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btrfs: Reset sblock->xxx_error stats before calling scrub_recheck_block_checksum
[deliverable/linux.git] / fs / btrfs / scrub.c
1 /*
2 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/blkdev.h>
20 #include <linux/ratelimit.h>
21 #include "ctree.h"
22 #include "volumes.h"
23 #include "disk-io.h"
24 #include "ordered-data.h"
25 #include "transaction.h"
26 #include "backref.h"
27 #include "extent_io.h"
28 #include "dev-replace.h"
29 #include "check-integrity.h"
30 #include "rcu-string.h"
31 #include "raid56.h"
32
33 /*
34 * This is only the first step towards a full-features scrub. It reads all
35 * extent and super block and verifies the checksums. In case a bad checksum
36 * is found or the extent cannot be read, good data will be written back if
37 * any can be found.
38 *
39 * Future enhancements:
40 * - In case an unrepairable extent is encountered, track which files are
41 * affected and report them
42 * - track and record media errors, throw out bad devices
43 * - add a mode to also read unallocated space
44 */
45
46 struct scrub_block;
47 struct scrub_ctx;
48
49 /*
50 * the following three values only influence the performance.
51 * The last one configures the number of parallel and outstanding I/O
52 * operations. The first two values configure an upper limit for the number
53 * of (dynamically allocated) pages that are added to a bio.
54 */
55 #define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
56 #define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
57 #define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
58
59 /*
60 * the following value times PAGE_SIZE needs to be large enough to match the
61 * largest node/leaf/sector size that shall be supported.
62 * Values larger than BTRFS_STRIPE_LEN are not supported.
63 */
64 #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
65
66 struct scrub_recover {
67 atomic_t refs;
68 struct btrfs_bio *bbio;
69 u64 map_length;
70 };
71
72 struct scrub_page {
73 struct scrub_block *sblock;
74 struct page *page;
75 struct btrfs_device *dev;
76 struct list_head list;
77 u64 flags; /* extent flags */
78 u64 generation;
79 u64 logical;
80 u64 physical;
81 u64 physical_for_dev_replace;
82 atomic_t refs;
83 struct {
84 unsigned int mirror_num:8;
85 unsigned int have_csum:1;
86 unsigned int io_error:1;
87 };
88 u8 csum[BTRFS_CSUM_SIZE];
89
90 struct scrub_recover *recover;
91 };
92
93 struct scrub_bio {
94 int index;
95 struct scrub_ctx *sctx;
96 struct btrfs_device *dev;
97 struct bio *bio;
98 int err;
99 u64 logical;
100 u64 physical;
101 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
102 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
103 #else
104 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
105 #endif
106 int page_count;
107 int next_free;
108 struct btrfs_work work;
109 };
110
111 struct scrub_block {
112 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
113 int page_count;
114 atomic_t outstanding_pages;
115 atomic_t refs; /* free mem on transition to zero */
116 struct scrub_ctx *sctx;
117 struct scrub_parity *sparity;
118 struct {
119 unsigned int header_error:1;
120 unsigned int checksum_error:1;
121 unsigned int no_io_error_seen:1;
122 unsigned int generation_error:1; /* also sets header_error */
123
124 /* The following is for the data used to check parity */
125 /* It is for the data with checksum */
126 unsigned int data_corrected:1;
127 };
128 struct btrfs_work work;
129 };
130
131 /* Used for the chunks with parity stripe such RAID5/6 */
132 struct scrub_parity {
133 struct scrub_ctx *sctx;
134
135 struct btrfs_device *scrub_dev;
136
137 u64 logic_start;
138
139 u64 logic_end;
140
141 int nsectors;
142
143 int stripe_len;
144
145 atomic_t refs;
146
147 struct list_head spages;
148
149 /* Work of parity check and repair */
150 struct btrfs_work work;
151
152 /* Mark the parity blocks which have data */
153 unsigned long *dbitmap;
154
155 /*
156 * Mark the parity blocks which have data, but errors happen when
157 * read data or check data
158 */
159 unsigned long *ebitmap;
160
161 unsigned long bitmap[0];
162 };
163
164 struct scrub_wr_ctx {
165 struct scrub_bio *wr_curr_bio;
166 struct btrfs_device *tgtdev;
167 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
168 atomic_t flush_all_writes;
169 struct mutex wr_lock;
170 };
171
172 struct scrub_ctx {
173 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
174 struct btrfs_root *dev_root;
175 int first_free;
176 int curr;
177 atomic_t bios_in_flight;
178 atomic_t workers_pending;
179 spinlock_t list_lock;
180 wait_queue_head_t list_wait;
181 u16 csum_size;
182 struct list_head csum_list;
183 atomic_t cancel_req;
184 int readonly;
185 int pages_per_rd_bio;
186 u32 sectorsize;
187 u32 nodesize;
188
189 int is_dev_replace;
190 struct scrub_wr_ctx wr_ctx;
191
192 /*
193 * statistics
194 */
195 struct btrfs_scrub_progress stat;
196 spinlock_t stat_lock;
197
198 /*
199 * Use a ref counter to avoid use-after-free issues. Scrub workers
200 * decrement bios_in_flight and workers_pending and then do a wakeup
201 * on the list_wait wait queue. We must ensure the main scrub task
202 * doesn't free the scrub context before or while the workers are
203 * doing the wakeup() call.
204 */
205 atomic_t refs;
206 };
207
208 struct scrub_fixup_nodatasum {
209 struct scrub_ctx *sctx;
210 struct btrfs_device *dev;
211 u64 logical;
212 struct btrfs_root *root;
213 struct btrfs_work work;
214 int mirror_num;
215 };
216
217 struct scrub_nocow_inode {
218 u64 inum;
219 u64 offset;
220 u64 root;
221 struct list_head list;
222 };
223
224 struct scrub_copy_nocow_ctx {
225 struct scrub_ctx *sctx;
226 u64 logical;
227 u64 len;
228 int mirror_num;
229 u64 physical_for_dev_replace;
230 struct list_head inodes;
231 struct btrfs_work work;
232 };
233
234 struct scrub_warning {
235 struct btrfs_path *path;
236 u64 extent_item_size;
237 const char *errstr;
238 sector_t sector;
239 u64 logical;
240 struct btrfs_device *dev;
241 };
242
243 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
244 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
245 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
246 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
247 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
248 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
249 struct scrub_block *sblocks_for_recheck);
250 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
251 struct scrub_block *sblock, int is_metadata,
252 int have_csum, u8 *csum, u64 generation,
253 u16 csum_size, int retry_failed_mirror);
254 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
255 struct scrub_block *sblock,
256 int is_metadata, int have_csum,
257 const u8 *csum, u64 generation,
258 u16 csum_size);
259 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
260 struct scrub_block *sblock_good);
261 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
262 struct scrub_block *sblock_good,
263 int page_num, int force_write);
264 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
265 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
266 int page_num);
267 static int scrub_checksum_data(struct scrub_block *sblock);
268 static int scrub_checksum_tree_block(struct scrub_block *sblock);
269 static int scrub_checksum_super(struct scrub_block *sblock);
270 static void scrub_block_get(struct scrub_block *sblock);
271 static void scrub_block_put(struct scrub_block *sblock);
272 static void scrub_page_get(struct scrub_page *spage);
273 static void scrub_page_put(struct scrub_page *spage);
274 static void scrub_parity_get(struct scrub_parity *sparity);
275 static void scrub_parity_put(struct scrub_parity *sparity);
276 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
277 struct scrub_page *spage);
278 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
279 u64 physical, struct btrfs_device *dev, u64 flags,
280 u64 gen, int mirror_num, u8 *csum, int force,
281 u64 physical_for_dev_replace);
282 static void scrub_bio_end_io(struct bio *bio);
283 static void scrub_bio_end_io_worker(struct btrfs_work *work);
284 static void scrub_block_complete(struct scrub_block *sblock);
285 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
286 u64 extent_logical, u64 extent_len,
287 u64 *extent_physical,
288 struct btrfs_device **extent_dev,
289 int *extent_mirror_num);
290 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
291 struct scrub_wr_ctx *wr_ctx,
292 struct btrfs_fs_info *fs_info,
293 struct btrfs_device *dev,
294 int is_dev_replace);
295 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
296 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
297 struct scrub_page *spage);
298 static void scrub_wr_submit(struct scrub_ctx *sctx);
299 static void scrub_wr_bio_end_io(struct bio *bio);
300 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
301 static int write_page_nocow(struct scrub_ctx *sctx,
302 u64 physical_for_dev_replace, struct page *page);
303 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
304 struct scrub_copy_nocow_ctx *ctx);
305 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
306 int mirror_num, u64 physical_for_dev_replace);
307 static void copy_nocow_pages_worker(struct btrfs_work *work);
308 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
309 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
310 static void scrub_put_ctx(struct scrub_ctx *sctx);
311
312
313 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
314 {
315 atomic_inc(&sctx->refs);
316 atomic_inc(&sctx->bios_in_flight);
317 }
318
319 static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
320 {
321 atomic_dec(&sctx->bios_in_flight);
322 wake_up(&sctx->list_wait);
323 scrub_put_ctx(sctx);
324 }
325
326 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
327 {
328 while (atomic_read(&fs_info->scrub_pause_req)) {
329 mutex_unlock(&fs_info->scrub_lock);
330 wait_event(fs_info->scrub_pause_wait,
331 atomic_read(&fs_info->scrub_pause_req) == 0);
332 mutex_lock(&fs_info->scrub_lock);
333 }
334 }
335
336 static void scrub_pause_on(struct btrfs_fs_info *fs_info)
337 {
338 atomic_inc(&fs_info->scrubs_paused);
339 wake_up(&fs_info->scrub_pause_wait);
340 }
341
342 static void scrub_pause_off(struct btrfs_fs_info *fs_info)
343 {
344 mutex_lock(&fs_info->scrub_lock);
345 __scrub_blocked_if_needed(fs_info);
346 atomic_dec(&fs_info->scrubs_paused);
347 mutex_unlock(&fs_info->scrub_lock);
348
349 wake_up(&fs_info->scrub_pause_wait);
350 }
351
352 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
353 {
354 scrub_pause_on(fs_info);
355 scrub_pause_off(fs_info);
356 }
357
358 /*
359 * used for workers that require transaction commits (i.e., for the
360 * NOCOW case)
361 */
362 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
363 {
364 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
365
366 atomic_inc(&sctx->refs);
367 /*
368 * increment scrubs_running to prevent cancel requests from
369 * completing as long as a worker is running. we must also
370 * increment scrubs_paused to prevent deadlocking on pause
371 * requests used for transactions commits (as the worker uses a
372 * transaction context). it is safe to regard the worker
373 * as paused for all matters practical. effectively, we only
374 * avoid cancellation requests from completing.
375 */
376 mutex_lock(&fs_info->scrub_lock);
377 atomic_inc(&fs_info->scrubs_running);
378 atomic_inc(&fs_info->scrubs_paused);
379 mutex_unlock(&fs_info->scrub_lock);
380
381 /*
382 * check if @scrubs_running=@scrubs_paused condition
383 * inside wait_event() is not an atomic operation.
384 * which means we may inc/dec @scrub_running/paused
385 * at any time. Let's wake up @scrub_pause_wait as
386 * much as we can to let commit transaction blocked less.
387 */
388 wake_up(&fs_info->scrub_pause_wait);
389
390 atomic_inc(&sctx->workers_pending);
391 }
392
393 /* used for workers that require transaction commits */
394 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
395 {
396 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
397
398 /*
399 * see scrub_pending_trans_workers_inc() why we're pretending
400 * to be paused in the scrub counters
401 */
402 mutex_lock(&fs_info->scrub_lock);
403 atomic_dec(&fs_info->scrubs_running);
404 atomic_dec(&fs_info->scrubs_paused);
405 mutex_unlock(&fs_info->scrub_lock);
406 atomic_dec(&sctx->workers_pending);
407 wake_up(&fs_info->scrub_pause_wait);
408 wake_up(&sctx->list_wait);
409 scrub_put_ctx(sctx);
410 }
411
412 static void scrub_free_csums(struct scrub_ctx *sctx)
413 {
414 while (!list_empty(&sctx->csum_list)) {
415 struct btrfs_ordered_sum *sum;
416 sum = list_first_entry(&sctx->csum_list,
417 struct btrfs_ordered_sum, list);
418 list_del(&sum->list);
419 kfree(sum);
420 }
421 }
422
423 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
424 {
425 int i;
426
427 if (!sctx)
428 return;
429
430 scrub_free_wr_ctx(&sctx->wr_ctx);
431
432 /* this can happen when scrub is cancelled */
433 if (sctx->curr != -1) {
434 struct scrub_bio *sbio = sctx->bios[sctx->curr];
435
436 for (i = 0; i < sbio->page_count; i++) {
437 WARN_ON(!sbio->pagev[i]->page);
438 scrub_block_put(sbio->pagev[i]->sblock);
439 }
440 bio_put(sbio->bio);
441 }
442
443 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
444 struct scrub_bio *sbio = sctx->bios[i];
445
446 if (!sbio)
447 break;
448 kfree(sbio);
449 }
450
451 scrub_free_csums(sctx);
452 kfree(sctx);
453 }
454
455 static void scrub_put_ctx(struct scrub_ctx *sctx)
456 {
457 if (atomic_dec_and_test(&sctx->refs))
458 scrub_free_ctx(sctx);
459 }
460
461 static noinline_for_stack
462 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
463 {
464 struct scrub_ctx *sctx;
465 int i;
466 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
467 int ret;
468
469 sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
470 if (!sctx)
471 goto nomem;
472 atomic_set(&sctx->refs, 1);
473 sctx->is_dev_replace = is_dev_replace;
474 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
475 sctx->curr = -1;
476 sctx->dev_root = dev->dev_root;
477 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
478 struct scrub_bio *sbio;
479
480 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
481 if (!sbio)
482 goto nomem;
483 sctx->bios[i] = sbio;
484
485 sbio->index = i;
486 sbio->sctx = sctx;
487 sbio->page_count = 0;
488 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
489 scrub_bio_end_io_worker, NULL, NULL);
490
491 if (i != SCRUB_BIOS_PER_SCTX - 1)
492 sctx->bios[i]->next_free = i + 1;
493 else
494 sctx->bios[i]->next_free = -1;
495 }
496 sctx->first_free = 0;
497 sctx->nodesize = dev->dev_root->nodesize;
498 sctx->sectorsize = dev->dev_root->sectorsize;
499 atomic_set(&sctx->bios_in_flight, 0);
500 atomic_set(&sctx->workers_pending, 0);
501 atomic_set(&sctx->cancel_req, 0);
502 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
503 INIT_LIST_HEAD(&sctx->csum_list);
504
505 spin_lock_init(&sctx->list_lock);
506 spin_lock_init(&sctx->stat_lock);
507 init_waitqueue_head(&sctx->list_wait);
508
509 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
510 fs_info->dev_replace.tgtdev, is_dev_replace);
511 if (ret) {
512 scrub_free_ctx(sctx);
513 return ERR_PTR(ret);
514 }
515 return sctx;
516
517 nomem:
518 scrub_free_ctx(sctx);
519 return ERR_PTR(-ENOMEM);
520 }
521
522 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
523 void *warn_ctx)
524 {
525 u64 isize;
526 u32 nlink;
527 int ret;
528 int i;
529 struct extent_buffer *eb;
530 struct btrfs_inode_item *inode_item;
531 struct scrub_warning *swarn = warn_ctx;
532 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
533 struct inode_fs_paths *ipath = NULL;
534 struct btrfs_root *local_root;
535 struct btrfs_key root_key;
536 struct btrfs_key key;
537
538 root_key.objectid = root;
539 root_key.type = BTRFS_ROOT_ITEM_KEY;
540 root_key.offset = (u64)-1;
541 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
542 if (IS_ERR(local_root)) {
543 ret = PTR_ERR(local_root);
544 goto err;
545 }
546
547 /*
548 * this makes the path point to (inum INODE_ITEM ioff)
549 */
550 key.objectid = inum;
551 key.type = BTRFS_INODE_ITEM_KEY;
552 key.offset = 0;
553
554 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
555 if (ret) {
556 btrfs_release_path(swarn->path);
557 goto err;
558 }
559
560 eb = swarn->path->nodes[0];
561 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
562 struct btrfs_inode_item);
563 isize = btrfs_inode_size(eb, inode_item);
564 nlink = btrfs_inode_nlink(eb, inode_item);
565 btrfs_release_path(swarn->path);
566
567 ipath = init_ipath(4096, local_root, swarn->path);
568 if (IS_ERR(ipath)) {
569 ret = PTR_ERR(ipath);
570 ipath = NULL;
571 goto err;
572 }
573 ret = paths_from_inode(inum, ipath);
574
575 if (ret < 0)
576 goto err;
577
578 /*
579 * we deliberately ignore the bit ipath might have been too small to
580 * hold all of the paths here
581 */
582 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
583 btrfs_warn_in_rcu(fs_info, "%s at logical %llu on dev "
584 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
585 "length %llu, links %u (path: %s)", swarn->errstr,
586 swarn->logical, rcu_str_deref(swarn->dev->name),
587 (unsigned long long)swarn->sector, root, inum, offset,
588 min(isize - offset, (u64)PAGE_SIZE), nlink,
589 (char *)(unsigned long)ipath->fspath->val[i]);
590
591 free_ipath(ipath);
592 return 0;
593
594 err:
595 btrfs_warn_in_rcu(fs_info, "%s at logical %llu on dev "
596 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
597 "resolving failed with ret=%d", swarn->errstr,
598 swarn->logical, rcu_str_deref(swarn->dev->name),
599 (unsigned long long)swarn->sector, root, inum, offset, ret);
600
601 free_ipath(ipath);
602 return 0;
603 }
604
605 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
606 {
607 struct btrfs_device *dev;
608 struct btrfs_fs_info *fs_info;
609 struct btrfs_path *path;
610 struct btrfs_key found_key;
611 struct extent_buffer *eb;
612 struct btrfs_extent_item *ei;
613 struct scrub_warning swarn;
614 unsigned long ptr = 0;
615 u64 extent_item_pos;
616 u64 flags = 0;
617 u64 ref_root;
618 u32 item_size;
619 u8 ref_level;
620 int ret;
621
622 WARN_ON(sblock->page_count < 1);
623 dev = sblock->pagev[0]->dev;
624 fs_info = sblock->sctx->dev_root->fs_info;
625
626 path = btrfs_alloc_path();
627 if (!path)
628 return;
629
630 swarn.sector = (sblock->pagev[0]->physical) >> 9;
631 swarn.logical = sblock->pagev[0]->logical;
632 swarn.errstr = errstr;
633 swarn.dev = NULL;
634
635 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
636 &flags);
637 if (ret < 0)
638 goto out;
639
640 extent_item_pos = swarn.logical - found_key.objectid;
641 swarn.extent_item_size = found_key.offset;
642
643 eb = path->nodes[0];
644 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
645 item_size = btrfs_item_size_nr(eb, path->slots[0]);
646
647 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
648 do {
649 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
650 item_size, &ref_root,
651 &ref_level);
652 btrfs_warn_in_rcu(fs_info,
653 "%s at logical %llu on dev %s, "
654 "sector %llu: metadata %s (level %d) in tree "
655 "%llu", errstr, swarn.logical,
656 rcu_str_deref(dev->name),
657 (unsigned long long)swarn.sector,
658 ref_level ? "node" : "leaf",
659 ret < 0 ? -1 : ref_level,
660 ret < 0 ? -1 : ref_root);
661 } while (ret != 1);
662 btrfs_release_path(path);
663 } else {
664 btrfs_release_path(path);
665 swarn.path = path;
666 swarn.dev = dev;
667 iterate_extent_inodes(fs_info, found_key.objectid,
668 extent_item_pos, 1,
669 scrub_print_warning_inode, &swarn);
670 }
671
672 out:
673 btrfs_free_path(path);
674 }
675
676 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
677 {
678 struct page *page = NULL;
679 unsigned long index;
680 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
681 int ret;
682 int corrected = 0;
683 struct btrfs_key key;
684 struct inode *inode = NULL;
685 struct btrfs_fs_info *fs_info;
686 u64 end = offset + PAGE_SIZE - 1;
687 struct btrfs_root *local_root;
688 int srcu_index;
689
690 key.objectid = root;
691 key.type = BTRFS_ROOT_ITEM_KEY;
692 key.offset = (u64)-1;
693
694 fs_info = fixup->root->fs_info;
695 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
696
697 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
698 if (IS_ERR(local_root)) {
699 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
700 return PTR_ERR(local_root);
701 }
702
703 key.type = BTRFS_INODE_ITEM_KEY;
704 key.objectid = inum;
705 key.offset = 0;
706 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
707 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
708 if (IS_ERR(inode))
709 return PTR_ERR(inode);
710
711 index = offset >> PAGE_CACHE_SHIFT;
712
713 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
714 if (!page) {
715 ret = -ENOMEM;
716 goto out;
717 }
718
719 if (PageUptodate(page)) {
720 if (PageDirty(page)) {
721 /*
722 * we need to write the data to the defect sector. the
723 * data that was in that sector is not in memory,
724 * because the page was modified. we must not write the
725 * modified page to that sector.
