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 46 struct scrub_block; 47 struct 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 66 struct scrub_recover { 67 atomic_t refs; 68 struct btrfs_bio *bbio; 69 u64 map_length; 70 }; 71 72 struct scrub_page { 73 struct scrub_block *sblock; 74 struct page *page; 75 struct btrfs_device *dev; 76 struct list_head list; 77 u64 flags; /* extent flags */ 78 u64 generation; 79 u64 logical; 80 u64 physical; 81 u64 physical_for_dev_replace; 82 atomic_t refs; 83 struct { 84 unsigned int mirror_num:8; 85 unsigned int have_csum:1; 86 unsigned int io_error:1; 87 }; 88 u8 csum[BTRFS_CSUM_SIZE]; 89 90 struct scrub_recover *recover; 91 }; 92 93 struct scrub_bio { 94 int index; 95 struct scrub_ctx *sctx; 96 struct btrfs_device *dev; 97 struct bio *bio; 98 int err; 99 u64 logical; 100 u64 physical; 101 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO 102 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO]; 103 #else 104 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO]; 105 #endif 106 int page_count; 107 int next_free; 108 struct btrfs_work work; 109 }; 110 111 struct scrub_block { 112 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK]; 113 int page_count; 114 atomic_t outstanding_pages; 115 atomic_t refs; /* free mem on transition to zero */ 116 struct scrub_ctx *sctx; 117 struct scrub_parity *sparity; 118 struct { 119 unsigned int header_error:1; 120 unsigned int checksum_error:1; 121 unsigned int no_io_error_seen:1; 122 unsigned int generation_error:1; /* also sets header_error */ 123 124 /* The following is for the data used to check parity */ 125 /* It is for the data with checksum */ 126 unsigned int data_corrected:1; 127 }; 128 struct btrfs_work work; 129 }; 130 131 /* Used for the chunks with parity stripe such RAID5/6 */ 132 struct scrub_parity { 133 struct scrub_ctx *sctx; 134 135 struct btrfs_device *scrub_dev; 136 137 u64 logic_start; 138 139 u64 logic_end; 140 141 int nsectors; 142 143 int stripe_len; 144 145 atomic_t refs; 146 147 struct list_head spages; 148 149 /* Work of parity check and repair */ 150 struct btrfs_work work; 151 152 /* Mark the parity blocks which have data */ 153 unsigned long *dbitmap; 154 155 /* 156 * Mark the parity blocks which have data, but errors happen when 157 * read data or check data 158 */ 159 unsigned long *ebitmap; 160 161 unsigned long bitmap[0]; 162 }; 163 164 struct scrub_wr_ctx { 165 struct scrub_bio *wr_curr_bio; 166 struct btrfs_device *tgtdev; 167 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */ 168 atomic_t flush_all_writes; 169 struct mutex wr_lock; 170 }; 171 172 struct scrub_ctx { 173 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX]; 174 struct btrfs_fs_info *fs_info; 175 int first_free; 176 int curr; 177 atomic_t bios_in_flight; 178 atomic_t workers_pending; 179 spinlock_t list_lock; 180 wait_queue_head_t list_wait; 181 u16 csum_size; 182 struct list_head csum_list; 183 atomic_t cancel_req; 184 int readonly; 185 int pages_per_rd_bio; 186 u32 sectorsize; 187 u32 nodesize; 188 189 int is_dev_replace; 190 struct scrub_wr_ctx wr_ctx; 191 192 /* 193 * statistics 194 */ 195 struct btrfs_scrub_progress stat; 196 spinlock_t stat_lock; 197 198 /* 199 * Use a ref counter to avoid use-after-free issues. Scrub workers 200 * decrement bios_in_flight and workers_pending and then do a wakeup 201 * on the list_wait wait queue. We must ensure the main scrub task 202 * doesn't free the scrub context before or while the workers are 203 * doing the wakeup() call. 204 */ 205 atomic_t refs; 206 }; 207 208 struct scrub_fixup_nodatasum { 209 struct scrub_ctx *sctx; 210 struct btrfs_device *dev; 211 u64 logical; 212 struct btrfs_root *root; 213 struct btrfs_work work; 214 int mirror_num; 215 }; 216 217 struct scrub_nocow_inode { 218 u64 inum; 219 u64 offset; 220 u64 root; 221 struct list_head list; 222 }; 223 224 struct scrub_copy_nocow_ctx { 225 struct scrub_ctx *sctx; 226 u64 logical; 227 u64 len; 228 int mirror_num; 229 u64 physical_for_dev_replace; 230 struct list_head inodes; 231 struct btrfs_work work; 232 }; 233 234 struct scrub_warning { 235 struct btrfs_path *path; 236 u64 extent_item_size; 237 const char *errstr; 238 sector_t sector; 239 u64 logical; 240 struct btrfs_device *dev; 241 }; 242 243 static void scrub_pending_bio_inc(struct scrub_ctx *sctx); 244 static void scrub_pending_bio_dec(struct scrub_ctx *sctx); 245 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx); 246 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx); 247 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check); 248 static int scrub_setup_recheck_block(struct scrub_block *original_sblock, 249 struct scrub_block *sblocks_for_recheck); 250 static void scrub_recheck_block(struct btrfs_fs_info *fs_info, 251 struct scrub_block *sblock, 252 int retry_failed_mirror); 253 static void scrub_recheck_block_checksum(struct scrub_block *sblock); 254 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, 255 struct scrub_block *sblock_good); 256 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, 257 struct scrub_block *sblock_good, 258 int page_num, int force_write); 259 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock); 260 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, 261 int page_num); 262 static int scrub_checksum_data(struct scrub_block *sblock); 263 static int scrub_checksum_tree_block(struct scrub_block *sblock); 264 static int scrub_checksum_super(struct scrub_block *sblock); 265 static void scrub_block_get(struct scrub_block *sblock); 266 static void scrub_block_put(struct scrub_block *sblock); 267 static void scrub_page_get(struct scrub_page *spage); 268 static void scrub_page_put(struct scrub_page *spage); 269 static void scrub_parity_get(struct scrub_parity *sparity); 270 static void scrub_parity_put(struct scrub_parity *sparity); 271 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, 272 struct scrub_page *spage); 273 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 274 u64 physical, struct btrfs_device *dev, u64 flags, 275 u64 gen, int mirror_num, u8 *csum, int force, 276 u64 physical_for_dev_replace); 277 static void scrub_bio_end_io(struct bio *bio); 278 static void scrub_bio_end_io_worker(struct btrfs_work *work); 279 static void scrub_block_complete(struct scrub_block *sblock); 280 static void scrub_remap_extent(struct btrfs_fs_info *fs_info, 281 u64 extent_logical, u64 extent_len, 282 u64 *extent_physical, 283 struct btrfs_device **extent_dev, 284 int *extent_mirror_num); 285 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx, 286 struct scrub_wr_ctx *wr_ctx, 287 struct btrfs_fs_info *fs_info, 288 struct btrfs_device *dev, 289 int is_dev_replace); 290 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx); 291 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, 292 struct scrub_page *spage); 293 static void scrub_wr_submit(struct scrub_ctx *sctx); 294 static void scrub_wr_bio_end_io(struct bio *bio); 295 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work); 296 static int write_page_nocow(struct scrub_ctx *sctx, 297 u64 physical_for_dev_replace, struct page *page); 298 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, 299 struct scrub_copy_nocow_ctx *ctx); 300 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 301 int mirror_num, u64 physical_for_dev_replace); 302 static void copy_nocow_pages_worker(struct btrfs_work *work); 303 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); 304 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); 305 static void scrub_put_ctx(struct scrub_ctx *sctx); 306 307 308 static void scrub_pending_bio_inc(struct scrub_ctx *sctx) 309 { 310 atomic_inc(&sctx->refs); 311 atomic_inc(&sctx->bios_in_flight); 312 } 313 314 static void scrub_pending_bio_dec(struct scrub_ctx *sctx) 315 { 316 atomic_dec(&sctx->bios_in_flight); 317 wake_up(&sctx->list_wait); 318 scrub_put_ctx(sctx); 319 } 320 321 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) 322 { 323 while (atomic_read(&fs_info->scrub_pause_req)) { 324 mutex_unlock(&fs_info->scrub_lock); 325 wait_event(fs_info->scrub_pause_wait, 326 atomic_read(&fs_info->scrub_pause_req) == 0); 327 mutex_lock(&fs_info->scrub_lock); 328 } 329 } 330 331 static void scrub_pause_on(struct btrfs_fs_info *fs_info) 332 { 333 atomic_inc(&fs_info->scrubs_paused); 334 wake_up(&fs_info->scrub_pause_wait); 335 } 336 337 static void scrub_pause_off(struct btrfs_fs_info *fs_info) 338 { 339 mutex_lock(&fs_info->scrub_lock); 340 __scrub_blocked_if_needed(fs_info); 341 atomic_dec(&fs_info->scrubs_paused); 342 mutex_unlock(&fs_info->scrub_lock); 343 344 wake_up(&fs_info->scrub_pause_wait); 345 } 346 347 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) 348 { 349 scrub_pause_on(fs_info); 350 scrub_pause_off(fs_info); 351 } 352 353 /* 354 * used for workers that require transaction commits (i.e., for the 355 * NOCOW case) 356 */ 357 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx) 358 { 359 struct btrfs_fs_info *fs_info = sctx->fs_info; 360 361 atomic_inc(&sctx->refs); 362 /* 363 * increment scrubs_running to prevent cancel requests from 364 * completing as long as a worker is running. we must also 365 * increment scrubs_paused to prevent deadlocking on pause 366 * requests used for transactions commits (as the worker uses a 367 * transaction context). it is safe to regard the worker 368 * as paused for all matters practical. effectively, we only 369 * avoid cancellation requests from completing. 370 */ 371 mutex_lock(&fs_info->scrub_lock); 372 atomic_inc(&fs_info->scrubs_running); 373 atomic_inc(&fs_info->scrubs_paused); 374 mutex_unlock(&fs_info->scrub_lock); 375 376 /* 377 * check if @scrubs_running=@scrubs_paused condition 378 * inside wait_event() is not an atomic operation. 379 * which means we may inc/dec @scrub_running/paused 380 * at any time. Let's wake up @scrub_pause_wait as 381 * much as we can to let commit transaction blocked less. 382 */ 383 wake_up(&fs_info->scrub_pause_wait); 384 385 atomic_inc(&sctx->workers_pending); 386 } 387 388 /* used for workers that require transaction commits */ 389 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx) 390 { 391 struct btrfs_fs_info *fs_info = sctx->fs_info; 392 393 /* 394 * see scrub_pending_trans_workers_inc() why we're pretending 395 * to be paused in the scrub counters 396 */ 397 mutex_lock(&fs_info->scrub_lock); 398 atomic_dec(&fs_info->scrubs_running); 399 atomic_dec(&fs_info->scrubs_paused); 400 mutex_unlock(&fs_info->scrub_lock); 401 atomic_dec(&sctx->workers_pending); 402 wake_up(&fs_info->scrub_pause_wait); 403 wake_up(&sctx->list_wait); 404 scrub_put_ctx(sctx); 405 } 406 407 static void scrub_free_csums(struct scrub_ctx *sctx) 408 { 409 while (!list_empty(&sctx->csum_list)) { 410 struct btrfs_ordered_sum *sum; 411 sum = list_first_entry(&sctx->csum_list, 412 struct btrfs_ordered_sum, list); 413 list_del(&sum->list); 414 kfree(sum); 415 } 416 } 417 418 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) 419 { 420 int i; 421 422 if (!sctx) 423 return; 424 425 scrub_free_wr_ctx(&sctx->wr_ctx); 426 427 /* this can happen when scrub is cancelled */ 428 if (sctx->curr != -1) { 429 struct scrub_bio *sbio = sctx->bios[sctx->curr]; 430 431 for (i = 0; i < sbio->page_count; i++) { 432 WARN_ON(!sbio->pagev[i]->page); 433 scrub_block_put(sbio->pagev[i]->sblock); 434 } 435 bio_put(sbio->bio); 436 } 437 438 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { 439 struct scrub_bio *sbio = sctx->bios[i]; 440 441 if (!sbio) 442 break; 443 kfree(sbio); 444 } 445 446 scrub_free_csums(sctx); 447 kfree(sctx); 448 } 449 450 static void scrub_put_ctx(struct scrub_ctx *sctx) 451 { 452 if (atomic_dec_and_test(&sctx->refs)) 453 scrub_free_ctx(sctx); 454 } 455 456 static noinline_for_stack 457 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace) 458 { 459 struct scrub_ctx *sctx; 460 int i; 461 struct btrfs_fs_info *fs_info = dev->fs_info; 462 int ret; 463 464 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL); 465 if (!sctx) 466 goto nomem; 467 atomic_set(&sctx->refs, 1); 468 sctx->is_dev_replace = is_dev_replace; 469 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO; 470 sctx->curr = -1; 471 sctx->fs_info = dev->fs_info; 472 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { 473 struct scrub_bio *sbio; 474 475 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL); 476 if (!sbio) 477 goto nomem; 478 sctx->bios[i] = sbio; 479 480 sbio->index = i; 481 sbio->sctx = sctx; 482 sbio->page_count = 0; 483 btrfs_init_work(&sbio->work, btrfs_scrub_helper, 484 scrub_bio_end_io_worker, NULL, NULL); 485 486 if (i != SCRUB_BIOS_PER_SCTX - 1) 487 sctx->bios[i]->next_free = i + 1; 488 else 489 sctx->bios[i]->next_free = -1; 490 } 491 sctx->first_free = 0; 492 sctx->nodesize = fs_info->nodesize; 493 sctx->sectorsize = fs_info->sectorsize; 494 atomic_set(&sctx->bios_in_flight, 0); 495 atomic_set(&sctx->workers_pending, 0); 496 atomic_set(&sctx->cancel_req, 0); 497 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy); 498 INIT_LIST_HEAD(&sctx->csum_list); 499 500 spin_lock_init(&sctx->list_lock); 501 spin_lock_init(&sctx->stat_lock); 502 init_waitqueue_head(&sctx->list_wait); 503 504 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info, 505 fs_info->dev_replace.tgtdev, is_dev_replace); 506 if (ret) { 507 scrub_free_ctx(sctx); 508 return ERR_PTR(ret); 509 } 510 return sctx; 511 512 nomem: 513 scrub_free_ctx(sctx); 514 return ERR_PTR(-ENOMEM); 515 } 516 517 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, 518 void *warn_ctx) 519 { 520 u64 isize; 521 u32 nlink; 522 int ret; 523 int i; 524 struct extent_buffer *eb; 525 struct btrfs_inode_item *inode_item; 526 struct scrub_warning *swarn = warn_ctx; 527 struct btrfs_fs_info *fs_info = swarn->dev->fs_info; 528 struct inode_fs_paths *ipath = NULL; 529 struct btrfs_root *local_root; 530 struct btrfs_key root_key; 531 struct btrfs_key key; 532 533 root_key.objectid = root; 534 root_key.type = BTRFS_ROOT_ITEM_KEY; 535 root_key.offset = (u64)-1; 536 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key); 537 if (IS_ERR(local_root)) { 538 ret = PTR_ERR(local_root); 539 goto err; 540 } 541 542 /* 543 * this makes the path point to (inum INODE_ITEM ioff) 544 */ 545 key.objectid = inum; 546 key.type = BTRFS_INODE_ITEM_KEY; 547 key.offset = 0; 548 549 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0); 550 if (ret) { 551 btrfs_release_path(swarn->path); 552 goto err; 553 } 554 555 eb = swarn->path->nodes[0]; 556 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0], 557 struct btrfs_inode_item); 558 isize = btrfs_inode_size(eb, inode_item); 559 nlink = btrfs_inode_nlink(eb, inode_item); 560 btrfs_release_path(swarn->path); 561 562 ipath = init_ipath(4096, local_root, swarn->path); 563 if (IS_ERR(ipath)) { 564 ret = PTR_ERR(ipath); 565 ipath = NULL; 566 goto err; 567 } 568 ret = paths_from_inode(inum, ipath); 569 570 if (ret < 0) 571 goto err; 572 573 /* 574 * we deliberately ignore the bit ipath might have been too small to 575 * hold all of the paths here 576 */ 577 for (i = 0; i < ipath->fspath->elem_cnt; ++i) 578 btrfs_warn_in_rcu(fs_info, 579 "%s at logical %llu on dev %s, sector %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)", 580 swarn->errstr, swarn->logical, 581 rcu_str_deref(swarn->dev->name), 582 (unsigned long long)swarn->sector, 583 root, inum, offset, 584 min(isize - offset, (u64)PAGE_SIZE), nlink, 585 (char *)(unsigned long)ipath->fspath->val[i]); 586 587 free_ipath(ipath); 588 return 0; 589 590 err: 591 btrfs_warn_in_rcu(fs_info, 592 "%s at logical %llu on dev %s, sector %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d", 593 swarn->errstr, swarn->logical, 594 rcu_str_deref(swarn->dev->name), 595 (unsigned long long)swarn->sector, 596 root, inum, offset, ret); 597 598 free_ipath(ipath); 599 return 0; 600 } 601 602 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) 603 { 604 