scrub.c revision d458b0540ebd728b4d6ef47cc5ef0dbfd4dd361a
1/* 2 * Copyright (C) 2011, 2012 STRATO. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19#include <linux/blkdev.h> 20#include <linux/ratelimit.h> 21#include "ctree.h" 22#include "volumes.h" 23#include "disk-io.h" 24#include "ordered-data.h" 25#include "transaction.h" 26#include "backref.h" 27#include "extent_io.h" 28#include "dev-replace.h" 29#include "check-integrity.h" 30#include "rcu-string.h" 31#include "raid56.h" 32 33/* 34 * This is only the first step towards a full-features scrub. It reads all 35 * extent and super block and verifies the checksums. In case a bad checksum 36 * is found or the extent cannot be read, good data will be written back if 37 * any can be found. 38 * 39 * Future enhancements: 40 * - In case an unrepairable extent is encountered, track which files are 41 * affected and report them 42 * - track and record media errors, throw out bad devices 43 * - add a mode to also read unallocated space 44 */ 45 46struct scrub_block; 47struct scrub_ctx; 48 49/* 50 * the following three values only influence the performance. 51 * The last one configures the number of parallel and outstanding I/O 52 * operations. The first two values configure an upper limit for the number 53 * of (dynamically allocated) pages that are added to a bio. 54 */ 55#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */ 56#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */ 57#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */ 58 59/* 60 * the following value times PAGE_SIZE needs to be large enough to match the 61 * largest node/leaf/sector size that shall be supported. 62 * Values larger than BTRFS_STRIPE_LEN are not supported. 63 */ 64#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */ 65 66struct scrub_page { 67 struct scrub_block *sblock; 68 struct page *page; 69 struct btrfs_device *dev; 70 u64 flags; /* extent flags */ 71 u64 generation; 72 u64 logical; 73 u64 physical; 74 u64 physical_for_dev_replace; 75 atomic_t ref_count; 76 struct { 77 unsigned int mirror_num:8; 78 unsigned int have_csum:1; 79 unsigned int io_error:1; 80 }; 81 u8 csum[BTRFS_CSUM_SIZE]; 82}; 83 84struct scrub_bio { 85 int index; 86 struct scrub_ctx *sctx; 87 struct btrfs_device *dev; 88 struct bio *bio; 89 int err; 90 u64 logical; 91 u64 physical; 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 97 int page_count; 98 int next_free; 99 struct btrfs_work work; 100}; 101 102struct scrub_block { 103 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK]; 104 int page_count; 105 atomic_t outstanding_pages; 106 atomic_t ref_count; /* free mem on transition to zero */ 107 struct scrub_ctx *sctx; 108 struct { 109 unsigned int header_error:1; 110 unsigned int checksum_error:1; 111 unsigned int no_io_error_seen:1; 112 unsigned int generation_error:1; /* also sets header_error */ 113 }; 114}; 115 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 124struct scrub_ctx { 125 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX]; 126 struct btrfs_root *dev_root; 127 int first_free; 128 int curr; 129 atomic_t bios_in_flight; 130 atomic_t workers_pending; 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; 136 int readonly; 137 int pages_per_rd_bio; 138 u32 sectorsize; 139 u32 nodesize; 140 u32 leafsize; 141 142 int is_dev_replace; 143 struct scrub_wr_ctx wr_ctx; 144 145 /* 146 * statistics 147 */ 148 struct btrfs_scrub_progress stat; 149 spinlock_t stat_lock; 150}; 151 152struct scrub_fixup_nodatasum { 153 struct scrub_ctx *sctx; 154 struct btrfs_device *dev; 155 u64 logical; 156 struct btrfs_root *root; 157 struct btrfs_work work; 158 int mirror_num; 159}; 160 161struct scrub_nocow_inode { 162 u64 inum; 163 u64 offset; 164 u64 root; 165 struct list_head list; 166}; 167 168struct scrub_copy_nocow_ctx { 169 struct scrub_ctx *sctx; 170 u64 logical; 171 u64 len; 172 int mirror_num; 173 u64 physical_for_dev_replace; 174 struct list_head inodes; 175 struct btrfs_work work; 176}; 177 178struct scrub_warning { 179 struct btrfs_path *path; 180 u64 extent_item_size; 181 char *scratch_buf; 182 char *msg_buf; 183 const char *errstr; 184 sector_t sector; 185 u64 logical; 186 struct btrfs_device *dev; 187 int msg_bufsize; 188 int scratch_bufsize; 189}; 190 191 192static void scrub_pending_bio_inc(struct scrub_ctx *sctx); 193static void scrub_pending_bio_dec(struct scrub_ctx *sctx); 194static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx); 195static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx); 196static int scrub_handle_errored_block(struct scrub_block *sblock_to_check); 197static int scrub_setup_recheck_block(struct scrub_ctx *sctx, 198 struct btrfs_fs_info *fs_info, 199 struct scrub_block *original_sblock, 200 u64 length, u64 logical, 201 struct scrub_block *sblocks_for_recheck); 202static void scrub_recheck_block(struct btrfs_fs_info *fs_info, 203 struct scrub_block *sblock, int is_metadata, 204 int have_csum, u8 *csum, u64 generation, 205 u16 csum_size); 206static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, 207 struct scrub_block *sblock, 208 int is_metadata, int have_csum, 209 const u8 *csum, u64 generation, 210 u16 csum_size); 211static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, 212 struct scrub_block *sblock_good, 213 int force_write); 214static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, 215 struct scrub_block *sblock_good, 216 int page_num, int force_write); 217static void scrub_write_block_to_dev_replace(struct scrub_block *sblock); 218static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, 219 int page_num); 220static int scrub_checksum_data(struct scrub_block *sblock); 221static int scrub_checksum_tree_block(struct scrub_block *sblock); 222static int scrub_checksum_super(struct scrub_block *sblock); 223static void scrub_block_get(struct scrub_block *sblock); 224static void scrub_block_put(struct scrub_block *sblock); 225static void scrub_page_get(struct scrub_page *spage); 226static void scrub_page_put(struct scrub_page *spage); 227static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, 228 struct scrub_page *spage); 229static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 230 u64 physical, struct btrfs_device *dev, u64 flags, 231 u64 gen, int mirror_num, u8 *csum, int force, 232 u64 physical_for_dev_replace); 233static void scrub_bio_end_io(struct bio *bio, int err); 234static void scrub_bio_end_io_worker(struct btrfs_work *work); 235static void scrub_block_complete(struct scrub_block *sblock); 236static void scrub_remap_extent(struct btrfs_fs_info *fs_info, 237 u64 extent_logical, u64 extent_len, 238 u64 *extent_physical, 239 struct btrfs_device **extent_dev, 240 int *extent_mirror_num); 241static int scrub_setup_wr_ctx(struct scrub_ctx *sctx, 242 struct scrub_wr_ctx *wr_ctx, 243 struct btrfs_fs_info *fs_info, 244 struct btrfs_device *dev, 245 int is_dev_replace); 246static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx); 247static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, 248 struct scrub_page *spage); 249static void scrub_wr_submit(struct scrub_ctx *sctx); 250static void scrub_wr_bio_end_io(struct bio *bio, int err); 251static void scrub_wr_bio_end_io_worker(struct btrfs_work *work); 252static int write_page_nocow(struct scrub_ctx *sctx, 253 u64 physical_for_dev_replace, struct page *page); 254static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, 255 struct scrub_copy_nocow_ctx *ctx); 256static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 257 int mirror_num, u64 physical_for_dev_replace); 258static void copy_nocow_pages_worker(struct btrfs_work *work); 259static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); 260static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); 261 262 263static void scrub_pending_bio_inc(struct scrub_ctx *sctx) 264{ 265 atomic_inc(&sctx->bios_in_flight); 266} 267 268static void scrub_pending_bio_dec(struct scrub_ctx *sctx) 269{ 270 atomic_dec(&sctx->bios_in_flight); 271 wake_up(&sctx->list_wait); 272} 273 274static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) 275{ 276 while (atomic_read(&fs_info->scrub_pause_req)) { 277 mutex_unlock(&fs_info->scrub_lock); 278 wait_event(fs_info->scrub_pause_wait, 279 atomic_read(&fs_info->scrub_pause_req) == 0); 280 mutex_lock(&fs_info->scrub_lock); 281 } 282} 283 284static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) 285{ 286 atomic_inc(&fs_info->scrubs_paused); 287 wake_up(&fs_info->scrub_pause_wait); 288 289 mutex_lock(&fs_info->scrub_lock); 290 __scrub_blocked_if_needed(fs_info); 291 atomic_dec(&fs_info->scrubs_paused); 292 mutex_unlock(&fs_info->scrub_lock); 293 294 wake_up(&fs_info->scrub_pause_wait); 295} 296 297/* 298 * used for workers that require transaction commits (i.e., for the 299 * NOCOW case) 300 */ 301static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx) 302{ 303 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 304 305 /* 306 * increment scrubs_running to prevent cancel requests from 307 * completing as long as a worker is running. we must also 308 * increment scrubs_paused to prevent deadlocking on pause 309 * requests used for transactions commits (as the worker uses a 310 * transaction context). it is safe to regard the worker 311 * as paused for all matters practical. effectively, we only 312 * avoid cancellation requests from completing. 313 */ 314 mutex_lock(&fs_info->scrub_lock); 315 atomic_inc(&fs_info->scrubs_running); 316 atomic_inc(&fs_info->scrubs_paused); 317 mutex_unlock(&fs_info->scrub_lock); 318 319 /* 320 * check if @scrubs_running=@scrubs_paused condition 321 * inside wait_event() is not an atomic operation. 322 * which means we may inc/dec @scrub_running/paused 323 * at any time. Let's wake up @scrub_pause_wait as 324 * much as we can to let commit transaction blocked less. 325 */ 326 wake_up(&fs_info->scrub_pause_wait); 327 328 atomic_inc(&sctx->workers_pending); 329} 330 331/* used for workers that require transaction commits */ 332static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx) 333{ 334 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 335 336 /* 337 * see scrub_pending_trans_workers_inc() why we're pretending 338 * to be paused in the scrub counters 339 */ 340 mutex_lock(&fs_info->scrub_lock); 341 atomic_dec(&fs_info->scrubs_running); 342 atomic_dec(&fs_info->scrubs_paused); 343 mutex_unlock(&fs_info->scrub_lock); 344 atomic_dec(&sctx->workers_pending); 345 wake_up(&fs_info->scrub_pause_wait); 346 wake_up(&sctx->list_wait); 347} 348 349static void scrub_free_csums(struct scrub_ctx *sctx) 350{ 351 while (!list_empty(&sctx->csum_list)) { 352 struct btrfs_ordered_sum *sum; 353 sum = list_first_entry(&sctx->csum_list, 354 struct btrfs_ordered_sum, list); 355 list_del(&sum->list); 356 kfree(sum); 357 } 358} 359 360static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) 361{ 362 int i; 363 364 if (!sctx) 365 return; 366 367 scrub_free_wr_ctx(&sctx->wr_ctx); 368 369 /* this can happen when scrub is cancelled */ 370 if (sctx->curr != -1) { 371 struct scrub_bio *sbio = sctx->bios[sctx->curr]; 372 373 for (i = 0; i < sbio->page_count; i++) { 374 WARN_ON(!sbio->pagev[i]->page); 375 scrub_block_put(sbio->pagev[i]->sblock); 376 } 377 bio_put(sbio->bio); 378 } 379 380 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { 381 struct scrub_bio *sbio = sctx->bios[i]; 382 383 if (!sbio) 384 break; 385 kfree(sbio); 386 } 387 388 scrub_free_csums(sctx); 389 kfree(sctx); 390} 391 392static noinline_for_stack 393struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace) 394{ 395 struct scrub_ctx *sctx; 396 int i; 397 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info; 398 int pages_per_rd_bio; 399 int ret; 400 401 /* 402 * the setting of pages_per_rd_bio is correct for scrub but might 403 * be wrong for the dev_replace code where we might read from 404 * different devices in the initial huge bios. However, that 405 * code is able to correctly handle the case when adding a page 406 * to a bio fails. 