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usb: ohci-at91: use descriptor-based gpio APIs correctly
[linux/fpc-iii.git] / fs / btrfs / scrub.c
blob9a94670536a698c7508f289c263ff9408da18821
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_fs_info *fs_info;
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->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->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->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->fs_info = dev->fs_info;
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 = fs_info->nodesize;
493 sctx->sectorsize = fs_info->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->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->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 struct btrfs_fs_info *fs_info;
793 int ret;
794 struct scrub_fixup_nodatasum *fixup;
795 struct scrub_ctx *sctx;
796 struct btrfs_trans_handle *trans = NULL;
797 struct btrfs_path *path;
798 int uncorrectable = 0;
799
800 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
801 sctx = fixup->sctx;
802 fs_info = fixup->root->fs_info;
803
804 path = btrfs_alloc_path();
805 if (!path) {
806 spin_lock(&sctx->stat_lock);
807 ++sctx->stat.malloc_errors;
808 spin_unlock(&sctx->stat_lock);
809 uncorrectable = 1;
810 goto out;
811 }
812
813 trans = btrfs_join_transaction(fixup->root);
814 if (IS_ERR(trans)) {
815 uncorrectable = 1;
816 goto out;
817 }
818
819 /*
820 * the idea is to trigger a regular read through the standard path. we
821 * read a page from the (failed) logical address by specifying the
822 * corresponding copynum of the failed sector. thus, that readpage is
823 * expected to fail.
824 * that is the point where on-the-fly error correction will kick in
825 * (once it's finished) and rewrite the failed sector if a good copy
826 * can be found.
827 */
828 ret = iterate_inodes_from_logical(fixup->logical, fs_info, path,
829 scrub_fixup_readpage, fixup);
830 if (ret < 0) {
831 uncorrectable = 1;
832 goto out;
833 }
834 WARN_ON(ret != 1);
835
836 spin_lock(&sctx->stat_lock);
837 ++sctx->stat.corrected_errors;
838 spin_unlock(&sctx->stat_lock);
839
840 out:
841 if (trans && !IS_ERR(trans))
842 btrfs_end_transaction(trans);
843 if (uncorrectable) {
844 spin_lock(&sctx->stat_lock);
845 ++sctx->stat.uncorrectable_errors;
846 spin_unlock(&sctx->stat_lock);
847 btrfs_dev_replace_stats_inc(
848 &fs_info->dev_replace.num_uncorrectable_read_errors);
849 btrfs_err_rl_in_rcu(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->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 &fs_info->dev_replace.num_write_errors);
1181 success = 0;
1182 }
1183 } else if (sblock_other) {
1184 ret = scrub_repair_page_from_good_copy(sblock_bad,
1185 sblock_other,
1186 page_num, 0);
1187 if (0 == ret)
1188 page_bad->io_error = 0;
1189 else
1190 success = 0;
1191 }
1192 }
1193
1194 if (success && !sctx->is_dev_replace) {
1195 if (is_metadata || have_csum) {
1196 /*
1197 * need to verify the checksum now that all
1198 * sectors on disk are repaired (the write
1199 * request for data to be repaired is on its way).
1200 * Just be lazy and use scrub_recheck_block()
1201 * which re-reads the data before the checksum
1202 * is verified, but most likely the data comes out
1203 * of the page cache.
1204 */
1205 scrub_recheck_block(fs_info, sblock_bad, 1);
1206 if (!sblock_bad->header_error &&
1207 !sblock_bad->checksum_error &&
1208 sblock_bad->no_io_error_seen)
1209 goto corrected_error;
1210 else
1211 goto did_not_correct_error;
1212 } else {
1213 corrected_error:
1214 spin_lock(&sctx->stat_lock);
1215 sctx->stat.corrected_errors++;
1216 sblock_to_check->data_corrected = 1;
1217 spin_unlock(&sctx->stat_lock);
1218 btrfs_err_rl_in_rcu(fs_info,
1219 "fixed up error at logical %llu on dev %s",
1220 logical, rcu_str_deref(dev->name));
1221 }
1222 } else {
1223 did_not_correct_error:
1224 spin_lock(&sctx->stat_lock);
1225 sctx->stat.uncorrectable_errors++;
1226 spin_unlock(&sctx->stat_lock);
1227 btrfs_err_rl_in_rcu(fs_info,
1228 "unable to fixup (regular) error at logical %llu on dev %s",
1229 logical, rcu_str_deref(dev->name));
1230 }
1231
1232 out:
1233 if (sblocks_for_recheck) {
1234 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1235 mirror_index++) {
1236 struct scrub_block *sblock = sblocks_for_recheck +
1237 mirror_index;
1238 struct scrub_recover *recover;
1239 int page_index;
1240
1241 for (page_index = 0; page_index < sblock->page_count;
1242 page_index++) {
1243 sblock->pagev[page_index]->sblock = NULL;
1244 recover = sblock->pagev[page_index]->recover;
1245 if (recover) {
1246 scrub_put_recover(recover);
1247 sblock->pagev[page_index]->recover =
1248 NULL;
1249 }
1250 scrub_page_put(sblock->pagev[page_index]);
1251 }
1252 }
1253 kfree(sblocks_for_recheck);
1254 }
1255
1256 return 0;
1257 }
1258
1259 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1260 {
1261 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1262 return 2;
1263 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1264 return 3;
1265 else
1266 return (int)bbio->num_stripes;
1267 }
1268
1269 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1270 u64 *raid_map,
1271 u64 mapped_length,
1272 int nstripes, int mirror,
1273 int *stripe_index,
1274 u64 *stripe_offset)
1275 {
1276 int i;
1277
1278 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1279 /* RAID5/6 */
1280 for (i = 0; i < nstripes; i++) {
1281 if (raid_map[i] == RAID6_Q_STRIPE ||
1282 raid_map[i] == RAID5_P_STRIPE)
1283 continue;
1284
1285 if (logical >= raid_map[i] &&
1286 logical < raid_map[i] + mapped_length)
1287 break;
1288 }
1289
1290 *stripe_index = i;
1291 *stripe_offset = logical - raid_map[i];
1292 } else {
1293 /* The other RAID type */
1294 *stripe_index = mirror;
1295 *stripe_offset = 0;
1296 }
1297 }
1298
1299 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1300 struct scrub_block *sblocks_for_recheck)
1301 {
1302 struct scrub_ctx *sctx = original_sblock->sctx;
1303 struct btrfs_fs_info *fs_info = sctx->fs_info;
1304 u64 length = original_sblock->page_count * PAGE_SIZE;
1305 u64 logical = original_sblock->pagev[0]->logical;
1306 u64 generation = original_sblock->pagev[0]->generation;
1307 u64 flags = original_sblock->pagev[0]->flags;
1308 u64 have_csum = original_sblock->pagev[0]->have_csum;
1309 struct scrub_recover *recover;
1310 struct btrfs_bio *bbio;
1311 u64 sublen;
1312 u64 mapped_length;
1313 u64 stripe_offset;
1314 int stripe_index;
1315 int page_index = 0;
1316 int mirror_index;
1317 int nmirrors;
1318 int ret;
1319
1320 /*
1321 * note: the two members refs and outstanding_pages
1322 * are not used (and not set) in the blocks that are used for
1323 * the recheck procedure
1324 */
1325
1326 while (length > 0) {
1327 sublen = min_t(u64, length, PAGE_SIZE);
1328 mapped_length = sublen;
1329 bbio = NULL;
1330
1331 /*
1332 * with a length of PAGE_SIZE, each returned stripe
1333 * represents one mirror
1334 */
1335 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
1336 logical, &mapped_length, &bbio, 0, 1);
1337 if (ret || !bbio || mapped_length < sublen) {
1338 btrfs_put_bbio(bbio);
1339 return -EIO;
1340 }
1341
1342 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1343 if (!recover) {
1344 btrfs_put_bbio(bbio);
1345 return -ENOMEM;
1346 }
1347
1348 atomic_set(&recover->refs, 1);
1349 recover->bbio = bbio;
1350 recover->map_length = mapped_length;
1351
1352 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1353
1354 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1355
1356 for (mirror_index = 0; mirror_index < nmirrors;
1357 mirror_index++) {
1358 struct scrub_block *sblock;
1359 struct scrub_page *page;
1360
1361 sblock = sblocks_for_recheck + mirror_index;
1362 sblock->sctx = sctx;
1363
1364 page = kzalloc(sizeof(*page), GFP_NOFS);
1365 if (!page) {
1366 leave_nomem:
1367 spin_lock(&sctx->stat_lock);
1368 sctx->stat.malloc_errors++;
1369 spin_unlock(&sctx->stat_lock);
1370 scrub_put_recover(recover);
1371 return -ENOMEM;
1372 }
1373 scrub_page_get(page);
1374 sblock->pagev[page_index] = page;
1375 page->sblock = sblock;
1376 page->flags = flags;
1377 page->generation = generation;
1378 page->logical = logical;
1379 page->have_csum = have_csum;
1380 if (have_csum)
1381 memcpy(page->csum,
1382 original_sblock->pagev[0]->csum,
1383 sctx->csum_size);
1384
1385 scrub_stripe_index_and_offset(logical,
1386 bbio->map_type,
1387 bbio->raid_map,
1388 mapped_length,
1389 bbio->num_stripes -
1390 bbio->num_tgtdevs,
1391 mirror_index,
1392 &stripe_index,
1393 &stripe_offset);
1394 page->physical = bbio->stripes[stripe_index].physical +
1395 stripe_offset;
1396 page->dev = bbio->stripes[stripe_index].dev;
1397
1398 BUG_ON(page_index >= original_sblock->page_count);
1399 page->physical_for_dev_replace =
1400 original_sblock->pagev[page_index]->
1401 physical_for_dev_replace;
1402 /* for missing devices, dev->bdev is NULL */
1403 page->mirror_num = mirror_index + 1;
1404 sblock->page_count++;
1405 page->page = alloc_page(GFP_NOFS);
1406 if (!page->page)
1407 goto leave_nomem;
1408
1409 scrub_get_recover(recover);
1410 page->recover = recover;
1411 }
1412 scrub_put_recover(recover);
1413 length -= sublen;
1414 logical += sublen;
1415 page_index++;
1416 }
1417
1418 return 0;
1419 }
1420
1421 struct scrub_bio_ret {
1422 struct completion event;
1423 int error;
1424 };
1425
1426 static void scrub_bio_wait_endio(struct bio *bio)
1427 {
1428 struct scrub_bio_ret *ret = bio->bi_private;
1429
1430 ret->error = bio->bi_error;
1431 complete(&ret->event);
1432 }
1433
1434 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
1435 {
1436 return page->recover &&
1437 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
1438 }
1439
1440 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1441 struct bio *bio,
1442 struct scrub_page *page)
1443 {
1444 struct scrub_bio_ret done;
1445 int ret;
1446
1447 init_completion(&done.event);
1448 done.error = 0;
1449 bio->bi_iter.bi_sector = page->logical >> 9;
1450 bio->bi_private = &done;
1451 bio->bi_end_io = scrub_bio_wait_endio;
1452
1453 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
1454 page->recover->map_length,
1455 page->mirror_num, 0);
1456 if (ret)
1457 return ret;
1458
1459 wait_for_completion(&done.event);
1460 if (done.error)
1461 return -EIO;
1462
1463 return 0;
1464 }
1465
1466 /*
1467 * this function will check the on disk data for checksum errors, header
1468 * errors and read I/O errors. If any I/O errors happen, the exact pages
1469 * which are errored are marked as being bad. The goal is to enable scrub
1470 * to take those pages that are not errored from all the mirrors so that
1471 * the pages that are errored in the just handled mirror can be repaired.
