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_page { 67 struct scrub_block *sblock; 68 struct page *page; 69 struct btrfs_device *dev; 70 u64 flags; /* extent flags */ 71 u64 generation; 72 u64 logical; 73 u64 physical; 74 u64 physical_for_dev_replace; 75 atomic_t ref_count; 76 struct { 77 unsigned int mirror_num:8; 78 unsigned int have_csum:1; 79 unsigned int io_error:1; 80 }; 81 u8 csum[BTRFS_CSUM_SIZE]; 82 }; 83 84 struct scrub_bio { 85 int index; 86 struct scrub_ctx *sctx; 87 struct btrfs_device *dev; 88 struct bio *bio; 89 int err; 90 u64 logical; 91 u64 physical; 92 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO 93 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO]; 94 #else 95 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO]; 96 #endif 97 int page_count; 98 int next_free; 99 struct btrfs_work work; 100 }; 101 102 struct scrub_block { 103 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK]; 104 int page_count; 105 atomic_t outstanding_pages; 106 atomic_t ref_count; /* free mem on transition to zero */ 107 struct scrub_ctx *sctx; 108 struct { 109 unsigned int header_error:1; 110 unsigned int checksum_error:1; 111 unsigned int no_io_error_seen:1; 112 unsigned int generation_error:1; /* also sets header_error */ 113 }; 114 }; 115 116 struct scrub_wr_ctx { 117 struct scrub_bio *wr_curr_bio; 118 struct btrfs_device *tgtdev; 119 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */ 120 atomic_t flush_all_writes; 121 struct mutex wr_lock; 122 }; 123 124 struct scrub_ctx { 125 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX]; 126 struct btrfs_root *dev_root; 127 int first_free; 128 int curr; 129 atomic_t bios_in_flight; 130 atomic_t workers_pending; 131 spinlock_t list_lock; 132 wait_queue_head_t list_wait; 133 u16 csum_size; 134 struct list_head csum_list; 135 atomic_t cancel_req; 136 int readonly; 137 int pages_per_rd_bio; 138 u32 sectorsize; 139 u32 nodesize; 140 u32 leafsize; 141 142 int is_dev_replace; 143 struct scrub_wr_ctx wr_ctx; 144 145 /* 146 * statistics 147 */ 148 struct btrfs_scrub_progress stat; 149 spinlock_t stat_lock; 150 }; 151 152 struct scrub_fixup_nodatasum { 153 struct scrub_ctx *sctx; 154 struct btrfs_device *dev; 155 u64 logical; 156 struct btrfs_root *root; 157 struct btrfs_work work; 158 int mirror_num; 159 }; 160 161 struct scrub_nocow_inode { 162 u64 inum; 163 u64 offset; 164 u64 root; 165 struct list_head list; 166 }; 167 168 struct scrub_copy_nocow_ctx { 169 struct scrub_ctx *sctx; 170 u64 logical; 171 u64 len; 172 int mirror_num; 173 u64 physical_for_dev_replace; 174 struct list_head inodes; 175 struct btrfs_work work; 176 }; 177 178 struct scrub_warning { 179 struct btrfs_path *path; 180 u64 extent_item_size; 181 char *scratch_buf; 182 char *msg_buf; 183 const char *errstr; 184 sector_t sector; 185 u64 logical; 186 struct btrfs_device *dev; 187 int msg_bufsize; 188 int scratch_bufsize; 189 }; 190 191 192 static void scrub_pending_bio_inc(struct scrub_ctx *sctx); 193 static void scrub_pending_bio_dec(struct scrub_ctx *sctx); 194 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx); 195 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx); 196 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check); 197 static int scrub_setup_recheck_block(struct scrub_ctx *sctx, 198 struct btrfs_fs_info *fs_info, 199 struct scrub_block *original_sblock, 200 u64 length, u64 logical, 201 struct scrub_block *sblocks_for_recheck); 202 static void scrub_recheck_block(struct btrfs_fs_info *fs_info, 203 struct scrub_block *sblock, int is_metadata, 204 int have_csum, u8 *csum, u64 generation, 205 u16 csum_size); 206 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, 207 struct scrub_block *sblock, 208 int is_metadata, int have_csum, 209 const u8 *csum, u64 generation, 210 u16 csum_size); 211 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, 212 struct scrub_block *sblock_good, 213 int force_write); 214 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, 215 struct scrub_block *sblock_good, 216 int page_num, int force_write); 217 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock); 218 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, 219 int page_num); 220 static int scrub_checksum_data(struct scrub_block *sblock); 221 static int scrub_checksum_tree_block(struct scrub_block *sblock); 222 static int scrub_checksum_super(struct scrub_block *sblock); 223 static void scrub_block_get(struct scrub_block *sblock); 224 static void scrub_block_put(struct scrub_block *sblock); 225 static void scrub_page_get(struct scrub_page *spage); 226 static void scrub_page_put(struct scrub_page *spage); 227 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, 228 struct scrub_page *spage); 229 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 230 u64 physical, struct btrfs_device *dev, u64 flags, 231 u64 gen, int mirror_num, u8 *csum, int force, 232 u64 physical_for_dev_replace); 233 static void scrub_bio_end_io(struct bio *bio, int err); 234 static void scrub_bio_end_io_worker(struct btrfs_work *work); 235 static void scrub_block_complete(struct scrub_block *sblock); 236 static void scrub_remap_extent(struct btrfs_fs_info *fs_info, 237 u64 extent_logical, u64 extent_len, 238 u64 *extent_physical, 239 struct btrfs_device **extent_dev, 240 int *extent_mirror_num); 241 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx, 242 struct scrub_wr_ctx *wr_ctx, 243 struct btrfs_fs_info *fs_info, 244 struct btrfs_device *dev, 245 int is_dev_replace); 246 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx); 247 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, 248 struct scrub_page *spage); 249 static void scrub_wr_submit(struct scrub_ctx *sctx); 250 static void scrub_wr_bio_end_io(struct bio *bio, int err); 251 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work); 252 static int write_page_nocow(struct scrub_ctx *sctx, 253 u64 physical_for_dev_replace, struct page *page); 254 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, 255 struct scrub_copy_nocow_ctx *ctx); 256 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 257 int mirror_num, u64 physical_for_dev_replace); 258 static void copy_nocow_pages_worker(struct btrfs_work *work); 259 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); 260 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info); 261 262 263 static void scrub_pending_bio_inc(struct scrub_ctx *sctx) 264 { 265 atomic_inc(&sctx->bios_in_flight); 266 } 267 268 static void scrub_pending_bio_dec(struct scrub_ctx *sctx) 269 { 270 atomic_dec(&sctx->bios_in_flight); 271 wake_up(&sctx->list_wait); 272 } 273 274 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) 275 { 276 while (atomic_read(&fs_info->scrub_pause_req)) { 277 mutex_unlock(&fs_info->scrub_lock); 278 wait_event(fs_info->scrub_pause_wait, 279 atomic_read(&fs_info->scrub_pause_req) == 0); 280 mutex_lock(&fs_info->scrub_lock); 281 } 282 } 283 284 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info) 285 { 286 atomic_inc(&fs_info->scrubs_paused); 287 wake_up(&fs_info->scrub_pause_wait); 288 289 mutex_lock(&fs_info->scrub_lock); 290 __scrub_blocked_if_needed(fs_info); 291 atomic_dec(&fs_info->scrubs_paused); 292 mutex_unlock(&fs_info->scrub_lock); 293 294 wake_up(&fs_info->scrub_pause_wait); 295 } 296 297 /* 298 * used for workers that require transaction commits (i.e., for the 299 * NOCOW case) 300 */ 301 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx) 302 { 303 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 304 305 /* 306 * increment scrubs_running to prevent cancel requests from 307 * completing as long as a worker is running. we must also 308 * increment scrubs_paused to prevent deadlocking on pause 309 * requests used for transactions commits (as the worker uses a 310 * transaction context). it is safe to regard the worker 311 * as paused for all matters practical. effectively, we only 312 * avoid cancellation requests from completing. 313 */ 314 mutex_lock(&fs_info->scrub_lock); 315 atomic_inc(&fs_info->scrubs_running); 316 atomic_inc(&fs_info->scrubs_paused); 317 mutex_unlock(&fs_info->scrub_lock); 318 319 /* 320 * check if @scrubs_running=@scrubs_paused condition 321 * inside wait_event() is not an atomic operation. 322 * which means we may inc/dec @scrub_running/paused 323 * at any time. Let's wake up @scrub_pause_wait as 324 * much as we can to let commit transaction blocked less. 325 */ 326 wake_up(&fs_info->scrub_pause_wait); 327 328 atomic_inc(&sctx->workers_pending); 329 } 330 331 /* used for workers that require transaction commits */ 332 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx) 333 { 334 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 335 336 /* 337 * see scrub_pending_trans_workers_inc() why we're pretending 338 * to be paused in the scrub counters 339 */ 340 mutex_lock(&fs_info->scrub_lock); 341 atomic_dec(&fs_info->scrubs_running); 342 atomic_dec(&fs_info->scrubs_paused); 343 mutex_unlock(&fs_info->scrub_lock); 344 atomic_dec(&sctx->workers_pending); 345 wake_up(&fs_info->scrub_pause_wait); 346 wake_up(&sctx->list_wait); 347 } 348 349 static void scrub_free_csums(struct scrub_ctx *sctx) 350 { 351 while (!list_empty(&sctx->csum_list)) { 352 struct btrfs_ordered_sum *sum; 353 sum = list_first_entry(&sctx->csum_list, 354 struct btrfs_ordered_sum, list); 355 list_del(&sum->list); 356 kfree(sum); 357 } 358 } 359 360 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) 361 { 362 int i; 363 364 if (!sctx) 365 return; 366 367 scrub_free_wr_ctx(&sctx->wr_ctx); 368 369 /* this can happen when scrub is cancelled */ 370 if (sctx->curr != -1) { 371 struct scrub_bio *sbio = sctx->bios[sctx->curr]; 372 373 for (i = 0; i < sbio->page_count; i++) { 374 WARN_ON(!sbio->pagev[i]->page); 375 scrub_block_put(sbio->pagev[i]->sblock); 376 } 377 bio_put(sbio->bio); 378 } 379 380 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { 381 struct scrub_bio *sbio = sctx->bios[i]; 382 383 if (!sbio) 384 break; 385 kfree(sbio); 386 } 387 388 scrub_free_csums(sctx); 389 kfree(sctx); 390 } 391 392 static noinline_for_stack 393 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace) 394 { 395 struct scrub_ctx *sctx; 396 int i; 397 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info; 398 int pages_per_rd_bio; 399 int ret; 400 401 /* 402 * the setting of pages_per_rd_bio is correct for scrub but might 403 * be wrong for the dev_replace code where we might read from 404 * different devices in the initial huge bios. However, that 405 * code is able to correctly handle the case when adding a page 406 * to a bio fails. 407 */ 408 if (dev->bdev) 409 pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO, 410 bio_get_nr_vecs(dev->bdev)); 411 else 412 pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO; 413 sctx = kzalloc(sizeof(*sctx), GFP_NOFS); 414 if (!sctx) 415 goto nomem; 416 sctx->is_dev_replace = is_dev_replace; 417 sctx->pages_per_rd_bio = pages_per_rd_bio; 418 sctx->curr = -1; 419 sctx->dev_root = dev->dev_root; 420 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) { 421 struct scrub_bio *sbio; 422 423 sbio = kzalloc(sizeof(*sbio), GFP_NOFS); 424 if (!sbio) 425 goto nomem; 426 sctx->bios[i] = sbio; 427 428 sbio->index = i; 429 sbio->sctx = sctx; 430 sbio->page_count = 0; 431 btrfs_init_work(&sbio->work, scrub_bio_end_io_worker, 432 NULL, NULL); 433 434 if (i != SCRUB_BIOS_PER_SCTX - 1) 435 sctx->bios[i]->next_free = i + 1; 436 else 437 sctx->bios[i]->next_free = -1; 438 } 439 sctx->first_free = 0; 440 sctx->nodesize = dev->dev_root->nodesize; 441 sctx->leafsize = dev->dev_root->leafsize; 442 sctx->sectorsize = dev->dev_root->sectorsize; 443 atomic_set(&sctx->bios_in_flight, 0); 444 atomic_set(&sctx->workers_pending, 0); 445 atomic_set(&sctx->cancel_req, 0); 446 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy); 447 INIT_LIST_HEAD(&sctx->csum_list); 448 449 spin_lock_init(&sctx->list_lock); 450 spin_lock_init(&sctx->stat_lock); 451 init_waitqueue_head(&sctx->list_wait); 452 453 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info, 454 fs_info->dev_replace.tgtdev, is_dev_replace); 455 if (ret) { 456 scrub_free_ctx(sctx); 457 return ERR_PTR(ret); 458 } 459 return sctx; 460 461 nomem: 462 scrub_free_ctx(sctx); 463 return ERR_PTR(-ENOMEM); 464 } 465 466 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, 467 void *warn_ctx) 468 { 469 u64 isize; 470 u32 nlink; 471 int ret; 472 int i; 473 struct extent_buffer *eb; 474 struct btrfs_inode_item *inode_item; 475 struct scrub_warning *swarn = warn_ctx; 476 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info; 477 struct inode_fs_paths *ipath = NULL; 478 struct btrfs_root *local_root; 