int first_slot = round_down(nr_stripes, SCRUB_STRIPES_PER_GROUP);
1829
1830 submit_initial_group_read(sctx, first_slot, nr_stripes - first_slot);
1831 }
1832
1833 for (int i = 0; i < nr_stripes; i++) {
1834 stripe = &sctx->stripes[i];
1835
1836 wait_event(stripe->repair_wait,
1837 test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state));
1838 }
1839
1840 /* Submit for dev-replace. */
1841 if (sctx->is_dev_replace) {
1842 /*
1843 * For dev-replace, if we know there is something wrong with
1844 * metadata, we should immediately abort.
1845 */
1846 for (int i = 0; i < nr_stripes; i++) {
1847 if (stripe_has_metadata_error(&sctx->stripes[i])) {
1848 ret = -EIO;
1849 goto out;
1850 }
1851 }
1852 for (int i = 0; i < nr_stripes; i++) {
1853 unsigned long good;
1854
1855 stripe = &sctx->stripes[i];
1856
1857 ASSERT(stripe->dev == fs_info->dev_replace.srcdev);
1858
1859 bitmap_andnot(&good, &stripe->extent_sector_bitmap,
1860 &stripe->error_bitmap, stripe->nr_sectors);
1861 scrub_write_sectors(sctx, stripe, good, true);
1862 }
1863 }
1864
1865 /* Wait for the above writebacks to finish. */
1866 for (int i = 0; i < nr_stripes; i++) {
1867 stripe = &sctx->stripes[i];
1868
1869 wait_scrub_stripe_io(stripe);
1870 scrub_reset_stripe(stripe);
1871 }
1872out:
1873 sctx->cur_stripe = 0;
1874 return ret;
1875}
1876
1877static void raid56_scrub_wait_endio(struct bio *bio)
1878{
1879 complete(bio->bi_private);
1880}
1881
1882static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg,
1883 struct btrfs_device *dev, int mirror_num,
1884 u64 logical, u32 length, u64 physical,
1885 u64 *found_logical_ret)
1886{
1887 struct scrub_stripe *stripe;
1888 int ret;
1889
1890 /*
1891 * There should always be one slot left, as caller filling the last
1892 * slot should flush them all.
1893 */
1894 ASSERT(sctx->cur_stripe < SCRUB_TOTAL_STRIPES);
1895
1896 /* @found_logical_ret must be specified. */
1897 ASSERT(found_logical_ret);
1898
1899 stripe = &sctx->stripes[sctx->cur_stripe];
1900 scrub_reset_stripe(stripe);
1901 ret = scrub_find_fill_first_stripe(bg, &sctx->extent_path,
1902 &sctx->csum_path, dev, physical,
1903 mirror_num, logical, length, stripe);
1904 /* Either >0 as no more extents or <0 for error. */
1905 if (ret)
1906 return ret;
1907 *found_logical_ret = stripe->logical;
1908 sctx->cur_stripe++;
1909
1910 /* We filled one group, submit it. */
1911 if (sctx->cur_stripe % SCRUB_STRIPES_PER_GROUP == 0) {
1912 const int first_slot = sctx->cur_stripe - SCRUB_STRIPES_PER_GROUP;
1913
1914 submit_initial_group_read(sctx, first_slot, SCRUB_STRIPES_PER_GROUP);
1915 }
1916
1917 /* Last slot used, flush them all. */
1918 if (sctx->cur_stripe == SCRUB_TOTAL_STRIPES)
1919 return flush_scrub_stripes(sctx);
1920 return 0;
1921}
1922
1923static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
1924 struct btrfs_device *scrub_dev,
1925 struct btrfs_block_group *bg,
1926 struct btrfs_chunk_map *map,
1927 u64 full_stripe_start)
1928{
1929 DECLARE_COMPLETION_ONSTACK(io_done);
1930 struct btrfs_fs_info *fs_info = sctx->fs_info;
1931 struct btrfs_raid_bio *rbio;
1932 struct btrfs_io_context *bioc = NULL;
1933 struct btrfs_path extent_path = { 0 };
1934 struct btrfs_path csum_path = { 0 };
1935 struct bio *bio;
1936 struct scrub_stripe *stripe;
1937 bool all_empty = true;
1938 const int data_stripes = nr_data_stripes(map);
1939 unsigned long extent_bitmap = 0;
1940 u64 length = btrfs_stripe_nr_to_offset(data_stripes);
1941 int ret;
1942
1943 ASSERT(sctx->raid56_data_stripes);
1944
1945 /*
1946 * For data stripe search, we cannot re-use the same extent/csum paths,
1947 * as the data stripe bytenr may be smaller than previous extent. Thus
1948 * we have to use our own extent/csum paths.
1949 */
1950 extent_path.search_commit_root = 1;
1951 extent_path.skip_locking = 1;
1952 csum_path.search_commit_root = 1;
1953 csum_path.skip_locking = 1;
1954
1955 for (int i = 0; i < data_stripes; i++) {
1956 int stripe_index;
1957 int rot;
1958 u64 physical;
1959
1960 stripe = &sctx->raid56_data_stripes[i];
1961 rot = div_u64(full_stripe_start - bg->start,
1962 data_stripes) >> BTRFS_STRIPE_LEN_SHIFT;
1963 stripe_index = (i + rot) % map->num_stripes;
1964 physical = map->stripes[stripe_index].physical +
1965 btrfs_stripe_nr_to_offset(rot);
1966
1967 scrub_reset_stripe(stripe);
1968 set_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state);
1969 ret = scrub_find_fill_first_stripe(bg, &extent_path, &csum_path,
1970 map->stripes[stripe_index].dev, physical, 1,
1971 full_stripe_start + btrfs_stripe_nr_to_offset(i),
1972 BTRFS_STRIPE_LEN, stripe);
1973 if (ret < 0)
1974 goto out;
1975 /*
1976 * No extent in this data stripe, need to manually mark them
1977 * initialized to make later read submission happy.
1978 */
1979 if (ret > 0) {
1980 stripe->logical = full_stripe_start +
1981 btrfs_stripe_nr_to_offset(i);
1982 stripe->dev = map->stripes[stripe_index].dev;
1983 stripe->mirror_num = 1;
1984 set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state);
1985 }
1986 }
1987
1988 /* Check if all data stripes are empty. */
1989 for (int i = 0; i < data_stripes; i++) {
1990 stripe = &sctx->raid56_data_stripes[i];
1991 if (!bitmap_empty(&stripe->extent_sector_bitmap, stripe->nr_sectors)) {
1992 all_empty = false;
1993 break;
1994 }
1995 }
1996 if (all_empty) {
1997 ret = 0;
1998 goto out;
1999 }
2000
2001 for (int i = 0; i < data_stripes; i++) {
2002 stripe = &sctx->raid56_data_stripes[i];
2003 scrub_submit_initial_read(sctx, stripe);
2004 }
2005 for (int i = 0; i < data_stripes; i++) {
2006 stripe = &sctx->raid56_data_stripes[i];
2007
2008 wait_event(stripe->repair_wait,
2009 test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state));
2010 }
2011 /* For now, no zoned support for RAID56. */
2012 ASSERT(!btrfs_is_zoned(sctx->fs_info));
2013
2014 /*
2015 * Now all data stripes are properly verified. Check if we have any
2016 * unrepaired, if so abort immediately or we could further corrupt the
2017 * P/Q stripes.
2018 *
2019 * During the loop, also populate extent_bitmap.
2020 */
2021 for (int i = 0; i < data_stripes; i++) {
2022 unsigned long error;
2023
2024 stripe = &sctx->raid56_data_stripes[i];
2025
2026 /*
2027 * We should only check the errors where there is an extent.
2028 * As we may hit an empty data stripe while it's missing.
2029 */
2030 bitmap_and(&error, &stripe->error_bitmap,
2031 &stripe->extent_sector_bitmap, stripe->nr_sectors);
2032 if (!bitmap_empty(&error, stripe->nr_sectors)) {
2033 btrfs_err(fs_info,
2034"unrepaired sectors detected, full stripe %llu data stripe %u errors %*pbl",
2035 full_stripe_start, i, stripe->nr_sectors,
2036 &error);
2037 ret = -EIO;
2038 goto out;
2039 }
2040 bitmap_or(&extent_bitmap, &extent_bitmap,
2041 &stripe->extent_sector_bitmap, stripe->nr_sectors);
2042 }
2043
2044 /* Now we can check and regenerate the P/Q stripe. */
2045 bio = bio_alloc(NULL, 1, REQ_OP_READ, GFP_NOFS);
2046 bio->bi_iter.bi_sector = full_stripe_start >> SECTOR_SHIFT;
2047 bio->bi_private = &io_done;
2048 bio->bi_end_io = raid56_scrub_wait_endio;
2049
2050 btrfs_bio_counter_inc_blocked(fs_info);
2051 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, full_stripe_start,
2052 &length, &bioc, NULL, NULL);
2053 if (ret < 0) {
2054 btrfs_put_bioc(bioc);
2055 btrfs_bio_counter_dec(fs_info);
2056 goto out;
2057 }
2058 rbio = raid56_parity_alloc_scrub_rbio(bio, bioc, scrub_dev, &extent_bitmap,
2059 BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits);
2060 btrfs_put_bioc(bioc);
2061 if (!rbio) {
2062 ret = -ENOMEM;
2063 btrfs_bio_counter_dec(fs_info);
2064 goto out;
2065 }
2066 /* Use the recovered stripes as cache to avoid read them from disk again. */
2067 for (int i = 0; i < data_stripes; i++) {
2068 stripe = &sctx->raid56_data_stripes[i];
2069
2070 raid56_parity_cache_data_pages(rbio, stripe->pages,
2071 full_stripe_start + (i << BTRFS_STRIPE_LEN_SHIFT));
2072 }
2073 raid56_parity_submit_scrub_rbio(rbio);
2074 wait_for_completion_io(&io_done);
2075 ret = blk_status_to_errno(bio->bi_status);
2076 bio_put(bio);
2077 btrfs_bio_counter_dec(fs_info);
2078
2079 btrfs_release_path(&extent_path);
2080 btrfs_release_path(&csum_path);
2081out:
2082 return ret;
2083}
2084
2085/*
2086 * Scrub one range which can only has simple mirror based profile.
2087 * (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in
2088 * RAID0/RAID10).
2089 *
2090 * Since we may need to handle a subset of block group, we need @logical_start
2091 * and @logical_length parameter.
