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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
[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 };
129
130 /* Used for the chunks with parity stripe such RAID5/6 */
131 struct scrub_parity {
132 struct scrub_ctx *sctx;
133
134 struct btrfs_device *scrub_dev;
135
136 u64 logic_start;
137
138 u64 logic_end;
139
140 int nsectors;
141
142 int stripe_len;
143
144 atomic_t refs;
145
146 struct list_head spages;
147
148 /* Work of parity check and repair */
149 struct btrfs_work work;
150
151 /* Mark the parity blocks which have data */
152 unsigned long *dbitmap;
153
154 /*
155 * Mark the parity blocks which have data, but errors happen when
156 * read data or check data
157 */
158 unsigned long *ebitmap;
159
160 unsigned long bitmap[0];
161 };
162
163 struct scrub_wr_ctx {
164 struct scrub_bio *wr_curr_bio;
165 struct btrfs_device *tgtdev;
166 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
167 atomic_t flush_all_writes;
168 struct mutex wr_lock;
169 };
170
171 struct scrub_ctx {
172 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
173 struct btrfs_root *dev_root;
174 int first_free;
175 int curr;
176 atomic_t bios_in_flight;
177 atomic_t workers_pending;
178 spinlock_t list_lock;
179 wait_queue_head_t list_wait;
180 u16 csum_size;
181 struct list_head csum_list;
182 atomic_t cancel_req;
183 int readonly;
184 int pages_per_rd_bio;
185 u32 sectorsize;
186 u32 nodesize;
187
188 int is_dev_replace;
189 struct scrub_wr_ctx wr_ctx;
190
191 /*
192 * statistics
193 */
194 struct btrfs_scrub_progress stat;
195 spinlock_t stat_lock;
196
197 /*
198 * Use a ref counter to avoid use-after-free issues. Scrub workers
199 * decrement bios_in_flight and workers_pending and then do a wakeup
200 * on the list_wait wait queue. We must ensure the main scrub task
201 * doesn't free the scrub context before or while the workers are
202 * doing the wakeup() call.
203 */
204 atomic_t refs;
205 };
206
207 struct scrub_fixup_nodatasum {
208 struct scrub_ctx *sctx;
209 struct btrfs_device *dev;
210 u64 logical;
211 struct btrfs_root *root;
212 struct btrfs_work work;
213 int mirror_num;
214 };
215
216 struct scrub_nocow_inode {
217 u64 inum;
218 u64 offset;
219 u64 root;
220 struct list_head list;
221 };
222
223 struct scrub_copy_nocow_ctx {
224 struct scrub_ctx *sctx;
225 u64 logical;
226 u64 len;
227 int mirror_num;
228 u64 physical_for_dev_replace;
229 struct list_head inodes;
230 struct btrfs_work work;
231 };
232
233 struct scrub_warning {
234 struct btrfs_path *path;
235 u64 extent_item_size;
236 const char *errstr;
237 sector_t sector;
238 u64 logical;
239 struct btrfs_device *dev;
240 };
241
242 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
243 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
244 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
245 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
246 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
247 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
248 struct scrub_block *sblocks_for_recheck);
249 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
250 struct scrub_block *sblock, int is_metadata,
251 int have_csum, u8 *csum, u64 generation,
252 u16 csum_size, int retry_failed_mirror);
253 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
254 struct scrub_block *sblock,
255 int is_metadata, int have_csum,
256 const u8 *csum, u64 generation,
257 u16 csum_size);
258 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
259 struct scrub_block *sblock_good);
260 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
261 struct scrub_block *sblock_good,
262 int page_num, int force_write);
263 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
264 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
265 int page_num);
266 static int scrub_checksum_data(struct scrub_block *sblock);
267 static int scrub_checksum_tree_block(struct scrub_block *sblock);
268 static int scrub_checksum_super(struct scrub_block *sblock);
269 static void scrub_block_get(struct scrub_block *sblock);
270 static void scrub_block_put(struct scrub_block *sblock);
271 static void scrub_page_get(struct scrub_page *spage);
272 static void scrub_page_put(struct scrub_page *spage);
273 static void scrub_parity_get(struct scrub_parity *sparity);
274 static void scrub_parity_put(struct scrub_parity *sparity);
275 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
276 struct scrub_page *spage);
277 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
278 u64 physical, struct btrfs_device *dev, u64 flags,
279 u64 gen, int mirror_num, u8 *csum, int force,
280 u64 physical_for_dev_replace);
281 static void scrub_bio_end_io(struct bio *bio);
282 static void scrub_bio_end_io_worker(struct btrfs_work *work);
283 static void scrub_block_complete(struct scrub_block *sblock);
284 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
285 u64 extent_logical, u64 extent_len,
286 u64 *extent_physical,
287 struct btrfs_device **extent_dev,
288 int *extent_mirror_num);
289 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
290 struct scrub_wr_ctx *wr_ctx,
291 struct btrfs_fs_info *fs_info,
292 struct btrfs_device *dev,
293 int is_dev_replace);
294 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
295 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
296 struct scrub_page *spage);
297 static void scrub_wr_submit(struct scrub_ctx *sctx);
298 static void scrub_wr_bio_end_io(struct bio *bio);
299 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
300 static int write_page_nocow(struct scrub_ctx *sctx,
301 u64 physical_for_dev_replace, struct page *page);
302 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
303 struct scrub_copy_nocow_ctx *ctx);
304 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
305 int mirror_num, u64 physical_for_dev_replace);
306 static void copy_nocow_pages_worker(struct btrfs_work *work);
307 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
308 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
309 static void scrub_put_ctx(struct scrub_ctx *sctx);
310
311
312 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
313 {
314 atomic_inc(&sctx->refs);
315 atomic_inc(&sctx->bios_in_flight);
316 }
317
318 static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
319 {
320 atomic_dec(&sctx->bios_in_flight);
321 wake_up(&sctx->list_wait);
322 scrub_put_ctx(sctx);
323 }
324
325 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
326 {
327 while (atomic_read(&fs_info->scrub_pause_req)) {
328 mutex_unlock(&fs_info->scrub_lock);
329 wait_event(fs_info->scrub_pause_wait,
330 atomic_read(&fs_info->scrub_pause_req) == 0);
331 mutex_lock(&fs_info->scrub_lock);
332 }
333 }
334
335 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
336 {
337 atomic_inc(&fs_info->scrubs_paused);
338 wake_up(&fs_info->scrub_pause_wait);
339
340 mutex_lock(&fs_info->scrub_lock);
341 __scrub_blocked_if_needed(fs_info);
342 atomic_dec(&fs_info->scrubs_paused);
343 mutex_unlock(&fs_info->scrub_lock);
344
345 wake_up(&fs_info->scrub_pause_wait);
346 }
347
348 /*
349 * used for workers that require transaction commits (i.e., for the
350 * NOCOW case)
351 */
352 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
353 {
354 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
355
356 atomic_inc(&sctx->refs);
357 /*
358 * increment scrubs_running to prevent cancel requests from
359 * completing as long as a worker is running. we must also
360 * increment scrubs_paused to prevent deadlocking on pause
361 * requests used for transactions commits (as the worker uses a
362 * transaction context). it is safe to regard the worker
363 * as paused for all matters practical. effectively, we only
364 * avoid cancellation requests from completing.
365 */
366 mutex_lock(&fs_info->scrub_lock);
367 atomic_inc(&fs_info->scrubs_running);
368 atomic_inc(&fs_info->scrubs_paused);
369 mutex_unlock(&fs_info->scrub_lock);
370
371 /*
372 * check if @scrubs_running=@scrubs_paused condition
373 * inside wait_event() is not an atomic operation.
374 * which means we may inc/dec @scrub_running/paused
375 * at any time. Let's wake up @scrub_pause_wait as
376 * much as we can to let commit transaction blocked less.
377 */
378 wake_up(&fs_info->scrub_pause_wait);
379
380 atomic_inc(&sctx->workers_pending);
381 }
382
383 /* used for workers that require transaction commits */
384 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
385 {
386 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
387
388 /*
389 * see scrub_pending_trans_workers_inc() why we're pretending
390 * to be paused in the scrub counters
391 */
392 mutex_lock(&fs_info->scrub_lock);
393 atomic_dec(&fs_info->scrubs_running);
394 atomic_dec(&fs_info->scrubs_paused);
395 mutex_unlock(&fs_info->scrub_lock);
396 atomic_dec(&sctx->workers_pending);
397 wake_up(&fs_info->scrub_pause_wait);
398 wake_up(&sctx->list_wait);
399 scrub_put_ctx(sctx);
400 }
401
402 static void scrub_free_csums(struct scrub_ctx *sctx)
403 {
404 while (!list_empty(&sctx->csum_list)) {
405 struct btrfs_ordered_sum *sum;
406 sum = list_first_entry(&sctx->csum_list,
407 struct btrfs_ordered_sum, list);
408 list_del(&sum->list);
409 kfree(sum);
410 }
411 }
412
413 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
414 {
415 int i;
416
417 if (!sctx)
418 return;
419
420 scrub_free_wr_ctx(&sctx->wr_ctx);
421
422 /* this can happen when scrub is cancelled */
423 if (sctx->curr != -1) {
424 struct scrub_bio *sbio = sctx->bios[sctx->curr];
425
426 for (i = 0; i < sbio->page_count; i++) {
427 WARN_ON(!sbio->pagev[i]->page);
428 scrub_block_put(sbio->pagev[i]->sblock);
429 }
430 bio_put(sbio->bio);
431 }
432
433 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
434 struct scrub_bio *sbio = sctx->bios[i];
435
436 if (!sbio)
437 break;
438 kfree(sbio);
439 }
440
441 scrub_free_csums(sctx);
442 kfree(sctx);
443 }
444
445 static void scrub_put_ctx(struct scrub_ctx *sctx)
446 {
447 if (atomic_dec_and_test(&sctx->refs))
448 scrub_free_ctx(sctx);
449 }
450
451 static noinline_for_stack
452 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
453 {
454 struct scrub_ctx *sctx;
455 int i;
456 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
457 int ret;
458
459 sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
460 if (!sctx)
461 goto nomem;
462 atomic_set(&sctx->refs, 1);
463 sctx->is_dev_replace = is_dev_replace;
464 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
465 sctx->curr = -1;
466 sctx->dev_root = dev->dev_root;
467 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
468 struct scrub_bio *sbio;
469
470 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
471 if (!sbio)
472 goto nomem;
473 sctx->bios[i] = sbio;
474
475 sbio->index = i;
476 sbio->sctx = sctx;
477 sbio->page_count = 0;
478 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
479 scrub_bio_end_io_worker, NULL, NULL);
480
481 if (i != SCRUB_BIOS_PER_SCTX - 1)
482 sctx->bios[i]->next_free = i + 1;
483 else
484 sctx->bios[i]->next_free = -1;
485 }
486 sctx->first_free = 0;
487 sctx->nodesize = dev->dev_root->nodesize;
488 sctx->sectorsize = dev->dev_root->sectorsize;
489 atomic_set(&sctx->bios_in_flight, 0);
490 atomic_set(&sctx->workers_pending, 0);
491 atomic_set(&sctx->cancel_req, 0);
492 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
493 INIT_LIST_HEAD(&sctx->csum_list);
494
495 spin_lock_init(&sctx->list_lock);
496 spin_lock_init(&sctx->stat_lock);
497 init_waitqueue_head(&sctx->list_wait);
498
499 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
500 fs_info->dev_replace.tgtdev, is_dev_replace);
501 if (ret) {
502 scrub_free_ctx(sctx);
503 return ERR_PTR(ret);
504 }
505 return sctx;
506
507 nomem:
508 scrub_free_ctx(sctx);
509 return ERR_PTR(-ENOMEM);
510 }
511
512 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
513 void *warn_ctx)
514 {
515 u64 isize;
516 u32 nlink;
517 int ret;
518 int i;
519 struct extent_buffer *eb;
520 struct btrfs_inode_item *inode_item;
521 struct scrub_warning *swarn = warn_ctx;
522 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
523 struct inode_fs_paths *ipath = NULL;
524 struct btrfs_root *local_root;
525 struct btrfs_key root_key;
526 struct btrfs_key key;
527
528 root_key.objectid = root;
529 root_key.type = BTRFS_ROOT_ITEM_KEY;
530 root_key.offset = (u64)-1;
531 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
532 if (IS_ERR(local_root)) {
533 ret = PTR_ERR(local_root);
534 goto err;
535 }
536
537 /*
538 * this makes the path point to (inum INODE_ITEM ioff)
539 */
540 key.objectid = inum;
541 key.type = BTRFS_INODE_ITEM_KEY;
542 key.offset = 0;
543
544 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
545 if (ret) {
546 btrfs_release_path(swarn->path);
547 goto err;
548 }
549
550 eb = swarn->path->nodes[0];
551 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
552 struct btrfs_inode_item);
553 isize = btrfs_inode_size(eb, inode_item);
554 nlink = btrfs_inode_nlink(eb, inode_item);
555 btrfs_release_path(swarn->path);
556
557 ipath = init_ipath(4096, local_root, swarn->path);
558 if (IS_ERR(ipath)) {
559 ret = PTR_ERR(ipath);
560 ipath = NULL;
561 goto err;
562 }
563 ret = paths_from_inode(inum, ipath);
564
565 if (ret < 0)
566 goto err;
567
568 /*
569 * we deliberately ignore the bit ipath might have been too small to
570 * hold all of the paths here
571 */
572 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
573 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
574 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
575 "length %llu, links %u (path: %s)\n", swarn->errstr,
576 swarn->logical, rcu_str_deref(swarn->dev->name),
577 (unsigned long long)swarn->sector, root, inum, offset,
578 min(isize - offset, (u64)PAGE_SIZE), nlink,
579 (char *)(unsigned long)ipath->fspath->val[i]);
580
581 free_ipath(ipath);
582 return 0;
583
584 err:
585 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
586 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
587 "resolving failed with ret=%d\n", swarn->errstr,
588 swarn->logical, rcu_str_deref(swarn->dev->name),
589 (unsigned long long)swarn->sector, root, inum, offset, ret);
590
591 free_ipath(ipath);
592 return 0;
593 }
594
595 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
596 {
597 struct btrfs_device *dev;
598 struct btrfs_fs_info *fs_info;
599 struct btrfs_path *path;
600 struct btrfs_key found_key;
601 struct extent_buffer *eb;
602 struct btrfs_extent_item *ei;
603 struct scrub_warning swarn;
604 unsigned long ptr = 0;
605 u64 extent_item_pos;
606 u64 flags = 0;
607 u64 ref_root;
608 u32 item_size;
609 u8 ref_level;
610 int ret;
611
612 WARN_ON(sblock->page_count < 1);
613 dev = sblock->pagev[0]->dev;
614 fs_info = sblock->sctx->dev_root->fs_info;
615
616 path = btrfs_alloc_path();
617 if (!path)
618 return;
619
620 swarn.sector = (sblock->pagev[0]->physical) >> 9;
621 swarn.logical = sblock->pagev[0]->logical;
622 swarn.errstr = errstr;
623 swarn.dev = NULL;
624
625 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
626 &flags);
627 if (ret < 0)
628 goto out;
629
630 extent_item_pos = swarn.logical - found_key.objectid;
631 swarn.extent_item_size = found_key.offset;
632
633 eb = path->nodes[0];
634 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
635 item_size = btrfs_item_size_nr(eb, path->slots[0]);
636
637 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
638 do {
639 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
640 item_size, &ref_root,
641 &ref_level);
642 printk_in_rcu(KERN_WARNING
643 "BTRFS: %s at logical %llu on dev %s, "
644 "sector %llu: metadata %s (level %d) in tree "
645 "%llu\n", errstr, swarn.logical,
646 rcu_str_deref(dev->name),
647 (unsigned long long)swarn.sector,
648 ref_level ? "node" : "leaf",
649 ret < 0 ? -1 : ref_level,
650 ret < 0 ? -1 : ref_root);
651 } while (ret != 1);
652 btrfs_release_path(path);
653 } else {
654 btrfs_release_path(path);
655 swarn.path = path;
656 swarn.dev = dev;
657 iterate_extent_inodes(fs_info, found_key.objectid,
658 extent_item_pos, 1,
659 scrub_print_warning_inode, &swarn);
660 }
661
662 out:
663 btrfs_free_path(path);
664 }
665
666 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
667 {
668 struct page *page = NULL;
669 unsigned long index;
670 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
671 int ret;
672 int corrected = 0;
673 struct btrfs_key key;
674 struct inode *inode = NULL;
675 struct btrfs_fs_info *fs_info;
676 u64 end = offset + PAGE_SIZE - 1;
677 struct btrfs_root *local_root;
678 int srcu_index;
679
680 key.objectid = root;
681 key.type = BTRFS_ROOT_ITEM_KEY;
682 key.offset = (u64)-1;
683
684 fs_info = fixup->root->fs_info;
685 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
686
687 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
688 if (IS_ERR(local_root)) {
689 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
690 return PTR_ERR(local_root);
691 }
692
693 key.type = BTRFS_INODE_ITEM_KEY;
694 key.objectid = inum;
695 key.offset = 0;
696 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
697 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
698 if (IS_ERR(inode))
699 return PTR_ERR(inode);
700
701 index = offset >> PAGE_CACHE_SHIFT;
702
703 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
704 if (!page) {
705 ret = -ENOMEM;
706 goto out;
707 }
708
709 if (PageUptodate(page)) {
710 if (PageDirty(page)) {
711 /*
712 * we need to write the data to the defect sector. the
713 * data that was in that sector is not in memory,
714 * because the page was modified. we must not write the
715 * modified page to that sector.
