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btrfs: fix inline compressed read err corruption
[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 430 sbio->page_count = 0;
0339ef2f
QW		 431 btrfs_init_work(&sbio->work, scrub_bio_end_io_worker,
432 NULL, NULL);
a2de733c 433
ff023aac 434 if (i != SCRUB_BIOS_PER_SCTX - 1)
d9d181c1 435 sctx->bios[i]->next_free = i + 1;
0ef8e451 436 else
d9d181c1
SB		 437 sctx->bios[i]->next_free = -1;
438 }
439 sctx->first_free = 0;
440 sctx->nodesize = dev->dev_root->nodesize;
441 sctx->leafsize = dev->dev_root->leafsize;
442 sctx->sectorsize = dev->dev_root->sectorsize;
b6bfebc1
SB		 443 atomic_set(&sctx->bios_in_flight, 0);
444 atomic_set(&sctx->workers_pending, 0);
d9d181c1
SB		 445 atomic_set(&sctx->cancel_req, 0);
446 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
447 INIT_LIST_HEAD(&sctx->csum_list);
448
449 spin_lock_init(&sctx->list_lock);
450 spin_lock_init(&sctx->stat_lock);
451 init_waitqueue_head(&sctx->list_wait);
ff023aac
SB		 452
453 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
454 fs_info->dev_replace.tgtdev, is_dev_replace);
455 if (ret) {
456 scrub_free_ctx(sctx);
457 return ERR_PTR(ret);
458 }
d9d181c1 459 return sctx;
a2de733c
AJ		 460
461nomem:
d9d181c1 462 scrub_free_ctx(sctx);
a2de733c
AJ		 463 return ERR_PTR(-ENOMEM);
464}
465
ff023aac
SB		 466static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
467 void *warn_ctx)
558540c1
JS		 468{
469 u64 isize;
470 u32 nlink;
471 int ret;
472 int i;
473 struct extent_buffer *eb;
474 struct btrfs_inode_item *inode_item;
ff023aac 475 struct scrub_warning *swarn = warn_ctx;
558540c1
JS		 476 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
477 struct inode_fs_paths *ipath = NULL;
478 struct btrfs_root *local_root;
479 struct btrfs_key root_key;
480
481 root_key.objectid = root;
482 root_key.type = BTRFS_ROOT_ITEM_KEY;
483 root_key.offset = (u64)-1;
484 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
485 if (IS_ERR(local_root)) {
486 ret = PTR_ERR(local_root);
487 goto err;
488 }
489
490 ret = inode_item_info(inum, 0, local_root, swarn->path);
491 if (ret) {
492 btrfs_release_path(swarn->path);
493 goto err;
494 }
495
496 eb = swarn->path->nodes[0];
497 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
498 struct btrfs_inode_item);
499 isize = btrfs_inode_size(eb, inode_item);
500 nlink = btrfs_inode_nlink(eb, inode_item);
501 btrfs_release_path(swarn->path);
502
503 ipath = init_ipath(4096, local_root, swarn->path);
26bdef54
DC		 504 if (IS_ERR(ipath)) {
505 ret = PTR_ERR(ipath);
506 ipath = NULL;
507 goto err;
508 }
558540c1
JS		 509 ret = paths_from_inode(inum, ipath);
510
511 if (ret < 0)
512 goto err;
513
514 /*
515 * we deliberately ignore the bit ipath might have been too small to
516 * hold all of the paths here
517 */
518 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
efe120a0 519 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
558540c1
JS		 520 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
521 "length %llu, links %u (path: %s)\n", swarn->errstr,
606686ee 522 swarn->logical, rcu_str_deref(swarn->dev->name),
558540c1
JS		 523 (unsigned long long)swarn->sector, root, inum, offset,
524 min(isize - offset, (u64)PAGE_SIZE), nlink,
745c4d8e 525 (char *)(unsigned long)ipath->fspath->val[i]);
558540c1
JS		 526
527 free_ipath(ipath);
528 return 0;
529
530err:
efe120a0 531 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
558540c1
JS		 532 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
533 "resolving failed with ret=%d\n", swarn->errstr,
606686ee 534 swarn->logical, rcu_str_deref(swarn->dev->name),
558540c1
JS		 535 (unsigned long long)swarn->sector, root, inum, offset, ret);
536
537 free_ipath(ipath);
538 return 0;
539}
540
b5d67f64 541static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
558540c1 542{
a36cf8b8
SB		 543 struct btrfs_device *dev;
544 struct btrfs_fs_info *fs_info;
558540c1
JS		 545 struct btrfs_path *path;
546 struct btrfs_key found_key;
547 struct extent_buffer *eb;
548 struct btrfs_extent_item *ei;
549 struct scrub_warning swarn;
69917e43
LB		 550 unsigned long ptr = 0;
551 u64 extent_item_pos;
552 u64 flags = 0;
558540c1 553 u64 ref_root;
69917e43 554 u32 item_size;
558540c1 555 u8 ref_level;
558540c1 556 const int bufsize = 4096;
69917e43 557 int ret;
558540c1 558
a36cf8b8 559 WARN_ON(sblock->page_count < 1);
7a9e9987 560 dev = sblock->pagev[0]->dev;
a36cf8b8
SB		 561 fs_info = sblock->sctx->dev_root->fs_info;
562
558540c1
JS		 563 path = btrfs_alloc_path();
564
565 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
566 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
7a9e9987
SB		 567 swarn.sector = (sblock->pagev[0]->physical) >> 9;
568 swarn.logical = sblock->pagev[0]->logical;
558540c1 569 swarn.errstr = errstr;
a36cf8b8 570 swarn.dev = NULL;
558540c1
JS		 571 swarn.msg_bufsize = bufsize;
572 swarn.scratch_bufsize = bufsize;
573
574 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
575 goto out;
576
69917e43
LB		 577 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
578 &flags);
558540c1
JS		 579 if (ret < 0)
580 goto out;
581
4692cf58 582 extent_item_pos = swarn.logical - found_key.objectid;
558540c1
JS		 583 swarn.extent_item_size = found_key.offset;
584
585 eb = path->nodes[0];
586 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
587 item_size = btrfs_item_size_nr(eb, path->slots[0]);
588
69917e43 589 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
558540c1
JS		 590 do {
591 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
592 &ref_root, &ref_level);
606686ee 593 printk_in_rcu(KERN_WARNING
efe120a0 594 "BTRFS: %s at logical %llu on dev %s, "
558540c1 595 "sector %llu: metadata %s (level %d) in tree "
606686ee
JB		 596 "%llu\n", errstr, swarn.logical,
597 rcu_str_deref(dev->name),
558540c1
JS		 598 (unsigned long long)swarn.sector,
599 ref_level ? "node" : "leaf",
600 ret < 0 ? -1 : ref_level,
601 ret < 0 ? -1 : ref_root);
602 } while (ret != 1);
d8fe29e9 603 btrfs_release_path(path);
558540c1 604 } else {
d8fe29e9 605 btrfs_release_path(path);
558540c1 606 swarn.path = path;
a36cf8b8 607 swarn.dev = dev;
7a3ae2f8
JS		 608 iterate_extent_inodes(fs_info, found_key.objectid,
609 extent_item_pos, 1,
558540c1
JS		 610 scrub_print_warning_inode, &swarn);
611 }
612
613out:
614 btrfs_free_path(path);
615 kfree(swarn.scratch_buf);
616 kfree(swarn.msg_buf);
617}
618
ff023aac 619static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
0ef8e451 620{
5da6fcbc 621 struct page *page = NULL;
0ef8e451 622 unsigned long index;
ff023aac 623 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
0ef8e451 624 int ret;
5da6fcbc 625 int corrected = 0;
0ef8e451 626 struct btrfs_key key;
5da6fcbc 627 struct inode *inode = NULL;
6f1c3605 628 struct btrfs_fs_info *fs_info;
0ef8e451
JS		 629 u64 end = offset + PAGE_SIZE - 1;
630 struct btrfs_root *local_root;
6f1c3605 631 int srcu_index;
0ef8e451
JS		 632
633 key.objectid = root;
634 key.type = BTRFS_ROOT_ITEM_KEY;
635 key.offset = (u64)-1;
6f1c3605
LB		 636
637 fs_info = fixup->root->fs_info;
638 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
639
640 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
641 if (IS_ERR(local_root)) {
642 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
0ef8e451 643 return PTR_ERR(local_root);
6f1c3605 644 }
0ef8e451
JS		 645
646 key.type = BTRFS_INODE_ITEM_KEY;
647 key.objectid = inum;
648 key.offset = 0;
6f1c3605
LB		 649 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
650 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
0ef8e451
JS		 651 if (IS_ERR(inode))
652 return PTR_ERR(inode);
653
0ef8e451
JS		 654 index = offset >> PAGE_CACHE_SHIFT;
655
656 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
5da6fcbc
JS		 657 if (!page) {
658 ret = -ENOMEM;
659 goto out;
660 }
661
662 if (PageUptodate(page)) {
5da6fcbc
JS		 663 if (PageDirty(page)) {
664 /*
665 * we need to write the data to the defect sector. the
666 * data that was in that sector is not in memory,
667 * because the page was modified. we must not write the
668 * modified page to that sector.
669 *
670 * TODO: what could be done here: wait for the delalloc
671 * runner to write out that page (might involve
672 * COW) and see whether the sector is still
673 * referenced afterwards.
674 *
675 * For the meantime, we'll treat this error
676 * incorrectable, although there is a chance that a
677 * later scrub will find the bad sector again and that
678 * there's no dirty page in memory, then.
679 */
680 ret = -EIO;
681 goto out;
682 }
3ec706c8
SB		 683 fs_info = BTRFS_I(inode)->root->fs_info;
684 ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
5da6fcbc
JS		 685 fixup->logical, page,
686 fixup->mirror_num);
687 unlock_page(page);
688 corrected = !ret;
689 } else {
690 /*
691 * we need to get good data first. the general readpage path
692 * will call repair_io_failure for us, we just have to make
693 * sure we read the bad mirror.
694 */
695 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
696 EXTENT_DAMAGED, GFP_NOFS);
697 if (ret) {
698 /* set_extent_bits should give proper error */
699 WARN_ON(ret > 0);
700 if (ret > 0)
701 ret = -EFAULT;
702 goto out;
703 }
704
705 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
706 btrfs_get_extent,
707 fixup->mirror_num);
708 wait_on_page_locked(page);
709
710 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
711 end, EXTENT_DAMAGED, 0, NULL);
712 if (!corrected)
713 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
714 EXTENT_DAMAGED, GFP_NOFS);
715 }
716
717out:
718 if (page)
719 put_page(page);
720 if (inode)
721 iput(inode);
0ef8e451
JS		 722
723 if (ret < 0)
724 return ret;
725
726 if (ret == 0 && corrected) {
727 /*
728 * we only need to call readpage for one of the inodes belonging
729 * to this extent. so make iterate_extent_inodes stop
730 */
731 return 1;
732 }
733
734 return -EIO;
735}
736
737static void scrub_fixup_nodatasum(struct btrfs_work *work)
738{
739 int ret;
740 struct scrub_fixup_nodatasum *fixup;
d9d181c1 741 struct scrub_ctx *sctx;
0ef8e451 742 struct btrfs_trans_handle *trans = NULL;
0ef8e451
JS		 743 struct btrfs_path *path;
744 int uncorrectable = 0;
745
746 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
d9d181c1 747 sctx = fixup->sctx;
0ef8e451
JS		 748
749 path = btrfs_alloc_path();
750 if (!path) {
d9d181c1
SB		 751 spin_lock(&sctx->stat_lock);
752 ++sctx->stat.malloc_errors;
753 spin_unlock(&sctx->stat_lock);
0ef8e451
JS		 754 uncorrectable = 1;
755 goto out;
756 }
757
758 trans = btrfs_join_transaction(fixup->root);
759 if (IS_ERR(trans)) {
760 uncorrectable = 1;
761 goto out;
762 }
763
764 /*
765 * the idea is to trigger a regular read through the standard path. we
766 * read a page from the (failed) logical address by specifying the
767 * corresponding copynum of the failed sector. thus, that readpage is
768 * expected to fail.
769 * that is the point where on-the-fly error correction will kick in
770 * (once it's finished) and rewrite the failed sector if a good copy
771 * can be found.
772 */
773 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
774 path, scrub_fixup_readpage,
775 fixup);
776 if (ret < 0) {
777 uncorrectable = 1;
778 goto out;
779 }
780 WARN_ON(ret != 1);
781
d9d181c1
SB		 782 spin_lock(&sctx->stat_lock);
783 ++sctx->stat.corrected_errors;
784 spin_unlock(&sctx->stat_lock);
0ef8e451
JS		 785
786out:
787 if (trans && !IS_ERR(trans))
788 btrfs_end_transaction(trans, fixup->root);
789 if (uncorrectable) {
d9d181c1
SB		 790 spin_lock(&sctx->stat_lock);
791 ++sctx->stat.uncorrectable_errors;
792 spin_unlock(&sctx->stat_lock);
ff023aac
SB		 793 btrfs_dev_replace_stats_inc(
794 &sctx->dev_root->fs_info->dev_replace.
795 num_uncorrectable_read_errors);
efe120a0
FH		 796 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
797 "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
c1c9ff7c 798 fixup->logical, rcu_str_deref(fixup->dev->name));
0ef8e451
JS		 799 }
800
801 btrfs_free_path(path);
802 kfree(fixup);
803
b6bfebc1 804 scrub_pending_trans_workers_dec(sctx);
0ef8e451
JS		 805}
806
a2de733c 807/*
b5d67f64
SB		 808 * scrub_handle_errored_block gets called when either verification of the
809 * pages failed or the bio failed to read, e.g. with EIO. In the latter
810 * case, this function handles all pages in the bio, even though only one
811 * may be bad.
812 * The goal of this function is to repair the errored block by using the
813 * contents of one of the mirrors.
a2de733c 814 */
b5d67f64 815static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
a2de733c 816{
d9d181c1 817 struct scrub_ctx *sctx = sblock_to_check->sctx;
a36cf8b8 818 struct btrfs_device *dev;
b5d67f64
SB		 819 struct btrfs_fs_info *fs_info;
820 u64 length;
821 u64 logical;
822 u64 generation;
823 unsigned int failed_mirror_index;
824 unsigned int is_metadata;
825 unsigned int have_csum;
826 u8 *csum;
827 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
828 struct scrub_block *sblock_bad;
829 int ret;
830 int mirror_index;
831 int page_num;
832 int success;
558540c1 833 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
b5d67f64
SB		 834 DEFAULT_RATELIMIT_BURST);
835
836 BUG_ON(sblock_to_check->page_count < 1);
a36cf8b8 837 fs_info = sctx->dev_root->fs_info;
4ded4f63
SB		 838 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
839 /*
840 * if we find an error in a super block, we just report it.
