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Btrfs: wake up @scrub_pause_wait as much as we can
[deliverable/linux.git] / fs / btrfs / scrub.c
CommitLineData
a2de733c 1/*
b6bfebc1 2 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
a2de733c
AJ		 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
a2de733c 19#include <linux/blkdev.h>
558540c1 20#include <linux/ratelimit.h>
a2de733c
AJ		 21#include "ctree.h"
22#include "volumes.h"
23#include "disk-io.h"
24#include "ordered-data.h"
0ef8e451 25#include "transaction.h"
558540c1 26#include "backref.h"
5da6fcbc 27#include "extent_io.h"
ff023aac 28#include "dev-replace.h"
21adbd5c 29#include "check-integrity.h"
606686ee 30#include "rcu-string.h"
53b381b3 31#include "raid56.h"
a2de733c
AJ		 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:
a2de733c
AJ		 40 * - In case an unrepairable extent is encountered, track which files are
41 * affected and report them
a2de733c 42 * - track and record media errors, throw out bad devices
a2de733c 43 * - add a mode to also read unallocated space
a2de733c
AJ		 44 */
45
b5d67f64 46struct scrub_block;
d9d181c1 47struct scrub_ctx;
a2de733c 48
ff023aac
SB		 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 */
7a9e9987
SB		 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 */
b5d67f64 64#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
a2de733c
AJ		 65
66struct scrub_page {
b5d67f64
SB		 67 struct scrub_block *sblock;
68 struct page *page;
442a4f63 69 struct btrfs_device *dev;
a2de733c
AJ		 70 u64 flags; /* extent flags */
71 u64 generation;
b5d67f64
SB		 72 u64 logical;
73 u64 physical;
ff023aac 74 u64 physical_for_dev_replace;
7a9e9987 75 atomic_t ref_count;
b5d67f64
SB		 76 struct {
77 unsigned int mirror_num:8;
78 unsigned int have_csum:1;
79 unsigned int io_error:1;
80 };
a2de733c
AJ		 81 u8 csum[BTRFS_CSUM_SIZE];
82};
83
84struct scrub_bio {
85 int index;
d9d181c1 86 struct scrub_ctx *sctx;
a36cf8b8 87 struct btrfs_device *dev;
a2de733c
AJ		 88 struct bio *bio;
89 int err;
90 u64 logical;
91 u64 physical;
ff023aac
SB		 92#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
93 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
94#else
95 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
96#endif
b5d67f64 97 int page_count;
a2de733c
AJ		 98 int next_free;
99 struct btrfs_work work;
100};
101
b5d67f64 102struct scrub_block {
7a9e9987 103 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
b5d67f64
SB		 104 int page_count;
105 atomic_t outstanding_pages;
106 atomic_t ref_count; /* free mem on transition to zero */
d9d181c1 107 struct scrub_ctx *sctx;
b5d67f64
SB		 108 struct {
109 unsigned int header_error:1;
110 unsigned int checksum_error:1;
111 unsigned int no_io_error_seen:1;
442a4f63 112 unsigned int generation_error:1; /* also sets header_error */
b5d67f64
SB		 113 };
114};
115
ff023aac
SB		 116struct scrub_wr_ctx {
117 struct scrub_bio *wr_curr_bio;
118 struct btrfs_device *tgtdev;
119 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
120 atomic_t flush_all_writes;
121 struct mutex wr_lock;
122};
123
d9d181c1 124struct scrub_ctx {
ff023aac 125 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
a36cf8b8 126 struct btrfs_root *dev_root;
a2de733c
AJ		 127 int first_free;
128 int curr;
b6bfebc1
SB		 129 atomic_t bios_in_flight;
130 atomic_t workers_pending;
a2de733c
AJ		 131 spinlock_t list_lock;
132 wait_queue_head_t list_wait;
133 u16 csum_size;
134 struct list_head csum_list;
135 atomic_t cancel_req;
8628764e 136 int readonly;
ff023aac 137 int pages_per_rd_bio;
b5d67f64
SB		 138 u32 sectorsize;
139 u32 nodesize;
140 u32 leafsize;
63a212ab
SB		 141
142 int is_dev_replace;
ff023aac 143 struct scrub_wr_ctx wr_ctx;
63a212ab 144
a2de733c
AJ		 145 /*
146 * statistics
147 */
148 struct btrfs_scrub_progress stat;
149 spinlock_t stat_lock;
150};
151
0ef8e451 152struct scrub_fixup_nodatasum {
d9d181c1 153 struct scrub_ctx *sctx;
a36cf8b8 154 struct btrfs_device *dev;
0ef8e451
JS		 155 u64 logical;
156 struct btrfs_root *root;
157 struct btrfs_work work;
158 int mirror_num;
159};
160
652f25a2
JB		 161struct scrub_nocow_inode {
162 u64 inum;
163 u64 offset;
164 u64 root;
165 struct list_head list;
166};
167
ff023aac
SB		 168struct scrub_copy_nocow_ctx {
169 struct scrub_ctx *sctx;
170 u64 logical;
171 u64 len;
172 int mirror_num;
173 u64 physical_for_dev_replace;
652f25a2 174 struct list_head inodes;
ff023aac
SB		 175 struct btrfs_work work;
176};
177
558540c1
JS		 178struct scrub_warning {
179 struct btrfs_path *path;
180 u64 extent_item_size;
181 char *scratch_buf;
182 char *msg_buf;
183 const char *errstr;
184 sector_t sector;
185 u64 logical;
186 struct btrfs_device *dev;
187 int msg_bufsize;
188 int scratch_bufsize;
189};
190
b5d67f64 191
b6bfebc1
SB		 192static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
193static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
194static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
195static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
b5d67f64 196static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
d9d181c1 197static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
3ec706c8 198 struct btrfs_fs_info *fs_info,
ff023aac 199 struct scrub_block *original_sblock,
b5d67f64 200 u64 length, u64 logical,
ff023aac 201 struct scrub_block *sblocks_for_recheck);
34f5c8e9
SB		 202static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
203 struct scrub_block *sblock, int is_metadata,
204 int have_csum, u8 *csum, u64 generation,
205 u16 csum_size);
b5d67f64
SB		 206static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
207 struct scrub_block *sblock,
208 int is_metadata, int have_csum,
209 const u8 *csum, u64 generation,
210 u16 csum_size);
b5d67f64
SB		 211static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
212 struct scrub_block *sblock_good,
213 int force_write);
214static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
215 struct scrub_block *sblock_good,
216 int page_num, int force_write);
ff023aac
SB		 217static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
218static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
219 int page_num);
b5d67f64
SB		 220static int scrub_checksum_data(struct scrub_block *sblock);
221static int scrub_checksum_tree_block(struct scrub_block *sblock);
222static int scrub_checksum_super(struct scrub_block *sblock);
223static void scrub_block_get(struct scrub_block *sblock);
224static void scrub_block_put(struct scrub_block *sblock);
7a9e9987
SB		 225static void scrub_page_get(struct scrub_page *spage);
226static void scrub_page_put(struct scrub_page *spage);
ff023aac
SB		 227static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
228 struct scrub_page *spage);
d9d181c1 229static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 230 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac
SB		 231 u64 gen, int mirror_num, u8 *csum, int force,
232 u64 physical_for_dev_replace);
1623edeb 233static void scrub_bio_end_io(struct bio *bio, int err);
b5d67f64
SB		 234static void scrub_bio_end_io_worker(struct btrfs_work *work);
235static void scrub_block_complete(struct scrub_block *sblock);
ff023aac
SB		 236static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
237 u64 extent_logical, u64 extent_len,
238 u64 *extent_physical,
239 struct btrfs_device **extent_dev,
240 int *extent_mirror_num);
241static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
242 struct scrub_wr_ctx *wr_ctx,
243 struct btrfs_fs_info *fs_info,
244 struct btrfs_device *dev,
245 int is_dev_replace);
246static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
247static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
248 struct scrub_page *spage);
249static void scrub_wr_submit(struct scrub_ctx *sctx);
250static void scrub_wr_bio_end_io(struct bio *bio, int err);
251static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
252static int write_page_nocow(struct scrub_ctx *sctx,
253 u64 physical_for_dev_replace, struct page *page);
254static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
652f25a2 255 struct scrub_copy_nocow_ctx *ctx);
ff023aac
SB		 256static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
257 int mirror_num, u64 physical_for_dev_replace);
258static void copy_nocow_pages_worker(struct btrfs_work *work);
cb7ab021 259static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
3cb0929a 260static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
1623edeb
SB		 261
262
b6bfebc1
SB		 263static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
264{
265 atomic_inc(&sctx->bios_in_flight);
266}
267
268static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
269{
270 atomic_dec(&sctx->bios_in_flight);
271 wake_up(&sctx->list_wait);
272}
273
cb7ab021 274static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
3cb0929a
WS		 275{
276 while (atomic_read(&fs_info->scrub_pause_req)) {
277 mutex_unlock(&fs_info->scrub_lock);
278 wait_event(fs_info->scrub_pause_wait,
279 atomic_read(&fs_info->scrub_pause_req) == 0);
280 mutex_lock(&fs_info->scrub_lock);
281 }
282}
283
cb7ab021
WS		 284static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
285{
286 atomic_inc(&fs_info->scrubs_paused);
287 wake_up(&fs_info->scrub_pause_wait);
288
289 mutex_lock(&fs_info->scrub_lock);
290 __scrub_blocked_if_needed(fs_info);
291 atomic_dec(&fs_info->scrubs_paused);
292 mutex_unlock(&fs_info->scrub_lock);
293
294 wake_up(&fs_info->scrub_pause_wait);
295}
296
b6bfebc1
SB		 297/*
298 * used for workers that require transaction commits (i.e., for the
299 * NOCOW case)
300 */
301static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
302{
303 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
304
305 /*
306 * increment scrubs_running to prevent cancel requests from
307 * completing as long as a worker is running. we must also
308 * increment scrubs_paused to prevent deadlocking on pause
309 * requests used for transactions commits (as the worker uses a
310 * transaction context). it is safe to regard the worker
311 * as paused for all matters practical. effectively, we only
312 * avoid cancellation requests from completing.
313 */
314 mutex_lock(&fs_info->scrub_lock);
315 atomic_inc(&fs_info->scrubs_running);
316 atomic_inc(&fs_info->scrubs_paused);
317 mutex_unlock(&fs_info->scrub_lock);
32a44789
WS		 318
319 /*
320 * check if @scrubs_running=@scrubs_paused condition
321 * inside wait_event() is not an atomic operation.
322 * which means we may inc/dec @scrub_running/paused
323 * at any time. Let's wake up @scrub_pause_wait as
324 * much as we can to let commit transaction blocked less.
325 */
326 wake_up(&fs_info->scrub_pause_wait);
327
b6bfebc1
SB		 328 atomic_inc(&sctx->workers_pending);
329}
330
331/* used for workers that require transaction commits */
332static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
333{
334 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
335
336 /*
337 * see scrub_pending_trans_workers_inc() why we're pretending
338 * to be paused in the scrub counters
339 */
340 mutex_lock(&fs_info->scrub_lock);
341 atomic_dec(&fs_info->scrubs_running);
342 atomic_dec(&fs_info->scrubs_paused);
343 mutex_unlock(&fs_info->scrub_lock);
344 atomic_dec(&sctx->workers_pending);
345 wake_up(&fs_info->scrub_pause_wait);
346 wake_up(&sctx->list_wait);
347}
348
d9d181c1 349static void scrub_free_csums(struct scrub_ctx *sctx)
a2de733c 350{
d9d181c1 351 while (!list_empty(&sctx->csum_list)) {
a2de733c 352 struct btrfs_ordered_sum *sum;
d9d181c1 353 sum = list_first_entry(&sctx->csum_list,
a2de733c
AJ		 354 struct btrfs_ordered_sum, list);
355 list_del(&sum->list);
356 kfree(sum);
357 }
358}
359
d9d181c1 360static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
a2de733c
AJ		 361{
362 int i;
a2de733c 363
d9d181c1 364 if (!sctx)
a2de733c
AJ		 365 return;
366
ff023aac
SB		 367 scrub_free_wr_ctx(&sctx->wr_ctx);
368
b5d67f64 369 /* this can happen when scrub is cancelled */
d9d181c1
SB		 370 if (sctx->curr != -1) {
371 struct scrub_bio *sbio = sctx->bios[sctx->curr];
b5d67f64
SB		 372
373 for (i = 0; i < sbio->page_count; i++) {
ff023aac 374 WARN_ON(!sbio->pagev[i]->page);
b5d67f64
SB		 375 scrub_block_put(sbio->pagev[i]->sblock);
376 }
377 bio_put(sbio->bio);
378 }
379
ff023aac 380 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
d9d181c1 381 struct scrub_bio *sbio = sctx->bios[i];
a2de733c
AJ		 382
383 if (!sbio)
384 break;
a2de733c
AJ		 385 kfree(sbio);
386 }
387
d9d181c1
SB		 388 scrub_free_csums(sctx);
389 kfree(sctx);
a2de733c
AJ		 390}
391
392static noinline_for_stack
63a212ab 393struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
a2de733c 394{
d9d181c1 395 struct scrub_ctx *sctx;
a2de733c 396 int i;
a2de733c 397 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
ff023aac
SB		 398 int pages_per_rd_bio;
399 int ret;
a2de733c 400
ff023aac
SB		 401 /*
402 * the setting of pages_per_rd_bio is correct for scrub but might
403 * be wrong for the dev_replace code where we might read from
404 * different devices in the initial huge bios. However, that
405 * code is able to correctly handle the case when adding a page
406 * to a bio fails.