716 *
717 * TODO: what could be done here: wait for the delalloc
718 * runner to write out that page (might involve
719 * COW) and see whether the sector is still
720 * referenced afterwards.
721 *
722 * For the meantime, we'll treat this error
723 * incorrectable, although there is a chance that a
724 * later scrub will find the bad sector again and that
725 * there's no dirty page in memory, then.
726 */
727 ret = -EIO;
728 goto out;
729 }
730 ret = repair_io_failure(inode, offset, PAGE_SIZE,
731 fixup->logical, page,
732 offset - page_offset(page),
733 fixup->mirror_num);
734 unlock_page(page);
735 corrected = !ret;
736 } else {
737 /*
738 * we need to get good data first. the general readpage path
739 * will call repair_io_failure for us, we just have to make
740 * sure we read the bad mirror.
741 */
742 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
743 EXTENT_DAMAGED, GFP_NOFS);
744 if (ret) {
745 /* set_extent_bits should give proper error */
746 WARN_ON(ret > 0);
747 if (ret > 0)
748 ret = -EFAULT;
749 goto out;
750 }
751
752 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
753 btrfs_get_extent,
754 fixup->mirror_num);
755 wait_on_page_locked(page);
756
757 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
758 end, EXTENT_DAMAGED, 0, NULL);
759 if (!corrected)
760 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
761 EXTENT_DAMAGED, GFP_NOFS);
762 }
763
764 out:
765 if (page)
766 put_page(page);
767
768 iput(inode);
769
770 if (ret < 0)
771 return ret;
772
773 if (ret == 0 && corrected) {
774 /*
775 * we only need to call readpage for one of the inodes belonging
776 * to this extent. so make iterate_extent_inodes stop
777 */
778 return 1;
779 }
780
781 return -EIO;
782 }
783
784 static void scrub_fixup_nodatasum(struct btrfs_work *work)
785 {
786 int ret;
787 struct scrub_fixup_nodatasum *fixup;
788 struct scrub_ctx *sctx;
789 struct btrfs_trans_handle *trans = NULL;
790 struct btrfs_path *path;
791 int uncorrectable = 0;
792
793 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
794 sctx = fixup->sctx;
795
796 path = btrfs_alloc_path();
797 if (!path) {
798 spin_lock(&sctx->stat_lock);
799 ++sctx->stat.malloc_errors;
800 spin_unlock(&sctx->stat_lock);
801 uncorrectable = 1;
802 goto out;
803 }
804
805 trans = btrfs_join_transaction(fixup->root);
806 if (IS_ERR(trans)) {
807 uncorrectable = 1;
808 goto out;
809 }
810
811 /*
812 * the idea is to trigger a regular read through the standard path. we
813 * read a page from the (failed) logical address by specifying the
814 * corresponding copynum of the failed sector. thus, that readpage is
815 * expected to fail.
816 * that is the point where on-the-fly error correction will kick in
817 * (once it's finished) and rewrite the failed sector if a good copy
818 * can be found.
819 */
820 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
821 path, scrub_fixup_readpage,
822 fixup);
823 if (ret < 0) {
824 uncorrectable = 1;
825 goto out;
826 }
827 WARN_ON(ret != 1);
828
829 spin_lock(&sctx->stat_lock);
830 ++sctx->stat.corrected_errors;
831 spin_unlock(&sctx->stat_lock);
832
833 out:
834 if (trans && !IS_ERR(trans))
835 btrfs_end_transaction(trans, fixup->root);
836 if (uncorrectable) {
837 spin_lock(&sctx->stat_lock);
838 ++sctx->stat.uncorrectable_errors;
839 spin_unlock(&sctx->stat_lock);
840 btrfs_dev_replace_stats_inc(
841 &sctx->dev_root->fs_info->dev_replace.
842 num_uncorrectable_read_errors);
843 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
844 "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
845 fixup->logical, rcu_str_deref(fixup->dev->name));
846 }
847
848 btrfs_free_path(path);
849 kfree(fixup);
850
851 scrub_pending_trans_workers_dec(sctx);
852 }
853
854 static inline void scrub_get_recover(struct scrub_recover *recover)
855 {
856 atomic_inc(&recover->refs);
857 }
858
859 static inline void scrub_put_recover(struct scrub_recover *recover)
860 {
861 if (atomic_dec_and_test(&recover->refs)) {
862 btrfs_put_bbio(recover->bbio);
863 kfree(recover);
864 }
865 }
866
867 /*
868 * scrub_handle_errored_block gets called when either verification of the
869 * pages failed or the bio failed to read, e.g. with EIO. In the latter
870 * case, this function handles all pages in the bio, even though only one
871 * may be bad.
872 * The goal of this function is to repair the errored block by using the
873 * contents of one of the mirrors.
874 */
875 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
876 {
877 struct scrub_ctx *sctx = sblock_to_check->sctx;
878 struct btrfs_device *dev;
879 struct btrfs_fs_info *fs_info;
880 u64 length;
881 u64 logical;
882 u64 generation;
883 unsigned int failed_mirror_index;
884 unsigned int is_metadata;
885 unsigned int have_csum;
886 u8 *csum;
887 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
888 struct scrub_block *sblock_bad;
889 int ret;
890 int mirror_index;
891 int page_num;
892 int success;
893 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
894 DEFAULT_RATELIMIT_BURST);
895
896 BUG_ON(sblock_to_check->page_count < 1);
897 fs_info = sctx->dev_root->fs_info;
898 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
899 /*
900 * if we find an error in a super block, we just report it.
901 * They will get written with the next transaction commit
902 * anyway
903 */
904 spin_lock(&sctx->stat_lock);
905 ++sctx->stat.super_errors;
906 spin_unlock(&sctx->stat_lock);
907 return 0;
908 }
909 length = sblock_to_check->page_count * PAGE_SIZE;
910 logical = sblock_to_check->pagev[0]->logical;
911 generation = sblock_to_check->pagev[0]->generation;
912 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
913 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
914 is_metadata = !(sblock_to_check->pagev[0]->flags &
915 BTRFS_EXTENT_FLAG_DATA);
916 have_csum = sblock_to_check->pagev[0]->have_csum;
917 csum = sblock_to_check->pagev[0]->csum;
918 dev = sblock_to_check->pagev[0]->dev;
919
920 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
921 sblocks_for_recheck = NULL;
922 goto nodatasum_case;
923 }
924
925 /*
926 * read all mirrors one after the other. This includes to
927 * re-read the extent or metadata block that failed (that was
928 * the cause that this fixup code is called) another time,
929 * page by page this time in order to know which pages
930 * caused I/O errors and which ones are good (for all mirrors).
931 * It is the goal to handle the situation when more than one
932 * mirror contains I/O errors, but the errors do not
933 * overlap, i.e. the data can be repaired by selecting the
934 * pages from those mirrors without I/O error on the
935 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
936 * would be that mirror #1 has an I/O error on the first page,
937 * the second page is good, and mirror #2 has an I/O error on
938 * the second page, but the first page is good.
939 * Then the first page of the first mirror can be repaired by
940 * taking the first page of the second mirror, and the
941 * second page of the second mirror can be repaired by
942 * copying the contents of the 2nd page of the 1st mirror.
943 * One more note: if the pages of one mirror contain I/O
944 * errors, the checksum cannot be verified. In order to get
945 * the best data for repairing, the first attempt is to find
946 * a mirror without I/O errors and with a validated checksum.
947 * Only if this is not possible, the pages are picked from
948 * mirrors with I/O errors without considering the checksum.
949 * If the latter is the case, at the end, the checksum of the
950 * repaired area is verified in order to correctly maintain
951 * the statistics.
952 */
953
954 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
955 sizeof(*sblocks_for_recheck), GFP_NOFS);
956 if (!sblocks_for_recheck) {
957 spin_lock(&sctx->stat_lock);
958 sctx->stat.malloc_errors++;
959 sctx->stat.read_errors++;
960 sctx->stat.uncorrectable_errors++;
961 spin_unlock(&sctx->stat_lock);
962 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
963 goto out;
964 }
965
966 /* setup the context, map the logical blocks and alloc the pages */
967 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
968 if (ret) {
969 spin_lock(&sctx->stat_lock);
970 sctx->stat.read_errors++;
971 sctx->stat.uncorrectable_errors++;
972 spin_unlock(&sctx->stat_lock);
973 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
974 goto out;
975 }
976 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
977 sblock_bad = sblocks_for_recheck + failed_mirror_index;
978
979 /* build and submit the bios for the failed mirror, check checksums */
980 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
981 csum, generation, sctx->csum_size, 1);
982
983 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
984 sblock_bad->no_io_error_seen) {
985 /*
986 * the error disappeared after reading page by page, or
987 * the area was part of a huge bio and other parts of the
988 * bio caused I/O errors, or the block layer merged several
989 * read requests into one and the error is caused by a
990 * different bio (usually one of the two latter cases is
991 * the cause)
992 */
993 spin_lock(&sctx->stat_lock);
994 sctx->stat.unverified_errors++;
995 sblock_to_check->data_corrected = 1;
996 spin_unlock(&sctx->stat_lock);
997
998 if (sctx->is_dev_replace)
999 scrub_write_block_to_dev_replace(sblock_bad);
1000 goto out;
1001 }
1002
1003 if (!sblock_bad->no_io_error_seen) {
1004 spin_lock(&sctx->stat_lock);
1005 sctx->stat.read_errors++;
1006 spin_unlock(&sctx->stat_lock);
1007 if (__ratelimit(&_rs))
1008 scrub_print_warning("i/o error", sblock_to_check);
1009 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1010 } else if (sblock_bad->checksum_error) {
1011 spin_lock(&sctx->stat_lock);
1012 sctx->stat.csum_errors++;
1013 spin_unlock(&sctx->stat_lock);
1014 if (__ratelimit(&_rs))
1015 scrub_print_warning("checksum error", sblock_to_check);
1016 btrfs_dev_stat_inc_and_print(dev,
1017 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1018 } else if (sblock_bad->header_error) {
1019 spin_lock(&sctx->stat_lock);
1020 sctx->stat.verify_errors++;
1021 spin_unlock(&sctx->stat_lock);
1022 if (__ratelimit(&_rs))
1023 scrub_print_warning("checksum/header error",
1024 sblock_to_check);
1025 if (sblock_bad->generation_error)
1026 btrfs_dev_stat_inc_and_print(dev,
1027 BTRFS_DEV_STAT_GENERATION_ERRS);
1028 else
1029 btrfs_dev_stat_inc_and_print(dev,
1030 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1031 }
1032
1033 if (sctx->readonly) {
1034 ASSERT(!sctx->is_dev_replace);
1035 goto out;
1036 }
1037
1038 if (!is_metadata && !have_csum) {
1039 struct scrub_fixup_nodatasum *fixup_nodatasum;
1040
1041 WARN_ON(sctx->is_dev_replace);
1042
1043 nodatasum_case:
1044
1045 /*
1046 * !is_metadata and !have_csum, this means that the data
1047 * might not be COW'ed, that it might be modified
1048 * concurrently. The general strategy to work on the
1049 * commit root does not help in the case when COW is not
1050 * used.
1051 */
1052 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
1053 if (!fixup_nodatasum)
1054 goto did_not_correct_error;
1055 fixup_nodatasum->sctx = sctx;
1056 fixup_nodatasum->dev = dev;
1057 fixup_nodatasum->logical = logical;
1058 fixup_nodatasum->root = fs_info->extent_root;
1059 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
1060 scrub_pending_trans_workers_inc(sctx);
1061 btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
1062 scrub_fixup_nodatasum, NULL, NULL);
1063 btrfs_queue_work(fs_info->scrub_workers,
1064 &fixup_nodatasum->work);
1065 goto out;
1066 }
1067
1068 /*
1069 * now build and submit the bios for the other mirrors, check
1070 * checksums.
1071 * First try to pick the mirror which is completely without I/O
1072 * errors and also does not have a checksum error.
1073 * If one is found, and if a checksum is present, the full block
1074 * that is known to contain an error is rewritten. Afterwards
1075 * the block is known to be corrected.
1076 * If a mirror is found which is completely correct, and no
1077 * checksum is present, only those pages are rewritten that had
1078 * an I/O error in the block to be repaired, since it cannot be
1079 * determined, which copy of the other pages is better (and it
1080 * could happen otherwise that a correct page would be
1081 * overwritten by a bad one).
1082 */
1083 for (mirror_index = 0;
1084 mirror_index < BTRFS_MAX_MIRRORS &&
1085 sblocks_for_recheck[mirror_index].page_count > 0;
1086 mirror_index++) {
1087 struct scrub_block *sblock_other;
1088
1089 if (mirror_index == failed_mirror_index)
1090 continue;
1091 sblock_other = sblocks_for_recheck + mirror_index;
1092
1093 /* build and submit the bios, check checksums */
1094 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1095 have_csum, csum, generation,
1096 sctx->csum_size, 0);
1097
1098 if (!sblock_other->header_error &&
1099 !sblock_other->checksum_error &&
1100 sblock_other->no_io_error_seen) {
1101 if (sctx->is_dev_replace) {
1102 scrub_write_block_to_dev_replace(sblock_other);
1103 goto corrected_error;
1104 } else {
1105 ret = scrub_repair_block_from_good_copy(
1106 sblock_bad, sblock_other);
1107 if (!ret)
1108 goto corrected_error;
1109 }
1110 }
1111 }
1112
1113 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1114 goto did_not_correct_error;
1115
1116 /*
1117 * In case of I/O errors in the area that is supposed to be
1118 * repaired, continue by picking good copies of those pages.
1119 * Select the good pages from mirrors to rewrite bad pages from
1120 * the area to fix. Afterwards verify the checksum of the block
1121 * that is supposed to be repaired. This verification step is
1122 * only done for the purpose of statistic counting and for the
1123 * final scrub report, whether errors remain.
1124 * A perfect algorithm could make use of the checksum and try
1125 * all possible combinations of pages from the different mirrors
1126 * until the checksum verification succeeds. For example, when
1127 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1128 * of mirror #2 is readable but the final checksum test fails,
1129 * then the 2nd page of mirror #3 could be tried, whether now
1130 * the final checksum succeedes. But this would be a rare
1131 * exception and is therefore not implemented. At least it is
1132 * avoided that the good copy is overwritten.
