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Btrfs: RAID5 and RAID6
[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
ff023aac
SB		 161struct scrub_copy_nocow_ctx {
162 struct scrub_ctx *sctx;
163 u64 logical;
164 u64 len;
165 int mirror_num;
166 u64 physical_for_dev_replace;
167 struct btrfs_work work;
168};
169
558540c1
JS		 170struct scrub_warning {
171 struct btrfs_path *path;
172 u64 extent_item_size;
173 char *scratch_buf;
174 char *msg_buf;
175 const char *errstr;
176 sector_t sector;
177 u64 logical;
178 struct btrfs_device *dev;
179 int msg_bufsize;
180 int scratch_bufsize;
181};
182
b5d67f64 183
b6bfebc1
SB		 184static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
185static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
186static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
187static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
b5d67f64 188static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
d9d181c1 189static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
3ec706c8 190 struct btrfs_fs_info *fs_info,
ff023aac 191 struct scrub_block *original_sblock,
b5d67f64 192 u64 length, u64 logical,
ff023aac 193 struct scrub_block *sblocks_for_recheck);
34f5c8e9
SB		 194static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
195 struct scrub_block *sblock, int is_metadata,
196 int have_csum, u8 *csum, u64 generation,
197 u16 csum_size);
b5d67f64
SB		 198static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
199 struct scrub_block *sblock,
200 int is_metadata, int have_csum,
201 const u8 *csum, u64 generation,
202 u16 csum_size);
203static void scrub_complete_bio_end_io(struct bio *bio, int err);
204static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
205 struct scrub_block *sblock_good,
206 int force_write);
207static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
208 struct scrub_block *sblock_good,
209 int page_num, int force_write);
ff023aac
SB		 210static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
211static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
212 int page_num);
b5d67f64
SB		 213static int scrub_checksum_data(struct scrub_block *sblock);
214static int scrub_checksum_tree_block(struct scrub_block *sblock);
215static int scrub_checksum_super(struct scrub_block *sblock);
216static void scrub_block_get(struct scrub_block *sblock);
217static void scrub_block_put(struct scrub_block *sblock);
7a9e9987
SB		 218static void scrub_page_get(struct scrub_page *spage);
219static void scrub_page_put(struct scrub_page *spage);
ff023aac
SB		 220static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
221 struct scrub_page *spage);
d9d181c1 222static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 223 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac
SB		 224 u64 gen, int mirror_num, u8 *csum, int force,
225 u64 physical_for_dev_replace);
1623edeb 226static void scrub_bio_end_io(struct bio *bio, int err);
b5d67f64
SB		 227static void scrub_bio_end_io_worker(struct btrfs_work *work);
228static void scrub_block_complete(struct scrub_block *sblock);
ff023aac
SB		 229static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
230 u64 extent_logical, u64 extent_len,
231 u64 *extent_physical,
232 struct btrfs_device **extent_dev,
233 int *extent_mirror_num);
234static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
235 struct scrub_wr_ctx *wr_ctx,
236 struct btrfs_fs_info *fs_info,
237 struct btrfs_device *dev,
238 int is_dev_replace);
239static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
240static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
241 struct scrub_page *spage);
242static void scrub_wr_submit(struct scrub_ctx *sctx);
243static void scrub_wr_bio_end_io(struct bio *bio, int err);
244static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
245static int write_page_nocow(struct scrub_ctx *sctx,
246 u64 physical_for_dev_replace, struct page *page);
247static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
248 void *ctx);
249static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
250 int mirror_num, u64 physical_for_dev_replace);
251static void copy_nocow_pages_worker(struct btrfs_work *work);
1623edeb
SB		 252
253
b6bfebc1
SB		 254static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
255{
256 atomic_inc(&sctx->bios_in_flight);
257}
258
259static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
260{
261 atomic_dec(&sctx->bios_in_flight);
262 wake_up(&sctx->list_wait);
263}
264
265/*
266 * used for workers that require transaction commits (i.e., for the
267 * NOCOW case)
268 */
269static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
270{
271 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
272
273 /*
274 * increment scrubs_running to prevent cancel requests from
275 * completing as long as a worker is running. we must also
276 * increment scrubs_paused to prevent deadlocking on pause
277 * requests used for transactions commits (as the worker uses a
278 * transaction context). it is safe to regard the worker
279 * as paused for all matters practical. effectively, we only
280 * avoid cancellation requests from completing.
281 */
282 mutex_lock(&fs_info->scrub_lock);
283 atomic_inc(&fs_info->scrubs_running);
284 atomic_inc(&fs_info->scrubs_paused);
285 mutex_unlock(&fs_info->scrub_lock);
286 atomic_inc(&sctx->workers_pending);
287}
288
289/* used for workers that require transaction commits */
290static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
291{
292 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
293
294 /*
295 * see scrub_pending_trans_workers_inc() why we're pretending
296 * to be paused in the scrub counters
297 */
298 mutex_lock(&fs_info->scrub_lock);
299 atomic_dec(&fs_info->scrubs_running);
300 atomic_dec(&fs_info->scrubs_paused);
301 mutex_unlock(&fs_info->scrub_lock);
302 atomic_dec(&sctx->workers_pending);
303 wake_up(&fs_info->scrub_pause_wait);
304 wake_up(&sctx->list_wait);
305}
306
d9d181c1 307static void scrub_free_csums(struct scrub_ctx *sctx)
a2de733c 308{
d9d181c1 309 while (!list_empty(&sctx->csum_list)) {
a2de733c 310 struct btrfs_ordered_sum *sum;
d9d181c1 311 sum = list_first_entry(&sctx->csum_list,
a2de733c
AJ		 312 struct btrfs_ordered_sum, list);
313 list_del(&sum->list);
314 kfree(sum);
315 }
316}
317
d9d181c1 318static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
a2de733c
AJ		 319{
320 int i;
a2de733c 321
d9d181c1 322 if (!sctx)
a2de733c
AJ		 323 return;
324
ff023aac
SB		 325 scrub_free_wr_ctx(&sctx->wr_ctx);
326
b5d67f64 327 /* this can happen when scrub is cancelled */
d9d181c1
SB		 328 if (sctx->curr != -1) {
329 struct scrub_bio *sbio = sctx->bios[sctx->curr];
b5d67f64
SB		 330
331 for (i = 0; i < sbio->page_count; i++) {
ff023aac 332 WARN_ON(!sbio->pagev[i]->page);
b5d67f64
SB		 333 scrub_block_put(sbio->pagev[i]->sblock);
334 }
335 bio_put(sbio->bio);
336 }
337
ff023aac 338 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
d9d181c1 339 struct scrub_bio *sbio = sctx->bios[i];
a2de733c
AJ		 340
341 if (!sbio)
342 break;
a2de733c
AJ		 343 kfree(sbio);
344 }
345
d9d181c1
SB		 346 scrub_free_csums(sctx);
347 kfree(sctx);
a2de733c
AJ		 348}
349
350static noinline_for_stack
63a212ab 351struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
a2de733c 352{
d9d181c1 353 struct scrub_ctx *sctx;
a2de733c 354 int i;
a2de733c 355 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
ff023aac
SB		 356 int pages_per_rd_bio;
357 int ret;
a2de733c 358
ff023aac
SB		 359 /*
360 * the setting of pages_per_rd_bio is correct for scrub but might
361 * be wrong for the dev_replace code where we might read from
362 * different devices in the initial huge bios. However, that
363 * code is able to correctly handle the case when adding a page
364 * to a bio fails.
365 */
366 if (dev->bdev)
367 pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO,
368 bio_get_nr_vecs(dev->bdev));
369 else
370 pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
d9d181c1
SB		 371 sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
372 if (!sctx)
a2de733c 373 goto nomem;
63a212ab 374 sctx->is_dev_replace = is_dev_replace;
ff023aac 375 sctx->pages_per_rd_bio = pages_per_rd_bio;
d9d181c1 376 sctx->curr = -1;
a36cf8b8 377 sctx->dev_root = dev->dev_root;
ff023aac 378 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
a2de733c
AJ		 379 struct scrub_bio *sbio;
380
381 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
382 if (!sbio)
383 goto nomem;
d9d181c1 384 sctx->bios[i] = sbio;
a2de733c 385
a2de733c 386 sbio->index = i;
d9d181c1 387 sbio->sctx = sctx;
b5d67f64
SB		 388 sbio->page_count = 0;
389 sbio->work.func = scrub_bio_end_io_worker;
a2de733c 390
ff023aac 391 if (i != SCRUB_BIOS_PER_SCTX - 1)
d9d181c1 392 sctx->bios[i]->next_free = i + 1;
0ef8e451 393 else
d9d181c1
SB		 394 sctx->bios[i]->next_free = -1;
395 }
396 sctx->first_free = 0;
397 sctx->nodesize = dev->dev_root->nodesize;
398 sctx->leafsize = dev->dev_root->leafsize;
399 sctx->sectorsize = dev->dev_root->sectorsize;
b6bfebc1
SB		 400 atomic_set(&sctx->bios_in_flight, 0);
401 atomic_set(&sctx->workers_pending, 0);
d9d181c1
SB		 402 atomic_set(&sctx->cancel_req, 0);
403 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
404 INIT_LIST_HEAD(&sctx->csum_list);
405
406 spin_lock_init(&sctx->list_lock);
407 spin_lock_init(&sctx->stat_lock);
408 init_waitqueue_head(&sctx->list_wait);
ff023aac
SB		 409
410 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
411 fs_info->dev_replace.tgtdev, is_dev_replace);
412 if (ret) {
413 scrub_free_ctx(sctx);
414 return ERR_PTR(ret);
415 }
d9d181c1 416 return sctx;
a2de733c
AJ		 417
418nomem:
d9d181c1 419 scrub_free_ctx(sctx);
a2de733c
AJ		 420 return ERR_PTR(-ENOMEM);
421}
422
ff023aac
SB		 423static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
424 void *warn_ctx)
558540c1
JS		 425{
426 u64 isize;
427 u32 nlink;
428 int ret;
429 int i;
430 struct extent_buffer *eb;
431 struct btrfs_inode_item *inode_item;
ff023aac 432 struct scrub_warning *swarn = warn_ctx;
558540c1
JS		 433 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
434 struct inode_fs_paths *ipath = NULL;
435 struct btrfs_root *local_root;
436 struct btrfs_key root_key;
437
438 root_key.objectid = root;
439 root_key.type = BTRFS_ROOT_ITEM_KEY;
440 root_key.offset = (u64)-1;
441 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
442 if (IS_ERR(local_root)) {
443 ret = PTR_ERR(local_root);
444 goto err;
445 }
446
447 ret = inode_item_info(inum, 0, local_root, swarn->path);
448 if (ret) {
449 btrfs_release_path(swarn->path);
450 goto err;
451 }
452
453 eb = swarn->path->nodes[0];
454 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
455 struct btrfs_inode_item);
456 isize = btrfs_inode_size(eb, inode_item);
457 nlink = btrfs_inode_nlink(eb, inode_item);
458 btrfs_release_path(swarn->path);
459
460 ipath = init_ipath(4096, local_root, swarn->path);
26bdef54
DC		 461 if (IS_ERR(ipath)) {
462 ret = PTR_ERR(ipath);
463 ipath = NULL;
464 goto err;
465 }
558540c1
JS		 466 ret = paths_from_inode(inum, ipath);
467
468 if (ret < 0)
469 goto err;
470
471 /*
472 * we deliberately ignore the bit ipath might have been too small to
473 * hold all of the paths here
474 */
475 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
606686ee 476 printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
558540c1
JS		 477 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
478 "length %llu, links %u (path: %s)\n", swarn->errstr,
606686ee 479 swarn->logical, rcu_str_deref(swarn->dev->name),
558540c1
JS		 480 (unsigned long long)swarn->sector, root, inum, offset,
481 min(isize - offset, (u64)PAGE_SIZE), nlink,
745c4d8e 482 (char *)(unsigned long)ipath->fspath->val[i]);
558540c1
JS		 483
484 free_ipath(ipath);
485 return 0;
486
487err:
606686ee 488 printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
558540c1
JS		 489 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
490 "resolving failed with ret=%d\n", swarn->errstr,
606686ee 491 swarn->logical, rcu_str_deref(swarn->dev->name),
558540c1
JS		 492 (unsigned long long)swarn->sector, root, inum, offset, ret);
493
494 free_ipath(ipath);
495 return 0;
496}
497
b5d67f64 498static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
558540c1 499{
a36cf8b8
SB		 500 struct btrfs_device *dev;
501 struct btrfs_fs_info *fs_info;
558540c1
JS		 502 struct btrfs_path *path;
503 struct btrfs_key found_key;
504 struct extent_buffer *eb;
505 struct btrfs_extent_item *ei;
506 struct scrub_warning swarn;
69917e43
LB		 507 unsigned long ptr = 0;
508 u64 extent_item_pos;
509 u64 flags = 0;
558540c1 510 u64 ref_root;
69917e43 511 u32 item_size;
558540c1 512 u8 ref_level;
558540c1 513 const int bufsize = 4096;
69917e43 514 int ret;
558540c1 515
a36cf8b8 516 WARN_ON(sblock->page_count < 1);
7a9e9987 517 dev = sblock->pagev[0]->dev;
a36cf8b8
SB		 518 fs_info = sblock->sctx->dev_root->fs_info;
519
558540c1
JS		 520 path = btrfs_alloc_path();
521
522 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
523 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
7a9e9987
SB		 524 swarn.sector = (sblock->pagev[0]->physical) >> 9;
525 swarn.logical = sblock->pagev[0]->logical;
558540c1 526 swarn.errstr = errstr;
a36cf8b8 527 swarn.dev = NULL;
558540c1
JS		 528 swarn.msg_bufsize = bufsize;
529 swarn.scratch_bufsize = bufsize;
530
531 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
532 goto out;
533
69917e43
LB		 534 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
535 &flags);
558540c1
JS		 536 if (ret < 0)
537 goto out;
538
4692cf58 539 extent_item_pos = swarn.logical - found_key.objectid;
558540c1
JS		 540 swarn.extent_item_size = found_key.offset;
541
542 eb = path->nodes[0];
543 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
544 item_size = btrfs_item_size_nr(eb, path->slots[0]);
4692cf58 545 btrfs_release_path(path);
558540c1 546
69917e43 547 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
558540c1
JS		 548 do {
549 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
550 &ref_root, &ref_level);
606686ee 551 printk_in_rcu(KERN_WARNING
1623edeb 552 "btrfs: %s at logical %llu on dev %s, "
558540c1 553 "sector %llu: metadata %s (level %d) in tree "
606686ee
JB		 554 "%llu\n", errstr, swarn.logical,
555 rcu_str_deref(dev->name),
558540c1
JS		 556 (unsigned long long)swarn.sector,
557 ref_level ? "node" : "leaf",
558 ret < 0 ? -1 : ref_level,
559 ret < 0 ? -1 : ref_root);
560 } while (ret != 1);
561 } else {
562 swarn.path = path;
a36cf8b8 563 swarn.dev = dev;
7a3ae2f8
JS		 564 iterate_extent_inodes(fs_info, found_key.objectid,
565 extent_item_pos, 1,
558540c1
JS		 566 scrub_print_warning_inode, &swarn);
567 }
568
569out:
570 btrfs_free_path(path);
571 kfree(swarn.scratch_buf);
572 kfree(swarn.msg_buf);
573}
574
ff023aac 575static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
0ef8e451 576{
5da6fcbc 577 struct page *page = NULL;
0ef8e451 578 unsigned long index;
ff023aac 579 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
0ef8e451 580 int ret;
5da6fcbc 581 int corrected = 0;
0ef8e451 582 struct btrfs_key key;
5da6fcbc 583 struct inode *inode = NULL;
0ef8e451
JS		 584 u64 end = offset + PAGE_SIZE - 1;
585 struct btrfs_root *local_root;
586
587 key.objectid = root;
588 key.type = BTRFS_ROOT_ITEM_KEY;
589 key.offset = (u64)-1;
590 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
591 if (IS_ERR(local_root))
592 return PTR_ERR(local_root);
593
594 key.type = BTRFS_INODE_ITEM_KEY;
595 key.objectid = inum;
596 key.offset = 0;
597 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
598 if (IS_ERR(inode))
599 return PTR_ERR(inode);
600
0ef8e451
JS		 601 index = offset >> PAGE_CACHE_SHIFT;
602
603 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
5da6fcbc
JS		 604 if (!page) {
605 ret = -ENOMEM;
606 goto out;
607 }
608
609 if (PageUptodate(page)) {
3ec706c8 610 struct btrfs_fs_info *fs_info;
5da6fcbc
JS		 611 if (PageDirty(page)) {
612 /*
613 * we need to write the data to the defect sector. the
614 * data that was in that sector is not in memory,
615 * because the page was modified. we must not write the
616 * modified page to that sector.
