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Merge tag 'edac/v4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[mirror_ubuntu-artful-kernel.git] / fs / btrfs / scrub.c
1 /*
2 * Copyright (C) 2011, 2012 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 <linux/ratelimit.h>
21 #include "ctree.h"
22 #include "volumes.h"
23 #include "disk-io.h"
24 #include "ordered-data.h"
25 #include "transaction.h"
26 #include "backref.h"
27 #include "extent_io.h"
28 #include "dev-replace.h"
29 #include "check-integrity.h"
30 #include "rcu-string.h"
31 #include "raid56.h"
32
33 /*
34 * This is only the first step towards a full-features scrub. It reads all
35 * extent and super block and verifies the checksums. In case a bad checksum
36 * is found or the extent cannot be read, good data will be written back if
37 * any can be found.
38 *
39 * Future enhancements:
40 * - In case an unrepairable extent is encountered, track which files are
41 * affected and report them
42 * - track and record media errors, throw out bad devices
43 * - add a mode to also read unallocated space
44 */
45
46 struct scrub_block;
47 struct scrub_ctx;
48
49 /*
50 * the following three values only influence the performance.
51 * The last one configures the number of parallel and outstanding I/O
52 * operations. The first two values configure an upper limit for the number
53 * of (dynamically allocated) pages that are added to a bio.
54 */
55 #define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
56 #define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
57 #define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
58
59 /*
60 * the following value times PAGE_SIZE needs to be large enough to match the
61 * largest node/leaf/sector size that shall be supported.
62 * Values larger than BTRFS_STRIPE_LEN are not supported.
63 */
64 #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
65
66 struct scrub_recover {
67 atomic_t refs;
68 struct btrfs_bio *bbio;
69 u64 map_length;
70 };
71
72 struct scrub_page {
73 struct scrub_block *sblock;
74 struct page *page;
75 struct btrfs_device *dev;
76 struct list_head list;
77 u64 flags; /* extent flags */
78 u64 generation;
79 u64 logical;
80 u64 physical;
81 u64 physical_for_dev_replace;
82 atomic_t refs;
83 struct {
84 unsigned int mirror_num:8;
85 unsigned int have_csum:1;
86 unsigned int io_error:1;
87 };
88 u8 csum[BTRFS_CSUM_SIZE];
89
90 struct scrub_recover *recover;
91 };
92
93 struct scrub_bio {
94 int index;
95 struct scrub_ctx *sctx;
96 struct btrfs_device *dev;
97 struct bio *bio;
98 int err;
99 u64 logical;
100 u64 physical;
101 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
102 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
103 #else
104 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
105 #endif
106 int page_count;
107 int next_free;
108 struct btrfs_work work;
109 };
110
111 struct scrub_block {
112 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
113 int page_count;
114 atomic_t outstanding_pages;
115 atomic_t refs; /* free mem on transition to zero */
116 struct scrub_ctx *sctx;
117 struct scrub_parity *sparity;
118 struct {
119 unsigned int header_error:1;
120 unsigned int checksum_error:1;
121 unsigned int no_io_error_seen:1;
122 unsigned int generation_error:1; /* also sets header_error */
123
124 /* The following is for the data used to check parity */
125 /* It is for the data with checksum */
126 unsigned int data_corrected:1;
127 };
128 struct btrfs_work work;
129 };
130
131 /* Used for the chunks with parity stripe such RAID5/6 */
132 struct scrub_parity {
133 struct scrub_ctx *sctx;
134
135 struct btrfs_device *scrub_dev;
136
137 u64 logic_start;
138
139 u64 logic_end;
140
141 int nsectors;
142
143 int stripe_len;
144
145 atomic_t refs;
146
147 struct list_head spages;
148
149 /* Work of parity check and repair */
150 struct btrfs_work work;
151
152 /* Mark the parity blocks which have data */
153 unsigned long *dbitmap;
154
155 /*
156 * Mark the parity blocks which have data, but errors happen when
157 * read data or check data
158 */
159 unsigned long *ebitmap;
160
161 unsigned long bitmap[0];
162 };
163
164 struct scrub_wr_ctx {
165 struct scrub_bio *wr_curr_bio;
166 struct btrfs_device *tgtdev;
167 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
168 atomic_t flush_all_writes;
169 struct mutex wr_lock;
170 };
171
172 struct scrub_ctx {
173 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
174 struct btrfs_root *dev_root;
175 int first_free;
176 int curr;
177 atomic_t bios_in_flight;
178 atomic_t workers_pending;
179 spinlock_t list_lock;
180 wait_queue_head_t list_wait;
181 u16 csum_size;
182 struct list_head csum_list;
183 atomic_t cancel_req;
184 int readonly;
185 int pages_per_rd_bio;
186 u32 sectorsize;
187 u32 nodesize;
188
189 int is_dev_replace;
190 struct scrub_wr_ctx wr_ctx;
191
192 /*
193 * statistics
194 */
195 struct btrfs_scrub_progress stat;
196 spinlock_t stat_lock;
197
198 /*
199 * Use a ref counter to avoid use-after-free issues. Scrub workers
200 * decrement bios_in_flight and workers_pending and then do a wakeup
201 * on the list_wait wait queue. We must ensure the main scrub task
202 * doesn't free the scrub context before or while the workers are
203 * doing the wakeup() call.
204 */
205 atomic_t refs;
206 };
207
208 struct scrub_fixup_nodatasum {
209 struct scrub_ctx *sctx;
210 struct btrfs_device *dev;
211 u64 logical;
212 struct btrfs_root *root;
213 struct btrfs_work work;
214 int mirror_num;
215 };
216
217 struct scrub_nocow_inode {
218 u64 inum;
219 u64 offset;
220 u64 root;
221 struct list_head list;
222 };
223
224 struct scrub_copy_nocow_ctx {
225 struct scrub_ctx *sctx;
226 u64 logical;
227 u64 len;
228 int mirror_num;
229 u64 physical_for_dev_replace;
230 struct list_head inodes;
231 struct btrfs_work work;
232 };
233
234 struct scrub_warning {
235 struct btrfs_path *path;
236 u64 extent_item_size;
237 const char *errstr;
238 sector_t sector;
239 u64 logical;
240 struct btrfs_device *dev;
241 };
242
243 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
244 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
245 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
246 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
247 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
248 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
249 struct scrub_block *sblocks_for_recheck);
250 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
251 struct scrub_block *sblock,
252 int retry_failed_mirror);
253 static void scrub_recheck_block_checksum(struct scrub_block *sblock);
254 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
255 struct scrub_block *sblock_good);
256 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
257 struct scrub_block *sblock_good,
258 int page_num, int force_write);
259 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
260 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
261 int page_num);
262 static int scrub_checksum_data(struct scrub_block *sblock);
263 static int scrub_checksum_tree_block(struct scrub_block *sblock);
264 static int scrub_checksum_super(struct scrub_block *sblock);
265 static void scrub_block_get(struct scrub_block *sblock);
266 static void scrub_block_put(struct scrub_block *sblock);
267 static void scrub_page_get(struct scrub_page *spage);
268 static void scrub_page_put(struct scrub_page *spage);
269 static void scrub_parity_get(struct scrub_parity *sparity);
270 static void scrub_parity_put(struct scrub_parity *sparity);
271 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
272 struct scrub_page *spage);
273 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
274 u64 physical, struct btrfs_device *dev, u64 flags,
275 u64 gen, int mirror_num, u8 *csum, int force,
276 u64 physical_for_dev_replace);
277 static void scrub_bio_end_io(struct bio *bio);
278 static void scrub_bio_end_io_worker(struct btrfs_work *work);
279 static void scrub_block_complete(struct scrub_block *sblock);
280 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
281 u64 extent_logical, u64 extent_len,
282 u64 *extent_physical,
283 struct btrfs_device **extent_dev,
284 int *extent_mirror_num);
285 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
286 struct scrub_wr_ctx *wr_ctx,
287 struct btrfs_fs_info *fs_info,
288 struct btrfs_device *dev,
289 int is_dev_replace);
290 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
291 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
292 struct scrub_page *spage);
293 static void scrub_wr_submit(struct scrub_ctx *sctx);
294 static void scrub_wr_bio_end_io(struct bio *bio);
295 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
296 static int write_page_nocow(struct scrub_ctx *sctx,
297 u64 physical_for_dev_replace, struct page *page);
298 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
299 struct scrub_copy_nocow_ctx *ctx);
300 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
301 int mirror_num, u64 physical_for_dev_replace);
302 static void copy_nocow_pages_worker(struct btrfs_work *work);
303 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
304 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
305 static void scrub_put_ctx(struct scrub_ctx *sctx);
306
307
308 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
309 {
310 atomic_inc(&sctx->refs);
311 atomic_inc(&sctx->bios_in_flight);
312 }
313
314 static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
315 {
316 atomic_dec(&sctx->bios_in_flight);
317 wake_up(&sctx->list_wait);
318 scrub_put_ctx(sctx);
319 }
320
321 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
322 {
323 while (atomic_read(&fs_info->scrub_pause_req)) {
324 mutex_unlock(&fs_info->scrub_lock);
325 wait_event(fs_info->scrub_pause_wait,
326 atomic_read(&fs_info->scrub_pause_req) == 0);
327 mutex_lock(&fs_info->scrub_lock);
328 }
329 }
330
331 static void scrub_pause_on(struct btrfs_fs_info *fs_info)
332 {
333 atomic_inc(&fs_info->scrubs_paused);
334 wake_up(&fs_info->scrub_pause_wait);
335 }
336
337 static void scrub_pause_off(struct btrfs_fs_info *fs_info)
338 {
339 mutex_lock(&fs_info->scrub_lock);
340 __scrub_blocked_if_needed(fs_info);
341 atomic_dec(&fs_info->scrubs_paused);
342 mutex_unlock(&fs_info->scrub_lock);
343
344 wake_up(&fs_info->scrub_pause_wait);
345 }
346
347 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
348 {
349 scrub_pause_on(fs_info);
350 scrub_pause_off(fs_info);
351 }
352
353 /*
354 * used for workers that require transaction commits (i.e., for the
355 * NOCOW case)
356 */
357 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
358 {
359 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
360
361 atomic_inc(&sctx->refs);
362 /*
363 * increment scrubs_running to prevent cancel requests from
364 * completing as long as a worker is running. we must also
365 * increment scrubs_paused to prevent deadlocking on pause
366 * requests used for transactions commits (as the worker uses a
367 * transaction context). it is safe to regard the worker
368 * as paused for all matters practical. effectively, we only
369 * avoid cancellation requests from completing.
370 */
371 mutex_lock(&fs_info->scrub_lock);
372 atomic_inc(&fs_info->scrubs_running);
373 atomic_inc(&fs_info->scrubs_paused);
374 mutex_unlock(&fs_info->scrub_lock);
375
376 /*
377 * check if @scrubs_running=@scrubs_paused condition
378 * inside wait_event() is not an atomic operation.
379 * which means we may inc/dec @scrub_running/paused
380 * at any time. Let's wake up @scrub_pause_wait as
381 * much as we can to let commit transaction blocked less.
382 */
383 wake_up(&fs_info->scrub_pause_wait);
384
385 atomic_inc(&sctx->workers_pending);
386 }
387
388 /* used for workers that require transaction commits */
389 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
390 {
391 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
392
393 /*
394 * see scrub_pending_trans_workers_inc() why we're pretending
395 * to be paused in the scrub counters
396 */
397 mutex_lock(&fs_info->scrub_lock);
398 atomic_dec(&fs_info->scrubs_running);
399 atomic_dec(&fs_info->scrubs_paused);
400 mutex_unlock(&fs_info->scrub_lock);
401 atomic_dec(&sctx->workers_pending);
402 wake_up(&fs_info->scrub_pause_wait);
403 wake_up(&sctx->list_wait);
404 scrub_put_ctx(sctx);
405 }
406
407 static void scrub_free_csums(struct scrub_ctx *sctx)
408 {
409 while (!list_empty(&sctx->csum_list)) {
410 struct btrfs_ordered_sum *sum;
411 sum = list_first_entry(&sctx->csum_list,
412 struct btrfs_ordered_sum, list);
413 list_del(&sum->list);
414 kfree(sum);
415 }
416 }
417
418 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
419 {
420 int i;
421
422 if (!sctx)
423 return;
424
425 scrub_free_wr_ctx(&sctx->wr_ctx);
426
427 /* this can happen when scrub is cancelled */
428 if (sctx->curr != -1) {
429 struct scrub_bio *sbio = sctx->bios[sctx->curr];
430
431 for (i = 0; i < sbio->page_count; i++) {
432 WARN_ON(!sbio->pagev[i]->page);
433 scrub_block_put(sbio->pagev[i]->sblock);
434 }
435 bio_put(sbio->bio);
436 }
437
438 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
439 struct scrub_bio *sbio = sctx->bios[i];
440
441 if (!sbio)
442 break;
443 kfree(sbio);
444 }
445
446 scrub_free_csums(sctx);
447 kfree(sctx);
448 }
449
450 static void scrub_put_ctx(struct scrub_ctx *sctx)
451 {
452 if (atomic_dec_and_test(&sctx->refs))
453 scrub_free_ctx(sctx);
454 }
455
456 static noinline_for_stack
457 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
458 {
459 struct scrub_ctx *sctx;
460 int i;
461 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
462 int ret;
463
464 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
465 if (!sctx)
466 goto nomem;
467 atomic_set(&sctx->refs, 1);
468 sctx->is_dev_replace = is_dev_replace;
469 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
470 sctx->curr = -1;
471 sctx->dev_root = dev->dev_root;
472 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
473 struct scrub_bio *sbio;
474
475 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
476 if (!sbio)
477 goto nomem;
478 sctx->bios[i] = sbio;
479
480 sbio->index = i;
481 sbio->sctx = sctx;
482 sbio->page_count = 0;
483 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
484 scrub_bio_end_io_worker, NULL, NULL);
485
486 if (i != SCRUB_BIOS_PER_SCTX - 1)
487 sctx->bios[i]->next_free = i + 1;
488 else
489 sctx->bios[i]->next_free = -1;
490 }
491 sctx->first_free = 0;
492 sctx->nodesize = dev->dev_root->nodesize;
493 sctx->sectorsize = dev->dev_root->sectorsize;
494 atomic_set(&sctx->bios_in_flight, 0);
495 atomic_set(&sctx->workers_pending, 0);
496 atomic_set(&sctx->cancel_req, 0);
497 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
498 INIT_LIST_HEAD(&sctx->csum_list);
499
500 spin_lock_init(&sctx->list_lock);
501 spin_lock_init(&sctx->stat_lock);
502 init_waitqueue_head(&sctx->list_wait);
503
504 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
505 fs_info->dev_replace.tgtdev, is_dev_replace);
506 if (ret) {
507 scrub_free_ctx(sctx);
508 return ERR_PTR(ret);
509 }
510 return sctx;
511
512 nomem:
513 scrub_free_ctx(sctx);
514 return ERR_PTR(-ENOMEM);
515 }
516
517 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
518 void *warn_ctx)
519 {
520 u64 isize;
521 u32 nlink;
522 int ret;
523 int i;
524 struct extent_buffer *eb;
525 struct btrfs_inode_item *inode_item;
526 struct scrub_warning *swarn = warn_ctx;
527 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
528 struct inode_fs_paths *ipath = NULL;
529 struct btrfs_root *local_root;
530 struct btrfs_key root_key;
531 struct btrfs_key key;
532
533 root_key.objectid = root;
534 root_key.type = BTRFS_ROOT_ITEM_KEY;
535 root_key.offset = (u64)-1;
536 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
537 if (IS_ERR(local_root)) {
538 ret = PTR_ERR(local_root);
539 goto err;
540 }
541
542 /*
543 * this makes the path point to (inum INODE_ITEM ioff)
544 */
545 key.objectid = inum;
546 key.type = BTRFS_INODE_ITEM_KEY;
547 key.offset = 0;
548
549 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
550 if (ret) {
551 btrfs_release_path(swarn->path);
552 goto err;
553 }
554
555 eb = swarn->path->nodes[0];
556 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
557 struct btrfs_inode_item);
558 isize = btrfs_inode_size(eb, inode_item);
559 nlink = btrfs_inode_nlink(eb, inode_item);
560 btrfs_release_path(swarn->path);
561
562 ipath = init_ipath(4096, local_root, swarn->path);
563 if (IS_ERR(ipath)) {
564 ret = PTR_ERR(ipath);
565 ipath = NULL;
566 goto err;
567 }
568 ret = paths_from_inode(inum, ipath);
569
570 if (ret < 0)
571 goto err;
572
573 /*
574 * we deliberately ignore the bit ipath might have been too small to
575 * hold all of the paths here
576 */
577 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
578 btrfs_warn_in_rcu(fs_info,
579 "%s at logical %llu on dev %s, sector %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
580 swarn->errstr, swarn->logical,
581 rcu_str_deref(swarn->dev->name),
582 (unsigned long long)swarn->sector,
583 root, inum, offset,
584 min(isize - offset, (u64)PAGE_SIZE), nlink,
585 (char *)(unsigned long)ipath->fspath->val[i]);
586
587 free_ipath(ipath);
588 return 0;
589
590 err:
591 btrfs_warn_in_rcu(fs_info,
592 "%s at logical %llu on dev %s, sector %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
593 swarn->errstr, swarn->logical,
594 rcu_str_deref(swarn->dev->name),
595 (unsigned long long)swarn->sector,
596 root, inum, offset, ret);
597
598 free_ipath(ipath);
599 return 0;
600 }
601
602 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
603 {
604 struct btrfs_device *dev;
605 struct btrfs_fs_info *fs_info;
606 struct btrfs_path *path;
607 struct btrfs_key found_key;
608 struct extent_buffer *eb;
609 struct btrfs_extent_item *ei;
610 struct scrub_warning swarn;
611 unsigned long ptr = 0;
612 u64 extent_item_pos;
613 u64 flags = 0;
614 u64 ref_root;
615 u32 item_size;
616 u8 ref_level = 0;
617 int ret;
618
619 WARN_ON(sblock->page_count < 1);
620 dev = sblock->pagev[0]->dev;
621 fs_info = sblock->sctx->dev_root->fs_info;
622
623 path = btrfs_alloc_path();
624 if (!path)
625 return;
626
627 swarn.sector = (sblock->pagev[0]->physical) >> 9;
628 swarn.logical = sblock->pagev[0]->logical;
629 swarn.errstr = errstr;
630 swarn.dev = NULL;
631
632 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
633 &flags);
634 if (ret < 0)
635 goto out;
636
637 extent_item_pos = swarn.logical - found_key.objectid;
638 swarn.extent_item_size = found_key.offset;
639
640 eb = path->nodes[0];
641 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
642 item_size = btrfs_item_size_nr(eb, path->slots[0]);
643
644 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
645 do {
646 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
647 item_size, &ref_root,
648 &ref_level);
649 btrfs_warn_in_rcu(fs_info,
650 "%s at logical %llu on dev %s, sector %llu: metadata %s (level %d) in tree %llu",
651 errstr, swarn.logical,
652 rcu_str_deref(dev->name),
653 (unsigned long long)swarn.sector,
654 ref_level ? "node" : "leaf",
655 ret < 0 ? -1 : ref_level,
656 ret < 0 ? -1 : ref_root);
657 } while (ret != 1);
658 btrfs_release_path(path);
659 } else {
660 btrfs_release_path(path);
661 swarn.path = path;
662 swarn.dev = dev;
663 iterate_extent_inodes(fs_info, found_key.objectid,
664 extent_item_pos, 1,
665 scrub_print_warning_inode, &swarn);
666 }
667
668 out:
669 btrfs_free_path(path);
670 }
671
672 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
673 {
674 struct page *page = NULL;
675 unsigned long index;
676 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
677 int ret;
678 int corrected = 0;
679 struct btrfs_key key;
680 struct inode *inode = NULL;
681 struct btrfs_fs_info *fs_info;
682 u64 end = offset + PAGE_SIZE - 1;
683 struct btrfs_root *local_root;
684 int srcu_index;
685
686 key.objectid = root;
687 key.type = BTRFS_ROOT_ITEM_KEY;
688 key.offset = (u64)-1;
689
690 fs_info = fixup->root->fs_info;
691 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
692
693 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
694 if (IS_ERR(local_root)) {
695 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
696 return PTR_ERR(local_root);
697 }
698
699 key.type = BTRFS_INODE_ITEM_KEY;
700 key.objectid = inum;
701 key.offset = 0;
702 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
703 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
704 if (IS_ERR(inode))
705 return PTR_ERR(inode);
706
707 index = offset >> PAGE_SHIFT;
708
709 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
710 if (!page) {
711 ret = -ENOMEM;
712 goto out;
713 }
714
715 if (PageUptodate(page)) {
716 if (PageDirty(page)) {
717 /*
718 * we need to write the data to the defect sector. the
719 * data that was in that sector is not in memory,
720 * because the page was modified. we must not write the
721 * modified page to that sector.