2092 */
2093static int scrub_simple_mirror(struct scrub_ctx *sctx,
2094 struct btrfs_block_group *bg,
2095 struct btrfs_chunk_map *map,
2096 u64 logical_start, u64 logical_length,
2097 struct btrfs_device *device,
2098 u64 physical, int mirror_num)
2099{
2100 struct btrfs_fs_info *fs_info = sctx->fs_info;
2101 const u64 logical_end = logical_start + logical_length;
2102 u64 cur_logical = logical_start;
2103 int ret;
2104
2105 /* The range must be inside the bg */
2106 ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
2107
2108 /* Go through each extent items inside the logical range */
2109 while (cur_logical < logical_end) {
2110 u64 found_logical = U64_MAX;
2111 u64 cur_physical = physical + cur_logical - logical_start;
2112
2113 /* Canceled? */
2114 if (atomic_read(&fs_info->scrub_cancel_req) ||
2115 atomic_read(&sctx->cancel_req)) {
2116 ret = -ECANCELED;
2117 break;
2118 }
2119 /* Paused? */
2120 if (atomic_read(&fs_info->scrub_pause_req)) {
2121 /* Push queued extents */
2122 scrub_blocked_if_needed(fs_info);
2123 }
2124 /* Block group removed? */
2125 spin_lock(&bg->lock);
2126 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) {
2127 spin_unlock(&bg->lock);
2128 ret = 0;
2129 break;
2130 }
2131 spin_unlock(&bg->lock);
2132
2133 ret = queue_scrub_stripe(sctx, bg, device, mirror_num,
2134 cur_logical, logical_end - cur_logical,
2135 cur_physical, &found_logical);
2136 if (ret > 0) {
2137 /* No more extent, just update the accounting */
2138 sctx->stat.last_physical = physical + logical_length;
2139 ret = 0;
2140 break;
2141 }
2142 if (ret < 0)
2143 break;
2144
2145 /* queue_scrub_stripe() returned 0, @found_logical must be updated. */
2146 ASSERT(found_logical != U64_MAX);
2147 cur_logical = found_logical + BTRFS_STRIPE_LEN;
2148
2149 /* Don't hold CPU for too long time */
2150 cond_resched();
2151 }
2152 return ret;
2153}
2154
2155/* Calculate the full stripe length for simple stripe based profiles */
2156static u64 simple_stripe_full_stripe_len(const struct btrfs_chunk_map *map)
2157{
2158 ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2159 BTRFS_BLOCK_GROUP_RAID10));
2160
2161 return btrfs_stripe_nr_to_offset(map->num_stripes / map->sub_stripes);
2162}
2163
2164/* Get the logical bytenr for the stripe */
2165static u64 simple_stripe_get_logical(struct btrfs_chunk_map *map,
2166 struct btrfs_block_group *bg,
2167 int stripe_index)
2168{
2169 ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2170 BTRFS_BLOCK_GROUP_RAID10));
2171 ASSERT(stripe_index < map->num_stripes);
2172
2173 /*
2174 * (stripe_index / sub_stripes) gives how many data stripes we need to
2175 * skip.
2176 */
2177 return btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes) +
2178 bg->start;
2179}
2180
2181/* Get the mirror number for the stripe */
2182static int simple_stripe_mirror_num(struct btrfs_chunk_map *map, int stripe_index)
2183{
2184 ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2185 BTRFS_BLOCK_GROUP_RAID10));
2186 ASSERT(stripe_index < map->num_stripes);
2187
2188 /* For RAID0, it's fixed to 1, for RAID10 it's 0,1,0,1... */
2189 return stripe_index % map->sub_stripes + 1;
2190}
2191
2192static int scrub_simple_stripe(struct scrub_ctx *sctx,
2193 struct btrfs_block_group *bg,
2194 struct btrfs_chunk_map *map,
2195 struct btrfs_device *device,
2196 int stripe_index)
2197{
2198 const u64 logical_increment = simple_stripe_full_stripe_len(map);
2199 const u64 orig_logical = simple_stripe_get_logical(map, bg, stripe_index);
2200 const u64 orig_physical = map->stripes[stripe_index].physical;
2201 const int mirror_num = simple_stripe_mirror_num(map, stripe_index);
2202 u64 cur_logical = orig_logical;
2203 u64 cur_physical = orig_physical;
2204 int ret = 0;
2205
2206 while (cur_logical < bg->start + bg->length) {
2207 /*
2208 * Inside each stripe, RAID0 is just SINGLE, and RAID10 is
2209 * just RAID1, so we can reuse scrub_simple_mirror() to scrub
2210 * this stripe.
2211 */
2212 ret = scrub_simple_mirror(sctx, bg, map, cur_logical,
2213 BTRFS_STRIPE_LEN, device, cur_physical,
2214 mirror_num);
2215 if (ret)
2216 return ret;
2217 /* Skip to next stripe which belongs to the target device */
2218 cur_logical += logical_increment;
2219 /* For physical offset, we just go to next stripe */
2220 cur_physical += BTRFS_STRIPE_LEN;
2221 }
2222 return ret;
2223}
2224
2225static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
2226 struct btrfs_block_group *bg,
2227 struct btrfs_chunk_map *map,
2228 struct btrfs_device *scrub_dev,
2229 int stripe_index)
2230{
2231 struct btrfs_fs_info *fs_info = sctx->fs_info;
2232 const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
2233 const u64 chunk_logical = bg->start;
2234 int ret;
2235 int ret2;
2236 u64 physical = map->stripes[stripe_index].physical;
2237 const u64 dev_stripe_len = btrfs_calc_stripe_length(map);
2238 const u64 physical_end = physical + dev_stripe_len;
2239 u64 logical;
2240 u64 logic_end;
2241 /* The logical increment after finishing one stripe */
2242 u64 increment;
2243 /* Offset inside the chunk */
2244 u64 offset;
2245 u64 stripe_logical;
2246 int stop_loop = 0;
2247
2248 /* Extent_path should be released by now. */
2249 ASSERT(sctx->extent_path.nodes[0] == NULL);
2250
2251 scrub_blocked_if_needed(fs_info);
2252
2253 if (sctx->is_dev_replace &&
2254 btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
2255 mutex_lock(&sctx->wr_lock);
2256 sctx->write_pointer = physical;
2257 mutex_unlock(&sctx->wr_lock);
2258 }
2259
2260 /* Prepare the extra data stripes used by RAID56. */
2261 if (profile & BTRFS_BLOCK_GROUP_RAID56_MASK) {
2262 ASSERT(sctx->raid56_data_stripes == NULL);
2263
2264 sctx->raid56_data_stripes = kcalloc(nr_data_stripes(map),
2265 sizeof(struct scrub_stripe),
2266 GFP_KERNEL);
2267 if (!sctx->raid56_data_stripes) {
2268 ret = -ENOMEM;
2269 goto out;
2270 }
2271 for (int i = 0; i < nr_data_stripes(map); i++) {
2272 ret = init_scrub_stripe(fs_info,
2273 &sctx->raid56_data_stripes[i]);
2274 if (ret < 0)
2275 goto out;
2276 sctx->raid56_data_stripes[i].bg = bg;
2277 sctx->raid56_data_stripes[i].sctx = sctx;
2278 }
2279 }
2280 /*
2281 * There used to be a big double loop to handle all profiles using the
2282 * same routine, which grows larger and more gross over time.
2283 *
2284 * So here we handle each profile differently, so simpler profiles
2285 * have simpler scrubbing function.
2286 */
2287 if (!(profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 |
2288 BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2289 /*
2290 * Above check rules out all complex profile, the remaining
2291 * profiles are SINGLE|DUP|RAID1|RAID1C*, which is simple
2292 * mirrored duplication without stripe.
2293 *
2294 * Only @physical and @mirror_num needs to calculated using
2295 * @stripe_index.
2296 */
2297 ret = scrub_simple_mirror(sctx, bg, map, bg->start, bg->length,
2298 scrub_dev, map->stripes[stripe_index].physical,
2299 stripe_index + 1);
2300 offset = 0;
2301 goto out;
2302 }
2303 if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
2304 ret = scrub_simple_stripe(sctx, bg, map, scrub_dev, stripe_index);
2305 offset = btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes);
2306 goto out;
2307 }
2308
2309 /* Only RAID56 goes through the old code */
2310 ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
2311 ret = 0;
2312
2313 /* Calculate the logical end of the stripe */
2314 get_raid56_logic_offset(physical_end, stripe_index,
2315 map, &logic_end, NULL);
2316 logic_end += chunk_logical;
2317
2318 /* Initialize @offset in case we need to go to out: label */
2319 get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
2320 increment = btrfs_stripe_nr_to_offset(nr_data_stripes(map));
2321
2322 /*
2323 * Due to the rotation, for RAID56 it's better to iterate each stripe
2324 * using their physical offset.
2325 */
2326 while (physical < physical_end) {
2327 ret = get_raid56_logic_offset(physical, stripe_index, map,
2328 &logical, &stripe_logical);
2329 logical += chunk_logical;
2330 if (ret) {
2331 /* it is parity strip */
2332 stripe_logical += chunk_logical;
2333 ret = scrub_raid56_parity_stripe(sctx, scrub_dev, bg,
2334 map, stripe_logical);
2335 if (ret)
2336 goto out;
2337 goto next;
2338 }
2339
2340 /*
2341 * Now we're at a data stripe, scrub each extents in the range.
2342 *
2343 * At this stage, if we ignore the repair part, inside each data
2344 * stripe it is no different than SINGLE profile.
2345 * We can reuse scrub_simple_mirror() here, as the repair part
2346 * is still based on @mirror_num.
2347 */
2348 ret = scrub_simple_mirror(sctx, bg, map, logical, BTRFS_STRIPE_LEN,
2349 scrub_dev, physical, 1);
2350 if (ret < 0)
2351 goto out;
2352next:
2353 logical += increment;
2354 physical += BTRFS_STRIPE_LEN;
2355 spin_lock(&sctx->stat_lock);
2356 if (stop_loop)
2357 sctx->stat.last_physical =
2358 map->stripes[stripe_index].physical + dev_stripe_len;
2359 else
2360 sctx->stat.last_physical = physical;
2361 spin_unlock(&sctx->stat_lock);
2362 if (stop_loop)
2363 break;
2364 }
2365out:
2366 ret2 = flush_scrub_stripes(sctx);
2367 if (!ret)
2368 ret = ret2;
2369 btrfs_release_path(&sctx->extent_path);
2370 btrfs_release_path(&sctx->csum_path);
2371
2372 if (sctx->raid56_data_stripes) {
2373 for (int i = 0; i < nr_data_stripes(map); i++)
2374 release_scrub_stripe(&sctx->raid56_data_stripes[i]);
2375 kfree(sctx->raid56_data_stripes);
2376 sctx->raid56_data_stripes = NULL;
2377 }
2378
2379 if (sctx->is_dev_replace && ret >= 0) {
2380 int ret2;
2381
2382 ret2 = sync_write_pointer_for_zoned(sctx,
2383 chunk_logical + offset,
2384 map->stripes[stripe_index].physical,
2385 physical_end);
2386 if (ret2)
2387 ret = ret2;
2388 }
2389
2390 return ret < 0 ? ret : 0;
2391}
2392
2393static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
2394 struct btrfs_block_group *bg,
2395 struct btrfs_device *scrub_dev,
2396 u64 dev_offset,
2397 u64 dev_extent_len)
2398{
2399 struct btrfs_fs_info *fs_info = sctx->fs_info;
2400 struct btrfs_chunk_map *map;
2401 int i;
2402 int ret = 0;
2403
2404 map = btrfs_find_chunk_map(fs_info, bg->start, bg->length);
2405 if (!map) {
2406 /*
2407 * Might have been an unused block group deleted by the cleaner
2408 * kthread or relocation.