1472 */
1473 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1474 struct scrub_block *sblock,
1475 int retry_failed_mirror)
1476 {
1477 int page_num;
1478
1479 sblock->no_io_error_seen = 1;
1480
1481 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1482 struct bio *bio;
1483 struct scrub_page *page = sblock->pagev[page_num];
1484
1485 if (page->dev->bdev == NULL) {
1486 page->io_error = 1;
1487 sblock->no_io_error_seen = 0;
1488 continue;
1489 }
1490
1491 WARN_ON(!page->page);
1492 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1493 if (!bio) {
1494 page->io_error = 1;
1495 sblock->no_io_error_seen = 0;
1496 continue;
1497 }
1498 bio->bi_bdev = page->dev->bdev;
1499
1500 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1501 if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
1502 if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
1503 sblock->no_io_error_seen = 0;
1504 } else {
1505 bio->bi_iter.bi_sector = page->physical >> 9;
1506 bio_set_op_attrs(bio, REQ_OP_READ, 0);
1507
1508 if (btrfsic_submit_bio_wait(bio))
1509 sblock->no_io_error_seen = 0;
1510 }
1511
1512 bio_put(bio);
1513 }
1514
1515 if (sblock->no_io_error_seen)
1516 scrub_recheck_block_checksum(sblock);
1517 }
1518
1519 static inline int scrub_check_fsid(u8 fsid[],
1520 struct scrub_page *spage)
1521 {
1522 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1523 int ret;
1524
1525 ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE);
1526 return !ret;
1527 }
1528
1529 static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1530 {
1531 sblock->header_error = 0;
1532 sblock->checksum_error = 0;
1533 sblock->generation_error = 0;
1534
1535 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1536 scrub_checksum_data(sblock);
1537 else
1538 scrub_checksum_tree_block(sblock);
1539 }
1540
1541 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1542 struct scrub_block *sblock_good)
1543 {
1544 int page_num;
1545 int ret = 0;
1546
1547 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1548 int ret_sub;
1549
1550 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1551 sblock_good,
1552 page_num, 1);
1553 if (ret_sub)
1554 ret = ret_sub;
1555 }
1556
1557 return ret;
1558 }
1559
1560 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1561 struct scrub_block *sblock_good,
1562 int page_num, int force_write)
1563 {
1564 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1565 struct scrub_page *page_good = sblock_good->pagev[page_num];
1566 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
1567
1568 BUG_ON(page_bad->page == NULL);
1569 BUG_ON(page_good->page == NULL);
1570 if (force_write || sblock_bad->header_error ||
1571 sblock_bad->checksum_error || page_bad->io_error) {
1572 struct bio *bio;
1573 int ret;
1574
1575 if (!page_bad->dev->bdev) {
1576 btrfs_warn_rl(fs_info,
1577 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1578 return -EIO;
1579 }
1580
1581 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1582 if (!bio)
1583 return -EIO;
1584 bio->bi_bdev = page_bad->dev->bdev;
1585 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1586 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1587
1588 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1589 if (PAGE_SIZE != ret) {
1590 bio_put(bio);
1591 return -EIO;
1592 }
1593
1594 if (btrfsic_submit_bio_wait(bio)) {
1595 btrfs_dev_stat_inc_and_print(page_bad->dev,
1596 BTRFS_DEV_STAT_WRITE_ERRS);
1597 btrfs_dev_replace_stats_inc(
1598 &fs_info->dev_replace.num_write_errors);
1599 bio_put(bio);
1600 return -EIO;
1601 }
1602 bio_put(bio);
1603 }
1604
1605 return 0;
1606 }
1607
1608 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1609 {
1610 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
1611 int page_num;
1612
1613 /*
1614 * This block is used for the check of the parity on the source device,
1615 * so the data needn't be written into the destination device.
1616 */
1617 if (sblock->sparity)
1618 return;
1619
1620 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1621 int ret;
1622
1623 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1624 if (ret)
1625 btrfs_dev_replace_stats_inc(
1626 &fs_info->dev_replace.num_write_errors);
1627 }
1628 }
1629
1630 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1631 int page_num)
1632 {
1633 struct scrub_page *spage = sblock->pagev[page_num];
1634
1635 BUG_ON(spage->page == NULL);
1636 if (spage->io_error) {
1637 void *mapped_buffer = kmap_atomic(spage->page);
1638
1639 memset(mapped_buffer, 0, PAGE_SIZE);
1640 flush_dcache_page(spage->page);
1641 kunmap_atomic(mapped_buffer);
1642 }
1643 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1644 }
1645
1646 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1647 struct scrub_page *spage)
1648 {
1649 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1650 struct scrub_bio *sbio;
1651 int ret;
1652
1653 mutex_lock(&wr_ctx->wr_lock);
1654 again:
1655 if (!wr_ctx->wr_curr_bio) {
1656 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1657 GFP_KERNEL);
1658 if (!wr_ctx->wr_curr_bio) {
1659 mutex_unlock(&wr_ctx->wr_lock);
1660 return -ENOMEM;
1661 }
1662 wr_ctx->wr_curr_bio->sctx = sctx;
1663 wr_ctx->wr_curr_bio->page_count = 0;
1664 }
1665 sbio = wr_ctx->wr_curr_bio;
1666 if (sbio->page_count == 0) {
1667 struct bio *bio;
1668
1669 sbio->physical = spage->physical_for_dev_replace;
1670 sbio->logical = spage->logical;
1671 sbio->dev = wr_ctx->tgtdev;
1672 bio = sbio->bio;
1673 if (!bio) {
1674 bio = btrfs_io_bio_alloc(GFP_KERNEL,
1675 wr_ctx->pages_per_wr_bio);
1676 if (!bio) {
1677 mutex_unlock(&wr_ctx->wr_lock);
1678 return -ENOMEM;
1679 }
1680 sbio->bio = bio;
1681 }
1682
1683 bio->bi_private = sbio;
1684 bio->bi_end_io = scrub_wr_bio_end_io;
1685 bio->bi_bdev = sbio->dev->bdev;
1686 bio->bi_iter.bi_sector = sbio->physical >> 9;
1687 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1688 sbio->err = 0;
1689 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1690 spage->physical_for_dev_replace ||
1691 sbio->logical + sbio->page_count * PAGE_SIZE !=
1692 spage->logical) {
1693 scrub_wr_submit(sctx);
1694 goto again;
1695 }
1696
1697 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1698 if (ret != PAGE_SIZE) {
1699 if (sbio->page_count < 1) {
1700 bio_put(sbio->bio);
1701 sbio->bio = NULL;
1702 mutex_unlock(&wr_ctx->wr_lock);
1703 return -EIO;
1704 }
1705 scrub_wr_submit(sctx);
1706 goto again;
1707 }
1708
1709 sbio->pagev[sbio->page_count] = spage;
1710 scrub_page_get(spage);
1711 sbio->page_count++;
1712 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1713 scrub_wr_submit(sctx);
1714 mutex_unlock(&wr_ctx->wr_lock);
1715
1716 return 0;
1717 }
1718
1719 static void scrub_wr_submit(struct scrub_ctx *sctx)
1720 {
1721 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1722 struct scrub_bio *sbio;
1723
1724 if (!wr_ctx->wr_curr_bio)
1725 return;
1726
1727 sbio = wr_ctx->wr_curr_bio;
1728 wr_ctx->wr_curr_bio = NULL;
1729 WARN_ON(!sbio->bio->bi_bdev);
1730 scrub_pending_bio_inc(sctx);
1731 /* process all writes in a single worker thread. Then the block layer
1732 * orders the requests before sending them to the driver which
1733 * doubled the write performance on spinning disks when measured
1734 * with Linux 3.5 */
1735 btrfsic_submit_bio(sbio->bio);
1736 }
1737
1738 static void scrub_wr_bio_end_io(struct bio *bio)
1739 {
1740 struct scrub_bio *sbio = bio->bi_private;
1741 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
1742
1743 sbio->err = bio->bi_error;
1744 sbio->bio = bio;
1745
1746 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1747 scrub_wr_bio_end_io_worker, NULL, NULL);
1748 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1749 }
1750
1751 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1752 {
1753 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1754 struct scrub_ctx *sctx = sbio->sctx;
1755 int i;
1756
1757 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1758 if (sbio->err) {
1759 struct btrfs_dev_replace *dev_replace =
1760 &sbio->sctx->fs_info->dev_replace;
1761
1762 for (i = 0; i < sbio->page_count; i++) {
1763 struct scrub_page *spage = sbio->pagev[i];
1764
1765 spage->io_error = 1;
1766 btrfs_dev_replace_stats_inc(&dev_replace->
1767 num_write_errors);
1768 }
1769 }
1770
1771 for (i = 0; i < sbio->page_count; i++)
1772 scrub_page_put(sbio->pagev[i]);
1773
1774 bio_put(sbio->bio);
1775 kfree(sbio);
1776 scrub_pending_bio_dec(sctx);
1777 }
1778
1779 static int scrub_checksum(struct scrub_block *sblock)
1780 {
1781 u64 flags;
1782 int ret;
1783
1784 /*
1785 * No need to initialize these stats currently,
1786 * because this function only use return value
1787 * instead of these stats value.
1788 *
1789 * Todo:
1790 * always use stats
1791 */
1792 sblock->header_error = 0;
1793 sblock->generation_error = 0;
1794 sblock->checksum_error = 0;
1795
1796 WARN_ON(sblock->page_count < 1);
1797 flags = sblock->pagev[0]->flags;
1798 ret = 0;
1799 if (flags & BTRFS_EXTENT_FLAG_DATA)
1800 ret = scrub_checksum_data(sblock);
1801 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1802 ret = scrub_checksum_tree_block(sblock);
1803 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1804 (void)scrub_checksum_super(sblock);
1805 else
1806 WARN_ON(1);
1807 if (ret)
1808 scrub_handle_errored_block(sblock);
1809
1810 return ret;
1811 }
1812
1813 static int scrub_checksum_data(struct scrub_block *sblock)
1814 {
1815 struct scrub_ctx *sctx = sblock->sctx;
1816 u8 csum[BTRFS_CSUM_SIZE];
1817 u8 *on_disk_csum;
1818 struct page *page;
1819 void *buffer;
1820 u32 crc = ~(u32)0;
1821 u64 len;
1822 int index;
1823
1824 BUG_ON(sblock->page_count < 1);
1825 if (!sblock->pagev[0]->have_csum)
1826 return 0;
1827
1828 on_disk_csum = sblock->pagev[0]->csum;
1829 page = sblock->pagev[0]->page;
1830 buffer = kmap_atomic(page);
1831
1832 len = sctx->sectorsize;
1833 index = 0;
1834 for (;;) {
1835 u64 l = min_t(u64, len, PAGE_SIZE);
1836
1837 crc = btrfs_csum_data(buffer, crc, l);
1838 kunmap_atomic(buffer);
1839 len -= l;
1840 if (len == 0)
1841 break;
1842 index++;
1843 BUG_ON(index >= sblock->page_count);
1844 BUG_ON(!sblock->pagev[index]->page);
1845 page = sblock->pagev[index]->page;
1846 buffer = kmap_atomic(page);
1847 }
1848
1849 btrfs_csum_final(crc, csum);
1850 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1851 sblock->checksum_error = 1;
1852
1853 return sblock->checksum_error;
1854 }
1855
1856 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1857 {
1858 struct scrub_ctx *sctx = sblock->sctx;
1859 struct btrfs_header *h;
1860 struct btrfs_fs_info *fs_info = sctx->fs_info;
1861 u8 calculated_csum[BTRFS_CSUM_SIZE];
1862 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1863 struct page *page;
1864 void *mapped_buffer;
1865 u64 mapped_size;
1866 void *p;
1867 u32 crc = ~(u32)0;
1868 u64 len;
1869 int index;
1870
1871 BUG_ON(sblock->page_count < 1);
1872 page = sblock->pagev[0]->page;
1873 mapped_buffer = kmap_atomic(page);
1874 h = (struct btrfs_header *)mapped_buffer;
1875 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1876
1877 /*
1878 * we don't use the getter functions here, as we
1879 * a) don't have an extent buffer and
1880 * b) the page is already kmapped
1881 */
1882 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1883 sblock->header_error = 1;
1884
1885 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1886 sblock->header_error = 1;
1887 sblock->generation_error = 1;
1888 }
1889
1890 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1891 sblock->header_error = 1;
1892
1893 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1894 BTRFS_UUID_SIZE))
1895 sblock->header_error = 1;
1896
1897 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1898 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1899 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1900 index = 0;
1901 for (;;) {
1902 u64 l = min_t(u64, len, mapped_size);
1903
1904 crc = btrfs_csum_data(p, crc, l);
1905 kunmap_atomic(mapped_buffer);
1906 len -= l;
1907 if (len == 0)
1908 break;
1909 index++;
1910 BUG_ON(index >= sblock->page_count);
1911 BUG_ON(!sblock->pagev[index]->page);
1912 page = sblock->pagev[index]->page;
1913 mapped_buffer = kmap_atomic(page);
1914 mapped_size = PAGE_SIZE;
1915 p = mapped_buffer;
1916 }
1917
1918 btrfs_csum_final(crc, calculated_csum);
1919 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1920 sblock->checksum_error = 1;
1921
1922 return sblock->header_error || sblock->checksum_error;
1923 }
1924
1925 static int scrub_checksum_super(struct scrub_block *sblock)
1926 {
1927 struct btrfs_super_block *s;
1928 struct scrub_ctx *sctx = sblock->sctx;
1929 u8 calculated_csum[BTRFS_CSUM_SIZE];
1930 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1931 struct page *page;
1932 void *mapped_buffer;
1933 u64 mapped_size;
1934 void *p;
1935 u32 crc = ~(u32)0;
1936 int fail_gen = 0;
1937 int fail_cor = 0;
1938 u64 len;
1939 int index;
1940
1941 BUG_ON(sblock->page_count < 1);
1942 page = sblock->pagev[0]->page;
1943 mapped_buffer = kmap_atomic(page);
1944 s = (struct btrfs_super_block *)mapped_buffer;
1945 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1946
1947 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1948 ++fail_cor;
1949
1950 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1951 ++fail_gen;
1952
1953 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1954 ++fail_cor;
1955
1956 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1957 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1958 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1959 index = 0;
1960 for (;;) {
1961 u64 l = min_t(u64, len, mapped_size);
1962
1963 crc = btrfs_csum_data(p, crc, l);
1964 kunmap_atomic(mapped_buffer);
1965 len -= l;
1966 if (len == 0)
1967 break;
1968 index++;
1969 BUG_ON(index >= sblock->page_count);
1970 BUG_ON(!sblock->pagev[index]->page);
1971 page = sblock->pagev[index]->page;
1972 mapped_buffer = kmap_atomic(page);
1973 mapped_size = PAGE_SIZE;
1974 p = mapped_buffer;
1975 }
1976
1977 btrfs_csum_final(crc, calculated_csum);
1978 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1979 ++fail_cor;
1980
1981 if (fail_cor + fail_gen) {
1982 /*
1983 * if we find an error in a super block, we just report it.