407 */
408 if (dev->bdev)
409 pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO,
410 bio_get_nr_vecs(dev->bdev));
411 else
412 pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
d9d181c1
SB		 413 sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
414 if (!sctx)
a2de733c 415 goto nomem;
63a212ab 416 sctx->is_dev_replace = is_dev_replace;
ff023aac 417 sctx->pages_per_rd_bio = pages_per_rd_bio;
d9d181c1 418 sctx->curr = -1;
a36cf8b8 419 sctx->dev_root = dev->dev_root;
ff023aac 420 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
a2de733c
AJ		 421 struct scrub_bio *sbio;
422
423 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
424 if (!sbio)
425 goto nomem;
d9d181c1 426 sctx->bios[i] = sbio;
a2de733c 427
a2de733c 428 sbio->index = i;
d9d181c1 429 sbio->sctx = sctx;
b5d67f64
SB		 430 sbio->page_count = 0;
431 sbio->work.func = scrub_bio_end_io_worker;
a2de733c 432
ff023aac 433 if (i != SCRUB_BIOS_PER_SCTX - 1)
d9d181c1 434 sctx->bios[i]->next_free = i + 1;
0ef8e451 435 else
d9d181c1
SB		 436 sctx->bios[i]->next_free = -1;
437 }
438 sctx->first_free = 0;
439 sctx->nodesize = dev->dev_root->nodesize;
440 sctx->leafsize = dev->dev_root->leafsize;
441 sctx->sectorsize = dev->dev_root->sectorsize;
b6bfebc1
SB		 442 atomic_set(&sctx->bios_in_flight, 0);
443 atomic_set(&sctx->workers_pending, 0);
d9d181c1
SB		 444 atomic_set(&sctx->cancel_req, 0);
445 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
446 INIT_LIST_HEAD(&sctx->csum_list);
447
448 spin_lock_init(&sctx->list_lock);
449 spin_lock_init(&sctx->stat_lock);
450 init_waitqueue_head(&sctx->list_wait);
ff023aac
SB		 451
452 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
453 fs_info->dev_replace.tgtdev, is_dev_replace);
454 if (ret) {
455 scrub_free_ctx(sctx);
456 return ERR_PTR(ret);
457 }
d9d181c1 458 return sctx;
a2de733c
AJ		 459
460nomem:
d9d181c1 461 scrub_free_ctx(sctx);
a2de733c
AJ		 462 return ERR_PTR(-ENOMEM);
463}
464
ff023aac
SB		 465static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
466 void *warn_ctx)
558540c1
JS		 467{
468 u64 isize;
469 u32 nlink;
470 int ret;
471 int i;
472 struct extent_buffer *eb;
473 struct btrfs_inode_item *inode_item;
ff023aac 474 struct scrub_warning *swarn = warn_ctx;
558540c1
JS		 475 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
476 struct inode_fs_paths *ipath = NULL;
477 struct btrfs_root *local_root;
478 struct btrfs_key root_key;
479
480 root_key.objectid = root;
481 root_key.type = BTRFS_ROOT_ITEM_KEY;
482 root_key.offset = (u64)-1;
483 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
484 if (IS_ERR(local_root)) {
485 ret = PTR_ERR(local_root);
486 goto err;
487 }
488
489 ret = inode_item_info(inum, 0, local_root, swarn->path);
490 if (ret) {
491 btrfs_release_path(swarn->path);
492 goto err;
493 }
494
495 eb = swarn->path->nodes[0];
496 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
497 struct btrfs_inode_item);
498 isize = btrfs_inode_size(eb, inode_item);
499 nlink = btrfs_inode_nlink(eb, inode_item);
500 btrfs_release_path(swarn->path);
501
502 ipath = init_ipath(4096, local_root, swarn->path);
26bdef54
DC		 503 if (IS_ERR(ipath)) {
504 ret = PTR_ERR(ipath);
505 ipath = NULL;
506 goto err;
507 }
558540c1
JS		 508 ret = paths_from_inode(inum, ipath);
509
510 if (ret < 0)
511 goto err;
512
513 /*
514 * we deliberately ignore the bit ipath might have been too small to
515 * hold all of the paths here
516 */
517 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
efe120a0 518 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
558540c1
JS		 519 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
520 "length %llu, links %u (path: %s)\n", swarn->errstr,
606686ee 521 swarn->logical, rcu_str_deref(swarn->dev->name),
558540c1
JS		 522 (unsigned long long)swarn->sector, root, inum, offset,
523 min(isize - offset, (u64)PAGE_SIZE), nlink,
745c4d8e 524 (char *)(unsigned long)ipath->fspath->val[i]);
558540c1
JS		 525
526 free_ipath(ipath);
527 return 0;
528
529err:
efe120a0 530 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
558540c1
JS		 531 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
532 "resolving failed with ret=%d\n", swarn->errstr,
606686ee 533 swarn->logical, rcu_str_deref(swarn->dev->name),
558540c1
JS		 534 (unsigned long long)swarn->sector, root, inum, offset, ret);
535
536 free_ipath(ipath);
537 return 0;
538}
539
b5d67f64 540static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
558540c1 541{
a36cf8b8
SB		 542 struct btrfs_device *dev;
543 struct btrfs_fs_info *fs_info;
558540c1
JS		 544 struct btrfs_path *path;
545 struct btrfs_key found_key;
546 struct extent_buffer *eb;
547 struct btrfs_extent_item *ei;
548 struct scrub_warning swarn;
69917e43
LB		 549 unsigned long ptr = 0;
550 u64 extent_item_pos;
551 u64 flags = 0;
558540c1 552 u64 ref_root;
69917e43 553 u32 item_size;
558540c1 554 u8 ref_level;
558540c1 555 const int bufsize = 4096;
69917e43 556 int ret;
558540c1 557
a36cf8b8 558 WARN_ON(sblock->page_count < 1);
7a9e9987 559 dev = sblock->pagev[0]->dev;
a36cf8b8
SB		 560 fs_info = sblock->sctx->dev_root->fs_info;
561
558540c1
JS		 562 path = btrfs_alloc_path();
563
564 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
565 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
7a9e9987
SB		 566 swarn.sector = (sblock->pagev[0]->physical) >> 9;
567 swarn.logical = sblock->pagev[0]->logical;
558540c1 568 swarn.errstr = errstr;
a36cf8b8 569 swarn.dev = NULL;
558540c1
JS		 570 swarn.msg_bufsize = bufsize;
571 swarn.scratch_bufsize = bufsize;
572
573 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
574 goto out;
575
69917e43
LB		 576 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
577 &flags);
558540c1
JS		 578 if (ret < 0)
579 goto out;
580
4692cf58 581 extent_item_pos = swarn.logical - found_key.objectid;
558540c1
JS		 582 swarn.extent_item_size = found_key.offset;
583
584 eb = path->nodes[0];
585 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
586 item_size = btrfs_item_size_nr(eb, path->slots[0]);
587
69917e43 588 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
558540c1
JS		 589 do {
590 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
591 &ref_root, &ref_level);
606686ee 592 printk_in_rcu(KERN_WARNING
efe120a0 593 "BTRFS: %s at logical %llu on dev %s, "
558540c1 594 "sector %llu: metadata %s (level %d) in tree "
606686ee
JB		 595 "%llu\n", errstr, swarn.logical,
596 rcu_str_deref(dev->name),
558540c1
JS		 597 (unsigned long long)swarn.sector,
598 ref_level ? "node" : "leaf",
599 ret < 0 ? -1 : ref_level,
600 ret < 0 ? -1 : ref_root);
601 } while (ret != 1);
d8fe29e9 602 btrfs_release_path(path);
558540c1 603 } else {
d8fe29e9 604 btrfs_release_path(path);
558540c1 605 swarn.path = path;
a36cf8b8 606 swarn.dev = dev;
7a3ae2f8
JS		 607 iterate_extent_inodes(fs_info, found_key.objectid,
608 extent_item_pos, 1,
558540c1
JS		 609 scrub_print_warning_inode, &swarn);
610 }
611
612out:
613 btrfs_free_path(path);
614 kfree(swarn.scratch_buf);
615 kfree(swarn.msg_buf);
616}
617
ff023aac 618static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
0ef8e451 619{
5da6fcbc 620 struct page *page = NULL;
0ef8e451 621 unsigned long index;
ff023aac 622 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
0ef8e451 623 int ret;
5da6fcbc 624 int corrected = 0;
0ef8e451 625 struct btrfs_key key;
5da6fcbc 626 struct inode *inode = NULL;
6f1c3605 627 struct btrfs_fs_info *fs_info;
0ef8e451
JS		 628 u64 end = offset + PAGE_SIZE - 1;
629 struct btrfs_root *local_root;
6f1c3605 630 int srcu_index;
0ef8e451
JS		 631
632 key.objectid = root;
633 key.type = BTRFS_ROOT_ITEM_KEY;
634 key.offset = (u64)-1;
6f1c3605
LB		 635
636 fs_info = fixup->root->fs_info;
637 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
638
639 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
640 if (IS_ERR(local_root)) {
641 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
0ef8e451 642 return PTR_ERR(local_root);
6f1c3605 643 }
0ef8e451
JS		 644
645 key.type = BTRFS_INODE_ITEM_KEY;
646 key.objectid = inum;
647 key.offset = 0;
6f1c3605
LB		 648 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
649 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
0ef8e451
JS		 650 if (IS_ERR(inode))
651 return PTR_ERR(inode);
652
0ef8e451
JS		 653 index = offset >> PAGE_CACHE_SHIFT;
654
655 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
5da6fcbc
JS		 656 if (!page) {
657 ret = -ENOMEM;
658 goto out;
659 }
660
661 if (PageUptodate(page)) {
5da6fcbc
JS		 662 if (PageDirty(page)) {
663 /*
664 * we need to write the data to the defect sector. the
665 * data that was in that sector is not in memory,
666 * because the page was modified. we must not write the
667 * modified page to that sector.
668 *
669 * TODO: what could be done here: wait for the delalloc
670 * runner to write out that page (might involve
671 * COW) and see whether the sector is still
672 * referenced afterwards.
673 *
674 * For the meantime, we'll treat this error
675 * incorrectable, although there is a chance that a
676 * later scrub will find the bad sector again and that
677 * there's no dirty page in memory, then.
678 */
679 ret = -EIO;
680 goto out;
681 }
3ec706c8
SB		 682 fs_info = BTRFS_I(inode)->root->fs_info;
683 ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
5da6fcbc
JS		 684 fixup->logical, page,
685 fixup->mirror_num);
686 unlock_page(page);
687 corrected = !ret;
688 } else {
689 /*
690 * we need to get good data first. the general readpage path
691 * will call repair_io_failure for us, we just have to make
692 * sure we read the bad mirror.
693 */
694 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
695 EXTENT_DAMAGED, GFP_NOFS);
696 if (ret) {
697 /* set_extent_bits should give proper error */
698 WARN_ON(ret > 0);
699 if (ret > 0)
700 ret = -EFAULT;
701 goto out;
702 }
703
704 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
705 btrfs_get_extent,
706 fixup->mirror_num);
707 wait_on_page_locked(page);
708
709 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
710 end, EXTENT_DAMAGED, 0, NULL);
711 if (!corrected)
712 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
713 EXTENT_DAMAGED, GFP_NOFS);
714 }
715
716out:
717 if (page)
718 put_page(page);
719 if (inode)
720 iput(inode);
0ef8e451
JS		 721
722 if (ret < 0)
723 return ret;
724
725 if (ret == 0 && corrected) {
726 /*
727 * we only need to call readpage for one of the inodes belonging
728 * to this extent. so make iterate_extent_inodes stop
729 */
730 return 1;
731 }
732
733 return -EIO;
734}
735
736static void scrub_fixup_nodatasum(struct btrfs_work *work)
737{
738 int ret;
739 struct scrub_fixup_nodatasum *fixup;
d9d181c1 740 struct scrub_ctx *sctx;
0ef8e451 741 struct btrfs_trans_handle *trans = NULL;
0ef8e451
JS		 742 struct btrfs_path *path;
743 int uncorrectable = 0;
744
745 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
d9d181c1 746 sctx = fixup->sctx;
0ef8e451
JS		 747
748 path = btrfs_alloc_path();
749 if (!path) {
d9d181c1
SB		 750 spin_lock(&sctx->stat_lock);
751 ++sctx->stat.malloc_errors;
752 spin_unlock(&sctx->stat_lock);
0ef8e451
JS		 753 uncorrectable = 1;
754 goto out;
755 }
756
757 trans = btrfs_join_transaction(fixup->root);
758 if (IS_ERR(trans)) {
759 uncorrectable = 1;
760 goto out;
761 }
762
763 /*
764 * the idea is to trigger a regular read through the standard path. we
765 * read a page from the (failed) logical address by specifying the
766 * corresponding copynum of the failed sector. thus, that readpage is
767 * expected to fail.
768 * that is the point where on-the-fly error correction will kick in
769 * (once it's finished) and rewrite the failed sector if a good copy
770 * can be found.
771 */
772 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
773 path, scrub_fixup_readpage,
774 fixup);
775 if (ret < 0) {
776 uncorrectable = 1;
777 goto out;
778 }
779 WARN_ON(ret != 1);
780
d9d181c1
SB		 781 spin_lock(&sctx->stat_lock);
782 ++sctx->stat.corrected_errors;
783 spin_unlock(&sctx->stat_lock);
0ef8e451
JS		 784
785out:
786 if (trans && !IS_ERR(trans))
787 btrfs_end_transaction(trans, fixup->root);
788 if (uncorrectable) {
d9d181c1
SB		 789 spin_lock(&sctx->stat_lock);
790 ++sctx->stat.uncorrectable_errors;
791 spin_unlock(&sctx->stat_lock);
ff023aac
SB		 792 btrfs_dev_replace_stats_inc(
793 &sctx->dev_root->fs_info->dev_replace.
794 num_uncorrectable_read_errors);
efe120a0
FH		 795 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
796 "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
c1c9ff7c 797 fixup->logical, rcu_str_deref(fixup->dev->name));
0ef8e451
JS		 798 }
799
800 btrfs_free_path(path);
801 kfree(fixup);
802
b6bfebc1 803 scrub_pending_trans_workers_dec(sctx);
0ef8e451
JS		 804}
805
a2de733c 806/*
b5d67f64
SB		 807 * scrub_handle_errored_block gets called when either verification of the
808 * pages failed or the bio failed to read, e.g. with EIO. In the latter
809 * case, this function handles all pages in the bio, even though only one
810 * may be bad.
811 * The goal of this function is to repair the errored block by using the
812 * contents of one of the mirrors.
a2de733c 813 */
b5d67f64 814static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
a2de733c 815{
d9d181c1 816 struct scrub_ctx *sctx = sblock_to_check->sctx;
a36cf8b8 817 struct btrfs_device *dev;
b5d67f64
SB		 818 struct btrfs_fs_info *fs_info;
819 u64 length;
820 u64 logical;
821 u64 generation;
822 unsigned int failed_mirror_index;
823 unsigned int is_metadata;
824 unsigned int have_csum;
825 u8 *csum;
826 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
827 struct scrub_block *sblock_bad;
828 int ret;
829 int mirror_index;
830 int page_num;
831 int success;
558540c1 832 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
b5d67f64
SB		 833 DEFAULT_RATELIMIT_BURST);
834
835 BUG_ON(sblock_to_check->page_count < 1);
a36cf8b8 836 fs_info = sctx->dev_root->fs_info;
4ded4f63
SB		 837 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
838 /*
839 * if we find an error in a super block, we just report it.
840 * They will get written with the next transaction commit
841 * anyway
842 */
843 spin_lock(&sctx->stat_lock);
844 ++sctx->stat.super_errors;
845 spin_unlock(&sctx->stat_lock);
846 return 0;
847 }
b5d67f64 848 length = sblock_to_check->page_count * PAGE_SIZE;
7a9e9987
SB		 849 logical = sblock_to_check->pagev[0]->logical;
850 generation = sblock_to_check->pagev[0]->generation;
851 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
852 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
853 is_metadata = !(sblock_to_check->pagev[0]->flags &
b5d67f64 854 BTRFS_EXTENT_FLAG_DATA);
7a9e9987
SB		 855 have_csum = sblock_to_check->pagev[0]->have_csum;
856 csum = sblock_to_check->pagev[0]->csum;
857 dev = sblock_to_check->pagev[0]->dev;
13db62b7 858
ff023aac
SB		 859 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
860 sblocks_for_recheck = NULL;
861 goto nodatasum_case;
862 }
863
b5d67f64
SB		 864 /*
865 * read all mirrors one after the other. This includes to
866 * re-read the extent or metadata block that failed (that was
867 * the cause that this fixup code is called) another time,
868 * page by page this time in order to know which pages
869 * caused I/O errors and which ones are good (for all mirrors).
870 * It is the goal to handle the situation when more than one
871 * mirror contains I/O errors, but the errors do not
872 * overlap, i.e. the data can be repaired by selecting the
873 * pages from those mirrors without I/O error on the
874 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
875 * would be that mirror #1 has an I/O error on the first page,
876 * the second page is good, and mirror #2 has an I/O error on
877 * the second page, but the first page is good.
878 * Then the first page of the first mirror can be repaired by
879 * taking the first page of the second mirror, and the
880 * second page of the second mirror can be repaired by
881 * copying the contents of the 2nd page of the 1st mirror.
882 * One more note: if the pages of one mirror contain I/O
883 * errors, the checksum cannot be verified. In order to get
884 * the best data for repairing, the first attempt is to find
885 * a mirror without I/O errors and with a validated checksum.
886 * Only if this is not possible, the pages are picked from
887 * mirrors with I/O errors without considering the checksum.
888 * If the latter is the case, at the end, the checksum of the
889 * repaired area is verified in order to correctly maintain
890 * the statistics.