726 *
727 * TODO: what could be done here: wait for the delalloc
728 * runner to write out that page (might involve
729 * COW) and see whether the sector is still
730 * referenced afterwards.
731 *
732 * For the meantime, we'll treat this error
733 * incorrectable, although there is a chance that a
734 * later scrub will find the bad sector again and that
735 * there's no dirty page in memory, then.
736 */
737 ret = -EIO;
738 goto out;
739 }
740 ret = repair_io_failure(inode, offset, PAGE_SIZE,
741 fixup->logical, page,
742 offset - page_offset(page),
743 fixup->mirror_num);
744 unlock_page(page);
745 corrected = !ret;
746 } else {
747 /*
748 * we need to get good data first. the general readpage path
749 * will call repair_io_failure for us, we just have to make
750 * sure we read the bad mirror.
751 */
752 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
753 EXTENT_DAMAGED, GFP_NOFS);
754 if (ret) {
755 /* set_extent_bits should give proper error */
756 WARN_ON(ret > 0);
757 if (ret > 0)
758 ret = -EFAULT;
759 goto out;
760 }
761
762 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
763 btrfs_get_extent,
764 fixup->mirror_num);
765 wait_on_page_locked(page);
766
767 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
768 end, EXTENT_DAMAGED, 0, NULL);
769 if (!corrected)
770 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
771 EXTENT_DAMAGED, GFP_NOFS);
772 }
773
774 out:
775 if (page)
776 put_page(page);
777
778 iput(inode);
779
780 if (ret < 0)
781 return ret;
782
783 if (ret == 0 && corrected) {
784 /*
785 * we only need to call readpage for one of the inodes belonging
786 * to this extent. so make iterate_extent_inodes stop
787 */
788 return 1;
789 }
790
791 return -EIO;
792 }
793
794 static void scrub_fixup_nodatasum(struct btrfs_work *work)
795 {
796 int ret;
797 struct scrub_fixup_nodatasum *fixup;
798 struct scrub_ctx *sctx;
799 struct btrfs_trans_handle *trans = NULL;
800 struct btrfs_path *path;
801 int uncorrectable = 0;
802
803 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
804 sctx = fixup->sctx;
805
806 path = btrfs_alloc_path();
807 if (!path) {
808 spin_lock(&sctx->stat_lock);
809 ++sctx->stat.malloc_errors;
810 spin_unlock(&sctx->stat_lock);
811 uncorrectable = 1;
812 goto out;
813 }
814
815 trans = btrfs_join_transaction(fixup->root);
816 if (IS_ERR(trans)) {
817 uncorrectable = 1;
818 goto out;
819 }
820
821 /*
822 * the idea is to trigger a regular read through the standard path. we
823 * read a page from the (failed) logical address by specifying the
824 * corresponding copynum of the failed sector. thus, that readpage is
825 * expected to fail.
826 * that is the point where on-the-fly error correction will kick in
827 * (once it's finished) and rewrite the failed sector if a good copy
828 * can be found.
829 */
830 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
831 path, scrub_fixup_readpage,
832 fixup);
833 if (ret < 0) {
834 uncorrectable = 1;
835 goto out;
836 }
837 WARN_ON(ret != 1);
838
839 spin_lock(&sctx->stat_lock);
840 ++sctx->stat.corrected_errors;
841 spin_unlock(&sctx->stat_lock);
842
843 out:
844 if (trans && !IS_ERR(trans))
845 btrfs_end_transaction(trans, fixup->root);
846 if (uncorrectable) {
847 spin_lock(&sctx->stat_lock);
848 ++sctx->stat.uncorrectable_errors;
849 spin_unlock(&sctx->stat_lock);
850 btrfs_dev_replace_stats_inc(
851 &sctx->dev_root->fs_info->dev_replace.
852 num_uncorrectable_read_errors);
853 btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
854 "unable to fixup (nodatasum) error at logical %llu on dev %s",
855 fixup->logical, rcu_str_deref(fixup->dev->name));
856 }
857
858 btrfs_free_path(path);
859 kfree(fixup);
860
861 scrub_pending_trans_workers_dec(sctx);
862 }
863
864 static inline void scrub_get_recover(struct scrub_recover *recover)
865 {
866 atomic_inc(&recover->refs);
867 }
868
869 static inline void scrub_put_recover(struct scrub_recover *recover)
870 {
871 if (atomic_dec_and_test(&recover->refs)) {
872 btrfs_put_bbio(recover->bbio);
873 kfree(recover);
874 }
875 }
876
877 /*
878 * scrub_handle_errored_block gets called when either verification of the
879 * pages failed or the bio failed to read, e.g. with EIO. In the latter
880 * case, this function handles all pages in the bio, even though only one
881 * may be bad.
882 * The goal of this function is to repair the errored block by using the
883 * contents of one of the mirrors.
884 */
885 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
886 {
887 struct scrub_ctx *sctx = sblock_to_check->sctx;
888 struct btrfs_device *dev;
889 struct btrfs_fs_info *fs_info;
890 u64 length;
891 u64 logical;
892 u64 generation;
893 unsigned int failed_mirror_index;
894 unsigned int is_metadata;
895 unsigned int have_csum;
896 u8 *csum;
897 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
898 struct scrub_block *sblock_bad;
899 int ret;
900 int mirror_index;
901 int page_num;
902 int success;
903 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
904 DEFAULT_RATELIMIT_BURST);
905
906 BUG_ON(sblock_to_check->page_count < 1);
907 fs_info = sctx->dev_root->fs_info;
908 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
909 /*
910 * if we find an error in a super block, we just report it.
911 * They will get written with the next transaction commit
912 * anyway
913 */
914 spin_lock(&sctx->stat_lock);
915 ++sctx->stat.super_errors;
916 spin_unlock(&sctx->stat_lock);
917 return 0;
918 }
919 length = sblock_to_check->page_count * PAGE_SIZE;
920 logical = sblock_to_check->pagev[0]->logical;
921 generation = sblock_to_check->pagev[0]->generation;
922 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
923 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
924 is_metadata = !(sblock_to_check->pagev[0]->flags &
925 BTRFS_EXTENT_FLAG_DATA);
926 have_csum = sblock_to_check->pagev[0]->have_csum;
927 csum = sblock_to_check->pagev[0]->csum;
928 dev = sblock_to_check->pagev[0]->dev;
929
930 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
931 sblocks_for_recheck = NULL;
932 goto nodatasum_case;
933 }
934
935 /*
936 * read all mirrors one after the other. This includes to
937 * re-read the extent or metadata block that failed (that was
938 * the cause that this fixup code is called) another time,
939 * page by page this time in order to know which pages
940 * caused I/O errors and which ones are good (for all mirrors).
941 * It is the goal to handle the situation when more than one
942 * mirror contains I/O errors, but the errors do not
943 * overlap, i.e. the data can be repaired by selecting the
944 * pages from those mirrors without I/O error on the
945 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
946 * would be that mirror #1 has an I/O error on the first page,
947 * the second page is good, and mirror #2 has an I/O error on
948 * the second page, but the first page is good.
949 * Then the first page of the first mirror can be repaired by
950 * taking the first page of the second mirror, and the
951 * second page of the second mirror can be repaired by
952 * copying the contents of the 2nd page of the 1st mirror.
953 * One more note: if the pages of one mirror contain I/O
954 * errors, the checksum cannot be verified. In order to get
955 * the best data for repairing, the first attempt is to find
956 * a mirror without I/O errors and with a validated checksum.
957 * Only if this is not possible, the pages are picked from
958 * mirrors with I/O errors without considering the checksum.
959 * If the latter is the case, at the end, the checksum of the
960 * repaired area is verified in order to correctly maintain
961 * the statistics.
962 */
963
964 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
965 sizeof(*sblocks_for_recheck), GFP_NOFS);
966 if (!sblocks_for_recheck) {
967 spin_lock(&sctx->stat_lock);
968 sctx->stat.malloc_errors++;
969 sctx->stat.read_errors++;
970 sctx->stat.uncorrectable_errors++;
971 spin_unlock(&sctx->stat_lock);
972 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
973 goto out;
974 }
975
976 /* setup the context, map the logical blocks and alloc the pages */
977 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
978 if (ret) {
979 spin_lock(&sctx->stat_lock);
980 sctx->stat.read_errors++;
981 sctx->stat.uncorrectable_errors++;
982 spin_unlock(&sctx->stat_lock);
983 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
984 goto out;
985 }
986 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
987 sblock_bad = sblocks_for_recheck + failed_mirror_index;
988
989 /* build and submit the bios for the failed mirror, check checksums */
990 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
991 csum, generation, sctx->csum_size, 1);
992
993 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
994 sblock_bad->no_io_error_seen) {
995 /*
996 * the error disappeared after reading page by page, or
997 * the area was part of a huge bio and other parts of the
998 * bio caused I/O errors, or the block layer merged several
999 * read requests into one and the error is caused by a
1000 * different bio (usually one of the two latter cases is
1001 * the cause)
1002 */
1003 spin_lock(&sctx->stat_lock);
1004 sctx->stat.unverified_errors++;
1005 sblock_to_check->data_corrected = 1;
1006 spin_unlock(&sctx->stat_lock);
1007
1008 if (sctx->is_dev_replace)
1009 scrub_write_block_to_dev_replace(sblock_bad);
1010 goto out;
1011 }
1012
1013 if (!sblock_bad->no_io_error_seen) {
1014 spin_lock(&sctx->stat_lock);
1015 sctx->stat.read_errors++;
1016 spin_unlock(&sctx->stat_lock);
1017 if (__ratelimit(&_rs))
1018 scrub_print_warning("i/o error", sblock_to_check);
1019 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1020 } else if (sblock_bad->checksum_error) {
1021 spin_lock(&sctx->stat_lock);
1022 sctx->stat.csum_errors++;
1023 spin_unlock(&sctx->stat_lock);
1024 if (__ratelimit(&_rs))
1025 scrub_print_warning("checksum error", sblock_to_check);
1026 btrfs_dev_stat_inc_and_print(dev,
1027 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1028 } else if (sblock_bad->header_error) {
1029 spin_lock(&sctx->stat_lock);
1030 sctx->stat.verify_errors++;
1031 spin_unlock(&sctx->stat_lock);
1032 if (__ratelimit(&_rs))
1033 scrub_print_warning("checksum/header error",
1034 sblock_to_check);
1035 if (sblock_bad->generation_error)
1036 btrfs_dev_stat_inc_and_print(dev,
1037 BTRFS_DEV_STAT_GENERATION_ERRS);
1038 else
1039 btrfs_dev_stat_inc_and_print(dev,
1040 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1041 }
1042
1043 if (sctx->readonly) {
1044 ASSERT(!sctx->is_dev_replace);
1045 goto out;
1046 }
1047
1048 if (!is_metadata && !have_csum) {
1049 struct scrub_fixup_nodatasum *fixup_nodatasum;
1050
1051 WARN_ON(sctx->is_dev_replace);
1052
1053 nodatasum_case:
1054
1055 /*
1056 * !is_metadata and !have_csum, this means that the data
1057 * might not be COW'ed, that it might be modified
1058 * concurrently. The general strategy to work on the
1059 * commit root does not help in the case when COW is not
1060 * used.
1061 */
1062 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
1063 if (!fixup_nodatasum)
1064 goto did_not_correct_error;
1065 fixup_nodatasum->sctx = sctx;
1066 fixup_nodatasum->dev = dev;
1067 fixup_nodatasum->logical = logical;
1068 fixup_nodatasum->root = fs_info->extent_root;
1069 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
1070 scrub_pending_trans_workers_inc(sctx);
1071 btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
1072 scrub_fixup_nodatasum, NULL, NULL);
1073 btrfs_queue_work(fs_info->scrub_workers,
1074 &fixup_nodatasum->work);
1075 goto out;
1076 }
1077
1078 /*
1079 * now build and submit the bios for the other mirrors, check
1080 * checksums.
1081 * First try to pick the mirror which is completely without I/O
1082 * errors and also does not have a checksum error.
1083 * If one is found, and if a checksum is present, the full block
1084 * that is known to contain an error is rewritten. Afterwards
1085 * the block is known to be corrected.
1086 * If a mirror is found which is completely correct, and no
1087 * checksum is present, only those pages are rewritten that had
1088 * an I/O error in the block to be repaired, since it cannot be
1089 * determined, which copy of the other pages is better (and it
1090 * could happen otherwise that a correct page would be
1091 * overwritten by a bad one).
1092 */
1093 for (mirror_index = 0;
1094 mirror_index < BTRFS_MAX_MIRRORS &&
1095 sblocks_for_recheck[mirror_index].page_count > 0;
1096 mirror_index++) {
1097 struct scrub_block *sblock_other;
1098
1099 if (mirror_index == failed_mirror_index)
1100 continue;
1101 sblock_other = sblocks_for_recheck + mirror_index;
1102
1103 /* build and submit the bios, check checksums */
1104 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1105 have_csum, csum, generation,
1106 sctx->csum_size, 0);
1107
1108 if (!sblock_other->header_error &&
1109 !sblock_other->checksum_error &&
1110 sblock_other->no_io_error_seen) {
1111 if (sctx->is_dev_replace) {
1112 scrub_write_block_to_dev_replace(sblock_other);
1113 goto corrected_error;
1114 } else {
1115 ret = scrub_repair_block_from_good_copy(
1116 sblock_bad, sblock_other);
1117 if (!ret)
1118 goto corrected_error;
1119 }
1120 }
1121 }
1122
1123 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1124 goto did_not_correct_error;
1125
1126 /*
1127 * In case of I/O errors in the area that is supposed to be
1128 * repaired, continue by picking good copies of those pages.
