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_key key; 74 struct btrfs_root *dev_root = fs_info->dev_root; 75 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 76 struct extent_buffer *eb; 77 int slot; 78 int ret = 0; 79 struct btrfs_path *path = NULL; 80 int item_size; 81 struct btrfs_dev_replace_item *ptr; 82 u64 src_devid; 83 84 if (!dev_root) 85 return 0; 86 87 path = btrfs_alloc_path(); 88 if (!path) { 89 ret = -ENOMEM; 90 goto out; 91 } 92 93 key.objectid = 0; 94 key.type = BTRFS_DEV_REPLACE_KEY; 95 key.offset = 0; 96 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 97 if (ret) { 98 no_valid_dev_replace_entry_found: 99 /* 100 * We don't have a replace item or it's corrupted. If there is 101 * a replace target, fail the mount. 102 */ 103 if (btrfs_find_device(fs_info->fs_devices, 104 BTRFS_DEV_REPLACE_DEVID, NULL, NULL)) { 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, 167 BTRFS_DEV_REPLACE_DEVID, NULL, NULL)) { 168 btrfs_err(fs_info, 169 "replace devid present without an active replace item"); 170 ret = -EUCLEAN; 171 } else { 172 dev_replace->srcdev = NULL; 173 dev_replace->tgtdev = NULL; 174 } 175 break; 176 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 177 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 178 dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices, 179 src_devid, NULL, NULL); 180 dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices, 181 BTRFS_DEV_REPLACE_DEVID, 182 NULL, NULL); 183 /* 184 * allow 'btrfs dev replace_cancel' if src/tgt device is 185 * missing 186 */ 187 if (!dev_replace->srcdev && 188 !btrfs_test_opt(fs_info, DEGRADED)) { 189 ret = -EIO; 190 btrfs_warn(fs_info, 191 "cannot mount because device replace operation is ongoing and"); 192 btrfs_warn(fs_info, 193 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 194 src_devid); 195 } 196 if (!dev_replace->tgtdev && 197 !btrfs_test_opt(fs_info, DEGRADED)) { 198 ret = -EIO; 199 btrfs_warn(fs_info, 200 "cannot mount because device replace operation is ongoing and"); 201 btrfs_warn(fs_info, 202 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 203 BTRFS_DEV_REPLACE_DEVID); 204 } 205 if (dev_replace->tgtdev) { 206 if (dev_replace->srcdev) { 207 dev_replace->tgtdev->total_bytes = 208 dev_replace->srcdev->total_bytes; 209 dev_replace->tgtdev->disk_total_bytes = 210 dev_replace->srcdev->disk_total_bytes; 211 dev_replace->tgtdev->commit_total_bytes = 212 dev_replace->srcdev->commit_total_bytes; 213 dev_replace->tgtdev->bytes_used = 214 dev_replace->srcdev->bytes_used; 215 dev_replace->tgtdev->commit_bytes_used = 216 dev_replace->srcdev->commit_bytes_used; 217 } 218 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 219 &dev_replace->tgtdev->dev_state); 220 221 WARN_ON(fs_info->fs_devices->rw_devices == 0); 222 dev_replace->tgtdev->io_width = fs_info->sectorsize; 223 dev_replace->tgtdev->io_align = fs_info->sectorsize; 224 dev_replace->tgtdev->sector_size = fs_info->sectorsize; 225 dev_replace->tgtdev->fs_info = fs_info; 226 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 227 &dev_replace->tgtdev->dev_state); 228 } 229 break; 230 } 231 232 out: 233 btrfs_free_path(path); 234 return ret; 235 } 236 237 /* 238 * Initialize a new device for device replace target from a given source dev 239 * and path. 240 * 241 * Return 0 and new device in @device_out, otherwise return < 0 242 */ 243 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, 244 const char *device_path, 245 struct btrfs_device *srcdev, 246 struct btrfs_device **device_out) 247 { 248 struct btrfs_device *device; 249 struct block_device *bdev; 250 struct rcu_string *name; 251 u64 devid = BTRFS_DEV_REPLACE_DEVID; 252 int ret = 0; 253 254 *device_out = NULL; 255 if (srcdev->fs_devices->seeding) { 256 btrfs_err(fs_info, "the filesystem is a seed filesystem!"); 257 return -EINVAL; 258 } 259 260 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, 261 fs_info->bdev_holder); 262 if (IS_ERR(bdev)) { 263 btrfs_err(fs_info, "target device %s is invalid!", device_path); 264 return PTR_ERR(bdev); 265 } 266 267 if (!btrfs_check_device_zone_type(fs_info, bdev)) { 268 btrfs_err(fs_info, 269 "dev-replace: zoned type of target device mismatch with filesystem"); 270 ret = -EINVAL; 271 goto error; 272 } 273 274 sync_blockdev(bdev); 275 276 list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) { 277 if (device->bdev == bdev) { 278 btrfs_err(fs_info, 279 "target device is in the filesystem!"); 280 ret = -EEXIST; 281 goto error; 282 } 283 } 284 285 286 if (i_size_read(bdev->bd_inode) < 287 btrfs_device_get_total_bytes(srcdev)) { 288 btrfs_err(fs_info, 289 "target device is smaller than source device!"); 290 ret = -EINVAL; 291 goto error; 292 } 293 294 295 device = btrfs_alloc_device(NULL, &devid, NULL); 296 if (IS_ERR(device)) { 297 ret = PTR_ERR(device); 298 goto error; 299 } 300 301 name = rcu_string_strdup(device_path, GFP_KERNEL); 302 if (!name) { 303 btrfs_free_device(device); 304 ret = -ENOMEM; 305 goto error; 306 } 307 rcu_assign_pointer(device->name, name); 308 309 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 310 device->generation = 0; 311 device->io_width = fs_info->sectorsize; 312 device->io_align = fs_info->sectorsize; 313 device->sector_size = fs_info->sectorsize; 314 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 315 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 316 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 317 device->commit_total_bytes = srcdev->commit_total_bytes; 318 device->commit_bytes_used = device->bytes_used; 319 device->fs_info = fs_info; 320 device->bdev = bdev; 321 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 322 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 323 device->mode = FMODE_EXCL; 324 device->dev_stats_valid = 1; 325 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 326 device->fs_devices = fs_info->fs_devices; 327 328 ret = btrfs_get_dev_zone_info(device); 329 if (ret) 330 goto error; 331 332 mutex_lock(&fs_info->fs_devices->device_list_mutex); 333 list_add(&device->dev_list, &fs_info->fs_devices->devices); 334 fs_info->fs_devices->num_devices++; 335 fs_info->fs_devices->open_devices++; 336 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 337 338 *device_out = device; 339 return 0; 340 341 error: 342 blkdev_put(bdev, FMODE_EXCL); 343 return ret; 344 } 345 346 /* 347 * called from commit_transaction. Writes changed device replace state to 348 * disk. 349 */ 350 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 351 { 352 struct btrfs_fs_info *fs_info = trans->fs_info; 353 int ret; 354 struct btrfs_root *dev_root = fs_info->dev_root; 355 struct btrfs_path *path; 356 struct btrfs_key key; 357 struct extent_buffer *eb; 358 struct btrfs_dev_replace_item *ptr; 359 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 360 361 down_read(&dev_replace->rwsem); 362 if (!dev_replace->is_valid || 363 !dev_replace->item_needs_writeback) { 364 up_read(&dev_replace->rwsem); 365 return 0; 366 } 367 up_read(&dev_replace->rwsem); 368 369 key.objectid = 0; 370 key.type = BTRFS_DEV_REPLACE_KEY; 371 key.offset = 0; 372 373 path = btrfs_alloc_path(); 374 if (!path) { 375 ret = -ENOMEM; 376 goto out; 377 } 378 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 379 if (ret < 0) { 380 btrfs_warn(fs_info, 381 "error %d while searching for dev_replace item!", 382 ret); 383 goto out; 384 } 385 386 if (ret == 0 && 387 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 388 /* 389 * need to delete old one and insert a new one. 390 * Since no attempt is made to recover any old state, if the 391 * dev_replace state is 'running', the data on the target 392 * drive is lost. 393 * It would be possible to recover the state: just make sure 394 * that the beginning of the item is never changed and always 395 * contains all the essential information. Then read this 396 * minimal set of information and use it as a base for the 397 * new state. 398 */ 399 ret = btrfs_del_item(trans, dev_root, path); 400 if (ret != 0) { 401 btrfs_warn(fs_info, 402 "delete too small dev_replace item failed %d!", 403 ret); 404 goto out; 405 } 406 ret = 1; 407 } 408 409 if (ret == 1) { 410 /* need to insert a new item */ 411 btrfs_release_path(path); 412 ret = btrfs_insert_empty_item(trans, dev_root, path, 413 &key, sizeof(*ptr)); 414 if (ret < 0) { 415 btrfs_warn(fs_info, 416 "insert dev_replace item failed %d!", ret); 417 goto out; 418 } 419 } 420 421 eb = path->nodes[0]; 422 ptr = btrfs_item_ptr(eb, path->slots[0], 423 struct btrfs_dev_replace_item); 424 425 down_write(&dev_replace->rwsem); 426 if (dev_replace->srcdev) 427 btrfs_set_dev_replace_src_devid(eb, ptr, 428 dev_replace->srcdev->devid); 429 else 430 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 