1 /* 2 * Copyright (C) 2011 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 29 /* 30 * This is only the first step towards a full-features scrub. It reads all 31 * extent and super block and verifies the checksums. In case a bad checksum 32 * is found or the extent cannot be read, good data will be written back if 33 * any can be found. 34 * 35 * Future enhancements: 36 * - In case an unrepairable extent is encountered, track which files are 37 * affected and report them 38 * - In case of a read error on files with nodatasum, map the file and read 39 * the extent to trigger a writeback of the good copy 40 * - track and record media errors, throw out bad devices 41 * - add a mode to also read unallocated space 42 */ 43 44 struct scrub_bio; 45 struct scrub_page; 46 struct scrub_dev; 47 static void scrub_bio_end_io(struct bio *bio, int err); 48 static void scrub_checksum(struct btrfs_work *work); 49 static int scrub_checksum_data(struct scrub_dev *sdev, 50 struct scrub_page *spag, void *buffer); 51 static int scrub_checksum_tree_block(struct scrub_dev *sdev, 52 struct scrub_page *spag, u64 logical, 53 void *buffer); 54 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer); 55 static int scrub_fixup_check(struct scrub_bio *sbio, int ix); 56 static void scrub_fixup_end_io(struct bio *bio, int err); 57 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector, 58 struct page *page); 59 static void scrub_fixup(struct scrub_bio *sbio, int ix); 60 61 #define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */ 62 #define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */ 63 64 struct scrub_page { 65 u64 flags; /* extent flags */ 66 u64 generation; 67 int mirror_num; 68 int have_csum; 69 u8 csum[BTRFS_CSUM_SIZE]; 70 }; 71 72 struct scrub_bio { 73 int index; 74 struct scrub_dev *sdev; 75 struct bio *bio; 76 int err; 77 u64 logical; 78 u64 physical; 79 struct scrub_page spag[SCRUB_PAGES_PER_BIO]; 80 u64 count; 81 int next_free; 82 struct btrfs_work work; 83 }; 84 85 struct scrub_dev { 86 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV]; 87 struct btrfs_device *dev; 88 int first_free; 89 int curr; 90 atomic_t in_flight; 91 atomic_t fixup_cnt; 92 spinlock_t list_lock; 93 wait_queue_head_t list_wait; 94 u16 csum_size; 95 struct list_head csum_list; 96 atomic_t cancel_req; 97 int readonly; 98 /* 99 * statistics 100 */ 101 struct btrfs_scrub_progress stat; 102 spinlock_t stat_lock; 103 }; 104 105 struct scrub_fixup_nodatasum { 106 struct scrub_dev *sdev; 107 u64 logical; 108 struct btrfs_root *root; 109 struct btrfs_work work; 110 int mirror_num; 111 }; 112 113 struct scrub_warning { 114 struct btrfs_path *path; 115 u64 extent_item_size; 116 char *scratch_buf; 117 char *msg_buf; 118 const char *errstr; 119 sector_t sector; 120 u64 logical; 121 struct btrfs_device *dev; 122 int msg_bufsize; 123 int scratch_bufsize; 124 }; 125 126 static void scrub_free_csums(struct scrub_dev *sdev) 127 { 128 while (!list_empty(&sdev->csum_list)) { 129 struct btrfs_ordered_sum *sum; 130 sum = list_first_entry(&sdev->csum_list, 131 struct btrfs_ordered_sum, list); 132 list_del(&sum->list); 133 kfree(sum); 134 } 135 } 136 137 static void scrub_free_bio(struct bio *bio) 138 { 139 int i; 140 struct page *last_page = NULL; 141 142 if (!bio) 143 return; 144 145 for (i = 0; i < bio->bi_vcnt; ++i) { 146 if (bio->bi_io_vec[i].bv_page == last_page) 147 continue; 148 last_page = bio->bi_io_vec[i].bv_page; 149 __free_page(last_page); 150 } 151 bio_put(bio); 152 } 153 154 static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev) 155 { 156 int i; 157 158 if (!sdev) 159 return; 160 161 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) { 162 struct scrub_bio *sbio = sdev->bios[i]; 163 164 if (!sbio) 165 break; 166 167 scrub_free_bio(sbio->bio); 168 kfree(sbio); 169 } 170 171 scrub_free_csums(sdev); 172 kfree(sdev); 173 } 174 175 static noinline_for_stack 176 struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev) 177 { 178 struct scrub_dev *sdev; 179 int i; 180 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info; 181 182 sdev = kzalloc(sizeof(*sdev), GFP_NOFS); 183 if (!sdev) 184 goto nomem; 185 sdev->dev = dev; 186 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) { 187 struct scrub_bio *sbio; 188 189 sbio = kzalloc(sizeof(*sbio), GFP_NOFS); 190 if (!sbio) 191 goto nomem; 192 sdev->bios[i] = sbio; 193 194 sbio->index = i; 195 sbio->sdev = sdev; 196 sbio->count = 0; 197 sbio->work.func = scrub_checksum; 198 199 if (i != SCRUB_BIOS_PER_DEV-1) 200 sdev->bios[i]->next_free = i + 1; 201 else 202 sdev->bios[i]->next_free = -1; 203 } 204 sdev->first_free = 0; 205 sdev->curr = -1; 206 atomic_set(&sdev->in_flight, 0); 207 atomic_set(&sdev->fixup_cnt, 0); 208 atomic_set(&sdev->cancel_req, 0); 209 sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy); 210 INIT_LIST_HEAD(&sdev->csum_list); 211 212 spin_lock_init(&sdev->list_lock); 213 spin_lock_init(&sdev->stat_lock); 214 init_waitqueue_head(&sdev->list_wait); 215 return sdev; 216 217 nomem: 218 scrub_free_dev(sdev); 219 return ERR_PTR(-ENOMEM); 220 } 221 222 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx) 223 { 224 u64 isize; 225 u32 nlink; 226 int ret; 227 int i; 228 struct extent_buffer *eb; 229 struct btrfs_inode_item *inode_item; 230 struct scrub_warning *swarn = ctx; 231 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info; 232 struct inode_fs_paths *ipath = NULL; 233 struct btrfs_root *local_root; 234 struct btrfs_key root_key; 235 236 root_key.objectid = root; 237 root_key.type = BTRFS_ROOT_ITEM_KEY; 238 root_key.offset = (u64)-1; 239 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key); 240 if (IS_ERR(local_root)) { 241 ret = PTR_ERR(local_root); 242 goto err; 243 } 244 245 ret = inode_item_info(inum, 0, local_root, swarn->path); 246 if (ret) { 247 btrfs_release_path(swarn->path); 248 goto err; 249 } 250 251 eb = swarn->path->nodes[0]; 252 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0], 253 struct btrfs_inode_item); 254 isize = btrfs_inode_size(eb, inode_item); 255 nlink = btrfs_inode_nlink(eb, inode_item); 256 btrfs_release_path(swarn->path); 257 258 ipath = init_ipath(4096, local_root, swarn->path); 259 ret = paths_from_inode(inum, ipath); 260 261 if (ret < 0) 262 goto err; 263 264 /* 265 * we deliberately ignore the bit ipath might have been too small to 266 * hold all of the paths here 267 */ 268 for (i = 0; i < ipath->fspath->elem_cnt; ++i) 269 printk(KERN_WARNING "btrfs: %s at logical %llu on dev " 270 "%s, sector %llu, root %llu, inode %llu, offset %llu, " 271 "length %llu, links %u (path: %s)\n", swarn->errstr, 272 swarn->logical, swarn->dev->name, 273 (unsigned long long)swarn->sector, root, inum, offset, 274 min(isize - offset, (u64)PAGE_SIZE), nlink, 275 (char *)ipath->fspath->val[i]); 276 277 free_ipath(ipath); 278 return 0; 279 280 err: 281 printk(KERN_WARNING "btrfs: %s at logical %llu on dev " 282 "%s, sector %llu, root %llu, inode %llu, offset %llu: path " 283 "resolving failed with ret=%d\n", swarn->errstr, 284 swarn->logical, swarn->dev->name, 285 (unsigned long long)swarn->sector, root, inum, offset, ret); 286 287 free_ipath(ipath); 288 return 0; 289 } 290 291 static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio, 292 int ix) 293 { 294 struct btrfs_device *dev = sbio->sdev->dev; 295 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info; 296 struct btrfs_path *path; 297 struct btrfs_key found_key; 298 struct extent_buffer *eb; 299 struct btrfs_extent_item *ei; 300 struct scrub_warning swarn; 301 u32 item_size; 302 int ret; 303 u64 ref_root; 304 u8 ref_level; 305 unsigned long ptr = 0; 306 const int bufsize = 4096; 307 u64 extent_offset; 308 309 path = btrfs_alloc_path(); 310 311 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS); 312 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS); 313 swarn.sector = (sbio->physical + ix * PAGE_SIZE) >> 9; 314 swarn.logical = sbio->logical + ix * PAGE_SIZE; 315 swarn.errstr = errstr; 316 swarn.dev = dev; 317 swarn.msg_bufsize = bufsize; 318 swarn.scratch_bufsize = bufsize; 319 320 if (!path || !swarn.scratch_buf || !swarn.msg_buf) 321 goto out; 322 323 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key); 324 if (ret < 0) 325 goto out; 326 327 extent_offset = swarn.logical - found_key.objectid; 328 swarn.extent_item_size = found_key.offset; 329 330 eb = path->nodes[0]; 331 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); 332 item_size = btrfs_item_size_nr(eb, path->slots[0]); 333 334 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 335 do { 336 ret = tree_backref_for_extent(&ptr, eb, ei, item_size, 337 &ref_root, &ref_level); 338 printk(KERN_WARNING "%s at logical %llu on dev %s, " 339 "sector %llu: metadata %s (level %d) in tree " 340 "%llu\n", errstr, swarn.logical, dev->name, 341 (unsigned long long)swarn.sector, 342 ref_level ? "node" : "leaf", 343 ret < 0 ? -1 : ref_level, 344 ret < 0 ? -1 : ref_root); 345 } while (ret != 1); 346 } else { 347 swarn.path = path; 348 iterate_extent_inodes(fs_info, path, found_key.objectid, 349 extent_offset, 350 scrub_print_warning_inode, &swarn); 351 } 352 353 out: 354 btrfs_free_path(path); 355 kfree(swarn.scratch_buf); 356 kfree(swarn.msg_buf); 357 } 358 359 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx) 360 { 361 struct page *page = NULL; 362 unsigned long index; 363 struct scrub_fixup_nodatasum *fixup = ctx; 364 int ret; 365 int corrected = 0; 366 struct btrfs_key key; 367 struct inode *inode = NULL; 368 u64 end = offset + PAGE_SIZE - 1; 369 struct btrfs_root *local_root; 370 371 key.objectid = root; 372 key.type = BTRFS_ROOT_ITEM_KEY; 373 key.offset = (u64)-1; 374 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key); 375 if (IS_ERR(local_root)) 376 return PTR_ERR(local_root); 377 378 key.type = BTRFS_INODE_ITEM_KEY; 379 key.objectid = inum; 380 key.offset = 0; 381 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL); 382 if (IS_ERR(inode)) 383 return PTR_ERR(inode); 384 385 index = offset >> PAGE_CACHE_SHIFT; 386 387 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); 388 if (!page) { 389 ret = -ENOMEM; 390 goto out; 391 } 392 393 if (PageUptodate(page)) { 394 struct btrfs_mapping_tree *map_tree; 395 if (PageDirty(page)) { 396 /* 397 * we need to write the data to the defect sector. the 398 * data that was in that sector is not in memory, 399 * because the page was modified. we must not write the 400 * modified page to that sector. 401 * 402 * TODO: what could be done here: wait for the delalloc 403 * runner to write out that page (might involve 404 * COW) and see whether the sector is still 405 * referenced afterwards. 406 * 407 * For the meantime, we'll treat this error 408 * incorrectable, although there is a chance that a 409 * later scrub will find the bad sector again and that 410 * there's no dirty page in memory, then. 411 */ 412 ret = -EIO; 413 goto out; 414 } 415 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree; 416 ret = repair_io_failure(map_tree, offset, PAGE_SIZE, 417 fixup->logical, page, 418 fixup->mirror_num); 419 unlock_page(page); 420 corrected = !ret; 421 } else { 422 /* 423 * we need to get good data first. the general readpage path 424 * will call repair_io_failure for us, we just have to make 425 * sure we read the bad mirror. 426 */ 427 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 428 EXTENT_DAMAGED, GFP_NOFS); 429 if (ret) { 430 /* set_extent_bits should give proper error */ 431 WARN_ON(ret > 0); 432 if (ret > 0) 433 ret = -EFAULT; 434 goto out; 435 } 436 437 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page, 438 btrfs_get_extent, 439 fixup->mirror_num); 440 wait_on_page_locked(page); 441 442 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset, 443 end, EXTENT_DAMAGED, 0, NULL); 444 if (!corrected) 445 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end, 446 EXTENT_DAMAGED, GFP_NOFS); 447 } 448 449 out: 450 if (page) 451 put_page(page); 452 if (inode) 453 iput(inode); 454 455 if (ret < 0) 456 return ret; 457 458 if (ret == 0 && corrected) { 459 /* 460 * we only need to call readpage for one of the inodes belonging 461 * to this extent. so make iterate_extent_inodes stop 462 */ 463 return 1; 464 } 465 466 return -EIO; 467 } 468 469 static void scrub_fixup_nodatasum(struct btrfs_work *work) 470 { 471 int ret; 472 struct scrub_fixup_nodatasum *fixup; 473 struct scrub_dev *sdev; 474 struct btrfs_trans_handle *trans = NULL; 475 struct btrfs_fs_info *fs_info; 476 struct btrfs_path *path; 477 int uncorrectable = 0; 478 479 fixup = container_of(work, struct scrub_fixup_nodatasum, work); 480 sdev = fixup->sdev; 481 fs_info = fixup->root->fs_info; 482 483 path = btrfs_alloc_path(); 484 if (!path) { 485 spin_lock(&sdev->stat_lock); 486 ++sdev->stat.malloc_errors; 487 spin_unlock(&sdev->stat_lock); 488 uncorrectable = 1; 489 goto out; 490 } 491 492 trans = btrfs_join_transaction(fixup->root); 493 if (IS_ERR(trans)) { 494 uncorrectable = 1; 495 goto out; 496 } 497 498 /* 499 * the idea is to trigger a regular read through the standard path. we 500 * read a page from the (failed) logical address by specifying the 501 * corresponding copynum of the failed sector. thus, that readpage is 502 * expected to fail. 503 * that is the point where on-the-fly error correction will kick in 504 * (once it's finished) and rewrite the failed sector if a good copy 505 * can be found. 506 */ 507 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info, 508 path, scrub_fixup_readpage, 509 fixup); 510 if (ret < 0) { 511 uncorrectable = 1; 512 goto out; 513 } 514 WARN_ON(ret != 1); 515 516 spin_lock(&sdev->stat_lock); 517 ++sdev->stat.corrected_errors; 518 spin_unlock(&sdev->stat_lock); 519 520 out: 521 if (trans && !IS_ERR(trans)) 522 btrfs_end_transaction(trans, fixup->root); 523 if (uncorrectable) { 524 spin_lock(&sdev->stat_lock); 525 ++sdev->stat.uncorrectable_errors; 526 spin_unlock(&sdev->stat_lock); 527 printk_ratelimited(KERN_ERR "btrfs: unable to fixup " 528 "(nodatasum) error at logical %llu\n", 529 fixup->logical); 530 } 531 532 btrfs_free_path(path); 533 kfree(fixup); 534 535 /* see caller why we're pretending to be paused in the scrub counters */ 536 mutex_lock(&fs_info->scrub_lock); 537 atomic_dec(&fs_info->scrubs_running); 538 atomic_dec(&fs_info->scrubs_paused); 539 mutex_unlock(&fs_info->scrub_lock); 540 atomic_dec(&sdev->fixup_cnt); 541 wake_up(&fs_info->scrub_pause_wait); 542 wake_up(&sdev->list_wait); 543 } 544 545 /* 546 * scrub_recheck_error gets called when either verification of the page 547 * failed or the bio failed to read, e.g. with EIO. In the latter case, 548 * recheck_error gets called for every page in the bio, even though only 549 * one may be bad 550 */ 551 static int scrub_recheck_error(struct scrub_bio *sbio, int ix) 552 { 553 struct scrub_dev *sdev = sbio->sdev; 554 u64 sector = (sbio->physical + ix * PAGE_SIZE) >> 9; 555 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 556 DEFAULT_RATELIMIT_BURST); 557 558 if (sbio->err) { 559 if (scrub_fixup_io(READ, sbio->sdev->dev->bdev, sector, 560 sbio->bio->bi_io_vec[ix].bv_page) == 0) { 561 if (scrub_fixup_check(sbio, ix) == 0) 562 return 0; 563 } 564 if (__ratelimit(&_rs)) 565 scrub_print_warning("i/o error", sbio, ix); 566 } else { 567 if (__ratelimit(&_rs)) 568 scrub_print_warning("checksum error", sbio, ix); 569 } 570 571 spin_lock(&sdev->stat_lock); 572 ++sdev->stat.read_errors; 573 spin_unlock(&sdev->stat_lock); 574 575 scrub_fixup(sbio, ix); 576 return 1; 577 } 578 579 static int scrub_fixup_check(struct scrub_bio *sbio, int ix) 580 { 581 int ret = 1; 582 struct page *page; 583 void *buffer; 584 u64 flags = sbio->spag[ix].flags; 585 586 page = sbio->bio->bi_io_vec[ix].bv_page; 587 buffer = kmap_atomic(page, KM_USER0); 588 if (flags & BTRFS_EXTENT_FLAG_DATA) { 589 ret = scrub_checksum_data(sbio->sdev, 590 sbio->spag + ix, buffer); 591 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 592 ret = scrub_checksum_tree_block(sbio->sdev, 593 sbio->spag + ix, 594 sbio->logical + ix * PAGE_SIZE, 595 buffer); 596 } else { 597 WARN_ON(1); 598 } 599 kunmap_atomic(buffer, KM_USER0); 600 601 return ret; 602 } 603 604 static void scrub_fixup_end_io(struct bio *bio, int err) 605 { 606 complete((struct completion *)bio->bi_private); 607 } 608 609 static void scrub_fixup(struct scrub_bio *sbio, int ix) 610 { 611 struct scrub_dev *sdev = sbio->sdev; 612 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info; 613 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; 614 struct btrfs_bio *bbio = NULL; 615 struct scrub_fixup_nodatasum *fixup; 616 u64 logical = sbio->logical + ix * PAGE_SIZE; 617 u64 length; 618 int i; 619 int ret; 620 DECLARE_COMPLETION_ONSTACK(complete); 621 622 if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) && 623 (sbio->spag[ix].have_csum == 0)) { 624 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 625 if (!fixup) 626 goto uncorrectable; 627 fixup->sdev = sdev; 628 fixup->logical = logical; 629 fixup->root = fs_info->extent_root; 630 fixup->mirror_num = sbio->spag[ix].mirror_num; 631 /* 632 * increment scrubs_running to prevent cancel requests from 633 * completing as long as a fixup worker is running. we must also 634 * increment scrubs_paused to prevent deadlocking on pause 635 * requests used for transactions commits (as the worker uses a 636 * transaction context). it is safe to regard the fixup worker 637 * as paused for all matters practical. effectively, we only 638 * avoid cancellation requests from completing. 639 */ 640 mutex_lock(&fs_info->scrub_lock); 641 atomic_inc(&fs_info->scrubs_running); 642 atomic_inc(&fs_info->scrubs_paused); 643 mutex_unlock(&fs_info->scrub_lock); 644 atomic_inc(&sdev->fixup_cnt); 645 fixup->work.func = scrub_fixup_nodatasum; 646 btrfs_queue_worker(&fs_info->scrub_workers, &fixup->work); 647 return; 648 } 649 650 length = PAGE_SIZE; 651 ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length, 652 &bbio, 0); 653 if (ret || !bbio || length < PAGE_SIZE) { 654 printk(KERN_ERR 655 "scrub_fixup: btrfs_map_block failed us for %llu\n", 656 (unsigned long long)logical); 657 WARN_ON(1); 658 kfree(bbio); 659 return; 660 } 661 662 if (bbio->num_stripes == 1) 663 /* there aren't any replicas */ 664 goto uncorrectable; 665 666 /* 667 * first find a good copy 668 */ 669 for (i = 0; i < bbio->num_stripes; ++i) { 670 if (i + 1 == sbio->spag[ix].mirror_num) 671 continue; 672 673 if (scrub_fixup_io(READ, bbio->stripes[i].dev->bdev, 674 bbio->stripes[i].physical >> 9, 675 sbio->bio->bi_io_vec[ix].bv_page)) { 676 /* I/O-error, this is not a good copy */ 677 continue; 678 } 679 680 if (scrub_fixup_check(sbio, ix) == 0) 681 break; 682 } 683 if (i == bbio->num_stripes) 684 goto uncorrectable; 685 686 if (!sdev->readonly) { 687 /* 688 * bi_io_vec[ix].bv_page now contains good data, write it back 689 */ 690 if (scrub_fixup_io(WRITE, sdev->dev->bdev, 691 (sbio->physical + ix * PAGE_SIZE) >> 9, 692 sbio->bio->bi_io_vec[ix].bv_page)) { 693 /* I/O-error, writeback failed, give up */ 694 goto uncorrectable; 695 } 696 } 697 698 kfree(bbio); 699 spin_lock(&sdev->stat_lock); 700 ++sdev->stat.corrected_errors; 701 spin_unlock(&sdev->stat_lock); 702 703 printk_ratelimited(KERN_ERR "btrfs: fixed up error at logical %llu\n", 704 (unsigned long long)logical); 705 return; 706 707 uncorrectable: 708 kfree(bbio); 709 spin_lock(&sdev->stat_lock); 710 ++sdev->stat.uncorrectable_errors; 711 spin_unlock(&sdev->stat_lock); 712 713 printk_ratelimited(KERN_ERR "btrfs: unable to fixup (regular) error at " 714 "logical %llu\n", (unsigned long long)logical); 715 } 716 717 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector, 718 struct page *page) 719 { 720 struct bio *bio = NULL; 721 int ret; 722 DECLARE_COMPLETION_ONSTACK(complete); 723 724 bio = bio_alloc(GFP_NOFS, 1); 725 bio->bi_bdev = bdev; 726 bio->bi_sector = sector; 727 bio_add_page(bio, page, PAGE_SIZE, 0); 728 bio->bi_end_io = scrub_fixup_end_io; 729 bio->bi_private = &complete; 730 submit_bio(rw, bio); 731 732 /* this will also unplug the queue */ 733 wait_for_completion(&complete); 734 735 ret = !test_bit(BIO_UPTODATE, &bio->bi_flags); 736 bio_put(bio); 737 return ret; 738 } 739 740 static void scrub_bio_end_io(struct bio *bio, int err) 741 { 742 struct scrub_bio *sbio = bio->bi_private; 743 struct scrub_dev *sdev = sbio->sdev; 744 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info; 745 746 sbio->err = err; 747 sbio->bio = bio; 748 749 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work); 750 } 751 752 static void scrub_checksum(struct btrfs_work *work) 753 { 754 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work); 755 struct scrub_dev *sdev = sbio->sdev; 756 struct page *page; 757 void *buffer; 758 int i; 759 u64 flags; 760 u64 logical; 761 int ret; 762 763 if (sbio->err) { 764 ret = 0; 765 for (i = 0; i < sbio->count; ++i) 766 ret |= scrub_recheck_error(sbio, i); 767 if (!ret) { 768 spin_lock(&sdev->stat_lock); 769 ++sdev->stat.unverified_errors; 770 spin_unlock(&sdev->stat_lock); 771 } 772 773 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1); 774 sbio->bio->bi_flags |= 1 << BIO_UPTODATE; 775 sbio->bio->bi_phys_segments = 0; 776 sbio->bio->bi_idx = 0; 777 778 for (i = 0; i < sbio->count; i++) { 779 struct bio_vec *bi; 780 bi = &sbio->bio->bi_io_vec[i]; 781 bi->bv_offset = 0; 782 bi->bv_len = PAGE_SIZE; 783 } 784 goto out; 785 } 786 for (i = 0; i < sbio->count; ++i) { 787 page = sbio->bio->bi_io_vec[i].bv_page; 788 buffer = kmap_atomic(page, KM_USER0); 789 flags = sbio->spag[i].flags; 790 logical = sbio->logical + i * PAGE_SIZE; 791 ret = 0; 792 if (flags & BTRFS_EXTENT_FLAG_DATA) { 793 ret = scrub_checksum_data(sdev, sbio->spag + i, buffer); 794 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 795 ret = scrub_checksum_tree_block(sdev, sbio->spag + i, 796 logical, buffer); 797 } else if (flags & BTRFS_EXTENT_FLAG_SUPER) { 798 BUG_ON(i); 799 (void)scrub_checksum_super(sbio, buffer); 800 } else { 801 WARN_ON(1); 802 } 803 kunmap_atomic(buffer, KM_USER0); 804 if (ret) { 805 ret = scrub_recheck_error(sbio, i); 806 if (!ret) { 807 spin_lock(&sdev->stat_lock); 808 ++sdev->stat.unverified_errors; 809 spin_unlock(&sdev->stat_lock); 810 } 811 } 812 } 813 814 out: 815 scrub_free_bio(sbio->bio); 816 sbio->bio = NULL; 817 spin_lock(&sdev->list_lock); 818 sbio->next_free = sdev->first_free; 819 sdev->first_free = sbio->index; 820 spin_unlock(&sdev->list_lock); 821 atomic_dec(&sdev->in_flight); 822 wake_up(&sdev->list_wait); 823 } 824 825 static int scrub_checksum_data(struct scrub_dev *sdev, 826 struct scrub_page *spag, void *buffer) 827 { 828 u8 csum[BTRFS_CSUM_SIZE]; 829 u32 crc = ~(u32)0; 830 int fail = 0; 831 struct btrfs_root *root = sdev->dev->dev_root; 832 833 if (!spag->have_csum) 834 return 0; 835 836 crc = btrfs_csum_data(root, buffer, crc, PAGE_SIZE); 837 btrfs_csum_final(crc, csum); 838 if (memcmp(csum, spag->csum, sdev->csum_size)) 839 fail = 1; 840 841 spin_lock(&sdev->stat_lock); 842 ++sdev->stat.data_extents_scrubbed; 843 sdev->stat.data_bytes_scrubbed += PAGE_SIZE; 844 if (fail) 845 ++sdev->stat.csum_errors; 846 spin_unlock(&sdev->stat_lock); 847 848 return fail; 849 } 850 851 static int scrub_checksum_tree_block(struct scrub_dev *sdev, 852 struct scrub_page *spag, u64 logical, 853 void *buffer) 854 { 855 struct btrfs_header *h; 856 struct btrfs_root *root = sdev->dev->dev_root; 857 struct btrfs_fs_info *fs_info = root->fs_info; 858 u8 csum[BTRFS_CSUM_SIZE]; 859 u32 crc = ~(u32)0; 860 int fail = 0; 861 int crc_fail = 0; 862 863 /* 864 * we don't use the getter functions here, as we 865 * a) don't have an extent buffer and 866 * b) the page is already kmapped 867 */ 868 h = (struct btrfs_header *)buffer; 869 870 if (logical != le64_to_cpu(h->bytenr)) 871 ++fail; 872 873 if (spag->generation != le64_to_cpu(h->generation)) 874 ++fail; 875 876 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) 877 ++fail; 878 879 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, 880 BTRFS_UUID_SIZE)) 881 ++fail; 882 883 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc, 884 PAGE_SIZE - BTRFS_CSUM_SIZE); 885 btrfs_csum_final(crc, csum); 886 if (memcmp(csum, h->csum, sdev->csum_size)) 887 ++crc_fail; 888 889 spin_lock(&sdev->stat_lock); 890 ++sdev->stat.tree_extents_scrubbed; 891 sdev->stat.tree_bytes_scrubbed += PAGE_SIZE; 892 if (crc_fail) 893 ++sdev->stat.csum_errors; 894 if (fail) 895 ++sdev->stat.verify_errors; 896 spin_unlock(&sdev->stat_lock); 897 898 return fail || crc_fail; 899 } 900 901 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer) 902 { 903 struct btrfs_super_block *s; 904 u64 logical; 905 struct scrub_dev *sdev = sbio->sdev; 906 struct btrfs_root *root = sdev->dev->dev_root; 907 struct btrfs_fs_info *fs_info = root->fs_info; 908 u8 csum[BTRFS_CSUM_SIZE]; 909 u32 crc = ~(u32)0; 910 int fail = 0; 911 912 s = (struct btrfs_super_block *)buffer; 913 logical = sbio->logical; 914 915 if (logical != le64_to_cpu(s->bytenr)) 916 ++fail; 917 918 if (sbio->spag[0].generation != le64_to_cpu(s->generation)) 919 ++fail; 920 921 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE)) 922 ++fail; 923 924 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc, 925 PAGE_SIZE - BTRFS_CSUM_SIZE); 926 btrfs_csum_final(crc, csum); 927 if (memcmp(csum, s->csum, sbio->sdev->csum_size)) 928 ++fail; 929 930 if (fail) { 931 /* 932 * if we find an error in a super block, we just report it. 933 * They will get written with the next transaction commit 934 * anyway 935 */ 936 spin_lock(&sdev->stat_lock); 937 ++sdev->stat.super_errors; 938 spin_unlock(&sdev->stat_lock); 939 } 940 941 return fail; 942 } 943 944 static int scrub_submit(struct scrub_dev *sdev) 945 { 946 struct scrub_bio *sbio; 947 948 if (sdev->curr == -1) 949 return 0; 950 951 sbio = sdev->bios[sdev->curr]; 952 sbio->err = 0; 953 sdev->curr = -1; 954 atomic_inc(&sdev->in_flight); 955 956 submit_bio(READ, sbio->bio); 957 958 return 0; 959 } 960 961 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len, 962 u64 physical, u64 flags, u64 gen, int mirror_num, 963 u8 *csum, int force) 964 { 965 struct scrub_bio *sbio; 966 struct page *page; 967 int ret; 968 969 again: 970 /* 971 * grab a fresh bio or wait for one to become available 972 */ 973 while (sdev->curr == -1) { 974 spin_lock(&sdev->list_lock); 975 sdev->curr = sdev->first_free; 976 if (sdev->curr != -1) { 977 sdev->first_free = sdev->bios[sdev->curr]->next_free; 978 sdev->bios[sdev->curr]->next_free = -1; 979 sdev->bios[sdev->curr]->count = 0; 980 spin_unlock(&sdev->list_lock); 981 } else { 982 spin_unlock(&sdev->list_lock); 983 wait_event(sdev->list_wait, sdev->first_free != -1); 984 } 985 } 986 sbio = sdev->bios[sdev->curr]; 987 if (sbio->count == 0) { 988 struct bio *bio; 989 990 sbio->physical = physical; 991 sbio->logical = logical; 992 bio = bio_alloc(GFP_NOFS, SCRUB_PAGES_PER_BIO); 993 if (!bio) 994 return -ENOMEM; 995 996 bio->bi_private = sbio; 997 bio->bi_end_io = scrub_bio_end_io; 998 bio->bi_bdev = sdev->dev->bdev; 999 bio->bi_sector = sbio->physical >> 9; 1000 sbio->err = 0; 1001 sbio->bio = bio; 1002 } else if (sbio->physical + sbio->count * PAGE_SIZE != physical || 1003 sbio->logical + sbio->count * PAGE_SIZE != logical) { 1004 ret = scrub_submit(sdev); 1005 if (ret) 1006 return ret; 1007 goto again; 1008 } 1009 sbio->spag[sbio->count].flags = flags; 1010 sbio->spag[sbio->count].generation = gen; 1011 sbio->spag[sbio->count].have_csum = 0; 1012 sbio->spag[sbio->count].mirror_num = mirror_num; 1013 1014 page = alloc_page(GFP_NOFS); 1015 if (!page) 1016 return -ENOMEM; 1017 1018 ret = bio_add_page(sbio->bio, page, PAGE_SIZE, 0); 1019 if (!ret) { 1020 __free_page(page); 1021 ret = scrub_submit(sdev); 1022 if (ret) 1023 return ret; 1024 goto again; 1025 } 1026 1027 if (csum) { 1028 sbio->spag[sbio->count].have_csum = 1; 1029 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size); 1030 } 1031 ++sbio->count; 1032 if (sbio->count == SCRUB_PAGES_PER_BIO || force) { 1033 int ret; 1034 1035 ret = scrub_submit(sdev); 1036 if (ret) 1037 return ret; 1038 } 1039 1040 return 0; 1041 } 1042 1043 static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len, 1044 u8 *csum) 1045 { 1046 struct btrfs_ordered_sum *sum = NULL; 1047 int ret = 0; 1048 unsigned long i; 1049 unsigned long num_sectors; 1050 u32 sectorsize = sdev->dev->dev_root->sectorsize; 1051 1052 while (!list_empty(&sdev->csum_list)) { 1053 sum = list_first_entry(&sdev->csum_list, 1054 struct btrfs_ordered_sum, list); 1055 if (sum->bytenr > logical) 1056 return 0; 1057 if (sum->bytenr + sum->len > logical) 1058 break; 1059 1060 ++sdev->stat.csum_discards; 1061 list_del(&sum->list); 1062 kfree(sum); 1063 sum = NULL; 1064 } 1065 if (!sum) 1066 return 0; 1067 1068 num_sectors = sum->len / sectorsize; 1069 for (i = 0; i < num_sectors; ++i) { 1070 if (sum->sums[i].bytenr == logical) { 1071 memcpy(csum, &sum->sums[i].sum, sdev->csum_size); 1072 ret = 1; 1073 break; 1074 } 1075 } 1076 if (ret && i == num_sectors - 1) { 1077 list_del(&sum->list); 1078 kfree(sum); 1079 } 1080 return ret; 1081 } 1082 1083 /* scrub extent tries to collect up to 64 kB for each bio */ 1084 static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len, 1085 u64 physical, u64 flags, u64 gen, int mirror_num) 1086 { 1087 int ret; 1088 u8 csum[BTRFS_CSUM_SIZE]; 1089 1090 while (len) { 1091 u64 l = min_t(u64, len, PAGE_SIZE); 1092 int have_csum = 0; 1093 1094 if (flags & BTRFS_EXTENT_FLAG_DATA) { 1095 /* push csums to sbio */ 1096 have_csum = scrub_find_csum(sdev, logical, l, csum); 1097 if (have_csum == 0) 1098 ++sdev->stat.no_csum; 1099 } 1100 ret = scrub_page(sdev, logical, l, physical, flags, gen, 1101 mirror_num, have_csum ? csum : NULL, 0); 1102 if (ret) 1103 return ret; 1104 len -= l; 1105 logical += l; 1106 physical += l; 1107 } 1108 return 0; 1109 } 1110 1111 static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev, 1112 struct map_lookup *map, int num, u64 base, u64 length) 1113 { 1114 struct btrfs_path *path; 1115 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info; 1116 struct btrfs_root *root = fs_info->extent_root; 1117 struct btrfs_root *csum_root = fs_info->csum_root; 1118 struct btrfs_extent_item *extent; 1119 struct blk_plug plug; 1120 u64 flags; 1121 int ret; 1122 int slot; 1123 int i; 1124 u64 nstripes; 1125 struct extent_buffer *l; 1126 struct btrfs_key key; 1127 u64 physical; 1128 u64 logical; 1129 u64 generation; 1130 int mirror_num; 1131 struct reada_control *reada1; 1132 struct reada_control *reada2; 1133 struct btrfs_key key_start; 1134 struct btrfs_key key_end; 1135 1136 u64 increment = map->stripe_len; 1137 u64 offset; 1138 1139 nstripes = length; 1140 offset = 0; 1141 do_div(nstripes, map->stripe_len); 1142 if (map->type & BTRFS_BLOCK_GROUP_RAID0) { 1143 offset = map->stripe_len * num; 1144 increment = map->stripe_len * map->num_stripes; 1145 mirror_num = 1; 1146 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 1147 int factor = map->num_stripes / map->sub_stripes; 1148 offset = map->stripe_len * (num / map->sub_stripes); 1149 increment = map->stripe_len * factor; 1150 mirror_num = num % map->sub_stripes + 1; 1151 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { 1152 increment = map->stripe_len; 1153 mirror_num = num % map->num_stripes + 1; 1154 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { 1155 increment = map->stripe_len; 1156 mirror_num = num % map->num_stripes + 1; 1157 } else { 1158 increment = map->stripe_len; 1159 mirror_num = 1; 1160 } 1161 1162 path = btrfs_alloc_path(); 1163 if (!path) 1164 return -ENOMEM; 1165 1166 path->search_commit_root = 1; 1167 path->skip_locking = 1; 1168 1169 /* 1170 * trigger the readahead for extent tree csum tree and wait for 1171 * completion. During readahead, the scrub is officially paused 1172 * to not hold off transaction commits 1173 */ 1174 logical = base + offset; 1175 1176 wait_event(sdev->list_wait, 1177 atomic_read(&sdev->in_flight) == 0); 1178 atomic_inc(&fs_info->scrubs_paused); 1179 wake_up(&fs_info->scrub_pause_wait); 1180 1181 /* FIXME it might be better to start readahead at commit root */ 1182 key_start.objectid = logical; 1183 key_start.type = BTRFS_EXTENT_ITEM_KEY; 1184 key_start.offset = (u64)0; 1185 key_end.objectid = base + offset + nstripes * increment; 1186 key_end.type = BTRFS_EXTENT_ITEM_KEY; 1187 key_end.offset = (u64)0; 1188 reada1 = btrfs_reada_add(root, &key_start, &key_end); 1189 1190 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 1191 key_start.type = BTRFS_EXTENT_CSUM_KEY; 1192 key_start.offset = logical; 1193 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 1194 key_end.type = BTRFS_EXTENT_CSUM_KEY; 1195 key_end.offset = base + offset + nstripes * increment; 1196 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end); 1197 1198 if (!IS_ERR(reada1)) 1199 btrfs_reada_wait(reada1); 1200 if (!IS_ERR(reada2)) 1201 btrfs_reada_wait(reada2); 1202 1203 mutex_lock(&fs_info->scrub_lock); 1204 while (atomic_read(&fs_info->scrub_pause_req)) { 1205 mutex_unlock(&fs_info->scrub_lock); 1206 wait_event(fs_info->scrub_pause_wait, 1207 atomic_read(&fs_info->scrub_pause_req) == 0); 1208 mutex_lock(&fs_info->scrub_lock); 1209 } 1210 atomic_dec(&fs_info->scrubs_paused); 1211 mutex_unlock(&fs_info->scrub_lock); 1212 wake_up(&fs_info->scrub_pause_wait); 1213 1214 /* 1215 * collect all data csums for the stripe to avoid seeking during 1216 * the scrub. This might currently (crc32) end up to be about 1MB 1217 */ 1218 blk_start_plug(&plug); 1219 1220 /* 1221 * now find all extents for each stripe and scrub them 1222 */ 1223 logical = base + offset; 1224 physical = map->stripes[num].physical; 1225 ret = 0; 1226 for (i = 0; i < nstripes; ++i) { 1227 /* 1228 * canceled? 1229 */ 1230 if (atomic_read(&fs_info->scrub_cancel_req) || 1231 atomic_read(&sdev->cancel_req)) { 1232 ret = -ECANCELED; 1233 goto out; 1234 } 1235 /* 1236 * check to see if we have to pause 1237 */ 1238 if (atomic_read(&fs_info->scrub_pause_req)) { 1239 /* push queued extents */ 1240 scrub_submit(sdev); 1241 wait_event(sdev->list_wait, 1242 atomic_read(&sdev->in_flight) == 0); 1243 atomic_inc(&fs_info->scrubs_paused); 1244 wake_up(&fs_info->scrub_pause_wait); 1245 mutex_lock(&fs_info->scrub_lock); 1246 while (atomic_read(&fs_info->scrub_pause_req)) { 1247 mutex_unlock(&fs_info->scrub_lock); 1248 wait_event(fs_info->scrub_pause_wait, 1249 atomic_read(&fs_info->scrub_pause_req) == 0); 1250 mutex_lock(&fs_info->scrub_lock); 1251 } 1252 atomic_dec(&fs_info->scrubs_paused); 1253 mutex_unlock(&fs_info->scrub_lock); 1254 wake_up(&fs_info->scrub_pause_wait); 1255 } 1256 1257 ret = btrfs_lookup_csums_range(csum_root, logical, 1258 logical + map->stripe_len - 1, 1259 &sdev->csum_list, 1); 1260 if (ret) 1261 goto out; 1262 1263 key.objectid = logical; 1264 key.type = BTRFS_EXTENT_ITEM_KEY; 1265 key.offset = (u64)0; 1266 1267 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1268 if (ret < 0) 1269 goto out; 1270 if (ret > 0) { 1271 ret = btrfs_previous_item(root, path, 0, 1272 BTRFS_EXTENT_ITEM_KEY); 1273 if (ret < 0) 1274 goto out; 1275 if (ret > 0) { 1276 /* there's no smaller item, so stick with the 1277 * larger one */ 1278 btrfs_release_path(path); 1279 ret = btrfs_search_slot(NULL, root, &key, 1280 path, 0, 0); 1281 if (ret < 0) 1282 goto out; 1283 } 1284 } 1285 1286 while (1) { 1287 l = path->nodes[0]; 1288 slot = path->slots[0]; 1289 if (slot >= btrfs_header_nritems(l)) { 1290 ret = btrfs_next_leaf(root, path); 1291 if (ret == 0) 1292 continue; 1293 if (ret < 0) 1294 goto out; 1295 1296 break; 1297 } 1298 btrfs_item_key_to_cpu(l, &key, slot); 1299 1300 if (key.objectid + key.offset <= logical) 1301 goto next; 1302 1303 if (key.objectid >= logical + map->stripe_len) 1304 break; 1305 1306 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) 1307 goto next; 1308 1309 extent = btrfs_item_ptr(l, slot, 1310 struct btrfs_extent_item); 1311 flags = btrfs_extent_flags(l, extent); 1312 generation = btrfs_extent_generation(l, extent); 1313 1314 if (key.objectid < logical && 1315 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) { 1316 printk(KERN_ERR 1317 "btrfs scrub: tree block %llu spanning " 1318 "stripes, ignored. logical=%llu\n", 1319 (unsigned long long)key.objectid, 1320 (unsigned long long)logical); 1321 goto next; 1322 } 1323 1324 /* 1325 * trim extent to this stripe 1326 */ 1327 if (key.objectid < logical) { 1328 key.offset -= logical - key.objectid; 1329 key.objectid = logical; 1330 } 1331 if (key.objectid + key.offset > 1332 logical + map->stripe_len) { 1333 key.offset = logical + map->stripe_len - 1334 key.objectid; 1335 } 1336 1337 ret = scrub_extent(sdev, key.objectid, key.offset, 1338 key.objectid - logical + physical, 1339 flags, generation, mirror_num); 1340 if (ret) 1341 goto out; 1342 1343 next: 1344 path->slots[0]++; 1345 } 1346 btrfs_release_path(path); 1347 logical += increment; 1348 physical += map->stripe_len; 1349 spin_lock(&sdev->stat_lock); 1350 sdev->stat.last_physical = physical; 1351 spin_unlock(&sdev->stat_lock); 1352 } 1353 /* push queued extents */ 1354 scrub_submit(sdev); 1355 1356 out: 1357 blk_finish_plug(&plug); 1358 btrfs_free_path(path); 1359 return ret < 0 ? ret : 0; 1360 } 1361 1362 static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev, 1363 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length) 1364 { 1365 struct btrfs_mapping_tree *map_tree = 1366 &sdev->dev->dev_root->fs_info->mapping_tree; 1367 struct map_lookup *map; 1368 struct extent_map *em; 1369 int i; 1370 int ret = -EINVAL; 1371 1372 read_lock(&map_tree->map_tree.lock); 1373 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); 1374 read_unlock(&map_tree->map_tree.lock); 1375 1376 if (!em) 1377 return -EINVAL; 1378 1379 map = (struct map_lookup *)em->bdev; 1380 if (em->start != chunk_offset) 1381 goto out; 1382 1383 if (em->len < length) 1384 goto out; 1385 1386 for (i = 0; i < map->num_stripes; ++i) { 1387 if (map->stripes[i].dev == sdev->dev) { 1388 ret = scrub_stripe(sdev, map, i, chunk_offset, length); 1389 if (ret) 1390 goto out; 1391 } 1392 } 1393 out: 1394 free_extent_map(em); 1395 1396 return ret; 1397 } 1398 1399 static noinline_for_stack 1400 int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end) 1401 { 1402 struct btrfs_dev_extent *dev_extent = NULL; 1403 struct btrfs_path *path; 1404 struct btrfs_root *root = sdev->dev->dev_root; 1405 struct btrfs_fs_info *fs_info = root->fs_info; 1406 u64 length; 1407 u64 chunk_tree; 1408 u64 chunk_objectid; 1409 u64 chunk_offset; 1410 int ret; 1411 int slot; 1412 struct extent_buffer *l; 1413 struct btrfs_key key; 1414 struct btrfs_key found_key; 1415 struct btrfs_block_group_cache *cache; 1416 1417 path = btrfs_alloc_path(); 1418 if (!path) 1419 return -ENOMEM; 1420 1421 path->reada = 2; 1422 path->search_commit_root = 1; 1423 path->skip_locking = 1; 1424 1425 key.objectid = sdev->dev->devid; 1426 key.offset = 0ull; 1427 key.type = BTRFS_DEV_EXTENT_KEY; 1428 1429 1430 while (1) { 1431 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1432 if (ret < 0) 1433 break; 1434 if (ret > 0) { 1435 if (path->slots[0] >= 1436 btrfs_header_nritems(path->nodes[0])) { 1437 ret = btrfs_next_leaf(root, path); 1438 if (ret) 1439 break; 1440 } 1441 } 1442 1443 l = path->nodes[0]; 1444 slot = path->slots[0]; 1445 1446 btrfs_item_key_to_cpu(l, &found_key, slot); 1447 1448 if (found_key.objectid != sdev->dev->devid) 1449 break; 1450 1451 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY) 1452 break; 1453 1454 if (found_key.offset >= end) 1455 break; 1456 1457 if (found_key.offset < key.offset) 1458 break; 1459 1460 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 1461 length = btrfs_dev_extent_length(l, dev_extent); 1462 1463 if (found_key.offset + length <= start) { 1464 key.offset = found_key.offset + length; 1465 btrfs_release_path(path); 1466 continue; 1467 } 1468 1469 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); 1470 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); 1471 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); 1472 1473 /* 1474 * get a reference on the corresponding block group to prevent 1475 * the chunk from going away while we scrub it 1476 */ 1477 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 1478 if (!cache) { 1479 ret = -ENOENT; 1480 break; 1481 } 1482 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid, 1483 chunk_offset, length); 1484 btrfs_put_block_group(cache); 1485 if (ret) 1486 break; 1487 1488 key.offset = found_key.offset + length; 1489 btrfs_release_path(path); 1490 } 1491 1492 btrfs_free_path(path); 1493 1494 /* 1495 * ret can still be 1 from search_slot or next_leaf, 1496 * that's not an error 1497 */ 1498 return ret < 0 ? ret : 0; 1499 } 1500 1501 static noinline_for_stack int scrub_supers(struct scrub_dev *sdev) 1502 { 1503 int i; 1504 u64 bytenr; 1505 u64 gen; 1506 int ret; 1507 struct btrfs_device *device = sdev->dev; 1508 struct btrfs_root *root = device->dev_root; 1509 1510 gen = root->fs_info->last_trans_committed; 1511 1512 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { 1513 bytenr = btrfs_sb_offset(i); 1514 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes) 1515 break; 1516 1517 ret = scrub_page(sdev, bytenr, PAGE_SIZE, bytenr, 1518 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1); 1519 if (ret) 1520 return ret; 1521 } 1522 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0); 1523 1524 return 0; 1525 } 1526 1527 /* 1528 * get a reference count on fs_info->scrub_workers. start worker if necessary 1529 */ 1530 static noinline_for_stack int scrub_workers_get(struct btrfs_root *root) 1531 { 1532 struct btrfs_fs_info *fs_info = root->fs_info; 1533 1534 mutex_lock(&fs_info->scrub_lock); 1535 if (fs_info->scrub_workers_refcnt == 0) { 1536 btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1537 fs_info->thread_pool_size, &fs_info->generic_worker); 1538 fs_info->scrub_workers.idle_thresh = 4; 1539 btrfs_start_workers(&fs_info->scrub_workers, 1); 1540 } 1541 ++fs_info->scrub_workers_refcnt; 1542 mutex_unlock(&fs_info->scrub_lock); 1543 1544 return 0; 1545 } 1546 1547 static noinline_for_stack void scrub_workers_put(struct btrfs_root *root) 1548 { 1549 struct btrfs_fs_info *fs_info = root->fs_info; 1550 1551 mutex_lock(&fs_info->scrub_lock); 1552 if (--fs_info->scrub_workers_refcnt == 0) 1553 btrfs_stop_workers(&fs_info->scrub_workers); 1554 WARN_ON(fs_info->scrub_workers_refcnt < 0); 1555 mutex_unlock(&fs_info->scrub_lock); 1556 } 1557 1558 1559 int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end, 