1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) STRATO AG 2012. All rights reserved. 4 */ 5 6 #include <linux/sched.h> 7 #include <linux/bio.h> 8 #include <linux/slab.h> 9 #include <linux/blkdev.h> 10 #include <linux/kthread.h> 11 #include <linux/math64.h> 12 #include "misc.h" 13 #include "ctree.h" 14 #include "extent_map.h" 15 #include "disk-io.h" 16 #include "transaction.h" 17 #include "print-tree.h" 18 #include "volumes.h" 19 #include "async-thread.h" 20 #include "check-integrity.h" 21 #include "rcu-string.h" 22 #include "dev-replace.h" 23 #include "sysfs.h" 24 #include "zoned.h" 25 #include "block-group.h" 26 27 /* 28 * Device replace overview 29 * 30 * [Objective] 31 * To copy all extents (both new and on-disk) from source device to target 32 * device, while still keeping the filesystem read-write. 33 * 34 * [Method] 35 * There are two main methods involved: 36 * 37 * - Write duplication 38 * 39 * All new writes will be written to both target and source devices, so even 40 * if replace gets canceled, sources device still contains up-to-date data. 41 * 42 * Location: handle_ops_on_dev_replace() from __btrfs_map_block() 43 * Start: btrfs_dev_replace_start() 44 * End: btrfs_dev_replace_finishing() 45 * Content: Latest data/metadata 46 * 47 * - Copy existing extents 48 * 49 * This happens by re-using scrub facility, as scrub also iterates through 50 * existing extents from commit root. 51 * 52 * Location: scrub_write_block_to_dev_replace() from 53 * scrub_block_complete() 54 * Content: Data/meta from commit root. 55 * 56 * Due to the content difference, we need to avoid nocow write when dev-replace 57 * is happening. This is done by marking the block group read-only and waiting 58 * for NOCOW writes. 59 * 60 * After replace is done, the finishing part is done by swapping the target and 61 * source devices. 62 * 63 * Location: btrfs_dev_replace_update_device_in_mapping_tree() from 64 * btrfs_dev_replace_finishing() 65 */ 66 67 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 68 int scrub_ret); 69 static int btrfs_dev_replace_kthread(void *data); 70 71 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 72 { 73 struct btrfs_dev_lookup_args args = { .devid = BTRFS_DEV_REPLACE_DEVID }; 74 struct btrfs_key key; 75 struct btrfs_root *dev_root = fs_info->dev_root; 76 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 77 struct extent_buffer *eb; 78 int slot; 79 int ret = 0; 80 struct btrfs_path *path = NULL; 81 int item_size; 82 struct btrfs_dev_replace_item *ptr; 83 u64 src_devid; 84 85 if (!dev_root) 86 return 0; 87 88 path = btrfs_alloc_path(); 89 if (!path) { 90 ret = -ENOMEM; 91 goto out; 92 } 93 94 key.objectid = 0; 95 key.type = BTRFS_DEV_REPLACE_KEY; 96 key.offset = 0; 97 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 98 if (ret) { 99 no_valid_dev_replace_entry_found: 100 /* 101 * We don't have a replace item or it's corrupted. If there is 102 * a replace target, fail the mount. 103 */ 104 if (btrfs_find_device(fs_info->fs_devices, &args)) { 105 btrfs_err(fs_info, 106 "found replace target device without a valid replace item"); 107 ret = -EUCLEAN; 108 goto out; 109 } 110 ret = 0; 111 dev_replace->replace_state = 112 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 113 dev_replace->cont_reading_from_srcdev_mode = 114 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 115 dev_replace->time_started = 0; 116 dev_replace->time_stopped = 0; 117 atomic64_set(&dev_replace->num_write_errors, 0); 118 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 119 dev_replace->cursor_left = 0; 120 dev_replace->committed_cursor_left = 0; 121 dev_replace->cursor_left_last_write_of_item = 0; 122 dev_replace->cursor_right = 0; 123 dev_replace->srcdev = NULL; 124 dev_replace->tgtdev = NULL; 125 dev_replace->is_valid = 0; 126 dev_replace->item_needs_writeback = 0; 127 goto out; 128 } 129 slot = path->slots[0]; 130 eb = path->nodes[0]; 131 item_size = btrfs_item_size(eb, slot); 132 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 133 134 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 135 btrfs_warn(fs_info, 136 "dev_replace entry found has unexpected size, ignore entry"); 137 goto no_valid_dev_replace_entry_found; 138 } 139 140 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 141 dev_replace->cont_reading_from_srcdev_mode = 142 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 143 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 144 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 145 dev_replace->time_stopped = 146 btrfs_dev_replace_time_stopped(eb, ptr); 147 atomic64_set(&dev_replace->num_write_errors, 148 btrfs_dev_replace_num_write_errors(eb, ptr)); 149 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 150 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 151 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 152 dev_replace->committed_cursor_left = dev_replace->cursor_left; 153 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 154 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 155 dev_replace->is_valid = 1; 156 157 dev_replace->item_needs_writeback = 0; 158 switch (dev_replace->replace_state) { 159 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 160 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 161 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 162 /* 163 * We don't have an active replace item but if there is a 164 * replace target, fail the mount. 