407 */ 408 if (dev->bdev) 409 pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO, 410 bio_get_nr_vecs(dev->bdev)); 411 else 412 pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO; 413 sctx = kzalloc(sizeof(*sctx), GFP_NOFS); 414 if (!sctx) 415 goto nomem; 416 sctx->is_dev_replace = is_dev_replace; 417 sctx->pages_per_rd_bio = pages_per_rd_bio; 418 sctx->curr = -1; 419 sctx->dev_root = dev->dev_root; 420 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { 421 struct scrub_bio *sbio; 422 423 sbio = kzalloc(sizeof(*sbio), GFP_NOFS); 424 if (!sbio) 425 goto nomem; 426 sctx->bios[i] = sbio; 427 428 sbio->index = i; 429 sbio->sctx = sctx; 430 sbio->page_count = 0; 431 btrfs_init_work(&sbio->work, scrub_bio_end_io_worker, 432 NULL, NULL); 433 434 if (i != SCRUB_BIOS_PER_SCTX - 1) 435 sctx->bios[i]->next_free = i + 1; 436 else 437 sctx->bios[i]->next_free = -1; 438 } 439 sctx->first_free = 0; 440 sctx->nodesize = dev->dev_root->nodesize; 441 sctx->leafsize = dev->dev_root->leafsize; 442 sctx->sectorsize = dev->dev_root->sectorsize; 443 atomic_set(&sctx->bios_in_flight, 0); 444 atomic_set(&sctx->workers_pending, 0); 445 atomic_set(&sctx->cancel_req, 0); 446 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy); 447 INIT_LIST_HEAD(&sctx->csum_list); 448 449 spin_lock_init(&sctx->list_lock); 450 spin_lock_init(&sctx->stat_lock); 451 init_waitqueue_head(&sctx->list_wait); 452 453 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info, 454 fs_info->dev_replace.tgtdev, is_dev_replace); 455 if (ret) { 456 scrub_free_ctx(sctx); 457 return ERR_PTR(ret); 458 } 459 return sctx; 460 461nomem: 462 scrub_free_ctx(sctx); 463 return ERR_PTR(-ENOMEM); 464} 465 466static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, 467 void *warn_ctx) 468{ 469 u64 isize; 470 u32 nlink; 471 int ret; 472 int i; 473 struct extent_buffer *eb; 474 struct btrfs_inode_item *inode_item; 475 struct scrub_warning *swarn = warn_ctx; 476 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info; 477 struct inode_fs_paths *ipath = NULL; 478 struct btrfs_root *local_root; 479 struct btrfs_key root_key; 480 481 root_key.objectid = root; 482 root_key.type = BTRFS_ROOT_ITEM_KEY; 483 root_key.offset = (u64)-1; 484 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key); 485 if (IS_ERR(local_root)) { 486 ret = PTR_ERR(local_root); 487 goto err; 488 } 489 490 ret = inode_item_info(inum, 0, local_root, swarn->path); 491 if (ret) { 492 btrfs_release_path(swarn->path); 493 goto err; 494 } 495 496 eb = swarn->path->nodes[0]; 497 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0], 498 struct btrfs_inode_item); 499 isize = btrfs_inode_size(eb, inode_item); 500 nlink = btrfs_inode_nlink(eb, inode_item); 501 btrfs_release_path(swarn->path); 502 503 ipath = init_ipath(4096, local_root, swarn->path); 504 if (IS_ERR(ipath)) { 505 ret = PTR_ERR(ipath); 506 ipath = NULL; 507 goto err; 508 } 509 ret = paths_from_inode(inum, ipath); 510 511 if (ret < 0) 512 goto err; 513 514 /* 515 * we deliberately ignore the bit ipath might have been too small to 516 * hold all of the paths here 517 */ 518 for (i = 0; i < ipath->fspath->elem_cnt; ++i) 519 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev " 520 "%s, sector %llu, root %llu, inode %llu, offset %llu, " 521 "length %llu, links %u (path: %s)\n", swarn->errstr, 522 swarn->logical, rcu_str_deref(swarn->dev->name), 523 (unsigned long long)swarn->sector, root, inum, offset, 524 min(isize - offset, (u64)PAGE_SIZE), nlink, 525 (char *)(unsigned long)ipath->fspath->val[i]); 526 527 free_ipath(ipath); 528 return 0; 529 530err: 531 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev " 532 "%s, sector %llu, root %llu, inode %llu, offset %llu: path " 533 "resolving failed with ret=%d\n", swarn->errstr, 534 swarn->logical, rcu_str_deref(swarn->dev->name), 535 (unsigned long long)swarn->sector, root, inum, offset, ret); 536 537 free_ipath(ipath); 538 return 0; 539} 540 541static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) 542{ 543 struct btrfs_device *dev; 544 struct btrfs_fs_info *fs_info; 545 struct btrfs_path *path; 546 struct btrfs_key found_key; 547 struct extent_buffer *eb; 548 struct btrfs_extent_item *ei; 549 struct scrub_warning swarn; 550 unsigned long ptr = 0; 551 u64 extent_item_pos; 552 u64 flags = 0; 553 u64 ref_root; 554 u32 item_size; 555 u8 ref_level; 556 const int bufsize = 4096; 557 int ret; 558 559 WARN_ON(sblock->page_count < 1); 560 dev = sblock->pagev[0]->dev; 561 fs_info = sblock->sctx->dev_root->fs_info; 562 563 path = btrfs_alloc_path(); 564 565 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS); 566 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS); 567 swarn.sector = (sblock->pagev[0]->physical) >> 9; 568 swarn.logical = sblock->pagev[0]->logical; 569 swarn.errstr = errstr; 570 swarn.dev = NULL; 571 swarn.msg_bufsize = bufsize; 572 swarn.scratch_bufsize = bufsize; 573 574 if (!path || !swarn.scratch_buf || !swarn.msg_buf) 575 goto out; 576 577 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, 578 &flags); 579 if (ret < 0) 580 goto out; 581 582 extent_item_pos = swarn.logical - found_key.objectid; 583 swarn.extent_item_size = found_key.offset; 584 585 eb = path->nodes[0]; 586 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); 587 item_size = btrfs_item_size_nr(eb, path->slots[0]); 588 589 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 590 do { 591 ret = tree_backref_for_extent(&ptr, eb, ei, item_size, 592 &ref_root, &ref_level); 593 printk_in_rcu(KERN_WARNING 594 "BTRFS: %s at logical %llu on dev %s, " 595 "sector %llu: metadata %s (level %d) in tree " 596 "%llu\n", errstr, swarn.logical, 597 rcu_str_deref(dev->name), 598 (unsigned long long)swarn.sector, 599 ref_level ? "node" : "leaf", 600 ret < 0 ? -1 : ref_level, 601 ret < 0 ? -1 : ref_root); 602 } while (ret != 1); 603 btrfs_release_path(path); 604 } else { 605 btrfs_release_path(path); 606 swarn.path = path; 607 swarn.dev = dev; 608 iterate_extent_inodes(fs_info, found_key.objectid, 609 extent_item_pos, 1, 610 scrub_print_warning_inode, &swarn); 611 } 612 613out: 614 btrfs_free_path(path); 615 kfree(swarn.scratch_buf); 616 kfree(swarn.msg_buf); 617} 618 619static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx) 620{ 621 struct page *page = NULL; 622 unsigned long index; 623 struct scrub_fixup_nodatasum *fixup = fixup_ctx; 624 int ret; 625 int corrected = 0; 626 struct btrfs_key key; 627 struct inode *inode = NULL; 628 struct btrfs_fs_info *fs_info; 629 u64 end = offset + PAGE_SIZE - 1; 630 struct btrfs_root *local_root; 631 int srcu_index; 632 633 key.objectid = root; 634 key.type = BTRFS_ROOT_ITEM_KEY; 635 key.offset = (u64)-1; 636 637 fs_info = fixup->root->fs_info; 638 srcu_index = srcu_read_lock(&fs_info->subvol_srcu); 639 640 local_root = btrfs_read_fs_root_no_name(fs_info, &key); 641 if (IS_ERR(local_root)) { 642 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 643 return PTR_ERR(local_root); 644 } 645 646 key.type = BTRFS_INODE_ITEM_KEY; 647 key.objectid = inum; 648 key.offset = 0; 649 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL); 650 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 651 if (IS_ERR(inode)) 652 return PTR_ERR(inode); 653 654 index = offset >> PAGE_CACHE_SHIFT; 655 656 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 657 if (!page) { 658 ret = -ENOMEM; 659 goto out; 660 } 661 662 if (PageUptodate(page)) { 663 if (PageDirty(page)) { 664 /* 665 * we need to write the data to the defect sector. the 666 * data that was in that sector is not in memory, 667 * because the page was modified. we must not write the 668 * modified page to that sector. 669 * 670 * TODO: what could be done here: wait for the delalloc 671 * runner to write out that page (might involve 672 * COW) and see whether the sector is still 673 * referenced afterwards. 674 * 675 * For the meantime, we'll treat this error 676 * incorrectable, although there is a chance that a 677 * later scrub will find the bad sector again and that 678 * there's no dirty page in memory, then. 679 */ 680 ret = -EIO; 681 goto out; 682 } 683 fs_info = BTRFS_I(inode)->root->fs_info; 684 ret = repair_io_failure(fs_info, offset, PAGE_SIZE, 685 fixup->logical, page, 686 fixup->mirror_num); 687 unlock_page(page); 688 corrected = !ret; 689 } else { 690 /* 691 * we need to get good data first. the general readpage path 692 * will call repair_io_failure for us, we just have to make 693 * sure we read the bad mirror. 694 */ 695 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 696 EXTENT_DAMAGED, GFP_NOFS); 697 if (ret) { 698 /* set_extent_bits should give proper error */ 699 WARN_ON(ret > 0); 700 if (ret > 0) 701 ret = -EFAULT; 702 goto out; 703 } 704 705 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page, 706 btrfs_get_extent, 707 fixup->mirror_num); 708 wait_on_page_locked(page); 709 710 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset, 711 end, EXTENT_DAMAGED, 0, NULL); 712 if (!corrected) 713 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 714 EXTENT_DAMAGED, GFP_NOFS); 715 } 716 717out: 718 if (page) 719 put_page(page); 720 if (inode) 721 iput(inode); 722 723 if (ret < 0) 724 return ret; 725 726 if (ret == 0 && corrected) { 727 /* 728 * we only need to call readpage for one of the inodes belonging 729 * to this extent. so make iterate_extent_inodes stop 730 */ 731 return 1; 732 } 733 734 return -EIO; 735} 736 737static void scrub_fixup_nodatasum(struct btrfs_work *work) 738{ 739 int ret; 740 struct scrub_fixup_nodatasum *fixup; 741 struct scrub_ctx *sctx; 742 struct btrfs_trans_handle *trans = NULL; 743 struct btrfs_path *path; 744 int uncorrectable = 0; 745 746 fixup = container_of(work, struct scrub_fixup_nodatasum, work); 747 sctx = fixup->sctx; 748 749 path = btrfs_alloc_path(); 750 if (!path) { 751 spin_lock(&sctx->stat_lock); 752 ++sctx->stat.malloc_errors; 753 spin_unlock(&sctx->stat_lock); 754 uncorrectable = 1; 755 goto out; 756 } 757 758 trans = btrfs_join_transaction(fixup->root); 759 if (IS_ERR(trans)) { 760 uncorrectable = 1; 761 goto out; 762 } 763 764 /* 765 * the idea is to trigger a regular read through the standard path. we 766 * read a page from the (failed) logical address by specifying the 767 * corresponding copynum of the failed sector. thus, that readpage is 768 * expected to fail. 769 * that is the point where on-the-fly error correction will kick in 770 * (once it's finished) and rewrite the failed sector if a good copy 771 * can be found. 772 */ 773 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info, 774 path, scrub_fixup_readpage, 775 fixup); 776 if (ret < 0) { 777 uncorrectable = 1; 778 goto out; 779 } 780 WARN_ON(ret != 1); 781 782 spin_lock(&sctx->stat_lock); 783 ++sctx->stat.corrected_errors; 784 spin_unlock(&sctx->stat_lock); 785 786out: 787 if (trans && !IS_ERR(trans)) 788 btrfs_end_transaction(trans, fixup->root); 789 if (uncorrectable) { 790 spin_lock(&sctx->stat_lock); 791 ++sctx->stat.uncorrectable_errors; 792 spin_unlock(&sctx->stat_lock); 793 btrfs_dev_replace_stats_inc( 794 &sctx->dev_root->fs_info->dev_replace. 795 num_uncorrectable_read_errors); 796 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: " 797 "unable to fixup (nodatasum) error at logical %llu on dev %s\n", 798 fixup->logical, rcu_str_deref(fixup->dev->name)); 799 } 800 801 btrfs_free_path(path); 802 kfree(fixup); 803 804 scrub_pending_trans_workers_dec(sctx); 805} 806 807/* 808 * scrub_handle_errored_block gets called when either verification of the 809 * pages failed or the bio failed to read, e.g. with EIO. In the latter 810 * case, this function handles all pages in the bio, even though only one 811 * may be bad. 812 * The goal of this function is to repair the errored block by using the 813 * contents of one of the mirrors. 814 */ 815static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) 816{ 817 struct scrub_ctx *sctx = sblock_to_check->sctx; 818 struct btrfs_device *dev; 819 struct btrfs_fs_info *fs_info; 820 u64 length; 821 u64 logical; 822 u64 generation; 823 unsigned int failed_mirror_index; 824 unsigned int is_metadata; 825 unsigned int have_csum; 826 u8 *csum; 827 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */ 828 struct scrub_block *sblock_bad; 829 int ret; 830 int mirror_index; 831 int page_num; 832 int success; 833 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 834 DEFAULT_RATELIMIT_BURST); 835 836 BUG_ON(sblock_to_check->page_count < 1); 837 fs_info = sctx->dev_root->fs_info; 838 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) { 839 /* 840 * if we find an error in a super block, we just report it. 841 * They will get written with the next transaction commit 842 * anyway 843 */ 844 spin_lock(&sctx->stat_lock); 845 ++sctx->stat.super_errors; 846 spin_unlock(&sctx->stat_lock); 847 return 0; 848 } 849 length = sblock_to_check->page_count * PAGE_SIZE; 850 logical = sblock_to_check->pagev[0]->logical; 851 generation = sblock_to_check->pagev[0]->generation; 852 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1); 853 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1; 854 is_metadata = !