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); 306 307 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 308 device->generation = 0; 309 device->io_width = fs_info->sectorsize; 310 device->io_align = fs_info->sectorsize; 311 device->sector_size = fs_info->sectorsize; 312 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 313 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 314 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 315 device->commit_total_bytes = srcdev->commit_total_bytes; 316 device->commit_bytes_used = device->bytes_used; 317 device->fs_info = fs_info; 318 device->bdev = bdev; 319 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 320 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 321 device->mode = FMODE_EXCL; 322 device->dev_stats_valid = 1; 323 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 324 device->fs_devices = fs_devices; 325 326 ret = btrfs_get_dev_zone_info(device, false); 327 if (ret) 328 goto error; 329 330 mutex_lock(&fs_devices->device_list_mutex); 331 list_add(&device->dev_list, &fs_devices->devices); 332 fs_devices->num_devices++; 333 fs_devices->open_devices++; 334 mutex_unlock(&fs_devices->device_list_mutex); 335 336 *device_out = device; 337 return 0; 338 339 error: 340 blkdev_put(bdev, FMODE_EXCL); 341 return ret; 342 } 343 344 /* 345 * called from commit_transaction. Writes changed device replace state to 346 * disk. 347 */ 348 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 349 { 350 struct btrfs_fs_info *fs_info = trans->fs_info; 351 int ret; 352 struct btrfs_root *dev_root = fs_info->dev_root; 353 struct btrfs_path *path; 354 struct btrfs_key key; 355 struct extent_buffer *eb; 356 struct btrfs_dev_replace_item *ptr; 357 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 358 359 down_read(&dev_replace->rwsem); 360 if (!dev_replace->is_valid || 361 !dev_replace->item_needs_writeback) { 362 up_read(&dev_replace->rwsem); 363 return 0; 364 } 365 up_read(&dev_replace->rwsem); 366 367 key.objectid = 0; 368 key.type = BTRFS_DEV_REPLACE_KEY; 369 key.offset = 0; 370 371 path = btrfs_alloc_path(); 372 if (!path) { 373 ret = -ENOMEM; 374 goto out; 375 } 376 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 377 if (ret < 0) { 378 btrfs_warn(fs_info, 379 "error %d while searching for dev_replace item!", 380 ret); 381 goto out; 382 } 383 384 if (ret == 0 && 385 btrfs_item_size(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 386 /* 387 * need to delete old one and insert a new one. 388 * Since no attempt is made to recover any old state, if the 389 * dev_replace state is 'running', the data on the target 390 * drive is lost. 391 * It would be possible to recover the state: just make sure 392 * that the beginning of the item is never changed and always 393 * contains all the essential information. Then read this 394 * minimal set of information and use it as a base for the 395 * new state. 396 */ 397 ret = btrfs_del_item(trans, dev_root, path); 398 if (ret != 0) { 399 btrfs_warn(fs_info, 400 "delete too small dev_replace item failed %d!", 401 ret); 402 goto out; 403 } 404 ret = 1; 405 } 406 407 if (ret == 1) { 408 /* need to insert a new item */ 409 btrfs_release_path(path); 410 ret = btrfs_insert_empty_item(trans, dev_root, path, 411 &key, sizeof(*ptr)); 412 if (ret < 0) { 413 btrfs_warn(fs_info, 414 "insert dev_replace item failed %d!", ret); 415 goto out; 416 } 417 } 418 419 eb = path->nodes[0]; 420 ptr = btrfs_item_ptr(eb, path->slots[0], 421 struct btrfs_dev_replace_item); 422 423 down_write(&dev_replace->rwsem); 424 if (dev_replace->srcdev) 425 btrfs_set_dev_replace_src_devid(eb, ptr, 426 dev_replace->srcdev->devid); 427 else 428 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 429 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 430 dev_replace->cont_reading_from_srcdev_mode); 431 btrfs_set_dev_replace_replace_state(eb, ptr, 432 dev_replace->replace_state); 433 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 434 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 