479 struct btrfs_key root_key; 480 481 root_key.objectid = root; 482 root_key.type = BTRFS_ROOT_ITEM_KEY; 483 root_key.offset = (u64)-1; 484 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key); 485 if (IS_ERR(local_root)) { 486 ret = PTR_ERR(local_root); 487 goto err; 488 } 489 490 ret = inode_item_info(inum, 0, local_root, swarn->path); 491 if (ret) { 492 btrfs_release_path(swarn->path); 493 goto err; 494 } 495 496 eb = swarn->path->nodes[0]; 497 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0], 498 struct btrfs_inode_item); 499 isize = btrfs_inode_size(eb, inode_item); 500 nlink = btrfs_inode_nlink(eb, inode_item); 501 btrfs_release_path(swarn->path); 502 503 ipath = init_ipath(4096, local_root, swarn->path); 504 if (IS_ERR(ipath)) { 505 ret = PTR_ERR(ipath); 506 ipath = NULL; 507 goto err; 508 } 509 ret = paths_from_inode(inum, ipath); 510 511 if (ret < 0) 512 goto err; 513 514 /* 515 * we deliberately ignore the bit ipath might have been too small to 516 * hold all of the paths here 517 */ 518 for (i = 0; i < ipath->fspath->elem_cnt; ++i) 519 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev " 520 "%s, sector %llu, root %llu, inode %llu, offset %llu, " 521 "length %llu, links %u (path: %s)\n", swarn->errstr, 522 swarn->logical, rcu_str_deref(swarn->dev->name), 523 (unsigned long long)swarn->sector, root, inum, offset, 524 min(isize - offset, (u64)PAGE_SIZE), nlink, 525 (char *)(unsigned long)ipath->fspath->val[i]); 526 527 free_ipath(ipath); 528 return 0; 529 530 err: 531 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev " 532 "%s, sector %llu, root %llu, inode %llu, offset %llu: path " 533 "resolving failed with ret=%d\n", swarn->errstr, 534 swarn->logical, rcu_str_deref(swarn->dev->name), 535 (unsigned long long)swarn->sector, root, inum, offset, ret); 536 537 free_ipath(ipath); 538 return 0; 539 } 540 541 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) 542 { 543 struct btrfs_device *dev; 544 struct btrfs_fs_info *fs_info; 545 struct btrfs_path *path; 546 struct btrfs_key found_key; 547 struct extent_buffer *eb; 548 struct btrfs_extent_item *ei; 549 struct scrub_warning swarn; 550 unsigned long ptr = 0; 551 u64 extent_item_pos; 552 u64 flags = 0; 553 u64 ref_root; 554 u32 item_size; 555 u8 ref_level; 556 const int bufsize = 4096; 557 int ret; 558 559 WARN_ON(sblock->page_count < 1); 560 dev = sblock->pagev[0]->dev; 561 fs_info = sblock->sctx->dev_root->fs_info; 562 563 path = btrfs_alloc_path(); 564 565 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS); 566 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS); 567 swarn.sector = (sblock->pagev[0]->physical) >> 9; 568 swarn.logical = sblock->pagev[0]->logical; 569 swarn.errstr = errstr; 570 swarn.dev = NULL; 571 swarn.msg_bufsize = bufsize; 572 swarn.scratch_bufsize = bufsize; 573 574 if (!path || !swarn.scratch_buf || !swarn.msg_buf) 575 goto out; 576 577 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, 578 &flags); 579 if (ret < 0) 580 goto out; 581 582 extent_item_pos = swarn.logical - found_key.objectid; 583 swarn.extent_item_size = found_key.offset; 584 585 eb = path->nodes[0]; 586 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); 587 item_size = btrfs_item_size_nr(eb, path->slots[0]); 588 589 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 590 do { 591 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei, 592 item_size, &ref_root, 593 &ref_level); 594 printk_in_rcu(KERN_WARNING 595 "BTRFS: %s at logical %llu on dev %s, " 596 "sector %llu: metadata %s (level %d) in tree " 597 "%llu\n", errstr, swarn.logical, 598 rcu_str_deref(dev->name), 599 (unsigned long long)swarn.sector, 600 ref_level ? "node" : "leaf", 601 ret < 0 ? -1 : ref_level, 602 ret < 0 ? -1 : ref_root); 603 } while (ret != 1); 604 btrfs_release_path(path); 605 } else { 606 btrfs_release_path(path); 607 swarn.path = path; 608 swarn.dev = dev; 609 iterate_extent_inodes(fs_info, found_key.objectid, 610 extent_item_pos, 1, 611 scrub_print_warning_inode, &swarn); 612 } 613 614 out: 615 btrfs_free_path(path); 616 kfree(swarn.scratch_buf); 617 kfree(swarn.msg_buf); 618 } 619 620 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx) 621 { 622 struct page *page = NULL; 623 unsigned long index; 624 struct scrub_fixup_nodatasum *fixup = fixup_ctx; 625 int ret; 626 int corrected = 0; 627 struct btrfs_key key; 628 struct inode *inode = NULL; 629 struct btrfs_fs_info *fs_info; 630 u64 end = offset + PAGE_SIZE - 1; 631 struct btrfs_root *local_root; 632 int srcu_index; 633 634 key.objectid = root; 635 key.type = BTRFS_ROOT_ITEM_KEY; 636 key.offset = (u64)-1; 637 638 fs_info = fixup->root->fs_info; 639 srcu_index = srcu_read_lock(&fs_info->subvol_srcu); 640 641 local_root = btrfs_read_fs_root_no_name(fs_info, &key); 642 if (IS_ERR(local_root)) { 643 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 644 return PTR_ERR(local_root); 645 } 646 647 key.type = BTRFS_INODE_ITEM_KEY; 648 key.objectid = inum; 649 key.offset = 0; 650 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL); 651 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 652 if (IS_ERR(inode)) 653 return PTR_ERR(inode); 654 655 index = offset >> PAGE_CACHE_SHIFT; 656 657 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 658 if (!page) { 659 ret = -ENOMEM; 660 goto out; 661 } 662 663 if (PageUptodate(page)) { 664 if (PageDirty(page)) { 665 /* 666 * we need to write the data to the defect sector. the 667 * data that was in that sector is not in memory, 668 * because the page was modified. we must not write the 669 * modified page to that sector. 670 * 671 * TODO: what could be done here: wait for the delalloc 672 * runner to write out that page (might involve 673 * COW) and see whether the sector is still 674 * referenced afterwards. 675 * 676 * For the meantime, we'll treat this error 677 * incorrectable, although there is a chance that a 678 * later scrub will find the bad sector again and that 679 * there's no dirty page in memory, then. 680 */ 681 ret = -EIO; 682 goto out; 683 } 684 fs_info = BTRFS_I(inode)->root->fs_info; 685 ret = repair_io_failure(fs_info, offset, PAGE_SIZE, 686 fixup->logical, page, 687 fixup->mirror_num); 688 unlock_page(page); 689 corrected = !ret; 690 } else { 691 /* 692 * we need to get good data first. the general readpage path 693 * will call repair_io_failure for us, we just have to make 694 * sure we read the bad mirror. 695 */ 696 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 697 EXTENT_DAMAGED, GFP_NOFS); 698 if (ret) { 699 /* set_extent_bits should give proper error */ 700 WARN_ON(ret > 0); 701 if (ret > 0) 702 ret = -EFAULT; 703 goto out; 704 } 705 706 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page, 707 btrfs_get_extent, 708 fixup->mirror_num); 709 wait_on_page_locked(page); 710 711 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset, 712 end, EXTENT_DAMAGED, 0, NULL); 713 if (!corrected) 714 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 715 EXTENT_DAMAGED, GFP_NOFS); 716 } 717 718 out: 719 if (page) 720 put_page(page); 721 722 iput(inode); 723 724 if (ret < 0) 725 return ret; 726 727 if (ret == 0 && corrected) { 728 /* 729 * we only need to call readpage for one of the inodes belonging 730 * to this extent. so make iterate_extent_inodes stop 731 */ 732 return 1; 733 } 734 735 return -EIO; 736 } 737 738 static void scrub_fixup_nodatasum(struct btrfs_work *work) 739 { 740 int ret; 741 struct scrub_fixup_nodatasum *fixup; 742 struct scrub_ctx *sctx; 743 struct btrfs_trans_handle *trans = NULL; 744 struct btrfs_path *path; 745 int uncorrectable = 0; 746 747 fixup = container_of(work, struct scrub_fixup_nodatasum, work); 748 sctx = fixup->sctx; 749 750 path = btrfs_alloc_path(); 751 if (!path) { 752 spin_lock(&sctx->stat_lock); 753 ++sctx->stat.malloc_errors; 754 spin_unlock(&sctx->stat_lock); 755 uncorrectable = 1; 756 goto out; 757 } 758 759 trans = btrfs_join_transaction(fixup->root); 760 if (IS_ERR(trans)) { 761 uncorrectable = 1; 762 goto out; 763 } 764 765 /* 766 * the idea is to trigger a regular read through the standard path. we 767 * read a page from the (failed) logical address by specifying the 768 * corresponding copynum of the failed sector. thus, that readpage is 769 * expected to fail. 770 * that is the point where on-the-fly error correction will kick in 771 * (once it's finished) and rewrite the failed sector if a good copy 772 * can be found. 773 */ 774 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info, 775 path, scrub_fixup_readpage, 776 fixup); 777 if (ret < 0) { 778 uncorrectable = 1; 779 goto out; 780 } 781 WARN_ON(ret != 1); 782 783 spin_lock(&sctx->stat_lock); 784 ++sctx->stat.corrected_errors; 785 spin_unlock(&sctx->stat_lock); 786 787 out: 788 if (trans && !IS_ERR(trans)) 789 btrfs_end_transaction(trans, fixup->root); 790 if (uncorrectable) { 791 spin_lock(&sctx->stat_lock); 792 ++sctx->stat.uncorrectable_errors; 793 spin_unlock(&sctx->stat_lock); 794 btrfs_dev_replace_stats_inc( 795 &sctx->dev_root->fs_info->dev_replace. 796 num_uncorrectable_read_errors); 797 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: " 798 "unable to fixup (nodatasum) error at logical %llu on dev %s\n", 799 fixup->logical, rcu_str_deref(fixup->dev->name)); 800 } 801 802 btrfs_free_path(path); 803 kfree(fixup); 804 805 scrub_pending_trans_workers_dec(sctx); 806 } 807 808 /* 809 * scrub_handle_errored_block gets called when either verification of the 810 * pages failed or the bio failed to read, e.g. with EIO. In the latter 811 * case, this function handles all pages in the bio, even though only one 812 * may be bad. 813 * The goal of this function is to repair the errored block by using the 814 * contents of one of the mirrors. 815 */ 816 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) 817 { 818 struct scrub_ctx *sctx = sblock_to_check->sctx; 819 struct btrfs_device *dev; 820 struct btrfs_fs_info *fs_info; 821 u64 length; 822 u64 logical; 823 u64 generation; 824 unsigned int failed_mirror_index; 825 unsigned int is_metadata; 826 unsigned int have_csum; 827 u8 *csum; 828 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */ 829 struct scrub_block *sblock_bad; 830 int ret; 831 int mirror_index; 832 int page_num; 833 int success; 834 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 835 DEFAULT_RATELIMIT_BURST); 836 837 BUG_ON(sblock_to_check->page_count < 1); 838 fs_info = sctx->dev_root->fs_info; 839 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) { 840 /* 841 * if we find an error in a super block, we just report it. 842 * They will get written with the next transaction commit 843 * anyway 844 */ 845 spin_lock(&sctx->stat_lock); 846 ++sctx->stat.super_errors; 847 spin_unlock(&sctx->stat_lock); 848 return 0; 849 } 850 length = sblock_to_check->page_count * PAGE_SIZE; 851 logical = sblock_to_check->pagev[0]->logical; 852 generation = sblock_to_check->pagev[0]->generation; 853 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1); 854 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1; 855 is_metadata = !(sblock_to_check->pagev[0]->flags & 856 BTRFS_EXTENT_FLAG_DATA); 857 have_csum = sblock_to_check->pagev[0]->have_csum; 858 csum = sblock_to_check->pagev[0]->csum; 859 dev = sblock_to_check->pagev[0]->dev; 860 861 if (sctx->is_dev_replace && !is_metadata && !have_csum) { 862 sblocks_for_recheck = NULL; 863 goto nodatasum_case; 864 } 865 866 /* 867 * read all mirrors one after the other. This includes to 868 * re-read the extent or metadata block that failed (that was 869 * the cause that this fixup code is called) another time, 870 * page by page this time in order to know which pages 871 * caused I/O errors and which ones are good (for all mirrors). 872 * It is the goal to handle the situation when more than one 873 * mirror contains I/O errors, but the errors do not 874 * overlap, i.e. the data can be repaired by selecting the 875 * pages from those mirrors without I/O error on the 876 * particular pages. One example (with blocks >= 2 * PAGE_SIZE) 877 * would be that mirror #1 has an I/O error on the first page, 878 * the second page is good, and mirror #2 has an I/O error on 879 * the second page, but the first page is good. 880 * Then the first page of the first mirror can be repaired by 881 * taking the first page of the second mirror, and the 882 * second page of the second mirror can be repaired by 883 * copying the contents of the 2nd page of the 1st mirror. 884 * One more note: if the pages of one mirror contain I/O 885 * errors, the checksum cannot be verified. In order to get 886 * the best data for repairing, the first attempt is to find 887 * a mirror without I/O errors and with a validated checksum. 