1984 * They will get written with the next transaction commit
1985 * anyway
1986 */
1987 spin_lock(&sctx->stat_lock);
1988 ++sctx->stat.super_errors;
1989 spin_unlock(&sctx->stat_lock);
1990 if (fail_cor)
1991 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1992 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1993 else
1994 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1995 BTRFS_DEV_STAT_GENERATION_ERRS);
1996 }
1997
1998 return fail_cor + fail_gen;
1999 }
2000
2001 static void scrub_block_get(struct scrub_block *sblock)
2002 {
2003 atomic_inc(&sblock->refs);
2004 }
2005
2006 static void scrub_block_put(struct scrub_block *sblock)
2007 {
2008 if (atomic_dec_and_test(&sblock->refs)) {
2009 int i;
2010
2011 if (sblock->sparity)
2012 scrub_parity_put(sblock->sparity);
2013
2014 for (i = 0; i < sblock->page_count; i++)
2015 scrub_page_put(sblock->pagev[i]);
2016 kfree(sblock);
2017 }
2018 }
2019
2020 static void scrub_page_get(struct scrub_page *spage)
2021 {
2022 atomic_inc(&spage->refs);
2023 }
2024
2025 static void scrub_page_put(struct scrub_page *spage)
2026 {
2027 if (atomic_dec_and_test(&spage->refs)) {
2028 if (spage->page)
2029 __free_page(spage->page);
2030 kfree(spage);
2031 }
2032 }
2033
2034 static void scrub_submit(struct scrub_ctx *sctx)
2035 {
2036 struct scrub_bio *sbio;
2037
2038 if (sctx->curr == -1)
2039 return;
2040
2041 sbio = sctx->bios[sctx->curr];
2042 sctx->curr = -1;
2043 scrub_pending_bio_inc(sctx);
2044 btrfsic_submit_bio(sbio->bio);
2045 }
2046
2047 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2048 struct scrub_page *spage)
2049 {
2050 struct scrub_block *sblock = spage->sblock;
2051 struct scrub_bio *sbio;
2052 int ret;
2053
2054 again:
2055 /*
2056 * grab a fresh bio or wait for one to become available
2057 */
2058 while (sctx->curr == -1) {
2059 spin_lock(&sctx->list_lock);
2060 sctx->curr = sctx->first_free;
2061 if (sctx->curr != -1) {
2062 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2063 sctx->bios[sctx->curr]->next_free = -1;
2064 sctx->bios[sctx->curr]->page_count = 0;
2065 spin_unlock(&sctx->list_lock);
2066 } else {
2067 spin_unlock(&sctx->list_lock);
2068 wait_event(sctx->list_wait, sctx->first_free != -1);
2069 }
2070 }
2071 sbio = sctx->bios[sctx->curr];
2072 if (sbio->page_count == 0) {
2073 struct bio *bio;
2074
2075 sbio->physical = spage->physical;
2076 sbio->logical = spage->logical;
2077 sbio->dev = spage->dev;
2078 bio = sbio->bio;
2079 if (!bio) {
2080 bio = btrfs_io_bio_alloc(GFP_KERNEL,
2081 sctx->pages_per_rd_bio);
2082 if (!bio)
2083 return -ENOMEM;
2084 sbio->bio = bio;
2085 }
2086
2087 bio->bi_private = sbio;
2088 bio->bi_end_io = scrub_bio_end_io;
2089 bio->bi_bdev = sbio->dev->bdev;
2090 bio->bi_iter.bi_sector = sbio->physical >> 9;
2091 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2092 sbio->err = 0;
2093 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2094 spage->physical ||
2095 sbio->logical + sbio->page_count * PAGE_SIZE !=
2096 spage->logical ||
2097 sbio->dev != spage->dev) {
2098 scrub_submit(sctx);
2099 goto again;
2100 }
2101
2102 sbio->pagev[sbio->page_count] = spage;
2103 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2104 if (ret != PAGE_SIZE) {
2105 if (sbio->page_count < 1) {
2106 bio_put(sbio->bio);
2107 sbio->bio = NULL;
2108 return -EIO;
2109 }
2110 scrub_submit(sctx);
2111 goto again;
2112 }
2113
2114 scrub_block_get(sblock); /* one for the page added to the bio */
2115 atomic_inc(&sblock->outstanding_pages);
2116 sbio->page_count++;
2117 if (sbio->page_count == sctx->pages_per_rd_bio)
2118 scrub_submit(sctx);
2119
2120 return 0;
2121 }
2122
2123 static void scrub_missing_raid56_end_io(struct bio *bio)
2124 {
2125 struct scrub_block *sblock = bio->bi_private;
2126 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2127
2128 if (bio->bi_error)
2129 sblock->no_io_error_seen = 0;
2130
2131 bio_put(bio);
2132
2133 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2134 }
2135
2136 static void scrub_missing_raid56_worker(struct btrfs_work *work)
2137 {
2138 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2139 struct scrub_ctx *sctx = sblock->sctx;
2140 struct btrfs_fs_info *fs_info = sctx->fs_info;
2141 u64 logical;
2142 struct btrfs_device *dev;
2143
2144 logical = sblock->pagev[0]->logical;
2145 dev = sblock->pagev[0]->dev;
2146
2147 if (sblock->no_io_error_seen)
2148 scrub_recheck_block_checksum(sblock);
2149
2150 if (!sblock->no_io_error_seen) {
2151 spin_lock(&sctx->stat_lock);
2152 sctx->stat.read_errors++;
2153 spin_unlock(&sctx->stat_lock);
2154 btrfs_err_rl_in_rcu(fs_info,
2155 "IO error rebuilding logical %llu for dev %s",
2156 logical, rcu_str_deref(dev->name));
2157 } else if (sblock->header_error || sblock->checksum_error) {
2158 spin_lock(&sctx->stat_lock);
2159 sctx->stat.uncorrectable_errors++;
2160 spin_unlock(&sctx->stat_lock);
2161 btrfs_err_rl_in_rcu(fs_info,
2162 "failed to rebuild valid logical %llu for dev %s",
2163 logical, rcu_str_deref(dev->name));
2164 } else {
2165 scrub_write_block_to_dev_replace(sblock);
2166 }
2167
2168 scrub_block_put(sblock);
2169
2170 if (sctx->is_dev_replace &&
2171 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2172 mutex_lock(&sctx->wr_ctx.wr_lock);
2173 scrub_wr_submit(sctx);
2174 mutex_unlock(&sctx->wr_ctx.wr_lock);
2175 }
2176
2177 scrub_pending_bio_dec(sctx);
2178 }
2179
2180 static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2181 {
2182 struct scrub_ctx *sctx = sblock->sctx;
2183 struct btrfs_fs_info *fs_info = sctx->fs_info;
2184 u64 length = sblock->page_count * PAGE_SIZE;
2185 u64 logical = sblock->pagev[0]->logical;
2186 struct btrfs_bio *bbio = NULL;
2187 struct bio *bio;
2188 struct btrfs_raid_bio *rbio;
2189 int ret;
2190 int i;
2191
2192 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2193 &length, &bbio, 0, 1);
2194 if (ret || !bbio || !bbio->raid_map)
2195 goto bbio_out;
2196
2197 if (WARN_ON(!sctx->is_dev_replace ||
2198 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2199 /*
2200 * We shouldn't be scrubbing a missing device. Even for dev
2201 * replace, we should only get here for RAID 5/6. We either
2202 * managed to mount something with no mirrors remaining or
2203 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2204 */
2205 goto bbio_out;
2206 }
2207
2208 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2209 if (!bio)
2210 goto bbio_out;
2211
2212 bio->bi_iter.bi_sector = logical >> 9;
2213 bio->bi_private = sblock;
2214 bio->bi_end_io = scrub_missing_raid56_end_io;
2215
2216 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2217 if (!rbio)
2218 goto rbio_out;
2219
2220 for (i = 0; i < sblock->page_count; i++) {
2221 struct scrub_page *spage = sblock->pagev[i];
2222
2223 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2224 }
2225
2226 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2227 scrub_missing_raid56_worker, NULL, NULL);
2228 scrub_block_get(sblock);
2229 scrub_pending_bio_inc(sctx);
2230 raid56_submit_missing_rbio(rbio);
2231 return;
2232
2233 rbio_out:
2234 bio_put(bio);
2235 bbio_out:
2236 btrfs_put_bbio(bbio);
2237 spin_lock(&sctx->stat_lock);
2238 sctx->stat.malloc_errors++;
2239 spin_unlock(&sctx->stat_lock);
2240 }
2241
2242 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2243 u64 physical, struct btrfs_device *dev, u64 flags,
2244 u64 gen, int mirror_num, u8 *csum, int force,
2245 u64 physical_for_dev_replace)
2246 {
2247 struct scrub_block *sblock;
2248 int index;
2249
2250 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2251 if (!sblock) {
2252 spin_lock(&sctx->stat_lock);
2253 sctx->stat.malloc_errors++;
2254 spin_unlock(&sctx->stat_lock);
2255 return -ENOMEM;
2256 }
2257
2258 /* one ref inside this function, plus one for each page added to
2259 * a bio later on */
2260 atomic_set(&sblock->refs, 1);
2261 sblock->sctx = sctx;
2262 sblock->no_io_error_seen = 1;
2263
2264 for (index = 0; len > 0; index++) {
2265 struct scrub_page *spage;
2266 u64 l = min_t(u64, len, PAGE_SIZE);
2267
2268 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2269 if (!spage) {
2270 leave_nomem:
2271 spin_lock(&sctx->stat_lock);
2272 sctx->stat.malloc_errors++;
2273 spin_unlock(&sctx->stat_lock);
2274 scrub_block_put(sblock);
2275 return -ENOMEM;
2276 }
2277 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2278 scrub_page_get(spage);
2279 sblock->pagev[index] = spage;
2280 spage->sblock = sblock;
2281 spage->dev = dev;
2282 spage->flags = flags;
2283 spage->generation = gen;
2284 spage->logical = logical;
2285 spage->physical = physical;
2286 spage->physical_for_dev_replace = physical_for_dev_replace;
2287 spage->mirror_num = mirror_num;
2288 if (csum) {
2289 spage->have_csum = 1;
2290 memcpy(spage->csum, csum, sctx->csum_size);
2291 } else {
2292 spage->have_csum = 0;
2293 }
2294 sblock->page_count++;
2295 spage->page = alloc_page(GFP_KERNEL);
2296 if (!spage->page)
2297 goto leave_nomem;
2298 len -= l;
2299 logical += l;
2300 physical += l;
2301 physical_for_dev_replace += l;
2302 }
2303
2304 WARN_ON(sblock->page_count == 0);
2305 if (dev->missing) {
2306 /*
2307 * This case should only be hit for RAID 5/6 device replace. See
2308 * the comment in scrub_missing_raid56_pages() for details.