(sblock_to_check->pagev[0]->flags & 855 BTRFS_EXTENT_FLAG_DATA); 856 have_csum = sblock_to_check->pagev[0]->have_csum; 857 csum = sblock_to_check->pagev[0]->csum; 858 dev = sblock_to_check->pagev[0]->dev; 859 860 if (sctx->is_dev_replace && !is_metadata && !have_csum) { 861 sblocks_for_recheck = NULL; 862 goto nodatasum_case; 863 } 864 865 /* 866 * read all mirrors one after the other. This includes to 867 * re-read the extent or metadata block that failed (that was 868 * the cause that this fixup code is called) another time, 869 * page by page this time in order to know which pages 870 * caused I/O errors and which ones are good (for all mirrors). 871 * It is the goal to handle the situation when more than one 872 * mirror contains I/O errors, but the errors do not 873 * overlap, i.e. the data can be repaired by selecting the 874 * pages from those mirrors without I/O error on the 875 * particular pages. One example (with blocks >= 2 * PAGE_SIZE) 876 * would be that mirror #1 has an I/O error on the first page, 877 * the second page is good, and mirror #2 has an I/O error on 878 * the second page, but the first page is good. 879 * Then the first page of the first mirror can be repaired by 880 * taking the first page of the second mirror, and the 881 * second page of the second mirror can be repaired by 882 * copying the contents of the 2nd page of the 1st mirror. 883 * One more note: if the pages of one mirror contain I/O 884 * errors, the checksum cannot be verified. In order to get 885 * the best data for repairing, the first attempt is to find 886 * a mirror without I/O errors and with a validated checksum. 887 * Only if this is not possible, the pages are picked from 888 * mirrors with I/O errors without considering the checksum. 889 * If the latter is the case, at the end, the checksum of the 890 * repaired area is verified in order to correctly maintain 891 * the statistics. 892 */ 893 894 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS * 895 sizeof(*sblocks_for_recheck), 896 GFP_NOFS); 897 if (!sblocks_for_recheck) { 898 spin_lock(&sctx->stat_lock); 899 sctx->stat.malloc_errors++; 900 sctx->stat.read_errors++; 901 sctx->stat.uncorrectable_errors++; 902 spin_unlock(&sctx->stat_lock); 903 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 904 goto out; 905 } 906 907 /* setup the context, map the logical blocks and alloc the pages */ 908 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length, 909 logical, sblocks_for_recheck); 910 if (ret) { 911 spin_lock(&sctx->stat_lock); 912 sctx->stat.read_errors++; 913 sctx->stat.uncorrectable_errors++; 914 spin_unlock(&sctx->stat_lock); 915 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 916 goto out; 917 } 918 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS); 919 sblock_bad = sblocks_for_recheck + failed_mirror_index; 920 921 /* build and submit the bios for the failed mirror, check checksums */ 922 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum, 923 csum, generation, sctx->csum_size); 924 925 if (!sblock_bad->header_error && !sblock_bad->checksum_error && 926 sblock_bad->no_io_error_seen) { 927 /* 928 * the error disappeared after reading page by page, or 929 * the area was part of a huge bio and other parts of the 930 * bio caused I/O errors, or the block layer merged several 931 * read requests into one and the error is caused by a 932 * different bio (usually one of the two latter cases is 933 * the cause) 934 */ 935 spin_lock(&sctx->stat_lock); 936 sctx->stat.unverified_errors++; 937 spin_unlock(&sctx->stat_lock); 938 939 if (sctx->is_dev_replace) 940 scrub_write_block_to_dev_replace(sblock_bad); 941 goto out; 942 } 943 944 if (!sblock_bad->no_io_error_seen) { 945 spin_lock(&sctx->stat_lock); 946 sctx->stat.read_errors++; 947 spin_unlock(&sctx->stat_lock); 948 if (__ratelimit(&_rs)) 949 scrub_print_warning("i/o error", sblock_to_check); 950 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 951 } else if (sblock_bad->checksum_error) { 952 spin_lock(&sctx->stat_lock); 953 sctx->stat.csum_errors++; 954 spin_unlock(&sctx->stat_lock); 955 if (__ratelimit(&_rs)) 956 scrub_print_warning("checksum error", sblock_to_check); 957 btrfs_dev_stat_inc_and_print(dev, 958 BTRFS_DEV_STAT_CORRUPTION_ERRS); 959 } else if (sblock_bad->header_error) { 960 spin_lock(&sctx->stat_lock); 961 sctx->stat.verify_errors++; 962 spin_unlock(&sctx->stat_lock); 963 if (__ratelimit(&_rs)) 964 scrub_print_warning("checksum/header error", 965 sblock_to_check); 966 if (sblock_bad->generation_error) 967 btrfs_dev_stat_inc_and_print(dev, 968 BTRFS_DEV_STAT_GENERATION_ERRS); 969 else 970 btrfs_dev_stat_inc_and_print(dev, 971 BTRFS_DEV_STAT_CORRUPTION_ERRS); 972 } 973 974 if (sctx->readonly) { 975 ASSERT(!sctx->is_dev_replace); 976 goto out; 977 } 978 979 if (!is_metadata && !have_csum) { 980 struct scrub_fixup_nodatasum *fixup_nodatasum; 981 982nodatasum_case: 983 WARN_ON(sctx->is_dev_replace); 984 985 /* 986 * !is_metadata and !have_csum, this means that the data 987 * might not be COW'ed, that it might be modified 988 * concurrently. The general strategy to work on the 989 * commit root does not help in the case when COW is not 990 * used. 991 */ 992 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS); 993 if (!fixup_nodatasum) 994 goto did_not_correct_error; 995 fixup_nodatasum->sctx = sctx; 996 fixup_nodatasum->dev = dev; 997 fixup_nodatasum->logical = logical; 998 fixup_nodatasum->root = fs_info->extent_root; 999 fixup_nodatasum->mirror_num = failed_mirror_index + 1; 1000 scrub_pending_trans_workers_inc(sctx); 1001 btrfs_init_work(&fixup_nodatasum->work, scrub_fixup_nodatasum, 1002 NULL, NULL); 1003 btrfs_queue_work(fs_info->scrub_workers, 1004 &fixup_nodatasum->work); 1005 goto out; 1006 } 1007 1008 /* 1009 * now build and submit the bios for the other mirrors, check 1010 * checksums. 1011 * First try to pick the mirror which is completely without I/O 1012 * errors and also does not have a checksum error. 1013 * If one is found, and if a checksum is present, the full block 1014 * that is known to contain an error is rewritten. Afterwards 1015 * the block is known to be corrected. 1016 * If a mirror is found which is completely correct, and no 1017 * checksum is present, only those pages are rewritten that had 1018 * an I/O error in the block to be repaired, since it cannot be 1019 * determined, which copy of the other pages is better (and it 1020 * could happen otherwise that a correct page would be 1021 * overwritten by a bad one). 1022 */ 1023 for (mirror_index = 0; 1024 mirror_index < BTRFS_MAX_MIRRORS && 1025 sblocks_for_recheck[mirror_index].page_count > 0; 1026 mirror_index++) { 1027 struct scrub_block *sblock_other; 1028 1029 if (mirror_index == failed_mirror_index) 1030 continue; 1031 sblock_other = sblocks_for_recheck + mirror_index; 1032 1033 /* build and submit the bios, check checksums */ 1034 scrub_recheck_block(fs_info, sblock_other, is_metadata, 1035 have_csum, csum, generation, 1036 sctx->csum_size); 1037 1038 if (!sblock_other->header_error && 1039 !sblock_other->checksum_error && 1040 sblock_other->no_io_error_seen) { 1041 if (sctx->is_dev_replace) { 1042 scrub_write_block_to_dev_replace(sblock_other); 1043 } else { 1044 int force_write = is_metadata || have_csum; 1045 1046 ret = scrub_repair_block_from_good_copy( 1047 sblock_bad, sblock_other, 1048 force_write); 1049 } 1050 if (0 == ret) 1051 goto corrected_error; 1052 } 1053 } 1054 1055 /* 1056 * for dev_replace, pick good pages and write to the target device. 1057 */ 1058 if (sctx->is_dev_replace) { 1059 success = 1; 1060 for (page_num = 0; page_num < sblock_bad->page_count; 1061 page_num++) { 1062 int sub_success; 1063 1064 sub_success = 0; 1065 for (mirror_index = 0; 1066 mirror_index < BTRFS_MAX_MIRRORS && 1067 sblocks_for_recheck[mirror_index].page_count > 0; 1068 mirror_index++) { 1069 struct scrub_block *sblock_other = 1070 sblocks_for_recheck + mirror_index; 1071 struct scrub_page *page_other = 1072 sblock_other->pagev[page_num]; 1073 1074 if (!page_other->io_error) { 1075 ret = scrub_write_page_to_dev_replace( 1076 sblock_other, page_num); 1077 if (ret == 0) { 1078 /* succeeded for this page */ 1079 sub_success = 1; 1080 break; 1081 } else { 1082 btrfs_dev_replace_stats_inc( 1083 &sctx->dev_root-> 1084 fs_info->dev_replace. 1085 num_write_errors); 1086 } 1087 } 1088 } 1089 1090 if (!sub_success) { 1091 /* 1092 * did not find a mirror to fetch the page 1093 * from. scrub_write_page_to_dev_replace() 1094 * handles this case (page->io_error), by 1095 * filling the block with zeros before 1096 * submitting the write request 1097 */ 1098 success = 0; 1099 ret = scrub_write_page_to_dev_replace( 1100 sblock_bad, page_num); 1101 if (ret) 1102 btrfs_dev_replace_stats_inc( 1103 &sctx->dev_root->fs_info-> 1104 dev_replace.num_write_errors); 1105 } 1106 } 1107 1108 goto out; 1109 } 1110 1111 /* 1112 * for regular scrub, repair those pages that are errored. 1113 * In case of I/O errors in the area that is supposed to be 1114 * repaired, continue by picking good copies of those pages. 1115 * Select the good pages from mirrors to rewrite bad pages from 1116 * the area to fix. Afterwards verify the checksum of the block 1117 * that is supposed to be repaired. This verification step is 1118 * only done for the purpose of statistic counting and for the 1119 * final scrub report, whether errors remain. 1120 * A perfect algorithm could make use of the checksum and try 1121 * all possible combinations of pages from the different mirrors 1122 * until the checksum verification succeeds. For example, when 1123 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page 1124 * of mirror #2 is readable but the final checksum test fails, 1125 * then the 2nd page of mirror #3 could be tried, whether now 1126 * the final checksum succeedes. But this would be a rare 1127 * exception and is therefore not implemented. At least it is 1128 * avoided that the good copy is overwritten. 1129 * A more useful improvement would be to pick the sectors 1130 * without I/O error based on sector sizes (512 bytes on legacy 1131 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one 1132 * mirror could be repaired by taking 512 byte of a different 1133 * mirror, even if other 512 byte sectors in the same PAGE_SIZE 1134 * area are unreadable. 1135 */ 1136 1137 /* can only fix I/O errors from here on */ 1138 if (sblock_bad->no_io_error_seen) 1139 goto did_not_correct_error; 1140 1141 success = 1; 1142 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { 1143 struct scrub_page *page_bad = sblock_bad->pagev[page_num]; 1144 1145 if (!page_bad->io_error) 1146 continue; 1147 1148 for (mirror_index = 0; 1149 mirror_index < BTRFS_MAX_MIRRORS && 1150 sblocks_for_recheck[mirror_index].page_count > 0; 1151 mirror_index++) { 1152 struct scrub_block *sblock_other = sblocks_for_recheck + 1153 mirror_index; 1154 struct scrub_page *page_other = sblock_other->pagev[ 1155 page_num]; 1156 1157 if (!page_other->io_error) { 1158 ret = scrub_repair_page_from_good_copy( 1159 sblock_bad, sblock_other, page_num, 0); 1160 if (0 == ret) { 1161 page_bad->io_error = 0; 1162 break; /* succeeded for this page */ 1163 } 1164 } 1165 } 1166 1167 if (page_bad->io_error) { 1168 /* did not find a mirror to copy the page from */ 1169 success = 0; 1170 } 1171 } 1172 1173 if (success) { 1174 if (is_metadata || have_csum) { 1175 /* 1176 * need to verify the checksum now that all 1177 * sectors on disk are repaired (the write 1178 * request for data to be repaired is on its way). 1179 * Just be lazy and use scrub_recheck_block() 1180 * which re-reads the data before the checksum 1181 * is verified, but most likely the data comes out 1182 * of the page cache. 