841 * They will get written with the next transaction commit
842 * anyway
843 */
844 spin_lock(&sctx->stat_lock);
845 ++sctx->stat.super_errors;
846 spin_unlock(&sctx->stat_lock);
847 return 0;
848 }
b5d67f64 849 length = sblock_to_check->page_count * PAGE_SIZE;
7a9e9987
SB		 850 logical = sblock_to_check->pagev[0]->logical;
851 generation = sblock_to_check->pagev[0]->generation;
852 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
853 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
854 is_metadata = !(sblock_to_check->pagev[0]->flags &
b5d67f64 855 BTRFS_EXTENT_FLAG_DATA);
7a9e9987
SB		 856 have_csum = sblock_to_check->pagev[0]->have_csum;
857 csum = sblock_to_check->pagev[0]->csum;
858 dev = sblock_to_check->pagev[0]->dev;
13db62b7 859
ff023aac
SB		 860 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
861 sblocks_for_recheck = NULL;
862 goto nodatasum_case;
863 }
864
b5d67f64
SB		 865 /*
866 * read all mirrors one after the other. This includes to
867 * re-read the extent or metadata block that failed (that was
868 * the cause that this fixup code is called) another time,
869 * page by page this time in order to know which pages
870 * caused I/O errors and which ones are good (for all mirrors).
871 * It is the goal to handle the situation when more than one
872 * mirror contains I/O errors, but the errors do not
873 * overlap, i.e. the data can be repaired by selecting the
874 * pages from those mirrors without I/O error on the
875 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
876 * would be that mirror #1 has an I/O error on the first page,
877 * the second page is good, and mirror #2 has an I/O error on
878 * the second page, but the first page is good.
879 * Then the first page of the first mirror can be repaired by
880 * taking the first page of the second mirror, and the
881 * second page of the second mirror can be repaired by
882 * copying the contents of the 2nd page of the 1st mirror.
883 * One more note: if the pages of one mirror contain I/O
884 * errors, the checksum cannot be verified. In order to get
885 * the best data for repairing, the first attempt is to find
886 * a mirror without I/O errors and with a validated checksum.
887 * Only if this is not possible, the pages are picked from
888 * mirrors with I/O errors without considering the checksum.
889 * If the latter is the case, at the end, the checksum of the
890 * repaired area is verified in order to correctly maintain
891 * the statistics.
892 */
893
894 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
895 sizeof(*sblocks_for_recheck),
896 GFP_NOFS);
897 if (!sblocks_for_recheck) {
d9d181c1
SB		 898 spin_lock(&sctx->stat_lock);
899 sctx->stat.malloc_errors++;
900 sctx->stat.read_errors++;
901 sctx->stat.uncorrectable_errors++;
902 spin_unlock(&sctx->stat_lock);
a36cf8b8 903 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64 904 goto out;
a2de733c
AJ		 905 }
906
b5d67f64 907 /* setup the context, map the logical blocks and alloc the pages */
ff023aac 908 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
b5d67f64
SB		 909 logical, sblocks_for_recheck);
910 if (ret) {
d9d181c1
SB		 911 spin_lock(&sctx->stat_lock);
912 sctx->stat.read_errors++;
913 sctx->stat.uncorrectable_errors++;
914 spin_unlock(&sctx->stat_lock);
a36cf8b8 915 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64
SB		 916 goto out;
917 }
918 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
919 sblock_bad = sblocks_for_recheck + failed_mirror_index;
13db62b7 920
b5d67f64 921 /* build and submit the bios for the failed mirror, check checksums */
34f5c8e9
SB		 922 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
923 csum, generation, sctx->csum_size);
a2de733c 924
b5d67f64
SB		 925 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
926 sblock_bad->no_io_error_seen) {
927 /*
928 * the error disappeared after reading page by page, or
929 * the area was part of a huge bio and other parts of the
930 * bio caused I/O errors, or the block layer merged several
931 * read requests into one and the error is caused by a
932 * different bio (usually one of the two latter cases is
933 * the cause)
934 */
d9d181c1
SB		 935 spin_lock(&sctx->stat_lock);
936 sctx->stat.unverified_errors++;
937 spin_unlock(&sctx->stat_lock);
a2de733c 938
ff023aac
SB		 939 if (sctx->is_dev_replace)
940 scrub_write_block_to_dev_replace(sblock_bad);
b5d67f64 941 goto out;
a2de733c 942 }
a2de733c 943
b5d67f64 944 if (!sblock_bad->no_io_error_seen) {
d9d181c1
SB		 945 spin_lock(&sctx->stat_lock);
946 sctx->stat.read_errors++;
947 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 948 if (__ratelimit(&_rs))
949 scrub_print_warning("i/o error", sblock_to_check);
a36cf8b8 950 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64 951 } else if (sblock_bad->checksum_error) {
d9d181c1
SB		 952 spin_lock(&sctx->stat_lock);
953 sctx->stat.csum_errors++;
954 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 955 if (__ratelimit(&_rs))
956 scrub_print_warning("checksum error", sblock_to_check);
a36cf8b8 957 btrfs_dev_stat_inc_and_print(dev,
442a4f63 958 BTRFS_DEV_STAT_CORRUPTION_ERRS);
b5d67f64 959 } else if (sblock_bad->header_error) {
d9d181c1
SB		 960 spin_lock(&sctx->stat_lock);
961 sctx->stat.verify_errors++;
962 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 963 if (__ratelimit(&_rs))
964 scrub_print_warning("checksum/header error",
965 sblock_to_check);
442a4f63 966 if (sblock_bad->generation_error)
a36cf8b8 967 btrfs_dev_stat_inc_and_print(dev,
442a4f63
SB		 968 BTRFS_DEV_STAT_GENERATION_ERRS);
969 else
a36cf8b8 970 btrfs_dev_stat_inc_and_print(dev,
442a4f63 971 BTRFS_DEV_STAT_CORRUPTION_ERRS);
b5d67f64 972 }
a2de733c 973
33ef30ad
ID		 974 if (sctx->readonly) {
975 ASSERT(!sctx->is_dev_replace);
976 goto out;
977 }
a2de733c 978
b5d67f64
SB		 979 if (!is_metadata && !have_csum) {
980 struct scrub_fixup_nodatasum *fixup_nodatasum;
a2de733c 981
ff023aac
SB		 982nodatasum_case:
983 WARN_ON(sctx->is_dev_replace);
984
b5d67f64
SB		 985 /*
986 * !is_metadata and !have_csum, this means that the data
987 * might not be COW'ed, that it might be modified
988 * concurrently. The general strategy to work on the
989 * commit root does not help in the case when COW is not
990 * used.
991 */
992 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
993 if (!fixup_nodatasum)
994 goto did_not_correct_error;
d9d181c1 995 fixup_nodatasum->sctx = sctx;
a36cf8b8 996 fixup_nodatasum->dev = dev;
b5d67f64
SB		 997 fixup_nodatasum->logical = logical;
998 fixup_nodatasum->root = fs_info->extent_root;
999 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
b6bfebc1 1000 scrub_pending_trans_workers_inc(sctx);
0339ef2f
QW		 1001 btrfs_init_work(&fixup_nodatasum->work, scrub_fixup_nodatasum,
1002 NULL, NULL);
1003 btrfs_queue_work(fs_info->scrub_workers,
1004 &fixup_nodatasum->work);
b5d67f64 1005 goto out;
a2de733c
AJ		 1006 }
1007
b5d67f64
SB		 1008 /*
1009 * now build and submit the bios for the other mirrors, check
cb2ced73
SB		 1010 * checksums.
1011 * First try to pick the mirror which is completely without I/O
b5d67f64
SB		 1012 * errors and also does not have a checksum error.
1013 * If one is found, and if a checksum is present, the full block
1014 * that is known to contain an error is rewritten. Afterwards
1015 * the block is known to be corrected.
1016 * If a mirror is found which is completely correct, and no
1017 * checksum is present, only those pages are rewritten that had
1018 * an I/O error in the block to be repaired, since it cannot be
1019 * determined, which copy of the other pages is better (and it
1020 * could happen otherwise that a correct page would be
1021 * overwritten by a bad one).
1022 */
1023 for (mirror_index = 0;
1024 mirror_index < BTRFS_MAX_MIRRORS &&
1025 sblocks_for_recheck[mirror_index].page_count > 0;
1026 mirror_index++) {
cb2ced73 1027 struct scrub_block *sblock_other;
b5d67f64 1028
cb2ced73
SB		 1029 if (mirror_index == failed_mirror_index)
1030 continue;
1031 sblock_other = sblocks_for_recheck + mirror_index;
1032
1033 /* build and submit the bios, check checksums */
34f5c8e9
SB		 1034 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1035 have_csum, csum, generation,
1036 sctx->csum_size);
1037
1038 if (!sblock_other->header_error &&
b5d67f64
SB		 1039 !sblock_other->checksum_error &&
1040 sblock_other->no_io_error_seen) {
ff023aac
SB		 1041 if (sctx->is_dev_replace) {
1042 scrub_write_block_to_dev_replace(sblock_other);
1043 } else {
1044 int force_write = is_metadata || have_csum;
1045
1046 ret = scrub_repair_block_from_good_copy(
1047 sblock_bad, sblock_other,
1048 force_write);
1049 }
b5d67f64
SB		 1050 if (0 == ret)
1051 goto corrected_error;
1052 }
1053 }
a2de733c
AJ		 1054
1055 /*
ff023aac
SB		 1056 * for dev_replace, pick good pages and write to the target device.
1057 */
1058 if (sctx->is_dev_replace) {
1059 success = 1;
1060 for (page_num = 0; page_num < sblock_bad->page_count;
1061 page_num++) {
1062 int sub_success;
1063
1064 sub_success = 0;
1065 for (mirror_index = 0;
1066 mirror_index < BTRFS_MAX_MIRRORS &&
1067 sblocks_for_recheck[mirror_index].page_count > 0;
1068 mirror_index++) {
1069 struct scrub_block *sblock_other =
1070 sblocks_for_recheck + mirror_index;
1071 struct scrub_page *page_other =
1072 sblock_other->pagev[page_num];
1073
1074 if (!page_other->io_error) {
1075 ret = scrub_write_page_to_dev_replace(
1076 sblock_other, page_num);
1077 if (ret == 0) {
1078 /* succeeded for this page */
1079 sub_success = 1;
1080 break;
1081 } else {
1082 btrfs_dev_replace_stats_inc(
1083 &sctx->dev_root->
1084 fs_info->dev_replace.
1085 num_write_errors);
1086 }
1087 }
1088 }
1089
1090 if (!sub_success) {
1091 /*
1092 * did not find a mirror to fetch the page
1093 * from. scrub_write_page_to_dev_replace()
1094 * handles this case (page->io_error), by
1095 * filling the block with zeros before
1096 * submitting the write request
1097 */
1098 success = 0;
1099 ret = scrub_write_page_to_dev_replace(
1100 sblock_bad, page_num);
1101 if (ret)
1102 btrfs_dev_replace_stats_inc(
1103 &sctx->dev_root->fs_info->
1104 dev_replace.num_write_errors);
1105 }
1106 }
1107
1108 goto out;
1109 }
1110
1111 /*
1112 * for regular scrub, repair those pages that are errored.
1113 * In case of I/O errors in the area that is supposed to be
b5d67f64
SB		 1114 * repaired, continue by picking good copies of those pages.
1115 * Select the good pages from mirrors to rewrite bad pages from
1116 * the area to fix. Afterwards verify the checksum of the block
1117 * that is supposed to be repaired. This verification step is
1118 * only done for the purpose of statistic counting and for the
1119 * final scrub report, whether errors remain.
1120 * A perfect algorithm could make use of the checksum and try
1121 * all possible combinations of pages from the different mirrors
1122 * until the checksum verification succeeds. For example, when
1123 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1124 * of mirror #2 is readable but the final checksum test fails,
1125 * then the 2nd page of mirror #3 could be tried, whether now
1126 * the final checksum succeedes. But this would be a rare
1127 * exception and is therefore not implemented. At least it is
1128 * avoided that the good copy is overwritten.
1129 * A more useful improvement would be to pick the sectors
1130 * without I/O error based on sector sizes (512 bytes on legacy
1131 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1132 * mirror could be repaired by taking 512 byte of a different
1133 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1134 * area are unreadable.
a2de733c 1135 */
a2de733c 1136
b5d67f64
SB		 1137 /* can only fix I/O errors from here on */
1138 if (sblock_bad->no_io_error_seen)
1139 goto did_not_correct_error;
1140
1141 success = 1;
1142 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
7a9e9987 1143 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
b5d67f64
SB		 1144
1145 if (!page_bad->io_error)
a2de733c 1146 continue;
b5d67f64
SB		 1147
1148 for (mirror_index = 0;
1149 mirror_index < BTRFS_MAX_MIRRORS &&
1150 sblocks_for_recheck[mirror_index].page_count > 0;
1151 mirror_index++) {
1152 struct scrub_block *sblock_other = sblocks_for_recheck +
1153 mirror_index;
7a9e9987
SB		 1154 struct scrub_page *page_other = sblock_other->pagev[
1155 page_num];
b5d67f64
SB		 1156
1157 if (!page_other->io_error) {
1158 ret = scrub_repair_page_from_good_copy(
1159 sblock_bad, sblock_other, page_num, 0);
1160 if (0 == ret) {
1161 page_bad->io_error = 0;
1162 break; /* succeeded for this page */
1163 }
1164 }
96e36920 1165 }
a2de733c 1166
b5d67f64
SB		 1167 if (page_bad->io_error) {
1168 /* did not find a mirror to copy the page from */
1169 success = 0;
1170 }
a2de733c 1171 }
a2de733c 1172
b5d67f64
SB		 1173 if (success) {
1174 if (is_metadata || have_csum) {
1175 /*
1176 * need to verify the checksum now that all
1177 * sectors on disk are repaired (the write
1178 * request for data to be repaired is on its way).
1179 * Just be lazy and use scrub_recheck_block()
1180 * which re-reads the data before the checksum
1181 * is verified, but most likely the data comes out
1182 * of the page cache.
