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Revert "Staging: comedi: integer overflow in do_insnlist_ioctl()"
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / scrub.c
blobfab420db5121b3c8229a4a2f50cea58e8b6cd022
1 /*
2 * Copyright (C) 2011 STRATO. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/blkdev.h>
20 #include <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
29 /*
30 * This is only the first step towards a full-features scrub. It reads all
31 * extent and super block and verifies the checksums. In case a bad checksum
32 * is found or the extent cannot be read, good data will be written back if
33 * any can be found.
34 *
35 * Future enhancements:
36 * - In case an unrepairable extent is encountered, track which files are
37 * affected and report them
38 * - In case of a read error on files with nodatasum, map the file and read
39 * the extent to trigger a writeback of the good copy
40 * - track and record media errors, throw out bad devices
41 * - add a mode to also read unallocated space
42 */
43
44 struct scrub_bio;
45 struct scrub_page;
46 struct scrub_dev;
47 static void scrub_bio_end_io(struct bio *bio, int err);
48 static void scrub_checksum(struct btrfs_work *work);
49 static int scrub_checksum_data(struct scrub_dev *sdev,
50 struct scrub_page *spag, void *buffer);
51 static int scrub_checksum_tree_block(struct scrub_dev *sdev,
52 struct scrub_page *spag, u64 logical,
53 void *buffer);
54 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer);
55 static int scrub_fixup_check(struct scrub_bio *sbio, int ix);
56 static void scrub_fixup_end_io(struct bio *bio, int err);
57 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
58 struct page *page);
59 static void scrub_fixup(struct scrub_bio *sbio, int ix);
60
61 #define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
62 #define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
63
64 struct scrub_page {
65 u64 flags; /* extent flags */
66 u64 generation;
67 int mirror_num;
68 int have_csum;
69 u8 csum[BTRFS_CSUM_SIZE];
70 };
71
72 struct scrub_bio {
73 int index;
74 struct scrub_dev *sdev;
75 struct bio *bio;
76 int err;
77 u64 logical;
78 u64 physical;
79 struct scrub_page spag[SCRUB_PAGES_PER_BIO];
80 u64 count;
81 int next_free;
82 struct btrfs_work work;
83 };
84
85 struct scrub_dev {
86 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
87 struct btrfs_device *dev;
88 int first_free;
89 int curr;
90 atomic_t in_flight;
91 atomic_t fixup_cnt;
92 spinlock_t list_lock;
93 wait_queue_head_t list_wait;
94 u16 csum_size;
95 struct list_head csum_list;
96 atomic_t cancel_req;
97 int readonly;
98 /*
99 * statistics
100 */
101 struct btrfs_scrub_progress stat;
102 spinlock_t stat_lock;
103 };
104
105 struct scrub_fixup_nodatasum {
106 struct scrub_dev *sdev;
107 u64 logical;
108 struct btrfs_root *root;
109 struct btrfs_work work;
110 int mirror_num;
111 };
112
113 struct scrub_warning {
114 struct btrfs_path *path;
115 u64 extent_item_size;
116 char *scratch_buf;
117 char *msg_buf;
118 const char *errstr;
119 sector_t sector;
120 u64 logical;
121 struct btrfs_device *dev;
122 int msg_bufsize;
123 int scratch_bufsize;
124 };
125
126 static void scrub_free_csums(struct scrub_dev *sdev)
127 {
128 while (!list_empty(&sdev->csum_list)) {
129 struct btrfs_ordered_sum *sum;
130 sum = list_first_entry(&sdev->csum_list,
131 struct btrfs_ordered_sum, list);
132 list_del(&sum->list);
133 kfree(sum);
134 }
135 }
136
137 static void scrub_free_bio(struct bio *bio)
138 {
139 int i;
140 struct page *last_page = NULL;
141
142 if (!bio)
143 return;
144
145 for (i = 0; i < bio->bi_vcnt; ++i) {
146 if (bio->bi_io_vec[i].bv_page == last_page)
147 continue;
148 last_page = bio->bi_io_vec[i].bv_page;
149 __free_page(last_page);
150 }
151 bio_put(bio);
152 }
153
154 static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
155 {
156 int i;
157
158 if (!sdev)
159 return;
160
161 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
162 struct scrub_bio *sbio = sdev->bios[i];
163
164 if (!sbio)
165 break;
166
167 scrub_free_bio(sbio->bio);
168 kfree(sbio);
169 }
170
171 scrub_free_csums(sdev);
172 kfree(sdev);
173 }
174
175 static noinline_for_stack
176 struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
177 {
178 struct scrub_dev *sdev;
179 int i;
180 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
181
182 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
183 if (!sdev)
184 goto nomem;
185 sdev->dev = dev;
186 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
187 struct scrub_bio *sbio;
188
189 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
190 if (!sbio)
191 goto nomem;
192 sdev->bios[i] = sbio;
193
194 sbio->index = i;
195 sbio->sdev = sdev;
196 sbio->count = 0;
197 sbio->work.func = scrub_checksum;
198
199 if (i != SCRUB_BIOS_PER_DEV-1)
200 sdev->bios[i]->next_free = i + 1;
201 else
202 sdev->bios[i]->next_free = -1;
203 }
204 sdev->first_free = 0;
205 sdev->curr = -1;
206 atomic_set(&sdev->in_flight, 0);
207 atomic_set(&sdev->fixup_cnt, 0);
208 atomic_set(&sdev->cancel_req, 0);
209 sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy);
210 INIT_LIST_HEAD(&sdev->csum_list);
211
212 spin_lock_init(&sdev->list_lock);
213 spin_lock_init(&sdev->stat_lock);
214 init_waitqueue_head(&sdev->list_wait);
215 return sdev;
216
217 nomem:
218 scrub_free_dev(sdev);
219 return ERR_PTR(-ENOMEM);
220 }
221
222 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
223 {
224 u64 isize;
225 u32 nlink;
226 int ret;
227 int i;
228 struct extent_buffer *eb;
229 struct btrfs_inode_item *inode_item;
230 struct scrub_warning *swarn = ctx;
231 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
232 struct inode_fs_paths *ipath = NULL;
233 struct btrfs_root *local_root;
234 struct btrfs_key root_key;
235
236 root_key.objectid = root;
237 root_key.type = BTRFS_ROOT_ITEM_KEY;
238 root_key.offset = (u64)-1;
239 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
240 if (IS_ERR(local_root)) {
241 ret = PTR_ERR(local_root);
242 goto err;
243 }
244
245 ret = inode_item_info(inum, 0, local_root, swarn->path);
246 if (ret) {
247 btrfs_release_path(swarn->path);
248 goto err;
249 }
250
251 eb = swarn->path->nodes[0];
252 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
253 struct btrfs_inode_item);
254 isize = btrfs_inode_size(eb, inode_item);
255 nlink = btrfs_inode_nlink(eb, inode_item);
256 btrfs_release_path(swarn->path);
257
258 ipath = init_ipath(4096, local_root, swarn->path);
259 ret = paths_from_inode(inum, ipath);
260
261 if (ret < 0)
262 goto err;
263
264 /*
265 * we deliberately ignore the bit ipath might have been too small to
266 * hold all of the paths here
267 */
268 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