1183 */ 1184 scrub_recheck_block(fs_info, sblock_bad, 1185 is_metadata, have_csum, csum, 1186 generation, sctx->csum_size); 1187 if (!sblock_bad->header_error && 1188 !sblock_bad->checksum_error && 1189 sblock_bad->no_io_error_seen) 1190 goto corrected_error; 1191 else 1192 goto did_not_correct_error; 1193 } else { 1194corrected_error: 1195 spin_lock(&sctx->stat_lock); 1196 sctx->stat.corrected_errors++; 1197 spin_unlock(&sctx->stat_lock); 1198 printk_ratelimited_in_rcu(KERN_ERR 1199 "BTRFS: fixed up error at logical %llu on dev %s\n", 1200 logical, rcu_str_deref(dev->name)); 1201 } 1202 } else { 1203did_not_correct_error: 1204 spin_lock(&sctx->stat_lock); 1205 sctx->stat.uncorrectable_errors++; 1206 spin_unlock(&sctx->stat_lock); 1207 printk_ratelimited_in_rcu(KERN_ERR 1208 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n", 1209 logical, rcu_str_deref(dev->name)); 1210 } 1211 1212out: 1213 if (sblocks_for_recheck) { 1214 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS; 1215 mirror_index++) { 1216 struct scrub_block *sblock = sblocks_for_recheck + 1217 mirror_index; 1218 int page_index; 1219 1220 for (page_index = 0; page_index < sblock->page_count; 1221 page_index++) { 1222 sblock->pagev[page_index]->sblock = NULL; 1223 scrub_page_put(sblock->pagev[page_index]); 1224 } 1225 } 1226 kfree(sblocks_for_recheck); 1227 } 1228 1229 return 0; 1230} 1231 1232static int scrub_setup_recheck_block(struct scrub_ctx *sctx, 1233 struct btrfs_fs_info *fs_info, 1234 struct scrub_block *original_sblock, 1235 u64 length, u64 logical, 1236 struct scrub_block *sblocks_for_recheck) 1237{ 1238 int page_index; 1239 int mirror_index; 1240 int ret; 1241 1242 /* 1243 * note: the two members ref_count and outstanding_pages 1244 * are not used (and not set) in the blocks that are used for 1245 * the recheck procedure 1246 */ 1247 1248 page_index = 0; 1249 while (length > 0) { 1250 u64 sublen = min_t(u64, length, PAGE_SIZE); 1251 u64 mapped_length = sublen; 1252 struct btrfs_bio *bbio = NULL; 1253 1254 /* 1255 * with a length of PAGE_SIZE, each returned stripe 1256 * represents one mirror 1257 */ 1258 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical, 1259 &mapped_length, &bbio, 0); 1260 if (ret || !bbio || mapped_length < sublen) { 1261 kfree(bbio); 1262 return -EIO; 1263 } 1264 1265 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO); 1266 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes; 1267 mirror_index++) { 1268 struct scrub_block *sblock; 1269 struct scrub_page *page; 1270 1271 if (mirror_index >= BTRFS_MAX_MIRRORS) 1272 continue; 1273 1274 sblock = sblocks_for_recheck + mirror_index; 1275 sblock->sctx = sctx; 1276 page = kzalloc(sizeof(*page), GFP_NOFS); 1277 if (!page) { 1278leave_nomem: 1279 spin_lock(&sctx->stat_lock); 1280 sctx->stat.malloc_errors++; 1281 spin_unlock(&sctx->stat_lock); 1282 kfree(bbio); 1283 return -ENOMEM; 1284 } 1285 scrub_page_get(page); 1286 sblock->pagev[page_index] = page; 1287 page->logical = logical; 1288 page->physical = bbio->stripes[mirror_index].physical; 1289 BUG_ON(page_index >= original_sblock->page_count); 1290 page->physical_for_dev_replace = 1291 original_sblock->pagev[page_index]-> 1292 physical_for_dev_replace; 1293 /* for missing devices, dev->bdev is NULL */ 1294 page->dev = bbio->stripes[mirror_index].dev; 1295 page->mirror_num = mirror_index + 1; 1296 sblock->page_count++; 1297 page->page = alloc_page(GFP_NOFS); 1298 if (!page->page) 1299 goto leave_nomem; 1300 } 1301 kfree(bbio); 1302 length -= sublen; 1303 logical += sublen; 1304 page_index++; 1305 } 1306 1307 return 0; 1308} 1309 1310/* 1311 * this function will check the on disk data for checksum errors, header 1312 * errors and read I/O errors. If any I/O errors happen, the exact pages 1313 * which are errored are marked as being bad. The goal is to enable scrub 1314 * to take those pages that are not errored from all the mirrors so that 1315 * the pages that are errored in the just handled mirror can be repaired. 1316 */ 1317static void scrub_recheck_block(struct btrfs_fs_info *fs_info, 1318 struct scrub_block *sblock, int is_metadata, 1319 int have_csum, u8 *csum, u64 generation, 1320 u16 csum_size) 1321{ 1322 int page_num; 1323 1324 sblock->no_io_error_seen = 1; 1325 sblock->header_error = 0; 1326 sblock->checksum_error = 0; 1327 1328 for (page_num = 0; page_num < sblock->page_count; page_num++) { 1329 struct bio *bio; 1330 struct scrub_page *page = sblock->pagev[page_num]; 1331 1332 if (page->dev->bdev == NULL) { 1333 page->io_error = 1; 1334 sblock->no_io_error_seen = 0; 1335 continue; 1336 } 1337 1338 WARN_ON(!page->page); 1339 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 1340 if (!bio) { 1341 page->io_error = 1; 1342 sblock->no_io_error_seen = 0; 1343 continue; 1344 } 1345 bio->bi_bdev = page->dev->bdev; 1346 bio->bi_sector = page->physical >> 9; 1347 1348 bio_add_page(bio, page->page, PAGE_SIZE, 0); 1349 if (btrfsic_submit_bio_wait(READ, bio)) 1350 sblock->no_io_error_seen = 0; 1351 1352 bio_put(bio); 1353 } 1354 1355 if (sblock->no_io_error_seen) 1356 scrub_recheck_block_checksum(fs_info, sblock, is_metadata, 1357 have_csum, csum, generation, 1358 csum_size); 1359 1360 return; 1361} 1362 1363static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, 1364 struct scrub_block *sblock, 1365 int is_metadata, int have_csum, 1366 const u8 *csum, u64 generation, 1367 u16 csum_size) 1368{ 1369 int page_num; 1370 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1371 u32 crc = ~(u32)0; 1372 void *mapped_buffer; 1373 1374 WARN_ON(!sblock->pagev[0]->page); 1375 if (is_metadata) { 1376 struct btrfs_header *h; 1377 1378 mapped_buffer = kmap_atomic(sblock->pagev[0]->page); 1379 h = (struct btrfs_header *)mapped_buffer; 1380 1381 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) || 1382 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) || 1383 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, 1384 BTRFS_UUID_SIZE)) { 1385 sblock->header_error = 1; 1386 } else if (generation != btrfs_stack_header_generation(h)) { 1387 sblock->header_error = 1; 1388 sblock->generation_error = 1; 1389 } 1390 csum = h->csum; 1391 } else { 1392 if (!have_csum) 1393 return; 1394 1395 mapped_buffer = kmap_atomic(sblock->pagev[0]->page); 1396 } 1397 1398 for (page_num = 0;;) { 1399 if (page_num == 0 && is_metadata) 1400 crc = btrfs_csum_data( 1401 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE, 1402 crc, PAGE_SIZE - BTRFS_CSUM_SIZE); 1403 else 1404 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE); 1405 1406 kunmap_atomic(mapped_buffer); 1407 page_num++; 1408 if (page_num >= sblock->page_count) 1409 break; 1410 WARN_ON(!sblock->pagev[page_num]->page); 1411 1412 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page); 1413 } 1414 1415 btrfs_csum_final(crc, calculated_csum); 1416 if (memcmp(calculated_csum, csum, csum_size)) 1417 sblock->checksum_error = 1; 1418} 1419 1420static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, 1421 struct scrub_block *sblock_good, 1422 int force_write) 1423{ 1424 int page_num; 1425 int ret = 0; 1426 1427 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { 1428 int ret_sub; 1429 1430 ret_sub = scrub_repair_page_from_good_copy(sblock_bad, 1431 sblock_good, 1432 page_num, 1433 force_write); 1434 if (ret_sub) 1435 ret = ret_sub; 1436 } 1437 1438 return ret; 1439} 1440 1441static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, 1442 struct scrub_block *sblock_good, 1443 int page_num, int force_write) 1444{ 1445 struct scrub_page *page_bad = sblock_bad->pagev[page_num]; 1446 struct scrub_page *page_good = sblock_good->pagev[page_num]; 1447 1448 BUG_ON(page_bad->page == NULL); 1449 BUG_ON(page_good->page == NULL); 1450 if (force_write || sblock_bad->header_error || 1451 sblock_bad->checksum_error || page_bad->io_error) { 1452 struct bio *bio; 1453 int ret; 1454 1455 if (!page_bad->dev->bdev) { 1456 printk_ratelimited(KERN_WARNING "BTRFS: " 1457 "scrub_repair_page_from_good_copy(bdev == NULL) " 1458 "is unexpected!\n"); 1459 return -EIO; 1460 } 1461 1462 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 1463 if (!bio) 1464 return -EIO; 1465 bio->bi_bdev = page_bad->dev->bdev; 1466 bio->bi_sector = page_bad->physical >> 9; 1467 1468 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0); 1469 if (PAGE_SIZE != ret) { 1470 bio_put(bio); 1471 return -EIO; 1472 } 1473 1474 if (btrfsic_submit_bio_wait(WRITE, bio)) { 1475 btrfs_dev_stat_inc_and_print(page_bad->dev, 1476 BTRFS_DEV_STAT_WRITE_ERRS); 1477 btrfs_dev_replace_stats_inc( 1478 &sblock_bad->sctx->dev_root->fs_info-> 1479 dev_replace.num_write_errors); 1480 bio_put(bio); 1481 return -EIO; 1482 } 1483 bio_put(bio); 1484 } 1485 1486 return 0; 1487} 1488 1489static void scrub_write_block_to_dev_replace(struct scrub_block *sblock) 1490{ 1491 int page_num; 1492 1493 for (page_num = 0; page_num < sblock->page_count; page_num++) { 1494 int ret; 1495 1496 ret = scrub_write_page_to_dev_replace(sblock, page_num); 1497 if (ret) 1498 btrfs_dev_replace_stats_inc( 1499 &sblock->sctx->dev_root->fs_info->dev_replace. 1500 num_write_errors); 1501 } 1502} 1503 1504static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, 1505 int page_num) 1506{ 1507 struct scrub_page *spage = sblock->pagev[page_num]; 1508 1509 BUG_ON(spage->page == NULL); 1510 if (spage->io_error) { 1511 void *mapped_buffer = kmap_atomic(spage->page); 1512 1513 memset(mapped_buffer, 0, PAGE_CACHE_SIZE); 1514 flush_dcache_page(spage->page); 1515 kunmap_atomic(mapped_buffer); 1516 } 1517 return scrub_add_page_to_wr_bio(sblock->sctx, spage); 1518} 1519 1520static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, 1521 struct scrub_page *spage) 1522{ 1523 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx; 1524 struct scrub_bio *sbio; 1525 int ret; 1526 1527 mutex_lock(&wr_ctx->wr_lock); 1528again: 1529 if (!wr_ctx->wr_curr_bio) { 1530 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio), 1531 GFP_NOFS); 1532 if (!wr_ctx->wr_curr_bio) { 1533 mutex_unlock(&wr_ctx->wr_lock); 1534 return -ENOMEM; 1535 } 1536 wr_ctx->wr_curr_bio->sctx = sctx; 1537 wr_ctx->wr_curr_bio->page_count = 0; 1538 } 1539 sbio = wr_ctx->wr_curr_bio; 1540 if (sbio->page_count == 0) { 1541 struct bio *bio; 1542 1543 sbio->physical = spage->physical_for_dev_replace; 1544 sbio->logical = spage->logical; 1545 sbio->dev = wr_ctx->tgtdev; 1546 bio = sbio->bio; 1547 if (!bio) { 1548 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio); 1549 if (!bio) { 1550 mutex_unlock(&wr_ctx->wr_lock); 1551 return -ENOMEM; 1552 } 1553 sbio->bio = bio; 1554 } 1555 1556 bio->bi_private = sbio; 1557 bio->bi_end_io = scrub_wr_bio_end_io; 1558 bio->bi_bdev = sbio->dev->bdev; 1559 bio->bi_sector = sbio->physical >> 9; 1560 sbio->err = 0; 1561 } else if (sbio->physical + sbio->page_count * PAGE_SIZE != 1562 spage->physical_for_dev_replace || 1563 sbio->logical + sbio->page_count * PAGE_SIZE != 1564 spage->logical) { 1565 scrub_wr_submit(sctx); 1566 goto again; 1567 } 1568 1569 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); 1570 if (ret != PAGE_SIZE) { 1571 if (sbio->page_count < 1) { 1572 bio_put(sbio->bio); 1573 sbio->bio = NULL; 1574 mutex_unlock(&wr_ctx->wr_lock); 1575 return -EIO; 1576 } 1577 scrub_wr_submit(sctx); 1578 goto again; 1579 } 1580 1581 sbio->pagev[sbio->page_count] = spage; 1582 scrub_page_get(spage); 1583 sbio->page_count++; 1584 if (sbio->page_count == wr_ctx->pages_per_wr_bio) 1585 scrub_wr_submit(sctx); 1586 mutex_unlock(&wr_ctx->wr_lock); 1587 1588 return 0; 1589} 1590 1591static void scrub_wr_submit(struct scrub_ctx *sctx) 1592{ 1593 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx; 1594 struct scrub_bio *sbio; 1595 1596 if (!wr_ctx->wr_curr_bio) 1597 return; 1598 1599 sbio = wr_ctx->wr_curr_bio; 1600 wr_ctx->wr_curr_bio = NULL; 1601 WARN_ON(!sbio->bio->bi_bdev); 1602 scrub_pending_bio_inc(sctx); 1603 /* process all writes in a single worker thread. Then the block layer 1604 * orders the requests before sending them to the driver which 1605 * doubled the write performance on spinning disks when measured 1606 * with Linux 3.5 */ 1607 btrfsic_submit_bio(WRITE, sbio->bio); 1608} 1609 1610static void scrub_wr_bio_end_io(struct bio *bio, int err) 1611{ 1612 struct scrub_bio *sbio = bio->bi_private; 1613 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info; 1614 1615 sbio->err = err; 1616 sbio->bio = bio; 1617 1618 btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL); 1619 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work); 1620} 1621 1622static void scrub_wr_bio_end_io_worker(struct btrfs_work *work) 1623{ 1624 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 1625 struct scrub_ctx *sctx = sbio->sctx; 1626 int i; 1627 1628 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO); 1629 if (sbio->err) { 1630 struct btrfs_dev_replace *dev_replace = 1631 &sbio->sctx->dev_root->fs_info->dev_replace; 1632 1633 for (i = 0; i < sbio->page_count; i++) { 1634 struct scrub_page *spage = sbio->pagev[i]; 1635 1636 spage->io_error = 1; 1637 btrfs_dev_replace_stats_inc(&dev_replace-> 1638 num_write_errors); 1639 } 1640 } 1641 1642 for (i = 0; i < sbio->page_count; i++) 1643 scrub_page_put(sbio->pagev[i]); 1644 1645 bio_put(sbio->bio); 1646 kfree(sbio); 1647 scrub_pending_bio_dec(sctx); 1648} 1649 1650static