2409 */
2410 spin_lock(&bg->lock);
2411 if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags))
2412 ret = -EINVAL;
2413 spin_unlock(&bg->lock);
2414
2415 return ret;
2416 }
2417 if (map->start != bg->start)
2418 goto out;
2419 if (map->chunk_len < dev_extent_len)
2420 goto out;
2421
2422 for (i = 0; i < map->num_stripes; ++i) {
2423 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
2424 map->stripes[i].physical == dev_offset) {
2425 ret = scrub_stripe(sctx, bg, map, scrub_dev, i);
2426 if (ret)
2427 goto out;
2428 }
2429 }
2430out:
2431 btrfs_free_chunk_map(map);
2432
2433 return ret;
2434}
2435
2436static int finish_extent_writes_for_zoned(struct btrfs_root *root,
2437 struct btrfs_block_group *cache)
2438{
2439 struct btrfs_fs_info *fs_info = cache->fs_info;
2440 struct btrfs_trans_handle *trans;
2441
2442 if (!btrfs_is_zoned(fs_info))
2443 return 0;
2444
2445 btrfs_wait_block_group_reservations(cache);
2446 btrfs_wait_nocow_writers(cache);
2447 btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
2448
2449 trans = btrfs_join_transaction(root);
2450 if (IS_ERR(trans))
2451 return PTR_ERR(trans);
2452 return btrfs_commit_transaction(trans);
2453}
2454
2455static noinline_for_stack
2456int scrub_enumerate_chunks(struct scrub_ctx *sctx,
2457 struct btrfs_device *scrub_dev, u64 start, u64 end)
2458{
2459 struct btrfs_dev_extent *dev_extent = NULL;
2460 struct btrfs_path *path;
2461 struct btrfs_fs_info *fs_info = sctx->fs_info;
2462 struct btrfs_root *root = fs_info->dev_root;
2463 u64 chunk_offset;
2464 int ret = 0;
2465 int ro_set;
2466 int slot;
2467 struct extent_buffer *l;
2468 struct btrfs_key key;
2469 struct btrfs_key found_key;
2470 struct btrfs_block_group *cache;
2471 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
2472
2473 path = btrfs_alloc_path();
2474 if (!path)
2475 return -ENOMEM;
2476
2477 path->reada = READA_FORWARD;
2478 path->search_commit_root = 1;
2479 path->skip_locking = 1;
2480
2481 key.objectid = scrub_dev->devid;
2482 key.offset = 0ull;
2483 key.type = BTRFS_DEV_EXTENT_KEY;
2484
2485 while (1) {
2486 u64 dev_extent_len;
2487
2488 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2489 if (ret < 0)
2490 break;
2491 if (ret > 0) {
2492 if (path->slots[0] >=
2493 btrfs_header_nritems(path->nodes[0])) {
2494 ret = btrfs_next_leaf(root, path);
2495 if (ret < 0)
2496 break;
2497 if (ret > 0) {
2498 ret = 0;
2499 break;
2500 }
2501 } else {
2502 ret = 0;
2503 }
2504 }
2505
2506 l = path->nodes[0];
2507 slot = path->slots[0];
2508
2509 btrfs_item_key_to_cpu(l, &found_key, slot);
2510
2511 if (found_key.objectid != scrub_dev->devid)
2512 break;
2513
2514 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
2515 break;
2516
2517 if (found_key.offset >= end)
2518 break;
2519
2520 if (found_key.offset < key.offset)
2521 break;
2522
2523 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2524 dev_extent_len = btrfs_dev_extent_length(l, dev_extent);
2525
2526 if (found_key.offset + dev_extent_len <= start)
2527 goto skip;
2528
2529 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2530
2531 /*
2532 * get a reference on the corresponding block group to prevent
2533 * the chunk from going away while we scrub it
2534 */
2535 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2536
2537 /* some chunks are removed but not committed to disk yet,
2538 * continue scrubbing */
2539 if (!cache)
2540 goto skip;
2541
2542 ASSERT(cache->start <= chunk_offset);
2543 /*
2544 * We are using the commit root to search for device extents, so
2545 * that means we could have found a device extent item from a
2546 * block group that was deleted in the current transaction. The
2547 * logical start offset of the deleted block group, stored at
2548 * @chunk_offset, might be part of the logical address range of
2549 * a new block group (which uses different physical extents).
2550 * In this case btrfs_lookup_block_group() has returned the new
2551 * block group, and its start address is less than @chunk_offset.
2552 *
2553 * We skip such new block groups, because it's pointless to
2554 * process them, as we won't find their extents because we search
2555 * for them using the commit root of the extent tree. For a device
2556 * replace it's also fine to skip it, we won't miss copying them
2557 * to the target device because we have the write duplication
2558 * setup through the regular write path (by btrfs_map_block()),
2559 * and we have committed a transaction when we started the device
2560 * replace, right after setting up the device replace state.
2561 */
2562 if (cache->start < chunk_offset) {
2563 btrfs_put_block_group(cache);
2564 goto skip;
2565 }
2566
2567 if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) {
2568 if (!test_bit(BLOCK_GROUP_FLAG_TO_COPY, &cache->runtime_flags)) {
2569 btrfs_put_block_group(cache);
2570 goto skip;
2571 }
2572 }
2573
2574 /*
2575 * Make sure that while we are scrubbing the corresponding block
2576 * group doesn't get its logical address and its device extents
2577 * reused for another block group, which can possibly be of a
2578 * different type and different profile. We do this to prevent
2579 * false error detections and crashes due to bogus attempts to
2580 * repair extents.
2581 */
2582 spin_lock(&cache->lock);
2583 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags)) {
2584 spin_unlock(&cache->lock);
2585 btrfs_put_block_group(cache);
2586 goto skip;
2587 }
2588 btrfs_freeze_block_group(cache);
2589 spin_unlock(&cache->lock);
2590
2591 /*
2592 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
2593 * to avoid deadlock caused by:
2594 * btrfs_inc_block_group_ro()
2595 * -> btrfs_wait_for_commit()
2596 * -> btrfs_commit_transaction()
2597 * -> btrfs_scrub_pause()
2598 */
2599 scrub_pause_on(fs_info);
2600
2601 /*
2602 * Don't do chunk preallocation for scrub.
2603 *
2604 * This is especially important for SYSTEM bgs, or we can hit
2605 * -EFBIG from btrfs_finish_chunk_alloc() like:
2606 * 1. The only SYSTEM bg is marked RO.
2607 * Since SYSTEM bg is small, that's pretty common.
2608 * 2. New SYSTEM bg will be allocated
2609 * Due to regular version will allocate new chunk.
2610 * 3. New SYSTEM bg is empty and will get cleaned up
2611 * Before cleanup really happens, it's marked RO again.
2612 * 4. Empty SYSTEM bg get scrubbed
2613 * We go back to 2.
2614 *
2615 * This can easily boost the amount of SYSTEM chunks if cleaner
2616 * thread can't be triggered fast enough, and use up all space
2617 * of btrfs_super_block::sys_chunk_array
2618 *
2619 * While for dev replace, we need to try our best to mark block
2620 * group RO, to prevent race between:
2621 * - Write duplication
2622 * Contains latest data
2623 * - Scrub copy
2624 * Contains data from commit tree
2625 *
2626 * If target block group is not marked RO, nocow writes can
2627 * be overwritten by scrub copy, causing data corruption.
2628 * So for dev-replace, it's not allowed to continue if a block
2629 * group is not RO.
2630 */
2631 ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
2632 if (!ret && sctx->is_dev_replace) {
2633 ret = finish_extent_writes_for_zoned(root, cache);
2634 if (ret) {
2635 btrfs_dec_block_group_ro(cache);
2636 scrub_pause_off(fs_info);
2637 btrfs_put_block_group(cache);
2638 break;
2639 }
2640 }
2641
2642 if (ret == 0) {
2643 ro_set = 1;
2644 } else if (ret == -ENOSPC && !sctx->is_dev_replace &&
2645 !(cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) {
2646 /*
2647 * btrfs_inc_block_group_ro return -ENOSPC when it
2648 * failed in creating new chunk for metadata.
2649 * It is not a problem for scrub, because
2650 * metadata are always cowed, and our scrub paused
2651 * commit_transactions.
2652 *
2653 * For RAID56 chunks, we have to mark them read-only
2654 * for scrub, as later we would use our own cache
2655 * out of RAID56 realm.
2656 * Thus we want the RAID56 bg to be marked RO to
2657 * prevent RMW from screwing up out cache.
2658 */
2659 ro_set = 0;
2660 } else if (ret == -ETXTBSY) {
2661 btrfs_warn(fs_info,
2662 "skipping scrub of block group %llu due to active swapfile",
2663 cache->start);
2664 scrub_pause_off(fs_info);
2665 ret = 0;
2666 goto skip_unfreeze;
2667 } else {
2668 btrfs_warn(fs_info,
2669 "failed setting block group ro: %d", ret);
2670 btrfs_unfreeze_block_group(cache);
2671 btrfs_put_block_group(cache);
2672 scrub_pause_off(fs_info);
2673 break;
2674 }
2675
2676 /*
2677 * Now the target block is marked RO, wait for nocow writes to
2678 * finish before dev-replace.
2679 * COW is fine, as COW never overwrites extents in commit tree.
2680 */
2681 if (sctx->is_dev_replace) {
2682 btrfs_wait_nocow_writers(cache);
2683 btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start,
2684 cache->length);
2685 }
2686
2687 scrub_pause_off(fs_info);
2688 down_write(&dev_replace->rwsem);
2689 dev_replace->cursor_right = found_key.offset + dev_extent_len;
2690 dev_replace->cursor_left = found_key.offset;
2691 dev_replace->item_needs_writeback = 1;
2692 up_write(&dev_replace->rwsem);
2693
2694 ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset,
2695 dev_extent_len);
2696 if (sctx->is_dev_replace &&
2697 !btrfs_finish_block_group_to_copy(dev_replace->srcdev,
2698 cache, found_key.offset))
2699 ro_set = 0;
2700
2701 down_write(&dev_replace->rwsem);
2702 dev_replace->cursor_left = dev_replace->cursor_right;
2703 dev_replace->item_needs_writeback = 1;
2704 up_write(&dev_replace->rwsem);
2705
2706 if (ro_set)
2707 btrfs_dec_block_group_ro(cache);
2708
2709 /*
2710 * We might have prevented the cleaner kthread from deleting
2711 * this block group if it was already unused because we raced
2712 * and set it to RO mode first. So add it back to the unused
2713 * list, otherwise it might not ever be deleted unless a manual
2714 * balance is triggered or it becomes used and unused again.