435 btrfs_set_dev_replace_num_write_errors(eb, ptr, 436 atomic64_read(&dev_replace->num_write_errors)); 437 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 438 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 439 dev_replace->cursor_left_last_write_of_item = 440 dev_replace->cursor_left; 441 btrfs_set_dev_replace_cursor_left(eb, ptr, 442 dev_replace->cursor_left_last_write_of_item); 443 btrfs_set_dev_replace_cursor_right(eb, ptr, 444 dev_replace->cursor_right); 445 dev_replace->item_needs_writeback = 0; 446 up_write(&dev_replace->rwsem); 447 448 btrfs_mark_buffer_dirty(eb); 449 450 out: 451 btrfs_free_path(path); 452 453 return ret; 454 } 455 456 static char* btrfs_dev_name(struct btrfs_device *device) 457 { 458 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 459 return "<missing disk>"; 460 else 461 return rcu_str_deref(device->name); 462 } 463 464 static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info, 465 struct btrfs_device *src_dev) 466 { 467 struct btrfs_path *path; 468 struct btrfs_key key; 469 struct btrfs_key found_key; 470 struct btrfs_root *root = fs_info->dev_root; 471 struct btrfs_dev_extent *dev_extent = NULL; 472 struct btrfs_block_group *cache; 473 struct btrfs_trans_handle *trans; 474 int ret = 0; 475 u64 chunk_offset; 476 477 /* Do not use "to_copy" on non zoned filesystem for now */ 478 if (!btrfs_is_zoned(fs_info)) 479 return 0; 480 481 mutex_lock(&fs_info->chunk_mutex); 482 483 /* Ensure we don't have pending new block group */ 484 spin_lock(&fs_info->trans_lock); 485 while (fs_info->running_transaction && 486 !list_empty(&fs_info->running_transaction->dev_update_list)) { 487 spin_unlock(&fs_info->trans_lock); 488 mutex_unlock(&fs_info->chunk_mutex); 489 trans = btrfs_attach_transaction(root); 490 if (IS_ERR(trans)) { 491 ret = PTR_ERR(trans); 492 mutex_lock(&fs_info->chunk_mutex); 493 if (ret == -ENOENT) { 494 spin_lock(&fs_info->trans_lock); 495 continue; 496 } else { 497 goto unlock; 498 } 499 } 500 501 ret = btrfs_commit_transaction(trans); 502 mutex_lock(&fs_info->chunk_mutex); 503 if (ret) 504 goto unlock; 505 506 spin_lock(&fs_info->trans_lock); 507 } 508 spin_unlock(&fs_info->trans_lock); 509 510 path = btrfs_alloc_path(); 511 if (!path) { 512 ret = -ENOMEM; 513 goto unlock; 514 } 515 516 path->reada = READA_FORWARD; 517 path->search_commit_root = 1; 518 path->skip_locking = 1; 519 520 key.objectid = src_dev->devid; 521 key.type = BTRFS_DEV_EXTENT_KEY; 522 key.offset = 0; 523 524 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 525 if (ret < 0) 526 goto free_path; 527 if (ret > 0) { 528 if (path->slots[0] >= 529 btrfs_header_nritems(path->nodes[0])) { 530 ret = btrfs_next_leaf(root, path); 531 if (ret < 0) 532 goto free_path; 533 if (ret > 0) { 534 ret = 0; 535 goto free_path; 536 } 537 } else { 538 ret = 0; 539 } 540 } 541 542 while (1) { 543 struct extent_buffer *leaf = path->nodes[0]; 544 int slot = path->slots[0]; 545 546 btrfs_item_key_to_cpu(leaf, &found_key, slot); 547 548 if (found_key.objectid != src_dev->devid) 549 break; 550 551 if (found_key.type != BTRFS_DEV_EXTENT_KEY) 552 break; 553 554 if (found_key.offset < key.offset) 555 break; 556 557 dev_extent = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent); 558 559 chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dev_extent); 560 561 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 562 if (!cache) 563 goto skip; 564 565 spin_lock(&cache->lock); 566 cache->to_copy = 1; 567 spin_unlock(&cache->lock); 568 569 btrfs_put_block_group(cache); 570 571 skip: 572 ret = btrfs_next_item(root, path); 573 if (ret != 0) { 574 if (ret > 0) 575 ret = 0; 576 break; 577 } 578 } 579 580 free_path: 581 btrfs_free_path(path); 582 unlock: 583 mutex_unlock(&fs_info->chunk_mutex); 584 585 return ret; 586 } 587 588 bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, 589 struct btrfs_block_group *cache, 590 u64 physical) 591 { 592 struct btrfs_fs_info *fs_info = cache->fs_info; 593 struct extent_map *em; 594 struct map_lookup *map; 595 u64 chunk_offset = cache->start; 596 int num_extents, cur_extent; 597 int i; 598 599 /* Do not use "to_copy" on non zoned filesystem for now */ 600 if (!btrfs_is_zoned(fs_info)) 601 return true; 602 603 spin_lock(&cache->lock); 604 if (cache->removed) { 605 spin_unlock(&cache->lock); 606 return true; 607 } 608 spin_unlock(&cache->lock); 609 610 em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); 611 ASSERT(!IS_ERR(em)); 612 map = em->map_lookup; 613 614 num_extents = cur_extent = 0; 615 for (i = 0; i < map->num_stripes; i++) { 616 /* We have more device extent to copy */ 617 if (srcdev != map->stripes[i].dev) 618 continue; 619 620 num_extents++; 621 if (physical == map->stripes[i].physical) 622 cur_extent = i; 623 } 624 625 free_extent_map(em); 626 627 if (num_extents > 1 && cur_extent < num_extents - 1) { 628 /* 629 * Has more stripes on this device. Keep this block group 630 * readonly until we finish all the stripes. 631 */ 632 return false; 633 } 634 635 /* Last stripe on this device */ 636 spin_lock(&cache->lock); 637 cache->to_copy = 0; 638 spin_unlock(&cache->lock); 639 640 return true; 641 } 642 643 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 644 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 645 int read_src) 646 { 647 struct btrfs_root *root = fs_info->dev_root; 648 struct btrfs_trans_handle *trans; 649 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 650 int ret; 651 struct btrfs_device *tgt_device = NULL; 652 struct btrfs_device *src_device = NULL; 653 654 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, 655 srcdev_name); 656 if (IS_ERR(src_device)) 657 return PTR_ERR(src_device); 658 659 if (btrfs_pinned_by_swapfile(fs_info, src_device)) { 660 btrfs_warn_in_rcu(fs_info, 661 "cannot replace device %s (devid %llu) due to active swapfile", 662 btrfs_dev_name(src_device), src_device->devid); 663 return -ETXTBSY; 664 } 665 666 /* 667 * Here we commit the transaction to make sure commit_total_bytes 668 * of all the devices are updated. 669 */ 670 trans = btrfs_attach_transaction(root); 671 if (!IS_ERR(trans)) { 672 ret = btrfs_commit_transaction(trans); 673 if (ret) 674 return ret; 675 } else if (PTR_ERR(trans) != -ENOENT) { 676 return PTR_ERR(trans); 677 } 678 679 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 680 src_device, &tgt_device); 681 if (ret) 682 return ret; 683 684 ret = mark_block_group_to_copy(fs_info, src_device); 685 if (ret) 686 return ret; 687 688 down_write(&dev_replace->rwsem); 689 switch (dev_replace->replace_state) { 690 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 691 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 692 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 693 break; 694 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 695 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 696 ASSERT(0); 697 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 698 up_write(&dev_replace->rwsem); 699 goto leave; 700 } 701 702 dev_replace->cont_reading_from_srcdev_mode = read_src; 703 dev_replace->srcdev = src_device; 704 dev_replace->tgtdev = tgt_device; 705 706 btrfs_info_in_rcu(fs_info, 707 "dev_replace from %s (devid %llu) to %s started", 708 btrfs_dev_name(src_device), 709 src_device->devid, 710 rcu_str_deref(tgt_device->name)); 711 712 /* 713 * from now on, the writes to the srcdev are all duplicated to 714 * go to the tgtdev as well (refer to btrfs_map_block()). 