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_nr(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_device *device; 247 struct block_device *bdev; 248 struct rcu_string *name; 249 u64 devid = BTRFS_DEV_REPLACE_DEVID; 250 int ret = 0; 251 252 *device_out = NULL; 253 if (srcdev->fs_devices->seeding) { 254 btrfs_err(fs_info, "the filesystem is a seed filesystem!"); 255 return -EINVAL; 256 } 257 258 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, 259 fs_info->bdev_holder); 260 if (IS_ERR(bdev)) { 261 btrfs_err(fs_info, "target device %s is invalid!", device_path); 262 return PTR_ERR(bdev); 263 } 264 265 if (!btrfs_check_device_zone_type(fs_info, bdev)) { 266 btrfs_err(fs_info, 267 "dev-replace: zoned type of target device mismatch with filesystem"); 268 ret = -EINVAL; 269 goto error; 270 } 271 272 sync_blockdev(bdev); 273 274 list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) { 275 if (device->bdev == bdev) { 276 btrfs_err(fs_info, 277 "target device is in the filesystem!"); 278 ret = -EEXIST; 279 goto error; 280 } 281 } 282 283 284 if (bdev_nr_bytes(bdev) < btrfs_device_get_total_bytes(srcdev)) { 285 btrfs_err(fs_info, 286 "target device is smaller than source device!"); 287 ret = -EINVAL; 288 goto error; 289 } 290 291 292 device = btrfs_alloc_device(NULL, &devid, NULL); 293 if (IS_ERR(device)) { 294 ret = PTR_ERR(device); 295 goto error; 296 } 297 298 name = rcu_string_strdup(device_path, GFP_KERNEL); 299 if (!name) { 300 btrfs_free_device(device); 301 ret = -ENOMEM; 302 goto error; 303 } 304 rcu_assign_pointer(device->name, name); 305 306 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 307 device->generation = 0; 308 device->io_width = fs_info->sectorsize; 309 device->io_align = fs_info->sectorsize; 310 device->sector_size = fs_info->sectorsize; 311 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 312 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 313 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 314 device->commit_total_bytes = srcdev->commit_total_bytes; 315 device->commit_bytes_used = device->bytes_used; 316 device->fs_info = fs_info; 317 device->bdev = bdev; 318 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 319 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 320 device->mode = FMODE_EXCL; 321 device->dev_stats_valid = 1; 322 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 323 device->fs_devices = fs_info->fs_devices; 324 325 ret = btrfs_get_dev_zone_info(device); 326 if (ret) 327 goto error; 328 329 mutex_lock(&fs_info->fs_devices->device_list_mutex); 330 list_add(&device->dev_list, &fs_info->fs_devices->devices); 331 fs_info->fs_devices->num_devices++; 332 fs_info->fs_devices->open_devices++; 333 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 334 335 *device_out = device; 336 return 0; 337 338 error: 339 blkdev_put(bdev, FMODE_EXCL); 340 return ret; 341 } 342 343 /* 344 * called from commit_transaction. Writes changed device replace state to 345 * disk. 346 */ 347 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 348 { 349 struct btrfs_fs_info *fs_info = trans->fs_info; 350 int ret; 351 struct btrfs_root *dev_root = fs_info->dev_root; 352 struct btrfs_path *path; 353 struct btrfs_key key; 354 struct extent_buffer *eb; 355 struct btrfs_dev_replace_item *ptr; 356 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 357 358 down_read(&dev_replace->rwsem); 359 if (!dev_replace->is_valid || 360 !dev_replace->item_needs_writeback) { 361 up_read(&dev_replace->rwsem); 362 return 0; 363 } 364 up_read(&dev_replace->rwsem); 365 366 key.objectid = 0; 367 key.type = BTRFS_DEV_REPLACE_KEY; 368 key.offset = 0; 369 370 path = btrfs_alloc_path(); 371 if (!path) { 372 ret = -ENOMEM; 373 goto out; 374 } 375 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 376 if (ret < 0) { 377 btrfs_warn(fs_info, 378 "error %d while searching for dev_replace item!", 379 ret); 380 goto out; 381 } 382 383 if (ret == 0 && 384 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 385 /* 386 * need to delete old one and insert a new one. 387 * Since no attempt is made to recover any old state, if the 388 * dev_replace state is 'running', the data on the target 389 * drive is lost. 390 * It would be possible to recover the state: just make sure 391 * that the beginning of the item is never changed and always 392 * contains all the essential information. Then read this 393 * minimal set of information and use it as a base for the 394 * new state. 