269 printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
270 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
271 "length %llu, links %u (path: %s)\n", swarn->errstr,
272 swarn->logical, swarn->dev->name,
273 (unsigned long long)swarn->sector, root, inum, offset,
274 min(isize - offset, (u64)PAGE_SIZE), nlink,
275 (char *)(unsigned long)ipath->fspath->val[i]);
276
277 free_ipath(ipath);
278 return 0;
279
280 err:
281 printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
282 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
283 "resolving failed with ret=%d\n", swarn->errstr,
284 swarn->logical, swarn->dev->name,
285 (unsigned long long)swarn->sector, root, inum, offset, ret);
286
287 free_ipath(ipath);
288 return 0;
289 }
290
291 static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
292 int ix)
293 {
294 struct btrfs_device *dev = sbio->sdev->dev;
295 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
296 struct btrfs_path *path;
297 struct btrfs_key found_key;
298 struct extent_buffer *eb;
299 struct btrfs_extent_item *ei;
300 struct scrub_warning swarn;
301 u32 item_size;
302 int ret;
303 u64 ref_root;
304 u8 ref_level;
305 unsigned long ptr = 0;
306 const int bufsize = 4096;
307 u64 extent_offset;
308
309 path = btrfs_alloc_path();
310
311 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
312 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
313 swarn.sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
314 swarn.logical = sbio->logical + ix * PAGE_SIZE;
315 swarn.errstr = errstr;
316 swarn.dev = dev;
317 swarn.msg_bufsize = bufsize;
318 swarn.scratch_bufsize = bufsize;
319
320 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
321 goto out;
322
323 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
324 if (ret < 0)
325 goto out;
326
327 extent_offset = swarn.logical - found_key.objectid;
328 swarn.extent_item_size = found_key.offset;
329
330 eb = path->nodes[0];
331 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
332 item_size = btrfs_item_size_nr(eb, path->slots[0]);
333
334 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
335 do {
336 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
337 &ref_root, &ref_level);
338 printk(KERN_WARNING "%s at logical %llu on dev %s, "
339 "sector %llu: metadata %s (level %d) in tree "
340 "%llu\n", errstr, swarn.logical, dev->name,
341 (unsigned long long)swarn.sector,
342 ref_level ? "node" : "leaf",
343 ret < 0 ? -1 : ref_level,
344 ret < 0 ? -1 : ref_root);
345 } while (ret != 1);
346 } else {
347 swarn.path = path;
348 iterate_extent_inodes(fs_info, path, found_key.objectid,
349 extent_offset,
350 scrub_print_warning_inode, &swarn);
351 }
352
353 out:
354 btrfs_free_path(path);
355 kfree(swarn.scratch_buf);
356 kfree(swarn.msg_buf);
357 }
358
359 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx)
360 {
361 struct page *page = NULL;
362 unsigned long index;
363 struct scrub_fixup_nodatasum *fixup = ctx;
364 int ret;
365 int corrected = 0;
366 struct btrfs_key key;
367 struct inode *inode = NULL;
368 u64 end = offset + PAGE_SIZE - 1;
369 struct btrfs_root *local_root;
370
371 key.objectid = root;
372 key.type = BTRFS_ROOT_ITEM_KEY;
373 key.offset = (u64)-1;
374 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
375 if (IS_ERR(local_root))
376 return PTR_ERR(local_root);
377
378 key.type = BTRFS_INODE_ITEM_KEY;
379 key.objectid = inum;
380 key.offset = 0;
381 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
382 if (IS_ERR(inode))
383 return PTR_ERR(inode);
384
385 index = offset >> PAGE_CACHE_SHIFT;
386
387 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
388 if (!page) {
389 ret = -ENOMEM;
390 goto out;
391 }
392
393 if (PageUptodate(page)) {
394 struct btrfs_mapping_tree *map_tree;
395 if (PageDirty(page)) {
396 /*
397 * we need to write the data to the defect sector. the
398 * data that was in that sector is not in memory,
399 * because the page was modified. we must not write the
400 * modified page to that sector.
401 *
402 * TODO: what could be done here: wait for the delalloc
403 * runner to write out that page (might involve
404 * COW) and see whether the sector is still
405 * referenced afterwards.
406 *
407 * For the meantime, we'll treat this error
408 * incorrectable, although there is a chance that a
409 * later scrub will find the bad sector again and that
410 * there's no dirty page in memory, then.
411 */
412 ret = -EIO;
413 goto out;
414 }
415 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
416 ret = repair_io_failure(map_tree, offset, PAGE_SIZE,
417 fixup->logical, page,
418 fixup->mirror_num);
419 unlock_page(page);
420 corrected = !ret;
421 } else {
422 /*
423 * we need to get good data first. the general readpage path
424 * will call repair_io_failure for us, we just have to make
425 * sure we read the bad mirror.
426 */
427 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
428 EXTENT_DAMAGED, GFP_NOFS);
429 if (ret) {
430 /* set_extent_bits should give proper error */
431 WARN_ON(ret > 0);
432 if (ret > 0)
433 ret = -EFAULT;
434 goto out;
435 }
436
437 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
438 btrfs_get_extent,
439 fixup->mirror_num);
440 wait_on_page_locked(page);
441
442 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
443 end, EXTENT_DAMAGED, 0, NULL);
444 if (!corrected)
445 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
446 EXTENT_DAMAGED, GFP_NOFS);
447 }
448
449 out:
450 if (page)
451 put_page(page);
452 if (inode)
453 iput(inode);
454
455 if (ret < 0)
456 return ret;
457
458 if (ret == 0 && corrected) {
459 /*
460 * we only need to call readpage for one of the inodes belonging
461 * to this extent. so make iterate_extent_inodes stop
462 */
463 return 1;
464 }
465
466 return -EIO;
467 }
468
469 static void scrub_fixup_nodatasum(struct btrfs_work *work)
470 {
471 int ret;
472 struct scrub_fixup_nodatasum *fixup;
473 struct scrub_dev *sdev;
474 struct btrfs_trans_handle *trans = NULL;
475 struct btrfs_fs_info *fs_info;
476 struct btrfs_path *path;
477 int uncorrectable = 0;
478
479 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
480 sdev = fixup->sdev;
481 fs_info = fixup->root->fs_info;
482
483 path = btrfs_alloc_path();
484 if (!path) {
485 spin_lock(&sdev->stat_lock);
486 ++sdev->stat.malloc_errors;
487 spin_unlock(&sdev->stat_lock);
488 uncorrectable = 1;
489 goto out;
490 }
491
492 trans = btrfs_join_transaction(fixup->root);
493 if (IS_ERR(trans)) {
494 uncorrectable = 1;
495 goto out;
496 }
497
498 /*
499 * the idea is to trigger a regular read through the standard path. we
500 * read a page from the (failed) logical address by specifying the
501 * corresponding copynum of the failed sector. thus, that readpage is
502 * expected to fail.