1129 * Select the good pages from mirrors to rewrite bad pages from
1130 * the area to fix. Afterwards verify the checksum of the block
1131 * that is supposed to be repaired. This verification step is
1132 * only done for the purpose of statistic counting and for the
1133 * final scrub report, whether errors remain.
1134 * A perfect algorithm could make use of the checksum and try
1135 * all possible combinations of pages from the different mirrors
1136 * until the checksum verification succeeds. For example, when
1137 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1138 * of mirror #2 is readable but the final checksum test fails,
1139 * then the 2nd page of mirror #3 could be tried, whether now
1140 * the final checksum succeedes. But this would be a rare
1141 * exception and is therefore not implemented. At least it is
1142 * avoided that the good copy is overwritten.
1143 * A more useful improvement would be to pick the sectors
1144 * without I/O error based on sector sizes (512 bytes on legacy
1145 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1146 * mirror could be repaired by taking 512 byte of a different
1147 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1148 * area are unreadable.
1149 */
1150 success = 1;
1151 for (page_num = 0; page_num < sblock_bad->page_count;
1152 page_num++) {
1153 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1154 struct scrub_block *sblock_other = NULL;
1155
1156 /* skip no-io-error page in scrub */
1157 if (!page_bad->io_error && !sctx->is_dev_replace)
1158 continue;
1159
1160 /* try to find no-io-error page in mirrors */
1161 if (page_bad->io_error) {
1162 for (mirror_index = 0;
1163 mirror_index < BTRFS_MAX_MIRRORS &&
1164 sblocks_for_recheck[mirror_index].page_count > 0;
1165 mirror_index++) {
1166 if (!sblocks_for_recheck[mirror_index].
1167 pagev[page_num]->io_error) {
1168 sblock_other = sblocks_for_recheck +
1169 mirror_index;
1170 break;
1171 }
1172 }
1173 if (!sblock_other)
1174 success = 0;
1175 }
1176
1177 if (sctx->is_dev_replace) {
1178 /*
1179 * did not find a mirror to fetch the page
1180 * from. scrub_write_page_to_dev_replace()
1181 * handles this case (page->io_error), by
1182 * filling the block with zeros before
1183 * submitting the write request
1184 */
1185 if (!sblock_other)
1186 sblock_other = sblock_bad;
1187
1188 if (scrub_write_page_to_dev_replace(sblock_other,
1189 page_num) != 0) {
1190 btrfs_dev_replace_stats_inc(
1191 &sctx->dev_root->
1192 fs_info->dev_replace.
1193 num_write_errors);
1194 success = 0;
1195 }
1196 } else if (sblock_other) {
1197 ret = scrub_repair_page_from_good_copy(sblock_bad,
1198 sblock_other,
1199 page_num, 0);
1200 if (0 == ret)
1201 page_bad->io_error = 0;
1202 else
1203 success = 0;
1204 }
1205 }
1206
1207 if (success && !sctx->is_dev_replace) {
1208 if (is_metadata || have_csum) {
1209 /*
1210 * need to verify the checksum now that all
1211 * sectors on disk are repaired (the write
1212 * request for data to be repaired is on its way).
1213 * Just be lazy and use scrub_recheck_block()
1214 * which re-reads the data before the checksum
1215 * is verified, but most likely the data comes out
1216 * of the page cache.
1217 */
1218 scrub_recheck_block(fs_info, sblock_bad,
1219 is_metadata, have_csum, csum,
1220 generation, sctx->csum_size, 1);
1221 if (!sblock_bad->header_error &&
1222 !sblock_bad->checksum_error &&
1223 sblock_bad->no_io_error_seen)
1224 goto corrected_error;
1225 else
1226 goto did_not_correct_error;
1227 } else {
1228 corrected_error:
1229 spin_lock(&sctx->stat_lock);
1230 sctx->stat.corrected_errors++;
1231 sblock_to_check->data_corrected = 1;
1232 spin_unlock(&sctx->stat_lock);
1233 btrfs_err_rl_in_rcu(fs_info,
1234 "fixed up error at logical %llu on dev %s",
1235 logical, rcu_str_deref(dev->name));
1236 }
1237 } else {
1238 did_not_correct_error:
1239 spin_lock(&sctx->stat_lock);
1240 sctx->stat.uncorrectable_errors++;
1241 spin_unlock(&sctx->stat_lock);
1242 btrfs_err_rl_in_rcu(fs_info,
1243 "unable to fixup (regular) error at logical %llu on dev %s",
1244 logical, rcu_str_deref(dev->name));
1245 }
1246
1247 out:
1248 if (sblocks_for_recheck) {
1249 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1250 mirror_index++) {
1251 struct scrub_block *sblock = sblocks_for_recheck +
1252 mirror_index;
1253 struct scrub_recover *recover;
1254 int page_index;
1255
1256 for (page_index = 0; page_index < sblock->page_count;
1257 page_index++) {
1258 sblock->pagev[page_index]->sblock = NULL;
1259 recover = sblock->pagev[page_index]->recover;
1260 if (recover) {
1261 scrub_put_recover(recover);
1262 sblock->pagev[page_index]->recover =
1263 NULL;
1264 }
1265 scrub_page_put(sblock->pagev[page_index]);
1266 }
1267 }
1268 kfree(sblocks_for_recheck);
1269 }
1270
1271 return 0;
1272 }
1273
1274 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1275 {
1276 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1277 return 2;
1278 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1279 return 3;
1280 else
1281 return (int)bbio->num_stripes;
1282 }
1283
1284 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1285 u64 *raid_map,
1286 u64 mapped_length,
1287 int nstripes, int mirror,
1288 int *stripe_index,
1289 u64 *stripe_offset)
1290 {
1291 int i;
1292
1293 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1294 /* RAID5/6 */
1295 for (i = 0; i < nstripes; i++) {
1296 if (raid_map[i] == RAID6_Q_STRIPE ||
1297 raid_map[i] == RAID5_P_STRIPE)
1298 continue;
1299
1300 if (logical >= raid_map[i] &&
1301 logical < raid_map[i] + mapped_length)
1302 break;
1303 }
1304
1305 *stripe_index = i;
1306 *stripe_offset = logical - raid_map[i];
1307 } else {
1308 /* The other RAID type */
1309 *stripe_index = mirror;
1310 *stripe_offset = 0;
1311 }
1312 }
1313
1314 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1315 struct scrub_block *sblocks_for_recheck)
1316 {
1317 struct scrub_ctx *sctx = original_sblock->sctx;
1318 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
1319 u64 length = original_sblock->page_count * PAGE_SIZE;
1320 u64 logical = original_sblock->pagev[0]->logical;
1321 u64 generation = original_sblock->pagev[0]->generation;
1322 u64 flags = original_sblock->pagev[0]->flags;
1323 u64 have_csum = original_sblock->pagev[0]->have_csum;
1324 struct scrub_recover *recover;
1325 struct btrfs_bio *bbio;
1326 u64 sublen;
1327 u64 mapped_length;
1328 u64 stripe_offset;
1329 int stripe_index;
1330 int page_index = 0;
1331 int mirror_index;
1332 int nmirrors;
1333 int ret;
1334
1335 /*
1336 * note: the two members refs and outstanding_pages
1337 * are not used (and not set) in the blocks that are used for
1338 * the recheck procedure
1339 */
1340
1341 while (length > 0) {
1342 sublen = min_t(u64, length, PAGE_SIZE);
1343 mapped_length = sublen;
1344 bbio = NULL;
1345
1346 /*
1347 * with a length of PAGE_SIZE, each returned stripe
1348 * represents one mirror
1349 */
1350 ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical,
1351 &mapped_length, &bbio, 0, 1);
1352 if (ret || !bbio || mapped_length < sublen) {
1353 btrfs_put_bbio(bbio);
1354 return -EIO;
1355 }
1356
1357 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1358 if (!recover) {
1359 btrfs_put_bbio(bbio);
1360 return -ENOMEM;
1361 }
1362
1363 atomic_set(&recover->refs, 1);
1364 recover->bbio = bbio;
1365 recover->map_length = mapped_length;
1366
1367 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
1368
1369 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1370
1371 for (mirror_index = 0; mirror_index < nmirrors;
1372 mirror_index++) {
1373 struct scrub_block *sblock;
1374 struct scrub_page *page;
1375
1376 sblock = sblocks_for_recheck + mirror_index;
1377 sblock->sctx = sctx;
1378
1379 page = kzalloc(sizeof(*page), GFP_NOFS);
1380 if (!page) {
1381 leave_nomem:
1382 spin_lock(&sctx->stat_lock);
1383 sctx->stat.malloc_errors++;
1384 spin_unlock(&sctx->stat_lock);
1385 scrub_put_recover(recover);
1386 return -ENOMEM;
1387 }
1388 scrub_page_get(page);
1389 sblock->pagev[page_index] = page;
1390 page->sblock = sblock;
1391 page->flags = flags;
1392 page->generation = generation;
1393 page->logical = logical;
1394 page->have_csum = have_csum;
1395 if (have_csum)
1396 memcpy(page->csum,
1397 original_sblock->pagev[0]->csum,
1398 sctx->csum_size);
1399
1400 scrub_stripe_index_and_offset(logical,
1401 bbio->map_type,
1402 bbio->raid_map,
1403 mapped_length,
1404 bbio->num_stripes -
1405 bbio->num_tgtdevs,
1406 mirror_index,
1407 &stripe_index,
1408 &stripe_offset);
1409 page->physical = bbio->stripes[stripe_index].physical +
1410 stripe_offset;
1411 page->dev = bbio->stripes[stripe_index].dev;
1412
1413 BUG_ON(page_index >= original_sblock->page_count);
1414 page->physical_for_dev_replace =
1415 original_sblock->pagev[page_index]->
1416 physical_for_dev_replace;
1417 /* for missing devices, dev->bdev is NULL */
1418 page->mirror_num = mirror_index + 1;
1419 sblock->page_count++;
1420 page->page = alloc_page(GFP_NOFS);
1421 if (!page->page)
1422 goto leave_nomem;
1423
1424 scrub_get_recover(recover);
1425 page->recover = recover;
1426 }
1427 scrub_put_recover(recover);
1428 length -= sublen;
1429 logical += sublen;
1430 page_index++;
1431 }
1432
1433 return 0;
1434 }
1435
1436 struct scrub_bio_ret {
1437 struct completion event;
1438 int error;
1439 };
1440
1441 static void scrub_bio_wait_endio(struct bio *bio)
1442 {
1443 struct scrub_bio_ret *ret = bio->bi_private;
1444
1445 ret->error = bio->bi_error;
1446 complete(&ret->event);
1447 }
1448
1449 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
1450 {
1451 return page->recover &&
1452 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
1453 }
1454
1455 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1456 struct bio *bio,
1457 struct scrub_page *page)
1458 {
1459 struct scrub_bio_ret done;
1460 int ret;
1461
1462 init_completion(&done.event);
1463 done.error = 0;
1464 bio->bi_iter.bi_sector = page->logical >> 9;
1465 bio->bi_private = &done;
1466 bio->bi_end_io = scrub_bio_wait_endio;
1467
1468 ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio,
1469 page->recover->map_length,
1470 page->mirror_num, 0);
1471 if (ret)
1472 return ret;
1473
1474 wait_for_completion(&done.event);
1475 if (done.error)
1476 return -EIO;
1477
1478 return 0;
1479 }
1480
1481 /*
1482 * this function will check the on disk data for checksum errors, header
1483 * errors and read I/O errors. If any I/O errors happen, the exact pages
1484 * which are errored are marked as being bad. The goal is to enable scrub
1485 * to take those pages that are not errored from all the mirrors so that
1486 * the pages that are errored in the just handled mirror can be repaired.
1487 */
1488 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1489 struct scrub_block *sblock, int is_metadata,
1490 int have_csum, u8 *csum, u64 generation,
1491 u16 csum_size, int retry_failed_mirror)
1492 {
1493 int page_num;
1494
1495 sblock->no_io_error_seen = 1;
1496 sblock->header_error = 0;
1497 sblock->checksum_error = 0;
1498 sblock->generation_error = 0;
1499
1500 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1501 struct bio *bio;
1502 struct scrub_page *page = sblock->pagev[page_num];
1503
1504 if (page->dev->bdev == NULL) {
1505 page->io_error = 1;
1506 sblock->no_io_error_seen = 0;
1507 continue;
1508 }
1509
1510 WARN_ON(!page->page);
1511 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1512 if (!bio) {
1513 page->io_error = 1;
1514 sblock->no_io_error_seen = 0;
1515 continue;
1516 }
1517 bio->bi_bdev = page->dev->bdev;
1518
1519 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1520 if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
1521 if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
1522 sblock->no_io_error_seen = 0;
1523 } else {
1524 bio->bi_iter.bi_sector = page->physical >> 9;
1525
1526 if (btrfsic_submit_bio_wait(READ, bio))
1527 sblock->no_io_error_seen = 0;
1528 }
1529
1530 bio_put(bio);
1531 }
1532
1533 if (sblock->no_io_error_seen)
1534 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1535 have_csum, csum, generation,
1536 csum_size);
1537
1538 return;
1539 }
1540
1541 static inline int scrub_check_fsid(u8 fsid[],
1542 struct scrub_page *spage)
1543 {
1544 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1545 int ret;
1546
1547 ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE);
1548 return !ret;
1549 }
1550
1551 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1552 struct scrub_block *sblock,
1553 int is_metadata, int have_csum,
1554 const u8 *csum, u64 generation,
1555 u16 csum_size)
1556 {
1557 int page_num;
1558 u8 calculated_csum[BTRFS_CSUM_SIZE];
1559 u32 crc = ~(u32)0;
1560 void *mapped_buffer;
1561
1562 WARN_ON(!sblock->pagev[0]->page);
1563 if (is_metadata) {
1564 struct btrfs_header *h;
1565
1566 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1567 h = (struct btrfs_header *)mapped_buffer;
1568
1569 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
1570 !scrub_check_fsid(h->fsid, sblock->pagev[0]) ||
1571 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1572 BTRFS_UUID_SIZE)) {
1573 sblock->header_error = 1;
1574 } else if (generation != btrfs_stack_header_generation(h)) {
1575 sblock->header_error = 1;
1576 sblock->generation_error = 1;
1577 }
1578 csum = h->csum;
1579 } else {
1580 if (!have_csum)
1581 return;
1582
1583 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1584 }
1585
1586 for (page_num = 0;;) {
1587 if (page_num == 0 && is_metadata)
1588 crc = btrfs_csum_data(
1589 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1590 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1591 else
1592 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
1593
1594 kunmap_atomic(mapped_buffer);
1595 page_num++;
1596 if (page_num >= sblock->page_count)
1597 break;
1598 WARN_ON(!sblock->pagev[page_num]->page);
1599
1600 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
1601 }
1602
1603 btrfs_csum_final(crc, calculated_csum);
1604 if (memcmp(calculated_csum, csum, csum_size))
1605 sblock->checksum_error = 1;
1606 }
1607
1608 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1609 struct scrub_block *sblock_good)
1610 {
1611 int page_num;
1612 int ret = 0;
1613
1614 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1615 int ret_sub;
1616
1617 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1618 sblock_good,
1619 page_num, 1);
1620 if (ret_sub)
1621 ret = ret_sub;
1622 }
1623
1624 return ret;
1625 }
1626
1627 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1628 struct scrub_block *sblock_good,
1629 int page_num, int force_write)
1630 {
1631 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1632 struct scrub_page *page_good = sblock_good->pagev[page_num];
1633
1634 BUG_ON(page_bad->page == NULL);
1635 BUG_ON(page_good->page == NULL);
1636 if (force_write || sblock_bad->header_error ||
1637 sblock_bad->checksum_error || page_bad->io_error) {
1638 struct bio *bio;
1639 int ret;
1640
1641 if (!page_bad->dev->bdev) {
1642 btrfs_warn_rl(sblock_bad->sctx->dev_root->fs_info,
1643 "scrub_repair_page_from_good_copy(bdev == NULL) "
1644 "is unexpected");
1645 return -EIO;
1646 }
1647
1648 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1649 if (!bio)
1650 return -EIO;
1651 bio->bi_bdev = page_bad->dev->bdev;
1652 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1653
1654 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1655 if (PAGE_SIZE != ret) {
1656 bio_put(bio);
1657 return -EIO;
1658 }
1659
1660 if (btrfsic_submit_bio_wait(WRITE, bio)) {
1661 btrfs_dev_stat_inc_and_print(page_bad->dev,
1662 BTRFS_DEV_STAT_WRITE_ERRS);
1663 btrfs_dev_replace_stats_inc(
1664 &sblock_bad->sctx->dev_root->fs_info->
1665 dev_replace.num_write_errors);
1666 bio_put(bio);
1667 return -EIO;
1668 }
1669 bio_put(bio);
1670 }
1671
1672 return 0;
1673 }
1674
1675 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1676 {
1677 int page_num;
1678
1679 /*
1680 * This block is used for the check of the parity on the source device,
1681 * so the data needn't be written into the destination device.