617 *
618 * TODO: what could be done here: wait for the delalloc
619 * runner to write out that page (might involve
620 * COW) and see whether the sector is still
621 * referenced afterwards.
622 *
623 * For the meantime, we'll treat this error
624 * incorrectable, although there is a chance that a
625 * later scrub will find the bad sector again and that
626 * there's no dirty page in memory, then.
627 */
628 ret = -EIO;
629 goto out;
630 }
3ec706c8
SB		 631 fs_info = BTRFS_I(inode)->root->fs_info;
632 ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
5da6fcbc
JS		 633 fixup->logical, page,
634 fixup->mirror_num);
635 unlock_page(page);
636 corrected = !ret;
637 } else {
638 /*
639 * we need to get good data first. the general readpage path
640 * will call repair_io_failure for us, we just have to make
641 * sure we read the bad mirror.
642 */
643 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
644 EXTENT_DAMAGED, GFP_NOFS);
645 if (ret) {
646 /* set_extent_bits should give proper error */
647 WARN_ON(ret > 0);
648 if (ret > 0)
649 ret = -EFAULT;
650 goto out;
651 }
652
653 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
654 btrfs_get_extent,
655 fixup->mirror_num);
656 wait_on_page_locked(page);
657
658 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
659 end, EXTENT_DAMAGED, 0, NULL);
660 if (!corrected)
661 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
662 EXTENT_DAMAGED, GFP_NOFS);
663 }
664
665out:
666 if (page)
667 put_page(page);
668 if (inode)
669 iput(inode);
0ef8e451
JS		 670
671 if (ret < 0)
672 return ret;
673
674 if (ret == 0 && corrected) {
675 /*
676 * we only need to call readpage for one of the inodes belonging
677 * to this extent. so make iterate_extent_inodes stop
678 */
679 return 1;
680 }
681
682 return -EIO;
683}
684
685static void scrub_fixup_nodatasum(struct btrfs_work *work)
686{
687 int ret;
688 struct scrub_fixup_nodatasum *fixup;
d9d181c1 689 struct scrub_ctx *sctx;
0ef8e451
JS		 690 struct btrfs_trans_handle *trans = NULL;
691 struct btrfs_fs_info *fs_info;
692 struct btrfs_path *path;
693 int uncorrectable = 0;
694
695 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
d9d181c1 696 sctx = fixup->sctx;
0ef8e451
JS		 697 fs_info = fixup->root->fs_info;
698
699 path = btrfs_alloc_path();
700 if (!path) {
d9d181c1
SB		 701 spin_lock(&sctx->stat_lock);
702 ++sctx->stat.malloc_errors;
703 spin_unlock(&sctx->stat_lock);
0ef8e451
JS		 704 uncorrectable = 1;
705 goto out;
706 }
707
708 trans = btrfs_join_transaction(fixup->root);
709 if (IS_ERR(trans)) {
710 uncorrectable = 1;
711 goto out;
712 }
713
714 /*
715 * the idea is to trigger a regular read through the standard path. we
716 * read a page from the (failed) logical address by specifying the
717 * corresponding copynum of the failed sector. thus, that readpage is
718 * expected to fail.
719 * that is the point where on-the-fly error correction will kick in
720 * (once it's finished) and rewrite the failed sector if a good copy
721 * can be found.
722 */
723 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
724 path, scrub_fixup_readpage,
725 fixup);
726 if (ret < 0) {
727 uncorrectable = 1;
728 goto out;
729 }
730 WARN_ON(ret != 1);
731
d9d181c1
SB		 732 spin_lock(&sctx->stat_lock);
733 ++sctx->stat.corrected_errors;
734 spin_unlock(&sctx->stat_lock);
0ef8e451
JS		 735
736out:
737 if (trans && !IS_ERR(trans))
738 btrfs_end_transaction(trans, fixup->root);
739 if (uncorrectable) {
d9d181c1
SB		 740 spin_lock(&sctx->stat_lock);
741 ++sctx->stat.uncorrectable_errors;
742 spin_unlock(&sctx->stat_lock);
ff023aac
SB		 743 btrfs_dev_replace_stats_inc(
744 &sctx->dev_root->fs_info->dev_replace.
745 num_uncorrectable_read_errors);
606686ee 746 printk_ratelimited_in_rcu(KERN_ERR
b5d67f64 747 "btrfs: unable to fixup (nodatasum) error at logical %llu on dev %s\n",
606686ee 748 (unsigned long long)fixup->logical,
a36cf8b8 749 rcu_str_deref(fixup->dev->name));
0ef8e451
JS		 750 }
751
752 btrfs_free_path(path);
753 kfree(fixup);
754
b6bfebc1 755 scrub_pending_trans_workers_dec(sctx);
0ef8e451
JS		 756}
757
a2de733c 758/*
b5d67f64
SB		 759 * scrub_handle_errored_block gets called when either verification of the
760 * pages failed or the bio failed to read, e.g. with EIO. In the latter
761 * case, this function handles all pages in the bio, even though only one
762 * may be bad.
763 * The goal of this function is to repair the errored block by using the
764 * contents of one of the mirrors.
a2de733c 765 */
b5d67f64 766static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
a2de733c 767{
d9d181c1 768 struct scrub_ctx *sctx = sblock_to_check->sctx;
a36cf8b8 769 struct btrfs_device *dev;
b5d67f64
SB		 770 struct btrfs_fs_info *fs_info;
771 u64 length;
772 u64 logical;
773 u64 generation;
774 unsigned int failed_mirror_index;
775 unsigned int is_metadata;
776 unsigned int have_csum;
777 u8 *csum;
778 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
779 struct scrub_block *sblock_bad;
780 int ret;
781 int mirror_index;
782 int page_num;
783 int success;
558540c1 784 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
b5d67f64
SB		 785 DEFAULT_RATELIMIT_BURST);
786
787 BUG_ON(sblock_to_check->page_count < 1);
a36cf8b8 788 fs_info = sctx->dev_root->fs_info;
4ded4f63
SB		 789 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
790 /*
791 * if we find an error in a super block, we just report it.
792 * They will get written with the next transaction commit
793 * anyway
794 */
795 spin_lock(&sctx->stat_lock);
796 ++sctx->stat.super_errors;
797 spin_unlock(&sctx->stat_lock);
798 return 0;
799 }
b5d67f64 800 length = sblock_to_check->page_count * PAGE_SIZE;
7a9e9987
SB		 801 logical = sblock_to_check->pagev[0]->logical;
802 generation = sblock_to_check->pagev[0]->generation;
803 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
804 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
805 is_metadata = !(sblock_to_check->pagev[0]->flags &
b5d67f64 806 BTRFS_EXTENT_FLAG_DATA);
7a9e9987
SB		 807 have_csum = sblock_to_check->pagev[0]->have_csum;
808 csum = sblock_to_check->pagev[0]->csum;
809 dev = sblock_to_check->pagev[0]->dev;
13db62b7 810
ff023aac
SB		 811 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
812 sblocks_for_recheck = NULL;
813 goto nodatasum_case;
814 }
815
b5d67f64
SB		 816 /*
817 * read all mirrors one after the other. This includes to
818 * re-read the extent or metadata block that failed (that was
819 * the cause that this fixup code is called) another time,
820 * page by page this time in order to know which pages
821 * caused I/O errors and which ones are good (for all mirrors).
822 * It is the goal to handle the situation when more than one
823 * mirror contains I/O errors, but the errors do not
824 * overlap, i.e. the data can be repaired by selecting the
825 * pages from those mirrors without I/O error on the
826 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
827 * would be that mirror #1 has an I/O error on the first page,
828 * the second page is good, and mirror #2 has an I/O error on
829 * the second page, but the first page is good.
830 * Then the first page of the first mirror can be repaired by
831 * taking the first page of the second mirror, and the
832 * second page of the second mirror can be repaired by
833 * copying the contents of the 2nd page of the 1st mirror.
834 * One more note: if the pages of one mirror contain I/O
835 * errors, the checksum cannot be verified. In order to get
836 * the best data for repairing, the first attempt is to find
837 * a mirror without I/O errors and with a validated checksum.
838 * Only if this is not possible, the pages are picked from
839 * mirrors with I/O errors without considering the checksum.
840 * If the latter is the case, at the end, the checksum of the
841 * repaired area is verified in order to correctly maintain
842 * the statistics.
843 */
844
845 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
846 sizeof(*sblocks_for_recheck),
847 GFP_NOFS);
848 if (!sblocks_for_recheck) {
d9d181c1
SB		 849 spin_lock(&sctx->stat_lock);
850 sctx->stat.malloc_errors++;
851 sctx->stat.read_errors++;
852 sctx->stat.uncorrectable_errors++;
853 spin_unlock(&sctx->stat_lock);
a36cf8b8 854 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64 855 goto out;
a2de733c
AJ		 856 }
857
b5d67f64 858 /* setup the context, map the logical blocks and alloc the pages */
ff023aac 859 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
b5d67f64
SB		 860 logical, sblocks_for_recheck);
861 if (ret) {
d9d181c1
SB		 862 spin_lock(&sctx->stat_lock);
863 sctx->stat.read_errors++;
864 sctx->stat.uncorrectable_errors++;
865 spin_unlock(&sctx->stat_lock);
a36cf8b8 866 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64
SB		 867 goto out;
868 }
869 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
870 sblock_bad = sblocks_for_recheck + failed_mirror_index;
13db62b7 871
b5d67f64 872 /* build and submit the bios for the failed mirror, check checksums */
34f5c8e9
SB		 873 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
874 csum, generation, sctx->csum_size);
a2de733c 875
b5d67f64
SB		 876 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
877 sblock_bad->no_io_error_seen) {
878 /*
879 * the error disappeared after reading page by page, or
880 * the area was part of a huge bio and other parts of the
881 * bio caused I/O errors, or the block layer merged several
882 * read requests into one and the error is caused by a
883 * different bio (usually one of the two latter cases is
884 * the cause)
885 */
d9d181c1
SB		 886 spin_lock(&sctx->stat_lock);
887 sctx->stat.unverified_errors++;
888 spin_unlock(&sctx->stat_lock);
a2de733c 889
ff023aac
SB		 890 if (sctx->is_dev_replace)
891 scrub_write_block_to_dev_replace(sblock_bad);
b5d67f64 892 goto out;
a2de733c 893 }
a2de733c 894
b5d67f64 895 if (!sblock_bad->no_io_error_seen) {
d9d181c1
SB		 896 spin_lock(&sctx->stat_lock);
897 sctx->stat.read_errors++;
898 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 899 if (__ratelimit(&_rs))
900 scrub_print_warning("i/o error", sblock_to_check);
a36cf8b8 901 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
b5d67f64 902 } else if (sblock_bad->checksum_error) {
d9d181c1
SB		 903 spin_lock(&sctx->stat_lock);
904 sctx->stat.csum_errors++;
905 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 906 if (__ratelimit(&_rs))
907 scrub_print_warning("checksum error", sblock_to_check);
a36cf8b8 908 btrfs_dev_stat_inc_and_print(dev,
442a4f63 909 BTRFS_DEV_STAT_CORRUPTION_ERRS);
b5d67f64 910 } else if (sblock_bad->header_error) {
d9d181c1
SB		 911 spin_lock(&sctx->stat_lock);
912 sctx->stat.verify_errors++;
913 spin_unlock(&sctx->stat_lock);
b5d67f64
SB		 914 if (__ratelimit(&_rs))
915 scrub_print_warning("checksum/header error",
916 sblock_to_check);
442a4f63 917 if (sblock_bad->generation_error)
a36cf8b8 918 btrfs_dev_stat_inc_and_print(dev,
442a4f63
SB		 919 BTRFS_DEV_STAT_GENERATION_ERRS);
920 else
a36cf8b8 921 btrfs_dev_stat_inc_and_print(dev,
442a4f63 922 BTRFS_DEV_STAT_CORRUPTION_ERRS);
b5d67f64 923 }
a2de733c 924
ff023aac 925 if (sctx->readonly && !sctx->is_dev_replace)
b5d67f64 926 goto did_not_correct_error;
a2de733c 927
b5d67f64
SB		 928 if (!is_metadata && !have_csum) {
929 struct scrub_fixup_nodatasum *fixup_nodatasum;
a2de733c 930
ff023aac
SB		 931nodatasum_case:
932 WARN_ON(sctx->is_dev_replace);
933
b5d67f64
SB		 934 /*
935 * !is_metadata and !have_csum, this means that the data
936 * might not be COW'ed, that it might be modified
937 * concurrently. The general strategy to work on the
938 * commit root does not help in the case when COW is not
939 * used.
940 */
941 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
942 if (!fixup_nodatasum)
943 goto did_not_correct_error;
d9d181c1 944 fixup_nodatasum->sctx = sctx;
a36cf8b8 945 fixup_nodatasum->dev = dev;
b5d67f64
SB		 946 fixup_nodatasum->logical = logical;
947 fixup_nodatasum->root = fs_info->extent_root;
948 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
b6bfebc1 949 scrub_pending_trans_workers_inc(sctx);
b5d67f64
SB		 950 fixup_nodatasum->work.func = scrub_fixup_nodatasum;
951 btrfs_queue_worker(&fs_info->scrub_workers,
952 &fixup_nodatasum->work);
953 goto out;
a2de733c
AJ		 954 }
955
b5d67f64
SB		 956 /*
957 * now build and submit the bios for the other mirrors, check
cb2ced73
SB		 958 * checksums.
959 * First try to pick the mirror which is completely without I/O
b5d67f64
SB		 960 * errors and also does not have a checksum error.