165 */ 166 if (btrfs_find_device(fs_info->fs_devices, &args)) { 167 btrfs_err(fs_info, 168 "replace devid present without an active replace item"); 169 ret = -EUCLEAN; 170 } else { 171 dev_replace->srcdev = NULL; 172 dev_replace->tgtdev = NULL; 173 } 174 break; 175 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 176 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 177 dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices, &args); 178 args.devid = src_devid; 179 dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices, &args); 180 181 /* 182 * allow 'btrfs dev replace_cancel' if src/tgt device is 183 * missing 184 */ 185 if (!dev_replace->srcdev && 186 !btrfs_test_opt(fs_info, DEGRADED)) { 187 ret = -EIO; 188 btrfs_warn(fs_info, 189 "cannot mount because device replace operation is ongoing and"); 190 btrfs_warn(fs_info, 191 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 192 src_devid); 193 } 194 if (!dev_replace->tgtdev && 195 !btrfs_test_opt(fs_info, DEGRADED)) { 196 ret = -EIO; 197 btrfs_warn(fs_info, 198 "cannot mount because device replace operation is ongoing and"); 199 btrfs_warn(fs_info, 200 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 201 BTRFS_DEV_REPLACE_DEVID); 202 } 203 if (dev_replace->tgtdev) { 204 if (dev_replace->srcdev) { 205 dev_replace->tgtdev->total_bytes = 206 dev_replace->srcdev->total_bytes; 207 dev_replace->tgtdev->disk_total_bytes = 208 dev_replace->srcdev->disk_total_bytes; 209 dev_replace->tgtdev->commit_total_bytes = 210 dev_replace->srcdev->commit_total_bytes; 211 dev_replace->tgtdev->bytes_used = 212 dev_replace->srcdev->bytes_used; 213 dev_replace->tgtdev->commit_bytes_used = 214 dev_replace->srcdev->commit_bytes_used; 215 } 216 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 217 &dev_replace->tgtdev->dev_state); 218 219 WARN_ON(fs_info->fs_devices->rw_devices == 0); 220 dev_replace->tgtdev->io_width = fs_info->sectorsize; 221 dev_replace->tgtdev->io_align = fs_info->sectorsize; 222 dev_replace->tgtdev->sector_size = fs_info->sectorsize; 223 dev_replace->tgtdev->fs_info = fs_info; 224 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 225 &dev_replace->tgtdev->dev_state); 226 } 227 break; 228 } 229 230 out: 231 btrfs_free_path(path); 232 return ret; 233 } 234 235 /* 236 * Initialize a new device for device replace target from a given source dev 237 * and path. 238 * 239 * Return 0 and new device in @device_out, otherwise return < 0 240 */ 241 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, 242 const char *device_path, 243 struct btrfs_device *srcdev, 244 struct btrfs_device **device_out) 245 { 246 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 247 struct btrfs_device *device; 248 struct block_device *bdev; 249 struct rcu_string *name; 250 u64 devid = BTRFS_DEV_REPLACE_DEVID; 251 int ret = 0; 252 253 *device_out = NULL; 254 if (srcdev->fs_devices->seeding) { 255 btrfs_err(fs_info, "the filesystem is a seed filesystem!"); 256 return -EINVAL; 257 } 258 259 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, 260 fs_info->bdev_holder); 261 if (IS_ERR(bdev)) { 262 btrfs_err(fs_info, "target device %s is invalid!", device_path); 263 return PTR_ERR(bdev); 264 } 265 266 if (!btrfs_check_device_zone_type(fs_info, bdev)) { 267 btrfs_err(fs_info, 268 "dev-replace: zoned type of target device mismatch with filesystem"); 269 ret = -EINVAL; 270 goto error; 271 } 272 273 sync_blockdev(bdev); 274 275 list_for_each_entry(device, &fs_devices->devices, dev_list) { 276 if (device->bdev == bdev) { 277 btrfs_err(fs_info, 278 "target device is in the filesystem!"); 279 ret = -EEXIST; 280 goto error; 281 } 282 } 283 284 285 if (bdev_nr_bytes(bdev) < btrfs_device_get_total_bytes(srcdev)) { 286 btrfs_err(fs_info, 287 "target device is smaller than source device!"); 288 ret = -EINVAL; 289 goto error; 290 } 291 292 293 device = btrfs_alloc_device(NULL, &devid, NULL); 294 if (IS_ERR(device)) { 295 ret = PTR_ERR(device); 296 goto error; 297 } 298 299 name = rcu_string_strdup(device_path, GFP_KERNEL); 300 if (!name) { 301 btrfs_free_device(device); 302 ret = -ENOMEM; 303 goto error; 304 } 305 rcu_assign_pointer(device->name, name); 306 ret = lookup_bdev(device_path, &device->devt); 307 if (ret) 308 goto error; 309 310 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 311 device->generation = 0; 312 device->io_width = fs_info->sectorsize; 313 device->io_align = fs_info->sectorsize; 314 device->sector_size = fs_info->sectorsize; 315 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 316 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 317 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 318 device->commit_total_bytes = srcdev->commit_total_bytes; 319 device->commit_bytes_used = device->bytes_used; 320 device->fs_info = fs_info; 321 device->bdev = bdev; 322 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 323 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 324 device->mode = FMODE_EXCL; 325 device->dev_stats_valid = 1; 326 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 