503 * that is the point where on-the-fly error correction will kick in
504 * (once it's finished) and rewrite the failed sector if a good copy
505 * can be found.
506 */
507 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
508 path, scrub_fixup_readpage,
509 fixup);
510 if (ret < 0) {
511 uncorrectable = 1;
512 goto out;
513 }
514 WARN_ON(ret != 1);
515
516 spin_lock(&sdev->stat_lock);
517 ++sdev->stat.corrected_errors;
518 spin_unlock(&sdev->stat_lock);
519
520 out:
521 if (trans && !IS_ERR(trans))
522 btrfs_end_transaction(trans, fixup->root);
523 if (uncorrectable) {
524 spin_lock(&sdev->stat_lock);
525 ++sdev->stat.uncorrectable_errors;
526 spin_unlock(&sdev->stat_lock);
527 printk_ratelimited(KERN_ERR "btrfs: unable to fixup "
528 "(nodatasum) error at logical %llu\n",
529 fixup->logical);
530 }
531
532 btrfs_free_path(path);
533 kfree(fixup);
534
535 /* see caller why we're pretending to be paused in the scrub counters */
536 mutex_lock(&fs_info->scrub_lock);
537 atomic_dec(&fs_info->scrubs_running);
538 atomic_dec(&fs_info->scrubs_paused);
539 mutex_unlock(&fs_info->scrub_lock);
540 atomic_dec(&sdev->fixup_cnt);
541 wake_up(&fs_info->scrub_pause_wait);
542 wake_up(&sdev->list_wait);
543 }
544
545 /*
546 * scrub_recheck_error gets called when either verification of the page
547 * failed or the bio failed to read, e.g. with EIO. In the latter case,
548 * recheck_error gets called for every page in the bio, even though only
549 * one may be bad
550 */
551 static int scrub_recheck_error(struct scrub_bio *sbio, int ix)
552 {
553 struct scrub_dev *sdev = sbio->sdev;
554 u64 sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
555 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
556 DEFAULT_RATELIMIT_BURST);
557
558 if (sbio->err) {
559 if (scrub_fixup_io(READ, sbio->sdev->dev->bdev, sector,
560 sbio->bio->bi_io_vec[ix].bv_page) == 0) {
561 if (scrub_fixup_check(sbio, ix) == 0)
562 return 0;
563 }
564 if (__ratelimit(&_rs))
565 scrub_print_warning("i/o error", sbio, ix);
566 } else {
567 if (__ratelimit(&_rs))
568 scrub_print_warning("checksum error", sbio, ix);
569 }
570
571 spin_lock(&sdev->stat_lock);
572 ++sdev->stat.read_errors;
573 spin_unlock(&sdev->stat_lock);
574
575 scrub_fixup(sbio, ix);
576 return 1;
577 }
578
579 static int scrub_fixup_check(struct scrub_bio *sbio, int ix)
580 {
581 int ret = 1;
582 struct page *page;
583 void *buffer;
584 u64 flags = sbio->spag[ix].flags;
585
586 page = sbio->bio->bi_io_vec[ix].bv_page;
587 buffer = kmap_atomic(page, KM_USER0);
588 if (flags & BTRFS_EXTENT_FLAG_DATA) {
589 ret = scrub_checksum_data(sbio->sdev,
590 sbio->spag + ix, buffer);
591 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
592 ret = scrub_checksum_tree_block(sbio->sdev,
593 sbio->spag + ix,
594 sbio->logical + ix * PAGE_SIZE,
595 buffer);
596 } else {
597 WARN_ON(1);
598 }
599 kunmap_atomic(buffer, KM_USER0);
600
601 return ret;
602 }
603
604 static void scrub_fixup_end_io(struct bio *bio, int err)
605 {
606 complete((struct completion *)bio->bi_private);
607 }
608
609 static void scrub_fixup(struct scrub_bio *sbio, int ix)
610 {
611 struct scrub_dev *sdev = sbio->sdev;
612 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
613 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
614 struct btrfs_bio *bbio = NULL;
615 struct scrub_fixup_nodatasum *fixup;
616 u64 logical = sbio->logical + ix * PAGE_SIZE;
617 u64 length;
618 int i;
619 int ret;
620 DECLARE_COMPLETION_ONSTACK(complete);
621
622 if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) &&
623 (sbio->spag[ix].have_csum == 0)) {
624 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
625 if (!fixup)
626 goto uncorrectable;
627 fixup->sdev = sdev;
628 fixup->logical = logical;
629 fixup->root = fs_info->extent_root;
630 fixup->mirror_num = sbio->spag[ix].mirror_num;
631 /*
632 * increment scrubs_running to prevent cancel requests from
633 * completing as long as a fixup worker is running. we must also
634 * increment scrubs_paused to prevent deadlocking on pause
635 * requests used for transactions commits (as the worker uses a
636 * transaction context). it is safe to regard the fixup worker
637 * as paused for all matters practical. effectively, we only
638 * avoid cancellation requests from completing.