961 * If one is found, and if a checksum is present, the full block
962 * that is known to contain an error is rewritten. Afterwards
963 * the block is known to be corrected.
964 * If a mirror is found which is completely correct, and no
965 * checksum is present, only those pages are rewritten that had
966 * an I/O error in the block to be repaired, since it cannot be
967 * determined, which copy of the other pages is better (and it
968 * could happen otherwise that a correct page would be
969 * overwritten by a bad one).
970 */
971 for (mirror_index = 0;
972 mirror_index < BTRFS_MAX_MIRRORS &&
973 sblocks_for_recheck[mirror_index].page_count > 0;
974 mirror_index++) {
cb2ced73 975 struct scrub_block *sblock_other;
b5d67f64 976
cb2ced73
SB		 977 if (mirror_index == failed_mirror_index)
978 continue;
979 sblock_other = sblocks_for_recheck + mirror_index;
980
981 /* build and submit the bios, check checksums */
34f5c8e9
SB		 982 scrub_recheck_block(fs_info, sblock_other, is_metadata,
983 have_csum, csum, generation,
984 sctx->csum_size);
985
986 if (!sblock_other->header_error &&
b5d67f64
SB		 987 !sblock_other->checksum_error &&
988 sblock_other->no_io_error_seen) {
ff023aac
SB		 989 if (sctx->is_dev_replace) {
990 scrub_write_block_to_dev_replace(sblock_other);
991 } else {
992 int force_write = is_metadata || have_csum;
993
994 ret = scrub_repair_block_from_good_copy(
995 sblock_bad, sblock_other,
996 force_write);
997 }
b5d67f64
SB		 998 if (0 == ret)
999 goto corrected_error;
1000 }
1001 }
a2de733c
AJ		 1002
1003 /*
ff023aac
SB		 1004 * for dev_replace, pick good pages and write to the target device.
1005 */
1006 if (sctx->is_dev_replace) {
1007 success = 1;
1008 for (page_num = 0; page_num < sblock_bad->page_count;
1009 page_num++) {
1010 int sub_success;
1011
1012 sub_success = 0;
1013 for (mirror_index = 0;
1014 mirror_index < BTRFS_MAX_MIRRORS &&
1015 sblocks_for_recheck[mirror_index].page_count > 0;
1016 mirror_index++) {
1017 struct scrub_block *sblock_other =
1018 sblocks_for_recheck + mirror_index;
1019 struct scrub_page *page_other =
1020 sblock_other->pagev[page_num];
1021
1022 if (!page_other->io_error) {
1023 ret = scrub_write_page_to_dev_replace(
1024 sblock_other, page_num);
1025 if (ret == 0) {
1026 /* succeeded for this page */
1027 sub_success = 1;
1028 break;
1029 } else {
1030 btrfs_dev_replace_stats_inc(
1031 &sctx->dev_root->
1032 fs_info->dev_replace.
1033 num_write_errors);
1034 }
1035 }
1036 }
1037
1038 if (!sub_success) {
1039 /*
1040 * did not find a mirror to fetch the page
1041 * from. scrub_write_page_to_dev_replace()
1042 * handles this case (page->io_error), by
1043 * filling the block with zeros before
1044 * submitting the write request
1045 */
1046 success = 0;
1047 ret = scrub_write_page_to_dev_replace(
1048 sblock_bad, page_num);
1049 if (ret)
1050 btrfs_dev_replace_stats_inc(
1051 &sctx->dev_root->fs_info->
1052 dev_replace.num_write_errors);
1053 }
1054 }
1055
1056 goto out;
1057 }
1058
1059 /*
1060 * for regular scrub, repair those pages that are errored.
1061 * In case of I/O errors in the area that is supposed to be
b5d67f64
SB		 1062 * repaired, continue by picking good copies of those pages.
1063 * Select the good pages from mirrors to rewrite bad pages from
1064 * the area to fix. Afterwards verify the checksum of the block
1065 * that is supposed to be repaired. This verification step is
1066 * only done for the purpose of statistic counting and for the
1067 * final scrub report, whether errors remain.
1068 * A perfect algorithm could make use of the checksum and try
1069 * all possible combinations of pages from the different mirrors
1070 * until the checksum verification succeeds. For example, when
1071 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1072 * of mirror #2 is readable but the final checksum test fails,
1073 * then the 2nd page of mirror #3 could be tried, whether now
1074 * the final checksum succeedes. But this would be a rare
1075 * exception and is therefore not implemented. At least it is
1076 * avoided that the good copy is overwritten.
1077 * A more useful improvement would be to pick the sectors
1078 * without I/O error based on sector sizes (512 bytes on legacy
1079 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1080 * mirror could be repaired by taking 512 byte of a different
1081 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1082 * area are unreadable.
a2de733c 1083 */
a2de733c 1084
b5d67f64
SB		 1085 /* can only fix I/O errors from here on */
1086 if (sblock_bad->no_io_error_seen)
1087 goto did_not_correct_error;
1088
1089 success = 1;
1090 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
7a9e9987 1091 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
b5d67f64
SB		 1092
1093 if (!page_bad->io_error)
a2de733c 1094 continue;
b5d67f64
SB		 1095
1096 for (mirror_index = 0;
1097 mirror_index < BTRFS_MAX_MIRRORS &&
1098 sblocks_for_recheck[mirror_index].page_count > 0;
1099 mirror_index++) {
1100 struct scrub_block *sblock_other = sblocks_for_recheck +
1101 mirror_index;
7a9e9987
SB		 1102 struct scrub_page *page_other = sblock_other->pagev[
1103 page_num];
b5d67f64
SB		 1104
1105 if (!page_other->io_error) {
1106 ret = scrub_repair_page_from_good_copy(
1107 sblock_bad, sblock_other, page_num, 0);
1108 if (0 == ret) {
1109 page_bad->io_error = 0;
1110 break; /* succeeded for this page */
1111 }
1112 }
96e36920 1113 }
a2de733c 1114
b5d67f64
SB		 1115 if (page_bad->io_error) {
1116 /* did not find a mirror to copy the page from */
1117 success = 0;
1118 }
a2de733c 1119 }
a2de733c 1120
b5d67f64
SB		 1121 if (success) {
1122 if (is_metadata || have_csum) {
1123 /*
1124 * need to verify the checksum now that all
1125 * sectors on disk are repaired (the write
1126 * request for data to be repaired is on its way).
1127 * Just be lazy and use scrub_recheck_block()
1128 * which re-reads the data before the checksum
1129 * is verified, but most likely the data comes out
1130 * of the page cache.
1131 */
34f5c8e9
SB		 1132 scrub_recheck_block(fs_info, sblock_bad,
1133 is_metadata, have_csum, csum,
1134 generation, sctx->csum_size);
1135 if (!sblock_bad->header_error &&
b5d67f64
SB		 1136 !sblock_bad->checksum_error &&
1137 sblock_bad->no_io_error_seen)
1138 goto corrected_error;
1139 else
1140 goto did_not_correct_error;
1141 } else {
1142corrected_error:
d9d181c1
SB		 1143 spin_lock(&sctx->stat_lock);
1144 sctx->stat.corrected_errors++;
1145 spin_unlock(&sctx->stat_lock);
606686ee 1146 printk_ratelimited_in_rcu(KERN_ERR
b5d67f64 1147 "btrfs: fixed up error at logical %llu on dev %s\n",
606686ee 1148 (unsigned long long)logical,
a36cf8b8 1149 rcu_str_deref(dev->name));
8628764e 1150 }
b5d67f64
SB		 1151 } else {
1152did_not_correct_error:
d9d181c1
SB		 1153 spin_lock(&sctx->stat_lock);
1154 sctx->stat.uncorrectable_errors++;
1155 spin_unlock(&sctx->stat_lock);
606686ee 1156 printk_ratelimited_in_rcu(KERN_ERR
b5d67f64 1157 "btrfs: unable to fixup (regular) error at logical %llu on dev %s\n",
606686ee 1158 (unsigned long long)logical,
a36cf8b8 1159 rcu_str_deref(dev->name));
96e36920 1160 }
a2de733c 1161
b5d67f64
SB		 1162out:
1163 if (sblocks_for_recheck) {
1164 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1165 mirror_index++) {
1166 struct scrub_block *sblock = sblocks_for_recheck +
1167 mirror_index;
1168 int page_index;
1169
7a9e9987
SB		 1170 for (page_index = 0; page_index < sblock->page_count;
1171 page_index++) {
1172 sblock->pagev[page_index]->sblock = NULL;
1173 scrub_page_put(sblock->pagev[page_index]);
1174 }
b5d67f64
SB		 1175 }
1176 kfree(sblocks_for_recheck);
1177 }
a2de733c 1178
b5d67f64
SB		 1179 return 0;
1180}
a2de733c 1181
d9d181c1 1182static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
3ec706c8 1183 struct btrfs_fs_info *fs_info,
ff023aac 1184 struct scrub_block *original_sblock,
b5d67f64
SB		 1185 u64 length, u64 logical,
1186 struct scrub_block *sblocks_for_recheck)
1187{
1188 int page_index;
1189 int mirror_index;
1190 int ret;
1191
1192 /*
7a9e9987 1193 * note: the two members ref_count and outstanding_pages
b5d67f64
SB		 1194 * are not used (and not set) in the blocks that are used for
1195 * the recheck procedure
1196 */
1197
1198 page_index = 0;
1199 while (length > 0) {
1200 u64 sublen = min_t(u64, length, PAGE_SIZE);
1201 u64 mapped_length = sublen;
1202 struct btrfs_bio *bbio = NULL;
a2de733c 1203
b5d67f64
SB		 1204 /*
1205 * with a length of PAGE_SIZE, each returned stripe
1206 * represents one mirror
1207 */
29a8d9a0
SB		 1208 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
1209 &mapped_length, &bbio, 0);
b5d67f64
SB		 1210 if (ret || !bbio || mapped_length < sublen) {
1211 kfree(bbio);
1212 return -EIO;
1213 }
a2de733c 1214
ff023aac 1215 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
b5d67f64
SB		 1216 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1217 mirror_index++) {
1218 struct scrub_block *sblock;
1219 struct scrub_page *page;
1220
1221 if (mirror_index >= BTRFS_MAX_MIRRORS)
1222 continue;
1223
1224 sblock = sblocks_for_recheck + mirror_index;
7a9e9987
SB		 1225 sblock->sctx = sctx;
1226 page = kzalloc(sizeof(*page), GFP_NOFS);
1227 if (!page) {
1228leave_nomem:
d9d181c1
SB		 1229 spin_lock(&sctx->stat_lock);
1230 sctx->stat.malloc_errors++;
1231 spin_unlock(&sctx->stat_lock);
cf93dcce 1232 kfree(bbio);
b5d67f64
SB		 1233 return -ENOMEM;
1234 }
7a9e9987
SB		 1235 scrub_page_get(page);
1236 sblock->pagev[page_index] = page;
1237 page->logical = logical;
1238 page->physical = bbio->stripes[mirror_index].physical;
ff023aac
SB		 1239 BUG_ON(page_index >= original_sblock->page_count);
1240 page->physical_for_dev_replace =
1241 original_sblock->pagev[page_index]->
1242 physical_for_dev_replace;
7a9e9987
SB		 1243 /* for missing devices, dev->bdev is NULL */
1244 page->dev = bbio->stripes[mirror_index].dev;
1245 page->mirror_num = mirror_index + 1;
b5d67f64 1246 sblock->page_count++;
7a9e9987
SB		 1247 page->page = alloc_page(GFP_NOFS);
1248 if (!page->page)
1249 goto leave_nomem;
b5d67f64
SB		 1250 }
1251 kfree(bbio);
1252 length -= sublen;
1253 logical += sublen;
1254 page_index++;
1255 }
1256
1257 return 0;
96e36920
ID		 1258}
1259
b5d67f64
SB		 1260/*
1261 * this function will check the on disk data for checksum errors, header
1262 * errors and read I/O errors. If any I/O errors happen, the exact pages
1263 * which are errored are marked as being bad. The goal is to enable scrub
1264 * to take those pages that are not errored from all the mirrors so that
1265 * the pages that are errored in the just handled mirror can be repaired.