327 device->fs_devices = fs_devices; 328 329 ret = btrfs_get_dev_zone_info(device, false); 330 if (ret) 331 goto error; 332 333 mutex_lock(&fs_devices->device_list_mutex); 334 list_add(&device->dev_list, &fs_devices->devices); 335 fs_devices->num_devices++; 336 fs_devices->open_devices++; 337 mutex_unlock(&fs_devices->device_list_mutex); 338 339 *device_out = device; 340 return 0; 341 342 error: 343 blkdev_put(bdev, FMODE_EXCL); 344 return ret; 345 } 346 347 /* 348 * called from commit_transaction. Writes changed device replace state to 349 * disk. 350 */ 351 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 352 { 353 struct btrfs_fs_info *fs_info = trans->fs_info; 354 int ret; 355 struct btrfs_root *dev_root = fs_info->dev_root; 356 struct btrfs_path *path; 357 struct btrfs_key key; 358 struct extent_buffer *eb; 359 struct btrfs_dev_replace_item *ptr; 360 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 361 362 down_read(&dev_replace->rwsem); 363 if (!dev_replace->is_valid || 364 !dev_replace->item_needs_writeback) { 365 up_read(&dev_replace->rwsem); 366 return 0; 367 } 368 up_read(&dev_replace->rwsem); 369 370 key.objectid = 0; 371 key.type = BTRFS_DEV_REPLACE_KEY; 372 key.offset = 0; 373 374 path = btrfs_alloc_path(); 375 if (!path) { 376 ret = -ENOMEM; 377 goto out; 378 } 379 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 380 if (ret < 0) { 381 btrfs_warn(fs_info, 382 "error %d while searching for dev_replace item!", 383 ret); 384 goto out; 385 } 386 387 if (ret == 0 && 388 btrfs_item_size(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 389 /* 390 * need to delete old one and insert a new one. 391 * Since no attempt is made to recover any old state, if the 392 * dev_replace state is 'running', the data on the target 393 * drive is lost. 394 * It would be possible to recover the state: just make sure 395 * that the beginning of the item is never changed and always 396 * contains all the essential information. Then read this 397 * minimal set of information and use it as a base for the 398 * new state. 399 */ 400 ret = btrfs_del_item(trans, dev_root, path); 401 if (ret != 0) { 402 btrfs_warn(fs_info, 403 "delete too small dev_replace item failed %d!", 404 ret); 405 goto out; 406 } 407 ret = 1; 408 } 409 410 if (ret == 1) { 411 /* need to insert a new item */ 412 btrfs_release_path(path); 413 ret = btrfs_insert_empty_item(trans, dev_root, path, 414 &key, sizeof(*ptr)); 415 if (ret < 0) { 416 btrfs_warn(fs_info, 417 "insert dev_replace item failed %d!", ret); 418 goto out; 419 } 420 } 421 422 eb = path->nodes[0]; 423 ptr = btrfs_item_ptr(eb, path->slots[0], 424 struct btrfs_dev_replace_item); 425 426 down_write(&dev_replace->rwsem); 427 if (dev_replace->srcdev) 428 btrfs_set_dev_replace_src_devid(eb, ptr, 429 dev_replace->srcdev->devid); 430 else 431 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 432 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 433 dev_replace->cont_reading_from_srcdev_mode); 434 btrfs_set_dev_replace_replace_state(eb, ptr, 435 dev_replace->replace_state); 436 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 437 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 438 btrfs_set_dev_replace_num_write_errors(eb, ptr, 439 atomic64_read(&dev_replace->num_write_errors)); 440 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 441 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 442 dev_replace->cursor_left_last_write_of_item = 443 dev_replace->cursor_left; 444 btrfs_set_dev_replace_cursor_left(eb, ptr, 445 dev_replace->cursor_left_last_write_of_item); 446 btrfs_set_dev_replace_cursor_right(eb, ptr, 447 dev_replace->cursor_right); 448 dev_replace->item_needs_writeback = 0; 449 up_write(&dev_replace->rwsem); 450 451 btrfs_mark_buffer_dirty(eb); 452 453 out: 454 btrfs_free_path(path); 455 456 return ret; 457 } 458 459 static char* btrfs_dev_name(struct btrfs_device *device) 460 { 461 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 462 return "<missing disk>"; 463 else 464 return rcu_str_deref(device->name); 465 } 466 467 static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info, 468 struct btrfs_device *src_dev) 469 { 470 struct btrfs_path *path; 471 struct btrfs_key key; 472 struct btrfs_key found_key; 473 struct btrfs_root *root = fs_info->dev_root; 474 struct btrfs_dev_extent *dev_extent = NULL; 475 struct btrfs_block_group *cache; 476 struct btrfs_trans_handle *trans; 477 int ret = 0; 478 u64 chunk_offset; 479 480 /* Do not use "to_copy" on non zoned filesystem for now */ 481 if (!btrfs_is_zoned(fs_info)) 482 return 0; 483 484 mutex_lock(&fs_info->chunk_mutex); 485 486 /* Ensure we don't have pending new block group */ 487 spin_lock(&fs_info->trans_lock); 488 while (fs_info->running_transaction && 489 !list_empty(&fs_info->running_transaction->dev_update_list)) { 490 spin_unlock(&fs_info->trans_lock); 491 mutex_unlock(&fs_info->chunk_mutex); 492 trans = btrfs_attach_transaction(root); 493 if (IS_ERR(trans)) { 494 ret = PTR_ERR(trans); 495 mutex_lock(&fs_info->chunk_mutex); 496 if (ret == -ENOENT) { 497 spin_lock(&fs_info->trans_lock); 498 continue; 499 } else { 500 goto unlock; 501 } 502 } 503 504 ret = btrfs_commit_transaction(trans); 