struct btrfs_device *dev; 605 struct btrfs_fs_info *fs_info; 606 struct btrfs_path *path; 607 struct btrfs_key found_key; 608 struct extent_buffer *eb; 609 struct btrfs_extent_item *ei; 610 struct scrub_warning swarn; 611 unsigned long ptr = 0; 612 u64 extent_item_pos; 613 u64 flags = 0; 614 u64 ref_root; 615 u32 item_size; 616 u8 ref_level = 0; 617 int ret; 618 619 WARN_ON(sblock->page_count < 1); 620 dev = sblock->pagev[0]->dev; 621 fs_info = sblock->sctx->fs_info; 622 623 path = btrfs_alloc_path(); 624 if (!path) 625 return; 626 627 swarn.sector = (sblock->pagev[0]->physical) >> 9; 628 swarn.logical = sblock->pagev[0]->logical; 629 swarn.errstr = errstr; 630 swarn.dev = NULL; 631 632 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, 633 &flags); 634 if (ret < 0) 635 goto out; 636 637 extent_item_pos = swarn.logical - found_key.objectid; 638 swarn.extent_item_size = found_key.offset; 639 640 eb = path->nodes[0]; 641 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); 642 item_size = btrfs_item_size_nr(eb, path->slots[0]); 643 644 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 645 do { 646 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei, 647 item_size, &ref_root, 648 &ref_level); 649 btrfs_warn_in_rcu(fs_info, 650 "%s at logical %llu on dev %s, sector %llu: metadata %s (level %d) in tree %llu", 651 errstr, swarn.logical, 652 rcu_str_deref(dev->name), 653 (unsigned long long)swarn.sector, 654 ref_level ? "node" : "leaf", 655 ret < 0 ? -1 : ref_level, 656 ret < 0 ? -1 : ref_root); 657 } while (ret != 1); 658 btrfs_release_path(path); 659 } else { 660 btrfs_release_path(path); 661 swarn.path = path; 662 swarn.dev = dev; 663 iterate_extent_inodes(fs_info, found_key.objectid, 664 extent_item_pos, 1, 665 scrub_print_warning_inode, &swarn); 666 } 667 668 out: 669 btrfs_free_path(path); 670 } 671 672 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx) 673 { 674 struct page *page = NULL; 675 unsigned long index; 676 struct scrub_fixup_nodatasum *fixup = fixup_ctx; 677 int ret; 678 int corrected = 0; 679 struct btrfs_key key; 680 struct inode *inode = NULL; 681 struct btrfs_fs_info *fs_info; 682 u64 end = offset + PAGE_SIZE - 1; 683 struct btrfs_root *local_root; 684 int srcu_index; 685 686 key.objectid = root; 687 key.type = BTRFS_ROOT_ITEM_KEY; 688 key.offset = (u64)-1; 689 690 fs_info = fixup->root->fs_info; 691 srcu_index = srcu_read_lock(&fs_info->subvol_srcu); 692 693 local_root = btrfs_read_fs_root_no_name(fs_info, &key); 694 if (IS_ERR(local_root)) { 695 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 696 return PTR_ERR(local_root); 697 } 698 699 key.type = BTRFS_INODE_ITEM_KEY; 700 key.objectid = inum; 701 key.offset = 0; 702 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL); 703 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 704 if (IS_ERR(inode)) 705 return PTR_ERR(inode); 706 707 index = offset >> PAGE_SHIFT; 708 709 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 710 if (!page) { 711 ret = -ENOMEM; 712 goto out; 713 } 714 715 if (PageUptodate(page)) { 716 if (PageDirty(page)) { 717 /* 718 * we need to write the data to the defect sector. the 719 * data that was in that sector is not in memory, 720 * because the page was modified. we must not write the 721 * modified page to that sector. 722 * 723 * TODO: what could be done here: wait for the delalloc 724 * runner to write out that page (might involve 725 * COW) and see whether the sector is still 726 * referenced afterwards. 727 * 728 * For the meantime, we'll treat this error 729 * incorrectable, although there is a chance that a 730 * later scrub will find the bad sector again and that 731 * there's no dirty page in memory, then. 732 */ 733 ret = -EIO; 734 goto out; 735 } 736 ret = repair_io_failure(inode, offset, PAGE_SIZE, 737 fixup->logical, page, 738 offset - page_offset(page), 739 fixup->mirror_num); 740 unlock_page(page); 741 corrected = !ret; 742 } else { 743 /* 744 * we need to get good data first. the general readpage path 745 * will call repair_io_failure for us, we just have to make 746 * sure we read the bad mirror. 747 */ 748 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 749 EXTENT_DAMAGED); 750 if (ret) { 751 /* set_extent_bits should give proper error */ 752 WARN_ON(ret > 0); 753 if (ret > 0) 754 ret = -EFAULT; 755 goto out; 756 } 757 758 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page, 759 btrfs_get_extent, 760 fixup->mirror_num); 761 wait_on_page_locked(page); 762 763 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset, 764 end, EXTENT_DAMAGED, 0, NULL); 765 if (!corrected) 766 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 767 EXTENT_DAMAGED); 768 } 769 770 out: 771 if (page) 772 put_page(page); 773 774 iput(inode); 775 776 if (ret < 0) 777 return ret; 778 779 if (ret == 0 && corrected) { 780 /* 781 * we only need to call readpage for one of the inodes belonging 782 * to this extent. so make iterate_extent_inodes stop 783 */ 784 return 1; 785 } 786 787 return -EIO; 788 } 789 790 static void scrub_fixup_nodatasum(struct btrfs_work *work) 791 { 792 struct btrfs_fs_info *fs_info; 793 int ret; 794 struct scrub_fixup_nodatasum *fixup; 795 struct scrub_ctx *sctx; 796 struct btrfs_trans_handle *trans = NULL; 797 struct btrfs_path *path; 798 int uncorrectable = 0; 799 800 fixup = container_of(work, struct scrub_fixup_nodatasum, work); 801 sctx = fixup->sctx; 802 fs_info = fixup->root->fs_info; 803 804 path = btrfs_alloc_path(); 805 if (!path) { 806 spin_lock(&sctx->stat_lock); 807 ++sctx->stat.malloc_errors; 808 spin_unlock(&sctx->stat_lock); 809 uncorrectable = 1; 810 goto out; 811 } 812 813 trans = btrfs_join_transaction(fixup->root); 814 if (IS_ERR(trans)) { 815 uncorrectable = 1; 816 goto out; 817 } 818 819 /* 820 * the idea is to trigger a regular read through the standard path. we 821 * read a page from the (failed) logical address by specifying the 822 * corresponding copynum of the failed sector. thus, that readpage is 823 * expected to fail. 824 * that is the point where on-the-fly error correction will kick in 825 * (once it's finished) and rewrite the failed sector if a good copy 826 * can be found. 827 */ 828 ret = iterate_inodes_from_logical(fixup->logical, fs_info, path, 829 scrub_fixup_readpage, fixup); 830 if (ret < 0) { 831 uncorrectable = 1; 832 goto out; 833 } 834 WARN_ON(ret != 1); 835 836 spin_lock(&sctx->stat_lock); 837 ++sctx->stat.corrected_errors; 838 spin_unlock(&sctx->stat_lock); 839 840 out: 841 if (trans && !IS_ERR(trans)) 842 btrfs_end_transaction(trans); 843 if (uncorrectable) { 844 spin_lock(&sctx->stat_lock); 845 ++sctx->stat.uncorrectable_errors; 846 spin_unlock(&sctx->stat_lock); 847 btrfs_dev_replace_stats_inc( 848 &fs_info->dev_replace.num_uncorrectable_read_errors); 849 btrfs_err_rl_in_rcu(fs_info, 850 "unable to fixup (nodatasum) error at logical %llu on dev %s", 851 fixup->logical, rcu_str_deref(fixup->dev->name)); 852 } 853 854 btrfs_free_path(path); 855 kfree(fixup); 856 857 scrub_pending_trans_workers_dec(sctx); 858 } 859 860 static inline void scrub_get_recover(struct scrub_recover *recover) 861 { 862 atomic_inc(&recover->refs); 863 } 864 865 static inline void scrub_put_recover(struct scrub_recover *recover) 866 { 867 if (atomic_dec_and_test(&recover->refs)) { 868 btrfs_put_bbio(recover->bbio); 869 kfree(recover); 870 } 871 } 872 873 /* 874 * scrub_handle_errored_block gets called when either verification of the 875 * pages failed or the bio failed to read, e.g. with EIO. In the latter 876 * case, this function handles all pages in the bio, even though only one 877 * may be bad. 878 * The goal of this function is to repair the errored block by using the 879 * contents of one of the mirrors. 880 */ 881 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) 882 { 883 struct scrub_ctx *sctx = sblock_to_check->sctx; 884 struct btrfs_device *dev; 885 struct btrfs_fs_info *fs_info; 886 u64 length; 887 u64 logical; 888 unsigned int failed_mirror_index; 889 unsigned int is_metadata; 890 unsigned int have_csum; 891 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */ 892 struct scrub_block *sblock_bad; 893 int ret; 894 int mirror_index; 895 int page_num; 896 int success; 897 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 898 DEFAULT_RATELIMIT_BURST); 899 900 BUG_ON(sblock_to_check->page_count < 1); 901 fs_info = sctx->fs_info; 902 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) { 903 /* 904 * if we find an error in a super block, we just report it. 905 * They will get written with the next transaction commit 906 * anyway 907 */ 908 spin_lock(&sctx->stat_lock); 909 ++sctx->stat.super_errors; 910 spin_unlock(&sctx->stat_lock); 911 return 0; 912 } 913 length = sblock_to_check->page_count * PAGE_SIZE; 914 logical = sblock_to_check->pagev[0]->logical; 915 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1); 916 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1; 917 is_metadata = !(sblock_to_check->pagev[0]->flags & 918 BTRFS_EXTENT_FLAG_DATA); 919 have_csum = sblock_to_check->pagev[0]->have_csum; 920 dev = sblock_to_check->pagev[0]->dev; 921 922 if (sctx->is_dev_replace && !is_metadata && !have_csum) { 923 sblocks_for_recheck = NULL; 924 goto nodatasum_case; 925 } 926 927 /* 928 * read all mirrors one after the other. This includes to 929 * re-read the extent or metadata block that failed (that was 930 * the cause that this fixup code is called) another time, 931 * page by page this time in order to know which pages 932 * caused I/O errors and which ones are good (for all mirrors). 933 * It is the goal to handle the situation when more than one 934 * mirror contains I/O errors, but the errors do not 935 * overlap, i.e. the data can be repaired by selecting the 936 * pages from those mirrors without I/O error on the 937 * particular pages. One example (with blocks >= 2 * PAGE_SIZE) 938 * would be that mirror #1 has an I/O error on the first page, 939 * the second page is good, and mirror #2 has an I/O error on 940 * the second page, but the first page is good. 941 * Then the first page of the first mirror can be repaired by 942 * taking the first page of the second mirror, and the 943 * second page of the second mirror can be repaired by 944 * copying the contents of the 2nd page of the 1st mirror. 945 * One more note: if the pages of one mirror contain I/O 946 * errors, the checksum cannot be verified. In order to get 947 * the best data for repairing, the first attempt is to find 948 * a mirror without I/O errors and with a validated checksum. 949 * Only if this is not possible, the pages are picked from 950 * mirrors with I/O errors without considering the checksum. 951 * If the latter is the case, at the end, the checksum of the 952 * repaired area is verified in order to correctly maintain 953 * the statistics. 954 */ 955 956 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS, 957 sizeof(*sblocks_for_recheck), GFP_NOFS); 958 if (!sblocks_for_recheck) { 959 spin_lock(&sctx->stat_lock); 960 sctx->stat.malloc_errors++; 961 sctx->stat.read_errors++; 962 sctx->stat.uncorrectable_errors++; 963 spin_unlock(&sctx->stat_lock); 964 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 965 goto out; 966 } 967 968 /* setup the context, map the logical blocks and alloc the pages */ 969 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck); 970 if (ret) { 971 spin_lock(&sctx->stat_lock); 972 sctx->stat.read_errors++; 973 sctx->stat.uncorrectable_errors++; 974 spin_unlock(&sctx->stat_lock); 975 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 976 goto out; 977 } 978 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS); 979 sblock_bad = sblocks_for_recheck + failed_mirror_index; 980 981 /* build and submit the bios for the failed mirror, check checksums */ 982 scrub_recheck_block(fs_info, sblock_bad, 1); 983 984 if (!sblock_bad->header_error && !sblock_bad->checksum_error && 985 sblock_bad->no_io_error_seen) { 986 /* 987 * the error disappeared after reading page by page, or 988 * the area was part of a huge bio and other parts of the 989 * bio caused I/O errors, or the block layer merged several 990 * read requests into one and the error is caused by a 991 * different bio (usually one of the two latter cases is 992 * the cause) 993 */ 994 spin_lock(&sctx->stat_lock); 995 sctx->stat.unverified_errors++; 996 sblock_to_check->data_corrected = 1; 997 spin_unlock(&sctx->stat_lock); 998 999 if (sctx->is_dev_replace) 1000 scrub_write_block_to_dev_replace(sblock_bad); 1001 goto out; 1002 } 1003 1004 if (!sblock_bad->no_io_error_seen) { 1005 spin_lock(&sctx->stat_lock); 1006 sctx->stat.read_errors++; 1007 spin_unlock(&sctx->stat_lock); 1008 if (__ratelimit(&_rs)) 1009 scrub_print_warning("i/o error", sblock_to_check); 1010 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 1011 } else if (sblock_bad->checksum_error) { 1012 spin_lock(&sctx->stat_lock); 1013 sctx->stat.csum_errors++; 1014 spin_unlock(&sctx->stat_lock); 1015 if (__ratelimit(&_rs)) 1016 scrub_print_warning("checksum error", sblock_to_check); 1017 btrfs_dev_stat_inc_and_print(dev, 1018 BTRFS_DEV_STAT_CORRUPTION_ERRS); 1019 } else if (sblock_bad->header_error) { 1020 spin_lock(&sctx->stat_lock); 1021 sctx->stat.verify_errors++; 1022 spin_unlock(&sctx->stat_lock); 1023 if (__ratelimit(&_rs)) 1024 scrub_print_warning("checksum/header error", 1025 sblock_to_check); 1026 if (sblock_bad->generation_error) 1027 btrfs_dev_stat_inc_and_print(dev, 1028 BTRFS_DEV_STAT_GENERATION_ERRS); 1029 else 1030 btrfs_dev_stat_inc_and_print(dev, 1031 BTRFS_DEV_STAT_CORRUPTION_ERRS); 1032 } 1033 1034 if (sctx->readonly) { 1035 ASSERT(!sctx->is_dev_replace); 1036 goto out; 1037 } 1038 1039 if (!is_metadata && !have_csum) { 1040 struct scrub_fixup_nodatasum *fixup_nodatasum; 1041 1042 WARN_ON(sctx->is_dev_replace); 1043 1044 nodatasum_case: 1045 1046 /* 1047 * !is_metadata and !have_csum, this means that the data 1048 * might not be COWed, that it might be modified 1049 * concurrently. The general strategy to work on the 1050 * commit root does not help in the case when COW is not 1051 * used. 1052 */ 1053 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS); 1054 if (!fixup_nodatasum) 1055 goto did_not_correct_error; 1056 fixup_nodatasum->sctx = sctx; 1057 fixup_nodatasum->dev = dev; 1058 fixup_nodatasum->logical = logical; 1059 fixup_nodatasum->root = fs_info->extent_root; 1060 fixup_nodatasum->mirror_num = failed_mirror_index + 1; 1061 scrub_pending_trans_workers_inc(sctx); 1062 btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper, 1063 scrub_fixup_nodatasum, NULL, NULL); 1064 btrfs_queue_work(fs_info->scrub_workers, 1065 &fixup_nodatasum->work); 1066 goto out; 1067 } 1068 1069 /* 1070 * now build and submit the bios for the other mirrors, check 1071 * checksums. 1072 * First try to pick the mirror which is completely without I/O 1073 * errors and also does not have a checksum error. 1074 * If one is found, and if a checksum is present, the full block 1075 * that is known to contain an error is rewritten. Afterwards 1076 * the block is known to be corrected. 1077 * If a mirror is found which is completely correct, and no 1078 * checksum is present, only those pages are rewritten that had 1079 * an I/O error in the block to be repaired, since it cannot be 1080 * determined, which copy of the other pages is better (and it 1081 * could happen otherwise that a correct page would be 1082 * overwritten by a bad one). 