395 */ 396 ret = btrfs_del_item(trans, dev_root, path); 397 if (ret != 0) { 398 btrfs_warn(fs_info, 399 "delete too small dev_replace item failed %d!", 400 ret); 401 goto out; 402 } 403 ret = 1; 404 } 405 406 if (ret == 1) { 407 /* need to insert a new item */ 408 btrfs_release_path(path); 409 ret = btrfs_insert_empty_item(trans, dev_root, path, 410 &key, sizeof(*ptr)); 411 if (ret < 0) { 412 btrfs_warn(fs_info, 413 "insert dev_replace item failed %d!", ret); 414 goto out; 415 } 416 } 417 418 eb = path->nodes[0]; 419 ptr = btrfs_item_ptr(eb, path->slots[0], 420 struct btrfs_dev_replace_item); 421 422 down_write(&dev_replace->rwsem); 423 if (dev_replace->srcdev) 424 btrfs_set_dev_replace_src_devid(eb, ptr, 425 dev_replace->srcdev->devid); 426 else 427 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 428 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 429 dev_replace->cont_reading_from_srcdev_mode); 430 btrfs_set_dev_replace_replace_state(eb, ptr, 431 dev_replace->replace_state); 432 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 433 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 434 btrfs_set_dev_replace_num_write_errors(eb, ptr, 435 atomic64_read(&dev_replace->num_write_errors)); 436 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 437 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 438 dev_replace->cursor_left_last_write_of_item = 439 dev_replace->cursor_left; 440 btrfs_set_dev_replace_cursor_left(eb, ptr, 441 dev_replace->cursor_left_last_write_of_item); 442 btrfs_set_dev_replace_cursor_right(eb, ptr, 443 dev_replace->cursor_right); 444 dev_replace->item_needs_writeback = 0; 445 up_write(&dev_replace->rwsem); 446 447 btrfs_mark_buffer_dirty(eb); 448 449 out: 450 btrfs_free_path(path); 451 452 return ret; 453 } 454 455 static char* btrfs_dev_name(struct btrfs_device *device) 456 { 457 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 458 return "<missing disk>"; 459 else 460 return rcu_str_deref(device->name); 461 } 462 463 static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info, 464 struct btrfs_device *src_dev) 465 { 466 struct btrfs_path *path; 467 struct btrfs_key key; 468 struct btrfs_key found_key; 469 struct btrfs_root *root = fs_info->dev_root; 470 struct btrfs_dev_extent *dev_extent = NULL; 471 struct btrfs_block_group *cache; 472 struct btrfs_trans_handle *trans; 473 int ret = 0; 474 u64 chunk_offset; 475 476 /* Do not use "to_copy" on non zoned filesystem for now */ 477 if (!btrfs_is_zoned(fs_info)) 478 return 0; 479 480 mutex_lock(&fs_info->chunk_mutex); 481 482 /* Ensure we don't have pending new block group */ 483 spin_lock(&fs_info->trans_lock); 484 while (fs_info->running_transaction && 485 !list_empty(&fs_info->running_transaction->dev_update_list)) { 486 spin_unlock(&fs_info->trans_lock); 487 mutex_unlock(&fs_info->chunk_mutex); 488 trans = btrfs_attach_transaction(root); 489 if (IS_ERR(trans)) { 490 ret = PTR_ERR(trans); 491 mutex_lock(&fs_info->chunk_mutex); 492 if (ret == -ENOENT) { 493 spin_lock(&fs_info->trans_lock); 494 continue; 495 } else { 496 goto unlock; 497 } 498 } 499 500 ret = btrfs_commit_transaction(trans); 501 mutex_lock(&fs_info->chunk_mutex); 502 if (ret) 503 goto unlock; 504 505 spin_lock(&fs_info->trans_lock); 506 } 507 spin_unlock(&fs_info->trans_lock); 508 509 path = btrfs_alloc_path(); 510 if (!path) { 511 ret = -ENOMEM; 512 goto unlock; 513 } 514 515 path->reada = READA_FORWARD; 516 path->search_commit_root = 1; 517 path->skip_locking = 1; 518 519 key.objectid = src_dev->devid; 520 key.type = BTRFS_DEV_EXTENT_KEY; 521 key.offset = 0; 522 523 