888 * Only if this is not possible, the pages are picked from 889 * mirrors with I/O errors without considering the checksum. 890 * If the latter is the case, at the end, the checksum of the 891 * repaired area is verified in order to correctly maintain 892 * the statistics. 893 */ 894 895 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS * 896 sizeof(*sblocks_for_recheck), 897 GFP_NOFS); 898 if (!sblocks_for_recheck) { 899 spin_lock(&sctx->stat_lock); 900 sctx->stat.malloc_errors++; 901 sctx->stat.read_errors++; 902 sctx->stat.uncorrectable_errors++; 903 spin_unlock(&sctx->stat_lock); 904 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 905 goto out; 906 } 907 908 /* setup the context, map the logical blocks and alloc the pages */ 909 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length, 910 logical, sblocks_for_recheck); 911 if (ret) { 912 spin_lock(&sctx->stat_lock); 913 sctx->stat.read_errors++; 914 sctx->stat.uncorrectable_errors++; 915 spin_unlock(&sctx->stat_lock); 916 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 917 goto out; 918 } 919 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS); 920 sblock_bad = sblocks_for_recheck + failed_mirror_index; 921 922 /* build and submit the bios for the failed mirror, check checksums */ 923 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum, 924 csum, generation, sctx->csum_size); 925 926 if (!sblock_bad->header_error && !sblock_bad->checksum_error && 927 sblock_bad->no_io_error_seen) { 928 /* 929 * the error disappeared after reading page by page, or 930 * the area was part of a huge bio and other parts of the 931 * bio caused I/O errors, or the block layer merged several 932 * read requests into one and the error is caused by a 933 * different bio (usually one of the two latter cases is 934 * the cause) 935 */ 936 spin_lock(&sctx->stat_lock); 937 sctx->stat.unverified_errors++; 938 spin_unlock(&sctx->stat_lock); 939 940 if (sctx->is_dev_replace) 941 scrub_write_block_to_dev_replace(sblock_bad); 942 goto out; 943 } 944 945 if (!sblock_bad->no_io_error_seen) { 946 spin_lock(&sctx->stat_lock); 947 sctx->stat.read_errors++; 948 spin_unlock(&sctx->stat_lock); 949 if (__ratelimit(&_rs)) 950 scrub_print_warning("i/o error", sblock_to_check); 951 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS); 952 } else if (sblock_bad->checksum_error) { 953 spin_lock(&sctx->stat_lock); 954 sctx->stat.csum_errors++; 955 spin_unlock(&sctx->stat_lock); 956 if (__ratelimit(&_rs)) 957 scrub_print_warning("checksum error", sblock_to_check); 958 btrfs_dev_stat_inc_and_print(dev, 959 BTRFS_DEV_STAT_CORRUPTION_ERRS); 960 } else if (sblock_bad->header_error) { 961 spin_lock(&sctx->stat_lock); 962 sctx->stat.verify_errors++; 963 spin_unlock(&sctx->stat_lock); 964 if (__ratelimit(&_rs)) 965 scrub_print_warning("checksum/header error", 966 sblock_to_check); 967 if (sblock_bad->generation_error) 968 btrfs_dev_stat_inc_and_print(dev, 969 BTRFS_DEV_STAT_GENERATION_ERRS); 970 else 971 btrfs_dev_stat_inc_and_print(dev, 972 BTRFS_DEV_STAT_CORRUPTION_ERRS); 973 } 974 975 if (sctx->readonly) { 976 ASSERT(!sctx->is_dev_replace); 977 goto out; 978 } 979 980 if (!is_metadata && !have_csum) { 981 struct scrub_fixup_nodatasum *fixup_nodatasum; 982 983 nodatasum_case: 984 WARN_ON(sctx->is_dev_replace); 985 986 /* 987 * !is_metadata and !have_csum, this means that the data 988 * might not be COW'ed, that it might be modified 989 * concurrently. The general strategy to work on the 990 * commit root does not help in the case when COW is not 991 * used. 992 */ 993 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS); 994 if (!fixup_nodatasum) 995 goto did_not_correct_error; 996 fixup_nodatasum->sctx = sctx; 997 fixup_nodatasum->dev = dev; 998 fixup_nodatasum->logical = logical; 999 fixup_nodatasum->root = fs_info->extent_root; 1000 fixup_nodatasum->mirror_num = failed_mirror_index + 1; 1001 scrub_pending_trans_workers_inc(sctx); 1002 btrfs_init_work(&fixup_nodatasum->work, scrub_fixup_nodatasum, 1003 NULL, NULL); 1004 btrfs_queue_work(fs_info->scrub_workers, 1005 &fixup_nodatasum->work); 1006 goto out; 1007 } 1008 1009 /* 1010 * now build and submit the bios for the other mirrors, check 1011 * checksums. 1012 * First try to pick the mirror which is completely without I/O 1013 * errors and also does not have a checksum error. 1014 * If one is found, and if a checksum is present, the full block 1015 * that is known to contain an error is rewritten. Afterwards 1016 * the block is known to be corrected. 1017 * If a mirror is found which is completely correct, and no 1018 * checksum is present, only those pages are rewritten that had 1019 * an I/O error in the block to be repaired, since it cannot be 1020 * determined, which copy of the other pages is better (and it 1021 * could happen otherwise that a correct page would be 1022 * overwritten by a bad one). 1023 */ 1024 for (mirror_index = 0; 1025 mirror_index < BTRFS_MAX_MIRRORS && 1026 sblocks_for_recheck[mirror_index].page_count > 0; 1027 mirror_index++) { 1028 struct scrub_block *sblock_other; 1029 1030 if (mirror_index == failed_mirror_index) 1031 continue; 1032 sblock_other = sblocks_for_recheck + mirror_index; 1033 1034 /* build and submit the bios, check checksums */ 1035 scrub_recheck_block(fs_info, sblock_other, is_metadata, 1036 have_csum, csum, generation, 1037 sctx->csum_size); 1038 1039 if (!sblock_other->header_error && 1040 !sblock_other->checksum_error && 1041 sblock_other->no_io_error_seen) { 1042 if (sctx->is_dev_replace) { 1043 scrub_write_block_to_dev_replace(sblock_other); 1044 } else { 1045 int force_write = is_metadata || have_csum; 1046 1047 ret = scrub_repair_block_from_good_copy( 1048 sblock_bad, sblock_other, 1049 force_write); 1050 } 1051 if (0 == ret) 1052 goto corrected_error; 1053 } 1054 } 1055 1056 /* 1057 * for dev_replace, pick good pages and write to the target device. 1058 */ 1059 if (sctx->is_dev_replace) { 1060 success = 1; 1061 for (page_num = 0; page_num < sblock_bad->page_count; 1062 page_num++) { 1063 int sub_success; 1064 1065 sub_success = 0; 1066 for (mirror_index = 0; 1067 mirror_index < BTRFS_MAX_MIRRORS && 1068 sblocks_for_recheck[mirror_index].page_count > 0; 1069 mirror_index++) { 1070 struct scrub_block *sblock_other = 1071 sblocks_for_recheck + mirror_index; 1072 struct scrub_page *page_other = 1073 sblock_other->pagev[page_num]; 1074 1075 if (!page_other->io_error) { 1076 ret = scrub_write_page_to_dev_replace( 1077 sblock_other, page_num); 1078 if (ret == 0) { 1079 /* succeeded for this page */ 1080 sub_success = 1; 1081 break; 1082 } else { 1083 btrfs_dev_replace_stats_inc( 1084 &sctx->dev_root-> 1085 fs_info->dev_replace. 1086 num_write_errors); 1087 } 1088 } 1089 } 1090 1091 if (!sub_success) { 1092 /* 1093 * did not find a mirror to fetch the page 1094 * from. scrub_write_page_to_dev_replace() 1095 * handles this case (page->io_error), by 1096 * filling the block with zeros before 1097 * submitting the write request 1098 */ 1099 success = 0; 1100 ret = scrub_write_page_to_dev_replace( 1101 sblock_bad, page_num); 1102 if (ret) 1103 btrfs_dev_replace_stats_inc( 1104 &sctx->dev_root->fs_info-> 1105 dev_replace.num_write_errors); 1106 } 1107 } 1108 1109 goto out; 1110 } 1111 1112 /* 1113 * for regular scrub, repair those pages that are errored. 1114 * In case of I/O errors in the area that is supposed to be 1115 * repaired, continue by picking good copies of those pages. 1116 * Select the good pages from mirrors to rewrite bad pages from 1117 * the area to fix. Afterwards verify the checksum of the block 1118 * that is supposed to be repaired. This verification step is 1119 * only done for the purpose of statistic counting and for the 1120 * final scrub report, whether errors remain. 1121 * A perfect algorithm could make use of the checksum and try 1122 * all possible combinations of pages from the different mirrors 1123 * until the checksum verification succeeds. For example, when 1124 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page 1125 * of mirror #2 is readable but the final checksum test fails, 1126 * then the 2nd page of mirror #3 could be tried, whether now 1127 * the final checksum succeedes. But this would be a rare 1128 * exception and is therefore not implemented. At least it is 1129 * avoided that the good copy is overwritten. 1130 * A more useful improvement would be to pick the sectors 1131 * without I/O error based on sector sizes (512 bytes on legacy 1132 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one 1133 * mirror could be repaired by taking 512 byte of a different 1134 * mirror, even if other 512 byte sectors in the same PAGE_SIZE 1135 * area are unreadable. 1136 */ 1137 1138 /* can only fix I/O errors from here on */ 1139 if (sblock_bad->no_io_error_seen) 1140 goto did_not_correct_error; 1141 1142 success = 1; 1143 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { 1144 struct scrub_page *page_bad = sblock_bad->pagev[page_num]; 1145 1146 if (!page_bad->io_error) 1147 continue; 1148 1149 for (mirror_index = 0; 1150 mirror_index < BTRFS_MAX_MIRRORS && 1151 sblocks_for_recheck[mirror_index].page_count > 0; 1152 mirror_index++) { 1153 struct scrub_block *sblock_other = sblocks_for_recheck + 1154 mirror_index; 1155 struct scrub_page *page_other = sblock_other->pagev[ 1156 page_num]; 1157 1158 if (!page_other->io_error) { 1159 ret = scrub_repair_page_from_good_copy( 1160 sblock_bad, sblock_other, page_num, 0); 1161 if (0 == ret) { 1162 page_bad->io_error = 0; 1163 break; /* succeeded for this page */ 1164 } 1165 } 1166 } 1167 1168 if (page_bad->io_error) { 1169 /* did not find a mirror to copy the page from */ 1170 success = 0; 1171 } 1172 } 1173 1174 if (success) { 1175 if (is_metadata || have_csum) { 1176 /* 1177 * need to verify the checksum now that all 1178 * sectors on disk are repaired (the write 1179 * request for data to be repaired is on its way). 1180 * Just be lazy and use scrub_recheck_block() 1181 * which re-reads the data before the checksum 1182 * is verified, but most likely the data comes out 1183 * of the page cache. 1184 */ 1185 scrub_recheck_block(fs_info, sblock_bad, 1186 is_metadata, have_csum, csum, 1187 generation, sctx->csum_size); 1188 if (!sblock_bad->header_error && 1189 !sblock_bad->checksum_error && 1190 sblock_bad->no_io_error_seen) 1191 goto corrected_error; 1192 else 1193 goto did_not_correct_error; 1194 } else { 1195 corrected_error: 1196 spin_lock(&sctx->stat_lock); 1197 sctx->stat.corrected_errors++; 1198 spin_unlock(&sctx->stat_lock); 1199 printk_ratelimited_in_rcu(KERN_ERR 1200 "BTRFS: fixed up error at logical %llu on dev %s\n", 1201 logical, rcu_str_deref(dev->name)); 1202 } 1203 } else { 1204 did_not_correct_error: 1205 spin_lock(&sctx->stat_lock); 1206 sctx->stat.uncorrectable_errors++; 1207 spin_unlock(&sctx->stat_lock); 1208 printk_ratelimited_in_rcu(KERN_ERR 1209 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n", 1210 logical, rcu_str_deref(dev->name)); 1211 } 1212 1213 out: 1214 if (sblocks_for_recheck) { 1215 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS; 1216 mirror_index++) { 1217 struct scrub_block *sblock = sblocks_for_recheck + 1218 mirror_index; 1219 int page_index; 1220 1221 for (page_index = 0; page_index < sblock->page_count; 1222 page_index++) { 1223 sblock->pagev[page_index]->sblock = NULL; 1224 scrub_page_put(sblock->pagev[page_index]); 1225 } 1226 } 1227 kfree(sblocks_for_recheck); 1228 } 1229 1230 return 0; 1231 } 1232 1233 static int scrub_setup_recheck_block(struct scrub_ctx *sctx, 1234 struct btrfs_fs_info *fs_info, 1235 struct scrub_block *original_sblock, 1236 u64 length, u64 logical, 1237 struct scrub_block *sblocks_for_recheck) 1238 { 1239 int page_index; 1240 int mirror_index; 1241 int ret; 1242 1243 /* 1244 * note: the two members ref_count and outstanding_pages 1245 * are not used (and not set) in the blocks that are used for 1246 * the recheck procedure 1247 */ 1248 1249 page_index = 0; 1250 while (length > 0) { 1251 u64 sublen = min_t(u64, length, PAGE_SIZE); 1252 u64 mapped_length = sublen; 1253 struct btrfs_bio *bbio = NULL; 1254 1255 /* 1256 * with a length of PAGE_SIZE, each returned stripe 1257 * represents one mirror 1258 */ 1259 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical, 1260 &mapped_length, &bbio, 0); 1261 if (ret || !bbio || mapped_length < sublen) { 1262 kfree(bbio); 1263 return -EIO; 1264 } 1265 1266 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO); 1267 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes; 1268 mirror_index++) { 1269 struct scrub_block *sblock; 1270 struct scrub_page *page; 1271 1272 if (mirror_index >= BTRFS_MAX_MIRRORS) 1273 continue; 1274 1275 sblock = sblocks_for_recheck + mirror_index; 1276 sblock->sctx = sctx; 1277 page = kzalloc(sizeof(*page), GFP_NOFS); 1278 if (!page) { 1279 leave_nomem: 1280 spin_lock(&sctx->stat_lock); 1281 sctx->stat.malloc_errors++; 1282 spin_unlock(&sctx->stat_lock); 1283 kfree(bbio); 1284 return -ENOMEM; 1285 } 1286 scrub_page_get(page); 1287 sblock->pagev[page_index] = page; 1288 page->logical = logical; 1289 page->physical = bbio->stripes[mirror_index].physical; 1290 BUG_ON(page_index >= original_sblock->page_count); 1291 page->physical_for_dev_replace = 1292 original_sblock->pagev[page_index]-> 1293 physical_for_dev_replace; 1294 /* for missing devices, dev->bdev is NULL */ 1295 page->dev = bbio->stripes[mirror_index].dev; 1296 page->mirror_num = mirror_index + 1; 1297 sblock->page_count++; 1298 page->page = alloc_page(GFP_NOFS); 1299 if (!page->page) 1300 goto leave_nomem; 1301 } 1302 kfree(bbio); 1303 length -= sublen; 1304 logical += sublen; 1305 page_index++; 1306 } 1307 1308 return 0; 1309 } 1310 1311 /* 1312 * this function will check the on disk data for checksum errors, header 1313 * errors and read I/O errors. If any I/O errors happen, the exact pages 1314 * which are errored are marked as being bad. The goal is to enable scrub 1315 * to take those pages that are not errored from all the mirrors so that 1316 * the pages that are errored in the just handled mirror can be repaired. 