1083 */ 1084 for (mirror_index = 0; 1085 mirror_index < BTRFS_MAX_MIRRORS && 1086 sblocks_for_recheck[mirror_index].page_count > 0; 1087 mirror_index++) { 1088 struct scrub_block *sblock_other; 1089 1090 if (mirror_index == failed_mirror_index) 1091 continue; 1092 sblock_other = sblocks_for_recheck + mirror_index; 1093 1094 /* build and submit the bios, check checksums */ 1095 scrub_recheck_block(fs_info, sblock_other, 0); 1096 1097 if (!sblock_other->header_error && 1098 !sblock_other->checksum_error && 1099 sblock_other->no_io_error_seen) { 1100 if (sctx->is_dev_replace) { 1101 scrub_write_block_to_dev_replace(sblock_other); 1102 goto corrected_error; 1103 } else { 1104 ret = scrub_repair_block_from_good_copy( 1105 sblock_bad, sblock_other); 1106 if (!ret) 1107 goto corrected_error; 1108 } 1109 } 1110 } 1111 1112 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace) 1113 goto did_not_correct_error; 1114 1115 /* 1116 * In case of I/O errors in the area that is supposed to be 1117 * repaired, continue by picking good copies of those pages. 1118 * Select the good pages from mirrors to rewrite bad pages from 1119 * the area to fix. Afterwards verify the checksum of the block 1120 * that is supposed to be repaired. This verification step is 1121 * only done for the purpose of statistic counting and for the 1122 * final scrub report, whether errors remain. 1123 * A perfect algorithm could make use of the checksum and try 1124 * all possible combinations of pages from the different mirrors 1125 * until the checksum verification succeeds. For example, when 1126 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page 1127 * of mirror #2 is readable but the final checksum test fails, 1128 * then the 2nd page of mirror #3 could be tried, whether now 1129 * the final checksum succeeds. But this would be a rare 1130 * exception and is therefore not implemented. At least it is 1131 * avoided that the good copy is overwritten. 1132 * A more useful improvement would be to pick the sectors 1133 * without I/O error based on sector sizes (512 bytes on legacy 1134 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one 1135 * mirror could be repaired by taking 512 byte of a different 1136 * mirror, even if other 512 byte sectors in the same PAGE_SIZE 1137 * area are unreadable. 1138 */ 1139 success = 1; 1140 for (page_num = 0; page_num < sblock_bad->page_count; 1141 page_num++) { 1142 struct scrub_page *page_bad = sblock_bad->pagev[page_num]; 1143 struct scrub_block *sblock_other = NULL; 1144 1145 /* skip no-io-error page in scrub */ 1146 if (!page_bad->io_error && !sctx->is_dev_replace) 1147 continue; 1148 1149 /* try to find no-io-error page in mirrors */ 1150 if (page_bad->io_error) { 1151 for (mirror_index = 0; 1152 mirror_index < BTRFS_MAX_MIRRORS && 1153 sblocks_for_recheck[mirror_index].page_count > 0; 1154 mirror_index++) { 1155 if (!sblocks_for_recheck[mirror_index]. 1156 pagev[page_num]->io_error) { 1157 sblock_other = sblocks_for_recheck + 1158 mirror_index; 1159 break; 1160 } 1161 } 1162 if (!sblock_other) 1163 success = 0; 1164 } 1165 1166 if (sctx->is_dev_replace) { 1167 /* 1168 * did not find a mirror to fetch the page 1169 * from. scrub_write_page_to_dev_replace() 1170 * handles this case (page->io_error), by 1171 * filling the block with zeros before 1172 * submitting the write request 1173 */ 1174 if (!sblock_other) 1175 sblock_other = sblock_bad; 1176 1177 if (scrub_write_page_to_dev_replace(sblock_other, 1178 page_num) != 0) { 1179 btrfs_dev_replace_stats_inc( 1180 &fs_info->dev_replace.num_write_errors); 1181 success = 0; 1182 } 1183 } else if (sblock_other) { 1184 ret = scrub_repair_page_from_good_copy(sblock_bad, 1185 sblock_other, 1186 page_num, 0); 1187 if (0 == ret) 1188 page_bad->io_error = 0; 1189 else 1190 success = 0; 1191 } 1192 } 1193 1194 if (success && !sctx->is_dev_replace) { 1195 if (is_metadata || have_csum) { 1196 /* 1197 * need to verify the checksum now that all 1198 * sectors on disk are repaired (the write 1199 * request for data to be repaired is on its way). 1200 * Just be lazy and use scrub_recheck_block() 1201 * which re-reads the data before the checksum 1202 * is verified, but most likely the data comes out 1203 * of the page cache. 1204 */ 1205 scrub_recheck_block(fs_info, sblock_bad, 1); 1206 if (!sblock_bad->header_error && 1207 !sblock_bad->checksum_error && 1208 sblock_bad->no_io_error_seen) 1209 goto corrected_error; 1210 else 1211 goto did_not_correct_error; 1212 } else { 1213 corrected_error: 1214 spin_lock(&sctx->stat_lock); 1215 sctx->stat.corrected_errors++; 1216 sblock_to_check->data_corrected = 1; 1217 spin_unlock(&sctx->stat_lock); 1218 btrfs_err_rl_in_rcu(fs_info, 1219 "fixed up error at logical %llu on dev %s", 1220 logical, rcu_str_deref(dev->name)); 1221 } 1222 } else { 1223 did_not_correct_error: 1224 spin_lock(&sctx->stat_lock); 1225 sctx->stat.uncorrectable_errors++; 1226 spin_unlock(&sctx->stat_lock); 1227 btrfs_err_rl_in_rcu(fs_info, 1228 "unable to fixup (regular) error at logical %llu on dev %s", 1229 logical, rcu_str_deref(dev->name)); 1230 } 1231 1232 out: 1233 if (sblocks_for_recheck) { 1234 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS; 1235 mirror_index++) { 1236 struct scrub_block *sblock = sblocks_for_recheck + 1237 mirror_index; 1238 struct scrub_recover *recover; 1239 int page_index; 1240 1241 for (page_index = 0; page_index < sblock->page_count; 1242 page_index++) { 1243 sblock->pagev[page_index]->sblock = NULL; 1244 recover = sblock->pagev[page_index]->recover; 1245 if (recover) { 1246 scrub_put_recover(recover); 1247 sblock->pagev[page_index]->recover = 1248 NULL; 1249 } 1250 scrub_page_put(sblock->pagev[page_index]); 1251 } 1252 } 1253 kfree(sblocks_for_recheck); 1254 } 1255 1256 return 0; 1257 } 1258 1259 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio) 1260 { 1261 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5) 1262 return 2; 1263 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) 1264 return 3; 1265 else 1266 return (int)bbio->num_stripes; 1267 } 1268 1269 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type, 1270 u64 *raid_map, 1271 u64 mapped_length, 1272 int nstripes, int mirror, 1273 int *stripe_index, 1274 u64 *stripe_offset) 1275 { 1276 int i; 1277 1278 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) { 1279 /* RAID5/6 */ 1280 for (i = 0; i < nstripes; i++) { 1281 if (raid_map[i] == RAID6_Q_STRIPE || 1282 raid_map[i] == RAID5_P_STRIPE) 1283 continue; 1284 1285 if (logical >= raid_map[i] && 1286 logical < raid_map[i] + mapped_length) 1287 break; 1288 } 1289 1290 *stripe_index = i; 1291 *stripe_offset = logical - raid_map[i]; 1292 } else { 1293 /* The other RAID type */ 1294 *stripe_index = mirror; 1295 *stripe_offset = 0; 1296 } 1297 } 1298 1299 static int scrub_setup_recheck_block(struct scrub_block *original_sblock, 1300 struct scrub_block *sblocks_for_recheck) 1301 { 1302 struct scrub_ctx *sctx = original_sblock->sctx; 1303 struct btrfs_fs_info *fs_info = sctx->fs_info; 1304 u64 length = original_sblock->page_count * PAGE_SIZE; 1305 u64 logical = original_sblock->pagev[0]->logical; 1306 u64 generation = original_sblock->pagev[0]->generation; 1307 u64 flags = original_sblock->pagev[0]->flags; 1308 u64 have_csum = original_sblock->pagev[0]->have_csum; 1309 struct scrub_recover *recover; 1310 struct btrfs_bio *bbio; 1311 u64 sublen; 1312 u64 mapped_length; 1313 u64 stripe_offset; 1314 int stripe_index; 1315 int page_index = 0; 1316 int mirror_index; 1317 int nmirrors; 1318 int ret; 1319 1320 /* 1321 * note: the two members refs and outstanding_pages 1322 * are not used (and not set) in the blocks that are used for 1323 * the recheck procedure 1324 */ 1325 1326 while (length > 0) { 1327 sublen = min_t(u64, length, PAGE_SIZE); 1328 mapped_length = sublen; 1329 bbio = NULL; 1330 1331 /* 1332 * with a length of PAGE_SIZE, each returned stripe 1333 * represents one mirror 1334 */ 1335 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, 1336 logical, &mapped_length, &bbio, 0, 1); 1337 if (ret || !bbio || mapped_length < sublen) { 1338 btrfs_put_bbio(bbio); 1339 return -EIO; 1340 } 1341 1342 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS); 1343 if (!recover) { 1344 btrfs_put_bbio(bbio); 1345 return -ENOMEM; 1346 } 1347 1348 atomic_set(&recover->refs, 1); 1349 recover->bbio = bbio; 1350 recover->map_length = mapped_length; 1351 1352 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK); 1353 1354 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS); 1355 1356 for (mirror_index = 0; mirror_index < nmirrors; 1357 mirror_index++) { 1358 struct scrub_block *sblock; 1359 struct scrub_page *page; 1360 1361 sblock = sblocks_for_recheck + mirror_index; 1362 sblock->sctx = sctx; 1363 1364 page = kzalloc(sizeof(*page), GFP_NOFS); 1365 if (!page) { 1366 leave_nomem: 1367 spin_lock(&sctx->stat_lock); 1368 sctx->stat.malloc_errors++; 1369 spin_unlock(&sctx->stat_lock); 1370 scrub_put_recover(recover); 1371 return -ENOMEM; 1372 } 1373 scrub_page_get(page); 1374 sblock->pagev[page_index] = page; 1375 page->sblock = sblock; 1376 page->flags = flags; 1377 page->generation = generation; 1378 page->logical = logical; 1379 page->have_csum = have_csum; 1380 if (have_csum) 1381 memcpy(page->csum, 1382 original_sblock->pagev[0]->csum, 1383 sctx->csum_size); 1384 1385 scrub_stripe_index_and_offset(logical, 1386 bbio->map_type, 1387 bbio->raid_map, 1388 mapped_length, 1389 bbio->num_stripes - 1390 bbio->num_tgtdevs, 1391 mirror_index, 1392 &stripe_index, 1393 &stripe_offset); 1394 page->physical = bbio->stripes[stripe_index].physical + 1395 stripe_offset; 1396 page->dev = bbio->stripes[stripe_index].dev; 1397 1398 BUG_ON(page_index >= original_sblock->page_count); 1399 page->physical_for_dev_replace = 1400 original_sblock->pagev[page_index]-> 1401 physical_for_dev_replace; 1402 /* for missing devices, dev->bdev is NULL */ 1403 page->mirror_num = mirror_index + 1; 1404 sblock->page_count++; 1405 page->page = alloc_page(GFP_NOFS); 1406 if (!page->page) 1407 goto leave_nomem; 1408 1409 scrub_get_recover(recover); 1410 page->recover = recover; 1411 } 1412 scrub_put_recover(recover); 1413 length -= sublen; 1414 logical += sublen; 1415 page_index++; 1416 } 1417 1418 return 0; 1419 } 1420 1421 struct scrub_bio_ret { 1422 struct completion event; 1423 int error; 1424 }; 1425 1426 static void scrub_bio_wait_endio(struct bio *bio) 1427 { 1428 struct scrub_bio_ret *ret = bio->bi_private; 1429 1430 ret->error = bio->bi_error; 1431 complete(&ret->event); 1432 } 1433 1434 static inline int scrub_is_page_on_raid56(struct scrub_page *page) 1435 { 1436 return page->recover && 1437 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK); 1438 } 1439 1440 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info, 1441 struct bio *bio, 1442 struct scrub_page *page) 1443 { 1444 struct scrub_bio_ret done; 1445 int ret; 1446 1447 init_completion(&done.event); 1448 done.error = 0; 1449 bio->bi_iter.bi_sector = page->logical >> 9; 1450 bio->bi_private = &done; 1451 bio->bi_end_io = scrub_bio_wait_endio; 1452 1453 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio, 1454 page->recover->map_length, 1455 page->mirror_num, 0); 1456 if (ret) 1457 return ret; 1458 1459 wait_for_completion(&done.event); 1460 if (done.error) 1461 return -EIO; 1462 1463 return 0; 1464 } 1465 1466 /* 1467 * this function will check the on disk data for checksum errors, header 1468 * errors and read I/O errors. If any I/O errors happen, the exact pages 1469 * which are errored are marked as being bad. The goal is to enable scrub 1470 * to take those pages that are not errored from all the mirrors so that 1471 * the pages that are errored in the just handled mirror can be repaired. 1472 */ 1473 static void scrub_recheck_block(struct btrfs_fs_info *fs_info, 1474 struct scrub_block *sblock, 1475 int retry_failed_mirror) 1476 { 1477 int page_num; 1478 1479 sblock->no_io_error_seen = 1; 1480 1481 for (page_num = 0; page_num < sblock->page_count; page_num++) { 1482 struct bio *bio; 1483 struct scrub_page *page = sblock->pagev[page_num]; 1484 1485 if (page->dev->bdev == NULL) { 1486 page->io_error = 1; 1487 sblock->no_io_error_seen = 0; 1488 continue; 1489 } 1490 1491 WARN_ON(!page->page); 1492 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 1493 if (!bio) { 1494 page->io_error = 1; 1495 sblock->no_io_error_seen = 0; 1496 continue; 1497 } 1498 bio->bi_bdev = page->dev->bdev; 1499 1500 bio_add_page(bio, page->page, PAGE_SIZE, 0); 1501 if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) { 1502 if (scrub_submit_raid56_bio_wait(fs_info, bio, page)) 1503 sblock->no_io_error_seen = 0; 1504 } else { 1505 bio->bi_iter.bi_sector = page->physical >> 9; 1506 bio_set_op_attrs(bio, REQ_OP_READ, 0); 1507 1508 if (btrfsic_submit_bio_wait(bio)) 1509 sblock->no_io_error_seen = 0; 1510 } 1511 1512 bio_put(bio); 1513 } 1514 1515 if (sblock->no_io_error_seen) 1516 scrub_recheck_block_checksum(sblock); 1517 } 1518 1519 static inline int scrub_check_fsid(u8 fsid[], 1520 struct scrub_page *spage) 1521 { 1522 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices; 1523 int ret; 1524 1525 ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE); 1526 return !ret; 1527 } 1528 1529 static void scrub_recheck_block_checksum(struct scrub_block *sblock) 1530 { 1531 sblock->header_error = 0; 1532 sblock->checksum_error = 0; 1533 sblock->generation_error = 0; 1534 1535 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA) 1536 scrub_checksum_data(sblock); 1537 else 1538 scrub_checksum_tree_block(sblock); 1539 } 1540 1541 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, 1542 struct scrub_block *sblock_good) 1543 { 1544 int page_num; 1545 int ret = 0; 1546 1547 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { 1548 int ret_sub; 1549 1550 ret_sub = scrub_repair_page_from_good_copy(sblock_bad, 1551 sblock_good, 1552 page_num, 1); 1553 if (ret_sub) 1554 ret = ret_sub; 1555 } 1556 1557 return ret; 1558 } 1559 1560 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, 1561 struct scrub_block *sblock_good, 1562 int page_num, int force_write) 1563 { 1564 struct scrub_page *page_bad = sblock_bad->pagev[page_num]; 1565 struct scrub_page *page_good = sblock_good->pagev[page_num]; 1566 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info; 1567 1568 BUG_ON(page_bad->page == NULL); 1569 BUG_ON(page_good->page == NULL); 1570 if (force_write || sblock_bad->header_error || 1571 sblock_bad->checksum_error || page_bad->io_error) { 1572 struct bio *bio; 1573 int ret; 1574 1575 if (!page_bad->dev->bdev) { 1576 btrfs_warn_rl(fs_info, 1577 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected"); 1578 return -EIO; 1579 } 1580 1581 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 1582 if (!bio) 1583 return -EIO; 1584 bio->bi_bdev = page_bad->dev->bdev; 1585 bio->bi_iter.bi_sector = page_bad->physical >> 9; 1586 bio_set_op_attrs(bio, REQ_OP_WRITE, 0); 1587 1588 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0); 1589 if (PAGE_SIZE != ret) { 1590 bio_put(bio); 1591 return -EIO; 1592 } 1593 1594 if (btrfsic_submit_bio_wait(bio)) { 1595 btrfs_dev_stat_inc_and_print(page_bad->dev, 1596 BTRFS_DEV_STAT_WRITE_ERRS); 1597 btrfs_dev_replace_stats_inc( 1598 &fs_info->dev_replace.num_write_errors); 1599 bio_put(bio); 1600 return -EIO; 1601 } 1602 bio_put(bio); 1603 } 1604 1605 return 0; 1606 } 1607 1608 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock) 1609 { 1610 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info; 1611 int page_num; 1612 1613 /* 1614 * This block is used for the check of the parity on the source device, 1615 * so the data needn't be written into the destination device. 