891 */
892
893 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
894 sizeof(*sblocks_for_recheck),
895 GFP_NOFS);
896 if (!sblocks_for_recheck) {
d9d181c1
SB		 897 spin_lock(&sctx->stat_lock);
898 sctx->stat.malloc_errors++;
899 sctx->stat.read_errors++;
900 sctx->stat.uncorrectable_errors++;
901 spin_unlock(&sctx->stat_lock);
a36cf8b8 902 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64 903 goto out;
a2de733c
AJ		 904 }
905
b5d67f64 906 /* setup the context, map the logical blocks and alloc the pages */
ff023aac 907 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
b5d67f64
SB		 908 logical, sblocks_for_recheck);
909 if (ret) {
d9d181c1
SB		 910 spin_lock(&sctx->stat_lock);
911 sctx->stat.read_errors++;
912 sctx->stat.uncorrectable_errors++;
913 spin_unlock(&sctx->stat_lock);
a36cf8b8 914 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64
SB		 915 goto out;
916 }
917 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
918 sblock_bad = sblocks_for_recheck + failed_mirror_index;
13db62b7 919
b5d67f64 920 /* build and submit the bios for the failed mirror, check checksums */
34f5c8e9
SB		 921 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
922 csum, generation, sctx->csum_size);
a2de733c 923
b5d67f64
SB		 924 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
925 sblock_bad->no_io_error_seen) {
926 /*
927 * the error disappeared after reading page by page, or
928 * the area was part of a huge bio and other parts of the
929 * bio caused I/O errors, or the block layer merged several
930 * read requests into one and the error is caused by a
931 * different bio (usually one of the two latter cases is
932 * the cause)
933 */
d9d181c1
SB		 934 spin_lock(&sctx->stat_lock);
935 sctx->stat.unverified_errors++;
936 spin_unlock(&sctx->stat_lock);
a2de733c 937
ff023aac
SB		 938 if (sctx->is_dev_replace)
939 scrub_write_block_to_dev_replace(sblock_bad);
b5d67f64 940 goto out;
a2de733c 941 }
a2de733c 942
b5d67f64 943 if (!sblock_bad->no_io_error_seen) {
d9d181c1
SB		 944 spin_lock(&sctx->stat_lock);
945 sctx->stat.read_errors++;
946 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 947 if (__ratelimit(&_rs))
948 scrub_print_warning("i/o error", sblock_to_check);
a36cf8b8 949 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64 950 } else if (sblock_bad->checksum_error) {
d9d181c1
SB		 951 spin_lock(&sctx->stat_lock);
952 sctx->stat.csum_errors++;
953 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 954 if (__ratelimit(&_rs))
955 scrub_print_warning("checksum error", sblock_to_check);
a36cf8b8 956 btrfs_dev_stat_inc_and_print(dev,
442a4f63 957 BTRFS_DEV_STAT_CORRUPTION_ERRS);
b5d67f64 958 } else if (sblock_bad->header_error) {
d9d181c1
SB		 959 spin_lock(&sctx->stat_lock);
960 sctx->stat.verify_errors++;
961 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 962 if (__ratelimit(&_rs))
963 scrub_print_warning("checksum/header error",
964 sblock_to_check);
442a4f63 965 if (sblock_bad->generation_error)
a36cf8b8 966 btrfs_dev_stat_inc_and_print(dev,
442a4f63
SB		 967 BTRFS_DEV_STAT_GENERATION_ERRS);
968 else
a36cf8b8 969 btrfs_dev_stat_inc_and_print(dev,
442a4f63 970 BTRFS_DEV_STAT_CORRUPTION_ERRS);
b5d67f64 971 }
a2de733c 972
33ef30ad
ID		 973 if (sctx->readonly) {
974 ASSERT(!sctx->is_dev_replace);
975 goto out;
976 }
a2de733c 977
b5d67f64
SB		 978 if (!is_metadata && !have_csum) {
979 struct scrub_fixup_nodatasum *fixup_nodatasum;
a2de733c 980
ff023aac
SB		 981nodatasum_case:
982 WARN_ON(sctx->is_dev_replace);
983
b5d67f64
SB		 984 /*
985 * !is_metadata and !have_csum, this means that the data
986 * might not be COW'ed, that it might be modified
987 * concurrently. The general strategy to work on the
988 * commit root does not help in the case when COW is not
989 * used.
990 */
991 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
992 if (!fixup_nodatasum)
993 goto did_not_correct_error;
d9d181c1 994 fixup_nodatasum->sctx = sctx;
a36cf8b8 995 fixup_nodatasum->dev = dev;
b5d67f64
SB		 996 fixup_nodatasum->logical = logical;
997 fixup_nodatasum->root = fs_info->extent_root;
998 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
b6bfebc1 999 scrub_pending_trans_workers_inc(sctx);
b5d67f64
SB		 1000 fixup_nodatasum->work.func = scrub_fixup_nodatasum;
1001 btrfs_queue_worker(&fs_info->scrub_workers,
1002 &fixup_nodatasum->work);
1003 goto out;
a2de733c
AJ		 1004 }
1005
b5d67f64
SB		 1006 /*
1007 * now build and submit the bios for the other mirrors, check
cb2ced73
SB		 1008 * checksums.
1009 * First try to pick the mirror which is completely without I/O
b5d67f64
SB		 1010 * errors and also does not have a checksum error.
1011 * If one is found, and if a checksum is present, the full block
1012 * that is known to contain an error is rewritten. Afterwards
1013 * the block is known to be corrected.
1014 * If a mirror is found which is completely correct, and no
1015 * checksum is present, only those pages are rewritten that had
1016 * an I/O error in the block to be repaired, since it cannot be
1017 * determined, which copy of the other pages is better (and it
1018 * could happen otherwise that a correct page would be
1019 * overwritten by a bad one).
1020 */
1021 for (mirror_index = 0;
1022 mirror_index < BTRFS_MAX_MIRRORS &&
1023 sblocks_for_recheck[mirror_index].page_count > 0;
1024 mirror_index++) {
cb2ced73 1025 struct scrub_block *sblock_other;
b5d67f64 1026
cb2ced73
SB		 1027 if (mirror_index == failed_mirror_index)
1028 continue;
1029 sblock_other = sblocks_for_recheck + mirror_index;
1030
1031 /* build and submit the bios, check checksums */
34f5c8e9
SB		 1032 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1033 have_csum, csum, generation,
1034 sctx->csum_size);
1035
1036 if (!sblock_other->header_error &&
b5d67f64
SB		 1037 !sblock_other->checksum_error &&
1038 sblock_other->no_io_error_seen) {
ff023aac
SB		 1039 if (sctx->is_dev_replace) {
1040 scrub_write_block_to_dev_replace(sblock_other);
1041 } else {
1042 int force_write = is_metadata || have_csum;
1043
1044 ret = scrub_repair_block_from_good_copy(
1045 sblock_bad, sblock_other,
1046 force_write);
1047 }
b5d67f64
SB		 1048 if (0 == ret)
1049 goto corrected_error;
1050 }
1051 }
a2de733c
AJ		 1052
1053 /*
ff023aac
SB		 1054 * for dev_replace, pick good pages and write to the target device.
1055 */
1056 if (sctx->is_dev_replace) {
1057 success = 1;
1058 for (page_num = 0; page_num < sblock_bad->page_count;
1059 page_num++) {
1060 int sub_success;
1061
1062 sub_success = 0;
1063 for (mirror_index = 0;
1064 mirror_index < BTRFS_MAX_MIRRORS &&
1065 sblocks_for_recheck[mirror_index].page_count > 0;
1066 mirror_index++) {
1067 struct scrub_block *sblock_other =
1068 sblocks_for_recheck + mirror_index;
1069 struct scrub_page *page_other =
1070 sblock_other->pagev[page_num];
1071
1072 if (!page_other->io_error) {
1073 ret = scrub_write_page_to_dev_replace(
1074 sblock_other, page_num);
1075 if (ret == 0) {
1076 /* succeeded for this page */
1077 sub_success = 1;
1078 break;
1079 } else {
1080 btrfs_dev_replace_stats_inc(
1081 &sctx->dev_root->
1082 fs_info->dev_replace.
1083 num_write_errors);
1084 }
1085 }
1086 }
1087
1088 if (!sub_success) {
1089 /*
1090 * did not find a mirror to fetch the page
1091 * from. scrub_write_page_to_dev_replace()
1092 * handles this case (page->io_error), by
1093 * filling the block with zeros before
1094 * submitting the write request
1095 */
1096 success = 0;
1097 ret = scrub_write_page_to_dev_replace(
1098 sblock_bad, page_num);
1099 if (ret)
1100 btrfs_dev_replace_stats_inc(
1101 &sctx->dev_root->fs_info->
1102 dev_replace.num_write_errors);
1103 }
1104 }
1105
1106 goto out;
1107 }
1108
1109 /*
1110 * for regular scrub, repair those pages that are errored.
1111 * In case of I/O errors in the area that is supposed to be
b5d67f64
SB		 1112 * repaired, continue by picking good copies of those pages.
1113 * Select the good pages from mirrors to rewrite bad pages from
1114 * the area to fix. Afterwards verify the checksum of the block
1115 * that is supposed to be repaired. This verification step is
1116 * only done for the purpose of statistic counting and for the
1117 * final scrub report, whether errors remain.
1118 * A perfect algorithm could make use of the checksum and try
1119 * all possible combinations of pages from the different mirrors
1120 * until the checksum verification succeeds. For example, when
1121 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1122 * of mirror #2 is readable but the final checksum test fails,
1123 * then the 2nd page of mirror #3 could be tried, whether now
1124 * the final checksum succeedes. But this would be a rare
1125 * exception and is therefore not implemented. At least it is
1126 * avoided that the good copy is overwritten.
1127 * A more useful improvement would be to pick the sectors
1128 * without I/O error based on sector sizes (512 bytes on legacy
1129 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1130 * mirror could be repaired by taking 512 byte of a different
1131 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1132 * area are unreadable.
a2de733c 1133 */
a2de733c 1134
b5d67f64
SB		 1135 /* can only fix I/O errors from here on */
1136 if (sblock_bad->no_io_error_seen)
1137 goto did_not_correct_error;
1138
1139 success = 1;
1140 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
7a9e9987 1141 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
b5d67f64
SB		 1142
1143 if (!page_bad->io_error)
a2de733c 1144 continue;
b5d67f64
SB		 1145
1146 for (mirror_index = 0;
1147 mirror_index < BTRFS_MAX_MIRRORS &&
1148 sblocks_for_recheck[mirror_index].page_count > 0;
1149 mirror_index++) {
1150 struct scrub_block *sblock_other = sblocks_for_recheck +
1151 mirror_index;
7a9e9987
SB		 1152 struct scrub_page *page_other = sblock_other->pagev[
1153 page_num];
b5d67f64
SB		 1154
1155 if (!page_other->io_error) {
1156 ret = scrub_repair_page_from_good_copy(
1157 sblock_bad, sblock_other, page_num, 0);
1158 if (0 == ret) {
1159 page_bad->io_error = 0;
1160 break; /* succeeded for this page */
1161 }
1162 }
96e36920 1163 }
a2de733c 1164
b5d67f64
SB		 1165 if (page_bad->io_error) {
1166 /* did not find a mirror to copy the page from */
1167 success = 0;
1168 }
a2de733c 1169 }
a2de733c 1170
b5d67f64
SB		 1171 if (success) {
1172 if (is_metadata || have_csum) {
1173 /*
1174 * need to verify the checksum now that all
1175 * sectors on disk are repaired (the write
1176 * request for data to be repaired is on its way).
1177 * Just be lazy and use scrub_recheck_block()
1178 * which re-reads the data before the checksum
1179 * is verified, but most likely the data comes out
1180 * of the page cache.
1181 */
34f5c8e9
SB		 1182 scrub_recheck_block(fs_info, sblock_bad,
1183 is_metadata, have_csum, csum,
1184 generation, sctx->csum_size);
1185 if (!sblock_bad->header_error &&
b5d67f64
SB		 1186 !sblock_bad->checksum_error &&
1187 sblock_bad->no_io_error_seen)
1188 goto corrected_error;
1189 else
1190 goto did_not_correct_error;
1191 } else {
1192corrected_error:
d9d181c1
SB		 1193 spin_lock(&sctx->stat_lock);
1194 sctx->stat.corrected_errors++;
1195 spin_unlock(&sctx->stat_lock);
606686ee 1196 printk_ratelimited_in_rcu(KERN_ERR
efe120a0 1197 "BTRFS: fixed up error at logical %llu on dev %s\n",
c1c9ff7c 1198 logical, rcu_str_deref(dev->name));
8628764e 1199 }
b5d67f64
SB		 1200 } else {
1201did_not_correct_error:
d9d181c1
SB		 1202 spin_lock(&sctx->stat_lock);
1203 sctx->stat.uncorrectable_errors++;
1204 spin_unlock(&sctx->stat_lock);
606686ee 1205 printk_ratelimited_in_rcu(KERN_ERR
efe120a0 1206 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
c1c9ff7c 1207 logical, rcu_str_deref(dev->name));
96e36920 1208 }
a2de733c 1209
b5d67f64
SB		 1210out:
1211 if (sblocks_for_recheck) {
1212 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1213 mirror_index++) {
1214 struct scrub_block *sblock = sblocks_for_recheck +
1215 mirror_index;
1216 int page_index;
1217
7a9e9987
SB		 1218 for (page_index = 0; page_index < sblock->page_count;
1219 page_index++) {
1220 sblock->pagev[page_index]->sblock = NULL;
1221 scrub_page_put(sblock->pagev[page_index]);
1222 }
b5d67f64
SB		 1223 }
1224 kfree(sblocks_for_recheck);
1225 }
a2de733c 1226
b5d67f64
SB		 1227 return 0;
1228}
a2de733c 1229
d9d181c1 1230static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
3ec706c8 1231 struct btrfs_fs_info *fs_info,
ff023aac 1232 struct scrub_block *original_sblock,
b5d67f64
SB		 1233 u64 length, u64 logical,
1234 struct scrub_block *sblocks_for_recheck)
1235{
1236 int page_index;
1237 int mirror_index;
1238 int ret;
1239
1240 /*
7a9e9987 1241 * note: the two members ref_count and outstanding_pages
b5d67f64
SB		 1242 * are not used (and not set) in the blocks that are used for
1243 * the recheck procedure
1244 */
1245
1246 page_index = 0;
1247 while (length > 0) {
1248 u64 sublen = min_t(u64, length, PAGE_SIZE);
1249 u64 mapped_length = sublen;
1250 struct btrfs_bio *bbio = NULL;
a2de733c 1251
b5d67f64
SB		 1252 /*
1253 * with a length of PAGE_SIZE, each returned stripe
1254 * represents one mirror
1255 */
29a8d9a0
SB		 1256 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
1257 &mapped_length, &bbio, 0);
b5d67f64
SB		 1258 if (ret || !bbio || mapped_length < sublen) {
1259 kfree(bbio);
1260 return -EIO;
1261 }
a2de733c 1262
ff023aac 1263 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
b5d67f64
SB		 1264 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1265 mirror_index++) {
1266 struct scrub_block *sblock;
1267 struct scrub_page *page;
1268
1269 if (mirror_index >= BTRFS_MAX_MIRRORS)
1270 continue;
1271
1272 sblock = sblocks_for_recheck + mirror_index;
7a9e9987
SB		 1273 sblock->sctx = sctx;
1274 page = kzalloc(sizeof(*page), GFP_NOFS);
1275 if (!page) {
1276leave_nomem:
d9d181c1
SB		 1277 spin_lock(&sctx->stat_lock);
1278 sctx->stat.malloc_errors++;
1279 spin_unlock(&sctx->stat_lock);
cf93dcce 1280 kfree(bbio);
b5d67f64
SB		 1281 return -ENOMEM;
1282 }
7a9e9987
SB		 1283 scrub_page_get(page);
1284 sblock->pagev[page_index] = page;
1285 page->logical = logical;
1286 page->physical = bbio->stripes[mirror_index].physical;
ff023aac
SB		 1287 BUG_ON(page_index >= original_sblock->page_count);
1288 page->physical_for_dev_replace =
1289 original_sblock->pagev[page_index]->
1290 physical_for_dev_replace;
7a9e9987
SB		 1291 /* for missing devices, dev->bdev is NULL */
1292 page->dev = bbio->stripes[mirror_index].dev;
1293 page->mirror_num = mirror_index + 1;
b5d67f64 1294 sblock->page_count++;
7a9e9987
SB		 1295 page->page = alloc_page(GFP_NOFS);
1296 if (!page->page)
1297 goto leave_nomem;
b5d67f64
SB		 1298 }
1299 kfree(bbio);
1300 length -= sublen;
1301 logical += sublen;
1302 page_index++;
1303 }
1304
1305 return 0;
96e36920
ID		 1306}
1307
b5d67f64
SB		 1308/*
1309 * this function will check the on disk data for checksum errors, header
1310 * errors and read I/O errors. If any I/O errors happen, the exact pages
1311 * which are errored are marked as being bad. The goal is to enable scrub
1312 * to take those pages that are not errored from all the mirrors so that
1313 * the pages that are errored in the just handled mirror can be repaired.