2309 */
2310 scrub_missing_raid56_pages(sblock);
2311 } else {
2312 for (index = 0; index < sblock->page_count; index++) {
2313 struct scrub_page *spage = sblock->pagev[index];
2314 int ret;
2315
2316 ret = scrub_add_page_to_rd_bio(sctx, spage);
2317 if (ret) {
2318 scrub_block_put(sblock);
2319 return ret;
2320 }
2321 }
2322
2323 if (force)
2324 scrub_submit(sctx);
2325 }
2326
2327 /* last one frees, either here or in bio completion for last page */
2328 scrub_block_put(sblock);
2329 return 0;
2330 }
2331
2332 static void scrub_bio_end_io(struct bio *bio)
2333 {
2334 struct scrub_bio *sbio = bio->bi_private;
2335 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2336
2337 sbio->err = bio->bi_error;
2338 sbio->bio = bio;
2339
2340 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2341 }
2342
2343 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2344 {
2345 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2346 struct scrub_ctx *sctx = sbio->sctx;
2347 int i;
2348
2349 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2350 if (sbio->err) {
2351 for (i = 0; i < sbio->page_count; i++) {
2352 struct scrub_page *spage = sbio->pagev[i];
2353
2354 spage->io_error = 1;
2355 spage->sblock->no_io_error_seen = 0;
2356 }
2357 }
2358
2359 /* now complete the scrub_block items that have all pages completed */
2360 for (i = 0; i < sbio->page_count; i++) {
2361 struct scrub_page *spage = sbio->pagev[i];
2362 struct scrub_block *sblock = spage->sblock;
2363
2364 if (atomic_dec_and_test(&sblock->outstanding_pages))
2365 scrub_block_complete(sblock);
2366 scrub_block_put(sblock);
2367 }
2368
2369 bio_put(sbio->bio);
2370 sbio->bio = NULL;
2371 spin_lock(&sctx->list_lock);
2372 sbio->next_free = sctx->first_free;
2373 sctx->first_free = sbio->index;
2374 spin_unlock(&sctx->list_lock);
2375
2376 if (sctx->is_dev_replace &&
2377 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2378 mutex_lock(&sctx->wr_ctx.wr_lock);
2379 scrub_wr_submit(sctx);
2380 mutex_unlock(&sctx->wr_ctx.wr_lock);
2381 }
2382
2383 scrub_pending_bio_dec(sctx);
2384 }
2385
2386 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2387 unsigned long *bitmap,
2388 u64 start, u64 len)
2389 {
2390 u32 offset;
2391 int nsectors;
2392 int sectorsize = sparity->sctx->fs_info->sectorsize;
2393
2394 if (len >= sparity->stripe_len) {
2395 bitmap_set(bitmap, 0, sparity->nsectors);
2396 return;
2397 }
2398
2399 start -= sparity->logic_start;
2400 start = div_u64_rem(start, sparity->stripe_len, &offset);
2401 offset /= sectorsize;
2402 nsectors = (int)len / sectorsize;
2403
2404 if (offset + nsectors <= sparity->nsectors) {
2405 bitmap_set(bitmap, offset, nsectors);
2406 return;
2407 }
2408
2409 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2410 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2411 }
2412
2413 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2414 u64 start, u64 len)
2415 {
2416 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2417 }
2418
2419 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2420 u64 start, u64 len)
2421 {
2422 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2423 }
2424
2425 static void scrub_block_complete(struct scrub_block *sblock)
2426 {
2427 int corrupted = 0;
2428
2429 if (!sblock->no_io_error_seen) {
2430 corrupted = 1;
2431 scrub_handle_errored_block(sblock);
2432 } else {
2433 /*
2434 * if has checksum error, write via repair mechanism in
2435 * dev replace case, otherwise write here in dev replace
2436 * case.
2437 */
2438 corrupted = scrub_checksum(sblock);
2439 if (!corrupted && sblock->sctx->is_dev_replace)
2440 scrub_write_block_to_dev_replace(sblock);
2441 }
2442
2443 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2444 u64 start = sblock->pagev[0]->logical;
2445 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2446 PAGE_SIZE;
2447
2448 scrub_parity_mark_sectors_error(sblock->sparity,
2449 start, end - start);
2450 }
2451 }
2452
2453 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2454 {
2455 struct btrfs_ordered_sum *sum = NULL;
2456 unsigned long index;
2457 unsigned long num_sectors;
2458
2459 while (!list_empty(&sctx->csum_list)) {
2460 sum = list_first_entry(&sctx->csum_list,
2461 struct btrfs_ordered_sum, list);
2462 if (sum->bytenr > logical)
2463 return 0;
2464 if (sum->bytenr + sum->len > logical)
2465 break;
2466
2467 ++sctx->stat.csum_discards;
2468 list_del(&sum->list);
2469 kfree(sum);
2470 sum = NULL;
2471 }
2472 if (!sum)
2473 return 0;
2474
2475 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2476 num_sectors = sum->len / sctx->sectorsize;
2477 memcpy(csum, sum->sums + index, sctx->csum_size);
2478 if (index == num_sectors - 1) {
2479 list_del(&sum->list);
2480 kfree(sum);
2481 }
2482 return 1;
2483 }
2484
2485 /* scrub extent tries to collect up to 64 kB for each bio */
2486 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2487 u64 physical, struct btrfs_device *dev, u64 flags,
2488 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2489 {
2490 int ret;
2491 u8 csum[BTRFS_CSUM_SIZE];
2492 u32 blocksize;
2493
2494 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2495 blocksize = sctx->sectorsize;
2496 spin_lock(&sctx->stat_lock);
2497 sctx->stat.data_extents_scrubbed++;
2498 sctx->stat.data_bytes_scrubbed += len;
2499 spin_unlock(&sctx->stat_lock);
2500 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2501 blocksize = sctx->nodesize;
2502 spin_lock(&sctx->stat_lock);
2503 sctx->stat.tree_extents_scrubbed++;
2504 sctx->stat.tree_bytes_scrubbed += len;
2505 spin_unlock(&sctx->stat_lock);
2506 } else {
2507 blocksize = sctx->sectorsize;
2508 WARN_ON(1);
2509 }
2510
2511 while (len) {
2512 u64 l = min_t(u64, len, blocksize);
2513 int have_csum = 0;
2514
2515 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2516 /* push csums to sbio */
2517 have_csum = scrub_find_csum(sctx, logical, csum);
2518 if (have_csum == 0)
2519 ++sctx->stat.no_csum;
2520 if (sctx->is_dev_replace && !have_csum) {
2521 ret = copy_nocow_pages(sctx, logical, l,
2522 mirror_num,
2523 physical_for_dev_replace);
2524 goto behind_scrub_pages;
2525 }
2526 }
2527 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2528 mirror_num, have_csum ? csum : NULL, 0,
2529 physical_for_dev_replace);
2530 behind_scrub_pages:
2531 if (ret)
2532 return ret;
2533 len -= l;
2534 logical += l;
2535 physical += l;
2536 physical_for_dev_replace += l;
2537 }
2538 return 0;
2539 }
2540
2541 static int scrub_pages_for_parity(struct scrub_parity *sparity,
2542 u64 logical, u64 len,
2543 u64 physical, struct btrfs_device *dev,
2544 u64 flags, u64 gen, int mirror_num, u8 *csum)
2545 {
2546 struct scrub_ctx *sctx = sparity->sctx;
2547 struct scrub_block *sblock;
2548 int index;
2549
2550 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2551 if (!sblock) {
2552 spin_lock(&sctx->stat_lock);
2553 sctx->stat.malloc_errors++;
2554 spin_unlock(&sctx->stat_lock);
2555 return -ENOMEM;
2556 }
2557
2558 /* one ref inside this function, plus one for each page added to
2559 * a bio later on */
2560 atomic_set(&sblock->refs, 1);
2561 sblock->sctx = sctx;
2562 sblock->no_io_error_seen = 1;
2563 sblock->sparity = sparity;
2564 scrub_parity_get(sparity);
2565
2566 for (index = 0; len > 0; index++) {
2567 struct scrub_page *spage;
2568 u64 l = min_t(u64, len, PAGE_SIZE);
2569
2570 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2571 if (!spage) {
2572 leave_nomem:
2573 spin_lock(&sctx->stat_lock);
2574 sctx->stat.malloc_errors++;
2575 spin_unlock(&sctx->stat_lock);
2576 scrub_block_put(sblock);
2577 return -ENOMEM;
2578 }
2579 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2580 /* For scrub block */
2581 scrub_page_get(spage);
2582 sblock->pagev[index] = spage;
2583 /* For scrub parity */
2584 scrub_page_get(spage);
2585 list_add_tail(&spage->list, &sparity->spages);
2586 spage->sblock = sblock;
2587 spage->dev = dev;
2588 spage->flags = flags;
2589 spage->generation = gen;
2590 spage->logical = logical;
2591 spage->physical = physical;
2592 spage->mirror_num = mirror_num;
2593 if (csum) {
2594 spage->have_csum = 1;
2595 memcpy(spage->csum, csum, sctx->csum_size);
2596 } else {
2597 spage->have_csum = 0;
2598 }
2599 sblock->page_count++;
2600 spage->page = alloc_page(GFP_KERNEL);
2601 if (!spage->page)
2602 goto leave_nomem;
2603 len -= l;
2604 logical += l;
2605 physical += l;
2606 }
2607
2608 WARN_ON(sblock->page_count == 0);
2609 for (index = 0; index < sblock->page_count; index++) {
2610 struct scrub_page *spage = sblock->pagev[index];
2611 int ret;
2612
2613 ret = scrub_add_page_to_rd_bio(sctx, spage);
2614 if (ret) {
2615 scrub_block_put(sblock);
2616 return ret;
2617 }
2618 }
2619
2620 /* last one frees, either here or in bio completion for last page */
2621 scrub_block_put(sblock);
2622 return 0;
2623 }
2624
2625 static int scrub_extent_for_parity(struct scrub_parity *sparity,
2626 u64 logical, u64 len,
2627 u64 physical, struct btrfs_device *dev,
2628 u64 flags, u64 gen, int mirror_num)
2629 {
2630 struct scrub_ctx *sctx = sparity->sctx;
2631 int ret;
2632 u8 csum[BTRFS_CSUM_SIZE];
2633 u32 blocksize;
2634
2635 if (dev->missing) {
2636 scrub_parity_mark_sectors_error(sparity, logical, len);
2637 return 0;
2638 }
2639
2640 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2641 blocksize = sctx->sectorsize;
2642 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2643 blocksize = sctx->nodesize;
2644 } else {
2645 blocksize = sctx->sectorsize;
2646 WARN_ON(1);
2647 }
2648
2649 while (len) {
2650 u64 l = min_t(u64, len, blocksize);
2651 int have_csum = 0;
2652
2653 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2654 /* push csums to sbio */
2655 have_csum = scrub_find_csum(sctx, logical, csum);
2656 if (have_csum == 0)
2657 goto skip;
2658 }
2659 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2660 flags, gen, mirror_num,
2661 have_csum ? csum : NULL);
2662 if (ret)
2663 return ret;
2664 skip:
2665 len -= l;
2666 logical += l;
2667 physical += l;
2668 }
2669 return 0;
2670 }
2671
2672 /*
2673 * Given a physical address, this will calculate it's
2674 * logical offset. if this is a parity stripe, it will return
2675 * the most left data stripe's logical offset.
2676 *
2677 * return 0 if it is a data stripe, 1 means parity stripe.