1682 */
1683 if (sblock->sparity)
1684 return;
1685
1686 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1687 int ret;
1688
1689 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1690 if (ret)
1691 btrfs_dev_replace_stats_inc(
1692 &sblock->sctx->dev_root->fs_info->dev_replace.
1693 num_write_errors);
1694 }
1695 }
1696
1697 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1698 int page_num)
1699 {
1700 struct scrub_page *spage = sblock->pagev[page_num];
1701
1702 BUG_ON(spage->page == NULL);
1703 if (spage->io_error) {
1704 void *mapped_buffer = kmap_atomic(spage->page);
1705
1706 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1707 flush_dcache_page(spage->page);
1708 kunmap_atomic(mapped_buffer);
1709 }
1710 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1711 }
1712
1713 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1714 struct scrub_page *spage)
1715 {
1716 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1717 struct scrub_bio *sbio;
1718 int ret;
1719
1720 mutex_lock(&wr_ctx->wr_lock);
1721 again:
1722 if (!wr_ctx->wr_curr_bio) {
1723 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1724 GFP_NOFS);
1725 if (!wr_ctx->wr_curr_bio) {
1726 mutex_unlock(&wr_ctx->wr_lock);
1727 return -ENOMEM;
1728 }
1729 wr_ctx->wr_curr_bio->sctx = sctx;
1730 wr_ctx->wr_curr_bio->page_count = 0;
1731 }
1732 sbio = wr_ctx->wr_curr_bio;
1733 if (sbio->page_count == 0) {
1734 struct bio *bio;
1735
1736 sbio->physical = spage->physical_for_dev_replace;
1737 sbio->logical = spage->logical;
1738 sbio->dev = wr_ctx->tgtdev;
1739 bio = sbio->bio;
1740 if (!bio) {
1741 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
1742 if (!bio) {
1743 mutex_unlock(&wr_ctx->wr_lock);
1744 return -ENOMEM;
1745 }
1746 sbio->bio = bio;
1747 }
1748
1749 bio->bi_private = sbio;
1750 bio->bi_end_io = scrub_wr_bio_end_io;
1751 bio->bi_bdev = sbio->dev->bdev;
1752 bio->bi_iter.bi_sector = sbio->physical >> 9;
1753 sbio->err = 0;
1754 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1755 spage->physical_for_dev_replace ||
1756 sbio->logical + sbio->page_count * PAGE_SIZE !=
1757 spage->logical) {
1758 scrub_wr_submit(sctx);
1759 goto again;
1760 }
1761
1762 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1763 if (ret != PAGE_SIZE) {
1764 if (sbio->page_count < 1) {
1765 bio_put(sbio->bio);
1766 sbio->bio = NULL;
1767 mutex_unlock(&wr_ctx->wr_lock);
1768 return -EIO;
1769 }
1770 scrub_wr_submit(sctx);
1771 goto again;
1772 }
1773
1774 sbio->pagev[sbio->page_count] = spage;
1775 scrub_page_get(spage);
1776 sbio->page_count++;
1777 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1778 scrub_wr_submit(sctx);
1779 mutex_unlock(&wr_ctx->wr_lock);
1780
1781 return 0;
1782 }
1783
1784 static void scrub_wr_submit(struct scrub_ctx *sctx)
1785 {
1786 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1787 struct scrub_bio *sbio;
1788
1789 if (!wr_ctx->wr_curr_bio)
1790 return;
1791
1792 sbio = wr_ctx->wr_curr_bio;
1793 wr_ctx->wr_curr_bio = NULL;
1794 WARN_ON(!sbio->bio->bi_bdev);
1795 scrub_pending_bio_inc(sctx);
1796 /* process all writes in a single worker thread. Then the block layer
1797 * orders the requests before sending them to the driver which
1798 * doubled the write performance on spinning disks when measured
1799 * with Linux 3.5 */
1800 btrfsic_submit_bio(WRITE, sbio->bio);
1801 }
1802
1803 static void scrub_wr_bio_end_io(struct bio *bio)
1804 {
1805 struct scrub_bio *sbio = bio->bi_private;
1806 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1807
1808 sbio->err = bio->bi_error;
1809 sbio->bio = bio;
1810
1811 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1812 scrub_wr_bio_end_io_worker, NULL, NULL);
1813 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1814 }
1815
1816 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1817 {
1818 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1819 struct scrub_ctx *sctx = sbio->sctx;
1820 int i;
1821
1822 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1823 if (sbio->err) {
1824 struct btrfs_dev_replace *dev_replace =
1825 &sbio->sctx->dev_root->fs_info->dev_replace;
1826
1827 for (i = 0; i < sbio->page_count; i++) {
1828 struct scrub_page *spage = sbio->pagev[i];
1829
1830 spage->io_error = 1;
1831 btrfs_dev_replace_stats_inc(&dev_replace->
1832 num_write_errors);
1833 }
1834 }
1835
1836 for (i = 0; i < sbio->page_count; i++)
1837 scrub_page_put(sbio->pagev[i]);
1838
1839 bio_put(sbio->bio);
1840 kfree(sbio);
1841 scrub_pending_bio_dec(sctx);
1842 }
1843
1844 static int scrub_checksum(struct scrub_block *sblock)
1845 {
1846 u64 flags;
1847 int ret;
1848
1849 WARN_ON(sblock->page_count < 1);
1850 flags = sblock->pagev[0]->flags;
1851 ret = 0;
1852 if (flags & BTRFS_EXTENT_FLAG_DATA)
1853 ret = scrub_checksum_data(sblock);
1854 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1855 ret = scrub_checksum_tree_block(sblock);
1856 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1857 (void)scrub_checksum_super(sblock);
1858 else
1859 WARN_ON(1);
1860 if (ret)
1861 scrub_handle_errored_block(sblock);
1862
1863 return ret;
1864 }
1865
1866 static int scrub_checksum_data(struct scrub_block *sblock)
1867 {
1868 struct scrub_ctx *sctx = sblock->sctx;
1869 u8 csum[BTRFS_CSUM_SIZE];
1870 u8 *on_disk_csum;
1871 struct page *page;
1872 void *buffer;
1873 u32 crc = ~(u32)0;
1874 int fail = 0;
1875 u64 len;
1876 int index;
1877
1878 BUG_ON(sblock->page_count < 1);
1879 if (!sblock->pagev[0]->have_csum)
1880 return 0;
1881
1882 on_disk_csum = sblock->pagev[0]->csum;
1883 page = sblock->pagev[0]->page;
1884 buffer = kmap_atomic(page);
1885
1886 len = sctx->sectorsize;
1887 index = 0;
1888 for (;;) {
1889 u64 l = min_t(u64, len, PAGE_SIZE);
1890
1891 crc = btrfs_csum_data(buffer, crc, l);
1892 kunmap_atomic(buffer);
1893 len -= l;
1894 if (len == 0)
1895 break;
1896 index++;
1897 BUG_ON(index >= sblock->page_count);
1898 BUG_ON(!sblock->pagev[index]->page);
1899 page = sblock->pagev[index]->page;
1900 buffer = kmap_atomic(page);
1901 }
1902
1903 btrfs_csum_final(crc, csum);
1904 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1905 fail = 1;
1906
1907 return fail;
1908 }
1909
1910 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1911 {
1912 struct scrub_ctx *sctx = sblock->sctx;
1913 struct btrfs_header *h;
1914 struct btrfs_root *root = sctx->dev_root;
1915 struct btrfs_fs_info *fs_info = root->fs_info;
1916 u8 calculated_csum[BTRFS_CSUM_SIZE];
1917 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1918 struct page *page;
1919 void *mapped_buffer;
1920 u64 mapped_size;
1921 void *p;
1922 u32 crc = ~(u32)0;
1923 int fail = 0;
1924 int crc_fail = 0;
1925 u64 len;
1926 int index;
1927
1928 BUG_ON(sblock->page_count < 1);
1929 page = sblock->pagev[0]->page;
1930 mapped_buffer = kmap_atomic(page);
1931 h = (struct btrfs_header *)mapped_buffer;
1932 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1933
1934 /*
1935 * we don't use the getter functions here, as we
1936 * a) don't have an extent buffer and
1937 * b) the page is already kmapped
1938 */
1939
1940 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1941 ++fail;
1942
1943 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
1944 ++fail;
1945
1946 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1947 ++fail;
1948
1949 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1950 BTRFS_UUID_SIZE))
1951 ++fail;
1952
1953 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1954 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1955 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1956 index = 0;
1957 for (;;) {
1958 u64 l = min_t(u64, len, mapped_size);
1959
1960 crc = btrfs_csum_data(p, crc, l);
1961 kunmap_atomic(mapped_buffer);
1962 len -= l;
1963 if (len == 0)
1964 break;
1965 index++;
1966 BUG_ON(index >= sblock->page_count);
1967 BUG_ON(!sblock->pagev[index]->page);
1968 page = sblock->pagev[index]->page;
1969 mapped_buffer = kmap_atomic(page);
1970 mapped_size = PAGE_SIZE;
1971 p = mapped_buffer;
1972 }
1973
1974 btrfs_csum_final(crc, calculated_csum);
1975 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1976 ++crc_fail;
1977
1978 return fail || crc_fail;
1979 }
1980
1981 static int scrub_checksum_super(struct scrub_block *sblock)
1982 {
1983 struct btrfs_super_block *s;
1984 struct scrub_ctx *sctx = sblock->sctx;
1985 u8 calculated_csum[BTRFS_CSUM_SIZE];
1986 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1987 struct page *page;
1988 void *mapped_buffer;
1989 u64 mapped_size;
1990 void *p;
1991 u32 crc = ~(u32)0;
1992 int fail_gen = 0;
1993 int fail_cor = 0;
1994 u64 len;
1995 int index;
1996
1997 BUG_ON(sblock->page_count < 1);
1998 page = sblock->pagev[0]->page;
1999 mapped_buffer = kmap_atomic(page);
2000 s = (struct btrfs_super_block *)mapped_buffer;
2001 memcpy(on_disk_csum, s->csum, sctx->csum_size);
2002
2003 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
2004 ++fail_cor;
2005
2006 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
2007 ++fail_gen;
2008
2009 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
2010 ++fail_cor;
2011
2012 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
2013 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
2014 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
2015 index = 0;
2016 for (;;) {
2017 u64 l = min_t(u64, len, mapped_size);
2018
2019 crc = btrfs_csum_data(p, crc, l);
2020 kunmap_atomic(mapped_buffer);
2021 len -= l;
2022 if (len == 0)
2023 break;
2024 index++;
2025 BUG_ON(index >= sblock->page_count);
2026 BUG_ON(!sblock->pagev[index]->page);
2027 page = sblock->pagev[index]->page;
2028 mapped_buffer = kmap_atomic(page);
2029 mapped_size = PAGE_SIZE;
2030 p = mapped_buffer;
2031 }
2032
2033 btrfs_csum_final(crc, calculated_csum);
2034 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
2035 ++fail_cor;
2036
2037 if (fail_cor + fail_gen) {
2038 /*
2039 * if we find an error in a super block, we just report it.
2040 * They will get written with the next transaction commit
2041 * anyway
2042 */
2043 spin_lock(&sctx->stat_lock);
2044 ++sctx->stat.super_errors;
2045 spin_unlock(&sctx->stat_lock);
2046 if (fail_cor)
2047 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
2048 BTRFS_DEV_STAT_CORRUPTION_ERRS);
2049 else
2050 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
2051 BTRFS_DEV_STAT_GENERATION_ERRS);
2052 }
2053
2054 return fail_cor + fail_gen;
2055 }
2056
2057 static void scrub_block_get(struct scrub_block *sblock)
2058 {
2059 atomic_inc(&sblock->refs);
2060 }
2061
2062 static void scrub_block_put(struct scrub_block *sblock)
2063 {
2064 if (atomic_dec_and_test(&sblock->refs)) {
2065 int i;
2066
2067 if (sblock->sparity)
2068 scrub_parity_put(sblock->sparity);
2069
2070 for (i = 0; i < sblock->page_count; i++)
2071 scrub_page_put(sblock->pagev[i]);
2072 kfree(sblock);
2073 }
2074 }
2075
2076 static void scrub_page_get(struct scrub_page *spage)
2077 {
2078 atomic_inc(&spage->refs);
2079 }
2080
2081 static void scrub_page_put(struct scrub_page *spage)
2082 {
2083 if (atomic_dec_and_test(&spage->refs)) {
2084 if (spage->page)
2085 __free_page(spage->page);
2086 kfree(spage);
2087 }
2088 }
2089
2090 static void scrub_submit(struct scrub_ctx *sctx)
2091 {
2092 struct scrub_bio *sbio;
2093
2094 if (sctx->curr == -1)
2095 return;
2096
2097 sbio = sctx->bios[sctx->curr];
2098 sctx->curr = -1;
2099 scrub_pending_bio_inc(sctx);
2100 btrfsic_submit_bio(READ, sbio->bio);
2101 }
2102
2103 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2104 struct scrub_page *spage)
2105 {
2106 struct scrub_block *sblock = spage->sblock;
2107 struct scrub_bio *sbio;
2108 int ret;
2109
2110 again:
2111 /*
2112 * grab a fresh bio or wait for one to become available
2113 */
2114 while (sctx->curr == -1) {
2115 spin_lock(&sctx->list_lock);
2116 sctx->curr = sctx->first_free;
2117 if (sctx->curr != -1) {
2118 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2119 sctx->bios[sctx->curr]->next_free = -1;
2120 sctx->bios[sctx->curr]->page_count = 0;
2121 spin_unlock(&sctx->list_lock);
2122 } else {
2123 spin_unlock(&sctx->list_lock);
2124 wait_event(sctx->list_wait, sctx->first_free != -1);
2125 }
2126 }
2127 sbio = sctx->bios[sctx->curr];
2128 if (sbio->page_count == 0) {
2129 struct bio *bio;
2130
2131 sbio->physical = spage->physical;
2132 sbio->logical = spage->logical;
2133 sbio->dev = spage->dev;
2134 bio = sbio->bio;
2135 if (!bio) {
2136 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
2137 if (!bio)
2138 return -ENOMEM;
2139 sbio->bio = bio;
2140 }
2141
2142 bio->bi_private = sbio;
2143 bio->bi_end_io = scrub_bio_end_io;
2144 bio->bi_bdev = sbio->dev->bdev;
2145 bio->bi_iter.bi_sector = sbio->physical >> 9;
2146 sbio->err = 0;
2147 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2148 spage->physical ||
2149 sbio->logical + sbio->page_count * PAGE_SIZE !=
2150 spage->logical ||
2151 sbio->dev != spage->dev) {
2152 scrub_submit(sctx);
2153 goto again;
2154 }
2155
2156 sbio->pagev[sbio->page_count] = spage;
2157 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2158 if (ret != PAGE_SIZE) {
2159 if (sbio->page_count < 1) {
2160 bio_put(sbio->bio);
2161 sbio->bio = NULL;
2162 return -EIO;
2163 }
2164 scrub_submit(sctx);
2165 goto again;
2166 }
2167
2168 scrub_block_get(sblock); /* one for the page added to the bio */
2169 atomic_inc(&sblock->outstanding_pages);
2170 sbio->page_count++;
2171 if (sbio->page_count == sctx->pages_per_rd_bio)
2172 scrub_submit(sctx);
2173
2174 return 0;
2175 }
2176
2177 static void scrub_missing_raid56_end_io(struct bio *bio)
2178 {
2179 struct scrub_block *sblock = bio->bi_private;
2180 struct btrfs_fs_info *fs_info = sblock->sctx->dev_root->fs_info;
2181
2182 if (bio->bi_error)
2183 sblock->no_io_error_seen = 0;
2184
2185 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2186 }
2187
2188 static void scrub_missing_raid56_worker(struct btrfs_work *work)
2189 {
2190 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2191 struct scrub_ctx *sctx = sblock->sctx;
2192 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2193 unsigned int is_metadata;
2194 unsigned int have_csum;
2195 u8 *csum;
2196 u64 generation;
2197 u64 logical;
2198 struct btrfs_device *dev;
2199
2200 is_metadata = !(sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA);
2201 have_csum = sblock->pagev[0]->have_csum;
2202 csum = sblock->pagev[0]->csum;
2203 generation = sblock->pagev[0]->generation;
2204 logical = sblock->pagev[0]->logical;
2205 dev = sblock->pagev[0]->dev;
2206
2207 sblock->header_error = 0;
2208 sblock->checksum_error = 0;
2209 sblock->generation_error = 0;
2210 if (sblock->no_io_error_seen) {
2211 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
2212 have_csum, csum, generation,
2213 sctx->csum_size);
2214 }
2215
2216 if (!sblock->no_io_error_seen) {
2217 spin_lock(&sctx->stat_lock);
2218 sctx->stat.read_errors++;
2219 spin_unlock(&sctx->stat_lock);
2220 btrfs_err_rl_in_rcu(fs_info,