1133 * A more useful improvement would be to pick the sectors
1134 * without I/O error based on sector sizes (512 bytes on legacy
1135 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1136 * mirror could be repaired by taking 512 byte of a different
1137 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1138 * area are unreadable.
1139 */
1140 success = 1;
1141 for (page_num = 0; page_num < sblock_bad->page_count;
1142 page_num++) {
1143 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1144 struct scrub_block *sblock_other = NULL;
1145
1146 /* skip no-io-error page in scrub */
1147 if (!page_bad->io_error && !sctx->is_dev_replace)
1148 continue;
1149
1150 /* try to find no-io-error page in mirrors */
1151 if (page_bad->io_error) {
1152 for (mirror_index = 0;
1153 mirror_index < BTRFS_MAX_MIRRORS &&
1154 sblocks_for_recheck[mirror_index].page_count > 0;
1155 mirror_index++) {
1156 if (!sblocks_for_recheck[mirror_index].
1157 pagev[page_num]->io_error) {
1158 sblock_other = sblocks_for_recheck +
1159 mirror_index;
1160 break;
1161 }
1162 }
1163 if (!sblock_other)
1164 success = 0;
1165 }
1166
1167 if (sctx->is_dev_replace) {
1168 /*
1169 * did not find a mirror to fetch the page
1170 * from. scrub_write_page_to_dev_replace()
1171 * handles this case (page->io_error), by
1172 * filling the block with zeros before
1173 * submitting the write request
1174 */
1175 if (!sblock_other)
1176 sblock_other = sblock_bad;
1177
1178 if (scrub_write_page_to_dev_replace(sblock_other,
1179 page_num) != 0) {
1180 btrfs_dev_replace_stats_inc(
1181 &sctx->dev_root->
1182 fs_info->dev_replace.
1183 num_write_errors);
1184 success = 0;
1185 }
1186 } else if (sblock_other) {
1187 ret = scrub_repair_page_from_good_copy(sblock_bad,
1188 sblock_other,
1189 page_num, 0);
1190 if (0 == ret)
1191 page_bad->io_error = 0;
1192 else
1193 success = 0;
1194 }
1195 }
1196
1197 if (success && !sctx->is_dev_replace) {
1198 if (is_metadata || have_csum) {
1199 /*
1200 * need to verify the checksum now that all
1201 * sectors on disk are repaired (the write
1202 * request for data to be repaired is on its way).
1203 * Just be lazy and use scrub_recheck_block()
1204 * which re-reads the data before the checksum
1205 * is verified, but most likely the data comes out
1206 * of the page cache.
1207 */
1208 scrub_recheck_block(fs_info, sblock_bad,
1209 is_metadata, have_csum, csum,
1210 generation, sctx->csum_size, 1);
1211 if (!sblock_bad->header_error &&
1212 !sblock_bad->checksum_error &&
1213 sblock_bad->no_io_error_seen)
1214 goto corrected_error;
1215 else
1216 goto did_not_correct_error;
1217 } else {
1218 corrected_error:
1219 spin_lock(&sctx->stat_lock);
1220 sctx->stat.corrected_errors++;
1221 sblock_to_check->data_corrected = 1;
1222 spin_unlock(&sctx->stat_lock);
1223 printk_ratelimited_in_rcu(KERN_ERR
1224 "BTRFS: fixed up error at logical %llu on dev %s\n",
1225 logical, rcu_str_deref(dev->name));
1226 }
1227 } else {
1228 did_not_correct_error:
1229 spin_lock(&sctx->stat_lock);
1230 sctx->stat.uncorrectable_errors++;
1231 spin_unlock(&sctx->stat_lock);
1232 printk_ratelimited_in_rcu(KERN_ERR
1233 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
1234 logical, rcu_str_deref(dev->name));
1235 }
1236
1237 out:
1238 if (sblocks_for_recheck) {
1239 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1240 mirror_index++) {
1241 struct scrub_block *sblock = sblocks_for_recheck +
1242 mirror_index;
1243 struct scrub_recover *recover;
1244 int page_index;
1245
1246 for (page_index = 0; page_index < sblock->page_count;
1247 page_index++) {
1248 sblock->pagev[page_index]->sblock = NULL;
1249 recover = sblock->pagev[page_index]->recover;
1250 if (recover) {
1251 scrub_put_recover(recover);
1252 sblock->pagev[page_index]->recover =
1253 NULL;
1254 }
1255 scrub_page_put(sblock->pagev[page_index]);
1256 }
1257 }
1258 kfree(sblocks_for_recheck);
1259 }
1260
1261 return 0;
1262 }
1263
1264 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1265 {
1266 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1267 return 2;
1268 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1269 return 3;
1270 else
1271 return (int)bbio->num_stripes;
1272 }
1273
1274 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1275 u64 *raid_map,
1276 u64 mapped_length,
1277 int nstripes, int mirror,
1278 int *stripe_index,
1279 u64 *stripe_offset)
1280 {
1281 int i;
1282
1283 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1284 /* RAID5/6 */
1285 for (i = 0; i < nstripes; i++) {
1286 if (raid_map[i] == RAID6_Q_STRIPE ||
1287 raid_map[i] == RAID5_P_STRIPE)
1288 continue;
1289
1290 if (logical >= raid_map[i] &&
1291 logical < raid_map[i] + mapped_length)
1292 break;
1293 }
1294
1295 *stripe_index = i;
1296 *stripe_offset = logical - raid_map[i];
1297 } else {
1298 /* The other RAID type */
1299 *stripe_index = mirror;
1300 *stripe_offset = 0;
1301 }
1302 }
1303
1304 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1305 struct scrub_block *sblocks_for_recheck)
1306 {
1307 struct scrub_ctx *sctx = original_sblock->sctx;
1308 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
1309 u64 length = original_sblock->page_count * PAGE_SIZE;
1310 u64 logical = original_sblock->pagev[0]->logical;
1311 struct scrub_recover *recover;
1312 struct btrfs_bio *bbio;
1313 u64 sublen;
1314 u64 mapped_length;
1315 u64 stripe_offset;
1316 int stripe_index;
1317 int page_index = 0;
1318 int mirror_index;
1319 int nmirrors;
1320 int ret;
1321
1322 /*
1323 * note: the two members refs and outstanding_pages
1324 * are not used (and not set) in the blocks that are used for
1325 * the recheck procedure
1326 */
1327
1328 while (length > 0) {
1329 sublen = min_t(u64, length, PAGE_SIZE);
1330 mapped_length = sublen;
1331 bbio = NULL;
1332
1333 /*
1334 * with a length of PAGE_SIZE, each returned stripe
1335 * represents one mirror
1336 */
1337 ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical,
1338 &mapped_length, &bbio, 0, 1);
1339 if (ret || !bbio || mapped_length < sublen) {
1340 btrfs_put_bbio(bbio);
1341 return -EIO;
1342 }
1343
1344 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1345 if (!recover) {
1346 btrfs_put_bbio(bbio);
1347 return -ENOMEM;
1348 }
1349
1350 atomic_set(&recover->refs, 1);
1351 recover->bbio = bbio;
1352 recover->map_length = mapped_length;
1353
1354 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
1355
1356 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1357
1358 for (mirror_index = 0; mirror_index < nmirrors;
1359 mirror_index++) {
1360 struct scrub_block *sblock;
1361 struct scrub_page *page;
1362
1363 sblock = sblocks_for_recheck + mirror_index;
1364 sblock->sctx = sctx;
1365 page = kzalloc(sizeof(*page), GFP_NOFS);
1366 if (!page) {
1367 leave_nomem:
1368 spin_lock(&sctx->stat_lock);
1369 sctx->stat.malloc_errors++;
1370 spin_unlock(&sctx->stat_lock);
1371 scrub_put_recover(recover);
1372 return -ENOMEM;
1373 }
1374 scrub_page_get(page);
1375 sblock->pagev[page_index] = page;
1376 page->logical = logical;
1377
1378 scrub_stripe_index_and_offset(logical,
1379 bbio->map_type,
1380 bbio->raid_map,
1381 mapped_length,
1382 bbio->num_stripes -
1383 bbio->num_tgtdevs,
1384 mirror_index,
1385 &stripe_index,
1386 &stripe_offset);
1387 page->physical = bbio->stripes[stripe_index].physical +
1388 stripe_offset;
1389 page->dev = bbio->stripes[stripe_index].dev;
1390
1391 BUG_ON(page_index >= original_sblock->page_count);
1392 page->physical_for_dev_replace =
1393 original_sblock->pagev[page_index]->
1394 physical_for_dev_replace;
1395 /* for missing devices, dev->bdev is NULL */
1396 page->mirror_num = mirror_index + 1;
1397 sblock->page_count++;
1398 page->page = alloc_page(GFP_NOFS);
1399 if (!page->page)
1400 goto leave_nomem;
1401
1402 scrub_get_recover(recover);
1403 page->recover = recover;
1404 }
1405 scrub_put_recover(recover);
1406 length -= sublen;
1407 logical += sublen;
1408 page_index++;
1409 }
1410
1411 return 0;
1412 }
1413
1414 struct scrub_bio_ret {
1415 struct completion event;
1416 int error;
1417 };
1418
1419 static void scrub_bio_wait_endio(struct bio *bio)
1420 {
1421 struct scrub_bio_ret *ret = bio->bi_private;
1422
1423 ret->error = bio->bi_error;
1424 complete(&ret->event);
1425 }
1426
1427 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
1428 {
1429 return page->recover &&
1430 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
1431 }
1432
1433 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1434 struct bio *bio,
1435 struct scrub_page *page)
1436 {
1437 struct scrub_bio_ret done;
1438 int ret;
1439
1440 init_completion(&done.event);
1441 done.error = 0;
1442 bio->bi_iter.bi_sector = page->logical >> 9;
1443 bio->bi_private = &done;
1444 bio->bi_end_io = scrub_bio_wait_endio;
1445
1446 ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio,
1447 page->recover->map_length,
1448 page->mirror_num, 0);
1449 if (ret)
1450 return ret;
1451
1452 wait_for_completion(&done.event);
1453 if (done.error)
1454 return -EIO;
1455
1456 return 0;
1457 }
1458
1459 /*
1460 * this function will check the on disk data for checksum errors, header
1461 * errors and read I/O errors. If any I/O errors happen, the exact pages
1462 * which are errored are marked as being bad. The goal is to enable scrub
1463 * to take those pages that are not errored from all the mirrors so that
1464 * the pages that are errored in the just handled mirror can be repaired.
1465 */
1466 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1467 struct scrub_block *sblock, int is_metadata,
1468 int have_csum, u8 *csum, u64 generation,
1469 u16 csum_size, int retry_failed_mirror)
1470 {
1471 int page_num;
1472
1473 sblock->no_io_error_seen = 1;
1474 sblock->header_error = 0;
1475 sblock->checksum_error = 0;
1476
1477 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1478 struct bio *bio;
1479 struct scrub_page *page = sblock->pagev[page_num];
1480
1481 if (page->dev->bdev == NULL) {
1482 page->io_error = 1;
1483 sblock->no_io_error_seen = 0;
1484 continue;
1485 }
1486
1487 WARN_ON(!page->page);
1488 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1489 if (!bio) {
1490 page->io_error = 1;
1491 sblock->no_io_error_seen = 0;
1492 continue;
1493 }
1494 bio->bi_bdev = page->dev->bdev;
1495
1496 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1497 if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
1498 if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
1499 sblock->no_io_error_seen = 0;
1500 } else {
1501 bio->bi_iter.bi_sector = page->physical >> 9;
1502
1503 if (btrfsic_submit_bio_wait(READ, bio))
1504 sblock->no_io_error_seen = 0;
1505 }
1506
1507 bio_put(bio);
1508 }
1509
1510 if (sblock->no_io_error_seen)
1511 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1512 have_csum, csum, generation,
1513 csum_size);
1514
1515 return;
1516 }
1517
1518 static inline int scrub_check_fsid(u8 fsid[],
1519 struct scrub_page *spage)
1520 {
1521 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1522 int ret;
1523
1524 ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE);
1525 return !ret;
1526 }
1527
1528 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1529 struct scrub_block *sblock,
1530 int is_metadata, int have_csum,
1531 const u8 *csum, u64 generation,
1532 u16 csum_size)
1533 {
1534 int page_num;
1535 u8 calculated_csum[BTRFS_CSUM_SIZE];
1536 u32 crc = ~(u32)0;
1537 void *mapped_buffer;
1538
1539 WARN_ON(!sblock->pagev[0]->page);
1540 if (is_metadata) {
1541 struct btrfs_header *h;
1542
1543 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1544 h = (struct btrfs_header *)mapped_buffer;
1545
1546 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
1547 !scrub_check_fsid(h->fsid, sblock->pagev[0]) ||
1548 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1549 BTRFS_UUID_SIZE)) {
1550 sblock->header_error = 1;
1551 } else if (generation != btrfs_stack_header_generation(h)) {
1552 sblock->header_error = 1;
1553 sblock->generation_error = 1;
1554 }
1555 csum = h->csum;
1556 } else {
1557 if (!have_csum)
1558 return;
1559
1560 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1561 }
1562
1563 for (page_num = 0;;) {
1564 if (page_num == 0 && is_metadata)
1565 crc = btrfs_csum_data(
1566 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1567 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1568 else
1569 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
1570
1571 kunmap_atomic(mapped_buffer);
1572 page_num++;
1573 if (page_num >= sblock->page_count)
1574 break;
1575 WARN_ON(!sblock->pagev[page_num]->page);
1576
1577 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
1578 }
1579
1580 btrfs_csum_final(crc, calculated_csum);
1581 if (memcmp(calculated_csum, csum, csum_size))
1582 sblock->checksum_error = 1;
1583 }
1584
1585 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1586 struct scrub_block *sblock_good)
1587 {
1588 int page_num;
1589 int ret = 0;
1590
1591 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1592 int ret_sub;
1593
1594 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1595 sblock_good,
1596 page_num, 1);
1597 if (ret_sub)
1598 ret = ret_sub;
1599 }
1600
1601 return ret;
1602 }
1603
1604 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1605 struct scrub_block *sblock_good,
1606 int page_num, int force_write)
1607 {
1608 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1609 struct scrub_page *page_good = sblock_good->pagev[page_num];
1610
1611 BUG_ON(page_bad->page == NULL);
1612 BUG_ON(page_good->page == NULL);
1613 if (force_write || sblock_bad->header_error ||
1614 sblock_bad->checksum_error || page_bad->io_error) {
1615 struct bio *bio;
1616 int ret;
1617
1618 if (!page_bad->dev->bdev) {
1619 printk_ratelimited(KERN_WARNING "BTRFS: "
1620 "scrub_repair_page_from_good_copy(bdev == NULL) "
1621 "is unexpected!\n");
1622 return -EIO;
1623 }
1624
1625 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1626 if (!bio)
1627 return -EIO;
1628 bio->bi_bdev = page_bad->dev->bdev;
1629 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1630
1631 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1632 if (PAGE_SIZE != ret) {
1633 bio_put(bio);
1634 return -EIO;
1635 }
1636
1637 if (btrfsic_submit_bio_wait(WRITE, bio)) {
1638 btrfs_dev_stat_inc_and_print(page_bad->dev,
1639 BTRFS_DEV_STAT_WRITE_ERRS);
1640 btrfs_dev_replace_stats_inc(
1641 &sblock_bad->sctx->dev_root->fs_info->
1642 dev_replace.num_write_errors);
1643 bio_put(bio);
1644 return -EIO;
1645 }
1646 bio_put(bio);
1647 }
1648
1649 return 0;
1650 }
1651
1652 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1653 {
1654 int page_num;
1655
1656 /*
1657 * This block is used for the check of the parity on the source device,
1658 * so the data needn't be written into the destination device.
1659 */
1660 if (sblock->sparity)
1661 return;
1662
1663 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1664 int ret;
1665
1666 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1667 if (ret)
1668 btrfs_dev_replace_stats_inc(
1669 &sblock->sctx->dev_root->fs_info->dev_replace.