1183 */
34f5c8e9
SB		 1184 scrub_recheck_block(fs_info, sblock_bad,
1185 is_metadata, have_csum, csum,
1186 generation, sctx->csum_size);
1187 if (!sblock_bad->header_error &&
b5d67f64
SB		 1188 !sblock_bad->checksum_error &&
1189 sblock_bad->no_io_error_seen)
1190 goto corrected_error;
1191 else
1192 goto did_not_correct_error;
1193 } else {
1194corrected_error:
d9d181c1
SB		 1195 spin_lock(&sctx->stat_lock);
1196 sctx->stat.corrected_errors++;
1197 spin_unlock(&sctx->stat_lock);
606686ee 1198 printk_ratelimited_in_rcu(KERN_ERR
efe120a0 1199 "BTRFS: fixed up error at logical %llu on dev %s\n",
c1c9ff7c 1200 logical, rcu_str_deref(dev->name));
8628764e 1201 }
b5d67f64
SB		 1202 } else {
1203did_not_correct_error:
d9d181c1
SB		 1204 spin_lock(&sctx->stat_lock);
1205 sctx->stat.uncorrectable_errors++;
1206 spin_unlock(&sctx->stat_lock);
606686ee 1207 printk_ratelimited_in_rcu(KERN_ERR
efe120a0 1208 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
c1c9ff7c 1209 logical, rcu_str_deref(dev->name));
96e36920 1210 }
a2de733c 1211
b5d67f64
SB		 1212out:
1213 if (sblocks_for_recheck) {
1214 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1215 mirror_index++) {
1216 struct scrub_block *sblock = sblocks_for_recheck +
1217 mirror_index;
1218 int page_index;
1219
7a9e9987
SB		 1220 for (page_index = 0; page_index < sblock->page_count;
1221 page_index++) {
1222 sblock->pagev[page_index]->sblock = NULL;
1223 scrub_page_put(sblock->pagev[page_index]);
1224 }
b5d67f64
SB		 1225 }
1226 kfree(sblocks_for_recheck);
1227 }
a2de733c 1228
b5d67f64
SB		 1229 return 0;
1230}
a2de733c 1231
d9d181c1 1232static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
3ec706c8 1233 struct btrfs_fs_info *fs_info,
ff023aac 1234 struct scrub_block *original_sblock,
b5d67f64
SB		 1235 u64 length, u64 logical,
1236 struct scrub_block *sblocks_for_recheck)
1237{
1238 int page_index;
1239 int mirror_index;
1240 int ret;
1241
1242 /*
7a9e9987 1243 * note: the two members ref_count and outstanding_pages
b5d67f64
SB		 1244 * are not used (and not set) in the blocks that are used for
1245 * the recheck procedure
1246 */
1247
1248 page_index = 0;
1249 while (length > 0) {
1250 u64 sublen = min_t(u64, length, PAGE_SIZE);
1251 u64 mapped_length = sublen;
1252 struct btrfs_bio *bbio = NULL;
a2de733c 1253
b5d67f64
SB		 1254 /*
1255 * with a length of PAGE_SIZE, each returned stripe
1256 * represents one mirror
1257 */
29a8d9a0
SB		 1258 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
1259 &mapped_length, &bbio, 0);
b5d67f64
SB		 1260 if (ret || !bbio || mapped_length < sublen) {
1261 kfree(bbio);
1262 return -EIO;
1263 }
a2de733c 1264
ff023aac 1265 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
b5d67f64
SB		 1266 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1267 mirror_index++) {
1268 struct scrub_block *sblock;
1269 struct scrub_page *page;
1270
1271 if (mirror_index >= BTRFS_MAX_MIRRORS)
1272 continue;
1273
1274 sblock = sblocks_for_recheck + mirror_index;
7a9e9987
SB		 1275 sblock->sctx = sctx;
1276 page = kzalloc(sizeof(*page), GFP_NOFS);
1277 if (!page) {
1278leave_nomem:
d9d181c1
SB		 1279 spin_lock(&sctx->stat_lock);
1280 sctx->stat.malloc_errors++;
1281 spin_unlock(&sctx->stat_lock);
cf93dcce 1282 kfree(bbio);
b5d67f64
SB		 1283 return -ENOMEM;
1284 }
7a9e9987
SB		 1285 scrub_page_get(page);
1286 sblock->pagev[page_index] = page;
1287 page->logical = logical;
1288 page->physical = bbio->stripes[mirror_index].physical;
ff023aac
SB		 1289 BUG_ON(page_index >= original_sblock->page_count);
1290 page->physical_for_dev_replace =
1291 original_sblock->pagev[page_index]->
1292 physical_for_dev_replace;
7a9e9987
SB		 1293 /* for missing devices, dev->bdev is NULL */
1294 page->dev = bbio->stripes[mirror_index].dev;
1295 page->mirror_num = mirror_index + 1;
b5d67f64 1296 sblock->page_count++;
7a9e9987
SB		 1297 page->page = alloc_page(GFP_NOFS);
1298 if (!page->page)
1299 goto leave_nomem;
b5d67f64
SB		 1300 }
1301 kfree(bbio);
1302 length -= sublen;
1303 logical += sublen;
1304 page_index++;
1305 }
1306
1307 return 0;
96e36920
ID		 1308}
1309
b5d67f64
SB		 1310/*
1311 * this function will check the on disk data for checksum errors, header
1312 * errors and read I/O errors. If any I/O errors happen, the exact pages
1313 * which are errored are marked as being bad. The goal is to enable scrub
1314 * to take those pages that are not errored from all the mirrors so that
1315 * the pages that are errored in the just handled mirror can be repaired.
1316 */
34f5c8e9
SB		 1317static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1318 struct scrub_block *sblock, int is_metadata,
1319 int have_csum, u8 *csum, u64 generation,
1320 u16 csum_size)
96e36920 1321{
b5d67f64 1322 int page_num;
96e36920 1323
b5d67f64
SB		 1324 sblock->no_io_error_seen = 1;
1325 sblock->header_error = 0;
1326 sblock->checksum_error = 0;
96e36920 1327
b5d67f64
SB		 1328 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1329 struct bio *bio;
7a9e9987 1330 struct scrub_page *page = sblock->pagev[page_num];
b5d67f64 1331
442a4f63 1332 if (page->dev->bdev == NULL) {
ea9947b4
SB		 1333 page->io_error = 1;
1334 sblock->no_io_error_seen = 0;
1335 continue;
1336 }
1337
7a9e9987 1338 WARN_ON(!page->page);
9be3395b 1339 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
34f5c8e9
SB		 1340 if (!bio) {
1341 page->io_error = 1;
1342 sblock->no_io_error_seen = 0;
1343 continue;
1344 }
442a4f63 1345 bio->bi_bdev = page->dev->bdev;
4f024f37 1346 bio->bi_iter.bi_sector = page->physical >> 9;
b5d67f64 1347
34f5c8e9 1348 bio_add_page(bio, page->page, PAGE_SIZE, 0);
33879d45 1349 if (btrfsic_submit_bio_wait(READ, bio))
b5d67f64 1350 sblock->no_io_error_seen = 0;
33879d45 1351
b5d67f64
SB		 1352 bio_put(bio);
1353 }
96e36920 1354
b5d67f64
SB		 1355 if (sblock->no_io_error_seen)
1356 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1357 have_csum, csum, generation,
1358 csum_size);
1359
34f5c8e9 1360 return;
a2de733c
AJ		 1361}
1362
b5d67f64
SB		 1363static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1364 struct scrub_block *sblock,
1365 int is_metadata, int have_csum,
1366 const u8 *csum, u64 generation,
1367 u16 csum_size)
a2de733c 1368{
b5d67f64
SB		 1369 int page_num;
1370 u8 calculated_csum[BTRFS_CSUM_SIZE];
1371 u32 crc = ~(u32)0;
b5d67f64
SB		 1372 void *mapped_buffer;
1373
7a9e9987 1374 WARN_ON(!sblock->pagev[0]->page);
b5d67f64
SB		 1375 if (is_metadata) {
1376 struct btrfs_header *h;
1377
7a9e9987 1378 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
b5d67f64
SB		 1379 h = (struct btrfs_header *)mapped_buffer;
1380
3cae210f 1381 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
b5d67f64
SB		 1382 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1383 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
442a4f63 1384 BTRFS_UUID_SIZE)) {
b5d67f64 1385 sblock->header_error = 1;
3cae210f 1386 } else if (generation != btrfs_stack_header_generation(h)) {
442a4f63
SB		 1387 sblock->header_error = 1;
1388 sblock->generation_error = 1;
1389 }
b5d67f64
SB		 1390 csum = h->csum;
1391 } else {
1392 if (!have_csum)
1393 return;
a2de733c 1394
7a9e9987 1395 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
b5d67f64 1396 }
a2de733c 1397
b5d67f64
SB		 1398 for (page_num = 0;;) {
1399 if (page_num == 0 && is_metadata)
b0496686 1400 crc = btrfs_csum_data(
b5d67f64
SB		 1401 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1402 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1403 else
b0496686 1404 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
b5d67f64 1405
9613bebb 1406 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1407 page_num++;
1408 if (page_num >= sblock->page_count)
1409 break;
7a9e9987 1410 WARN_ON(!sblock->pagev[page_num]->page);
b5d67f64 1411
7a9e9987 1412 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
b5d67f64
SB		 1413 }
1414
1415 btrfs_csum_final(crc, calculated_csum);
1416 if (memcmp(calculated_csum, csum, csum_size))
1417 sblock->checksum_error = 1;
a2de733c
AJ		 1418}
1419
b5d67f64
SB		 1420static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1421 struct scrub_block *sblock_good,
1422 int force_write)
1423{
1424 int page_num;
1425 int ret = 0;
96e36920 1426
b5d67f64
SB		 1427 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1428 int ret_sub;
96e36920 1429
b5d67f64
SB		 1430 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1431 sblock_good,
1432 page_num,
1433 force_write);
1434 if (ret_sub)
1435 ret = ret_sub;
a2de733c 1436 }
b5d67f64
SB		 1437
1438 return ret;
1439}
1440
1441static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1442 struct scrub_block *sblock_good,
1443 int page_num, int force_write)
1444{
7a9e9987
SB		 1445 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1446 struct scrub_page *page_good = sblock_good->pagev[page_num];
b5d67f64 1447
7a9e9987
SB		 1448 BUG_ON(page_bad->page == NULL);
1449 BUG_ON(page_good->page == NULL);
b5d67f64
SB		 1450 if (force_write || sblock_bad->header_error ||
1451 sblock_bad->checksum_error || page_bad->io_error) {
1452 struct bio *bio;
1453 int ret;
b5d67f64 1454
ff023aac 1455 if (!page_bad->dev->bdev) {
efe120a0
FH		 1456 printk_ratelimited(KERN_WARNING "BTRFS: "
1457 "scrub_repair_page_from_good_copy(bdev == NULL) "
1458 "is unexpected!\n");
ff023aac
SB		 1459 return -EIO;
1460 }
1461
9be3395b 1462 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
e627ee7b
TI		 1463 if (!bio)
1464 return -EIO;
442a4f63 1465 bio->bi_bdev = page_bad->dev->bdev;
4f024f37 1466 bio->bi_iter.bi_sector = page_bad->physical >> 9;
b5d67f64
SB		 1467
1468 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1469 if (PAGE_SIZE != ret) {
1470 bio_put(bio);
1471 return -EIO;
13db62b7 1472 }
b5d67f64 1473
33879d45 1474 if (btrfsic_submit_bio_wait(WRITE, bio)) {
442a4f63
SB		 1475 btrfs_dev_stat_inc_and_print(page_bad->dev,
1476 BTRFS_DEV_STAT_WRITE_ERRS);
ff023aac
SB		 1477 btrfs_dev_replace_stats_inc(
1478 &sblock_bad->sctx->dev_root->fs_info->
1479 dev_replace.num_write_errors);
442a4f63
SB		 1480 bio_put(bio);
1481 return -EIO;
1482 }
b5d67f64 1483 bio_put(bio);
a2de733c
AJ		 1484 }
1485
b5d67f64
SB		 1486 return 0;
1487}
1488
ff023aac
SB		 1489static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1490{
1491 int page_num;
1492
1493 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1494 int ret;
1495
1496 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1497 if (ret)
1498 btrfs_dev_replace_stats_inc(
1499 &sblock->sctx->dev_root->fs_info->dev_replace.