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 524 if (ret < 0) 525 goto free_path; 526 if (ret > 0) { 527 if (path->slots[0] >= 528 btrfs_header_nritems(path->nodes[0])) { 529 ret = btrfs_next_leaf(root, path); 530 if (ret < 0) 531 goto free_path; 532 if (ret > 0) { 533 ret = 0; 534 goto free_path; 535 } 536 } else { 537 ret = 0; 538 } 539 } 540 541 while (1) { 542 struct extent_buffer *leaf = path->nodes[0]; 543 int slot = path->slots[0]; 544 545 btrfs_item_key_to_cpu(leaf, &found_key, slot); 546 547 if (found_key.objectid != src_dev->devid) 548 break; 549 550 if (found_key.type != BTRFS_DEV_EXTENT_KEY) 551 break; 552 553 if (found_key.offset < key.offset) 554 break; 555 556 dev_extent = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent); 557 558 chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dev_extent); 559 560 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 561 if (!cache) 562 goto skip; 563 564 spin_lock(&cache->lock); 565 cache->to_copy = 1; 566 spin_unlock(&cache->lock); 567 568 btrfs_put_block_group(cache); 569 570 skip: 571 ret = btrfs_next_item(root, path); 572 if (ret != 0) { 573 if (ret > 0) 574 ret = 0; 575 break; 576 } 577 } 578 579 free_path: 580 btrfs_free_path(path); 581 unlock: 582 mutex_unlock(&fs_info->chunk_mutex); 583 584 return ret; 585 } 586 587 bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, 588 struct btrfs_block_group *cache, 589 u64 physical) 590 { 591 struct btrfs_fs_info *fs_info = cache->fs_info; 592 struct extent_map *em; 593 struct map_lookup *map; 594 u64 chunk_offset = cache->start; 595 int num_extents, cur_extent; 596 int i; 597 598 /* Do not use "to_copy" on non zoned filesystem for now */ 599 if (!btrfs_is_zoned(fs_info)) 600 return true; 601 602 spin_lock(&cache->lock); 603 if (cache->removed) { 604 spin_unlock(&cache->lock); 605 return true; 606 } 607 spin_unlock(&cache->lock); 608 609 em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); 610 ASSERT(!IS_ERR(em)); 611 map = em->map_lookup; 612 613 num_extents = cur_extent = 0; 614 for (i = 0; i < map->num_stripes; i++) { 615 /* We have more device extent to copy */ 616 if (srcdev != map->stripes[i].dev) 617 continue; 618 619 num_extents++; 620 if (physical == map->stripes[i].physical) 621 cur_extent = i; 622 } 623 624 free_extent_map(em); 625 626 if (num_extents > 1 && cur_extent < num_extents - 1) { 627 /* 628 * Has more stripes on this device. Keep this block group 629 * readonly until we finish all the stripes. 630 */ 631 return false; 632 } 633 634 /* Last stripe on this device */ 635 spin_lock(&cache->lock); 636 cache->to_copy = 0; 637 spin_unlock(&cache->lock); 638 639 return true; 640 } 641 642 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 643 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 644 int read_src) 645 { 646 struct btrfs_root *root = fs_info->dev_root; 647 struct btrfs_trans_handle *trans; 648 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 649 int ret; 650 struct btrfs_device *tgt_device = NULL; 651 struct btrfs_device *src_device = NULL; 652 653 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, 654 srcdev_name); 655 if (IS_ERR(src_device)) 656 return PTR_ERR(src_device); 657 658 if (btrfs_pinned_by_swapfile(fs_info, src_device)) { 659 btrfs_warn_in_rcu(fs_info, 660 "cannot replace device %s (devid %llu) due to active swapfile", 661 btrfs_dev_name(src_device), src_device->devid); 662 return -ETXTBSY; 663 } 664 665 /* 666 * Here we commit the transaction to make sure commit_total_bytes 667 * of all the devices are updated. 