2715 */
2716 spin_lock(&cache->lock);
2717 if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags) &&
2718 !cache->ro && cache->reserved == 0 && cache->used == 0) {
2719 spin_unlock(&cache->lock);
2720 if (btrfs_test_opt(fs_info, DISCARD_ASYNC))
2721 btrfs_discard_queue_work(&fs_info->discard_ctl,
2722 cache);
2723 else
2724 btrfs_mark_bg_unused(cache);
2725 } else {
2726 spin_unlock(&cache->lock);
2727 }
2728skip_unfreeze:
2729 btrfs_unfreeze_block_group(cache);
2730 btrfs_put_block_group(cache);
2731 if (ret)
2732 break;
2733 if (sctx->is_dev_replace &&
2734 atomic64_read(&dev_replace->num_write_errors) > 0) {
2735 ret = -EIO;
2736 break;
2737 }
2738 if (sctx->stat.malloc_errors > 0) {
2739 ret = -ENOMEM;
2740 break;
2741 }
2742skip:
2743 key.offset = found_key.offset + dev_extent_len;
2744 btrfs_release_path(path);
2745 }
2746
2747 btrfs_free_path(path);
2748
2749 return ret;
2750}
2751
2752static int scrub_one_super(struct scrub_ctx *sctx, struct btrfs_device *dev,
2753 struct page *page, u64 physical, u64 generation)
2754{
2755 struct btrfs_fs_info *fs_info = sctx->fs_info;
2756 struct bio_vec bvec;
2757 struct bio bio;
2758 struct btrfs_super_block *sb = page_address(page);
2759 int ret;
2760
2761 bio_init(&bio, dev->bdev, &bvec, 1, REQ_OP_READ);
2762 bio.bi_iter.bi_sector = physical >> SECTOR_SHIFT;
2763 __bio_add_page(&bio, page, BTRFS_SUPER_INFO_SIZE, 0);
2764 ret = submit_bio_wait(&bio);
2765 bio_uninit(&bio);
2766
2767 if (ret < 0)
2768 return ret;
2769 ret = btrfs_check_super_csum(fs_info, sb);
2770 if (ret != 0) {
2771 btrfs_err_rl(fs_info,
2772 "super block at physical %llu devid %llu has bad csum",
2773 physical, dev->devid);
2774 return -EIO;
2775 }
2776 if (btrfs_super_generation(sb) != generation) {
2777 btrfs_err_rl(fs_info,
2778"super block at physical %llu devid %llu has bad generation %llu expect %llu",
2779 physical, dev->devid,
2780 btrfs_super_generation(sb), generation);
2781 return -EUCLEAN;
2782 }
2783
2784 return btrfs_validate_super(fs_info, sb, -1);
2785}
2786
2787static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2788 struct btrfs_device *scrub_dev)
2789{
2790 int i;
2791 u64 bytenr;
2792 u64 gen;
2793 int ret = 0;
2794 struct page *page;
2795 struct btrfs_fs_info *fs_info = sctx->fs_info;
2796
2797 if (BTRFS_FS_ERROR(fs_info))
2798 return -EROFS;
2799
2800 page = alloc_page(GFP_KERNEL);
2801 if (!page) {
2802 spin_lock(&sctx->stat_lock);
2803 sctx->stat.malloc_errors++;
2804 spin_unlock(&sctx->stat_lock);
2805 return -ENOMEM;
2806 }
2807
2808 /* Seed devices of a new filesystem has their own generation. */
2809 if (scrub_dev->fs_devices != fs_info->fs_devices)
2810 gen = scrub_dev->generation;
2811 else
2812 gen = btrfs_get_last_trans_committed(fs_info);
2813
2814 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2815 ret = btrfs_sb_log_location(scrub_dev, i, 0, &bytenr);
2816 if (ret == -ENOENT)
2817 break;
2818
2819 if (ret) {
2820 spin_lock(&sctx->stat_lock);
2821 sctx->stat.super_errors++;
2822 spin_unlock(&sctx->stat_lock);
2823 continue;
2824 }
2825
2826 if (bytenr + BTRFS_SUPER_INFO_SIZE >
2827 scrub_dev->commit_total_bytes)
2828 break;
2829 if (!btrfs_check_super_location(scrub_dev, bytenr))
2830 continue;
2831
2832 ret = scrub_one_super(sctx, scrub_dev, page, bytenr, gen);
2833 if (ret) {
2834 spin_lock(&sctx->stat_lock);
2835 sctx->stat.super_errors++;
2836 spin_unlock(&sctx->stat_lock);
2837 }
2838 }
2839 __free_page(page);
2840 return 0;
2841}
2842
2843static void scrub_workers_put(struct btrfs_fs_info *fs_info)
2844{
2845 if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt,
2846 &fs_info->scrub_lock)) {
2847 struct workqueue_struct *scrub_workers = fs_info->scrub_workers;
2848
2849 fs_info->scrub_workers = NULL;
2850 mutex_unlock(&fs_info->scrub_lock);
2851
2852 if (scrub_workers)
2853 destroy_workqueue(scrub_workers);
2854 }
2855}
2856
2857/*
2858 * get a reference count on fs_info->scrub_workers. start worker if necessary
2859 */
2860static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info)
2861{
2862 struct workqueue_struct *scrub_workers = NULL;
2863 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
2864 int max_active = fs_info->thread_pool_size;
2865 int ret = -ENOMEM;
2866
2867 if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
2868 return 0;
2869
2870 scrub_workers = alloc_workqueue("btrfs-scrub", flags, max_active);
2871 if (!scrub_workers)
2872 return -ENOMEM;
2873
2874 mutex_lock(&fs_info->scrub_lock);
2875 if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
2876 ASSERT(fs_info->scrub_workers == NULL);
2877 fs_info->scrub_workers = scrub_workers;
2878 refcount_set(&fs_info->scrub_workers_refcnt, 1);
2879 mutex_unlock(&fs_info->scrub_lock);
2880 return 0;
2881 }
2882 /* Other thread raced in and created the workers for us */
2883 refcount_inc(&fs_info->scrub_workers_refcnt);
2884 mutex_unlock(&fs_info->scrub_lock);
2885
2886 ret = 0;
2887
2888 destroy_workqueue(scrub_workers);
2889 return ret;
2890}
2891
2892int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2893 u64 end, struct btrfs_scrub_progress *progress,
2894 int readonly, int is_dev_replace)
2895{
2896 struct btrfs_dev_lookup_args args = { .devid = devid };
2897 struct scrub_ctx *sctx;
2898 int ret;
2899 struct btrfs_device *dev;
2900 unsigned int nofs_flag;
2901 bool need_commit = false;
2902
2903 if (btrfs_fs_closing(fs_info))
2904 return -EAGAIN;
2905
2906 /* At mount time we have ensured nodesize is in the range of [4K, 64K]. */
2907 ASSERT(fs_info->nodesize <= BTRFS_STRIPE_LEN);
2908
2909 /*
2910 * SCRUB_MAX_SECTORS_PER_BLOCK is calculated using the largest possible
2911 * value (max nodesize / min sectorsize), thus nodesize should always
2912 * be fine.
2913 */
2914 ASSERT(fs_info->nodesize <=
2915 SCRUB_MAX_SECTORS_PER_BLOCK << fs_info->sectorsize_bits);
2916
2917 /* Allocate outside of device_list_mutex */
2918 sctx = scrub_setup_ctx(fs_info, is_dev_replace);
2919 if (IS_ERR(sctx))
2920 return PTR_ERR(sctx);
2921
2922 ret = scrub_workers_get(fs_info);
2923 if (ret)
2924 goto out_free_ctx;
2925
2926 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2927 dev = btrfs_find_device(fs_info->fs_devices, &args);
2928 if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
2929 !is_dev_replace)) {
2930 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2931 ret = -ENODEV;
2932 goto out;
2933 }
2934
2935 if (!is_dev_replace && !readonly &&
2936 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2937 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2938 btrfs_err_in_rcu(fs_info,
2939 "scrub on devid %llu: filesystem on %s is not writable",
2940 devid, btrfs_dev_name(dev));
2941 ret = -EROFS;
2942 goto out;
2943 }
2944
2945 mutex_lock(&fs_info->scrub_lock);
2946 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
2947 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
2948 mutex_unlock(&fs_info->scrub_lock);
2949 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2950 ret = -EIO;
2951 goto out;
2952 }
2953
2954 down_read(&fs_info->dev_replace.rwsem);
2955 if (dev->scrub_ctx ||
2956 (!is_dev_replace &&
2957 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2958 up_read(&fs_info->dev_replace.rwsem);
2959 mutex_unlock(&fs_info->scrub_lock);
2960 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2961 ret = -EINPROGRESS;
2962 goto out;
2963 }
2964 up_read(&fs_info->dev_replace.rwsem);
2965
2966 sctx->readonly = readonly;
2967 dev->scrub_ctx = sctx;
2968 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2969
2970 /*
2971 * checking @scrub_pause_req here, we can avoid
2972 * race between committing transaction and scrubbing.
2973 */
2974 __scrub_blocked_if_needed(fs_info);
2975 atomic_inc(&fs_info->scrubs_running);
2976 mutex_unlock(&fs_info->scrub_lock);
2977
2978 /*
2979 * In order to avoid deadlock with reclaim when there is a transaction
2980 * trying to pause scrub, make sure we use GFP_NOFS for all the
2981 * allocations done at btrfs_scrub_sectors() and scrub_sectors_for_parity()
2982 * invoked by our callees. The pausing request is done when the
2983 * transaction commit starts, and it blocks the transaction until scrub
2984 * is paused (done at specific points at scrub_stripe() or right above
2985 * before incrementing fs_info->scrubs_running).
2986 */
2987 nofs_flag = memalloc_nofs_save();
2988 if (!is_dev_replace) {
2989 u64 old_super_errors;
2990
2991 spin_lock(&sctx->stat_lock);
2992 old_super_errors = sctx->stat.super_errors;
2993 spin_unlock(&sctx->stat_lock);
2994
2995 btrfs_info(fs_info, "scrub: started on devid %llu", devid);
2996 /*
2997 * by holding device list mutex, we can
2998 * kick off writing super in log tree sync.
2999 */
3000 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3001 ret = scrub_supers(sctx, dev);
3002 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3003
3004 spin_lock(&sctx->stat_lock);
3005 /*
3006 * Super block errors found, but we can not commit transaction
3007 * at current context, since btrfs_commit_transaction() needs
3008 * to pause the current running scrub (hold by ourselves).
3009 */
3010 if (sctx->stat.super_errors > old_super_errors && !sctx->readonly)
3011 need_commit = true;
3012 spin_unlock(&sctx->stat_lock);
3013 }
3014
3015 if (!ret)
3016 ret = scrub_enumerate_chunks(sctx, dev, start, end);
3017 memalloc_nofs_restore(nofs_flag);
3018
3019 atomic_dec(&fs_info->scrubs_running);
3020 wake_up(&fs_info->scrub_pause_wait);
3021
3022 if (progress)
3023 memcpy(progress, &sctx->stat, sizeof(*progress));
3024
3025 if (!is_dev_replace)
3026 btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
3027 ret ? "not finished" : "finished", devid, ret);
3028
3029 mutex_lock(&fs_info->scrub_lock);
3030 dev->scrub_ctx = NULL;
3031 mutex_unlock(&fs_info->scrub_lock);
3032
3033 scrub_workers_put(fs_info);
3034 scrub_put_ctx(sctx);
3035
3036 /*
3037 * We found some super block errors before, now try to force a
3038 * transaction commit, as scrub has finished.