1500 num_write_errors);
1501 }
1502}
1503
1504static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1505 int page_num)
1506{
1507 struct scrub_page *spage = sblock->pagev[page_num];
1508
1509 BUG_ON(spage->page == NULL);
1510 if (spage->io_error) {
1511 void *mapped_buffer = kmap_atomic(spage->page);
1512
1513 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1514 flush_dcache_page(spage->page);
1515 kunmap_atomic(mapped_buffer);
1516 }
1517 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1518}
1519
1520static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1521 struct scrub_page *spage)
1522{
1523 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1524 struct scrub_bio *sbio;
1525 int ret;
1526
1527 mutex_lock(&wr_ctx->wr_lock);
1528again:
1529 if (!wr_ctx->wr_curr_bio) {
1530 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1531 GFP_NOFS);
1532 if (!wr_ctx->wr_curr_bio) {
1533 mutex_unlock(&wr_ctx->wr_lock);
1534 return -ENOMEM;
1535 }
1536 wr_ctx->wr_curr_bio->sctx = sctx;
1537 wr_ctx->wr_curr_bio->page_count = 0;
1538 }
1539 sbio = wr_ctx->wr_curr_bio;
1540 if (sbio->page_count == 0) {
1541 struct bio *bio;
1542
1543 sbio->physical = spage->physical_for_dev_replace;
1544 sbio->logical = spage->logical;
1545 sbio->dev = wr_ctx->tgtdev;
1546 bio = sbio->bio;
1547 if (!bio) {
9be3395b 1548 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
ff023aac
SB		 1549 if (!bio) {
1550 mutex_unlock(&wr_ctx->wr_lock);
1551 return -ENOMEM;
1552 }
1553 sbio->bio = bio;
1554 }
1555
1556 bio->bi_private = sbio;
1557 bio->bi_end_io = scrub_wr_bio_end_io;
1558 bio->bi_bdev = sbio->dev->bdev;
4f024f37 1559 bio->bi_iter.bi_sector = sbio->physical >> 9;
ff023aac
SB		 1560 sbio->err = 0;
1561 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1562 spage->physical_for_dev_replace ||
1563 sbio->logical + sbio->page_count * PAGE_SIZE !=
1564 spage->logical) {
1565 scrub_wr_submit(sctx);
1566 goto again;
1567 }
1568
1569 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1570 if (ret != PAGE_SIZE) {
1571 if (sbio->page_count < 1) {
1572 bio_put(sbio->bio);
1573 sbio->bio = NULL;
1574 mutex_unlock(&wr_ctx->wr_lock);
1575 return -EIO;
1576 }
1577 scrub_wr_submit(sctx);
1578 goto again;
1579 }
1580
1581 sbio->pagev[sbio->page_count] = spage;
1582 scrub_page_get(spage);
1583 sbio->page_count++;
1584 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1585 scrub_wr_submit(sctx);
1586 mutex_unlock(&wr_ctx->wr_lock);
1587
1588 return 0;
1589}
1590
1591static void scrub_wr_submit(struct scrub_ctx *sctx)
1592{
1593 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1594 struct scrub_bio *sbio;
1595
1596 if (!wr_ctx->wr_curr_bio)
1597 return;
1598
1599 sbio = wr_ctx->wr_curr_bio;
1600 wr_ctx->wr_curr_bio = NULL;
1601 WARN_ON(!sbio->bio->bi_bdev);
1602 scrub_pending_bio_inc(sctx);
1603 /* process all writes in a single worker thread. Then the block layer
1604 * orders the requests before sending them to the driver which
1605 * doubled the write performance on spinning disks when measured
1606 * with Linux 3.5 */
1607 btrfsic_submit_bio(WRITE, sbio->bio);
1608}
1609
1610static void scrub_wr_bio_end_io(struct bio *bio, int err)
1611{
1612 struct scrub_bio *sbio = bio->bi_private;
1613 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1614
1615 sbio->err = err;
1616 sbio->bio = bio;
1617
0339ef2f
QW		 1618 btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL);
1619 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
ff023aac
SB		 1620}
1621
1622static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1623{
1624 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1625 struct scrub_ctx *sctx = sbio->sctx;
1626 int i;
1627
1628 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1629 if (sbio->err) {
1630 struct btrfs_dev_replace *dev_replace =
1631 &sbio->sctx->dev_root->fs_info->dev_replace;
1632
1633 for (i = 0; i < sbio->page_count; i++) {
1634 struct scrub_page *spage = sbio->pagev[i];
1635
1636 spage->io_error = 1;
1637 btrfs_dev_replace_stats_inc(&dev_replace->
1638 num_write_errors);
1639 }
1640 }
1641
1642 for (i = 0; i < sbio->page_count; i++)
1643 scrub_page_put(sbio->pagev[i]);
1644
1645 bio_put(sbio->bio);
1646 kfree(sbio);
1647 scrub_pending_bio_dec(sctx);
1648}
1649
1650static int scrub_checksum(struct scrub_block *sblock)
b5d67f64
SB		 1651{
1652 u64 flags;
1653 int ret;
1654
7a9e9987
SB		 1655 WARN_ON(sblock->page_count < 1);
1656 flags = sblock->pagev[0]->flags;
b5d67f64
SB		 1657 ret = 0;
1658 if (flags & BTRFS_EXTENT_FLAG_DATA)
1659 ret = scrub_checksum_data(sblock);
1660 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1661 ret = scrub_checksum_tree_block(sblock);
1662 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1663 (void)scrub_checksum_super(sblock);
1664 else
1665 WARN_ON(1);
1666 if (ret)
1667 scrub_handle_errored_block(sblock);
ff023aac
SB		 1668
1669 return ret;
a2de733c
AJ		 1670}
1671
b5d67f64 1672static int scrub_checksum_data(struct scrub_block *sblock)
a2de733c 1673{
d9d181c1 1674 struct scrub_ctx *sctx = sblock->sctx;
a2de733c 1675 u8 csum[BTRFS_CSUM_SIZE];
b5d67f64
SB		 1676 u8 *on_disk_csum;
1677 struct page *page;
1678 void *buffer;
a2de733c
AJ		 1679 u32 crc = ~(u32)0;
1680 int fail = 0;
b5d67f64
SB		 1681 u64 len;
1682 int index;
a2de733c 1683
b5d67f64 1684 BUG_ON(sblock->page_count < 1);
7a9e9987 1685 if (!sblock->pagev[0]->have_csum)
a2de733c
AJ		 1686 return 0;
1687
7a9e9987
SB		 1688 on_disk_csum = sblock->pagev[0]->csum;
1689 page = sblock->pagev[0]->page;
9613bebb 1690 buffer = kmap_atomic(page);
b5d67f64 1691
d9d181c1 1692 len = sctx->sectorsize;
b5d67f64
SB		 1693 index = 0;
1694 for (;;) {
1695 u64 l = min_t(u64, len, PAGE_SIZE);
1696
b0496686 1697 crc = btrfs_csum_data(buffer, crc, l);
9613bebb 1698 kunmap_atomic(buffer);
b5d67f64
SB		 1699 len -= l;
1700 if (len == 0)
1701 break;
1702 index++;
1703 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1704 BUG_ON(!sblock->pagev[index]->page);
1705 page = sblock->pagev[index]->page;
9613bebb 1706 buffer = kmap_atomic(page);
b5d67f64
SB		 1707 }
1708
a2de733c 1709 btrfs_csum_final(crc, csum);
d9d181c1 1710 if (memcmp(csum, on_disk_csum, sctx->csum_size))
a2de733c
AJ		 1711 fail = 1;
1712
a2de733c
AJ		 1713 return fail;
1714}
1715
b5d67f64 1716static int scrub_checksum_tree_block(struct scrub_block *sblock)
a2de733c 1717{
d9d181c1 1718 struct scrub_ctx *sctx = sblock->sctx;
a2de733c 1719 struct btrfs_header *h;
a36cf8b8 1720 struct btrfs_root *root = sctx->dev_root;
a2de733c 1721 struct btrfs_fs_info *fs_info = root->fs_info;
b5d67f64
SB		 1722 u8 calculated_csum[BTRFS_CSUM_SIZE];
1723 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1724 struct page *page;
1725 void *mapped_buffer;
1726 u64 mapped_size;
1727 void *p;
a2de733c
AJ		 1728 u32 crc = ~(u32)0;
1729 int fail = 0;
1730 int crc_fail = 0;
b5d67f64
SB		 1731 u64 len;
1732 int index;
1733
1734 BUG_ON(sblock->page_count < 1);
7a9e9987 1735 page = sblock->pagev[0]->page;
9613bebb 1736 mapped_buffer = kmap_atomic(page);
b5d67f64 1737 h = (struct btrfs_header *)mapped_buffer;
d9d181c1 1738 memcpy(on_disk_csum, h->csum, sctx->csum_size);
a2de733c
AJ		 1739
1740 /*
1741 * we don't use the getter functions here, as we
1742 * a) don't have an extent buffer and
1743 * b) the page is already kmapped
1744 */
a2de733c 1745
3cae210f 1746 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
a2de733c
AJ		 1747 ++fail;
1748
3cae210f 1749 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
a2de733c
AJ		 1750 ++fail;
1751
1752 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1753 ++fail;
1754
1755 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1756 BTRFS_UUID_SIZE))
1757 ++fail;
1758
ff023aac 1759 WARN_ON(sctx->nodesize != sctx->leafsize);
d9d181c1 1760 len = sctx->nodesize - BTRFS_CSUM_SIZE;
b5d67f64
SB		 1761 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1762 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1763 index = 0;
1764 for (;;) {
1765 u64 l = min_t(u64, len, mapped_size);
1766
b0496686 1767 crc = btrfs_csum_data(p, crc, l);
9613bebb 1768 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1769 len -= l;
1770 if (len == 0)
1771 break;
1772 index++;
1773 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1774 BUG_ON(!sblock->pagev[index]->page);
1775 page = sblock->pagev[index]->page;
9613bebb 1776 mapped_buffer = kmap_atomic(page);
b5d67f64
SB		 1777 mapped_size = PAGE_SIZE;
1778 p = mapped_buffer;
1779 }
1780
1781 btrfs_csum_final(crc, calculated_csum);
d9d181c1 1782 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
a2de733c
AJ		 1783 ++crc_fail;
1784
a2de733c
AJ		 1785 return fail || crc_fail;
1786}
1787
b5d67f64 1788static int scrub_checksum_super(struct scrub_block *sblock)
a2de733c
AJ		 1789{
1790 struct btrfs_super_block *s;
d9d181c1 1791 struct scrub_ctx *sctx = sblock->sctx;
a36cf8b8 1792 struct btrfs_root *root = sctx->dev_root;
a2de733c 1793 struct btrfs_fs_info *fs_info = root->fs_info;
b5d67f64
SB		 1794 u8 calculated_csum[BTRFS_CSUM_SIZE];
1795 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1796 struct page *page;
1797 void *mapped_buffer;
1798 u64 mapped_size;
1799 void *p;
a2de733c 1800 u32 crc = ~(u32)0;
442a4f63
SB		 1801 int fail_gen = 0;
1802 int fail_cor = 0;
b5d67f64
SB		 1803 u64 len;
1804 int index;
a2de733c 1805
b5d67f64 1806 BUG_ON(sblock->page_count < 1);
7a9e9987 1807 page = sblock->pagev[0]->page;
9613bebb 1808 mapped_buffer = kmap_atomic(page);
b5d67f64 1809 s = (struct btrfs_super_block *)mapped_buffer;
d9d181c1 1810 memcpy(on_disk_csum, s->csum, sctx->csum_size);
a2de733c 1811
3cae210f 1812 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
442a4f63 1813 ++fail_cor;
a2de733c 1814
3cae210f 1815 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
442a4f63 1816 ++fail_gen;
a2de733c
AJ		 1817
1818 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
442a4f63 1819 ++fail_cor;
a2de733c 1820
b5d67f64
SB		 1821 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1822 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1823 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1824 index = 0;
1825 for (;;) {
1826 u64 l = min_t(u64, len, mapped_size);
1827
b0496686 1828 crc = btrfs_csum_data(p, crc, l);
9613bebb 1829 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1830 len -= l;
1831 if (len == 0)
1832 break;
1833 index++;
1834 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1835 BUG_ON(!sblock->pagev[index]->page);
1836 page = sblock->pagev[index]->page;
9613bebb 1837 mapped_buffer = kmap_atomic(page);
b5d67f64
SB		 1838 mapped_size = PAGE_SIZE;
1839 p = mapped_buffer;
1840 }
1841
1842 btrfs_csum_final(crc, calculated_csum);
d9d181c1 1843 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
442a4f63 1844 ++fail_cor;
a2de733c 1845
442a4f63 1846 if (fail_cor + fail_gen) {
a2de733c
AJ		 1847 /*
1848 * if we find an error in a super block, we just report it.
1849 * They will get written with the next transaction commit
1850 * anyway
1851 */
d9d181c1
SB		 1852 spin_lock(&sctx->stat_lock);
1853 ++sctx->stat.super_errors;
1854 spin_unlock(&sctx->stat_lock);
442a4f63 1855 if (fail_cor)
7a9e9987 1856 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
442a4f63
SB		 1857 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1858 else
7a9e9987 1859 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
442a4f63 1860 BTRFS_DEV_STAT_GENERATION_ERRS);
a2de733c
AJ		 1861 }
1862
442a4f63 1863 return fail_cor + fail_gen;
a2de733c
AJ		 1864}
1865
b5d67f64
SB		 1866static void scrub_block_get(struct scrub_block *sblock)
1867{
1868 atomic_inc(&sblock->ref_count);
1869}
1870
1871static void scrub_block_put(struct scrub_block *sblock)
1872{
1873 if (atomic_dec_and_test(&sblock->ref_count)) {
1874 int i;
1875
1876 for (i = 0; i < sblock->page_count; i++)
7a9e9987 1877 scrub_page_put(sblock->pagev[i]);
b5d67f64
SB		 1878 kfree(sblock);
1879 }
1880}
1881
7a9e9987
SB		 1882static void scrub_page_get(struct scrub_page *spage)
1883{
1884 atomic_inc(&spage->ref_count);
1885}
1886
1887static void scrub_page_put(struct scrub_page *spage)
1888{
1889 if (atomic_dec_and_test(&spage->ref_count)) {
1890 if (spage->page)
1891 __free_page(spage->page);
1892 kfree(spage);
1893 }
1894}
1895
d9d181c1 1896static void scrub_submit(struct scrub_ctx *sctx)
a2de733c
AJ		 1897{
1898 struct scrub_bio *sbio;
1899
d9d181c1 1900 if (sctx->curr == -1)
1623edeb 1901 return;
a2de733c 1902
d9d181c1
SB		 1903 sbio = sctx->bios[sctx->curr];
1904 sctx->curr = -1;
b6bfebc1 1905 scrub_pending_bio_inc(sctx);
a2de733c 1906
ff023aac
SB		 1907 if (!sbio->bio->bi_bdev) {
1908 /*
1909 * this case should not happen. If btrfs_map_block() is
1910 * wrong, it could happen for dev-replace operations on
1911 * missing devices when no mirrors are available, but in
1912 * this case it should already fail the mount.
1913 * This case is handled correctly (but _very_ slowly).