668 */ 669 trans = btrfs_attach_transaction(root); 670 if (!IS_ERR(trans)) { 671 ret = btrfs_commit_transaction(trans); 672 if (ret) 673 return ret; 674 } else if (PTR_ERR(trans) != -ENOENT) { 675 return PTR_ERR(trans); 676 } 677 678 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 679 src_device, &tgt_device); 680 if (ret) 681 return ret; 682 683 ret = mark_block_group_to_copy(fs_info, src_device); 684 if (ret) 685 return ret; 686 687 down_write(&dev_replace->rwsem); 688 switch (dev_replace->replace_state) { 689 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 690 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 691 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 692 break; 693 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 694 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 695 ASSERT(0); 696 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 697 up_write(&dev_replace->rwsem); 698 goto leave; 699 } 700 701 dev_replace->cont_reading_from_srcdev_mode = read_src; 702 dev_replace->srcdev = src_device; 703 dev_replace->tgtdev = tgt_device; 704 705 btrfs_info_in_rcu(fs_info, 706 "dev_replace from %s (devid %llu) to %s started", 707 btrfs_dev_name(src_device), 708 src_device->devid, 709 rcu_str_deref(tgt_device->name)); 710 711 /* 712 * from now on, the writes to the srcdev are all duplicated to 713 * go to the tgtdev as well (refer to btrfs_map_block()). 714 */ 715 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 716 dev_replace->time_started = ktime_get_real_seconds(); 717 dev_replace->cursor_left = 0; 718 dev_replace->committed_cursor_left = 0; 719 dev_replace->cursor_left_last_write_of_item = 0; 720 dev_replace->cursor_right = 0; 721 dev_replace->is_valid = 1; 722 dev_replace->item_needs_writeback = 1; 723 atomic64_set(&dev_replace->num_write_errors, 0); 724 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 725 up_write(&dev_replace->rwsem); 726 727 ret = btrfs_sysfs_add_device(tgt_device); 728 if (ret) 729 btrfs_err(fs_info, "kobj add dev failed %d", ret); 730 731 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 732 733 /* Commit dev_replace state and reserve 1 item for it. */ 734 trans = btrfs_start_transaction(root, 1); 735 if (IS_ERR(trans)) { 736 ret = PTR_ERR(trans); 737 down_write(&dev_replace->rwsem); 738 dev_replace->replace_state = 739 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 740 dev_replace->srcdev = NULL; 741 dev_replace->tgtdev = NULL; 742 up_write(&dev_replace->rwsem); 743 goto leave; 744 } 745 746 ret = btrfs_commit_transaction(trans); 747 WARN_ON(ret); 748 749 /* the disk copy procedure reuses the scrub code */ 750 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 751 btrfs_device_get_total_bytes(src_device), 752 &dev_replace->scrub_progress, 0, 1); 753 754 ret = btrfs_dev_replace_finishing(fs_info, ret); 755 if (ret == -EINPROGRESS) 756 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 757 758 return ret; 759 760 leave: 761 btrfs_destroy_dev_replace_tgtdev(tgt_device); 762 return ret; 763 } 764 765 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 766 struct btrfs_ioctl_dev_replace_args *args) 767 { 768 int ret; 769 770 switch (args->start.cont_reading_from_srcdev_mode) { 771 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 772 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 773 break; 774 default: 775 return -EINVAL; 776 } 777 778 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 779 args->start.tgtdev_name[0] == '\0') 780 return -EINVAL; 781 782 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 783 args->start.srcdevid, 784 args->start.srcdev_name, 785 args->start.cont_reading_from_srcdev_mode); 786 args->result = ret; 787 /* don't warn if EINPROGRESS, someone else might be running scrub */ 788 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 789 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 790 return 0; 791 792 return ret; 793 } 794 795 /* 796 * blocked until all in-flight bios operations are finished. 797 */ 798 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 799 { 800 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 801 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 802 &fs_info->dev_replace.bio_counter)); 803 } 804 805 /* 806 * we have removed target device, it is safe to allow new bios request. 