1616 */ 1617 if (sblock->sparity) 1618 return; 1619 1620 for (page_num = 0; page_num < sblock->page_count; page_num++) { 1621 int ret; 1622 1623 ret = scrub_write_page_to_dev_replace(sblock, page_num); 1624 if (ret) 1625 btrfs_dev_replace_stats_inc( 1626 &fs_info->dev_replace.num_write_errors); 1627 } 1628 } 1629 1630 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, 1631 int page_num) 1632 { 1633 struct scrub_page *spage = sblock->pagev[page_num]; 1634 1635 BUG_ON(spage->page == NULL); 1636 if (spage->io_error) { 1637 void *mapped_buffer = kmap_atomic(spage->page); 1638 1639 memset(mapped_buffer, 0, PAGE_SIZE); 1640 flush_dcache_page(spage->page); 1641 kunmap_atomic(mapped_buffer); 1642 } 1643 return scrub_add_page_to_wr_bio(sblock->sctx, spage); 1644 } 1645 1646 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, 1647 struct scrub_page *spage) 1648 { 1649 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx; 1650 struct scrub_bio *sbio; 1651 int ret; 1652 1653 mutex_lock(&wr_ctx->wr_lock); 1654 again: 1655 if (!wr_ctx->wr_curr_bio) { 1656 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio), 1657 GFP_KERNEL); 1658 if (!wr_ctx->wr_curr_bio) { 1659 mutex_unlock(&wr_ctx->wr_lock); 1660 return -ENOMEM; 1661 } 1662 wr_ctx->wr_curr_bio->sctx = sctx; 1663 wr_ctx->wr_curr_bio->page_count = 0; 1664 } 1665 sbio = wr_ctx->wr_curr_bio; 1666 if (sbio->page_count == 0) { 1667 struct bio *bio; 1668 1669 sbio->physical = spage->physical_for_dev_replace; 1670 sbio->logical = spage->logical; 1671 sbio->dev = wr_ctx->tgtdev; 1672 bio = sbio->bio; 1673 if (!bio) { 1674 bio = btrfs_io_bio_alloc(GFP_KERNEL, 1675 wr_ctx->pages_per_wr_bio); 1676 if (!bio) { 1677 mutex_unlock(&wr_ctx->wr_lock); 1678 return -ENOMEM; 1679 } 1680 sbio->bio = bio; 1681 } 1682 1683 bio->bi_private = sbio; 1684 bio->bi_end_io = scrub_wr_bio_end_io; 1685 bio->bi_bdev = sbio->dev->bdev; 1686 bio->bi_iter.bi_sector = sbio->physical >> 9; 1687 bio_set_op_attrs(bio, REQ_OP_WRITE, 0); 1688 sbio->err = 0; 1689 } else if (sbio->physical + sbio->page_count * PAGE_SIZE != 1690 spage->physical_for_dev_replace || 1691 sbio->logical + sbio->page_count * PAGE_SIZE != 1692 spage->logical) { 1693 scrub_wr_submit(sctx); 1694 goto again; 1695 } 1696 1697 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); 1698 if (ret != PAGE_SIZE) { 1699 if (sbio->page_count < 1) { 1700 bio_put(sbio->bio); 1701 sbio->bio = NULL; 1702 mutex_unlock(&wr_ctx->wr_lock); 1703 return -EIO; 1704 } 1705 scrub_wr_submit(sctx); 1706 goto again; 1707 } 1708 1709 sbio->pagev[sbio->page_count] = spage; 1710 scrub_page_get(spage); 1711 sbio->page_count++; 1712 if (sbio->page_count == wr_ctx->pages_per_wr_bio) 1713 scrub_wr_submit(sctx); 1714 mutex_unlock(&wr_ctx->wr_lock); 1715 1716 return 0; 1717 } 1718 1719 static void scrub_wr_submit(struct scrub_ctx *sctx) 1720 { 1721 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx; 1722 struct scrub_bio *sbio; 1723 1724 if (!wr_ctx->wr_curr_bio) 1725 return; 1726 1727 sbio = wr_ctx->wr_curr_bio; 1728 wr_ctx->wr_curr_bio = NULL; 1729 WARN_ON(!sbio->bio->bi_bdev); 1730 scrub_pending_bio_inc(sctx); 1731 /* process all writes in a single worker thread. Then the block layer 1732 * orders the requests before sending them to the driver which 1733 * doubled the write performance on spinning disks when measured 1734 * with Linux 3.5 */ 1735 btrfsic_submit_bio(sbio->bio); 1736 } 1737 1738 static void scrub_wr_bio_end_io(struct bio *bio) 1739 { 1740 struct scrub_bio *sbio = bio->bi_private; 1741 struct btrfs_fs_info *fs_info = sbio->dev->fs_info; 1742 1743 sbio->err = bio->bi_error; 1744 sbio->bio = bio; 1745 1746 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper, 1747 scrub_wr_bio_end_io_worker, NULL, NULL); 1748 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work); 1749 } 1750 1751 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work) 1752 { 1753 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 1754 struct scrub_ctx *sctx = sbio->sctx; 1755 int i; 1756 1757 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO); 1758 if (sbio->err) { 1759 struct btrfs_dev_replace *dev_replace = 1760 &sbio->sctx->fs_info->dev_replace; 1761 1762 for (i = 0; i < sbio->page_count; i++) { 1763 struct scrub_page *spage = sbio->pagev[i]; 1764 1765 spage->io_error = 1; 1766 btrfs_dev_replace_stats_inc(&dev_replace-> 1767 num_write_errors); 1768 } 1769 } 1770 1771 for (i = 0; i < sbio->page_count; i++) 1772 scrub_page_put(sbio->pagev[i]); 1773 1774 bio_put(sbio->bio); 1775 kfree(sbio); 1776 scrub_pending_bio_dec(sctx); 1777 } 1778 1779 static int scrub_checksum(struct scrub_block *sblock) 1780 { 1781 u64 flags; 1782 int ret; 1783 1784 /* 1785 * No need to initialize these stats currently, 1786 * because this function only use return value 1787 * instead of these stats value. 1788 * 1789 * Todo: 1790 * always use stats 1791 */ 1792 sblock->header_error = 0; 1793 sblock->generation_error = 0; 1794 sblock->checksum_error = 0; 1795 1796 WARN_ON(sblock->page_count < 1); 1797 flags = sblock->pagev[0]->flags; 1798 ret = 0; 1799 if (flags & BTRFS_EXTENT_FLAG_DATA) 1800 ret = scrub_checksum_data(sblock); 1801 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) 1802 ret = scrub_checksum_tree_block(sblock); 1803 else if (flags & BTRFS_EXTENT_FLAG_SUPER) 1804 (void)scrub_checksum_super(sblock); 1805 else 1806 WARN_ON(1); 1807 if (ret) 1808 scrub_handle_errored_block(sblock); 1809 1810 return ret; 1811 } 1812 1813 static int scrub_checksum_data(struct scrub_block *sblock) 1814 { 1815 struct scrub_ctx *sctx = sblock->sctx; 1816 u8 csum[BTRFS_CSUM_SIZE]; 1817 u8 *on_disk_csum; 1818 struct page *page; 1819 void *buffer; 1820 u32 crc = ~(u32)0; 1821 u64 len; 1822 int index; 1823 1824 BUG_ON(sblock->page_count < 1); 1825 if (!sblock->pagev[0]->have_csum) 1826 return 0; 1827 1828 on_disk_csum = sblock->pagev[0]->csum; 1829 page = sblock->pagev[0]->page; 1830 buffer = kmap_atomic(page); 1831 1832 len = sctx->sectorsize; 1833 index = 0; 1834 for (;;) { 1835 u64 l = min_t(u64, len, PAGE_SIZE); 1836 1837 crc = btrfs_csum_data(buffer, crc, l); 1838 kunmap_atomic(buffer); 1839 len -= l; 1840 if (len == 0) 1841 break; 1842 index++; 1843 BUG_ON(index >= sblock->page_count); 1844 BUG_ON(!sblock->pagev[index]->page); 1845 page = sblock->pagev[index]->page; 1846 buffer = kmap_atomic(page); 1847 } 1848 1849 btrfs_csum_final(crc, csum); 1850 if (memcmp(csum, on_disk_csum, sctx->csum_size)) 1851 sblock->checksum_error = 1; 1852 1853 return sblock->checksum_error; 1854 } 1855 1856 static int scrub_checksum_tree_block(struct scrub_block *sblock) 1857 { 1858 struct scrub_ctx *sctx = sblock->sctx; 1859 struct btrfs_header *h; 1860 struct btrfs_fs_info *fs_info = sctx->fs_info; 1861 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1862 u8 on_disk_csum[BTRFS_CSUM_SIZE]; 1863 struct page *page; 1864 void *mapped_buffer; 1865 u64 mapped_size; 1866 void *p; 1867 u32 crc = ~(u32)0; 1868 u64 len; 1869 int index; 1870 1871 BUG_ON(sblock->page_count < 1); 1872 page = sblock->pagev[0]->page; 1873 mapped_buffer = kmap_atomic(page); 1874 h = (struct btrfs_header *)mapped_buffer; 1875 memcpy(on_disk_csum, h->csum, sctx->csum_size); 1876 1877 /* 1878 * we don't use the getter functions here, as we 1879 * a) don't have an extent buffer and 1880 * b) the page is already kmapped 1881 */ 1882 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h)) 1883 sblock->header_error = 1; 1884 1885 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) { 1886 sblock->header_error = 1; 1887 sblock->generation_error = 1; 1888 } 1889 1890 if (!scrub_check_fsid(h->fsid, sblock->pagev[0])) 1891 sblock->header_error = 1; 1892 1893 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, 1894 BTRFS_UUID_SIZE)) 1895 sblock->header_error = 1; 1896 1897 len = sctx->nodesize - BTRFS_CSUM_SIZE; 1898 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; 1899 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; 1900 index = 0; 1901 for (;;) { 1902 u64 l = min_t(u64, len, mapped_size); 1903 1904 crc = btrfs_csum_data(p, crc, l); 1905 kunmap_atomic(mapped_buffer); 1906 len -= l; 1907 if (len == 0) 1908 break; 1909 index++; 1910 BUG_ON(index >= sblock->page_count); 1911 BUG_ON(!sblock->pagev[index]->page); 1912 page = sblock->pagev[index]->page; 1913 mapped_buffer = kmap_atomic(page); 1914 mapped_size = PAGE_SIZE; 1915 p = mapped_buffer; 1916 } 1917 1918 btrfs_csum_final(crc, calculated_csum); 1919 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size)) 1920 sblock->checksum_error = 1; 1921 1922 return sblock->header_error || sblock->checksum_error; 1923 } 1924 1925 static int scrub_checksum_super(struct scrub_block *sblock) 1926 { 1927 struct btrfs_super_block *s; 1928 struct scrub_ctx *sctx = sblock->sctx; 1929 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1930 u8 on_disk_csum[BTRFS_CSUM_SIZE]; 1931 struct page *page; 1932 void *mapped_buffer; 1933 u64 mapped_size; 1934 void *p; 1935 u32 crc = ~(u32)0; 1936 int fail_gen = 0; 1937 int fail_cor = 0; 1938 u64 len; 1939 int index; 1940 1941 BUG_ON(sblock->page_count < 1); 1942 page = sblock->pagev[0]->page; 1943 mapped_buffer = kmap_atomic(page); 1944 s = (struct btrfs_super_block *)mapped_buffer; 1945 memcpy(on_disk_csum, s->csum, sctx->csum_size); 1946 1947 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s)) 1948 ++fail_cor; 1949 1950 if (sblock->pagev[0]->generation != btrfs_super_generation(s)) 1951 ++fail_gen; 1952 1953 if (!scrub_check_fsid(s->fsid, sblock->pagev[0])) 1954 ++fail_cor; 1955 1956 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE; 1957 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; 1958 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; 1959 index = 0; 1960 for (;;) { 1961 u64 l = min_t(u64, len, mapped_size); 1962 1963 crc = btrfs_csum_data(p, crc, l); 1964 kunmap_atomic(mapped_buffer); 1965 len -= l; 1966 if (len == 0) 1967 break; 1968 index++; 1969 BUG_ON(index >= sblock->page_count); 1970 BUG_ON(!sblock->pagev[index]->page); 1971 page = sblock->pagev[index]->page; 1972 mapped_buffer = kmap_atomic(page); 1973 mapped_size = PAGE_SIZE; 1974 p = mapped_buffer; 1975 } 1976 1977 btrfs_csum_final(crc, calculated_csum); 1978 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size)) 1979 ++fail_cor; 1980 1981 if (fail_cor + fail_gen) { 1982 /* 1983 * if we find an error in a super block, we just report it. 1984 * They will get written with the next transaction commit 1985 * anyway 1986 */ 1987 spin_lock(&sctx->stat_lock); 1988 ++sctx->stat.super_errors; 1989 spin_unlock(&sctx->stat_lock); 1990 if (fail_cor) 1991 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev, 1992 BTRFS_DEV_STAT_CORRUPTION_ERRS); 1993 else 1994 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev, 1995 BTRFS_DEV_STAT_GENERATION_ERRS); 1996 } 1997 1998 return fail_cor + fail_gen; 1999 } 2000 2001 static void scrub_block_get(struct scrub_block *sblock) 2002 { 2003 atomic_inc(&sblock->refs); 2004 } 2005 2006 static void scrub_block_put(struct scrub_block *sblock) 2007 { 2008 if (atomic_dec_and_test(&sblock->refs)) { 2009 int i; 2010 2011 if (sblock->sparity) 2012 scrub_parity_put(sblock->sparity); 2013 2014 for (i = 0; i < sblock->page_count; i++) 2015 scrub_page_put(sblock->pagev[i]); 2016 kfree(sblock); 2017 } 2018 } 2019 2020 static void scrub_page_get(struct scrub_page *spage) 2021 { 2022 atomic_inc(&spage->refs); 2023 } 2024 2025 static void scrub_page_put(struct scrub_page *spage) 2026 { 2027 if (atomic_dec_and_test(&spage->refs)) { 2028 if (spage->page) 2029 __free_page(spage->page); 2030 kfree(spage); 2031 } 2032 } 2033 2034 static void scrub_submit(struct scrub_ctx *sctx) 2035 { 2036 struct scrub_bio *sbio; 2037 2038 if (sctx->curr == -1) 2039 return; 2040 2041 sbio = sctx->bios[sctx->curr]; 2042 sctx->curr = -1; 2043 scrub_pending_bio_inc(sctx); 2044 btrfsic_submit_bio(sbio->bio); 2045 } 2046 2047 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, 2048 struct scrub_page *spage) 2049 { 2050 struct scrub_block *sblock = spage->sblock; 2051 struct scrub_bio *sbio; 2052 int ret; 2053 2054 again: 2055 /* 2056 * grab a fresh bio or wait for one to become available 2057 */ 2058 while (sctx->curr == -1) { 2059 spin_lock(&sctx->list_lock); 2060 sctx->curr = sctx->first_free; 2061 if (sctx->curr != -1) { 2062 sctx->first_free = sctx->bios[sctx->curr]->next_free; 2063 sctx->bios[sctx->curr]->next_free = -1; 2064 sctx->bios[sctx->curr]->page_count = 0; 2065 spin_unlock(&sctx->list_lock); 2066 } else { 2067 spin_unlock(&sctx->list_lock); 2068 wait_event(sctx->list_wait, sctx->first_free != -1); 2069 } 2070 } 2071 sbio = sctx->bios[sctx->curr]; 2072 if (sbio->page_count == 0) { 2073 struct bio *bio; 2074 2075 sbio->physical = spage->physical; 2076 sbio->logical = spage->logical; 2077 sbio->dev = spage->dev; 2078 bio = sbio->bio; 2079 if (!bio) { 2080 bio = btrfs_io_bio_alloc(GFP_KERNEL, 2081 sctx->pages_per_rd_bio); 2082 if (!bio) 2083 return -ENOMEM; 2084 sbio->bio = bio; 2085 } 2086 2087 bio->bi_private = sbio; 2088 bio->bi_end_io = scrub_bio_end_io; 2089 bio->bi_bdev = sbio->dev->bdev; 2090 bio->bi_iter.bi_sector = sbio->physical >> 9; 2091 bio_set_op_attrs(bio, REQ_OP_READ, 0); 2092 sbio->err = 0; 2093 } else if (sbio->physical + sbio->page_count * PAGE_SIZE != 2094 spage->physical || 2095 sbio->logical + sbio->page_count * PAGE_SIZE != 2096 spage->logical || 2097 sbio->dev != spage->dev) { 2098 scrub_submit(sctx); 2099 goto again; 2100 } 2101 2102 sbio->pagev[sbio->page_count] = spage; 2103 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); 2104 if (ret != PAGE_SIZE) { 2105 if (sbio->page_count < 1) { 2106 bio_put(sbio->bio); 2107 sbio->bio = NULL; 2108 return -EIO; 2109 } 2110 scrub_submit(sctx); 2111 goto again; 2112 } 2113 2114 scrub_block_get(sblock); /* one for the page added to the bio */ 2115 atomic_inc(&sblock->outstanding_pages); 2116 sbio->page_count++; 2117 if (sbio->page_count == sctx->pages_per_rd_bio) 2118 scrub_submit(sctx); 2119 2120 return 0; 2121 } 2122 2123 static void scrub_missing_raid56_end_io(struct bio *bio) 2124 { 2125 struct scrub_block *sblock = bio->bi_private; 2126 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info; 2127 2128 if (bio->bi_error) 2129 sblock->no_io_error_seen = 0; 2130 2131 bio_put(bio); 2132 2133 btrfs_queue_work(fs_info->scrub_workers, &sblock->work); 2134 } 2135 2136 static void scrub_missing_raid56_worker(struct btrfs_work *work) 2137 { 2138 struct scrub_block *sblock = container_of(work, struct scrub_block, work); 2139 struct scrub_ctx *sctx = sblock->sctx; 2140 struct btrfs_fs_info *fs_info = sctx->fs_info; 2141 u64 logical; 2142 struct btrfs_device *dev; 2143 2144 logical = sblock->pagev[0]->logical; 2145 dev = sblock->pagev[0]->dev; 2146 2147 if (sblock->no_io_error_seen) 2148 scrub_recheck_block_checksum(sblock); 2149 2150 if (!sblock->no_io_error_seen) { 2151 spin_lock(&sctx->stat_lock); 2152 sctx->stat.read_errors++; 2153 spin_unlock(&sctx->stat_lock); 2154 btrfs_err_rl_in_rcu(fs_info, 2155 "IO error rebuilding logical %llu for dev %s", 2156 logical, rcu_str_deref(dev->name)); 2157 } else if (sblock->header_error || sblock->checksum_error) { 2158 spin_lock(&sctx->stat_lock); 2159 sctx->stat.uncorrectable_errors++; 2160 spin_unlock(&sctx->stat_lock); 2161 btrfs_err_rl_in_rcu(fs_info, 2162 "failed to rebuild valid logical %llu for dev %s", 2163 logical, rcu_str_deref(dev->name)); 2164 } else { 2165 scrub_write_block_to_dev_replace(sblock); 2166 } 2167 2168 scrub_block_put(sblock); 2169 2170 if (sctx->is_dev_replace && 2171 atomic_read(&sctx->wr_ctx.flush_all_writes)) { 2172 mutex_lock(&sctx->wr_ctx.wr_lock); 2173 scrub_wr_submit(sctx); 2174 mutex_unlock(&sctx->wr_ctx.wr_lock); 2175 } 2176 2177 scrub_pending_bio_dec(sctx); 2178 } 2179 2180 static void scrub_missing_raid56_pages(struct scrub_block *sblock) 2181 { 2182 struct scrub_ctx *sctx = sblock->sctx; 2183 struct btrfs_fs_info *fs_info = sctx->fs_info; 2184 u64 length = sblock->page_count * PAGE_SIZE; 2185 u64 logical = sblock->pagev[0]->logical; 2186 struct btrfs_bio *bbio = NULL; 2187 struct bio *bio; 2188 struct btrfs_raid_bio *rbio; 2189 int ret; 2190 int i; 2191 2192 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical, 2193 &length, &bbio, 0, 1); 2194 if (ret || !bbio || !bbio->raid_map) 2195 goto bbio_out; 2196 2197 if (WARN_ON(!sctx->is_dev_replace || 2198 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) { 2199 /* 2200 * We shouldn't be scrubbing a missing device. Even for dev 2201 * replace, we should only get here for RAID 5/6. We either 2202 * managed to mount something with no mirrors remaining or 2203 * there's a bug in scrub_remap_extent()/btrfs_map_block(). 