1266 */
34f5c8e9
SB		 1267static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1268 struct scrub_block *sblock, int is_metadata,
1269 int have_csum, u8 *csum, u64 generation,
1270 u16 csum_size)
96e36920 1271{
b5d67f64 1272 int page_num;
96e36920 1273
b5d67f64
SB		 1274 sblock->no_io_error_seen = 1;
1275 sblock->header_error = 0;
1276 sblock->checksum_error = 0;
96e36920 1277
b5d67f64
SB		 1278 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1279 struct bio *bio;
7a9e9987 1280 struct scrub_page *page = sblock->pagev[page_num];
b5d67f64
SB		 1281 DECLARE_COMPLETION_ONSTACK(complete);
1282
442a4f63 1283 if (page->dev->bdev == NULL) {
ea9947b4
SB		 1284 page->io_error = 1;
1285 sblock->no_io_error_seen = 0;
1286 continue;
1287 }
1288
7a9e9987 1289 WARN_ON(!page->page);
b5d67f64 1290 bio = bio_alloc(GFP_NOFS, 1);
34f5c8e9
SB		 1291 if (!bio) {
1292 page->io_error = 1;
1293 sblock->no_io_error_seen = 0;
1294 continue;
1295 }
442a4f63 1296 bio->bi_bdev = page->dev->bdev;
b5d67f64
SB		 1297 bio->bi_sector = page->physical >> 9;
1298 bio->bi_end_io = scrub_complete_bio_end_io;
1299 bio->bi_private = &complete;
1300
34f5c8e9 1301 bio_add_page(bio, page->page, PAGE_SIZE, 0);
b5d67f64 1302 btrfsic_submit_bio(READ, bio);
96e36920 1303
b5d67f64
SB		 1304 /* this will also unplug the queue */
1305 wait_for_completion(&complete);
96e36920 1306
b5d67f64
SB		 1307 page->io_error = !test_bit(BIO_UPTODATE, &bio->bi_flags);
1308 if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
1309 sblock->no_io_error_seen = 0;
1310 bio_put(bio);
1311 }
96e36920 1312
b5d67f64
SB		 1313 if (sblock->no_io_error_seen)
1314 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1315 have_csum, csum, generation,
1316 csum_size);
1317
34f5c8e9 1318 return;
a2de733c
AJ		 1319}
1320
b5d67f64
SB		 1321static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1322 struct scrub_block *sblock,
1323 int is_metadata, int have_csum,
1324 const u8 *csum, u64 generation,
1325 u16 csum_size)
a2de733c 1326{
b5d67f64
SB		 1327 int page_num;
1328 u8 calculated_csum[BTRFS_CSUM_SIZE];
1329 u32 crc = ~(u32)0;
1330 struct btrfs_root *root = fs_info->extent_root;
1331 void *mapped_buffer;
1332
7a9e9987 1333 WARN_ON(!sblock->pagev[0]->page);
b5d67f64
SB		 1334 if (is_metadata) {
1335 struct btrfs_header *h;
1336
7a9e9987 1337 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
b5d67f64
SB		 1338 h = (struct btrfs_header *)mapped_buffer;
1339
7a9e9987 1340 if (sblock->pagev[0]->logical != le64_to_cpu(h->bytenr) ||
b5d67f64
SB		 1341 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1342 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
442a4f63 1343 BTRFS_UUID_SIZE)) {
b5d67f64 1344 sblock->header_error = 1;
442a4f63
SB		 1345 } else if (generation != le64_to_cpu(h->generation)) {
1346 sblock->header_error = 1;
1347 sblock->generation_error = 1;
1348 }
b5d67f64
SB		 1349 csum = h->csum;
1350 } else {
1351 if (!have_csum)
1352 return;
a2de733c 1353
7a9e9987 1354 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
b5d67f64 1355 }
a2de733c 1356
b5d67f64
SB		 1357 for (page_num = 0;;) {
1358 if (page_num == 0 && is_metadata)
1359 crc = btrfs_csum_data(root,
1360 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1361 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1362 else
1363 crc = btrfs_csum_data(root, mapped_buffer, crc,
1364 PAGE_SIZE);
1365
9613bebb 1366 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1367 page_num++;
1368 if (page_num >= sblock->page_count)
1369 break;
7a9e9987 1370 WARN_ON(!sblock->pagev[page_num]->page);
b5d67f64 1371
7a9e9987 1372 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
b5d67f64
SB		 1373 }
1374
1375 btrfs_csum_final(crc, calculated_csum);
1376 if (memcmp(calculated_csum, csum, csum_size))
1377 sblock->checksum_error = 1;
a2de733c
AJ		 1378}
1379
b5d67f64 1380static void scrub_complete_bio_end_io(struct bio *bio, int err)
a2de733c 1381{
b5d67f64
SB		 1382 complete((struct completion *)bio->bi_private);
1383}
a2de733c 1384
b5d67f64
SB		 1385static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1386 struct scrub_block *sblock_good,
1387 int force_write)
1388{
1389 int page_num;
1390 int ret = 0;
96e36920 1391
b5d67f64
SB		 1392 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1393 int ret_sub;
96e36920 1394
b5d67f64
SB		 1395 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1396 sblock_good,
1397 page_num,
1398 force_write);
1399 if (ret_sub)
1400 ret = ret_sub;
a2de733c 1401 }
b5d67f64
SB		 1402
1403 return ret;
1404}
1405
1406static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1407 struct scrub_block *sblock_good,
1408 int page_num, int force_write)
1409{
7a9e9987
SB		 1410 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1411 struct scrub_page *page_good = sblock_good->pagev[page_num];
b5d67f64 1412
7a9e9987
SB		 1413 BUG_ON(page_bad->page == NULL);
1414 BUG_ON(page_good->page == NULL);
b5d67f64
SB		 1415 if (force_write || sblock_bad->header_error ||
1416 sblock_bad->checksum_error || page_bad->io_error) {
1417 struct bio *bio;
1418 int ret;
1419 DECLARE_COMPLETION_ONSTACK(complete);
1420
ff023aac
SB		 1421 if (!page_bad->dev->bdev) {
1422 printk_ratelimited(KERN_WARNING
1423 "btrfs: scrub_repair_page_from_good_copy(bdev == NULL) is unexpected!\n");
1424 return -EIO;
1425 }
1426
b5d67f64 1427 bio = bio_alloc(GFP_NOFS, 1);
e627ee7b
TI		 1428 if (!bio)
1429 return -EIO;
442a4f63 1430 bio->bi_bdev = page_bad->dev->bdev;
b5d67f64
SB		 1431 bio->bi_sector = page_bad->physical >> 9;
1432 bio->bi_end_io = scrub_complete_bio_end_io;
1433 bio->bi_private = &complete;
1434
1435 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1436 if (PAGE_SIZE != ret) {
1437 bio_put(bio);
1438 return -EIO;
13db62b7 1439 }
b5d67f64
SB		 1440 btrfsic_submit_bio(WRITE, bio);
1441
1442 /* this will also unplug the queue */
1443 wait_for_completion(&complete);
442a4f63
SB		 1444 if (!bio_flagged(bio, BIO_UPTODATE)) {
1445 btrfs_dev_stat_inc_and_print(page_bad->dev,
1446 BTRFS_DEV_STAT_WRITE_ERRS);
ff023aac
SB		 1447 btrfs_dev_replace_stats_inc(
1448 &sblock_bad->sctx->dev_root->fs_info->
1449 dev_replace.num_write_errors);
442a4f63
SB		 1450 bio_put(bio);
1451 return -EIO;
1452 }
b5d67f64 1453 bio_put(bio);
a2de733c
AJ		 1454 }
1455
b5d67f64
SB		 1456 return 0;
1457}
1458
ff023aac
SB		 1459static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1460{
1461 int page_num;
1462
1463 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1464 int ret;
1465
1466 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1467 if (ret)
1468 btrfs_dev_replace_stats_inc(
1469 &sblock->sctx->dev_root->fs_info->dev_replace.
1470 num_write_errors);
1471 }
1472}
1473
1474static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1475 int page_num)
1476{
1477 struct scrub_page *spage = sblock->pagev[page_num];
1478
1479 BUG_ON(spage->page == NULL);
1480 if (spage->io_error) {
1481 void *mapped_buffer = kmap_atomic(spage->page);
1482
1483 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1484 flush_dcache_page(spage->page);
1485 kunmap_atomic(mapped_buffer);
1486 }
1487 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1488}
1489
1490static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1491 struct scrub_page *spage)
1492{
1493 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1494 struct scrub_bio *sbio;
1495 int ret;
1496
1497 mutex_lock(&wr_ctx->wr_lock);
1498again:
1499 if (!wr_ctx->wr_curr_bio) {
1500 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1501 GFP_NOFS);
1502 if (!wr_ctx->wr_curr_bio) {
1503 mutex_unlock(&wr_ctx->wr_lock);
1504 return -ENOMEM;
1505 }
1506 wr_ctx->wr_curr_bio->sctx = sctx;
1507 wr_ctx->wr_curr_bio->page_count = 0;
1508 }
1509 sbio = wr_ctx->wr_curr_bio;
1510 if (sbio->page_count == 0) {
1511 struct bio *bio;
1512
1513 sbio->physical = spage->physical_for_dev_replace;
1514 sbio->logical = spage->logical;
1515 sbio->dev = wr_ctx->tgtdev;
1516 bio = sbio->bio;
1517 if (!bio) {
1518 bio = bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
1519 if (!bio) {
1520 mutex_unlock(&wr_ctx->wr_lock);
1521 return -ENOMEM;
1522 }
1523 sbio->bio = bio;
1524 }
1525
1526 bio->bi_private = sbio;
1527 bio->bi_end_io = scrub_wr_bio_end_io;
1528 bio->bi_bdev = sbio->dev->bdev;
1529 bio->bi_sector = sbio->physical >> 9;
1530 sbio->err = 0;
1531 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1532 spage->physical_for_dev_replace ||
1533 sbio->logical + sbio->page_count * PAGE_SIZE !=
1534 spage->logical) {
1535 scrub_wr_submit(sctx);
1536 goto again;
1537 }
1538
1539 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1540 if (ret != PAGE_SIZE) {
1541 if (sbio->page_count < 1) {
1542 bio_put(sbio->bio);
1543 sbio->bio = NULL;
1544 mutex_unlock(&wr_ctx->wr_lock);
1545 return -EIO;
1546 }
1547 scrub_wr_submit(sctx);
1548 goto again;
1549 }
1550
1551 sbio->pagev[sbio->page_count] = spage;
1552 scrub_page_get(spage);
1553 sbio->page_count++;
1554 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1555 scrub_wr_submit(sctx);
1556 mutex_unlock(&wr_ctx->wr_lock);
1557
1558 return 0;
1559}
1560
1561static void scrub_wr_submit(struct scrub_ctx *sctx)
1562{
1563 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1564 struct scrub_bio *sbio;
1565
1566 if (!wr_ctx->wr_curr_bio)
1567 return;
1568
1569 sbio = wr_ctx->wr_curr_bio;
1570 wr_ctx->wr_curr_bio = NULL;
1571 WARN_ON(!sbio->bio->bi_bdev);
1572 scrub_pending_bio_inc(sctx);
1573 /* process all writes in a single worker thread. Then the block layer
1574 * orders the requests before sending them to the driver which
1575 * doubled the write performance on spinning disks when measured
1576 * with Linux 3.5 */
1577 btrfsic_submit_bio(WRITE, sbio->bio);
1578}
1579
1580static void scrub_wr_bio_end_io(struct bio *bio, int err)
1581{
1582 struct scrub_bio *sbio = bio->bi_private;
1583 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1584
1585 sbio->err = err;
1586 sbio->bio = bio;
1587
1588 sbio->work.func = scrub_wr_bio_end_io_worker;
1589 btrfs_queue_worker(&fs_info->scrub_wr_completion_workers, &sbio->work);
1590}
1591
1592static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1593{
1594 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1595 struct scrub_ctx *sctx = sbio->sctx;
1596 int i;
1597
1598 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1599 if (sbio->err) {
1600 struct btrfs_dev_replace *dev_replace =
1601 &sbio->sctx->dev_root->fs_info->dev_replace;
1602
1603 for (i = 0; i < sbio->page_count; i++) {
1604 struct scrub_page *spage = sbio->pagev[i];
1605
1606 spage->io_error = 1;
1607 btrfs_dev_replace_stats_inc(&dev_replace->
1608 num_write_errors);
1609 }
1610 }
1611
1612 for (i = 0; i < sbio->page_count; i++)
1613 scrub_page_put(sbio->pagev[i]);
1614
1615 bio_put(sbio->bio);
1616 kfree(sbio);
1617 scrub_pending_bio_dec(sctx);
1618}
1619
1620static int scrub_checksum(struct scrub_block *sblock)
b5d67f64
SB		 1621{
1622 u64 flags;
1623 int ret;
1624
7a9e9987
SB		 1625 WARN_ON(sblock->page_count < 1);
1626 flags = sblock->pagev[0]->flags;
b5d67f64
SB		 1627 ret = 0;
1628 if (flags & BTRFS_EXTENT_FLAG_DATA)
1629 ret = scrub_checksum_data(sblock);
1630 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1631 ret = scrub_checksum_tree_block(sblock);
1632 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1633 (void)scrub_checksum_super(sblock);
1634 else
1635 WARN_ON(1);
1636 if (ret)
1637 scrub_handle_errored_block(sblock);
ff023aac
SB		 1638
1639 return ret;
a2de733c
AJ		 1640}
1641
b5d67f64 1642static int scrub_checksum_data(struct scrub_block *sblock)
a2de733c 1643{
d9d181c1 1644 struct scrub_ctx *sctx = sblock->sctx;
a2de733c 1645 u8 csum[BTRFS_CSUM_SIZE];
b5d67f64
SB		 1646 u8 *on_disk_csum;
1647 struct page *page;
1648 void *buffer;
a2de733c
AJ		 1649 u32 crc = ~(u32)0;
1650 int fail = 0;
a36cf8b8 1651 struct btrfs_root *root = sctx->dev_root;
b5d67f64
SB		 1652 u64 len;
1653 int index;
a2de733c 1654
b5d67f64 1655 BUG_ON(sblock->page_count < 1);
7a9e9987 1656 if (!sblock->pagev[0]->have_csum)
a2de733c
AJ		 1657 return 0;
1658
7a9e9987
SB		 1659 on_disk_csum = sblock->pagev[0]->csum;
1660 page = sblock->pagev[0]->page;
9613bebb 1661 buffer = kmap_atomic(page);
b5d67f64 1662
d9d181c1 1663 len = sctx->sectorsize;
b5d67f64
SB		 1664 index = 0;
1665 for (;;) {
1666 u64 l = min_t(u64, len, PAGE_SIZE);
1667
1668 crc = btrfs_csum_data(root, buffer, crc, l);
9613bebb 1669 kunmap_atomic(buffer);
b5d67f64
SB		 1670 len -= l;
1671 if (len == 0)
1672 break;
1673 index++;
1674 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1675 BUG_ON(!sblock->pagev[index]->page);
1676 page = sblock->pagev[index]->page;
9613bebb 1677 buffer = kmap_atomic(page);
b5d67f64
SB		 1678 }
1679
a2de733c 1680 btrfs_csum_final(crc, csum);
d9d181c1 1681 if (memcmp(csum, on_disk_csum, sctx->csum_size))
a2de733c
AJ		 1682 fail = 1;
1683
a2de733c
AJ		 1684 return fail;
1685}
1686
b5d67f64 1687static int scrub_checksum_tree_block(struct scrub_block *sblock)
a2de733c 1688{
d9d181c1 1689 struct scrub_ctx *sctx = sblock->sctx;
a2de733c 1690 struct btrfs_header *h;
a36cf8b8 1691 struct btrfs_root *root = sctx->dev_root;
a2de733c 1692 struct btrfs_fs_info *fs_info = root->fs_info;
b5d67f64
SB		 1693 u8 calculated_csum[BTRFS_CSUM_SIZE];
1694 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1695 struct page *page;
1696 void *mapped_buffer;
1697 u64 mapped_size;
1698 void *p;
a2de733c
AJ		 1699 u32 crc = ~(u32)0;
1700 int fail = 0;
1701 int crc_fail = 0;
b5d67f64
SB		 1702 u64 len;
1703 int index;
1704
1705 BUG_ON(sblock->page_count < 1);
7a9e9987 1706 page = sblock->pagev[0]->page;
9613bebb 1707 mapped_buffer = kmap_atomic(page);
b5d67f64 1708 h = (struct btrfs_header *)mapped_buffer;
d9d181c1 1709 memcpy(on_disk_csum, h->csum, sctx->csum_size);
a2de733c
AJ		 1710
1711 /*
1712 * we don't use the getter functions here, as we
1713 * a) don't have an extent buffer and
1714 * b) the page is already kmapped
1715 */
a2de733c 1716
7a9e9987 1717 if (sblock->pagev[0]->logical != le64_to_cpu(h->bytenr))
a2de733c
AJ		 1718 ++fail;
1719
7a9e9987 1720 if (sblock->pagev[0]->generation != le64_to_cpu(h->generation))
a2de733c
AJ		 1721 ++fail;
1722
1723 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1724 ++fail;
1725
1726 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1727 BTRFS_UUID_SIZE))
1728 ++fail;
1729
ff023aac 1730 WARN_ON(sctx->nodesize != sctx->leafsize);
d9d181c1 1731 len = sctx->nodesize - BTRFS_CSUM_SIZE;
b5d67f64
SB		 1732 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1733 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1734 index = 0;
1735 for (;;) {
1736 u64 l = min_t(u64, len, mapped_size);
1737
1738 crc = btrfs_csum_data(root, p, crc, l);
9613bebb 1739 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1740 len -= l;
1741 if (len == 0)
1742 break;
1743 index++;
1744 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1745 BUG_ON(!sblock->pagev[index]->page);
1746 page = sblock->pagev[index]->page;
9613bebb 1747 mapped_buffer = kmap_atomic(page);
b5d67f64
SB		 1748 mapped_size = PAGE_SIZE;
1749 p = mapped_buffer;
1750 }
1751
1752 btrfs_csum_final(crc, calculated_csum);
d9d181c1 1753 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
a2de733c
AJ		 1754 ++crc_fail;
1755
a2de733c
AJ		 1756 return fail || crc_fail;
1757}
1758
b5d67f64 1759static int scrub_checksum_super(struct scrub_block *sblock)
a2de733c
AJ		 1760{
1761 struct btrfs_super_block *s;
d9d181c1 1762 struct scrub_ctx *sctx = sblock->sctx;
a36cf8b8 1763 struct btrfs_root *root = sctx->dev_root;
a2de733c 1764 struct btrfs_fs_info *fs_info = root->fs_info;
b5d67f64
SB		 1765 u8 calculated_csum[BTRFS_CSUM_SIZE];
1766 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1767 struct page *page;
1768 void *mapped_buffer;
1769 u64 mapped_size;
1770 void *p;
a2de733c 1771 u32 crc = ~(u32)0;
442a4f63
SB		 1772 int fail_gen = 0;
1773 int fail_cor = 0;
b5d67f64
SB		 1774 u64 len;
1775 int index;
a2de733c 1776
b5d67f64 1777 BUG_ON(sblock->page_count < 1);
7a9e9987 1778 page = sblock->pagev[0]->page;
9613bebb 1779 mapped_buffer = kmap_atomic(page);
b5d67f64 1780 s = (struct btrfs_super_block *)mapped_buffer;
d9d181c1 1781 memcpy(on_disk_csum, s->csum, sctx->csum_size);
a2de733c 1782
7a9e9987 1783 if (sblock->pagev[0]->logical != le64_to_cpu(s->bytenr))
442a4f63 1784 ++fail_cor;
a2de733c 1785
7a9e9987 1786 if (sblock->pagev[0]->generation != le64_to_cpu(s->generation))
442a4f63 1787 ++fail_gen;
a2de733c
AJ		 1788
1789 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
442a4f63 1790 ++fail_cor;
a2de733c 1791
b5d67f64
SB		 1792 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1793 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1794 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1795 index = 0;
1796 for (;;) {
1797 u64 l = min_t(u64, len, mapped_size);
1798
1799 crc = btrfs_csum_data(root, p, crc, l);
9613bebb 1800 kunmap_atomic(mapped_buffer);
b5d67f64
SB		 1801 len -= l;
1802 if (len == 0)
1803 break;
1804 index++;
1805 BUG_ON(index >= sblock->page_count);
7a9e9987
SB		 1806 BUG_ON(!sblock->pagev[index]->page);
1807 page = sblock->pagev[index]->page;
9613bebb 1808 mapped_buffer = kmap_atomic(page);
b5d67f64
SB		 1809 mapped_size = PAGE_SIZE;
1810 p = mapped_buffer;
1811 }
1812
1813 btrfs_csum_final(crc, calculated_csum);
d9d181c1 1814 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
442a4f63 1815 ++fail_cor;
a2de733c 1816
442a4f63 1817 if (fail_cor + fail_gen) {
a2de733c
AJ		 1818 /*
1819 * if we find an error in a super block, we just report it.