807 */ 808 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 809 { 810 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 811 wake_up(&fs_info->dev_replace.replace_wait); 812 } 813 814 /* 815 * When finishing the device replace, before swapping the source device with the 816 * target device we must update the chunk allocation state in the target device, 817 * as it is empty because replace works by directly copying the chunks and not 818 * through the normal chunk allocation path. 819 */ 820 static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev, 821 struct btrfs_device *tgtdev) 822 { 823 struct extent_state *cached_state = NULL; 824 u64 start = 0; 825 u64 found_start; 826 u64 found_end; 827 int ret = 0; 828 829 lockdep_assert_held(&srcdev->fs_info->chunk_mutex); 830 831 while (!find_first_extent_bit(&srcdev->alloc_state, start, 832 &found_start, &found_end, 833 CHUNK_ALLOCATED, &cached_state)) { 834 ret = set_extent_bits(&tgtdev->alloc_state, found_start, 835 found_end, CHUNK_ALLOCATED); 836 if (ret) 837 break; 838 start = found_end + 1; 839 } 840 841 free_extent_state(cached_state); 842 return ret; 843 } 844 845 static void btrfs_dev_replace_update_device_in_mapping_tree( 846 struct btrfs_fs_info *fs_info, 847 struct btrfs_device *srcdev, 848 struct btrfs_device *tgtdev) 849 { 850 struct extent_map_tree *em_tree = &fs_info->mapping_tree; 851 struct extent_map *em; 852 struct map_lookup *map; 853 u64 start = 0; 854 int i; 855 856 write_lock(&em_tree->lock); 857 do { 858 em = lookup_extent_mapping(em_tree, start, (u64)-1); 859 if (!em) 860 break; 861 map = em->map_lookup; 862 for (i = 0; i < map->num_stripes; i++) 863 if (srcdev == map->stripes[i].dev) 864 map->stripes[i].dev = tgtdev; 865 start = em->start + em->len; 866 free_extent_map(em); 867 } while (start); 868 write_unlock(&em_tree->lock); 869 } 870 871 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 872 int scrub_ret) 873 { 874 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 875 struct btrfs_device *tgt_device; 876 struct btrfs_device *src_device; 877 struct btrfs_root *root = fs_info->tree_root; 878 u8 uuid_tmp[BTRFS_UUID_SIZE]; 879 struct btrfs_trans_handle *trans; 880 int ret = 0; 881 882 /* don't allow cancel or unmount to disturb the finishing procedure */ 883 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 884 885 down_read(&dev_replace->rwsem); 886 /* was the operation canceled, or is it finished? */ 887 if (dev_replace->replace_state != 888 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 889 up_read(&dev_replace->rwsem); 890 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 891 return 0; 892 } 893 894 tgt_device = dev_replace->tgtdev; 895 src_device = dev_replace->srcdev; 896 up_read(&dev_replace->rwsem); 897 898 /* 899 * flush all outstanding I/O and inode extent mappings before the 900 * copy operation is declared as being finished 901 */ 902 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false); 903 if (ret) { 904 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 905 return ret; 906 } 907 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 908 909 if (!scrub_ret) 910 btrfs_reada_remove_dev(src_device); 911 912 /* 913 * We have to use this loop approach because at this point src_device 914 * has to be available for transaction commit to complete, yet new 915 * chunks shouldn't be allocated on the device. 916 */ 917 while (1) { 918 trans = btrfs_start_transaction(root, 0); 919 if (IS_ERR(trans)) { 920 btrfs_reada_undo_remove_dev(src_device); 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_reada_undo_remove_dev(src_device); 972 btrfs_rm_dev_replace_blocked(fs_info); 973 if (tgt_device) 974 btrfs_destroy_dev_replace_tgtdev(tgt_device); 975 btrfs_rm_dev_replace_unblocked(fs_info); 976 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 977 978 return scrub_ret; 979 } 980 981 btrfs_info_in_rcu(fs_info, 982 "dev_replace from %s (devid %llu) to %s finished", 983 btrfs_dev_name(src_device), 984 src_device->devid, 985 rcu_str_deref(tgt_device->name)); 986 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 987 tgt_device->devid = src_device->devid; 988 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 989 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 