3039 */
3040 if (need_commit) {
3041 struct btrfs_trans_handle *trans;
3042
3043 trans = btrfs_start_transaction(fs_info->tree_root, 0);
3044 if (IS_ERR(trans)) {
3045 ret = PTR_ERR(trans);
3046 btrfs_err(fs_info,
3047 "scrub: failed to start transaction to fix super block errors: %d", ret);
3048 return ret;
3049 }
3050 ret = btrfs_commit_transaction(trans);
3051 if (ret < 0)
3052 btrfs_err(fs_info,
3053 "scrub: failed to commit transaction to fix super block errors: %d", ret);
3054 }
3055 return ret;
3056out:
3057 scrub_workers_put(fs_info);
3058out_free_ctx:
3059 scrub_free_ctx(sctx);
3060
3061 return ret;
3062}
3063
3064void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
3065{
3066 mutex_lock(&fs_info->scrub_lock);
3067 atomic_inc(&fs_info->scrub_pause_req);
3068 while (atomic_read(&fs_info->scrubs_paused) !=
3069 atomic_read(&fs_info->scrubs_running)) {
3070 mutex_unlock(&fs_info->scrub_lock);
3071 wait_event(fs_info->scrub_pause_wait,
3072 atomic_read(&fs_info->scrubs_paused) ==
3073 atomic_read(&fs_info->scrubs_running));
3074 mutex_lock(&fs_info->scrub_lock);
3075 }
3076 mutex_unlock(&fs_info->scrub_lock);
3077}
3078
3079void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
3080{
3081 atomic_dec(&fs_info->scrub_pause_req);
3082 wake_up(&fs_info->scrub_pause_wait);
3083}
3084
3085int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3086{
3087 mutex_lock(&fs_info->scrub_lock);
3088 if (!atomic_read(&fs_info->scrubs_running)) {
3089 mutex_unlock(&fs_info->scrub_lock);
3090 return -ENOTCONN;
3091 }
3092
3093 atomic_inc(&fs_info->scrub_cancel_req);
3094 while (atomic_read(&fs_info->scrubs_running)) {
3095 mutex_unlock(&fs_info->scrub_lock);
3096 wait_event(fs_info->scrub_pause_wait,
3097 atomic_read(&fs_info->scrubs_running) == 0);
3098 mutex_lock(&fs_info->scrub_lock);
3099 }
3100 atomic_dec(&fs_info->scrub_cancel_req);
3101 mutex_unlock(&fs_info->scrub_lock);
3102
3103 return 0;
3104}
3105
3106int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
3107{
3108 struct btrfs_fs_info *fs_info = dev->fs_info;
3109 struct scrub_ctx *sctx;
3110
3111 mutex_lock(&fs_info->scrub_lock);
3112 sctx = dev->scrub_ctx;
3113 if (!sctx) {
3114 mutex_unlock(&fs_info->scrub_lock);
3115 return -ENOTCONN;
3116 }
3117 atomic_inc(&sctx->cancel_req);
3118 while (dev->scrub_ctx) {
3119 mutex_unlock(&fs_info->scrub_lock);
3120 wait_event(fs_info->scrub_pause_wait,
3121 dev->scrub_ctx == NULL);
3122 mutex_lock(&fs_info->scrub_lock);
3123 }
3124 mutex_unlock(&fs_info->scrub_lock);
3125
3126 return 0;
3127}
3128
3129int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
3130 struct btrfs_scrub_progress *progress)
3131{
3132 struct btrfs_dev_lookup_args args = { .devid = devid };
3133 struct btrfs_device *dev;
3134 struct scrub_ctx *sctx = NULL;
3135
3136 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3137 dev = btrfs_find_device(fs_info->fs_devices, &args);
3138 if (dev)
3139 sctx = dev->scrub_ctx;
3140 if (sctx)
3141 memcpy(progress, &sctx->stat, sizeof(*progress));
3142 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3143
3144 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
3145}
1/*
2 * Copyright (C) 2011 STRATO. All rights reserved.
3 *
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.
7 *
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.
12 *
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.
17 */
18
19#include <linux/blkdev.h>
20#include "ctree.h"
21#include "volumes.h"
22#include "disk-io.h"
23#include "ordered-data.h"
24
25/*
26 * This is only the first step towards a full-features scrub. It reads all
27 * extent and super block and verifies the checksums. In case a bad checksum
28 * is found or the extent cannot be read, good data will be written back if
29 * any can be found.
30 *
31 * Future enhancements:
32 * - To enhance the performance, better read-ahead strategies for the
33 * extent-tree can be employed.
34 * - In case an unrepairable extent is encountered, track which files are
35 * affected and report them
36 * - In case of a read error on files with nodatasum, map the file and read
37 * the extent to trigger a writeback of the good copy
38 * - track and record media errors, throw out bad devices
39 * - add a mode to also read unallocated space
40 * - make the prefetch cancellable
41 */
42
43struct scrub_bio;
44struct scrub_page;
45struct scrub_dev;
46static void scrub_bio_end_io(struct bio *bio, int err);
47static void scrub_checksum(struct btrfs_work *work);
48static int scrub_checksum_data(struct scrub_dev *sdev,
49 struct scrub_page *spag, void *buffer);
50static int scrub_checksum_tree_block(struct scrub_dev *sdev,
51 struct scrub_page *spag, u64 logical,
52 void *buffer);
53static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer);
54static int scrub_fixup_check(struct scrub_bio *sbio, int ix);
55static void scrub_fixup_end_io(struct bio *bio, int err);
56static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
57 struct page *page);
58static void scrub_fixup(struct scrub_bio *sbio, int ix);
59
60#define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
61#define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
62
63struct scrub_page {
64 u64 flags; /* extent flags */
65 u64 generation;
66 u64 mirror_num;
67 int have_csum;
68 u8 csum[BTRFS_CSUM_SIZE];
69};
70
71struct scrub_bio {
72 int index;
73 struct scrub_dev *sdev;
74 struct bio *bio;
75 int err;
76 u64 logical;
77 u64 physical;
78 struct scrub_page spag[SCRUB_PAGES_PER_BIO];
79 u64 count;
80 int next_free;
81 struct btrfs_work work;
82};
83
84struct scrub_dev {
85 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
86 struct btrfs_device *dev;
87 int first_free;
88 int curr;
89 atomic_t in_flight;
90 spinlock_t list_lock;
91 wait_queue_head_t list_wait;
92 u16 csum_size;
93 struct list_head csum_list;
94 atomic_t cancel_req;
95 int readonly;
96 /*
97 * statistics
98 */
99 struct btrfs_scrub_progress stat;
100 spinlock_t stat_lock;
101};
102
103static void scrub_free_csums(struct scrub_dev *sdev)
104{
105 while (!list_empty(&sdev->csum_list)) {
106 struct btrfs_ordered_sum *sum;
107 sum = list_first_entry(&sdev->csum_list,
108 struct btrfs_ordered_sum, list);
109 list_del(&sum->list);
110 kfree(sum);
111 }
112}
113
114static void scrub_free_bio(struct bio *bio)
115{
116 int i;
117 struct page *last_page = NULL;
118
119 if (!bio)
120 return;
121
122 for (i = 0; i < bio->bi_vcnt; ++i) {
123 if (bio->bi_io_vec[i].bv_page == last_page)
124 continue;
125 last_page = bio->bi_io_vec[i].bv_page;
126 __free_page(last_page);
127 }
128 bio_put(bio);
129}
130
131static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
132{
133 int i;
134
135 if (!sdev)
136 return;
137
138 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
139 struct scrub_bio *sbio = sdev->bios[i];
140
141 if (!sbio)
142 break;
143
144 scrub_free_bio(sbio->bio);
145 kfree(sbio);
146 }
147
148 scrub_free_csums(sdev);
149 kfree(sdev);
150}
151
152static noinline_for_stack
153struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
154{
155 struct scrub_dev *sdev;
156 int i;
157 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
158
159 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
160 if (!sdev)
161 goto nomem;
162 sdev->dev = dev;
163 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
164 struct scrub_bio *sbio;
165
166 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
167 if (!sbio)
168 goto nomem;
169 sdev->bios[i] = sbio;
170
171 sbio->index = i;
172 sbio->sdev = sdev;
173 sbio->count = 0;
174 sbio->work.func = scrub_checksum;
175
176 if (i != SCRUB_BIOS_PER_DEV-1)
177 sdev->bios[i]->next_free = i + 1;
178 else
179 sdev->bios[i]->next_free = -1;
180 }
181 sdev->first_free = 0;
182 sdev->curr = -1;
183 atomic_set(&sdev->in_flight, 0);
184 atomic_set(&sdev->cancel_req, 0);
185 sdev->csum_size = btrfs_super_csum_size(&fs_info->super_copy);
186 INIT_LIST_HEAD(&sdev->csum_list);
187
188 spin_lock_init(&sdev->list_lock);
189 spin_lock_init(&sdev->stat_lock);
190 init_waitqueue_head(&sdev->list_wait);
191 return sdev;
192
193nomem:
194 scrub_free_dev(sdev);
195 return ERR_PTR(-ENOMEM);
196}
197
198/*
199 * scrub_recheck_error gets called when either verification of the page
200 * failed or the bio failed to read, e.g. with EIO. In the latter case,
201 * recheck_error gets called for every page in the bio, even though only
202 * one may be bad
203 */
204static void scrub_recheck_error(struct scrub_bio *sbio, int ix)
205{
206 if (sbio->err) {
207 if (scrub_fixup_io(READ, sbio->sdev->dev->bdev,
208 (sbio->physical + ix * PAGE_SIZE) >> 9,
209 sbio->bio->bi_io_vec[ix].bv_page) == 0) {
210 if (scrub_fixup_check(sbio, ix) == 0)
211 return;
212 }
213 }
214
215 scrub_fixup(sbio, ix);
216}
217