1820 * They will get written with the next transaction commit
1821 * anyway
1822 */
d9d181c1
SB		 1823 spin_lock(&sctx->stat_lock);
1824 ++sctx->stat.super_errors;
1825 spin_unlock(&sctx->stat_lock);
442a4f63 1826 if (fail_cor)
7a9e9987 1827 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
442a4f63
SB		 1828 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1829 else
7a9e9987 1830 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
442a4f63 1831 BTRFS_DEV_STAT_GENERATION_ERRS);
a2de733c
AJ		 1832 }
1833
442a4f63 1834 return fail_cor + fail_gen;
a2de733c
AJ		 1835}
1836
b5d67f64
SB		 1837static void scrub_block_get(struct scrub_block *sblock)
1838{
1839 atomic_inc(&sblock->ref_count);
1840}
1841
1842static void scrub_block_put(struct scrub_block *sblock)
1843{
1844 if (atomic_dec_and_test(&sblock->ref_count)) {
1845 int i;
1846
1847 for (i = 0; i < sblock->page_count; i++)
7a9e9987 1848 scrub_page_put(sblock->pagev[i]);
b5d67f64
SB		 1849 kfree(sblock);
1850 }
1851}
1852
7a9e9987
SB		 1853static void scrub_page_get(struct scrub_page *spage)
1854{
1855 atomic_inc(&spage->ref_count);
1856}
1857
1858static void scrub_page_put(struct scrub_page *spage)
1859{
1860 if (atomic_dec_and_test(&spage->ref_count)) {
1861 if (spage->page)
1862 __free_page(spage->page);
1863 kfree(spage);
1864 }
1865}
1866
d9d181c1 1867static void scrub_submit(struct scrub_ctx *sctx)
a2de733c
AJ		 1868{
1869 struct scrub_bio *sbio;
1870
d9d181c1 1871 if (sctx->curr == -1)
1623edeb 1872 return;
a2de733c 1873
d9d181c1
SB		 1874 sbio = sctx->bios[sctx->curr];
1875 sctx->curr = -1;
b6bfebc1 1876 scrub_pending_bio_inc(sctx);
a2de733c 1877
ff023aac
SB		 1878 if (!sbio->bio->bi_bdev) {
1879 /*
1880 * this case should not happen. If btrfs_map_block() is
1881 * wrong, it could happen for dev-replace operations on
1882 * missing devices when no mirrors are available, but in
1883 * this case it should already fail the mount.
1884 * This case is handled correctly (but _very_ slowly).
1885 */
1886 printk_ratelimited(KERN_WARNING
1887 "btrfs: scrub_submit(bio bdev == NULL) is unexpected!\n");
1888 bio_endio(sbio->bio, -EIO);
1889 } else {
1890 btrfsic_submit_bio(READ, sbio->bio);
1891 }
a2de733c
AJ		 1892}
1893
ff023aac
SB		 1894static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
1895 struct scrub_page *spage)
a2de733c 1896{
b5d67f64 1897 struct scrub_block *sblock = spage->sblock;
a2de733c 1898 struct scrub_bio *sbio;
69f4cb52 1899 int ret;
a2de733c
AJ		 1900
1901again:
1902 /*
1903 * grab a fresh bio or wait for one to become available
1904 */
d9d181c1
SB		 1905 while (sctx->curr == -1) {
1906 spin_lock(&sctx->list_lock);
1907 sctx->curr = sctx->first_free;
1908 if (sctx->curr != -1) {
1909 sctx->first_free = sctx->bios[sctx->curr]->next_free;
1910 sctx->bios[sctx->curr]->next_free = -1;
1911 sctx->bios[sctx->curr]->page_count = 0;
1912 spin_unlock(&sctx->list_lock);
a2de733c 1913 } else {
d9d181c1
SB		 1914 spin_unlock(&sctx->list_lock);
1915 wait_event(sctx->list_wait, sctx->first_free != -1);
a2de733c
AJ		 1916 }
1917 }
d9d181c1 1918 sbio = sctx->bios[sctx->curr];
b5d67f64 1919 if (sbio->page_count == 0) {
69f4cb52
AJ		 1920 struct bio *bio;
1921
b5d67f64
SB		 1922 sbio->physical = spage->physical;
1923 sbio->logical = spage->logical;
a36cf8b8 1924 sbio->dev = spage->dev;
b5d67f64
SB		 1925 bio = sbio->bio;
1926 if (!bio) {
ff023aac 1927 bio = bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
b5d67f64
SB		 1928 if (!bio)
1929 return -ENOMEM;
1930 sbio->bio = bio;
1931 }
69f4cb52
AJ		 1932
1933 bio->bi_private = sbio;
1934 bio->bi_end_io = scrub_bio_end_io;
a36cf8b8
SB		 1935 bio->bi_bdev = sbio->dev->bdev;
1936 bio->bi_sector = sbio->physical >> 9;
69f4cb52 1937 sbio->err = 0;
b5d67f64
SB		 1938 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1939 spage->physical ||
1940 sbio->logical + sbio->page_count * PAGE_SIZE !=
a36cf8b8
SB		 1941 spage->logical ||
1942 sbio->dev != spage->dev) {
d9d181c1 1943 scrub_submit(sctx);
a2de733c
AJ		 1944 goto again;
1945 }
69f4cb52 1946
b5d67f64
SB		 1947 sbio->pagev[sbio->page_count] = spage;
1948 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1949 if (ret != PAGE_SIZE) {
1950 if (sbio->page_count < 1) {
1951 bio_put(sbio->bio);
1952 sbio->bio = NULL;
1953 return -EIO;
1954 }
d9d181c1 1955 scrub_submit(sctx);
69f4cb52
AJ		 1956 goto again;
1957 }
1958
ff023aac 1959 scrub_block_get(sblock); /* one for the page added to the bio */
b5d67f64
SB		 1960 atomic_inc(&sblock->outstanding_pages);
1961 sbio->page_count++;
ff023aac 1962 if (sbio->page_count == sctx->pages_per_rd_bio)
d9d181c1 1963 scrub_submit(sctx);
b5d67f64
SB		 1964
1965 return 0;
1966}
1967
d9d181c1 1968static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 1969 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac
SB		 1970 u64 gen, int mirror_num, u8 *csum, int force,
1971 u64 physical_for_dev_replace)
b5d67f64
SB		 1972{
1973 struct scrub_block *sblock;
1974 int index;
1975
1976 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
1977 if (!sblock) {
d9d181c1
SB		 1978 spin_lock(&sctx->stat_lock);
1979 sctx->stat.malloc_errors++;
1980 spin_unlock(&sctx->stat_lock);
b5d67f64 1981 return -ENOMEM;
a2de733c 1982 }
b5d67f64 1983
7a9e9987
SB		 1984 /* one ref inside this function, plus one for each page added to
1985 * a bio later on */
b5d67f64 1986 atomic_set(&sblock->ref_count, 1);
d9d181c1 1987 sblock->sctx = sctx;
b5d67f64
SB		 1988 sblock->no_io_error_seen = 1;
1989
1990 for (index = 0; len > 0; index++) {
7a9e9987 1991 struct scrub_page *spage;
b5d67f64
SB		 1992 u64 l = min_t(u64, len, PAGE_SIZE);
1993
7a9e9987
SB		 1994 spage = kzalloc(sizeof(*spage), GFP_NOFS);
1995 if (!spage) {
1996leave_nomem:
d9d181c1
SB		 1997 spin_lock(&sctx->stat_lock);
1998 sctx->stat.malloc_errors++;
1999 spin_unlock(&sctx->stat_lock);
7a9e9987 2000 scrub_block_put(sblock);
b5d67f64
SB		 2001 return -ENOMEM;
2002 }
7a9e9987
SB		 2003 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2004 scrub_page_get(spage);
2005 sblock->pagev[index] = spage;
b5d67f64 2006 spage->sblock = sblock;
a36cf8b8 2007 spage->dev = dev;
b5d67f64
SB		 2008 spage->flags = flags;
2009 spage->generation = gen;
2010 spage->logical = logical;
2011 spage->physical = physical;
ff023aac 2012 spage->physical_for_dev_replace = physical_for_dev_replace;
b5d67f64
SB		 2013 spage->mirror_num = mirror_num;
2014 if (csum) {
2015 spage->have_csum = 1;
d9d181c1 2016 memcpy(spage->csum, csum, sctx->csum_size);
b5d67f64
SB		 2017 } else {
2018 spage->have_csum = 0;
2019 }
2020 sblock->page_count++;
7a9e9987
SB		 2021 spage->page = alloc_page(GFP_NOFS);
2022 if (!spage->page)
2023 goto leave_nomem;
b5d67f64
SB		 2024 len -= l;
2025 logical += l;
2026 physical += l;
ff023aac 2027 physical_for_dev_replace += l;
b5d67f64
SB		 2028 }
2029
7a9e9987 2030 WARN_ON(sblock->page_count == 0);
b5d67f64 2031 for (index = 0; index < sblock->page_count; index++) {
7a9e9987 2032 struct scrub_page *spage = sblock->pagev[index];
1bc87793
AJ		 2033 int ret;
2034
ff023aac 2035 ret = scrub_add_page_to_rd_bio(sctx, spage);
b5d67f64
SB		 2036 if (ret) {
2037 scrub_block_put(sblock);
1bc87793 2038 return ret;
b5d67f64 2039 }
1bc87793 2040 }
a2de733c 2041
b5d67f64 2042 if (force)
d9d181c1 2043 scrub_submit(sctx);
a2de733c 2044
b5d67f64
SB		 2045 /* last one frees, either here or in bio completion for last page */
2046 scrub_block_put(sblock);
a2de733c
AJ		 2047 return 0;
2048}
2049
b5d67f64
SB		 2050static void scrub_bio_end_io(struct bio *bio, int err)
2051{
2052 struct scrub_bio *sbio = bio->bi_private;
a36cf8b8 2053 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
b5d67f64
SB		 2054
2055 sbio->err = err;
2056 sbio->bio = bio;
2057
2058 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
2059}
2060
2061static void scrub_bio_end_io_worker(struct btrfs_work *work)
2062{
2063 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
d9d181c1 2064 struct scrub_ctx *sctx = sbio->sctx;
b5d67f64
SB		 2065 int i;
2066
ff023aac 2067 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
b5d67f64
SB		 2068 if (sbio->err) {
2069 for (i = 0; i < sbio->page_count; i++) {
2070 struct scrub_page *spage = sbio->pagev[i];
2071
2072 spage->io_error = 1;
2073 spage->sblock->no_io_error_seen = 0;
2074 }
2075 }
2076
2077 /* now complete the scrub_block items that have all pages completed */
2078 for (i = 0; i < sbio->page_count; i++) {
2079 struct scrub_page *spage = sbio->pagev[i];
2080 struct scrub_block *sblock = spage->sblock;
2081
2082 if (atomic_dec_and_test(&sblock->outstanding_pages))
2083 scrub_block_complete(sblock);
2084 scrub_block_put(sblock);
2085 }
2086
b5d67f64
SB		 2087 bio_put(sbio->bio);
2088 sbio->bio = NULL;
d9d181c1
SB		 2089 spin_lock(&sctx->list_lock);
2090 sbio->next_free = sctx->first_free;
2091 sctx->first_free = sbio->index;
2092 spin_unlock(&sctx->list_lock);
ff023aac
SB		 2093
2094 if (sctx->is_dev_replace &&
2095 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2096 mutex_lock(&sctx->wr_ctx.wr_lock);
2097 scrub_wr_submit(sctx);
2098 mutex_unlock(&sctx->wr_ctx.wr_lock);
2099 }
2100
b6bfebc1 2101 scrub_pending_bio_dec(sctx);
b5d67f64
SB		 2102}
2103
2104static void scrub_block_complete(struct scrub_block *sblock)
2105{
ff023aac 2106 if (!sblock->no_io_error_seen) {
b5d67f64 2107 scrub_handle_errored_block(sblock);
ff023aac
SB		 2108 } else {
2109 /*
2110 * if has checksum error, write via repair mechanism in
2111 * dev replace case, otherwise write here in dev replace
2112 * case.