990 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 991 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 992 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 993 btrfs_device_set_disk_total_bytes(tgt_device, 994 src_device->disk_total_bytes); 995 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 996 tgt_device->commit_bytes_used = src_device->bytes_used; 997 998 btrfs_assign_next_active_device(src_device, tgt_device); 999 1000 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 1001 fs_info->fs_devices->rw_devices++; 1002 1003 up_write(&dev_replace->rwsem); 1004 btrfs_rm_dev_replace_blocked(fs_info); 1005 1006 btrfs_rm_dev_replace_remove_srcdev(src_device); 1007 1008 btrfs_rm_dev_replace_unblocked(fs_info); 1009 1010 /* 1011 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will 1012 * update on-disk dev stats value during commit transaction 1013 */ 1014 atomic_inc(&tgt_device->dev_stats_ccnt); 1015 1016 /* 1017 * this is again a consistent state where no dev_replace procedure 1018 * is running, the target device is part of the filesystem, the 1019 * source device is not part of the filesystem anymore and its 1st 1020 * superblock is scratched out so that it is no longer marked to 1021 * belong to this filesystem. 1022 */ 1023 mutex_unlock(&fs_info->chunk_mutex); 1024 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1025 1026 /* replace the sysfs entry */ 1027 btrfs_sysfs_remove_device(src_device); 1028 btrfs_sysfs_update_devid(tgt_device); 1029 if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &src_device->dev_state)) 1030 btrfs_scratch_superblocks(fs_info, src_device->bdev, 1031 src_device->name->str); 1032 1033 /* write back the superblocks */ 1034 trans = btrfs_start_transaction(root, 0); 1035 if (!IS_ERR(trans)) 1036 btrfs_commit_transaction(trans); 1037 1038 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1039 1040 btrfs_rm_dev_replace_free_srcdev(src_device); 1041 1042 return 0; 1043 } 1044 1045 /* 1046 * Read progress of device replace status according to the state and last 1047 * stored position. The value format is the same as for 1048 * btrfs_dev_replace::progress_1000 1049 */ 1050 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 1051 { 1052 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1053 u64 ret = 0; 1054 1055 switch (dev_replace->replace_state) { 1056 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1057 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1058 ret = 0; 1059 break; 1060 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1061 ret = 1000; 1062 break; 1063 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1064 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1065 ret = div64_u64(dev_replace->cursor_left, 1066 div_u64(btrfs_device_get_total_bytes( 1067 dev_replace->srcdev), 1000)); 1068 break; 1069 } 1070 1071 return ret; 1072 } 1073 1074 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 1075 struct btrfs_ioctl_dev_replace_args *args) 1076 { 1077 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1078 1079 down_read(&dev_replace->rwsem); 1080 /* even if !dev_replace_is_valid, the values are good enough for 1081 * the replace_status ioctl */ 1082 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1083 args->status.replace_state = dev_replace->replace_state; 1084 args->status.time_started = dev_replace->time_started; 1085 args->status.time_stopped = dev_replace->time_stopped; 1086 args->status.num_write_errors = 1087 atomic64_read(&dev_replace->num_write_errors); 1088 args->status.num_uncorrectable_read_errors = 1089 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 1090 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 1091 up_read(&dev_replace->rwsem); 1092 } 1093 1094 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 1095 { 1096 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1097 struct btrfs_device *tgt_device = NULL; 1098 struct btrfs_device *src_device = NULL; 1099 struct btrfs_trans_handle *trans; 1100 struct btrfs_root *root = fs_info->tree_root; 1101 int result; 1102 int ret; 1103 1104 if (sb_rdonly(fs_info->sb)) 1105 return -EROFS; 1106 1107 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1108 down_write(&dev_replace->rwsem); 1109 switch (dev_replace->replace_state) { 1110 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1111 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1112 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1113 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1114 up_write(&dev_replace->rwsem); 1115 break; 1116 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1117 tgt_device = dev_replace->tgtdev; 1118 src_device = dev_replace->srcdev; 1119 up_write(&dev_replace->rwsem); 1120 ret = btrfs_scrub_cancel(fs_info); 1121 if (ret < 0) { 1122 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1123 } else { 1124 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1125 /* 1126 * btrfs_dev_replace_finishing() will handle the 1127 * cleanup part 1128 */ 1129 btrfs_info_in_rcu(fs_info, 1130 "dev_replace from %s (devid %llu) to %s canceled", 1131 btrfs_dev_name(src_device), src_device->devid, 1132 btrfs_dev_name(tgt_device)); 1133 } 1134 break; 1135 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1136 /* 1137 * Scrub doing the replace isn't running so we need to do the 1138 * cleanup step of btrfs_dev_replace_finishing() here 1139 */ 1140 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1141 tgt_device = dev_replace->tgtdev; 1142 src_device = dev_replace->srcdev; 1143 dev_replace->tgtdev = NULL; 1144 dev_replace->srcdev = NULL; 1145 dev_replace->replace_state = 1146 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 1147 dev_replace->time_stopped = ktime_get_real_seconds(); 1148 dev_replace->item_needs_writeback = 1; 1149 1150 up_write(&dev_replace->rwsem); 1151 1152 /* Scrub for replace must not be running in suspended state */ 1153 ret = btrfs_scrub_cancel(fs_info); 1154 ASSERT(ret != -ENOTCONN); 1155 1156 trans = btrfs_start_transaction(root, 0); 1157 if (IS_ERR(trans)) { 1158 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1159 return PTR_ERR(trans); 1160 } 1161 ret = btrfs_commit_transaction(trans); 1162 WARN_ON(ret); 1163 1164 btrfs_info_in_rcu(fs_info, 1165 "suspended dev_replace from %s (devid %llu) to %s canceled", 1166 btrfs_dev_name(src_device), src_device->devid, 1167 btrfs_dev_name(tgt_device)); 1168 1169 if (tgt_device) 1170 btrfs_destroy_dev_replace_tgtdev(tgt_device); 1171 break; 1172 default: 1173 up_write(&dev_replace->rwsem); 1174 result = -EINVAL; 1175 } 1176 1177 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1178 return result; 1179 } 1180 1181 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 1182 { 1183 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1184 1185 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1186 down_write(&dev_replace->rwsem); 1187 1188 switch (dev_replace->replace_state) { 1189 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1190 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1191 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1192 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1193 break; 1194 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1195 dev_replace->replace_state = 1196 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1197 dev_replace->time_stopped = ktime_get_real_seconds(); 1198 dev_replace->item_needs_writeback = 1; 1199 btrfs_info(fs_info, "suspending dev_replace for unmount"); 1200 break; 1201 } 1202 1203 up_write(&dev_replace->rwsem); 1204 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1205 } 1206 1207 /* resume dev_replace procedure that was interrupted by unmount */ 1208 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 1209 { 1210 struct task_struct *task; 1211 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1212 1213 down_write(&dev_replace->rwsem); 1214 1215 switch (dev_replace->replace_state) { 1216 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1217 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1218 