715 */ 716 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 717 dev_replace->time_started = ktime_get_real_seconds(); 718 dev_replace->cursor_left = 0; 719 dev_replace->committed_cursor_left = 0; 720 dev_replace->cursor_left_last_write_of_item = 0; 721 dev_replace->cursor_right = 0; 722 dev_replace->is_valid = 1; 723 dev_replace->item_needs_writeback = 1; 724 atomic64_set(&dev_replace->num_write_errors, 0); 725 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 726 up_write(&dev_replace->rwsem); 727 728 ret = btrfs_sysfs_add_device(tgt_device); 729 if (ret) 730 btrfs_err(fs_info, "kobj add dev failed %d", ret); 731 732 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 733 734 /* Commit dev_replace state and reserve 1 item for it. */ 735 trans = btrfs_start_transaction(root, 1); 736 if (IS_ERR(trans)) { 737 ret = PTR_ERR(trans); 738 down_write(&dev_replace->rwsem); 739 dev_replace->replace_state = 740 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 741 dev_replace->srcdev = NULL; 742 dev_replace->tgtdev = NULL; 743 up_write(&dev_replace->rwsem); 744 goto leave; 745 } 746 747 ret = btrfs_commit_transaction(trans); 748 WARN_ON(ret); 749 750 /* the disk copy procedure reuses the scrub code */ 751 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 752 btrfs_device_get_total_bytes(src_device), 753 &dev_replace->scrub_progress, 0, 1); 754 755 ret = btrfs_dev_replace_finishing(fs_info, ret); 756 if (ret == -EINPROGRESS) 757 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 758 759 return ret; 760 761 leave: 762 btrfs_destroy_dev_replace_tgtdev(tgt_device); 763 return ret; 764 } 765 766 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 767 struct btrfs_ioctl_dev_replace_args *args) 768 { 769 int ret; 770 771 switch (args->start.cont_reading_from_srcdev_mode) { 772 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 773 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 774 break; 775 default: 776 return -EINVAL; 777 } 778 779 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 780 args->start.tgtdev_name[0] == '\0') 781 return -EINVAL; 782 783 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 784 args->start.srcdevid, 785 args->start.srcdev_name, 786 args->start.cont_reading_from_srcdev_mode); 787 args->result = ret; 788 /* don't warn if EINPROGRESS, someone else might be running scrub */ 789 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 790 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 791 return 0; 792 793 return ret; 794 } 795 796 /* 797 * blocked until all in-flight bios operations are finished. 798 */ 799 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 800 { 801 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 802 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 803 &fs_info->dev_replace.bio_counter)); 804 } 805 806 /* 807 * we have removed target device, it is safe to allow new bios request. 808 */ 809 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 810 { 811 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 812 wake_up(&fs_info->dev_replace.replace_wait); 813 } 814 815 /* 816 * When finishing the device replace, before swapping the source device with the 817 * target device we must update the chunk allocation state in the target device, 818 * as it is empty because replace works by directly copying the chunks and not 819 * through the normal chunk allocation path. 820 */ 821 static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev, 822 struct btrfs_device *tgtdev) 823 { 824 struct extent_state *cached_state = NULL; 825 u64 start = 0; 826 u64 found_start; 827 u64 found_end; 828 int ret = 0; 829 830 lockdep_assert_held(&srcdev->fs_info->chunk_mutex); 831 832 while (!find_first_extent_bit(&srcdev->alloc_state, start, 833 &found_start, &found_end, 834 CHUNK_ALLOCATED, &cached_state)) { 835 ret = set_extent_bits(&tgtdev->alloc_state, found_start, 836 found_end, CHUNK_ALLOCATED); 837 if (ret) 838 break; 839 start = found_end + 1; 840 } 841 842 free_extent_state(cached_state); 843 return ret; 844 } 845 846 static void btrfs_dev_replace_update_device_in_mapping_tree( 847 struct btrfs_fs_info *fs_info, 848 struct btrfs_device *srcdev, 849 struct btrfs_device *tgtdev) 850 { 851 struct extent_map_tree *em_tree = &fs_info->mapping_tree; 852 struct extent_map *em; 853 struct map_lookup *map; 854 u64 start = 0; 855 int i; 856 857 write_lock(&em_tree->lock); 858 do { 859 em = lookup_extent_mapping(em_tree, start, (u64)-1); 860 if (!em) 861 break; 862 map = em->map_lookup; 863 for (i = 0; i < map->num_stripes; i++) 864 if (srcdev == map->stripes[i].dev) 865 map->stripes[i].dev = tgtdev; 866 start = em->start + em->len; 867 free_extent_map(em); 868 } while (start); 869 write_unlock(&em_tree->lock); 870 } 871 872 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 873 int scrub_ret) 874 { 875 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 876 struct btrfs_device *tgt_device; 877 struct btrfs_device *src_device; 878 struct btrfs_root *root = fs_info->tree_root; 879 u8 uuid_tmp[BTRFS_UUID_SIZE]; 880 struct btrfs_trans_handle *trans; 881 int ret = 0; 882 883 /* don't allow cancel or unmount to disturb the finishing procedure */ 884 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 885 886 down_read(&dev_replace->rwsem); 887 /* was the operation canceled, or is it finished? */ 888 if (dev_replace->replace_state != 889 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 890 up_read(&dev_replace->rwsem); 891 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 892 return 0; 893 } 894 895 tgt_device = dev_replace->tgtdev; 896 src_device = dev_replace->srcdev; 897 up_read(&dev_replace->rwsem); 898 899 /* 900 * flush all outstanding I/O and inode extent mappings before the 901 * copy operation is declared as being finished 902 */ 903 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false); 904 if (ret) { 905 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 906 return ret; 907 } 908 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 909 910 /* 911 * We have to use this loop approach because at this point src_device 912 * has to be available for transaction commit to complete, yet new 913 * chunks shouldn't be allocated on the device. 914 */ 915 while (1) { 916 trans = btrfs_start_transaction(root, 0); 917 if (IS_ERR(trans)) { 918 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 919 return PTR_ERR(trans); 920 } 921 ret = btrfs_commit_transaction(trans); 922 WARN_ON(ret); 923 924 /* Prevent write_all_supers() during the finishing procedure */ 925 mutex_lock(&fs_info->fs_devices->device_list_mutex); 926 /* Prevent new chunks being allocated on the source device */ 927 mutex_lock(&fs_info->chunk_mutex); 928 929 if (!list_empty(&src_device->post_commit_list)) { 930 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 931 mutex_unlock(&fs_info->chunk_mutex); 932 } else { 933 break; 934 } 935 } 936 937 down_write(&dev_replace->rwsem); 938 dev_replace->replace_state = 939 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 940 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 941 dev_replace->tgtdev = NULL; 942 dev_replace->srcdev = NULL; 943 dev_replace->time_stopped = ktime_get_real_seconds(); 944 dev_replace->item_needs_writeback = 1; 945 946 /* 947 * Update allocation state in the new device and replace the old device 948 * with the new one in the mapping tree. 949 */ 950 if (!scrub_ret) { 951 scrub_ret = btrfs_set_target_alloc_state(src_device, tgt_device); 952 if (scrub_ret) 953 goto error; 954 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 955 src_device, 956 tgt_device); 957 } else { 958 if (scrub_ret != -ECANCELED) 959 btrfs_err_in_rcu(fs_info, 960 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 961 btrfs_dev_name(src_device), 962 src_device->devid, 963 rcu_str_deref(tgt_device->name), scrub_ret); 964 error: 965 up_write(&dev_replace->rwsem); 966 mutex_unlock(&fs_info->chunk_mutex); 967 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 968 btrfs_rm_dev_replace_blocked(fs_info); 969 if (tgt_device) 970 btrfs_destroy_dev_replace_tgtdev(tgt_device); 971 btrfs_rm_dev_replace_unblocked(fs_info); 972 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 973 974 return scrub_ret; 975 } 976 977 btrfs_info_in_rcu(fs_info, 978 "dev_replace from %s (devid %llu) to %s finished", 979 btrfs_dev_name(src_device), 980 src_device->devid, 981 rcu_str_deref(tgt_device->name)); 982 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 983 tgt_device->devid = src_device->devid; 984 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 985 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 986 