2678 */
2679 static int get_raid56_logic_offset(u64 physical, int num,
2680 struct map_lookup *map, u64 *offset,
2681 u64 *stripe_start)
2682 {
2683 int i;
2684 int j = 0;
2685 u64 stripe_nr;
2686 u64 last_offset;
2687 u32 stripe_index;
2688 u32 rot;
2689
2690 last_offset = (physical - map->stripes[num].physical) *
2691 nr_data_stripes(map);
2692 if (stripe_start)
2693 *stripe_start = last_offset;
2694
2695 *offset = last_offset;
2696 for (i = 0; i < nr_data_stripes(map); i++) {
2697 *offset = last_offset + i * map->stripe_len;
2698
2699 stripe_nr = div_u64(*offset, map->stripe_len);
2700 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
2701
2702 /* Work out the disk rotation on this stripe-set */
2703 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2704 /* calculate which stripe this data locates */
2705 rot += i;
2706 stripe_index = rot % map->num_stripes;
2707 if (stripe_index == num)
2708 return 0;
2709 if (stripe_index < num)
2710 j++;
2711 }
2712 *offset = last_offset + j * map->stripe_len;
2713 return 1;
2714 }
2715
2716 static void scrub_free_parity(struct scrub_parity *sparity)
2717 {
2718 struct scrub_ctx *sctx = sparity->sctx;
2719 struct scrub_page *curr, *next;
2720 int nbits;
2721
2722 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2723 if (nbits) {
2724 spin_lock(&sctx->stat_lock);
2725 sctx->stat.read_errors += nbits;
2726 sctx->stat.uncorrectable_errors += nbits;
2727 spin_unlock(&sctx->stat_lock);
2728 }
2729
2730 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2731 list_del_init(&curr->list);
2732 scrub_page_put(curr);
2733 }
2734
2735 kfree(sparity);
2736 }
2737
2738 static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2739 {
2740 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2741 work);
2742 struct scrub_ctx *sctx = sparity->sctx;
2743
2744 scrub_free_parity(sparity);
2745 scrub_pending_bio_dec(sctx);
2746 }
2747
2748 static void scrub_parity_bio_endio(struct bio *bio)
2749 {
2750 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2751 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
2752
2753 if (bio->bi_error)
2754 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2755 sparity->nsectors);
2756
2757 bio_put(bio);
2758
2759 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2760 scrub_parity_bio_endio_worker, NULL, NULL);
2761 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
2762 }
2763
2764 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2765 {
2766 struct scrub_ctx *sctx = sparity->sctx;
2767 struct btrfs_fs_info *fs_info = sctx->fs_info;
2768 struct bio *bio;
2769 struct btrfs_raid_bio *rbio;
2770 struct scrub_page *spage;
2771 struct btrfs_bio *bbio = NULL;
2772 u64 length;
2773 int ret;
2774
2775 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2776 sparity->nsectors))
2777 goto out;
2778
2779 length = sparity->logic_end - sparity->logic_start;
2780 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
2781 &length, &bbio, 0, 1);
2782 if (ret || !bbio || !bbio->raid_map)
2783 goto bbio_out;
2784
2785 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2786 if (!bio)
2787 goto bbio_out;
2788
2789 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2790 bio->bi_private = sparity;
2791 bio->bi_end_io = scrub_parity_bio_endio;
2792
2793 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
2794 length, sparity->scrub_dev,
2795 sparity->dbitmap,
2796 sparity->nsectors);
2797 if (!rbio)
2798 goto rbio_out;
2799
2800 list_for_each_entry(spage, &sparity->spages, list)
2801 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2802
2803 scrub_pending_bio_inc(sctx);
2804 raid56_parity_submit_scrub_rbio(rbio);
2805 return;
2806
2807 rbio_out:
2808 bio_put(bio);
2809 bbio_out:
2810 btrfs_put_bbio(bbio);
2811 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2812 sparity->nsectors);
2813 spin_lock(&sctx->stat_lock);
2814 sctx->stat.malloc_errors++;
2815 spin_unlock(&sctx->stat_lock);
2816 out:
2817 scrub_free_parity(sparity);
2818 }
2819
2820 static inline int scrub_calc_parity_bitmap_len(int nsectors)
2821 {
2822 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2823 }
2824
2825 static void scrub_parity_get(struct scrub_parity *sparity)
2826 {
2827 atomic_inc(&sparity->refs);
2828 }
2829
2830 static void scrub_parity_put(struct scrub_parity *sparity)
2831 {
2832 if (!atomic_dec_and_test(&sparity->refs))
2833 return;
2834
2835 scrub_parity_check_and_repair(sparity);
2836 }
2837
2838 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2839 struct map_lookup *map,
2840 struct btrfs_device *sdev,
2841 struct btrfs_path *path,
2842 u64 logic_start,
2843 u64 logic_end)
2844 {
2845 struct btrfs_fs_info *fs_info = sctx->fs_info;
2846 struct btrfs_root *root = fs_info->extent_root;
2847 struct btrfs_root *csum_root = fs_info->csum_root;
2848 struct btrfs_extent_item *extent;
2849 struct btrfs_bio *bbio = NULL;
2850 u64 flags;
2851 int ret;
2852 int slot;
2853 struct extent_buffer *l;
2854 struct btrfs_key key;
2855 u64 generation;
2856 u64 extent_logical;
2857 u64 extent_physical;
2858 u64 extent_len;
2859 u64 mapped_length;
2860 struct btrfs_device *extent_dev;
2861 struct scrub_parity *sparity;
2862 int nsectors;
2863 int bitmap_len;
2864 int extent_mirror_num;
2865 int stop_loop = 0;
2866
2867 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
2868 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2869 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2870 GFP_NOFS);
2871 if (!sparity) {
2872 spin_lock(&sctx->stat_lock);
2873 sctx->stat.malloc_errors++;
2874 spin_unlock(&sctx->stat_lock);
2875 return -ENOMEM;
2876 }
2877
2878 sparity->stripe_len = map->stripe_len;
2879 sparity->nsectors = nsectors;
2880 sparity->sctx = sctx;
2881 sparity->scrub_dev = sdev;
2882 sparity->logic_start = logic_start;
2883 sparity->logic_end = logic_end;
2884 atomic_set(&sparity->refs, 1);
2885 INIT_LIST_HEAD(&sparity->spages);
2886 sparity->dbitmap = sparity->bitmap;
2887 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2888
2889 ret = 0;
2890 while (logic_start < logic_end) {
2891 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2892 key.type = BTRFS_METADATA_ITEM_KEY;
2893 else
2894 key.type = BTRFS_EXTENT_ITEM_KEY;
2895 key.objectid = logic_start;
2896 key.offset = (u64)-1;
2897
2898 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2899 if (ret < 0)
2900 goto out;
2901
2902 if (ret > 0) {
2903 ret = btrfs_previous_extent_item(root, path, 0);
2904 if (ret < 0)
2905 goto out;
2906 if (ret > 0) {
2907 btrfs_release_path(path);
2908 ret = btrfs_search_slot(NULL, root, &key,
2909 path, 0, 0);
2910 if (ret < 0)
2911 goto out;
2912 }
2913 }
2914
2915 stop_loop = 0;
2916 while (1) {
2917 u64 bytes;
2918
2919 l = path->nodes[0];
2920 slot = path->slots[0];
2921 if (slot >= btrfs_header_nritems(l)) {
2922 ret = btrfs_next_leaf(root, path);
2923 if (ret == 0)
2924 continue;
2925 if (ret < 0)
2926 goto out;
2927
2928 stop_loop = 1;
2929 break;
2930 }
2931 btrfs_item_key_to_cpu(l, &key, slot);
2932
2933 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2934 key.type != BTRFS_METADATA_ITEM_KEY)
2935 goto next;
2936
2937 if (key.type == BTRFS_METADATA_ITEM_KEY)
2938 bytes = fs_info->nodesize;
2939 else
2940 bytes = key.offset;
2941
2942 if (key.objectid + bytes <= logic_start)
2943 goto next;
2944
2945 if (key.objectid >= logic_end) {
2946 stop_loop = 1;
2947 break;
2948 }
2949
2950 while (key.objectid >= logic_start + map->stripe_len)
2951 logic_start += map->stripe_len;
2952
2953 extent = btrfs_item_ptr(l, slot,
2954 struct btrfs_extent_item);
2955 flags = btrfs_extent_flags(l, extent);
2956 generation = btrfs_extent_generation(l, extent);
2957
2958 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2959 (key.objectid < logic_start ||
2960 key.objectid + bytes >
2961 logic_start + map->stripe_len)) {
2962 btrfs_err(fs_info,
2963 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2964 key.objectid, logic_start);
2965 spin_lock(&sctx->stat_lock);
2966 sctx->stat.uncorrectable_errors++;
2967 spin_unlock(&sctx->stat_lock);
2968 goto next;
2969 }
2970 again:
2971 extent_logical = key.objectid;
2972 extent_len = bytes;
2973
2974 if (extent_logical < logic_start) {
2975 extent_len -= logic_start - extent_logical;
2976 extent_logical = logic_start;
2977 }
2978
2979 if (extent_logical + extent_len >
2980 logic_start + map->stripe_len)
2981 extent_len = logic_start + map->stripe_len -
2982 extent_logical;
2983
2984 scrub_parity_mark_sectors_data(sparity, extent_logical,
2985 extent_len);
2986
2987 mapped_length = extent_len;
2988 bbio = NULL;
2989 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
2990 extent_logical, &mapped_length, &bbio,
2991 0);
2992 if (!ret) {
2993 if (!bbio || mapped_length < extent_len)
2994 ret = -EIO;
2995 }
2996 if (ret) {
2997 btrfs_put_bbio(bbio);
2998 goto out;
2999 }
3000 extent_physical = bbio->stripes[0].physical;
3001 extent_mirror_num = bbio->mirror_num;
3002 extent_dev = bbio->stripes[0].dev;
3003 btrfs_put_bbio(bbio);
3004
3005 ret = btrfs_lookup_csums_range(csum_root,
3006 extent_logical,
3007 extent_logical + extent_len - 1,
3008 &sctx->csum_list, 1);
3009 if (ret)
3010 goto out;
3011
3012 ret = scrub_extent_for_parity(sparity, extent_logical,
3013 extent_len,
3014 extent_physical,
3015 extent_dev, flags,
3016 generation,
3017 extent_mirror_num);
3018
3019 scrub_free_csums(sctx);
3020
3021 if (ret)
3022 goto out;
3023
3024 if (extent_logical + extent_len <
3025 key.objectid + bytes) {
3026 logic_start += map->stripe_len;
3027
3028 if (logic_start >= logic_end) {
3029 stop_loop = 1;
3030 break;
3031 }
3032
3033 if (logic_start < key.objectid + bytes) {
3034 cond_resched();
3035 goto again;
3036 }
3037 }
3038 next:
3039 path->slots[0]++;
3040 }
3041
3042 btrfs_release_path(path);
3043
3044 if (stop_loop)
3045 break;
3046
3047 logic_start += map->stripe_len;
3048 }
3049 out:
3050 if (ret < 0)
3051 scrub_parity_mark_sectors_error(sparity, logic_start,
3052 logic_end - logic_start);
3053 scrub_parity_put(sparity);
3054 scrub_submit(sctx);
3055 mutex_lock(&sctx->wr_ctx.wr_lock);
3056 scrub_wr_submit(sctx);
3057 mutex_unlock(&sctx->wr_ctx.wr_lock);
3058
3059 btrfs_release_path(path);
3060 return ret < 0 ? ret : 0;
3061 }
3062
3063 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3064 struct map_lookup *map,
3065 struct btrfs_device *scrub_dev,
3066 int num, u64 base, u64 length,
3067 int is_dev_replace)
3068 {
3069 struct btrfs_path *path, *ppath;
3070 struct btrfs_fs_info *fs_info = sctx->fs_info;
3071 struct btrfs_root *root = fs_info->extent_root;
3072 struct btrfs_root *csum_root = fs_info->csum_root;
3073 struct btrfs_extent_item *extent;
3074 struct blk_plug plug;
3075 u64 flags;
3076 int ret;
3077 int slot;
3078 u64 nstripes;
3079 struct extent_buffer *l;
3080 u64 physical;
3081 u64 logical;
3082 u64 logic_end;
3083 u64 physical_end;
3084 u64 generation;
3085 int mirror_num;
3086 struct reada_control *reada1;
3087 struct reada_control *reada2;
3088 struct btrfs_key key;
3089 struct btrfs_key key_end;
3090 u64 increment = map->stripe_len;
3091 u64 offset;
3092 u64 extent_logical;
3093 u64 extent_physical;
3094 u64 extent_len;
3095 u64 stripe_logical;
3096 u64 stripe_end;
3097 struct btrfs_device *extent_dev;
3098 int extent_mirror_num;
3099 int stop_loop = 0;
3100
3101 physical = map->stripes[num].physical;
3102 offset = 0;
3103 nstripes = div_u64(length, map->stripe_len);
3104 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3105 offset = map->stripe_len * num;
3106 increment = map->stripe_len * map->num_stripes;
3107 mirror_num = 1;
3108 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3109 int factor = map->num_stripes / map->sub_stripes;
3110 offset = map->stripe_len * (num / map->sub_stripes);
3111 increment = map->stripe_len * factor;
3112 mirror_num = num % map->sub_stripes + 1;
3113 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3114 increment = map->stripe_len;
3115 mirror_num = num % map->num_stripes + 1;
3116 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3117 increment = map->stripe_len;
3118 mirror_num = num % map->num_stripes + 1;
3119 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3120 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3121 increment = map->stripe_len * nr_data_stripes(map);
3122 mirror_num = 1;
3123 } else {
3124 increment = map->stripe_len;
3125 mirror_num = 1;
3126 }
3127
3128 path = btrfs_alloc_path();
3129 if (!path)
3130 return -ENOMEM;
3131
3132 ppath = btrfs_alloc_path();
3133 if (!ppath) {
3134 btrfs_free_path(path);
3135 return -ENOMEM;
3136 }
3137
3138 /*
3139 * work on commit root. The related disk blocks are static as
3140 * long as COW is applied. This means, it is save to rewrite
3141 * them to repair disk errors without any race conditions
3142 */
3143 path->search_commit_root = 1;
3144 path->skip_locking = 1;
3145
3146 ppath->search_commit_root = 1;
3147 ppath->skip_locking = 1;
3148 /*
3149 * trigger the readahead for extent tree csum tree and wait for
3150 * completion. During readahead, the scrub is officially paused
3151 * to not hold off transaction commits
3152 */
3153 logical = base + offset;
3154 physical_end = physical + nstripes * map->stripe_len;
3155 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3156 get_raid56_logic_offset(physical_end, num,
3157 map, &logic_end, NULL);
3158 logic_end += base;
3159 } else {
3160 logic_end = logical + increment * nstripes;
3161 }
3162 wait_event(sctx->list_wait,
3163 atomic_read(&sctx->bios_in_flight) == 0);
3164 scrub_blocked_if_needed(fs_info);
3165
3166 /* FIXME it might be better to start readahead at commit root */
3167 key.objectid = logical;
3168 key.type = BTRFS_EXTENT_ITEM_KEY;
3169 key.offset = (u64)0;
3170 key_end.objectid = logic_end;
3171 key_end.type = BTRFS_METADATA_ITEM_KEY;
3172 key_end.offset = (u64)-1;
3173 reada1 = btrfs_reada_add(root, &key, &key_end);
3174
3175 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3176 key.type = BTRFS_EXTENT_CSUM_KEY;
3177 key.offset = logical;
3178 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3179 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3180 key_end.offset = logic_end;
3181 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3182
3183 if (!IS_ERR(reada1))
3184 btrfs_reada_wait(reada1);
3185 if (!IS_ERR(reada2))
3186 btrfs_reada_wait(reada2);
3187
3188
3189 /*
3190 * collect all data csums for the stripe to avoid seeking during
3191 * the scrub. This might currently (crc32) end up to be about 1MB
3192 */
3193 blk_start_plug(&plug);
3194
3195 /*
3196 * now find all extents for each stripe and scrub them
3197 */
3198 ret = 0;
3199 while (physical < physical_end) {
3200 /*
3201 * canceled?