722 *
723 * TODO: what could be done here: wait for the delalloc
724 * runner to write out that page (might involve
725 * COW) and see whether the sector is still
726 * referenced afterwards.
727 *
728 * For the meantime, we'll treat this error
729 * incorrectable, although there is a chance that a
730 * later scrub will find the bad sector again and that
731 * there's no dirty page in memory, then.
732 */
733 ret = -EIO;
734 goto out;
735 }
736 ret = repair_io_failure(inode, offset, PAGE_SIZE,
737 fixup->logical, page,
738 offset - page_offset(page),
739 fixup->mirror_num);
740 unlock_page(page);
741 corrected = !ret;
742 } else {
743 /*
744 * we need to get good data first. the general readpage path
745 * will call repair_io_failure for us, we just have to make
746 * sure we read the bad mirror.
747 */
748 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
749 EXTENT_DAMAGED);
750 if (ret) {
751 /* set_extent_bits should give proper error */
752 WARN_ON(ret > 0);
753 if (ret > 0)
754 ret = -EFAULT;
755 goto out;
756 }
757
758 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
759 btrfs_get_extent,
760 fixup->mirror_num);
761 wait_on_page_locked(page);
762
763 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
764 end, EXTENT_DAMAGED, 0, NULL);
765 if (!corrected)
766 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
767 EXTENT_DAMAGED);
768 }
769
770 out:
771 if (page)
772 put_page(page);
773
774 iput(inode);
775
776 if (ret < 0)
777 return ret;
778
779 if (ret == 0 && corrected) {
780 /*
781 * we only need to call readpage for one of the inodes belonging
782 * to this extent. so make iterate_extent_inodes stop
783 */
784 return 1;
785 }
786
787 return -EIO;
788 }
789
790 static void scrub_fixup_nodatasum(struct btrfs_work *work)
791 {
792 int ret;
793 struct scrub_fixup_nodatasum *fixup;
794 struct scrub_ctx *sctx;
795 struct btrfs_trans_handle *trans = NULL;
796 struct btrfs_path *path;
797 int uncorrectable = 0;
798
799 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
800 sctx = fixup->sctx;
801
802 path = btrfs_alloc_path();
803 if (!path) {
804 spin_lock(&sctx->stat_lock);
805 ++sctx->stat.malloc_errors;
806 spin_unlock(&sctx->stat_lock);
807 uncorrectable = 1;
808 goto out;
809 }
810
811 trans = btrfs_join_transaction(fixup->root);
812 if (IS_ERR(trans)) {
813 uncorrectable = 1;
814 goto out;
815 }
816
817 /*
818 * the idea is to trigger a regular read through the standard path. we
819 * read a page from the (failed) logical address by specifying the
820 * corresponding copynum of the failed sector. thus, that readpage is
821 * expected to fail.
822 * that is the point where on-the-fly error correction will kick in
823 * (once it's finished) and rewrite the failed sector if a good copy
824 * can be found.
825 */
826 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
827 path, scrub_fixup_readpage,
828 fixup);
829 if (ret < 0) {
830 uncorrectable = 1;
831 goto out;
832 }
833 WARN_ON(ret != 1);
834
835 spin_lock(&sctx->stat_lock);
836 ++sctx->stat.corrected_errors;
837 spin_unlock(&sctx->stat_lock);
838
839 out:
840 if (trans && !IS_ERR(trans))
841 btrfs_end_transaction(trans, fixup->root);
842 if (uncorrectable) {
843 spin_lock(&sctx->stat_lock);
844 ++sctx->stat.uncorrectable_errors;
845 spin_unlock(&sctx->stat_lock);
846 btrfs_dev_replace_stats_inc(
847 &sctx->dev_root->fs_info->dev_replace.
848 num_uncorrectable_read_errors);
849 btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
850 "unable to fixup (nodatasum) error at logical %llu on dev %s",
851 fixup->logical, rcu_str_deref(fixup->dev->name));
852 }
853
854 btrfs_free_path(path);
855 kfree(fixup);
856
857 scrub_pending_trans_workers_dec(sctx);
858 }
859
860 static inline void scrub_get_recover(struct scrub_recover *recover)
861 {
862 atomic_inc(&recover->refs);
863 }
864
865 static inline void scrub_put_recover(struct scrub_recover *recover)
866 {
867 if (atomic_dec_and_test(&recover->refs)) {
868 btrfs_put_bbio(recover->bbio);
869 kfree(recover);
870 }
871 }
872
873 /*
874 * scrub_handle_errored_block gets called when either verification of the
875 * pages failed or the bio failed to read, e.g. with EIO. In the latter
876 * case, this function handles all pages in the bio, even though only one
877 * may be bad.
878 * The goal of this function is to repair the errored block by using the
879 * contents of one of the mirrors.
880 */
881 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
882 {
883 struct scrub_ctx *sctx = sblock_to_check->sctx;
884 struct btrfs_device *dev;
885 struct btrfs_fs_info *fs_info;
886 u64 length;
887 u64 logical;
888 unsigned int failed_mirror_index;
889 unsigned int is_metadata;
890 unsigned int have_csum;
891 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
892 struct scrub_block *sblock_bad;
893 int ret;
894 int mirror_index;
895 int page_num;
896 int success;
897 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
898 DEFAULT_RATELIMIT_BURST);
899
900 BUG_ON(sblock_to_check->page_count < 1);
901 fs_info = sctx->dev_root->fs_info;
902 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
903 /*
904 * if we find an error in a super block, we just report it.
905 * They will get written with the next transaction commit
906 * anyway
907 */
908 spin_lock(&sctx->stat_lock);
909 ++sctx->stat.super_errors;
910 spin_unlock(&sctx->stat_lock);
911 return 0;
912 }
913 length = sblock_to_check->page_count * PAGE_SIZE;
914 logical = sblock_to_check->pagev[0]->logical;
915 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
916 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
917 is_metadata = !(sblock_to_check->pagev[0]->flags &
918 BTRFS_EXTENT_FLAG_DATA);
919 have_csum = sblock_to_check->pagev[0]->have_csum;
920 dev = sblock_to_check->pagev[0]->dev;
921
922 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
923 sblocks_for_recheck = NULL;
924 goto nodatasum_case;
925 }
926
927 /*
928 * read all mirrors one after the other. This includes to
929 * re-read the extent or metadata block that failed (that was
930 * the cause that this fixup code is called) another time,
931 * page by page this time in order to know which pages
932 * caused I/O errors and which ones are good (for all mirrors).
933 * It is the goal to handle the situation when more than one
934 * mirror contains I/O errors, but the errors do not
935 * overlap, i.e. the data can be repaired by selecting the
936 * pages from those mirrors without I/O error on the
937 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
938 * would be that mirror #1 has an I/O error on the first page,
939 * the second page is good, and mirror #2 has an I/O error on
940 * the second page, but the first page is good.
941 * Then the first page of the first mirror can be repaired by
942 * taking the first page of the second mirror, and the
943 * second page of the second mirror can be repaired by
944 * copying the contents of the 2nd page of the 1st mirror.
945 * One more note: if the pages of one mirror contain I/O
946 * errors, the checksum cannot be verified. In order to get
947 * the best data for repairing, the first attempt is to find
948 * a mirror without I/O errors and with a validated checksum.
949 * Only if this is not possible, the pages are picked from
950 * mirrors with I/O errors without considering the checksum.
951 * If the latter is the case, at the end, the checksum of the
952 * repaired area is verified in order to correctly maintain
953 * the statistics.
954 */
955
956 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
957 sizeof(*sblocks_for_recheck), GFP_NOFS);
958 if (!sblocks_for_recheck) {
959 spin_lock(&sctx->stat_lock);
960 sctx->stat.malloc_errors++;
961 sctx->stat.read_errors++;
962 sctx->stat.uncorrectable_errors++;
963 spin_unlock(&sctx->stat_lock);
964 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
965 goto out;
966 }
967
968 /* setup the context, map the logical blocks and alloc the pages */
969 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
970 if (ret) {
971 spin_lock(&sctx->stat_lock);
972 sctx->stat.read_errors++;
973 sctx->stat.uncorrectable_errors++;
974 spin_unlock(&sctx->stat_lock);
975 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
976 goto out;
977 }
978 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
979 sblock_bad = sblocks_for_recheck + failed_mirror_index;
980
981 /* build and submit the bios for the failed mirror, check checksums */
982 scrub_recheck_block(fs_info, sblock_bad, 1);
983
984 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
985 sblock_bad->no_io_error_seen) {
986 /*
987 * the error disappeared after reading page by page, or
988 * the area was part of a huge bio and other parts of the
989 * bio caused I/O errors, or the block layer merged several
990 * read requests into one and the error is caused by a
991 * different bio (usually one of the two latter cases is
992 * the cause)
993 */
994 spin_lock(&sctx->stat_lock);
995 sctx->stat.unverified_errors++;
996 sblock_to_check->data_corrected = 1;
997 spin_unlock(&sctx->stat_lock);
998
999 if (sctx->is_dev_replace)
1000 scrub_write_block_to_dev_replace(sblock_bad);
1001 goto out;
1002 }
1003
1004 if (!sblock_bad->no_io_error_seen) {
1005 spin_lock(&sctx->stat_lock);
1006 sctx->stat.read_errors++;
1007 spin_unlock(&sctx->stat_lock);
1008 if (__ratelimit(&_rs))
1009 scrub_print_warning("i/o error", sblock_to_check);
1010 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1011 } else if (sblock_bad->checksum_error) {
1012 spin_lock(&sctx->stat_lock);
1013 sctx->stat.csum_errors++;
1014 spin_unlock(&sctx->stat_lock);
1015 if (__ratelimit(&_rs))
1016 scrub_print_warning("checksum error", sblock_to_check);
1017 btrfs_dev_stat_inc_and_print(dev,
1018 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1019 } else if (sblock_bad->header_error) {
1020 spin_lock(&sctx->stat_lock);
1021 sctx->stat.verify_errors++;
1022 spin_unlock(&sctx->stat_lock);
1023 if (__ratelimit(&_rs))
1024 scrub_print_warning("checksum/header error",
1025 sblock_to_check);
1026 if (sblock_bad->generation_error)
1027 btrfs_dev_stat_inc_and_print(dev,
1028 BTRFS_DEV_STAT_GENERATION_ERRS);
1029 else
1030 btrfs_dev_stat_inc_and_print(dev,
1031 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1032 }
1033
1034 if (sctx->readonly) {
1035 ASSERT(!sctx->is_dev_replace);
1036 goto out;
1037 }
1038
1039 if (!is_metadata && !have_csum) {
1040 struct scrub_fixup_nodatasum *fixup_nodatasum;
1041
1042 WARN_ON(sctx->is_dev_replace);
1043
1044 nodatasum_case:
1045
1046 /*
1047 * !is_metadata and !have_csum, this means that the data
1048 * might not be COWed, that it might be modified
1049 * concurrently. The general strategy to work on the
1050 * commit root does not help in the case when COW is not
1051 * used.
1052 */
1053 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
1054 if (!fixup_nodatasum)
1055 goto did_not_correct_error;
1056 fixup_nodatasum->sctx = sctx;
1057 fixup_nodatasum->dev = dev;
1058 fixup_nodatasum->logical = logical;
1059 fixup_nodatasum->root = fs_info->extent_root;
1060 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
1061 scrub_pending_trans_workers_inc(sctx);
1062 btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
1063 scrub_fixup_nodatasum, NULL, NULL);
1064 btrfs_queue_work(fs_info->scrub_workers,
1065 &fixup_nodatasum->work);
1066 goto out;
1067 }
1068
1069 /*
1070 * now build and submit the bios for the other mirrors, check
1071 * checksums.
1072 * First try to pick the mirror which is completely without I/O
1073 * errors and also does not have a checksum error.
1074 * If one is found, and if a checksum is present, the full block
1075 * that is known to contain an error is rewritten. Afterwards
1076 * the block is known to be corrected.
1077 * If a mirror is found which is completely correct, and no
1078 * checksum is present, only those pages are rewritten that had
1079 * an I/O error in the block to be repaired, since it cannot be
1080 * determined, which copy of the other pages is better (and it
1081 * could happen otherwise that a correct page would be
1082 * overwritten by a bad one).
1083 */
1084 for (mirror_index = 0;
1085 mirror_index < BTRFS_MAX_MIRRORS &&
1086 sblocks_for_recheck[mirror_index].page_count > 0;
1087 mirror_index++) {
1088 struct scrub_block *sblock_other;
1089
1090 if (mirror_index == failed_mirror_index)
1091 continue;
1092 sblock_other = sblocks_for_recheck + mirror_index;
1093
1094 /* build and submit the bios, check checksums */
1095 scrub_recheck_block(fs_info, sblock_other, 0);
1096
1097 if (!sblock_other->header_error &&
1098 !sblock_other->checksum_error &&
1099 sblock_other->no_io_error_seen) {
1100 if (sctx->is_dev_replace) {
1101 scrub_write_block_to_dev_replace(sblock_other);
1102 goto corrected_error;
1103 } else {
1104 ret = scrub_repair_block_from_good_copy(
1105 sblock_bad, sblock_other);
1106 if (!ret)
1107 goto corrected_error;
1108 }
1109 }
1110 }
1111
1112 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1113 goto did_not_correct_error;
1114
1115 /*
1116 * In case of I/O errors in the area that is supposed to be
1117 * repaired, continue by picking good copies of those pages.
1118 * Select the good pages from mirrors to rewrite bad pages from
1119 * the area to fix. Afterwards verify the checksum of the block
1120 * that is supposed to be repaired. This verification step is
1121 * only done for the purpose of statistic counting and for the
1122 * final scrub report, whether errors remain.