639 */
640 mutex_lock(&fs_info->scrub_lock);
641 atomic_inc(&fs_info->scrubs_running);
642 atomic_inc(&fs_info->scrubs_paused);
643 mutex_unlock(&fs_info->scrub_lock);
644 atomic_inc(&sdev->fixup_cnt);
645 fixup->work.func = scrub_fixup_nodatasum;
646 btrfs_queue_worker(&fs_info->scrub_workers, &fixup->work);
647 return;
648 }
649
650 length = PAGE_SIZE;
651 ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length,
652 &bbio, 0);
653 if (ret || !bbio || length < PAGE_SIZE) {
654 printk(KERN_ERR
655 "scrub_fixup: btrfs_map_block failed us for %llu\n",
656 (unsigned long long)logical);
657 WARN_ON(1);
658 kfree(bbio);
659 return;
660 }
661
662 if (bbio->num_stripes == 1)
663 /* there aren't any replicas */
664 goto uncorrectable;
665
666 /*
667 * first find a good copy
668 */
669 for (i = 0; i < bbio->num_stripes; ++i) {
670 if (i + 1 == sbio->spag[ix].mirror_num)
671 continue;
672
673 if (scrub_fixup_io(READ, bbio->stripes[i].dev->bdev,
674 bbio->stripes[i].physical >> 9,
675 sbio->bio->bi_io_vec[ix].bv_page)) {
676 /* I/O-error, this is not a good copy */
677 continue;
678 }
679
680 if (scrub_fixup_check(sbio, ix) == 0)
681 break;
682 }
683 if (i == bbio->num_stripes)
684 goto uncorrectable;
685
686 if (!sdev->readonly) {
687 /*
688 * bi_io_vec[ix].bv_page now contains good data, write it back
689 */
690 if (scrub_fixup_io(WRITE, sdev->dev->bdev,
691 (sbio->physical + ix * PAGE_SIZE) >> 9,
692 sbio->bio->bi_io_vec[ix].bv_page)) {
693 /* I/O-error, writeback failed, give up */
694 goto uncorrectable;
695 }
696 }
697
698 kfree(bbio);
699 spin_lock(&sdev->stat_lock);
700 ++sdev->stat.corrected_errors;
701 spin_unlock(&sdev->stat_lock);
702
703 printk_ratelimited(KERN_ERR "btrfs: fixed up error at logical %llu\n",
704 (unsigned long long)logical);
705 return;
706
707 uncorrectable:
708 kfree(bbio);
709 spin_lock(&sdev->stat_lock);
710 ++sdev->stat.uncorrectable_errors;
711 spin_unlock(&sdev->stat_lock);
712
713 printk_ratelimited(KERN_ERR "btrfs: unable to fixup (regular) error at "
714 "logical %llu\n", (unsigned long long)logical);
715 }
716
717 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
718 struct page *page)
719 {
720 struct bio *bio = NULL;
721 int ret;
722 DECLARE_COMPLETION_ONSTACK(complete);
723
724 bio = bio_alloc(GFP_NOFS, 1);
725 bio->bi_bdev = bdev;
726 bio->bi_sector = sector;
727 bio_add_page(bio, page, PAGE_SIZE, 0);
728 bio->bi_end_io = scrub_fixup_end_io;
729 bio->bi_private = &complete;
730 submit_bio(rw, bio);
731
732 /* this will also unplug the queue */
733 wait_for_completion(&complete);
734
735 ret = !test_bit(BIO_UPTODATE, &bio->bi_flags);
736 bio_put(bio);
737 return ret;
738 }
739
740 static void scrub_bio_end_io(struct bio *bio, int err)
741 {
742 struct scrub_bio *sbio = bio->bi_private;
743 struct scrub_dev *sdev = sbio->sdev;
744 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
745
746 sbio->err = err;
747 sbio->bio = bio;
748
749 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
750 }
751
752 static void scrub_checksum(struct btrfs_work *work)
753 {
754 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
755 struct scrub_dev *sdev = sbio->sdev;
756 struct page *page;
757 void *buffer;
758 int i;
759 u64 flags;
760 u64 logical;
761 int ret;
762
763 if (sbio->err) {
764 ret = 0;
765 for (i = 0; i < sbio->count; ++i)
766 ret |= scrub_recheck_error(sbio, i);
767 if (!ret) {
768 spin_lock(&sdev->stat_lock);
769 ++sdev->stat.unverified_errors;
770 spin_unlock(&sdev->stat_lock);
771 }
772
773 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
774 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
775 sbio->bio->bi_phys_segments = 0;
776 sbio->bio->bi_idx = 0;
777
778 for (i = 0; i < sbio->count; i++) {
779 struct bio_vec *bi;
780 bi = &sbio->bio->bi_io_vec[i];
781 bi->bv_offset = 0;
782 bi->bv_len = PAGE_SIZE;
783 }
784 goto out;
785 }
786 for (i = 0; i < sbio->count; ++i) {
787 page = sbio->bio->bi_io_vec[i].bv_page;
788 buffer = kmap_atomic(page, KM_USER0);
789 flags = sbio->spag[i].flags;
790 logical = sbio->logical + i * PAGE_SIZE;
791 ret = 0;
792 if (flags & BTRFS_EXTENT_FLAG_DATA) {
793 ret = scrub_checksum_data(sdev, sbio->spag + i, buffer);
794 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
795 ret = scrub_checksum_tree_block(sdev, sbio->spag + i,
796 logical, buffer);
797 } else if (flags & BTRFS_EXTENT_FLAG_SUPER) {
798 BUG_ON(i);
799 (void)scrub_checksum_super(sbio, buffer);
800 } else {
801 WARN_ON(1);
802 }
803 kunmap_atomic(buffer, KM_USER0);
804 if (ret) {
805 ret = scrub_recheck_error(sbio, i);
806 if (!ret) {
807 spin_lock(&sdev->stat_lock);
808 ++sdev->stat.unverified_errors;
809 spin_unlock(&sdev->stat_lock);
810 }
811 }
812 }
813
814 out:
815 scrub_free_bio(sbio->bio);
816 sbio->bio = NULL;
817 spin_lock(&sdev->list_lock);
818 sbio->next_free = sdev->first_free;
819 sdev->first_free = sbio->index;
820 spin_unlock(&sdev->list_lock);
821 atomic_dec(&sdev->in_flight);
822 wake_up(&sdev->list_wait);
823 }
824
825 static int scrub_checksum_data(struct scrub_dev *sdev,
826 struct scrub_page *spag, void *buffer)
827 {
828 u8 csum[BTRFS_CSUM_SIZE];
829 u32 crc = ~(u32)0;
830 int fail = 0;
831 struct btrfs_root *root = sdev->dev->dev_root;
832
833 if (!spag->have_csum)
834 return 0;
835
836 crc = btrfs_csum_data(root, buffer, crc, PAGE_SIZE);
837 btrfs_csum_final(crc, csum);
838 if (memcmp(csum, spag->csum, sdev->csum_size))
839 fail = 1;
840
841 spin_lock(&sdev->stat_lock);
842 ++sdev->stat.data_extents_scrubbed;
843 sdev->stat.data_bytes_scrubbed += PAGE_SIZE;
844 if (fail)
845 ++sdev->stat.csum_errors;
846 spin_unlock(&sdev->stat_lock);
847
848 return fail;
849 }
850
851 static int scrub_checksum_tree_block(struct scrub_dev *sdev,
852 struct scrub_page *spag, u64 logical,
853 void *buffer)
854 {
855 struct btrfs_header *h;
856 struct btrfs_root *root = sdev->dev->dev_root;
857 struct btrfs_fs_info *fs_info = root->fs_info;
858 u8 csum[BTRFS_CSUM_SIZE];
859 u32 crc = ~(u32)0;
860 int fail = 0;
861 int crc_fail = 0;
862
863 /*
864 * we don't use the getter functions here, as we
865 * a) don't have an extent buffer and
866 * b) the page is already kmapped
867 */
868 h = (struct btrfs_header *)buffer;
869
870 if (logical != le64_to_cpu(h->bytenr))
871 ++fail;
872
873 if (spag->generation != le64_to_cpu(h->generation))
874 ++fail;
875
876 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
877 ++fail;
878
879 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
880 BTRFS_UUID_SIZE))
881 ++fail;
882
883 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
884 PAGE_SIZE - BTRFS_CSUM_SIZE);
885 btrfs_csum_final(crc, csum);
886 if (memcmp(csum, h->csum, sdev->csum_size))
887 ++crc_fail;
888
889 spin_lock(&sdev->stat_lock);
890 ++sdev->stat.tree_extents_scrubbed;
891 sdev->stat.tree_bytes_scrubbed += PAGE_SIZE;
892 if (crc_fail)
893 ++sdev->stat.csum_errors;
894 if (fail)
895 ++sdev->stat.verify_errors;
896 spin_unlock(&sdev->stat_lock);
897
898 return fail || crc_fail;
899 }
900
901 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer)
902 {
903 struct btrfs_super_block *s;
904 u64 logical;
905 struct scrub_dev *sdev = sbio->sdev;
906 struct btrfs_root *root = sdev->dev->dev_root;
907 struct btrfs_fs_info *fs_info = root->fs_info;
908 u8 csum[BTRFS_CSUM_SIZE];
909 u32 crc = ~(u32)0;
910 int fail = 0;
911
912 s = (struct btrfs_super_block *)buffer;
913 logical = sbio->logical;
914
915 if (logical != le64_to_cpu(s->bytenr))
916 ++fail;
917
918 if (sbio->spag[0].generation != le64_to_cpu(s->generation))
919 ++fail;
920
921 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
922 ++fail;
923
924 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
925 PAGE_SIZE - BTRFS_CSUM_SIZE);
926 btrfs_csum_final(crc, csum);
927 if (memcmp(csum, s->csum, sbio->sdev->csum_size))
928 ++fail;
929
930 if (fail) {
931 /*
932 * if we find an error in a super block, we just report it.