1317 */ 1318 static void scrub_recheck_block(struct btrfs_fs_info *fs_info, 1319 struct scrub_block *sblock, int is_metadata, 1320 int have_csum, u8 *csum, u64 generation, 1321 u16 csum_size) 1322 { 1323 int page_num; 1324 1325 sblock->no_io_error_seen = 1; 1326 sblock->header_error = 0; 1327 sblock->checksum_error = 0; 1328 1329 for (page_num = 0; page_num < sblock->page_count; page_num++) { 1330 struct bio *bio; 1331 struct scrub_page *page = sblock->pagev[page_num]; 1332 1333 if (page->dev->bdev == NULL) { 1334 page->io_error = 1; 1335 sblock->no_io_error_seen = 0; 1336 continue; 1337 } 1338 1339 WARN_ON(!page->page); 1340 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 1341 if (!bio) { 1342 page->io_error = 1; 1343 sblock->no_io_error_seen = 0; 1344 continue; 1345 } 1346 bio->bi_bdev = page->dev->bdev; 1347 bio->bi_iter.bi_sector = page->physical >> 9; 1348 1349 bio_add_page(bio, page->page, PAGE_SIZE, 0); 1350 if (btrfsic_submit_bio_wait(READ, bio)) 1351 sblock->no_io_error_seen = 0; 1352 1353 bio_put(bio); 1354 } 1355 1356 if (sblock->no_io_error_seen) 1357 scrub_recheck_block_checksum(fs_info, sblock, is_metadata, 1358 have_csum, csum, generation, 1359 csum_size); 1360 1361 return; 1362 } 1363 1364 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, 1365 struct scrub_block *sblock, 1366 int is_metadata, int have_csum, 1367 const u8 *csum, u64 generation, 1368 u16 csum_size) 1369 { 1370 int page_num; 1371 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1372 u32 crc = ~(u32)0; 1373 void *mapped_buffer; 1374 1375 WARN_ON(!sblock->pagev[0]->page); 1376 if (is_metadata) { 1377 struct btrfs_header *h; 1378 1379 mapped_buffer = kmap_atomic(sblock->pagev[0]->page); 1380 h = (struct btrfs_header *)mapped_buffer; 1381 1382 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) || 1383 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) || 1384 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, 1385 BTRFS_UUID_SIZE)) { 1386 sblock->header_error = 1; 1387 } else if (generation != btrfs_stack_header_generation(h)) { 1388 sblock->header_error = 1; 1389 sblock->generation_error = 1; 1390 } 1391 csum = h->csum; 1392 } else { 1393 if (!have_csum) 1394 return; 1395 1396 mapped_buffer = kmap_atomic(sblock->pagev[0]->page); 1397 } 1398 1399 for (page_num = 0;;) { 1400 if (page_num == 0 && is_metadata) 1401 crc = btrfs_csum_data( 1402 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE, 1403 crc, PAGE_SIZE - BTRFS_CSUM_SIZE); 1404 else 1405 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE); 1406 1407 kunmap_atomic(mapped_buffer); 1408 page_num++; 1409 if (page_num >= sblock->page_count) 1410 break; 1411 WARN_ON(!sblock->pagev[page_num]->page); 1412 1413 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page); 1414 } 1415 1416 btrfs_csum_final(crc, calculated_csum); 1417 if (memcmp(calculated_csum, csum, csum_size)) 1418 sblock->checksum_error = 1; 1419 } 1420 1421 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad, 1422 struct scrub_block *sblock_good, 1423 int force_write) 1424 { 1425 int page_num; 1426 int ret = 0; 1427 1428 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) { 1429 int ret_sub; 1430 1431 ret_sub = scrub_repair_page_from_good_copy(sblock_bad, 1432 sblock_good, 1433 page_num, 1434 force_write); 1435 if (ret_sub) 1436 ret = ret_sub; 1437 } 1438 1439 return ret; 1440 } 1441 1442 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad, 1443 struct scrub_block *sblock_good, 1444 int page_num, int force_write) 1445 { 1446 struct scrub_page *page_bad = sblock_bad->pagev[page_num]; 1447 struct scrub_page *page_good = sblock_good->pagev[page_num]; 1448 1449 BUG_ON(page_bad->page == NULL); 1450 BUG_ON(page_good->page == NULL); 1451 if (force_write || sblock_bad->header_error || 1452 sblock_bad->checksum_error || page_bad->io_error) { 1453 struct bio *bio; 1454 int ret; 1455 1456 if (!page_bad->dev->bdev) { 1457 printk_ratelimited(KERN_WARNING "BTRFS: " 1458 "scrub_repair_page_from_good_copy(bdev == NULL) " 1459 "is unexpected!\n"); 1460 return -EIO; 1461 } 1462 1463 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 1464 if (!bio) 1465 return -EIO; 1466 bio->bi_bdev = page_bad->dev->bdev; 1467 bio->bi_iter.bi_sector = page_bad->physical >> 9; 1468 1469 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0); 1470 if (PAGE_SIZE != ret) { 1471 bio_put(bio); 1472 return -EIO; 1473 } 1474 1475 if (btrfsic_submit_bio_wait(WRITE, bio)) { 1476 btrfs_dev_stat_inc_and_print(page_bad->dev, 1477 BTRFS_DEV_STAT_WRITE_ERRS); 1478 btrfs_dev_replace_stats_inc( 1479 &sblock_bad->sctx->dev_root->fs_info-> 1480 dev_replace.num_write_errors); 1481 bio_put(bio); 1482 return -EIO; 1483 } 1484 bio_put(bio); 1485 } 1486 1487 return 0; 1488 } 1489 1490 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock) 1491 { 1492 int page_num; 1493 1494 for (page_num = 0; page_num < sblock->page_count; page_num++) { 1495 int ret; 1496 1497 ret = scrub_write_page_to_dev_replace(sblock, page_num); 1498 if (ret) 1499 btrfs_dev_replace_stats_inc( 1500 &sblock->sctx->dev_root->fs_info->dev_replace. 1501 num_write_errors); 1502 } 1503 } 1504 1505 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock, 1506 int page_num) 1507 { 1508 struct scrub_page *spage = sblock->pagev[page_num]; 1509 1510 BUG_ON(spage->page == NULL); 1511 if (spage->io_error) { 1512 void *mapped_buffer = kmap_atomic(spage->page); 1513 1514 memset(mapped_buffer, 0, PAGE_CACHE_SIZE); 1515 flush_dcache_page(spage->page); 1516 kunmap_atomic(mapped_buffer); 1517 } 1518 return scrub_add_page_to_wr_bio(sblock->sctx, spage); 1519 } 1520 1521 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, 1522 struct scrub_page *spage) 1523 { 1524 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx; 1525 struct scrub_bio *sbio; 1526 int ret; 1527 1528 mutex_lock(&wr_ctx->wr_lock); 1529 again: 1530 if (!wr_ctx->wr_curr_bio) { 1531 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio), 1532 GFP_NOFS); 1533 if (!wr_ctx->wr_curr_bio) { 1534 mutex_unlock(&wr_ctx->wr_lock); 1535 return -ENOMEM; 1536 } 1537 wr_ctx->wr_curr_bio->sctx = sctx; 1538 wr_ctx->wr_curr_bio->page_count = 0; 1539 } 1540 sbio = wr_ctx->wr_curr_bio; 1541 if (sbio->page_count == 0) { 1542 struct bio *bio; 1543 1544 sbio->physical = spage->physical_for_dev_replace; 1545 sbio->logical = spage->logical; 1546 sbio->dev = wr_ctx->tgtdev; 1547 bio = sbio->bio; 1548 if (!bio) { 1549 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio); 1550 if (!bio) { 1551 mutex_unlock(&wr_ctx->wr_lock); 1552 return -ENOMEM; 1553 } 1554 sbio->bio = bio; 1555 } 1556 1557 bio->bi_private = sbio; 1558 bio->bi_end_io = scrub_wr_bio_end_io; 1559 bio->bi_bdev = sbio->dev->bdev; 1560 bio->bi_iter.bi_sector = sbio->physical >> 9; 1561 sbio->err = 0; 1562 } else if (sbio->physical + sbio->page_count * PAGE_SIZE != 1563 spage->physical_for_dev_replace || 1564 sbio->logical + sbio->page_count * PAGE_SIZE != 1565 spage->logical) { 1566 scrub_wr_submit(sctx); 1567 goto again; 1568 } 1569 1570 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); 1571 if (ret != PAGE_SIZE) { 1572 if (sbio->page_count < 1) { 1573 bio_put(sbio->bio); 1574 sbio->bio = NULL; 1575 mutex_unlock(&wr_ctx->wr_lock); 1576 return -EIO; 1577 } 1578 scrub_wr_submit(sctx); 1579 goto again; 1580 } 1581 1582 sbio->pagev[sbio->page_count] = spage; 1583 scrub_page_get(spage); 1584 sbio->page_count++; 1585 if (sbio->page_count == wr_ctx->pages_per_wr_bio) 1586 scrub_wr_submit(sctx); 1587 mutex_unlock(&wr_ctx->wr_lock); 1588 1589 return 0; 1590 } 1591 1592 static void scrub_wr_submit(struct scrub_ctx *sctx) 1593 { 1594 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx; 1595 struct scrub_bio *sbio; 1596 1597 if (!wr_ctx->wr_curr_bio) 1598 return; 1599 1600 sbio = wr_ctx->wr_curr_bio; 1601 wr_ctx->wr_curr_bio = NULL; 1602 WARN_ON(!sbio->bio->bi_bdev); 1603 scrub_pending_bio_inc(sctx); 1604 /* process all writes in a single worker thread. Then the block layer 1605 * orders the requests before sending them to the driver which 1606 * doubled the write performance on spinning disks when measured 1607 * with Linux 3.5 */ 1608 btrfsic_submit_bio(WRITE, sbio->bio); 1609 } 1610 1611 static void scrub_wr_bio_end_io(struct bio *bio, int err) 1612 { 1613 struct scrub_bio *sbio = bio->bi_private; 1614 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info; 1615 1616 sbio->err = err; 1617 sbio->bio = bio; 1618 1619 btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL); 1620 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work); 1621 } 1622 1623 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work) 1624 { 1625 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 1626 struct scrub_ctx *sctx = sbio->sctx; 1627 int i; 1628 1629 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO); 1630 if (sbio->err) { 1631 struct btrfs_dev_replace *dev_replace = 1632 &sbio->sctx->dev_root->fs_info->dev_replace; 1633 1634 for (i = 0; i < sbio->page_count; i++) { 1635 struct scrub_page *spage = sbio->pagev[i]; 1636 1637 spage->io_error = 1; 1638 btrfs_dev_replace_stats_inc(&dev_replace-> 1639 num_write_errors); 1640 } 1641 } 1642 1643 for (i = 0; i < sbio->page_count; i++) 1644 scrub_page_put(sbio->pagev[i]); 1645 1646 bio_put(sbio->bio); 1647 kfree(sbio); 1648 scrub_pending_bio_dec(sctx); 1649 } 1650 1651 static int scrub_checksum(struct scrub_block *sblock) 1652 { 1653 u64 flags; 1654 int ret; 1655 1656 WARN_ON(sblock->page_count < 1); 1657 flags = sblock->pagev[0]->flags; 1658 ret = 0; 1659 if (flags & BTRFS_EXTENT_FLAG_DATA) 1660 ret = scrub_checksum_data(sblock); 1661 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) 1662 ret = scrub_checksum_tree_block(sblock); 1663 else if (flags & BTRFS_EXTENT_FLAG_SUPER) 1664 (void)scrub_checksum_super(sblock); 1665 else 1666 WARN_ON(1); 1667 if (ret) 1668 scrub_handle_errored_block(sblock); 1669 1670 return ret; 1671 } 1672 1673 static int scrub_checksum_data(struct scrub_block *sblock) 1674 { 1675 struct scrub_ctx *sctx = sblock->sctx; 1676 u8 csum[BTRFS_CSUM_SIZE]; 1677 u8 *on_disk_csum; 1678 struct page *page; 1679 void *buffer; 1680 u32 crc = ~(u32)0; 1681 int fail = 0; 1682 u64 len; 1683 int index; 1684 1685 BUG_ON(sblock->page_count < 1); 1686 if (!sblock->pagev[0]->have_csum) 1687 return 0; 1688 1689 on_disk_csum = sblock->pagev[0]->csum; 1690 page = sblock->pagev[0]->page; 1691 buffer = kmap_atomic(page); 1692 1693 len = sctx->sectorsize; 1694 index = 0; 1695 for (;;) { 1696 u64 l = min_t(u64, len, PAGE_SIZE); 1697 1698 crc = btrfs_csum_data(buffer, crc, l); 1699 kunmap_atomic(buffer); 1700 len -= l; 1701 if (len == 0) 1702 break; 1703 index++; 1704 BUG_ON(index >= sblock->page_count); 1705 BUG_ON(!sblock->pagev[index]->page); 1706 page = sblock->pagev[index]->page; 1707 buffer = kmap_atomic(page); 1708 } 1709 1710 btrfs_csum_final(crc, csum); 1711 if (memcmp(csum, on_disk_csum, sctx->csum_size)) 1712 fail = 1; 1713 1714 return fail; 1715 } 1716 1717 static int scrub_checksum_tree_block(struct scrub_block *sblock) 1718 { 1719 struct scrub_ctx *sctx = sblock->sctx; 1720 struct btrfs_header *h; 1721 struct btrfs_root *root = sctx->dev_root; 1722 struct btrfs_fs_info *fs_info = root->fs_info; 1723 