1123 * A perfect algorithm could make use of the checksum and try
1124 * all possible combinations of pages from the different mirrors
1125 * until the checksum verification succeeds. For example, when
1126 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1127 * of mirror #2 is readable but the final checksum test fails,
1128 * then the 2nd page of mirror #3 could be tried, whether now
1129 * the final checksum succeeds. But this would be a rare
1130 * exception and is therefore not implemented. At least it is
1131 * avoided that the good copy is overwritten.
1132 * A more useful improvement would be to pick the sectors
1133 * without I/O error based on sector sizes (512 bytes on legacy
1134 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1135 * mirror could be repaired by taking 512 byte of a different
1136 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1137 * area are unreadable.
1138 */
1139 success = 1;
1140 for (page_num = 0; page_num < sblock_bad->page_count;
1141 page_num++) {
1142 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1143 struct scrub_block *sblock_other = NULL;
1144
1145 /* skip no-io-error page in scrub */
1146 if (!page_bad->io_error && !sctx->is_dev_replace)
1147 continue;
1148
1149 /* try to find no-io-error page in mirrors */
1150 if (page_bad->io_error) {
1151 for (mirror_index = 0;
1152 mirror_index < BTRFS_MAX_MIRRORS &&
1153 sblocks_for_recheck[mirror_index].page_count > 0;
1154 mirror_index++) {
1155 if (!sblocks_for_recheck[mirror_index].
1156 pagev[page_num]->io_error) {
1157 sblock_other = sblocks_for_recheck +
1158 mirror_index;
1159 break;
1160 }
1161 }
1162 if (!sblock_other)
1163 success = 0;
1164 }
1165
1166 if (sctx->is_dev_replace) {
1167 /*
1168 * did not find a mirror to fetch the page
1169 * from. scrub_write_page_to_dev_replace()
1170 * handles this case (page->io_error), by
1171 * filling the block with zeros before
1172 * submitting the write request
1173 */
1174 if (!sblock_other)
1175 sblock_other = sblock_bad;
1176
1177 if (scrub_write_page_to_dev_replace(sblock_other,
1178 page_num) != 0) {
1179 btrfs_dev_replace_stats_inc(
1180 &sctx->dev_root->
1181 fs_info->dev_replace.
1182 num_write_errors);
1183 success = 0;
1184 }
1185 } else if (sblock_other) {
1186 ret = scrub_repair_page_from_good_copy(sblock_bad,
1187 sblock_other,
1188 page_num, 0);
1189 if (0 == ret)
1190 page_bad->io_error = 0;
1191 else
1192 success = 0;
1193 }
1194 }
1195
1196 if (success && !sctx->is_dev_replace) {
1197 if (is_metadata || have_csum) {
1198 /*
1199 * need to verify the checksum now that all
1200 * sectors on disk are repaired (the write
1201 * request for data to be repaired is on its way).
1202 * Just be lazy and use scrub_recheck_block()
1203 * which re-reads the data before the checksum
1204 * is verified, but most likely the data comes out
1205 * of the page cache.
1206 */
1207 scrub_recheck_block(fs_info, sblock_bad, 1);
1208 if (!sblock_bad->header_error &&
1209 !sblock_bad->checksum_error &&
1210 sblock_bad->no_io_error_seen)
1211 goto corrected_error;
1212 else
1213 goto did_not_correct_error;
1214 } else {
1215 corrected_error:
1216 spin_lock(&sctx->stat_lock);
1217 sctx->stat.corrected_errors++;
1218 sblock_to_check->data_corrected = 1;
1219 spin_unlock(&sctx->stat_lock);
1220 btrfs_err_rl_in_rcu(fs_info,
1221 "fixed up error at logical %llu on dev %s",
1222 logical, rcu_str_deref(dev->name));
1223 }
1224 } else {
1225 did_not_correct_error:
1226 spin_lock(&sctx->stat_lock);
1227 sctx->stat.uncorrectable_errors++;
1228 spin_unlock(&sctx->stat_lock);
1229 btrfs_err_rl_in_rcu(fs_info,
1230 "unable to fixup (regular) error at logical %llu on dev %s",
1231 logical, rcu_str_deref(dev->name));
1232 }
1233
1234 out:
1235 if (sblocks_for_recheck) {
1236 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1237 mirror_index++) {
1238 struct scrub_block *sblock = sblocks_for_recheck +
1239 mirror_index;
1240 struct scrub_recover *recover;
1241 int page_index;
1242
1243 for (page_index = 0; page_index < sblock->page_count;
1244 page_index++) {
1245 sblock->pagev[page_index]->sblock = NULL;
1246 recover = sblock->pagev[page_index]->recover;
1247 if (recover) {
1248 scrub_put_recover(recover);
1249 sblock->pagev[page_index]->recover =
1250 NULL;
1251 }
1252 scrub_page_put(sblock->pagev[page_index]);
1253 }
1254 }
1255 kfree(sblocks_for_recheck);
1256 }
1257
1258 return 0;
1259 }
1260
1261 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1262 {
1263 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1264 return 2;
1265 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1266 return 3;
1267 else
1268 return (int)bbio->num_stripes;
1269 }
1270
1271 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1272 u64 *raid_map,
1273 u64 mapped_length,
1274 int nstripes, int mirror,
1275 int *stripe_index,
1276 u64 *stripe_offset)
1277 {
1278 int i;
1279
1280 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1281 /* RAID5/6 */
1282 for (i = 0; i < nstripes; i++) {
1283 if (raid_map[i] == RAID6_Q_STRIPE ||
1284 raid_map[i] == RAID5_P_STRIPE)
1285 continue;
1286
1287 if (logical >= raid_map[i] &&
1288 logical < raid_map[i] + mapped_length)
1289 break;
1290 }
1291
1292 *stripe_index = i;
1293 *stripe_offset = logical - raid_map[i];
1294 } else {
1295 /* The other RAID type */
1296 *stripe_index = mirror;
1297 *stripe_offset = 0;
1298 }
1299 }
1300
1301 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1302 struct scrub_block *sblocks_for_recheck)
1303 {
1304 struct scrub_ctx *sctx = original_sblock->sctx;
1305 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
1306 u64 length = original_sblock->page_count * PAGE_SIZE;
1307 u64 logical = original_sblock->pagev[0]->logical;
1308 u64 generation = original_sblock->pagev[0]->generation;
1309 u64 flags = original_sblock->pagev[0]->flags;
1310 u64 have_csum = original_sblock->pagev[0]->have_csum;
1311 struct scrub_recover *recover;
1312 struct btrfs_bio *bbio;
1313 u64 sublen;
1314 u64 mapped_length;
1315 u64 stripe_offset;
1316 int stripe_index;
1317 int page_index = 0;
1318 int mirror_index;
1319 int nmirrors;
1320 int ret;
1321
1322 /*
1323 * note: the two members refs and outstanding_pages
1324 * are not used (and not set) in the blocks that are used for
1325 * the recheck procedure
1326 */
1327
1328 while (length > 0) {
1329 sublen = min_t(u64, length, PAGE_SIZE);
1330 mapped_length = sublen;
1331 bbio = NULL;
1332
1333 /*
1334 * with a length of PAGE_SIZE, each returned stripe
1335 * represents one mirror
1336 */
1337 ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical,
1338 &mapped_length, &bbio, 0, 1);
1339 if (ret || !bbio || mapped_length < sublen) {
1340 btrfs_put_bbio(bbio);
1341 return -EIO;
1342 }
1343
1344 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1345 if (!recover) {
1346 btrfs_put_bbio(bbio);
1347 return -ENOMEM;
1348 }
1349
1350 atomic_set(&recover->refs, 1);
1351 recover->bbio = bbio;
1352 recover->map_length = mapped_length;
1353
1354 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1355
1356 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1357
1358 for (mirror_index = 0; mirror_index < nmirrors;
1359 mirror_index++) {
1360 struct scrub_block *sblock;
1361 struct scrub_page *page;
1362
1363 sblock = sblocks_for_recheck + mirror_index;
1364 sblock->sctx = sctx;
1365
1366 page = kzalloc(sizeof(*page), GFP_NOFS);
1367 if (!page) {
1368 leave_nomem:
1369 spin_lock(&sctx->stat_lock);
1370 sctx->stat.malloc_errors++;
1371 spin_unlock(&sctx->stat_lock);
1372 scrub_put_recover(recover);
1373 return -ENOMEM;
1374 }
1375 scrub_page_get(page);
1376 sblock->pagev[page_index] = page;
1377 page->sblock = sblock;
1378 page->flags = flags;
1379 page->generation = generation;
1380 page->logical = logical;
1381 page->have_csum = have_csum;
1382 if (have_csum)
1383 memcpy(page->csum,
1384 original_sblock->pagev[0]->csum,
1385 sctx->csum_size);
1386
1387 scrub_stripe_index_and_offset(logical,
1388 bbio->map_type,
1389 bbio->raid_map,
1390 mapped_length,
1391 bbio->num_stripes -
1392 bbio->num_tgtdevs,
1393 mirror_index,
1394 &stripe_index,
1395 &stripe_offset);
1396 page->physical = bbio->stripes[stripe_index].physical +
1397 stripe_offset;
1398 page->dev = bbio->stripes[stripe_index].dev;
1399
1400 BUG_ON(page_index >= original_sblock->page_count);
1401 page->physical_for_dev_replace =
1402 original_sblock->pagev[page_index]->
1403 physical_for_dev_replace;
1404 /* for missing devices, dev->bdev is NULL */
1405 page->mirror_num = mirror_index + 1;
1406 sblock->page_count++;
1407 page->page = alloc_page(GFP_NOFS);
1408 if (!page->page)
1409 goto leave_nomem;
1410
1411 scrub_get_recover(recover);
1412 page->recover = recover;
1413 }
1414 scrub_put_recover(recover);
1415 length -= sublen;
1416 logical += sublen;
1417 page_index++;
1418 }
1419
1420 return 0;
1421 }
1422
1423 struct scrub_bio_ret {
1424 struct completion event;
1425 int error;
1426 };
1427
1428 static void scrub_bio_wait_endio(struct bio *bio)
1429 {
1430 struct scrub_bio_ret *ret = bio->bi_private;
1431
1432 ret->error = bio->bi_error;
1433 complete(&ret->event);
1434 }
1435
1436 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
1437 {
1438 return page->recover &&
1439 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
1440 }
1441
1442 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1443 struct bio *bio,
1444 struct scrub_page *page)
1445 {
1446 struct scrub_bio_ret done;
1447 int ret;
1448
1449 init_completion(&done.event);
1450 done.error = 0;
1451 bio->bi_iter.bi_sector = page->logical >> 9;
1452 bio->bi_private = &done;
1453 bio->bi_end_io = scrub_bio_wait_endio;
1454
1455 ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio,
1456 page->recover->map_length,
1457 page->mirror_num, 0);
1458 if (ret)
1459 return ret;
1460
1461 wait_for_completion(&done.event);
1462 if (done.error)
1463 return -EIO;
1464
1465 return 0;
1466 }
1467
1468 /*
1469 * this function will check the on disk data for checksum errors, header
1470 * errors and read I/O errors. If any I/O errors happen, the exact pages
1471 * which are errored are marked as being bad. The goal is to enable scrub
1472 * to take those pages that are not errored from all the mirrors so that
1473 * the pages that are errored in the just handled mirror can be repaired.
1474 */
1475 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1476 struct scrub_block *sblock,
1477 int retry_failed_mirror)
1478 {
1479 int page_num;
1480
1481 sblock->no_io_error_seen = 1;
1482
1483 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1484 struct bio *bio;
1485 struct scrub_page *page = sblock->pagev[page_num];
1486
1487 if (page->dev->bdev == NULL) {
1488 page->io_error = 1;
1489 sblock->no_io_error_seen = 0;
1490 continue;
1491 }
1492
1493 WARN_ON(!page->page);
1494 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1495 if (!bio) {
1496 page->io_error = 1;
1497 sblock->no_io_error_seen = 0;
1498 continue;
1499 }
1500 bio->bi_bdev = page->dev->bdev;
1501
1502 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1503 if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
1504 if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
1505 sblock->no_io_error_seen = 0;
1506 } else {
1507 bio->bi_iter.bi_sector = page->physical >> 9;
1508 bio_set_op_attrs(bio, REQ_OP_READ, 0);
1509
1510 if (btrfsic_submit_bio_wait(bio))
1511 sblock->no_io_error_seen = 0;
1512 }
1513
1514 bio_put(bio);
1515 }
1516
1517 if (sblock->no_io_error_seen)
1518 scrub_recheck_block_checksum(sblock);
1519 }
1520
1521 static inline int scrub_check_fsid(u8 fsid[],
1522 struct scrub_page *spage)
1523 {
1524 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1525 int ret;
1526
1527 ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE);
1528 return !ret;
1529 }
1530
1531 static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1532 {
1533 sblock->header_error = 0;
1534 sblock->checksum_error = 0;
1535 sblock->generation_error = 0;
1536
1537 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1538 scrub_checksum_data(sblock);
1539 else
1540 scrub_checksum_tree_block(sblock);
1541 }
1542
1543 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1544 struct scrub_block *sblock_good)
1545 {
1546 int page_num;
1547 int ret = 0;
1548
1549 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1550 int ret_sub;
1551
1552 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1553 sblock_good,
1554 page_num, 1);
1555 if (ret_sub)
1556 ret = ret_sub;
1557 }
1558
1559 return ret;
1560 }
1561
1562 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1563 struct scrub_block *sblock_good,
1564 int page_num, int force_write)
1565 {
1566 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1567 struct scrub_page *page_good = sblock_good->pagev[page_num];
1568
1569 BUG_ON(page_bad->page == NULL);
1570 BUG_ON(page_good->page == NULL);
1571 if (force_write || sblock_bad->header_error ||
1572 sblock_bad->checksum_error || page_bad->io_error) {
1573 struct bio *bio;
1574 int ret;
1575
1576 if (!page_bad->dev->bdev) {
1577 btrfs_warn_rl(sblock_bad->sctx->dev_root->fs_info,
1578 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1579 return -EIO;
1580 }
1581
1582 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1583 if (!bio)
1584 return -EIO;
1585 bio->bi_bdev = page_bad->dev->bdev;
1586 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1587 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1588
1589 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1590 if (PAGE_SIZE != ret) {
1591 bio_put(bio);
1592 return -EIO;
1593 }
1594
1595 if (btrfsic_submit_bio_wait(bio)) {
1596 btrfs_dev_stat_inc_and_print(page_bad->dev,
1597 BTRFS_DEV_STAT_WRITE_ERRS);
1598 btrfs_dev_replace_stats_inc(
1599 &sblock_bad->sctx->dev_root->fs_info->
1600 dev_replace.num_write_errors);
1601 bio_put(bio);
1602 return -EIO;
1603 }
1604 bio_put(bio);
1605 }
1606
1607 return 0;
1608 }
1609
1610 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1611 {
1612 int page_num;
1613
1614 /*
1615 * This block is used for the check of the parity on the source device,
1616 * so the data needn't be written into the destination device.
1617 */
1618 if (sblock->sparity)
1619 return;
1620
1621 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1622 int ret;
1623
1624 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1625 if (ret)
1626 btrfs_dev_replace_stats_inc(
1627 &sblock->sctx->dev_root->fs_info->dev_replace.