933 * They will get written with the next transaction commit
934 * anyway
935 */
936 spin_lock(&sdev->stat_lock);
937 ++sdev->stat.super_errors;
938 spin_unlock(&sdev->stat_lock);
939 }
940
941 return fail;
942 }
943
944 static int scrub_submit(struct scrub_dev *sdev)
945 {
946 struct scrub_bio *sbio;
947
948 if (sdev->curr == -1)
949 return 0;
950
951 sbio = sdev->bios[sdev->curr];
952 sbio->err = 0;
953 sdev->curr = -1;
954 atomic_inc(&sdev->in_flight);
955
956 submit_bio(READ, sbio->bio);
957
958 return 0;
959 }
960
961 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
962 u64 physical, u64 flags, u64 gen, int mirror_num,
963 u8 *csum, int force)
964 {
965 struct scrub_bio *sbio;
966 struct page *page;
967 int ret;
968
969 again:
970 /*
971 * grab a fresh bio or wait for one to become available
972 */
973 while (sdev->curr == -1) {
974 spin_lock(&sdev->list_lock);
975 sdev->curr = sdev->first_free;
976 if (sdev->curr != -1) {
977 sdev->first_free = sdev->bios[sdev->curr]->next_free;
978 sdev->bios[sdev->curr]->next_free = -1;
979 sdev->bios[sdev->curr]->count = 0;
980 spin_unlock(&sdev->list_lock);
981 } else {
982 spin_unlock(&sdev->list_lock);
983 wait_event(sdev->list_wait, sdev->first_free != -1);
984 }
985 }
986 sbio = sdev->bios[sdev->curr];
987 if (sbio->count == 0) {
988 struct bio *bio;
989
990 sbio->physical = physical;
991 sbio->logical = logical;
992 bio = bio_alloc(GFP_NOFS, SCRUB_PAGES_PER_BIO);
993 if (!bio)
994 return -ENOMEM;
995
996 bio->bi_private = sbio;
997 bio->bi_end_io = scrub_bio_end_io;
998 bio->bi_bdev = sdev->dev->bdev;
999 bio->bi_sector = sbio->physical >> 9;
1000 sbio->err = 0;
1001 sbio->bio = bio;
1002 } else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
1003 sbio->logical + sbio->count * PAGE_SIZE != logical) {
1004 ret = scrub_submit(sdev);
1005 if (ret)
1006 return ret;
1007 goto again;
1008 }
1009 sbio->spag[sbio->count].flags = flags;
1010 sbio->spag[sbio->count].generation = gen;
1011 sbio->spag[sbio->count].have_csum = 0;
1012 sbio->spag[sbio->count].mirror_num = mirror_num;
1013
1014 page = alloc_page(GFP_NOFS);
1015 if (!page)
1016 return -ENOMEM;
1017
1018 ret = bio_add_page(sbio->bio, page, PAGE_SIZE, 0);
1019 if (!ret) {
1020 __free_page(page);
1021 ret = scrub_submit(sdev);
1022 if (ret)
1023 return ret;
1024 goto again;
1025 }
1026
1027 if (csum) {
1028 sbio->spag[sbio->count].have_csum = 1;
1029 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
1030 }
1031 ++sbio->count;
1032 if (sbio->count == SCRUB_PAGES_PER_BIO || force) {
1033 int ret;
1034
1035 ret = scrub_submit(sdev);
1036 if (ret)
1037 return ret;
1038 }
1039
1040 return 0;
1041 }
1042
1043 static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
1044 u8 *csum)
1045 {
1046 struct btrfs_ordered_sum *sum = NULL;
1047 int ret = 0;
1048 unsigned long i;
1049 unsigned long num_sectors;
1050 u32 sectorsize = sdev->dev->dev_root->sectorsize;
1051
1052 while (!list_empty(&sdev->csum_list)) {
1053 sum = list_first_entry(&sdev->csum_list,
1054 struct btrfs_ordered_sum, list);
1055 if (sum->bytenr > logical)
1056 return 0;
1057 if (sum->bytenr + sum->len > logical)
1058 break;
1059
1060 ++sdev->stat.csum_discards;
1061 list_del(&sum->list);
1062 kfree(sum);
1063 sum = NULL;
1064 }
1065 if (!sum)
1066 return 0;
1067
1068 num_sectors = sum->len / sectorsize;
1069 for (i = 0; i < num_sectors; ++i) {
1070 if (sum->sums[i].bytenr == logical) {
1071 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
1072 ret = 1;
1073 break;
1074 }
1075 }
1076 if (ret && i == num_sectors - 1) {
1077 list_del(&sum->list);
1078 kfree(sum);
1079 }
1080 return ret;
1081 }
1082
1083 /* scrub extent tries to collect up to 64 kB for each bio */
1084 static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
1085 u64 physical, u64 flags, u64 gen, int mirror_num)
1086 {
1087 int ret;
1088 u8 csum[BTRFS_CSUM_SIZE];
1089
1090 while (len) {
1091 u64 l = min_t(u64, len, PAGE_SIZE);
1092 int have_csum = 0;
1093
1094 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1095 /* push csums to sbio */
1096 have_csum = scrub_find_csum(sdev, logical, l, csum);
1097 if (have_csum == 0)
1098 ++sdev->stat.no_csum;
1099 }
1100 ret = scrub_page(sdev, logical, l, physical, flags, gen,
1101 mirror_num, have_csum ? csum : NULL, 0);
1102 if (ret)
1103 return ret;
1104 len -= l;
1105 logical += l;
1106 physical += l;
1107 }
1108 return 0;
1109 }
1110
1111 static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
1112 struct map_lookup *map, int num, u64 base, u64 length)
1113 {
1114 struct btrfs_path *path;
1115 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1116 struct btrfs_root *root = fs_info->extent_root;
1117 struct btrfs_root *csum_root = fs_info->csum_root;
1118 struct btrfs_extent_item *extent;
1119 struct blk_plug plug;
1120 u64 flags;
1121 int ret;
1122 int slot;
1123 int i;
1124 u64 nstripes;
1125 struct extent_buffer *l;
1126 struct btrfs_key key;
1127 u64 physical;
1128 u64 logical;
1129 u64 generation;
1130 int mirror_num;
1131 struct reada_control *reada1;
1132 struct reada_control *reada2;
1133 struct btrfs_key key_start;
1134 struct btrfs_key key_end;
1135
1136 u64 increment = map->stripe_len;
1137 u64 offset;
1138
1139 nstripes = length;
1140 offset = 0;
1141 do_div(nstripes, map->stripe_len);
1142 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1143 offset = map->stripe_len * num;
1144 increment = map->stripe_len * map->num_stripes;
1145 mirror_num = 1;
1146 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1147 int factor = map->num_stripes / map->sub_stripes;
1148 offset = map->stripe_len * (num / map->sub_stripes);
1149 increment = map->stripe_len * factor;
1150 mirror_num = num % map->sub_stripes + 1;
1151 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1152 increment = map->stripe_len;