431 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 432 dev_replace->cont_reading_from_srcdev_mode); 433 btrfs_set_dev_replace_replace_state(eb, ptr, 434 dev_replace->replace_state); 435 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 436 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 437 btrfs_set_dev_replace_num_write_errors(eb, ptr, 438 atomic64_read(&dev_replace->num_write_errors)); 439 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 440 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 441 dev_replace->cursor_left_last_write_of_item = 442 dev_replace->cursor_left; 443 btrfs_set_dev_replace_cursor_left(eb, ptr, 444 dev_replace->cursor_left_last_write_of_item); 445 btrfs_set_dev_replace_cursor_right(eb, ptr, 446 dev_replace->cursor_right); 447 dev_replace->item_needs_writeback = 0; 448 up_write(&dev_replace->rwsem); 449 450 btrfs_mark_buffer_dirty(eb); 451 452 out: 453 btrfs_free_path(path); 454 455 return ret; 456 } 457 458 static char* btrfs_dev_name(struct btrfs_device *device) 459 { 460 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 461 return "<missing disk>"; 462 else 463 return rcu_str_deref(device->name); 464 } 465 466 static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info, 467 struct btrfs_device *src_dev) 468 { 469 struct btrfs_path *path; 470 struct btrfs_key key; 471 struct btrfs_key found_key; 472 struct btrfs_root *root = fs_info->dev_root; 473 struct btrfs_dev_extent *dev_extent = NULL; 474 struct btrfs_block_group *cache; 475 struct btrfs_trans_handle *trans; 476 int ret = 0; 477 u64 chunk_offset; 478 479 /* Do not use "to_copy" on non zoned filesystem for now */ 480 if (!btrfs_is_zoned(fs_info)) 481 return 0; 482 483 mutex_lock(&fs_info->chunk_mutex); 484 485 /* Ensure we don't have pending new block group */ 486 spin_lock(&fs_info->trans_lock); 487 while (fs_info->running_transaction && 488 !list_empty(&fs_info->running_transaction->dev_update_list)) { 489 spin_unlock(&fs_info->trans_lock); 490 mutex_unlock(&fs_info->chunk_mutex); 491 trans = btrfs_attach_transaction(root); 492 if (IS_ERR(trans)) { 493 ret = PTR_ERR(trans); 494 mutex_lock(&fs_info->chunk_mutex); 495 if (ret == -ENOENT) { 496 spin_lock(&fs_info->trans_lock); 497 continue; 498 } else { 499 goto unlock; 500 } 501 } 502 503 ret = btrfs_commit_transaction(trans); 504 mutex_lock(&fs_info->chunk_mutex); 505 if (ret) 506 goto unlock; 507 508 spin_lock(&fs_info->trans_lock); 509 } 510 spin_unlock(&fs_info->trans_lock); 511 512 path = btrfs_alloc_path(); 513 if (!path) { 514 ret = -ENOMEM; 515 goto unlock; 516 } 517 518 path->reada = READA_FORWARD; 519 path->search_commit_root = 1; 520 path->skip_locking = 1; 521 522 key.objectid = src_dev->devid; 523 key.type = BTRFS_DEV_EXTENT_KEY; 524 key.offset = 0; 525 526 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 527 if (ret < 0) 528 goto free_path; 529 if (ret > 0) { 530 if (path->slots[0] >= 531 btrfs_header_nritems(path->nodes[0])) { 532 ret = btrfs_next_leaf(root, path); 533 if (ret < 0) 534 goto free_path; 535 if (ret > 0) { 536 ret = 0; 537 goto free_path; 538 } 539 } else { 540 ret = 0; 541 } 542 } 543 544 while (1) { 545 struct extent_buffer *leaf = path->nodes[0]; 546 int slot = path->slots[0]; 547 548 btrfs_item_key_to_cpu(leaf, &found_key, slot); 549 550 if (found_key.objectid != src_dev->devid) 551 break; 552 553 if (found_key.type != BTRFS_DEV_EXTENT_KEY) 554 break; 555 556 if (found_key.offset < key.offset) 557 break; 558 559 dev_extent = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent); 560 561 chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dev_extent); 562 563 cache = btrfs_lookup_block_group(fs_info, chunk_offset); 564 if (!cache) 565 goto skip; 566 567 spin_lock(&cache->lock); 568 cache->to_copy = 1; 569 spin_unlock(&cache->lock); 570 571 btrfs_put_block_group(cache); 572 573 skip: 574 ret = btrfs_next_item(root, path); 575 if (ret != 0) { 576 if (ret > 0) 577 ret = 0; 578 break; 579 } 580 } 581 582 free_path: 583 btrfs_free_path(path); 584 unlock: 585 mutex_unlock(&fs_info->chunk_mutex); 586 587 return ret; 588 } 589 590 bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, 591 struct btrfs_block_group *cache, 592 u64 physical) 593 { 594 struct btrfs_fs_info *fs_info = cache->fs_info; 595 struct extent_map *em; 596 struct map_lookup *map; 597 u64 chunk_offset = cache->start; 598 int