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 987 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 988 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 989 btrfs_device_set_disk_total_bytes(tgt_device, 990 src_device->disk_total_bytes); 991 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 992 tgt_device->commit_bytes_used = src_device->bytes_used; 993 994 btrfs_assign_next_active_device(src_device, tgt_device); 995 996 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 997 fs_info->fs_devices->rw_devices++; 998 999 up_write(&dev_replace->rwsem); 1000 btrfs_rm_dev_replace_blocked(fs_info); 1001 1002 btrfs_rm_dev_replace_remove_srcdev(src_device); 1003 1004 btrfs_rm_dev_replace_unblocked(fs_info); 1005 1006 /* 1007 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will 1008 * update on-disk dev stats value during commit transaction 1009 */ 1010 atomic_inc(&tgt_device->dev_stats_ccnt); 1011 1012 /* 1013 * this is again a consistent state where no dev_replace procedure 1014 * is running, the target device is part of the filesystem, the 1015 * source device is not part of the filesystem anymore and its 1st 1016 * superblock is scratched out so that it is no longer marked to 1017 * belong to this filesystem. 1018 */ 1019 mutex_unlock(&fs_info->chunk_mutex); 1020 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1021 1022 /* replace the sysfs entry */ 1023 btrfs_sysfs_remove_device(src_device); 1024 btrfs_sysfs_update_devid(tgt_device); 1025 if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &src_device->dev_state)) 1026 btrfs_scratch_superblocks(fs_info, src_device->bdev, 1027 src_device->name->str); 1028 1029 /* write back the superblocks */ 1030 trans = btrfs_start_transaction(root, 0); 1031 if (!IS_ERR(trans)) 1032 btrfs_commit_transaction(trans); 1033 1034 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1035 1036 btrfs_rm_dev_replace_free_srcdev(src_device); 1037 1038 return 0; 1039 } 1040 1041 /* 1042 * Read progress of device replace status according to the state and last 1043 * stored position. The value format is the same as for 1044 * btrfs_dev_replace::progress_1000 1045 */ 1046 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 1047 { 1048 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1049 u64 ret = 0; 1050 1051 switch (dev_replace->replace_state) { 1052 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1053 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1054 ret = 0; 1055 break; 1056 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1057 ret = 1000; 1058 break; 1059 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1060 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1061 ret = div64_u64(dev_replace->cursor_left, 1062 div_u64(btrfs_device_get_total_bytes( 1063 dev_replace->srcdev), 1000)); 1064 break; 1065 } 1066 1067 return ret; 1068 } 1069 1070 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 1071 struct btrfs_ioctl_dev_replace_args *args) 1072 { 1073 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1074 1075 down_read(&dev_replace->rwsem); 1076 /* even if !dev_replace_is_valid, the values are good enough for 1077 * the replace_status ioctl */ 1078 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1079 args->status.replace_state = dev_replace->replace_state; 1080 args->status.time_started = dev_replace->time_started; 1081 args->status.time_stopped = dev_replace->time_stopped; 1082 args->status.num_write_errors = 1083 atomic64_read(&dev_replace->num_write_errors); 1084 args->status.num_uncorrectable_read_errors = 1085 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 1086 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 1087 up_read(&dev_replace->rwsem); 1088 } 1089 1090 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 1091 { 1092 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1093 struct btrfs_device *tgt_device = NULL; 1094 struct btrfs_device *src_device = NULL; 1095 struct btrfs_trans_handle *trans; 1096 struct btrfs_root *root = fs_info->tree_root; 