1670 num_write_errors);
1671 }
1672 }
1673
1674 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1675 int page_num)
1676 {
1677 struct scrub_page *spage = sblock->pagev[page_num];
1678
1679 BUG_ON(spage->page == NULL);
1680 if (spage->io_error) {
1681 void *mapped_buffer = kmap_atomic(spage->page);
1682
1683 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1684 flush_dcache_page(spage->page);
1685 kunmap_atomic(mapped_buffer);
1686 }
1687 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1688 }
1689
1690 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1691 struct scrub_page *spage)
1692 {
1693 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1694 struct scrub_bio *sbio;
1695 int ret;
1696
1697 mutex_lock(&wr_ctx->wr_lock);
1698 again:
1699 if (!wr_ctx->wr_curr_bio) {
1700 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1701 GFP_NOFS);
1702 if (!wr_ctx->wr_curr_bio) {
1703 mutex_unlock(&wr_ctx->wr_lock);
1704 return -ENOMEM;
1705 }
1706 wr_ctx->wr_curr_bio->sctx = sctx;
1707 wr_ctx->wr_curr_bio->page_count = 0;
1708 }
1709 sbio = wr_ctx->wr_curr_bio;
1710 if (sbio->page_count == 0) {
1711 struct bio *bio;
1712
1713 sbio->physical = spage->physical_for_dev_replace;
1714 sbio->logical = spage->logical;
1715 sbio->dev = wr_ctx->tgtdev;
1716 bio = sbio->bio;
1717 if (!bio) {
1718 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
1719 if (!bio) {
1720 mutex_unlock(&wr_ctx->wr_lock);
1721 return -ENOMEM;
1722 }
1723 sbio->bio = bio;
1724 }
1725
1726 bio->bi_private = sbio;
1727 bio->bi_end_io = scrub_wr_bio_end_io;
1728 bio->bi_bdev = sbio->dev->bdev;
1729 bio->bi_iter.bi_sector = sbio->physical >> 9;
1730 sbio->err = 0;
1731 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1732 spage->physical_for_dev_replace ||
1733 sbio->logical + sbio->page_count * PAGE_SIZE !=
1734 spage->logical) {
1735 scrub_wr_submit(sctx);
1736 goto again;
1737 }
1738
1739 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1740 if (ret != PAGE_SIZE) {
1741 if (sbio->page_count < 1) {
1742 bio_put(sbio->bio);
1743 sbio->bio = NULL;
1744 mutex_unlock(&wr_ctx->wr_lock);
1745 return -EIO;
1746 }
1747 scrub_wr_submit(sctx);
1748 goto again;
1749 }
1750
1751 sbio->pagev[sbio->page_count] = spage;
1752 scrub_page_get(spage);
1753 sbio->page_count++;
1754 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1755 scrub_wr_submit(sctx);
1756 mutex_unlock(&wr_ctx->wr_lock);
1757
1758 return 0;
1759 }
1760
1761 static void scrub_wr_submit(struct scrub_ctx *sctx)
1762 {
1763 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1764 struct scrub_bio *sbio;
1765
1766 if (!wr_ctx->wr_curr_bio)
1767 return;
1768
1769 sbio = wr_ctx->wr_curr_bio;
1770 wr_ctx->wr_curr_bio = NULL;
1771 WARN_ON(!sbio->bio->bi_bdev);
1772 scrub_pending_bio_inc(sctx);
1773 /* process all writes in a single worker thread. Then the block layer
1774 * orders the requests before sending them to the driver which
1775 * doubled the write performance on spinning disks when measured
1776 * with Linux 3.5 */
1777 btrfsic_submit_bio(WRITE, sbio->bio);
1778 }
1779
1780 static void scrub_wr_bio_end_io(struct bio *bio)
1781 {
1782 struct scrub_bio *sbio = bio->bi_private;
1783 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1784
1785 sbio->err = bio->bi_error;
1786 sbio->bio = bio;
1787
1788 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1789 scrub_wr_bio_end_io_worker, NULL, NULL);
1790 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1791 }
1792
1793 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1794 {
1795 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1796 struct scrub_ctx *sctx = sbio->sctx;
1797 int i;
1798
1799 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1800 if (sbio->err) {
1801 struct btrfs_dev_replace *dev_replace =
1802 &sbio->sctx->dev_root->fs_info->dev_replace;
1803
1804 for (i = 0; i < sbio->page_count; i++) {
1805 struct scrub_page *spage = sbio->pagev[i];
1806
1807 spage->io_error = 1;
1808 btrfs_dev_replace_stats_inc(&dev_replace->
1809 num_write_errors);
1810 }
1811 }
1812
1813 for (i = 0; i < sbio->page_count; i++)
1814 scrub_page_put(sbio->pagev[i]);
1815
1816 bio_put(sbio->bio);
1817 kfree(sbio);
1818 scrub_pending_bio_dec(sctx);
1819 }
1820
1821 static int scrub_checksum(struct scrub_block *sblock)
1822 {
1823 u64 flags;
1824 int ret;
1825
1826 WARN_ON(sblock->page_count < 1);
1827 flags = sblock->pagev[0]->flags;
1828 ret = 0;
1829 if (flags & BTRFS_EXTENT_FLAG_DATA)
1830 ret = scrub_checksum_data(sblock);
1831 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1832 ret = scrub_checksum_tree_block(sblock);
1833 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1834 (void)scrub_checksum_super(sblock);
1835 else
1836 WARN_ON(1);
1837 if (ret)
1838 scrub_handle_errored_block(sblock);
1839
1840 return ret;
1841 }
1842
1843 static int scrub_checksum_data(struct scrub_block *sblock)
1844 {
1845 struct scrub_ctx *sctx = sblock->sctx;
1846 u8 csum[BTRFS_CSUM_SIZE];
1847 u8 *on_disk_csum;
1848 struct page *page;
1849 void *buffer;
1850 u32 crc = ~(u32)0;
1851 int fail = 0;
1852 u64 len;
1853 int index;
1854
1855 BUG_ON(sblock->page_count < 1);
1856 if (!sblock->pagev[0]->have_csum)
1857 return 0;
1858
1859 on_disk_csum = sblock->pagev[0]->csum;
1860 page = sblock->pagev[0]->page;
1861 buffer = kmap_atomic(page);
1862
1863 len = sctx->sectorsize;
1864 index = 0;
1865 for (;;) {
1866 u64 l = min_t(u64, len, PAGE_SIZE);
1867
1868 crc = btrfs_csum_data(buffer, crc, l);
1869 kunmap_atomic(buffer);
1870 len -= l;
1871 if (len == 0)
1872 break;
1873 index++;
1874 BUG_ON(index >= sblock->page_count);
1875 BUG_ON(!sblock->pagev[index]->page);
1876 page = sblock->pagev[index]->page;
1877 buffer = kmap_atomic(page);
1878 }
1879
1880 btrfs_csum_final(crc, csum);
1881 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1882 fail = 1;
1883
1884 return fail;
1885 }
1886
1887 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1888 {
1889 struct scrub_ctx *sctx = sblock->sctx;
1890 struct btrfs_header *h;
1891 struct btrfs_root *root = sctx->dev_root;
1892 struct btrfs_fs_info *fs_info = root->fs_info;
1893 u8 calculated_csum[BTRFS_CSUM_SIZE];
1894 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1895 struct page *page;
1896 void *mapped_buffer;
1897 u64 mapped_size;
1898 void *p;
1899 u32 crc = ~(u32)0;
1900 int fail = 0;
1901 int crc_fail = 0;
1902 u64 len;
1903 int index;
1904
1905 BUG_ON(sblock->page_count < 1);
1906 page = sblock->pagev[0]->page;
1907 mapped_buffer = kmap_atomic(page);
1908 h = (struct btrfs_header *)mapped_buffer;
1909 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1910
1911 /*
1912 * we don't use the getter functions here, as we
1913 * a) don't have an extent buffer and
1914 * b) the page is already kmapped
1915 */
1916
1917 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1918 ++fail;
1919
1920 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
1921 ++fail;
1922
1923 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1924 ++fail;
1925
1926 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1927 BTRFS_UUID_SIZE))
1928 ++fail;
1929
1930 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1931 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1932 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1933 index = 0;
1934 for (;;) {
1935 u64 l = min_t(u64, len, mapped_size);
1936
1937 crc = btrfs_csum_data(p, crc, l);
1938 kunmap_atomic(mapped_buffer);
1939 len -= l;
1940 if (len == 0)
1941 break;
1942 index++;
1943 BUG_ON(index >= sblock->page_count);
1944 BUG_ON(!sblock->pagev[index]->page);
1945 page = sblock->pagev[index]->page;
1946 mapped_buffer = kmap_atomic(page);
1947 mapped_size = PAGE_SIZE;
1948 p = mapped_buffer;
1949 }
1950
1951 btrfs_csum_final(crc, calculated_csum);
1952 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1953 ++crc_fail;
1954
1955 return fail || crc_fail;
1956 }
1957
1958 static int scrub_checksum_super(struct scrub_block *sblock)
1959 {
1960 struct btrfs_super_block *s;
1961 struct scrub_ctx *sctx = sblock->sctx;
1962 u8 calculated_csum[BTRFS_CSUM_SIZE];
1963 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1964 struct page *page;
1965 void *mapped_buffer;
1966 u64 mapped_size;
1967 void *p;
1968 u32 crc = ~(u32)0;
1969 int fail_gen = 0;
1970 int fail_cor = 0;
1971 u64 len;
1972 int index;
1973
1974 BUG_ON(sblock->page_count < 1);
1975 page = sblock->pagev[0]->page;
1976 mapped_buffer = kmap_atomic(page);
1977 s = (struct btrfs_super_block *)mapped_buffer;
1978 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1979
1980 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1981 ++fail_cor;
1982
1983 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1984 ++fail_gen;
1985
1986 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1987 ++fail_cor;
1988
1989 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1990 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1991 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1992 index = 0;
1993 for (;;) {
1994 u64 l = min_t(u64, len, mapped_size);
1995
1996 crc = btrfs_csum_data(p, crc, l);
1997 kunmap_atomic(mapped_buffer);
1998 len -= l;
1999 if (len == 0)
2000 break;
2001 index++;
2002 BUG_ON(index >= sblock->page_count);
2003 BUG_ON(!sblock->pagev[index]->page);
2004 page = sblock->pagev[index]->page;
2005 mapped_buffer = kmap_atomic(page);
2006 mapped_size = PAGE_SIZE;
2007 p = mapped_buffer;
2008 }
2009
2010 btrfs_csum_final(crc, calculated_csum);
2011 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
2012 ++fail_cor;
2013
2014 if (fail_cor + fail_gen) {
2015 /*
2016 * if we find an error in a super block, we just report it.
2017 * They will get written with the next transaction commit
2018 * anyway
2019 */
2020 spin_lock(&sctx->stat_lock);
2021 ++sctx->stat.super_errors;
2022 spin_unlock(&sctx->stat_lock);
2023 if (fail_cor)
2024 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
2025 BTRFS_DEV_STAT_CORRUPTION_ERRS);
2026 else
2027 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
2028 BTRFS_DEV_STAT_GENERATION_ERRS);
2029 }
2030
2031 return fail_cor + fail_gen;
2032 }
2033
2034 static void scrub_block_get(struct scrub_block *sblock)
2035 {
2036 atomic_inc(&sblock->refs);
2037 }
2038
2039 static void scrub_block_put(struct scrub_block *sblock)
2040 {
2041 if (atomic_dec_and_test(&sblock->refs)) {
2042 int i;
2043
2044 if (sblock->sparity)
2045 scrub_parity_put(sblock->sparity);
2046
2047 for (i = 0; i < sblock->page_count; i++)
2048 scrub_page_put(sblock->pagev[i]);
2049 kfree(sblock);
2050 }
2051 }
2052
2053 static void scrub_page_get(struct scrub_page *spage)
2054 {
2055 atomic_inc(&spage->refs);
2056 }
2057
2058 static void scrub_page_put(struct scrub_page *spage)
2059 {
2060 if (atomic_dec_and_test(&spage->refs)) {
2061 if (spage->page)
2062 __free_page(spage->page);
2063 kfree(spage);
2064 }
2065 }
2066
2067 static void scrub_submit(struct scrub_ctx *sctx)
2068 {
2069 struct scrub_bio *sbio;
2070
2071 if (sctx->curr == -1)
2072 return;
2073
2074 sbio = sctx->bios[sctx->curr];
2075 sctx->curr = -1;
2076 scrub_pending_bio_inc(sctx);
2077
2078 if (!sbio->bio->bi_bdev) {
2079 /*
2080 * this case should not happen. If btrfs_map_block() is
2081 * wrong, it could happen for dev-replace operations on
2082 * missing devices when no mirrors are available, but in
2083 * this case it should already fail the mount.
2084 * This case is handled correctly (but _very_ slowly).