505 mutex_lock(&fs_info->chunk_mutex); 506 if (ret) 507 goto unlock; 508 509 spin_lock(&fs_info->trans_lock); 510 } 511 spin_unlock(&fs_info->trans_lock); 512 513 path = btrfs_alloc_path(); 514 if (!path) { 515 ret = -ENOMEM; 516 goto unlock; 517 } 518 519 path->reada = READA_FORWARD; 520 path->search_commit_root = 1; 521 path->skip_locking = 1; 522 523 key.objectid = src_dev->devid; 524 key.type = BTRFS_DEV_EXTENT_KEY; 525 key.offset = 0; 526 527 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 528 if (ret < 0) 529 goto free_path; 530 if (ret > 0) { 531 if (path->slots[0] >= 532 btrfs_header_nritems(path->nodes[0])) { 533 ret = btrfs_next_leaf(root, path); 534 if (ret < 0) 535 goto free_path; 536 if (ret > 0) { 537 ret = 0; 538 goto free_path; 539 } 540 } else { 541 ret = 0; 542 } 543 } 544 545 while (1) { 546 struct extent_buffer *leaf = path->nodes[0]; 547 int slot = path->slots[0]; 548 549 btrfs_item_key_to_cpu(leaf, &found_key, slot); 550 551 if (found_key.objectid != src_dev->devid) 552 break; 553 554 if (found_key.type != BTRFS_DEV_EXTENT_KEY) 555 break; 556 557 if (found_key.offset < key.offset) 558 break; 559 560 dev_extent = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent); 561 562 chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dev_extent); 563 564 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 565 if (!cache) 566 goto skip; 567 568 spin_lock(&cache->lock); 569 cache->to_copy = 1; 570 spin_unlock(&cache->lock); 571 572 btrfs_put_block_group(cache); 573 574 skip: 575 ret = btrfs_next_item(root, path); 576 if (ret != 0) { 577 if (ret > 0) 578 ret = 0; 579 break; 580 } 581 } 582 583 free_path: 584 btrfs_free_path(path); 585 unlock: 586 mutex_unlock(&fs_info->chunk_mutex); 587 588 return ret; 589 } 590 591 bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, 592 struct btrfs_block_group *cache, 593 u64 physical) 594 { 595 struct btrfs_fs_info *fs_info = cache->fs_info; 596 struct extent_map *em; 597 struct map_lookup *map; 598 u64 chunk_offset = cache->start; 599 int num_extents, cur_extent; 600 int i; 601 602 /* Do not use "to_copy" on non zoned filesystem for now */ 603 if (!btrfs_is_zoned(fs_info)) 604 return true; 605 606 spin_lock(&cache->lock); 607 if (cache->removed) { 608 spin_unlock(&cache->lock); 609 return true; 610 } 611 spin_unlock(&cache->lock); 612 613 em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); 614 ASSERT(!IS_ERR(em)); 615 map = em->map_lookup; 616 617 num_extents = cur_extent = 0; 618 for (i = 0; i < map->num_stripes; i++) { 619 /* We have more device extent to copy */ 620 if (srcdev != map->stripes[i].dev) 621 continue; 622 623 num_extents++; 624 if (physical == map->stripes[i].physical) 625 cur_extent = i; 626 } 627 628 free_extent_map(em); 629 630 if (num_extents > 1 && cur_extent < num_extents - 1) { 631 /* 632 * Has more stripes on this device. Keep this block group 633 * readonly until we finish all the stripes. 634 */ 635 return false; 636 } 637 638 /* Last stripe on this device */ 639 spin_lock(&cache->lock); 640 cache->to_copy = 0; 641 spin_unlock(&cache->lock); 642 643 return true; 644 } 645 646 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 647 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 648 int read_src) 649 { 650 struct btrfs_root *root = fs_info->dev_root; 651 struct btrfs_trans_handle *trans; 652 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 653 int ret; 654 struct btrfs_device *tgt_device = NULL; 655 struct btrfs_device *src_device = NULL; 656 657 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, 658 srcdev_name); 659 if (IS_ERR(src_device)) 660 return PTR_ERR(src_device); 661 662 if (btrfs_pinned_by_swapfile(fs_info, src_device)) { 663 btrfs_warn_in_rcu(fs_info, 664 "cannot replace device %s (devid %llu) due to active swapfile", 665 btrfs_dev_name(src_device), src_device->devid); 666 return -ETXTBSY; 667 } 668 669 /* 670 * Here we commit the transaction to make sure commit_total_bytes 671 * of all the devices are updated. 672 */ 673 trans = btrfs_attach_transaction(root); 674 if (!IS_ERR(trans)) { 675 ret = btrfs_commit_transaction(trans); 676 if (ret) 677 return ret; 678 } else if (PTR_ERR(trans) != -ENOENT) { 679 return PTR_ERR(trans); 680 } 681 682 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 683 src_device, &tgt_device); 684 if (ret) 685 return ret; 686 687 ret = mark_block_group_to_copy(fs_info, src_device); 688 if (ret) 689 return ret; 690 691 down_write(&dev_replace->rwsem); 692 switch (dev_replace->replace_state) { 693 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 694 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 695 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 696 break; 697 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 698 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 699 ASSERT(0); 700 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 701 up_write(&dev_replace->rwsem); 702 goto leave; 703 } 704 705 dev_replace->cont_reading_from_srcdev_mode = read_src; 706 dev_replace->srcdev = src_device; 707 dev_replace->tgtdev = tgt_device; 708 709 btrfs_info_in_rcu(fs_info, 710 "dev_replace from %s (devid %llu) to %s started", 711 btrfs_dev_name(src_device), 712 src_device->devid, 713 rcu_str_deref(tgt_device->name)); 714 715 /* 716 * from now on, the writes to the srcdev are all duplicated to 717 * go to the tgtdev as well (refer to btrfs_map_block()). 