1097 int result; 1098 int ret; 1099 1100 if (sb_rdonly(fs_info->sb)) 1101 return -EROFS; 1102 1103 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1104 down_write(&dev_replace->rwsem); 1105 switch (dev_replace->replace_state) { 1106 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1107 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1108 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1109 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1110 up_write(&dev_replace->rwsem); 1111 break; 1112 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1113 tgt_device = dev_replace->tgtdev; 1114 src_device = dev_replace->srcdev; 1115 up_write(&dev_replace->rwsem); 1116 ret = btrfs_scrub_cancel(fs_info); 1117 if (ret < 0) { 1118 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1119 } else { 1120 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1121 /* 1122 * btrfs_dev_replace_finishing() will handle the 1123 * cleanup part 1124 */ 1125 btrfs_info_in_rcu(fs_info, 1126 "dev_replace from %s (devid %llu) to %s canceled", 1127 btrfs_dev_name(src_device), src_device->devid, 1128 btrfs_dev_name(tgt_device)); 1129 } 1130 break; 1131 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1132 /* 1133 * Scrub doing the replace isn't running so we need to do the 1134 * cleanup step of btrfs_dev_replace_finishing() here 1135 */ 1136 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1137 tgt_device = dev_replace->tgtdev; 1138 src_device = dev_replace->srcdev; 1139 dev_replace->tgtdev = NULL; 1140 dev_replace->srcdev = NULL; 1141 dev_replace->replace_state = 1142 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 1143 dev_replace->time_stopped = ktime_get_real_seconds(); 1144 dev_replace->item_needs_writeback = 1; 1145 1146 up_write(&dev_replace->rwsem); 1147 1148 /* Scrub for replace must not be running in suspended state */ 1149 ret = btrfs_scrub_cancel(fs_info); 1150 ASSERT(ret != -ENOTCONN); 1151 1152 trans = btrfs_start_transaction(root, 0); 1153 if (IS_ERR(trans)) { 1154 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1155 return PTR_ERR(trans); 1156 } 1157 ret = btrfs_commit_transaction(trans); 1158 WARN_ON(ret); 1159 1160 btrfs_info_in_rcu(fs_info, 1161 "suspended dev_replace from %s (devid %llu) to %s canceled", 1162 btrfs_dev_name(src_device), src_device->devid, 1163 btrfs_dev_name(tgt_device)); 1164 1165 if (tgt_device) 1166 btrfs_destroy_dev_replace_tgtdev(tgt_device); 1167 break; 1168 default: 1169 up_write(&dev_replace->rwsem); 1170 result = -EINVAL; 1171 } 1172 1173 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1174 return result; 1175 } 1176 1177 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 1178 { 1179 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1180 1181 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1182 down_write(&dev_replace->rwsem); 1183 1184 switch (dev_replace->replace_state) { 1185 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1186 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1187 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1188 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1189 break; 1190 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1191 dev_replace->replace_state = 1192 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1193 dev_replace->time_stopped = ktime_get_real_seconds(); 1194 dev_replace->item_needs_writeback = 1; 1195 btrfs_info(fs_info, "suspending dev_replace for unmount"); 1196 break; 1197 } 1198 1199 up_write(&dev_replace->rwsem); 1200 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1201 } 1202 1203 /* resume dev_replace procedure that was interrupted by unmount */ 1204 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 1205 { 1206 struct task_struct *task; 1207 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1208 1209 down_write(&dev_replace->rwsem); 1210 1211 switch (dev_replace->replace_state) { 1212 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1213 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1214 