1628 num_write_errors);
1629 }
1630 }
1631
1632 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1633 int page_num)
1634 {
1635 struct scrub_page *spage = sblock->pagev[page_num];
1636
1637 BUG_ON(spage->page == NULL);
1638 if (spage->io_error) {
1639 void *mapped_buffer = kmap_atomic(spage->page);
1640
1641 memset(mapped_buffer, 0, PAGE_SIZE);
1642 flush_dcache_page(spage->page);
1643 kunmap_atomic(mapped_buffer);
1644 }
1645 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1646 }
1647
1648 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1649 struct scrub_page *spage)
1650 {
1651 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1652 struct scrub_bio *sbio;
1653 int ret;
1654
1655 mutex_lock(&wr_ctx->wr_lock);
1656 again:
1657 if (!wr_ctx->wr_curr_bio) {
1658 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1659 GFP_KERNEL);
1660 if (!wr_ctx->wr_curr_bio) {
1661 mutex_unlock(&wr_ctx->wr_lock);
1662 return -ENOMEM;
1663 }
1664 wr_ctx->wr_curr_bio->sctx = sctx;
1665 wr_ctx->wr_curr_bio->page_count = 0;
1666 }
1667 sbio = wr_ctx->wr_curr_bio;
1668 if (sbio->page_count == 0) {
1669 struct bio *bio;
1670
1671 sbio->physical = spage->physical_for_dev_replace;
1672 sbio->logical = spage->logical;
1673 sbio->dev = wr_ctx->tgtdev;
1674 bio = sbio->bio;
1675 if (!bio) {
1676 bio = btrfs_io_bio_alloc(GFP_KERNEL,
1677 wr_ctx->pages_per_wr_bio);
1678 if (!bio) {
1679 mutex_unlock(&wr_ctx->wr_lock);
1680 return -ENOMEM;
1681 }
1682 sbio->bio = bio;
1683 }
1684
1685 bio->bi_private = sbio;
1686 bio->bi_end_io = scrub_wr_bio_end_io;
1687 bio->bi_bdev = sbio->dev->bdev;
1688 bio->bi_iter.bi_sector = sbio->physical >> 9;
1689 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1690 sbio->err = 0;
1691 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1692 spage->physical_for_dev_replace ||
1693 sbio->logical + sbio->page_count * PAGE_SIZE !=
1694 spage->logical) {
1695 scrub_wr_submit(sctx);
1696 goto again;
1697 }
1698
1699 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1700 if (ret != PAGE_SIZE) {
1701 if (sbio->page_count < 1) {
1702 bio_put(sbio->bio);
1703 sbio->bio = NULL;
1704 mutex_unlock(&wr_ctx->wr_lock);
1705 return -EIO;
1706 }
1707 scrub_wr_submit(sctx);
1708 goto again;
1709 }
1710
1711 sbio->pagev[sbio->page_count] = spage;
1712 scrub_page_get(spage);
1713 sbio->page_count++;
1714 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1715 scrub_wr_submit(sctx);
1716 mutex_unlock(&wr_ctx->wr_lock);
1717
1718 return 0;
1719 }
1720
1721 static void scrub_wr_submit(struct scrub_ctx *sctx)
1722 {
1723 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1724 struct scrub_bio *sbio;
1725
1726 if (!wr_ctx->wr_curr_bio)
1727 return;
1728
1729 sbio = wr_ctx->wr_curr_bio;
1730 wr_ctx->wr_curr_bio = NULL;
1731 WARN_ON(!sbio->bio->bi_bdev);
1732 scrub_pending_bio_inc(sctx);
1733 /* process all writes in a single worker thread. Then the block layer
1734 * orders the requests before sending them to the driver which
1735 * doubled the write performance on spinning disks when measured
1736 * with Linux 3.5 */
1737 btrfsic_submit_bio(sbio->bio);
1738 }
1739
1740 static void scrub_wr_bio_end_io(struct bio *bio)
1741 {
1742 struct scrub_bio *sbio = bio->bi_private;
1743 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1744
1745 sbio->err = bio->bi_error;
1746 sbio->bio = bio;
1747
1748 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1749 scrub_wr_bio_end_io_worker, NULL, NULL);
1750 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1751 }
1752
1753 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1754 {
1755 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1756 struct scrub_ctx *sctx = sbio->sctx;
1757 int i;
1758
1759 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1760 if (sbio->err) {
1761 struct btrfs_dev_replace *dev_replace =
1762 &sbio->sctx->dev_root->fs_info->dev_replace;
1763
1764 for (i = 0; i < sbio->page_count; i++) {
1765 struct scrub_page *spage = sbio->pagev[i];
1766
1767 spage->io_error = 1;
1768 btrfs_dev_replace_stats_inc(&dev_replace->
1769 num_write_errors);
1770 }
1771 }
1772
1773 for (i = 0; i < sbio->page_count; i++)
1774 scrub_page_put(sbio->pagev[i]);
1775
1776 bio_put(sbio->bio);
1777 kfree(sbio);
1778 scrub_pending_bio_dec(sctx);
1779 }
1780
1781 static int scrub_checksum(struct scrub_block *sblock)
1782 {
1783 u64 flags;
1784 int ret;
1785
1786 /*
1787 * No need to initialize these stats currently,
1788 * because this function only use return value
1789 * instead of these stats value.
1790 *
1791 * Todo:
1792 * always use stats
1793 */
1794 sblock->header_error = 0;
1795 sblock->generation_error = 0;
1796 sblock->checksum_error = 0;
1797
1798 WARN_ON(sblock->page_count < 1);
1799 flags = sblock->pagev[0]->flags;
1800 ret = 0;
1801 if (flags & BTRFS_EXTENT_FLAG_DATA)
1802 ret = scrub_checksum_data(sblock);
1803 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1804 ret = scrub_checksum_tree_block(sblock);
1805 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1806 (void)scrub_checksum_super(sblock);
1807 else
1808 WARN_ON(1);
1809 if (ret)
1810 scrub_handle_errored_block(sblock);
1811
1812 return ret;
1813 }
1814
1815 static int scrub_checksum_data(struct scrub_block *sblock)
1816 {
1817 struct scrub_ctx *sctx = sblock->sctx;
1818 u8 csum[BTRFS_CSUM_SIZE];
1819 u8 *on_disk_csum;
1820 struct page *page;
1821 void *buffer;
1822 u32 crc = ~(u32)0;
1823 u64 len;
1824 int index;
1825
1826 BUG_ON(sblock->page_count < 1);
1827 if (!sblock->pagev[0]->have_csum)
1828 return 0;
1829
1830 on_disk_csum = sblock->pagev[0]->csum;
1831 page = sblock->pagev[0]->page;
1832 buffer = kmap_atomic(page);
1833
1834 len = sctx->sectorsize;
1835 index = 0;
1836 for (;;) {
1837 u64 l = min_t(u64, len, PAGE_SIZE);
1838
1839 crc = btrfs_csum_data(buffer, crc, l);
1840 kunmap_atomic(buffer);
1841 len -= l;
1842 if (len == 0)
1843 break;
1844 index++;
1845 BUG_ON(index >= sblock->page_count);
1846 BUG_ON(!sblock->pagev[index]->page);
1847 page = sblock->pagev[index]->page;
1848 buffer = kmap_atomic(page);
1849 }
1850
1851 btrfs_csum_final(crc, csum);
1852 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1853 sblock->checksum_error = 1;
1854
1855 return sblock->checksum_error;
1856 }
1857
1858 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1859 {
1860 struct scrub_ctx *sctx = sblock->sctx;
1861 struct btrfs_header *h;
1862 struct btrfs_root *root = sctx->dev_root;
1863 struct btrfs_fs_info *fs_info = root->fs_info;
1864 u8 calculated_csum[BTRFS_CSUM_SIZE];
1865 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1866 struct page *page;
1867 void *mapped_buffer;
1868 u64 mapped_size;
1869 void *p;
1870 u32 crc = ~(u32)0;
1871 u64 len;
1872 int index;
1873
1874 BUG_ON(sblock->page_count < 1);
1875 page = sblock->pagev[0]->page;
1876 mapped_buffer = kmap_atomic(page);
1877 h = (struct btrfs_header *)mapped_buffer;
1878 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1879
1880 /*
1881 * we don't use the getter functions here, as we
1882 * a) don't have an extent buffer and
1883 * b) the page is already kmapped
1884 */
1885 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1886 sblock->header_error = 1;
1887
1888 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1889 sblock->header_error = 1;
1890 sblock->generation_error = 1;
1891 }
1892
1893 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1894 sblock->header_error = 1;
1895
1896 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1897 BTRFS_UUID_SIZE))
1898 sblock->header_error = 1;
1899
1900 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1901 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1902 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1903 index = 0;
1904 for (;;) {
1905 u64 l = min_t(u64, len, mapped_size);
1906
1907 crc = btrfs_csum_data(p, crc, l);
1908 kunmap_atomic(mapped_buffer);
1909 len -= l;
1910 if (len == 0)
1911 break;
1912 index++;
1913 BUG_ON(index >= sblock->page_count);
1914 BUG_ON(!sblock->pagev[index]->page);
1915 page = sblock->pagev[index]->page;
1916 mapped_buffer = kmap_atomic(page);
1917 mapped_size = PAGE_SIZE;
1918 p = mapped_buffer;
1919 }
1920
1921 btrfs_csum_final(crc, calculated_csum);
1922 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1923 sblock->checksum_error = 1;
1924
1925 return sblock->header_error || sblock->checksum_error;
1926 }
1927
1928 static int scrub_checksum_super(struct scrub_block *sblock)
1929 {
1930 struct btrfs_super_block *s;
1931 struct scrub_ctx *sctx = sblock->sctx;
1932 u8 calculated_csum[BTRFS_CSUM_SIZE];
1933 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1934 struct page *page;
1935 void *mapped_buffer;
1936 u64 mapped_size;
1937 void *p;
1938 u32 crc = ~(u32)0;
1939 int fail_gen = 0;
1940 int fail_cor = 0;
1941 u64 len;
1942 int index;
1943
1944 BUG_ON(sblock->page_count < 1);
1945 page = sblock->pagev[0]->page;
1946 mapped_buffer = kmap_atomic(page);
1947 s = (struct btrfs_super_block *)mapped_buffer;
1948 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1949
1950 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1951 ++fail_cor;
1952
1953 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1954 ++fail_gen;
1955
1956 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1957 ++fail_cor;
1958
1959 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1960 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1961 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1962 index = 0;
1963 for (;;) {
1964 u64 l = min_t(u64, len, mapped_size);
1965
1966 crc = btrfs_csum_data(p, crc, l);
1967 kunmap_atomic(mapped_buffer);
1968 len -= l;
1969 if (len == 0)
1970 break;
1971 index++;
1972 BUG_ON(index >= sblock->page_count);
1973 BUG_ON(!sblock->pagev[index]->page);
1974 page = sblock->pagev[index]->page;
1975 mapped_buffer = kmap_atomic(page);
1976 mapped_size = PAGE_SIZE;
1977 p = mapped_buffer;
1978 }
1979
1980 btrfs_csum_final(crc, calculated_csum);
1981 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1982 ++fail_cor;
1983
1984 if (fail_cor + fail_gen) {
1985 /*
1986 * if we find an error in a super block, we just report it.
1987 * They will get written with the next transaction commit
1988 * anyway
1989 */
1990 spin_lock(&sctx->stat_lock);
1991 ++sctx->stat.super_errors;
1992 spin_unlock(&sctx->stat_lock);
1993 if (fail_cor)
1994 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1995 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1996 else
1997 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1998 BTRFS_DEV_STAT_GENERATION_ERRS);
1999 }
2000
2001 return fail_cor + fail_gen;
2002 }
2003
2004 static void scrub_block_get(struct scrub_block *sblock)
2005 {
2006 atomic_inc(&sblock->refs);
2007 }
2008
2009 static void scrub_block_put(struct scrub_block *sblock)
2010 {
2011 if (atomic_dec_and_test(&sblock->refs)) {
2012 int i;
2013
2014 if (sblock->sparity)
2015 scrub_parity_put(sblock->sparity);
2016
2017 for (i = 0; i < sblock->page_count; i++)
2018 scrub_page_put(sblock->pagev[i]);
2019 kfree(sblock);
2020 }
2021 }
2022
2023 static void scrub_page_get(struct scrub_page *spage)
2024 {
2025 atomic_inc(&spage->refs);
2026 }
2027
2028 static void scrub_page_put(struct scrub_page *spage)
2029 {
2030 if (atomic_dec_and_test(&spage->refs)) {
2031 if (spage->page)
2032 __free_page(spage->page);
2033 kfree(spage);
2034 }
2035 }
2036
2037 static void scrub_submit(struct scrub_ctx *sctx)
2038 {
2039 struct scrub_bio *sbio;
2040
2041 if (sctx->curr == -1)
2042 return;
2043
2044 sbio = sctx->bios[sctx->curr];
2045 sctx->curr = -1;
2046 scrub_pending_bio_inc(sctx);
2047 btrfsic_submit_bio(sbio->bio);
2048 }
2049
2050 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2051 struct scrub_page *spage)
2052 {
2053 struct scrub_block *sblock = spage->sblock;
2054 struct scrub_bio *sbio;
2055 int ret;
2056
2057 again:
2058 /*
2059 * grab a fresh bio or wait for one to become available
2060 */
2061 while (sctx->curr == -1) {
2062 spin_lock(&sctx->list_lock);
2063 sctx->curr = sctx->first_free;
2064 if (sctx->curr != -1) {
2065 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2066 sctx->bios[sctx->curr]->next_free = -1;
2067 sctx->bios[sctx->curr]->page_count = 0;
2068 spin_unlock(&sctx->list_lock);
2069 } else {
2070 spin_unlock(&sctx->list_lock);
2071 wait_event(sctx->list_wait, sctx->first_free != -1);
2072 }
2073 }
2074 sbio = sctx->bios[sctx->curr];
2075 if (sbio->page_count == 0) {
2076 struct bio *bio;
2077
2078 sbio->physical = spage->physical;
2079 sbio->logical = spage->logical;
2080 sbio->dev = spage->dev;
2081 bio = sbio->bio;
2082 if (!bio) {
2083 bio = btrfs_io_bio_alloc(GFP_KERNEL,
2084 sctx->pages_per_rd_bio);
2085 if (!bio)
2086 return -ENOMEM;
2087 sbio->bio = bio;
2088 }
2089
2090 bio->bi_private = sbio;
2091 bio->bi_end_io = scrub_bio_end_io;
2092 bio->bi_bdev = sbio->dev->bdev;
2093 bio->bi_iter.bi_sector = sbio->physical >> 9;
2094 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2095 sbio->err = 0;
2096 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2097 spage->physical ||
2098 sbio->logical + sbio->page_count * PAGE_SIZE !=
2099 spage->logical ||
2100 sbio->dev != spage->dev) {
2101 scrub_submit(sctx);
2102 goto again;
2103 }
2104
2105 sbio->pagev[sbio->page_count] = spage;
2106 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2107 if (ret != PAGE_SIZE) {
2108 if (sbio->page_count < 1) {
2109 bio_put(sbio->bio);
2110 sbio->bio = NULL;
2111 return -EIO;
2112 }
2113 scrub_submit(sctx);
2114 goto again;
2115 }
2116
2117 scrub_block_get(sblock); /* one for the page added to the bio */
2118 atomic_inc(&sblock->outstanding_pages);
2119 sbio->page_count++;
2120 if (sbio->page_count == sctx->pages_per_rd_bio)
2121 scrub_submit(sctx);
2122
2123 return 0;
2124 }
2125
2126 static void scrub_missing_raid56_end_io(struct bio *bio)
2127 {
2128 struct scrub_block *sblock = bio->bi_private;
2129 struct btrfs_fs_info *fs_info = sblock->sctx->dev_root->fs_info;
2130
2131 if (bio->bi_error)
2132 sblock->no_io_error_seen = 0;
2133
2134 bio_put(bio);
2135
2136 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2137 }
2138
2139 static void scrub_missing_raid56_worker(struct btrfs_work *work)
2140 {
2141 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2142 struct scrub_ctx *sctx = sblock->sctx;
2143 u64 logical;
2144 struct btrfs_device *dev;
2145
2146 logical = sblock->pagev[0]->logical;
2147 dev = sblock->pagev[0]->dev;
2148
2149 if (sblock->no_io_error_seen)
2150 scrub_recheck_block_checksum(sblock);
2151
2152 if (!sblock->no_io_error_seen) {
2153 spin_lock(&sctx->stat_lock);
2154 sctx->stat.read_errors++;
2155 spin_unlock(&sctx->stat_lock);
2156 btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
2157 "IO error rebuilding logical %llu for dev %s",
2158 logical, rcu_str_deref(dev->name));
2159 } else if (sblock->header_error || sblock->checksum_error) {
2160 spin_lock(&sctx->stat_lock);
2161 sctx->stat.uncorrectable_errors++;
2162 spin_unlock(&sctx->stat_lock);
2163 btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
2164 "failed to rebuild valid logical %llu for dev %s",
2165 logical, rcu_str_deref(dev->name));
2166 } else {
2167 scrub_write_block_to_dev_replace(sblock);
2168 }
2169
2170 scrub_block_put(sblock);
2171
2172 if (sctx->is_dev_replace &&
2173 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2174 mutex_lock(&sctx->wr_ctx.wr_lock);
2175 scrub_wr_submit(sctx);
2176 mutex_unlock(&sctx->wr_ctx.wr_lock);
2177 }
2178
2179 scrub_pending_bio_dec(sctx);
2180 }
2181
2182 static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2183 {
2184 struct scrub_ctx *sctx = sblock->sctx;
2185 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2186 u64 length = sblock->page_count * PAGE_SIZE;
2187 u64 logical = sblock->pagev[0]->logical;
2188 struct btrfs_bio *bbio = NULL;
2189 struct bio *bio;
2190 struct btrfs_raid_bio *rbio;
2191 int ret;
2192 int i;
2193
2194 ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical, &length,
2195 &bbio, 0, 1);
2196 if (ret || !bbio || !bbio->raid_map)
2197 goto bbio_out;
2198
2199 if (WARN_ON(!sctx->is_dev_replace ||
2200 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2201 /*
2202 * We shouldn't be scrubbing a missing device. Even for dev
2203 * replace, we should only get here for RAID 5/6. We either
2204 * managed to mount something with no mirrors remaining or
2205 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2206 */
2207 goto bbio_out;
2208 }
2209
2210 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2211 if (!bio)
2212 goto bbio_out;
2213
2214 bio->bi_iter.bi_sector = logical >> 9;
2215 bio->bi_private = sblock;
2216 bio->bi_end_io = scrub_missing_raid56_end_io;
2217
2218 rbio = raid56_alloc_missing_rbio(sctx->dev_root, bio, bbio, length);
2219 if (!rbio)
2220 goto rbio_out;
2221
2222 for (i = 0; i < sblock->page_count; i++) {
2223 struct scrub_page *spage = sblock->pagev[i];
2224
2225 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2226 }
2227
2228 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2229 scrub_missing_raid56_worker, NULL, NULL);
2230 scrub_block_get(sblock);
2231 scrub_pending_bio_inc(sctx);
2232 raid56_submit_missing_rbio(rbio);
2233 return;
2234
2235 rbio_out:
2236 bio_put(bio);
2237 bbio_out:
2238 btrfs_put_bbio(bbio);
2239 spin_lock(&sctx->stat_lock);
2240 sctx->stat.malloc_errors++;
2241 spin_unlock(&sctx->stat_lock);
2242 }
2243
2244 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2245 u64 physical, struct btrfs_device *dev, u64 flags,
2246 u64 gen, int mirror_num, u8 *csum, int force,
2247 u64 physical_for_dev_replace)
2248 {
2249 struct scrub_block *sblock;
2250 int index;
2251
2252 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2253 if (!sblock) {
2254 spin_lock(&sctx->stat_lock);
2255 sctx->stat.malloc_errors++;
2256 spin_unlock(&sctx->stat_lock);
2257 return -ENOMEM;
2258 }
2259
2260 /* one ref inside this function, plus one for each page added to
2261 * a bio later on */
2262 atomic_set(&sblock->refs, 1);
2263 sblock->sctx = sctx;
2264 sblock->no_io_error_seen = 1;
2265
2266 for (index = 0; len > 0; index++) {
2267 struct scrub_page *spage;
2268 u64 l = min_t(u64, len, PAGE_SIZE);
2269
2270 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2271 if (!spage) {
2272 leave_nomem:
2273 spin_lock(&sctx->stat_lock);
2274 sctx->stat.malloc_errors++;
2275 spin_unlock(&sctx->stat_lock);
2276 scrub_block_put(sblock);
2277 return -ENOMEM;
2278 }
2279 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2280 scrub_page_get(spage);
2281 sblock->pagev[index] = spage;
2282 spage->sblock = sblock;
2283 spage->dev = dev;
2284 spage->flags = flags;
2285 spage->generation = gen;
2286 spage->logical = logical;
2287 spage->physical = physical;
2288 spage->physical_for_dev_replace = physical_for_dev_replace;
2289 spage->mirror_num = mirror_num;
2290 if (csum) {
2291 spage->have_csum = 1;
2292 memcpy(spage->csum, csum, sctx->csum_size);
2293 } else {
2294 spage->have_csum = 0;
2295 }
2296 sblock->page_count++;
2297 spage->page = alloc_page(GFP_KERNEL);
2298 if (!spage->page)
2299 goto leave_nomem;
2300 len -= l;
2301 logical += l;
2302 physical += l;
2303 physical_for_dev_replace += l;
2304 }
2305
2306 WARN_ON(sblock->page_count == 0);
2307 if (dev->missing) {
2308 /*
2309 * This case should only be hit for RAID 5/6 device replace. See
2310 * the comment in scrub_missing_raid56_pages() for details.