218static int scrub_fixup_check(struct scrub_bio *sbio, int ix)
219{
220 int ret = 1;
221 struct page *page;
222 void *buffer;
223 u64 flags = sbio->spag[ix].flags;
224
225 page = sbio->bio->bi_io_vec[ix].bv_page;
226 buffer = kmap_atomic(page, KM_USER0);
227 if (flags & BTRFS_EXTENT_FLAG_DATA) {
228 ret = scrub_checksum_data(sbio->sdev,
229 sbio->spag + ix, buffer);
230 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
231 ret = scrub_checksum_tree_block(sbio->sdev,
232 sbio->spag + ix,
233 sbio->logical + ix * PAGE_SIZE,
234 buffer);
235 } else {
236 WARN_ON(1);
237 }
238 kunmap_atomic(buffer, KM_USER0);
239
240 return ret;
241}
242
243static void scrub_fixup_end_io(struct bio *bio, int err)
244{
245 complete((struct completion *)bio->bi_private);
246}
247
248static void scrub_fixup(struct scrub_bio *sbio, int ix)
249{
250 struct scrub_dev *sdev = sbio->sdev;
251 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
252 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
253 struct btrfs_multi_bio *multi = NULL;
254 u64 logical = sbio->logical + ix * PAGE_SIZE;
255 u64 length;
256 int i;
257 int ret;
258 DECLARE_COMPLETION_ONSTACK(complete);
259
260 if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) &&
261 (sbio->spag[ix].have_csum == 0)) {
262 /*
263 * nodatasum, don't try to fix anything
264 * FIXME: we can do better, open the inode and trigger a
265 * writeback
266 */
267 goto uncorrectable;
268 }
269
270 length = PAGE_SIZE;
271 ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length,
272 &multi, 0);
273 if (ret || !multi || length < PAGE_SIZE) {
274 printk(KERN_ERR
275 "scrub_fixup: btrfs_map_block failed us for %llu\n",
276 (unsigned long long)logical);
277 WARN_ON(1);
278 return;
279 }
280
281 if (multi->num_stripes == 1)
282 /* there aren't any replicas */
283 goto uncorrectable;
284
285 /*
286 * first find a good copy
287 */
288 for (i = 0; i < multi->num_stripes; ++i) {
289 if (i == sbio->spag[ix].mirror_num)
290 continue;
291
292 if (scrub_fixup_io(READ, multi->stripes[i].dev->bdev,
293 multi->stripes[i].physical >> 9,
294 sbio->bio->bi_io_vec[ix].bv_page)) {
295 /* I/O-error, this is not a good copy */
296 continue;
297 }
298
299 if (scrub_fixup_check(sbio, ix) == 0)
300 break;
301 }
302 if (i == multi->num_stripes)
303 goto uncorrectable;
304
305 if (!sdev->readonly) {
306 /*
307 * bi_io_vec[ix].bv_page now contains good data, write it back
308 */
309 if (scrub_fixup_io(WRITE, sdev->dev->bdev,
310 (sbio->physical + ix * PAGE_SIZE) >> 9,
311 sbio->bio->bi_io_vec[ix].bv_page)) {
312 /* I/O-error, writeback failed, give up */
313 goto uncorrectable;
314 }
315 }
316
317 kfree(multi);
318 spin_lock(&sdev->stat_lock);
319 ++sdev->stat.corrected_errors;
320 spin_unlock(&sdev->stat_lock);
321
322 if (printk_ratelimit())
323 printk(KERN_ERR "btrfs: fixed up at %llu\n",
324 (unsigned long long)logical);
325 return;
326
327uncorrectable:
328 kfree(multi);
329 spin_lock(&sdev->stat_lock);
330 ++sdev->stat.uncorrectable_errors;
331 spin_unlock(&sdev->stat_lock);
332
333 if (printk_ratelimit())
334 printk(KERN_ERR "btrfs: unable to fixup at %llu\n",
335 (unsigned long long)logical);
336}
337
338static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
339 struct page *page)
340{
341 struct bio *bio = NULL;
342 int ret;
343 DECLARE_COMPLETION_ONSTACK(complete);
344
345 bio = bio_alloc(GFP_NOFS, 1);
346 bio->bi_bdev = bdev;
347 bio->bi_sector = sector;
348 bio_add_page(bio, page, PAGE_SIZE, 0);
349 bio->bi_end_io = scrub_fixup_end_io;
350 bio->bi_private = &complete;
351 submit_bio(rw, bio);
352
353 /* this will also unplug the queue */
354 wait_for_completion(&complete);
355
356 ret = !test_bit(BIO_UPTODATE, &bio->bi_flags);
357 bio_put(bio);
358 return ret;
359}
360
361static void scrub_bio_end_io(struct bio *bio, int err)
362{
363 struct scrub_bio *sbio = bio->bi_private;
364 struct scrub_dev *sdev = sbio->sdev;
365 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
366
367 sbio->err = err;
368 sbio->bio = bio;
369
370 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
371}
372
373static void scrub_checksum(struct btrfs_work *work)
374{
375 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
376 struct scrub_dev *sdev = sbio->sdev;
377 struct page *page;
378 void *buffer;
379 int i;
380 u64 flags;
381 u64 logical;
382 int ret;
383
384 if (sbio->err) {
385 for (i = 0; i < sbio->count; ++i)
386 scrub_recheck_error(sbio, i);
387
388 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
389 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
390 sbio->bio->bi_phys_segments = 0;
391 sbio->bio->bi_idx = 0;
392
393 for (i = 0; i < sbio->count; i++) {
394 struct bio_vec *bi;
395 bi = &sbio->bio->bi_io_vec[i];
396 bi->bv_offset = 0;
397 bi->bv_len = PAGE_SIZE;
398 }
399
400 spin_lock(&sdev->stat_lock);
401 ++sdev->stat.read_errors;
402 spin_unlock(&sdev->stat_lock);
403 goto out;
404 }
405 for (i = 0; i < sbio->count; ++i) {
406 page = sbio->bio->bi_io_vec[i].bv_page;
407 buffer = kmap_atomic(page, KM_USER0);
408 flags = sbio->spag[i].flags;
409 logical = sbio->logical + i * PAGE_SIZE;
410 ret = 0;
411 if (flags & BTRFS_EXTENT_FLAG_DATA) {
412 ret = scrub_checksum_data(sdev, sbio->spag + i, buffer);
413 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
414 ret = scrub_checksum_tree_block(sdev, sbio->spag + i,
415 logical, buffer);
416 } else if (flags & BTRFS_EXTENT_FLAG_SUPER) {
417 BUG_ON(i);
418 (void)scrub_checksum_super(sbio, buffer);
419 } else {
420 WARN_ON(1);
421 }
422 kunmap_atomic(buffer, KM_USER0);
423 if (ret)
424 scrub_recheck_error(sbio, i);
425 }
426
427out:
428 scrub_free_bio(sbio->bio);
429 sbio->bio = NULL;
430 spin_lock(&sdev->list_lock);
431 sbio->next_free = sdev->first_free;
432 sdev->first_free = sbio->index;
433 spin_unlock(&sdev->list_lock);
434 atomic_dec(&sdev->in_flight);
435 wake_up(&sdev->list_wait);
436}
437
438static int scrub_checksum_data(struct scrub_dev *sdev,
439 struct scrub_page *spag, void *buffer)
440{
441 u8 csum[BTRFS_CSUM_SIZE];
442 u32 crc = ~(u32)0;
443 int fail = 0;
444 struct btrfs_root *root = sdev->dev->dev_root;
445
446 if (!spag->have_csum)
447 return 0;
448
449 crc = btrfs_csum_data(root, buffer, crc, PAGE_SIZE);
450 btrfs_csum_final(crc, csum);
451 if (memcmp(csum, spag->csum, sdev->csum_size))
452 fail = 1;
453
454 spin_lock(&sdev->stat_lock);
455 ++sdev->stat.data_extents_scrubbed;
456 sdev->stat.data_bytes_scrubbed += PAGE_SIZE;
457 if (fail)
458 ++sdev->stat.csum_errors;
459 spin_unlock(&sdev->stat_lock);
460
461 return fail;
462}
463
464static int scrub_checksum_tree_block(struct scrub_dev *sdev,
465 struct scrub_page *spag, u64 logical,
466 void *buffer)
467{
468 struct btrfs_header *h;
469 struct btrfs_root *root = sdev->dev->dev_root;
470 struct btrfs_fs_info *fs_info = root->fs_info;
471 u8 csum[BTRFS_CSUM_SIZE];
472 u32 crc = ~(u32)0;
473 int fail = 0;
474 int crc_fail = 0;
475
476 /*
477 * we don't use the getter functions here, as we
478 * a) don't have an extent buffer and
479 * b) the page is already kmapped
480 */
481 h = (struct btrfs_header *)buffer;
482
483 if (logical != le64_to_cpu(h->bytenr))
484 ++fail;
485
486 if (spag->generation != le64_to_cpu(h->generation))
487 ++fail;
488
489 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
490 ++fail;
491
492 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
493 BTRFS_UUID_SIZE))
494 ++fail;
495
496 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
497 PAGE_SIZE - BTRFS_CSUM_SIZE);
498 btrfs_csum_final(crc, csum);
499 if (memcmp(csum, h->csum, sdev->csum_size))
500 ++crc_fail;
501
502 spin_lock(&sdev->stat_lock);
503 ++sdev->stat.tree_extents_scrubbed;
504 sdev->stat.tree_bytes_scrubbed += PAGE_SIZE;
505 if (crc_fail)
506 ++sdev->stat.csum_errors;
507 if (fail)
508 ++sdev->stat.verify_errors;
509 spin_unlock(&sdev->stat_lock);
510
511 return fail || crc_fail;
512}
513
514static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer)
515{
516 struct btrfs_super_block *s;
517 u64 logical;
518 struct scrub_dev *sdev = sbio->sdev;
519 struct btrfs_root *root = sdev->dev->dev_root;
520 struct btrfs_fs_info *fs_info = root->fs_info;
521 u8 csum[BTRFS_CSUM_SIZE];
522 u32 crc = ~(u32)0;
523 int fail = 0;
524
525 s = (struct btrfs_super_block *)buffer;
526 logical = sbio->logical;
527
528 if (logical != le64_to_cpu(s->bytenr))
529 ++fail;
530
531 if (sbio->spag[0].generation != le64_to_cpu(s->generation))
532 ++fail;
533
534 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
535 ++fail;
536
537 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
538 PAGE_SIZE - BTRFS_CSUM_SIZE);
539 btrfs_csum_final(crc, csum);
540 if (memcmp(csum, s->csum, sbio->sdev->csum_size))
541 ++fail;
542
543 if (fail) {
544 /*
545 * if we find an error in a super block, we just report it.