1914 */
1915 printk_ratelimited(KERN_WARNING
efe120a0 1916 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
ff023aac
SB		 1917 bio_endio(sbio->bio, -EIO);
1918 } else {
1919 btrfsic_submit_bio(READ, sbio->bio);
1920 }
a2de733c
AJ		 1921}
1922
ff023aac
SB		 1923static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
1924 struct scrub_page *spage)
a2de733c 1925{
b5d67f64 1926 struct scrub_block *sblock = spage->sblock;
a2de733c 1927 struct scrub_bio *sbio;
69f4cb52 1928 int ret;
a2de733c
AJ		 1929
1930again:
1931 /*
1932 * grab a fresh bio or wait for one to become available
1933 */
d9d181c1
SB		 1934 while (sctx->curr == -1) {
1935 spin_lock(&sctx->list_lock);
1936 sctx->curr = sctx->first_free;
1937 if (sctx->curr != -1) {
1938 sctx->first_free = sctx->bios[sctx->curr]->next_free;
1939 sctx->bios[sctx->curr]->next_free = -1;
1940 sctx->bios[sctx->curr]->page_count = 0;
1941 spin_unlock(&sctx->list_lock);
a2de733c 1942 } else {
d9d181c1
SB		 1943 spin_unlock(&sctx->list_lock);
1944 wait_event(sctx->list_wait, sctx->first_free != -1);
a2de733c
AJ		 1945 }
1946 }
d9d181c1 1947 sbio = sctx->bios[sctx->curr];
b5d67f64 1948 if (sbio->page_count == 0) {
69f4cb52
AJ		 1949 struct bio *bio;
1950
b5d67f64
SB		 1951 sbio->physical = spage->physical;
1952 sbio->logical = spage->logical;
a36cf8b8 1953 sbio->dev = spage->dev;
b5d67f64
SB		 1954 bio = sbio->bio;
1955 if (!bio) {
9be3395b 1956 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
b5d67f64
SB		 1957 if (!bio)
1958 return -ENOMEM;
1959 sbio->bio = bio;
1960 }
69f4cb52
AJ		 1961
1962 bio->bi_private = sbio;
1963 bio->bi_end_io = scrub_bio_end_io;
a36cf8b8 1964 bio->bi_bdev = sbio->dev->bdev;
4f024f37 1965 bio->bi_iter.bi_sector = sbio->physical >> 9;
69f4cb52 1966 sbio->err = 0;
b5d67f64
SB		 1967 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1968 spage->physical ||
1969 sbio->logical + sbio->page_count * PAGE_SIZE !=
a36cf8b8
SB		 1970 spage->logical ||
1971 sbio->dev != spage->dev) {
d9d181c1 1972 scrub_submit(sctx);
a2de733c
AJ		 1973 goto again;
1974 }
69f4cb52 1975
b5d67f64
SB		 1976 sbio->pagev[sbio->page_count] = spage;
1977 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1978 if (ret != PAGE_SIZE) {
1979 if (sbio->page_count < 1) {
1980 bio_put(sbio->bio);
1981 sbio->bio = NULL;
1982 return -EIO;
1983 }
d9d181c1 1984 scrub_submit(sctx);
69f4cb52
AJ		 1985 goto again;
1986 }
1987
ff023aac 1988 scrub_block_get(sblock); /* one for the page added to the bio */
b5d67f64
SB		 1989 atomic_inc(&sblock->outstanding_pages);
1990 sbio->page_count++;
ff023aac 1991 if (sbio->page_count == sctx->pages_per_rd_bio)
d9d181c1 1992 scrub_submit(sctx);
b5d67f64
SB		 1993
1994 return 0;
1995}
1996
d9d181c1 1997static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 1998 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac
SB		 1999 u64 gen, int mirror_num, u8 *csum, int force,
2000 u64 physical_for_dev_replace)
b5d67f64
SB		 2001{
2002 struct scrub_block *sblock;
2003 int index;
2004
2005 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2006 if (!sblock) {
d9d181c1
SB		 2007 spin_lock(&sctx->stat_lock);
2008 sctx->stat.malloc_errors++;
2009 spin_unlock(&sctx->stat_lock);
b5d67f64 2010 return -ENOMEM;
a2de733c 2011 }
b5d67f64 2012
7a9e9987
SB		 2013 /* one ref inside this function, plus one for each page added to
2014 * a bio later on */
b5d67f64 2015 atomic_set(&sblock->ref_count, 1);
d9d181c1 2016 sblock->sctx = sctx;
b5d67f64
SB		 2017 sblock->no_io_error_seen = 1;
2018
2019 for (index = 0; len > 0; index++) {
7a9e9987 2020 struct scrub_page *spage;
b5d67f64
SB		 2021 u64 l = min_t(u64, len, PAGE_SIZE);
2022
7a9e9987
SB		 2023 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2024 if (!spage) {
2025leave_nomem:
d9d181c1
SB		 2026 spin_lock(&sctx->stat_lock);
2027 sctx->stat.malloc_errors++;
2028 spin_unlock(&sctx->stat_lock);
7a9e9987 2029 scrub_block_put(sblock);
b5d67f64
SB		 2030 return -ENOMEM;
2031 }
7a9e9987
SB		 2032 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2033 scrub_page_get(spage);
2034 sblock->pagev[index] = spage;
b5d67f64 2035 spage->sblock = sblock;
a36cf8b8 2036 spage->dev = dev;
b5d67f64
SB		 2037 spage->flags = flags;
2038 spage->generation = gen;
2039 spage->logical = logical;
2040 spage->physical = physical;
ff023aac 2041 spage->physical_for_dev_replace = physical_for_dev_replace;
b5d67f64
SB		 2042 spage->mirror_num = mirror_num;
2043 if (csum) {
2044 spage->have_csum = 1;
d9d181c1 2045 memcpy(spage->csum, csum, sctx->csum_size);
b5d67f64
SB		 2046 } else {
2047 spage->have_csum = 0;
2048 }
2049 sblock->page_count++;
7a9e9987
SB		 2050 spage->page = alloc_page(GFP_NOFS);
2051 if (!spage->page)
2052 goto leave_nomem;
b5d67f64
SB		 2053 len -= l;
2054 logical += l;
2055 physical += l;
ff023aac 2056 physical_for_dev_replace += l;
b5d67f64
SB		 2057 }
2058
7a9e9987 2059 WARN_ON(sblock->page_count == 0);
b5d67f64 2060 for (index = 0; index < sblock->page_count; index++) {
7a9e9987 2061 struct scrub_page *spage = sblock->pagev[index];
1bc87793
AJ		 2062 int ret;
2063
ff023aac 2064 ret = scrub_add_page_to_rd_bio(sctx, spage);
b5d67f64
SB		 2065 if (ret) {
2066 scrub_block_put(sblock);
1bc87793 2067 return ret;
b5d67f64 2068 }
1bc87793 2069 }
a2de733c 2070
b5d67f64 2071 if (force)
d9d181c1 2072 scrub_submit(sctx);
a2de733c 2073
b5d67f64
SB		 2074 /* last one frees, either here or in bio completion for last page */
2075 scrub_block_put(sblock);
a2de733c
AJ		 2076 return 0;
2077}
2078
b5d67f64
SB		 2079static void scrub_bio_end_io(struct bio *bio, int err)
2080{
2081 struct scrub_bio *sbio = bio->bi_private;
a36cf8b8 2082 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
b5d67f64
SB		 2083
2084 sbio->err = err;
2085 sbio->bio = bio;
2086
0339ef2f 2087 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
b5d67f64
SB		 2088}
2089
2090static void scrub_bio_end_io_worker(struct btrfs_work *work)
2091{
2092 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
d9d181c1 2093 struct scrub_ctx *sctx = sbio->sctx;
b5d67f64
SB		 2094 int i;
2095
ff023aac 2096 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
b5d67f64
SB		 2097 if (sbio->err) {
2098 for (i = 0; i < sbio->page_count; i++) {
2099 struct scrub_page *spage = sbio->pagev[i];
2100
2101 spage->io_error = 1;
2102 spage->sblock->no_io_error_seen = 0;
2103 }
2104 }
2105
2106 /* now complete the scrub_block items that have all pages completed */
2107 for (i = 0; i < sbio->page_count; i++) {
2108 struct scrub_page *spage = sbio->pagev[i];
2109 struct scrub_block *sblock = spage->sblock;
2110
2111 if (atomic_dec_and_test(&sblock->outstanding_pages))
2112 scrub_block_complete(sblock);
2113 scrub_block_put(sblock);
2114 }
2115
b5d67f64
SB		 2116 bio_put(sbio->bio);
2117 sbio->bio = NULL;
d9d181c1
SB		 2118 spin_lock(&sctx->list_lock);
2119 sbio->next_free = sctx->first_free;
2120 sctx->first_free = sbio->index;
2121 spin_unlock(&sctx->list_lock);
ff023aac
SB		 2122
2123 if (sctx->is_dev_replace &&
2124 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2125 mutex_lock(&sctx->wr_ctx.wr_lock);
2126 scrub_wr_submit(sctx);
2127 mutex_unlock(&sctx->wr_ctx.wr_lock);
2128 }
2129
b6bfebc1 2130 scrub_pending_bio_dec(sctx);
b5d67f64
SB		 2131}
2132
2133static void scrub_block_complete(struct scrub_block *sblock)
2134{
ff023aac 2135 if (!sblock->no_io_error_seen) {
b5d67f64 2136 scrub_handle_errored_block(sblock);
ff023aac
SB		 2137 } else {
2138 /*
2139 * if has checksum error, write via repair mechanism in
2140 * dev replace case, otherwise write here in dev replace
2141 * case.
2142 */
2143 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
2144 scrub_write_block_to_dev_replace(sblock);
2145 }
b5d67f64
SB		 2146}
2147
d9d181c1 2148static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
a2de733c
AJ		 2149 u8 *csum)
2150{
2151 struct btrfs_ordered_sum *sum = NULL;
f51a4a18 2152 unsigned long index;
a2de733c 2153 unsigned long num_sectors;
a2de733c 2154
d9d181c1
SB		 2155 while (!list_empty(&sctx->csum_list)) {
2156 sum = list_first_entry(&sctx->csum_list,
a2de733c
AJ		 2157 struct btrfs_ordered_sum, list);
2158 if (sum->bytenr > logical)
2159 return 0;
2160 if (sum->bytenr + sum->len > logical)
2161 break;
2162
d9d181c1 2163 ++sctx->stat.csum_discards;
a2de733c
AJ		 2164 list_del(&sum->list);
2165 kfree(sum);
2166 sum = NULL;
2167 }
2168 if (!sum)
2169 return 0;
2170
f51a4a18 2171 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
d9d181c1 2172 num_sectors = sum->len / sctx->sectorsize;
f51a4a18
MX		 2173 memcpy(csum, sum->sums + index, sctx->csum_size);
2174 if (index == num_sectors - 1) {
a2de733c
AJ		 2175 list_del(&sum->list);
2176 kfree(sum);
2177 }
f51a4a18 2178 return 1;
a2de733c
AJ		 2179}
2180
2181/* scrub extent tries to collect up to 64 kB for each bio */
d9d181c1 2182static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 2183 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac 2184 u64 gen, int mirror_num, u64 physical_for_dev_replace)
a2de733c
AJ		 2185{
2186 int ret;
2187 u8 csum[BTRFS_CSUM_SIZE];
b5d67f64
SB		 2188 u32 blocksize;
2189
2190 if (flags & BTRFS_EXTENT_FLAG_DATA) {
d9d181c1
SB		 2191 blocksize = sctx->sectorsize;
2192 spin_lock(&sctx->stat_lock);
2193 sctx->stat.data_extents_scrubbed++;
2194 sctx->stat.data_bytes_scrubbed += len;
2195 spin_unlock(&sctx->stat_lock);
b5d67f64 2196 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
ff023aac 2197 WARN_ON(sctx->nodesize != sctx->leafsize);
d9d181c1
SB		 2198 blocksize = sctx->nodesize;
2199 spin_lock(&sctx->stat_lock);
2200 sctx->stat.tree_extents_scrubbed++;
2201 sctx->stat.tree_bytes_scrubbed += len;
2202 spin_unlock(&sctx->stat_lock);
b5d67f64 2203 } else {
d9d181c1 2204 blocksize = sctx->sectorsize;
ff023aac 2205 WARN_ON(1);
b5d67f64 2206 }
a2de733c
AJ		 2207
2208 while (len) {
b5d67f64 2209 u64 l = min_t(u64, len, blocksize);
a2de733c
AJ		 2210 int have_csum = 0;
2211
2212 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2213 /* push csums to sbio */
d9d181c1 2214 have_csum = scrub_find_csum(sctx, logical, l, csum);
a2de733c 2215 if (have_csum == 0)
d9d181c1 2216 ++sctx->stat.no_csum;
ff023aac
SB		 2217 if (sctx->is_dev_replace && !have_csum) {
2218 ret = copy_nocow_pages(sctx, logical, l,
2219 mirror_num,
2220 physical_for_dev_replace);
2221 goto behind_scrub_pages;
2222 }
a2de733c 2223 }
a36cf8b8 2224 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
ff023aac
SB		 2225 mirror_num, have_csum ? csum : NULL, 0,
2226 physical_for_dev_replace);
2227behind_scrub_pages:
a2de733c
AJ		 2228 if (ret)
2229 return ret;
2230 len -= l;
2231 logical += l;
2232 physical += l;
ff023aac 2233 physical_for_dev_replace += l;
a2de733c
AJ		 2234 }
2235 return 0;
2236}
2237
3b080b25
WS		 2238/*
2239 * Given a physical address, this will calculate it's
2240 * logical offset. if this is a parity stripe, it will return
2241 * the most left data stripe's logical offset.
2242 *
2243 * return 0 if it is a data stripe, 1 means parity stripe.