num_extents, cur_extent; 599 int i; 600 601 /* Do not use "to_copy" on non zoned filesystem for now */ 602 if (!btrfs_is_zoned(fs_info)) 603 return true; 604 605 spin_lock(&cache->lock); 606 if (cache->removed) { 607 spin_unlock(&cache->lock); 608 return true; 609 } 610 spin_unlock(&cache->lock); 611 612 em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); 613 ASSERT(!IS_ERR(em)); 614 map = em->map_lookup; 615 616 num_extents = cur_extent = 0; 617 for (i = 0; i < map->num_stripes; i++) { 618 /* We have more device extent to copy */ 619 if (srcdev != map->stripes[i].dev) 620 continue; 621 622 num_extents++; 623 if (physical == map->stripes[i].physical) 624 cur_extent = i; 625 } 626 627 free_extent_map(em); 628 629 if (num_extents > 1 && cur_extent < num_extents - 1) { 630 /* 631 * Has more stripes on this device. Keep this block group 632 * readonly until we finish all the stripes. 633 */ 634 return false; 635 } 636 637 /* Last stripe on this device */ 638 spin_lock(&cache->lock); 639 cache->to_copy = 0; 640 spin_unlock(&cache->lock); 641 642 return true; 643 } 644 645 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 646 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 647 int read_src) 648 { 649 struct btrfs_root *root = fs_info->dev_root; 650 struct btrfs_trans_handle *trans; 651 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 652 int ret; 653 struct btrfs_device *tgt_device = NULL; 654 struct btrfs_device *src_device = NULL; 655 656 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, 657 srcdev_name); 658 if (IS_ERR(src_device)) 659 return PTR_ERR(src_device); 660 661 if (btrfs_pinned_by_swapfile(fs_info, src_device)) { 662 btrfs_warn_in_rcu(fs_info, 663 "cannot replace device %s (devid %llu) due to active swapfile", 664 btrfs_dev_name(src_device), src_device->devid); 665 return -ETXTBSY; 666 } 667 668 /* 669 * Here we commit the transaction to make sure commit_total_bytes 670 * of all the devices are updated. 671 */ 672 trans = btrfs_attach_transaction(root); 673 if (!IS_ERR(trans)) { 674 ret = btrfs_commit_transaction(trans); 675 if (ret) 676 return ret; 677 } else if (PTR_ERR(trans) != -ENOENT) { 678 return PTR_ERR(trans); 679 } 680 681 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 682 src_device, &tgt_device); 683 if (ret) 684 return ret; 685 686 ret = mark_block_group_to_copy(fs_info, src_device); 687 if (ret) 688 return ret; 689 690 down_write(&dev_replace->rwsem); 691 switch (dev_replace->replace_state) { 692 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 693 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 694 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 695 break; 696 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 697 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 698 ASSERT(0); 699 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 700 up_write(&dev_replace->rwsem); 701 goto leave; 702 } 703 704 dev_replace->cont_reading_from_srcdev_mode = read_src; 705 dev_replace->srcdev = src_device; 706 dev_replace->tgtdev = tgt_device; 707 708 btrfs_info_in_rcu(fs_info, 709 "dev_replace from %s (devid %llu) to %s started", 710 btrfs_dev_name(src_device), 711 src_device->devid, 712 rcu_str_deref(tgt_device->name)); 713 714 /* 715 * from now on, the writes to the srcdev are all duplicated to 716 * go to the tgtdev as well (refer to btrfs_map_block()). 717 */ 718 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 719 dev_replace->time_started = ktime_get_real_seconds(); 720 dev_replace->cursor_left = 0; 721 dev_replace->committed_cursor_left = 0; 722 dev_replace->cursor_left_last_write_of_item = 0; 723 dev_replace->cursor_right = 0; 724 dev_replace->is_valid = 1; 725 dev_replace->item_needs_writeback = 1; 726 atomic64_set(&dev_replace->num_write_errors, 0); 727 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 728 up_write(&dev_replace->rwsem); 729 730 ret = btrfs_sysfs_add_device(tgt_device); 731 if (ret) 732 btrfs_err(fs_info, "kobj add dev failed %d", ret); 733 734 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 735 736 /* Commit dev_replace state and reserve 1 item for it. */ 737 trans = btrfs_start_transaction(root, 1); 738 if (IS_ERR(trans)) { 739 ret = PTR_ERR(trans); 740 down_write(&dev_replace->rwsem); 741 dev_replace->replace_state = 742 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 743 dev_replace->srcdev = NULL; 744 dev_replace->tgtdev = NULL; 745 up_write(&dev_replace->rwsem); 746 goto leave; 747 } 748 749 ret = btrfs_commit_transaction(trans); 750 WARN_ON(ret); 751 752 /* the disk copy procedure reuses the scrub code */ 753 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 754 btrfs_device_get_total_bytes(src_device), 755 &dev_replace->scrub_progress, 0, 1); 756 757 ret = btrfs_dev_replace_finishing(fs_info, ret); 758 if (ret == -EINPROGRESS) 759 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 760 761 return ret; 762 763 leave: 764 btrfs_destroy_dev_replace_tgtdev(tgt_device); 765 return ret; 766 } 767 768 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 769 struct btrfs_ioctl_dev_replace_args *args) 770 { 771 int ret; 772 773 switch (args->start.cont_reading_from_srcdev_mode) { 774 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 775 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 776 break; 777 default: 778 return -EINVAL; 779 } 780 781 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 782 args->start.tgtdev_name[0] == '\0') 783 return -EINVAL; 784 785 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 786 args->start.srcdevid, 787 args->start.srcdev_name, 788 args->start.cont_reading_from_srcdev_mode); 789 args->result = ret; 790 /* don't warn if EINPROGRESS, someone else might be running scrub */ 791 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 792 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 793 return 0; 794 795 return ret; 796 } 797 798 /* 799 * blocked until all in-flight bios operations are finished. 800 */ 801 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 802 { 803 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 804 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 805 &fs_info->dev_replace.bio_counter)); 806 } 807 808 /* 809 * we have removed target device, it is safe to allow new bios request. 810 */ 811 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 812 { 813 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 814 wake_up(&fs_info->dev_replace.replace_wait); 815 } 816 817 /* 818 * When finishing the device replace, before swapping the source device with the 819 * target device we must update the chunk allocation state in the target device, 820 * as it is empty because replace works by directly copying the chunks and not 821 * through the normal chunk allocation path. 822 */ 823 static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev, 824 struct btrfs_device *tgtdev) 825 { 826 struct extent_state *cached_state = NULL; 827 u64 start = 0; 828 u64 found_start; 829 u64 found_end; 830 int ret = 0; 831 832 lockdep_assert_held(&srcdev->fs_info->chunk_mutex); 833 834 while (!find_first_extent_bit(&srcdev->alloc_state, start, 835 &found_start, &found_end, 836 CHUNK_ALLOCATED, &cached_state)) { 837 ret = set_extent_bits(&tgtdev->alloc_state, found_start, 838 found_end, CHUNK_ALLOCATED); 839 if (ret) 840 break; 841 start = found_end + 1; 842 } 843 844 free_extent_state(cached_state); 845 return ret; 846 } 847 848 static void btrfs_dev_replace_update_device_in_mapping_tree( 849 struct btrfs_fs_info *fs_info, 850 struct btrfs_device *srcdev, 851 struct btrfs_device *tgtdev) 852 { 853 struct extent_map_tree *em_tree = &fs_info->mapping_tree; 854 struct extent_map *em; 855 struct map_lookup *map; 856 u64 start = 0; 857 int i; 858 859 write_lock(&em_tree->lock); 860 do { 861 em = lookup_extent_mapping(em_tree, start, (u64)-1); 862 if (!em) 863 break; 864 map = em->map_lookup; 865 for (i = 0; i < map->num_stripes; i++) 866 if (srcdev == map->stripes[i].dev) 867 map->stripes[i].dev = tgtdev; 868 start = em->start + em->len; 869 free_extent_map(em); 870 } while (start); 871 write_unlock(&em_tree->lock); 872 } 873 874 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 875 int scrub_ret) 876 { 877 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 878 struct btrfs_device *tgt_device; 879 struct btrfs_device *src_device; 880 struct btrfs_root *root = fs_info->tree_root; 881 u8 uuid_tmp[BTRFS_UUID_SIZE]; 882 struct btrfs_trans_handle *trans; 883 int ret = 0; 884 885 /* don't allow cancel or unmount to disturb the finishing procedure */ 886 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 887 888 down_read(&dev_replace->rwsem); 889 /* was the operation canceled, or is it finished? */ 890 if (dev_replace->replace_state != 891 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 892 up_read(&dev_replace->rwsem); 893 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 894 return 0; 895 } 896 897 tgt_device = dev_replace->tgtdev; 898 src_device = dev_replace->srcdev; 899 up_read(&dev_replace->rwsem); 900 901 /* 902 * flush all outstanding I/O and inode extent mappings before the 903 * copy operation is declared as being finished 904 */ 905 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false); 906 if (ret) { 907 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 908 return ret; 909 } 910 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 911 912 if (!scrub_ret) 913 btrfs_reada_remove_dev(src_device); 914 915 /* 916 * We have to use this loop approach because at this point src_device 917 * has to be available for transaction commit to complete, yet new 918 * chunks shouldn't be allocated on the device. 919 */ 920 while (1) { 921 trans = btrfs_start_transaction(root, 0); 922 if (IS_ERR(trans)) { 923 btrfs_reada_undo_remove_dev(src_device); 924 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 925 return PTR_ERR(trans); 926 } 927 ret = btrfs_commit_transaction(trans); 928 WARN_ON(ret); 929 930 /* Prevent write_all_supers() during the finishing procedure */ 931 mutex_lock(&fs_info->fs_devices->device_list_mutex); 932 /* Prevent new chunks being allocated on the source device */ 933 mutex_lock(&fs_info->chunk_mutex); 934 935 if (!list_empty(&src_device->post_commit_list)) { 936 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 937 mutex_unlock(&fs_info->chunk_mutex); 938 } else { 939 break; 940 } 941 } 942 943 down_write(&dev_replace->rwsem); 944 dev_replace->replace_state = 945 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 946 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 947 dev_replace->tgtdev = NULL; 948 dev_replace->srcdev = NULL; 949 dev_replace->time_stopped = ktime_get_real_seconds(); 950 dev_replace->item_needs_writeback = 1; 951 952 /* 953 * Update allocation state in the new device and replace the old device 954 * with the new one in the mapping tree. 955 */ 956 if (!scrub_ret) { 957 scrub_ret = btrfs_set_target_alloc_state(src_device, tgt_device); 958 if (scrub_ret) 959 goto error; 960 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 961 src_device, 962 tgt_device); 963 } else { 964 if (scrub_ret != -ECANCELED) 965 btrfs_err_in_rcu(fs_info, 966 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 967 btrfs_dev_name(src_device), 968 src_device->devid, 969 rcu_str_deref(tgt_device->name), scrub_ret); 970 error: 971 up_write(&dev_replace->rwsem); 972 mutex_unlock(&fs_info->chunk_mutex); 973 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 974 btrfs_reada_undo_remove_dev(src_device); 975 btrfs_rm_dev_replace_blocked(fs_info); 976 if (tgt_device) 977 btrfs_destroy_dev_replace_tgtdev(tgt_device); 978 btrfs_rm_dev_replace_unblocked(fs_info); 979 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 980 981 return scrub_ret; 982 } 983 984 btrfs_info_in_rcu(fs_info, 985 "dev_replace from %s (devid %llu) to %s finished", 986 btrfs_dev_name(src_device), 987 src_device->devid, 988 rcu_str_deref(tgt_device->name)); 989 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 990 tgt_device->devid = src_device->devid; 991 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 992 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 993 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 994 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 995 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 996 btrfs_device_set_disk_total_bytes(tgt_device, 997 src_device->disk_total_bytes); 998 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 999 tgt_device->commit_bytes_used = src_device->bytes_used; 1000 1001 btrfs_assign_next_active_device(src_device, tgt_device); 1002 1003 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 1004 fs_info->fs_devices->rw_devices++; 1005 1006 up_write(&dev_replace->rwsem); 1007 btrfs_rm_dev_replace_blocked(fs_info); 1008 1009 btrfs_rm_dev_replace_remove_srcdev(src_device); 1010 1011 btrfs_rm_dev_replace_unblocked(fs_info); 1012 1013 /* 1014 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will 1015 * update on-disk dev stats value during commit transaction 1016 */ 1017 atomic_inc(&tgt_device->dev_stats_ccnt); 1018 1019 /* 1020 * this is again a consistent state where no dev_replace procedure 1021 * is running, the target device is part of the filesystem, the 1022 * source device is not part of the filesystem anymore and its 1st 1023 * superblock is scratched out so that it is no longer marked to 1024 * belong to this filesystem. 