1153 mirror_num = num % map->num_stripes + 1;
1154 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1155 increment = map->stripe_len;
1156 mirror_num = num % map->num_stripes + 1;
1157 } else {
1158 increment = map->stripe_len;
1159 mirror_num = 1;
1160 }
1161
1162 path = btrfs_alloc_path();
1163 if (!path)
1164 return -ENOMEM;
1165
1166 path->search_commit_root = 1;
1167 path->skip_locking = 1;
1168
1169 /*
1170 * trigger the readahead for extent tree csum tree and wait for
1171 * completion. During readahead, the scrub is officially paused
1172 * to not hold off transaction commits
1173 */
1174 logical = base + offset;
1175
1176 wait_event(sdev->list_wait,
1177 atomic_read(&sdev->in_flight) == 0);
1178 atomic_inc(&fs_info->scrubs_paused);
1179 wake_up(&fs_info->scrub_pause_wait);
1180
1181 /* FIXME it might be better to start readahead at commit root */
1182 key_start.objectid = logical;
1183 key_start.type = BTRFS_EXTENT_ITEM_KEY;
1184 key_start.offset = (u64)0;
1185 key_end.objectid = base + offset + nstripes * increment;
1186 key_end.type = BTRFS_EXTENT_ITEM_KEY;
1187 key_end.offset = (u64)0;
1188 reada1 = btrfs_reada_add(root, &key_start, &key_end);
1189
1190 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1191 key_start.type = BTRFS_EXTENT_CSUM_KEY;
1192 key_start.offset = logical;
1193 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1194 key_end.type = BTRFS_EXTENT_CSUM_KEY;
1195 key_end.offset = base + offset + nstripes * increment;
1196 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
1197
1198 if (!IS_ERR(reada1))
1199 btrfs_reada_wait(reada1);
1200 if (!IS_ERR(reada2))
1201 btrfs_reada_wait(reada2);
1202
1203 mutex_lock(&fs_info->scrub_lock);
1204 while (atomic_read(&fs_info->scrub_pause_req)) {
1205 mutex_unlock(&fs_info->scrub_lock);
1206 wait_event(fs_info->scrub_pause_wait,
1207 atomic_read(&fs_info->scrub_pause_req) == 0);
1208 mutex_lock(&fs_info->scrub_lock);
1209 }
1210 atomic_dec(&fs_info->scrubs_paused);
1211 mutex_unlock(&fs_info->scrub_lock);
1212 wake_up(&fs_info->scrub_pause_wait);
1213
1214 /*
1215 * collect all data csums for the stripe to avoid seeking during
1216 * the scrub. This might currently (crc32) end up to be about 1MB
1217 */
1218 blk_start_plug(&plug);
1219
1220 /*
1221 * now find all extents for each stripe and scrub them
1222 */
1223 logical = base + offset;
1224 physical = map->stripes[num].physical;
1225 ret = 0;
1226 for (i = 0; i < nstripes; ++i) {
1227 /*
1228 * canceled?
1229 */
1230 if (atomic_read(&fs_info->scrub_cancel_req) ||
1231 atomic_read(&sdev->cancel_req)) {
1232 ret = -ECANCELED;
1233 goto out;
1234 }
1235 /*
1236 * check to see if we have to pause
1237 */
1238 if (atomic_read(&fs_info->scrub_pause_req)) {
1239 /* push queued extents */
1240 scrub_submit(sdev);
1241 wait_event(sdev->list_wait,
1242 atomic_read(&sdev->in_flight) == 0);
1243 atomic_inc(&fs_info->scrubs_paused);
1244 wake_up(&fs_info->scrub_pause_wait);
1245 mutex_lock(&fs_info->scrub_lock);
1246 while (atomic_read(&fs_info->scrub_pause_req)) {
1247 mutex_unlock(&fs_info->scrub_lock);
1248 wait_event(fs_info->scrub_pause_wait,
1249 atomic_read(&fs_info->scrub_pause_req) == 0);
1250 mutex_lock(&fs_info->scrub_lock);
1251 }
1252 atomic_dec(&fs_info->scrubs_paused);
1253 mutex_unlock(&fs_info->scrub_lock);
1254 wake_up(&fs_info->scrub_pause_wait);
1255 }
1256
1257 ret = btrfs_lookup_csums_range(csum_root, logical,
1258 logical + map->stripe_len - 1,
1259 &sdev->csum_list, 1);
1260 if (ret)
1261 goto out;
1262
1263 key.objectid = logical;
1264 key.type = BTRFS_EXTENT_ITEM_KEY;
1265 key.offset = (u64)0;
1266
1267 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1268 if (ret < 0)
1269 goto out;
1270 if (ret > 0) {
1271 ret = btrfs_previous_item(root, path, 0,
1272 BTRFS_EXTENT_ITEM_KEY);
1273 if (ret < 0)
1274 goto out;
1275 if (ret > 0) {
1276 /* there's no smaller item, so stick with the
1277 * larger one */
1278 btrfs_release_path(path);
1279 ret = btrfs_search_slot(NULL, root, &key,
1280 path, 0, 0);
1281 if (ret < 0)
1282 goto out;
1283 }
1284 }
1285
1286 while (1) {
1287 l = path->nodes[0];
1288 slot = path->slots[0];
1289 if (slot >= btrfs_header_nritems(l)) {
1290 ret = btrfs_next_leaf(root, path);
1291 if (ret == 0)
1292 continue;
1293 if (ret < 0)
1294 goto out;
1295
1296 break;
1297 }
1298 btrfs_item_key_to_cpu(l, &key, slot);
1299
1300 if (key.objectid + key.offset <= logical)
1301 goto next;
1302
1303 if (key.objectid >= logical + map->stripe_len)
1304 break;
1305
1306 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1307 goto next;
1308
1309 extent = btrfs_item_ptr(l, slot,
1310 struct btrfs_extent_item);
1311 flags = btrfs_extent_flags(l, extent);
1312 generation = btrfs_extent_generation(l, extent);
1313
1314 if (key.objectid < logical &&
1315 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1316 printk(KERN_ERR
1317 "btrfs scrub: tree block %llu spanning "
1318 "stripes, ignored. logical=%llu\n",
1319 (unsigned long long)key.objectid,
1320 (unsigned long long)logical);
1321 goto next;
1322 }
1323
1324 /*
1325 * trim extent to this stripe
1326 */
1327 if (key.objectid < logical) {
1328 key.offset -= logical - key.objectid;
1329 key.objectid = logical;
1330 }
1331 if (key.objectid + key.offset >
1332 logical + map->stripe_len) {
1333 key.offset = logical + map->stripe_len -
1334 key.objectid;
1335 }
1336
1337 ret = scrub_extent(sdev, key.objectid, key.offset,
1338 key.objectid - logical + physical,
1339 flags, generation, mirror_num);
1340 if (ret)
1341 goto out;
1342
1343 next:
1344 path->slots[0]++;
1345 }
1346 btrfs_release_path(path);
1347 logical += increment;
1348 physical += map->stripe_len;
1349 spin_lock(&sdev->stat_lock);
1350 sdev->stat.last_physical = physical;
1351 spin_unlock(&sdev->stat_lock);