2113 */
2114 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
2115 scrub_write_block_to_dev_replace(sblock);
2116 }
b5d67f64
SB		 2117}
2118
d9d181c1 2119static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
a2de733c
AJ		 2120 u8 *csum)
2121{
2122 struct btrfs_ordered_sum *sum = NULL;
2123 int ret = 0;
2124 unsigned long i;
2125 unsigned long num_sectors;
a2de733c 2126
d9d181c1
SB		 2127 while (!list_empty(&sctx->csum_list)) {
2128 sum = list_first_entry(&sctx->csum_list,
a2de733c
AJ		 2129 struct btrfs_ordered_sum, list);
2130 if (sum->bytenr > logical)
2131 return 0;
2132 if (sum->bytenr + sum->len > logical)
2133 break;
2134
d9d181c1 2135 ++sctx->stat.csum_discards;
a2de733c
AJ		 2136 list_del(&sum->list);
2137 kfree(sum);
2138 sum = NULL;
2139 }
2140 if (!sum)
2141 return 0;
2142
d9d181c1 2143 num_sectors = sum->len / sctx->sectorsize;
a2de733c
AJ		 2144 for (i = 0; i < num_sectors; ++i) {
2145 if (sum->sums[i].bytenr == logical) {
d9d181c1 2146 memcpy(csum, &sum->sums[i].sum, sctx->csum_size);
a2de733c
AJ		 2147 ret = 1;
2148 break;
2149 }
2150 }
2151 if (ret && i == num_sectors - 1) {
2152 list_del(&sum->list);
2153 kfree(sum);
2154 }
2155 return ret;
2156}
2157
2158/* scrub extent tries to collect up to 64 kB for each bio */
d9d181c1 2159static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
a36cf8b8 2160 u64 physical, struct btrfs_device *dev, u64 flags,
ff023aac 2161 u64 gen, int mirror_num, u64 physical_for_dev_replace)
a2de733c
AJ		 2162{
2163 int ret;
2164 u8 csum[BTRFS_CSUM_SIZE];
b5d67f64
SB		 2165 u32 blocksize;
2166
2167 if (flags & BTRFS_EXTENT_FLAG_DATA) {
d9d181c1
SB		 2168 blocksize = sctx->sectorsize;
2169 spin_lock(&sctx->stat_lock);
2170 sctx->stat.data_extents_scrubbed++;
2171 sctx->stat.data_bytes_scrubbed += len;
2172 spin_unlock(&sctx->stat_lock);
b5d67f64 2173 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
ff023aac 2174 WARN_ON(sctx->nodesize != sctx->leafsize);
d9d181c1
SB		 2175 blocksize = sctx->nodesize;
2176 spin_lock(&sctx->stat_lock);
2177 sctx->stat.tree_extents_scrubbed++;
2178 sctx->stat.tree_bytes_scrubbed += len;
2179 spin_unlock(&sctx->stat_lock);
b5d67f64 2180 } else {
d9d181c1 2181 blocksize = sctx->sectorsize;
ff023aac 2182 WARN_ON(1);
b5d67f64 2183 }
a2de733c
AJ		 2184
2185 while (len) {
b5d67f64 2186 u64 l = min_t(u64, len, blocksize);
a2de733c
AJ		 2187 int have_csum = 0;
2188
2189 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2190 /* push csums to sbio */
d9d181c1 2191 have_csum = scrub_find_csum(sctx, logical, l, csum);
a2de733c 2192 if (have_csum == 0)
d9d181c1 2193 ++sctx->stat.no_csum;
ff023aac
SB		 2194 if (sctx->is_dev_replace && !have_csum) {
2195 ret = copy_nocow_pages(sctx, logical, l,
2196 mirror_num,
2197 physical_for_dev_replace);
2198 goto behind_scrub_pages;
2199 }
a2de733c 2200 }
a36cf8b8 2201 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
ff023aac
SB		 2202 mirror_num, have_csum ? csum : NULL, 0,
2203 physical_for_dev_replace);
2204behind_scrub_pages:
a2de733c
AJ		 2205 if (ret)
2206 return ret;
2207 len -= l;
2208 logical += l;
2209 physical += l;
ff023aac 2210 physical_for_dev_replace += l;
a2de733c
AJ		 2211 }
2212 return 0;
2213}
2214
d9d181c1 2215static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
a36cf8b8
SB		 2216 struct map_lookup *map,
2217 struct btrfs_device *scrub_dev,
ff023aac
SB		 2218 int num, u64 base, u64 length,
2219 int is_dev_replace)
a2de733c
AJ		 2220{
2221 struct btrfs_path *path;
a36cf8b8 2222 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
a2de733c
AJ		 2223 struct btrfs_root *root = fs_info->extent_root;
2224 struct btrfs_root *csum_root = fs_info->csum_root;
2225 struct btrfs_extent_item *extent;
e7786c3a 2226 struct blk_plug plug;
a2de733c
AJ		 2227 u64 flags;
2228 int ret;
2229 int slot;
2230 int i;
2231 u64 nstripes;
a2de733c
AJ		 2232 struct extent_buffer *l;
2233 struct btrfs_key key;
2234 u64 physical;
2235 u64 logical;
2236 u64 generation;
e12fa9cd 2237 int mirror_num;
7a26285e
AJ		 2238 struct reada_control *reada1;
2239 struct reada_control *reada2;
2240 struct btrfs_key key_start;
2241 struct btrfs_key key_end;
a2de733c
AJ		 2242 u64 increment = map->stripe_len;
2243 u64 offset;
ff023aac
SB		 2244 u64 extent_logical;
2245 u64 extent_physical;
2246 u64 extent_len;
2247 struct btrfs_device *extent_dev;
2248 int extent_mirror_num;
a2de733c 2249
53b381b3
DW		 2250 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2251 BTRFS_BLOCK_GROUP_RAID6)) {
2252 if (num >= nr_data_stripes(map)) {
2253 return 0;
2254 }
2255 }
2256
a2de733c
AJ		 2257 nstripes = length;
2258 offset = 0;
2259 do_div(nstripes, map->stripe_len);
2260 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2261 offset = map->stripe_len * num;
2262 increment = map->stripe_len * map->num_stripes;
193ea74b 2263 mirror_num = 1;
a2de733c
AJ		 2264 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2265 int factor = map->num_stripes / map->sub_stripes;
2266 offset = map->stripe_len * (num / map->sub_stripes);
2267 increment = map->stripe_len * factor;
193ea74b 2268 mirror_num = num % map->sub_stripes + 1;
a2de733c
AJ		 2269 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2270 increment = map->stripe_len;
193ea74b 2271 mirror_num = num % map->num_stripes + 1;
a2de733c
AJ		 2272 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2273 increment = map->stripe_len;
193ea74b 2274 mirror_num = num % map->num_stripes + 1;
a2de733c
AJ		 2275 } else {
2276 increment = map->stripe_len;
193ea74b 2277 mirror_num = 1;
a2de733c
AJ		 2278 }
2279
2280 path = btrfs_alloc_path();
2281 if (!path)
2282 return -ENOMEM;
2283
b5d67f64
SB		 2284 /*
2285 * work on commit root. The related disk blocks are static as
2286 * long as COW is applied. This means, it is save to rewrite
2287 * them to repair disk errors without any race conditions
2288 */
a2de733c
AJ		 2289 path->search_commit_root = 1;
2290 path->skip_locking = 1;
2291
2292 /*
7a26285e
AJ		 2293 * trigger the readahead for extent tree csum tree and wait for
2294 * completion. During readahead, the scrub is officially paused
2295 * to not hold off transaction commits
a2de733c
AJ		 2296 */
2297 logical = base + offset;
a2de733c 2298
d9d181c1 2299 wait_event(sctx->list_wait,
b6bfebc1 2300 atomic_read(&sctx->bios_in_flight) == 0);
7a26285e
AJ		 2301 atomic_inc(&fs_info->scrubs_paused);
2302 wake_up(&fs_info->scrub_pause_wait);
2303
2304 /* FIXME it might be better to start readahead at commit root */
2305 key_start.objectid = logical;
2306 key_start.type = BTRFS_EXTENT_ITEM_KEY;
2307 key_start.offset = (u64)0;
2308 key_end.objectid = base + offset + nstripes * increment;
2309 key_end.type = BTRFS_EXTENT_ITEM_KEY;
2310 key_end.offset = (u64)0;
2311 reada1 = btrfs_reada_add(root, &key_start, &key_end);
2312
2313 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2314 key_start.type = BTRFS_EXTENT_CSUM_KEY;
2315 key_start.offset = logical;
2316 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2317 key_end.type = BTRFS_EXTENT_CSUM_KEY;
2318 key_end.offset = base + offset + nstripes * increment;
2319 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
2320
2321 if (!IS_ERR(reada1))
2322 btrfs_reada_wait(reada1);
2323 if (!IS_ERR(reada2))
2324 btrfs_reada_wait(reada2);
2325
2326 mutex_lock(&fs_info->scrub_lock);
2327 while (atomic_read(&fs_info->scrub_pause_req)) {
2328 mutex_unlock(&fs_info->scrub_lock);
2329 wait_event(fs_info->scrub_pause_wait,
2330 atomic_read(&fs_info->scrub_pause_req) == 0);
2331 mutex_lock(&fs_info->scrub_lock);
a2de733c 2332 }
7a26285e
AJ		 2333 atomic_dec(&fs_info->scrubs_paused);
2334 mutex_unlock(&fs_info->scrub_lock);
2335 wake_up(&fs_info->scrub_pause_wait);
a2de733c
AJ		 2336
2337 /*
2338 * collect all data csums for the stripe to avoid seeking during
2339 * the scrub. This might currently (crc32) end up to be about 1MB
2340 */
e7786c3a 2341 blk_start_plug(&plug);
a2de733c 2342
a2de733c
AJ		 2343 /*
2344 * now find all extents for each stripe and scrub them
2345 */
7a26285e
AJ		 2346 logical = base + offset;
2347 physical = map->stripes[num].physical;
a2de733c 2348 ret = 0;
7a26285e 2349 for (i = 0; i < nstripes; ++i) {
a2de733c
AJ		 2350 /*
2351 * canceled?
2352 */
2353 if (atomic_read(&fs_info->scrub_cancel_req) ||
d9d181c1 2354 atomic_read(&sctx->cancel_req)) {
a2de733c
AJ		 2355 ret = -ECANCELED;
2356 goto out;
2357 }
2358 /*
2359 * check to see if we have to pause
2360 */
2361 if (atomic_read(&fs_info->scrub_pause_req)) {
2362 /* push queued extents */
ff023aac 2363 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
d9d181c1 2364 scrub_submit(sctx);
ff023aac
SB		 2365 mutex_lock(&sctx->wr_ctx.wr_lock);
2366 scrub_wr_submit(sctx);
2367 mutex_unlock(&sctx->wr_ctx.wr_lock);
d9d181c1 2368 wait_event(sctx->list_wait,
b6bfebc1 2369 atomic_read(&sctx->bios_in_flight) == 0);
ff023aac 2370 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
a2de733c
AJ		 2371 atomic_inc(&fs_info->scrubs_paused);
2372 wake_up(&fs_info->scrub_pause_wait);
2373 mutex_lock(&fs_info->scrub_lock);
2374 while (atomic_read(&fs_info->scrub_pause_req)) {
2375 mutex_unlock(&fs_info->scrub_lock);
2376 wait_event(fs_info->scrub_pause_wait,
2377 atomic_read(&fs_info->scrub_pause_req) == 0);
2378 mutex_lock(&fs_info->scrub_lock);
2379 }
2380 atomic_dec(&fs_info->scrubs_paused);
2381 mutex_unlock(&fs_info->scrub_lock);
2382 wake_up(&fs_info->scrub_pause_wait);
a2de733c
AJ		 2383 }
2384
7a26285e
AJ		 2385 ret = btrfs_lookup_csums_range(csum_root, logical,
2386 logical + map->stripe_len - 1,
d9d181c1 2387 &sctx->csum_list, 1);
7a26285e
AJ		 2388 if (ret)
2389 goto out;
2390
a2de733c
AJ		 2391 key.objectid = logical;
2392 key.type = BTRFS_EXTENT_ITEM_KEY;
2393 key.offset = (u64)0;
2394
2395 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2396 if (ret < 0)
2397 goto out;
8c51032f 2398 if (ret > 0) {
a2de733c
AJ		 2399 ret = btrfs_previous_item(root, path, 0,
2400 BTRFS_EXTENT_ITEM_KEY);
2401 if (ret < 0)
2402 goto out;
8c51032f
AJ		 2403 if (ret > 0) {
2404 /* there's no smaller item, so stick with the
2405 * larger one */
2406 btrfs_release_path(path);
2407 ret = btrfs_search_slot(NULL, root, &key,
2408 path, 0, 0);
2409 if (ret < 0)
2410 goto out;
2411 }
a2de733c
AJ		 2412 }
2413
2414 while (1) {
2415 l = path->nodes[0];
2416 slot = path->slots[0];
2417 if (slot >= btrfs_header_nritems(l)) {
2418 ret = btrfs_next_leaf(root, path);
2419 if (ret == 0)
2420 continue;
2421 if (ret < 0)
2422 goto out;
2423
2424 break;
2425 }
2426 btrfs_item_key_to_cpu(l, &key, slot);
2427
2428 if (key.objectid + key.offset <= logical)
2429 goto next;
2430
2431 if (key.objectid >= logical + map->stripe_len)
2432 break;
2433
2434 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
2435 goto next;
2436
2437 extent = btrfs_item_ptr(l, slot,
2438 struct btrfs_extent_item);
2439 flags = btrfs_extent_flags(l, extent);
2440 generation = btrfs_extent_generation(l, extent);
2441
2442 if (key.objectid < logical &&
2443 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
2444 printk(KERN_ERR
2445 "btrfs scrub: tree block %llu spanning "
2446 "stripes, ignored. logical=%llu\n",
2447 (unsigned long long)key.objectid,
2448 (unsigned long long)logical);
2449 goto next;
2450 }
2451
2452 /*
2453 * trim extent to this stripe
2454 */
2455 if (key.objectid < logical) {
2456 key.offset -= logical - key.objectid;
2457 key.objectid = logical;
2458 }
2459 if (key.objectid + key.offset >
2460 logical + map->stripe_len) {