2311 */
2312 scrub_missing_raid56_pages(sblock);
2313 } else {
2314 for (index = 0; index < sblock->page_count; index++) {
2315 struct scrub_page *spage = sblock->pagev[index];
2316 int ret;
2317
2318 ret = scrub_add_page_to_rd_bio(sctx, spage);
2319 if (ret) {
2320 scrub_block_put(sblock);
2321 return ret;
2322 }
2323 }
2324
2325 if (force)
2326 scrub_submit(sctx);
2327 }
2328
2329 /* last one frees, either here or in bio completion for last page */
2330 scrub_block_put(sblock);
2331 return 0;
2332 }
2333
2334 static void scrub_bio_end_io(struct bio *bio)
2335 {
2336 struct scrub_bio *sbio = bio->bi_private;
2337 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
2338
2339 sbio->err = bio->bi_error;
2340 sbio->bio = bio;
2341
2342 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2343 }
2344
2345 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2346 {
2347 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2348 struct scrub_ctx *sctx = sbio->sctx;
2349 int i;
2350
2351 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2352 if (sbio->err) {
2353 for (i = 0; i < sbio->page_count; i++) {
2354 struct scrub_page *spage = sbio->pagev[i];
2355
2356 spage->io_error = 1;
2357 spage->sblock->no_io_error_seen = 0;
2358 }
2359 }
2360
2361 /* now complete the scrub_block items that have all pages completed */
2362 for (i = 0; i < sbio->page_count; i++) {
2363 struct scrub_page *spage = sbio->pagev[i];
2364 struct scrub_block *sblock = spage->sblock;
2365
2366 if (atomic_dec_and_test(&sblock->outstanding_pages))
2367 scrub_block_complete(sblock);
2368 scrub_block_put(sblock);
2369 }
2370
2371 bio_put(sbio->bio);
2372 sbio->bio = NULL;
2373 spin_lock(&sctx->list_lock);
2374 sbio->next_free = sctx->first_free;
2375 sctx->first_free = sbio->index;
2376 spin_unlock(&sctx->list_lock);
2377
2378 if (sctx->is_dev_replace &&
2379 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2380 mutex_lock(&sctx->wr_ctx.wr_lock);
2381 scrub_wr_submit(sctx);
2382 mutex_unlock(&sctx->wr_ctx.wr_lock);
2383 }
2384
2385 scrub_pending_bio_dec(sctx);
2386 }
2387
2388 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2389 unsigned long *bitmap,
2390 u64 start, u64 len)
2391 {
2392 u32 offset;
2393 int nsectors;
2394 int sectorsize = sparity->sctx->dev_root->sectorsize;
2395
2396 if (len >= sparity->stripe_len) {
2397 bitmap_set(bitmap, 0, sparity->nsectors);
2398 return;
2399 }
2400
2401 start -= sparity->logic_start;
2402 start = div_u64_rem(start, sparity->stripe_len, &offset);
2403 offset /= sectorsize;
2404 nsectors = (int)len / sectorsize;
2405
2406 if (offset + nsectors <= sparity->nsectors) {
2407 bitmap_set(bitmap, offset, nsectors);
2408 return;
2409 }
2410
2411 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2412 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2413 }
2414
2415 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2416 u64 start, u64 len)
2417 {
2418 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2419 }
2420
2421 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2422 u64 start, u64 len)
2423 {
2424 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2425 }
2426
2427 static void scrub_block_complete(struct scrub_block *sblock)
2428 {
2429 int corrupted = 0;
2430
2431 if (!sblock->no_io_error_seen) {
2432 corrupted = 1;
2433 scrub_handle_errored_block(sblock);
2434 } else {
2435 /*
2436 * if has checksum error, write via repair mechanism in
2437 * dev replace case, otherwise write here in dev replace
2438 * case.
2439 */
2440 corrupted = scrub_checksum(sblock);
2441 if (!corrupted && sblock->sctx->is_dev_replace)
2442 scrub_write_block_to_dev_replace(sblock);
2443 }
2444
2445 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2446 u64 start = sblock->pagev[0]->logical;
2447 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2448 PAGE_SIZE;
2449
2450 scrub_parity_mark_sectors_error(sblock->sparity,
2451 start, end - start);
2452 }
2453 }
2454
2455 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2456 {
2457 struct btrfs_ordered_sum *sum = NULL;
2458 unsigned long index;
2459 unsigned long num_sectors;
2460
2461 while (!list_empty(&sctx->csum_list)) {
2462 sum = list_first_entry(&sctx->csum_list,
2463 struct btrfs_ordered_sum, list);
2464 if (sum->bytenr > logical)
2465 return 0;
2466 if (sum->bytenr + sum->len > logical)
2467 break;
2468
2469 ++sctx->stat.csum_discards;
2470 list_del(&sum->list);
2471 kfree(sum);
2472 sum = NULL;
2473 }
2474 if (!sum)
2475 return 0;
2476
2477 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2478 num_sectors = sum->len / sctx->sectorsize;
2479 memcpy(csum, sum->sums + index, sctx->csum_size);
2480 if (index == num_sectors - 1) {
2481 list_del(&sum->list);
2482 kfree(sum);
2483 }
2484 return 1;
2485 }
2486
2487 /* scrub extent tries to collect up to 64 kB for each bio */
2488 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2489 u64 physical, struct btrfs_device *dev, u64 flags,
2490 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2491 {
2492 int ret;
2493 u8 csum[BTRFS_CSUM_SIZE];
2494 u32 blocksize;
2495
2496 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2497 blocksize = sctx->sectorsize;
2498 spin_lock(&sctx->stat_lock);
2499 sctx->stat.data_extents_scrubbed++;
2500 sctx->stat.data_bytes_scrubbed += len;
2501 spin_unlock(&sctx->stat_lock);
2502 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2503 blocksize = sctx->nodesize;
2504 spin_lock(&sctx->stat_lock);
2505 sctx->stat.tree_extents_scrubbed++;
2506 sctx->stat.tree_bytes_scrubbed += len;
2507 spin_unlock(&sctx->stat_lock);
2508 } else {
2509 blocksize = sctx->sectorsize;
2510 WARN_ON(1);
2511 }
2512
2513 while (len) {
2514 u64 l = min_t(u64, len, blocksize);
2515 int have_csum = 0;
2516
2517 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2518 /* push csums to sbio */
2519 have_csum = scrub_find_csum(sctx, logical, csum);
2520 if (have_csum == 0)
2521 ++sctx->stat.no_csum;
2522 if (sctx->is_dev_replace && !have_csum) {
2523 ret = copy_nocow_pages(sctx, logical, l,
2524 mirror_num,
2525 physical_for_dev_replace);
2526 goto behind_scrub_pages;
2527 }
2528 }
2529 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2530 mirror_num, have_csum ? csum : NULL, 0,
2531 physical_for_dev_replace);
2532 behind_scrub_pages:
2533 if (ret)
2534 return ret;
2535 len -= l;
2536 logical += l;
2537 physical += l;
2538 physical_for_dev_replace += l;
2539 }
2540 return 0;
2541 }
2542
2543 static int scrub_pages_for_parity(struct scrub_parity *sparity,
2544 u64 logical, u64 len,
2545 u64 physical, struct btrfs_device *dev,
2546 u64 flags, u64 gen, int mirror_num, u8 *csum)
2547 {
2548 struct scrub_ctx *sctx = sparity->sctx;
2549 struct scrub_block *sblock;
2550 int index;
2551
2552 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2553 if (!sblock) {
2554 spin_lock(&sctx->stat_lock);
2555 sctx->stat.malloc_errors++;
2556 spin_unlock(&sctx->stat_lock);
2557 return -ENOMEM;
2558 }
2559
2560 /* one ref inside this function, plus one for each page added to
2561 * a bio later on */
2562 atomic_set(&sblock->refs, 1);
2563 sblock->sctx = sctx;
2564 sblock->no_io_error_seen = 1;
2565 sblock->sparity = sparity;
2566 scrub_parity_get(sparity);
2567
2568 for (index = 0; len > 0; index++) {
2569 struct scrub_page *spage;
2570 u64 l = min_t(u64, len, PAGE_SIZE);
2571
2572 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2573 if (!spage) {
2574 leave_nomem:
2575 spin_lock(&sctx->stat_lock);
2576 sctx->stat.malloc_errors++;
2577 spin_unlock(&sctx->stat_lock);
2578 scrub_block_put(sblock);
2579 return -ENOMEM;
2580 }
2581 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2582 /* For scrub block */
2583 scrub_page_get(spage);
2584 sblock->pagev[index] = spage;
2585 /* For scrub parity */
2586 scrub_page_get(spage);
2587 list_add_tail(&spage->list, &sparity->spages);
2588 spage->sblock = sblock;
2589 spage->dev = dev;
2590 spage->flags = flags;
2591 spage->generation = gen;
2592 spage->logical = logical;
2593 spage->physical = physical;
2594 spage->mirror_num = mirror_num;
2595 if (csum) {
2596 spage->have_csum = 1;
2597 memcpy(spage->csum, csum, sctx->csum_size);
2598 } else {
2599 spage->have_csum = 0;
2600 }
2601 sblock->page_count++;
2602 spage->page = alloc_page(GFP_KERNEL);
2603 if (!spage->page)
2604 goto leave_nomem;
2605 len -= l;
2606 logical += l;
2607 physical += l;
2608 }
2609
2610 WARN_ON(sblock->page_count == 0);
2611 for (index = 0; index < sblock->page_count; index++) {
2612 struct scrub_page *spage = sblock->pagev[index];
2613 int ret;
2614
2615 ret = scrub_add_page_to_rd_bio(sctx, spage);
2616 if (ret) {
2617 scrub_block_put(sblock);
2618 return ret;
2619 }
2620 }
2621
2622 /* last one frees, either here or in bio completion for last page */
2623 scrub_block_put(sblock);
2624 return 0;
2625 }
2626
2627 static int scrub_extent_for_parity(struct scrub_parity *sparity,
2628 u64 logical, u64 len,
2629 u64 physical, struct btrfs_device *dev,
2630 u64 flags, u64 gen, int mirror_num)
2631 {
2632 struct scrub_ctx *sctx = sparity->sctx;
2633 int ret;
2634 u8 csum[BTRFS_CSUM_SIZE];
2635 u32 blocksize;
2636
2637 if (dev->missing) {
2638 scrub_parity_mark_sectors_error(sparity, logical, len);
2639 return 0;
2640 }
2641
2642 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2643 blocksize = sctx->sectorsize;
2644 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2645 blocksize = sctx->nodesize;
2646 } else {
2647 blocksize = sctx->sectorsize;
2648 WARN_ON(1);
2649 }
2650
2651 while (len) {
2652 u64 l = min_t(u64, len, blocksize);
2653 int have_csum = 0;
2654
2655 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2656 /* push csums to sbio */
2657 have_csum = scrub_find_csum(sctx, logical, csum);
2658 if (have_csum == 0)
2659 goto skip;
2660 }
2661 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2662 flags, gen, mirror_num,
2663 have_csum ? csum : NULL);
2664 if (ret)
2665 return ret;
2666 skip:
2667 len -= l;
2668 logical += l;
2669 physical += l;
2670 }
2671 return 0;
2672 }
2673
2674 /*
2675 * Given a physical address, this will calculate it's
2676 * logical offset. if this is a parity stripe, it will return
2677 * the most left data stripe's logical offset.
2678 *
2679 * return 0 if it is a data stripe, 1 means parity stripe.