718 */ 719 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 720 dev_replace->time_started = ktime_get_real_seconds(); 721 dev_replace->cursor_left = 0; 722 dev_replace->committed_cursor_left = 0; 723 dev_replace->cursor_left_last_write_of_item = 0; 724 dev_replace->cursor_right = 0; 725 dev_replace->is_valid = 1; 726 dev_replace->item_needs_writeback = 1; 727 atomic64_set(&dev_replace->num_write_errors, 0); 728 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 729 up_write(&dev_replace->rwsem); 730 731 ret = btrfs_sysfs_add_device(tgt_device); 732 if (ret) 733 btrfs_err(fs_info, "kobj add dev failed %d", ret); 734 735 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 736 737 /* Commit dev_replace state and reserve 1 item for it. */ 738 trans = btrfs_start_transaction(root, 1); 739 if (IS_ERR(trans)) { 740 ret = PTR_ERR(trans); 741 down_write(&dev_replace->rwsem); 742 dev_replace->replace_state = 743 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 744 dev_replace->srcdev = NULL; 745 dev_replace->tgtdev = NULL; 746 up_write(&dev_replace->rwsem); 747 goto leave; 748 } 749 750 ret = btrfs_commit_transaction(trans); 751 WARN_ON(ret); 752 753 /* the disk copy procedure reuses the scrub code */ 754 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 755 btrfs_device_get_total_bytes(src_device), 756 &dev_replace->scrub_progress, 0, 1); 757 758 ret = btrfs_dev_replace_finishing(fs_info, ret); 759 if (ret == -EINPROGRESS) 760 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 761 762 return ret; 763 764 leave: 765 btrfs_destroy_dev_replace_tgtdev(tgt_device); 766 return ret; 767 } 768 769 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 770 struct btrfs_ioctl_dev_replace_args *args) 771 { 772 int ret; 773 774 switch (args->start.cont_reading_from_srcdev_mode) { 775 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 776 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 777 break; 778 default: 779 return -EINVAL; 780 } 781 782 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 783 args->start.tgtdev_name[0] == '\0') 784 return -EINVAL; 785 786 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 787 args->start.srcdevid, 788 args->start.srcdev_name, 789 args->start.cont_reading_from_srcdev_mode); 790 args->result = ret; 791 /* don't warn if EINPROGRESS, someone else might be running scrub */ 792 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 793 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 794 return 0; 795 796 return ret; 797 } 798 799 /* 800 * blocked until all in-flight bios operations are finished. 801 */ 802 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 803 { 804 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 805 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 806 &fs_info->dev_replace.bio_counter)); 807 } 808 809 /* 810 * we have removed target device, it is safe to allow new bios request. 811 */ 812 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 813 { 814 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 815 wake_up(&fs_info->dev_replace.replace_wait); 816 } 817 818 /* 819 * When finishing the device replace, before swapping the source device with the 820 * target device we must update the chunk allocation state in the target device, 821 * as it is empty because replace works by directly copying the chunks and not 822 * through the normal chunk allocation path. 823 */ 824 static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev, 825 struct btrfs_device *tgtdev) 826 { 827 struct extent_state *cached_state = NULL; 828 u64 start = 0; 829 u64 found_start; 830 u64 found_end; 831 int ret = 0; 832 833 lockdep_assert_held(&srcdev->fs_info->chunk_mutex); 834 835 while (!find_first_extent_bit(&srcdev->alloc_state, start, 836 &found_start, &found_end, 837 CHUNK_ALLOCATED, &cached_state)) { 838 ret = set_extent_bits(&tgtdev->alloc_state, found_start, 839 found_end, CHUNK_ALLOCATED); 840 if (ret) 841 break; 842 start = found_end + 1; 843 } 844 845 free_extent_state(cached_state); 846 return ret; 847 } 848 849 static void btrfs_dev_replace_update_device_in_mapping_tree( 850 struct btrfs_fs_info *fs_info, 851 struct btrfs_device *srcdev, 852 struct btrfs_device *tgtdev) 853 { 854 struct extent_map_tree *em_tree = &fs_info->mapping_tree; 855 struct extent_map *em; 856 struct map_lookup *map; 857 u64 start = 0; 858 int i; 859 860 write_lock(&em_tree->lock); 861 do { 862 em = lookup_extent_mapping(em_tree, start, (u64)-1); 863 if (!em) 864 break; 865 map = em->map_lookup; 866 for (i = 0; i < map->num_stripes; i++) 867 if (srcdev == map->stripes[i].dev) 868 map->stripes[i].dev = tgtdev; 869 start = em->start + em->len; 870 free_extent_map(em); 871 } while (start); 872 write_unlock(&em_tree->lock); 873 } 874 875 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 876 int scrub_ret) 877 { 878 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 879 struct btrfs_device *tgt_device; 880 struct btrfs_device *src_device; 881 struct btrfs_root *root = fs_info->tree_root; 882 u8 