2461 key.offset = logical + map->stripe_len -
2462 key.objectid;
2463 }
2464
ff023aac
SB		 2465 extent_logical = key.objectid;
2466 extent_physical = key.objectid - logical + physical;
2467 extent_len = key.offset;
2468 extent_dev = scrub_dev;
2469 extent_mirror_num = mirror_num;
2470 if (is_dev_replace)
2471 scrub_remap_extent(fs_info, extent_logical,
2472 extent_len, &extent_physical,
2473 &extent_dev,
2474 &extent_mirror_num);
2475 ret = scrub_extent(sctx, extent_logical, extent_len,
2476 extent_physical, extent_dev, flags,
2477 generation, extent_mirror_num,
2478 key.objectid - logical + physical);
a2de733c
AJ		 2479 if (ret)
2480 goto out;
2481
2482next:
2483 path->slots[0]++;
2484 }
71267333 2485 btrfs_release_path(path);
a2de733c
AJ		 2486 logical += increment;
2487 physical += map->stripe_len;
d9d181c1
SB		 2488 spin_lock(&sctx->stat_lock);
2489 sctx->stat.last_physical = physical;
2490 spin_unlock(&sctx->stat_lock);
a2de733c 2491 }
ff023aac 2492out:
a2de733c 2493 /* push queued extents */
d9d181c1 2494 scrub_submit(sctx);
ff023aac
SB		 2495 mutex_lock(&sctx->wr_ctx.wr_lock);
2496 scrub_wr_submit(sctx);
2497 mutex_unlock(&sctx->wr_ctx.wr_lock);
a2de733c 2498
e7786c3a 2499 blk_finish_plug(&plug);
a2de733c
AJ		 2500 btrfs_free_path(path);
2501 return ret < 0 ? ret : 0;
2502}
2503
d9d181c1 2504static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
a36cf8b8
SB		 2505 struct btrfs_device *scrub_dev,
2506 u64 chunk_tree, u64 chunk_objectid,
2507 u64 chunk_offset, u64 length,
ff023aac 2508 u64 dev_offset, int is_dev_replace)
a2de733c
AJ		 2509{
2510 struct btrfs_mapping_tree *map_tree =
a36cf8b8 2511 &sctx->dev_root->fs_info->mapping_tree;
a2de733c
AJ		 2512 struct map_lookup *map;
2513 struct extent_map *em;
2514 int i;
ff023aac 2515 int ret = 0;
a2de733c
AJ		 2516
2517 read_lock(&map_tree->map_tree.lock);
2518 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2519 read_unlock(&map_tree->map_tree.lock);
2520
2521 if (!em)
2522 return -EINVAL;
2523
2524 map = (struct map_lookup *)em->bdev;
2525 if (em->start != chunk_offset)
2526 goto out;
2527
2528 if (em->len < length)
2529 goto out;
2530
2531 for (i = 0; i < map->num_stripes; ++i) {
a36cf8b8 2532 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
859acaf1 2533 map->stripes[i].physical == dev_offset) {
a36cf8b8 2534 ret = scrub_stripe(sctx, map, scrub_dev, i,
ff023aac
SB		 2535 chunk_offset, length,
2536 is_dev_replace);
a2de733c
AJ		 2537 if (ret)
2538 goto out;
2539 }
2540 }
2541out:
2542 free_extent_map(em);
2543
2544 return ret;
2545}
2546
2547static noinline_for_stack
a36cf8b8 2548int scrub_enumerate_chunks(struct scrub_ctx *sctx,
ff023aac
SB		 2549 struct btrfs_device *scrub_dev, u64 start, u64 end,
2550 int is_dev_replace)
a2de733c
AJ		 2551{
2552 struct btrfs_dev_extent *dev_extent = NULL;
2553 struct btrfs_path *path;
a36cf8b8 2554 struct btrfs_root *root = sctx->dev_root;
a2de733c
AJ		 2555 struct btrfs_fs_info *fs_info = root->fs_info;
2556 u64 length;
2557 u64 chunk_tree;
2558 u64 chunk_objectid;
2559 u64 chunk_offset;
2560 int ret;
2561 int slot;
2562 struct extent_buffer *l;
2563 struct btrfs_key key;
2564 struct btrfs_key found_key;
2565 struct btrfs_block_group_cache *cache;
ff023aac 2566 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
a2de733c
AJ		 2567
2568 path = btrfs_alloc_path();
2569 if (!path)
2570 return -ENOMEM;
2571
2572 path->reada = 2;
2573 path->search_commit_root = 1;
2574 path->skip_locking = 1;
2575
a36cf8b8 2576 key.objectid = scrub_dev->devid;
a2de733c
AJ		 2577 key.offset = 0ull;
2578 key.type = BTRFS_DEV_EXTENT_KEY;
2579
a2de733c
AJ		 2580 while (1) {
2581 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2582 if (ret < 0)
8c51032f
AJ		 2583 break;
2584 if (ret > 0) {
2585 if (path->slots[0] >=
2586 btrfs_header_nritems(path->nodes[0])) {
2587 ret = btrfs_next_leaf(root, path);
2588 if (ret)
2589 break;
2590 }
2591 }
a2de733c
AJ		 2592
2593 l = path->nodes[0];
2594 slot = path->slots[0];
2595
2596 btrfs_item_key_to_cpu(l, &found_key, slot);
2597
a36cf8b8 2598 if (found_key.objectid != scrub_dev->devid)
a2de733c
AJ		 2599 break;
2600
8c51032f 2601 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
a2de733c
AJ		 2602 break;
2603
2604 if (found_key.offset >= end)
2605 break;
2606
2607 if (found_key.offset < key.offset)
2608 break;
2609
2610 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2611 length = btrfs_dev_extent_length(l, dev_extent);
2612
2613 if (found_key.offset + length <= start) {
2614 key.offset = found_key.offset + length;
71267333 2615 btrfs_release_path(path);
a2de733c
AJ		 2616 continue;
2617 }
2618
2619 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2620 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2621 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2622
2623 /*
2624 * get a reference on the corresponding block group to prevent
2625 * the chunk from going away while we scrub it
2626 */
2627 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2628 if (!cache) {
2629 ret = -ENOENT;
8c51032f 2630 break;
a2de733c 2631 }
ff023aac
SB		 2632 dev_replace->cursor_right = found_key.offset + length;
2633 dev_replace->cursor_left = found_key.offset;
2634 dev_replace->item_needs_writeback = 1;
a36cf8b8 2635 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
ff023aac
SB		 2636 chunk_offset, length, found_key.offset,
2637 is_dev_replace);
2638
2639 /*
2640 * flush, submit all pending read and write bios, afterwards
2641 * wait for them.
2642 * Note that in the dev replace case, a read request causes
2643 * write requests that are submitted in the read completion
2644 * worker. Therefore in the current situation, it is required
2645 * that all write requests are flushed, so that all read and
2646 * write requests are really completed when bios_in_flight
2647 * changes to 0.
2648 */
2649 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2650 scrub_submit(sctx);
2651 mutex_lock(&sctx->wr_ctx.wr_lock);
2652 scrub_wr_submit(sctx);
2653 mutex_unlock(&sctx->wr_ctx.wr_lock);
2654
2655 wait_event(sctx->list_wait,
2656 atomic_read(&sctx->bios_in_flight) == 0);
2657 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2658 atomic_inc(&fs_info->scrubs_paused);
2659 wake_up(&fs_info->scrub_pause_wait);
2660 wait_event(sctx->list_wait,
2661 atomic_read(&sctx->workers_pending) == 0);
2662
2663 mutex_lock(&fs_info->scrub_lock);
2664 while (atomic_read(&fs_info->scrub_pause_req)) {
2665 mutex_unlock(&fs_info->scrub_lock);
2666 wait_event(fs_info->scrub_pause_wait,
2667 atomic_read(&fs_info->scrub_pause_req) == 0);
2668 mutex_lock(&fs_info->scrub_lock);
2669 }
2670 atomic_dec(&fs_info->scrubs_paused);
2671 mutex_unlock(&fs_info->scrub_lock);
2672 wake_up(&fs_info->scrub_pause_wait);
2673
2674 dev_replace->cursor_left = dev_replace->cursor_right;
2675 dev_replace->item_needs_writeback = 1;
a2de733c
AJ		 2676 btrfs_put_block_group(cache);
2677 if (ret)
2678 break;
af1be4f8
SB		 2679 if (is_dev_replace &&
2680 atomic64_read(&dev_replace->num_write_errors) > 0) {
ff023aac
SB		 2681 ret = -EIO;
2682 break;
2683 }
2684 if (sctx->stat.malloc_errors > 0) {
2685 ret = -ENOMEM;
2686 break;
2687 }
a2de733c
AJ		 2688
2689 key.offset = found_key.offset + length;
71267333 2690 btrfs_release_path(path);
a2de733c
AJ		 2691 }
2692
a2de733c 2693 btrfs_free_path(path);
8c51032f
AJ		 2694
2695 /*
2696 * ret can still be 1 from search_slot or next_leaf,
2697 * that's not an error
2698 */
2699 return ret < 0 ? ret : 0;
a2de733c
AJ		 2700}
2701
a36cf8b8
SB		 2702static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2703 struct btrfs_device *scrub_dev)
a2de733c
AJ		 2704{
2705 int i;
2706 u64 bytenr;
2707 u64 gen;
2708 int ret;
a36cf8b8 2709 struct btrfs_root *root = sctx->dev_root;
a2de733c 2710
79787eaa
JM		 2711 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2712 return -EIO;
2713
a2de733c
AJ		 2714 gen = root->fs_info->last_trans_committed;
2715
2716 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2717 bytenr = btrfs_sb_offset(i);
a36cf8b8 2718 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
a2de733c
AJ		 2719 break;
2720
d9d181c1 2721 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
a36cf8b8 2722 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
ff023aac 2723 NULL, 1, bytenr);
a2de733c
AJ		 2724 if (ret)
2725 return ret;
2726 }
b6bfebc1 2727 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
a2de733c
AJ		 2728
2729 return 0;
2730}
2731
2732/*
2733 * get a reference count on fs_info->scrub_workers. start worker if necessary
2734 */
ff023aac
SB		 2735static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
2736 int is_dev_replace)
a2de733c 2737{
0dc3b84a 2738 int ret = 0;
a2de733c
AJ		 2739
2740 mutex_lock(&fs_info->scrub_lock);
632dd772 2741 if (fs_info->scrub_workers_refcnt == 0) {
ff023aac
SB		 2742 if (is_dev_replace)
2743 btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1,
2744 &fs_info->generic_worker);
2745 else
2746 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
2747 fs_info->thread_pool_size,
2748 &fs_info->generic_worker);
632dd772 2749 fs_info->scrub_workers.idle_thresh = 4;
0dc3b84a
JB		 2750 ret = btrfs_start_workers(&fs_info->scrub_workers);
2751 if (ret)
2752 goto out;
ff023aac
SB		 2753 btrfs_init_workers(&fs_info->scrub_wr_completion_workers,
2754 "scrubwrc",
2755 fs_info->thread_pool_size,
2756 &fs_info->generic_worker);
2757 fs_info->scrub_wr_completion_workers.idle_thresh = 2;
2758 ret = btrfs_start_workers(
2759 &fs_info->scrub_wr_completion_workers);
2760 if (ret)
2761 goto out;
2762 btrfs_init_workers(&fs_info->scrub_nocow_workers, "scrubnc", 1,
2763 &fs_info->generic_worker);
2764 ret = btrfs_start_workers(&fs_info->scrub_nocow_workers);
2765 if (ret)
2766 goto out;
632dd772 2767 }
a2de733c 2768 ++fs_info->scrub_workers_refcnt;
0dc3b84a 2769out:
a2de733c
AJ		 2770 mutex_unlock(&fs_info->scrub_lock);
2771
0dc3b84a 2772 return ret;
a2de733c
AJ		 2773}
2774
aa1b8cd4 2775static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
a2de733c 2776{
a2de733c 2777 mutex_lock(&fs_info->scrub_lock);
ff023aac 2778 if (--fs_info->scrub_workers_refcnt == 0) {
a2de733c 2779 btrfs_stop_workers(&fs_info->scrub_workers);
ff023aac
SB		 2780 btrfs_stop_workers(&fs_info->scrub_wr_completion_workers);
2781 btrfs_stop_workers(&fs_info->scrub_nocow_workers);
2782 }
a2de733c
AJ		 2783 WARN_ON(fs_info->scrub_workers_refcnt < 0);
2784 mutex_unlock(&fs_info->scrub_lock);
2785}
2786
aa1b8cd4
SB		 2787int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2788 u64 end, struct btrfs_scrub_progress *progress,
63a212ab 2789 int readonly, int is_dev_replace)
a2de733c 2790{
d9d181c1 2791 struct scrub_ctx *sctx;
a2de733c
AJ		 2792 int ret;
2793 struct btrfs_device *dev;
2794
aa1b8cd4 2795 if (btrfs_fs_closing(fs_info))
a2de733c
AJ		 2796 return -EINVAL;
2797
2798 /*
2799 * check some assumptions
2800 */
aa1b8cd4 2801 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
b5d67f64
SB		 2802 printk(KERN_ERR
2803 "btrfs_scrub: size assumption nodesize == leafsize (%d == %d) fails\n",
aa1b8cd4
SB		 2804 fs_info->chunk_root->nodesize,
2805 fs_info->chunk_root->leafsize);
b5d67f64
SB		 2806 return -EINVAL;
2807 }
2808
aa1b8cd4 2809 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
b5d67f64
SB		 2810 /*
2811 * in this case scrub is unable to calculate the checksum
2812 * the way scrub is implemented. Do not handle this
2813 * situation at all because it won't ever happen.