2221 "IO error rebuilding logical %llu for dev %s",
2222 logical, rcu_str_deref(dev->name));
2223 } else if (sblock->header_error || sblock->checksum_error) {
2224 spin_lock(&sctx->stat_lock);
2225 sctx->stat.uncorrectable_errors++;
2226 spin_unlock(&sctx->stat_lock);
2227 btrfs_err_rl_in_rcu(fs_info,
2228 "failed to rebuild valid logical %llu for dev %s",
2229 logical, rcu_str_deref(dev->name));
2230 } else {
2231 scrub_write_block_to_dev_replace(sblock);
2232 }
2233
2234 scrub_block_put(sblock);
2235
2236 if (sctx->is_dev_replace &&
2237 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2238 mutex_lock(&sctx->wr_ctx.wr_lock);
2239 scrub_wr_submit(sctx);
2240 mutex_unlock(&sctx->wr_ctx.wr_lock);
2241 }
2242
2243 scrub_pending_bio_dec(sctx);
2244 }
2245
2246 static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2247 {
2248 struct scrub_ctx *sctx = sblock->sctx;
2249 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2250 u64 length = sblock->page_count * PAGE_SIZE;
2251 u64 logical = sblock->pagev[0]->logical;
2252 struct btrfs_bio *bbio;
2253 struct bio *bio;
2254 struct btrfs_raid_bio *rbio;
2255 int ret;
2256 int i;
2257
2258 ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical, &length,
2259 &bbio, 0, 1);
2260 if (ret || !bbio || !bbio->raid_map)
2261 goto bbio_out;
2262
2263 if (WARN_ON(!sctx->is_dev_replace ||
2264 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2265 /*
2266 * We shouldn't be scrubbing a missing device. Even for dev
2267 * replace, we should only get here for RAID 5/6. We either
2268 * managed to mount something with no mirrors remaining or
2269 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2270 */
2271 goto bbio_out;
2272 }
2273
2274 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2275 if (!bio)
2276 goto bbio_out;
2277
2278 bio->bi_iter.bi_sector = logical >> 9;
2279 bio->bi_private = sblock;
2280 bio->bi_end_io = scrub_missing_raid56_end_io;
2281
2282 rbio = raid56_alloc_missing_rbio(sctx->dev_root, bio, bbio, length);
2283 if (!rbio)
2284 goto rbio_out;
2285
2286 for (i = 0; i < sblock->page_count; i++) {
2287 struct scrub_page *spage = sblock->pagev[i];
2288
2289 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2290 }
2291
2292 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2293 scrub_missing_raid56_worker, NULL, NULL);
2294 scrub_block_get(sblock);
2295 scrub_pending_bio_inc(sctx);
2296 raid56_submit_missing_rbio(rbio);
2297 return;
2298
2299 rbio_out:
2300 bio_put(bio);
2301 bbio_out:
2302 btrfs_put_bbio(bbio);
2303 spin_lock(&sctx->stat_lock);
2304 sctx->stat.malloc_errors++;
2305 spin_unlock(&sctx->stat_lock);
2306 }
2307
2308 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2309 u64 physical, struct btrfs_device *dev, u64 flags,
2310 u64 gen, int mirror_num, u8 *csum, int force,
2311 u64 physical_for_dev_replace)
2312 {
2313 struct scrub_block *sblock;
2314 int index;
2315
2316 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2317 if (!sblock) {
2318 spin_lock(&sctx->stat_lock);
2319 sctx->stat.malloc_errors++;
2320 spin_unlock(&sctx->stat_lock);
2321 return -ENOMEM;
2322 }
2323
2324 /* one ref inside this function, plus one for each page added to
2325 * a bio later on */
2326 atomic_set(&sblock->refs, 1);
2327 sblock->sctx = sctx;
2328 sblock->no_io_error_seen = 1;
2329
2330 for (index = 0; len > 0; index++) {
2331 struct scrub_page *spage;
2332 u64 l = min_t(u64, len, PAGE_SIZE);
2333
2334 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2335 if (!spage) {
2336 leave_nomem:
2337 spin_lock(&sctx->stat_lock);
2338 sctx->stat.malloc_errors++;
2339 spin_unlock(&sctx->stat_lock);
2340 scrub_block_put(sblock);
2341 return -ENOMEM;
2342 }
2343 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2344 scrub_page_get(spage);
2345 sblock->pagev[index] = spage;
2346 spage->sblock = sblock;
2347 spage->dev = dev;
2348 spage->flags = flags;
2349 spage->generation = gen;
2350 spage->logical = logical;
2351 spage->physical = physical;
2352 spage->physical_for_dev_replace = physical_for_dev_replace;
2353 spage->mirror_num = mirror_num;
2354 if (csum) {
2355 spage->have_csum = 1;
2356 memcpy(spage->csum, csum, sctx->csum_size);
2357 } else {
2358 spage->have_csum = 0;
2359 }
2360 sblock->page_count++;
2361 spage->page = alloc_page(GFP_NOFS);
2362 if (!spage->page)
2363 goto leave_nomem;
2364 len -= l;
2365 logical += l;
2366 physical += l;
2367 physical_for_dev_replace += l;
2368 }
2369
2370 WARN_ON(sblock->page_count == 0);
2371 if (dev->missing) {
2372 /*
2373 * This case should only be hit for RAID 5/6 device replace. See
2374 * the comment in scrub_missing_raid56_pages() for details.
2375 */
2376 scrub_missing_raid56_pages(sblock);
2377 } else {
2378 for (index = 0; index < sblock->page_count; index++) {
2379 struct scrub_page *spage = sblock->pagev[index];
2380 int ret;
2381
2382 ret = scrub_add_page_to_rd_bio(sctx, spage);
2383 if (ret) {
2384 scrub_block_put(sblock);
2385 return ret;
2386 }
2387 }
2388
2389 if (force)
2390 scrub_submit(sctx);
2391 }
2392
2393 /* last one frees, either here or in bio completion for last page */
2394 scrub_block_put(sblock);
2395 return 0;
2396 }
2397
2398 static void scrub_bio_end_io(struct bio *bio)
2399 {
2400 struct scrub_bio *sbio = bio->bi_private;
2401 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
2402
2403 sbio->err = bio->bi_error;
2404 sbio->bio = bio;
2405
2406 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2407 }
2408
2409 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2410 {
2411 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2412 struct scrub_ctx *sctx = sbio->sctx;
2413 int i;
2414
2415 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2416 if (sbio->err) {
2417 for (i = 0; i < sbio->page_count; i++) {
2418 struct scrub_page *spage = sbio->pagev[i];
2419
2420 spage->io_error = 1;
2421 spage->sblock->no_io_error_seen = 0;
2422 }
2423 }
2424
2425 /* now complete the scrub_block items that have all pages completed */
2426 for (i = 0; i < sbio->page_count; i++) {
2427 struct scrub_page *spage = sbio->pagev[i];
2428 struct scrub_block *sblock = spage->sblock;
2429
2430 if (atomic_dec_and_test(&sblock->outstanding_pages))
2431 scrub_block_complete(sblock);
2432 scrub_block_put(sblock);
2433 }
2434
2435 bio_put(sbio->bio);
2436 sbio->bio = NULL;
2437 spin_lock(&sctx->list_lock);
2438 sbio->next_free = sctx->first_free;
2439 sctx->first_free = sbio->index;
2440 spin_unlock(&sctx->list_lock);
2441
2442 if (sctx->is_dev_replace &&
2443 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2444 mutex_lock(&sctx->wr_ctx.wr_lock);
2445 scrub_wr_submit(sctx);
2446 mutex_unlock(&sctx->wr_ctx.wr_lock);
2447 }
2448
2449 scrub_pending_bio_dec(sctx);
2450 }
2451
2452 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2453 unsigned long *bitmap,
2454 u64 start, u64 len)
2455 {
2456 u32 offset;
2457 int nsectors;
2458 int sectorsize = sparity->sctx->dev_root->sectorsize;
2459
2460 if (len >= sparity->stripe_len) {
2461 bitmap_set(bitmap, 0, sparity->nsectors);
2462 return;
2463 }
2464
2465 start -= sparity->logic_start;
2466 start = div_u64_rem(start, sparity->stripe_len, &offset);
2467 offset /= sectorsize;
2468 nsectors = (int)len / sectorsize;
2469
2470 if (offset + nsectors <= sparity->nsectors) {
2471 bitmap_set(bitmap, offset, nsectors);
2472 return;
2473 }
2474
2475 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2476 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2477 }
2478
2479 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2480 u64 start, u64 len)
2481 {
2482 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2483 }
2484
2485 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2486 u64 start, u64 len)
2487 {
2488 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2489 }
2490
2491 static void scrub_block_complete(struct scrub_block *sblock)
2492 {
2493 int corrupted = 0;
2494
2495 if (!sblock->no_io_error_seen) {
2496 corrupted = 1;
2497 scrub_handle_errored_block(sblock);
2498 } else {
2499 /*
2500 * if has checksum error, write via repair mechanism in
2501 * dev replace case, otherwise write here in dev replace
2502 * case.
2503 */
2504 corrupted = scrub_checksum(sblock);
2505 if (!corrupted && sblock->sctx->is_dev_replace)
2506 scrub_write_block_to_dev_replace(sblock);
2507 }
2508
2509 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2510 u64 start = sblock->pagev[0]->logical;
2511 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2512 PAGE_SIZE;
2513
2514 scrub_parity_mark_sectors_error(sblock->sparity,
2515 start, end - start);
2516 }
2517 }
2518
2519 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
2520 u8 *csum)
2521 {
2522 struct btrfs_ordered_sum *sum = NULL;
2523 unsigned long index;
2524 unsigned long num_sectors;
2525
2526 while (!list_empty(&sctx->csum_list)) {
2527 sum = list_first_entry(&sctx->csum_list,
2528 struct btrfs_ordered_sum, list);
2529 if (sum->bytenr > logical)
2530 return 0;
2531 if (sum->bytenr + sum->len > logical)
2532 break;
2533
2534 ++sctx->stat.csum_discards;
2535 list_del(&sum->list);
2536 kfree(sum);
2537 sum = NULL;
2538 }
2539 if (!sum)
2540 return 0;
2541
2542 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2543 num_sectors = sum->len / sctx->sectorsize;
2544 memcpy(csum, sum->sums + index, sctx->csum_size);
2545 if (index == num_sectors - 1) {
2546 list_del(&sum->list);
2547 kfree(sum);
2548 }
2549 return 1;
2550 }
2551
2552 /* scrub extent tries to collect up to 64 kB for each bio */
2553 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2554 u64 physical, struct btrfs_device *dev, u64 flags,
2555 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2556 {
2557 int ret;
2558 u8 csum[BTRFS_CSUM_SIZE];
2559 u32 blocksize;
2560
2561 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2562 blocksize = sctx->sectorsize;
2563 spin_lock(&sctx->stat_lock);
2564 sctx->stat.data_extents_scrubbed++;
2565 sctx->stat.data_bytes_scrubbed += len;
2566 spin_unlock(&sctx->stat_lock);
2567 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2568 blocksize = sctx->nodesize;
2569 spin_lock(&sctx->stat_lock);
2570 sctx->stat.tree_extents_scrubbed++;
2571 sctx->stat.tree_bytes_scrubbed += len;
2572 spin_unlock(&sctx->stat_lock);
2573 } else {
2574 blocksize = sctx->sectorsize;
2575 WARN_ON(1);
2576 }
2577
2578 while (len) {
2579 u64 l = min_t(u64, len, blocksize);
2580 int have_csum = 0;
2581
2582 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2583 /* push csums to sbio */
2584 have_csum = scrub_find_csum(sctx, logical, l, csum);
2585 if (have_csum == 0)
2586 ++sctx->stat.no_csum;
2587 if (sctx->is_dev_replace && !have_csum) {
2588 ret = copy_nocow_pages(sctx, logical, l,
2589 mirror_num,
2590 physical_for_dev_replace);
2591 goto behind_scrub_pages;
2592 }
2593 }
2594 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2595 mirror_num, have_csum ? csum : NULL, 0,
2596 physical_for_dev_replace);
2597 behind_scrub_pages:
2598 if (ret)
2599 return ret;
2600 len -= l;
2601 logical += l;
2602 physical += l;
2603 physical_for_dev_replace += l;
2604 }
2605 return 0;
2606 }
2607
2608 static int scrub_pages_for_parity(struct scrub_parity *sparity,
2609 u64 logical, u64 len,
2610 u64 physical, struct btrfs_device *dev,
2611 u64 flags, u64 gen, int mirror_num, u8 *csum)
2612 {
2613 struct scrub_ctx *sctx = sparity->sctx;
2614 struct scrub_block *sblock;
2615 int index;
2616
2617 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2618 if (!sblock) {
2619 spin_lock(&sctx->stat_lock);
2620 sctx->stat.malloc_errors++;
2621 spin_unlock(&sctx->stat_lock);
2622 return -ENOMEM;
2623 }
2624
2625 /* one ref inside this function, plus one for each page added to
2626 * a bio later on */
2627 atomic_set(&sblock->refs, 1);
2628 sblock->sctx = sctx;
2629 sblock->no_io_error_seen = 1;
2630 sblock->sparity = sparity;
2631 scrub_parity_get(sparity);
2632
2633 for (index = 0; len > 0; index++) {
2634 struct scrub_page *spage;
2635 u64 l = min_t(u64, len, PAGE_SIZE);
2636
2637 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2638 if (!spage) {
2639 leave_nomem:
2640 spin_lock(&sctx->stat_lock);
2641 sctx->stat.malloc_errors++;
2642 spin_unlock(&sctx->stat_lock);
2643 scrub_block_put(sblock);
2644 return -ENOMEM;
2645 }
2646 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2647 /* For scrub block */
2648 scrub_page_get(spage);
2649 sblock->pagev[index] = spage;
2650 /* For scrub parity */
2651 scrub_page_get(spage);
2652 list_add_tail(&spage->list, &sparity->spages);
2653 spage->sblock = sblock;
2654 spage->dev = dev;
2655 spage->flags = flags;
2656 spage->generation = gen;
2657 spage->logical = logical;
2658 spage->physical = physical;
2659 spage->mirror_num = mirror_num;
2660 if (csum) {
2661 spage->have_csum = 1;
2662 memcpy(spage->csum, csum, sctx->csum_size);
2663 } else {
2664 spage->have_csum = 0;
2665 }
2666 sblock->page_count++;
2667 spage->page = alloc_page(GFP_NOFS);
2668 if (!spage->page)
2669 goto leave_nomem;
2670 len -= l;
2671 logical += l;
2672 physical += l;
2673 }
2674
2675 WARN_ON(sblock->page_count == 0);
2676 for (index = 0; index < sblock->page_count; index++) {
2677 struct scrub_page *spage = sblock->pagev[index];
2678 int ret;
2679
2680 ret = scrub_add_page_to_rd_bio(sctx, spage);
2681 if (ret) {
2682 scrub_block_put(sblock);
2683 return ret;
2684 }
2685 }
2686
2687 /* last one frees, either here or in bio completion for last page */
2688 scrub_block_put(sblock);
2689 return 0;
2690 }
2691
2692 static int scrub_extent_for_parity(struct scrub_parity *sparity,
2693 u64 logical, u64 len,
2694 u64 physical, struct btrfs_device *dev,
2695 u64 flags, u64 gen, int mirror_num)
2696 {
2697 struct scrub_ctx *sctx = sparity->sctx;
2698 int ret;
2699 u8 csum[BTRFS_CSUM_SIZE];
2700 u32 blocksize;
2701
2702 if (dev->missing) {
2703 scrub_parity_mark_sectors_error(sparity, logical, len);
2704 return 0;
2705 }
2706
2707 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2708 blocksize = sctx->sectorsize;
2709 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2710 blocksize = sctx->nodesize;
2711 } else {
2712 blocksize = sctx->sectorsize;
2713 WARN_ON(1);
2714 }
2715
2716 while (len) {
2717 u64 l = min_t(u64, len, blocksize);
2718 int have_csum = 0;
2719
2720 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2721 /* push csums to sbio */
2722 have_csum = scrub_find_csum(sctx, logical, l, csum);
2723 if (have_csum == 0)
2724 goto skip;
2725 }
2726 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2727 flags, gen, mirror_num,
2728 have_csum ? csum : NULL);
2729 if (ret)
2730 return ret;
2731 skip:
2732 len -= l;
2733 logical += l;
2734 physical += l;
2735 }
2736 return 0;
2737 }
2738
2739 /*
2740 * Given a physical address, this will calculate it's
2741 * logical offset. if this is a parity stripe, it will return
2742 * the most left data stripe's logical offset.
2743 *
2744 * return 0 if it is a data stripe, 1 means parity stripe.