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1724 u8 on_disk_csum[BTRFS_CSUM_SIZE]; 1725 struct page *page; 1726 void *mapped_buffer; 1727 u64 mapped_size; 1728 void *p; 1729 u32 crc = ~(u32)0; 1730 int fail = 0; 1731 int crc_fail = 0; 1732 u64 len; 1733 int index; 1734 1735 BUG_ON(sblock->page_count < 1); 1736 page = sblock->pagev[0]->page; 1737 mapped_buffer = kmap_atomic(page); 1738 h = (struct btrfs_header *)mapped_buffer; 1739 memcpy(on_disk_csum, h->csum, sctx->csum_size); 1740 1741 /* 1742 * we don't use the getter functions here, as we 1743 * a) don't have an extent buffer and 1744 * b) the page is already kmapped 1745 */ 1746 1747 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h)) 1748 ++fail; 1749 1750 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) 1751 ++fail; 1752 1753 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) 1754 ++fail; 1755 1756 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, 1757 BTRFS_UUID_SIZE)) 1758 ++fail; 1759 1760 WARN_ON(sctx->nodesize != sctx->leafsize); 1761 len = sctx->nodesize - BTRFS_CSUM_SIZE; 1762 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; 1763 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; 1764 index = 0; 1765 for (;;) { 1766 u64 l = min_t(u64, len, mapped_size); 1767 1768 crc = btrfs_csum_data(p, crc, l); 1769 kunmap_atomic(mapped_buffer); 1770 len -= l; 1771 if (len == 0) 1772 break; 1773 index++; 1774 BUG_ON(index >= sblock->page_count); 1775 BUG_ON(!sblock->pagev[index]->page); 1776 page = sblock->pagev[index]->page; 1777 mapped_buffer = kmap_atomic(page); 1778 mapped_size = PAGE_SIZE; 1779 p = mapped_buffer; 1780 } 1781 1782 btrfs_csum_final(crc, calculated_csum); 1783 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size)) 1784 ++crc_fail; 1785 1786 return fail || crc_fail; 1787 } 1788 1789 static int scrub_checksum_super(struct scrub_block *sblock) 1790 { 1791 struct btrfs_super_block *s; 1792 struct scrub_ctx *sctx = sblock->sctx; 1793 struct btrfs_root *root = sctx->dev_root; 1794 struct btrfs_fs_info *fs_info = root->fs_info; 1795 u8 calculated_csum[BTRFS_CSUM_SIZE]; 1796 u8 on_disk_csum[BTRFS_CSUM_SIZE]; 1797 struct page *page; 1798 void *mapped_buffer; 1799 u64 mapped_size; 1800 void *p; 1801 u32 crc = ~(u32)0; 1802 int fail_gen = 0; 1803 int fail_cor = 0; 1804 u64 len; 1805 int index; 1806 1807 BUG_ON(sblock->page_count < 1); 1808 page = sblock->pagev[0]->page; 1809 mapped_buffer = kmap_atomic(page); 1810 s = (struct btrfs_super_block *)mapped_buffer; 1811 memcpy(on_disk_csum, s->csum, sctx->csum_size); 1812 1813 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s)) 1814 ++fail_cor; 1815 1816 if (sblock->pagev[0]->generation != btrfs_super_generation(s)) 1817 ++fail_gen; 1818 1819 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) 1820 ++fail_cor; 1821 1822 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE; 1823 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE; 1824 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE; 1825 index = 0; 1826 for (;;) { 1827 u64 l = min_t(u64, len, mapped_size); 1828 1829 crc = btrfs_csum_data(p, crc, l); 1830 kunmap_atomic(mapped_buffer); 1831 len -= l; 1832 if (len == 0) 1833 break; 1834 index++; 1835 BUG_ON(index >= sblock->page_count); 1836 BUG_ON(!sblock->pagev[index]->page); 1837 page = sblock->pagev[index]->page; 1838 mapped_buffer = kmap_atomic(page); 1839 mapped_size = PAGE_SIZE; 1840 p = mapped_buffer; 1841 } 1842 1843 btrfs_csum_final(crc, calculated_csum); 1844 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size)) 1845 ++fail_cor; 1846 1847 if (fail_cor + fail_gen) { 1848 /* 1849 * if we find an error in a super block, we just report it. 1850 * They will get written with the next transaction commit 1851 * anyway 1852 */ 1853 spin_lock(&sctx->stat_lock); 1854 ++sctx->stat.super_errors; 1855 spin_unlock(&sctx->stat_lock); 1856 if (fail_cor) 1857 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev, 1858 BTRFS_DEV_STAT_CORRUPTION_ERRS); 1859 else 1860 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev, 1861 BTRFS_DEV_STAT_GENERATION_ERRS); 1862 } 1863 1864 return fail_cor + fail_gen; 1865 } 1866 1867 static void scrub_block_get(struct scrub_block *sblock) 1868 { 1869 atomic_inc(&sblock->ref_count); 1870 } 1871 1872 static void scrub_block_put(struct scrub_block *sblock) 1873 { 1874 if (atomic_dec_and_test(&sblock->ref_count)) { 1875 int i; 1876 1877 for (i = 0; i < sblock->page_count; i++) 1878 scrub_page_put(sblock->pagev[i]); 1879 kfree(sblock); 1880 } 1881 } 1882 1883 static void scrub_page_get(struct scrub_page *spage) 1884 { 1885 atomic_inc(&spage->ref_count); 1886 } 1887 1888 static void scrub_page_put(struct scrub_page *spage) 1889 { 1890 if (atomic_dec_and_test(&spage->ref_count)) { 1891 if (spage->page) 1892 __free_page(spage->page); 1893 kfree(spage); 1894 } 1895 } 1896 1897 static void scrub_submit(struct scrub_ctx *sctx) 1898 { 1899 struct scrub_bio *sbio; 1900 1901 if (sctx->curr == -1) 1902 return; 1903 1904 sbio = sctx->bios[sctx->curr]; 1905 sctx->curr = -1; 1906 scrub_pending_bio_inc(sctx); 1907 1908 if (!sbio->bio->bi_bdev) { 1909 /* 1910 * this case should not happen. If btrfs_map_block() is 1911 * wrong, it could happen for dev-replace operations on 1912 * missing devices when no mirrors are available, but in 1913 * this case it should already fail the mount. 1914 * This case is handled correctly (but _very_ slowly). 1915 */ 1916 printk_ratelimited(KERN_WARNING 1917 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n"); 1918 bio_endio(sbio->bio, -EIO); 1919 } else { 1920 btrfsic_submit_bio(READ, sbio->bio); 1921 } 1922 } 1923 1924 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, 1925 struct scrub_page *spage) 1926 { 1927 struct scrub_block *sblock = spage->sblock; 1928 struct scrub_bio *sbio; 1929 int ret; 1930 1931 again: 1932 /* 1933 * grab a fresh bio or wait for one to become available 1934 */ 1935 while (sctx->curr == -1) { 1936 spin_lock(&sctx->list_lock); 1937 sctx->curr = sctx->first_free; 1938 if (sctx->curr != -1) { 1939 sctx->first_free = sctx->bios[sctx->curr]->next_free; 1940 sctx->bios[sctx->curr]->next_free = -1; 1941 sctx->bios[sctx->curr]->page_count = 0; 1942 spin_unlock(&sctx->list_lock); 1943 } else { 1944 spin_unlock(&sctx->list_lock); 1945 wait_event(sctx->list_wait, sctx->first_free != -1); 1946 } 1947 } 1948 sbio = sctx->bios[sctx->curr]; 1949 if (sbio->page_count == 0) { 1950 struct bio *bio; 1951 1952 sbio->physical = spage->physical; 1953 sbio->logical = spage->logical; 1954 sbio->dev = spage->dev; 1955 bio = sbio->bio; 1956 if (!bio) { 1957 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio); 1958 if (!bio) 1959 return -ENOMEM; 1960 sbio->bio = bio; 1961 } 1962 1963 bio->bi_private = sbio; 1964 bio->bi_end_io = scrub_bio_end_io; 1965 bio->bi_bdev = sbio->dev->bdev; 1966 bio->bi_iter.bi_sector = sbio->physical >> 9; 1967 sbio->err = 0; 1968 } else if (sbio->physical + sbio->page_count * PAGE_SIZE != 1969 spage->physical || 1970 sbio->logical + sbio->page_count * PAGE_SIZE != 1971 spage->logical || 1972 sbio->dev != spage->dev) { 1973 scrub_submit(sctx); 1974 goto again; 1975 } 1976 1977 sbio->pagev[sbio->page_count] = spage; 1978 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0); 1979 if (ret != PAGE_SIZE) { 1980 if (sbio->page_count < 1) { 1981 bio_put(sbio->bio); 1982 sbio->bio = NULL; 1983 return -EIO; 1984 } 1985 scrub_submit(sctx); 1986 goto again; 1987 } 1988 1989 scrub_block_get(sblock); /* one for the page added to the bio */ 1990 atomic_inc(&sblock->outstanding_pages); 1991 sbio->page_count++; 1992 if (sbio->page_count == sctx->pages_per_rd_bio) 1993 scrub_submit(sctx); 1994 1995 return 0; 1996 } 1997 1998 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 1999 u64 physical, struct btrfs_device *dev, u64 flags, 2000 u64 gen, int mirror_num, u8 *csum, int force, 2001 u64 physical_for_dev_replace) 2002 { 2003 struct scrub_block *sblock; 2004 int index; 2005 2006 sblock = kzalloc(sizeof(*sblock), GFP_NOFS); 2007 if (!sblock) { 2008 spin_lock(&sctx->stat_lock); 2009 sctx->stat.malloc_errors++; 2010 spin_unlock(&sctx->stat_lock); 2011 return -ENOMEM; 2012 } 2013 2014 /* one ref inside this function, plus one for each page added to 2015 * a bio later on */ 2016 atomic_set(&sblock->ref_count, 1); 2017 sblock->sctx = sctx; 2018 sblock->no_io_error_seen = 1; 2019 2020 for (index = 0; len > 0; index++) { 2021 struct scrub_page *spage; 2022 u64 l = min_t(u64, len, PAGE_SIZE); 2023 2024 spage = kzalloc(sizeof(*spage), GFP_NOFS); 2025 if (!spage) { 2026 leave_nomem: 2027 spin_lock(&sctx->stat_lock); 2028 sctx->stat.malloc_errors++; 2029 spin_unlock(&sctx->stat_lock); 2030 scrub_block_put(sblock); 2031 return -ENOMEM; 2032 } 2033 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); 2034 scrub_page_get(spage); 2035 sblock->pagev[index] = spage; 2036 spage->sblock = sblock; 2037 spage->dev = dev; 2038 spage->flags = flags; 2039 spage->generation = gen; 2040 spage->logical = logical; 2041 spage->physical = physical; 2042 spage->physical_for_dev_replace = physical_for_dev_replace; 2043 spage->mirror_num = mirror_num; 2044 if (csum) { 2045 spage->have_csum = 1; 2046 memcpy(spage->csum, csum, sctx->csum_size); 2047 } else { 2048 spage->have_csum = 0; 2049 } 2050 sblock->page_count++; 2051 spage->page = alloc_page(GFP_NOFS); 2052 if (!spage->page) 2053 goto leave_nomem; 2054 len -= l; 2055 logical += l; 2056 physical += l; 2057 physical_for_dev_replace += l; 2058 } 2059 2060 WARN_ON(sblock->page_count == 0); 2061 for (index = 0; index < sblock->page_count; index++) { 2062 struct scrub_page *spage = sblock->pagev[index]; 2063 int ret; 2064 2065 ret = scrub_add_page_to_rd_bio(sctx, spage); 2066 if (ret) { 2067 scrub_block_put(sblock); 2068 return ret; 2069 } 2070 } 2071 2072 if (force) 2073 scrub_submit(sctx); 2074 2075 /* last one frees, either here or in bio completion for last page */ 2076 scrub_block_put(sblock); 2077 return 0; 2078 } 2079 2080 static void scrub_bio_end_io(struct bio *bio, int err) 2081 { 2082 struct scrub_bio *sbio = bio->bi_private; 2083 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info; 2084 2085 sbio->err = err; 2086 sbio->bio = bio; 2087 2088 btrfs_queue_work(fs_info->scrub_workers, &sbio->work); 2089 } 2090 2091 static void scrub_bio_end_io_worker(struct btrfs_work *work) 2092 { 2093 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 2094 struct scrub_ctx *sctx = sbio->sctx; 2095 int i; 2096 2097 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO); 2098 if (sbio->err) { 2099 for (i = 0; i < sbio->page_count; i++) { 2100 struct scrub_page *spage = sbio->pagev[i]; 2101 2102 spage->io_error = 1; 2103 spage->sblock->no_io_error_seen = 0; 2104 } 2105 } 2106 2107 /* now complete the scrub_block items that have all pages completed */ 2108 for (i = 0; i < sbio->page_count; i++) { 2109 struct scrub_page *spage = sbio->pagev[i]; 2110 struct scrub_block *sblock = spage->sblock; 2111 2112 if (atomic_dec_and_test(&sblock->outstanding_pages)) 2113 scrub_block_complete(sblock); 2114 scrub_block_put(sblock); 2115 } 2116 2117 bio_put(sbio->bio); 2118 sbio->bio = NULL; 2119 spin_lock(&sctx->list_lock); 2120 sbio->next_free = sctx->first_free; 2121 sctx->first_free = sbio->index; 2122 spin_unlock(&sctx->list_lock); 2123 2124 if (sctx->is_dev_replace && 2125 atomic_read(&sctx->wr_ctx.flush_all_writes)) { 2126 mutex_lock(&sctx->wr_ctx.wr_lock); 2127 scrub_wr_submit(sctx); 2128 mutex_unlock(&sctx->wr_ctx.wr_lock); 2129 } 2130 2131 scrub_pending_bio_dec(sctx); 2132 } 2133 2134 static void scrub_block_complete(struct scrub_block *sblock) 2135 { 2136 if (!sblock->no_io_error_seen) { 2137 scrub_handle_errored_block(sblock); 2138 } else { 2139 /* 2140 * if has checksum error, write via repair mechanism in 2141 * dev replace case, otherwise write here in dev replace 2142 * case. 2143 */ 2144 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace) 2145 scrub_write_block_to_dev_replace(sblock); 2146 } 2147 } 2148 2149 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len, 2150 u8 *csum) 2151 { 2152 struct btrfs_ordered_sum *sum = NULL; 2153 unsigned long index; 2154 unsigned long num_sectors; 2155 2156 while (!list_empty(&sctx->csum_list)) { 2157 sum = list_first_entry(&sctx->csum_list, 2158 struct btrfs_ordered_sum, list); 2159 if (sum->bytenr > logical) 2160 return 0; 2161 if (sum->bytenr + sum->len > logical) 2162 break; 2163 2164 ++sctx->stat.csum_discards; 2165 list_del(&sum->list); 2166 kfree(sum); 2167 sum = NULL; 2168 } 2169 if (!sum) 2170 return 0; 2171 2172 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize; 2173 num_sectors = sum->len / sctx->sectorsize; 2174 memcpy(csum, sum->sums + index, sctx->csum_size); 2175 if (index == num_sectors - 1) { 2176 list_del(&sum->list); 2177 kfree(sum); 2178 } 2179 return 1; 2180 } 2181 2182 /* scrub extent tries to collect up to 64 kB for each bio */ 2183 static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len, 2184 u64 physical, struct btrfs_device *dev, u64 flags, 2185 u64 gen, int mirror_num, u64 physical_for_dev_replace) 2186 { 2187 int ret; 2188 u8 csum[BTRFS_CSUM_SIZE]; 2189 u32 blocksize; 2190 2191 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2192 blocksize = sctx->sectorsize; 2193 spin_lock(&sctx->stat_lock); 2194 sctx->stat.data_extents_scrubbed++; 2195 sctx->stat.data_bytes_scrubbed += len; 2196 spin_unlock(&sctx->stat_lock); 2197 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 2198 WARN_ON(sctx->nodesize != sctx->leafsize); 2199 blocksize = sctx->nodesize; 2200 spin_lock(&sctx->stat_lock); 2201 sctx->stat.tree_extents_scrubbed++; 2202 sctx->stat.tree_bytes_scrubbed += len; 2203 spin_unlock(&sctx->stat_lock); 2204 } else { 2205 blocksize = sctx->sectorsize; 2206 WARN_ON(1); 2207 } 2208 2209 while (len) { 2210 u64 l = min_t(u64, len, blocksize); 2211 int have_csum = 0; 2212 2213 if (flags & BTRFS_EXTENT_FLAG_DATA) { 2214 /* push csums to sbio */ 2215 have_csum = scrub_find_csum(sctx, logical, l, csum); 2216 if (have_csum == 0) 2217 ++sctx->stat.no_csum; 2218 if (sctx->is_dev_replace && !have_csum) { 2219 ret = copy_nocow_pages(sctx, logical, l, 2220 mirror_num, 2221 physical_for_dev_replace); 2222 goto behind_scrub_pages; 2223 } 2224 } 2225 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen, 2226 mirror_num, have_csum ? csum : NULL, 0, 2227 physical_for_dev_replace); 2228 behind_scrub_pages: 2229 if (ret) 2230 return ret; 2231 len -= l; 2232 logical += l; 2233 physical += l; 2234 physical_for_dev_replace += l; 2235 } 2236 return 0; 2237 } 2238 2239 /* 2240 * Given a physical address, this will calculate it's 2241 * logical offset. if this is a parity stripe, it will return 2242 * the most left data stripe's logical offset. 2243 * 2244 * return 0 if it is a data stripe, 1 means parity stripe. 2245 */ 2246 static int get_raid56_logic_offset(u64 physical, int num, 2247 struct map_lookup *map, u64 *offset) 2248 { 2249 int i; 2250 int j = 0; 2251 u64 stripe_nr; 2252 u64 last_offset; 2253 int stripe_index; 2254 int rot; 2255 2256 last_offset = (physical - map->stripes[num].physical) * 2257 nr_data_stripes(map); 2258 *offset = last_offset; 2259 for (i = 0; i < nr_data_stripes(map); i++) { 2260 *offset = last_offset + i * map->stripe_len; 2261 2262 stripe_nr = *offset; 2263 do_div(stripe_nr, map->stripe_len); 2264 do_div(stripe_nr, nr_data_stripes(map)); 2265 2266 /* Work out the disk rotation on this stripe-set */ 2267 rot = do_div(stripe_nr, map->num_stripes); 2268 /* calculate which stripe this data locates */ 2269 rot += i; 2270 stripe_index = rot % map->num_stripes; 2271 if (stripe_index == num) 2272 return 0; 2273 if (stripe_index < num) 2274 j++; 2275 } 2276 *offset = last_offset + j * map->stripe_len; 2277 return 1; 2278 } 2279 2280 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 2281 struct map_lookup *map, 2282 struct btrfs_device *scrub_dev, 2283 int num, u64 base, u64 length, 2284 int is_dev_replace) 2285 { 2286 struct btrfs_path *path; 2287 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 2288 struct btrfs_root *root = fs_info->extent_root; 2289 struct btrfs_root *csum_root = fs_info->csum_root; 2290 struct btrfs_extent_item *extent; 2291 struct blk_plug plug; 2292 u64 flags; 2293 int ret; 2294 int slot; 2295 u64 nstripes; 2296 struct extent_buffer *l; 2297 struct btrfs_key key; 2298 u64 physical; 2299 u64 logical; 2300 u64 logic_end; 2301 u64 physical_end; 2302 u64 generation; 2303 int mirror_num; 2304 struct reada_control *reada1; 2305 struct reada_control *reada2; 2306 struct btrfs_key key_start; 2307 struct btrfs_key key_end; 2308 u64 increment = map->stripe_len; 2309 u64 offset; 2310 u64 extent_logical; 2311 u64 extent_physical; 2312 u64 extent_len; 2313 struct btrfs_device *extent_dev; 2314 int extent_mirror_num; 2315 int stop_loop = 0; 2316 2317 nstripes = length; 2318 physical = map->stripes[num].physical; 2319 offset = 0; 2320 do_div(nstripes, map->stripe_len); 2321 if (map->type & BTRFS_BLOCK_GROUP_RAID0) { 2322 offset = map->stripe_len * num; 2323 increment = map->stripe_len * map->num_stripes; 2324 mirror_num = 1; 2325 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 2326 int factor = map->num_stripes / map->sub_stripes; 2327 offset = map->stripe_len * (num / map->sub_stripes); 2328 increment = map->stripe_len * factor; 2329 mirror_num = num % map->sub_stripes + 1; 2330 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { 2331 increment = map->stripe_len; 2332 mirror_num = num % map->num_stripes + 1; 2333 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { 2334 increment = map->stripe_len; 2335 mirror_num = num % map->num_stripes + 1; 2336 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | 2337 BTRFS_BLOCK_GROUP_RAID6)) { 2338 get_raid56_logic_offset(physical, num, map, &offset); 2339 increment = map->stripe_len * nr_data_stripes(map); 2340 mirror_num = 1; 2341 } else { 2342 increment = map->stripe_len; 2343 mirror_num = 1; 2344 } 2345 2346 path = btrfs_alloc_path(); 2347 if (!path) 2348 return -ENOMEM; 2349 2350 /* 2351 * work on commit root. The related disk blocks are static as 2352 * long as COW is applied. This means, it is save to rewrite 2353 * them to repair disk errors without any race conditions 2354 */ 2355 path->search_commit_root = 1; 2356 path->skip_locking = 1; 2357 2358 /* 2359 * trigger the readahead for extent tree csum tree and wait for 2360 * completion. During readahead, the scrub is officially paused 2361 * to not hold off transaction commits 2362 */ 2363 logical = base + offset; 2364 physical_end = physical + nstripes * map->stripe_len; 2365 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | 2366 BTRFS_BLOCK_GROUP_RAID6)) { 2367 get_raid56_logic_offset(physical_end, num, 2368 map, &logic_end); 2369 logic_end += base; 2370 } else { 2371 logic_end = logical + increment * nstripes; 2372 } 2373 wait_event(sctx->list_wait, 2374 atomic_read(&sctx->bios_in_flight) == 0); 2375 scrub_blocked_if_needed(fs_info); 2376 2377 /* FIXME it might be better to start readahead at commit root */ 2378 key_start.objectid = logical; 2379 key_start.type = BTRFS_EXTENT_ITEM_KEY; 2380 key_start.offset = (u64)0; 2381 key_end.objectid = logic_end; 2382 key_end.type = BTRFS_METADATA_ITEM_KEY; 2383 key_end.offset = (u64)-1; 2384 reada1 = btrfs_reada_add(root, &key_start, &key_end); 2385 2386 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 2387 key_start.type = BTRFS_EXTENT_CSUM_KEY; 2388 key_start.offset = logical; 2389 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 2390 key_end.type = BTRFS_EXTENT_CSUM_KEY; 2391 key_end.offset = logic_end; 2392 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end); 2393 2394 if (!IS_ERR(reada1)) 2395 btrfs_reada_wait(reada1); 2396 if (!IS_ERR(reada2)) 2397 btrfs_reada_wait(reada2); 2398 2399 2400 /* 2401 * collect all data csums for the stripe to avoid seeking during 2402 * the scrub. This might currently (crc32) end up to be about 1MB 2403 */ 2404 blk_start_plug(&plug); 2405 2406 /* 2407 * now find all extents for each stripe and scrub them 2408 */ 2409 ret = 0; 2410 while (physical < physical_end) { 2411 /* for raid56, we skip parity stripe */ 2412 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | 2413 BTRFS_BLOCK_GROUP_RAID6)) { 2414 ret = get_raid56_logic_offset(physical, num, 2415 map, &logical); 2416 logical += base; 2417 if (ret) 2418 goto skip; 2419 } 2420 /* 2421 * canceled? 2422 */ 2423 if (atomic_read(&fs_info->scrub_cancel_req) || 2424 atomic_read(&sctx->cancel_req)) { 2425 ret = -ECANCELED; 2426 goto out; 2427 } 2428 /* 2429 * check to see if we have to pause 2430 */ 2431 if (atomic_read(&fs_info->scrub_pause_req)) { 2432 /* push queued extents */ 2433 atomic_set(&sctx->wr_ctx.flush_all_writes, 1); 2434 scrub_submit(sctx); 2435 mutex_lock(&sctx->wr_ctx.wr_lock); 2436 scrub_wr_submit(sctx); 2437 mutex_unlock(&sctx->wr_ctx.wr_lock); 2438 wait_event(sctx->list_wait, 2439 atomic_read(&sctx->bios_in_flight) == 0); 2440 atomic_set(&sctx->wr_ctx.flush_all_writes, 0); 2441 scrub_blocked_if_needed(fs_info); 2442 } 2443 2444 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) 2445 key.type = BTRFS_METADATA_ITEM_KEY; 2446 else 2447 key.type = BTRFS_EXTENT_ITEM_KEY; 2448 key.objectid = logical; 2449 key.offset = (u64)-1; 2450 2451 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2452 if (ret < 0) 2453 goto out; 2454 2455 if (ret > 0) { 2456 ret = btrfs_previous_extent_item(root, path, 0); 2457 if (ret < 0) 2458 goto out; 2459 if (ret > 0) { 2460 /* there's no smaller item, so stick with the 2461 * larger one */ 2462 btrfs_release_path(path); 2463 ret = btrfs_search_slot(NULL, root, &key, 2464 path, 0, 0); 2465 if (ret < 0) 2466 goto out; 2467 } 2468 } 2469 2470 stop_loop = 0; 2471 while (1) { 2472 u64 bytes; 2473 2474 l = path->nodes[0]; 2475 slot = path->slots[0]; 2476 if (slot >= btrfs_header_nritems(l)) { 2477 ret = btrfs_next_leaf(root, path); 2478 if (ret == 0) 2479 continue; 2480 if (ret < 0) 2481 goto out; 2482 2483 stop_loop = 1; 2484 break; 2485 } 2486 btrfs_item_key_to_cpu(l, &key, slot); 2487 2488 if (key.type == BTRFS_METADATA_ITEM_KEY) 2489 bytes = root->leafsize; 2490 else 2491 bytes = key.offset; 2492 2493 if (key.objectid + bytes <= logical) 2494 goto next; 2495 2496 if (key.type != BTRFS_EXTENT_ITEM_KEY && 2497 key.type != BTRFS_METADATA_ITEM_KEY) 2498 goto next; 2499 2500 if (key.objectid >= logical + map->stripe_len) { 2501 /* out of this device extent */ 2502 if (key.objectid >= logic_end) 2503 stop_loop = 1; 2504 break; 2505 } 2506 2507 extent = btrfs_item_ptr(l, slot, 2508 struct btrfs_extent_item); 2509 flags = btrfs_extent_flags(l, extent); 2510 generation = btrfs_extent_generation(l, extent); 2511 2512 if (key.objectid < logical && 2513 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) { 2514 btrfs_err(fs_info, 2515 "scrub: tree block %llu spanning " 2516 "stripes, ignored. logical=%llu", 2517 key.objectid, logical); 2518 goto next; 2519 } 2520 2521 again: 2522 extent_logical = key.objectid; 2523 extent_len = bytes; 2524 2525 /* 2526 * trim extent to this stripe 2527 */ 2528 if (extent_logical < logical) { 2529 extent_len -= logical - extent_logical; 2530 extent_logical = logical; 2531 } 2532 if (extent_logical + extent_len > 2533 logical + map->stripe_len) { 2534 extent_len = logical + map->stripe_len - 2535 extent_logical; 2536 } 2537 2538 extent_physical = extent_logical - logical + physical; 2539 extent_dev = scrub_dev; 2540 extent_mirror_num = mirror_num; 2541 if (is_dev_replace) 2542 scrub_remap_extent(fs_info, extent_logical, 2543 extent_len, &extent_physical, 2544 &extent_dev, 2545 &extent_mirror_num); 2546 2547 ret = btrfs_lookup_csums_range(csum_root, logical, 2548 logical + map->stripe_len - 1, 2549 &sctx->csum_list, 1); 2550 if (ret) 2551 goto out; 2552 2553 ret = scrub_extent(sctx, extent_logical, extent_len, 2554 extent_physical, extent_dev, flags, 2555 generation, extent_mirror_num, 2556 extent_logical - logical + physical); 2557 if (ret) 2558 goto out; 2559 2560 scrub_free_csums(sctx); 2561 if (extent_logical + extent_len < 2562 key.objectid + bytes) { 2563 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | 2564 BTRFS_BLOCK_GROUP_RAID6)) { 2565 /* 2566 * loop until we find next data stripe 2567 * or we have finished all stripes. 2568 */ 2569 do { 2570 physical += map->stripe_len; 2571 ret = get_raid56_logic_offset( 2572 physical, num, 2573 map, &logical); 2574 logical += base; 2575 } while (physical < physical_end && ret); 2576 } else { 2577 physical += map->stripe_len; 2578 logical += increment; 2579 } 2580 if (logical < key.objectid + bytes) { 2581 cond_resched(); 2582 goto again; 2583 } 2584 2585 if (physical >= physical_end) { 2586 stop_loop = 1; 2587 break; 2588 } 2589 } 2590 next: 2591 path->slots[0]++; 2592 } 2593 btrfs_release_path(path); 2594 skip: 2595 logical += increment; 2596 physical += map->stripe_len; 2597 spin_lock(&sctx->stat_lock); 2598 if (stop_loop) 2599 sctx->stat.last_physical = map->stripes[num].physical + 2600 length; 2601 else 2602 sctx->stat.last_physical = physical; 2603 spin_unlock(&sctx->stat_lock); 2604 if (stop_loop) 2605 break; 2606 } 2607 out: 2608 /* push queued extents */ 2609 scrub_submit(sctx); 2610 mutex_lock(&sctx->wr_ctx.wr_lock); 2611 scrub_wr_submit(sctx); 2612 mutex_unlock(&sctx->wr_ctx.wr_lock); 2613 2614 blk_finish_plug(&plug); 2615 btrfs_free_path(path); 2616 return ret < 0 ? ret : 0; 2617 } 2618 2619 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx, 2620 struct btrfs_device *scrub_dev, 2621 u64 chunk_tree, u64 chunk_objectid, 2622 u64 chunk_offset, u64 length, 2623 u64 dev_offset, int is_dev_replace) 2624 { 2625 struct btrfs_mapping_tree *map_tree = 2626 &sctx->dev_root->fs_info->mapping_tree; 2627 struct map_lookup *map; 2628 struct extent_map *em; 2629 int i; 2630 int ret = 0; 2631 2632 read_lock(&map_tree->map_tree.lock); 2633 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); 2634 read_unlock(&map_tree->map_tree.lock); 2635 2636 if (!em) 2637 return -EINVAL; 2638 2639 map = (struct map_lookup *)em->bdev; 2640 if (em->start != chunk_offset) 2641 goto out; 2642 2643 if (em->len < length) 2644 goto out; 2645 2646 for (i = 0; i < map->num_stripes; ++i) { 2647 if (map->stripes[i].dev->bdev == scrub_dev->bdev && 2648 map->stripes[i].physical == dev_offset) { 2649 ret = scrub_stripe(sctx, map, scrub_dev, i, 2650 chunk_offset, length, 2651 is_dev_replace); 2652 if (ret) 2653 goto out; 2654 } 2655 } 2656 out: 2657 free_extent_map(em); 2658 2659 return ret; 2660 } 2661 2662 static noinline_for_stack 2663 int scrub_enumerate_chunks(struct scrub_ctx *sctx, 2664 struct btrfs_device *scrub_dev, u64 start, u64 end, 2665 int is_dev_replace) 2666 { 2667 struct btrfs_dev_extent *dev_extent = NULL; 2668 struct btrfs_path *path; 2669 struct btrfs_root *root = sctx->dev_root; 2670 struct btrfs_fs_info *fs_info = root->fs_info; 2671 u64 length; 2672 u64 chunk_tree; 2673 u64 chunk_objectid; 2674 u64 chunk_offset; 2675 int ret; 2676 int slot; 2677 struct extent_buffer *l; 2678 struct btrfs_key key; 2679 struct btrfs_key found_key; 2680 struct btrfs_block_group_cache *cache; 2681 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 2682 2683 path = btrfs_alloc_path(); 2684 if (!path) 2685 return -ENOMEM; 2686 2687 path->reada = 2; 2688 path->search_commit_root = 1; 2689 path->skip_locking = 1; 2690 2691 key.objectid = scrub_dev->devid; 2692 key.offset = 0ull; 2693 key.type = BTRFS_DEV_EXTENT_KEY; 2694 2695 while (1) { 2696 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2697 if (ret < 0) 2698 break; 2699 if (ret > 0) { 2700 if (path->slots[0] >= 2701 btrfs_header_nritems(path->nodes[0])) { 2702 ret = btrfs_next_leaf(root, path); 2703 if (ret) 2704 break; 2705 } 2706 } 2707 2708 l = path->nodes[0]; 2709 slot = path->slots[0]; 2710 2711 btrfs_item_key_to_cpu(l, &found_key, slot); 2712 2713 if (found_key.objectid != scrub_dev->devid) 2714 break; 2715 2716 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY) 2717 break; 2718 2719 if (found_key.offset >= end) 2720 break; 2721 2722 if (found_key.offset < key.offset) 2723 break; 2724 2725 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 2726 length = btrfs_dev_extent_length(l, dev_extent); 2727 2728 if (found_key.offset + length <= start) { 2729 key.offset = found_key.offset + length; 2730 btrfs_release_path(path); 2731 continue; 2732 } 2733 2734 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); 2735 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); 2736 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); 2737 2738 /* 2739 * get a reference on the corresponding block group to prevent 2740 * the chunk from going away while we scrub it 2741 */ 2742 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 2743 if (!cache) { 2744 ret = -ENOENT; 2745 break; 2746 } 2747 dev_replace->cursor_right = found_key.offset + length; 2748 dev_replace->cursor_left = found_key.offset; 2749 dev_replace->item_needs_writeback = 1; 2750 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid, 2751 chunk_offset, length, found_key.offset, 2752 is_dev_replace); 2753 2754 /* 2755 * flush, submit all pending read and write bios, afterwards 2756 * wait for them. 2757 * Note that in the dev replace case, a read request causes 2758 * write requests that are submitted in the read completion 2759 * worker. Therefore in the current situation, it is required 2760 * that all write requests are flushed, so that all read and 2761 * write requests are really completed when bios_in_flight 2762 * changes to 0. 2763 */ 2764 atomic_set(&sctx->wr_ctx.flush_all_writes, 1); 2765 scrub_submit(sctx); 2766 mutex_lock(&sctx->wr_ctx.wr_lock); 2767 scrub_wr_submit(sctx); 2768 mutex_unlock(&sctx->wr_ctx.wr_lock); 2769 2770 wait_event(sctx->list_wait, 2771 atomic_read(&sctx->bios_in_flight) == 0); 2772 atomic_inc(&fs_info->scrubs_paused); 2773 wake_up(&fs_info->scrub_pause_wait); 2774 2775 /* 2776 * must be called before we decrease @scrub_paused. 2777 * make sure we don't block transaction commit while 2778 * we are waiting pending workers finished. 2779 */ 2780 wait_event(sctx->list_wait, 2781 atomic_read(&sctx->workers_pending) == 0); 2782 atomic_set(&sctx->wr_ctx.flush_all_writes, 0); 2783 2784 mutex_lock(&fs_info->scrub_lock); 2785 __scrub_blocked_if_needed(fs_info); 2786 atomic_dec(&fs_info->scrubs_paused); 2787 mutex_unlock(&fs_info->scrub_lock); 2788 wake_up(&fs_info->scrub_pause_wait); 2789 2790 btrfs_put_block_group(cache); 2791 if (ret) 2792 break; 2793 if (is_dev_replace && 2794 atomic64_read(&dev_replace->num_write_errors) > 0) { 2795 ret = -EIO; 2796 break; 2797 } 2798 if (sctx->stat.malloc_errors > 0) { 2799 ret = -ENOMEM; 2800 break; 2801 } 2802 2803 dev_replace->cursor_left = dev_replace->cursor_right; 2804 dev_replace->item_needs_writeback = 1; 2805 2806 key.offset = found_key.offset + length; 2807 btrfs_release_path(path); 2808 } 2809 2810 btrfs_free_path(path); 2811 2812 /* 2813 * ret can still be 1 from search_slot or next_leaf, 2814 * that's not an error 2815 */ 2816 return ret < 0 ? ret : 0; 2817 } 2818 2819 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, 2820 struct btrfs_device *scrub_dev) 2821 { 2822 int i; 2823 u64 bytenr; 2824 u64 gen; 2825 int ret; 2826 struct btrfs_root *root = sctx->dev_root; 2827 2828 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 2829 return -EIO; 2830 2831 gen = root->fs_info->last_trans_committed; 2832 2833 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { 2834 bytenr = btrfs_sb_offset(i); 2835 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes) 2836 break; 2837 2838 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr, 2839 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i, 2840 NULL, 1, bytenr); 2841 if (ret) 2842 return ret; 2843 } 2844 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 2845 2846 return 0; 2847 } 2848 2849 /* 2850 * get a reference count on fs_info->scrub_workers. start worker if necessary 2851 */ 2852 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info, 2853 int is_dev_replace) 2854 { 2855 int ret = 0; 2856 int flags = WQ_FREEZABLE | WQ_UNBOUND; 2857 int max_active = fs_info->thread_pool_size; 2858 2859 if (fs_info->scrub_workers_refcnt == 0) { 2860 if (is_dev_replace) 2861 fs_info->scrub_workers = 2862 btrfs_alloc_workqueue("btrfs-scrub", flags, 2863 1, 4); 2864 else 2865 fs_info->scrub_workers = 2866 btrfs_alloc_workqueue("btrfs-scrub", flags, 2867 max_active, 4); 2868 if (!fs_info->scrub_workers) { 2869 ret = -ENOMEM; 2870 goto out; 2871 } 2872 fs_info->scrub_wr_completion_workers = 2873 btrfs_alloc_workqueue("btrfs-scrubwrc", flags, 2874 max_active, 2); 2875 if (!fs_info->scrub_wr_completion_workers) { 2876 ret = -ENOMEM; 2877 goto out; 2878 } 2879 fs_info->scrub_nocow_workers = 2880 btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0); 2881 if (!fs_info->scrub_nocow_workers) { 2882 ret = -ENOMEM; 2883 goto out; 2884 } 2885 } 2886 ++fs_info->scrub_workers_refcnt; 2887 out: 2888 return ret; 2889 } 2890 2891 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info) 2892 { 2893 if (--fs_info->scrub_workers_refcnt == 0) { 2894 btrfs_destroy_workqueue(fs_info->scrub_workers); 2895 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers); 2896 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers); 2897 } 2898 WARN_ON(fs_info->scrub_workers_refcnt < 0); 2899 } 2900 2901 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, 2902 u64 end, struct btrfs_scrub_progress *progress, 2903 int readonly, int is_dev_replace) 2904 { 2905 struct scrub_ctx *sctx; 2906 int ret; 2907 struct btrfs_device *dev; 2908 2909 if (btrfs_fs_closing(fs_info)) 2910 return -EINVAL; 2911 2912 /* 2913 * check some assumptions 2914 */ 2915 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) { 2916 btrfs_err(fs_info, 2917 "scrub: size assumption nodesize == leafsize (%d == %d) fails", 2918 fs_info->chunk_root->nodesize, 2919 fs_info->chunk_root->leafsize); 2920 return -EINVAL; 2921 } 2922 2923 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) { 2924 /* 2925 * in this case scrub is unable to calculate the checksum 2926 * the way scrub is implemented. Do not handle this 2927 * situation at all because it won't ever happen. 2928 */ 2929 btrfs_err(fs_info, 2930 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails", 2931 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN); 2932 return -EINVAL; 2933 } 2934 2935 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) { 2936 /* not supported for data w/o checksums */ 2937 btrfs_err(fs_info, 2938 "scrub: size assumption sectorsize != PAGE_SIZE " 2939 "(%d != %lu) fails", 2940 fs_info->chunk_root->sectorsize, PAGE_SIZE); 2941 return -EINVAL; 2942 } 2943 2944 if (fs_info->chunk_root->nodesize > 2945 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK || 2946 fs_info->chunk_root->sectorsize > 2947 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) { 2948 /* 2949 * would exhaust the array bounds of pagev member in 2950 * struct scrub_block 2951 */ 2952 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize " 2953 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails", 2954 fs_info->chunk_root->nodesize, 2955 SCRUB_MAX_PAGES_PER_BLOCK, 2956 fs_info->chunk_root->sectorsize, 2957 SCRUB_MAX_PAGES_PER_BLOCK); 2958 return -EINVAL; 2959 } 2960 2961 2962 mutex_lock(&fs_info->fs_devices->device_list_mutex); 2963 dev = btrfs_find_device(fs_info, devid, NULL, NULL); 2964 if (!dev || (dev->missing && !is_dev_replace)) { 2965 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2966 return -ENODEV; 2967 } 2968 2969 mutex_lock(&fs_info->scrub_lock); 2970 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) { 2971 mutex_unlock(&fs_info->scrub_lock); 2972 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2973 return -EIO; 2974 } 2975 2976 btrfs_dev_replace_lock(&fs_info->dev_replace); 2977 if (dev->scrub_device || 2978 (!is_dev_replace && 2979 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) { 2980 btrfs_dev_replace_unlock(&fs_info->dev_replace); 2981 mutex_unlock(&fs_info->scrub_lock); 2982 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2983 return -EINPROGRESS; 2984 } 2985 btrfs_dev_replace_unlock(&fs_info->dev_replace); 2986 2987 ret = scrub_workers_get(fs_info, is_dev_replace); 2988 if (ret) { 2989 mutex_unlock(&fs_info->scrub_lock); 2990 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2991 return ret; 2992 } 2993 2994 sctx = scrub_setup_ctx(dev, is_dev_replace); 2995 if (IS_ERR(sctx)) { 2996 mutex_unlock(&fs_info->scrub_lock); 2997 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2998 scrub_workers_put(fs_info); 2999 return PTR_ERR(sctx); 3000 } 3001 sctx->readonly = readonly; 3002 dev->scrub_device = sctx; 3003 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3004 3005 /* 3006 * checking @scrub_pause_req here, we can avoid 3007 * race between committing transaction and scrubbing. 