1314 */
34f5c8e9
SB		 1315static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1316 struct scrub_block *sblock, int is_metadata,
1317 int have_csum, u8 *csum, u64 generation,
1318 u16 csum_size)
96e36920 1319{
b5d67f64 1320 int page_num;
96e36920 1321
b5d67f64
SB		 1322 sblock->no_io_error_seen = 1;
1323 sblock->header_error = 0;
1324 sblock->checksum_error = 0;
96e36920 1325
b5d67f64
SB		 1326 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1327 struct bio *bio;
7a9e9987 1328 struct scrub_page *page = sblock->pagev[page_num];
b5d67f64 1329
442a4f63 1330 if (page->dev->bdev == NULL) {
ea9947b4
SB		 1331 page->io_error = 1;
1332 sblock->no_io_error_seen = 0;
1333 continue;
1334 }
1335
7a9e9987 1336 WARN_ON(!page->page);
9be3395b 1337 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
34f5c8e9
SB		 1338 if (!bio) {
1339 page->io_error = 1;
1340 sblock->no_io_error_seen = 0;
1341 continue;
1342 }
442a4f63 1343 bio->bi_bdev = page->dev->bdev;
b5d67f64 1344 bio->bi_sector = page->physical >> 9;
b5d67f64 1345
34f5c8e9 1346 bio_add_page(bio, page->page, PAGE_SIZE, 0);
c170bbb4 1347 if (btrfsic_submit_bio_wait(READ, bio))
b5d67f64 1348 sblock->no_io_error_seen = 0;
c170bbb4 1349
b5d67f64
SB		 1350 bio_put(bio);
1351 }
96e36920 1352
b5d67f64
SB		 1353 if (sblock->no_io_error_seen)
1354 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1355 have_csum, csum, generation,
1356 csum_size);
1357
34f5c8e9 1358 return;
a2de733c
AJ		 1359}
1360
b5d67f64
SB		 1361static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1362 struct scrub_block *sblock,
1363 int is_metadata, int have_csum,
1364 const u8 *csum, u64 generation,
1365 u16 csum_size)
a2de733c 1366{
b5d67f64
SB		 1367 int page_num;
1368 u8 calculated_csum[BTRFS_CSUM_SIZE];
1369 u32 crc = ~(u32)0;
b5d67f64
SB		 1370 void *mapped_buffer;
1371
7a9e9987 1372 WARN_ON(!sblock->pagev[0]->page);
b5d67f64
SB		 1373 if (is_metadata) {
1374 struct btrfs_header *h;
1375
7a9e9987 1376 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
b5d67f64
SB		 1377 h = (struct btrfs_header *)mapped_buffer;
1378
3cae210f 1379 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
b5d67f64
SB		 1380 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1381 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
442a4f63 1382 BTRFS_UUID_SIZE)) {
b5d67f64 1383 sblock->header_error = 1;
3cae210f 1384 } else if (generation != btrfs_stack_header_generation(h)) {
442a4f63
SB		 1385 sblock->header_error = 1;
1386 sblock->generation_error = 1;
1387 }
b5d67f64
SB		 1388 csum = h->csum;
1389 } else {
1390 if (!have_csum)
1391 return;
a2de733c 1392
7a9e9987 1393 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
b5d67f64 1394 }
a2de733c 1395
b5d67f64
SB		 1396 for (page_num = 0;;) {
1397 if (page_num == 0 && is_metadata)
b0496686 1398 crc = btrfs_csum_data(
b5d67f64
SB		 1399 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1400 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1401 else
b0496686 1402 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
b5d67f64 1403
9613bebb 1404 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1405 page_num++;
1406 if (page_num >= sblock->page_count)
1407 break;
7a9e9987 1408 WARN_ON(!sblock->pagev[page_num]->page);
b5d67f64 1409
7a9e9987 1410 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
b5d67f64
SB		 1411 }
1412
1413 btrfs_csum_final(crc, calculated_csum);
1414 if (memcmp(calculated_csum, csum, csum_size))
1415 sblock->checksum_error = 1;
a2de733c
AJ		 1416}
1417
b5d67f64
SB		 1418static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1419 struct scrub_block *sblock_good,
1420 int force_write)
1421{
1422 int page_num;
1423 int ret = 0;
96e36920 1424
b5d67f64
SB		 1425 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1426 int ret_sub;
96e36920 1427
b5d67f64
SB		 1428 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1429 sblock_good,
1430 page_num,
1431 force_write);
1432 if (ret_sub)
1433 ret = ret_sub;
a2de733c 1434 }
b5d67f64
SB		 1435
1436 return ret;
1437}
1438
1439static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1440 struct scrub_block *sblock_good,
1441 int page_num, int force_write)
1442{
7a9e9987
SB		 1443 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1444 struct scrub_page *page_good = sblock_good->pagev[page_num];
b5d67f64 1445
7a9e9987
SB		 1446 BUG_ON(page_bad->page == NULL);
1447 BUG_ON(page_good->page == NULL);
b5d67f64
SB		 1448 if (force_write || sblock_bad->header_error ||
1449 sblock_bad->checksum_error || page_bad->io_error) {
1450 struct bio *bio;
1451 int ret;
b5d67f64 1452
ff023aac 1453 if (!page_bad->dev->bdev) {
efe120a0
FH		 1454 printk_ratelimited(KERN_WARNING "BTRFS: "
1455 "scrub_repair_page_from_good_copy(bdev == NULL) "
1456 "is unexpected!\n");
ff023aac
SB		 1457 return -EIO;
1458 }
1459
9be3395b 1460 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
e627ee7b
TI		 1461 if (!bio)
1462 return -EIO;
442a4f63 1463 bio->bi_bdev = page_bad->dev->bdev;
b5d67f64 1464 bio->bi_sector = page_bad->physical >> 9;
b5d67f64
SB		 1465
1466 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1467 if (PAGE_SIZE != ret) {
1468 bio_put(bio);
1469 return -EIO;
13db62b7 1470 }
b5d67f64 1471
c170bbb4 1472 if (btrfsic_submit_bio_wait(WRITE, bio)) {
442a4f63
SB		 1473 btrfs_dev_stat_inc_and_print(page_bad->dev,
1474 BTRFS_DEV_STAT_WRITE_ERRS);
ff023aac
SB		 1475 btrfs_dev_replace_stats_inc(
1476 &sblock_bad->sctx->dev_root->fs_info->
1477 dev_replace.num_write_errors);
442a4f63
SB		 1478 bio_put(bio);
1479 return -EIO;
1480 }
b5d67f64 1481 bio_put(bio);
a2de733c
AJ		 1482 }
1483
b5d67f64
SB		 1484 return 0;
1485}
1486
ff023aac
SB		 1487static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1488{
1489 int page_num;
1490
1491 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1492 int ret;
1493
1494 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1495 if (ret)
1496 btrfs_dev_replace_stats_inc(
1497 &sblock->sctx->dev_root->fs_info->dev_replace.
1498 num_write_errors);
1499 }
1500}
1501
1502static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1503 int page_num)
1504{
1505 struct scrub_page *spage = sblock->pagev[page_num];
1506
1507 BUG_ON(spage->page == NULL);
1508 if (spage->io_error) {
1509 void *mapped_buffer = kmap_atomic(spage->page);
1510
1511 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1512 flush_dcache_page(spage->page);
1513 kunmap_atomic(mapped_buffer);
1514 }
1515 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1516}
1517
1518static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1519 struct scrub_page *spage)
1520{
1521 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1522 struct scrub_bio *sbio;
1523 int ret;
1524
1525 mutex_lock(&wr_ctx->wr_lock);
1526again:
1527 if (!wr_ctx->wr_curr_bio) {
1528 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1529 GFP_NOFS);
1530 if (!wr_ctx->wr_curr_bio) {
1531 mutex_unlock(&wr_ctx->wr_lock);
1532 return -ENOMEM;
1533 }
1534 wr_ctx->wr_curr_bio->sctx = sctx;
1535 wr_ctx->wr_curr_bio->page_count = 0;
1536 }
1537 sbio = wr_ctx->wr_curr_bio;
1538 if (sbio->page_count == 0) {
1539 struct bio *bio;
1540
1541 sbio->physical = spage->physical_for_dev_replace;
1542 sbio->logical = spage->logical;
1543 sbio->dev = wr_ctx->tgtdev;
1544 bio = sbio->bio;
1545 if (!bio) {
9be3395b 1546 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
ff023aac
SB		 1547 if (!bio) {
1548 mutex_unlock(&wr_ctx->wr_lock);
1549 return -ENOMEM;
1550 }
1551 sbio->bio = bio;
1552 }
1553
1554 bio->bi_private = sbio;
1555 bio->bi_end_io = scrub_wr_bio_end_io;
1556 bio->bi_bdev = sbio->dev->bdev;
1557 bio->bi_sector = sbio->physical >> 9;
1558 sbio->err = 0;
1559 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1560 spage->physical_for_dev_replace ||
1561 sbio->logical + sbio->page_count * PAGE_SIZE !=
1562 spage->logical) {
1563 scrub_wr_submit(sctx);
1564 goto again;
1565 }
1566
1567 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1568 if (ret != PAGE_SIZE) {
1569 if (sbio->page_count < 1) {
1570 bio_put(sbio->bio);
1571 sbio->bio = NULL;
1572 mutex_unlock(&wr_ctx->wr_lock);
1573 return -EIO;
1574 }
1575 scrub_wr_submit(sctx);
1576 goto again;
1577 }
1578
1579 sbio->pagev[sbio->page_count] = spage;
1580 scrub_page_get(spage);
1581 sbio->page_count++;
1582 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1583 scrub_wr_submit(sctx);
1584 mutex_unlock(&wr_ctx->wr_lock);
1585
1586 return 0;
1587}
1588
1589static void scrub_wr_submit(struct scrub_ctx *sctx)
1590{
1591 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1592 struct scrub_bio *sbio;
1593
1594 if (!wr_ctx->wr_curr_bio)
1595 return;
1596
1597 sbio = wr_ctx->wr_curr_bio;
1598 wr_ctx->wr_curr_bio = NULL;
1599 WARN_ON(!sbio->bio->bi_bdev);
1600 scrub_pending_bio_inc(sctx);
1601 /* process all writes in a single worker thread. Then the block layer
1602 * orders the requests before sending them to the driver which
1603 * doubled the write performance on spinning disks when measured
1604 * with Linux 3.5 */
1605 btrfsic_submit_bio(WRITE, sbio->bio);
1606}
1607
1608static void scrub_wr_bio_end_io(struct bio *bio, int err)
1609{
1610 struct scrub_bio *sbio = bio->bi_private;
1611 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1612
1613 sbio->err = err;
1614 sbio->bio = bio;
1615
1616 sbio->work.func = scrub_wr_bio_end_io_worker;
1617 btrfs_queue_worker(&fs_info->scrub_wr_completion_workers, &sbio->work);
1618}
1619
1620static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1621{
1622 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1623 struct scrub_ctx *sctx = sbio->sctx;
1624 int i;
1625
1626 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1627 if (sbio->err) {
1628 struct btrfs_dev_replace *dev_replace =
1629 &sbio->sctx->dev_root->fs_info->dev_replace;
1630
1631 for (i = 0; i < sbio->page_count; i++) {
1632 struct scrub_page *spage = sbio->pagev[i];
1633
1634 spage->io_error = 1;
1635 btrfs_dev_replace_stats_inc(&dev_replace->
1636 num_write_errors);
1637 }
1638 }
1639
1640 for (i = 0; i < sbio->page_count; i++)
1641 scrub_page_put(sbio->pagev[i]);
1642
1643 bio_put(sbio->bio);
1644 kfree(sbio);
1645 scrub_pending_bio_dec(sctx);
1646}
1647
1648static int scrub_checksum(struct scrub_block *sblock)
b5d67f64
SB		 1649{
1650 u64 flags;
1651 int ret;
1652
7a9e9987
SB		 1653 WARN_ON(sblock->page_count < 1);
1654 flags = sblock->pagev[0]->flags;
b5d67f64
SB		 1655 ret = 0;
1656 if (flags & BTRFS_EXTENT_FLAG_DATA)
1657 ret = scrub_checksum_data(sblock);
1658 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1659 ret = scrub_checksum_tree_block(sblock);
1660 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1661 (void)scrub_checksum_super(sblock);
1662 else
1663 WARN_ON(1);
1664 if (ret)
1665 scrub_handle_errored_block(sblock);
ff023aac
SB		 1666
1667 return ret;
a2de733c
AJ		 1668}
1669
b5d67f64 1670static int scrub_checksum_data(struct scrub_block *sblock)
a2de733c 1671{
d9d181c1 1672 struct scrub_ctx *sctx = sblock->sctx;
a2de733c 1673 u8 csum[BTRFS_CSUM_SIZE];
b5d67f64
SB		 1674 u8 *on_disk_csum;
1675 struct page *page;
1676 void *buffer;
a2de733c
AJ		 1677 u32 crc = ~(u32)0;
1678 int fail = 0;
b5d67f64
SB		 1679 u64 len;
1680 int index;
a2de733c 1681
b5d67f64 1682 BUG_ON(sblock->page_count < 1);
7a9e9987 1683 if (!sblock->pagev[0]->have_csum)
a2de733c
AJ		 1684 return 0;
1685
7a9e9987
SB		 1686 on_disk_csum = sblock->pagev[0]->csum;
1687 page = sblock->pagev[0]->page;
9613bebb 1688 buffer = kmap_atomic(page);
b5d67f64 1689
d9d181c1 1690 len = sctx->sectorsize;
b5d67f64
SB		 1691 index = 0;
1692 for (;;) {
1693 u64 l = min_t(u64, len, PAGE_SIZE);
1694
b0496686 1695 crc = btrfs_csum_data(buffer, crc, l);
9613bebb 1696 kunmap_atomic(buffer);
b5d67f64
SB		 1697 len -= l;
1698 if (len == 0)
1699 break;
1700 index++;
1701 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1702 BUG_ON(!sblock->pagev[index]->page);
1703 page = sblock->pagev[index]->page;
9613bebb 1704 buffer = kmap_atomic(page);
b5d67f64
SB		 1705 }
1706
a2de733c 1707 btrfs_csum_final(crc, csum);
d9d181c1 1708 if (memcmp(csum, on_disk_csum, sctx->csum_size))
a2de733c
AJ		 1709 fail = 1;
1710
a2de733c
AJ		 1711 return fail;
1712}
1713
b5d67f64 1714static int scrub_checksum_tree_block(struct scrub_block *sblock)
a2de733c 1715{
d9d181c1 1716 struct scrub_ctx *sctx = sblock->sctx;
a2de733c 1717 struct btrfs_header *h;
a36cf8b8 1718 struct btrfs_root *root = sctx->dev_root;
a2de733c 1719 struct btrfs_fs_info *fs_info = root->fs_info;
b5d67f64
SB		 1720 u8 calculated_csum[BTRFS_CSUM_SIZE];
1721 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1722 struct page *page;
1723 void *mapped_buffer;
1724 u64 mapped_size;
1725 void *p;
a2de733c
AJ		 1726 u32 crc = ~(u32)0;
1727 int fail = 0;
1728 int crc_fail = 0;
b5d67f64
SB		 1729 u64 len;
1730 int index;
1731
1732 BUG_ON(sblock->page_count < 1);
7a9e9987 1733 page = sblock->pagev[0]->page;
9613bebb 1734 mapped_buffer = kmap_atomic(page);
b5d67f64 1735 h = (struct btrfs_header *)mapped_buffer;
d9d181c1 1736 memcpy(on_disk_csum, h->csum, sctx->csum_size);
a2de733c
AJ		 1737
1738 /*
1739 * we don't use the getter functions here, as we
1740 * a) don't have an extent buffer and
1741 * b) the page is already kmapped
1742 */
a2de733c 1743
3cae210f 1744 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
a2de733c
AJ		 1745 ++fail;
1746
3cae210f 1747 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
a2de733c
AJ		 1748 ++fail;
1749
1750 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1751 ++fail;
1752
1753 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1754 BTRFS_UUID_SIZE))
1755 ++fail;
1756
ff023aac 1757 WARN_ON(sctx->nodesize != sctx->leafsize);
d9d181c1 1758 len = sctx->nodesize - BTRFS_CSUM_SIZE;
b5d67f64
SB		 1759 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1760 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1761 index = 0;
1762 for (;;) {
1763 u64 l = min_t(u64, len, mapped_size);
1764
b0496686 1765 crc = btrfs_csum_data(p, crc, l);
9613bebb 1766 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1767 len -= l;
1768 if (len == 0)
1769 break;
1770 index++;
1771 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1772 BUG_ON(!sblock->pagev[index]->page);
1773 page = sblock->pagev[index]->page;
9613bebb 1774 mapped_buffer = kmap_atomic(page);
b5d67f64
SB		 1775 mapped_size = PAGE_SIZE;
1776 p = mapped_buffer;
1777 }
1778
1779 btrfs_csum_final(crc, calculated_csum);
d9d181c1 1780 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
a2de733c
AJ		 1781 ++crc_fail;
1782
a2de733c
AJ		 1783 return fail || crc_fail;
1784}
1785
b5d67f64 1786static int scrub_checksum_super(struct scrub_block *sblock)
a2de733c
AJ		 1787{
1788 struct btrfs_super_block *s;
d9d181c1 1789 struct scrub_ctx *sctx = sblock->sctx;
a36cf8b8 1790 struct btrfs_root *root = sctx->dev_root;
a2de733c 1791 struct btrfs_fs_info *fs_info = root->fs_info;
b5d67f64
SB		 1792 u8 calculated_csum[BTRFS_CSUM_SIZE];
1793 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1794 struct page *page;
1795 void *mapped_buffer;
1796 u64 mapped_size;
1797 void *p;
a2de733c 1798 u32 crc = ~(u32)0;
442a4f63
SB		 1799 int fail_gen = 0;
1800 int fail_cor = 0;
b5d67f64
SB		 1801 u64 len;
1802 int index;
a2de733c 1803
b5d67f64 1804 BUG_ON(sblock->page_count < 1);
7a9e9987 1805 page = sblock->pagev[0]->page;
9613bebb 1806 mapped_buffer = kmap_atomic(page);
b5d67f64 1807 s = (struct btrfs_super_block *)mapped_buffer;
d9d181c1 1808 memcpy(on_disk_csum, s->csum, sctx->csum_size);
a2de733c 1809
3cae210f 1810 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
442a4f63 1811 ++fail_cor;
a2de733c 1812
3cae210f 1813 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
442a4f63 1814 ++fail_gen;
a2de733c
AJ		 1815
1816 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
442a4f63 1817 ++fail_cor;
a2de733c 1818
b5d67f64
SB		 1819 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1820 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1821 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1822 index = 0;
1823 for (;;) {
1824 u64 l = min_t(u64, len, mapped_size);
1825
b0496686 1826 crc = btrfs_csum_data(p, crc, l);
9613bebb 1827 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1828 len -= l;
1829 if (len == 0)
1830 break;
1831 index++;
1832 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1833 BUG_ON(!sblock->pagev[index]->page);
1834 page = sblock->pagev[index]->page;
9613bebb 1835 mapped_buffer = kmap_atomic(page);
b5d67f64
SB		 1836 mapped_size = PAGE_SIZE;
1837 p = mapped_buffer;
1838 }
1839
1840 btrfs_csum_final(crc, calculated_csum);
d9d181c1 1841 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
442a4f63 1842 ++fail_cor;
a2de733c 1843
442a4f63 1844 if (fail_cor + fail_gen) {
a2de733c
AJ		 1845 /*
1846 * if we find an error in a super block, we just report it.