2085 */
2086 printk_ratelimited(KERN_WARNING
2087 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
2088 bio_io_error(sbio->bio);
2089 } else {
2090 btrfsic_submit_bio(READ, sbio->bio);
2091 }
2092 }
2093
2094 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2095 struct scrub_page *spage)
2096 {
2097 struct scrub_block *sblock = spage->sblock;
2098 struct scrub_bio *sbio;
2099 int ret;
2100
2101 again:
2102 /*
2103 * grab a fresh bio or wait for one to become available
2104 */
2105 while (sctx->curr == -1) {
2106 spin_lock(&sctx->list_lock);
2107 sctx->curr = sctx->first_free;
2108 if (sctx->curr != -1) {
2109 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2110 sctx->bios[sctx->curr]->next_free = -1;
2111 sctx->bios[sctx->curr]->page_count = 0;
2112 spin_unlock(&sctx->list_lock);
2113 } else {
2114 spin_unlock(&sctx->list_lock);
2115 wait_event(sctx->list_wait, sctx->first_free != -1);
2116 }
2117 }
2118 sbio = sctx->bios[sctx->curr];
2119 if (sbio->page_count == 0) {
2120 struct bio *bio;
2121
2122 sbio->physical = spage->physical;
2123 sbio->logical = spage->logical;
2124 sbio->dev = spage->dev;
2125 bio = sbio->bio;
2126 if (!bio) {
2127 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
2128 if (!bio)
2129 return -ENOMEM;
2130 sbio->bio = bio;
2131 }
2132
2133 bio->bi_private = sbio;
2134 bio->bi_end_io = scrub_bio_end_io;
2135 bio->bi_bdev = sbio->dev->bdev;
2136 bio->bi_iter.bi_sector = sbio->physical >> 9;
2137 sbio->err = 0;
2138 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2139 spage->physical ||
2140 sbio->logical + sbio->page_count * PAGE_SIZE !=
2141 spage->logical ||
2142 sbio->dev != spage->dev) {
2143 scrub_submit(sctx);
2144 goto again;
2145 }
2146
2147 sbio->pagev[sbio->page_count] = spage;
2148 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2149 if (ret != PAGE_SIZE) {
2150 if (sbio->page_count < 1) {
2151 bio_put(sbio->bio);
2152 sbio->bio = NULL;
2153 return -EIO;
2154 }
2155 scrub_submit(sctx);
2156 goto again;
2157 }
2158
2159 scrub_block_get(sblock); /* one for the page added to the bio */
2160 atomic_inc(&sblock->outstanding_pages);
2161 sbio->page_count++;
2162 if (sbio->page_count == sctx->pages_per_rd_bio)
2163 scrub_submit(sctx);
2164
2165 return 0;
2166 }
2167
2168 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2169 u64 physical, struct btrfs_device *dev, u64 flags,
2170 u64 gen, int mirror_num, u8 *csum, int force,
2171 u64 physical_for_dev_replace)
2172 {
2173 struct scrub_block *sblock;
2174 int index;
2175
2176 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2177 if (!sblock) {
2178 spin_lock(&sctx->stat_lock);
2179 sctx->stat.malloc_errors++;
2180 spin_unlock(&sctx->stat_lock);
2181 return -ENOMEM;
2182 }
2183
2184 /* one ref inside this function, plus one for each page added to
2185 * a bio later on */
2186 atomic_set(&sblock->refs, 1);
2187 sblock->sctx = sctx;
2188 sblock->no_io_error_seen = 1;
2189
2190 for (index = 0; len > 0; index++) {
2191 struct scrub_page *spage;
2192 u64 l = min_t(u64, len, PAGE_SIZE);
2193
2194 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2195 if (!spage) {
2196 leave_nomem:
2197 spin_lock(&sctx->stat_lock);
2198 sctx->stat.malloc_errors++;
2199 spin_unlock(&sctx->stat_lock);
2200 scrub_block_put(sblock);
2201 return -ENOMEM;
2202 }
2203 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2204 scrub_page_get(spage);
2205 sblock->pagev[index] = spage;
2206 spage->sblock = sblock;
2207 spage->dev = dev;
2208 spage->flags = flags;
2209 spage->generation = gen;
2210 spage->logical = logical;
2211 spage->physical = physical;
2212 spage->physical_for_dev_replace = physical_for_dev_replace;
2213 spage->mirror_num = mirror_num;
2214 if (csum) {
2215 spage->have_csum = 1;
2216 memcpy(spage->csum, csum, sctx->csum_size);
2217 } else {
2218 spage->have_csum = 0;
2219 }
2220 sblock->page_count++;
2221 spage->page = alloc_page(GFP_NOFS);
2222 if (!spage->page)
2223 goto leave_nomem;
2224 len -= l;
2225 logical += l;
2226 physical += l;
2227 physical_for_dev_replace += l;
2228 }
2229
2230 WARN_ON(sblock->page_count == 0);
2231 for (index = 0; index < sblock->page_count; index++) {
2232 struct scrub_page *spage = sblock->pagev[index];
2233 int ret;
2234
2235 ret = scrub_add_page_to_rd_bio(sctx, spage);
2236 if (ret) {
2237 scrub_block_put(sblock);
2238 return ret;
2239 }
2240 }
2241
2242 if (force)
2243 scrub_submit(sctx);
2244
2245 /* last one frees, either here or in bio completion for last page */
2246 scrub_block_put(sblock);
2247 return 0;
2248 }
2249
2250 static void scrub_bio_end_io(struct bio *bio)
2251 {
2252 struct scrub_bio *sbio = bio->bi_private;
2253 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
2254
2255 sbio->err = bio->bi_error;
2256 sbio->bio = bio;
2257
2258 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2259 }
2260
2261 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2262 {
2263 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2264 struct scrub_ctx *sctx = sbio->sctx;
2265 int i;
2266
2267 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2268 if (sbio->err) {
2269 for (i = 0; i < sbio->page_count; i++) {
2270 struct scrub_page *spage = sbio->pagev[i];
2271
2272 spage->io_error = 1;
2273 spage->sblock->no_io_error_seen = 0;
2274 }
2275 }
2276
2277 /* now complete the scrub_block items that have all pages completed */
2278 for (i = 0; i < sbio->page_count; i++) {
2279 struct scrub_page *spage = sbio->pagev[i];
2280 struct scrub_block *sblock = spage->sblock;
2281
2282 if (atomic_dec_and_test(&sblock->outstanding_pages))
2283 scrub_block_complete(sblock);
2284 scrub_block_put(sblock);
2285 }
2286
2287 bio_put(sbio->bio);
2288 sbio->bio = NULL;
2289 spin_lock(&sctx->list_lock);
2290 sbio->next_free = sctx->first_free;
2291 sctx->first_free = sbio->index;
2292 spin_unlock(&sctx->list_lock);
2293
2294 if (sctx->is_dev_replace &&
2295 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2296 mutex_lock(&sctx->wr_ctx.wr_lock);
2297 scrub_wr_submit(sctx);
2298 mutex_unlock(&sctx->wr_ctx.wr_lock);
2299 }
2300
2301 scrub_pending_bio_dec(sctx);
2302 }
2303
2304 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2305 unsigned long *bitmap,
2306 u64 start, u64 len)
2307 {
2308 u32 offset;
2309 int nsectors;
2310 int sectorsize = sparity->sctx->dev_root->sectorsize;
2311
2312 if (len >= sparity->stripe_len) {
2313 bitmap_set(bitmap, 0, sparity->nsectors);
2314 return;
2315 }
2316
2317 start -= sparity->logic_start;
2318 start = div_u64_rem(start, sparity->stripe_len, &offset);
2319 offset /= sectorsize;
2320 nsectors = (int)len / sectorsize;
2321
2322 if (offset + nsectors <= sparity->nsectors) {
2323 bitmap_set(bitmap, offset, nsectors);
2324 return;
2325 }
2326
2327 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2328 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2329 }
2330
2331 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2332 u64 start, u64 len)
2333 {
2334 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2335 }
2336
2337 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2338 u64 start, u64 len)
2339 {
2340 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2341 }
2342
2343 static void scrub_block_complete(struct scrub_block *sblock)
2344 {
2345 int corrupted = 0;
2346
2347 if (!sblock->no_io_error_seen) {
2348 corrupted = 1;
2349 scrub_handle_errored_block(sblock);
2350 } else {
2351 /*
2352 * if has checksum error, write via repair mechanism in
2353 * dev replace case, otherwise write here in dev replace
2354 * case.
2355 */
2356 corrupted = scrub_checksum(sblock);
2357 if (!corrupted && sblock->sctx->is_dev_replace)
2358 scrub_write_block_to_dev_replace(sblock);
2359 }
2360
2361 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2362 u64 start = sblock->pagev[0]->logical;
2363 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2364 PAGE_SIZE;
2365
2366 scrub_parity_mark_sectors_error(sblock->sparity,
2367 start, end - start);
2368 }
2369 }
2370
2371 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
2372 u8 *csum)
2373 {
2374 struct btrfs_ordered_sum *sum = NULL;
2375 unsigned long index;
2376 unsigned long num_sectors;
2377
2378 while (!list_empty(&sctx->csum_list)) {
2379 sum = list_first_entry(&sctx->csum_list,
2380 struct btrfs_ordered_sum, list);
2381 if (sum->bytenr > logical)
2382 return 0;
2383 if (sum->bytenr + sum->len > logical)
2384 break;
2385
2386 ++sctx->stat.csum_discards;
2387 list_del(&sum->list);
2388 kfree(sum);
2389 sum = NULL;
2390 }
2391 if (!sum)
2392 return 0;
2393
2394 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2395 num_sectors = sum->len / sctx->sectorsize;
2396 memcpy(csum, sum->sums + index, sctx->csum_size);
2397 if (index == num_sectors - 1) {
2398 list_del(&sum->list);
2399 kfree(sum);
2400 }
2401 return 1;
2402 }
2403
2404 /* scrub extent tries to collect up to 64 kB for each bio */
2405 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2406 u64 physical, struct btrfs_device *dev, u64 flags,
2407 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2408 {
2409 int ret;
2410 u8 csum[BTRFS_CSUM_SIZE];
2411 u32 blocksize;
2412
2413 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2414 blocksize = sctx->sectorsize;
2415 spin_lock(&sctx->stat_lock);
2416 sctx->stat.data_extents_scrubbed++;
2417 sctx->stat.data_bytes_scrubbed += len;
2418 spin_unlock(&sctx->stat_lock);
2419 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2420 blocksize = sctx->nodesize;
2421 spin_lock(&sctx->stat_lock);
2422 sctx->stat.tree_extents_scrubbed++;
2423 sctx->stat.tree_bytes_scrubbed += len;
2424 spin_unlock(&sctx->stat_lock);
2425 } else {
2426 blocksize = sctx->sectorsize;
2427 WARN_ON(1);
2428 }
2429
2430 while (len) {
2431 u64 l = min_t(u64, len, blocksize);
2432 int have_csum = 0;
2433
2434 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2435 /* push csums to sbio */
2436 have_csum = scrub_find_csum(sctx, logical, l, csum);
2437 if (have_csum == 0)
2438 ++sctx->stat.no_csum;
2439 if (sctx->is_dev_replace && !have_csum) {
2440 ret = copy_nocow_pages(sctx, logical, l,
2441 mirror_num,
2442 physical_for_dev_replace);
2443 goto behind_scrub_pages;
2444 }
2445 }
2446 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2447 mirror_num, have_csum ? csum : NULL, 0,
2448 physical_for_dev_replace);
2449 behind_scrub_pages:
2450 if (ret)
2451 return ret;
2452 len -= l;
2453 logical += l;
2454 physical += l;
2455 physical_for_dev_replace += l;
2456 }
2457 return 0;
2458 }
2459
2460 static int scrub_pages_for_parity(struct scrub_parity *sparity,
2461 u64 logical, u64 len,
2462 u64 physical, struct btrfs_device *dev,
2463 u64 flags, u64 gen, int mirror_num, u8 *csum)
2464 {
2465 struct scrub_ctx *sctx = sparity->sctx;
2466 struct scrub_block *sblock;
2467 int index;
2468
2469 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2470 if (!sblock) {
2471 spin_lock(&sctx->stat_lock);
2472 sctx->stat.malloc_errors++;
2473 spin_unlock(&sctx->stat_lock);
2474 return -ENOMEM;
2475 }
2476
2477 /* one ref inside this function, plus one for each page added to
2478 * a bio later on */
2479 atomic_set(&sblock->refs, 1);
2480 sblock->sctx = sctx;
2481 sblock->no_io_error_seen = 1;
2482 sblock->sparity = sparity;
2483 scrub_parity_get(sparity);
2484
2485 for (index = 0; len > 0; index++) {
2486 struct scrub_page *spage;
2487 u64 l = min_t(u64, len, PAGE_SIZE);
2488
2489 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2490 if (!spage) {
2491 leave_nomem:
2492 spin_lock(&sctx->stat_lock);
2493 sctx->stat.malloc_errors++;
2494 spin_unlock(&sctx->stat_lock);
2495 scrub_block_put(sblock);
2496 return -ENOMEM;
2497 }
2498 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2499 /* For scrub block */
2500 scrub_page_get(spage);
2501 sblock->pagev[index] = spage;
2502 /* For scrub parity */
2503 scrub_page_get(spage);
2504 list_add_tail(&spage->list, &sparity->spages);
2505 spage->sblock = sblock;
2506 spage->dev = dev;
2507 spage->flags = flags;
2508 spage->generation = gen;
2509 spage->logical = logical;
2510 spage->physical = physical;
2511 spage->mirror_num = mirror_num;
2512 if (csum) {
2513 spage->have_csum = 1;
2514 memcpy(spage->csum, csum, sctx->csum_size);
2515 } else {
2516 spage->have_csum = 0;
2517 }
2518 sblock->page_count++;
2519 spage->page = alloc_page(GFP_NOFS);
2520 if (!spage->page)
2521 goto leave_nomem;
2522 len -= l;
2523 logical += l;
2524 physical += l;
2525 }
2526
2527 WARN_ON(sblock->page_count == 0);
2528 for (index = 0; index < sblock->page_count; index++) {
2529 struct scrub_page *spage = sblock->pagev[index];
2530 int ret;
2531
2532 ret = scrub_add_page_to_rd_bio(sctx, spage);
2533 if (ret) {
2534 scrub_block_put(sblock);
2535 return ret;
2536 }
2537 }
2538
2539 /* last one frees, either here or in bio completion for last page */
2540 scrub_block_put(sblock);
2541 return 0;
2542 }
2543
2544 static int scrub_extent_for_parity(struct scrub_parity *sparity,
2545 u64 logical, u64 len,
2546 u64 physical, struct btrfs_device *dev,
2547 u64 flags, u64 gen, int mirror_num)
2548 {
2549 struct scrub_ctx *sctx = sparity->sctx;
2550 int ret;
2551 u8 csum[BTRFS_CSUM_SIZE];
2552 u32 blocksize;
2553
2554 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2555 blocksize = sctx->sectorsize;
2556 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2557 blocksize = sctx->nodesize;
2558 } else {
2559 blocksize = sctx->sectorsize;
2560 WARN_ON(1);
2561 }
2562
2563 while (len) {
2564 u64 l = min_t(u64, len, blocksize);
2565 int have_csum = 0;
2566
2567 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2568 /* push csums to sbio */
2569 have_csum = scrub_find_csum(sctx, logical, l, csum);
2570 if (have_csum == 0)
2571 goto skip;
2572 }
2573 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2574 flags, gen, mirror_num,
2575 have_csum ? csum : NULL);
2576 if (ret)
2577 return ret;
2578 skip:
2579 len -= l;
2580 logical += l;
2581 physical += l;
2582 }
2583 return 0;
2584 }
2585
2586 /*
2587 * Given a physical address, this will calculate it's
2588 * logical offset. if this is a parity stripe, it will return
2589 * the most left data stripe's logical offset.
2590 *
2591 * return 0 if it is a data stripe, 1 means parity stripe.