1025 */ 1026 mutex_unlock(&fs_info->chunk_mutex); 1027 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1028 1029 /* replace the sysfs entry */ 1030 btrfs_sysfs_remove_device(src_device); 1031 btrfs_sysfs_update_devid(tgt_device); 1032 if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &src_device->dev_state)) 1033 btrfs_scratch_superblocks(fs_info, src_device->bdev, 1034 src_device->name->str); 1035 1036 /* write back the superblocks */ 1037 trans = btrfs_start_transaction(root, 0); 1038 if (!IS_ERR(trans)) 1039 btrfs_commit_transaction(trans); 1040 1041 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1042 1043 btrfs_rm_dev_replace_free_srcdev(src_device); 1044 1045 return 0; 1046 } 1047 1048 /* 1049 * Read progress of device replace status according to the state and last 1050 * stored position. The value format is the same as for 1051 * btrfs_dev_replace::progress_1000 1052 */ 1053 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 1054 { 1055 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1056 u64 ret = 0; 1057 1058 switch (dev_replace->replace_state) { 1059 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1060 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1061 ret = 0; 1062 break; 1063 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1064 ret = 1000; 1065 break; 1066 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1067 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1068 ret = div64_u64(dev_replace->cursor_left, 1069 div_u64(btrfs_device_get_total_bytes( 1070 dev_replace->srcdev), 1000)); 1071 break; 1072 } 1073 1074 return ret; 1075 } 1076 1077 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 1078 struct btrfs_ioctl_dev_replace_args *args) 1079 { 1080 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1081 1082 down_read(&dev_replace->rwsem); 1083 /* even if !dev_replace_is_valid, the values are good enough for 1084 * the replace_status ioctl */ 1085 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1086 args->status.replace_state = dev_replace->replace_state; 1087 args->status.time_started = dev_replace->time_started; 1088 args->status.time_stopped = dev_replace->time_stopped; 1089 args->status.num_write_errors = 1090 atomic64_read(&dev_replace->num_write_errors); 1091 args->status.num_uncorrectable_read_errors = 1092 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 1093 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 1094 up_read(&dev_replace->rwsem); 1095 } 1096 1097 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 1098 { 1099 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1100 struct btrfs_device *tgt_device = NULL; 1101 struct btrfs_device *src_device = NULL; 1102 struct btrfs_trans_handle *trans; 1103 struct btrfs_root *root = fs_info->tree_root; 1104 int result; 1105 int ret; 1106 1107 if (sb_rdonly(fs_info->sb)) 1108 return -EROFS; 1109 1110 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1111 down_write(&dev_replace->rwsem); 1112 switch (dev_replace->replace_state) { 1113 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1114 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1115 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1116 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1117 up_write(&dev_replace->rwsem); 1118 break; 1119 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1120 tgt_device = dev_replace->tgtdev; 1121 src_device = dev_replace->srcdev; 1122 up_write(&dev_replace->rwsem); 1123 ret = btrfs_scrub_cancel(fs_info); 1124 if (ret < 0) { 1125 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 1126 } else { 1127 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1128 /* 1129 * btrfs_dev_replace_finishing() will handle the 1130 * cleanup part 1131 */ 1132 btrfs_info_in_rcu(fs_info, 1133 "dev_replace from %s (devid %llu) to %s canceled", 1134 btrfs_dev_name(src_device), src_device->devid, 1135 btrfs_dev_name(tgt_device)); 1136 } 1137 break; 1138 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1139 /* 1140 * Scrub doing the replace isn't running so we