2244 */
2245static int get_raid56_logic_offset(u64 physical, int num,
2246 struct map_lookup *map, u64 *offset)
2247{
2248 int i;
2249 int j = 0;
2250 u64 stripe_nr;
2251 u64 last_offset;
2252 int stripe_index;
2253 int rot;
2254
2255 last_offset = (physical - map->stripes[num].physical) *
2256 nr_data_stripes(map);
2257 *offset = last_offset;
2258 for (i = 0; i < nr_data_stripes(map); i++) {
2259 *offset = last_offset + i * map->stripe_len;
2260
2261 stripe_nr = *offset;
2262 do_div(stripe_nr, map->stripe_len);
2263 do_div(stripe_nr, nr_data_stripes(map));
2264
2265 /* Work out the disk rotation on this stripe-set */
2266 rot = do_div(stripe_nr, map->num_stripes);
2267 /* calculate which stripe this data locates */
2268 rot += i;
e4fbaee2 2269 stripe_index = rot % map->num_stripes;
3b080b25
WS		 2270 if (stripe_index == num)
2271 return 0;
2272 if (stripe_index < num)
2273 j++;
2274 }
2275 *offset = last_offset + j * map->stripe_len;
2276 return 1;
2277}
2278
d9d181c1 2279static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
a36cf8b8
SB		 2280 struct map_lookup *map,
2281 struct btrfs_device *scrub_dev,
ff023aac
SB		 2282 int num, u64 base, u64 length,
2283 int is_dev_replace)
a2de733c
AJ		 2284{
2285 struct btrfs_path *path;
a36cf8b8 2286 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
a2de733c
AJ		 2287 struct btrfs_root *root = fs_info->extent_root;
2288 struct btrfs_root *csum_root = fs_info->csum_root;
2289 struct btrfs_extent_item *extent;
e7786c3a 2290 struct blk_plug plug;
a2de733c
AJ		 2291 u64 flags;
2292 int ret;
2293 int slot;
a2de733c 2294 u64 nstripes;
a2de733c
AJ		 2295 struct extent_buffer *l;
2296 struct btrfs_key key;
2297 u64 physical;
2298 u64 logical;
625f1c8d 2299 u64 logic_end;
3b080b25 2300 u64 physical_end;
a2de733c 2301 u64 generation;
e12fa9cd 2302 int mirror_num;
7a26285e
AJ		 2303 struct reada_control *reada1;
2304 struct reada_control *reada2;
2305 struct btrfs_key key_start;
2306 struct btrfs_key key_end;
a2de733c
AJ		 2307 u64 increment = map->stripe_len;
2308 u64 offset;
ff023aac
SB		 2309 u64 extent_logical;
2310 u64 extent_physical;
2311 u64 extent_len;
2312 struct btrfs_device *extent_dev;
2313 int extent_mirror_num;
3b080b25 2314 int stop_loop = 0;
53b381b3 2315
a2de733c 2316 nstripes = length;
3b080b25 2317 physical = map->stripes[num].physical;
a2de733c
AJ		 2318 offset = 0;
2319 do_div(nstripes, map->stripe_len);
2320 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2321 offset = map->stripe_len * num;
2322 increment = map->stripe_len * map->num_stripes;
193ea74b 2323 mirror_num = 1;
a2de733c
AJ		 2324 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2325 int factor = map->num_stripes / map->sub_stripes;
2326 offset = map->stripe_len * (num / map->sub_stripes);
2327 increment = map->stripe_len * factor;
193ea74b 2328 mirror_num = num % map->sub_stripes + 1;
a2de733c
AJ		 2329 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2330 increment = map->stripe_len;
193ea74b 2331 mirror_num = num % map->num_stripes + 1;
a2de733c
AJ		 2332 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2333 increment = map->stripe_len;
193ea74b 2334 mirror_num = num % map->num_stripes + 1;
3b080b25
WS		 2335 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2336 BTRFS_BLOCK_GROUP_RAID6)) {
2337 get_raid56_logic_offset(physical, num, map, &offset);
2338 increment = map->stripe_len * nr_data_stripes(map);
2339 mirror_num = 1;
a2de733c
AJ		 2340 } else {
2341 increment = map->stripe_len;
193ea74b 2342 mirror_num = 1;
a2de733c
AJ		 2343 }
2344
2345 path = btrfs_alloc_path();
2346 if (!path)
2347 return -ENOMEM;
2348
b5d67f64
SB		 2349 /*
2350 * work on commit root. The related disk blocks are static as
2351 * long as COW is applied. This means, it is save to rewrite
2352 * them to repair disk errors without any race conditions
2353 */
a2de733c
AJ		 2354 path->search_commit_root = 1;
2355 path->skip_locking = 1;
2356
2357 /*
7a26285e
AJ		 2358 * trigger the readahead for extent tree csum tree and wait for
2359 * completion. During readahead, the scrub is officially paused
2360 * to not hold off transaction commits
a2de733c
AJ		 2361 */
2362 logical = base + offset;
3b080b25
WS		 2363 physical_end = physical + nstripes * map->stripe_len;
2364 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2365 BTRFS_BLOCK_GROUP_RAID6)) {
2366 get_raid56_logic_offset(physical_end, num,
2367 map, &logic_end);
2368 logic_end += base;
2369 } else {
2370 logic_end = logical + increment * nstripes;
2371 }
d9d181c1 2372 wait_event(sctx->list_wait,
b6bfebc1 2373 atomic_read(&sctx->bios_in_flight) == 0);
cb7ab021 2374 scrub_blocked_if_needed(fs_info);
7a26285e
AJ		 2375
2376 /* FIXME it might be better to start readahead at commit root */
2377 key_start.objectid = logical;
2378 key_start.type = BTRFS_EXTENT_ITEM_KEY;
2379 key_start.offset = (u64)0;
3b080b25 2380 key_end.objectid = logic_end;
3173a18f
JB		 2381 key_end.type = BTRFS_METADATA_ITEM_KEY;
2382 key_end.offset = (u64)-1;
7a26285e
AJ		 2383 reada1 = btrfs_reada_add(root, &key_start, &key_end);
2384
2385 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2386 key_start.type = BTRFS_EXTENT_CSUM_KEY;
2387 key_start.offset = logical;
2388 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2389 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3b080b25 2390 key_end.offset = logic_end;
7a26285e
AJ		 2391 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
2392
2393 if (!IS_ERR(reada1))
2394 btrfs_reada_wait(reada1);
2395 if (!IS_ERR(reada2))
2396 btrfs_reada_wait(reada2);
2397
a2de733c
AJ		 2398
2399 /*
2400 * collect all data csums for the stripe to avoid seeking during
2401 * the scrub. This might currently (crc32) end up to be about 1MB
2402 */
e7786c3a 2403 blk_start_plug(&plug);
a2de733c 2404
a2de733c
AJ		 2405 /*
2406 * now find all extents for each stripe and scrub them
2407 */
a2de733c 2408 ret = 0;
3b080b25
WS		 2409 while (physical < physical_end) {
2410 /* for raid56, we skip parity stripe */
2411 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2412 BTRFS_BLOCK_GROUP_RAID6)) {
2413 ret = get_raid56_logic_offset(physical, num,
2414 map, &logical);
2415 logical += base;
2416 if (ret)
2417 goto skip;
2418 }
a2de733c
AJ		 2419 /*
2420 * canceled?
2421 */
2422 if (atomic_read(&fs_info->scrub_cancel_req) ||
d9d181c1 2423 atomic_read(&sctx->cancel_req)) {
a2de733c
AJ		 2424 ret = -ECANCELED;
2425 goto out;
2426 }
2427 /*
2428 * check to see if we have to pause
2429 */
2430 if (atomic_read(&fs_info->scrub_pause_req)) {
2431 /* push queued extents */
ff023aac 2432 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
d9d181c1 2433 scrub_submit(sctx);
ff023aac
SB		 2434 mutex_lock(&sctx->wr_ctx.wr_lock);
2435 scrub_wr_submit(sctx);
2436 mutex_unlock(&sctx->wr_ctx.wr_lock);
d9d181c1 2437 wait_event(sctx->list_wait,
b6bfebc1 2438 atomic_read(&sctx->bios_in_flight) == 0);
ff023aac 2439 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3cb0929a 2440 scrub_blocked_if_needed(fs_info);
a2de733c
AJ		 2441 }
2442
7c76edb7
WS		 2443 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2444 key.type = BTRFS_METADATA_ITEM_KEY;
2445 else
2446 key.type = BTRFS_EXTENT_ITEM_KEY;
a2de733c 2447 key.objectid = logical;
625f1c8d 2448 key.offset = (u64)-1;
a2de733c
AJ		 2449
2450 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2451 if (ret < 0)
2452 goto out;
3173a18f 2453
8c51032f 2454 if (ret > 0) {
ade2e0b3 2455 ret = btrfs_previous_extent_item(root, path, 0);
a2de733c
AJ		 2456 if (ret < 0)
2457 goto out;
8c51032f
AJ		 2458 if (ret > 0) {
2459 /* there's no smaller item, so stick with the
2460 * larger one */
2461 btrfs_release_path(path);
2462 ret = btrfs_search_slot(NULL, root, &key,
2463 path, 0, 0);
2464 if (ret < 0)
2465 goto out;
2466 }
a2de733c
AJ		 2467 }
2468
625f1c8d 2469 stop_loop = 0;
a2de733c 2470 while (1) {
3173a18f
JB		 2471 u64 bytes;
2472
a2de733c
AJ		 2473 l = path->nodes[0];
2474 slot = path->slots[0];
2475 if (slot >= btrfs_header_nritems(l)) {
2476 ret = btrfs_next_leaf(root, path);
2477 if (ret == 0)
2478 continue;
2479 if (ret < 0)
2480 goto out;
2481
625f1c8d 2482 stop_loop = 1;
a2de733c
AJ		 2483 break;
2484 }
2485 btrfs_item_key_to_cpu(l, &key, slot);
2486
3173a18f
JB		 2487 if (key.type == BTRFS_METADATA_ITEM_KEY)
2488 bytes = root->leafsize;
2489 else
2490 bytes = key.offset;
2491
2492 if (key.objectid + bytes <= logical)
a2de733c
AJ		 2493 goto next;
2494
625f1c8d
LB		 2495 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2496 key.type != BTRFS_METADATA_ITEM_KEY)
2497 goto next;
a2de733c 2498
625f1c8d
LB		 2499 if (key.objectid >= logical + map->stripe_len) {
2500 /* out of this device extent */
2501 if (key.objectid >= logic_end)
2502 stop_loop = 1;
2503 break;
2504 }
a2de733c
AJ		 2505
2506 extent = btrfs_item_ptr(l, slot,
2507 struct btrfs_extent_item);
2508 flags = btrfs_extent_flags(l, extent);
2509 generation = btrfs_extent_generation(l, extent);
2510
2511 if (key.objectid < logical &&
2512 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
efe120a0
FH		 2513 btrfs_err(fs_info,
2514 "scrub: tree block %llu spanning "
2515 "stripes, ignored. logical=%llu",
c1c9ff7c 2516 key.objectid, logical);
a2de733c
AJ		 2517 goto next;
2518 }
2519
625f1c8d
LB		 2520again:
2521 extent_logical = key.objectid;
2522 extent_len = bytes;
2523
a2de733c
AJ		 2524 /*
2525 * trim extent to this stripe
2526 */
625f1c8d
LB		 2527 if (extent_logical < logical) {
2528 extent_len -= logical - extent_logical;
2529 extent_logical = logical;
a2de733c 2530 }
625f1c8d 2531 if (extent_logical + extent_len >
a2de733c 2532 logical + map->stripe_len) {
625f1c8d
LB		 2533 extent_len = logical + map->stripe_len -
2534 extent_logical;
a2de733c
AJ		 2535 }
2536
625f1c8d 2537 extent_physical = extent_logical - logical + physical;
ff023aac
SB		 2538 extent_dev = scrub_dev;
2539 extent_mirror_num = mirror_num;
2540 if (is_dev_replace)
2541 scrub_remap_extent(fs_info, extent_logical,
2542 extent_len, &extent_physical,
2543 &extent_dev,
2544 &extent_mirror_num);
625f1c8d
LB		 2545
2546 ret = btrfs_lookup_csums_range(csum_root, logical,
2547 logical + map->stripe_len - 1,
2548 &sctx->csum_list, 1);
2549 if (ret)
2550 goto out;
2551
ff023aac
SB		 2552 ret = scrub_extent(sctx, extent_logical, extent_len,
2553 extent_physical, extent_dev, flags,
2554 generation, extent_mirror_num,
115930cb 2555 extent_logical - logical + physical);
a2de733c
AJ		 2556 if (ret)
2557 goto out;
2558
d88d46c6 2559 scrub_free_csums(sctx);
625f1c8d
LB		 2560 if (extent_logical + extent_len <
2561 key.objectid + bytes) {
3b080b25
WS		 2562 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2563 BTRFS_BLOCK_GROUP_RAID6)) {
2564 /*
2565 * loop until we find next data stripe
2566 * or we have finished all stripes.
2567 */
2568 do {
2569 physical += map->stripe_len;
2570 ret = get_raid56_logic_offset(
2571 physical, num,
2572 map, &logical);
2573 logical += base;
2574 } while (physical < physical_end && ret);
2575 } else {
2576 physical += map->stripe_len;
2577 logical += increment;
2578 }
625f1c8d
LB		 2579 if (logical < key.objectid + bytes) {
2580 cond_resched();
2581 goto again;
2582 }
2583
3b080b25 2584 if (physical >= physical_end) {
625f1c8d
LB		 2585 stop_loop = 1;
2586 break;
2587 }
2588 }
a2de733c
AJ		 2589next:
2590 path->slots[0]++;
2591 }
71267333 2592 btrfs_release_path(path);
3b080b25 2593skip:
a2de733c
AJ		 2594 logical += increment;
2595 physical += map->stripe_len;
d9d181c1 2596 spin_lock(&sctx->stat_lock);
625f1c8d
LB		 2597 if (stop_loop)
2598 sctx->stat.last_physical = map->stripes[num].physical +
2599 length;
2600 else
2601 sctx->stat.last_physical = physical;
d9d181c1 2602 spin_unlock(&sctx->stat_lock);
625f1c8d
LB		 2603 if (stop_loop)
2604 break;
a2de733c 2605 }
ff023aac 2606out:
a2de733c 2607 /* push queued extents */
d9d181c1 2608 scrub_submit(sctx);
ff023aac
SB		 2609 mutex_lock(&sctx->wr_ctx.wr_lock);
2610 scrub_wr_submit(sctx);
2611 mutex_unlock(&sctx->wr_ctx.wr_lock);
a2de733c 2612
e7786c3a 2613 blk_finish_plug(&plug);
a2de733c
AJ		 2614 btrfs_free_path(path);
2615 return ret < 0 ? ret : 0;
2616}
2617
d9d181c1 2618static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
a36cf8b8
SB		 2619 struct btrfs_device *scrub_dev,
2620 u64 chunk_tree, u64 chunk_objectid,
2621 u64 chunk_offset, u64 length,
ff023aac 2622 u64 dev_offset, int is_dev_replace)
a2de733c
AJ		 2623{
2624 struct btrfs_mapping_tree *map_tree =
a36cf8b8 2625 &sctx->dev_root->fs_info->mapping_tree;
a2de733c
AJ		 2626 struct map_lookup *map;
2627 struct extent_map *em;
2628 int i;
ff023aac 2629 int ret = 0;
a2de733c
AJ		 2630
2631 read_lock(&map_tree->map_tree.lock);
2632 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2633 read_unlock(&map_tree->map_tree.lock);
2634
2635 if (!em)
2636 return -EINVAL;
2637
2638 map = (struct map_lookup *)em->bdev;
2639 if (em->start != chunk_offset)
2640 goto out;
2641
2642 if (em->len < length)
2643 goto out;
2644
2645 for (i = 0; i < map->num_stripes; ++i) {
a36cf8b8 2646 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
859acaf1 2647 map->stripes[i].physical == dev_offset) {
a36cf8b8 2648 ret = scrub_stripe(sctx, map, scrub_dev, i,
ff023aac
SB		 2649 chunk_offset, length,
2650 is_dev_replace);
a2de733c
AJ		 2651 if (ret)
2652 goto out;
2653 }
2654 }
2655out:
2656 free_extent_map(em);
2657
2658 return ret;
2659}
2660
2661static noinline_for_stack
a36cf8b8 2662int scrub_enumerate_chunks(struct scrub_ctx *sctx,
ff023aac
SB		 2663 struct btrfs_device *scrub_dev, u64 start, u64 end,
2664 int is_dev_replace)
a2de733c
AJ		 2665{
2666 struct btrfs_dev_extent *dev_extent = NULL;
2667 struct btrfs_path *path;
a36cf8b8 2668 struct btrfs_root *root = sctx->dev_root;
a2de733c
AJ		 2669 struct btrfs_fs_info *fs_info = root->fs_info;
2670 u64 length;
2671 u64 chunk_tree;
2672 u64 chunk_objectid;
2673 u64 chunk_offset;
2674 int ret;
2675 int slot;
2676 struct extent_buffer *l;
2677 struct btrfs_key key;
2678 struct btrfs_key found_key;
2679 struct btrfs_block_group_cache *cache;
ff023aac 2680 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
a2de733c
AJ		 2681
2682 path = btrfs_alloc_path();
2683 if (!path)
2684 return -ENOMEM;
2685
2686 path->reada = 2;
2687 path->search_commit_root = 1;
2688 path->skip_locking = 1;
2689
a36cf8b8 2690 key.objectid = scrub_dev->devid;
a2de733c
AJ		 2691 key.offset = 0ull;
2692 key.type = BTRFS_DEV_EXTENT_KEY;
2693
a2de733c
AJ		 2694 while (1) {
2695 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2696 if (ret < 0)
8c51032f
AJ		 2697 break;
2698 if (ret > 0) {
2699 if (path->slots[0] >=
2700 btrfs_header_nritems(path->nodes[0])) {
2701 ret = btrfs_next_leaf(root, path);
2702 if (ret)
2703 break;
2704 }
2705 }
a2de733c
AJ		 2706
2707 l = path->nodes[0];
2708 slot = path->slots[0];
2709
2710 btrfs_item_key_to_cpu(l, &found_key, slot);
2711
a36cf8b8 2712 if (found_key.objectid != scrub_dev->devid)
a2de733c
AJ		 2713 break;
2714
8c51032f 2715 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
a2de733c
AJ		 2716 break;
2717
2718 if (found_key.offset >= end)
2719 break;
2720
2721 if (found_key.offset < key.offset)
2722 break;
2723
2724 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2725 length = btrfs_dev_extent_length(l, dev_extent);
2726
2727 if (found_key.offset + length <= start) {
2728 key.offset = found_key.offset + length;
71267333 2729 btrfs_release_path(path);
a2de733c
AJ		 2730 continue;
2731 }
2732
2733 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2734 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2735 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2736
2737 /*
2738 * get a reference on the corresponding block group to prevent
2739 * the chunk from going away while we scrub it
2740 */
2741 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2742 if (!cache) {
2743 ret = -ENOENT;
8c51032f 2744 break;
a2de733c 2745 }
ff023aac
SB		 2746 dev_replace->cursor_right = found_key.offset + length;
2747 dev_replace->cursor_left = found_key.offset;
2748 dev_replace->item_needs_writeback = 1;
a36cf8b8 2749 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
ff023aac
SB		 2750 chunk_offset, length, found_key.offset,
2751 is_dev_replace);
2752
2753 /*
2754 * flush, submit all pending read and write bios, afterwards
2755 * wait for them.