1352 }
1353 /* push queued extents */
1354 scrub_submit(sdev);
1355
1356 out:
1357 blk_finish_plug(&plug);
1358 btrfs_free_path(path);
1359 return ret < 0 ? ret : 0;
1360 }
1361
1362 static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
1363 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length)
1364 {
1365 struct btrfs_mapping_tree *map_tree =
1366 &sdev->dev->dev_root->fs_info->mapping_tree;
1367 struct map_lookup *map;
1368 struct extent_map *em;
1369 int i;
1370 int ret = -EINVAL;
1371
1372 read_lock(&map_tree->map_tree.lock);
1373 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
1374 read_unlock(&map_tree->map_tree.lock);
1375
1376 if (!em)
1377 return -EINVAL;
1378
1379 map = (struct map_lookup *)em->bdev;
1380 if (em->start != chunk_offset)
1381 goto out;
1382
1383 if (em->len < length)
1384 goto out;
1385
1386 for (i = 0; i < map->num_stripes; ++i) {
1387 if (map->stripes[i].dev == sdev->dev) {
1388 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
1389 if (ret)
1390 goto out;
1391 }
1392 }
1393 out:
1394 free_extent_map(em);
1395
1396 return ret;
1397 }
1398
1399 static noinline_for_stack
1400 int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
1401 {
1402 struct btrfs_dev_extent *dev_extent = NULL;
1403 struct btrfs_path *path;
1404 struct btrfs_root *root = sdev->dev->dev_root;
1405 struct btrfs_fs_info *fs_info = root->fs_info;
1406 u64 length;
1407 u64 chunk_tree;
1408 u64 chunk_objectid;
1409 u64 chunk_offset;
1410 int ret;
1411 int slot;
1412 struct extent_buffer *l;
1413 struct btrfs_key key;
1414 struct btrfs_key found_key;
1415 struct btrfs_block_group_cache *cache;
1416
1417 path = btrfs_alloc_path();
1418 if (!path)
1419 return -ENOMEM;
1420
1421 path->reada = 2;
1422 path->search_commit_root = 1;
1423 path->skip_locking = 1;
1424
1425 key.objectid = sdev->dev->devid;
1426 key.offset = 0ull;
1427 key.type = BTRFS_DEV_EXTENT_KEY;
1428
1429
1430 while (1) {
1431 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1432 if (ret < 0)
1433 break;
1434 if (ret > 0) {
1435 if (path->slots[0] >=
1436 btrfs_header_nritems(path->nodes[0])) {
1437 ret = btrfs_next_leaf(root, path);
1438 if (ret)
1439 break;
1440 }
1441 }
1442
1443 l = path->nodes[0];
1444 slot = path->slots[0];
1445
1446 btrfs_item_key_to_cpu(l, &found_key, slot);
1447
1448 if (found_key.objectid != sdev->dev->devid)
1449 break;
1450
1451 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
1452 break;
1453
1454 if (found_key.offset >= end)
1455 break;
1456
1457 if (found_key.offset < key.offset)
1458 break;
1459
1460 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1461 length = btrfs_dev_extent_length(l, dev_extent);
1462
1463 if (found_key.offset + length <= start) {
1464 key.offset = found_key.offset + length;
1465 btrfs_release_path(path);
1466 continue;
1467 }
1468
1469 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1470 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1471 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1472
1473 /*
1474 * get a reference on the corresponding block group to prevent
1475 * the chunk from going away while we scrub it
1476 */
1477 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
1478 if (!cache) {
1479 ret = -ENOENT;
1480 break;
1481 }
1482 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
1483 chunk_offset, length);
1484 btrfs_put_block_group(cache);
1485 if (ret)
1486 break;
1487
1488 key.offset = found_key.offset + length;
1489 btrfs_release_path(path);
1490 }
1491
1492 btrfs_free_path(path);
1493
1494 /*
1495 * ret can still be 1 from search_slot or next_leaf,
1496 * that's not an error
1497 */
1498 return ret < 0 ? ret : 0;
1499 }
1500
1501 static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
1502 {
1503 int i;
1504 u64 bytenr;
1505 u64 gen;
1506 int ret;
1507 struct btrfs_device *device = sdev->dev;
1508 struct btrfs_root *root = device->dev_root;
1509
1510 gen = root->fs_info->last_trans_committed;
1511
1512 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1513 bytenr = btrfs_sb_offset(i);
1514 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1515 break;
1516
1517 ret = scrub_page(sdev, bytenr, PAGE_SIZE, bytenr,
1518 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
1519 if (ret)
1520 return ret;
1521 }
1522 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1523
1524 return 0;
1525 }
1526
1527 /*
1528 * get a reference count on fs_info->scrub_workers. start worker if necessary
1529 */
1530 static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
1531 {
1532 struct btrfs_fs_info *fs_info = root->fs_info;
1533
1534 mutex_lock(&fs_info->scrub_lock);
1535 if (fs_info->scrub_workers_refcnt == 0) {
1536 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
1537 fs_info->thread_pool_size, &fs_info->generic_worker);
1538 fs_info->scrub_workers.idle_thresh = 4;
1539 btrfs_start_workers(&fs_info->scrub_workers, 1);
1540 }
1541 ++fs_info->scrub_workers_refcnt;
1542 mutex_unlock(&fs_info->scrub_lock);
1543
1544 return 0;
1545 }
1546
1547 static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
1548 {
1549 struct btrfs_fs_info *fs_info = root->fs_info;
1550
1551 mutex_lock(&fs_info->scrub_lock);
1552 if (--fs_info->scrub_workers_refcnt == 0)
1553 btrfs_stop_workers(&fs_info->scrub_workers);
1554 WARN_ON(fs_info->scrub_workers_refcnt < 0);
1555 mutex_unlock(&fs_info->scrub_lock);
1556 }
1557
1558
1559 int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
1560 struct btrfs_scrub_progress *progress, int readonly)
1561 {
1562 struct scrub_dev *sdev;
1563 struct btrfs_fs_info *fs_info = root->fs_info;
1564 int ret;
1565 struct btrfs_device *dev;
1566
1567 if (btrfs_fs_closing(root->fs_info))
1568 return -EINVAL;
1569
1570 /*
1571 * check some assumptions
1572 */