2204 */ 2205 goto bbio_out; 2206 } 2207 2208 bio = btrfs_io_bio_alloc(GFP_NOFS, 0); 2209 if (!bio) 2210 goto bbio_out; 2211 2212 bio->bi_iter.bi_sector = logical >> 9; 2213 bio->bi_private = sblock; 2214 bio->bi_end_io = scrub_missing_raid56_end_io; 2215 2216 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length); 2217 if (!rbio) 2218 goto rbio_out; 2219 2220 for (i = 0; i < sblock->page_count; i++) { 2221 struct scrub_page *spage = sblock->pagev[i]; 2222 2223 raid56_add_scrub_pages(rbio, spage->page, spage->logical); 2224 } 2225 2226 btrfs_init_work(&sblock->work, btrfs_scrub_helper, 2227 scrub_missing_raid56_worker, NULL, NULL); 2228 scrub_block_get(sblock); 2229 scrub_pending_bio_inc(sctx); 2230 raid56_submit_missing_rbio(rbio); 2231 return; 2232 2233 rbio_out: 2234 bio_put(bio); 2235 bbio_out: 2236 btrfs_put_bbio(bbio); 2237 spin_lock(&sctx->stat_lock); 2238 sctx->stat.malloc_errors++; 2239 spin_unlock(&sctx->stat_lock); 2240 } 2241 2242 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 2243 u64 physical, struct btrfs_device *dev, u64 flags, 2244 u64 gen, int mirror_num, u8 *csum, int force, 2245 u64 physical_for_dev_replace) 2246 { 2247 struct scrub_block *sblock; 2248 int index; 2249 2250 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL); 2251 if (!sblock) { 2252 spin_lock(&sctx->stat_lock); 2253 sctx->stat.malloc_errors++; 2254 spin_unlock(&sctx->stat_lock); 2255 return -ENOMEM; 2256 } 2257 2258 /* one ref inside this function, plus one for each page added to 2259 * a bio later on */ 2260 atomic_set(&sblock->refs, 1); 2261 sblock->sctx = sctx; 2262 sblock->no_io_error_seen = 1; 2263 2264 for (index = 0; len > 0; index++) { 2265 struct scrub_page *spage; 2266 u64 l = min_t(u64, len, PAGE_SIZE); 2267 2268 spage = kzalloc(sizeof(*spage), GFP_KERNEL); 2269 if (!spage) { 2270 leave_nomem: 2271 spin_lock(&sctx->stat_lock); 2272 sctx->stat.malloc_errors++; 2273 spin_unlock(&sctx->stat_lock); 2274 scrub_block_put(sblock); 2275 return -ENOMEM; 2276 } 2277 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); 2278 scrub_page_get(spage); 2279 sblock->pagev[index] = spage; 2280 spage->sblock = sblock; 2281 spage->dev = dev; 2282 spage->flags = flags; 2283 spage->generation = gen; 2284 spage->logical = logical; 2285 spage->physical = physical; 2286 spage->physical_for_dev_replace = physical_for_dev_replace; 2287 spage->mirror_num = mirror_num; 2288 if (csum) { 2289 spage->have_csum = 1; 2290 memcpy(spage->csum, csum, sctx->csum_size); 2291 } else { 2292 spage->have_csum = 0; 2293 } 2294 sblock->page_count++; 2295 spage->page = alloc_page(GFP_KERNEL); 2296 if (!spage->page) 2297 goto leave_nomem; 2298 len -= l; 2299 logical += l; 2300 physical += l; 2301 physical_for_dev_replace += l; 2302 } 2303 2304 WARN_ON(sblock->page_count == 0); 2305 if (dev->missing) { 2306 /* 2307 * This case should only be hit for RAID 5/6 device replace. See 2308 * the comment in scrub_missing_raid56_pages() for details. 2309 */ 2310 scrub_missing_raid56_pages(sblock); 2311 } else { 2312 for (index = 0; index < sblock->page_count; index++) { 2313 struct scrub_page *spage = sblock->pagev[index]; 2314 int ret; 2315 2316 ret = scrub_add_page_to_rd_bio(sctx, spage); 2317 if (ret) { 2318 scrub_block_put(sblock); 2319 return ret; 2320 } 2321 } 2322 2323 if (force) 2324 scrub_submit(sctx); 2325 } 2326 2327 /* last one frees, either here or in bio completion for last page */ 2328 scrub_block_put(sblock); 2329 return 0; 2330 } 2331 2332 static void scrub_bio_end_io(struct bio *bio) 2333 { 2334 struct scrub_bio *sbio = bio->bi_private; 2335 struct btrfs_fs_info *fs_info = sbio->dev->fs_info; 2336 2337 sbio->err = bio->bi_error; 2338 sbio->bio = bio; 2339 2340 btrfs_queue_work(fs_info->scrub_workers, &sbio->work); 2341 } 2342 2343 static void scrub_bio_end_io_worker(struct btrfs_work *work) 2344 { 2345 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 2346 struct scrub_ctx *sctx = sbio->sctx; 2347 int i; 2348 2349 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO); 2350 if (sbio->err) { 2351 for (i = 0; i < sbio->page_count; i++) { 2352 struct scrub_page *spage = sbio->pagev[i]; 2353 2354 spage->io_error = 1; 2355 spage->sblock->no_io_error_seen = 0; 2356 } 2357 } 2358 2359 /* now complete the scrub_block items that have all pages completed */ 2360 for (i = 0; i < sbio->page_count; i++) { 2361 struct scrub_page *spage = sbio->pagev[i]; 2362 struct scrub_block *sblock = spage->sblock; 2363 2364 if (atomic_dec_and_test(&sblock->outstanding_pages)) 2365 scrub_block_complete(sblock); 2366 scrub_block_put(sblock); 2367 } 2368 2369 bio_put(sbio->bio); 2370 sbio->bio = NULL; 2371 spin_lock(&sctx->list_lock); 2372 sbio->next_free = sctx->first_free; 2373 sctx->first_free = sbio->index; 2374 spin_unlock(&sctx->list_lock); 2375 2376 if (sctx->is_dev_replace && 2377 atomic_read(&sctx->wr_ctx.flush_all_writes)) { 2378 mutex_lock(&sctx->wr_ctx.wr_lock); 2379 scrub_wr_submit(sctx); 2380 mutex_unlock(&sctx->wr_ctx.wr_lock); 2381 } 2382 2383 scrub_pending_bio_dec(sctx); 2384 } 2385 2386 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity, 2387 unsigned long *bitmap, 2388 u64 start, u64 len) 2389 { 2390 u32 offset; 2391 int nsectors; 2392 int sectorsize = sparity->sctx->fs_info->sectorsize; 2393 2394 if (len >= sparity->stripe_len) { 2395 bitmap_set(bitmap, 0, sparity->nsectors); 2396 return; 2397 } 2398 2399 start -= sparity->logic_start; 2400 start = div_u64_rem(start, sparity->stripe_len, &offset); 2401 offset /= sectorsize; 2402 nsectors = (int)len / sectorsize; 2403 2404 if (offset + nsectors <= sparity->nsectors) { 2405 bitmap_set(bitmap, offset, nsectors); 2406 return; 2407 } 2408 2409 bitmap_set(bitmap, offset, sparity->nsectors - offset); 2410 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset)); 2411 } 2412 2413 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity, 2414 u64 start, u64 len) 2415 { 2416 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len); 2417 } 2418 2419 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity, 2420 u64 start, u64 len) 2421 { 2422 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len); 2423 } 2424 2425 static void scrub_block_complete(struct scrub_block *sblock) 2426 { 2427 int corrupted = 0; 2428 2429 if (!sblock->no_io_error_seen) { 2430 corrupted = 1; 2431 scrub_handle_errored_block(sblock); 2432 } else { 2433 /* 2434 * if has checksum error, write via repair mechanism in 2435 * dev replace case, otherwise write here in dev replace 2436 * case. 2437 */ 2438 corrupted = scrub_checksum(sblock); 2439 if (!corrupted && sblock->sctx->is_dev_replace) 2440 scrub_write_block_to_dev_replace(sblock); 2441 } 2442 2443 if (sblock->sparity && corrupted && !sblock->data_corrected) { 2444 u64 start = sblock->pagev[0]->logical; 2445 u64 end = sblock->pagev[sblock->page_count - 1]->logical + 2446 PAGE_SIZE; 2447 2448 scrub_parity_mark_sectors_error(sblock->sparity, 2449 start, end - start); 2450 } 2451 } 2452 2453 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum) 2454 { 2455 struct btrfs_ordered_sum *sum = NULL; 2456 unsigned long index; 2457 unsigned long num_sectors; 2458 2459 while (!list_empty(&sctx->csum_list)) { 2460 sum = list_first_entry(&sctx->csum_list, 2461 struct btrfs_ordered_sum, list); 2462 if (sum->bytenr > logical) 2463 return 0; 2464 if (sum->bytenr + sum->len > logical) 2465 break; 2466 2467 ++sctx->stat.csum_discards; 2468 list_del(&sum->list); 2469 kfree(sum); 2470 sum = NULL; 2471 } 2472 if (!sum) 2473 return 0; 2474 2475 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize; 2476 num_sectors = sum->len / sctx->sectorsize; 2477 memcpy(csum, sum->sums + index, sctx->csum_size); 2478 if (index == num_sectors - 1) { 2479 list_del(&sum->list); 2480 kfree(sum); 2481 } 2482 return 1; 2483 } 2484 2485 /* scrub extent tries to collect up to 64 kB for each bio */ 2486 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len, 2487 u64 physical, struct btrfs_device *dev, u64 flags, 2488 u64 gen, int mirror_num, u64 physical_for_dev_replace) 2489 { 2490 int ret; 2491 u8 csum[BTRFS_CSUM_SIZE]; 2492 u32 blocksize; 2493 2494 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2495 blocksize = sctx->sectorsize; 2496 spin_lock(&sctx->stat_lock); 2497 sctx->stat.data_extents_scrubbed++; 2498 sctx->stat.data_bytes_scrubbed += len; 2499 spin_unlock(&sctx->stat_lock); 2500 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 2501 blocksize = sctx->nodesize; 2502 spin_lock(&sctx->stat_lock); 2503 sctx->stat.tree_extents_scrubbed++; 2504 sctx->stat.tree_bytes_scrubbed += len; 2505 spin_unlock(&sctx->stat_lock); 2506 } else { 2507 blocksize = sctx->sectorsize; 2508 WARN_ON(1); 2509 } 2510 2511 while (len) { 2512 u64 l = min_t(u64, len, blocksize); 2513 int have_csum = 0; 2514 2515 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2516 /* push csums to sbio */ 2517 have_csum = scrub_find_csum(sctx, logical, csum); 2518 if (have_csum == 0) 2519 ++sctx->stat.no_csum; 2520 if (sctx->is_dev_replace && !have_csum) { 2521 ret = copy_nocow_pages(sctx, logical, l, 2522 mirror_num, 2523 physical_for_dev_replace); 2524 goto behind_scrub_pages; 2525 } 2526 } 2527 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen, 2528 mirror_num, have_csum ? csum : NULL, 0, 2529 physical_for_dev_replace); 2530 behind_scrub_pages: 2531 if (ret) 2532 return ret; 2533 len -= l; 2534 logical += l; 2535 physical += l; 2536 physical_for_dev_replace += l; 2537 } 2538 return 0; 2539 } 2540 2541 static int scrub_pages_for_parity(struct scrub_parity *sparity, 2542 u64 logical, u64 len, 2543 u64 physical, struct btrfs_device *dev, 2544 u64 flags, u64 gen, int mirror_num, u8 *csum) 2545 { 2546 struct scrub_ctx *sctx = sparity->sctx; 2547 struct scrub_block *sblock; 2548 int index; 2549 2550 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL); 2551 if (!sblock) { 2552 spin_lock(&sctx->stat_lock); 2553 sctx->stat.malloc_errors++; 2554 spin_unlock(&sctx->stat_lock); 2555 return -ENOMEM; 2556 } 2557 2558 /* one ref inside this function, plus one for each page added to 2559 * a bio later on */ 2560 atomic_set(&sblock->refs, 1); 2561 sblock->sctx = sctx; 2562 sblock->no_io_error_seen = 1; 2563 sblock->sparity = sparity; 2564 scrub_parity_get(sparity); 2565 2566 for (index = 0; len > 0; index++) { 2567 struct scrub_page *spage; 2568 u64 l = min_t(u64, len, PAGE_SIZE); 2569 2570 spage = kzalloc(sizeof(*spage), GFP_KERNEL); 2571 if (!spage) { 2572 leave_nomem: 2573 spin_lock(&sctx->stat_lock); 2574 sctx->stat.malloc_errors++; 2575 spin_unlock(&sctx->stat_lock); 2576 scrub_block_put(sblock); 2577 return -ENOMEM; 2578 } 2579 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); 2580 /* For scrub block */ 2581 scrub_page_get(spage); 2582 sblock->pagev[index] = spage; 2583 /* For scrub parity */ 2584 scrub_page_get(spage); 2585 list_add_tail(&spage->list, &sparity->spages); 2586 spage->sblock = sblock; 2587 spage->dev = dev; 2588 spage->flags = flags; 2589 spage->generation = gen; 2590 spage->logical = logical; 2591 spage->physical = physical; 2592 spage->mirror_num = mirror_num; 2593 if (csum) { 2594 spage->have_csum = 1; 2595 memcpy(spage->csum, csum, sctx->csum_size); 2596 } else { 2597 spage->have_csum = 0; 2598 } 2599 sblock->page_count++; 2600 spage->page = alloc_page(GFP_KERNEL); 2601 if (!spage->page) 2602 goto leave_nomem; 2603 len -= l; 2604 logical += l; 2605 physical += l; 2606 } 2607 2608 WARN_ON(sblock->page_count == 0); 2609 for (index = 0; index < sblock->page_count; index++) { 2610 struct scrub_page *spage = sblock->pagev[index]; 2611 int ret; 2612 2613 ret = scrub_add_page_to_rd_bio(sctx, spage); 2614 if (ret) { 2615 scrub_block_put(sblock); 2616 return ret; 2617 } 2618 } 2619 2620 /* last one frees, either here or in bio completion for last page */ 2621 scrub_block_put(sblock); 2622 return 0; 2623 } 2624 2625 static int scrub_extent_for_parity(struct scrub_parity *sparity, 2626 u64 logical, u64 len, 2627 u64 physical, struct btrfs_device *dev, 2628 u64 flags, u64 gen, int mirror_num) 2629 { 2630 struct scrub_ctx *sctx = sparity->sctx; 2631 int ret; 2632 u8 csum[BTRFS_CSUM_SIZE]; 2633 u32 blocksize; 2634 2635 if (dev->missing) { 2636 scrub_parity_mark_sectors_error(sparity, logical, len); 2637 return 0; 2638 } 2639 2640 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2641 blocksize = sctx->sectorsize; 2642 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 2643 blocksize = sctx->nodesize; 2644 } else { 2645 blocksize = sctx->sectorsize; 2646 WARN_ON(1); 2647 } 2648 2649 while (len) { 2650 u64 l = min_t(u64, len, blocksize); 2651 int have_csum = 0; 2652 2653 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2654 /* push csums to sbio */ 2655 have_csum = scrub_find_csum(sctx, logical, csum); 2656 if (have_csum == 0) 2657 goto skip; 2658 } 2659 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev, 2660 flags, gen, mirror_num, 2661 have_csum ? csum : NULL); 2662 if (ret) 2663 return ret; 2664 skip: 2665 len -= l; 2666 logical += l; 2667 physical += l; 2668 } 2669 return 0; 2670 } 2671 2672 /* 2673 * Given a physical address, this will calculate it's 2674 * logical offset. if this is a parity stripe, it will return 2675 * the most left data stripe's logical offset. 2676 * 2677 * return 0 if it is a data stripe, 1 means parity stripe. 2678 */ 2679 static int get_raid56_logic_offset(u64 physical, int num, 2680 struct map_lookup *map, u64 *offset, 2681 u64 *stripe_start) 2682 { 2683 int i; 2684 int j = 0; 2685 u64 stripe_nr; 2686 u64 last_offset; 2687 u32 stripe_index; 2688 u32 rot; 2689 2690 last_offset = (physical - map->stripes[num].physical) * 2691 nr_data_stripes(map); 2692 if (stripe_start) 2693 *stripe_start = last_offset; 2694 2695 *offset = last_offset; 2696 for (i = 0; i < nr_data_stripes(map); i++) { 2697 *offset = last_offset + i * map->stripe_len; 2698 2699 stripe_nr = div_u64(*offset, map->stripe_len); 2700 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map)); 2701 2702 /* Work out the disk rotation on this stripe-set */ 2703 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot); 2704 /* calculate which stripe this data locates */ 2705 rot += i; 2706 stripe_index = rot % map->num_stripes; 2707 if (stripe_index == num) 2708 return 0; 2709 if (stripe_index < num) 2710 j++; 2711 } 2712 *offset = last_offset + j * map->stripe_len; 2713 return 1; 2714 } 2715 2716 static void scrub_free_parity(struct scrub_parity *sparity) 2717 { 2718 struct scrub_ctx *sctx = sparity->sctx; 2719 struct scrub_page *curr, *next; 2720 int nbits; 2721 2722 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors); 2723 if (nbits) { 2724 spin_lock(&sctx->stat_lock); 2725 sctx->stat.read_errors += nbits; 2726 sctx->stat.uncorrectable_errors += nbits; 2727 spin_unlock(&sctx->stat_lock); 2728 } 2729 2730 list_for_each_entry_safe(curr, next, &sparity->spages, list) { 2731 list_del_init(&curr->list); 2732 scrub_page_put(curr); 2733 } 2734 2735 kfree(sparity); 2736 } 2737 2738 static void scrub_parity_bio_endio_worker(struct btrfs_work *work) 2739 { 2740 struct scrub_parity *sparity = container_of(work, struct scrub_parity, 2741 work); 2742 struct scrub_ctx *sctx = sparity->sctx; 2743 2744 scrub_free_parity(sparity); 2745 scrub_pending_bio_dec(sctx); 2746 } 2747 2748 static void scrub_parity_bio_endio(struct bio *bio) 2749 { 2750 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private; 2751 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info; 2752 2753 if (bio->bi_error) 2754 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap, 2755 sparity->nsectors); 2756 2757 bio_put(bio); 2758 2759 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper, 2760 scrub_parity_bio_endio_worker, NULL, NULL); 2761 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work); 2762 } 2763 2764 static void scrub_parity_check_and_repair(struct scrub_parity *sparity) 2765 { 2766 struct