int scrub_checksum(struct scrub_block *sblock) 1651{ 1652 u64 flags; 1653 int ret; 1654 1655 WARN_ON(sblock->page_count < 1); 1656 flags = sblock->pagev[0]->flags; 1657 ret = 0; 1658 if (flags & BTRFS_EXTENT_FLAG_DATA) 1659 ret = scrub_checksum_data(sblock); 1660 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) 1661 ret = scrub_checksum_tree_block(sblock); 1662 else if (flags & BTRFS_EXTENT_FLAG_SUPER) 1663 (void)scrub_checksum_super(sblock); 1664 else 1665 WARN_ON(1); 1666 if (ret) 1667 scrub_handle_errored_block(sblock); 1668 1669 return ret; 1670} 1671 1672static int scrub_checksum_data(struct scrub_block *sblock) 1673{ 1674 struct scrub_ctx *sctx = sblock->sctx; 1675 u8 csum[BTRFS_CSUM_SIZE]; 1676 u8 *on_disk_csum; 1677 struct page *page; 1678 void *buffer; 1679 u32 crc = ~(u32)0; 1680 int fail = 0; 1681 u64 len; 1682 int index; 1683 1684 BUG_ON(sblock->page_count < 1); 1685 if (!sblock->pagev[0]->have_csum) 1686 return 0; 1687 1688 on_disk_csum = sblock->pagev[0]->csum; 1689 page = sblock->pagev[0]->page; 1690 buffer = kmap_atomic(page); 1691 1692 len = sctx->sectorsize; 1693 index = 0; 1694 for (;;) { 1695 u64 l = min_t(u64, len, PAGE_SIZE); 1696 1697 crc = btrfs_csum_data(buffer, crc, l); 1698 kunmap_atomic(buffer); 1699 len -= l; 1700 if (len == 0) 1701 break; 1702 index++; 1703 BUG_ON(index >= sblock->page_count); 1704 BUG_ON(!sblock->pagev[index]->page); 1705 page = sblock->pagev[index]->page; 1706 buffer = kmap_atomic(page); 1707 } 1708 1709 btrfs_csum_final(crc, csum); 1710 if (memcmp(csum, on_disk_csum, sctx->csum_size)) 1711 fail = 1; 1712 1713 return fail; 1714} 1715 1716static int scrub_checksum_tree_block(struct scrub_block *sblock) 1717{ 1718 struct scrub_ctx *sctx = sblock->sctx; 1719 struct btrfs_header *h; 1720 struct btrfs_root *root = sctx->dev_root; 1721 struct btrfs_fs_info *fs_info = root->fs_info; 1722 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1723 u8 on_disk_csum[BTRFS_CSUM_SIZE]; 1724 struct page *page; 1725 void *mapped_buffer; 1726 u64 mapped_size; 1727 void *p; 1728 u32 crc = ~(u32)0; 1729 int fail = 0; 1730 int crc_fail = 0; 1731 u64 len; 1732 int index; 1733 1734 BUG_ON(sblock->page_count < 1); 1735 page = sblock->pagev[0]->page; 1736 mapped_buffer = kmap_atomic(page); 1737 h = (struct btrfs_header *)mapped_buffer; 1738 memcpy(on_disk_csum, h->csum, sctx->csum_size); 1739 1740 /* 1741 * we don't use the getter functions here, as we 1742 * a) don't have an extent buffer and 1743 * b) the page is already kmapped 1744 */ 1745 1746 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h)) 1747 ++fail; 1748 1749 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) 1750 ++fail; 1751 1752 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) 1753 ++fail; 1754 1755 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, 1756 BTRFS_UUID_SIZE)) 1757 ++fail; 1758 1759 WARN_ON(sctx->nodesize != sctx->leafsize); 1760 len = sctx->nodesize - BTRFS_CSUM_SIZE; 1761 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; 1762 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; 1763 index = 0; 1764 for (;;) { 1765 u64 l = min_t(u64, len, mapped_size); 1766 1767 crc = btrfs_csum_data(p, crc, l); 1768 kunmap_atomic(mapped_buffer); 1769 len -= l; 1770 if (len == 0) 1771 break; 1772 index++; 1773 BUG_ON(index >= sblock->page_count); 1774 BUG_ON(!sblock->pagev[index]->page); 1775 page = sblock->pagev[index]->page; 1776 mapped_buffer = kmap_atomic(page); 1777 mapped_size = PAGE_SIZE; 1778 p = mapped_buffer; 1779 } 1780 1781 btrfs_csum_final(crc, calculated_csum); 1782 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size)) 1783 ++crc_fail; 1784 1785 return fail || crc_fail; 1786} 1787 1788static int scrub_checksum_super(struct scrub_block *sblock) 1789{ 1790 struct btrfs_super_block *s; 1791 struct scrub_ctx *sctx = sblock->sctx; 1792 struct btrfs_root *root = sctx->dev_root; 1793 struct btrfs_fs_info *fs_info = root->fs_info; 1794 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1795 u8 on_disk_csum[BTRFS_CSUM_SIZE]; 1796 struct page *page; 1797 void *mapped_buffer; 1798 u64 mapped_size; 1799 void *p; 1800 u32 crc = ~(u32)0; 1801 int fail_gen = 0; 1802 int fail_cor = 0; 1803 u64 len; 1804 int index; 1805 1806 BUG_ON(sblock->page_count < 1); 1807 page = sblock->pagev[0]->page; 1808 mapped_buffer = kmap_atomic(page); 1809 s = (struct btrfs_super_block *)mapped_buffer; 1810 memcpy(on_disk_csum, s->csum, sctx->csum_size); 1811 1812 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s)) 1813 ++fail_cor; 1814 1815 if (sblock->pagev[0]->generation != btrfs_super_generation(s)) 1816 ++fail_gen; 1817 1818 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) 1819 ++fail_cor; 1820 1821 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE; 1822 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; 1823 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; 1824 index = 0; 1825 for (;;) { 1826 u64 l = min_t(u64, len, mapped_size); 1827 1828 crc = btrfs_csum_data(p, crc, l); 1829 kunmap_atomic(mapped_buffer); 1830 len -= l; 1831 if (len == 0) 1832 break; 1833 index++; 1834 BUG_ON(index >= sblock->page_count); 1835 BUG_ON(!sblock->pagev[index]->page); 1836 page = sblock->pagev[index]->page; 1837 mapped_buffer = kmap_atomic(page); 1838 mapped_size = PAGE_SIZE; 1839 p = mapped_buffer; 1840 } 1841 1842 btrfs_csum_final(crc, calculated_csum); 1843 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size)) 1844 ++fail_cor; 1845 1846 if (fail_cor + fail_gen) { 1847 /* 1848 * if we find an error in a super block, we just report it. 1849 * They will get written with the next transaction commit 1850 * anyway 1851 */ 1852 spin_lock(&sctx->stat_lock); 1853 ++sctx->stat.super_errors; 1854 spin_unlock(&sctx->stat_lock); 1855 if (fail_cor) 1856 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev, 1857 BTRFS_DEV_STAT_CORRUPTION_ERRS); 1858 else 1859 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev, 1860 BTRFS_DEV_STAT_GENERATION_ERRS); 1861 } 1862 1863 return fail_cor + fail_gen; 1864} 1865 1866static void scrub_block_get(struct scrub_block *sblock) 1867{ 1868 atomic_inc(&sblock->ref_count); 1869} 1870 1871static void scrub_block_put(struct scrub_block *sblock) 1872{ 1873 if (atomic_dec_and_test(&sblock->ref_count)) { 1874 int i; 1875 1876 for (i = 0; i < sblock->page_count; i++) 1877 scrub_page_put(sblock->pagev[i]); 1878 kfree(sblock); 1879 } 1880} 1881 1882static void scrub_page_get(struct scrub_page *spage) 1883{ 1884 atomic_inc(&spage->ref_count); 1885} 1886 1887static void scrub_page_put(struct scrub_page *spage) 1888{ 1889 if (atomic_dec_and_test(&spage->ref_count)) { 1890 if (spage->page) 1891 __free_page(spage->page); 1892 kfree(spage); 1893 } 1894} 1895 1896static void scrub_submit(struct scrub_ctx *sctx) 1897{ 1898 struct scrub_bio *sbio; 1899 1900 if (sctx->curr == -1) 1901 return; 1902 1903 sbio = sctx->bios[sctx->curr]; 1904 sctx->curr = -1; 1905 scrub_pending_bio_inc(sctx); 1906 1907 if (!sbio->bio->bi_bdev) { 1908 /* 1909 * this case should not happen. If btrfs_map_block() is 1910 * wrong, it could happen for dev-replace operations on 1911 * missing devices when no mirrors are available, but in 1912 * this case it should already fail the mount. 1913 * This case is handled correctly (but _very_ slowly). 1914 */ 1915 printk_ratelimited(KERN_WARNING 1916 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n"); 1917 bio_endio(sbio->bio, -EIO); 1918 } else { 1919 btrfsic_submit_bio(READ, sbio->bio); 1920 } 1921} 1922 1923static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, 1924 struct scrub_page *spage) 1925{ 1926 struct scrub_block *sblock = spage->sblock; 1927 struct scrub_bio *sbio; 1928 int ret; 1929 1930again: 1931 /* 1932 * grab a fresh bio or wait for one to become available 1933 */ 1934 while (sctx->curr == -1) { 1935 spin_lock(&sctx->list_lock); 1936 sctx->curr = sctx->first_free; 1937 if (sctx->curr != -1) { 1938 sctx->first_free = sctx->bios[sctx->curr]->next_free; 1939 sctx->bios[sctx->curr]->next_free = -1; 1940 sctx->bios[sctx->curr]->page_count = 0; 1941 spin_unlock(&sctx->list_lock); 1942 } else { 1943 spin_unlock(&sctx->list_lock); 1944 wait_event(sctx->list_wait, sctx->first_free != -1); 1945 } 1946 } 1947 sbio = sctx->bios[sctx->curr]; 1948 if (sbio->page_count == 0) { 1949 struct bio *bio; 1950 1951 sbio->physical = spage->physical; 1952 sbio->logical = spage->logical; 1953 sbio->dev = spage->dev; 1954 bio = sbio->bio; 1955 if (!bio) { 1956 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio); 1957 if (!bio) 1958 return -ENOMEM; 1959 sbio->bio = bio; 1960 } 1961 1962 bio->bi_private = sbio; 1963 bio->bi_end_io = scrub_bio_end_io; 1964 bio->bi_bdev = sbio->dev->bdev; 1965 bio->bi_sector = sbio->physical >> 9; 1966 sbio->err = 0; 1967 } else if (sbio->physical + sbio->page_count * PAGE_SIZE != 1968 spage->physical || 1969 sbio->logical + sbio->page_count * PAGE_SIZE != 1970 spage->logical || 1971 sbio->dev != spage->dev) { 1972 scrub_submit(sctx); 1973 goto again; 1974 } 1975 1976 sbio->pagev[sbio->page_count] = spage; 1977 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); 1978 if (ret != PAGE_SIZE) { 1979 if (sbio->page_count < 1) { 1980 bio_put(sbio->bio); 1981 sbio->bio = NULL; 1982 return -EIO; 1983 } 1984 scrub_submit(sctx); 1985 goto again; 1986 } 1987 1988 scrub_block_get(sblock); /* one for the page added to the bio */ 1989 atomic_inc(&sblock->outstanding_pages); 1990 sbio->page_count++; 1991 if (sbio->page_count == sctx->pages_per_rd_bio) 1992 scrub_submit(sctx); 1993 1994 return 0; 1995} 1996 1997static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 1998 u64 physical, struct btrfs_device *dev, u64 flags, 1999 u64 gen, int mirror_num, u8 *csum, int force, 2000 u64 physical_for_dev_replace) 2001{ 2002 struct scrub_block *sblock; 2003 int index; 2004 2005 sblock = kzalloc(sizeof(*sblock), GFP_NOFS); 2006 if (!sblock) { 2007 spin_lock(&sctx->stat_lock); 2008 sctx->stat.malloc_errors++; 2009 spin_unlock(&sctx->stat_lock); 2010 return -ENOMEM; 2011 } 2012 2013 /* one ref inside this function, plus one for each page added to 2014 * a bio later on */ 2015 atomic_set(&sblock->ref_count, 1); 2016 sblock->sctx = sctx; 2017 sblock->no_io_error_seen = 1; 2018 2019 for (index = 0; len > 0; index++) { 2020 struct scrub_page *spage; 2021 u64 l = min_t(u64, len, PAGE_SIZE); 2022 2023 spage = kzalloc(sizeof(*spage), GFP_NOFS); 2024 if (!spage) { 2025leave_nomem: 2026 spin_lock(&sctx->stat_lock); 2027 sctx->stat.malloc_errors++; 2028 spin_unlock(&sctx->stat_lock); 2029 scrub_block_put(sblock); 2030 return -ENOMEM; 2031 } 2032 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); 2033 scrub_page_get(spage); 2034 sblock->pagev[index] = spage; 2035 spage->sblock = sblock; 2036 spage->dev = dev; 2037 spage->flags = flags; 2038 spage->generation = gen; 2039 spage->logical = logical; 2040 spage->physical = physical; 2041 spage->physical_for_dev_replace = physical_for_dev_replace; 2042 spage->mirror_num = mirror_num; 2043 if (csum) { 2044 spage->have_csum = 1; 2045 memcpy(spage->csum, csum, sctx->csum_size); 2046 } else { 2047 spage->have_csum = 0; 2048 } 2049 sblock->page_count++; 2050 spage->page = alloc_page(GFP_NOFS); 2051 if (!spage->page) 2052 goto leave_nomem; 2053 len -= l; 2054 logical += l; 2055 physical += l; 2056 physical_for_dev_replace += l; 2057 } 2058 2059 WARN_ON(sblock->page_count == 0); 2060 for (index = 0; index < sblock->page_count; index++) { 2061 struct scrub_page *spage = sblock->pagev[index]; 2062 int ret; 2063 2064 ret = scrub_add_page_to_rd_bio(sctx, spage); 2065 if (ret) { 2066 scrub_block_put(sblock); 2067 return ret; 2068 } 2069 } 2070 2071 if (force) 2072 scrub_submit(sctx); 2073 2074 /* last one frees, either here or in bio completion for last page */ 2075 scrub_block_put(sblock); 2076 return 0; 2077} 2078 2079static void scrub_bio_end_io(struct bio *bio, int err) 2080{ 2081 struct scrub_bio *sbio = bio->bi_private; 2082 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info; 2083 2084 sbio->err = err; 2085 sbio->bio = bio; 2086 2087 btrfs_queue_work(fs_info->scrub_workers, &sbio->work); 2088} 2089 2090static void scrub_bio_end_io_worker(struct btrfs_work *work) 2091{ 2092 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 2093 struct scrub_ctx *sctx = sbio->sctx; 2094 int i; 2095 2096 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO); 2097 if (sbio->err) { 2098 for (i = 0; i < sbio->page_count; i++) { 2099 struct scrub_page *spage = sbio->pagev[i]; 2100 2101 spage->io_error = 1; 2102 spage->sblock->no_io_error_seen = 0; 2103 } 2104 } 2105 2106 /* now complete the scrub_block items that have all pages completed */ 2107 for (i = 0; i < sbio->page_count; i++) { 2108 struct scrub_page *spage = sbio->pagev[i]; 2109 struct scrub_block *sblock = spage->sblock; 2110 2111 if (atomic_dec_and_test(&sblock->outstanding_pages)) 2112 scrub_block_complete(sblock); 2113 scrub_block_put(sblock); 2114 } 2115 2116 bio_put(sbio->bio); 2117 sbio->bio = NULL; 2118 spin_lock(&sctx->list_lock); 2119 sbio->next_free = sctx->first_free; 2120 sctx->first_free = sbio->index; 2121 spin_unlock(&sctx->list_lock); 2122 2123 if (sctx->is_dev_replace && 2124 atomic_read(&sctx->wr_ctx.flush_all_writes)) { 2125 mutex_lock(&sctx->wr_ctx.wr_lock); 2126 scrub_wr_submit(sctx); 2127 mutex_unlock(&sctx->wr_ctx.wr_lock); 2128 } 2129 2130 scrub_pending_bio_dec(sctx); 2131} 2132 2133static void scrub_block_complete(struct scrub_block *sblock) 2134{ 2135 if (!sblock->no_io_error_seen) { 2136 scrub_handle_errored_block(sblock); 2137 } else { 2138 /* 2139 * if has checksum error, write via repair mechanism in 2140 * dev replace case, otherwise write here in dev replace 2141 * case. 2142 */ 2143 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace) 2144 scrub_write_block_to_dev_replace(sblock); 2145 } 2146} 2147 2148static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len, 2149 u8 *csum) 2150{ 2151 struct btrfs_ordered_sum *sum = NULL; 2152 unsigned long index; 2153 unsigned long num_sectors; 2154 2155 while (!list_empty(&sctx->csum_list)) { 2156 sum = list_first_entry(&sctx->csum_list, 2157 struct btrfs_ordered_sum, list); 2158 if (sum->bytenr > logical) 2159 return 0; 2160 if (sum->bytenr + sum->len > logical) 2161 break; 2162 2163 ++sctx->stat.csum_discards; 2164 list_del(&sum->list); 2165 kfree(sum); 2166 sum = NULL; 2167 } 2168 if (!sum) 2169 return 0; 2170 2171 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize; 2172 num_sectors = sum->len / sctx->sectorsize; 2173 memcpy(csum, sum->sums + index, sctx->csum_size); 2174 if (index == num_sectors - 1) { 2175 list_del(&sum->list); 2176 kfree(sum); 2177 } 2178 return 1; 2179} 2180 2181/* scrub extent tries to collect up to 64 kB for each bio */ 2182static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len, 2183 u64 physical, struct btrfs_device *dev, u64 flags, 2184 u64 gen, int mirror_num, u64 physical_for_dev_replace) 2185{ 2186 int ret; 2187 u8 csum[BTRFS_CSUM_SIZE]; 2188 u32 blocksize; 2189 2190 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2191 blocksize = sctx->sectorsize; 2192 spin_lock(&sctx->stat_lock); 2193 sctx->stat.data_extents_scrubbed++; 2194 sctx->stat.data_bytes_scrubbed += len; 2195 spin_unlock(&sctx->stat_lock); 2196 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 2197 WARN_ON(sctx->nodesize != sctx->leafsize); 2198 blocksize = sctx->nodesize; 2199 spin_lock(&sctx->stat_lock); 2200 sctx->stat.tree_extents_scrubbed++; 2201 sctx->stat.tree_bytes_scrubbed += len; 2202 spin_unlock(&sctx->stat_lock); 2203 } else { 2204 blocksize = sctx->sectorsize; 2205 WARN_ON(1); 2206 } 2207 2208 while (len) { 2209 u64 l = min_t(u64, len, blocksize); 2210 int have_csum = 0; 2211 2212 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2213 /* push csums to sbio */ 2214 have_csum = scrub_find_csum(sctx, logical, l, csum); 2215 if (have_csum == 0) 2216 ++sctx->stat.no_csum; 2217 if (sctx->is_dev_replace && !have_csum) { 2218 ret = copy_nocow_pages(sctx, logical, l, 2219 mirror_num, 2220 physical_for_dev_replace); 2221 goto behind_scrub_pages; 2222 } 2223 } 2224 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen, 2225 mirror_num, have_csum ? csum : NULL, 0, 2226 physical_for_dev_replace); 2227behind_scrub_pages: 2228 if (ret) 2229 return ret; 2230 len -= l; 2231 logical += l; 2232 physical += l; 2233 physical_for_dev_replace += l; 2234 } 2235 return 0; 2236} 2237 2238static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 2239 struct map_lookup *map, 2240 struct btrfs_device *scrub_dev, 2241 int num, u64 base, u64 length, 2242 int is_dev_replace) 2243{ 2244 struct btrfs_path *path; 2245 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 2246 struct btrfs_root *root = fs_info->extent_root; 2247 struct btrfs_root *csum_root = fs_info->csum_root; 2248 struct btrfs_extent_item *extent; 2249 struct blk_plug plug; 2250 u64 flags; 2251 int ret; 2252 int slot; 2253 u64 nstripes; 2254 struct extent_buffer *l; 2255 struct btrfs_key key; 2256 u64 physical; 2257 u64 logical; 2258 u64 logic_end; 2259 u64 generation; 2260 int mirror_num; 2261 struct reada_control *reada1; 2262 struct reada_control *reada2; 2263 struct btrfs_key key_start; 2264 struct btrfs_key key_end; 2265 u64 increment = map->stripe_len; 2266 u64 offset; 2267 u64 extent_logical; 2268 u64 extent_physical; 2269 u64 extent_len; 2270 struct btrfs_device *extent_dev; 2271 int extent_mirror_num; 2272 int stop_loop; 2273 2274 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | 2275 BTRFS_BLOCK_GROUP_RAID6)) { 2276 if (num >= nr_data_stripes(map)) { 2277 return 0; 2278 } 2279 } 2280 2281 nstripes = length; 2282 offset = 0; 2283 do_div(nstripes, map->stripe_len); 2284 if (map->type & BTRFS_BLOCK_GROUP_RAID0) { 2285 offset = map->stripe_len * num; 2286 increment = map->stripe_len * map->num_stripes; 2287 mirror_num = 1; 2288 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 2289 int factor = map->num_stripes / map->sub_stripes; 2290 offset = map->stripe_len * (num / map->sub_stripes); 2291 increment = map->stripe_len * factor; 2292 mirror_num = num % map->sub_stripes + 1; 2293 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { 2294 increment = map->stripe_len; 2295 mirror_num = num % map->num_stripes + 1; 2296 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { 2297 increment = map->stripe_len; 2298 mirror_num = num % map->num_stripes + 1; 2299 } else { 2300 increment = map->stripe_len; 2301 mirror_num = 1; 2302 } 2303 2304 path = btrfs_alloc_path(); 2305 if (!path) 2306 return -ENOMEM; 2307 2308 /* 2309 * work on commit root. The related disk blocks are static as 2310 * long as COW is applied. This means, it is save to rewrite 2311 * them to repair disk errors without any race conditions 2312 */ 2313 path->search_commit_root = 1; 2314 path->skip_locking = 1; 2315 2316 /* 2317 * trigger the readahead for extent tree csum tree and wait for 2318 * completion. During readahead, the scrub is officially paused 2319 * to not hold off transaction commits 2320 */ 2321 logical = base + offset; 2322 2323 wait_event(sctx->list_wait, 2324 atomic_read(&sctx->bios_in_flight) == 0); 2325 scrub_blocked_if_needed(fs_info); 2326 2327 /* FIXME it might be better to start readahead at commit root */ 2328 key_start.objectid = logical; 2329 key_start.type = BTRFS_EXTENT_ITEM_KEY; 2330 key_start.offset = (u64)0; 2331 key_end.objectid = base + offset + nstripes * increment; 2332 key_end.type = BTRFS_METADATA_ITEM_KEY; 2333 key_end.offset = (u64)-1; 2334 reada1 = btrfs_reada_add(root, &key_start, &key_end); 2335 2336 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 2337 key_start.type = BTRFS_EXTENT_CSUM_KEY; 2338 key_start.offset = logical; 2339 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 2340 key_end.type = BTRFS_EXTENT_CSUM_KEY; 2341 key_end.offset = base + offset + nstripes * increment; 2342 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end); 2343 2344 if (!IS_ERR(reada1)) 2345 btrfs_reada_wait(reada1); 2346 if (!IS_ERR(reada2)) 2347 btrfs_reada_wait(reada2); 2348 2349 2350 /* 2351 * collect all data csums for the stripe to avoid seeking during 2352 * the scrub. This might currently (crc32) end up to be about 1MB 2353 */ 2354 blk_start_plug(&plug); 2355 2356 /* 2357 * now find all extents for each stripe and scrub them 2358 */ 2359 logical = base + offset; 2360 physical = map->stripes[num].physical; 2361 logic_end = logical + increment * nstripes; 2362 ret = 0; 2363 while (logical < logic_end) { 2364 /* 2365 * canceled? 2366 */ 2367 if (atomic_read(&fs_info->scrub_cancel_req) || 2368 atomic_read(&sctx->cancel_req)) { 2369 ret = -ECANCELED; 2370 goto out; 2371 } 2372 /* 2373 * check to see if we have to pause 2374 */ 2375 if (atomic_read(&fs_info->scrub_pause_req)) { 2376 /* push queued extents */ 2377 atomic_set(&sctx->wr_ctx.flush_all_writes, 1); 2378 scrub_submit(sctx); 2379 mutex_lock(&sctx->wr_ctx.wr_lock); 2380 scrub_wr_submit(sctx); 2381 mutex_unlock(&sctx->wr_ctx.wr_lock); 2382 wait_event(sctx->list_wait, 2383 atomic_read(&sctx->bios_in_flight) == 0); 2384 atomic_set(&sctx->wr_ctx.flush_all_writes, 0); 2385 scrub_blocked_if_needed(fs_info); 2386 } 2387 2388 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) 2389 key.type = BTRFS_METADATA_ITEM_KEY; 2390 else 2391 key.type = BTRFS_EXTENT_ITEM_KEY; 2392 key.objectid = logical; 2393 key.offset = (u64)-1; 2394 2395 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2396 if (ret < 0) 2397 goto out; 2398 2399 if (ret > 0) { 2400 ret = btrfs_previous_extent_item(root, path, 0); 2401 if (ret < 0) 2402 goto out; 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 } 2412 } 2413 2414 stop_loop = 0; 2415 while (1) { 2416 u64 bytes; 2417 2418 l = path->nodes[0]; 2419 slot = path->slots[0]; 2420 if (slot >= btrfs_header_nritems(l)) { 2421 ret = btrfs_next_leaf(root, path); 2422 if (ret == 0) 2423 continue; 2424 if (ret < 0) 2425 goto out; 2426 2427 stop_loop = 1; 2428 break; 2429 } 2430 btrfs_item_key_to_cpu(l, &key, slot); 2431 2432 if (key.type == BTRFS_METADATA_ITEM_KEY) 2433 bytes = root->leafsize; 2434 else 2435 bytes = key.offset; 2436 2437 if (key.objectid + bytes <= logical) 2438 goto next; 2439 2440 if (key.type != BTRFS_EXTENT_ITEM_KEY && 2441 key.type != BTRFS_METADATA_ITEM_KEY) 2442 goto next; 2443 2444 if (key.objectid >= logical + map->stripe_len) { 2445 /* out of this device extent */ 2446 if (key.objectid >= logic_end) 2447 stop_loop = 1; 2448 break; 2449 } 2450 2451 extent = btrfs_item_ptr(l, slot, 2452 struct btrfs_extent_item); 2453 flags = btrfs_extent_flags(l, extent); 2454 generation = btrfs_extent_generation(l, extent); 2455 2456 if (key.objectid < logical && 2457 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) { 2458 btrfs_err(fs_info, 2459 "scrub: tree block %llu spanning " 2460 "stripes, ignored. logical=%llu", 2461 key.objectid, logical); 2462 goto next; 2463 } 2464 2465again: 2466 extent_logical = key.objectid; 2467 extent_len = bytes; 2468 2469 /* 2470 * trim extent to this stripe 2471 */ 2472 if (extent_logical < logical) { 2473 extent_len -= logical - extent_logical; 2474 extent_logical = logical; 2475 } 2476 if (extent_logical + extent_len > 2477 logical + map->stripe_len) { 2478 extent_len = logical + map->stripe_len - 2479 extent_logical; 2480 } 2481 2482 extent_physical = extent_logical - logical + physical; 2483 extent_dev = scrub_dev; 2484 extent_mirror_num = mirror_num; 2485 if (is_dev_replace) 2486 scrub_remap_extent(fs_info, extent_logical, 2487 extent_len, &extent_physical, 2488 &extent_dev, 2489 &extent_mirror_num); 2490 2491 ret = btrfs_lookup_csums_range(csum_root, logical, 2492 logical + map->stripe_len - 1, 2493 &sctx->csum_list, 1); 2494 if (ret) 2495 goto out; 2496 2497 ret = scrub_extent(sctx, extent_logical, extent_len, 2498 extent_physical, extent_dev, flags, 2499 generation, extent_mirror_num, 2500 extent_logical - logical + physical); 2501 if (ret) 2502 goto out; 2503 2504 scrub_free_csums(sctx); 2505 if (extent_logical + extent_len < 2506 key.objectid + bytes) { 2507 logical += increment; 2508 physical += map->stripe_len; 2509 2510 if (logical < key.objectid + bytes) { 2511 cond_resched(); 2512 goto again; 2513 } 2514 2515 if (logical >= logic_end) { 2516 stop_loop = 1; 2517 break; 2518 } 2519 } 2520next: 2521 path->slots[0]++; 2522 } 2523 btrfs_release_path(path); 2524 logical += increment; 2525 physical += map->stripe_len; 2526 spin_lock(&sctx->stat_lock); 2527 if (stop_loop) 2528 sctx->stat.last_physical = map->stripes[num].physical + 2529 length; 2530 else 2531 sctx->stat.last_physical = physical; 2532 spin_unlock(&sctx->stat_lock); 2533 if (stop_loop) 2534 break; 2535 } 2536out: 2537 /* push queued extents */ 2538 scrub_submit(sctx); 2539 mutex_lock(&sctx->wr_ctx.wr_lock); 2540 scrub_wr_submit(sctx); 2541 mutex_unlock(&sctx->wr_ctx.wr_lock); 2542 2543 blk_finish_plug(&plug); 2544 btrfs_free_path(path); 2545 return ret < 0 ? ret : 0; 2546} 2547 2548static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, 2549 struct btrfs_device *scrub_dev, 2550 u64 chunk_tree, u64 chunk_objectid, 2551 