3202 */
3203 if (atomic_read(&fs_info->scrub_cancel_req) ||
3204 atomic_read(&sctx->cancel_req)) {
3205 ret = -ECANCELED;
3206 goto out;
3207 }
3208 /*
3209 * check to see if we have to pause
3210 */
3211 if (atomic_read(&fs_info->scrub_pause_req)) {
3212 /* push queued extents */
3213 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3214 scrub_submit(sctx);
3215 mutex_lock(&sctx->wr_ctx.wr_lock);
3216 scrub_wr_submit(sctx);
3217 mutex_unlock(&sctx->wr_ctx.wr_lock);
3218 wait_event(sctx->list_wait,
3219 atomic_read(&sctx->bios_in_flight) == 0);
3220 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3221 scrub_blocked_if_needed(fs_info);
3222 }
3223
3224 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3225 ret = get_raid56_logic_offset(physical, num, map,
3226 &logical,
3227 &stripe_logical);
3228 logical += base;
3229 if (ret) {
3230 /* it is parity strip */
3231 stripe_logical += base;
3232 stripe_end = stripe_logical + increment;
3233 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3234 ppath, stripe_logical,
3235 stripe_end);
3236 if (ret)
3237 goto out;
3238 goto skip;
3239 }
3240 }
3241
3242 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3243 key.type = BTRFS_METADATA_ITEM_KEY;
3244 else
3245 key.type = BTRFS_EXTENT_ITEM_KEY;
3246 key.objectid = logical;
3247 key.offset = (u64)-1;
3248
3249 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3250 if (ret < 0)
3251 goto out;
3252
3253 if (ret > 0) {
3254 ret = btrfs_previous_extent_item(root, path, 0);
3255 if (ret < 0)
3256 goto out;
3257 if (ret > 0) {
3258 /* there's no smaller item, so stick with the
3259 * larger one */
3260 btrfs_release_path(path);
3261 ret = btrfs_search_slot(NULL, root, &key,
3262 path, 0, 0);
3263 if (ret < 0)
3264 goto out;
3265 }
3266 }
3267
3268 stop_loop = 0;
3269 while (1) {
3270 u64 bytes;
3271
3272 l = path->nodes[0];
3273 slot = path->slots[0];
3274 if (slot >= btrfs_header_nritems(l)) {
3275 ret = btrfs_next_leaf(root, path);
3276 if (ret == 0)
3277 continue;
3278 if (ret < 0)
3279 goto out;
3280
3281 stop_loop = 1;
3282 break;
3283 }
3284 btrfs_item_key_to_cpu(l, &key, slot);
3285
3286 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3287 key.type != BTRFS_METADATA_ITEM_KEY)
3288 goto next;
3289
3290 if (key.type == BTRFS_METADATA_ITEM_KEY)
3291 bytes = fs_info->nodesize;
3292 else
3293 bytes = key.offset;
3294
3295 if (key.objectid + bytes <= logical)
3296 goto next;
3297
3298 if (key.objectid >= logical + map->stripe_len) {
3299 /* out of this device extent */
3300 if (key.objectid >= logic_end)
3301 stop_loop = 1;
3302 break;
3303 }
3304
3305 extent = btrfs_item_ptr(l, slot,
3306 struct btrfs_extent_item);
3307 flags = btrfs_extent_flags(l, extent);
3308 generation = btrfs_extent_generation(l, extent);
3309
3310 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3311 (key.objectid < logical ||
3312 key.objectid + bytes >
3313 logical + map->stripe_len)) {
3314 btrfs_err(fs_info,
3315 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3316 key.objectid, logical);
3317 spin_lock(&sctx->stat_lock);
3318 sctx->stat.uncorrectable_errors++;
3319 spin_unlock(&sctx->stat_lock);
3320 goto next;
3321 }
3322
3323 again:
3324 extent_logical = key.objectid;
3325 extent_len = bytes;
3326
3327 /*
3328 * trim extent to this stripe
3329 */
3330 if (extent_logical < logical) {
3331 extent_len -= logical - extent_logical;
3332 extent_logical = logical;
3333 }
3334 if (extent_logical + extent_len >
3335 logical + map->stripe_len) {
3336 extent_len = logical + map->stripe_len -
3337 extent_logical;
3338 }
3339
3340 extent_physical = extent_logical - logical + physical;
3341 extent_dev = scrub_dev;
3342 extent_mirror_num = mirror_num;
3343 if (is_dev_replace)
3344 scrub_remap_extent(fs_info, extent_logical,
3345 extent_len, &extent_physical,
3346 &extent_dev,
3347 &extent_mirror_num);
3348
3349 ret = btrfs_lookup_csums_range(csum_root,
3350 extent_logical,
3351 extent_logical +
3352 extent_len - 1,
3353 &sctx->csum_list, 1);
3354 if (ret)
3355 goto out;
3356
3357 ret = scrub_extent(sctx, extent_logical, extent_len,
3358 extent_physical, extent_dev, flags,
3359 generation, extent_mirror_num,
3360 extent_logical - logical + physical);
3361
3362 scrub_free_csums(sctx);
3363
3364 if (ret)
3365 goto out;
3366
3367 if (extent_logical + extent_len <
3368 key.objectid + bytes) {
3369 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3370 /*
3371 * loop until we find next data stripe
3372 * or we have finished all stripes.
3373 */
3374 loop:
3375 physical += map->stripe_len;
3376 ret = get_raid56_logic_offset(physical,
3377 num, map, &logical,
3378 &stripe_logical);
3379 logical += base;
3380
3381 if (ret && physical < physical_end) {
3382 stripe_logical += base;
3383 stripe_end = stripe_logical +
3384 increment;
3385 ret = scrub_raid56_parity(sctx,
3386 map, scrub_dev, ppath,
3387 stripe_logical,
3388 stripe_end);
3389 if (ret)
3390 goto out;
3391 goto loop;
3392 }
3393 } else {
3394 physical += map->stripe_len;
3395 logical += increment;
3396 }
3397 if (logical < key.objectid + bytes) {
3398 cond_resched();
3399 goto again;
3400 }
3401
3402 if (physical >= physical_end) {
3403 stop_loop = 1;
3404 break;
3405 }
3406 }
3407 next:
3408 path->slots[0]++;
3409 }
3410 btrfs_release_path(path);
3411 skip:
3412 logical += increment;
3413 physical += map->stripe_len;
3414 spin_lock(&sctx->stat_lock);
3415 if (stop_loop)
3416 sctx->stat.last_physical = map->stripes[num].physical +
3417 length;
3418 else
3419 sctx->stat.last_physical = physical;
3420 spin_unlock(&sctx->stat_lock);
3421 if (stop_loop)
3422 break;
3423 }
3424 out:
3425 /* push queued extents */
3426 scrub_submit(sctx);
3427 mutex_lock(&sctx->wr_ctx.wr_lock);
3428 scrub_wr_submit(sctx);
3429 mutex_unlock(&sctx->wr_ctx.wr_lock);
3430
3431 blk_finish_plug(&plug);
3432 btrfs_free_path(path);
3433 btrfs_free_path(ppath);
3434 return ret < 0 ? ret : 0;
3435 }
3436
3437 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3438 struct btrfs_device *scrub_dev,
3439 u64 chunk_offset, u64 length,
3440 u64 dev_offset,
3441 struct btrfs_block_group_cache *cache,
3442 int is_dev_replace)
3443 {
3444 struct btrfs_fs_info *fs_info = sctx->fs_info;
3445 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
3446 struct map_lookup *map;
3447 struct extent_map *em;
3448 int i;
3449 int ret = 0;
3450
3451 read_lock(&map_tree->map_tree.lock);
3452 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3453 read_unlock(&map_tree->map_tree.lock);
3454
3455 if (!em) {
3456 /*
3457 * Might have been an unused block group deleted by the cleaner
3458 * kthread or relocation.
3459 */
3460 spin_lock(&cache->lock);
3461 if (!cache->removed)
3462 ret = -EINVAL;
3463 spin_unlock(&cache->lock);
3464
3465 return ret;
3466 }
3467
3468 map = em->map_lookup;
3469 if (em->start != chunk_offset)
3470 goto out;
3471
3472 if (em->len < length)
3473 goto out;
3474
3475 for (i = 0; i < map->num_stripes; ++i) {
3476 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3477 map->stripes[i].physical == dev_offset) {
3478 ret = scrub_stripe(sctx, map, scrub_dev, i,
3479 chunk_offset, length,
3480 is_dev_replace);
3481 if (ret)
3482 goto out;
3483 }
3484 }
3485 out:
3486 free_extent_map(em);
3487
3488 return ret;
3489 }
3490
3491 static noinline_for_stack
3492 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3493 struct btrfs_device *scrub_dev, u64 start, u64 end,
3494 int is_dev_replace)
3495 {
3496 struct btrfs_dev_extent *dev_extent = NULL;
3497 struct btrfs_path *path;
3498 struct btrfs_fs_info *fs_info = sctx->fs_info;
3499 struct btrfs_root *root = fs_info->dev_root;
3500 u64 length;
3501 u64 chunk_offset;
3502 int ret = 0;
3503 int ro_set;
3504 int slot;
3505 struct extent_buffer *l;
3506 struct btrfs_key key;
3507 struct btrfs_key found_key;
3508 struct btrfs_block_group_cache *cache;
3509 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3510
3511 path = btrfs_alloc_path();
3512 if (!path)
3513 return -ENOMEM;
3514
3515 path->reada = READA_FORWARD;
3516 path->search_commit_root = 1;
3517 path->skip_locking = 1;
3518
3519 key.objectid = scrub_dev->devid;
3520 key.offset = 0ull;
3521 key.type = BTRFS_DEV_EXTENT_KEY;
3522
3523 while (1) {
3524 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3525 if (ret < 0)
3526 break;
3527 if (ret > 0) {
3528 if (path->slots[0] >=
3529 btrfs_header_nritems(path->nodes[0])) {
3530 ret = btrfs_next_leaf(root, path);
3531 if (ret < 0)
3532 break;
3533 if (ret > 0) {
3534 ret = 0;
3535 break;
3536 }
3537 } else {
3538 ret = 0;
3539 }
3540 }
3541
3542 l = path->nodes[0];
3543 slot = path->slots[0];
3544
3545 btrfs_item_key_to_cpu(l, &found_key, slot);
3546
3547 if (found_key.objectid != scrub_dev->devid)
3548 break;
3549
3550 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3551 break;
3552
3553 if (found_key.offset >= end)
3554 break;
3555
3556 if (found_key.offset < key.offset)
3557 break;
3558
3559 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3560 length = btrfs_dev_extent_length(l, dev_extent);
3561
3562 if (found_key.offset + length <= start)
3563 goto skip;
3564
3565 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3566
3567 /*
3568 * get a reference on the corresponding block group to prevent
3569 * the chunk from going away while we scrub it
3570 */
3571 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3572
3573 /* some chunks are removed but not committed to disk yet,
3574 * continue scrubbing */
3575 if (!cache)
3576 goto skip;
3577
3578 /*
3579 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3580 * to avoid deadlock caused by:
3581 * btrfs_inc_block_group_ro()
3582 * -> btrfs_wait_for_commit()
3583 * -> btrfs_commit_transaction()
3584 * -> btrfs_scrub_pause()
3585 */
3586 scrub_pause_on(fs_info);
3587 ret = btrfs_inc_block_group_ro(root, cache);
3588 if (!ret && is_dev_replace) {
3589 /*
3590 * If we are doing a device replace wait for any tasks
3591 * that started dellaloc right before we set the block
3592 * group to RO mode, as they might have just allocated
3593 * an extent from it or decided they could do a nocow
3594 * write. And if any such tasks did that, wait for their
3595 * ordered extents to complete and then commit the
3596 * current transaction, so that we can later see the new
3597 * extent items in the extent tree - the ordered extents
3598 * create delayed data references (for cow writes) when
3599 * they complete, which will be run and insert the
3600 * corresponding extent items into the extent tree when
3601 * we commit the transaction they used when running
3602 * inode.c:btrfs_finish_ordered_io(). We later use
3603 * the commit root of the extent tree to find extents
3604 * to copy from the srcdev into the tgtdev, and we don't
3605 * want to miss any new extents.
3606 */
3607 btrfs_wait_block_group_reservations(cache);
3608 btrfs_wait_nocow_writers(cache);
3609 ret = btrfs_wait_ordered_roots(fs_info, -1,
3610 cache->key.objectid,
3611 cache->key.offset);
3612 if (ret > 0) {
3613 struct btrfs_trans_handle *trans;
3614
3615 trans = btrfs_join_transaction(root);
3616 if (IS_ERR(trans))
3617 ret = PTR_ERR(trans);
3618 else
3619 ret = btrfs_commit_transaction(trans);
3620 if (ret) {
3621 scrub_pause_off(fs_info);
3622 btrfs_put_block_group(cache);
3623 break;
3624 }
3625 }
3626 }
3627 scrub_pause_off(fs_info);
3628
3629 if (ret == 0) {
3630 ro_set = 1;
3631 } else if (ret == -ENOSPC) {
3632 /*
3633 * btrfs_inc_block_group_ro return -ENOSPC when it
3634 * failed in creating new chunk for metadata.