uuid_tmp[BTRFS_UUID_SIZE]; 883 struct btrfs_trans_handle *trans; 884 int ret = 0; 885 886 /* don't allow cancel or unmount to disturb the finishing procedure */ 887 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 888 889 down_read(&dev_replace->rwsem); 890 /* was the operation canceled, or is it finished? */ 891 if (dev_replace->replace_state != 892 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 893 up_read(&dev_replace->rwsem); 894 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 895 return 0; 896 } 897 898 tgt_device = dev_replace->tgtdev; 899 src_device = dev_replace->srcdev; 900 up_read(&dev_replace->rwsem); 901 902 /* 903 * flush all outstanding I/O and inode extent mappings before the 904 * copy operation is declared as being finished 905 */ 906 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false); 907 if (ret) { 908 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 909 return ret; 910 } 911 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 912 913 /* 914 * We have to use this loop approach because at this point src_device 915 * has to be available for transaction commit to complete, yet new 916 * chunks shouldn't be allocated on the device. 917 */ 918 while (1) { 919 trans = btrfs_start_transaction(root, 0); 920 if (IS_ERR(trans)) { 921 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 922 return PTR_ERR(trans); 923 } 924 ret = btrfs_commit_transaction(trans); 925 WARN_ON(ret); 926 927 /* Prevent write_all_supers() during the finishing procedure */ 928 mutex_lock(&fs_info->fs_devices->device_list_mutex); 929 /* Prevent new chunks being allocated on the source device */ 930 mutex_lock(&fs_info->chunk_mutex); 931 932 if (!list_empty(&src_device->post_commit_list)) { 933 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 934 mutex_unlock(&fs_info->chunk_mutex); 935 } else { 936 break; 937 } 938 } 939 940 down_write(&dev_replace->rwsem); 941 dev_replace->replace_state = 942 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 943 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 944 dev_replace->tgtdev = NULL; 945 dev_replace->srcdev = NULL; 946 dev_replace->time_stopped = ktime_get_real_seconds(); 947 dev_replace->item_needs_writeback = 1; 948 949 /* 950 * Update allocation state in the new device and replace the old device 951 * with the new one in the mapping tree. 952 */ 953 if (!scrub_ret) { 954 scrub_ret = btrfs_set_target_alloc_state(src_device, tgt_device); 955 if (scrub_ret) 956 goto error; 957 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 958 src_device, 959 tgt_device); 960 } else { 961 if (scrub_ret != -ECANCELED) 962 btrfs_err_in_rcu(fs_info, 963 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 964 btrfs_dev_name(src_device), 965 src_device->devid, 966 rcu_str_deref(tgt_device->name), scrub_ret); 967 error: 968 up_write(&dev_replace->rwsem); 969 mutex_unlock(&fs_info->chunk_mutex); 970 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 971 btrfs_rm_dev_replace_blocked(fs_info); 972 if (tgt_device) 973 btrfs_destroy_dev_replace_tgtdev(tgt_device); 974 btrfs_rm_dev_replace_unblocked(fs_info); 975 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 976 977 return scrub_ret; 978 } 979 980 btrfs_info_in_rcu(fs_info, 981 "dev_replace from %s (devid %llu) to %s finished", 982 btrfs_dev_name(src_device), 983 src_device->devid, 984 rcu_str_deref(tgt_device->name)); 985 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 986 tgt_device->devid = src_device->devid; 987 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 988 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 989 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 990 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 991 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 992 btrfs_device_set_disk_total_bytes(tgt_device, 993 src_device->disk_total_bytes); 994 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 995 tgt_device->commit_bytes_used = src_device->bytes_used; 996 997 btrfs_assign_next_active_device(src_device, tgt_device); 998 999 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 1000 fs_info->fs_devices->rw_devices++; 1001 1002 up_write(&dev_replace->rwsem); 1003 btrfs_rm_dev_replace_blocked(fs_info); 1004 1005 btrfs_rm_dev_replace_remove_srcdev(src_device); 1006 1007 btrfs_rm_dev_replace_unblocked(fs_info); 1008 1009 /* 1010 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will 1011 * update on-disk dev stats value during commit transaction 1012 */ 1013 atomic_inc(&tgt_device->dev_stats_ccnt); 1014 1015 /* 1016 * this is again a consistent state where no dev_replace procedure 1017 * is running, the target device is part of the filesystem, the 1018 * source device is not part of the filesystem anymore and its 1st 1019 * superblock is scratched out so that it is no longer marked to 1020 * belong to this filesystem. 