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1215 up_write(&dev_replace->rwsem); 1216 return 0; 1217 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1218 break; 1219 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1220 dev_replace->replace_state = 1221 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 1222 break; 1223 } 1224 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 1225 btrfs_info(fs_info, 1226 "cannot continue dev_replace, tgtdev is missing"); 1227 btrfs_info(fs_info, 1228 "you may cancel the operation after 'mount -o degraded'"); 1229 dev_replace->replace_state = 1230 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1231 up_write(&dev_replace->rwsem); 1232 return 0; 1233 } 1234 up_write(&dev_replace->rwsem); 1235 1236 /* 1237 * This could collide with a paused balance, but the exclusive op logic 1238 * should never allow both to start and pause. We don't want to allow 1239 * dev-replace to start anyway. 1240 */ 1241 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { 1242 down_write(&dev_replace->rwsem); 1243 dev_replace->replace_state = 1244 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1245 up_write(&dev_replace->rwsem); 1246 btrfs_info(fs_info, 1247 "cannot resume dev-replace, other exclusive operation running"); 1248 return 0; 1249 } 1250 1251 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 1252 return PTR_ERR_OR_ZERO(task); 1253 } 1254 1255 static int btrfs_dev_replace_kthread(void *data) 1256 { 1257 struct btrfs_fs_info *fs_info = data; 1258 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1259 u64 progress; 1260 int ret; 1261 1262 progress = btrfs_dev_replace_progress(fs_info); 1263 progress = div_u64(progress, 10); 1264 btrfs_info_in_rcu(fs_info, 1265 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 1266 btrfs_dev_name(dev_replace->srcdev), 1267 dev_replace->srcdev->devid, 1268 btrfs_dev_name(dev_replace->tgtdev), 1269 (unsigned int)progress); 1270 1271 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 1272 dev_replace->committed_cursor_left, 1273 btrfs_device_get_total_bytes(dev_replace->srcdev), 1274 &dev_replace->scrub_progress, 0, 1); 1275 ret = btrfs_dev_replace_finishing(fs_info, ret); 1276 WARN_ON(ret && ret != -ECANCELED); 1277 1278 btrfs_exclop_finish(fs_info); 1279 return 0; 1280 } 1281 1282 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 1283 { 1284 if (!dev_replace->is_valid) 1285 return 0; 1286 1287 switch (dev_replace->replace_state) { 1288 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1289 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1290 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1291 return 0; 1292 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1293 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1294 /* 1295 * return true even if tgtdev is missing (this is 1296 * something that can happen if the dev_replace 1297 * procedure is suspended by an umount and then 1298 * the tgtdev is missing (or "btrfs dev scan") was 1299 * not called and the filesystem is remounted 1300 * in degraded state. This does not stop the 1301 * dev_replace procedure. It needs to be canceled 1302 * manually if the cancellation is wanted. 1303 */ 1304 break; 1305 } 1306 return 1; 1307 } 1308 1309 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1310 { 1311 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1312 } 1313 1314 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1315 { 1316 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); 1317 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); 1318 } 1319 1320 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1321 { 1322 while (1) { 1323 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1324 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1325 &fs_info->fs_state))) 1326 break; 1327 1328 btrfs_bio_counter_dec(fs_info); 1329 wait_event(fs_info->dev_replace.replace_wait, 1330 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1331 &fs_info->fs_state)); 1332 } 1333 } 1334