1847 * They will get written with the next transaction commit
1848 * anyway
1849 */
d9d181c1
SB		 1850 spin_lock(&sctx->stat_lock);
1851 ++sctx->stat.super_errors;
1852 spin_unlock(&sctx->stat_lock);
442a4f63 1853 if (fail_cor)
7a9e9987 1854 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
442a4f63
SB		 1855 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1856 else
7a9e9987 1857 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
442a4f63 1858 BTRFS_DEV_STAT_GENERATION_ERRS);
a2de733c
AJ		 1859 }
1860
442a4f63 1861 return fail_cor + fail_gen;
a2de733c
AJ		 1862}
1863
b5d67f64
SB		 1864static void scrub_block_get(struct scrub_block *sblock)
1865{
1866 atomic_inc(&sblock->ref_count);
1867}
1868
1869static void scrub_block_put(struct scrub_block *sblock)
1870{
1871 if (atomic_dec_and_test(&sblock->ref_count)) {
1872 int i;
1873
1874 for (i = 0; i < sblock->page_count; i++)
7a9e9987 1875 scrub_page_put(sblock->pagev[i]);
b5d67f64
SB		 1876 kfree(sblock);
1877 }
1878}
1879
7a9e9987
SB		 1880static void scrub_page_get(struct scrub_page *spage)
1881{
1882 atomic_inc(&spage->ref_count);
1883}
1884
1885static void scrub_page_put(struct scrub_page *spage)
1886{
1887 if (atomic_dec_and_test(&spage->ref_count)) {
1888 if (spage->page)
1889 __free_page(spage->page);
1890 kfree(spage);
1891 }
1892}
1893
d9d181c1 1894static void scrub_submit(struct scrub_ctx *sctx)
a2de733c
AJ		 1895{
1896 struct scrub_bio *sbio;
1897
d9d181c1 1898 if (sctx->curr == -1)
1623edeb 1899 return;
a2de733c 1900
d9d181c1
SB		 1901 sbio = sctx->bios[sctx->curr];
1902 sctx->curr = -1;
b6bfebc1 1903 scrub_pending_bio_inc(sctx);
a2de733c 1904
ff023aac
SB		 1905 if (!sbio->bio->bi_bdev) {
1906 /*
1907 * this case should not happen. If btrfs_map_block() is
1908 * wrong, it could happen for dev-replace operations on
1909 * missing devices when no mirrors are available, but in
1910 * this case it should already fail the mount.
1911 * This case is handled correctly (but _very_ slowly).
1912 */
1913 printk_ratelimited(KERN_WARNING
efe120a0 1914 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
ff023aac
SB		 1915 bio_endio(sbio->bio, -EIO);
1916 } else {
1917 btrfsic_submit_bio(READ, sbio->bio);
1918 }
a2de733c
AJ		 1919}
1920
ff023aac
SB		 1921static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
1922 struct scrub_page *spage)
a2de733c 1923{
b5d67f64 1924 struct scrub_block *sblock = spage->sblock;
a2de733c 1925 struct scrub_bio *sbio;
69f4cb52 1926 int ret;
a2de733c
AJ		 1927
1928again:
1929 /*
1930 * grab a fresh bio or wait for one to become available
1931 */
d9d181c1
SB		 1932 while (sctx->curr == -1) {
1933 spin_lock(&sctx->list_lock);
1934 sctx->curr = sctx->first_free;
1935 if (sctx->curr != -1) {
1936 sctx->first_free = sctx->bios[sctx->curr]->next_free;
1937 sctx->bios[sctx->curr]->next_free = -1;
1938 sctx->bios[sctx->curr]->page_count = 0;
1939 spin_unlock(&sctx->list_lock);
a2de733c 1940 } else {
d9d181c1
SB		 1941 spin_unlock(&sctx->list_lock);
1942 wait_event(sctx->list_wait, sctx->first_free != -1);
a2de733c
AJ		 1943 }
1944 }
d9d181c1 1945 sbio = sctx->bios[sctx->curr];
b5d67f64 1946 if (sbio->page_count == 0) {
69f4cb52
AJ		 1947 struct bio *bio;
1948
b5d67f64
SB		 1949 sbio->physical = spage->physical;
1950 sbio->logical = spage->logical;
a36cf8b8 1951 sbio->dev = spage->dev;
b5d67f64
SB		 1952 bio = sbio->bio;
1953 if (!bio) {
9be3395b 1954 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
b5d67f64
SB		 1955 if (!bio)
1956 return -ENOMEM;
1957 sbio->bio = bio;
1958 }
69f4cb52
AJ		 1959
1960 bio->bi_private = sbio;
1961 bio->bi_end_io = scrub_bio_end_io;
a36cf8b8
SB		 1962 bio->bi_bdev = sbio->dev->bdev;
1963 bio->bi_sector = sbio->physical >> 9;
69f4cb52 1964 sbio->err = 0;
b5d67f64
SB		 1965 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1966 spage->physical ||
1967 sbio->logical + sbio->page_count * PAGE_SIZE !=
a36cf8b8
SB		 1968 spage->logical ||
1969 sbio->dev != spage->dev) {
d9d181c1 1970 scrub_submit(sctx);
a2de733c
AJ		 1971 goto again;
1972 }
69f4cb52 1973
b5d67f64
SB		 1974 sbio->pagev[sbio->page_count] = spage;
1975 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1976 if (ret != PAGE_SIZE) {
1977 if (sbio->page_count < 1) {
1978 bio_put(sbio->bio);
1979 sbio->bio = NULL;
1980 return -EIO;
1981 }
d9d181c1 1982 scrub_submit(sctx);
69f4cb52
AJ		 1983 goto again;
1984 }
1985
ff023aac 1986 scrub_block_get(sblock); /* one for the page added to the bio */
b5d67f64
SB		 1987 atomic_inc(&sblock->outstanding_pages);
1988 sbio->page_count++;
ff023aac 1989 if (sbio->page_count == sctx->pages_per_rd_bio)
d9d181c1 1990 scrub_submit(sctx);
b5d67f64
SB		 1991
1992 return 0;
1993}
1994
d9d181c1 1995static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 1996 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac
SB		 1997 u64 gen, int mirror_num, u8 *csum, int force,
1998 u64 physical_for_dev_replace)
b5d67f64
SB		 1999{
2000 struct scrub_block *sblock;
2001 int index;
2002
2003 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2004 if (!sblock) {
d9d181c1
SB		 2005 spin_lock(&sctx->stat_lock);
2006 sctx->stat.malloc_errors++;
2007 spin_unlock(&sctx->stat_lock);
b5d67f64 2008 return -ENOMEM;
a2de733c 2009 }
b5d67f64 2010
7a9e9987
SB		 2011 /* one ref inside this function, plus one for each page added to
2012 * a bio later on */
b5d67f64 2013 atomic_set(&sblock->ref_count, 1);
d9d181c1 2014 sblock->sctx = sctx;
b5d67f64
SB		 2015 sblock->no_io_error_seen = 1;
2016
2017 for (index = 0; len > 0; index++) {
7a9e9987 2018 struct scrub_page *spage;
b5d67f64
SB		 2019 u64 l = min_t(u64, len, PAGE_SIZE);
2020
7a9e9987
SB		 2021 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2022 if (!spage) {
2023leave_nomem:
d9d181c1
SB		 2024 spin_lock(&sctx->stat_lock);
2025 sctx->stat.malloc_errors++;
2026 spin_unlock(&sctx->stat_lock);
7a9e9987 2027 scrub_block_put(sblock);
b5d67f64
SB		 2028 return -ENOMEM;
2029 }
7a9e9987
SB		 2030 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2031 scrub_page_get(spage);
2032 sblock->pagev[index] = spage;
b5d67f64 2033 spage->sblock = sblock;
a36cf8b8 2034 spage->dev = dev;
b5d67f64
SB		 2035 spage->flags = flags;
2036 spage->generation = gen;
2037 spage->logical = logical;
2038 spage->physical = physical;
ff023aac 2039 spage->physical_for_dev_replace = physical_for_dev_replace;
b5d67f64
SB		 2040 spage->mirror_num = mirror_num;
2041 if (csum) {
2042 spage->have_csum = 1;
d9d181c1 2043 memcpy(spage->csum, csum, sctx->csum_size);
b5d67f64
SB		 2044 } else {
2045 spage->have_csum = 0;
2046 }
2047 sblock->page_count++;
7a9e9987
SB		 2048 spage->page = alloc_page(GFP_NOFS);
2049 if (!spage->page)
2050 goto leave_nomem;
b5d67f64
SB		 2051 len -= l;
2052 logical += l;
2053 physical += l;
ff023aac 2054 physical_for_dev_replace += l;
b5d67f64
SB		 2055 }
2056
7a9e9987 2057 WARN_ON(sblock->page_count == 0);
b5d67f64 2058 for (index = 0; index < sblock->page_count; index++) {
7a9e9987 2059 struct scrub_page *spage = sblock->pagev[index];
1bc87793
AJ		 2060 int ret;
2061
ff023aac 2062 ret = scrub_add_page_to_rd_bio(sctx, spage);
b5d67f64
SB		 2063 if (ret) {
2064 scrub_block_put(sblock);
1bc87793 2065 return ret;
b5d67f64 2066 }
1bc87793 2067 }
a2de733c 2068
b5d67f64 2069 if (force)
d9d181c1 2070 scrub_submit(sctx);
a2de733c 2071
b5d67f64
SB		 2072 /* last one frees, either here or in bio completion for last page */
2073 scrub_block_put(sblock);
a2de733c
AJ		 2074 return 0;
2075}
2076
b5d67f64
SB		 2077static void scrub_bio_end_io(struct bio *bio, int err)
2078{
2079 struct scrub_bio *sbio = bio->bi_private;
a36cf8b8 2080 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
b5d67f64
SB		 2081
2082 sbio->err = err;
2083 sbio->bio = bio;
2084
2085 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
2086}
2087
2088static void scrub_bio_end_io_worker(struct btrfs_work *work)
2089{
2090 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
d9d181c1 2091 struct scrub_ctx *sctx = sbio->sctx;
b5d67f64
SB		 2092 int i;
2093
ff023aac 2094 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
b5d67f64
SB		 2095 if (sbio->err) {
2096 for (i = 0; i < sbio->page_count; i++) {
2097 struct scrub_page *spage = sbio->pagev[i];
2098
2099 spage->io_error = 1;
2100 spage->sblock->no_io_error_seen = 0;
2101 }
2102 }
2103
2104 /* now complete the scrub_block items that have all pages completed */
2105 for (i = 0; i < sbio->page_count; i++) {
2106 struct scrub_page *spage = sbio->pagev[i];
2107 struct scrub_block *sblock = spage->sblock;
2108
2109 if (atomic_dec_and_test(&sblock->outstanding_pages))
2110 scrub_block_complete(sblock);
2111 scrub_block_put(sblock);
2112 }
2113
b5d67f64
SB		 2114 bio_put(sbio->bio);
2115 sbio->bio = NULL;
d9d181c1
SB		 2116 spin_lock(&sctx->list_lock);
2117 sbio->next_free = sctx->first_free;
2118 sctx->first_free = sbio->index;
2119 spin_unlock(&sctx->list_lock);
ff023aac
SB		 2120
2121 if (sctx->is_dev_replace &&
2122 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2123 mutex_lock(&sctx->wr_ctx.wr_lock);
2124 scrub_wr_submit(sctx);
2125 mutex_unlock(&sctx->wr_ctx.wr_lock);
2126 }
2127
b6bfebc1 2128 scrub_pending_bio_dec(sctx);
b5d67f64
SB		 2129}
2130
2131static void scrub_block_complete(struct scrub_block *sblock)
2132{
ff023aac 2133 if (!sblock->no_io_error_seen) {
b5d67f64 2134 scrub_handle_errored_block(sblock);
ff023aac
SB		 2135 } else {
2136 /*
2137 * if has checksum error, write via repair mechanism in
2138 * dev replace case, otherwise write here in dev replace
2139 * case.