scrub_ctx *sctx = sparity->sctx; 2767 struct btrfs_fs_info *fs_info = sctx->fs_info; 2768 struct bio *bio; 2769 struct btrfs_raid_bio *rbio; 2770 struct scrub_page *spage; 2771 struct btrfs_bio *bbio = NULL; 2772 u64 length; 2773 int ret; 2774 2775 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap, 2776 sparity->nsectors)) 2777 goto out; 2778 2779 length = sparity->logic_end - sparity->logic_start; 2780 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start, 2781 &length, &bbio, 0, 1); 2782 if (ret || !bbio || !bbio->raid_map) 2783 goto bbio_out; 2784 2785 bio = btrfs_io_bio_alloc(GFP_NOFS, 0); 2786 if (!bio) 2787 goto bbio_out; 2788 2789 bio->bi_iter.bi_sector = sparity->logic_start >> 9; 2790 bio->bi_private = sparity; 2791 bio->bi_end_io = scrub_parity_bio_endio; 2792 2793 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio, 2794 length, sparity->scrub_dev, 2795 sparity->dbitmap, 2796 sparity->nsectors); 2797 if (!rbio) 2798 goto rbio_out; 2799 2800 list_for_each_entry(spage, &sparity->spages, list) 2801 raid56_add_scrub_pages(rbio, spage->page, spage->logical); 2802 2803 scrub_pending_bio_inc(sctx); 2804 raid56_parity_submit_scrub_rbio(rbio); 2805 return; 2806 2807 rbio_out: 2808 bio_put(bio); 2809 bbio_out: 2810 btrfs_put_bbio(bbio); 2811 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap, 2812 sparity->nsectors); 2813 spin_lock(&sctx->stat_lock); 2814 sctx->stat.malloc_errors++; 2815 spin_unlock(&sctx->stat_lock); 2816 out: 2817 scrub_free_parity(sparity); 2818 } 2819 2820 static inline int scrub_calc_parity_bitmap_len(int nsectors) 2821 { 2822 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long); 2823 } 2824 2825 static void scrub_parity_get(struct scrub_parity *sparity) 2826 { 2827 atomic_inc(&sparity->refs); 2828 } 2829 2830 static void scrub_parity_put(struct scrub_parity *sparity) 2831 { 2832 if (!atomic_dec_and_test(&sparity->refs)) 2833 return; 2834 2835 scrub_parity_check_and_repair(sparity); 2836 } 2837 2838 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, 2839 struct map_lookup *map, 2840 struct btrfs_device *sdev, 2841 struct btrfs_path *path, 2842 u64 logic_start, 2843 u64 logic_end) 2844 { 2845 struct btrfs_fs_info *fs_info = sctx->fs_info; 2846 struct btrfs_root *root = fs_info->extent_root; 2847 struct btrfs_root *csum_root = fs_info->csum_root; 2848 struct btrfs_extent_item *extent; 2849 struct btrfs_bio *bbio = NULL; 2850 u64 flags; 2851 int ret; 2852 int slot; 2853 struct extent_buffer *l; 2854 struct btrfs_key key; 2855 u64 generation; 2856 u64 extent_logical; 2857 u64 extent_physical; 2858 u64 extent_len; 2859 u64 mapped_length; 2860 struct btrfs_device *extent_dev; 2861 struct scrub_parity *sparity; 2862 int nsectors; 2863 int bitmap_len; 2864 int extent_mirror_num; 2865 int stop_loop = 0; 2866 2867 nsectors = div_u64(map->stripe_len, fs_info->sectorsize); 2868 bitmap_len = scrub_calc_parity_bitmap_len(nsectors); 2869 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len, 2870 GFP_NOFS); 2871 if (!sparity) { 2872 spin_lock(&sctx->stat_lock); 2873 sctx->stat.malloc_errors++; 2874 spin_unlock(&sctx->stat_lock); 2875 return -ENOMEM; 2876 } 2877 2878 sparity->stripe_len = map->stripe_len; 2879 sparity->nsectors = nsectors; 2880 sparity->sctx = sctx; 2881 sparity->scrub_dev = sdev; 2882 sparity->logic_start = logic_start; 2883 sparity->logic_end = logic_end; 2884 atomic_set(&sparity->refs, 1); 2885 INIT_LIST_HEAD(&sparity->spages); 2886 sparity->dbitmap = sparity->bitmap; 2887 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len; 2888 2889 ret = 0; 2890 while (logic_start < logic_end) { 2891 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) 2892 key.type = BTRFS_METADATA_ITEM_KEY; 2893 else 2894 key.type = BTRFS_EXTENT_ITEM_KEY; 2895 key.objectid = logic_start; 2896 key.offset = (u64)-1; 2897 2898 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2899 if (ret < 0) 2900 goto out; 2901 2902 if (ret > 0) { 2903 ret = btrfs_previous_extent_item(root, path, 0); 2904 if (ret < 0) 2905 goto out; 2906 if (ret > 0) { 2907 btrfs_release_path(path); 2908 ret = btrfs_search_slot(NULL, root, &key, 2909 path, 0, 0); 2910 if (ret < 0) 2911 goto out; 2912 } 2913 } 2914 2915 stop_loop = 0; 2916 while (1) { 2917 u64 bytes; 2918 2919 l = path->nodes[0]; 2920 slot = path->slots[0]; 2921 if (slot >= btrfs_header_nritems(l)) { 2922 ret = btrfs_next_leaf(root, path); 2923 if (ret == 0) 2924 continue; 2925 if (ret < 0) 2926 goto out; 2927 2928 stop_loop = 1; 2929 break; 2930 } 2931 btrfs_item_key_to_cpu(l, &key, slot); 2932 2933 if (key.type != BTRFS_EXTENT_ITEM_KEY && 2934 key.type != BTRFS_METADATA_ITEM_KEY) 2935 goto next; 2936 2937 if (key.type == BTRFS_METADATA_ITEM_KEY) 2938 bytes = fs_info->nodesize; 2939 else 2940 bytes = key.offset; 2941 2942 if (key.objectid + bytes <= logic_start) 2943 goto next; 2944 2945 if (key.objectid >= logic_end) { 2946 stop_loop = 1; 2947 break; 2948 } 2949 2950 while (key.objectid >= logic_start + map->stripe_len) 2951 logic_start += map->stripe_len; 2952 2953 extent = btrfs_item_ptr(l, slot, 2954 struct btrfs_extent_item); 2955 flags = btrfs_extent_flags(l, extent); 2956 generation = btrfs_extent_generation(l, extent); 2957 2958 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) && 2959 (key.objectid < logic_start || 2960 key.objectid + bytes > 2961 logic_start + map->stripe_len)) { 2962 btrfs_err(fs_info, 2963 "scrub: tree block %llu spanning stripes, ignored. logical=%llu", 2964 key.objectid, logic_start); 2965 spin_lock(&sctx->stat_lock); 2966 sctx->stat.uncorrectable_errors++; 2967 spin_unlock(&sctx->stat_lock); 2968 goto next; 2969 } 2970 again: 2971 extent_logical = key.objectid; 2972 extent_len = bytes; 2973 2974 if (extent_logical < logic_start) { 2975 extent_len -= logic_start - extent_logical; 2976 extent_logical = logic_start; 2977 } 2978 2979 if (extent_logical + extent_len > 2980 logic_start + map->stripe_len) 2981 extent_len = logic_start + map->stripe_len - 2982 extent_logical; 2983 2984 scrub_parity_mark_sectors_data(sparity, extent_logical, 2985 extent_len); 2986 2987 mapped_length = extent_len; 2988 bbio = NULL; 2989 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, 2990 extent_logical, &mapped_length, &bbio, 2991 0); 2992 if (!ret) { 2993 if (!bbio || mapped_length < extent_len) 2994 ret = -EIO; 2995 } 2996 if (ret) { 2997 btrfs_put_bbio(bbio); 2998 goto out; 2999 } 3000 extent_physical = bbio->stripes[0].physical; 3001 extent_mirror_num = bbio->mirror_num; 3002 extent_dev = bbio->stripes[0].dev; 3003 btrfs_put_bbio(bbio); 3004 3005 ret = btrfs_lookup_csums_range(csum_root, 3006 extent_logical, 3007 extent_logical + extent_len - 1, 3008 &sctx->csum_list, 1); 3009 if (ret) 3010 goto out; 3011 3012 ret = scrub_extent_for_parity(sparity, extent_logical, 3013 extent_len, 3014 extent_physical, 3015 extent_dev, flags, 3016 generation, 3017 extent_mirror_num); 3018 3019 scrub_free_csums(sctx); 3020 3021 if (ret) 3022 goto out; 3023 3024 if (extent_logical + extent_len < 3025 key.objectid + bytes) { 3026 logic_start += map->stripe_len; 3027 3028 if (logic_start >= logic_end) { 3029 stop_loop = 1; 3030 break; 3031 } 3032 3033 if (logic_start < key.objectid + bytes) { 3034 cond_resched(); 3035 goto again; 3036 } 3037 } 3038 next: 3039 path->slots[0]++; 3040 } 3041 3042 btrfs_release_path(path); 3043 3044 if (stop_loop) 3045 break; 3046 3047 logic_start += map->stripe_len; 3048 } 3049 out: 3050 if (ret < 0) 3051 scrub_parity_mark_sectors_error(sparity, logic_start, 3052 logic_end - logic_start); 3053 scrub_parity_put(sparity); 3054 scrub_submit(sctx); 3055 mutex_lock(&sctx->wr_ctx.wr_lock); 3056 scrub_wr_submit(sctx); 3057 mutex_unlock(&sctx->wr_ctx.wr_lock); 3058 3059 btrfs_release_path(path); 3060 return ret < 0 ? ret : 0; 3061 } 3062 3063 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 3064 struct map_lookup *map, 3065 struct btrfs_device *scrub_dev, 3066 int num, u64 base, u64 length, 3067 int is_dev_replace) 3068 { 3069 struct btrfs_path *path, *ppath; 3070 struct btrfs_fs_info *fs_info = sctx->fs_info; 3071 struct btrfs_root *root = fs_info->extent_root; 3072 struct btrfs_root *csum_root = fs_info->csum_root; 3073 struct btrfs_extent_item *extent; 3074 struct blk_plug plug; 3075 u64 flags; 3076 int ret; 3077 int slot; 3078 u64 nstripes; 3079 struct extent_buffer *l; 3080 u64 physical; 3081 u64 logical; 3082 u64 logic_end; 3083 u64 physical_end; 3084 u64 generation; 3085 int mirror_num; 3086 struct reada_control *reada1; 3087 struct reada_control *reada2; 3088 struct btrfs_key key; 3089 struct btrfs_key key_end; 3090 u64 increment = map->stripe_len; 3091 u64 offset; 3092 u64 extent_logical; 3093 u64 extent_physical; 3094 u64 extent_len; 3095 u64 stripe_logical; 3096 u64 stripe_end; 3097 struct btrfs_device *extent_dev; 3098 int extent_mirror_num; 3099 int stop_loop = 0; 3100 3101 physical = map->stripes[num].physical; 3102 offset = 0; 3103 nstripes = div_u64(length, map->stripe_len); 3104 if (map->type & BTRFS_BLOCK_GROUP_RAID0) { 3105 offset = map->stripe_len * num; 3106 increment = map->stripe_len * map->num_stripes; 3107 mirror_num = 1; 3108 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 3109 int factor = map->num_stripes / map->sub_stripes; 3110 offset = map->stripe_len * (num / map->sub_stripes); 3111 increment = map->stripe_len * factor; 3112 mirror_num = num % map->sub_stripes + 1; 3113 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { 3114 increment = map->stripe_len; 3115 mirror_num = num % map->num_stripes + 1; 3116 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { 3117 increment = map->stripe_len; 3118 mirror_num = num % map->num_stripes + 1; 3119 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { 3120 get_raid56_logic_offset(physical, num, map, &offset, NULL); 3121 increment = map->stripe_len * nr_data_stripes(map); 3122 mirror_num = 1; 3123 } else { 3124 increment = map->stripe_len; 3125 mirror_num = 1; 3126 } 3127 3128 path = btrfs_alloc_path(); 3129 if (!path) 3130 return -ENOMEM; 3131 3132 ppath = btrfs_alloc_path(); 3133 if (!ppath) { 3134 btrfs_free_path(path); 3135 return -ENOMEM; 3136 } 3137 3138 /* 3139 * work on commit root. The related disk blocks are static as 3140 * long as COW is applied. This means, it is save to rewrite 3141 * them to repair disk errors without any race conditions 3142 */ 3143 path->search_commit_root = 1; 3144 path->skip_locking = 1; 3145 3146 ppath->search_commit_root = 1; 3147 ppath->skip_locking = 1; 3148 /* 3149 * trigger the readahead for extent tree csum tree and wait for 3150 * completion. During readahead, the scrub is officially paused 3151 * to not hold off transaction commits 3152 */ 3153 logical = base + offset; 3154 physical_end = physical + nstripes * map->stripe_len; 3155 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { 3156 get_raid56_logic_offset(physical_end, num, 3157 map, &logic_end, NULL); 3158 logic_end += base; 3159 } else { 3160 logic_end = logical + increment * nstripes; 3161 } 3162 wait_event(sctx->list_wait, 3163 atomic_read(&sctx->bios_in_flight) == 0); 3164 scrub_blocked_if_needed(fs_info); 3165 3166 /* FIXME it might be better to start readahead at commit root */ 3167 key.objectid = logical; 3168 key.type = BTRFS_EXTENT_ITEM_KEY; 3169 key.offset = (u64)0; 3170 key_end.objectid = logic_end; 3171 key_end.type = BTRFS_METADATA_ITEM_KEY; 3172 key_end.offset = (u64)-1; 3173 reada1 = btrfs_reada_add(root, &key, &key_end); 3174 3175 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 3176 key.type = BTRFS_EXTENT_CSUM_KEY; 3177 key.offset = logical; 3178 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 3179 key_end.type = BTRFS_EXTENT_CSUM_KEY; 3180 key_end.offset = logic_end; 3181 reada2 = btrfs_reada_add(csum_root, &key, &key_end); 3182 3183 if (!IS_ERR(reada1)) 3184 btrfs_reada_wait(reada1); 3185 if (!IS_ERR(reada2)) 3186 btrfs_reada_wait(reada2); 3187 3188 3189 /* 3190 * collect all data csums for the stripe to avoid seeking during 3191 * the scrub. This might currently (crc32) end up to be about 1MB 3192 */ 3193 blk_start_plug(&plug); 3194 3195 /* 3196 * now find all extents for each stripe and scrub them 3197 */ 3198 ret = 0; 3199 while (physical < physical_end) { 3200 /* 3201 * canceled? 3202 */ 3203 if (atomic_read(&fs_info->scrub_cancel_req) || 3204 atomic_read(&sctx->cancel_req)) { 3205 ret = -ECANCELED; 3206 goto out; 3207 } 3208 /* 3209 * check to see if we have to pause 3210 */ 3211 if (atomic_read(&fs_info->scrub_pause_req)) { 3212 /* push queued extents */ 3213 atomic_set(&sctx->wr_ctx.flush_all_writes, 1); 3214 scrub_submit(sctx); 3215 mutex_lock(&sctx->wr_ctx.wr_lock); 3216 scrub_wr_submit(sctx); 3217 mutex_unlock(&sctx->wr_ctx.wr_lock); 3218 wait_event(sctx->list_wait, 3219 atomic_read(&sctx->bios_in_flight) == 0); 3220 atomic_set(&sctx->wr_ctx.flush_all_writes, 0); 3221 scrub_blocked_if_needed(fs_info); 3222 } 3223 3224 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { 3225 ret = get_raid56_logic_offset(physical, num, map, 3226 &logical, 3227 &stripe_logical); 3228 logical += base; 3229 if (ret) { 3230 /* it is parity strip */ 3231 stripe_logical += base; 3232 stripe_end = stripe_logical + increment; 3233 ret = scrub_raid56_parity(sctx, map, scrub_dev, 3234 ppath, stripe_logical, 3235 stripe_end); 3236 if (ret) 3237 goto out; 3238 goto skip; 3239 } 3240 } 3241 3242 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) 3243 key.type = BTRFS_METADATA_ITEM_KEY; 3244 else 3245 key.type = BTRFS_EXTENT_ITEM_KEY; 3246 key.objectid = logical; 3247 key.offset = (u64)-1; 3248 3249 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3250 if (ret < 0) 3251 goto out; 3252 3253 if (ret > 0) { 3254 ret = btrfs_previous_extent_item(root, path, 0); 3255 if (ret < 0) 3256 goto out; 3257 if (ret > 0) { 3258 /* there's no smaller item, so stick with the 3259 * larger one */ 3260 btrfs_release_path(path); 3261 ret = btrfs_search_slot(NULL, root, &key, 3262 path, 0, 0); 3263 if (ret < 0) 3264 goto out; 3265 } 3266 } 3267 3268 stop_loop = 0; 3269 while (1) { 3270 u64 bytes; 3271 3272 l = path->nodes[0]; 3273 slot = path->slots[0]; 3274 if (slot >= btrfs_header_nritems(l)) { 3275 ret = btrfs_next_leaf(root, path); 3276 if (ret == 0) 3277 continue; 3278 if (ret < 0) 3279 goto out; 3280 3281 stop_loop = 1; 3282 break; 3283 } 3284 btrfs_item_key_to_cpu(l, &key, slot); 3285 3286 if (key.type != BTRFS_EXTENT_ITEM_KEY && 3287 key.type != BTRFS_METADATA_ITEM_KEY) 3288 goto next; 3289 3290 if (key.type == BTRFS_METADATA_ITEM_KEY) 3291 bytes = fs_info->nodesize; 3292 else 3293 bytes = key.offset; 3294 3295 if (key.objectid + bytes <= logical) 3296 goto next; 3297 3298 if (key.objectid >= logical + map->stripe_len) { 3299 /* out of this device extent */ 3300 if (key.objectid >= logic_end) 3301 stop_loop = 1; 3302 break; 3303 } 3304 3305 extent = btrfs_item_ptr(l, slot, 3306 struct btrfs_extent_item); 3307 flags = btrfs_extent_flags(l, extent); 3308 generation = btrfs_extent_generation(l, extent); 3309 3310 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) && 3311 (key.objectid < logical || 3312 key.objectid + bytes > 3313 logical + map->stripe_len)) { 3314 btrfs_err(fs_info, 3315 "scrub: tree block %llu spanning stripes, ignored. logical=%llu", 3316 key.objectid, logical); 3317 spin_lock(&sctx->stat_lock); 3318 sctx->stat.uncorrectable_errors++; 3319 spin_unlock(&sctx->stat_lock); 3320 goto next; 3321 } 3322 3323 again: 3324 extent_logical = key.objectid; 3325 extent_len = bytes; 3326 3327 /* 3328 * trim extent to this stripe 3329 */ 3330 if (extent_logical < logical) { 3331 extent_len -= logical - extent_logical; 3332 extent_logical = logical; 3333 } 3334 if (extent_logical + extent_len > 3335 logical + map->stripe_len) { 3336 extent_len = logical + map->stripe_len - 3337 extent_logical; 3338 } 3339 3340 extent_physical = extent_logical - logical + physical; 3341 extent_dev = scrub_dev; 3342 extent_mirror_num = mirror_num; 3343 if (is_dev_replace) 3344 scrub_remap_extent(fs_info, extent_logical, 3345 extent_len, &extent_physical, 3346 &extent_dev, 3347 &extent_mirror_num); 3348 3349 ret = btrfs_lookup_csums_range(csum_root, 3350 extent_logical, 3351 extent_logical + 3352 extent_len - 1, 3353 &sctx->csum_list, 1); 3354 if (ret) 3355 goto out; 3356 3357 ret = scrub_extent(sctx, extent_logical, extent_len, 3358 extent_physical, extent_dev, flags, 3359 generation, extent_mirror_num, 3360 extent_logical - logical + physical); 3361 3362 scrub_free_csums(sctx); 3363 3364 if (ret) 3365 goto out; 3366 3367 if (extent_logical + extent_len < 3368 key.objectid + bytes) { 3369 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { 3370 /* 3371 * loop until we find next data stripe 3372 * or we have finished all stripes. 