2680 */
2681 static int get_raid56_logic_offset(u64 physical, int num,
2682 struct map_lookup *map, u64 *offset,
2683 u64 *stripe_start)
2684 {
2685 int i;
2686 int j = 0;
2687 u64 stripe_nr;
2688 u64 last_offset;
2689 u32 stripe_index;
2690 u32 rot;
2691
2692 last_offset = (physical - map->stripes[num].physical) *
2693 nr_data_stripes(map);
2694 if (stripe_start)
2695 *stripe_start = last_offset;
2696
2697 *offset = last_offset;
2698 for (i = 0; i < nr_data_stripes(map); i++) {
2699 *offset = last_offset + i * map->stripe_len;
2700
2701 stripe_nr = div_u64(*offset, map->stripe_len);
2702 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
2703
2704 /* Work out the disk rotation on this stripe-set */
2705 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2706 /* calculate which stripe this data locates */
2707 rot += i;
2708 stripe_index = rot % map->num_stripes;
2709 if (stripe_index == num)
2710 return 0;
2711 if (stripe_index < num)
2712 j++;
2713 }
2714 *offset = last_offset + j * map->stripe_len;
2715 return 1;
2716 }
2717
2718 static void scrub_free_parity(struct scrub_parity *sparity)
2719 {
2720 struct scrub_ctx *sctx = sparity->sctx;
2721 struct scrub_page *curr, *next;
2722 int nbits;
2723
2724 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2725 if (nbits) {
2726 spin_lock(&sctx->stat_lock);
2727 sctx->stat.read_errors += nbits;
2728 sctx->stat.uncorrectable_errors += nbits;
2729 spin_unlock(&sctx->stat_lock);
2730 }
2731
2732 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2733 list_del_init(&curr->list);
2734 scrub_page_put(curr);
2735 }
2736
2737 kfree(sparity);
2738 }
2739
2740 static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2741 {
2742 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2743 work);
2744 struct scrub_ctx *sctx = sparity->sctx;
2745
2746 scrub_free_parity(sparity);
2747 scrub_pending_bio_dec(sctx);
2748 }
2749
2750 static void scrub_parity_bio_endio(struct bio *bio)
2751 {
2752 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2753
2754 if (bio->bi_error)
2755 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2756 sparity->nsectors);
2757
2758 bio_put(bio);
2759
2760 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2761 scrub_parity_bio_endio_worker, NULL, NULL);
2762 btrfs_queue_work(sparity->sctx->dev_root->fs_info->scrub_parity_workers,
2763 &sparity->work);
2764 }
2765
2766 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2767 {
2768 struct scrub_ctx *sctx = sparity->sctx;
2769 struct bio *bio;
2770 struct btrfs_raid_bio *rbio;
2771 struct scrub_page *spage;
2772 struct btrfs_bio *bbio = NULL;
2773 u64 length;
2774 int ret;
2775
2776 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2777 sparity->nsectors))
2778 goto out;
2779
2780 length = sparity->logic_end - sparity->logic_start;
2781 ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
2782 sparity->logic_start,
2783 &length, &bbio, 0, 1);
2784 if (ret || !bbio || !bbio->raid_map)
2785 goto bbio_out;
2786
2787 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2788 if (!bio)
2789 goto bbio_out;
2790
2791 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2792 bio->bi_private = sparity;
2793 bio->bi_end_io = scrub_parity_bio_endio;
2794
2795 rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio,
2796 length, sparity->scrub_dev,
2797 sparity->dbitmap,
2798 sparity->nsectors);
2799 if (!rbio)
2800 goto rbio_out;
2801
2802 list_for_each_entry(spage, &sparity->spages, list)
2803 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2804
2805 scrub_pending_bio_inc(sctx);
2806 raid56_parity_submit_scrub_rbio(rbio);
2807 return;
2808
2809 rbio_out:
2810 bio_put(bio);
2811 bbio_out:
2812 btrfs_put_bbio(bbio);
2813 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2814 sparity->nsectors);
2815 spin_lock(&sctx->stat_lock);
2816 sctx->stat.malloc_errors++;
2817 spin_unlock(&sctx->stat_lock);
2818 out:
2819 scrub_free_parity(sparity);
2820 }
2821
2822 static inline int scrub_calc_parity_bitmap_len(int nsectors)
2823 {
2824 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2825 }
2826
2827 static void scrub_parity_get(struct scrub_parity *sparity)
2828 {
2829 atomic_inc(&sparity->refs);
2830 }
2831
2832 static void scrub_parity_put(struct scrub_parity *sparity)
2833 {
2834 if (!atomic_dec_and_test(&sparity->refs))
2835 return;
2836
2837 scrub_parity_check_and_repair(sparity);
2838 }
2839
2840 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2841 struct map_lookup *map,
2842 struct btrfs_device *sdev,
2843 struct btrfs_path *path,
2844 u64 logic_start,
2845 u64 logic_end)
2846 {
2847 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2848 struct btrfs_root *root = fs_info->extent_root;
2849 struct btrfs_root *csum_root = fs_info->csum_root;
2850 struct btrfs_extent_item *extent;
2851 struct btrfs_bio *bbio = NULL;
2852 u64 flags;
2853 int ret;
2854 int slot;
2855 struct extent_buffer *l;
2856 struct btrfs_key key;
2857 u64 generation;
2858 u64 extent_logical;
2859 u64 extent_physical;
2860 u64 extent_len;
2861 u64 mapped_length;
2862 struct btrfs_device *extent_dev;
2863 struct scrub_parity *sparity;
2864 int nsectors;
2865 int bitmap_len;
2866 int extent_mirror_num;
2867 int stop_loop = 0;
2868
2869 nsectors = div_u64(map->stripe_len, root->sectorsize);
2870 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2871 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2872 GFP_NOFS);
2873 if (!sparity) {
2874 spin_lock(&sctx->stat_lock);
2875 sctx->stat.malloc_errors++;
2876 spin_unlock(&sctx->stat_lock);
2877 return -ENOMEM;
2878 }
2879
2880 sparity->stripe_len = map->stripe_len;
2881 sparity->nsectors = nsectors;
2882 sparity->sctx = sctx;
2883 sparity->scrub_dev = sdev;
2884 sparity->logic_start = logic_start;
2885 sparity->logic_end = logic_end;
2886 atomic_set(&sparity->refs, 1);
2887 INIT_LIST_HEAD(&sparity->spages);
2888 sparity->dbitmap = sparity->bitmap;
2889 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2890
2891 ret = 0;
2892 while (logic_start < logic_end) {
2893 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2894 key.type = BTRFS_METADATA_ITEM_KEY;
2895 else
2896 key.type = BTRFS_EXTENT_ITEM_KEY;
2897 key.objectid = logic_start;
2898 key.offset = (u64)-1;
2899
2900 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2901 if (ret < 0)
2902 goto out;
2903
2904 if (ret > 0) {
2905 ret = btrfs_previous_extent_item(root, path, 0);
2906 if (ret < 0)
2907 goto out;
2908 if (ret > 0) {
2909 btrfs_release_path(path);
2910 ret = btrfs_search_slot(NULL, root, &key,
2911 path, 0, 0);
2912 if (ret < 0)
2913 goto out;
2914 }
2915 }
2916
2917 stop_loop = 0;
2918 while (1) {
2919 u64 bytes;
2920
2921 l = path->nodes[0];
2922 slot = path->slots[0];
2923 if (slot >= btrfs_header_nritems(l)) {
2924 ret = btrfs_next_leaf(root, path);
2925 if (ret == 0)
2926 continue;
2927 if (ret < 0)
2928 goto out;
2929
2930 stop_loop = 1;
2931 break;
2932 }
2933 btrfs_item_key_to_cpu(l, &key, slot);
2934
2935 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2936 key.type != BTRFS_METADATA_ITEM_KEY)
2937 goto next;
2938
2939 if (key.type == BTRFS_METADATA_ITEM_KEY)
2940 bytes = root->nodesize;
2941 else
2942 bytes = key.offset;
2943
2944 if (key.objectid + bytes <= logic_start)
2945 goto next;
2946
2947 if (key.objectid >= logic_end) {
2948 stop_loop = 1;
2949 break;
2950 }
2951
2952 while (key.objectid >= logic_start + map->stripe_len)
2953 logic_start += map->stripe_len;
2954
2955 extent = btrfs_item_ptr(l, slot,
2956 struct btrfs_extent_item);
2957 flags = btrfs_extent_flags(l, extent);
2958 generation = btrfs_extent_generation(l, extent);
2959
2960 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2961 (key.objectid < logic_start ||
2962 key.objectid + bytes >
2963 logic_start + map->stripe_len)) {
2964 btrfs_err(fs_info,
2965 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2966 key.objectid, logic_start);
2967 spin_lock(&sctx->stat_lock);
2968 sctx->stat.uncorrectable_errors++;
2969 spin_unlock(&sctx->stat_lock);
2970 goto next;
2971 }
2972 again:
2973 extent_logical = key.objectid;
2974 extent_len = bytes;
2975
2976 if (extent_logical < logic_start) {
2977 extent_len -= logic_start - extent_logical;
2978 extent_logical = logic_start;
2979 }
2980
2981 if (extent_logical + extent_len >
2982 logic_start + map->stripe_len)
2983 extent_len = logic_start + map->stripe_len -
2984 extent_logical;
2985
2986 scrub_parity_mark_sectors_data(sparity, extent_logical,
2987 extent_len);
2988
2989 mapped_length = extent_len;
2990 bbio = NULL;
2991 ret = btrfs_map_block(fs_info, READ, extent_logical,
2992 &mapped_length, &bbio, 0);
2993 if (!ret) {
2994 if (!bbio || mapped_length < extent_len)
2995 ret = -EIO;
2996 }
2997 if (ret) {
2998 btrfs_put_bbio(bbio);
2999 goto out;
3000 }
3001 extent_physical = bbio->stripes[0].physical;
3002 extent_mirror_num = bbio->mirror_num;
3003 extent_dev = bbio->stripes[0].dev;
3004 btrfs_put_bbio(bbio);
3005
3006 ret = btrfs_lookup_csums_range(csum_root,
3007 extent_logical,
3008 extent_logical + extent_len - 1,
3009 &sctx->csum_list, 1);
3010 if (ret)
3011 goto out;
3012
3013 ret = scrub_extent_for_parity(sparity, extent_logical,
3014 extent_len,
3015 extent_physical,
3016 extent_dev, flags,
3017 generation,
3018 extent_mirror_num);
3019
3020 scrub_free_csums(sctx);
3021
3022 if (ret)
3023 goto out;
3024
3025 if (extent_logical + extent_len <
3026 key.objectid + bytes) {
3027 logic_start += map->stripe_len;
3028
3029 if (logic_start >= logic_end) {
3030 stop_loop = 1;
3031 break;
3032 }
3033
3034 if (logic_start < key.objectid + bytes) {
3035 cond_resched();
3036 goto again;
3037 }
3038 }
3039 next:
3040 path->slots[0]++;
3041 }
3042
3043 btrfs_release_path(path);
3044
3045 if (stop_loop)
3046 break;
3047
3048 logic_start += map->stripe_len;
3049 }
3050 out:
3051 if (ret < 0)
3052 scrub_parity_mark_sectors_error(sparity, logic_start,
3053 logic_end - logic_start);
3054 scrub_parity_put(sparity);
3055 scrub_submit(sctx);
3056 mutex_lock(&sctx->wr_ctx.wr_lock);
3057 scrub_wr_submit(sctx);
3058 mutex_unlock(&sctx->wr_ctx.wr_lock);
3059
3060 btrfs_release_path(path);
3061 return ret < 0 ? ret : 0;
3062 }
3063
3064 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3065 struct map_lookup *map,
3066 struct btrfs_device *scrub_dev,
3067 int num, u64 base, u64 length,
3068 int is_dev_replace)
3069 {
3070 struct btrfs_path *path, *ppath;
3071 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3072 struct btrfs_root *root = fs_info->extent_root;
3073 struct btrfs_root *csum_root = fs_info->csum_root;
3074 struct btrfs_extent_item *extent;
3075 struct blk_plug plug;
3076 u64 flags;
3077 int ret;
3078 int slot;
3079 u64 nstripes;
3080 struct extent_buffer *l;
3081 u64 physical;
3082 u64 logical;
3083 u64 logic_end;
3084 u64 physical_end;
3085 u64 generation;
3086 int mirror_num;
3087 struct reada_control *reada1;
3088 struct reada_control *reada2;
3089 struct btrfs_key key;
3090 struct btrfs_key key_end;
3091 u64 increment = map->stripe_len;
3092 u64 offset;
3093 u64 extent_logical;
3094 u64 extent_physical;
3095 u64 extent_len;
3096 u64 stripe_logical;
3097 u64 stripe_end;
3098 struct btrfs_device *extent_dev;
3099 int extent_mirror_num;
3100 int stop_loop = 0;
3101
3102 physical = map->stripes[num].physical;
3103 offset = 0;
3104 nstripes = div_u64(length, map->stripe_len);
3105 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3106 offset = map->stripe_len * num;
3107 increment = map->stripe_len * map->num_stripes;
3108 mirror_num = 1;
3109 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3110 int factor = map->num_stripes / map->sub_stripes;
3111 offset = map->stripe_len * (num / map->sub_stripes);
3112 increment = map->stripe_len * factor;
3113 mirror_num = num % map->sub_stripes + 1;
3114 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3115 increment = map->stripe_len;
3116 mirror_num = num % map->num_stripes + 1;
3117 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3118 increment = map->stripe_len;
3119 mirror_num = num % map->num_stripes + 1;
3120 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3121 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3122 increment = map->stripe_len * nr_data_stripes(map);
3123 mirror_num = 1;
3124 } else {
3125 increment = map->stripe_len;
3126 mirror_num = 1;
3127 }
3128
3129 path = btrfs_alloc_path();
3130 if (!path)
3131 return -ENOMEM;
3132
3133 ppath = btrfs_alloc_path();
3134 if (!ppath) {
3135 btrfs_free_path(path);
3136 return -ENOMEM;
3137 }
3138
3139 /*
3140 * work on commit root. The related disk blocks are static as
3141 * long as COW is applied. This means, it is save to rewrite
3142 * them to repair disk errors without any race conditions
3143 */
3144 path->search_commit_root = 1;
3145 path->skip_locking = 1;
3146
3147 ppath->search_commit_root = 1;
3148 ppath->skip_locking = 1;
3149 /*
3150 * trigger the readahead for extent tree csum tree and wait for
3151 * completion. During readahead, the scrub is officially paused
3152 * to not hold off transaction commits
3153 */
3154 logical = base + offset;
3155 physical_end = physical + nstripes * map->stripe_len;
3156 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3157 get_raid56_logic_offset(physical_end, num,
3158 map, &logic_end, NULL);
3159 logic_end += base;
3160 } else {
3161 logic_end = logical + increment * nstripes;
3162 }
3163 wait_event(sctx->list_wait,
3164 atomic_read(&sctx->bios_in_flight) == 0);
3165 scrub_blocked_if_needed(fs_info);
3166
3167 /* FIXME it might be better to start readahead at commit root */
3168 key.objectid = logical;
3169 key.type = BTRFS_EXTENT_ITEM_KEY;
3170 key.offset = (u64)0;
3171 key_end.objectid = logic_end;
3172 key_end.type = BTRFS_METADATA_ITEM_KEY;
3173 key_end.offset = (u64)-1;
3174 reada1 = btrfs_reada_add(root, &key, &key_end);
3175
3176 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3177 key.type = BTRFS_EXTENT_CSUM_KEY;
3178 key.offset = logical;
3179 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3180 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3181 key_end.offset = logic_end;
3182 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3183
3184 if (!IS_ERR(reada1))
3185 btrfs_reada_wait(reada1);
3186 if (!IS_ERR(reada2))
3187 btrfs_reada_wait(reada2);
3188
3189
3190 /*
3191 * collect all data csums for the stripe to avoid seeking during
3192 * the scrub. This might currently (crc32) end up to be about 1MB
3193 */
3194 blk_start_plug(&plug);
3195
3196 /*
3197 * now find all extents for each stripe and scrub them
3198 */
3199 ret = 0;
3200 while (physical < physical_end) {
3201 /*
3202 * canceled?
3203 */
3204 if (atomic_read(&fs_info->scrub_cancel_req) ||
3205 atomic_read(&sctx->cancel_req)) {
3206 ret = -ECANCELED;
3207 goto out;
3208 }
3209 /*
3210 * check to see if we have to pause
3211 */
3212 if (atomic_read(&fs_info->scrub_pause_req)) {
3213 /* push queued extents */
3214 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3215 scrub_submit(sctx);
3216 mutex_lock(&sctx->wr_ctx.wr_lock);
3217 scrub_wr_submit(sctx);
3218 mutex_unlock(&sctx->wr_ctx.wr_lock);
3219 wait_event(sctx->list_wait,
3220 atomic_read(&sctx->bios_in_flight) == 0);
3221 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3222 scrub_blocked_if_needed(fs_info);
3223 }
3224
3225 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3226 ret = get_raid56_logic_offset(physical, num, map,
3227 &logical,
3228 &stripe_logical);
3229 logical += base;
3230 if (ret) {
3231 /* it is parity strip */
3232 stripe_logical += base;
3233 stripe_end = stripe_logical + increment;
3234 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3235 ppath, stripe_logical,
3236 stripe_end);
3237 if (ret)
3238 goto out;
3239 goto skip;
3240 }
3241 }
3242
3243 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3244 key.type = BTRFS_METADATA_ITEM_KEY;
3245 else
3246 key.type = BTRFS_EXTENT_ITEM_KEY;
3247 key.objectid = logical;
3248 key.offset = (u64)-1;
3249
3250 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3251 if (ret < 0)
3252 goto out;
3253
3254 if (ret > 0) {
3255 ret = btrfs_previous_extent_item(root, path, 0);
3256 if (ret < 0)
3257 goto out;
3258 if (ret > 0) {
3259 /* there's no smaller item, so stick with the
3260 * larger one */
3261 btrfs_release_path(path);
3262 ret = btrfs_search_slot(NULL, root, &key,
3263 path, 0, 0);
3264 if (ret < 0)
3265 goto out;
3266 }
3267 }
3268
3269 stop_loop = 0;
3270 while (1) {
3271 u64 bytes;
3272
3273 l = path->nodes[0];
3274 slot = path->slots[0];
3275 if (slot >= btrfs_header_nritems(l)) {
3276 ret = btrfs_next_leaf(root, path);
3277 if (ret == 0)
3278 continue;
3279 if (ret < 0)
3280 goto out;
3281
3282 stop_loop = 1;
3283 break;
3284 }
3285 btrfs_item_key_to_cpu(l, &key, slot);
3286
3287 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3288 key.type != BTRFS_METADATA_ITEM_KEY)
3289 goto next;
3290
3291 if (key.type == BTRFS_METADATA_ITEM_KEY)
3292 bytes = root->nodesize;
3293 else
3294 bytes = key.offset;
3295
3296 if (key.objectid + bytes <= logical)
3297 goto next;
3298
3299 if (key.objectid >= logical + map->stripe_len) {
3300 /* out of this device extent */
3301 if (key.objectid >= logic_end)
3302 stop_loop = 1;
3303 break;
3304 }
3305
3306 extent = btrfs_item_ptr(l, slot,
3307 struct btrfs_extent_item);
3308 flags = btrfs_extent_flags(l, extent);
3309 generation = btrfs_extent_generation(l, extent);
3310
3311 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3312 (key.objectid < logical ||
3313 key.objectid + bytes >
3314 logical + map->stripe_len)) {
3315 btrfs_err(fs_info,
3316 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3317 key.objectid, logical);
3318 spin_lock(&sctx->stat_lock);
3319 sctx->stat.uncorrectable_errors++;
3320 spin_unlock(&sctx->stat_lock);
3321 goto next;
3322 }
3323
3324 again:
3325 extent_logical = key.objectid;
3326 extent_len = bytes;
3327
3328 /*
3329 * trim extent to this stripe
3330 */
3331 if (extent_logical < logical) {
3332 extent_len -= logical - extent_logical;
3333 extent_logical = logical;
3334 }
3335 if (extent_logical + extent_len >
3336 logical + map->stripe_len) {
3337 extent_len = logical + map->stripe_len -
3338 extent_logical;
3339 }
3340
3341 extent_physical = extent_logical - logical + physical;
3342 extent_dev = scrub_dev;
3343 extent_mirror_num = mirror_num;
3344 if (is_dev_replace)
3345 scrub_remap_extent(fs_info, extent_logical,
3346 extent_len, &extent_physical,
3347 &extent_dev,
3348 &extent_mirror_num);
3349
3350 ret = btrfs_lookup_csums_range(csum_root,
3351 extent_logical,
3352 extent_logical +
3353 extent_len - 1,
3354 &sctx->csum_list, 1);
3355 if (ret)
3356 goto out;
3357
3358 ret = scrub_extent(sctx, extent_logical, extent_len,
3359 extent_physical, extent_dev, flags,
3360 generation, extent_mirror_num,
3361 extent_logical - logical + physical);
3362
3363 scrub_free_csums(sctx);
3364
3365 if (ret)
3366 goto out;
3367
3368 if (extent_logical + extent_len <
3369 key.objectid + bytes) {
3370 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3371 /*
3372 * loop until we find next data stripe
3373 * or we have finished all stripes.