2756 * Note that in the dev replace case, a read request causes
2757 * write requests that are submitted in the read completion
2758 * worker. Therefore in the current situation, it is required
2759 * that all write requests are flushed, so that all read and
2760 * write requests are really completed when bios_in_flight
2761 * changes to 0.
2762 */
2763 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2764 scrub_submit(sctx);
2765 mutex_lock(&sctx->wr_ctx.wr_lock);
2766 scrub_wr_submit(sctx);
2767 mutex_unlock(&sctx->wr_ctx.wr_lock);
2768
2769 wait_event(sctx->list_wait,
2770 atomic_read(&sctx->bios_in_flight) == 0);
12cf9372
WS		 2771 atomic_inc(&fs_info->scrubs_paused);
2772 wake_up(&fs_info->scrub_pause_wait);
2773
2774 /*
2775 * must be called before we decrease @scrub_paused.
2776 * make sure we don't block transaction commit while
2777 * we are waiting pending workers finished.
2778 */
ff023aac
SB		 2779 wait_event(sctx->list_wait,
2780 atomic_read(&sctx->workers_pending) == 0);
12cf9372
WS		 2781 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2782
2783 mutex_lock(&fs_info->scrub_lock);
2784 __scrub_blocked_if_needed(fs_info);
2785 atomic_dec(&fs_info->scrubs_paused);
2786 mutex_unlock(&fs_info->scrub_lock);
2787 wake_up(&fs_info->scrub_pause_wait);
ff023aac 2788
a2de733c
AJ		 2789 btrfs_put_block_group(cache);
2790 if (ret)
2791 break;
af1be4f8
SB		 2792 if (is_dev_replace &&
2793 atomic64_read(&dev_replace->num_write_errors) > 0) {
ff023aac
SB		 2794 ret = -EIO;
2795 break;
2796 }
2797 if (sctx->stat.malloc_errors > 0) {
2798 ret = -ENOMEM;
2799 break;
2800 }
a2de733c 2801
539f358a
ID		 2802 dev_replace->cursor_left = dev_replace->cursor_right;
2803 dev_replace->item_needs_writeback = 1;
2804
a2de733c 2805 key.offset = found_key.offset + length;
71267333 2806 btrfs_release_path(path);
a2de733c
AJ		 2807 }
2808
a2de733c 2809 btrfs_free_path(path);
8c51032f
AJ		 2810
2811 /*
2812 * ret can still be 1 from search_slot or next_leaf,
2813 * that's not an error
2814 */
2815 return ret < 0 ? ret : 0;
a2de733c
AJ		 2816}
2817
a36cf8b8
SB		 2818static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2819 struct btrfs_device *scrub_dev)
a2de733c
AJ		 2820{
2821 int i;
2822 u64 bytenr;
2823 u64 gen;
2824 int ret;
a36cf8b8 2825 struct btrfs_root *root = sctx->dev_root;
a2de733c 2826
87533c47 2827 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
79787eaa
JM		 2828 return -EIO;
2829
a2de733c
AJ		 2830 gen = root->fs_info->last_trans_committed;
2831
2832 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2833 bytenr = btrfs_sb_offset(i);
a36cf8b8 2834 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
a2de733c
AJ		 2835 break;
2836
d9d181c1 2837 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
a36cf8b8 2838 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
ff023aac 2839 NULL, 1, bytenr);
a2de733c
AJ		 2840 if (ret)
2841 return ret;
2842 }
b6bfebc1 2843 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
a2de733c
AJ		 2844
2845 return 0;
2846}
2847
2848/*
2849 * get a reference count on fs_info->scrub_workers. start worker if necessary
2850 */
ff023aac
SB		 2851static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
2852 int is_dev_replace)
a2de733c 2853{
0dc3b84a 2854 int ret = 0;
0339ef2f
QW		 2855 int flags = WQ_FREEZABLE | WQ_UNBOUND;
2856 int max_active = fs_info->thread_pool_size;
a2de733c 2857
632dd772 2858 if (fs_info->scrub_workers_refcnt == 0) {
ff023aac 2859 if (is_dev_replace)
0339ef2f
QW		 2860 fs_info->scrub_workers =
2861 btrfs_alloc_workqueue("btrfs-scrub", flags,
2862 1, 4);
ff023aac 2863 else
0339ef2f
QW		 2864 fs_info->scrub_workers =
2865 btrfs_alloc_workqueue("btrfs-scrub", flags,
2866 max_active, 4);
2867 if (!fs_info->scrub_workers) {
2868 ret = -ENOMEM;
0dc3b84a 2869 goto out;
0339ef2f
QW		 2870 }
2871 fs_info->scrub_wr_completion_workers =
2872 btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
2873 max_active, 2);
2874 if (!fs_info->scrub_wr_completion_workers) {
2875 ret = -ENOMEM;
ff023aac 2876 goto out;
0339ef2f
QW		 2877 }
2878 fs_info->scrub_nocow_workers =
2879 btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
2880 if (!fs_info->scrub_nocow_workers) {
2881 ret = -ENOMEM;
ff023aac 2882 goto out;
0339ef2f 2883 }
632dd772 2884 }
a2de733c 2885 ++fs_info->scrub_workers_refcnt;
0dc3b84a 2886out:
0dc3b84a 2887 return ret;
a2de733c
AJ		 2888}
2889
aa1b8cd4 2890static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
a2de733c 2891{
ff023aac 2892 if (--fs_info->scrub_workers_refcnt == 0) {
0339ef2f
QW		 2893 btrfs_destroy_workqueue(fs_info->scrub_workers);
2894 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
2895 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
ff023aac 2896 }
a2de733c 2897 WARN_ON(fs_info->scrub_workers_refcnt < 0);
a2de733c
AJ		 2898}
2899
aa1b8cd4
SB		 2900int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2901 u64 end, struct btrfs_scrub_progress *progress,
63a212ab 2902 int readonly, int is_dev_replace)
a2de733c 2903{
d9d181c1 2904 struct scrub_ctx *sctx;
a2de733c
AJ		 2905 int ret;
2906 struct btrfs_device *dev;
2907
aa1b8cd4 2908 if (btrfs_fs_closing(fs_info))
a2de733c
AJ		 2909 return -EINVAL;
2910
2911 /*
2912 * check some assumptions
2913 */
aa1b8cd4 2914 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
efe120a0
FH		 2915 btrfs_err(fs_info,
2916 "scrub: size assumption nodesize == leafsize (%d == %d) fails",
aa1b8cd4
SB		 2917 fs_info->chunk_root->nodesize,
2918 fs_info->chunk_root->leafsize);
b5d67f64
SB		 2919 return -EINVAL;
2920 }
2921
aa1b8cd4 2922 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
b5d67f64
SB		 2923 /*
2924 * in this case scrub is unable to calculate the checksum
2925 * the way scrub is implemented. Do not handle this
2926 * situation at all because it won't ever happen.
2927 */
efe120a0
FH		 2928 btrfs_err(fs_info,
2929 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
aa1b8cd4 2930 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
b5d67f64
SB		 2931 return -EINVAL;
2932 }
2933
aa1b8cd4 2934 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
b5d67f64 2935 /* not supported for data w/o checksums */
efe120a0
FH		 2936 btrfs_err(fs_info,
2937 "scrub: size assumption sectorsize != PAGE_SIZE "
2938 "(%d != %lu) fails",
27f9f023 2939 fs_info->chunk_root->sectorsize, PAGE_SIZE);
a2de733c
AJ		 2940 return -EINVAL;
2941 }
2942
7a9e9987
SB		 2943 if (fs_info->chunk_root->nodesize >
2944 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
2945 fs_info->chunk_root->sectorsize >
2946 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
2947 /*
2948 * would exhaust the array bounds of pagev member in
2949 * struct scrub_block
2950 */
efe120a0
FH		 2951 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
2952 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
7a9e9987
SB		 2953 fs_info->chunk_root->nodesize,
2954 SCRUB_MAX_PAGES_PER_BLOCK,
2955 fs_info->chunk_root->sectorsize,
2956 SCRUB_MAX_PAGES_PER_BLOCK);
2957 return -EINVAL;
2958 }
2959
a2de733c 2960
aa1b8cd4
SB		 2961 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2962 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
63a212ab 2963 if (!dev || (dev->missing && !is_dev_replace)) {
aa1b8cd4 2964 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c
AJ		 2965 return -ENODEV;
2966 }
a2de733c 2967
3b7a016f 2968 mutex_lock(&fs_info->scrub_lock);
63a212ab 2969 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
a2de733c 2970 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4 2971 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
aa1b8cd4 2972 return -EIO;
a2de733c
AJ		 2973 }
2974
8dabb742
SB		 2975 btrfs_dev_replace_lock(&fs_info->dev_replace);
2976 if (dev->scrub_device ||
2977 (!is_dev_replace &&
2978 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2979 btrfs_dev_replace_unlock(&fs_info->dev_replace);
a2de733c 2980 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4 2981 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c
AJ		 2982 return -EINPROGRESS;
2983 }
8dabb742 2984 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3b7a016f
WS		 2985
2986 ret = scrub_workers_get(fs_info, is_dev_replace);
2987 if (ret) {
2988 mutex_unlock(&fs_info->scrub_lock);
2989 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2990 return ret;
2991 }
2992
63a212ab 2993 sctx = scrub_setup_ctx(dev, is_dev_replace);
d9d181c1 2994 if (IS_ERR(sctx)) {
a2de733c 2995 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4
SB		 2996 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2997 scrub_workers_put(fs_info);
d9d181c1 2998 return PTR_ERR(sctx);
a2de733c 2999 }
d9d181c1
SB		 3000 sctx->readonly = readonly;
3001 dev->scrub_device = sctx;
3cb0929a 3002 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c 3003
3cb0929a
WS		 3004 /*
3005 * checking @scrub_pause_req here, we can avoid
3006 * race between committing transaction and scrubbing.
3007 */
cb7ab021 3008 __scrub_blocked_if_needed(fs_info);
a2de733c
AJ		 3009 atomic_inc(&fs_info->scrubs_running);
3010 mutex_unlock(&fs_info->scrub_lock);
a2de733c 3011
ff023aac 3012 if (!is_dev_replace) {
9b011adf
WS		 3013 /*
3014 * by holding device list mutex, we can
3015 * kick off writing super in log tree sync.