2592 */
2593 static int get_raid56_logic_offset(u64 physical, int num,
2594 struct map_lookup *map, u64 *offset,
2595 u64 *stripe_start)
2596 {
2597 int i;
2598 int j = 0;
2599 u64 stripe_nr;
2600 u64 last_offset;
2601 u32 stripe_index;
2602 u32 rot;
2603
2604 last_offset = (physical - map->stripes[num].physical) *
2605 nr_data_stripes(map);
2606 if (stripe_start)
2607 *stripe_start = last_offset;
2608
2609 *offset = last_offset;
2610 for (i = 0; i < nr_data_stripes(map); i++) {
2611 *offset = last_offset + i * map->stripe_len;
2612
2613 stripe_nr = div_u64(*offset, map->stripe_len);
2614 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
2615
2616 /* Work out the disk rotation on this stripe-set */
2617 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2618 /* calculate which stripe this data locates */
2619 rot += i;
2620 stripe_index = rot % map->num_stripes;
2621 if (stripe_index == num)
2622 return 0;
2623 if (stripe_index < num)
2624 j++;
2625 }
2626 *offset = last_offset + j * map->stripe_len;
2627 return 1;
2628 }
2629
2630 static void scrub_free_parity(struct scrub_parity *sparity)
2631 {
2632 struct scrub_ctx *sctx = sparity->sctx;
2633 struct scrub_page *curr, *next;
2634 int nbits;
2635
2636 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2637 if (nbits) {
2638 spin_lock(&sctx->stat_lock);
2639 sctx->stat.read_errors += nbits;
2640 sctx->stat.uncorrectable_errors += nbits;
2641 spin_unlock(&sctx->stat_lock);
2642 }
2643
2644 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2645 list_del_init(&curr->list);
2646 scrub_page_put(curr);
2647 }
2648
2649 kfree(sparity);
2650 }
2651
2652 static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2653 {
2654 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2655 work);
2656 struct scrub_ctx *sctx = sparity->sctx;
2657
2658 scrub_free_parity(sparity);
2659 scrub_pending_bio_dec(sctx);
2660 }
2661
2662 static void scrub_parity_bio_endio(struct bio *bio)
2663 {
2664 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2665
2666 if (bio->bi_error)
2667 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2668 sparity->nsectors);
2669
2670 bio_put(bio);
2671
2672 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2673 scrub_parity_bio_endio_worker, NULL, NULL);
2674 btrfs_queue_work(sparity->sctx->dev_root->fs_info->scrub_parity_workers,
2675 &sparity->work);
2676 }
2677
2678 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2679 {
2680 struct scrub_ctx *sctx = sparity->sctx;
2681 struct bio *bio;
2682 struct btrfs_raid_bio *rbio;
2683 struct scrub_page *spage;
2684 struct btrfs_bio *bbio = NULL;
2685 u64 length;
2686 int ret;
2687
2688 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2689 sparity->nsectors))
2690 goto out;
2691
2692 length = sparity->logic_end - sparity->logic_start + 1;
2693 ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
2694 sparity->logic_start,
2695 &length, &bbio, 0, 1);
2696 if (ret || !bbio || !bbio->raid_map)
2697 goto bbio_out;
2698
2699 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2700 if (!bio)
2701 goto bbio_out;
2702
2703 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2704 bio->bi_private = sparity;
2705 bio->bi_end_io = scrub_parity_bio_endio;
2706
2707 rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio,
2708 length, sparity->scrub_dev,
2709 sparity->dbitmap,
2710 sparity->nsectors);
2711 if (!rbio)
2712 goto rbio_out;
2713
2714 list_for_each_entry(spage, &sparity->spages, list)
2715 raid56_parity_add_scrub_pages(rbio, spage->page,
2716 spage->logical);
2717
2718 scrub_pending_bio_inc(sctx);
2719 raid56_parity_submit_scrub_rbio(rbio);
2720 return;
2721
2722 rbio_out:
2723 bio_put(bio);
2724 bbio_out:
2725 btrfs_put_bbio(bbio);
2726 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2727 sparity->nsectors);
2728 spin_lock(&sctx->stat_lock);
2729 sctx->stat.malloc_errors++;
2730 spin_unlock(&sctx->stat_lock);
2731 out:
2732 scrub_free_parity(sparity);
2733 }
2734
2735 static inline int scrub_calc_parity_bitmap_len(int nsectors)
2736 {
2737 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * (BITS_PER_LONG / 8);
2738 }
2739
2740 static void scrub_parity_get(struct scrub_parity *sparity)
2741 {
2742 atomic_inc(&sparity->refs);
2743 }
2744
2745 static void scrub_parity_put(struct scrub_parity *sparity)
2746 {
2747 if (!atomic_dec_and_test(&sparity->refs))
2748 return;
2749
2750 scrub_parity_check_and_repair(sparity);
2751 }
2752
2753 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2754 struct map_lookup *map,
2755 struct btrfs_device *sdev,
2756 struct btrfs_path *path,
2757 u64 logic_start,
2758 u64 logic_end)
2759 {
2760 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2761 struct btrfs_root *root = fs_info->extent_root;
2762 struct btrfs_root *csum_root = fs_info->csum_root;
2763 struct btrfs_extent_item *extent;
2764 u64 flags;
2765 int ret;
2766 int slot;
2767 struct extent_buffer *l;
2768 struct btrfs_key key;
2769 u64 generation;
2770 u64 extent_logical;
2771 u64 extent_physical;
2772 u64 extent_len;
2773 struct btrfs_device *extent_dev;
2774 struct scrub_parity *sparity;
2775 int nsectors;
2776 int bitmap_len;
2777 int extent_mirror_num;
2778 int stop_loop = 0;
2779
2780 nsectors = map->stripe_len / root->sectorsize;
2781 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2782 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2783 GFP_NOFS);
2784 if (!sparity) {
2785 spin_lock(&sctx->stat_lock);
2786 sctx->stat.malloc_errors++;
2787 spin_unlock(&sctx->stat_lock);
2788 return -ENOMEM;
2789 }
2790
2791 sparity->stripe_len = map->stripe_len;
2792 sparity->nsectors = nsectors;
2793 sparity->sctx = sctx;
2794 sparity->scrub_dev = sdev;
2795 sparity->logic_start = logic_start;
2796 sparity->logic_end = logic_end;
2797 atomic_set(&sparity->refs, 1);
2798 INIT_LIST_HEAD(&sparity->spages);
2799 sparity->dbitmap = sparity->bitmap;
2800 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2801
2802 ret = 0;
2803 while (logic_start < logic_end) {
2804 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2805 key.type = BTRFS_METADATA_ITEM_KEY;
2806 else
2807 key.type = BTRFS_EXTENT_ITEM_KEY;
2808 key.objectid = logic_start;
2809 key.offset = (u64)-1;
2810
2811 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2812 if (ret < 0)
2813 goto out;
2814
2815 if (ret > 0) {
2816 ret = btrfs_previous_extent_item(root, path, 0);
2817 if (ret < 0)
2818 goto out;
2819 if (ret > 0) {
2820 btrfs_release_path(path);
2821 ret = btrfs_search_slot(NULL, root, &key,
2822 path, 0, 0);
2823 if (ret < 0)
2824 goto out;
2825 }
2826 }
2827
2828 stop_loop = 0;
2829 while (1) {
2830 u64 bytes;
2831
2832 l = path->nodes[0];
2833 slot = path->slots[0];
2834 if (slot >= btrfs_header_nritems(l)) {
2835 ret = btrfs_next_leaf(root, path);
2836 if (ret == 0)
2837 continue;
2838 if (ret < 0)
2839 goto out;
2840
2841 stop_loop = 1;
2842 break;
2843 }
2844 btrfs_item_key_to_cpu(l, &key, slot);
2845
2846 if (key.type == BTRFS_METADATA_ITEM_KEY)
2847 bytes = root->nodesize;
2848 else
2849 bytes = key.offset;
2850
2851 if (key.objectid + bytes <= logic_start)
2852 goto next;
2853
2854 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2855 key.type != BTRFS_METADATA_ITEM_KEY)
2856 goto next;
2857
2858 if (key.objectid > logic_end) {
2859 stop_loop = 1;
2860 break;
2861 }
2862
2863 while (key.objectid >= logic_start + map->stripe_len)
2864 logic_start += map->stripe_len;
2865
2866 extent = btrfs_item_ptr(l, slot,
2867 struct btrfs_extent_item);
2868 flags = btrfs_extent_flags(l, extent);
2869 generation = btrfs_extent_generation(l, extent);
2870
2871 if (key.objectid < logic_start &&
2872 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
2873 btrfs_err(fs_info,
2874 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2875 key.objectid, logic_start);
2876 goto next;
2877 }
2878 again:
2879 extent_logical = key.objectid;
2880 extent_len = bytes;
2881
2882 if (extent_logical < logic_start) {
2883 extent_len -= logic_start - extent_logical;
2884 extent_logical = logic_start;
2885 }
2886
2887 if (extent_logical + extent_len >
2888 logic_start + map->stripe_len)
2889 extent_len = logic_start + map->stripe_len -
2890 extent_logical;
2891
2892 scrub_parity_mark_sectors_data(sparity, extent_logical,
2893 extent_len);
2894
2895 scrub_remap_extent(fs_info, extent_logical,
2896 extent_len, &extent_physical,
2897 &extent_dev,
2898 &extent_mirror_num);
2899
2900 ret = btrfs_lookup_csums_range(csum_root,
2901 extent_logical,
2902 extent_logical + extent_len - 1,
2903 &sctx->csum_list, 1);
2904 if (ret)
2905 goto out;
2906
2907 ret = scrub_extent_for_parity(sparity, extent_logical,
2908 extent_len,
2909 extent_physical,
2910 extent_dev, flags,
2911 generation,
2912 extent_mirror_num);
2913 if (ret)
2914 goto out;
2915
2916 scrub_free_csums(sctx);
2917 if (extent_logical + extent_len <
2918 key.objectid + bytes) {
2919 logic_start += map->stripe_len;
2920
2921 if (logic_start >= logic_end) {
2922 stop_loop = 1;
2923 break;
2924 }
2925
2926 if (logic_start < key.objectid + bytes) {
2927 cond_resched();
2928 goto again;
2929 }
2930 }
2931 next:
2932 path->slots[0]++;
2933 }
2934
2935 btrfs_release_path(path);
2936
2937 if (stop_loop)
2938 break;
2939
2940 logic_start += map->stripe_len;
2941 }
2942 out:
2943 if (ret < 0)
2944 scrub_parity_mark_sectors_error(sparity, logic_start,
2945 logic_end - logic_start + 1);
2946 scrub_parity_put(sparity);
2947 scrub_submit(sctx);
2948 mutex_lock(&sctx->wr_ctx.wr_lock);
2949 scrub_wr_submit(sctx);
2950 mutex_unlock(&sctx->wr_ctx.wr_lock);
2951
2952 btrfs_release_path(path);
2953 return ret < 0 ? ret : 0;
2954 }
2955
2956 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
2957 struct map_lookup *map,
2958 struct btrfs_device *scrub_dev,
2959 int num, u64 base, u64 length,
2960 int is_dev_replace)
2961 {
2962 struct btrfs_path *path, *ppath;
2963 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2964 struct btrfs_root *root = fs_info->extent_root;
2965 struct btrfs_root *csum_root = fs_info->csum_root;
2966 struct btrfs_extent_item *extent;
2967 struct blk_plug plug;
2968 u64 flags;
2969 int ret;
2970 int slot;
2971 u64 nstripes;
2972 struct extent_buffer *l;
2973 struct btrfs_key key;
2974 u64 physical;
2975 u64 logical;
2976 u64 logic_end;
2977 u64 physical_end;
2978 u64 generation;
2979 int mirror_num;
2980 struct reada_control *reada1;
2981 struct reada_control *reada2;
2982 struct btrfs_key key_start;
2983 struct btrfs_key key_end;
2984 u64 increment = map->stripe_len;
2985 u64 offset;
2986 u64 extent_logical;
2987 u64 extent_physical;
2988 u64 extent_len;
2989 u64 stripe_logical;
2990 u64 stripe_end;
2991 struct btrfs_device *extent_dev;
2992 int extent_mirror_num;
2993 int stop_loop = 0;
2994
2995 physical = map->stripes[num].physical;
2996 offset = 0;
2997 nstripes = div_u64(length, map->stripe_len);
2998 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2999 offset = map->stripe_len * num;
3000 increment = map->stripe_len * map->num_stripes;
3001 mirror_num = 1;
3002 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3003 int factor = map->num_stripes / map->sub_stripes;
3004 offset = map->stripe_len * (num / map->sub_stripes);
3005 increment = map->stripe_len * factor;
3006 mirror_num = num % map->sub_stripes + 1;
3007 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3008 increment = map->stripe_len;
3009 mirror_num = num % map->num_stripes + 1;
3010 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3011 increment = map->stripe_len;
3012 mirror_num = num % map->num_stripes + 1;
3013 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3014 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3015 increment = map->stripe_len * nr_data_stripes(map);
3016 mirror_num = 1;
3017 } else {
3018 increment = map->stripe_len;
3019 mirror_num = 1;
3020 }
3021
3022 path = btrfs_alloc_path();
3023 if (!path)
3024 return -ENOMEM;
3025
3026 ppath = btrfs_alloc_path();
3027 if (!ppath) {
3028 btrfs_free_path(path);
3029 return -ENOMEM;
3030 }
3031
3032 /*
3033 * work on commit root. The related disk blocks are static as
3034 * long as COW is applied. This means, it is save to rewrite
3035 * them to repair disk errors without any race conditions
3036 */
3037 path->search_commit_root = 1;
3038 path->skip_locking = 1;
3039
3040 ppath->search_commit_root = 1;
3041 ppath->skip_locking = 1;
3042 /*
3043 * trigger the readahead for extent tree csum tree and wait for
3044 * completion. During readahead, the scrub is officially paused
3045 * to not hold off transaction commits
3046 */
3047 logical = base + offset;
3048 physical_end = physical + nstripes * map->stripe_len;
3049 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3050 get_raid56_logic_offset(physical_end, num,
3051 map, &logic_end, NULL);
3052 logic_end += base;
3053 } else {
3054 logic_end = logical + increment * nstripes;
3055 }
3056 wait_event(sctx->list_wait,
3057 atomic_read(&sctx->bios_in_flight) == 0);
3058 scrub_blocked_if_needed(fs_info);
3059
3060 /* FIXME it might be better to start readahead at commit root */
3061 key_start.objectid = logical;
3062 key_start.type = BTRFS_EXTENT_ITEM_KEY;
3063 key_start.offset = (u64)0;
3064 key_end.objectid = logic_end;
3065 key_end.type = BTRFS_METADATA_ITEM_KEY;
3066 key_end.offset = (u64)-1;
3067 reada1 = btrfs_reada_add(root, &key_start, &key_end);
3068
3069 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3070 key_start.type = BTRFS_EXTENT_CSUM_KEY;
3071 key_start.offset = logical;
3072 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3073 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3074 key_end.offset = logic_end;
3075 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
3076
3077 if (!IS_ERR(reada1))
3078 btrfs_reada_wait(reada1);
3079 if (!IS_ERR(reada2))
3080 btrfs_reada_wait(reada2);
3081
3082
3083 /*
3084 * collect all data csums for the stripe to avoid seeking during
3085 * the scrub. This might currently (crc32) end up to be about 1MB
3086 */
3087 blk_start_plug(&plug);
3088
3089 /*
3090 * now find all extents for each stripe and scrub them
3091 */
3092 ret = 0;
3093 while (physical < physical_end) {
3094 /* for raid56, we skip parity stripe */
3095 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3096 ret = get_raid56_logic_offset(physical, num,
3097 map, &logical, &stripe_logical);
3098 logical += base;
3099 if (ret) {
3100 stripe_logical += base;
3101 stripe_end = stripe_logical + increment - 1;
3102 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3103 ppath, stripe_logical,
3104 stripe_end);
3105 if (ret)
3106 goto out;
3107 goto skip;
3108 }
3109 }
3110 /*
3111 * canceled?
3112 */
3113 if (atomic_read(&fs_info->scrub_cancel_req) ||
3114 atomic_read(&sctx->cancel_req)) {
3115 ret = -ECANCELED;
3116 goto out;
3117 }
3118 /*
3119 * check to see if we have to pause
3120 */
3121 if (atomic_read(&fs_info->scrub_pause_req)) {
3122 /* push queued extents */
3123 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3124 scrub_submit(sctx);
3125 mutex_lock(&sctx->wr_ctx.wr_lock);
3126 scrub_wr_submit(sctx);
3127 mutex_unlock(&sctx->wr_ctx.wr_lock);
3128 wait_event(sctx->list_wait,
3129 atomic_read(&sctx->bios_in_flight) == 0);
3130 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3131 scrub_blocked_if_needed(fs_info);
3132 }
3133
3134 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3135 key.type = BTRFS_METADATA_ITEM_KEY;
3136 else
3137 key.type = BTRFS_EXTENT_ITEM_KEY;
3138 key.objectid = logical;
3139 key.offset = (u64)-1;
3140
3141 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3142 if (ret < 0)
3143 goto out;
3144
3145 if (ret > 0) {
3146 ret = btrfs_previous_extent_item(root, path, 0);
3147 if (ret < 0)
3148 goto out;
3149 if (ret > 0) {
3150 /* there's no smaller item, so stick with the
3151 * larger one */
3152 btrfs_release_path(path);
3153 ret = btrfs_search_slot(NULL, root, &key,
3154 path, 0, 0);
3155 if (ret < 0)
3156 goto out;
3157 }
3158 }
3159
3160 stop_loop = 0;
3161 while (1) {
3162 u64 bytes;
3163
3164 l = path->nodes[0];
3165 slot = path->slots[0];
3166 if (slot >= btrfs_header_nritems(l)) {
3167 ret = btrfs_next_leaf(root, path);
3168 if (ret == 0)
3169 continue;
3170 if (ret < 0)
3171 goto out;
3172
3173 stop_loop = 1;
3174 break;
3175 }
3176 btrfs_item_key_to_cpu(l, &key, slot);
3177
3178 if (key.type == BTRFS_METADATA_ITEM_KEY)
3179 bytes = root->nodesize;
3180 else
3181 bytes = key.offset;
3182
3183 if (key.objectid + bytes <= logical)
3184 goto next;
3185
3186 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3187 key.type != BTRFS_METADATA_ITEM_KEY)
3188 goto next;
3189
3190 if (key.objectid >= logical + map->stripe_len) {
3191 /* out of this device extent */
3192 if (key.objectid >= logic_end)
3193 stop_loop = 1;
3194 break;
3195 }
3196
3197 extent = btrfs_item_ptr(l, slot,
3198 struct btrfs_extent_item);
3199 flags = btrfs_extent_flags(l, extent);
3200 generation = btrfs_extent_generation(l, extent);
3201
3202 if (key.objectid < logical &&
3203 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
3204 btrfs_err(fs_info,
3205 "scrub: tree block %llu spanning "
3206 "stripes, ignored. logical=%llu",
3207 key.objectid, logical);
3208 goto next;
3209 }
3210
3211 again:
3212 extent_logical = key.objectid;
3213 extent_len = bytes;
3214
3215 /*
3216 * trim extent to this stripe
3217 */
3218 if (extent_logical < logical) {
3219 extent_len -= logical - extent_logical;
3220 extent_logical = logical;
3221 }
3222 if (extent_logical + extent_len >
3223 logical + map->stripe_len) {
3224 extent_len = logical + map->stripe_len -
3225 extent_logical;
3226 }
3227
3228 extent_physical = extent_logical - logical + physical;
3229 extent_dev = scrub_dev;
3230 extent_mirror_num = mirror_num;
3231 if (is_dev_replace)
3232 scrub_remap_extent(fs_info, extent_logical,
3233 extent_len, &extent_physical,
3234 &extent_dev,
3235 &extent_mirror_num);
3236
3237 ret = btrfs_lookup_csums_range(csum_root, logical,
3238 logical + map->stripe_len - 1,
3239 &sctx->csum_list, 1);
3240 if (ret)
3241 goto out;
3242
3243 ret = scrub_extent(sctx, extent_logical, extent_len,
3244 extent_physical, extent_dev, flags,
3245 generation, extent_mirror_num,
3246 extent_logical - logical + physical);
3247 if (ret)
3248 goto out;
3249
3250 scrub_free_csums(sctx);
3251 if (extent_logical + extent_len <
3252 key.objectid + bytes) {
3253 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3254 /*
3255 * loop until we find next data stripe
3256 * or we have finished all stripes.