1021 */ 1022 mutex_unlock(&fs_info->chunk_mutex); 1023 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1024 1025 /* replace the sysfs entry */ 1026 btrfs_sysfs_remove_device(src_device); 1027 btrfs_sysfs_update_devid(tgt_device); 1028 if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &src_device->dev_state)) 1029 btrfs_scratch_superblocks(fs_info, src_device->bdev, 1030 src_device->name->str); 1031 1032 /* write back the superblocks */ 1033 trans = btrfs_start_transaction(root, 0); 1034 if (!IS_ERR(trans)) 1035 btrfs_commit_transaction(trans); 1036 1037 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1038 1039 btrfs_rm_dev_replace_free_srcdev(src_device); 1040 1041 return 0; 1042 } 1043 1044 /* 1045 * Read progress of device replace status according to the state and last 1046 * stored position. The value format is the same as for 1047 * btrfs_dev_replace::progress_1000 1048 */ 1049 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 1050 { 1051 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1052 u64 ret = 0; 1053 1054 switch (dev_replace->replace_state) { 1055 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1056 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1057 ret = 0; 1058 break; 1059 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1060 ret = 1000; 1061 break; 1062 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1063 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1064 ret = div64_u64(dev_replace->cursor_left, 1065 div_u64(btrfs_device_get_total_bytes( 1066 dev_replace->srcdev), 1000)); 1067 break; 1068 } 1069 1070 return ret; 1071 } 1072 1073 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 1074 struct btrfs_ioctl_dev_replace_args *args) 1075 { 1076 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1077 1078 down_read(&dev_replace->rwsem); 1079 /* even if !dev_replace_is_valid, the values are good enough for 1080 * the replace_status ioctl */ 1081 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1082 args->status.replace_state = dev_replace->replace_state; 1083 args->status.time_started = dev_replace->time_started; 1084 args->status.time_stopped = dev_replace->time_stopped; 1085 args->status.num_write_errors = 1086 atomic64_read(&dev_replace->num_write_errors); 1087 args->status.num_uncorrectable_read_errors = 1088 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 1089 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 1090 up_read(&dev_replace->rwsem); 1091 } 1092 1093 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 1094 { 1095 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1096 struct btrfs_device *tgt_device = NULL; 1097 struct btrfs_device *src_device = NULL; 1098 struct btrfs_trans_handle *trans; 1099 struct btrfs_root *root = fs_info->tree_root; 1100 int result; 1101 int ret; 1102 1103 if (sb_rdonly(fs_info->sb)) 1104 return -EROFS; 1105 1106 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1107 down_write(&dev_replace->rwsem); 1108 switch (dev_replace->replace_state) { 1109 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1110 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1111 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1112 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1113 up_write(&dev_replace->rwsem); 1114 break; 1115 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1116 tgt_device = dev_replace->tgtdev; 1117 src_device = dev_replace->srcdev; 1118 up_write(&dev_replace->rwsem); 1119 ret = btrfs_scrub_cancel(fs_info); 1120 if (ret < 0) { 1121 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1122 } else { 1123 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1124 /* 1125 * btrfs_dev_replace_finishing() will handle the 1126 * cleanup part 1127 */ 1128 btrfs_info_in_rcu(fs_info, 1129 "dev_replace from %s (devid %llu) to %s canceled", 1130 btrfs_dev_name(src_device), src_device->devid, 1131 btrfs_dev_name(tgt_device)); 1132 } 1133 break; 1134 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1135 /* 1136 * Scrub doing the replace isn't running so we need to do the 1137 * cleanup step of btrfs_dev_replace_finishing() here 1138 */ 1139 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1140 tgt_device = dev_replace->tgtdev; 1141 src_device = dev_replace->srcdev; 1142 dev_replace->tgtdev = NULL; 1143 dev_replace->srcdev = NULL; 1144 dev_replace->replace_state = 1145 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 1146 dev_replace->time_stopped = ktime_get_real_seconds(); 1147 dev_replace->item_needs_writeback = 1; 1148 1149 up_write(&dev_replace->rwsem); 1150 1151 /* Scrub for replace must not be running in suspended state */ 1152 ret = btrfs_scrub_cancel(fs_info); 1153 ASSERT(ret != -ENOTCONN); 1154 1155 trans = btrfs_start_transaction(root, 0); 1156 if (IS_ERR(trans)) { 1157 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1158 return PTR_ERR(trans); 1159 } 1160 ret = btrfs_commit_transaction(trans); 1161 WARN_ON(ret); 1162 1163 btrfs_info_in_rcu(fs_info, 1164 "suspended dev_replace from %s (devid %llu) to %s canceled", 1165 btrfs_dev_name(src_device), src_device->devid, 1166 btrfs_dev_name(tgt_device)); 1167 1168 if (tgt_device) 1169 btrfs_destroy_dev_replace_tgtdev(tgt_device); 1170 break; 1171 default: 1172 up_write(&dev_replace->rwsem); 1173 result = -EINVAL; 1174 } 1175 1176 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1177 return result; 1178 } 1179 1180 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 1181 { 1182 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1183 1184 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1185 