3374 */
3375 loop:
3376 physical += map->stripe_len;
3377 ret = get_raid56_logic_offset(physical,
3378 num, map, &logical,
3379 &stripe_logical);
3380 logical += base;
3381
3382 if (ret && physical < physical_end) {
3383 stripe_logical += base;
3384 stripe_end = stripe_logical +
3385 increment;
3386 ret = scrub_raid56_parity(sctx,
3387 map, scrub_dev, ppath,
3388 stripe_logical,
3389 stripe_end);
3390 if (ret)
3391 goto out;
3392 goto loop;
3393 }
3394 } else {
3395 physical += map->stripe_len;
3396 logical += increment;
3397 }
3398 if (logical < key.objectid + bytes) {
3399 cond_resched();
3400 goto again;
3401 }
3402
3403 if (physical >= physical_end) {
3404 stop_loop = 1;
3405 break;
3406 }
3407 }
3408 next:
3409 path->slots[0]++;
3410 }
3411 btrfs_release_path(path);
3412 skip:
3413 logical += increment;
3414 physical += map->stripe_len;
3415 spin_lock(&sctx->stat_lock);
3416 if (stop_loop)
3417 sctx->stat.last_physical = map->stripes[num].physical +
3418 length;
3419 else
3420 sctx->stat.last_physical = physical;
3421 spin_unlock(&sctx->stat_lock);
3422 if (stop_loop)
3423 break;
3424 }
3425 out:
3426 /* push queued extents */
3427 scrub_submit(sctx);
3428 mutex_lock(&sctx->wr_ctx.wr_lock);
3429 scrub_wr_submit(sctx);
3430 mutex_unlock(&sctx->wr_ctx.wr_lock);
3431
3432 blk_finish_plug(&plug);
3433 btrfs_free_path(path);
3434 btrfs_free_path(ppath);
3435 return ret < 0 ? ret : 0;
3436 }
3437
3438 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3439 struct btrfs_device *scrub_dev,
3440 u64 chunk_offset, u64 length,
3441 u64 dev_offset,
3442 struct btrfs_block_group_cache *cache,
3443 int is_dev_replace)
3444 {
3445 struct btrfs_mapping_tree *map_tree =
3446 &sctx->dev_root->fs_info->mapping_tree;
3447 struct map_lookup *map;
3448 struct extent_map *em;
3449 int i;
3450 int ret = 0;
3451
3452 read_lock(&map_tree->map_tree.lock);
3453 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3454 read_unlock(&map_tree->map_tree.lock);
3455
3456 if (!em) {
3457 /*
3458 * Might have been an unused block group deleted by the cleaner
3459 * kthread or relocation.
3460 */
3461 spin_lock(&cache->lock);
3462 if (!cache->removed)
3463 ret = -EINVAL;
3464 spin_unlock(&cache->lock);
3465
3466 return ret;
3467 }
3468
3469 map = em->map_lookup;
3470 if (em->start != chunk_offset)
3471 goto out;
3472
3473 if (em->len < length)
3474 goto out;
3475
3476 for (i = 0; i < map->num_stripes; ++i) {
3477 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3478 map->stripes[i].physical == dev_offset) {
3479 ret = scrub_stripe(sctx, map, scrub_dev, i,
3480 chunk_offset, length,
3481 is_dev_replace);
3482 if (ret)
3483 goto out;
3484 }
3485 }
3486 out:
3487 free_extent_map(em);
3488
3489 return ret;
3490 }
3491
3492 static noinline_for_stack
3493 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3494 struct btrfs_device *scrub_dev, u64 start, u64 end,
3495 int is_dev_replace)
3496 {
3497 struct btrfs_dev_extent *dev_extent = NULL;
3498 struct btrfs_path *path;
3499 struct btrfs_root *root = sctx->dev_root;
3500 struct btrfs_fs_info *fs_info = root->fs_info;
3501 u64 length;
3502 u64 chunk_offset;
3503 int ret = 0;
3504 int ro_set;
3505 int slot;
3506 struct extent_buffer *l;
3507 struct btrfs_key key;
3508 struct btrfs_key found_key;
3509 struct btrfs_block_group_cache *cache;
3510 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3511
3512 path = btrfs_alloc_path();
3513 if (!path)
3514 return -ENOMEM;
3515
3516 path->reada = READA_FORWARD;
3517 path->search_commit_root = 1;
3518 path->skip_locking = 1;
3519
3520 key.objectid = scrub_dev->devid;
3521 key.offset = 0ull;
3522 key.type = BTRFS_DEV_EXTENT_KEY;
3523
3524 while (1) {
3525 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3526 if (ret < 0)
3527 break;
3528 if (ret > 0) {
3529 if (path->slots[0] >=
3530 btrfs_header_nritems(path->nodes[0])) {
3531 ret = btrfs_next_leaf(root, path);
3532 if (ret < 0)
3533 break;
3534 if (ret > 0) {
3535 ret = 0;
3536 break;
3537 }
3538 } else {
3539 ret = 0;
3540 }
3541 }
3542
3543 l = path->nodes[0];
3544 slot = path->slots[0];
3545
3546 btrfs_item_key_to_cpu(l, &found_key, slot);
3547
3548 if (found_key.objectid != scrub_dev->devid)
3549 break;
3550
3551 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3552 break;
3553
3554 if (found_key.offset >= end)
3555 break;
3556
3557 if (found_key.offset < key.offset)
3558 break;
3559
3560 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3561 length = btrfs_dev_extent_length(l, dev_extent);
3562
3563 if (found_key.offset + length <= start)
3564 goto skip;
3565
3566 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3567
3568 /*
3569 * get a reference on the corresponding block group to prevent
3570 * the chunk from going away while we scrub it
3571 */
3572 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3573
3574 /* some chunks are removed but not committed to disk yet,
3575 * continue scrubbing */
3576 if (!cache)
3577 goto skip;
3578
3579 /*
3580 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3581 * to avoid deadlock caused by:
3582 * btrfs_inc_block_group_ro()
3583 * -> btrfs_wait_for_commit()
3584 * -> btrfs_commit_transaction()
3585 * -> btrfs_scrub_pause()
3586 */
3587 scrub_pause_on(fs_info);
3588 ret = btrfs_inc_block_group_ro(root, cache);
3589 if (!ret && is_dev_replace) {
3590 /*
3591 * If we are doing a device replace wait for any tasks
3592 * that started dellaloc right before we set the block
3593 * group to RO mode, as they might have just allocated
3594 * an extent from it or decided they could do a nocow
3595 * write. And if any such tasks did that, wait for their
3596 * ordered extents to complete and then commit the
3597 * current transaction, so that we can later see the new
3598 * extent items in the extent tree - the ordered extents
3599 * create delayed data references (for cow writes) when
3600 * they complete, which will be run and insert the
3601 * corresponding extent items into the extent tree when
3602 * we commit the transaction they used when running
3603 * inode.c:btrfs_finish_ordered_io(). We later use
3604 * the commit root of the extent tree to find extents
3605 * to copy from the srcdev into the tgtdev, and we don't
3606 * want to miss any new extents.
3607 */
3608 btrfs_wait_block_group_reservations(cache);
3609 btrfs_wait_nocow_writers(cache);
3610 ret = btrfs_wait_ordered_roots(fs_info, -1,
3611 cache->key.objectid,
3612 cache->key.offset);
3613 if (ret > 0) {
3614 struct btrfs_trans_handle *trans;
3615
3616 trans = btrfs_join_transaction(root);
3617 if (IS_ERR(trans))
3618 ret = PTR_ERR(trans);
3619 else
3620 ret = btrfs_commit_transaction(trans,
3621 root);
3622 if (ret) {
3623 scrub_pause_off(fs_info);
3624 btrfs_put_block_group(cache);
3625 break;
3626 }
3627 }
3628 }
3629 scrub_pause_off(fs_info);
3630
3631 if (ret == 0) {
3632 ro_set = 1;
3633 } else if (ret == -ENOSPC) {
3634 /*
3635 * btrfs_inc_block_group_ro return -ENOSPC when it
3636 * failed in creating new chunk for metadata.
3637 * It is not a problem for scrub/replace, because
3638 * metadata are always cowed, and our scrub paused
3639 * commit_transactions.
3640 */
3641 ro_set = 0;
3642 } else {
3643 btrfs_warn(fs_info,
3644 "failed setting block group ro, ret=%d\n",
3645 ret);
3646 btrfs_put_block_group(cache);
3647 break;
3648 }
3649
3650 btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
3651 dev_replace->cursor_right = found_key.offset + length;
3652 dev_replace->cursor_left = found_key.offset;
3653 dev_replace->item_needs_writeback = 1;
3654 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
3655 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3656 found_key.offset, cache, is_dev_replace);
3657
3658 /*
3659 * flush, submit all pending read and write bios, afterwards
3660 * wait for them.
3661 * Note that in the dev replace case, a read request causes
3662 * write requests that are submitted in the read completion
3663 * worker. Therefore in the current situation, it is required
3664 * that all write requests are flushed, so that all read and
3665 * write requests are really completed when bios_in_flight
3666 * changes to 0.
3667 */
3668 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3669 scrub_submit(sctx);
3670 mutex_lock(&sctx->wr_ctx.wr_lock);
3671 scrub_wr_submit(sctx);
3672 mutex_unlock(&sctx->wr_ctx.wr_lock);
3673
3674 wait_event(sctx->list_wait,
3675 atomic_read(&sctx->bios_in_flight) == 0);
3676
3677 scrub_pause_on(fs_info);
3678
3679 /*
3680 * must be called before we decrease @scrub_paused.
3681 * make sure we don't block transaction commit while
3682 * we are waiting pending workers finished.
3683 */
3684 wait_event(sctx->list_wait,
3685 atomic_read(&sctx->workers_pending) == 0);
3686 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3687
3688 scrub_pause_off(fs_info);
3689
3690 btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
3691 dev_replace->cursor_left = dev_replace->cursor_right;
3692 dev_replace->item_needs_writeback = 1;
3693 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
3694
3695 if (ro_set)
3696 btrfs_dec_block_group_ro(root, cache);
3697
3698 /*
3699 * We might have prevented the cleaner kthread from deleting
3700 * this block group if it was already unused because we raced
3701 * and set it to RO mode first. So add it back to the unused
3702 * list, otherwise it might not ever be deleted unless a manual
3703 * balance is triggered or it becomes used and unused again.
3704 */
3705 spin_lock(&cache->lock);
3706 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3707 btrfs_block_group_used(&cache->item) == 0) {
3708 spin_unlock(&cache->lock);
3709 spin_lock(&fs_info->unused_bgs_lock);
3710 if (list_empty(&cache->bg_list)) {
3711 btrfs_get_block_group(cache);
3712 list_add_tail(&cache->bg_list,
3713 &fs_info->unused_bgs);
3714 }
3715 spin_unlock(&fs_info->unused_bgs_lock);
3716 } else {
3717 spin_unlock(&cache->lock);
3718 }
3719
3720 btrfs_put_block_group(cache);
3721 if (ret)
3722 break;
3723 if (is_dev_replace &&
3724 atomic64_read(&dev_replace->num_write_errors) > 0) {
3725 ret = -EIO;
3726 break;
3727 }
3728 if (sctx->stat.malloc_errors > 0) {
3729 ret = -ENOMEM;
3730 break;
3731 }
3732 skip:
3733 key.offset = found_key.offset + length;
3734 btrfs_release_path(path);
3735 }
3736
3737 btrfs_free_path(path);
3738
3739 return ret;
3740 }
3741
3742 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3743 struct btrfs_device *scrub_dev)
3744 {
3745 int i;
3746 u64 bytenr;
3747 u64 gen;
3748 int ret;
3749 struct btrfs_root *root = sctx->dev_root;
3750
3751 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
3752 return -EIO;
3753
3754 /* Seed devices of a new filesystem has their own generation. */
3755 if (scrub_dev->fs_devices != root->fs_info->fs_devices)
3756 gen = scrub_dev->generation;
3757 else
3758 gen = root->fs_info->last_trans_committed;
3759
3760 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3761 bytenr = btrfs_sb_offset(i);
3762 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3763 scrub_dev->commit_total_bytes)
3764 break;
3765
3766 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3767 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3768 NULL, 1, bytenr);
3769 if (ret)
3770 return ret;
3771 }
3772 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3773
3774 return 0;
3775 }
3776
3777 /*
3778 * get a reference count on fs_info->scrub_workers. start worker if necessary
3779 */
3780 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3781 int is_dev_replace)
3782 {
3783 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3784 int max_active = fs_info->thread_pool_size;
3785
3786 if (fs_info->scrub_workers_refcnt == 0) {
3787 if (is_dev_replace)
3788 fs_info->scrub_workers =
3789 btrfs_alloc_workqueue(fs_info, "scrub", flags,
3790 1, 4);
3791 else
3792 fs_info->scrub_workers =
3793 btrfs_alloc_workqueue(fs_info, "scrub", flags,
3794 max_active, 4);
3795 if (!fs_info->scrub_workers)
3796 goto fail_scrub_workers;
3797
3798 fs_info->scrub_wr_completion_workers =
3799 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3800 max_active, 2);
3801 if (!fs_info->scrub_wr_completion_workers)
3802 goto fail_scrub_wr_completion_workers;
3803
3804 fs_info->scrub_nocow_workers =
3805 btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0);
3806 if (!fs_info->scrub_nocow_workers)
3807 goto fail_scrub_nocow_workers;
3808 fs_info->scrub_parity_workers =
3809 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3810 max_active, 2);
3811 if (!fs_info->scrub_parity_workers)
3812 goto fail_scrub_parity_workers;
3813 }
3814 ++fs_info->scrub_workers_refcnt;
3815 return 0;
3816
3817 fail_scrub_parity_workers:
3818 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3819 fail_scrub_nocow_workers:
3820 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3821 fail_scrub_wr_completion_workers:
3822 btrfs_destroy_workqueue(fs_info->scrub_workers);
3823 fail_scrub_workers:
3824 return -ENOMEM;
3825 }
3826
3827 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
3828 {
3829 if (--fs_info->scrub_workers_refcnt == 0) {
3830 btrfs_destroy_workqueue(fs_info->scrub_workers);
3831 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3832 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3833 btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
3834 }
3835 WARN_ON(fs_info->scrub_workers_refcnt < 0);
3836 }
3837
3838 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3839 u64 end, struct btrfs_scrub_progress *progress,
3840 int readonly, int is_dev_replace)
3841 {
3842 struct scrub_ctx *sctx;
3843 int ret;
3844 struct btrfs_device *dev;
3845 struct rcu_string *name;
3846
3847 if (btrfs_fs_closing(fs_info))
3848 return -EINVAL;
3849
3850 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
3851 /*
3852 * in this case scrub is unable to calculate the checksum
3853 * the way scrub is implemented. Do not handle this
3854 * situation at all because it won't ever happen.
3855 */
3856 btrfs_err(fs_info,
3857 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3858 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
3859 return -EINVAL;
3860 }
3861
3862 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
3863 /* not supported for data w/o checksums */
3864 btrfs_err_rl(fs_info,
3865 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3866 fs_info->chunk_root->sectorsize, PAGE_SIZE);
3867 return -EINVAL;
3868 }
3869
3870 if (fs_info->chunk_root->nodesize >
3871 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3872 fs_info->chunk_root->sectorsize >
3873 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3874 /*
3875 * would exhaust the array bounds of pagev member in
3876 * struct scrub_block
3877 */
3878 btrfs_err(fs_info,
3879 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3880 fs_info->chunk_root->nodesize,
3881 SCRUB_MAX_PAGES_PER_BLOCK,
3882 fs_info->chunk_root->sectorsize,
3883 SCRUB_MAX_PAGES_PER_BLOCK);
3884 return -EINVAL;
3885 }
3886
3887
3888 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3889 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
3890 if (!dev || (dev->missing && !is_dev_replace)) {
3891 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3892 return -ENODEV;
3893 }
3894
3895 if (!is_dev_replace && !readonly && !dev->writeable) {
3896 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3897 rcu_read_lock();
3898 name = rcu_dereference(dev->name);
3899 btrfs_err(fs_info, "scrub: device %s is not writable",
3900 name->str);
3901 rcu_read_unlock();
3902 return -EROFS;
3903 }
3904
3905 mutex_lock(&fs_info->scrub_lock);
3906 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
3907 mutex_unlock(&fs_info->scrub_lock);
3908 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3909 return -EIO;
3910 }
3911
3912 btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
3913 if (dev->scrub_device ||
3914 (!is_dev_replace &&
3915 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3916 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3917 mutex_unlock(&fs_info->scrub_lock);
3918 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3919 return -EINPROGRESS;
3920 }
3921 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3922
3923 ret = scrub_workers_get(fs_info, is_dev_replace);
3924 if (ret) {
3925 mutex_unlock(&fs_info->scrub_lock);
3926 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3927 return ret;
3928 }
3929
3930 sctx = scrub_setup_ctx(dev, is_dev_replace);
3931 if (IS_ERR(sctx)) {
3932 mutex_unlock(&fs_info->scrub_lock);
3933 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3934 scrub_workers_put(fs_info);
3935 return PTR_ERR(sctx);
3936 }
3937 sctx->readonly = readonly;
3938 dev->scrub_device = sctx;
3939 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3940
3941 /*
3942 * checking @scrub_pause_req here, we can avoid
3943 * race between committing transaction and scrubbing.