546 * They will get written with the next transaction commit
547 * anyway
548 */
549 spin_lock(&sdev->stat_lock);
550 ++sdev->stat.super_errors;
551 spin_unlock(&sdev->stat_lock);
552 }
553
554 return fail;
555}
556
557static int scrub_submit(struct scrub_dev *sdev)
558{
559 struct scrub_bio *sbio;
560 struct bio *bio;
561 int i;
562
563 if (sdev->curr == -1)
564 return 0;
565
566 sbio = sdev->bios[sdev->curr];
567
568 bio = bio_alloc(GFP_NOFS, sbio->count);
569 if (!bio)
570 goto nomem;
571
572 bio->bi_private = sbio;
573 bio->bi_end_io = scrub_bio_end_io;
574 bio->bi_bdev = sdev->dev->bdev;
575 bio->bi_sector = sbio->physical >> 9;
576
577 for (i = 0; i < sbio->count; ++i) {
578 struct page *page;
579 int ret;
580
581 page = alloc_page(GFP_NOFS);
582 if (!page)
583 goto nomem;
584
585 ret = bio_add_page(bio, page, PAGE_SIZE, 0);
586 if (!ret) {
587 __free_page(page);
588 goto nomem;
589 }
590 }
591
592 sbio->err = 0;
593 sdev->curr = -1;
594 atomic_inc(&sdev->in_flight);
595
596 submit_bio(READ, bio);
597
598 return 0;
599
600nomem:
601 scrub_free_bio(bio);
602
603 return -ENOMEM;
604}
605
606static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
607 u64 physical, u64 flags, u64 gen, u64 mirror_num,
608 u8 *csum, int force)
609{
610 struct scrub_bio *sbio;
611
612again:
613 /*
614 * grab a fresh bio or wait for one to become available
615 */
616 while (sdev->curr == -1) {
617 spin_lock(&sdev->list_lock);
618 sdev->curr = sdev->first_free;
619 if (sdev->curr != -1) {
620 sdev->first_free = sdev->bios[sdev->curr]->next_free;
621 sdev->bios[sdev->curr]->next_free = -1;
622 sdev->bios[sdev->curr]->count = 0;
623 spin_unlock(&sdev->list_lock);
624 } else {
625 spin_unlock(&sdev->list_lock);
626 wait_event(sdev->list_wait, sdev->first_free != -1);
627 }
628 }
629 sbio = sdev->bios[sdev->curr];
630 if (sbio->count == 0) {
631 sbio->physical = physical;
632 sbio->logical = logical;
633 } else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
634 sbio->logical + sbio->count * PAGE_SIZE != logical) {
635 int ret;
636
637 ret = scrub_submit(sdev);
638 if (ret)
639 return ret;
640 goto again;
641 }
642 sbio->spag[sbio->count].flags = flags;
643 sbio->spag[sbio->count].generation = gen;
644 sbio->spag[sbio->count].have_csum = 0;
645 sbio->spag[sbio->count].mirror_num = mirror_num;
646 if (csum) {
647 sbio->spag[sbio->count].have_csum = 1;
648 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
649 }
650 ++sbio->count;
651 if (sbio->count == SCRUB_PAGES_PER_BIO || force) {
652 int ret;
653
654 ret = scrub_submit(sdev);
655 if (ret)
656 return ret;
657 }
658
659 return 0;
660}
661
662static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
663 u8 *csum)
664{
665 struct btrfs_ordered_sum *sum = NULL;
666 int ret = 0;
667 unsigned long i;
668 unsigned long num_sectors;
669 u32 sectorsize = sdev->dev->dev_root->sectorsize;
670
671 while (!list_empty(&sdev->csum_list)) {
672 sum = list_first_entry(&sdev->csum_list,
673 struct btrfs_ordered_sum, list);
674 if (sum->bytenr > logical)
675 return 0;
676 if (sum->bytenr + sum->len > logical)
677 break;
678
679 ++sdev->stat.csum_discards;
680 list_del(&sum->list);
681 kfree(sum);
682 sum = NULL;
683 }
684 if (!sum)
685 return 0;
686
687 num_sectors = sum->len / sectorsize;
688 for (i = 0; i < num_sectors; ++i) {
689 if (sum->sums[i].bytenr == logical) {
690 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
691 ret = 1;
692 break;
693 }
694 }
695 if (ret && i == num_sectors - 1) {
696 list_del(&sum->list);
697 kfree(sum);
698 }
699 return ret;
700}
701
702/* scrub extent tries to collect up to 64 kB for each bio */
703static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
704 u64 physical, u64 flags, u64 gen, u64 mirror_num)
705{
706 int ret;
707 u8 csum[BTRFS_CSUM_SIZE];
708
709 while (len) {
710 u64 l = min_t(u64, len, PAGE_SIZE);
711 int have_csum = 0;
712
713 if (flags & BTRFS_EXTENT_FLAG_DATA) {
714 /* push csums to sbio */
715 have_csum = scrub_find_csum(sdev, logical, l, csum);
716 if (have_csum == 0)
717 ++sdev->stat.no_csum;
718 }
719 ret = scrub_page(sdev, logical, l, physical, flags, gen,
720 mirror_num, have_csum ? csum : NULL, 0);
721 if (ret)
722 return ret;
723 len -= l;
724 logical += l;
725 physical += l;
726 }
727 return 0;
728}
729
730static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
731 struct map_lookup *map, int num, u64 base, u64 length)
732{
733 struct btrfs_path *path;
734 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
735 struct btrfs_root *root = fs_info->extent_root;
736 struct btrfs_root *csum_root = fs_info->csum_root;
737 struct btrfs_extent_item *extent;
738 struct blk_plug plug;
739 u64 flags;
740 int ret;
741 int slot;
742 int i;
743 u64 nstripes;
744 int start_stripe;
745 struct extent_buffer *l;
746 struct btrfs_key key;
747 u64 physical;
748 u64 logical;
749 u64 generation;
750 u64 mirror_num;
751
752 u64 increment = map->stripe_len;
753 u64 offset;
754
755 nstripes = length;
756 offset = 0;
757 do_div(nstripes, map->stripe_len);
758 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
759 offset = map->stripe_len * num;
760 increment = map->stripe_len * map->num_stripes;
761 mirror_num = 0;
762 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
763 int factor = map->num_stripes / map->sub_stripes;
764 offset = map->stripe_len * (num / map->sub_stripes);
765 increment = map->stripe_len * factor;
766 mirror_num = num % map->sub_stripes;
767 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
768 increment = map->stripe_len;
769 mirror_num = num % map->num_stripes;
770 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
771 increment = map->stripe_len;
772 mirror_num = num % map->num_stripes;
773 } else {
774 increment = map->stripe_len;
775 mirror_num = 0;
776 }
777
778 path = btrfs_alloc_path();
779 if (!path)
780 return -ENOMEM;
781
782 path->reada = 2;
783 path->search_commit_root = 1;
784 path->skip_locking = 1;
785
786 /*
787 * find all extents for each stripe and just read them to get
788 * them into the page cache
789 * FIXME: we can do better. build a more intelligent prefetching
790 */
791 logical = base + offset;
792 physical = map->stripes[num].physical;
793 ret = 0;
794 for (i = 0; i < nstripes; ++i) {
795 key.objectid = logical;
796 key.type = BTRFS_EXTENT_ITEM_KEY;
797 key.offset = (u64)0;
798
799 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
800 if (ret < 0)
801 goto out_noplug;
802
803 /*
804 * we might miss half an extent here, but that doesn't matter,
805 * as it's only the prefetch
806 */
807 while (1) {
808 l = path->nodes[0];
809 slot = path->slots[0];
810 if (slot >= btrfs_header_nritems(l)) {
811 ret = btrfs_next_leaf(root, path);
812 if (ret == 0)
813 continue;
814 if (ret < 0)
815 goto out_noplug;
816
817 break;
818 }
819 btrfs_item_key_to_cpu(l, &key, slot);
820
821 if (key.objectid >= logical + map->stripe_len)
822 break;
823
824 path->slots[0]++;
825 }
826 btrfs_release_path(path);
827 logical += increment;
828 physical += map->stripe_len;
829 cond_resched();
830 }
831
832 /*
833 * collect all data csums for the stripe to avoid seeking during
834 * the scrub. This might currently (crc32) end up to be about 1MB
835 */
836 start_stripe = 0;
837 blk_start_plug(&plug);
838again:
839 logical = base + offset + start_stripe * increment;
840 for (i = start_stripe; i < nstripes; ++i) {
841 ret = btrfs_lookup_csums_range(csum_root, logical,
842 logical + map->stripe_len - 1,
843 &sdev->csum_list, 1);
844 if (ret)
845 goto out;
846
847 logical += increment;
848 cond_resched();
849 }
850 /*
851 * now find all extents for each stripe and scrub them
852 */
853 logical = base + offset + start_stripe * increment;
854 physical = map->stripes[num].physical + start_stripe * map->stripe_len;
855 ret = 0;
856 for (i = start_stripe; i < nstripes; ++i) {
857 /*
858 * canceled?
859 */
860 if (atomic_read(&fs_info->scrub_cancel_req) ||
861 atomic_read(&sdev->cancel_req)) {
862 ret = -ECANCELED;
863 goto out;
864 }
865 /*
866 * check to see if we have to pause
867 */
868 if (atomic_read(&fs_info->scrub_pause_req)) {
869 /* push queued extents */
870 scrub_submit(sdev);
871 wait_event(sdev->list_wait,
872 atomic_read(&sdev->in_flight) == 0);
873 atomic_inc(&fs_info->scrubs_paused);
874 wake_up(&fs_info->scrub_pause_wait);
875 mutex_lock(&fs_info->scrub_lock);
876 while (atomic_read(&fs_info->scrub_pause_req)) {
877 mutex_unlock(&fs_info->scrub_lock);
878 wait_event(fs_info->scrub_pause_wait,
879 atomic_read(&fs_info->scrub_pause_req) == 0);
880 mutex_lock(&fs_info->scrub_lock);
881 }
882 atomic_dec(&fs_info->scrubs_paused);
883 mutex_unlock(&fs_info->scrub_lock);
884 wake_up(&fs_info->scrub_pause_wait);
885 scrub_free_csums(sdev);
886 start_stripe = i;
887 goto again;
888 }
889
890 key.objectid = logical;
891 key.type = BTRFS_EXTENT_ITEM_KEY;
892 key.offset = (u64)0;
893
894 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
895 if (ret < 0)
896 goto out;
897 if (ret > 0) {
898 ret = btrfs_previous_item(root, path, 0,
899 BTRFS_EXTENT_ITEM_KEY);
900 if (ret < 0)
901 goto out;
902 if (ret > 0) {
903 /* there's no smaller item, so stick with the
904 * larger one */
905 btrfs_release_path(path);
906 ret = btrfs_search_slot(NULL, root, &key,
907 path, 0, 0);
908 if (ret < 0)
909 goto out;
910 }
911 }
912
913 while (1) {
914 l = path->nodes[0];
915 slot = path->slots[0];
916 if (slot >= btrfs_header_nritems(l)) {
917 ret = btrfs_next_leaf(root, path);
918 if (ret == 0)
919 continue;
920 if (ret < 0)
921 goto out;
922
923 break;
924 }
925 btrfs_item_key_to_cpu(l, &key, slot);
926
927 if (key.objectid + key.offset <= logical)
928 goto next;
929
930 if (key.objectid >= logical + map->stripe_len)
931 break;
932
933 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
934 goto next;
935
936 extent = btrfs_item_ptr(l, slot,
937 struct btrfs_extent_item);
938 flags = btrfs_extent_flags(l, extent);
939 generation = btrfs_extent_generation(l, extent);
940
941 if (key.objectid < logical &&
942 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
943 printk(KERN_ERR
944 "btrfs scrub: tree block %llu spanning "
945 "stripes, ignored. logical=%llu\n",
946 (unsigned long long)key.objectid,
947 (unsigned long long)logical);
948 goto next;
949 }
950
951 /*
952 * trim extent to this stripe
953 */
954 if (key.objectid < logical) {
955 key.offset -= logical - key.objectid;
956 key.objectid = logical;
957 }
958 if (key.objectid + key.offset >
959 logical + map->stripe_len) {
960 key.offset = logical + map->stripe_len -
961 key.objectid;
962 }
963
964 ret = scrub_extent(sdev, key.objectid, key.offset,
965 key.objectid - logical + physical,
966 flags, generation, mirror_num);
967 if (ret)
968 goto out;
969
970next:
971 path->slots[0]++;
972 }
973 btrfs_release_path(path);
974 logical += increment;
975 physical += map->stripe_len;
976 spin_lock(&sdev->stat_lock);
977 sdev->stat.last_physical = physical;
978 spin_unlock(&sdev->stat_lock);
979 }
980 /* push queued extents */
981 scrub_submit(sdev);
982
983out:
984 blk_finish_plug(&plug);
985out_noplug:
986 btrfs_free_path(path);
987 return ret < 0 ? ret : 0;
988}
989
990static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