2745 */
2746 static int get_raid56_logic_offset(u64 physical, int num,
2747 struct map_lookup *map, u64 *offset,
2748 u64 *stripe_start)
2749 {
2750 int i;
2751 int j = 0;
2752 u64 stripe_nr;
2753 u64 last_offset;
2754 u32 stripe_index;
2755 u32 rot;
2756
2757 last_offset = (physical - map->stripes[num].physical) *
2758 nr_data_stripes(map);
2759 if (stripe_start)
2760 *stripe_start = last_offset;
2761
2762 *offset = last_offset;
2763 for (i = 0; i < nr_data_stripes(map); i++) {
2764 *offset = last_offset + i * map->stripe_len;
2765
2766 stripe_nr = div_u64(*offset, map->stripe_len);
2767 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
2768
2769 /* Work out the disk rotation on this stripe-set */
2770 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2771 /* calculate which stripe this data locates */
2772 rot += i;
2773 stripe_index = rot % map->num_stripes;
2774 if (stripe_index == num)
2775 return 0;
2776 if (stripe_index < num)
2777 j++;
2778 }
2779 *offset = last_offset + j * map->stripe_len;
2780 return 1;
2781 }
2782
2783 static void scrub_free_parity(struct scrub_parity *sparity)
2784 {
2785 struct scrub_ctx *sctx = sparity->sctx;
2786 struct scrub_page *curr, *next;
2787 int nbits;
2788
2789 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2790 if (nbits) {
2791 spin_lock(&sctx->stat_lock);
2792 sctx->stat.read_errors += nbits;
2793 sctx->stat.uncorrectable_errors += nbits;
2794 spin_unlock(&sctx->stat_lock);
2795 }
2796
2797 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2798 list_del_init(&curr->list);
2799 scrub_page_put(curr);
2800 }
2801
2802 kfree(sparity);
2803 }
2804
2805 static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2806 {
2807 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2808 work);
2809 struct scrub_ctx *sctx = sparity->sctx;
2810
2811 scrub_free_parity(sparity);
2812 scrub_pending_bio_dec(sctx);
2813 }
2814
2815 static void scrub_parity_bio_endio(struct bio *bio)
2816 {
2817 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2818
2819 if (bio->bi_error)
2820 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2821 sparity->nsectors);
2822
2823 bio_put(bio);
2824
2825 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2826 scrub_parity_bio_endio_worker, NULL, NULL);
2827 btrfs_queue_work(sparity->sctx->dev_root->fs_info->scrub_parity_workers,
2828 &sparity->work);
2829 }
2830
2831 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2832 {
2833 struct scrub_ctx *sctx = sparity->sctx;
2834 struct bio *bio;
2835 struct btrfs_raid_bio *rbio;
2836 struct scrub_page *spage;
2837 struct btrfs_bio *bbio = NULL;
2838 u64 length;
2839 int ret;
2840
2841 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2842 sparity->nsectors))
2843 goto out;
2844
2845 length = sparity->logic_end - sparity->logic_start;
2846 ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
2847 sparity->logic_start,
2848 &length, &bbio, 0, 1);
2849 if (ret || !bbio || !bbio->raid_map)
2850 goto bbio_out;
2851
2852 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2853 if (!bio)
2854 goto bbio_out;
2855
2856 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2857 bio->bi_private = sparity;
2858 bio->bi_end_io = scrub_parity_bio_endio;
2859
2860 rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio,
2861 length, sparity->scrub_dev,
2862 sparity->dbitmap,
2863 sparity->nsectors);
2864 if (!rbio)
2865 goto rbio_out;
2866
2867 list_for_each_entry(spage, &sparity->spages, list)
2868 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2869
2870 scrub_pending_bio_inc(sctx);
2871 raid56_parity_submit_scrub_rbio(rbio);
2872 return;
2873
2874 rbio_out:
2875 bio_put(bio);
2876 bbio_out:
2877 btrfs_put_bbio(bbio);
2878 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2879 sparity->nsectors);
2880 spin_lock(&sctx->stat_lock);
2881 sctx->stat.malloc_errors++;
2882 spin_unlock(&sctx->stat_lock);
2883 out:
2884 scrub_free_parity(sparity);
2885 }
2886
2887 static inline int scrub_calc_parity_bitmap_len(int nsectors)
2888 {
2889 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * (BITS_PER_LONG / 8);
2890 }
2891
2892 static void scrub_parity_get(struct scrub_parity *sparity)
2893 {
2894 atomic_inc(&sparity->refs);
2895 }
2896
2897 static void scrub_parity_put(struct scrub_parity *sparity)
2898 {
2899 if (!atomic_dec_and_test(&sparity->refs))
2900 return;
2901
2902 scrub_parity_check_and_repair(sparity);
2903 }
2904
2905 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2906 struct map_lookup *map,
2907 struct btrfs_device *sdev,
2908 struct btrfs_path *path,
2909 u64 logic_start,
2910 u64 logic_end)
2911 {
2912 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2913 struct btrfs_root *root = fs_info->extent_root;
2914 struct btrfs_root *csum_root = fs_info->csum_root;
2915 struct btrfs_extent_item *extent;
2916 struct btrfs_bio *bbio = NULL;
2917 u64 flags;
2918 int ret;
2919 int slot;
2920 struct extent_buffer *l;
2921 struct btrfs_key key;
2922 u64 generation;
2923 u64 extent_logical;
2924 u64 extent_physical;
2925 u64 extent_len;
2926 u64 mapped_length;
2927 struct btrfs_device *extent_dev;
2928 struct scrub_parity *sparity;
2929 int nsectors;
2930 int bitmap_len;
2931 int extent_mirror_num;
2932 int stop_loop = 0;
2933
2934 nsectors = map->stripe_len / root->sectorsize;
2935 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2936 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2937 GFP_NOFS);
2938 if (!sparity) {
2939 spin_lock(&sctx->stat_lock);
2940 sctx->stat.malloc_errors++;
2941 spin_unlock(&sctx->stat_lock);
2942 return -ENOMEM;
2943 }
2944
2945 sparity->stripe_len = map->stripe_len;
2946 sparity->nsectors = nsectors;
2947 sparity->sctx = sctx;
2948 sparity->scrub_dev = sdev;
2949 sparity->logic_start = logic_start;
2950 sparity->logic_end = logic_end;
2951 atomic_set(&sparity->refs, 1);
2952 INIT_LIST_HEAD(&sparity->spages);
2953 sparity->dbitmap = sparity->bitmap;
2954 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2955
2956 ret = 0;
2957 while (logic_start < logic_end) {
2958 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2959 key.type = BTRFS_METADATA_ITEM_KEY;
2960 else
2961 key.type = BTRFS_EXTENT_ITEM_KEY;
2962 key.objectid = logic_start;
2963 key.offset = (u64)-1;
2964
2965 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2966 if (ret < 0)
2967 goto out;
2968
2969 if (ret > 0) {
2970 ret = btrfs_previous_extent_item(root, path, 0);
2971 if (ret < 0)
2972 goto out;
2973 if (ret > 0) {
2974 btrfs_release_path(path);
2975 ret = btrfs_search_slot(NULL, root, &key,
2976 path, 0, 0);
2977 if (ret < 0)
2978 goto out;
2979 }
2980 }
2981
2982 stop_loop = 0;
2983 while (1) {
2984 u64 bytes;
2985
2986 l = path->nodes[0];
2987 slot = path->slots[0];
2988 if (slot >= btrfs_header_nritems(l)) {
2989 ret = btrfs_next_leaf(root, path);
2990 if (ret == 0)
2991 continue;
2992 if (ret < 0)
2993 goto out;
2994
2995 stop_loop = 1;
2996 break;
2997 }
2998 btrfs_item_key_to_cpu(l, &key, slot);
2999
3000 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3001 key.type != BTRFS_METADATA_ITEM_KEY)
3002 goto next;
3003
3004 if (key.type == BTRFS_METADATA_ITEM_KEY)
3005 bytes = root->nodesize;
3006 else
3007 bytes = key.offset;
3008
3009 if (key.objectid + bytes <= logic_start)
3010 goto next;
3011
3012 if (key.objectid >= logic_end) {
3013 stop_loop = 1;
3014 break;
3015 }
3016
3017 while (key.objectid >= logic_start + map->stripe_len)
3018 logic_start += map->stripe_len;
3019
3020 extent = btrfs_item_ptr(l, slot,
3021 struct btrfs_extent_item);
3022 flags = btrfs_extent_flags(l, extent);
3023 generation = btrfs_extent_generation(l, extent);
3024
3025 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3026 (key.objectid < logic_start ||
3027 key.objectid + bytes >
3028 logic_start + map->stripe_len)) {
3029 btrfs_err(fs_info, "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3030 key.objectid, logic_start);
3031 spin_lock(&sctx->stat_lock);
3032 sctx->stat.uncorrectable_errors++;
3033 spin_unlock(&sctx->stat_lock);
3034 goto next;
3035 }
3036 again:
3037 extent_logical = key.objectid;
3038 extent_len = bytes;
3039
3040 if (extent_logical < logic_start) {
3041 extent_len -= logic_start - extent_logical;
3042 extent_logical = logic_start;
3043 }
3044
3045 if (extent_logical + extent_len >
3046 logic_start + map->stripe_len)
3047 extent_len = logic_start + map->stripe_len -
3048 extent_logical;
3049
3050 scrub_parity_mark_sectors_data(sparity, extent_logical,
3051 extent_len);
3052
3053 mapped_length = extent_len;
3054 ret = btrfs_map_block(fs_info, READ, extent_logical,
3055 &mapped_length, &bbio, 0);
3056 if (!ret) {
3057 if (!bbio || mapped_length < extent_len)
3058 ret = -EIO;
3059 }
3060 if (ret) {
3061 btrfs_put_bbio(bbio);
3062 goto out;
3063 }
3064 extent_physical = bbio->stripes[0].physical;
3065 extent_mirror_num = bbio->mirror_num;
3066 extent_dev = bbio->stripes[0].dev;
3067 btrfs_put_bbio(bbio);
3068
3069 ret = btrfs_lookup_csums_range(csum_root,
3070 extent_logical,
3071 extent_logical + extent_len - 1,
3072 &sctx->csum_list, 1);
3073 if (ret)
3074 goto out;
3075
3076 ret = scrub_extent_for_parity(sparity, extent_logical,
3077 extent_len,
3078 extent_physical,
3079 extent_dev, flags,
3080 generation,
3081 extent_mirror_num);
3082
3083 scrub_free_csums(sctx);
3084
3085 if (ret)
3086 goto out;
3087
3088 if (extent_logical + extent_len <
3089 key.objectid + bytes) {
3090 logic_start += map->stripe_len;
3091
3092 if (logic_start >= logic_end) {
3093 stop_loop = 1;
3094 break;
3095 }
3096
3097 if (logic_start < key.objectid + bytes) {
3098 cond_resched();
3099 goto again;
3100 }
3101 }
3102 next:
3103 path->slots[0]++;
3104 }
3105
3106 btrfs_release_path(path);
3107
3108 if (stop_loop)
3109 break;
3110
3111 logic_start += map->stripe_len;
3112 }
3113 out:
3114 if (ret < 0)
3115 scrub_parity_mark_sectors_error(sparity, logic_start,
3116 logic_end - logic_start);
3117 scrub_parity_put(sparity);
3118 scrub_submit(sctx);
3119 mutex_lock(&sctx->wr_ctx.wr_lock);
3120 scrub_wr_submit(sctx);
3121 mutex_unlock(&sctx->wr_ctx.wr_lock);
3122
3123 btrfs_release_path(path);
3124 return ret < 0 ? ret : 0;
3125 }
3126
3127 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3128 struct map_lookup *map,
3129 struct btrfs_device *scrub_dev,
3130 int num, u64 base, u64 length,
3131 int is_dev_replace)
3132 {
3133 struct btrfs_path *path, *ppath;
3134 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3135 struct btrfs_root *root = fs_info->extent_root;
3136 struct btrfs_root *csum_root = fs_info->csum_root;
3137 struct btrfs_extent_item *extent;
3138 struct blk_plug plug;
3139 u64 flags;
3140 int ret;
3141 int slot;
3142 u64 nstripes;
3143 struct extent_buffer *l;
3144 struct btrfs_key key;
3145 u64 physical;
3146 u64 logical;
3147 u64 logic_end;
3148 u64 physical_end;
3149 u64 generation;
3150 int mirror_num;
3151 struct reada_control *reada1;
3152 struct reada_control *reada2;
3153 struct btrfs_key key_start;
3154 struct btrfs_key key_end;
3155 u64 increment = map->stripe_len;
3156 u64 offset;
3157 u64 extent_logical;
3158 u64 extent_physical;
3159 u64 extent_len;
3160 u64 stripe_logical;
3161 u64 stripe_end;
3162 struct btrfs_device *extent_dev;
3163 int extent_mirror_num;
3164 int stop_loop = 0;
3165
3166 physical = map->stripes[num].physical;
3167 offset = 0;
3168 nstripes = div_u64(length, map->stripe_len);
3169 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3170 offset = map->stripe_len * num;
3171 increment = map->stripe_len * map->num_stripes;
3172 mirror_num = 1;
3173 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3174 int factor = map->num_stripes / map->sub_stripes;
3175 offset = map->stripe_len * (num / map->sub_stripes);
3176 increment = map->stripe_len * factor;
3177 mirror_num = num % map->sub_stripes + 1;
3178 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3179 increment = map->stripe_len;
3180 mirror_num = num % map->num_stripes + 1;
3181 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3182 increment = map->stripe_len;
3183 mirror_num = num % map->num_stripes + 1;
3184 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3185 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3186 increment = map->stripe_len * nr_data_stripes(map);
3187 mirror_num = 1;
3188 } else {
3189 increment = map->stripe_len;
3190 mirror_num = 1;
3191 }
3192
3193 path = btrfs_alloc_path();
3194 if (!path)
3195 return -ENOMEM;
3196
3197 ppath = btrfs_alloc_path();
3198 if (!ppath) {
3199 btrfs_free_path(path);
3200 return -ENOMEM;
3201 }
3202
3203 /*
3204 * work on commit root. The related disk blocks are static as
3205 * long as COW is applied. This means, it is save to rewrite
3206 * them to repair disk errors without any race conditions
3207 */
3208 path->search_commit_root = 1;
3209 path->skip_locking = 1;
3210
3211 ppath->search_commit_root = 1;
3212 ppath->skip_locking = 1;
3213 /*
3214 * trigger the readahead for extent tree csum tree and wait for
3215 * completion. During readahead, the scrub is officially paused
3216 * to not hold off transaction commits
3217 */
3218 logical = base + offset;
3219 physical_end = physical + nstripes * map->stripe_len;
3220 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3221 get_raid56_logic_offset(physical_end, num,
3222 map, &logic_end, NULL);
3223 logic_end += base;
3224 } else {
3225 logic_end = logical + increment * nstripes;
3226 }
3227 wait_event(sctx->list_wait,
3228 atomic_read(&sctx->bios_in_flight) == 0);
3229 scrub_blocked_if_needed(fs_info);
3230
3231 /* FIXME it might be better to start readahead at commit root */
3232 key_start.objectid = logical;
3233 key_start.type = BTRFS_EXTENT_ITEM_KEY;
3234 key_start.offset = (u64)0;
3235 key_end.objectid = logic_end;
3236 key_end.type = BTRFS_METADATA_ITEM_KEY;
3237 key_end.offset = (u64)-1;
3238 reada1 = btrfs_reada_add(root, &key_start, &key_end);
3239
3240 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3241 key_start.type = BTRFS_EXTENT_CSUM_KEY;
3242 key_start.offset = logical;
3243 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3244 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3245 key_end.offset = logic_end;
3246 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
3247
3248 if (!IS_ERR(reada1))
3249 btrfs_reada_wait(reada1);
3250 if (!IS_ERR(reada2))
3251 btrfs_reada_wait(reada2);
3252
3253
3254 /*
3255 * collect all data csums for the stripe to avoid seeking during
3256 * the scrub. This might currently (crc32) end up to be about 1MB
3257 */
3258 blk_start_plug(&plug);
3259
3260 /*
3261 * now find all extents for each stripe and scrub them
3262 */
3263 ret = 0;
3264 while (physical < physical_end) {
3265 /*
3266 * canceled?