1573 if (root->sectorsize != PAGE_SIZE ||
1574 root->sectorsize != root->leafsize ||
1575 root->sectorsize != root->nodesize) {
1576 printk(KERN_ERR "btrfs_scrub: size assumptions fail\n");
1577 return -EINVAL;
1578 }
1579
1580 ret = scrub_workers_get(root);
1581 if (ret)
1582 return ret;
1583
1584 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1585 dev = btrfs_find_device(root, devid, NULL, NULL);
1586 if (!dev || dev->missing) {
1587 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1588 scrub_workers_put(root);
1589 return -ENODEV;
1590 }
1591 mutex_lock(&fs_info->scrub_lock);
1592
1593 if (!dev->in_fs_metadata) {
1594 mutex_unlock(&fs_info->scrub_lock);
1595 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1596 scrub_workers_put(root);
1597 return -ENODEV;
1598 }
1599
1600 if (dev->scrub_device) {
1601 mutex_unlock(&fs_info->scrub_lock);
1602 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1603 scrub_workers_put(root);
1604 return -EINPROGRESS;
1605 }
1606 sdev = scrub_setup_dev(dev);
1607 if (IS_ERR(sdev)) {
1608 mutex_unlock(&fs_info->scrub_lock);
1609 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1610 scrub_workers_put(root);
1611 return PTR_ERR(sdev);
1612 }
1613 sdev->readonly = readonly;
1614 dev->scrub_device = sdev;
1615
1616 atomic_inc(&fs_info->scrubs_running);
1617 mutex_unlock(&fs_info->scrub_lock);
1618 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1619
1620 down_read(&fs_info->scrub_super_lock);
1621 ret = scrub_supers(sdev);
1622 up_read(&fs_info->scrub_super_lock);
1623
1624 if (!ret)
1625 ret = scrub_enumerate_chunks(sdev, start, end);
1626
1627 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1628 atomic_dec(&fs_info->scrubs_running);
1629 wake_up(&fs_info->scrub_pause_wait);
1630
1631 wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0);
1632
1633 if (progress)
1634 memcpy(progress, &sdev->stat, sizeof(*progress));
1635
1636 mutex_lock(&fs_info->scrub_lock);
1637 dev->scrub_device = NULL;
1638 mutex_unlock(&fs_info->scrub_lock);
1639
1640 scrub_free_dev(sdev);
1641 scrub_workers_put(root);
1642
1643 return ret;
1644 }
1645
1646 int btrfs_scrub_pause(struct btrfs_root *root)
1647 {
1648 struct btrfs_fs_info *fs_info = root->fs_info;
1649
1650 mutex_lock(&fs_info->scrub_lock);
1651 atomic_inc(&fs_info->scrub_pause_req);
1652 while (atomic_read(&fs_info->scrubs_paused) !=
1653 atomic_read(&fs_info->scrubs_running)) {
1654 mutex_unlock(&fs_info->scrub_lock);
1655 wait_event(fs_info->scrub_pause_wait,
1656 atomic_read(&fs_info->scrubs_paused) ==
1657 atomic_read(&fs_info->scrubs_running));
1658 mutex_lock(&fs_info->scrub_lock);
1659 }
1660 mutex_unlock(&fs_info->scrub_lock);
1661
1662 return 0;
1663 }
1664
1665 int btrfs_scrub_continue(struct btrfs_root *root)
1666 {
1667 struct btrfs_fs_info *fs_info = root->fs_info;
1668
1669 atomic_dec(&fs_info->scrub_pause_req);
1670 wake_up(&fs_info->scrub_pause_wait);
1671 return 0;
1672 }
1673
1674 int btrfs_scrub_pause_super(struct btrfs_root *root)
1675 {
1676 down_write(&root->fs_info->scrub_super_lock);
1677 return 0;
1678 }
1679
1680 int btrfs_scrub_continue_super(struct btrfs_root *root)
1681 {
1682 up_write(&root->fs_info->scrub_super_lock);
1683 return 0;
1684 }
1685
1686 int btrfs_scrub_cancel(struct btrfs_root *root)
1687 {
1688 struct btrfs_fs_info *fs_info = root->fs_info;
1689
1690 mutex_lock(&fs_info->scrub_lock);
1691 if (!atomic_read(&fs_info->scrubs_running)) {
1692 mutex_unlock(&fs_info->scrub_lock);
1693 return -ENOTCONN;
1694 }
1695
1696 atomic_inc(&fs_info->scrub_cancel_req);
1697 while (atomic_read(&fs_info->scrubs_running)) {
1698 mutex_unlock(&fs_info->scrub_lock);
1699 wait_event(fs_info->scrub_pause_wait,
1700 atomic_read(&fs_info->scrubs_running) == 0);
1701 mutex_lock(&fs_info->scrub_lock);
1702 }
1703 atomic_dec(&fs_info->scrub_cancel_req);
1704 mutex_unlock(&fs_info->scrub_lock);
1705
1706 return 0;
1707 }
1708
1709 int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
1710 {
1711 struct btrfs_fs_info *fs_info = root->fs_info;
1712 struct scrub_dev *sdev;
1713
1714 mutex_lock(&fs_info->scrub_lock);
1715 sdev = dev->scrub_device;
1716 if (!sdev) {
1717 mutex_unlock(&fs_info->scrub_lock);
1718 return -ENOTCONN;
1719 }
1720 atomic_inc(&sdev->cancel_req);
1721 while (dev->scrub_device) {
1722 mutex_unlock(&fs_info->scrub_lock);
1723 wait_event(fs_info->scrub_pause_wait,
1724 dev->scrub_device == NULL);
1725 mutex_lock(&fs_info->scrub_lock);
1726 }
1727 mutex_unlock(&fs_info->scrub_lock);
1728
1729 return 0;
1730 }
1731 int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
1732 {
1733 struct btrfs_fs_info *fs_info = root->fs_info;
1734 struct btrfs_device *dev;
1735 int ret;
1736
1737 /*
1738 * we have to hold the device_list_mutex here so the device
1739 * does not go away in cancel_dev. FIXME: find a better solution
1740 */
1741 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1742 dev = btrfs_find_device(root, devid, NULL, NULL);
1743 if (!dev) {
1744 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1745 return -ENODEV;
1746 }
1747 ret = btrfs_scrub_cancel_dev(root, dev);
1748 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1749
1750 return ret;
1751 }
1752
1753 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
1754 struct btrfs_scrub_progress *progress)
1755 {
1756 struct btrfs_device *dev;
1757 struct scrub_dev *sdev = NULL;
1758
1759 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1760 dev = btrfs_find_device(root, devid, NULL, NULL);
1761 if (dev)
1762 sdev = dev->scrub_device;
1763 if (sdev)
1764 memcpy(progress, &sdev->stat, sizeof(*progress));
1765 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1766
1767 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;
1768 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree