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