1560 struct btrfs_scrub_progress *progress, int readonly) 1561 { 1562 struct scrub_dev *sdev; 1563 struct btrfs_fs_info *fs_info = root->fs_info; 1564 int ret; 1565 struct btrfs_device *dev; 1566 1567 if (btrfs_fs_closing(root->fs_info)) 1568 return -EINVAL; 1569 1570 /* 1571 * check some assumptions 1572 */ 1573 if (root->sectorsize != PAGE_SIZE || 1574 root->sectorsize != root->leafsize || 1575 root->sectorsize != root->nodesize) { 1576 printk(KERN_ERR "btrfs_scrub: size assumptions fail\n"); 1577 return -EINVAL; 1578 } 1579 1580 ret = scrub_workers_get(root); 1581 if (ret) 1582 return ret; 1583 1584 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 1585 dev = btrfs_find_device(root, devid, NULL, NULL); 1586 if (!dev || dev->missing) { 1587 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1588 scrub_workers_put(root); 1589 return -ENODEV; 1590 } 1591 mutex_lock(&fs_info->scrub_lock); 1592 1593 if (!dev->in_fs_metadata) { 1594 mutex_unlock(&fs_info->scrub_lock); 1595 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1596 scrub_workers_put(root); 1597 return -ENODEV; 1598 } 1599 1600 if (dev->scrub_device) { 1601 mutex_unlock(&fs_info->scrub_lock); 1602 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1603 scrub_workers_put(root); 1604 return -EINPROGRESS; 1605 } 1606 sdev = scrub_setup_dev(dev); 1607 if (IS_ERR(sdev)) { 1608 mutex_unlock(&fs_info->scrub_lock); 1609 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1610 scrub_workers_put(root); 1611 return PTR_ERR(sdev); 1612 } 1613 sdev->readonly = readonly; 1614 dev->scrub_device = sdev; 1615 1616 atomic_inc(&fs_info->scrubs_running); 1617 mutex_unlock(&fs_info->scrub_lock); 1618 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1619 1620 down_read(&fs_info->scrub_super_lock); 1621 ret = scrub_supers(sdev); 1622 up_read(&fs_info->scrub_super_lock); 1623 1624 if (!ret) 1625 ret = scrub_enumerate_chunks(sdev, start, end); 1626 1627 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0); 1628 atomic_dec(&fs_info->scrubs_running); 1629 wake_up(&fs_info->scrub_pause_wait); 1630 1631 wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0); 1632 1633 if (progress) 1634 memcpy(progress, &sdev->stat, sizeof(*progress)); 1635 1636 mutex_lock(&fs_info->scrub_lock); 1637 dev->scrub_device = NULL; 1638 mutex_unlock(&fs_info->scrub_lock); 1639 1640 scrub_free_dev(sdev); 1641 scrub_workers_put(root); 1642 1643 return ret; 1644 } 1645 1646 int btrfs_scrub_pause(struct btrfs_root *root) 1647 { 1648 struct btrfs_fs_info *fs_info = root->fs_info; 1649 1650 mutex_lock(&fs_info->scrub_lock); 1651 atomic_inc(&fs_info->scrub_pause_req); 1652 while (atomic_read(&fs_info->scrubs_paused) != 1653 atomic_read(&fs_info->scrubs_running)) { 1654 mutex_unlock(&fs_info->scrub_lock); 1655 wait_event(fs_info->scrub_pause_wait, 1656 atomic_read(&fs_info->scrubs_paused) == 1657 atomic_read(&fs_info->scrubs_running)); 1658 mutex_lock(&fs_info->scrub_lock); 1659 } 1660 mutex_unlock(&fs_info->scrub_lock); 1661 1662 return 0; 1663 } 1664 1665 int btrfs_scrub_continue(struct btrfs_root *root) 1666 { 1667 struct btrfs_fs_info *fs_info = root->fs_info; 1668 1669 atomic_dec(&fs_info->scrub_pause_req); 1670 wake_up(&fs_info->scrub_pause_wait); 1671 return 0; 1672 } 1673 1674 int btrfs_scrub_pause_super(struct btrfs_root *root) 1675 { 1676 down_write(&root->fs_info->scrub_super_lock); 1677 return 0; 1678 } 1679 1680 int btrfs_scrub_continue_super(struct btrfs_root *root) 1681 { 1682 up_write(&root->fs_info->scrub_super_lock); 1683 return 0; 1684 } 1685 1686 int btrfs_scrub_cancel(struct btrfs_root *root) 1687 { 1688 struct btrfs_fs_info *fs_info = root->fs_info; 1689 1690 mutex_lock(&fs_info->scrub_lock); 1691 if (!atomic_read(&fs_info->scrubs_running)) { 1692 mutex_unlock(&fs_info->scrub_lock); 1693 return -ENOTCONN; 1694 } 1695 1696 atomic_inc(&fs_info->scrub_cancel_req); 1697 while (atomic_read(&fs_info->scrubs_running)) { 1698 mutex_unlock(&fs_info->scrub_lock); 1699 wait_event(fs_info->scrub_pause_wait, 1700 atomic_read(&fs_info->scrubs_running) == 0); 1701 mutex_lock(&fs_info->scrub_lock); 1702 } 1703 atomic_dec(&fs_info->scrub_cancel_req); 1704 mutex_unlock(&fs_info->scrub_lock); 1705 1706 return 0; 1707 } 1708 1709 int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev) 1710 { 1711 struct btrfs_fs_info *fs_info = root->fs_info; 1712 struct scrub_dev *sdev; 1713 1714 mutex_lock(&fs_info->scrub_lock); 1715 sdev = dev->scrub_device; 1716 if (!sdev) { 1717 mutex_unlock(&fs_info->scrub_lock); 1718 return -ENOTCONN; 1719 } 1720 atomic_inc(&sdev->cancel_req); 1721 while (dev->scrub_device) { 1722 mutex_unlock(&fs_info->scrub_lock); 1723 wait_event(fs_info->scrub_pause_wait, 1724 dev->scrub_device == NULL); 1725 mutex_lock(&fs_info->scrub_lock); 1726 } 1727 mutex_unlock(&fs_info->scrub_lock); 1728 1729 return 0; 1730 } 1731 int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid) 1732 { 1733 struct btrfs_fs_info *fs_info = root->fs_info; 1734 struct btrfs_device *dev; 1735 int ret; 1736 1737 /* 1738 * we have to hold the device_list_mutex here so the device 1739 * does not go away in cancel_dev. FIXME: find a better solution 1740 */ 1741 mutex_lock(&fs_info->fs_devices->device_list_mutex); 1742 dev = btrfs_find_device(root, devid, NULL, NULL); 1743 if (!dev) { 1744 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1745 return -ENODEV; 1746 } 1747 ret = btrfs_scrub_cancel_dev(root, dev); 1748 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1749 1750 return ret; 1751 } 1752 1753 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid, 1754 struct btrfs_scrub_progress *progress) 1755 { 1756 struct btrfs_device *dev; 1757 struct scrub_dev *sdev = NULL; 1758 1759 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 1760 dev = btrfs_find_device(root, devid, NULL, NULL); 1761 if (dev) 1762 sdev = dev->scrub_device; 1763 if (sdev) 1764 memcpy(progress, &sdev->stat, sizeof(*progress)); 1765 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1766 1767 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV; 1768 } 1769