u64 chunk_offset, u64 length, 2552 u64 dev_offset, int is_dev_replace) 2553{ 2554 struct btrfs_mapping_tree *map_tree = 2555 &sctx->dev_root->fs_info->mapping_tree; 2556 struct map_lookup *map; 2557 struct extent_map *em; 2558 int i; 2559 int ret = 0; 2560 2561 read_lock(&map_tree->map_tree.lock); 2562 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); 2563 read_unlock(&map_tree->map_tree.lock); 2564 2565 if (!em) 2566 return -EINVAL; 2567 2568 map = (struct map_lookup *)em->bdev; 2569 if (em->start != chunk_offset) 2570 goto out; 2571 2572 if (em->len < length) 2573 goto out; 2574 2575 for (i = 0; i < map->num_stripes; ++i) { 2576 if (map->stripes[i].dev->bdev == scrub_dev->bdev && 2577 map->stripes[i].physical == dev_offset) { 2578 ret = scrub_stripe(sctx, map, scrub_dev, i, 2579 chunk_offset, length, 2580 is_dev_replace); 2581 if (ret) 2582 goto out; 2583 } 2584 } 2585out: 2586 free_extent_map(em); 2587 2588 return ret; 2589} 2590 2591static noinline_for_stack 2592int scrub_enumerate_chunks(struct scrub_ctx *sctx, 2593 struct btrfs_device *scrub_dev, u64 start, u64 end, 2594 int is_dev_replace) 2595{ 2596 struct btrfs_dev_extent *dev_extent = NULL; 2597 struct btrfs_path *path; 2598 struct btrfs_root *root = sctx->dev_root; 2599 struct btrfs_fs_info *fs_info = root->fs_info; 2600 u64 length; 2601 u64 chunk_tree; 2602 u64 chunk_objectid; 2603 u64 chunk_offset; 2604 int ret; 2605 int slot; 2606 struct extent_buffer *l; 2607 struct btrfs_key key; 2608 struct btrfs_key found_key; 2609 struct btrfs_block_group_cache *cache; 2610 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 2611 2612 path = btrfs_alloc_path(); 2613 if (!path) 2614 return -ENOMEM; 2615 2616 path->reada = 2; 2617 path->search_commit_root = 1; 2618 path->skip_locking = 1; 2619 2620 key.objectid = scrub_dev->devid; 2621 key.offset = 0ull; 2622 key.type = BTRFS_DEV_EXTENT_KEY; 2623 2624 while (1) { 2625 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2626 if (ret < 0) 2627 break; 2628 if (ret > 0) { 2629 if (path->slots[0] >= 2630 btrfs_header_nritems(path->nodes[0])) { 2631 ret = btrfs_next_leaf(root, path); 2632 if (ret) 2633 break; 2634 } 2635 } 2636 2637 l = path->nodes[0]; 2638 slot = path->slots[0]; 2639 2640 btrfs_item_key_to_cpu(l, &found_key, slot); 2641 2642 if (found_key.objectid != scrub_dev->devid) 2643 break; 2644 2645 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY) 2646 break; 2647 2648 if (found_key.offset >= end) 2649 break; 2650 2651 if (found_key.offset < key.offset) 2652 break; 2653 2654 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 2655 length = btrfs_dev_extent_length(l, dev_extent); 2656 2657 if (found_key.offset + length <= start) { 2658 key.offset = found_key.offset + length; 2659 btrfs_release_path(path); 2660 continue; 2661 } 2662 2663 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); 2664 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); 2665 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); 2666 2667 /* 2668 * get a reference on the corresponding block group to prevent 2669 * the chunk from going away while we scrub it 2670 */ 2671 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 2672 if (!cache) { 2673 ret = -ENOENT; 2674 break; 2675 } 2676 dev_replace->cursor_right = found_key.offset + length; 2677 dev_replace->cursor_left = found_key.offset; 2678 dev_replace->item_needs_writeback = 1; 2679 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid, 2680 chunk_offset, length, found_key.offset, 2681 is_dev_replace); 2682 2683 /* 2684 * flush, submit all pending read and write bios, afterwards 2685 * wait for them. 2686 * Note that in the dev replace case, a read request causes 2687 * write requests that are submitted in the read completion 2688 * worker. Therefore in the current situation, it is required 2689 * that all write requests are flushed, so that all read and 2690 * write requests are really completed when bios_in_flight 2691 * changes to 0. 2692 */ 2693 atomic_set(&sctx->wr_ctx.flush_all_writes, 1); 2694 scrub_submit(sctx); 2695 mutex_lock(&sctx->wr_ctx.wr_lock); 2696 scrub_wr_submit(sctx); 2697 mutex_unlock(&sctx->wr_ctx.wr_lock); 2698 2699 wait_event(sctx->list_wait, 2700 atomic_read(&sctx->bios_in_flight) == 0); 2701 atomic_inc(&fs_info->scrubs_paused); 2702 wake_up(&fs_info->scrub_pause_wait); 2703 2704 /* 2705 * must be called before we decrease @scrub_paused. 2706 * make sure we don't block transaction commit while 2707 * we are waiting pending workers finished. 2708 */ 2709 wait_event(sctx->list_wait, 2710 atomic_read(&sctx->workers_pending) == 0); 2711 atomic_set(&sctx->wr_ctx.flush_all_writes, 0); 2712 2713 mutex_lock(&fs_info->scrub_lock); 2714 __scrub_blocked_if_needed(fs_info); 2715 atomic_dec(&fs_info->scrubs_paused); 2716 mutex_unlock(&fs_info->scrub_lock); 2717 wake_up(&fs_info->scrub_pause_wait); 2718 2719 btrfs_put_block_group(cache); 2720 if (ret) 2721 break; 2722 if (is_dev_replace && 2723 atomic64_read(&dev_replace->num_write_errors) > 0) { 2724 ret = -EIO; 2725 break; 2726 } 2727 if (sctx->stat.malloc_errors > 0) { 2728 ret = -ENOMEM; 2729 break; 2730 } 2731 2732 dev_replace->cursor_left = dev_replace->cursor_right; 2733 dev_replace->item_needs_writeback = 1; 2734 2735 key.offset = found_key.offset + length; 2736 btrfs_release_path(path); 2737 } 2738 2739 btrfs_free_path(path); 2740 2741 /* 2742 * ret can still be 1 from search_slot or next_leaf, 2743 * that's not an error 2744 */ 2745 return ret < 0 ? ret : 0; 2746} 2747 2748static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, 2749 struct btrfs_device *scrub_dev) 2750{ 2751 int i; 2752 u64 bytenr; 2753 u64 gen; 2754 int ret; 2755 struct btrfs_root *root = sctx->dev_root; 2756 2757 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 2758 return -EIO; 2759 2760 gen = root->fs_info->last_trans_committed; 2761 2762 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { 2763 bytenr = btrfs_sb_offset(i); 2764 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes) 2765 break; 2766 2767 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr, 2768 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i, 2769 NULL, 1, bytenr); 2770 if (ret) 2771 return ret; 2772 } 2773 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 2774 2775 return 0; 2776} 2777 2778/* 2779 * get a reference count on fs_info->scrub_workers. start worker if necessary 2780 */ 2781static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info, 2782 int is_dev_replace) 2783{ 2784 int ret = 0; 2785 int flags = WQ_FREEZABLE | WQ_UNBOUND; 2786 int max_active = fs_info->thread_pool_size; 2787 2788 if (fs_info->scrub_workers_refcnt == 0) { 2789 if (is_dev_replace) 2790 fs_info->scrub_workers = 2791 btrfs_alloc_workqueue("btrfs-scrub", flags, 2792 1, 4); 2793 else 2794 fs_info->scrub_workers = 2795 btrfs_alloc_workqueue("btrfs-scrub", flags, 2796 max_active, 4); 2797 if (!fs_info->scrub_workers) { 2798 ret = -ENOMEM; 2799 goto out; 2800 } 2801 fs_info->scrub_wr_completion_workers = 2802 btrfs_alloc_workqueue("btrfs-scrubwrc", flags, 2803 max_active, 2); 2804 if (!fs_info->scrub_wr_completion_workers) { 2805 ret = -ENOMEM; 2806 goto out; 2807 } 2808 fs_info->scrub_nocow_workers = 2809 btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0); 2810 if (!fs_info->scrub_nocow_workers) { 2811 ret = -ENOMEM; 2812 goto out; 2813 } 2814 } 2815 ++fs_info->scrub_workers_refcnt; 2816out: 2817 return ret; 2818} 2819 2820static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info) 2821{ 2822 if (--fs_info->scrub_workers_refcnt == 0) { 2823 btrfs_destroy_workqueue(fs_info->scrub_workers); 2824 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers); 2825 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers); 2826 } 2827 WARN_ON(fs_info->scrub_workers_refcnt < 0); 2828} 2829 2830int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, 2831 u64 end, struct btrfs_scrub_progress *progress, 2832 int readonly, int is_dev_replace) 2833{ 2834 struct scrub_ctx *sctx; 2835 int ret; 2836 struct btrfs_device *dev; 2837 2838 if (btrfs_fs_closing(fs_info)) 2839 return -EINVAL; 2840 2841 /* 2842 * check some assumptions 2843 */ 2844 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) { 2845 btrfs_err(fs_info, 2846 "scrub: size assumption nodesize == leafsize (%d == %d) fails", 2847 fs_info->chunk_root->nodesize, 2848 fs_info->chunk_root->leafsize); 2849 return -EINVAL; 2850 } 2851 2852 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) { 2853 /* 2854 * in this case scrub is unable to calculate the checksum 2855 * the way scrub is implemented. Do not handle this 2856 * situation at all because it won't ever happen. 2857 */ 2858 btrfs_err(fs_info, 2859 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails", 2860 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN); 2861 return -EINVAL; 2862 } 2863 2864 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) { 2865 /* not supported for data w/o checksums */ 2866 btrfs_err(fs_info, 2867 "scrub: size assumption sectorsize != PAGE_SIZE " 2868 "(%d != %lu) fails", 2869 fs_info->chunk_root->sectorsize, PAGE_SIZE); 2870 return -EINVAL; 2871 } 2872 2873 if (fs_info->chunk_root->nodesize > 2874 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK || 2875 fs_info->chunk_root->sectorsize > 2876 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) { 2877 /* 2878 * would exhaust the array bounds of pagev member in 2879 * struct scrub_block 2880 */ 2881 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize " 2882 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails", 2883 fs_info->chunk_root->nodesize, 2884 SCRUB_MAX_PAGES_PER_BLOCK, 2885 fs_info->chunk_root->sectorsize, 2886 SCRUB_MAX_PAGES_PER_BLOCK); 2887 return -EINVAL; 2888 } 2889 2890 2891 mutex_lock(&fs_info->fs_devices->device_list_mutex); 2892 dev = btrfs_find_device(fs_info, devid, NULL, NULL); 2893 if (!dev || (dev->missing && !is_dev_replace)) { 2894 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2895 return -ENODEV; 2896 } 2897 2898 mutex_lock(&fs_info->scrub_lock); 2899 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) { 2900 mutex_unlock(&fs_info->scrub_lock); 2901 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2902 return -EIO; 2903 } 2904 2905 btrfs_dev_replace_lock(&fs_info->dev_replace); 2906 if (dev->scrub_device || 2907 (!is_dev_replace && 2908 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) { 2909 btrfs_dev_replace_unlock(&fs_info->dev_replace); 2910 mutex_unlock(&fs_info->scrub_lock); 2911 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2912 return -EINPROGRESS; 2913 } 2914 btrfs_dev_replace_unlock(&fs_info->dev_replace); 2915 2916 ret = scrub_workers_get(fs_info, is_dev_replace); 2917 if (ret) { 2918 mutex_unlock(&fs_info->scrub_lock); 2919 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2920 return ret; 2921 } 2922 2923 sctx = scrub_setup_ctx(dev, is_dev_replace); 2924 if (IS_ERR(sctx)) { 2925 mutex_unlock(&fs_info->scrub_lock); 2926 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2927 scrub_workers_put(fs_info); 2928 return PTR_ERR(sctx); 2929 } 2930 sctx->readonly = readonly; 2931 dev->scrub_device = sctx; 2932 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2933 2934 /* 2935 * checking @scrub_pause_req here, we can avoid 2936 * race between committing transaction and scrubbing. 