3257 */
3258 loop:
3259 physical += map->stripe_len;
3260 ret = get_raid56_logic_offset(physical,
3261 num, map, &logical,
3262 &stripe_logical);
3263 logical += base;
3264
3265 if (ret && physical < physical_end) {
3266 stripe_logical += base;
3267 stripe_end = stripe_logical +
3268 increment - 1;
3269 ret = scrub_raid56_parity(sctx,
3270 map, scrub_dev, ppath,
3271 stripe_logical,
3272 stripe_end);
3273 if (ret)
3274 goto out;
3275 goto loop;
3276 }
3277 } else {
3278 physical += map->stripe_len;
3279 logical += increment;
3280 }
3281 if (logical < key.objectid + bytes) {
3282 cond_resched();
3283 goto again;
3284 }
3285
3286 if (physical >= physical_end) {
3287 stop_loop = 1;
3288 break;
3289 }
3290 }
3291 next:
3292 path->slots[0]++;
3293 }
3294 btrfs_release_path(path);
3295 skip:
3296 logical += increment;
3297 physical += map->stripe_len;
3298 spin_lock(&sctx->stat_lock);
3299 if (stop_loop)
3300 sctx->stat.last_physical = map->stripes[num].physical +
3301 length;
3302 else
3303 sctx->stat.last_physical = physical;
3304 spin_unlock(&sctx->stat_lock);
3305 if (stop_loop)
3306 break;
3307 }
3308 out:
3309 /* push queued extents */
3310 scrub_submit(sctx);
3311 mutex_lock(&sctx->wr_ctx.wr_lock);
3312 scrub_wr_submit(sctx);
3313 mutex_unlock(&sctx->wr_ctx.wr_lock);
3314
3315 blk_finish_plug(&plug);
3316 btrfs_free_path(path);
3317 btrfs_free_path(ppath);
3318 return ret < 0 ? ret : 0;
3319 }
3320
3321 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3322 struct btrfs_device *scrub_dev,
3323 u64 chunk_tree, u64 chunk_objectid,
3324 u64 chunk_offset, u64 length,
3325 u64 dev_offset, int is_dev_replace)
3326 {
3327 struct btrfs_mapping_tree *map_tree =
3328 &sctx->dev_root->fs_info->mapping_tree;
3329 struct map_lookup *map;
3330 struct extent_map *em;
3331 int i;
3332 int ret = 0;
3333
3334 read_lock(&map_tree->map_tree.lock);
3335 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3336 read_unlock(&map_tree->map_tree.lock);
3337
3338 if (!em)
3339 return -EINVAL;
3340
3341 map = (struct map_lookup *)em->bdev;
3342 if (em->start != chunk_offset)
3343 goto out;
3344
3345 if (em->len < length)
3346 goto out;
3347
3348 for (i = 0; i < map->num_stripes; ++i) {
3349 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3350 map->stripes[i].physical == dev_offset) {
3351 ret = scrub_stripe(sctx, map, scrub_dev, i,
3352 chunk_offset, length,
3353 is_dev_replace);
3354 if (ret)
3355 goto out;
3356 }
3357 }
3358 out:
3359 free_extent_map(em);
3360
3361 return ret;
3362 }
3363
3364 static noinline_for_stack
3365 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3366 struct btrfs_device *scrub_dev, u64 start, u64 end,
3367 int is_dev_replace)
3368 {
3369 struct btrfs_dev_extent *dev_extent = NULL;
3370 struct btrfs_path *path;
3371 struct btrfs_root *root = sctx->dev_root;
3372 struct btrfs_fs_info *fs_info = root->fs_info;
3373 u64 length;
3374 u64 chunk_tree;
3375 u64 chunk_objectid;
3376 u64 chunk_offset;
3377 int ret;
3378 int slot;
3379 struct extent_buffer *l;
3380 struct btrfs_key key;
3381 struct btrfs_key found_key;
3382 struct btrfs_block_group_cache *cache;
3383 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3384
3385 path = btrfs_alloc_path();
3386 if (!path)
3387 return -ENOMEM;
3388
3389 path->reada = 2;
3390 path->search_commit_root = 1;
3391 path->skip_locking = 1;
3392
3393 key.objectid = scrub_dev->devid;
3394 key.offset = 0ull;
3395 key.type = BTRFS_DEV_EXTENT_KEY;
3396
3397 while (1) {
3398 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3399 if (ret < 0)
3400 break;
3401 if (ret > 0) {
3402 if (path->slots[0] >=
3403 btrfs_header_nritems(path->nodes[0])) {
3404 ret = btrfs_next_leaf(root, path);
3405 if (ret)
3406 break;
3407 }
3408 }
3409
3410 l = path->nodes[0];
3411 slot = path->slots[0];
3412
3413 btrfs_item_key_to_cpu(l, &found_key, slot);
3414
3415 if (found_key.objectid != scrub_dev->devid)
3416 break;
3417
3418 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3419 break;
3420
3421 if (found_key.offset >= end)
3422 break;
3423
3424 if (found_key.offset < key.offset)
3425 break;
3426
3427 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3428 length = btrfs_dev_extent_length(l, dev_extent);
3429
3430 if (found_key.offset + length <= start)
3431 goto skip;
3432
3433 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3434 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3435 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3436
3437 /*
3438 * get a reference on the corresponding block group to prevent
3439 * the chunk from going away while we scrub it
3440 */
3441 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3442
3443 /* some chunks are removed but not committed to disk yet,
3444 * continue scrubbing */
3445 if (!cache)
3446 goto skip;
3447
3448 dev_replace->cursor_right = found_key.offset + length;
3449 dev_replace->cursor_left = found_key.offset;
3450 dev_replace->item_needs_writeback = 1;
3451 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
3452 chunk_offset, length, found_key.offset,
3453 is_dev_replace);
3454
3455 /*
3456 * flush, submit all pending read and write bios, afterwards
3457 * wait for them.
3458 * Note that in the dev replace case, a read request causes
3459 * write requests that are submitted in the read completion
3460 * worker. Therefore in the current situation, it is required
3461 * that all write requests are flushed, so that all read and
3462 * write requests are really completed when bios_in_flight
3463 * changes to 0.
3464 */
3465 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3466 scrub_submit(sctx);
3467 mutex_lock(&sctx->wr_ctx.wr_lock);
3468 scrub_wr_submit(sctx);
3469 mutex_unlock(&sctx->wr_ctx.wr_lock);
3470
3471 wait_event(sctx->list_wait,
3472 atomic_read(&sctx->bios_in_flight) == 0);
3473 atomic_inc(&fs_info->scrubs_paused);
3474 wake_up(&fs_info->scrub_pause_wait);
3475
3476 /*
3477 * must be called before we decrease @scrub_paused.
3478 * make sure we don't block transaction commit while
3479 * we are waiting pending workers finished.
3480 */
3481 wait_event(sctx->list_wait,
3482 atomic_read(&sctx->workers_pending) == 0);
3483 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3484
3485 mutex_lock(&fs_info->scrub_lock);
3486 __scrub_blocked_if_needed(fs_info);
3487 atomic_dec(&fs_info->scrubs_paused);
3488 mutex_unlock(&fs_info->scrub_lock);
3489 wake_up(&fs_info->scrub_pause_wait);
3490
3491 btrfs_put_block_group(cache);
3492 if (ret)
3493 break;
3494 if (is_dev_replace &&
3495 atomic64_read(&dev_replace->num_write_errors) > 0) {
3496 ret = -EIO;
3497 break;
3498 }
3499 if (sctx->stat.malloc_errors > 0) {
3500 ret = -ENOMEM;
3501 break;
3502 }
3503
3504 dev_replace->cursor_left = dev_replace->cursor_right;
3505 dev_replace->item_needs_writeback = 1;
3506 skip:
3507 key.offset = found_key.offset + length;
3508 btrfs_release_path(path);
3509 }
3510
3511 btrfs_free_path(path);
3512
3513 /*
3514 * ret can still be 1 from search_slot or next_leaf,
3515 * that's not an error
3516 */
3517 return ret < 0 ? ret : 0;
3518 }
3519
3520 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3521 struct btrfs_device *scrub_dev)
3522 {
3523 int i;
3524 u64 bytenr;
3525 u64 gen;
3526 int ret;
3527 struct btrfs_root *root = sctx->dev_root;
3528
3529 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
3530 return -EIO;
3531
3532 /* Seed devices of a new filesystem has their own generation. */
3533 if (scrub_dev->fs_devices != root->fs_info->fs_devices)
3534 gen = scrub_dev->generation;
3535 else
3536 gen = root->fs_info->last_trans_committed;
3537
3538 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3539 bytenr = btrfs_sb_offset(i);
3540 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3541 scrub_dev->commit_total_bytes)
3542 break;
3543
3544 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3545 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3546 NULL, 1, bytenr);
3547 if (ret)
3548 return ret;
3549 }
3550 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3551
3552 return 0;
3553 }
3554
3555 /*
3556 * get a reference count on fs_info->scrub_workers. start worker if necessary
3557 */
3558 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3559 int is_dev_replace)
3560 {
3561 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3562 int max_active = fs_info->thread_pool_size;
3563
3564 if (fs_info->scrub_workers_refcnt == 0) {
3565 if (is_dev_replace)
3566 fs_info->scrub_workers =
3567 btrfs_alloc_workqueue("btrfs-scrub", flags,
3568 1, 4);
3569 else
3570 fs_info->scrub_workers =
3571 btrfs_alloc_workqueue("btrfs-scrub", flags,
3572 max_active, 4);
3573 if (!fs_info->scrub_workers)
3574 goto fail_scrub_workers;
3575
3576 fs_info->scrub_wr_completion_workers =
3577 btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
3578 max_active, 2);
3579 if (!fs_info->scrub_wr_completion_workers)
3580 goto fail_scrub_wr_completion_workers;
3581
3582 fs_info->scrub_nocow_workers =
3583 btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
3584 if (!fs_info->scrub_nocow_workers)
3585 goto fail_scrub_nocow_workers;
3586 fs_info->scrub_parity_workers =
3587 btrfs_alloc_workqueue("btrfs-scrubparity", flags,
3588 max_active, 2);
3589 if (!fs_info->scrub_parity_workers)
3590 goto fail_scrub_parity_workers;
3591 }
3592 ++fs_info->scrub_workers_refcnt;
3593 return 0;
3594
3595 fail_scrub_parity_workers:
3596 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3597 fail_scrub_nocow_workers:
3598 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3599 fail_scrub_wr_completion_workers:
3600 btrfs_destroy_workqueue(fs_info->scrub_workers);
3601 fail_scrub_workers:
3602 return -ENOMEM;
3603 }
3604
3605 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
3606 {
3607 if (--fs_info->scrub_workers_refcnt == 0) {
3608 btrfs_destroy_workqueue(fs_info->scrub_workers);
3609 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3610 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3611 btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
3612 }
3613 WARN_ON(fs_info->scrub_workers_refcnt < 0);
3614 }
3615
3616 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3617 u64 end, struct btrfs_scrub_progress *progress,
3618 int readonly, int is_dev_replace)
3619 {
3620 struct scrub_ctx *sctx;
3621 int ret;
3622 struct btrfs_device *dev;
3623 struct rcu_string *name;
3624
3625 if (btrfs_fs_closing(fs_info))
3626 return -EINVAL;
3627
3628 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
3629 /*
3630 * in this case scrub is unable to calculate the checksum
3631 * the way scrub is implemented. Do not handle this
3632 * situation at all because it won't ever happen.
3633 */
3634 btrfs_err(fs_info,
3635 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3636 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
3637 return -EINVAL;
3638 }
3639
3640 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
3641 /* not supported for data w/o checksums */
3642 btrfs_err(fs_info,
3643 "scrub: size assumption sectorsize != PAGE_SIZE "
3644 "(%d != %lu) fails",
3645 fs_info->chunk_root->sectorsize, PAGE_SIZE);
3646 return -EINVAL;
3647 }
3648
3649 if (fs_info->chunk_root->nodesize >
3650 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3651 fs_info->chunk_root->sectorsize >
3652 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3653 /*
3654 * would exhaust the array bounds of pagev member in
3655 * struct scrub_block
3656 */
3657 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
3658 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3659 fs_info->chunk_root->nodesize,
3660 SCRUB_MAX_PAGES_PER_BLOCK,
3661 fs_info->chunk_root->sectorsize,
3662 SCRUB_MAX_PAGES_PER_BLOCK);
3663 return -EINVAL;
3664 }
3665
3666
3667 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3668 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
3669 if (!dev || (dev->missing && !is_dev_replace)) {
3670 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3671 return -ENODEV;
3672 }
3673
3674 if (!is_dev_replace && !readonly && !dev->writeable) {
3675 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3676 rcu_read_lock();
3677 name = rcu_dereference(dev->name);
3678 btrfs_err(fs_info, "scrub: device %s is not writable",
3679 name->str);
3680 rcu_read_unlock();
3681 return -EROFS;
3682 }
3683
3684 mutex_lock(&fs_info->scrub_lock);
3685 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
3686 mutex_unlock(&fs_info->scrub_lock);
3687 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3688 return -EIO;
3689 }
3690
3691 btrfs_dev_replace_lock(&fs_info->dev_replace);
3692 if (dev->scrub_device ||
3693 (!is_dev_replace &&
3694 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3695 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3696 mutex_unlock(&fs_info->scrub_lock);
3697 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3698 return -EINPROGRESS;
3699 }
3700 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3701
3702 ret = scrub_workers_get(fs_info, is_dev_replace);
3703 if (ret) {
3704 mutex_unlock(&fs_info->scrub_lock);
3705 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3706 return ret;
3707 }
3708
3709 sctx = scrub_setup_ctx(dev, is_dev_replace);
3710 if (IS_ERR(sctx)) {
3711 mutex_unlock(&fs_info->scrub_lock);
3712 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3713 scrub_workers_put(fs_info);
3714 return PTR_ERR(sctx);
3715 }
3716 sctx->readonly = readonly;
3717 dev->scrub_device = sctx;
3718 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3719
3720 /*
3721 * checking @scrub_pause_req here, we can avoid
3722 * race between committing transaction and scrubbing.
3723 */
3724 __scrub_blocked_if_needed(fs_info);
3725 atomic_inc(&fs_info->scrubs_running);
3726 mutex_unlock(&fs_info->scrub_lock);
3727
3728 if (!is_dev_replace) {
3729 /*
3730 * by holding device list mutex, we can
3731 * kick off writing super in log tree sync.