2140 */
2141 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
2142 scrub_write_block_to_dev_replace(sblock);
2143 }
b5d67f64
SB		 2144}
2145
d9d181c1 2146static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
a2de733c
AJ		 2147 u8 *csum)
2148{
2149 struct btrfs_ordered_sum *sum = NULL;
f51a4a18 2150 unsigned long index;
a2de733c 2151 unsigned long num_sectors;
a2de733c 2152
d9d181c1
SB		 2153 while (!list_empty(&sctx->csum_list)) {
2154 sum = list_first_entry(&sctx->csum_list,
a2de733c
AJ		 2155 struct btrfs_ordered_sum, list);
2156 if (sum->bytenr > logical)
2157 return 0;
2158 if (sum->bytenr + sum->len > logical)
2159 break;
2160
d9d181c1 2161 ++sctx->stat.csum_discards;
a2de733c
AJ		 2162 list_del(&sum->list);
2163 kfree(sum);
2164 sum = NULL;
2165 }
2166 if (!sum)
2167 return 0;
2168
f51a4a18 2169 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
d9d181c1 2170 num_sectors = sum->len / sctx->sectorsize;
f51a4a18
MX		 2171 memcpy(csum, sum->sums + index, sctx->csum_size);
2172 if (index == num_sectors - 1) {
a2de733c
AJ		 2173 list_del(&sum->list);
2174 kfree(sum);
2175 }
f51a4a18 2176 return 1;
a2de733c
AJ		 2177}
2178
2179/* scrub extent tries to collect up to 64 kB for each bio */
d9d181c1 2180static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 2181 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac 2182 u64 gen, int mirror_num, u64 physical_for_dev_replace)
a2de733c
AJ		 2183{
2184 int ret;
2185 u8 csum[BTRFS_CSUM_SIZE];
b5d67f64
SB		 2186 u32 blocksize;
2187
2188 if (flags & BTRFS_EXTENT_FLAG_DATA) {
d9d181c1
SB		 2189 blocksize = sctx->sectorsize;
2190 spin_lock(&sctx->stat_lock);
2191 sctx->stat.data_extents_scrubbed++;
2192 sctx->stat.data_bytes_scrubbed += len;
2193 spin_unlock(&sctx->stat_lock);
b5d67f64 2194 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
ff023aac 2195 WARN_ON(sctx->nodesize != sctx->leafsize);
d9d181c1
SB		 2196 blocksize = sctx->nodesize;
2197 spin_lock(&sctx->stat_lock);
2198 sctx->stat.tree_extents_scrubbed++;
2199 sctx->stat.tree_bytes_scrubbed += len;
2200 spin_unlock(&sctx->stat_lock);
b5d67f64 2201 } else {
d9d181c1 2202 blocksize = sctx->sectorsize;
ff023aac 2203 WARN_ON(1);
b5d67f64 2204 }
a2de733c
AJ		 2205
2206 while (len) {
b5d67f64 2207 u64 l = min_t(u64, len, blocksize);
a2de733c
AJ		 2208 int have_csum = 0;
2209
2210 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2211 /* push csums to sbio */
d9d181c1 2212 have_csum = scrub_find_csum(sctx, logical, l, csum);
a2de733c 2213 if (have_csum == 0)
d9d181c1 2214 ++sctx->stat.no_csum;
ff023aac
SB		 2215 if (sctx->is_dev_replace && !have_csum) {
2216 ret = copy_nocow_pages(sctx, logical, l,
2217 mirror_num,
2218 physical_for_dev_replace);
2219 goto behind_scrub_pages;
2220 }
a2de733c 2221 }
a36cf8b8 2222 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
ff023aac
SB		 2223 mirror_num, have_csum ? csum : NULL, 0,
2224 physical_for_dev_replace);
2225behind_scrub_pages:
a2de733c
AJ		 2226 if (ret)
2227 return ret;
2228 len -= l;
2229 logical += l;
2230 physical += l;
ff023aac 2231 physical_for_dev_replace += l;
a2de733c
AJ		 2232 }
2233 return 0;
2234}
2235
d9d181c1 2236static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
a36cf8b8
SB		 2237 struct map_lookup *map,
2238 struct btrfs_device *scrub_dev,
ff023aac
SB		 2239 int num, u64 base, u64 length,
2240 int is_dev_replace)
a2de733c
AJ		 2241{
2242 struct btrfs_path *path;
a36cf8b8 2243 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
a2de733c
AJ		 2244 struct btrfs_root *root = fs_info->extent_root;
2245 struct btrfs_root *csum_root = fs_info->csum_root;
2246 struct btrfs_extent_item *extent;
e7786c3a 2247 struct blk_plug plug;
a2de733c
AJ		 2248 u64 flags;
2249 int ret;
2250 int slot;
a2de733c 2251 u64 nstripes;
a2de733c
AJ		 2252 struct extent_buffer *l;
2253 struct btrfs_key key;
2254 u64 physical;
2255 u64 logical;
625f1c8d 2256 u64 logic_end;
a2de733c 2257 u64 generation;
e12fa9cd 2258 int mirror_num;
7a26285e
AJ		 2259 struct reada_control *reada1;
2260 struct reada_control *reada2;
2261 struct btrfs_key key_start;
2262 struct btrfs_key key_end;
a2de733c
AJ		 2263 u64 increment = map->stripe_len;
2264 u64 offset;
ff023aac
SB		 2265 u64 extent_logical;
2266 u64 extent_physical;
2267 u64 extent_len;
2268 struct btrfs_device *extent_dev;
2269 int extent_mirror_num;
625f1c8d 2270 int stop_loop;
a2de733c 2271
53b381b3
DW		 2272 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2273 BTRFS_BLOCK_GROUP_RAID6)) {
2274 if (num >= nr_data_stripes(map)) {
2275 return 0;
2276 }
2277 }
2278
a2de733c
AJ		 2279 nstripes = length;
2280 offset = 0;
2281 do_div(nstripes, map->stripe_len);
2282 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2283 offset = map->stripe_len * num;
2284 increment = map->stripe_len * map->num_stripes;
193ea74b 2285 mirror_num = 1;
a2de733c
AJ		 2286 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2287 int factor = map->num_stripes / map->sub_stripes;
2288 offset = map->stripe_len * (num / map->sub_stripes);
2289 increment = map->stripe_len * factor;
193ea74b 2290 mirror_num = num % map->sub_stripes + 1;
a2de733c
AJ		 2291 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2292 increment = map->stripe_len;
193ea74b 2293 mirror_num = num % map->num_stripes + 1;
a2de733c
AJ		 2294 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2295 increment = map->stripe_len;
193ea74b 2296 mirror_num = num % map->num_stripes + 1;
a2de733c
AJ		 2297 } else {
2298 increment = map->stripe_len;
193ea74b 2299 mirror_num = 1;
a2de733c
AJ		 2300 }
2301
2302 path = btrfs_alloc_path();
2303 if (!path)
2304 return -ENOMEM;
2305
b5d67f64
SB		 2306 /*
2307 * work on commit root. The related disk blocks are static as
2308 * long as COW is applied. This means, it is save to rewrite
2309 * them to repair disk errors without any race conditions
2310 */
a2de733c
AJ		 2311 path->search_commit_root = 1;
2312 path->skip_locking = 1;
2313
2314 /*
7a26285e
AJ		 2315 * trigger the readahead for extent tree csum tree and wait for
2316 * completion. During readahead, the scrub is officially paused
2317 * to not hold off transaction commits
a2de733c
AJ		 2318 */
2319 logical = base + offset;
a2de733c 2320
d9d181c1 2321 wait_event(sctx->list_wait,
b6bfebc1 2322 atomic_read(&sctx->bios_in_flight) == 0);
cb7ab021 2323 scrub_blocked_if_needed(fs_info);
7a26285e
AJ		 2324
2325 /* FIXME it might be better to start readahead at commit root */
2326 key_start.objectid = logical;
2327 key_start.type = BTRFS_EXTENT_ITEM_KEY;
2328 key_start.offset = (u64)0;
2329 key_end.objectid = base + offset + nstripes * increment;
3173a18f
JB		 2330 key_end.type = BTRFS_METADATA_ITEM_KEY;
2331 key_end.offset = (u64)-1;
7a26285e
AJ		 2332 reada1 = btrfs_reada_add(root, &key_start, &key_end);
2333
2334 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2335 key_start.type = BTRFS_EXTENT_CSUM_KEY;
2336 key_start.offset = logical;
2337 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2338 key_end.type = BTRFS_EXTENT_CSUM_KEY;
2339 key_end.offset = base + offset + nstripes * increment;
2340 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
2341
2342 if (!IS_ERR(reada1))
2343 btrfs_reada_wait(reada1);
2344 if (!IS_ERR(reada2))
2345 btrfs_reada_wait(reada2);
2346
a2de733c
AJ		 2347
2348 /*
2349 * collect all data csums for the stripe to avoid seeking during
2350 * the scrub. This might currently (crc32) end up to be about 1MB
2351 */
e7786c3a 2352 blk_start_plug(&plug);
a2de733c 2353
a2de733c
AJ		 2354 /*
2355 * now find all extents for each stripe and scrub them
2356 */
7a26285e
AJ		 2357 logical = base + offset;
2358 physical = map->stripes[num].physical;
625f1c8d 2359 logic_end = logical + increment * nstripes;
a2de733c 2360 ret = 0;
625f1c8d 2361 while (logical < logic_end) {
a2de733c
AJ		 2362 /*
2363 * canceled?
2364 */
2365 if (atomic_read(&fs_info->scrub_cancel_req) ||
d9d181c1 2366 atomic_read(&sctx->cancel_req)) {
a2de733c
AJ		 2367 ret = -ECANCELED;
2368 goto out;
2369 }
2370 /*
2371 * check to see if we have to pause
2372 */
2373 if (atomic_read(&fs_info->scrub_pause_req)) {
2374 /* push queued extents */
ff023aac 2375 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
d9d181c1 2376 scrub_submit(sctx);
ff023aac
SB		 2377 mutex_lock(&sctx->wr_ctx.wr_lock);
2378 scrub_wr_submit(sctx);
2379 mutex_unlock(&sctx->wr_ctx.wr_lock);
d9d181c1 2380 wait_event(sctx->list_wait,
b6bfebc1 2381 atomic_read(&sctx->bios_in_flight) == 0);
ff023aac 2382 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3cb0929a 2383 scrub_blocked_if_needed(fs_info);
a2de733c
AJ		 2384 }
2385
7c76edb7
WS		 2386 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2387 key.type = BTRFS_METADATA_ITEM_KEY;
2388 else
2389 key.type = BTRFS_EXTENT_ITEM_KEY;
a2de733c 2390 key.objectid = logical;
625f1c8d 2391 key.offset = (u64)-1;
a2de733c
AJ		 2392
2393 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2394 if (ret < 0)
2395 goto out;
3173a18f 2396
8c51032f 2397 if (ret > 0) {
ade2e0b3 2398 ret = btrfs_previous_extent_item(root, path, 0);
a2de733c
AJ		 2399 if (ret < 0)
2400 goto out;
8c51032f
AJ		 2401 if (ret > 0) {
2402 /* there's no smaller item, so stick with the
2403 * larger one */
2404 btrfs_release_path(path);
2405 ret = btrfs_search_slot(NULL, root, &key,
2406 path, 0, 0);
2407 if (ret < 0)
2408 goto out;
2409 }
a2de733c
AJ		 2410 }
2411
625f1c8d 2412 stop_loop = 0;
a2de733c 2413 while (1) {
3173a18f
JB		 2414 u64 bytes;
2415
a2de733c
AJ		 2416 l = path->nodes[0];
2417 slot = path->slots[0];
2418 if (slot >= btrfs_header_nritems(l)) {
2419 ret = btrfs_next_leaf(root, path);
2420 if (ret == 0)
2421 continue;
2422 if (ret < 0)
2423 goto out;
2424
625f1c8d 2425 stop_loop = 1;
a2de733c
AJ		 2426 break;
2427 }
2428 btrfs_item_key_to_cpu(l, &key, slot);
2429
3173a18f
JB		 2430 if (key.type == BTRFS_METADATA_ITEM_KEY)
2431 bytes = root->leafsize;
2432 else
2433 bytes = key.offset;
2434
2435 if (key.objectid + bytes <= logical)
a2de733c
AJ		 2436 goto next;
2437
625f1c8d
LB		 2438 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2439 key.type != BTRFS_METADATA_ITEM_KEY)
2440 goto next;
a2de733c 2441
625f1c8d
LB		 2442 if (key.objectid >= logical + map->stripe_len) {
2443 /* out of this device extent */
2444 if (key.objectid >= logic_end)
2445 stop_loop = 1;
2446 break;
2447 }
a2de733c
AJ		 2448
2449 extent = btrfs_item_ptr(l, slot,
2450 struct btrfs_extent_item);
2451 flags = btrfs_extent_flags(l, extent);
2452 generation = btrfs_extent_generation(l, extent);
2453
2454 if (key.objectid < logical &&
2455 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
efe120a0
FH		 2456 btrfs_err(fs_info,
2457 "scrub: tree block %llu spanning "
2458 "stripes, ignored. logical=%llu",
c1c9ff7c 2459 key.objectid, logical);
a2de733c
AJ		 2460 goto next;
2461 }
2462
625f1c8d
LB		 2463again:
2464 extent_logical = key.objectid;
2465 extent_len = bytes;
2466
a2de733c
AJ		 2467 /*
2468 * trim extent to this stripe
2469 */
625f1c8d
LB		 2470 if (extent_logical < logical) {
2471 extent_len -= logical - extent_logical;
2472 extent_logical = logical;
a2de733c 2473 }
625f1c8d 2474 if (extent_logical + extent_len >
a2de733c 2475 logical + map->stripe_len) {
625f1c8d
LB		 2476 extent_len = logical + map->stripe_len -
2477 extent_logical;
a2de733c
AJ		 2478 }
2479
625f1c8d 2480 extent_physical = extent_logical - logical + physical;
ff023aac
SB		 2481 extent_dev = scrub_dev;
2482 extent_mirror_num = mirror_num;
2483 if (is_dev_replace)
2484 scrub_remap_extent(fs_info, extent_logical,
2485 extent_len, &extent_physical,
2486 &extent_dev,
2487 &extent_mirror_num);
625f1c8d
LB		 2488
2489 ret = btrfs_lookup_csums_range(csum_root, logical,
2490 logical + map->stripe_len - 1,
2491 &sctx->csum_list, 1);
2492 if (ret)
2493 goto out;
2494
ff023aac
SB		 2495 ret = scrub_extent(sctx, extent_logical, extent_len,
2496 extent_physical, extent_dev, flags,
2497 generation, extent_mirror_num,
115930cb 2498 extent_logical - logical + physical);
a2de733c
AJ		 2499 if (ret)
2500 goto out;
2501
d88d46c6 2502 scrub_free_csums(sctx);
625f1c8d
LB		 2503 if (extent_logical + extent_len <
2504 key.objectid + bytes) {
2505 logical += increment;
2506 physical += map->stripe_len;
2507
2508 if (logical < key.objectid + bytes) {
2509 cond_resched();
2510 goto again;
2511 }
2512
2513 if (logical >= logic_end) {
2514 stop_loop = 1;
2515 break;
2516 }
2517 }
a2de733c
AJ		 2518next:
2519 path->slots[0]++;
2520 }
71267333 2521 btrfs_release_path(path);
a2de733c
AJ		 2522 logical += increment;
2523 physical += map->stripe_len;
d9d181c1 2524 spin_lock(&sctx->stat_lock);
625f1c8d
LB		 2525 if (stop_loop)
2526 sctx->stat.last_physical = map->stripes[num].physical +
2527 length;
2528 else
2529 sctx->stat.last_physical = physical;
d9d181c1 2530 spin_unlock(&sctx->stat_lock);
625f1c8d
LB		 2531 if (stop_loop)
2532 break;
a2de733c 2533 }
ff023aac 2534out:
a2de733c 2535 /* push queued extents */
d9d181c1 2536 scrub_submit(sctx);
ff023aac
SB		 2537 mutex_lock(&sctx->wr_ctx.wr_lock);
2538 scrub_wr_submit(sctx);
2539 mutex_unlock(&sctx->wr_ctx.wr_lock);
a2de733c 2540
e7786c3a 2541 blk_finish_plug(&plug);
a2de733c
AJ		 2542 btrfs_free_path(path);
2543 return ret < 0 ? ret : 0;
2544}
2545
d9d181c1 2546static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
a36cf8b8
SB		 2547 struct btrfs_device *scrub_dev,
2548 u64 chunk_tree, u64 chunk_objectid,
2549 u64 chunk_offset, u64 length,
ff023aac 2550 u64 dev_offset, int is_dev_replace)
a2de733c
AJ		 2551{
2552 struct btrfs_mapping_tree *map_tree =
a36cf8b8 2553 &sctx->dev_root->fs_info->mapping_tree;
a2de733c
AJ		 2554 struct map_lookup *map;
2555 struct extent_map *em;
2556 int i;
ff023aac 2557 int ret = 0;
a2de733c
AJ		 2558
2559 read_lock(&map_tree->map_tree.lock);
2560 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2561 read_unlock(&map_tree->map_tree.lock);
2562
2563 if (!em)
2564 return -EINVAL;
2565
2566 map = (struct map_lookup *)em->bdev;
2567 if (em->start != chunk_offset)
2568 goto out;
2569
2570 if (em->len < length)
2571 goto out;
2572
2573 for (i = 0; i < map->num_stripes; ++i) {
a36cf8b8 2574 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
859acaf1 2575 map->stripes[i].physical == dev_offset) {
a36cf8b8 2576 ret = scrub_stripe(sctx, map, scrub_dev, i,
ff023aac
SB		 2577 chunk_offset, length,
2578 is_dev_replace);
a2de733c
AJ		 2579 if (ret)
2580 goto out;
2581 }
2582 }
2583out:
2584 free_extent_map(em);
2585
2586 return ret;
2587}
2588
2589static noinline_for_stack
a36cf8b8 2590int scrub_enumerate_chunks(struct scrub_ctx *sctx,
ff023aac
SB		 2591 struct btrfs_device *scrub_dev, u64 start, u64 end,
2592 int is_dev_replace)
a2de733c
AJ		 2593{
2594 struct btrfs_dev_extent *dev_extent = NULL;
2595 struct btrfs_path *path;
a36cf8b8 2596 struct btrfs_root *root = sctx->dev_root;
a2de733c
AJ		 2597 struct btrfs_fs_info *fs_info = root->fs_info;
2598 u64 length;
2599 u64 chunk_tree;
2600 u64 chunk_objectid;
2601 u64 chunk_offset;
2602 int ret;
2603 int slot;
2604 struct extent_buffer *l;
2605 struct btrfs_key key;
2606 struct btrfs_key found_key;
2607 struct btrfs_block_group_cache *cache;
ff023aac 2608 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
a2de733c
AJ		 2609
2610 path = btrfs_alloc_path();
2611 if (!path)
2612 return -ENOMEM;
2613
2614 path->reada = 2;
2615 path->search_commit_root = 1;
2616 path->skip_locking = 1;
2617
a36cf8b8 2618 key.objectid = scrub_dev->devid;
a2de733c
AJ		 2619 key.offset = 0ull;
2620 key.type = BTRFS_DEV_EXTENT_KEY;
2621
a2de733c
AJ		 2622 while (1) {
2623 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2624 if (ret < 0)
8c51032f
AJ		 2625 break;
2626 if (ret > 0) {
2627 if (path->slots[0] >=
2628 btrfs_header_nritems(path->nodes[0])) {
2629 ret = btrfs_next_leaf(root, path);
2630 if (ret)
2631 break;
2632 }
2633 }
a2de733c
AJ		 2634
2635 l = path->nodes[0];
2636 slot = path->slots[0];
2637
2638 btrfs_item_key_to_cpu(l, &found_key, slot);
2639
a36cf8b8 2640 if (found_key.objectid != scrub_dev->devid)
a2de733c
AJ		 2641 break;
2642
8c51032f 2643 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
a2de733c
AJ		 2644 break;
2645
2646 if (found_key.offset >= end)
2647 break;
2648
2649 if (found_key.offset < key.offset)
2650 break;
2651
2652 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2653 length = btrfs_dev_extent_length(l, dev_extent);
2654
2655 if (found_key.offset + length <= start) {
2656 key.offset = found_key.offset + length;
71267333 2657 btrfs_release_path(path);
a2de733c
AJ		 2658 continue;
2659 }
2660
2661 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2662 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2663 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2664
2665 /*
2666 * get a reference on the corresponding block group to prevent
2667 * the chunk from going away while we scrub it
2668 */
2669 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2670 if (!cache) {
2671 ret = -ENOENT;
8c51032f 2672 break;
a2de733c 2673 }
ff023aac
SB		 2674 dev_replace->cursor_right = found_key.offset + length;
2675 dev_replace->cursor_left = found_key.offset;
2676 dev_replace->item_needs_writeback = 1;
a36cf8b8 2677 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
ff023aac
SB		 2678 chunk_offset, length, found_key.offset,
2679 is_dev_replace);
2680
2681 /*
2682 * flush, submit all pending read and write bios, afterwards
2683 * wait for them.