3635 * It is not a problem for scrub/replace, because
3636 * metadata are always cowed, and our scrub paused
3637 * commit_transactions.
3638 */
3639 ro_set = 0;
3640 } else {
3641 btrfs_warn(fs_info,
3642 "failed setting block group ro, ret=%d\n",
3643 ret);
3644 btrfs_put_block_group(cache);
3645 break;
3646 }
3647
3648 btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
3649 dev_replace->cursor_right = found_key.offset + length;
3650 dev_replace->cursor_left = found_key.offset;
3651 dev_replace->item_needs_writeback = 1;
3652 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
3653 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3654 found_key.offset, cache, is_dev_replace);
3655
3656 /*
3657 * flush, submit all pending read and write bios, afterwards
3658 * wait for them.
3659 * Note that in the dev replace case, a read request causes
3660 * write requests that are submitted in the read completion
3661 * worker. Therefore in the current situation, it is required
3662 * that all write requests are flushed, so that all read and
3663 * write requests are really completed when bios_in_flight
3664 * changes to 0.
3665 */
3666 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3667 scrub_submit(sctx);
3668 mutex_lock(&sctx->wr_ctx.wr_lock);
3669 scrub_wr_submit(sctx);
3670 mutex_unlock(&sctx->wr_ctx.wr_lock);
3671
3672 wait_event(sctx->list_wait,
3673 atomic_read(&sctx->bios_in_flight) == 0);
3674
3675 scrub_pause_on(fs_info);
3676
3677 /*
3678 * must be called before we decrease @scrub_paused.
3679 * make sure we don't block transaction commit while
3680 * we are waiting pending workers finished.
3681 */
3682 wait_event(sctx->list_wait,
3683 atomic_read(&sctx->workers_pending) == 0);
3684 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3685
3686 scrub_pause_off(fs_info);
3687
3688 btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
3689 dev_replace->cursor_left = dev_replace->cursor_right;
3690 dev_replace->item_needs_writeback = 1;
3691 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
3692
3693 if (ro_set)
3694 btrfs_dec_block_group_ro(cache);
3695
3696 /*
3697 * We might have prevented the cleaner kthread from deleting
3698 * this block group if it was already unused because we raced
3699 * and set it to RO mode first. So add it back to the unused
3700 * list, otherwise it might not ever be deleted unless a manual
3701 * balance is triggered or it becomes used and unused again.
3702 */
3703 spin_lock(&cache->lock);
3704 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3705 btrfs_block_group_used(&cache->item) == 0) {
3706 spin_unlock(&cache->lock);
3707 spin_lock(&fs_info->unused_bgs_lock);
3708 if (list_empty(&cache->bg_list)) {
3709 btrfs_get_block_group(cache);
3710 list_add_tail(&cache->bg_list,
3711 &fs_info->unused_bgs);
3712 }
3713 spin_unlock(&fs_info->unused_bgs_lock);
3714 } else {
3715 spin_unlock(&cache->lock);
3716 }
3717
3718 btrfs_put_block_group(cache);
3719 if (ret)
3720 break;
3721 if (is_dev_replace &&
3722 atomic64_read(&dev_replace->num_write_errors) > 0) {
3723 ret = -EIO;
3724 break;
3725 }
3726 if (sctx->stat.malloc_errors > 0) {
3727 ret = -ENOMEM;
3728 break;
3729 }
3730 skip:
3731 key.offset = found_key.offset + length;
3732 btrfs_release_path(path);
3733 }
3734
3735 btrfs_free_path(path);
3736
3737 return ret;
3738 }
3739
3740 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3741 struct btrfs_device *scrub_dev)
3742 {
3743 int i;
3744 u64 bytenr;
3745 u64 gen;
3746 int ret;
3747 struct btrfs_fs_info *fs_info = sctx->fs_info;
3748
3749 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3750 return -EIO;
3751
3752 /* Seed devices of a new filesystem has their own generation. */
3753 if (scrub_dev->fs_devices != fs_info->fs_devices)
3754 gen = scrub_dev->generation;
3755 else
3756 gen = fs_info->last_trans_committed;
3757
3758 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3759 bytenr = btrfs_sb_offset(i);
3760 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3761 scrub_dev->commit_total_bytes)
3762 break;
3763
3764 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3765 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3766 NULL, 1, bytenr);
3767 if (ret)
3768 return ret;
3769 }
3770 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3771
3772 return 0;
3773 }
3774
3775 /*
3776 * get a reference count on fs_info->scrub_workers. start worker if necessary
3777 */
3778 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3779 int is_dev_replace)
3780 {
3781 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3782 int max_active = fs_info->thread_pool_size;
3783
3784 if (fs_info->scrub_workers_refcnt == 0) {
3785 if (is_dev_replace)
3786 fs_info->scrub_workers =
3787 btrfs_alloc_workqueue(fs_info, "scrub", flags,
3788 1, 4);
3789 else
3790 fs_info->scrub_workers =
3791 btrfs_alloc_workqueue(fs_info, "scrub", flags,
3792 max_active, 4);
3793 if (!fs_info->scrub_workers)
3794 goto fail_scrub_workers;
3795
3796 fs_info->scrub_wr_completion_workers =
3797 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3798 max_active, 2);
3799 if (!fs_info->scrub_wr_completion_workers)
3800 goto fail_scrub_wr_completion_workers;
3801
3802 fs_info->scrub_nocow_workers =
3803 btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0);
3804 if (!fs_info->scrub_nocow_workers)
3805 goto fail_scrub_nocow_workers;
3806 fs_info->scrub_parity_workers =
3807 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3808 max_active, 2);
3809 if (!fs_info->scrub_parity_workers)
3810 goto fail_scrub_parity_workers;
3811 }
3812 ++fs_info->scrub_workers_refcnt;
3813 return 0;
3814
3815 fail_scrub_parity_workers:
3816 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3817 fail_scrub_nocow_workers:
3818 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3819 fail_scrub_wr_completion_workers:
3820 btrfs_destroy_workqueue(fs_info->scrub_workers);
3821 fail_scrub_workers:
3822 return -ENOMEM;
3823 }
3824
3825 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
3826 {
3827 if (--fs_info->scrub_workers_refcnt == 0) {
3828 btrfs_destroy_workqueue(fs_info->scrub_workers);
3829 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3830 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3831 btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
3832 }
3833 WARN_ON(fs_info->scrub_workers_refcnt < 0);
3834 }
3835
3836 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3837 u64 end, struct btrfs_scrub_progress *progress,
3838 int readonly, int is_dev_replace)
3839 {
3840 struct scrub_ctx *sctx;
3841 int ret;
3842 struct btrfs_device *dev;
3843 struct rcu_string *name;
3844
3845 if (btrfs_fs_closing(fs_info))
3846 return -EINVAL;
3847
3848 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
3849 /*
3850 * in this case scrub is unable to calculate the checksum
3851 * the way scrub is implemented. Do not handle this
3852 * situation at all because it won't ever happen.
3853 */
3854 btrfs_err(fs_info,
3855 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3856 fs_info->nodesize,
3857 BTRFS_STRIPE_LEN);
3858 return -EINVAL;
3859 }
3860
3861 if (fs_info->sectorsize != PAGE_SIZE) {
3862 /* not supported for data w/o checksums */
3863 btrfs_err_rl(fs_info,
3864 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3865 fs_info->sectorsize, PAGE_SIZE);
3866 return -EINVAL;
3867 }
3868
3869 if (fs_info->nodesize >
3870 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3871 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3872 /*
3873 * would exhaust the array bounds of pagev member in
3874 * struct scrub_block
3875 */
3876 btrfs_err(fs_info,
3877 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3878 fs_info->nodesize,
3879 SCRUB_MAX_PAGES_PER_BLOCK,
3880 fs_info->sectorsize,
3881 SCRUB_MAX_PAGES_PER_BLOCK);
3882 return -EINVAL;
3883 }
3884
3885
3886 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3887 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
3888 if (!dev || (dev->missing && !is_dev_replace)) {
3889 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3890 return -ENODEV;
3891 }
3892
3893 if (!is_dev_replace && !readonly && !dev->writeable) {
3894 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3895 rcu_read_lock();
3896 name = rcu_dereference(dev->name);
3897 btrfs_err(fs_info, "scrub: device %s is not writable",
3898 name->str);
3899 rcu_read_unlock();
3900 return -EROFS;
3901 }
3902
3903 mutex_lock(&fs_info->scrub_lock);
3904 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
3905 mutex_unlock(&fs_info->scrub_lock);
3906 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3907 return -EIO;
3908 }
3909
3910 btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
3911 if (dev->scrub_device ||
3912 (!is_dev_replace &&
3913 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3914 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3915 mutex_unlock(&fs_info->scrub_lock);
3916 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3917 return -EINPROGRESS;
3918 }
3919 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3920
3921 ret = scrub_workers_get(fs_info, is_dev_replace);
3922 if (ret) {
3923 mutex_unlock(&fs_info->scrub_lock);
3924 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3925 return ret;
3926 }
3927
3928 sctx = scrub_setup_ctx(dev, is_dev_replace);
3929 if (IS_ERR(sctx)) {
3930 mutex_unlock(&fs_info->scrub_lock);
3931 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3932 scrub_workers_put(fs_info);
3933 return PTR_ERR(sctx);
3934 }
3935 sctx->readonly = readonly;
3936 dev->scrub_device = sctx;
3937 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3938
3939 /*
3940 * checking @scrub_pause_req here, we can avoid
3941 * race between committing transaction and scrubbing.
3942 */
3943 __scrub_blocked_if_needed(fs_info);
3944 atomic_inc(&fs_info->scrubs_running);
3945 mutex_unlock(&fs_info->scrub_lock);
3946
3947 if (!is_dev_replace) {
3948 /*
3949 * by holding device list mutex, we can
3950 * kick off writing super in log tree sync.