991 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length)
992{
993 struct btrfs_mapping_tree *map_tree =
994 &sdev->dev->dev_root->fs_info->mapping_tree;
995 struct map_lookup *map;
996 struct extent_map *em;
997 int i;
998 int ret = -EINVAL;
999
1000 read_lock(&map_tree->map_tree.lock);
1001 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
1002 read_unlock(&map_tree->map_tree.lock);
1003
1004 if (!em)
1005 return -EINVAL;
1006
1007 map = (struct map_lookup *)em->bdev;
1008 if (em->start != chunk_offset)
1009 goto out;
1010
1011 if (em->len < length)
1012 goto out;
1013
1014 for (i = 0; i < map->num_stripes; ++i) {
1015 if (map->stripes[i].dev == sdev->dev) {
1016 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
1017 if (ret)
1018 goto out;
1019 }
1020 }
1021out:
1022 free_extent_map(em);
1023
1024 return ret;
1025}
1026
1027static noinline_for_stack
1028int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
1029{
1030 struct btrfs_dev_extent *dev_extent = NULL;
1031 struct btrfs_path *path;
1032 struct btrfs_root *root = sdev->dev->dev_root;
1033 struct btrfs_fs_info *fs_info = root->fs_info;
1034 u64 length;
1035 u64 chunk_tree;
1036 u64 chunk_objectid;
1037 u64 chunk_offset;
1038 int ret;
1039 int slot;
1040 struct extent_buffer *l;
1041 struct btrfs_key key;
1042 struct btrfs_key found_key;
1043 struct btrfs_block_group_cache *cache;
1044
1045 path = btrfs_alloc_path();
1046 if (!path)
1047 return -ENOMEM;
1048
1049 path->reada = 2;
1050 path->search_commit_root = 1;
1051 path->skip_locking = 1;
1052
1053 key.objectid = sdev->dev->devid;
1054 key.offset = 0ull;
1055 key.type = BTRFS_DEV_EXTENT_KEY;
1056
1057
1058 while (1) {
1059 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1060 if (ret < 0)
1061 break;
1062 if (ret > 0) {
1063 if (path->slots[0] >=
1064 btrfs_header_nritems(path->nodes[0])) {
1065 ret = btrfs_next_leaf(root, path);
1066 if (ret)
1067 break;
1068 }
1069 }
1070
1071 l = path->nodes[0];
1072 slot = path->slots[0];
1073
1074 btrfs_item_key_to_cpu(l, &found_key, slot);
1075
1076 if (found_key.objectid != sdev->dev->devid)
1077 break;
1078
1079 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
1080 break;
1081
1082 if (found_key.offset >= end)
1083 break;
1084
1085 if (found_key.offset < key.offset)
1086 break;
1087
1088 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1089 length = btrfs_dev_extent_length(l, dev_extent);
1090
1091 if (found_key.offset + length <= start) {
1092 key.offset = found_key.offset + length;
1093 btrfs_release_path(path);
1094 continue;
1095 }
1096
1097 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1098 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1099 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1100
1101 /*
1102 * get a reference on the corresponding block group to prevent
1103 * the chunk from going away while we scrub it
1104 */
1105 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
1106 if (!cache) {
1107 ret = -ENOENT;
1108 break;
1109 }
1110 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
1111 chunk_offset, length);
1112 btrfs_put_block_group(cache);
1113 if (ret)
1114 break;
1115
1116 key.offset = found_key.offset + length;
1117 btrfs_release_path(path);
1118 }
1119
1120 btrfs_free_path(path);
1121
1122 /*
1123 * ret can still be 1 from search_slot or next_leaf,
1124 * that's not an error
1125 */
1126 return ret < 0 ? ret : 0;
1127}
1128
1129static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
1130{
1131 int i;
1132 u64 bytenr;
1133 u64 gen;
1134 int ret;
1135 struct btrfs_device *device = sdev->dev;
1136 struct btrfs_root *root = device->dev_root;
1137
1138 gen = root->fs_info->last_trans_committed;
1139
1140 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1141 bytenr = btrfs_sb_offset(i);
1142 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1143 break;
1144
1145 ret = scrub_page(sdev, bytenr, PAGE_SIZE, bytenr,
1146 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
1147 if (ret)
1148 return ret;
1149 }
1150 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1151
1152 return 0;
1153}
1154
1155/*
1156 * get a reference count on fs_info->scrub_workers. start worker if necessary
1157 */
1158static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
1159{
1160 struct btrfs_fs_info *fs_info = root->fs_info;
1161
1162 mutex_lock(&fs_info->scrub_lock);
1163 if (fs_info->scrub_workers_refcnt == 0) {
1164 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
1165 fs_info->thread_pool_size, &fs_info->generic_worker);
1166 fs_info->scrub_workers.idle_thresh = 4;
1167 btrfs_start_workers(&fs_info->scrub_workers, 1);
1168 }
1169 ++fs_info->scrub_workers_refcnt;
1170 mutex_unlock(&fs_info->scrub_lock);
1171
1172 return 0;
1173}
1174
1175static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
1176{
1177 struct btrfs_fs_info *fs_info = root->fs_info;
1178
1179 mutex_lock(&fs_info->scrub_lock);
1180 if (--fs_info->scrub_workers_refcnt == 0)
1181 btrfs_stop_workers(&fs_info->scrub_workers);
1182 WARN_ON(fs_info->scrub_workers_refcnt < 0);
1183 mutex_unlock(&fs_info->scrub_lock);
1184}
1185
1186
1187int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
1188 struct btrfs_scrub_progress *progress, int readonly)
1189{
1190 struct scrub_dev *sdev;
1191 struct btrfs_fs_info *fs_info = root->fs_info;
1192 int ret;
1193 struct btrfs_device *dev;
1194
1195 if (btrfs_fs_closing(root->fs_info))
1196 return -EINVAL;
1197
1198 /*
1199 * check some assumptions
1200 */
1201 if (root->sectorsize != PAGE_SIZE ||
1202 root->sectorsize != root->leafsize ||
1203 root->sectorsize != root->nodesize) {
1204 printk(KERN_ERR "btrfs_scrub: size assumptions fail\n");
1205 return -EINVAL;
1206 }
1207
1208 ret = scrub_workers_get(root);
1209 if (ret)
1210 return ret;
1211
1212 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1213 dev = btrfs_find_device(root, devid, NULL, NULL);
1214 if (!dev || dev->missing) {
1215 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1216 scrub_workers_put(root);
1217 return -ENODEV;
1218 }
1219 mutex_lock(&fs_info->scrub_lock);
1220
1221 if (!dev->in_fs_metadata) {
1222 mutex_unlock(&fs_info->scrub_lock);
1223 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1224 scrub_workers_put(root);
1225 return -ENODEV;
1226 }
1227
1228 if (dev->scrub_device) {
1229 mutex_unlock(&fs_info->scrub_lock);
1230 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1231 scrub_workers_put(root);
1232 return -EINPROGRESS;
1233 }
1234 sdev = scrub_setup_dev(dev);
1235 if (IS_ERR(sdev)) {
1236 mutex_unlock(&fs_info->scrub_lock);
1237 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1238 scrub_workers_put(root);
1239 return PTR_ERR(sdev);
1240 }
1241 sdev->readonly = readonly;
1242 dev->scrub_device = sdev;
1243
1244 atomic_inc(&fs_info->scrubs_running);
1245 mutex_unlock(&fs_info->scrub_lock);
1246 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1247
1248 down_read(&fs_info->scrub_super_lock);
1249 ret = scrub_supers(sdev);
1250 up_read(&fs_info->scrub_super_lock);
1251
1252 if (!ret)
1253 ret = scrub_enumerate_chunks(sdev, start, end);
1254
1255 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1256
1257 atomic_dec(&fs_info->scrubs_running);
1258 wake_up(&fs_info->scrub_pause_wait);
1259
1260 if (progress)
1261 memcpy(progress, &sdev->stat, sizeof(*progress));
1262
1263 mutex_lock(&fs_info->scrub_lock);
1264 dev->scrub_device = NULL;
1265 mutex_unlock(&fs_info->scrub_lock);
1266
1267 scrub_free_dev(sdev);
1268 scrub_workers_put(root);
1269
1270 return ret;
1271}
1272
1273int btrfs_scrub_pause(struct btrfs_root *root)
1274{
1275 struct btrfs_fs_info *fs_info = root->fs_info;
1276
1277 mutex_lock(&fs_info->scrub_lock);
1278 atomic_inc(&fs_info->scrub_pause_req);
1279 while (atomic_read(&fs_info->scrubs_paused) !=
1280 atomic_read(&fs_info->scrubs_running)) {
1281 mutex_unlock(&fs_info->scrub_lock);
1282 wait_event(fs_info->scrub_pause_wait,
1283 atomic_read(&fs_info->scrubs_paused) ==
1284 atomic_read(&fs_info->scrubs_running));
1285 mutex_lock(&fs_info->scrub_lock);
1286 }
1287 mutex_unlock(&fs_info->scrub_lock);
1288
1289 return 0;
1290}
1291
1292int btrfs_scrub_continue(struct btrfs_root *root)
1293{
1294 struct btrfs_fs_info *fs_info = root->fs_info;
1295
1296 atomic_dec(&fs_info->scrub_pause_req);
1297 wake_up(&fs_info->scrub_pause_wait);
1298 return 0;
1299}
1300
1301int btrfs_scrub_pause_super(struct btrfs_root *root)
1302{
1303 down_write(&root->fs_info->scrub_super_lock);
1304 return 0;
1305}
1306
1307int btrfs_scrub_continue_super(struct btrfs_root *root)
1308{
1309 up_write(&root->fs_info->scrub_super_lock);
1310 return 0;
1311}
1312
1313int btrfs_scrub_cancel(struct btrfs_root *root)
1314{
1315 struct btrfs_fs_info *fs_info = root->fs_info;
1316
1317 mutex_lock(&fs_info->scrub_lock);
1318 if (!atomic_read(&fs_info->scrubs_running)) {
1319 mutex_unlock(&fs_info->scrub_lock);
1320 return -ENOTCONN;
1321 }
1322
1323 atomic_inc(&fs_info->scrub_cancel_req);
1324 while (atomic_read(&fs_info->scrubs_running)) {
1325 mutex_unlock(&fs_info->scrub_lock);
1326 wait_event(fs_info->scrub_pause_wait,
1327 atomic_read(&fs_info->scrubs_running) == 0);
1328 mutex_lock(&fs_info->scrub_lock);
1329 }
1330 atomic_dec(&fs_info->scrub_cancel_req);
1331 mutex_unlock(&fs_info->scrub_lock);
1332
1333 return 0;
1334}
1335
1336int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
1337{
1338 struct btrfs_fs_info *fs_info = root->fs_info;
1339 struct scrub_dev *sdev;
1340
1341 mutex_lock(&fs_info->scrub_lock);
1342 sdev = dev->scrub_device;
1343 if (!sdev) {
1344 mutex_unlock(&fs_info->scrub_lock);
1345 return -ENOTCONN;
1346 }
1347 atomic_inc(&sdev->cancel_req);
1348 while (dev->scrub_device) {
1349 mutex_unlock(&fs_info->scrub_lock);
1350 wait_event(fs_info->scrub_pause_wait,
1351 dev->scrub_device == NULL);
1352 mutex_lock(&fs_info->scrub_lock);
1353 }
1354 mutex_unlock(&fs_info->scrub_lock);
1355
1356 return 0;
1357}
1358int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
1359{
1360 struct btrfs_fs_info *fs_info = root->fs_info;
1361 struct btrfs_device *dev;
1362 int ret;
1363
1364 /*
1365 * we have to hold the device_list_mutex here so the device
1366 * does not go away in cancel_dev. FIXME: find a better solution
1367 */
1368 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1369 dev = btrfs_find_device(root, devid, NULL, NULL);
1370 if (!dev) {
1371 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1372 return -ENODEV;
1373 }
1374 ret = btrfs_scrub_cancel_dev(root, dev);
1375 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1376
1377 return ret;
1378}
1379
1380int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
1381 struct btrfs_scrub_progress *progress)
1382{
1383 struct btrfs_device *dev;
1384 struct scrub_dev *sdev = NULL;
1385
1386 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1387 dev = btrfs_find_device(root, devid, NULL, NULL);
1388 if (dev)
1389 sdev = dev->scrub_device;
1390 if (sdev)
1391 memcpy(progress, &sdev->stat, sizeof(*progress));
1392 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1393
1394 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;
1395}