2684 * Note that in the dev replace case, a read request causes
2685 * write requests that are submitted in the read completion
2686 * worker. Therefore in the current situation, it is required
2687 * that all write requests are flushed, so that all read and
2688 * write requests are really completed when bios_in_flight
2689 * changes to 0.
2690 */
2691 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2692 scrub_submit(sctx);
2693 mutex_lock(&sctx->wr_ctx.wr_lock);
2694 scrub_wr_submit(sctx);
2695 mutex_unlock(&sctx->wr_ctx.wr_lock);
2696
2697 wait_event(sctx->list_wait,
2698 atomic_read(&sctx->bios_in_flight) == 0);
12cf9372
WS		 2699 atomic_inc(&fs_info->scrubs_paused);
2700 wake_up(&fs_info->scrub_pause_wait);
2701
2702 /*
2703 * must be called before we decrease @scrub_paused.
2704 * make sure we don't block transaction commit while
2705 * we are waiting pending workers finished.
2706 */
ff023aac
SB		 2707 wait_event(sctx->list_wait,
2708 atomic_read(&sctx->workers_pending) == 0);
12cf9372
WS		 2709 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2710
2711 mutex_lock(&fs_info->scrub_lock);
2712 __scrub_blocked_if_needed(fs_info);
2713 atomic_dec(&fs_info->scrubs_paused);
2714 mutex_unlock(&fs_info->scrub_lock);
2715 wake_up(&fs_info->scrub_pause_wait);
ff023aac 2716
a2de733c
AJ		 2717 btrfs_put_block_group(cache);
2718 if (ret)
2719 break;
af1be4f8
SB		 2720 if (is_dev_replace &&
2721 atomic64_read(&dev_replace->num_write_errors) > 0) {
ff023aac
SB		 2722 ret = -EIO;
2723 break;
2724 }
2725 if (sctx->stat.malloc_errors > 0) {
2726 ret = -ENOMEM;
2727 break;
2728 }
a2de733c 2729
539f358a
ID		 2730 dev_replace->cursor_left = dev_replace->cursor_right;
2731 dev_replace->item_needs_writeback = 1;
2732
a2de733c 2733 key.offset = found_key.offset + length;
71267333 2734 btrfs_release_path(path);
a2de733c
AJ		 2735 }
2736
a2de733c 2737 btrfs_free_path(path);
8c51032f
AJ		 2738
2739 /*
2740 * ret can still be 1 from search_slot or next_leaf,
2741 * that's not an error
2742 */
2743 return ret < 0 ? ret : 0;
a2de733c
AJ		 2744}
2745
a36cf8b8
SB		 2746static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2747 struct btrfs_device *scrub_dev)
a2de733c
AJ		 2748{
2749 int i;
2750 u64 bytenr;
2751 u64 gen;
2752 int ret;
a36cf8b8 2753 struct btrfs_root *root = sctx->dev_root;
a2de733c 2754
87533c47 2755 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
79787eaa
JM		 2756 return -EIO;
2757
a2de733c
AJ		 2758 gen = root->fs_info->last_trans_committed;
2759
2760 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2761 bytenr = btrfs_sb_offset(i);
a36cf8b8 2762 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
a2de733c
AJ		 2763 break;
2764
d9d181c1 2765 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
a36cf8b8 2766 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
ff023aac 2767 NULL, 1, bytenr);
a2de733c
AJ		 2768 if (ret)
2769 return ret;
2770 }
b6bfebc1 2771 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
a2de733c
AJ		 2772
2773 return 0;
2774}
2775
2776/*
2777 * get a reference count on fs_info->scrub_workers. start worker if necessary
2778 */
ff023aac
SB		 2779static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
2780 int is_dev_replace)
a2de733c 2781{
0dc3b84a 2782 int ret = 0;
a2de733c 2783
632dd772 2784 if (fs_info->scrub_workers_refcnt == 0) {
ff023aac
SB		 2785 if (is_dev_replace)
2786 btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1,
2787 &fs_info->generic_worker);
2788 else
2789 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
2790 fs_info->thread_pool_size,
2791 &fs_info->generic_worker);
632dd772 2792 fs_info->scrub_workers.idle_thresh = 4;
0dc3b84a
JB		 2793 ret = btrfs_start_workers(&fs_info->scrub_workers);
2794 if (ret)
2795 goto out;
ff023aac
SB		 2796 btrfs_init_workers(&fs_info->scrub_wr_completion_workers,
2797 "scrubwrc",
2798 fs_info->thread_pool_size,
2799 &fs_info->generic_worker);
2800 fs_info->scrub_wr_completion_workers.idle_thresh = 2;
2801 ret = btrfs_start_workers(
2802 &fs_info->scrub_wr_completion_workers);
2803 if (ret)
2804 goto out;
2805 btrfs_init_workers(&fs_info->scrub_nocow_workers, "scrubnc", 1,
2806 &fs_info->generic_worker);
2807 ret = btrfs_start_workers(&fs_info->scrub_nocow_workers);
2808 if (ret)
2809 goto out;
632dd772 2810 }
a2de733c 2811 ++fs_info->scrub_workers_refcnt;
0dc3b84a 2812out:
0dc3b84a 2813 return ret;
a2de733c
AJ		 2814}
2815
aa1b8cd4 2816static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
a2de733c 2817{
ff023aac 2818 if (--fs_info->scrub_workers_refcnt == 0) {
a2de733c 2819 btrfs_stop_workers(&fs_info->scrub_workers);
ff023aac
SB		 2820 btrfs_stop_workers(&fs_info->scrub_wr_completion_workers);
2821 btrfs_stop_workers(&fs_info->scrub_nocow_workers);
2822 }
a2de733c 2823 WARN_ON(fs_info->scrub_workers_refcnt < 0);
a2de733c
AJ		 2824}
2825
aa1b8cd4
SB		 2826int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2827 u64 end, struct btrfs_scrub_progress *progress,
63a212ab 2828 int readonly, int is_dev_replace)
a2de733c 2829{
d9d181c1 2830 struct scrub_ctx *sctx;
a2de733c
AJ		 2831 int ret;
2832 struct btrfs_device *dev;
2833
aa1b8cd4 2834 if (btrfs_fs_closing(fs_info))
a2de733c
AJ		 2835 return -EINVAL;
2836
2837 /*
2838 * check some assumptions
2839 */
aa1b8cd4 2840 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
efe120a0
FH		 2841 btrfs_err(fs_info,
2842 "scrub: size assumption nodesize == leafsize (%d == %d) fails",
aa1b8cd4
SB		 2843 fs_info->chunk_root->nodesize,
2844 fs_info->chunk_root->leafsize);
b5d67f64
SB		 2845 return -EINVAL;
2846 }
2847
aa1b8cd4 2848 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
b5d67f64
SB		 2849 /*
2850 * in this case scrub is unable to calculate the checksum
2851 * the way scrub is implemented. Do not handle this
2852 * situation at all because it won't ever happen.
2853 */
efe120a0
FH		 2854 btrfs_err(fs_info,
2855 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
aa1b8cd4 2856 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
b5d67f64
SB		 2857 return -EINVAL;
2858 }
2859
aa1b8cd4 2860 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
b5d67f64 2861 /* not supported for data w/o checksums */
efe120a0
FH		 2862 btrfs_err(fs_info,
2863 "scrub: size assumption sectorsize != PAGE_SIZE "
2864 "(%d != %lu) fails",
27f9f023 2865 fs_info->chunk_root->sectorsize, PAGE_SIZE);
a2de733c
AJ		 2866 return -EINVAL;
2867 }
2868
7a9e9987
SB		 2869 if (fs_info->chunk_root->nodesize >
2870 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
2871 fs_info->chunk_root->sectorsize >
2872 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
2873 /*
2874 * would exhaust the array bounds of pagev member in
2875 * struct scrub_block
2876 */
efe120a0
FH		 2877 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
2878 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
7a9e9987
SB		 2879 fs_info->chunk_root->nodesize,
2880 SCRUB_MAX_PAGES_PER_BLOCK,
2881 fs_info->chunk_root->sectorsize,
2882 SCRUB_MAX_PAGES_PER_BLOCK);
2883 return -EINVAL;
2884 }
2885
a2de733c 2886
aa1b8cd4
SB		 2887 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2888 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
63a212ab 2889 if (!dev || (dev->missing && !is_dev_replace)) {
aa1b8cd4 2890 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c
AJ		 2891 return -ENODEV;
2892 }
a2de733c 2893
3b7a016f 2894 mutex_lock(&fs_info->scrub_lock);
63a212ab 2895 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
a2de733c 2896 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4 2897 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
aa1b8cd4 2898 return -EIO;
a2de733c
AJ		 2899 }
2900
8dabb742
SB		 2901 btrfs_dev_replace_lock(&fs_info->dev_replace);
2902 if (dev->scrub_device ||
2903 (!is_dev_replace &&
2904 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2905 btrfs_dev_replace_unlock(&fs_info->dev_replace);
a2de733c 2906 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4 2907 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c
AJ		 2908 return -EINPROGRESS;
2909 }
8dabb742 2910 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3b7a016f
WS		 2911
2912 ret = scrub_workers_get(fs_info, is_dev_replace);
2913 if (ret) {
2914 mutex_unlock(&fs_info->scrub_lock);
2915 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2916 return ret;
2917 }
2918
63a212ab 2919 sctx = scrub_setup_ctx(dev, is_dev_replace);
d9d181c1 2920 if (IS_ERR(sctx)) {
a2de733c 2921 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4
SB		 2922 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2923 scrub_workers_put(fs_info);
d9d181c1 2924 return PTR_ERR(sctx);
a2de733c 2925 }
d9d181c1
SB		 2926 sctx->readonly = readonly;
2927 dev->scrub_device = sctx;
3cb0929a 2928 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c 2929
3cb0929a
WS		 2930 /*
2931 * checking @scrub_pause_req here, we can avoid
2932 * race between committing transaction and scrubbing.
2933 */
cb7ab021 2934 __scrub_blocked_if_needed(fs_info);
a2de733c
AJ		 2935 atomic_inc(&fs_info->scrubs_running);
2936 mutex_unlock(&fs_info->scrub_lock);
a2de733c 2937
ff023aac 2938 if (!is_dev_replace) {
9b011adf
WS		 2939 /*
2940 * by holding device list mutex, we can
2941 * kick off writing super in log tree sync.