2937 */ 2938 __scrub_blocked_if_needed(fs_info); 2939 atomic_inc(&fs_info->scrubs_running); 2940 mutex_unlock(&fs_info->scrub_lock); 2941 2942 if (!is_dev_replace) { 2943 /* 2944 * by holding device list mutex, we can 2945 * kick off writing super in log tree sync. 2946 */ 2947 mutex_lock(&fs_info->fs_devices->device_list_mutex); 2948 ret = scrub_supers(sctx, dev); 2949 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2950 } 2951 2952 if (!ret) 2953 ret = scrub_enumerate_chunks(sctx, dev, start, end, 2954 is_dev_replace); 2955 2956 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 2957 atomic_dec(&fs_info->scrubs_running); 2958 wake_up(&fs_info->scrub_pause_wait); 2959 2960 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0); 2961 2962 if (progress) 2963 memcpy(progress, &sctx->stat, sizeof(*progress)); 2964 2965 mutex_lock(&fs_info->scrub_lock); 2966 dev->scrub_device = NULL; 2967 scrub_workers_put(fs_info); 2968 mutex_unlock(&fs_info->scrub_lock); 2969 2970 scrub_free_ctx(sctx); 2971 2972 return ret; 2973} 2974 2975void btrfs_scrub_pause(struct btrfs_root *root) 2976{ 2977 struct btrfs_fs_info *fs_info = root->fs_info; 2978 2979 mutex_lock(&fs_info->scrub_lock); 2980 atomic_inc(&fs_info->scrub_pause_req); 2981 while (atomic_read(&fs_info->scrubs_paused) != 2982 atomic_read(&fs_info->scrubs_running)) { 2983 mutex_unlock(&fs_info->scrub_lock); 2984 wait_event(fs_info->scrub_pause_wait, 2985 atomic_read(&fs_info->scrubs_paused) == 2986 atomic_read(&fs_info->scrubs_running)); 2987 mutex_lock(&fs_info->scrub_lock); 2988 } 2989 mutex_unlock(&fs_info->scrub_lock); 2990} 2991 2992void btrfs_scrub_continue(struct btrfs_root *root) 2993{ 2994 struct btrfs_fs_info *fs_info = root->fs_info; 2995 2996 atomic_dec(&fs_info->scrub_pause_req); 2997 wake_up(&fs_info->scrub_pause_wait); 2998} 2999 3000int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info) 3001{ 3002 mutex_lock(&fs_info->scrub_lock); 3003 if (!atomic_read(&fs_info->scrubs_running)) { 3004 mutex_unlock(&fs_info->scrub_lock); 3005 return -ENOTCONN; 3006 } 3007 3008 atomic_inc(&fs_info->scrub_cancel_req); 3009 while (atomic_read(&fs_info->scrubs_running)) { 3010 mutex_unlock(&fs_info->scrub_lock); 3011 wait_event(fs_info->scrub_pause_wait, 3012 atomic_read(&fs_info->scrubs_running) == 0); 3013 mutex_lock(&fs_info->scrub_lock); 3014 } 3015 atomic_dec(&fs_info->scrub_cancel_req); 3016 mutex_unlock(&fs_info->scrub_lock); 3017 3018 return 0; 3019} 3020 3021int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info, 3022 struct btrfs_device *dev) 3023{ 3024 struct scrub_ctx *sctx; 3025 3026 mutex_lock(&fs_info->scrub_lock); 3027 sctx = dev->scrub_device; 3028 if (!sctx) { 3029 mutex_unlock(&fs_info->scrub_lock); 3030 return -ENOTCONN; 3031 } 3032 atomic_inc(&sctx->cancel_req); 3033 while (dev->scrub_device) { 3034 mutex_unlock(&fs_info->scrub_lock); 3035 wait_event(fs_info->scrub_pause_wait, 3036 dev->scrub_device == NULL); 3037 mutex_lock(&fs_info->scrub_lock); 3038 } 3039 mutex_unlock(&fs_info->scrub_lock); 3040 3041 return 0; 3042} 3043 3044int btrfs_scrub_progress(struct btrfs_root *root, u64 devid, 3045 struct btrfs_scrub_progress *progress) 3046{ 3047 struct btrfs_device *dev; 3048 struct scrub_ctx *sctx = NULL; 3049 3050 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 3051 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL); 3052 if (dev) 3053 sctx = dev->scrub_device; 3054 if (sctx) 3055 memcpy(progress, &sctx->stat, sizeof(*progress)); 3056 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 3057 3058 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV; 3059} 3060 3061static void scrub_remap_extent(struct btrfs_fs_info *fs_info, 3062 u64 extent_logical, u64 extent_len, 3063 u64 *extent_physical, 3064 struct btrfs_device **extent_dev, 3065 int *extent_mirror_num) 3066{ 3067 u64 mapped_length; 3068 struct btrfs_bio *bbio = NULL; 3069 int ret; 3070 3071 mapped_length = extent_len; 3072 ret = btrfs_map_block(fs_info, READ, extent_logical, 3073 &mapped_length, &bbio, 0); 3074 if (ret || !bbio || mapped_length < extent_len || 3075 !bbio->stripes[0].dev->bdev) { 3076 kfree(bbio); 3077 return; 3078 } 3079 3080 *extent_physical = bbio->stripes[0].physical; 3081 *extent_mirror_num = bbio->mirror_num; 3082 *extent_dev = bbio->stripes[0].dev; 3083 kfree(bbio); 3084} 3085 3086static int scrub_setup_wr_ctx(struct scrub_ctx *sctx, 3087 struct scrub_wr_ctx *wr_ctx, 3088 struct btrfs_fs_info *fs_info, 3089 struct btrfs_device *dev, 3090 int is_dev_replace) 3091{ 3092 WARN_ON(wr_ctx->wr_curr_bio != NULL); 3093 3094 mutex_init(&wr_ctx->wr_lock); 3095 wr_ctx->wr_curr_bio = NULL; 3096 if (!is_dev_replace) 3097 return 0; 3098 3099 WARN_ON(!dev->bdev); 3100 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO, 3101 bio_get_nr_vecs(dev->bdev)); 3102 wr_ctx->tgtdev = dev; 3103 atomic_set(&wr_ctx->flush_all_writes, 0); 3104 return 0; 3105} 3106 3107static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx) 3108{ 3109 mutex_lock(&wr_ctx->wr_lock); 3110 kfree(wr_ctx->wr_curr_bio); 3111 wr_ctx->wr_curr_bio = NULL; 3112 mutex_unlock(&wr_ctx->wr_lock); 3113} 3114 3115static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 3116 int mirror_num, u64 physical_for_dev_replace) 3117{ 3118 struct scrub_copy_nocow_ctx *nocow_ctx; 3119 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 3120 3121 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS); 3122 if (!nocow_ctx) { 3123 spin_lock(&sctx->stat_lock); 3124 sctx->stat.malloc_errors++; 3125 spin_unlock(&sctx->stat_lock); 3126 return -ENOMEM; 3127 } 3128 3129 scrub_pending_trans_workers_inc(sctx); 3130 3131 nocow_ctx->sctx = sctx; 3132 nocow_ctx->logical = logical; 3133 nocow_ctx->len = len; 3134 nocow_ctx->mirror_num = mirror_num; 3135 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace; 3136 btrfs_init_work(&nocow_ctx->work, copy_nocow_pages_worker, NULL, NULL); 3137 INIT_LIST_HEAD(&nocow_ctx->inodes); 3138 btrfs_queue_work(fs_info->scrub_nocow_workers, 3139 &nocow_ctx->work); 3140 3141 return 0; 3142} 3143 3144static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx) 3145{ 3146 struct scrub_copy_nocow_ctx *nocow_ctx = ctx; 3147 struct scrub_nocow_inode *nocow_inode; 3148 3149 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS); 3150 if (!nocow_inode) 3151 return -ENOMEM; 3152 nocow_inode->inum = inum; 3153 nocow_inode->offset = offset; 3154 nocow_inode->root = root; 3155 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes); 3156 return 0; 3157} 3158 3159#define COPY_COMPLETE 1 3160 3161static void copy_nocow_pages_worker(struct btrfs_work *work) 3162{ 3163 struct scrub_copy_nocow_ctx *nocow_ctx = 3164 container_of(work, struct scrub_copy_nocow_ctx, work); 3165 struct scrub_ctx *sctx = nocow_ctx->sctx; 3166 u64 logical = nocow_ctx->logical; 3167 u64 len = nocow_ctx->len; 3168 int mirror_num = nocow_ctx->mirror_num; 3169 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace; 3170 int ret; 3171 struct btrfs_trans_handle *trans = NULL; 3172 struct btrfs_fs_info *fs_info; 3173 struct btrfs_path *path; 3174 struct btrfs_root *root; 3175 int not_written = 0; 3176 3177 fs_info = sctx->dev_root->fs_info; 3178 root = fs_info->extent_root; 3179 3180 path = btrfs_alloc_path(); 3181 if (!path) { 3182 spin_lock(&sctx->stat_lock); 3183 sctx->stat.malloc_errors++; 3184 spin_unlock(&sctx->stat_lock); 3185 not_written = 1; 3186 goto out; 3187 } 3188 3189 trans = btrfs_join_transaction(root); 3190 if (IS_ERR(trans)) { 3191 not_written = 1; 3192 goto out; 3193 } 3194 3195 ret = iterate_inodes_from_logical(logical, fs_info, path, 3196 record_inode_for_nocow, nocow_ctx); 3197 if (ret != 0 && ret != -ENOENT) { 3198 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, " 3199 "phys %llu, len %llu, mir %u, ret %d", 3200 logical, physical_for_dev_replace, len, mirror_num, 3201 ret); 3202 not_written = 1; 3203 goto out; 3204 } 3205 3206 btrfs_end_transaction(trans, root); 3207 trans = NULL; 3208 while (!list_empty(&nocow_ctx->inodes)) { 3209 struct scrub_nocow_inode *entry; 3210 entry = list_first_entry(&nocow_ctx->inodes, 3211 struct scrub_nocow_inode, 3212 list); 3213 list_del_init(&entry->list); 3214 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset, 3215 entry->root, nocow_ctx); 3216 kfree(entry); 3217 if (ret == COPY_COMPLETE) { 3218 ret = 0; 3219 break; 3220 } else if (ret) { 3221 break; 3222 } 3223 } 3224out: 3225 while (!list_empty(&nocow_ctx->inodes)) { 3226 struct scrub_nocow_inode *entry; 3227 entry = list_first_entry(&nocow_ctx->inodes, 3228 struct scrub_nocow_inode, 3229 list); 3230 list_del_init(&entry->list); 3231 kfree(entry); 3232 } 3233 if (trans && !IS_ERR(trans)) 3234 btrfs_end_transaction(trans, root); 3235 if (not_written) 3236 btrfs_dev_replace_stats_inc(&fs_info->dev_replace. 3237 num_uncorrectable_read_errors); 3238 3239 btrfs_free_path(path); 3240 kfree(nocow_ctx); 3241 3242 scrub_pending_trans_workers_dec(sctx); 3243} 3244 3245static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, 3246 struct scrub_copy_nocow_ctx *nocow_ctx) 3247{ 3248 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info; 3249 struct btrfs_key key; 3250 struct inode *inode; 3251 struct page *page; 3252 struct btrfs_root *local_root; 3253 struct btrfs_ordered_extent *ordered; 3254 struct extent_map *em; 3255 struct extent_state *cached_state = NULL; 3256 struct extent_io_tree *io_tree; 3257 u64 physical_for_dev_replace; 3258 u64 len = nocow_ctx->len; 3259 u64 lockstart = offset, lockend = offset + len - 1; 3260 unsigned long index; 3261 int srcu_index; 3262 int ret = 0; 3263 int err = 0; 3264 3265 key.objectid = root; 3266 key.type = BTRFS_ROOT_ITEM_KEY; 3267 key.offset = (u64)-1; 3268 3269 srcu_index = srcu_read_lock(&fs_info->subvol_srcu); 3270 3271 local_root = btrfs_read_fs_root_no_name(fs_info, &key); 3272 if (IS_ERR(local_root)) { 3273 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 3274 return PTR_ERR(local_root); 3275 } 3276 3277 key.type = BTRFS_INODE_ITEM_KEY; 3278 key.objectid = inum; 3279 key.offset = 0; 3280 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL); 3281 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 3282 if (IS_ERR(inode)) 3283 return PTR_ERR(inode); 3284 3285 /* Avoid truncate/dio/punch hole.. */ 3286 mutex_lock(&inode->i_mutex); 3287 inode_dio_wait(inode); 3288 3289 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace; 3290 io_tree = &BTRFS_I(inode)->io_tree; 3291 3292 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state); 3293 ordered = btrfs_lookup_ordered_range(inode, lockstart, len); 3294 if (ordered) { 3295 btrfs_put_ordered_extent(ordered); 3296 goto out_unlock; 3297 } 3298 3299 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0); 3300 if (IS_ERR(em)) { 3301 ret = PTR_ERR(em); 3302 goto out_unlock; 3303 } 3304 3305 /* 3306 * This extent does not actually cover the logical extent anymore, 3307 * move on to the next inode. 3308 */ 3309 if (em->block_start > nocow_ctx->logical || 3310 em->block_start + em->block_len < nocow_ctx->logical + len) { 3311 free_extent_map(em); 3312 goto out_unlock; 3313 } 3314 free_extent_map(em); 3315 3316 while (len >= PAGE_CACHE_SIZE) { 3317 index = offset >> PAGE_CACHE_SHIFT; 3318again: 3319 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 3320 if (!page) { 3321 btrfs_err(fs_info, "find_or_create_page() failed"); 3322 ret = -ENOMEM; 3323 goto out; 3324 } 3325 3326 if (PageUptodate(page)) { 3327 if (PageDirty(page)) 3328 goto next_page; 3329 } else { 3330 ClearPageError(page); 3331 err = extent_read_full_page_nolock(io_tree, page, 3332 btrfs_get_extent, 3333 nocow_ctx->mirror_num); 3334 if (err) { 3335 ret = err; 3336 goto next_page; 3337 } 3338 3339 lock_page(page); 3340 /* 3341 * If the page has been remove from the page cache, 3342 * the data on it is meaningless, because it may be 3343 * old one, the new data may be written into the new 3344 * page in the page cache. 3345 */ 3346 if (page->mapping != inode->i_mapping) { 3347 unlock_page(page); 3348 page_cache_release(page); 3349 goto again; 3350 } 3351 if (!PageUptodate(page)) { 3352 ret = -EIO; 3353 goto next_page; 3354 } 3355 } 3356 err = write_page_nocow(nocow_ctx->sctx, 3357 physical_for_dev_replace, page); 3358 if (err) 3359 ret = err; 3360next_page: 3361 unlock_page(page); 3362 page_cache_release(page); 3363 3364 if (ret) 3365 break; 3366 3367 offset += PAGE_CACHE_SIZE; 3368 physical_for_dev_replace += PAGE_CACHE_SIZE; 3369 len -= PAGE_CACHE_SIZE; 3370 } 3371 ret = COPY_COMPLETE; 3372out_unlock: 3373 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state, 3374 GFP_NOFS); 3375out: 3376 mutex_unlock(&inode->i_mutex); 3377 iput(inode); 3378 return ret; 3379} 3380 3381static int write_page_nocow(struct scrub_ctx *sctx, 3382 u64 physical_for_dev_replace, struct page *page) 3383{ 3384 struct bio *bio; 3385 struct btrfs_device *dev; 3386 int ret; 3387 3388 dev = sctx->wr_ctx.tgtdev; 3389 if (!dev) 3390 return -EIO; 3391 if (!dev->bdev) { 3392 printk_ratelimited(KERN_WARNING 3393 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n"); 3394 return -EIO; 3395 } 3396 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 3397 if (!bio) { 3398 spin_lock(&sctx->stat_lock); 3399 sctx->stat.malloc_errors++; 3400 spin_unlock(&sctx->stat_lock); 3401 return -ENOMEM; 3402 } 3403 bio->bi_size = 0; 3404 bio->bi_sector = physical_for_dev_replace >> 9; 3405 bio->bi_bdev = dev->bdev; 3406 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0); 3407 if (ret != PAGE_CACHE_SIZE) { 3408leave_with_eio: 3409 bio_put(bio); 3410 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS); 3411 return -EIO; 3412 } 3413 3414 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio)) 3415 goto leave_with_eio; 3416 3417 bio_put(bio); 3418 return 0; 3419} 3420