3016 */
3cb0929a 3017 mutex_lock(&fs_info->fs_devices->device_list_mutex);
ff023aac 3018 ret = scrub_supers(sctx, dev);
3cb0929a 3019 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ff023aac 3020 }
a2de733c
AJ		 3021
3022 if (!ret)
ff023aac
SB		 3023 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3024 is_dev_replace);
a2de733c 3025
b6bfebc1 3026 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
a2de733c
AJ		 3027 atomic_dec(&fs_info->scrubs_running);
3028 wake_up(&fs_info->scrub_pause_wait);
3029
b6bfebc1 3030 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
0ef8e451 3031
a2de733c 3032 if (progress)
d9d181c1 3033 memcpy(progress, &sctx->stat, sizeof(*progress));
a2de733c
AJ		 3034
3035 mutex_lock(&fs_info->scrub_lock);
3036 dev->scrub_device = NULL;
3b7a016f 3037 scrub_workers_put(fs_info);
a2de733c
AJ		 3038 mutex_unlock(&fs_info->scrub_lock);
3039
d9d181c1 3040 scrub_free_ctx(sctx);
a2de733c
AJ		 3041
3042 return ret;
3043}
3044
143bede5 3045void btrfs_scrub_pause(struct btrfs_root *root)
a2de733c
AJ		 3046{
3047 struct btrfs_fs_info *fs_info = root->fs_info;
3048
3049 mutex_lock(&fs_info->scrub_lock);
3050 atomic_inc(&fs_info->scrub_pause_req);
3051 while (atomic_read(&fs_info->scrubs_paused) !=
3052 atomic_read(&fs_info->scrubs_running)) {
3053 mutex_unlock(&fs_info->scrub_lock);
3054 wait_event(fs_info->scrub_pause_wait,
3055 atomic_read(&fs_info->scrubs_paused) ==
3056 atomic_read(&fs_info->scrubs_running));
3057 mutex_lock(&fs_info->scrub_lock);
3058 }
3059 mutex_unlock(&fs_info->scrub_lock);
a2de733c
AJ		 3060}
3061
143bede5 3062void btrfs_scrub_continue(struct btrfs_root *root)
a2de733c
AJ		 3063{
3064 struct btrfs_fs_info *fs_info = root->fs_info;
3065
3066 atomic_dec(&fs_info->scrub_pause_req);
3067 wake_up(&fs_info->scrub_pause_wait);
a2de733c
AJ		 3068}
3069
aa1b8cd4 3070int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
a2de733c 3071{
a2de733c
AJ		 3072 mutex_lock(&fs_info->scrub_lock);
3073 if (!atomic_read(&fs_info->scrubs_running)) {
3074 mutex_unlock(&fs_info->scrub_lock);
3075 return -ENOTCONN;
3076 }
3077
3078 atomic_inc(&fs_info->scrub_cancel_req);
3079 while (atomic_read(&fs_info->scrubs_running)) {
3080 mutex_unlock(&fs_info->scrub_lock);
3081 wait_event(fs_info->scrub_pause_wait,
3082 atomic_read(&fs_info->scrubs_running) == 0);
3083 mutex_lock(&fs_info->scrub_lock);
3084 }
3085 atomic_dec(&fs_info->scrub_cancel_req);
3086 mutex_unlock(&fs_info->scrub_lock);
3087
3088 return 0;
3089}
3090
aa1b8cd4
SB		 3091int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
3092 struct btrfs_device *dev)
49b25e05 3093{
d9d181c1 3094 struct scrub_ctx *sctx;
a2de733c
AJ		 3095
3096 mutex_lock(&fs_info->scrub_lock);
d9d181c1
SB		 3097 sctx = dev->scrub_device;
3098 if (!sctx) {
a2de733c
AJ		 3099 mutex_unlock(&fs_info->scrub_lock);
3100 return -ENOTCONN;
3101 }
d9d181c1 3102 atomic_inc(&sctx->cancel_req);
a2de733c
AJ		 3103 while (dev->scrub_device) {
3104 mutex_unlock(&fs_info->scrub_lock);
3105 wait_event(fs_info->scrub_pause_wait,
3106 dev->scrub_device == NULL);
3107 mutex_lock(&fs_info->scrub_lock);
3108 }
3109 mutex_unlock(&fs_info->scrub_lock);
3110
3111 return 0;
3112}
1623edeb 3113
a2de733c
AJ		 3114int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3115 struct btrfs_scrub_progress *progress)
3116{
3117 struct btrfs_device *dev;
d9d181c1 3118 struct scrub_ctx *sctx = NULL;
a2de733c
AJ		 3119
3120 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
aa1b8cd4 3121 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
a2de733c 3122 if (dev)
d9d181c1
SB		 3123 sctx = dev->scrub_device;
3124 if (sctx)
3125 memcpy(progress, &sctx->stat, sizeof(*progress));
a2de733c
AJ		 3126 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3127
d9d181c1 3128 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
a2de733c 3129}
ff023aac
SB		 3130
3131static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3132 u64 extent_logical, u64 extent_len,
3133 u64 *extent_physical,
3134 struct btrfs_device **extent_dev,
3135 int *extent_mirror_num)
3136{
3137 u64 mapped_length;
3138 struct btrfs_bio *bbio = NULL;
3139 int ret;
3140
3141 mapped_length = extent_len;
3142 ret = btrfs_map_block(fs_info, READ, extent_logical,
3143 &mapped_length, &bbio, 0);
3144 if (ret || !bbio || mapped_length < extent_len ||
3145 !bbio->stripes[0].dev->bdev) {
3146 kfree(bbio);
3147 return;
3148 }
3149
3150 *extent_physical = bbio->stripes[0].physical;
3151 *extent_mirror_num = bbio->mirror_num;
3152 *extent_dev = bbio->stripes[0].dev;
3153 kfree(bbio);
3154}
3155
3156static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3157 struct scrub_wr_ctx *wr_ctx,
3158 struct btrfs_fs_info *fs_info,
3159 struct btrfs_device *dev,
3160 int is_dev_replace)
3161{
3162 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3163
3164 mutex_init(&wr_ctx->wr_lock);
3165 wr_ctx->wr_curr_bio = NULL;
3166 if (!is_dev_replace)
3167 return 0;
3168
3169 WARN_ON(!dev->bdev);
3170 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
3171 bio_get_nr_vecs(dev->bdev));
3172 wr_ctx->tgtdev = dev;
3173 atomic_set(&wr_ctx->flush_all_writes, 0);
3174 return 0;
3175}
3176
3177static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3178{
3179 mutex_lock(&wr_ctx->wr_lock);
3180 kfree(wr_ctx->wr_curr_bio);
3181 wr_ctx->wr_curr_bio = NULL;
3182 mutex_unlock(&wr_ctx->wr_lock);
3183}
3184
3185static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3186 int mirror_num, u64 physical_for_dev_replace)
3187{
3188 struct scrub_copy_nocow_ctx *nocow_ctx;
3189 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3190
3191 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3192 if (!nocow_ctx) {
3193 spin_lock(&sctx->stat_lock);
3194 sctx->stat.malloc_errors++;
3195 spin_unlock(&sctx->stat_lock);
3196 return -ENOMEM;
3197 }
3198
3199 scrub_pending_trans_workers_inc(sctx);
3200
3201 nocow_ctx->sctx = sctx;
3202 nocow_ctx->logical = logical;
3203 nocow_ctx->len = len;
3204 nocow_ctx->mirror_num = mirror_num;
3205 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
0339ef2f 3206 btrfs_init_work(&nocow_ctx->work, copy_nocow_pages_worker, NULL, NULL);
652f25a2 3207 INIT_LIST_HEAD(&nocow_ctx->inodes);
0339ef2f
QW		 3208 btrfs_queue_work(fs_info->scrub_nocow_workers,
3209 &nocow_ctx->work);
ff023aac
SB		 3210
3211 return 0;
3212}
3213
652f25a2
JB		 3214static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
3215{
3216 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3217 struct scrub_nocow_inode *nocow_inode;
3218
3219 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
3220 if (!nocow_inode)
3221 return -ENOMEM;
3222 nocow_inode->inum = inum;
3223 nocow_inode->offset = offset;
3224 nocow_inode->root = root;
3225 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
3226 return 0;
3227}
3228
3229#define COPY_COMPLETE 1
3230
ff023aac
SB		 3231static void copy_nocow_pages_worker(struct btrfs_work *work)
3232{
3233 struct scrub_copy_nocow_ctx *nocow_ctx =
3234 container_of(work, struct scrub_copy_nocow_ctx, work);
3235 struct scrub_ctx *sctx = nocow_ctx->sctx;
3236 u64 logical = nocow_ctx->logical;
3237 u64 len = nocow_ctx->len;
3238 int mirror_num = nocow_ctx->mirror_num;
3239 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3240 int ret;
3241 struct btrfs_trans_handle *trans = NULL;
3242 struct btrfs_fs_info *fs_info;
3243 struct btrfs_path *path;
3244 struct btrfs_root *root;
3245 int not_written = 0;
3246
3247 fs_info = sctx->dev_root->fs_info;
3248 root = fs_info->extent_root;
3249
3250 path = btrfs_alloc_path();
3251 if (!path) {
3252 spin_lock(&sctx->stat_lock);
3253 sctx->stat.malloc_errors++;
3254 spin_unlock(&sctx->stat_lock);
3255 not_written = 1;
3256 goto out;
3257 }
3258
3259 trans = btrfs_join_transaction(root);
3260 if (IS_ERR(trans)) {
3261 not_written = 1;
3262 goto out;
3263 }
3264
3265 ret = iterate_inodes_from_logical(logical, fs_info, path,
652f25a2 3266 record_inode_for_nocow, nocow_ctx);
ff023aac 3267 if (ret != 0 && ret != -ENOENT) {
efe120a0
FH		 3268 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
3269 "phys %llu, len %llu, mir %u, ret %d",
118a0a25
GU		 3270 logical, physical_for_dev_replace, len, mirror_num,
3271 ret);
ff023aac
SB		 3272 not_written = 1;
3273 goto out;
3274 }
3275
652f25a2
JB		 3276 btrfs_end_transaction(trans, root);
3277 trans = NULL;
3278 while (!list_empty(&nocow_ctx->inodes)) {
3279 struct scrub_nocow_inode *entry;
3280 entry = list_first_entry(&nocow_ctx->inodes,
3281 struct scrub_nocow_inode,
3282 list);
3283 list_del_init(&entry->list);
3284 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
3285 entry->root, nocow_ctx);
3286 kfree(entry);
3287 if (ret == COPY_COMPLETE) {
3288 ret = 0;
3289 break;
3290 } else if (ret) {
3291 break;
3292 }
3293 }
ff023aac 3294out:
652f25a2
JB		 3295 while (!list_empty(&nocow_ctx->inodes)) {
3296 struct scrub_nocow_inode *entry;
3297 entry = list_first_entry(&nocow_ctx->inodes,
3298 struct scrub_nocow_inode,
3299 list);
3300 list_del_init(&entry->list);
3301 kfree(entry);
3302 }
ff023aac
SB		 3303 if (trans && !IS_ERR(trans))
3304 btrfs_end_transaction(trans, root);
3305 if (not_written)
3306 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
3307 num_uncorrectable_read_errors);
3308
3309 btrfs_free_path(path);
3310 kfree(nocow_ctx);
3311
3312 scrub_pending_trans_workers_dec(sctx);
3313}
3314
652f25a2
JB		 3315static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
3316 struct scrub_copy_nocow_ctx *nocow_ctx)
ff023aac 3317{
826aa0a8 3318 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
ff023aac 3319 struct btrfs_key key;
826aa0a8
MX		 3320 struct inode *inode;
3321 struct page *page;
ff023aac 3322 struct btrfs_root *local_root;
652f25a2
JB		 3323 struct btrfs_ordered_extent *ordered;
3324 struct extent_map *em;
3325 struct extent_state *cached_state = NULL;
3326 struct extent_io_tree *io_tree;
ff023aac 3327 u64 physical_for_dev_replace;
652f25a2
JB		 3328 u64 len = nocow_ctx->len;
3329 u64 lockstart = offset, lockend = offset + len - 1;
826aa0a8 3330 unsigned long index;
6f1c3605 3331 int srcu_index;
652f25a2
JB		 3332 int ret = 0;
3333 int err = 0;
ff023aac
SB		 3334
3335 key.objectid = root;
3336 key.type = BTRFS_ROOT_ITEM_KEY;
3337 key.offset = (u64)-1;
6f1c3605
LB		 3338
3339 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
3340
ff023aac 3341 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
6f1c3605
LB		 3342 if (IS_ERR(local_root)) {
3343 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
ff023aac 3344 return PTR_ERR(local_root);
6f1c3605 3345 }
ff023aac
SB		 3346
3347 key.type = BTRFS_INODE_ITEM_KEY;
3348 key.objectid = inum;
3349 key.offset = 0;
3350 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
6f1c3605 3351 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
ff023aac
SB		 3352 if (IS_ERR(inode))
3353 return PTR_ERR(inode);
3354
edd1400b
MX		 3355 /* Avoid truncate/dio/punch hole.. */
3356 mutex_lock(&inode->i_mutex);
3357 inode_dio_wait(inode);
3358
ff023aac 3359 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
652f25a2
JB		 3360 io_tree = &BTRFS_I(inode)->io_tree;
3361
3362 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
3363 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
3364 if (ordered) {
3365 btrfs_put_ordered_extent(ordered);
3366 goto out_unlock;
3367 }
3368
3369 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0);
3370 if (IS_ERR(em)) {
3371 ret = PTR_ERR(em);
3372 goto out_unlock;
3373 }
3374
3375 /*
3376 * This extent does not actually cover the logical extent anymore,
3377 * move on to the next inode.
3378 */
3379 if (em->block_start > nocow_ctx->logical ||
3380 em->block_start + em->block_len < nocow_ctx->logical + len) {
3381 free_extent_map(em);
3382 goto out_unlock;
3383 }
3384 free_extent_map(em);
3385
ff023aac 3386 while (len >= PAGE_CACHE_SIZE) {
ff023aac 3387 index = offset >> PAGE_CACHE_SHIFT;
edd1400b 3388again:
ff023aac
SB		 3389 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3390 if (!page) {
efe120a0 3391 btrfs_err(fs_info, "find_or_create_page() failed");
ff023aac 3392 ret = -ENOMEM;
826aa0a8 3393 goto out;
ff023aac
SB		 3394 }
3395
3396 if (PageUptodate(page)) {
3397 if (PageDirty(page))
3398 goto next_page;
3399 } else {
3400 ClearPageError(page);
652f25a2
JB		 3401 err = extent_read_full_page_nolock(io_tree, page,
3402 btrfs_get_extent,
3403 nocow_ctx->mirror_num);
826aa0a8
MX		 3404 if (err) {
3405 ret = err;
ff023aac
SB		 3406 goto next_page;
3407 }
edd1400b 3408
26b25891 3409 lock_page(page);
edd1400b
MX		 3410 /*
3411 * If the page has been remove from the page cache,
3412 * the data on it is meaningless, because it may be
3413 * old one, the new data may be written into the new
3414 * page in the page cache.
3415 */
3416 if (page->mapping != inode->i_mapping) {
652f25a2 3417 unlock_page(page);
edd1400b
MX		 3418 page_cache_release(page);
3419 goto again;
3420 }
ff023aac
SB		 3421 if (!PageUptodate(page)) {
3422 ret = -EIO;
3423 goto next_page;
3424 }
3425 }
826aa0a8
MX		 3426 err = write_page_nocow(nocow_ctx->sctx,
3427 physical_for_dev_replace, page);
3428 if (err)
3429 ret = err;
ff023aac 3430next_page:
826aa0a8
MX		 3431 unlock_page(page);
3432 page_cache_release(page);
3433
3434 if (ret)
3435 break;
3436
ff023aac
SB		 3437 offset += PAGE_CACHE_SIZE;
3438 physical_for_dev_replace += PAGE_CACHE_SIZE;
3439 len -= PAGE_CACHE_SIZE;
3440 }
652f25a2
JB		 3441 ret = COPY_COMPLETE;
3442out_unlock:
3443 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
3444 GFP_NOFS);
826aa0a8 3445out:
edd1400b 3446 mutex_unlock(&inode->i_mutex);
826aa0a8 3447 iput(inode);
ff023aac
SB		 3448 return ret;
3449}
3450
3451static int write_page_nocow(struct scrub_ctx *sctx,
3452 u64 physical_for_dev_replace, struct page *page)
3453{
3454 struct bio *bio;
3455 struct btrfs_device *dev;
3456 int ret;
ff023aac
SB		 3457
3458 dev = sctx->wr_ctx.tgtdev;
3459 if (!dev)
3460 return -EIO;
3461 if (!dev->bdev) {
3462 printk_ratelimited(KERN_WARNING
efe120a0 3463 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
ff023aac
SB		 3464 return -EIO;
3465 }
9be3395b 3466 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
ff023aac
SB		 3467 if (!bio) {
3468 spin_lock(&sctx->stat_lock);
3469 sctx->stat.malloc_errors++;
3470 spin_unlock(&sctx->stat_lock);
3471 return -ENOMEM;
3472 }
4f024f37
KO		 3473 bio->bi_iter.bi_size = 0;
3474 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
ff023aac
SB		 3475 bio->bi_bdev = dev->bdev;
3476 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
3477 if (ret != PAGE_CACHE_SIZE) {
3478leave_with_eio:
3479 bio_put(bio);
3480 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
3481 return -EIO;
3482 }
ff023aac 3483
33879d45 3484 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
ff023aac
SB		 3485 goto leave_with_eio;
3486
3487 bio_put(bio);
3488 return 0;
3489}
Linux kernel - Deliverables
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