3373 */ 3374 loop: 3375 physical += map->stripe_len; 3376 ret = get_raid56_logic_offset(physical, 3377 num, map, &logical, 3378 &stripe_logical); 3379 logical += base; 3380 3381 if (ret && physical < physical_end) { 3382 stripe_logical += base; 3383 stripe_end = stripe_logical + 3384 increment; 3385 ret = scrub_raid56_parity(sctx, 3386 map, scrub_dev, ppath, 3387 stripe_logical, 3388 stripe_end); 3389 if (ret) 3390 goto out; 3391 goto loop; 3392 } 3393 } else { 3394 physical += map->stripe_len; 3395 logical += increment; 3396 } 3397 if (logical < key.objectid + bytes) { 3398 cond_resched(); 3399 goto again; 3400 } 3401 3402 if (physical >= physical_end) { 3403 stop_loop = 1; 3404 break; 3405 } 3406 } 3407 next: 3408 path->slots[0]++; 3409 } 3410 btrfs_release_path(path); 3411 skip: 3412 logical += increment; 3413 physical += map->stripe_len; 3414 spin_lock(&sctx->stat_lock); 3415 if (stop_loop) 3416 sctx->stat.last_physical = map->stripes[num].physical + 3417 length; 3418 else 3419 sctx->stat.last_physical = physical; 3420 spin_unlock(&sctx->stat_lock); 3421 if (stop_loop) 3422 break; 3423 } 3424 out: 3425 /* push queued extents */ 3426 scrub_submit(sctx); 3427 mutex_lock(&sctx->wr_ctx.wr_lock); 3428 scrub_wr_submit(sctx); 3429 mutex_unlock(&sctx->wr_ctx.wr_lock); 3430 3431 blk_finish_plug(&plug); 3432 btrfs_free_path(path); 3433 btrfs_free_path(ppath); 3434 return ret < 0 ? ret : 0; 3435 } 3436 3437 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, 3438 struct btrfs_device *scrub_dev, 3439 u64 chunk_offset, u64 length, 3440 u64 dev_offset, 3441 struct btrfs_block_group_cache *cache, 3442 int is_dev_replace) 3443 { 3444 struct btrfs_fs_info *fs_info = sctx->fs_info; 3445 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; 3446 struct map_lookup *map; 3447 struct extent_map *em; 3448 int i; 3449 int ret = 0; 3450 3451 read_lock(&map_tree->map_tree.lock); 3452 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); 3453 read_unlock(&map_tree->map_tree.lock); 3454 3455 if (!em) { 3456 /* 3457 * Might have been an unused block group deleted by the cleaner 3458 * kthread or relocation. 3459 */ 3460 spin_lock(&cache->lock); 3461 if (!cache->removed) 3462 ret = -EINVAL; 3463 spin_unlock(&cache->lock); 3464 3465 return ret; 3466 } 3467 3468 map = em->map_lookup; 3469 if (em->start != chunk_offset) 3470 goto out; 3471 3472 if (em->len < length) 3473 goto out; 3474 3475 for (i = 0; i < map->num_stripes; ++i) { 3476 if (map->stripes[i].dev->bdev == scrub_dev->bdev && 3477 map->stripes[i].physical == dev_offset) { 3478 ret = scrub_stripe(sctx, map, scrub_dev, i, 3479 chunk_offset, length, 3480 is_dev_replace); 3481 if (ret) 3482 goto out; 3483 } 3484 } 3485 out: 3486 free_extent_map(em); 3487 3488 return ret; 3489 } 3490 3491 static noinline_for_stack 3492 int scrub_enumerate_chunks(struct scrub_ctx *sctx, 3493 struct btrfs_device *scrub_dev, u64 start, u64 end, 3494 int is_dev_replace) 3495 { 3496 struct btrfs_dev_extent *dev_extent = NULL; 3497 struct btrfs_path *path; 3498 struct btrfs_fs_info *fs_info = sctx->fs_info; 3499 struct btrfs_root *root = fs_info->dev_root; 3500 u64 length; 3501 u64 chunk_offset; 3502 int ret = 0; 3503 int ro_set; 3504 int slot; 3505 struct extent_buffer *l; 3506 struct btrfs_key key; 3507 struct btrfs_key found_key; 3508 struct btrfs_block_group_cache *cache; 3509 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 3510 3511 path = btrfs_alloc_path(); 3512 if (!path) 3513 return -ENOMEM; 3514 3515 path->reada = READA_FORWARD; 3516 path->search_commit_root = 1; 3517 path->skip_locking = 1; 3518 3519 key.objectid = scrub_dev->devid; 3520 key.offset = 0ull; 3521 key.type = BTRFS_DEV_EXTENT_KEY; 3522 3523 while (1) { 3524 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3525 if (ret < 0) 3526 break; 3527 if (ret > 0) { 3528 if (path->slots[0] >= 3529 btrfs_header_nritems(path->nodes[0])) { 3530 ret = btrfs_next_leaf(root, path); 3531 if (ret < 0) 3532 break; 3533 if (ret > 0) { 3534 ret = 0; 3535 break; 3536 } 3537 } else { 3538 ret = 0; 3539 } 3540 } 3541 3542 l = path->nodes[0]; 3543 slot = path->slots[0]; 3544 3545 btrfs_item_key_to_cpu(l, &found_key, slot); 3546 3547 if (found_key.objectid != scrub_dev->devid) 3548 break; 3549 3550 if (found_key.type != BTRFS_DEV_EXTENT_KEY) 3551 break; 3552 3553 if (found_key.offset >= end) 3554 break; 3555 3556 if (found_key.offset < key.offset) 3557 break; 3558 3559 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 3560 length = btrfs_dev_extent_length(l, dev_extent); 3561 3562 if (found_key.offset + length <= start) 3563 goto skip; 3564 3565 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); 3566 3567 /* 3568 * get a reference on the corresponding block group to prevent 3569 * the chunk from going away while we scrub it 3570 */ 3571 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 3572 3573 /* some chunks are removed but not committed to disk yet, 3574 * continue scrubbing */ 3575 if (!cache) 3576 goto skip; 3577 3578 /* 3579 * we need call btrfs_inc_block_group_ro() with scrubs_paused, 3580 * to avoid deadlock caused by: 3581 * btrfs_inc_block_group_ro() 3582 * -> btrfs_wait_for_commit() 3583 * -> btrfs_commit_transaction() 3584 * -> btrfs_scrub_pause() 3585 */ 3586 scrub_pause_on(fs_info); 3587 ret = btrfs_inc_block_group_ro(root, cache); 3588 if (!ret && is_dev_replace) { 3589 /* 3590 * If we are doing a device replace wait for any tasks 3591 * that started dellaloc right before we set the block 3592 * group to RO mode, as they might have just allocated 3593 * an extent from it or decided they could do a nocow 3594 * write. And if any such tasks did that, wait for their 3595 * ordered extents to complete and then commit the 3596 * current transaction, so that we can later see the new 3597 * extent items in the extent tree - the ordered extents 3598 * create delayed data references (for cow writes) when 3599 * they complete, which will be run and insert the 3600 * corresponding extent items into the extent tree when 3601 * we commit the transaction they used when running 3602 * inode.c:btrfs_finish_ordered_io(). We later use 3603 * the commit root of the extent tree to find extents 3604 * to copy from the srcdev into the tgtdev, and we don't 3605 * want to miss any new extents. 3606 */ 3607 btrfs_wait_block_group_reservations(cache); 3608 btrfs_wait_nocow_writers(cache); 3609 ret = btrfs_wait_ordered_roots(fs_info, -1, 3610 cache->key.objectid, 3611 cache->key.offset); 3612 if (ret > 0) { 3613 struct btrfs_trans_handle *trans; 3614 3615 trans = btrfs_join_transaction(root); 3616 if (IS_ERR(trans)) 3617 ret = PTR_ERR(trans); 3618 else 3619 ret = btrfs_commit_transaction(trans); 3620 if (ret) { 3621 scrub_pause_off(fs_info); 3622 btrfs_put_block_group(cache); 3623 break; 3624 } 3625 } 3626 } 3627 scrub_pause_off(fs_info); 3628 3629 if (ret == 0) { 3630 ro_set = 1; 3631 } else if (ret == -ENOSPC) { 3632 /* 3633 * btrfs_inc_block_group_ro return -ENOSPC when it 3634 * failed in creating new chunk for metadata. 3635 * It is not a problem for scrub/replace, because 3636 * metadata are always cowed, and our scrub paused 3637 * commit_transactions. 3638 */ 3639 ro_set = 0; 3640 } else { 3641 btrfs_warn(fs_info, 3642 "failed setting block group ro, ret=%d\n", 3643 ret); 3644 btrfs_put_block_group(cache); 3645 break; 3646 } 3647 3648 btrfs_dev_replace_lock(&fs_info->dev_replace, 1); 3649 dev_replace->cursor_right = found_key.offset + length; 3650 dev_replace->cursor_left = found_key.offset; 3651 dev_replace->item_needs_writeback = 1; 3652 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1); 3653 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length, 3654 found_key.offset, cache, is_dev_replace); 3655 3656 /* 3657 * flush, submit all pending read and write bios, afterwards 3658 * wait for them. 3659 * Note that in the dev replace case, a read request causes 3660 * write requests that are submitted in the read completion 3661 * worker. Therefore in the current situation, it is required 3662 * that all write requests are flushed, so that all read and 3663 * write requests are really completed when bios_in_flight 3664 * changes to 0. 3665 */ 3666 atomic_set(&sctx->wr_ctx.flush_all_writes, 1); 3667 scrub_submit(sctx); 3668 mutex_lock(&sctx->wr_ctx.wr_lock); 3669 scrub_wr_submit(sctx); 3670 mutex_unlock(&sctx->wr_ctx.wr_lock); 3671 3672 wait_event(sctx->list_wait, 3673 atomic_read(&sctx->bios_in_flight) == 0); 3674 3675 scrub_pause_on(fs_info); 3676 3677 /* 3678 * must be called before we decrease @scrub_paused. 3679 * make sure we don't block transaction commit while 3680 * we are waiting pending workers finished. 3681 */ 3682 wait_event(sctx->list_wait, 3683 atomic_read(&sctx->workers_pending) == 0); 3684 atomic_set(&sctx->wr_ctx.flush_all_writes, 0); 3685 3686 scrub_pause_off(fs_info); 3687 3688 btrfs_dev_replace_lock(&fs_info->dev_replace, 1); 3689 dev_replace->cursor_left = dev_replace->cursor_right; 3690 dev_replace->item_needs_writeback = 1; 3691 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1); 3692 3693 if (ro_set) 3694 btrfs_dec_block_group_ro(cache); 3695 3696 /* 3697 * We might have prevented the cleaner kthread from deleting 3698 * this block group if it was already unused because we raced 3699 * and set it to RO mode first. So add it back to the unused 3700 * list, otherwise it might not ever be deleted unless a manual 3701 * balance is triggered or it becomes used and unused again. 3702 */ 3703 spin_lock(&cache->lock); 3704 if (!cache->removed && !cache->ro && cache->reserved == 0 && 3705 btrfs_block_group_used(&cache->item) == 0) { 3706 spin_unlock(&cache->lock); 3707 spin_lock(&fs_info->unused_bgs_lock); 3708 if (list_empty(&cache->bg_list)) { 3709 btrfs_get_block_group(cache); 3710 list_add_tail(&cache->bg_list, 3711 &fs_info->unused_bgs); 3712 } 3713 spin_unlock(&fs_info->unused_bgs_lock); 3714 } else { 3715 spin_unlock(&cache->lock); 3716 } 3717 3718 btrfs_put_block_group(cache); 3719 if (ret) 3720 break; 3721 if (is_dev_replace && 3722 atomic64_read(&dev_replace->num_write_errors) > 0) { 3723 ret = -EIO; 3724 break; 3725 } 3726 if (sctx->stat.malloc_errors > 0) { 3727 ret = -ENOMEM; 3728 break; 3729 } 3730 skip: 3731 key.offset = found_key.offset + length; 3732 btrfs_release_path(path); 3733 } 3734 3735 btrfs_free_path(path); 3736 3737 return ret; 3738 } 3739 3740 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, 3741 struct btrfs_device *scrub_dev) 3742 { 3743 int i; 3744 u64 bytenr; 3745 u64 gen; 3746 int ret; 3747 struct btrfs_fs_info *fs_info = sctx->fs_info; 3748 3749 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 3750 return -EIO; 3751 3752 /* Seed devices of a new filesystem has their own generation. */ 3753 if (scrub_dev->fs_devices != fs_info->fs_devices) 3754 gen = scrub_dev->generation; 3755 else 3756 gen = fs_info->last_trans_committed; 3757 3758 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { 3759 bytenr = btrfs_sb_offset(i); 3760 if (bytenr + BTRFS_SUPER_INFO_SIZE > 3761 scrub_dev->commit_total_bytes) 3762 break; 3763 3764 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr, 3765 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i, 3766 NULL, 1, bytenr); 3767 if (ret) 3768 return ret; 3769 } 3770 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 3771 3772 return 0; 3773 } 3774 3775 /* 3776 * get a reference count on fs_info->scrub_workers. start worker if necessary 3777 */ 3778 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info, 3779 int is_dev_replace) 3780 { 3781 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND; 3782 int max_active = fs_info->thread_pool_size; 3783 3784 if (fs_info->scrub_workers_refcnt == 0) { 3785 if (is_dev_replace) 3786 fs_info->scrub_workers = 3787 btrfs_alloc_workqueue(fs_info, "scrub", flags, 3788 1, 4); 3789 else 3790 fs_info->scrub_workers = 3791 btrfs_alloc_workqueue(fs_info, "scrub", flags, 3792 max_active, 4); 3793 if (!fs_info->scrub_workers) 3794 goto fail_scrub_workers; 3795 3796 fs_info->scrub_wr_completion_workers = 3797 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags, 3798 max_active, 2); 3799 if (!fs_info->scrub_wr_completion_workers) 3800 goto fail_scrub_wr_completion_workers; 3801 3802 fs_info->scrub_nocow_workers = 3803 btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0); 3804 if (!fs_info->scrub_nocow_workers) 3805 goto fail_scrub_nocow_workers; 3806 fs_info->scrub_parity_workers = 3807 btrfs_alloc_workqueue(fs_info, "scrubparity", flags, 3808 max_active, 2); 3809 if (!fs_info->scrub_parity_workers) 3810 goto fail_scrub_parity_workers; 3811 } 3812 ++fs_info->scrub_workers_refcnt; 3813 return 0; 3814 3815 fail_scrub_parity_workers: 3816 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers); 3817 fail_scrub_nocow_workers: 3818 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers); 3819 fail_scrub_wr_completion_workers: 3820 btrfs_destroy_workqueue(fs_info->scrub_workers); 3821 fail_scrub_workers: 3822 return -ENOMEM; 3823 } 3824 3825 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info) 3826 { 3827 if (--fs_info->scrub_workers_refcnt == 0) { 3828 btrfs_destroy_workqueue(fs_info->scrub_workers); 3829 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers); 3830 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers); 3831 btrfs_destroy_workqueue(fs_info->scrub_parity_workers); 3832 } 3833 WARN_ON(fs_info->scrub_workers_refcnt < 0); 3834 } 3835 3836 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, 3837 u64 end, struct btrfs_scrub_progress *progress, 3838 int readonly, int is_dev_replace) 3839 { 3840 struct scrub_ctx *sctx; 3841 int ret; 3842 struct btrfs_device *dev; 3843 struct rcu_string *name; 3844 3845 if (btrfs_fs_closing(fs_info)) 3846 return -EINVAL; 3847 3848 if (fs_info->nodesize > BTRFS_STRIPE_LEN) { 3849 /* 3850 * in this case scrub is unable to calculate the checksum 3851 * the way scrub is implemented. Do not handle this 3852 * situation at all because it won't ever happen. 