3944 */
3945 __scrub_blocked_if_needed(fs_info);
3946 atomic_inc(&fs_info->scrubs_running);
3947 mutex_unlock(&fs_info->scrub_lock);
3948
3949 if (!is_dev_replace) {
3950 /*
3951 * by holding device list mutex, we can
3952 * kick off writing super in log tree sync.
3953 */
3954 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3955 ret = scrub_supers(sctx, dev);
3956 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3957 }
3958
3959 if (!ret)
3960 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3961 is_dev_replace);
3962
3963 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3964 atomic_dec(&fs_info->scrubs_running);
3965 wake_up(&fs_info->scrub_pause_wait);
3966
3967 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3968
3969 if (progress)
3970 memcpy(progress, &sctx->stat, sizeof(*progress));
3971
3972 mutex_lock(&fs_info->scrub_lock);
3973 dev->scrub_device = NULL;
3974 scrub_workers_put(fs_info);
3975 mutex_unlock(&fs_info->scrub_lock);
3976
3977 scrub_put_ctx(sctx);
3978
3979 return ret;
3980 }
3981
3982 void btrfs_scrub_pause(struct btrfs_root *root)
3983 {
3984 struct btrfs_fs_info *fs_info = root->fs_info;
3985
3986 mutex_lock(&fs_info->scrub_lock);
3987 atomic_inc(&fs_info->scrub_pause_req);
3988 while (atomic_read(&fs_info->scrubs_paused) !=
3989 atomic_read(&fs_info->scrubs_running)) {
3990 mutex_unlock(&fs_info->scrub_lock);
3991 wait_event(fs_info->scrub_pause_wait,
3992 atomic_read(&fs_info->scrubs_paused) ==
3993 atomic_read(&fs_info->scrubs_running));
3994 mutex_lock(&fs_info->scrub_lock);
3995 }
3996 mutex_unlock(&fs_info->scrub_lock);
3997 }
3998
3999 void btrfs_scrub_continue(struct btrfs_root *root)
4000 {
4001 struct btrfs_fs_info *fs_info = root->fs_info;
4002
4003 atomic_dec(&fs_info->scrub_pause_req);
4004 wake_up(&fs_info->scrub_pause_wait);
4005 }
4006
4007 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
4008 {
4009 mutex_lock(&fs_info->scrub_lock);
4010 if (!atomic_read(&fs_info->scrubs_running)) {
4011 mutex_unlock(&fs_info->scrub_lock);
4012 return -ENOTCONN;
4013 }
4014
4015 atomic_inc(&fs_info->scrub_cancel_req);
4016 while (atomic_read(&fs_info->scrubs_running)) {
4017 mutex_unlock(&fs_info->scrub_lock);
4018 wait_event(fs_info->scrub_pause_wait,
4019 atomic_read(&fs_info->scrubs_running) == 0);
4020 mutex_lock(&fs_info->scrub_lock);
4021 }
4022 atomic_dec(&fs_info->scrub_cancel_req);
4023 mutex_unlock(&fs_info->scrub_lock);
4024
4025 return 0;
4026 }
4027
4028 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
4029 struct btrfs_device *dev)
4030 {
4031 struct scrub_ctx *sctx;
4032
4033 mutex_lock(&fs_info->scrub_lock);
4034 sctx = dev->scrub_device;
4035 if (!sctx) {
4036 mutex_unlock(&fs_info->scrub_lock);
4037 return -ENOTCONN;
4038 }
4039 atomic_inc(&sctx->cancel_req);
4040 while (dev->scrub_device) {
4041 mutex_unlock(&fs_info->scrub_lock);
4042 wait_event(fs_info->scrub_pause_wait,
4043 dev->scrub_device == NULL);
4044 mutex_lock(&fs_info->scrub_lock);
4045 }
4046 mutex_unlock(&fs_info->scrub_lock);
4047
4048 return 0;
4049 }
4050
4051 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
4052 struct btrfs_scrub_progress *progress)
4053 {
4054 struct btrfs_device *dev;
4055 struct scrub_ctx *sctx = NULL;
4056
4057 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
4058 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
4059 if (dev)
4060 sctx = dev->scrub_device;
4061 if (sctx)
4062 memcpy(progress, &sctx->stat, sizeof(*progress));
4063 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
4064
4065 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4066 }
4067
4068 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4069 u64 extent_logical, u64 extent_len,
4070 u64 *extent_physical,
4071 struct btrfs_device **extent_dev,
4072 int *extent_mirror_num)
4073 {
4074 u64 mapped_length;
4075 struct btrfs_bio *bbio = NULL;
4076 int ret;
4077
4078 mapped_length = extent_len;
4079 ret = btrfs_map_block(fs_info, READ, extent_logical,
4080 &mapped_length, &bbio, 0);
4081 if (ret || !bbio || mapped_length < extent_len ||
4082 !bbio->stripes[0].dev->bdev) {
4083 btrfs_put_bbio(bbio);
4084 return;
4085 }
4086
4087 *extent_physical = bbio->stripes[0].physical;
4088 *extent_mirror_num = bbio->mirror_num;
4089 *extent_dev = bbio->stripes[0].dev;
4090 btrfs_put_bbio(bbio);
4091 }
4092
4093 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
4094 struct scrub_wr_ctx *wr_ctx,
4095 struct btrfs_fs_info *fs_info,
4096 struct btrfs_device *dev,
4097 int is_dev_replace)
4098 {
4099 WARN_ON(wr_ctx->wr_curr_bio != NULL);
4100
4101 mutex_init(&wr_ctx->wr_lock);
4102 wr_ctx->wr_curr_bio = NULL;
4103 if (!is_dev_replace)
4104 return 0;
4105
4106 WARN_ON(!dev->bdev);
4107 wr_ctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
4108 wr_ctx->tgtdev = dev;
4109 atomic_set(&wr_ctx->flush_all_writes, 0);
4110 return 0;
4111 }
4112
4113 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
4114 {
4115 mutex_lock(&wr_ctx->wr_lock);
4116 kfree(wr_ctx->wr_curr_bio);
4117 wr_ctx->wr_curr_bio = NULL;
4118 mutex_unlock(&wr_ctx->wr_lock);
4119 }
4120
4121 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
4122 int mirror_num, u64 physical_for_dev_replace)
4123 {
4124 struct scrub_copy_nocow_ctx *nocow_ctx;
4125 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
4126
4127 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
4128 if (!nocow_ctx) {
4129 spin_lock(&sctx->stat_lock);
4130 sctx->stat.malloc_errors++;
4131 spin_unlock(&sctx->stat_lock);
4132 return -ENOMEM;
4133 }
4134
4135 scrub_pending_trans_workers_inc(sctx);
4136
4137 nocow_ctx->sctx = sctx;
4138 nocow_ctx->logical = logical;
4139 nocow_ctx->len = len;
4140 nocow_ctx->mirror_num = mirror_num;
4141 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
4142 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
4143 copy_nocow_pages_worker, NULL, NULL);
4144 INIT_LIST_HEAD(&nocow_ctx->inodes);
4145 btrfs_queue_work(fs_info->scrub_nocow_workers,
4146 &nocow_ctx->work);
4147
4148 return 0;
4149 }
4150
4151 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
4152 {
4153 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
4154 struct scrub_nocow_inode *nocow_inode;
4155
4156 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
4157 if (!nocow_inode)
4158 return -ENOMEM;
4159 nocow_inode->inum = inum;
4160 nocow_inode->offset = offset;
4161 nocow_inode->root = root;
4162 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
4163 return 0;
4164 }
4165
4166 #define COPY_COMPLETE 1
4167
4168 static void copy_nocow_pages_worker(struct btrfs_work *work)
4169 {
4170 struct scrub_copy_nocow_ctx *nocow_ctx =
4171 container_of(work, struct scrub_copy_nocow_ctx, work);
4172 struct scrub_ctx *sctx = nocow_ctx->sctx;
4173 u64 logical = nocow_ctx->logical;
4174 u64 len = nocow_ctx->len;
4175 int mirror_num = nocow_ctx->mirror_num;
4176 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4177 int ret;
4178 struct btrfs_trans_handle *trans = NULL;
4179 struct btrfs_fs_info *fs_info;
4180 struct btrfs_path *path;
4181 struct btrfs_root *root;
4182 int not_written = 0;
4183
4184 fs_info = sctx->dev_root->fs_info;
4185 root = fs_info->extent_root;
4186
4187 path = btrfs_alloc_path();
4188 if (!path) {
4189 spin_lock(&sctx->stat_lock);
4190 sctx->stat.malloc_errors++;
4191 spin_unlock(&sctx->stat_lock);
4192 not_written = 1;
4193 goto out;
4194 }
4195
4196 trans = btrfs_join_transaction(root);
4197 if (IS_ERR(trans)) {
4198 not_written = 1;
4199 goto out;
4200 }
4201
4202 ret = iterate_inodes_from_logical(logical, fs_info, path,
4203 record_inode_for_nocow, nocow_ctx);
4204 if (ret != 0 && ret != -ENOENT) {
4205 btrfs_warn(fs_info,
4206 "iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %u, ret %d",
4207 logical, physical_for_dev_replace, len, mirror_num,
4208 ret);
4209 not_written = 1;
4210 goto out;
4211 }
4212
4213 btrfs_end_transaction(trans, root);
4214 trans = NULL;
4215 while (!list_empty(&nocow_ctx->inodes)) {
4216 struct scrub_nocow_inode *entry;
4217 entry = list_first_entry(&nocow_ctx->inodes,
4218 struct scrub_nocow_inode,
4219 list);
4220 list_del_init(&entry->list);
4221 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
4222 entry->root, nocow_ctx);
4223 kfree(entry);
4224 if (ret == COPY_COMPLETE) {
4225 ret = 0;
4226 break;
4227 } else if (ret) {
4228 break;
4229 }
4230 }
4231 out:
4232 while (!list_empty(&nocow_ctx->inodes)) {
4233 struct scrub_nocow_inode *entry;
4234 entry = list_first_entry(&nocow_ctx->inodes,
4235 struct scrub_nocow_inode,
4236 list);
4237 list_del_init(&entry->list);
4238 kfree(entry);
4239 }
4240 if (trans && !IS_ERR(trans))
4241 btrfs_end_transaction(trans, root);
4242 if (not_written)
4243 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
4244 num_uncorrectable_read_errors);
4245
4246 btrfs_free_path(path);
4247 kfree(nocow_ctx);
4248
4249 scrub_pending_trans_workers_dec(sctx);
4250 }
4251
4252 static int check_extent_to_block(struct inode *inode, u64 start, u64 len,
4253 u64 logical)
4254 {
4255 struct extent_state *cached_state = NULL;
4256 struct btrfs_ordered_extent *ordered;
4257 struct extent_io_tree *io_tree;
4258 struct extent_map *em;
4259 u64 lockstart = start, lockend = start + len - 1;
4260 int ret = 0;
4261
4262 io_tree = &BTRFS_I(inode)->io_tree;
4263
4264 lock_extent_bits(io_tree, lockstart, lockend, &cached_state);
4265 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
4266 if (ordered) {
4267 btrfs_put_ordered_extent(ordered);
4268 ret = 1;
4269 goto out_unlock;
4270 }
4271
4272 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
4273 if (IS_ERR(em)) {
4274 ret = PTR_ERR(em);
4275 goto out_unlock;
4276 }
4277
4278 /*
4279 * This extent does not actually cover the logical extent anymore,
4280 * move on to the next inode.
4281 */
4282 if (em->block_start > logical ||
4283 em->block_start + em->block_len < logical + len) {
4284 free_extent_map(em);
4285 ret = 1;
4286 goto out_unlock;
4287 }
4288 free_extent_map(em);
4289
4290 out_unlock:
4291 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
4292 GFP_NOFS);
4293 return ret;
4294 }
4295
4296 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
4297 struct scrub_copy_nocow_ctx *nocow_ctx)
4298 {
4299 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
4300 struct btrfs_key key;
4301 struct inode *inode;
4302 struct page *page;
4303 struct btrfs_root *local_root;
4304 struct extent_io_tree *io_tree;
4305 u64 physical_for_dev_replace;
4306 u64 nocow_ctx_logical;
4307 u64 len = nocow_ctx->len;
4308 unsigned long index;
4309 int srcu_index;
4310 int ret = 0;
4311 int err = 0;
4312
4313 key.objectid = root;
4314 key.type = BTRFS_ROOT_ITEM_KEY;
4315 key.offset = (u64)-1;
4316
4317 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
4318
4319 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
4320 if (IS_ERR(local_root)) {
4321 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4322 return PTR_ERR(local_root);
4323 }
4324
4325 key.type = BTRFS_INODE_ITEM_KEY;
4326 key.objectid = inum;
4327 key.offset = 0;
4328 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
4329 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4330 if (IS_ERR(inode))
4331 return PTR_ERR(inode);
4332
4333 /* Avoid truncate/dio/punch hole.. */
4334 inode_lock(inode);
4335 inode_dio_wait(inode);
4336
4337 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4338 io_tree = &BTRFS_I(inode)->io_tree;
4339 nocow_ctx_logical = nocow_ctx->logical;
4340
4341 ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical);
4342 if (ret) {
4343 ret = ret > 0 ? 0 : ret;
4344 goto out;
4345 }
4346
4347 while (len >= PAGE_SIZE) {
4348 index = offset >> PAGE_SHIFT;
4349 again:
4350 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4351 if (!page) {
4352 btrfs_err(fs_info, "find_or_create_page() failed");
4353 ret = -ENOMEM;
4354 goto out;
4355 }
4356
4357 if (PageUptodate(page)) {
4358 if (PageDirty(page))
4359 goto next_page;
4360 } else {
4361 ClearPageError(page);
4362 err = extent_read_full_page(io_tree, page,
4363 btrfs_get_extent,
4364 nocow_ctx->mirror_num);
4365 if (err) {
4366 ret = err;
4367 goto next_page;
4368 }
4369
4370 lock_page(page);
4371 /*
4372 * If the page has been remove from the page cache,
4373 * the data on it is meaningless, because it may be
4374 * old one, the new data may be written into the new
4375 * page in the page cache.
4376 */
4377 if (page->mapping != inode->i_mapping) {
4378 unlock_page(page);
4379 put_page(page);
4380 goto again;
4381 }
4382 if (!PageUptodate(page)) {
4383 ret = -EIO;
4384 goto next_page;
4385 }
4386 }
4387
4388 ret = check_extent_to_block(inode, offset, len,
4389 nocow_ctx_logical);
4390 if (ret) {
4391 ret = ret > 0 ? 0 : ret;
4392 goto next_page;
4393 }
4394
4395 err = write_page_nocow(nocow_ctx->sctx,
4396 physical_for_dev_replace, page);
4397 if (err)
4398 ret = err;
4399 next_page:
4400 unlock_page(page);
4401 put_page(page);
4402
4403 if (ret)
4404 break;
4405
4406 offset += PAGE_SIZE;
4407 physical_for_dev_replace += PAGE_SIZE;
4408 nocow_ctx_logical += PAGE_SIZE;
4409 len -= PAGE_SIZE;
4410 }
4411 ret = COPY_COMPLETE;
4412 out:
4413 inode_unlock(inode);
4414 iput(inode);
4415 return ret;
4416 }
4417
4418 static int write_page_nocow(struct scrub_ctx *sctx,
4419 u64 physical_for_dev_replace, struct page *page)
4420 {
4421 struct bio *bio;
4422 struct btrfs_device *dev;
4423 int ret;
4424
4425 dev = sctx->wr_ctx.tgtdev;
4426 if (!dev)
4427 return -EIO;
4428 if (!dev->bdev) {
4429 btrfs_warn_rl(dev->dev_root->fs_info,
4430 "scrub write_page_nocow(bdev == NULL) is unexpected");
4431 return -EIO;
4432 }
4433 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
4434 if (!bio) {
4435 spin_lock(&sctx->stat_lock);
4436 sctx->stat.malloc_errors++;
4437 spin_unlock(&sctx->stat_lock);
4438 return -ENOMEM;
4439 }
4440 bio->bi_iter.bi_size = 0;
4441 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
4442 bio->bi_bdev = dev->bdev;
4443 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
4444 ret = bio_add_page(bio, page, PAGE_SIZE, 0);
4445 if (ret != PAGE_SIZE) {
4446 leave_with_eio:
4447 bio_put(bio);
4448 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
4449 return -EIO;
4450 }
4451
4452 if (btrfsic_submit_bio_wait(bio))
4453 goto leave_with_eio;
4454
4455 bio_put(bio);
4456 return 0;
4457 }
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