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1219 up_write(&dev_replace->rwsem); 1220 return 0; 1221 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1222 break; 1223 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1224 dev_replace->replace_state = 1225 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 1226 break; 1227 } 1228 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 1229 btrfs_info(fs_info, 1230 "cannot continue dev_replace, tgtdev is missing"); 1231 btrfs_info(fs_info, 1232 "you may cancel the operation after 'mount -o degraded'"); 1233 dev_replace->replace_state = 1234 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1235 up_write(&dev_replace->rwsem); 1236 return 0; 1237 } 1238 up_write(&dev_replace->rwsem); 1239 1240 /* 1241 * This could collide with a paused balance, but the exclusive op logic 1242 * should never allow both to start and pause. We don't want to allow 1243 * dev-replace to start anyway. 1244 */ 1245 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { 1246 down_write(&dev_replace->rwsem); 1247 dev_replace->replace_state = 1248 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1249 up_write(&dev_replace->rwsem); 1250 btrfs_info(fs_info, 1251 "cannot resume dev-replace, other exclusive operation running"); 1252 return 0; 1253 } 1254 1255 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 1256 return PTR_ERR_OR_ZERO(task); 1257 } 1258 1259 static int btrfs_dev_replace_kthread(void *data) 1260 { 1261 struct btrfs_fs_info *fs_info = data; 1262 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1263 u64 progress; 1264 int ret; 1265 1266 progress = btrfs_dev_replace_progress(fs_info); 1267 progress = div_u64(progress, 10); 1268 btrfs_info_in_rcu(fs_info, 1269 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 1270 btrfs_dev_name(dev_replace->srcdev), 1271 dev_replace->srcdev->devid, 1272 btrfs_dev_name(dev_replace->tgtdev), 1273 (unsigned int)progress); 1274 1275 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 1276 dev_replace->committed_cursor_left, 1277 btrfs_device_get_total_bytes(dev_replace->srcdev), 1278 &dev_replace->scrub_progress, 0, 1); 1279 ret = btrfs_dev_replace_finishing(fs_info, ret); 1280 WARN_ON(ret && ret != -ECANCELED); 1281 1282 btrfs_exclop_finish(fs_info); 1283 return 0; 1284 } 1285 1286 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 1287 { 1288 if (!dev_replace->is_valid) 1289 return 0; 1290 1291 switch (dev_replace->replace_state) { 1292 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1293 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1294 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1295 return 0; 1296 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1297 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1298 /* 1299 * return true even if tgtdev is missing (this is 1300 * something that can happen if the dev_replace 1301 * procedure is suspended by an umount and then 1302 * the tgtdev is missing (or "btrfs dev scan") was 1303 * not called and the filesystem is remounted 1304 * in degraded state. This does not stop the 1305 * dev_replace procedure. It needs to be canceled 1306 * manually if the cancellation is wanted. 1307 */ 1308 break; 1309 } 1310 return 1; 1311 } 1312 1313 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1314 { 1315 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1316 } 1317 1318 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1319 { 1320 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); 1321 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); 1322 } 1323 1324 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1325 { 1326 while (1) { 1327 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1328 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1329 &fs_info->fs_state))) 1330 break; 1331 1332 btrfs_bio_counter_dec(fs_info); 1333 wait_event(fs_info->dev_replace.replace_wait, 1334 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1335 &fs_info->fs_state)); 1336 } 1337 } 1338