3267 */
3268 if (atomic_read(&fs_info->scrub_cancel_req) ||
3269 atomic_read(&sctx->cancel_req)) {
3270 ret = -ECANCELED;
3271 goto out;
3272 }
3273 /*
3274 * check to see if we have to pause
3275 */
3276 if (atomic_read(&fs_info->scrub_pause_req)) {
3277 /* push queued extents */
3278 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3279 scrub_submit(sctx);
3280 mutex_lock(&sctx->wr_ctx.wr_lock);
3281 scrub_wr_submit(sctx);
3282 mutex_unlock(&sctx->wr_ctx.wr_lock);
3283 wait_event(sctx->list_wait,
3284 atomic_read(&sctx->bios_in_flight) == 0);
3285 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3286 scrub_blocked_if_needed(fs_info);
3287 }
3288
3289 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3290 ret = get_raid56_logic_offset(physical, num, map,
3291 &logical,
3292 &stripe_logical);
3293 logical += base;
3294 if (ret) {
3295 /* it is parity strip */
3296 stripe_logical += base;
3297 stripe_end = stripe_logical + increment;
3298 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3299 ppath, stripe_logical,
3300 stripe_end);
3301 if (ret)
3302 goto out;
3303 goto skip;
3304 }
3305 }
3306
3307 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3308 key.type = BTRFS_METADATA_ITEM_KEY;
3309 else
3310 key.type = BTRFS_EXTENT_ITEM_KEY;
3311 key.objectid = logical;
3312 key.offset = (u64)-1;
3313
3314 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3315 if (ret < 0)
3316 goto out;
3317
3318 if (ret > 0) {
3319 ret = btrfs_previous_extent_item(root, path, 0);
3320 if (ret < 0)
3321 goto out;
3322 if (ret > 0) {
3323 /* there's no smaller item, so stick with the
3324 * larger one */
3325 btrfs_release_path(path);
3326 ret = btrfs_search_slot(NULL, root, &key,
3327 path, 0, 0);
3328 if (ret < 0)
3329 goto out;
3330 }
3331 }
3332
3333 stop_loop = 0;
3334 while (1) {
3335 u64 bytes;
3336
3337 l = path->nodes[0];
3338 slot = path->slots[0];
3339 if (slot >= btrfs_header_nritems(l)) {
3340 ret = btrfs_next_leaf(root, path);
3341 if (ret == 0)
3342 continue;
3343 if (ret < 0)
3344 goto out;
3345
3346 stop_loop = 1;
3347 break;
3348 }
3349 btrfs_item_key_to_cpu(l, &key, slot);
3350
3351 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3352 key.type != BTRFS_METADATA_ITEM_KEY)
3353 goto next;
3354
3355 if (key.type == BTRFS_METADATA_ITEM_KEY)
3356 bytes = root->nodesize;
3357 else
3358 bytes = key.offset;
3359
3360 if (key.objectid + bytes <= logical)
3361 goto next;
3362
3363 if (key.objectid >= logical + map->stripe_len) {
3364 /* out of this device extent */
3365 if (key.objectid >= logic_end)
3366 stop_loop = 1;
3367 break;
3368 }
3369
3370 extent = btrfs_item_ptr(l, slot,
3371 struct btrfs_extent_item);
3372 flags = btrfs_extent_flags(l, extent);
3373 generation = btrfs_extent_generation(l, extent);
3374
3375 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3376 (key.objectid < logical ||
3377 key.objectid + bytes >
3378 logical + map->stripe_len)) {
3379 btrfs_err(fs_info,
3380 "scrub: tree block %llu spanning "
3381 "stripes, ignored. logical=%llu",
3382 key.objectid, logical);
3383 spin_lock(&sctx->stat_lock);
3384 sctx->stat.uncorrectable_errors++;
3385 spin_unlock(&sctx->stat_lock);
3386 goto next;
3387 }
3388
3389 again:
3390 extent_logical = key.objectid;
3391 extent_len = bytes;
3392
3393 /*
3394 * trim extent to this stripe
3395 */
3396 if (extent_logical < logical) {
3397 extent_len -= logical - extent_logical;
3398 extent_logical = logical;
3399 }
3400 if (extent_logical + extent_len >
3401 logical + map->stripe_len) {
3402 extent_len = logical + map->stripe_len -
3403 extent_logical;
3404 }
3405
3406 extent_physical = extent_logical - logical + physical;
3407 extent_dev = scrub_dev;
3408 extent_mirror_num = mirror_num;
3409 if (is_dev_replace)
3410 scrub_remap_extent(fs_info, extent_logical,
3411 extent_len, &extent_physical,
3412 &extent_dev,
3413 &extent_mirror_num);
3414
3415 ret = btrfs_lookup_csums_range(csum_root,
3416 extent_logical,
3417 extent_logical +
3418 extent_len - 1,
3419 &sctx->csum_list, 1);
3420 if (ret)
3421 goto out;
3422
3423 ret = scrub_extent(sctx, extent_logical, extent_len,
3424 extent_physical, extent_dev, flags,
3425 generation, extent_mirror_num,
3426 extent_logical - logical + physical);
3427
3428 scrub_free_csums(sctx);
3429
3430 if (ret)
3431 goto out;
3432
3433 if (extent_logical + extent_len <
3434 key.objectid + bytes) {
3435 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3436 /*
3437 * loop until we find next data stripe
3438 * or we have finished all stripes.
3439 */
3440 loop:
3441 physical += map->stripe_len;
3442 ret = get_raid56_logic_offset(physical,
3443 num, map, &logical,
3444 &stripe_logical);
3445 logical += base;
3446
3447 if (ret && physical < physical_end) {
3448 stripe_logical += base;
3449 stripe_end = stripe_logical +
3450 increment;
3451 ret = scrub_raid56_parity(sctx,
3452 map, scrub_dev, ppath,
3453 stripe_logical,
3454 stripe_end);
3455 if (ret)
3456 goto out;
3457 goto loop;
3458 }
3459 } else {
3460 physical += map->stripe_len;
3461 logical += increment;
3462 }
3463 if (logical < key.objectid + bytes) {
3464 cond_resched();
3465 goto again;
3466 }
3467
3468 if (physical >= physical_end) {
3469 stop_loop = 1;
3470 break;
3471 }
3472 }
3473 next:
3474 path->slots[0]++;
3475 }
3476 btrfs_release_path(path);
3477 skip:
3478 logical += increment;
3479 physical += map->stripe_len;
3480 spin_lock(&sctx->stat_lock);
3481 if (stop_loop)
3482 sctx->stat.last_physical = map->stripes[num].physical +
3483 length;
3484 else
3485 sctx->stat.last_physical = physical;
3486 spin_unlock(&sctx->stat_lock);
3487 if (stop_loop)
3488 break;
3489 }
3490 out:
3491 /* push queued extents */
3492 scrub_submit(sctx);
3493 mutex_lock(&sctx->wr_ctx.wr_lock);
3494 scrub_wr_submit(sctx);
3495 mutex_unlock(&sctx->wr_ctx.wr_lock);
3496
3497 blk_finish_plug(&plug);
3498 btrfs_free_path(path);
3499 btrfs_free_path(ppath);
3500 return ret < 0 ? ret : 0;
3501 }
3502
3503 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3504 struct btrfs_device *scrub_dev,
3505 u64 chunk_offset, u64 length,
3506 u64 dev_offset, int is_dev_replace)
3507 {
3508 struct btrfs_mapping_tree *map_tree =
3509 &sctx->dev_root->fs_info->mapping_tree;
3510 struct map_lookup *map;
3511 struct extent_map *em;
3512 int i;
3513 int ret = 0;
3514
3515 read_lock(&map_tree->map_tree.lock);
3516 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3517 read_unlock(&map_tree->map_tree.lock);
3518
3519 if (!em)
3520 return -EINVAL;
3521
3522 map = (struct map_lookup *)em->bdev;
3523 if (em->start != chunk_offset)
3524 goto out;
3525
3526 if (em->len < length)
3527 goto out;
3528
3529 for (i = 0; i < map->num_stripes; ++i) {
3530 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3531 map->stripes[i].physical == dev_offset) {
3532 ret = scrub_stripe(sctx, map, scrub_dev, i,
3533 chunk_offset, length,
3534 is_dev_replace);
3535 if (ret)
3536 goto out;
3537 }
3538 }
3539 out:
3540 free_extent_map(em);
3541
3542 return ret;
3543 }
3544
3545 static noinline_for_stack
3546 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3547 struct btrfs_device *scrub_dev, u64 start, u64 end,
3548 int is_dev_replace)
3549 {
3550 struct btrfs_dev_extent *dev_extent = NULL;
3551 struct btrfs_path *path;
3552 struct btrfs_root *root = sctx->dev_root;
3553 struct btrfs_fs_info *fs_info = root->fs_info;
3554 u64 length;
3555 u64 chunk_offset;
3556 int ret = 0;
3557 int slot;
3558 struct extent_buffer *l;
3559 struct btrfs_key key;
3560 struct btrfs_key found_key;
3561 struct btrfs_block_group_cache *cache;
3562 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3563
3564 path = btrfs_alloc_path();
3565 if (!path)
3566 return -ENOMEM;
3567
3568 path->reada = 2;
3569 path->search_commit_root = 1;
3570 path->skip_locking = 1;
3571
3572 key.objectid = scrub_dev->devid;
3573 key.offset = 0ull;
3574 key.type = BTRFS_DEV_EXTENT_KEY;
3575
3576 while (1) {
3577 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3578 if (ret < 0)
3579 break;
3580 if (ret > 0) {
3581 if (path->slots[0] >=
3582 btrfs_header_nritems(path->nodes[0])) {
3583 ret = btrfs_next_leaf(root, path);
3584 if (ret < 0)
3585 break;
3586 if (ret > 0) {
3587 ret = 0;
3588 break;
3589 }
3590 } else {
3591 ret = 0;
3592 }
3593 }
3594
3595 l = path->nodes[0];
3596 slot = path->slots[0];
3597
3598 btrfs_item_key_to_cpu(l, &found_key, slot);
3599
3600 if (found_key.objectid != scrub_dev->devid)
3601 break;
3602
3603 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3604 break;
3605
3606 if (found_key.offset >= end)
3607 break;
3608
3609 if (found_key.offset < key.offset)
3610 break;
3611
3612 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3613 length = btrfs_dev_extent_length(l, dev_extent);
3614
3615 if (found_key.offset + length <= start)
3616 goto skip;
3617
3618 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3619
3620 /*
3621 * get a reference on the corresponding block group to prevent
3622 * the chunk from going away while we scrub it
3623 */
3624 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3625
3626 /* some chunks are removed but not committed to disk yet,
3627 * continue scrubbing */
3628 if (!cache)
3629 goto skip;
3630
3631 /*
3632 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3633 * to avoid deadlock caused by:
3634 * btrfs_inc_block_group_ro()
3635 * -> btrfs_wait_for_commit()
3636 * -> btrfs_commit_transaction()
3637 * -> btrfs_scrub_pause()
3638 */
3639 scrub_pause_on(fs_info);
3640 ret = btrfs_inc_block_group_ro(root, cache);
3641 scrub_pause_off(fs_info);
3642 if (ret) {
3643 btrfs_put_block_group(cache);
3644 break;
3645 }
3646
3647 dev_replace->cursor_right = found_key.offset + length;
3648 dev_replace->cursor_left = found_key.offset;
3649 dev_replace->item_needs_writeback = 1;
3650 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3651 found_key.offset, is_dev_replace);
3652
3653 /*
3654 * flush, submit all pending read and write bios, afterwards
3655 * wait for them.
3656 * Note that in the dev replace case, a read request causes
3657 * write requests that are submitted in the read completion
3658 * worker. Therefore in the current situation, it is required
3659 * that all write requests are flushed, so that all read and
3660 * write requests are really completed when bios_in_flight
3661 * changes to 0.
3662 */
3663 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3664 scrub_submit(sctx);
3665 mutex_lock(&sctx->wr_ctx.wr_lock);
3666 scrub_wr_submit(sctx);
3667 mutex_unlock(&sctx->wr_ctx.wr_lock);
3668
3669 wait_event(sctx->list_wait,
3670 atomic_read(&sctx->bios_in_flight) == 0);
3671
3672 scrub_pause_on(fs_info);
3673
3674 /*
3675 * must be called before we decrease @scrub_paused.
3676 * make sure we don't block transaction commit while
3677 * we are waiting pending workers finished.
3678 */
3679 wait_event(sctx->list_wait,
3680 atomic_read(&sctx->workers_pending) == 0);
3681 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3682
3683 scrub_pause_off(fs_info);
3684
3685 btrfs_dec_block_group_ro(root, cache);
3686
3687 btrfs_put_block_group(cache);
3688 if (ret)
3689 break;
3690 if (is_dev_replace &&
3691 atomic64_read(&dev_replace->num_write_errors) > 0) {
3692 ret = -EIO;
3693 break;
3694 }
3695 if (sctx->stat.malloc_errors > 0) {
3696 ret = -ENOMEM;
3697 break;
3698 }
3699
3700 dev_replace->cursor_left = dev_replace->cursor_right;
3701 dev_replace->item_needs_writeback = 1;
3702 skip:
3703 key.offset = found_key.offset + length;
3704 btrfs_release_path(path);
3705 }
3706
3707 btrfs_free_path(path);
3708
3709 return ret;
3710 }
3711
3712 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3713 struct btrfs_device *scrub_dev)
3714 {
3715 int i;
3716 u64 bytenr;
3717 u64 gen;
3718 int ret;
3719 struct btrfs_root *root = sctx->dev_root;
3720
3721 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
3722 return -EIO;
3723
3724 /* Seed devices of a new filesystem has their own generation. */
3725 if (scrub_dev->fs_devices != root->fs_info->fs_devices)
3726 gen = scrub_dev->generation;
3727 else
3728 gen = root->fs_info->last_trans_committed;
3729
3730 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3731 bytenr = btrfs_sb_offset(i);
3732 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3733 scrub_dev->commit_total_bytes)
3734 break;
3735
3736 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3737 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3738 NULL, 1, bytenr);
3739 if (ret)
3740 return ret;
3741 }
3742 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3743
3744 return 0;
3745 }
3746
3747 /*
3748 * get a reference count on fs_info->scrub_workers. start worker if necessary
3749 */
3750 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3751 int is_dev_replace)
3752 {
3753 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3754 int max_active = fs_info->thread_pool_size;
3755
3756 if (fs_info->scrub_workers_refcnt == 0) {
3757 if (is_dev_replace)
3758 fs_info->scrub_workers =
3759 btrfs_alloc_workqueue("btrfs-scrub", flags,
3760 1, 4);
3761 else
3762 fs_info->scrub_workers =
3763 btrfs_alloc_workqueue("btrfs-scrub", flags,
3764 max_active, 4);
3765 if (!fs_info->scrub_workers)
3766 goto fail_scrub_workers;
3767
3768 fs_info->scrub_wr_completion_workers =
3769 btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
3770 max_active, 2);
3771 if (!fs_info->scrub_wr_completion_workers)
3772 goto fail_scrub_wr_completion_workers;
3773
3774 fs_info->scrub_nocow_workers =
3775 btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
3776 if (!fs_info->scrub_nocow_workers)
3777 goto fail_scrub_nocow_workers;
3778 fs_info->scrub_parity_workers =
3779 btrfs_alloc_workqueue("btrfs-scrubparity", flags,
3780 max_active, 2);
3781 if (!fs_info->scrub_parity_workers)
3782 goto fail_scrub_parity_workers;
3783 }
3784 ++fs_info->scrub_workers_refcnt;
3785 return 0;
3786
3787 fail_scrub_parity_workers:
3788 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3789 fail_scrub_nocow_workers:
3790 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3791 fail_scrub_wr_completion_workers:
3792 btrfs_destroy_workqueue(fs_info->scrub_workers);
3793 fail_scrub_workers:
3794 return -ENOMEM;
3795 }
3796
3797 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
3798 {
3799 if (--fs_info->scrub_workers_refcnt == 0) {
3800 btrfs_destroy_workqueue(fs_info->scrub_workers);
3801 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3802 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3803 btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
3804 }
3805 WARN_ON(fs_info->scrub_workers_refcnt < 0);
3806 }
3807
3808 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3809 u64 end, struct btrfs_scrub_progress *progress,
3810 int readonly, int is_dev_replace)
3811 {
3812 struct scrub_ctx *sctx;
3813 int ret;
3814 struct btrfs_device *dev;
3815 struct rcu_string *name;
3816
3817 if (btrfs_fs_closing(fs_info))
3818 return -EINVAL;
3819
3820 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
3821 /*
3822 * in this case scrub is unable to calculate the checksum
3823 * the way scrub is implemented. Do not handle this
3824 * situation at all because it won't ever happen.
3825 */
3826 btrfs_err(fs_info,
3827 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3828 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
3829 return -EINVAL;
3830 }
3831
3832 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
3833 /* not supported for data w/o checksums */
3834 btrfs_err(fs_info,
3835 "scrub: size assumption sectorsize != PAGE_SIZE "
3836 "(%d != %lu) fails",
3837 fs_info->chunk_root->sectorsize, PAGE_SIZE);
3838 return -EINVAL;
3839 }
3840
3841 if (fs_info->chunk_root->nodesize >
3842 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3843 fs_info->chunk_root->sectorsize >
3844 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3845 /*
3846 * would exhaust the array bounds of pagev member in
3847 * struct scrub_block
3848 */
3849 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
3850 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3851 fs_info->chunk_root->nodesize,
3852 SCRUB_MAX_PAGES_PER_BLOCK,
3853 fs_info->chunk_root->sectorsize,
3854 SCRUB_MAX_PAGES_PER_BLOCK);
3855 return -EINVAL;
3856 }
3857
3858
3859 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3860 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
3861 if (!dev || (dev->missing && !is_dev_replace)) {
3862 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3863 return -ENODEV;
3864 }
3865
3866 if (!is_dev_replace && !readonly && !dev->writeable) {
3867 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3868 rcu_read_lock();
3869 name = rcu_dereference(dev->name);
3870 btrfs_err(fs_info, "scrub: device %s is not writable",
3871 name->str);
3872 rcu_read_unlock();
3873 return -EROFS;
3874 }
3875
3876 mutex_lock(&fs_info->scrub_lock);
3877 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
3878 mutex_unlock(&fs_info->scrub_lock);
3879 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3880 return -EIO;
3881 }
3882
3883 btrfs_dev_replace_lock(&fs_info->dev_replace);
3884 if (dev->scrub_device ||
3885 (!is_dev_replace &&
3886 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3887 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3888 mutex_unlock(&fs_info->scrub_lock);
3889 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3890 return -EINPROGRESS;
3891 }
3892 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3893
3894 ret = scrub_workers_get(fs_info, is_dev_replace);
3895 if (ret) {
3896 mutex_unlock(&fs_info->scrub_lock);
3897 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3898 return ret;
3899 }
3900
3901 sctx = scrub_setup_ctx(dev, is_dev_replace);
3902 if (IS_ERR(sctx)) {
3903 mutex_unlock(&fs_info->scrub_lock);
3904 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3905 scrub_workers_put(fs_info);
3906 return PTR_ERR(sctx);
3907 }
3908 sctx->readonly = readonly;
3909 dev->scrub_device = sctx;
3910 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3911
3912 /*
3913 * checking @scrub_pause_req here, we can avoid
3914 * race between committing transaction and scrubbing.