2942 */
3cb0929a 2943 mutex_lock(&fs_info->fs_devices->device_list_mutex);
ff023aac 2944 ret = scrub_supers(sctx, dev);
3cb0929a 2945 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ff023aac 2946 }
a2de733c
AJ		 2947
2948 if (!ret)
ff023aac
SB		 2949 ret = scrub_enumerate_chunks(sctx, dev, start, end,
2950 is_dev_replace);
a2de733c 2951
b6bfebc1 2952 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
a2de733c
AJ		 2953 atomic_dec(&fs_info->scrubs_running);
2954 wake_up(&fs_info->scrub_pause_wait);
2955
b6bfebc1 2956 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
0ef8e451 2957
a2de733c 2958 if (progress)
d9d181c1 2959 memcpy(progress, &sctx->stat, sizeof(*progress));
a2de733c
AJ		 2960
2961 mutex_lock(&fs_info->scrub_lock);
2962 dev->scrub_device = NULL;
3b7a016f 2963 scrub_workers_put(fs_info);
a2de733c
AJ		 2964 mutex_unlock(&fs_info->scrub_lock);
2965
d9d181c1 2966 scrub_free_ctx(sctx);
a2de733c
AJ		 2967
2968 return ret;
2969}
2970
143bede5 2971void btrfs_scrub_pause(struct btrfs_root *root)
a2de733c
AJ		 2972{
2973 struct btrfs_fs_info *fs_info = root->fs_info;
2974
2975 mutex_lock(&fs_info->scrub_lock);
2976 atomic_inc(&fs_info->scrub_pause_req);
2977 while (atomic_read(&fs_info->scrubs_paused) !=
2978 atomic_read(&fs_info->scrubs_running)) {
2979 mutex_unlock(&fs_info->scrub_lock);
2980 wait_event(fs_info->scrub_pause_wait,
2981 atomic_read(&fs_info->scrubs_paused) ==
2982 atomic_read(&fs_info->scrubs_running));
2983 mutex_lock(&fs_info->scrub_lock);
2984 }
2985 mutex_unlock(&fs_info->scrub_lock);
a2de733c
AJ		 2986}
2987
143bede5 2988void btrfs_scrub_continue(struct btrfs_root *root)
a2de733c
AJ		 2989{
2990 struct btrfs_fs_info *fs_info = root->fs_info;
2991
2992 atomic_dec(&fs_info->scrub_pause_req);
2993 wake_up(&fs_info->scrub_pause_wait);
a2de733c
AJ		 2994}
2995
aa1b8cd4 2996int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
a2de733c 2997{
a2de733c
AJ		 2998 mutex_lock(&fs_info->scrub_lock);
2999 if (!atomic_read(&fs_info->scrubs_running)) {
3000 mutex_unlock(&fs_info->scrub_lock);
3001 return -ENOTCONN;
3002 }
3003
3004 atomic_inc(&fs_info->scrub_cancel_req);
3005 while (atomic_read(&fs_info->scrubs_running)) {
3006 mutex_unlock(&fs_info->scrub_lock);
3007 wait_event(fs_info->scrub_pause_wait,
3008 atomic_read(&fs_info->scrubs_running) == 0);
3009 mutex_lock(&fs_info->scrub_lock);
3010 }
3011 atomic_dec(&fs_info->scrub_cancel_req);
3012 mutex_unlock(&fs_info->scrub_lock);
3013
3014 return 0;
3015}
3016
aa1b8cd4
SB		 3017int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
3018 struct btrfs_device *dev)
49b25e05 3019{
d9d181c1 3020 struct scrub_ctx *sctx;
a2de733c
AJ		 3021
3022 mutex_lock(&fs_info->scrub_lock);
d9d181c1
SB		 3023 sctx = dev->scrub_device;
3024 if (!sctx) {
a2de733c
AJ		 3025 mutex_unlock(&fs_info->scrub_lock);
3026 return -ENOTCONN;
3027 }
d9d181c1 3028 atomic_inc(&sctx->cancel_req);
a2de733c
AJ		 3029 while (dev->scrub_device) {
3030 mutex_unlock(&fs_info->scrub_lock);
3031 wait_event(fs_info->scrub_pause_wait,
3032 dev->scrub_device == NULL);
3033 mutex_lock(&fs_info->scrub_lock);
3034 }
3035 mutex_unlock(&fs_info->scrub_lock);
3036
3037 return 0;
3038}
1623edeb 3039
a2de733c
AJ		 3040int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3041 struct btrfs_scrub_progress *progress)
3042{
3043 struct btrfs_device *dev;
d9d181c1 3044 struct scrub_ctx *sctx = NULL;
a2de733c
AJ		 3045
3046 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
aa1b8cd4 3047 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
a2de733c 3048 if (dev)
d9d181c1
SB		 3049 sctx = dev->scrub_device;
3050 if (sctx)
3051 memcpy(progress, &sctx->stat, sizeof(*progress));
a2de733c
AJ		 3052 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3053
d9d181c1 3054 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
a2de733c 3055}
ff023aac
SB		 3056
3057static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3058 u64 extent_logical, u64 extent_len,
3059 u64 *extent_physical,
3060 struct btrfs_device **extent_dev,
3061 int *extent_mirror_num)
3062{
3063 u64 mapped_length;
3064 struct btrfs_bio *bbio = NULL;
3065 int ret;
3066
3067 mapped_length = extent_len;
3068 ret = btrfs_map_block(fs_info, READ, extent_logical,
3069 &mapped_length, &bbio, 0);
3070 if (ret || !bbio || mapped_length < extent_len ||
3071 !bbio->stripes[0].dev->bdev) {
3072 kfree(bbio);
3073 return;
3074 }
3075
3076 *extent_physical = bbio->stripes[0].physical;
3077 *extent_mirror_num = bbio->mirror_num;
3078 *extent_dev = bbio->stripes[0].dev;
3079 kfree(bbio);
3080}
3081
3082static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3083 struct scrub_wr_ctx *wr_ctx,
3084 struct btrfs_fs_info *fs_info,
3085 struct btrfs_device *dev,
3086 int is_dev_replace)
3087{
3088 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3089
3090 mutex_init(&wr_ctx->wr_lock);
3091 wr_ctx->wr_curr_bio = NULL;
3092 if (!is_dev_replace)
3093 return 0;
3094
3095 WARN_ON(!dev->bdev);
3096 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
3097 bio_get_nr_vecs(dev->bdev));
3098 wr_ctx->tgtdev = dev;
3099 atomic_set(&wr_ctx->flush_all_writes, 0);
3100 return 0;
3101}
3102
3103static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3104{
3105 mutex_lock(&wr_ctx->wr_lock);
3106 kfree(wr_ctx->wr_curr_bio);
3107 wr_ctx->wr_curr_bio = NULL;
3108 mutex_unlock(&wr_ctx->wr_lock);
3109}
3110
3111static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3112 int mirror_num, u64 physical_for_dev_replace)
3113{
3114 struct scrub_copy_nocow_ctx *nocow_ctx;
3115 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3116
3117 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3118 if (!nocow_ctx) {
3119 spin_lock(&sctx->stat_lock);
3120 sctx->stat.malloc_errors++;
3121 spin_unlock(&sctx->stat_lock);
3122 return -ENOMEM;
3123 }
3124
3125 scrub_pending_trans_workers_inc(sctx);
3126
3127 nocow_ctx->sctx = sctx;
3128 nocow_ctx->logical = logical;
3129 nocow_ctx->len = len;
3130 nocow_ctx->mirror_num = mirror_num;
3131 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
3132 nocow_ctx->work.func = copy_nocow_pages_worker;
652f25a2 3133 INIT_LIST_HEAD(&nocow_ctx->inodes);
ff023aac
SB		 3134 btrfs_queue_worker(&fs_info->scrub_nocow_workers,
3135 &nocow_ctx->work);
3136
3137 return 0;
3138}
3139
652f25a2
JB		 3140static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
3141{
3142 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3143 struct scrub_nocow_inode *nocow_inode;
3144
3145 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
3146 if (!nocow_inode)
3147 return -ENOMEM;
3148 nocow_inode->inum = inum;
3149 nocow_inode->offset = offset;
3150 nocow_inode->root = root;
3151 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
3152 return 0;
3153}
3154
3155#define COPY_COMPLETE 1
3156
ff023aac
SB		 3157static void copy_nocow_pages_worker(struct btrfs_work *work)
3158{
3159 struct scrub_copy_nocow_ctx *nocow_ctx =
3160 container_of(work, struct scrub_copy_nocow_ctx, work);
3161 struct scrub_ctx *sctx = nocow_ctx->sctx;
3162 u64 logical = nocow_ctx->logical;
3163 u64 len = nocow_ctx->len;
3164 int mirror_num = nocow_ctx->mirror_num;
3165 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3166 int ret;
3167 struct btrfs_trans_handle *trans = NULL;
3168 struct btrfs_fs_info *fs_info;
3169 struct btrfs_path *path;
3170 struct btrfs_root *root;
3171 int not_written = 0;
3172
3173 fs_info = sctx->dev_root->fs_info;
3174 root = fs_info->extent_root;
3175
3176 path = btrfs_alloc_path();
3177 if (!path) {
3178 spin_lock(&sctx->stat_lock);
3179 sctx->stat.malloc_errors++;
3180 spin_unlock(&sctx->stat_lock);
3181 not_written = 1;
3182 goto out;
3183 }
3184
3185 trans = btrfs_join_transaction(root);
3186 if (IS_ERR(trans)) {
3187 not_written = 1;
3188 goto out;
3189 }
3190
3191 ret = iterate_inodes_from_logical(logical, fs_info, path,
652f25a2 3192 record_inode_for_nocow, nocow_ctx);
ff023aac 3193 if (ret != 0 && ret != -ENOENT) {
efe120a0
FH		 3194 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
3195 "phys %llu, len %llu, mir %u, ret %d",
118a0a25
GU		 3196 logical, physical_for_dev_replace, len, mirror_num,
3197 ret);
ff023aac
SB		 3198 not_written = 1;
3199 goto out;
3200 }
3201
652f25a2
JB		 3202 btrfs_end_transaction(trans, root);
3203 trans = NULL;
3204 while (!list_empty(&nocow_ctx->inodes)) {
3205 struct scrub_nocow_inode *entry;
3206 entry = list_first_entry(&nocow_ctx->inodes,
3207 struct scrub_nocow_inode,
3208 list);
3209 list_del_init(&entry->list);
3210 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
3211 entry->root, nocow_ctx);
3212 kfree(entry);
3213 if (ret == COPY_COMPLETE) {
3214 ret = 0;
3215 break;
3216 } else if (ret) {
3217 break;
3218 }
3219 }
ff023aac 3220out:
652f25a2
JB		 3221 while (!list_empty(&nocow_ctx->inodes)) {
3222 struct scrub_nocow_inode *entry;
3223 entry = list_first_entry(&nocow_ctx->inodes,
3224 struct scrub_nocow_inode,
3225 list);
3226 list_del_init(&entry->list);
3227 kfree(entry);
3228 }
ff023aac
SB		 3229 if (trans && !IS_ERR(trans))
3230 btrfs_end_transaction(trans, root);
3231 if (not_written)
3232 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
3233 num_uncorrectable_read_errors);
3234
3235 btrfs_free_path(path);
3236 kfree(nocow_ctx);
3237
3238 scrub_pending_trans_workers_dec(sctx);
3239}
3240
652f25a2
JB		 3241static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
3242 struct scrub_copy_nocow_ctx *nocow_ctx)
ff023aac 3243{
826aa0a8 3244 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
ff023aac 3245 struct btrfs_key key;
826aa0a8
MX		 3246 struct inode *inode;
3247 struct page *page;
ff023aac 3248 struct btrfs_root *local_root;
652f25a2
JB		 3249 struct btrfs_ordered_extent *ordered;
3250 struct extent_map *em;
3251 struct extent_state *cached_state = NULL;
3252 struct extent_io_tree *io_tree;
ff023aac 3253 u64 physical_for_dev_replace;
652f25a2
JB		 3254 u64 len = nocow_ctx->len;
3255 u64 lockstart = offset, lockend = offset + len - 1;
826aa0a8 3256 unsigned long index;
6f1c3605 3257 int srcu_index;
652f25a2
JB		 3258 int ret = 0;
3259 int err = 0;
ff023aac
SB		 3260
3261 key.objectid = root;
3262 key.type = BTRFS_ROOT_ITEM_KEY;
3263 key.offset = (u64)-1;
6f1c3605
LB		 3264
3265 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
3266
ff023aac 3267 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
6f1c3605
LB		 3268 if (IS_ERR(local_root)) {
3269 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
ff023aac 3270 return PTR_ERR(local_root);
6f1c3605 3271 }
ff023aac
SB		 3272
3273 key.type = BTRFS_INODE_ITEM_KEY;
3274 key.objectid = inum;
3275 key.offset = 0;
3276 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
6f1c3605 3277 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
ff023aac
SB		 3278 if (IS_ERR(inode))
3279 return PTR_ERR(inode);
3280
edd1400b
MX		 3281 /* Avoid truncate/dio/punch hole.. */
3282 mutex_lock(&inode->i_mutex);
3283 inode_dio_wait(inode);
3284
ff023aac 3285 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
652f25a2
JB		 3286 io_tree = &BTRFS_I(inode)->io_tree;
3287
3288 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
3289 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
3290 if (ordered) {
3291 btrfs_put_ordered_extent(ordered);
3292 goto out_unlock;
3293 }
3294
3295 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0);
3296 if (IS_ERR(em)) {
3297 ret = PTR_ERR(em);
3298 goto out_unlock;
3299 }
3300
3301 /*
3302 * This extent does not actually cover the logical extent anymore,
3303 * move on to the next inode.
3304 */
3305 if (em->block_start > nocow_ctx->logical ||
3306 em->block_start + em->block_len < nocow_ctx->logical + len) {
3307 free_extent_map(em);
3308 goto out_unlock;
3309 }
3310 free_extent_map(em);
3311
ff023aac 3312 while (len >= PAGE_CACHE_SIZE) {
ff023aac 3313 index = offset >> PAGE_CACHE_SHIFT;
edd1400b 3314again:
ff023aac
SB		 3315 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3316 if (!page) {
efe120a0 3317 btrfs_err(fs_info, "find_or_create_page() failed");
ff023aac 3318 ret = -ENOMEM;
826aa0a8 3319 goto out;
ff023aac
SB		 3320 }
3321
3322 if (PageUptodate(page)) {
3323 if (PageDirty(page))
3324 goto next_page;
3325 } else {
3326 ClearPageError(page);
652f25a2
JB		 3327 err = extent_read_full_page_nolock(io_tree, page,
3328 btrfs_get_extent,
3329 nocow_ctx->mirror_num);
826aa0a8
MX		 3330 if (err) {
3331 ret = err;
ff023aac
SB		 3332 goto next_page;
3333 }
edd1400b 3334
26b25891 3335 lock_page(page);
edd1400b
MX		 3336 /*
3337 * If the page has been remove from the page cache,
3338 * the data on it is meaningless, because it may be
3339 * old one, the new data may be written into the new
3340 * page in the page cache.
3341 */
3342 if (page->mapping != inode->i_mapping) {
652f25a2 3343 unlock_page(page);
edd1400b
MX		 3344 page_cache_release(page);
3345 goto again;
3346 }
ff023aac
SB		 3347 if (!PageUptodate(page)) {
3348 ret = -EIO;
3349 goto next_page;
3350 }
3351 }
826aa0a8
MX		 3352 err = write_page_nocow(nocow_ctx->sctx,
3353 physical_for_dev_replace, page);
3354 if (err)
3355 ret = err;
ff023aac 3356next_page:
826aa0a8
MX		 3357 unlock_page(page);
3358 page_cache_release(page);
3359
3360 if (ret)
3361 break;
3362
ff023aac
SB		 3363 offset += PAGE_CACHE_SIZE;
3364 physical_for_dev_replace += PAGE_CACHE_SIZE;
3365 len -= PAGE_CACHE_SIZE;
3366 }
652f25a2
JB		 3367 ret = COPY_COMPLETE;
3368out_unlock:
3369 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
3370 GFP_NOFS);
826aa0a8 3371out:
edd1400b 3372 mutex_unlock(&inode->i_mutex);
826aa0a8 3373 iput(inode);
ff023aac
SB		 3374 return ret;
3375}
3376
3377static int write_page_nocow(struct scrub_ctx *sctx,
3378 u64 physical_for_dev_replace, struct page *page)
3379{
3380 struct bio *bio;
3381 struct btrfs_device *dev;
3382 int ret;
ff023aac
SB		 3383
3384 dev = sctx->wr_ctx.tgtdev;
3385 if (!dev)
3386 return -EIO;
3387 if (!dev->bdev) {
3388 printk_ratelimited(KERN_WARNING
efe120a0 3389 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
ff023aac
SB		 3390 return -EIO;
3391 }
9be3395b 3392 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
ff023aac
SB		 3393 if (!bio) {
3394 spin_lock(&sctx->stat_lock);
3395 sctx->stat.malloc_errors++;
3396 spin_unlock(&sctx->stat_lock);
3397 return -ENOMEM;
3398 }
ff023aac
SB		 3399 bio->bi_size = 0;
3400 bio->bi_sector = physical_for_dev_replace >> 9;
3401 bio->bi_bdev = dev->bdev;
3402 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
3403 if (ret != PAGE_CACHE_SIZE) {
3404leave_with_eio:
3405 bio_put(bio);
3406 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
3407 return -EIO;
3408 }
ff023aac 3409
c170bbb4 3410 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
ff023aac
SB		 3411 goto leave_with_eio;
3412
3413 bio_put(bio);
3414 return 0;
3415}
Linux kernel - Deliverables
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