2814 */
2815 printk(KERN_ERR
2816 "btrfs_scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails\n",
aa1b8cd4 2817 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
b5d67f64
SB		 2818 return -EINVAL;
2819 }
2820
aa1b8cd4 2821 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
b5d67f64
SB		 2822 /* not supported for data w/o checksums */
2823 printk(KERN_ERR
2824 "btrfs_scrub: size assumption sectorsize != PAGE_SIZE (%d != %lld) fails\n",
aa1b8cd4
SB		 2825 fs_info->chunk_root->sectorsize,
2826 (unsigned long long)PAGE_SIZE);
a2de733c
AJ		 2827 return -EINVAL;
2828 }
2829
7a9e9987
SB		 2830 if (fs_info->chunk_root->nodesize >
2831 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
2832 fs_info->chunk_root->sectorsize >
2833 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
2834 /*
2835 * would exhaust the array bounds of pagev member in
2836 * struct scrub_block
2837 */
2838 pr_err("btrfs_scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails\n",
2839 fs_info->chunk_root->nodesize,
2840 SCRUB_MAX_PAGES_PER_BLOCK,
2841 fs_info->chunk_root->sectorsize,
2842 SCRUB_MAX_PAGES_PER_BLOCK);
2843 return -EINVAL;
2844 }
2845
ff023aac 2846 ret = scrub_workers_get(fs_info, is_dev_replace);
a2de733c
AJ		 2847 if (ret)
2848 return ret;
2849
aa1b8cd4
SB		 2850 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2851 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
63a212ab 2852 if (!dev || (dev->missing && !is_dev_replace)) {
aa1b8cd4
SB		 2853 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2854 scrub_workers_put(fs_info);
a2de733c
AJ		 2855 return -ENODEV;
2856 }
2857 mutex_lock(&fs_info->scrub_lock);
2858
63a212ab 2859 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
a2de733c 2860 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4
SB		 2861 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2862 scrub_workers_put(fs_info);
2863 return -EIO;
a2de733c
AJ		 2864 }
2865
8dabb742
SB		 2866 btrfs_dev_replace_lock(&fs_info->dev_replace);
2867 if (dev->scrub_device ||
2868 (!is_dev_replace &&
2869 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2870 btrfs_dev_replace_unlock(&fs_info->dev_replace);
a2de733c 2871 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4
SB		 2872 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2873 scrub_workers_put(fs_info);
a2de733c
AJ		 2874 return -EINPROGRESS;
2875 }
8dabb742 2876 btrfs_dev_replace_unlock(&fs_info->dev_replace);
63a212ab 2877 sctx = scrub_setup_ctx(dev, is_dev_replace);
d9d181c1 2878 if (IS_ERR(sctx)) {
a2de733c 2879 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4
SB		 2880 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2881 scrub_workers_put(fs_info);
d9d181c1 2882 return PTR_ERR(sctx);
a2de733c 2883 }
d9d181c1
SB		 2884 sctx->readonly = readonly;
2885 dev->scrub_device = sctx;
a2de733c
AJ		 2886
2887 atomic_inc(&fs_info->scrubs_running);
2888 mutex_unlock(&fs_info->scrub_lock);
aa1b8cd4 2889 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
a2de733c 2890
ff023aac
SB		 2891 if (!is_dev_replace) {
2892 down_read(&fs_info->scrub_super_lock);
2893 ret = scrub_supers(sctx, dev);
2894 up_read(&fs_info->scrub_super_lock);
2895 }
a2de733c
AJ		 2896
2897 if (!ret)
ff023aac
SB		 2898 ret = scrub_enumerate_chunks(sctx, dev, start, end,
2899 is_dev_replace);
a2de733c 2900
b6bfebc1 2901 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
a2de733c
AJ		 2902 atomic_dec(&fs_info->scrubs_running);
2903 wake_up(&fs_info->scrub_pause_wait);
2904
b6bfebc1 2905 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
0ef8e451 2906
a2de733c 2907 if (progress)
d9d181c1 2908 memcpy(progress, &sctx->stat, sizeof(*progress));
a2de733c
AJ		 2909
2910 mutex_lock(&fs_info->scrub_lock);
2911 dev->scrub_device = NULL;
2912 mutex_unlock(&fs_info->scrub_lock);
2913
d9d181c1 2914 scrub_free_ctx(sctx);
aa1b8cd4 2915 scrub_workers_put(fs_info);
a2de733c
AJ		 2916
2917 return ret;
2918}
2919
143bede5 2920void btrfs_scrub_pause(struct btrfs_root *root)
a2de733c
AJ		 2921{
2922 struct btrfs_fs_info *fs_info = root->fs_info;
2923
2924 mutex_lock(&fs_info->scrub_lock);
2925 atomic_inc(&fs_info->scrub_pause_req);
2926 while (atomic_read(&fs_info->scrubs_paused) !=
2927 atomic_read(&fs_info->scrubs_running)) {
2928 mutex_unlock(&fs_info->scrub_lock);
2929 wait_event(fs_info->scrub_pause_wait,
2930 atomic_read(&fs_info->scrubs_paused) ==
2931 atomic_read(&fs_info->scrubs_running));
2932 mutex_lock(&fs_info->scrub_lock);
2933 }
2934 mutex_unlock(&fs_info->scrub_lock);
a2de733c
AJ		 2935}
2936
143bede5 2937void btrfs_scrub_continue(struct btrfs_root *root)
a2de733c
AJ		 2938{
2939 struct btrfs_fs_info *fs_info = root->fs_info;
2940
2941 atomic_dec(&fs_info->scrub_pause_req);
2942 wake_up(&fs_info->scrub_pause_wait);
a2de733c
AJ		 2943}
2944
143bede5 2945void btrfs_scrub_pause_super(struct btrfs_root *root)
a2de733c
AJ		 2946{
2947 down_write(&root->fs_info->scrub_super_lock);
a2de733c
AJ		 2948}
2949
143bede5 2950void btrfs_scrub_continue_super(struct btrfs_root *root)
a2de733c
AJ		 2951{
2952 up_write(&root->fs_info->scrub_super_lock);
a2de733c
AJ		 2953}
2954
aa1b8cd4 2955int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
a2de733c 2956{
a2de733c
AJ		 2957 mutex_lock(&fs_info->scrub_lock);
2958 if (!atomic_read(&fs_info->scrubs_running)) {
2959 mutex_unlock(&fs_info->scrub_lock);
2960 return -ENOTCONN;
2961 }
2962
2963 atomic_inc(&fs_info->scrub_cancel_req);
2964 while (atomic_read(&fs_info->scrubs_running)) {
2965 mutex_unlock(&fs_info->scrub_lock);
2966 wait_event(fs_info->scrub_pause_wait,
2967 atomic_read(&fs_info->scrubs_running) == 0);
2968 mutex_lock(&fs_info->scrub_lock);
2969 }
2970 atomic_dec(&fs_info->scrub_cancel_req);
2971 mutex_unlock(&fs_info->scrub_lock);
2972
2973 return 0;
2974}
2975
aa1b8cd4
SB		 2976int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
2977 struct btrfs_device *dev)
49b25e05 2978{
d9d181c1 2979 struct scrub_ctx *sctx;
a2de733c
AJ		 2980
2981 mutex_lock(&fs_info->scrub_lock);
d9d181c1
SB		 2982 sctx = dev->scrub_device;
2983 if (!sctx) {
a2de733c
AJ		 2984 mutex_unlock(&fs_info->scrub_lock);
2985 return -ENOTCONN;
2986 }
d9d181c1 2987 atomic_inc(&sctx->cancel_req);
a2de733c
AJ		 2988 while (dev->scrub_device) {
2989 mutex_unlock(&fs_info->scrub_lock);
2990 wait_event(fs_info->scrub_pause_wait,
2991 dev->scrub_device == NULL);
2992 mutex_lock(&fs_info->scrub_lock);
2993 }
2994 mutex_unlock(&fs_info->scrub_lock);
2995
2996 return 0;
2997}
1623edeb 2998
a2de733c
AJ		 2999int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
3000{
3001 struct btrfs_fs_info *fs_info = root->fs_info;
3002 struct btrfs_device *dev;
3003 int ret;
3004
3005 /*
3006 * we have to hold the device_list_mutex here so the device
3007 * does not go away in cancel_dev. FIXME: find a better solution
3008 */
3009 mutex_lock(&fs_info->fs_devices->device_list_mutex);
aa1b8cd4 3010 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
a2de733c
AJ		 3011 if (!dev) {
3012 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3013 return -ENODEV;
3014 }
aa1b8cd4 3015 ret = btrfs_scrub_cancel_dev(fs_info, dev);
a2de733c
AJ		 3016 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3017
3018 return ret;
3019}
3020
3021int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3022 struct btrfs_scrub_progress *progress)
3023{
3024 struct btrfs_device *dev;
d9d181c1 3025 struct scrub_ctx *sctx = NULL;
a2de733c
AJ		 3026
3027 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
aa1b8cd4 3028 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
a2de733c 3029 if (dev)
d9d181c1
SB		 3030 sctx = dev->scrub_device;
3031 if (sctx)
3032 memcpy(progress, &sctx->stat, sizeof(*progress));
a2de733c
AJ		 3033 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3034
d9d181c1 3035 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
a2de733c 3036}
ff023aac
SB		 3037
3038static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3039 u64 extent_logical, u64 extent_len,
3040 u64 *extent_physical,
3041 struct btrfs_device **extent_dev,
3042 int *extent_mirror_num)
3043{
3044 u64 mapped_length;
3045 struct btrfs_bio *bbio = NULL;
3046 int ret;
3047
3048 mapped_length = extent_len;
3049 ret = btrfs_map_block(fs_info, READ, extent_logical,
3050 &mapped_length, &bbio, 0);
3051 if (ret || !bbio || mapped_length < extent_len ||
3052 !bbio->stripes[0].dev->bdev) {
3053 kfree(bbio);
3054 return;
3055 }
3056
3057 *extent_physical = bbio->stripes[0].physical;
3058 *extent_mirror_num = bbio->mirror_num;
3059 *extent_dev = bbio->stripes[0].dev;
3060 kfree(bbio);
3061}
3062
3063static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3064 struct scrub_wr_ctx *wr_ctx,
3065 struct btrfs_fs_info *fs_info,
3066 struct btrfs_device *dev,
3067 int is_dev_replace)
3068{
3069 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3070
3071 mutex_init(&wr_ctx->wr_lock);
3072 wr_ctx->wr_curr_bio = NULL;
3073 if (!is_dev_replace)
3074 return 0;
3075
3076 WARN_ON(!dev->bdev);
3077 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
3078 bio_get_nr_vecs(dev->bdev));
3079 wr_ctx->tgtdev = dev;
3080 atomic_set(&wr_ctx->flush_all_writes, 0);
3081 return 0;
3082}
3083
3084static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3085{
3086 mutex_lock(&wr_ctx->wr_lock);
3087 kfree(wr_ctx->wr_curr_bio);
3088 wr_ctx->wr_curr_bio = NULL;
3089 mutex_unlock(&wr_ctx->wr_lock);
3090}
3091
3092static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3093 int mirror_num, u64 physical_for_dev_replace)
3094{
3095 struct scrub_copy_nocow_ctx *nocow_ctx;
3096 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3097
3098 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3099 if (!nocow_ctx) {
3100 spin_lock(&sctx->stat_lock);
3101 sctx->stat.malloc_errors++;
3102 spin_unlock(&sctx->stat_lock);
3103 return -ENOMEM;
3104 }
3105
3106 scrub_pending_trans_workers_inc(sctx);
3107
3108 nocow_ctx->sctx = sctx;
3109 nocow_ctx->logical = logical;
3110 nocow_ctx->len = len;
3111 nocow_ctx->mirror_num = mirror_num;
3112 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
3113 nocow_ctx->work.func = copy_nocow_pages_worker;
3114 btrfs_queue_worker(&fs_info->scrub_nocow_workers,
3115 &nocow_ctx->work);
3116
3117 return 0;
3118}
3119
3120static void copy_nocow_pages_worker(struct btrfs_work *work)
3121{
3122 struct scrub_copy_nocow_ctx *nocow_ctx =
3123 container_of(work, struct scrub_copy_nocow_ctx, work);
3124 struct scrub_ctx *sctx = nocow_ctx->sctx;
3125 u64 logical = nocow_ctx->logical;
3126 u64 len = nocow_ctx->len;
3127 int mirror_num = nocow_ctx->mirror_num;
3128 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3129 int ret;
3130 struct btrfs_trans_handle *trans = NULL;
3131 struct btrfs_fs_info *fs_info;
3132 struct btrfs_path *path;
3133 struct btrfs_root *root;
3134 int not_written = 0;
3135
3136 fs_info = sctx->dev_root->fs_info;
3137 root = fs_info->extent_root;
3138
3139 path = btrfs_alloc_path();
3140 if (!path) {
3141 spin_lock(&sctx->stat_lock);
3142 sctx->stat.malloc_errors++;
3143 spin_unlock(&sctx->stat_lock);
3144 not_written = 1;
3145 goto out;
3146 }
3147
3148 trans = btrfs_join_transaction(root);
3149 if (IS_ERR(trans)) {
3150 not_written = 1;
3151 goto out;
3152 }
3153
3154 ret = iterate_inodes_from_logical(logical, fs_info, path,
3155 copy_nocow_pages_for_inode,
3156 nocow_ctx);
3157 if (ret != 0 && ret != -ENOENT) {
3158 pr_warn("iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %llu, ret %d\n",
3159 (unsigned long long)logical,
3160 (unsigned long long)physical_for_dev_replace,
3161 (unsigned long long)len,
3162 (unsigned long long)mirror_num, ret);
3163 not_written = 1;
3164 goto out;
3165 }
3166
3167out:
3168 if (trans && !IS_ERR(trans))
3169 btrfs_end_transaction(trans, root);
3170 if (not_written)
3171 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
3172 num_uncorrectable_read_errors);
3173
3174 btrfs_free_path(path);
3175 kfree(nocow_ctx);
3176
3177 scrub_pending_trans_workers_dec(sctx);
3178}
3179
3180static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, void *ctx)
3181{
3182 unsigned long index;
3183 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3184 int ret = 0;
3185 struct btrfs_key key;
3186 struct inode *inode = NULL;
3187 struct btrfs_root *local_root;
3188 u64 physical_for_dev_replace;
3189 u64 len;
3190 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
3191
3192 key.objectid = root;
3193 key.type = BTRFS_ROOT_ITEM_KEY;
3194 key.offset = (u64)-1;
3195 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
3196 if (IS_ERR(local_root))
3197 return PTR_ERR(local_root);
3198
3199 key.type = BTRFS_INODE_ITEM_KEY;
3200 key.objectid = inum;
3201 key.offset = 0;
3202 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
3203 if (IS_ERR(inode))
3204 return PTR_ERR(inode);
3205
3206 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3207 len = nocow_ctx->len;
3208 while (len >= PAGE_CACHE_SIZE) {
3209 struct page *page = NULL;
3210 int ret_sub;
3211
3212 index = offset >> PAGE_CACHE_SHIFT;
3213
3214 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3215 if (!page) {
3216 pr_err("find_or_create_page() failed\n");
3217 ret = -ENOMEM;
3218 goto next_page;
3219 }
3220
3221 if (PageUptodate(page)) {
3222 if (PageDirty(page))
3223 goto next_page;
3224 } else {
3225 ClearPageError(page);
3226 ret_sub = extent_read_full_page(&BTRFS_I(inode)->
3227 io_tree,
3228 page, btrfs_get_extent,
3229 nocow_ctx->mirror_num);
3230 if (ret_sub) {
3231 ret = ret_sub;
3232 goto next_page;
3233 }
3234 wait_on_page_locked(page);
3235 if (!PageUptodate(page)) {
3236 ret = -EIO;
3237 goto next_page;
3238 }
3239 }
3240 ret_sub = write_page_nocow(nocow_ctx->sctx,
3241 physical_for_dev_replace, page);
3242 if (ret_sub) {
3243 ret = ret_sub;
3244 goto next_page;
3245 }
3246
3247next_page:
3248 if (page) {
3249 unlock_page(page);
3250 put_page(page);
3251 }
3252 offset += PAGE_CACHE_SIZE;
3253 physical_for_dev_replace += PAGE_CACHE_SIZE;
3254 len -= PAGE_CACHE_SIZE;
3255 }
3256
3257 if (inode)
3258 iput(inode);
3259 return ret;
3260}
3261
3262static int write_page_nocow(struct scrub_ctx *sctx,
3263 u64 physical_for_dev_replace, struct page *page)
3264{
3265 struct bio *bio;
3266 struct btrfs_device *dev;
3267 int ret;
3268 DECLARE_COMPLETION_ONSTACK(compl);
3269
3270 dev = sctx->wr_ctx.tgtdev;
3271 if (!dev)
3272 return -EIO;
3273 if (!dev->bdev) {
3274 printk_ratelimited(KERN_WARNING
3275 "btrfs: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
3276 return -EIO;
3277 }
3278 bio = bio_alloc(GFP_NOFS, 1);
3279 if (!bio) {
3280 spin_lock(&sctx->stat_lock);
3281 sctx->stat.malloc_errors++;
3282 spin_unlock(&sctx->stat_lock);
3283 return -ENOMEM;
3284 }
3285 bio->bi_private = &compl;
3286 bio->bi_end_io = scrub_complete_bio_end_io;
3287 bio->bi_size = 0;
3288 bio->bi_sector = physical_for_dev_replace >> 9;
3289 bio->bi_bdev = dev->bdev;
3290 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
3291 if (ret != PAGE_CACHE_SIZE) {
3292leave_with_eio:
3293 bio_put(bio);
3294 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
3295 return -EIO;
3296 }
3297 btrfsic_submit_bio(WRITE_SYNC, bio);
3298 wait_for_completion(&compl);
3299
3300 if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
3301 goto leave_with_eio;
3302
3303 bio_put(bio);
3304 return 0;
3305}
Linux kernel - Deliverables
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