3915 */
3916 __scrub_blocked_if_needed(fs_info);
3917 atomic_inc(&fs_info->scrubs_running);
3918 mutex_unlock(&fs_info->scrub_lock);
3919
3920 if (!is_dev_replace) {
3921 /*
3922 * by holding device list mutex, we can
3923 * kick off writing super in log tree sync.
3924 */
3925 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3926 ret = scrub_supers(sctx, dev);
3927 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3928 }
3929
3930 if (!ret)
3931 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3932 is_dev_replace);
3933
3934 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3935 atomic_dec(&fs_info->scrubs_running);
3936 wake_up(&fs_info->scrub_pause_wait);
3937
3938 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3939
3940 if (progress)
3941 memcpy(progress, &sctx->stat, sizeof(*progress));
3942
3943 mutex_lock(&fs_info->scrub_lock);
3944 dev->scrub_device = NULL;
3945 scrub_workers_put(fs_info);
3946 mutex_unlock(&fs_info->scrub_lock);
3947
3948 scrub_put_ctx(sctx);
3949
3950 return ret;
3951 }
3952
3953 void btrfs_scrub_pause(struct btrfs_root *root)
3954 {
3955 struct btrfs_fs_info *fs_info = root->fs_info;
3956
3957 mutex_lock(&fs_info->scrub_lock);
3958 atomic_inc(&fs_info->scrub_pause_req);
3959 while (atomic_read(&fs_info->scrubs_paused) !=
3960 atomic_read(&fs_info->scrubs_running)) {
3961 mutex_unlock(&fs_info->scrub_lock);
3962 wait_event(fs_info->scrub_pause_wait,
3963 atomic_read(&fs_info->scrubs_paused) ==
3964 atomic_read(&fs_info->scrubs_running));
3965 mutex_lock(&fs_info->scrub_lock);
3966 }
3967 mutex_unlock(&fs_info->scrub_lock);
3968 }
3969
3970 void btrfs_scrub_continue(struct btrfs_root *root)
3971 {
3972 struct btrfs_fs_info *fs_info = root->fs_info;
3973
3974 atomic_dec(&fs_info->scrub_pause_req);
3975 wake_up(&fs_info->scrub_pause_wait);
3976 }
3977
3978 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3979 {
3980 mutex_lock(&fs_info->scrub_lock);
3981 if (!atomic_read(&fs_info->scrubs_running)) {
3982 mutex_unlock(&fs_info->scrub_lock);
3983 return -ENOTCONN;
3984 }
3985
3986 atomic_inc(&fs_info->scrub_cancel_req);
3987 while (atomic_read(&fs_info->scrubs_running)) {
3988 mutex_unlock(&fs_info->scrub_lock);
3989 wait_event(fs_info->scrub_pause_wait,
3990 atomic_read(&fs_info->scrubs_running) == 0);
3991 mutex_lock(&fs_info->scrub_lock);
3992 }
3993 atomic_dec(&fs_info->scrub_cancel_req);
3994 mutex_unlock(&fs_info->scrub_lock);
3995
3996 return 0;
3997 }
3998
3999 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
4000 struct btrfs_device *dev)
4001 {
4002 struct scrub_ctx *sctx;
4003
4004 mutex_lock(&fs_info->scrub_lock);
4005 sctx = dev->scrub_device;
4006 if (!sctx) {
4007 mutex_unlock(&fs_info->scrub_lock);
4008 return -ENOTCONN;
4009 }
4010 atomic_inc(&sctx->cancel_req);
4011 while (dev->scrub_device) {
4012 mutex_unlock(&fs_info->scrub_lock);
4013 wait_event(fs_info->scrub_pause_wait,
4014 dev->scrub_device == NULL);
4015 mutex_lock(&fs_info->scrub_lock);
4016 }
4017 mutex_unlock(&fs_info->scrub_lock);
4018
4019 return 0;
4020 }
4021
4022 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
4023 struct btrfs_scrub_progress *progress)
4024 {
4025 struct btrfs_device *dev;
4026 struct scrub_ctx *sctx = NULL;
4027
4028 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
4029 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
4030 if (dev)
4031 sctx = dev->scrub_device;
4032 if (sctx)
4033 memcpy(progress, &sctx->stat, sizeof(*progress));
4034 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
4035
4036 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4037 }
4038
4039 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4040 u64 extent_logical, u64 extent_len,
4041 u64 *extent_physical,
4042 struct btrfs_device **extent_dev,
4043 int *extent_mirror_num)
4044 {
4045 u64 mapped_length;
4046 struct btrfs_bio *bbio = NULL;
4047 int ret;
4048
4049 mapped_length = extent_len;
4050 ret = btrfs_map_block(fs_info, READ, extent_logical,
4051 &mapped_length, &bbio, 0);
4052 if (ret || !bbio || mapped_length < extent_len ||
4053 !bbio->stripes[0].dev->bdev) {
4054 btrfs_put_bbio(bbio);
4055 return;
4056 }
4057
4058 *extent_physical = bbio->stripes[0].physical;
4059 *extent_mirror_num = bbio->mirror_num;
4060 *extent_dev = bbio->stripes[0].dev;
4061 btrfs_put_bbio(bbio);
4062 }
4063
4064 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
4065 struct scrub_wr_ctx *wr_ctx,
4066 struct btrfs_fs_info *fs_info,
4067 struct btrfs_device *dev,
4068 int is_dev_replace)
4069 {
4070 WARN_ON(wr_ctx->wr_curr_bio != NULL);
4071
4072 mutex_init(&wr_ctx->wr_lock);
4073 wr_ctx->wr_curr_bio = NULL;
4074 if (!is_dev_replace)
4075 return 0;
4076
4077 WARN_ON(!dev->bdev);
4078 wr_ctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
4079 wr_ctx->tgtdev = dev;
4080 atomic_set(&wr_ctx->flush_all_writes, 0);
4081 return 0;
4082 }
4083
4084 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
4085 {
4086 mutex_lock(&wr_ctx->wr_lock);
4087 kfree(wr_ctx->wr_curr_bio);
4088 wr_ctx->wr_curr_bio = NULL;
4089 mutex_unlock(&wr_ctx->wr_lock);
4090 }
4091
4092 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
4093 int mirror_num, u64 physical_for_dev_replace)
4094 {
4095 struct scrub_copy_nocow_ctx *nocow_ctx;
4096 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
4097
4098 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
4099 if (!nocow_ctx) {
4100 spin_lock(&sctx->stat_lock);
4101 sctx->stat.malloc_errors++;
4102 spin_unlock(&sctx->stat_lock);
4103 return -ENOMEM;
4104 }
4105
4106 scrub_pending_trans_workers_inc(sctx);
4107
4108 nocow_ctx->sctx = sctx;
4109 nocow_ctx->logical = logical;
4110 nocow_ctx->len = len;
4111 nocow_ctx->mirror_num = mirror_num;
4112 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
4113 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
4114 copy_nocow_pages_worker, NULL, NULL);
4115 INIT_LIST_HEAD(&nocow_ctx->inodes);
4116 btrfs_queue_work(fs_info->scrub_nocow_workers,
4117 &nocow_ctx->work);
4118
4119 return 0;
4120 }
4121
4122 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
4123 {
4124 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
4125 struct scrub_nocow_inode *nocow_inode;
4126
4127 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
4128 if (!nocow_inode)
4129 return -ENOMEM;
4130 nocow_inode->inum = inum;
4131 nocow_inode->offset = offset;
4132 nocow_inode->root = root;
4133 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
4134 return 0;
4135 }
4136
4137 #define COPY_COMPLETE 1
4138
4139 static void copy_nocow_pages_worker(struct btrfs_work *work)
4140 {
4141 struct scrub_copy_nocow_ctx *nocow_ctx =
4142 container_of(work, struct scrub_copy_nocow_ctx, work);
4143 struct scrub_ctx *sctx = nocow_ctx->sctx;
4144 u64 logical = nocow_ctx->logical;
4145 u64 len = nocow_ctx->len;
4146 int mirror_num = nocow_ctx->mirror_num;
4147 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4148 int ret;
4149 struct btrfs_trans_handle *trans = NULL;
4150 struct btrfs_fs_info *fs_info;
4151 struct btrfs_path *path;
4152 struct btrfs_root *root;
4153 int not_written = 0;
4154
4155 fs_info = sctx->dev_root->fs_info;
4156 root = fs_info->extent_root;
4157
4158 path = btrfs_alloc_path();
4159 if (!path) {
4160 spin_lock(&sctx->stat_lock);
4161 sctx->stat.malloc_errors++;
4162 spin_unlock(&sctx->stat_lock);
4163 not_written = 1;
4164 goto out;
4165 }
4166
4167 trans = btrfs_join_transaction(root);
4168 if (IS_ERR(trans)) {
4169 not_written = 1;
4170 goto out;
4171 }
4172
4173 ret = iterate_inodes_from_logical(logical, fs_info, path,
4174 record_inode_for_nocow, nocow_ctx);
4175 if (ret != 0 && ret != -ENOENT) {
4176 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
4177 "phys %llu, len %llu, mir %u, ret %d",
4178 logical, physical_for_dev_replace, len, mirror_num,
4179 ret);
4180 not_written = 1;
4181 goto out;
4182 }
4183
4184 btrfs_end_transaction(trans, root);
4185 trans = NULL;
4186 while (!list_empty(&nocow_ctx->inodes)) {
4187 struct scrub_nocow_inode *entry;
4188 entry = list_first_entry(&nocow_ctx->inodes,
4189 struct scrub_nocow_inode,
4190 list);
4191 list_del_init(&entry->list);
4192 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
4193 entry->root, nocow_ctx);
4194 kfree(entry);
4195 if (ret == COPY_COMPLETE) {
4196 ret = 0;
4197 break;
4198 } else if (ret) {
4199 break;
4200 }
4201 }
4202 out:
4203 while (!list_empty(&nocow_ctx->inodes)) {
4204 struct scrub_nocow_inode *entry;
4205 entry = list_first_entry(&nocow_ctx->inodes,
4206 struct scrub_nocow_inode,
4207 list);
4208 list_del_init(&entry->list);
4209 kfree(entry);
4210 }
4211 if (trans && !IS_ERR(trans))
4212 btrfs_end_transaction(trans, root);
4213 if (not_written)
4214 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
4215 num_uncorrectable_read_errors);
4216
4217 btrfs_free_path(path);
4218 kfree(nocow_ctx);
4219
4220 scrub_pending_trans_workers_dec(sctx);
4221 }
4222
4223 static int check_extent_to_block(struct inode *inode, u64 start, u64 len,
4224 u64 logical)
4225 {
4226 struct extent_state *cached_state = NULL;
4227 struct btrfs_ordered_extent *ordered;
4228 struct extent_io_tree *io_tree;
4229 struct extent_map *em;
4230 u64 lockstart = start, lockend = start + len - 1;
4231 int ret = 0;
4232
4233 io_tree = &BTRFS_I(inode)->io_tree;
4234
4235 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
4236 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
4237 if (ordered) {
4238 btrfs_put_ordered_extent(ordered);
4239 ret = 1;
4240 goto out_unlock;
4241 }
4242
4243 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
4244 if (IS_ERR(em)) {
4245 ret = PTR_ERR(em);
4246 goto out_unlock;
4247 }
4248
4249 /*
4250 * This extent does not actually cover the logical extent anymore,
4251 * move on to the next inode.
4252 */
4253 if (em->block_start > logical ||
4254 em->block_start + em->block_len < logical + len) {
4255 free_extent_map(em);
4256 ret = 1;
4257 goto out_unlock;
4258 }
4259 free_extent_map(em);
4260
4261 out_unlock:
4262 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
4263 GFP_NOFS);
4264 return ret;
4265 }
4266
4267 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
4268 struct scrub_copy_nocow_ctx *nocow_ctx)
4269 {
4270 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
4271 struct btrfs_key key;
4272 struct inode *inode;
4273 struct page *page;
4274 struct btrfs_root *local_root;
4275 struct extent_io_tree *io_tree;
4276 u64 physical_for_dev_replace;
4277 u64 nocow_ctx_logical;
4278 u64 len = nocow_ctx->len;
4279 unsigned long index;
4280 int srcu_index;
4281 int ret = 0;
4282 int err = 0;
4283
4284 key.objectid = root;
4285 key.type = BTRFS_ROOT_ITEM_KEY;
4286 key.offset = (u64)-1;
4287
4288 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
4289
4290 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
4291 if (IS_ERR(local_root)) {
4292 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4293 return PTR_ERR(local_root);
4294 }
4295
4296 key.type = BTRFS_INODE_ITEM_KEY;
4297 key.objectid = inum;
4298 key.offset = 0;
4299 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
4300 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4301 if (IS_ERR(inode))
4302 return PTR_ERR(inode);
4303
4304 /* Avoid truncate/dio/punch hole.. */
4305 mutex_lock(&inode->i_mutex);
4306 inode_dio_wait(inode);
4307
4308 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4309 io_tree = &BTRFS_I(inode)->io_tree;
4310 nocow_ctx_logical = nocow_ctx->logical;
4311
4312 ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical);
4313 if (ret) {
4314 ret = ret > 0 ? 0 : ret;
4315 goto out;
4316 }
4317
4318 while (len >= PAGE_CACHE_SIZE) {
4319 index = offset >> PAGE_CACHE_SHIFT;
4320 again:
4321 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4322 if (!page) {
4323 btrfs_err(fs_info, "find_or_create_page() failed");
4324 ret = -ENOMEM;
4325 goto out;
4326 }
4327
4328 if (PageUptodate(page)) {
4329 if (PageDirty(page))
4330 goto next_page;
4331 } else {
4332 ClearPageError(page);
4333 err = extent_read_full_page(io_tree, page,
4334 btrfs_get_extent,
4335 nocow_ctx->mirror_num);
4336 if (err) {
4337 ret = err;
4338 goto next_page;
4339 }
4340
4341 lock_page(page);
4342 /*
4343 * If the page has been remove from the page cache,
4344 * the data on it is meaningless, because it may be
4345 * old one, the new data may be written into the new
4346 * page in the page cache.
4347 */
4348 if (page->mapping != inode->i_mapping) {
4349 unlock_page(page);
4350 page_cache_release(page);
4351 goto again;
4352 }
4353 if (!PageUptodate(page)) {
4354 ret = -EIO;
4355 goto next_page;
4356 }
4357 }
4358
4359 ret = check_extent_to_block(inode, offset, len,
4360 nocow_ctx_logical);
4361 if (ret) {
4362 ret = ret > 0 ? 0 : ret;
4363 goto next_page;
4364 }
4365
4366 err = write_page_nocow(nocow_ctx->sctx,
4367 physical_for_dev_replace, page);
4368 if (err)
4369 ret = err;
4370 next_page:
4371 unlock_page(page);
4372 page_cache_release(page);
4373
4374 if (ret)
4375 break;
4376
4377 offset += PAGE_CACHE_SIZE;
4378 physical_for_dev_replace += PAGE_CACHE_SIZE;
4379 nocow_ctx_logical += PAGE_CACHE_SIZE;
4380 len -= PAGE_CACHE_SIZE;
4381 }
4382 ret = COPY_COMPLETE;
4383 out:
4384 mutex_unlock(&inode->i_mutex);
4385 iput(inode);
4386 return ret;
4387 }
4388
4389 static int write_page_nocow(struct scrub_ctx *sctx,
4390 u64 physical_for_dev_replace, struct page *page)
4391 {
4392 struct bio *bio;
4393 struct btrfs_device *dev;
4394 int ret;
4395
4396 dev = sctx->wr_ctx.tgtdev;
4397 if (!dev)
4398 return -EIO;
4399 if (!dev->bdev) {
4400 btrfs_warn_rl(dev->dev_root->fs_info,
4401 "scrub write_page_nocow(bdev == NULL) is unexpected");
4402 return -EIO;
4403 }
4404 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
4405 if (!bio) {
4406 spin_lock(&sctx->stat_lock);
4407 sctx->stat.malloc_errors++;
4408 spin_unlock(&sctx->stat_lock);
4409 return -ENOMEM;
4410 }
4411 bio->bi_iter.bi_size = 0;
4412 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
4413 bio->bi_bdev = dev->bdev;
4414 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
4415 if (ret != PAGE_CACHE_SIZE) {
4416 leave_with_eio:
4417 bio_put(bio);
4418 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
4419 return -EIO;
4420 }
4421
4422 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
4423 goto leave_with_eio;
4424
4425 bio_put(bio);
4426 return 0;
4427 }
Linux kernel - Deliverables
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