down_write(&dev_replace->rwsem); 1186 1187 switch (dev_replace->replace_state) { 1188 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1189 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1190 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1191 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1192 break; 1193 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1194 dev_replace->replace_state = 1195 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1196 dev_replace->time_stopped = ktime_get_real_seconds(); 1197 dev_replace->item_needs_writeback = 1; 1198 btrfs_info(fs_info, "suspending dev_replace for unmount"); 1199 break; 1200 } 1201 1202 up_write(&dev_replace->rwsem); 1203 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1204 } 1205 1206 /* resume dev_replace procedure that was interrupted by unmount */ 1207 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 1208 { 1209 struct task_struct *task; 1210 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1211 1212 down_write(&dev_replace->rwsem); 1213 1214 switch (dev_replace->replace_state) { 1215 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1216 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1217 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1218 up_write(&dev_replace->rwsem); 1219 return 0; 1220 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1221 break; 1222 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1223 dev_replace->replace_state = 1224 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 1225 break; 1226 } 1227 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 1228 btrfs_info(fs_info, 1229 "cannot continue dev_replace, tgtdev is missing"); 1230 btrfs_info(fs_info, 1231 "you may cancel the operation after 'mount -o degraded'"); 1232 dev_replace->replace_state = 1233 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1234 up_write(&dev_replace->rwsem); 1235 return 0; 1236 } 1237 up_write(&dev_replace->rwsem); 1238 1239 /* 1240 * This could collide with a paused balance, but the exclusive op logic 1241 * should never allow both to start and pause. We don't want to allow 1242 * dev-replace to start anyway. 1243 */ 1244 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { 1245 down_write(&dev_replace->rwsem); 1246 dev_replace->replace_state = 1247 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1248 up_write(&dev_replace->rwsem); 1249 btrfs_info(fs_info, 1250 "cannot resume dev-replace, other exclusive operation running"); 1251 return 0; 1252 } 1253 1254 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 1255 return PTR_ERR_OR_ZERO(task); 1256 } 1257 1258 static int btrfs_dev_replace_kthread(void *data) 1259 { 1260 struct btrfs_fs_info *fs_info = data; 1261 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1262 u64 progress; 1263 int ret; 1264 1265 progress = btrfs_dev_replace_progress(fs_info); 1266 progress = div_u64(progress, 10); 1267 btrfs_info_in_rcu(fs_info, 1268 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 1269 btrfs_dev_name(dev_replace->srcdev), 1270 dev_replace->srcdev->devid, 1271 btrfs_dev_name(dev_replace->tgtdev), 1272 (unsigned int)progress); 1273 1274 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 1275 dev_replace->committed_cursor_left, 1276 btrfs_device_get_total_bytes(dev_replace->srcdev), 1277 &dev_replace->scrub_progress, 0, 1); 1278 ret = btrfs_dev_replace_finishing(fs_info, ret); 1279 WARN_ON(ret && ret != -ECANCELED); 1280 1281 btrfs_exclop_finish(fs_info); 1282 return 0; 1283 } 1284 1285 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 1286 { 1287 if (!dev_replace->is_valid) 1288 return 0; 1289 1290 switch (dev_replace->replace_state) { 1291 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1292 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1293 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1294 return 0; 1295 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1296 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1297 /* 1298 * return true even if tgtdev is missing (this is 1299 * something that can happen if the dev_replace 1300 * procedure is suspended by an umount and then 1301 * the tgtdev is missing (or "btrfs dev scan") was 1302 * not called and the filesystem is remounted 1303 * in degraded state. This does not stop the 1304 * dev_replace procedure. It needs to be canceled 1305 * manually if the cancellation is wanted. 1306 */ 1307 break; 1308 } 1309 return 1; 1310 } 1311 1312 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1313 { 1314 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1315 } 1316 1317 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1318 { 1319 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); 1320 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); 1321 } 1322 1323 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1324 { 1325 while (1) { 1326 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1327 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1328 &fs_info->fs_state))) 1329 break; 1330 1331 btrfs_bio_counter_dec(fs_info); 1332 wait_event(fs_info->dev_replace.replace_wait, 1333 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1334 &fs_info->fs_state)); 1335 } 1336 } 1337