3951 */
3952 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3953 ret = scrub_supers(sctx, dev);
3954 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3955 }
3956
3957 if (!ret)
3958 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3959 is_dev_replace);
3960
3961 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3962 atomic_dec(&fs_info->scrubs_running);
3963 wake_up(&fs_info->scrub_pause_wait);
3964
3965 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3966
3967 if (progress)
3968 memcpy(progress, &sctx->stat, sizeof(*progress));
3969
3970 mutex_lock(&fs_info->scrub_lock);
3971 dev->scrub_device = NULL;
3972 scrub_workers_put(fs_info);
3973 mutex_unlock(&fs_info->scrub_lock);
3974
3975 scrub_put_ctx(sctx);
3976
3977 return ret;
3978 }
3979
3980 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
3981 {
3982 mutex_lock(&fs_info->scrub_lock);
3983 atomic_inc(&fs_info->scrub_pause_req);
3984 while (atomic_read(&fs_info->scrubs_paused) !=
3985 atomic_read(&fs_info->scrubs_running)) {
3986 mutex_unlock(&fs_info->scrub_lock);
3987 wait_event(fs_info->scrub_pause_wait,
3988 atomic_read(&fs_info->scrubs_paused) ==
3989 atomic_read(&fs_info->scrubs_running));
3990 mutex_lock(&fs_info->scrub_lock);
3991 }
3992 mutex_unlock(&fs_info->scrub_lock);
3993 }
3994
3995 void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
3996 {
3997 atomic_dec(&fs_info->scrub_pause_req);
3998 wake_up(&fs_info->scrub_pause_wait);
3999 }
4000
4001 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
4002 {
4003 mutex_lock(&fs_info->scrub_lock);
4004 if (!atomic_read(&fs_info->scrubs_running)) {
4005 mutex_unlock(&fs_info->scrub_lock);
4006 return -ENOTCONN;
4007 }
4008
4009 atomic_inc(&fs_info->scrub_cancel_req);
4010 while (atomic_read(&fs_info->scrubs_running)) {
4011 mutex_unlock(&fs_info->scrub_lock);
4012 wait_event(fs_info->scrub_pause_wait,
4013 atomic_read(&fs_info->scrubs_running) == 0);
4014 mutex_lock(&fs_info->scrub_lock);
4015 }
4016 atomic_dec(&fs_info->scrub_cancel_req);
4017 mutex_unlock(&fs_info->scrub_lock);
4018
4019 return 0;
4020 }
4021
4022 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
4023 struct btrfs_device *dev)
4024 {
4025 struct scrub_ctx *sctx;
4026
4027 mutex_lock(&fs_info->scrub_lock);
4028 sctx = dev->scrub_device;
4029 if (!sctx) {
4030 mutex_unlock(&fs_info->scrub_lock);
4031 return -ENOTCONN;
4032 }
4033 atomic_inc(&sctx->cancel_req);
4034 while (dev->scrub_device) {
4035 mutex_unlock(&fs_info->scrub_lock);
4036 wait_event(fs_info->scrub_pause_wait,
4037 dev->scrub_device == NULL);
4038 mutex_lock(&fs_info->scrub_lock);
4039 }
4040 mutex_unlock(&fs_info->scrub_lock);
4041
4042 return 0;
4043 }
4044
4045 int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4046 struct btrfs_scrub_progress *progress)
4047 {
4048 struct btrfs_device *dev;
4049 struct scrub_ctx *sctx = NULL;
4050
4051 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4052 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
4053 if (dev)
4054 sctx = dev->scrub_device;
4055 if (sctx)
4056 memcpy(progress, &sctx->stat, sizeof(*progress));
4057 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4058
4059 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4060 }
4061
4062 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4063 u64 extent_logical, u64 extent_len,
4064 u64 *extent_physical,
4065 struct btrfs_device **extent_dev,
4066 int *extent_mirror_num)
4067 {
4068 u64 mapped_length;
4069 struct btrfs_bio *bbio = NULL;
4070 int ret;
4071
4072 mapped_length = extent_len;
4073 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4074 &mapped_length, &bbio, 0);
4075 if (ret || !bbio || mapped_length < extent_len ||
4076 !bbio->stripes[0].dev->bdev) {
4077 btrfs_put_bbio(bbio);
4078 return;
4079 }
4080
4081 *extent_physical = bbio->stripes[0].physical;
4082 *extent_mirror_num = bbio->mirror_num;
4083 *extent_dev = bbio->stripes[0].dev;
4084 btrfs_put_bbio(bbio);
4085 }
4086
4087 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
4088 struct scrub_wr_ctx *wr_ctx,
4089 struct btrfs_fs_info *fs_info,
4090 struct btrfs_device *dev,
4091 int is_dev_replace)
4092 {
4093 WARN_ON(wr_ctx->wr_curr_bio != NULL);
4094
4095 mutex_init(&wr_ctx->wr_lock);
4096 wr_ctx->wr_curr_bio = NULL;
4097 if (!is_dev_replace)
4098 return 0;
4099
4100 WARN_ON(!dev->bdev);
4101 wr_ctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
4102 wr_ctx->tgtdev = dev;
4103 atomic_set(&wr_ctx->flush_all_writes, 0);
4104 return 0;
4105 }
4106
4107 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
4108 {
4109 mutex_lock(&wr_ctx->wr_lock);
4110 kfree(wr_ctx->wr_curr_bio);
4111 wr_ctx->wr_curr_bio = NULL;
4112 mutex_unlock(&wr_ctx->wr_lock);
4113 }
4114
4115 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
4116 int mirror_num, u64 physical_for_dev_replace)
4117 {
4118 struct scrub_copy_nocow_ctx *nocow_ctx;
4119 struct btrfs_fs_info *fs_info = sctx->fs_info;
4120
4121 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
4122 if (!nocow_ctx) {
4123 spin_lock(&sctx->stat_lock);
4124 sctx->stat.malloc_errors++;
4125 spin_unlock(&sctx->stat_lock);
4126 return -ENOMEM;
4127 }
4128
4129 scrub_pending_trans_workers_inc(sctx);
4130
4131 nocow_ctx->sctx = sctx;
4132 nocow_ctx->logical = logical;
4133 nocow_ctx->len = len;
4134 nocow_ctx->mirror_num = mirror_num;
4135 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
4136 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
4137 copy_nocow_pages_worker, NULL, NULL);
4138 INIT_LIST_HEAD(&nocow_ctx->inodes);
4139 btrfs_queue_work(fs_info->scrub_nocow_workers,
4140 &nocow_ctx->work);
4141
4142 return 0;
4143 }
4144
4145 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
4146 {
4147 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
4148 struct scrub_nocow_inode *nocow_inode;
4149
4150 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
4151 if (!nocow_inode)
4152 return -ENOMEM;
4153 nocow_inode->inum = inum;
4154 nocow_inode->offset = offset;
4155 nocow_inode->root = root;
4156 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
4157 return 0;
4158 }
4159
4160 #define COPY_COMPLETE 1
4161
4162 static void copy_nocow_pages_worker(struct btrfs_work *work)
4163 {
4164 struct scrub_copy_nocow_ctx *nocow_ctx =
4165 container_of(work, struct scrub_copy_nocow_ctx, work);
4166 struct scrub_ctx *sctx = nocow_ctx->sctx;
4167 struct btrfs_fs_info *fs_info = sctx->fs_info;
4168 struct btrfs_root *root = fs_info->extent_root;
4169 u64 logical = nocow_ctx->logical;
4170 u64 len = nocow_ctx->len;
4171 int mirror_num = nocow_ctx->mirror_num;
4172 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4173 int ret;
4174 struct btrfs_trans_handle *trans = NULL;
4175 struct btrfs_path *path;
4176 int not_written = 0;
4177
4178 path = btrfs_alloc_path();
4179 if (!path) {
4180 spin_lock(&sctx->stat_lock);
4181 sctx->stat.malloc_errors++;
4182 spin_unlock(&sctx->stat_lock);
4183 not_written = 1;
4184 goto out;
4185 }
4186
4187 trans = btrfs_join_transaction(root);
4188 if (IS_ERR(trans)) {
4189 not_written = 1;
4190 goto out;
4191 }
4192
4193 ret = iterate_inodes_from_logical(logical, fs_info, path,
4194 record_inode_for_nocow, nocow_ctx);
4195 if (ret != 0 && ret != -ENOENT) {
4196 btrfs_warn(fs_info,
4197 "iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %u, ret %d",
4198 logical, physical_for_dev_replace, len, mirror_num,
4199 ret);
4200 not_written = 1;
4201 goto out;
4202 }
4203
4204 btrfs_end_transaction(trans);
4205 trans = NULL;
4206 while (!list_empty(&nocow_ctx->inodes)) {
4207 struct scrub_nocow_inode *entry;
4208 entry = list_first_entry(&nocow_ctx->inodes,
4209 struct scrub_nocow_inode,
4210 list);
4211 list_del_init(&entry->list);
4212 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
4213 entry->root, nocow_ctx);
4214 kfree(entry);
4215 if (ret == COPY_COMPLETE) {
4216 ret = 0;
4217 break;
4218 } else if (ret) {
4219 break;
4220 }
4221 }
4222 out:
4223 while (!list_empty(&nocow_ctx->inodes)) {
4224 struct scrub_nocow_inode *entry;
4225 entry = list_first_entry(&nocow_ctx->inodes,
4226 struct scrub_nocow_inode,
4227 list);
4228 list_del_init(&entry->list);
4229 kfree(entry);
4230 }
4231 if (trans && !IS_ERR(trans))
4232 btrfs_end_transaction(trans);
4233 if (not_written)
4234 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
4235 num_uncorrectable_read_errors);
4236
4237 btrfs_free_path(path);
4238 kfree(nocow_ctx);
4239
4240 scrub_pending_trans_workers_dec(sctx);
4241 }
4242
4243 static int check_extent_to_block(struct inode *inode, u64 start, u64 len,
4244 u64 logical)
4245 {
4246 struct extent_state *cached_state = NULL;
4247 struct btrfs_ordered_extent *ordered;
4248 struct extent_io_tree *io_tree;
4249 struct extent_map *em;
4250 u64 lockstart = start, lockend = start + len - 1;
4251 int ret = 0;
4252
4253 io_tree = &BTRFS_I(inode)->io_tree;
4254
4255 lock_extent_bits(io_tree, lockstart, lockend, &cached_state);
4256 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
4257 if (ordered) {
4258 btrfs_put_ordered_extent(ordered);
4259 ret = 1;
4260 goto out_unlock;
4261 }
4262
4263 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
4264 if (IS_ERR(em)) {
4265 ret = PTR_ERR(em);
4266 goto out_unlock;
4267 }
4268
4269 /*
4270 * This extent does not actually cover the logical extent anymore,
4271 * move on to the next inode.
4272 */
4273 if (em->block_start > logical ||
4274 em->block_start + em->block_len < logical + len) {
4275 free_extent_map(em);
4276 ret = 1;
4277 goto out_unlock;
4278 }
4279 free_extent_map(em);
4280
4281 out_unlock:
4282 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
4283 GFP_NOFS);
4284 return ret;
4285 }
4286
4287 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
4288 struct scrub_copy_nocow_ctx *nocow_ctx)
4289 {
4290 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->fs_info;
4291 struct btrfs_key key;
4292 struct inode *inode;
4293 struct page *page;
4294 struct btrfs_root *local_root;
4295 struct extent_io_tree *io_tree;
4296 u64 physical_for_dev_replace;
4297 u64 nocow_ctx_logical;
4298 u64 len = nocow_ctx->len;
4299 unsigned long index;
4300 int srcu_index;
4301 int ret = 0;
4302 int err = 0;
4303
4304 key.objectid = root;
4305 key.type = BTRFS_ROOT_ITEM_KEY;
4306 key.offset = (u64)-1;
4307
4308 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
4309
4310 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
4311 if (IS_ERR(local_root)) {
4312 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4313 return PTR_ERR(local_root);
4314 }
4315
4316 key.type = BTRFS_INODE_ITEM_KEY;
4317 key.objectid = inum;
4318 key.offset = 0;
4319 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
4320 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4321 if (IS_ERR(inode))
4322 return PTR_ERR(inode);
4323
4324 /* Avoid truncate/dio/punch hole.. */
4325 inode_lock(inode);
4326 inode_dio_wait(inode);
4327
4328 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4329 io_tree = &BTRFS_I(inode)->io_tree;
4330 nocow_ctx_logical = nocow_ctx->logical;
4331
4332 ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical);
4333 if (ret) {
4334 ret = ret > 0 ? 0 : ret;
4335 goto out;
4336 }
4337
4338 while (len >= PAGE_SIZE) {
4339 index = offset >> PAGE_SHIFT;
4340 again:
4341 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4342 if (!page) {
4343 btrfs_err(fs_info, "find_or_create_page() failed");
4344 ret = -ENOMEM;
4345 goto out;
4346 }
4347
4348 if (PageUptodate(page)) {
4349 if (PageDirty(page))
4350 goto next_page;
4351 } else {
4352 ClearPageError(page);
4353 err = extent_read_full_page(io_tree, page,
4354 btrfs_get_extent,
4355 nocow_ctx->mirror_num);
4356 if (err) {
4357 ret = err;
4358 goto next_page;
4359 }
4360
4361 lock_page(page);
4362 /*
4363 * If the page has been remove from the page cache,
4364 * the data on it is meaningless, because it may be
4365 * old one, the new data may be written into the new
4366 * page in the page cache.
4367 */
4368 if (page->mapping != inode->i_mapping) {
4369 unlock_page(page);
4370 put_page(page);
4371 goto again;
4372 }
4373 if (!PageUptodate(page)) {
4374 ret = -EIO;
4375 goto next_page;
4376 }
4377 }
4378
4379 ret = check_extent_to_block(inode, offset, len,
4380 nocow_ctx_logical);
4381 if (ret) {
4382 ret = ret > 0 ? 0 : ret;
4383 goto next_page;
4384 }
4385
4386 err = write_page_nocow(nocow_ctx->sctx,
4387 physical_for_dev_replace, page);
4388 if (err)
4389 ret = err;
4390 next_page:
4391 unlock_page(page);
4392 put_page(page);
4393
4394 if (ret)
4395 break;
4396
4397 offset += PAGE_SIZE;
4398 physical_for_dev_replace += PAGE_SIZE;
4399 nocow_ctx_logical += PAGE_SIZE;
4400 len -= PAGE_SIZE;
4401 }
4402 ret = COPY_COMPLETE;
4403 out:
4404 inode_unlock(inode);
4405 iput(inode);
4406 return ret;
4407 }
4408
4409 static int write_page_nocow(struct scrub_ctx *sctx,
4410 u64 physical_for_dev_replace, struct page *page)
4411 {
4412 struct bio *bio;
4413 struct btrfs_device *dev;
4414 int ret;
4415
4416 dev = sctx->wr_ctx.tgtdev;
4417 if (!dev)
4418 return -EIO;
4419 if (!dev->bdev) {
4420 btrfs_warn_rl(dev->fs_info,
4421 "scrub write_page_nocow(bdev == NULL) is unexpected");
4422 return -EIO;
4423 }
4424 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
4425 if (!bio) {
4426 spin_lock(&sctx->stat_lock);
4427 sctx->stat.malloc_errors++;
4428 spin_unlock(&sctx->stat_lock);
4429 return -ENOMEM;
4430 }
4431 bio->bi_iter.bi_size = 0;
4432 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
4433 bio->bi_bdev = dev->bdev;
4434 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
4435 ret = bio_add_page(bio, page, PAGE_SIZE, 0);
4436 if (ret != PAGE_SIZE) {
4437 leave_with_eio:
4438 bio_put(bio);
4439 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
4440 return -EIO;
4441 }
4442
4443 if (btrfsic_submit_bio_wait(bio))
4444 goto leave_with_eio;
4445
4446 bio_put(bio);
4447 return 0;
4448 }
Linux with added FPC-III support