3732 */
3733 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3734 ret = scrub_supers(sctx, dev);
3735 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3736 }
3737
3738 if (!ret)
3739 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3740 is_dev_replace);
3741
3742 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3743 atomic_dec(&fs_info->scrubs_running);
3744 wake_up(&fs_info->scrub_pause_wait);
3745
3746 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3747
3748 if (progress)
3749 memcpy(progress, &sctx->stat, sizeof(*progress));
3750
3751 mutex_lock(&fs_info->scrub_lock);
3752 dev->scrub_device = NULL;
3753 scrub_workers_put(fs_info);
3754 mutex_unlock(&fs_info->scrub_lock);
3755
3756 scrub_put_ctx(sctx);
3757
3758 return ret;
3759 }
3760
3761 void btrfs_scrub_pause(struct btrfs_root *root)
3762 {
3763 struct btrfs_fs_info *fs_info = root->fs_info;
3764
3765 mutex_lock(&fs_info->scrub_lock);
3766 atomic_inc(&fs_info->scrub_pause_req);
3767 while (atomic_read(&fs_info->scrubs_paused) !=
3768 atomic_read(&fs_info->scrubs_running)) {
3769 mutex_unlock(&fs_info->scrub_lock);
3770 wait_event(fs_info->scrub_pause_wait,
3771 atomic_read(&fs_info->scrubs_paused) ==
3772 atomic_read(&fs_info->scrubs_running));
3773 mutex_lock(&fs_info->scrub_lock);
3774 }
3775 mutex_unlock(&fs_info->scrub_lock);
3776 }
3777
3778 void btrfs_scrub_continue(struct btrfs_root *root)
3779 {
3780 struct btrfs_fs_info *fs_info = root->fs_info;
3781
3782 atomic_dec(&fs_info->scrub_pause_req);
3783 wake_up(&fs_info->scrub_pause_wait);
3784 }
3785
3786 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3787 {
3788 mutex_lock(&fs_info->scrub_lock);
3789 if (!atomic_read(&fs_info->scrubs_running)) {
3790 mutex_unlock(&fs_info->scrub_lock);
3791 return -ENOTCONN;
3792 }
3793
3794 atomic_inc(&fs_info->scrub_cancel_req);
3795 while (atomic_read(&fs_info->scrubs_running)) {
3796 mutex_unlock(&fs_info->scrub_lock);
3797 wait_event(fs_info->scrub_pause_wait,
3798 atomic_read(&fs_info->scrubs_running) == 0);
3799 mutex_lock(&fs_info->scrub_lock);
3800 }
3801 atomic_dec(&fs_info->scrub_cancel_req);
3802 mutex_unlock(&fs_info->scrub_lock);
3803
3804 return 0;
3805 }
3806
3807 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
3808 struct btrfs_device *dev)
3809 {
3810 struct scrub_ctx *sctx;
3811
3812 mutex_lock(&fs_info->scrub_lock);
3813 sctx = dev->scrub_device;
3814 if (!sctx) {
3815 mutex_unlock(&fs_info->scrub_lock);
3816 return -ENOTCONN;
3817 }
3818 atomic_inc(&sctx->cancel_req);
3819 while (dev->scrub_device) {
3820 mutex_unlock(&fs_info->scrub_lock);
3821 wait_event(fs_info->scrub_pause_wait,
3822 dev->scrub_device == NULL);
3823 mutex_lock(&fs_info->scrub_lock);
3824 }
3825 mutex_unlock(&fs_info->scrub_lock);
3826
3827 return 0;
3828 }
3829
3830 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3831 struct btrfs_scrub_progress *progress)
3832 {
3833 struct btrfs_device *dev;
3834 struct scrub_ctx *sctx = NULL;
3835
3836 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3837 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
3838 if (dev)
3839 sctx = dev->scrub_device;
3840 if (sctx)
3841 memcpy(progress, &sctx->stat, sizeof(*progress));
3842 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3843
3844 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
3845 }
3846
3847 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3848 u64 extent_logical, u64 extent_len,
3849 u64 *extent_physical,
3850 struct btrfs_device **extent_dev,
3851 int *extent_mirror_num)
3852 {
3853 u64 mapped_length;
3854 struct btrfs_bio *bbio = NULL;
3855 int ret;
3856
3857 mapped_length = extent_len;
3858 ret = btrfs_map_block(fs_info, READ, extent_logical,
3859 &mapped_length, &bbio, 0);
3860 if (ret || !bbio || mapped_length < extent_len ||
3861 !bbio->stripes[0].dev->bdev) {
3862 btrfs_put_bbio(bbio);
3863 return;
3864 }
3865
3866 *extent_physical = bbio->stripes[0].physical;
3867 *extent_mirror_num = bbio->mirror_num;
3868 *extent_dev = bbio->stripes[0].dev;
3869 btrfs_put_bbio(bbio);
3870 }
3871
3872 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3873 struct scrub_wr_ctx *wr_ctx,
3874 struct btrfs_fs_info *fs_info,
3875 struct btrfs_device *dev,
3876 int is_dev_replace)
3877 {
3878 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3879
3880 mutex_init(&wr_ctx->wr_lock);
3881 wr_ctx->wr_curr_bio = NULL;
3882 if (!is_dev_replace)
3883 return 0;
3884
3885 WARN_ON(!dev->bdev);
3886 wr_ctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
3887 wr_ctx->tgtdev = dev;
3888 atomic_set(&wr_ctx->flush_all_writes, 0);
3889 return 0;
3890 }
3891
3892 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3893 {
3894 mutex_lock(&wr_ctx->wr_lock);
3895 kfree(wr_ctx->wr_curr_bio);
3896 wr_ctx->wr_curr_bio = NULL;
3897 mutex_unlock(&wr_ctx->wr_lock);
3898 }
3899
3900 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3901 int mirror_num, u64 physical_for_dev_replace)
3902 {
3903 struct scrub_copy_nocow_ctx *nocow_ctx;
3904 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3905
3906 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3907 if (!nocow_ctx) {
3908 spin_lock(&sctx->stat_lock);
3909 sctx->stat.malloc_errors++;
3910 spin_unlock(&sctx->stat_lock);
3911 return -ENOMEM;
3912 }
3913
3914 scrub_pending_trans_workers_inc(sctx);
3915
3916 nocow_ctx->sctx = sctx;
3917 nocow_ctx->logical = logical;
3918 nocow_ctx->len = len;
3919 nocow_ctx->mirror_num = mirror_num;
3920 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
3921 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
3922 copy_nocow_pages_worker, NULL, NULL);
3923 INIT_LIST_HEAD(&nocow_ctx->inodes);
3924 btrfs_queue_work(fs_info->scrub_nocow_workers,
3925 &nocow_ctx->work);
3926
3927 return 0;
3928 }
3929
3930 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
3931 {
3932 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3933 struct scrub_nocow_inode *nocow_inode;
3934
3935 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
3936 if (!nocow_inode)
3937 return -ENOMEM;
3938 nocow_inode->inum = inum;
3939 nocow_inode->offset = offset;
3940 nocow_inode->root = root;
3941 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
3942 return 0;
3943 }
3944
3945 #define COPY_COMPLETE 1
3946
3947 static void copy_nocow_pages_worker(struct btrfs_work *work)
3948 {
3949 struct scrub_copy_nocow_ctx *nocow_ctx =
3950 container_of(work, struct scrub_copy_nocow_ctx, work);
3951 struct scrub_ctx *sctx = nocow_ctx->sctx;
3952 u64 logical = nocow_ctx->logical;
3953 u64 len = nocow_ctx->len;
3954 int mirror_num = nocow_ctx->mirror_num;
3955 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3956 int ret;
3957 struct btrfs_trans_handle *trans = NULL;
3958 struct btrfs_fs_info *fs_info;
3959 struct btrfs_path *path;
3960 struct btrfs_root *root;
3961 int not_written = 0;
3962
3963 fs_info = sctx->dev_root->fs_info;
3964 root = fs_info->extent_root;
3965
3966 path = btrfs_alloc_path();
3967 if (!path) {
3968 spin_lock(&sctx->stat_lock);
3969 sctx->stat.malloc_errors++;
3970 spin_unlock(&sctx->stat_lock);
3971 not_written = 1;
3972 goto out;
3973 }
3974
3975 trans = btrfs_join_transaction(root);
3976 if (IS_ERR(trans)) {
3977 not_written = 1;
3978 goto out;
3979 }
3980
3981 ret = iterate_inodes_from_logical(logical, fs_info, path,
3982 record_inode_for_nocow, nocow_ctx);
3983 if (ret != 0 && ret != -ENOENT) {
3984 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
3985 "phys %llu, len %llu, mir %u, ret %d",
3986 logical, physical_for_dev_replace, len, mirror_num,
3987 ret);
3988 not_written = 1;
3989 goto out;
3990 }
3991
3992 btrfs_end_transaction(trans, root);
3993 trans = NULL;
3994 while (!list_empty(&nocow_ctx->inodes)) {
3995 struct scrub_nocow_inode *entry;
3996 entry = list_first_entry(&nocow_ctx->inodes,
3997 struct scrub_nocow_inode,
3998 list);
3999 list_del_init(&entry->list);
4000 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
4001 entry->root, nocow_ctx);
4002 kfree(entry);
4003 if (ret == COPY_COMPLETE) {
4004 ret = 0;
4005 break;
4006 } else if (ret) {
4007 break;
4008 }
4009 }
4010 out:
4011 while (!list_empty(&nocow_ctx->inodes)) {
4012 struct scrub_nocow_inode *entry;
4013 entry = list_first_entry(&nocow_ctx->inodes,
4014 struct scrub_nocow_inode,
4015 list);
4016 list_del_init(&entry->list);
4017 kfree(entry);
4018 }
4019 if (trans && !IS_ERR(trans))
4020 btrfs_end_transaction(trans, root);
4021 if (not_written)
4022 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
4023 num_uncorrectable_read_errors);
4024
4025 btrfs_free_path(path);
4026 kfree(nocow_ctx);
4027
4028 scrub_pending_trans_workers_dec(sctx);
4029 }
4030
4031 static int check_extent_to_block(struct inode *inode, u64 start, u64 len,
4032 u64 logical)
4033 {
4034 struct extent_state *cached_state = NULL;
4035 struct btrfs_ordered_extent *ordered;
4036 struct extent_io_tree *io_tree;
4037 struct extent_map *em;
4038 u64 lockstart = start, lockend = start + len - 1;
4039 int ret = 0;
4040
4041 io_tree = &BTRFS_I(inode)->io_tree;
4042
4043 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
4044 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
4045 if (ordered) {
4046 btrfs_put_ordered_extent(ordered);
4047 ret = 1;
4048 goto out_unlock;
4049 }
4050
4051 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
4052 if (IS_ERR(em)) {
4053 ret = PTR_ERR(em);
4054 goto out_unlock;
4055 }
4056
4057 /*
4058 * This extent does not actually cover the logical extent anymore,
4059 * move on to the next inode.
4060 */
4061 if (em->block_start > logical ||
4062 em->block_start + em->block_len < logical + len) {
4063 free_extent_map(em);
4064 ret = 1;
4065 goto out_unlock;
4066 }
4067 free_extent_map(em);
4068
4069 out_unlock:
4070 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
4071 GFP_NOFS);
4072 return ret;
4073 }
4074
4075 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
4076 struct scrub_copy_nocow_ctx *nocow_ctx)
4077 {
4078 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
4079 struct btrfs_key key;
4080 struct inode *inode;
4081 struct page *page;
4082 struct btrfs_root *local_root;
4083 struct extent_io_tree *io_tree;
4084 u64 physical_for_dev_replace;
4085 u64 nocow_ctx_logical;
4086 u64 len = nocow_ctx->len;
4087 unsigned long index;
4088 int srcu_index;
4089 int ret = 0;
4090 int err = 0;
4091
4092 key.objectid = root;
4093 key.type = BTRFS_ROOT_ITEM_KEY;
4094 key.offset = (u64)-1;
4095
4096 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
4097
4098 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
4099 if (IS_ERR(local_root)) {
4100 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4101 return PTR_ERR(local_root);
4102 }
4103
4104 key.type = BTRFS_INODE_ITEM_KEY;
4105 key.objectid = inum;
4106 key.offset = 0;
4107 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
4108 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4109 if (IS_ERR(inode))
4110 return PTR_ERR(inode);
4111
4112 /* Avoid truncate/dio/punch hole.. */
4113 mutex_lock(&inode->i_mutex);
4114 inode_dio_wait(inode);
4115
4116 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4117 io_tree = &BTRFS_I(inode)->io_tree;
4118 nocow_ctx_logical = nocow_ctx->logical;
4119
4120 ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical);
4121 if (ret) {
4122 ret = ret > 0 ? 0 : ret;
4123 goto out;
4124 }
4125
4126 while (len >= PAGE_CACHE_SIZE) {
4127 index = offset >> PAGE_CACHE_SHIFT;
4128 again:
4129 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4130 if (!page) {
4131 btrfs_err(fs_info, "find_or_create_page() failed");
4132 ret = -ENOMEM;
4133 goto out;
4134 }
4135
4136 if (PageUptodate(page)) {
4137 if (PageDirty(page))
4138 goto next_page;
4139 } else {
4140 ClearPageError(page);
4141 err = extent_read_full_page(io_tree, page,
4142 btrfs_get_extent,
4143 nocow_ctx->mirror_num);
4144 if (err) {
4145 ret = err;
4146 goto next_page;
4147 }
4148
4149 lock_page(page);
4150 /*
4151 * If the page has been remove from the page cache,
4152 * the data on it is meaningless, because it may be
4153 * old one, the new data may be written into the new
4154 * page in the page cache.
4155 */
4156 if (page->mapping != inode->i_mapping) {
4157 unlock_page(page);
4158 page_cache_release(page);
4159 goto again;
4160 }
4161 if (!PageUptodate(page)) {
4162 ret = -EIO;
4163 goto next_page;
4164 }
4165 }
4166
4167 ret = check_extent_to_block(inode, offset, len,
4168 nocow_ctx_logical);
4169 if (ret) {
4170 ret = ret > 0 ? 0 : ret;
4171 goto next_page;
4172 }
4173
4174 err = write_page_nocow(nocow_ctx->sctx,
4175 physical_for_dev_replace, page);
4176 if (err)
4177 ret = err;
4178 next_page:
4179 unlock_page(page);
4180 page_cache_release(page);
4181
4182 if (ret)
4183 break;
4184
4185 offset += PAGE_CACHE_SIZE;
4186 physical_for_dev_replace += PAGE_CACHE_SIZE;
4187 nocow_ctx_logical += PAGE_CACHE_SIZE;
4188 len -= PAGE_CACHE_SIZE;
4189 }
4190 ret = COPY_COMPLETE;
4191 out:
4192 mutex_unlock(&inode->i_mutex);
4193 iput(inode);
4194 return ret;
4195 }
4196
4197 static int write_page_nocow(struct scrub_ctx *sctx,
4198 u64 physical_for_dev_replace, struct page *page)
4199 {
4200 struct bio *bio;
4201 struct btrfs_device *dev;
4202 int ret;
4203
4204 dev = sctx->wr_ctx.tgtdev;
4205 if (!dev)
4206 return -EIO;
4207 if (!dev->bdev) {
4208 printk_ratelimited(KERN_WARNING
4209 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
4210 return -EIO;
4211 }
4212 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
4213 if (!bio) {
4214 spin_lock(&sctx->stat_lock);
4215 sctx->stat.malloc_errors++;
4216 spin_unlock(&sctx->stat_lock);
4217 return -ENOMEM;
4218 }
4219 bio->bi_iter.bi_size = 0;
4220 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
4221 bio->bi_bdev = dev->bdev;
4222 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
4223 if (ret != PAGE_CACHE_SIZE) {
4224 leave_with_eio:
4225 bio_put(bio);
4226 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
4227 return -EIO;
4228 }
4229
4230 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
4231 goto leave_with_eio;
4232
4233 bio_put(bio);
4234 return 0;
4235 }
Linux kernel - Deliverables
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