3853 */ 3854 btrfs_err(fs_info, 3855 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails", 3856 fs_info->nodesize, 3857 BTRFS_STRIPE_LEN); 3858 return -EINVAL; 3859 } 3860 3861 if (fs_info->sectorsize != PAGE_SIZE) { 3862 /* not supported for data w/o checksums */ 3863 btrfs_err_rl(fs_info, 3864 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails", 3865 fs_info->sectorsize, PAGE_SIZE); 3866 return -EINVAL; 3867 } 3868 3869 if (fs_info->nodesize > 3870 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK || 3871 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) { 3872 /* 3873 * would exhaust the array bounds of pagev member in 3874 * struct scrub_block 3875 */ 3876 btrfs_err(fs_info, 3877 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails", 3878 fs_info->nodesize, 3879 SCRUB_MAX_PAGES_PER_BLOCK, 3880 fs_info->sectorsize, 3881 SCRUB_MAX_PAGES_PER_BLOCK); 3882 return -EINVAL; 3883 } 3884 3885 3886 mutex_lock(&fs_info->fs_devices->device_list_mutex); 3887 dev = btrfs_find_device(fs_info, devid, NULL, NULL); 3888 if (!dev || (dev->missing && !is_dev_replace)) { 3889 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3890 return -ENODEV; 3891 } 3892 3893 if (!is_dev_replace && !readonly && !dev->writeable) { 3894 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3895 rcu_read_lock(); 3896 name = rcu_dereference(dev->name); 3897 btrfs_err(fs_info, "scrub: device %s is not writable", 3898 name->str); 3899 rcu_read_unlock(); 3900 return -EROFS; 3901 } 3902 3903 mutex_lock(&fs_info->scrub_lock); 3904 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) { 3905 mutex_unlock(&fs_info->scrub_lock); 3906 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3907 return -EIO; 3908 } 3909 3910 btrfs_dev_replace_lock(&fs_info->dev_replace, 0); 3911 if (dev->scrub_device || 3912 (!is_dev_replace && 3913 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) { 3914 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); 3915 mutex_unlock(&fs_info->scrub_lock); 3916 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3917 return -EINPROGRESS; 3918 } 3919 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); 3920 3921 ret = scrub_workers_get(fs_info, is_dev_replace); 3922 if (ret) { 3923 mutex_unlock(&fs_info->scrub_lock); 3924 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3925 return ret; 3926 } 3927 3928 sctx = scrub_setup_ctx(dev, is_dev_replace); 3929 if (IS_ERR(sctx)) { 3930 mutex_unlock(&fs_info->scrub_lock); 3931 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3932 scrub_workers_put(fs_info); 3933 return PTR_ERR(sctx); 3934 } 3935 sctx->readonly = readonly; 3936 dev->scrub_device = sctx; 3937 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3938 3939 /* 3940 * checking @scrub_pause_req here, we can avoid 3941 * race between committing transaction and scrubbing. 3942 */ 3943 __scrub_blocked_if_needed(fs_info); 3944 atomic_inc(&fs_info->scrubs_running); 3945 mutex_unlock(&fs_info->scrub_lock); 3946 3947 if (!is_dev_replace) { 3948 /* 3949 * by holding device list mutex, we can 3950 * kick off writing super in log tree sync. 3951 */ 3952 mutex_lock(&fs_info->fs_devices->device_list_mutex); 3953 ret = scrub_supers(sctx, dev); 3954 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3955 } 3956 3957 if (!ret) 3958 ret = scrub_enumerate_chunks(sctx, dev, start, end, 3959 is_dev_replace); 3960 3961 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 3962 atomic_dec(&fs_info->scrubs_running); 3963 wake_up(&fs_info->scrub_pause_wait); 3964 3965 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0); 3966 3967 if (progress) 3968 memcpy(progress, &sctx->stat, sizeof(*progress)); 3969 3970 mutex_lock(&fs_info->scrub_lock); 3971 dev->scrub_device = NULL; 3972 scrub_workers_put(fs_info); 3973 mutex_unlock(&fs_info->scrub_lock); 3974 3975 scrub_put_ctx(sctx); 3976 3977 return ret; 3978 } 3979 3980 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info) 3981 { 3982 mutex_lock(&fs_info->scrub_lock); 3983 atomic_inc(&fs_info->scrub_pause_req); 3984 while (atomic_read(&fs_info->scrubs_paused) != 3985 atomic_read(&fs_info->scrubs_running)) { 3986 mutex_unlock(&fs_info->scrub_lock); 3987 wait_event(fs_info->scrub_pause_wait, 3988 atomic_read(&fs_info->scrubs_paused) == 3989 atomic_read(&fs_info->scrubs_running)); 3990 mutex_lock(&fs_info->scrub_lock); 3991 } 3992 mutex_unlock(&fs_info->scrub_lock); 3993 } 3994 3995 void btrfs_scrub_continue(struct btrfs_fs_info *fs_info) 3996 { 3997 atomic_dec(&fs_info->scrub_pause_req); 3998 wake_up(&fs_info->scrub_pause_wait); 3999 } 4000 4001 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info) 4002 { 4003 mutex_lock(&fs_info->scrub_lock); 4004 if (!atomic_read(&fs_info->scrubs_running)) { 4005 mutex_unlock(&fs_info->scrub_lock); 4006 return -ENOTCONN; 4007 } 4008 4009 atomic_inc(&fs_info->scrub_cancel_req); 4010 while (atomic_read(&fs_info->scrubs_running)) { 4011 mutex_unlock(&fs_info->scrub_lock); 4012 wait_event(fs_info->scrub_pause_wait, 4013 atomic_read(&fs_info->scrubs_running) == 0); 4014 mutex_lock(&fs_info->scrub_lock); 4015 } 4016 atomic_dec(&fs_info->scrub_cancel_req); 4017 mutex_unlock(&fs_info->scrub_lock); 4018 4019 return 0; 4020 } 4021 4022 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info, 4023 struct btrfs_device *dev) 4024 { 4025 struct scrub_ctx *sctx; 4026 4027 mutex_lock(&fs_info->scrub_lock); 4028 sctx = dev->scrub_device; 4029 if (!sctx) { 4030 mutex_unlock(&fs_info->scrub_lock); 4031 return -ENOTCONN; 4032 } 4033 atomic_inc(&sctx->cancel_req); 4034 while (dev->scrub_device) { 4035 mutex_unlock(&fs_info->scrub_lock); 4036 wait_event(fs_info->scrub_pause_wait, 4037 dev->scrub_device == NULL); 4038 mutex_lock(&fs_info->scrub_lock); 4039 } 4040 mutex_unlock(&fs_info->scrub_lock); 4041 4042 return 0; 4043 } 4044 4045 int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid, 4046 struct btrfs_scrub_progress *progress) 4047 { 4048 struct btrfs_device *dev; 4049 struct scrub_ctx *sctx = NULL; 4050 4051 mutex_lock(&fs_info->fs_devices->device_list_mutex); 4052 dev = btrfs_find_device(fs_info, devid, NULL, NULL); 4053 if (dev) 4054 sctx = dev->scrub_device; 4055 if (sctx) 4056 memcpy(progress, &sctx->stat, sizeof(*progress)); 4057 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 4058 4059 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV; 4060 } 4061 4062 static void scrub_remap_extent(struct btrfs_fs_info *fs_info, 4063 u64 extent_logical, u64 extent_len, 4064 u64 *extent_physical, 4065 struct btrfs_device **extent_dev, 4066 int *extent_mirror_num) 4067 { 4068 u64 mapped_length; 4069 struct btrfs_bio *bbio = NULL; 4070 int ret; 4071 4072 mapped_length = extent_len; 4073 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical, 4074 &mapped_length, &bbio, 0); 4075 if (ret || !bbio || mapped_length < extent_len || 4076 !bbio->stripes[0].dev->bdev) { 4077 btrfs_put_bbio(bbio); 4078 return; 4079 } 4080 4081 *extent_physical = bbio->stripes[0].physical; 4082 *extent_mirror_num = bbio->mirror_num; 4083 *extent_dev = bbio->stripes[0].dev; 4084 btrfs_put_bbio(bbio); 4085 } 4086 4087 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx, 4088 struct scrub_wr_ctx *wr_ctx, 4089 struct btrfs_fs_info *fs_info, 4090 struct btrfs_device *dev, 4091 int is_dev_replace) 4092 { 4093 WARN_ON(wr_ctx->wr_curr_bio != NULL); 4094 4095 mutex_init(&wr_ctx->wr_lock); 4096 wr_ctx->wr_curr_bio = NULL; 4097 if (!is_dev_replace) 4098 return 0; 4099 4100 WARN_ON(!dev->bdev); 4101 wr_ctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO; 4102 wr_ctx->tgtdev = dev; 4103 atomic_set(&wr_ctx->flush_all_writes, 0); 4104 return 0; 4105 } 4106 4107 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx) 4108 { 4109 mutex_lock(&wr_ctx->wr_lock); 4110 kfree(wr_ctx->wr_curr_bio); 4111 wr_ctx->wr_curr_bio = NULL; 4112 mutex_unlock(&wr_ctx->wr_lock); 4113 } 4114 4115 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 4116 int mirror_num, u64 physical_for_dev_replace) 4117 { 4118 struct scrub_copy_nocow_ctx *nocow_ctx; 4119 struct btrfs_fs_info *fs_info = sctx->fs_info; 4120 4121 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS); 4122 if (!nocow_ctx) { 4123 spin_lock(&sctx->stat_lock); 4124 sctx->stat.malloc_errors++; 4125 spin_unlock(&sctx->stat_lock); 4126 return -ENOMEM; 4127 } 4128 4129 scrub_pending_trans_workers_inc(sctx); 4130 4131 nocow_ctx->sctx = sctx; 4132 nocow_ctx->logical = logical; 4133 nocow_ctx->len = len; 4134 nocow_ctx->mirror_num = mirror_num; 4135 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace; 4136 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper, 4137 copy_nocow_pages_worker, NULL, NULL); 4138 INIT_LIST_HEAD(&nocow_ctx->inodes); 4139 btrfs_queue_work(fs_info->scrub_nocow_workers, 4140 &nocow_ctx->work); 4141 4142 return 0; 4143 } 4144 4145 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx) 4146 { 4147 struct scrub_copy_nocow_ctx *nocow_ctx = ctx; 4148 struct scrub_nocow_inode *nocow_inode; 4149 4150 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS); 4151 if (!nocow_inode) 4152 return -ENOMEM; 4153 nocow_inode->inum = inum; 4154 nocow_inode->offset = offset; 4155 nocow_inode->root = root; 4156 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes); 4157 return 0; 4158 } 4159 4160 #define COPY_COMPLETE 1 4161 4162 static void copy_nocow_pages_worker(struct btrfs_work *work) 4163 { 4164 struct scrub_copy_nocow_ctx *nocow_ctx = 4165 container_of(work, struct scrub_copy_nocow_ctx, work); 4166 struct scrub_ctx *sctx = nocow_ctx->sctx; 4167 struct btrfs_fs_info *fs_info = sctx->fs_info; 4168 struct btrfs_root *root = fs_info->extent_root; 4169 u64 logical = nocow_ctx->logical; 4170 u64 len = nocow_ctx->len; 4171 int mirror_num = nocow_ctx->mirror_num; 4172 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace; 4173 int ret; 4174 struct btrfs_trans_handle *trans = NULL; 4175 struct btrfs_path *path; 4176 int not_written = 0; 4177 4178 path = btrfs_alloc_path(); 4179 if (!path) { 4180 spin_lock(&sctx->stat_lock); 4181 sctx->stat.malloc_errors++; 4182 spin_unlock(&sctx->stat_lock); 4183 not_written = 1; 4184 goto out; 4185 } 4186 4187 trans = btrfs_join_transaction(root); 4188 if (IS_ERR(trans)) { 4189 not_written = 1; 4190 goto out; 4191 } 4192 4193 ret = iterate_inodes_from_logical(logical, fs_info, path, 4194 record_inode_for_nocow, nocow_ctx); 4195 if (ret != 0 && ret != -ENOENT) { 4196 btrfs_warn(fs_info, 4197 "iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %u, ret %d", 4198 logical, physical_for_dev_replace, len, mirror_num, 4199 ret); 4200 not_written = 1; 4201 goto out; 4202 } 4203 4204 btrfs_end_transaction(trans); 4205 trans = NULL; 4206 while (!list_empty(&nocow_ctx->inodes)) { 4207 struct scrub_nocow_inode *entry; 4208 entry = list_first_entry(&nocow_ctx->inodes, 4209 struct scrub_nocow_inode, 4210 list); 4211 list_del_init(&entry->list); 4212 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset, 4213 entry->root, nocow_ctx); 4214 kfree(entry); 4215 if (ret == COPY_COMPLETE) { 4216 ret = 0; 4217 break; 4218 } else if (ret) { 4219 break; 4220 } 4221 } 4222 out: 4223 while (!list_empty(&nocow_ctx->inodes)) { 4224 struct scrub_nocow_inode *entry; 4225 entry = list_first_entry(&nocow_ctx->inodes, 4226 struct scrub_nocow_inode, 4227 list); 4228 list_del_init(&entry->list); 4229 kfree(entry); 4230 } 4231 if (trans && !IS_ERR(trans)) 4232 btrfs_end_transaction(trans); 4233 if (not_written) 4234 btrfs_dev_replace_stats_inc(&fs_info->dev_replace. 4235 num_uncorrectable_read_errors); 4236 4237 btrfs_free_path(path); 4238 kfree(nocow_ctx); 4239 4240 scrub_pending_trans_workers_dec(sctx); 4241 } 4242 4243 static int check_extent_to_block(struct inode *inode, u64 start, u64 len, 4244 u64 logical) 4245 { 4246 struct extent_state *cached_state = NULL; 4247 struct btrfs_ordered_extent *ordered; 4248 struct extent_io_tree *io_tree; 4249 struct extent_map *em; 4250 u64 lockstart = start, lockend = start + len - 1; 4251 int ret = 0; 4252 4253 io_tree = &BTRFS_I(inode)->io_tree; 4254 4255 lock_extent_bits(io_tree, lockstart, lockend, &cached_state); 4256 ordered = btrfs_lookup_ordered_range(inode, lockstart, len); 4257 if (ordered) { 4258 btrfs_put_ordered_extent(ordered); 4259 ret = 1; 4260 goto out_unlock; 4261 } 4262 4263 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 4264 if (IS_ERR(em)) { 4265 ret = PTR_ERR(em); 4266 goto out_unlock; 4267 } 4268 4269 /* 4270 * This extent does not actually cover the logical extent anymore, 4271 * move on to the next inode. 4272 */ 4273 if (em->block_start > logical || 4274 em->block_start + em->block_len < logical + len) { 4275 free_extent_map(em); 4276 ret = 1; 4277 goto out_unlock; 4278 } 4279 free_extent_map(em); 4280 4281 out_unlock: 4282 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state, 4283 GFP_NOFS); 4284 return ret; 4285 } 4286 4287 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, 4288 struct scrub_copy_nocow_ctx *nocow_ctx) 4289 { 4290 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->fs_info; 4291 struct btrfs_key key; 4292 struct inode *inode; 4293 struct page *page; 4294 struct btrfs_root *local_root; 4295 struct extent_io_tree *io_tree; 4296 u64 physical_for_dev_replace; 4297 u64 nocow_ctx_logical; 4298 u64 len = nocow_ctx->len; 4299 unsigned long index; 4300 int srcu_index; 4301 int ret = 0; 4302 int err = 0; 4303 4304 key.objectid = root; 4305 key.type = BTRFS_ROOT_ITEM_KEY; 4306 key.offset = (u64)-1; 4307 4308 srcu_index = srcu_read_lock(&fs_info->subvol_srcu); 4309 4310 local_root = btrfs_read_fs_root_no_name(fs_info, &key); 4311 if (IS_ERR(local_root)) { 4312 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 4313 return PTR_ERR(local_root); 4314 } 4315 4316 key.type = BTRFS_INODE_ITEM_KEY; 4317 key.objectid = inum; 4318 key.offset = 0; 4319 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL); 4320 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 4321 if (IS_ERR(inode)) 4322 return PTR_ERR(inode); 4323 4324 /* Avoid truncate/dio/punch hole.. */ 4325 inode_lock(inode); 4326 inode_dio_wait(inode); 4327 4328 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace; 4329 io_tree = &BTRFS_I(inode)->io_tree; 4330 nocow_ctx_logical = nocow_ctx->logical; 4331 4332 ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical); 4333 if (ret) { 4334 ret = ret > 0 ? 0 : ret; 4335 goto out; 4336 } 4337 4338 while (len >= PAGE_SIZE) { 4339 index = offset >> PAGE_SHIFT; 4340 again: 4341 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 4342 if (!page) { 4343 btrfs_err(fs_info, "find_or_create_page() failed"); 4344 ret = -ENOMEM; 4345 goto out; 4346 } 4347 4348 if (PageUptodate(page)) { 4349 if (PageDirty(page)) 4350 goto next_page; 4351 } else { 4352 ClearPageError(page); 4353 err = extent_read_full_page(io_tree, page, 4354 btrfs_get_extent, 4355 nocow_ctx->mirror_num); 4356 if (err) { 4357 ret = err; 4358 goto next_page; 4359 } 4360 4361 lock_page(page); 4362 /* 4363 * If the page has been remove from the page cache, 4364 * the data on it is meaningless, because it may be 4365 * old one, the new data may be written into the new 4366 * page in the page cache. 4367 */ 4368 if (page->mapping != inode->i_mapping) { 4369 unlock_page(page); 4370 put_page(page); 4371 goto again; 4372 } 4373 if (!PageUptodate(page)) { 4374 ret = -EIO; 4375 goto next_page; 4376 } 4377 } 4378 4379 ret = check_extent_to_block(inode, offset, len, 4380 nocow_ctx_logical); 4381 if (ret) { 4382 ret = ret > 0 ? 0 : ret; 4383 goto next_page; 4384 } 4385 4386 err = write_page_nocow(nocow_ctx->sctx, 4387 physical_for_dev_replace, page); 4388 if (err) 4389 ret = err; 4390 next_page: 4391 unlock_page(page); 4392 put_page(page); 4393 4394 if (ret) 4395 break; 4396 4397 offset += PAGE_SIZE; 4398 physical_for_dev_replace += PAGE_SIZE; 4399 nocow_ctx_logical += PAGE_SIZE; 4400 len -= PAGE_SIZE; 4401 } 4402 ret = COPY_COMPLETE; 4403 out: 4404 inode_unlock(inode); 4405 iput(inode); 4406 return ret; 4407 } 4408 4409 static int write_page_nocow(struct scrub_ctx *sctx, 4410 u64 physical_for_dev_replace, struct page *page) 4411 { 4412 struct bio *bio; 4413 struct btrfs_device *dev; 4414 int ret; 4415 4416 dev = sctx->wr_ctx.tgtdev; 4417 if (!dev) 4418 return -EIO; 4419 if (!dev->bdev) { 4420 btrfs_warn_rl(dev->fs_info, 4421 "scrub write_page_nocow(bdev == NULL) is unexpected"); 4422 return -EIO; 4423 } 4424 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 4425 if (!bio) { 4426 spin_lock(&sctx->stat_lock); 4427 sctx->stat.malloc_errors++; 4428 spin_unlock(&sctx->stat_lock); 4429 return -ENOMEM; 4430 } 4431 bio->bi_iter.bi_size = 0; 4432 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9; 4433 bio->bi_bdev = dev->bdev; 4434 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC; 4435 ret = bio_add_page(bio, page, PAGE_SIZE, 0); 4436 if (ret != PAGE_SIZE) { 4437 leave_with_eio: 4438 bio_put(bio); 4439 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS); 4440 return -EIO; 4441 } 4442 4443 if (btrfsic_submit_bio_wait(bio)) 4444 goto leave_with_eio; 4445 4446 bio_put(bio); 4447 return 0; 4448 } 4449