3008 */ 3009 __scrub_blocked_if_needed(fs_info); 3010 atomic_inc(&fs_info->scrubs_running); 3011 mutex_unlock(&fs_info->scrub_lock); 3012 3013 if (!is_dev_replace) { 3014 /* 3015 * by holding device list mutex, we can 3016 * kick off writing super in log tree sync. 3017 */ 3018 mutex_lock(&fs_info->fs_devices->device_list_mutex); 3019 ret = scrub_supers(sctx, dev); 3020 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 3021 } 3022 3023 if (!ret) 3024 ret = scrub_enumerate_chunks(sctx, dev, start, end, 3025 is_dev_replace); 3026 3027 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); 3028 atomic_dec(&fs_info->scrubs_running); 3029 wake_up(&fs_info->scrub_pause_wait); 3030 3031 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0); 3032 3033 if (progress) 3034 memcpy(progress, &sctx->stat, sizeof(*progress)); 3035 3036 mutex_lock(&fs_info->scrub_lock); 3037 dev->scrub_device = NULL; 3038 scrub_workers_put(fs_info); 3039 mutex_unlock(&fs_info->scrub_lock); 3040 3041 scrub_free_ctx(sctx); 3042 3043 return ret; 3044 } 3045 3046 void btrfs_scrub_pause(struct btrfs_root *root) 3047 { 3048 struct btrfs_fs_info *fs_info = root->fs_info; 3049 3050 mutex_lock(&fs_info->scrub_lock); 3051 atomic_inc(&fs_info->scrub_pause_req); 3052 while (atomic_read(&fs_info->scrubs_paused) != 3053 atomic_read(&fs_info->scrubs_running)) { 3054 mutex_unlock(&fs_info->scrub_lock); 3055 wait_event(fs_info->scrub_pause_wait, 3056 atomic_read(&fs_info->scrubs_paused) == 3057 atomic_read(&fs_info->scrubs_running)); 3058 mutex_lock(&fs_info->scrub_lock); 3059 } 3060 mutex_unlock(&fs_info->scrub_lock); 3061 } 3062 3063 void btrfs_scrub_continue(struct btrfs_root *root) 3064 { 3065 struct btrfs_fs_info *fs_info = root->fs_info; 3066 3067 atomic_dec(&fs_info->scrub_pause_req); 3068 wake_up(&fs_info->scrub_pause_wait); 3069 } 3070 3071 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info) 3072 { 3073 mutex_lock(&fs_info->scrub_lock); 3074 if (!atomic_read(&fs_info->scrubs_running)) { 3075 mutex_unlock(&fs_info->scrub_lock); 3076 return -ENOTCONN; 3077 } 3078 3079 atomic_inc(&fs_info->scrub_cancel_req); 3080 while (atomic_read(&fs_info->scrubs_running)) { 3081 mutex_unlock(&fs_info->scrub_lock); 3082 wait_event(fs_info->scrub_pause_wait, 3083 atomic_read(&fs_info->scrubs_running) == 0); 3084 mutex_lock(&fs_info->scrub_lock); 3085 } 3086 atomic_dec(&fs_info->scrub_cancel_req); 3087 mutex_unlock(&fs_info->scrub_lock); 3088 3089 return 0; 3090 } 3091 3092 int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info, 3093 struct btrfs_device *dev) 3094 { 3095 struct scrub_ctx *sctx; 3096 3097 mutex_lock(&fs_info->scrub_lock); 3098 sctx = dev->scrub_device; 3099 if (!sctx) { 3100 mutex_unlock(&fs_info->scrub_lock); 3101 return -ENOTCONN; 3102 } 3103 atomic_inc(&sctx->cancel_req); 3104 while (dev->scrub_device) { 3105 mutex_unlock(&fs_info->scrub_lock); 3106 wait_event(fs_info->scrub_pause_wait, 3107 dev->scrub_device == NULL); 3108 mutex_lock(&fs_info->scrub_lock); 3109 } 3110 mutex_unlock(&fs_info->scrub_lock); 3111 3112 return 0; 3113 } 3114 3115 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid, 3116 struct btrfs_scrub_progress *progress) 3117 { 3118 struct btrfs_device *dev; 3119 struct scrub_ctx *sctx = NULL; 3120 3121 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 3122 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL); 3123 if (dev) 3124 sctx = dev->scrub_device; 3125 if (sctx) 3126 memcpy(progress, &sctx->stat, sizeof(*progress)); 3127 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 3128 3129 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV; 3130 } 3131 3132 static void scrub_remap_extent(struct btrfs_fs_info *fs_info, 3133 u64 extent_logical, u64 extent_len, 3134 u64 *extent_physical, 3135 struct btrfs_device **extent_dev, 3136 int *extent_mirror_num) 3137 { 3138 u64 mapped_length; 3139 struct btrfs_bio *bbio = NULL; 3140 int ret; 3141 3142 mapped_length = extent_len; 3143 ret = btrfs_map_block(fs_info, READ, extent_logical, 3144 &mapped_length, &bbio, 0); 3145 if (ret || !bbio || mapped_length < extent_len || 3146 !bbio->stripes[0].dev->bdev) { 3147 kfree(bbio); 3148 return; 3149 } 3150 3151 *extent_physical = bbio->stripes[0].physical; 3152 *extent_mirror_num = bbio->mirror_num; 3153 *extent_dev = bbio->stripes[0].dev; 3154 kfree(bbio); 3155 } 3156 3157 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx, 3158 struct scrub_wr_ctx *wr_ctx, 3159 struct btrfs_fs_info *fs_info, 3160 struct btrfs_device *dev, 3161 int is_dev_replace) 3162 { 3163 WARN_ON(wr_ctx->wr_curr_bio != NULL); 3164 3165 mutex_init(&wr_ctx->wr_lock); 3166 wr_ctx->wr_curr_bio = NULL; 3167 if (!is_dev_replace) 3168 return 0; 3169 3170 WARN_ON(!dev->bdev); 3171 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO, 3172 bio_get_nr_vecs(dev->bdev)); 3173 wr_ctx->tgtdev = dev; 3174 atomic_set(&wr_ctx->flush_all_writes, 0); 3175 return 0; 3176 } 3177 3178 static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx) 3179 { 3180 mutex_lock(&wr_ctx->wr_lock); 3181 kfree(wr_ctx->wr_curr_bio); 3182 wr_ctx->wr_curr_bio = NULL; 3183 mutex_unlock(&wr_ctx->wr_lock); 3184 } 3185 3186 static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len, 3187 int mirror_num, u64 physical_for_dev_replace) 3188 { 3189 struct scrub_copy_nocow_ctx *nocow_ctx; 3190 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; 3191 3192 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS); 3193 if (!nocow_ctx) { 3194 spin_lock(&sctx->stat_lock); 3195 sctx->stat.malloc_errors++; 3196 spin_unlock(&sctx->stat_lock); 3197 return -ENOMEM; 3198 } 3199 3200 scrub_pending_trans_workers_inc(sctx); 3201 3202 nocow_ctx->sctx = sctx; 3203 nocow_ctx->logical = logical; 3204 nocow_ctx->len = len; 3205 nocow_ctx->mirror_num = mirror_num; 3206 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace; 3207 btrfs_init_work(&nocow_ctx->work, copy_nocow_pages_worker, NULL, NULL); 3208 INIT_LIST_HEAD(&nocow_ctx->inodes); 3209 btrfs_queue_work(fs_info->scrub_nocow_workers, 3210 &nocow_ctx->work); 3211 3212 return 0; 3213 } 3214 3215 static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx) 3216 { 3217 struct scrub_copy_nocow_ctx *nocow_ctx = ctx; 3218 struct scrub_nocow_inode *nocow_inode; 3219 3220 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS); 3221 if (!nocow_inode) 3222 return -ENOMEM; 3223 nocow_inode->inum = inum; 3224 nocow_inode->offset = offset; 3225 nocow_inode->root = root; 3226 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes); 3227 return 0; 3228 } 3229 3230 #define COPY_COMPLETE 1 3231 3232 static void copy_nocow_pages_worker(struct btrfs_work *work) 3233 { 3234 struct scrub_copy_nocow_ctx *nocow_ctx = 3235 container_of(work, struct scrub_copy_nocow_ctx, work); 3236 struct scrub_ctx *sctx = nocow_ctx->sctx; 3237 u64 logical = nocow_ctx->logical; 3238 u64 len = nocow_ctx->len; 3239 int mirror_num = nocow_ctx->mirror_num; 3240 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace; 3241 int ret; 3242 struct btrfs_trans_handle *trans = NULL; 3243 struct btrfs_fs_info *fs_info; 3244 struct btrfs_path *path; 3245 struct btrfs_root *root; 3246 int not_written = 0; 3247 3248 fs_info = sctx->dev_root->fs_info; 3249 root = fs_info->extent_root; 3250 3251 path = btrfs_alloc_path(); 3252 if (!path) { 3253 spin_lock(&sctx->stat_lock); 3254 sctx->stat.malloc_errors++; 3255 spin_unlock(&sctx->stat_lock); 3256 not_written = 1; 3257 goto out; 3258 } 3259 3260 trans = btrfs_join_transaction(root); 3261 if (IS_ERR(trans)) { 3262 not_written = 1; 3263 goto out; 3264 } 3265 3266 ret = iterate_inodes_from_logical(logical, fs_info, path, 3267 record_inode_for_nocow, nocow_ctx); 3268 if (ret != 0 && ret != -ENOENT) { 3269 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, " 3270 "phys %llu, len %llu, mir %u, ret %d", 3271 logical, physical_for_dev_replace, len, mirror_num, 3272 ret); 3273 not_written = 1; 3274 goto out; 3275 } 3276 3277 btrfs_end_transaction(trans, root); 3278 trans = NULL; 3279 while (!list_empty(&nocow_ctx->inodes)) { 3280 struct scrub_nocow_inode *entry; 3281 entry = list_first_entry(&nocow_ctx->inodes, 3282 struct scrub_nocow_inode, 3283 list); 3284 list_del_init(&entry->list); 3285 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset, 3286 entry->root, nocow_ctx); 3287 kfree(entry); 3288 if (ret == COPY_COMPLETE) { 3289 ret = 0; 3290 break; 3291 } else if (ret) { 3292 break; 3293 } 3294 } 3295 out: 3296 while (!list_empty(&nocow_ctx->inodes)) { 3297 struct scrub_nocow_inode *entry; 3298 entry = list_first_entry(&nocow_ctx->inodes, 3299 struct scrub_nocow_inode, 3300 list); 3301 list_del_init(&entry->list); 3302 kfree(entry); 3303 } 3304 if (trans && !IS_ERR(trans)) 3305 btrfs_end_transaction(trans, root); 3306 if (not_written) 3307 btrfs_dev_replace_stats_inc(&fs_info->dev_replace. 3308 num_uncorrectable_read_errors); 3309 3310 btrfs_free_path(path); 3311 kfree(nocow_ctx); 3312 3313 scrub_pending_trans_workers_dec(sctx); 3314 } 3315 3316 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root, 3317 struct scrub_copy_nocow_ctx *nocow_ctx) 3318 { 3319 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info; 3320 struct btrfs_key key; 3321 struct inode *inode; 3322 struct page *page; 3323 struct btrfs_root *local_root; 3324 struct btrfs_ordered_extent *ordered; 3325 struct extent_map *em; 3326 struct extent_state *cached_state = NULL; 3327 struct extent_io_tree *io_tree; 3328 u64 physical_for_dev_replace; 3329 u64 len = nocow_ctx->len; 3330 u64 lockstart = offset, lockend = offset + len - 1; 3331 unsigned long index; 3332 int srcu_index; 3333 int ret = 0; 3334 int err = 0; 3335 3336 key.objectid = root; 3337 key.type = BTRFS_ROOT_ITEM_KEY; 3338 key.offset = (u64)-1; 3339 3340 srcu_index = srcu_read_lock(&fs_info->subvol_srcu); 3341 3342 local_root = btrfs_read_fs_root_no_name(fs_info, &key); 3343 if (IS_ERR(local_root)) { 3344 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 3345 return PTR_ERR(local_root); 3346 } 3347 3348 key.type = BTRFS_INODE_ITEM_KEY; 3349 key.objectid = inum; 3350 key.offset = 0; 3351 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL); 3352 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index); 3353 if (IS_ERR(inode)) 3354 return PTR_ERR(inode); 3355 3356 /* Avoid truncate/dio/punch hole.. */ 3357 mutex_lock(&inode->i_mutex); 3358 inode_dio_wait(inode); 3359 3360 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace; 3361 io_tree = &BTRFS_I(inode)->io_tree; 3362 3363 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state); 3364 ordered = btrfs_lookup_ordered_range(inode, lockstart, len); 3365 if (ordered) { 3366 btrfs_put_ordered_extent(ordered); 3367 goto out_unlock; 3368 } 3369 3370 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0); 3371 if (IS_ERR(em)) { 3372 ret = PTR_ERR(em); 3373 goto out_unlock; 3374 } 3375 3376 /* 3377 * This extent does not actually cover the logical extent anymore, 3378 * move on to the next inode. 3379 */ 3380 if (em->block_start > nocow_ctx->logical || 3381 em->block_start + em->block_len < nocow_ctx->logical + len) { 3382 free_extent_map(em); 3383 goto out_unlock; 3384 } 3385 free_extent_map(em); 3386 3387 while (len >= PAGE_CACHE_SIZE) { 3388 index = offset >> PAGE_CACHE_SHIFT; 3389 again: 3390 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 3391 if (!page) { 3392 btrfs_err(fs_info, "find_or_create_page() failed"); 3393 ret = -ENOMEM; 3394 goto out; 3395 } 3396 3397 if (PageUptodate(page)) { 3398 if (PageDirty(page)) 3399 goto next_page; 3400 } else { 3401 ClearPageError(page); 3402 err = extent_read_full_page_nolock(io_tree, page, 3403 btrfs_get_extent, 3404 nocow_ctx->mirror_num); 3405 if (err) { 3406 ret = err; 3407 goto next_page; 3408 } 3409 3410 lock_page(page); 3411 /* 3412 * If the page has been remove from the page cache, 3413 * the data on it is meaningless, because it may be 3414 * old one, the new data may be written into the new 3415 * page in the page cache. 3416 */ 3417 if (page->mapping != inode->i_mapping) { 3418 unlock_page(page); 3419 page_cache_release(page); 3420 goto again; 3421 } 3422 if (!PageUptodate(page)) { 3423 ret = -EIO; 3424 goto next_page; 3425 } 3426 } 3427 err = write_page_nocow(nocow_ctx->sctx, 3428 physical_for_dev_replace, page); 3429 if (err) 3430 ret = err; 3431 next_page: 3432 unlock_page(page); 3433 page_cache_release(page); 3434 3435 if (ret) 3436 break; 3437 3438 offset += PAGE_CACHE_SIZE; 3439 physical_for_dev_replace += PAGE_CACHE_SIZE; 3440 len -= PAGE_CACHE_SIZE; 3441 } 3442 ret = COPY_COMPLETE; 3443 out_unlock: 3444 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state, 3445 GFP_NOFS); 3446 out: 3447 mutex_unlock(&inode->i_mutex); 3448 iput(inode); 3449 return ret; 3450 } 3451 3452 static int write_page_nocow(struct scrub_ctx *sctx, 3453 u64 physical_for_dev_replace, struct page *page) 3454 { 3455 struct bio *bio; 3456 struct btrfs_device *dev; 3457 int ret; 3458 3459 dev = sctx->wr_ctx.tgtdev; 3460 if (!dev) 3461 return -EIO; 3462 if (!dev->bdev) { 3463 printk_ratelimited(KERN_WARNING 3464 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n"); 3465 return -EIO; 3466 } 3467 bio = btrfs_io_bio_alloc(GFP_NOFS, 1); 3468 if (!bio) { 3469 spin_lock(&sctx->stat_lock); 3470 sctx->stat.malloc_errors++; 3471 spin_unlock(&sctx->stat_lock); 3472 return -ENOMEM; 3473 } 3474 bio->bi_iter.bi_size = 0; 3475 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9; 3476 bio->bi_bdev = dev->bdev; 3477 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0); 3478 if (ret != PAGE_CACHE_SIZE) { 3479 leave_with_eio: 3480 bio_put(bio); 3481 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS); 3482 return -EIO; 3483 } 3484 3485 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio)) 3486 goto leave_with_eio; 3487 3488 bio_put(bio); 3489 return 0; 3490 } 3491