need to do the 1141 * cleanup step of btrfs_dev_replace_finishing() here 1142 */ 1143 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 1144 tgt_device = dev_replace->tgtdev; 1145 src_device = dev_replace->srcdev; 1146 dev_replace->tgtdev = NULL; 1147 dev_replace->srcdev = NULL; 1148 dev_replace->replace_state = 1149 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 1150 dev_replace->time_stopped = ktime_get_real_seconds(); 1151 dev_replace->item_needs_writeback = 1; 1152 1153 up_write(&dev_replace->rwsem); 1154 1155 /* Scrub for replace must not be running in suspended state */ 1156 ret = btrfs_scrub_cancel(fs_info); 1157 ASSERT(ret != -ENOTCONN); 1158 1159 trans = btrfs_start_transaction(root, 0); 1160 if (IS_ERR(trans)) { 1161 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1162 return PTR_ERR(trans); 1163 } 1164 ret = btrfs_commit_transaction(trans); 1165 WARN_ON(ret); 1166 1167 btrfs_info_in_rcu(fs_info, 1168 "suspended dev_replace from %s (devid %llu) to %s canceled", 1169 btrfs_dev_name(src_device), src_device->devid, 1170 btrfs_dev_name(tgt_device)); 1171 1172 if (tgt_device) 1173 btrfs_destroy_dev_replace_tgtdev(tgt_device); 1174 break; 1175 default: 1176 up_write(&dev_replace->rwsem); 1177 result = -EINVAL; 1178 } 1179 1180 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1181 return result; 1182 } 1183 1184 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 1185 { 1186 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1187 1188 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 1189 down_write(&dev_replace->rwsem); 1190 1191 switch (dev_replace->replace_state) { 1192 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1193 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1194 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1195 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1196 break; 1197 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1198 dev_replace->replace_state = 1199 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1200 dev_replace->time_stopped = ktime_get_real_seconds(); 1201 dev_replace->item_needs_writeback = 1; 1202 btrfs_info(fs_info, "suspending dev_replace for unmount"); 1203 break; 1204 } 1205 1206 up_write(&dev_replace->rwsem); 1207 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 1208 } 1209 1210 /* resume dev_replace procedure that was interrupted by unmount */ 1211 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 1212 { 1213 struct task_struct *task; 1214 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1215 1216 down_write(&dev_replace->rwsem); 1217 1218 switch (dev_replace->replace_state) { 1219 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1220 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1221 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1222 up_write(&dev_replace->rwsem); 1223 return 0; 1224 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1225 break; 1226 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1227 dev_replace->replace_state = 1228 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 1229 break; 1230 } 1231 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 1232 btrfs_info(fs_info, 1233 "cannot continue dev_replace, tgtdev is missing"); 1234 btrfs_info(fs_info, 1235 "you may cancel the operation after 'mount -o degraded'"); 1236 dev_replace->replace_state = 1237 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1238 up_write(&dev_replace->rwsem); 1239 return 0; 1240 } 1241 up_write(&dev_replace->rwsem); 1242 1243 /* 1244 * This could collide with a paused balance, but the exclusive op logic 1245 * should never allow both to start and pause. We don't want to allow 1246 * dev-replace to start anyway. 1247 */ 1248 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { 1249 down_write(&dev_replace->rwsem); 1250 dev_replace->replace_state = 1251 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 1252 up_write(&dev_replace->rwsem); 1253 btrfs_info(fs_info, 1254 "cannot resume dev-replace, other exclusive operation running"); 1255 return 0; 1256 } 1257 1258 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 1259 return PTR_ERR_OR_ZERO(task); 1260 } 1261 1262 static int btrfs_dev_replace_kthread(void *data) 1263 { 1264 struct btrfs_fs_info *fs_info = data; 1265 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 1266 u64 progress; 1267 int ret; 1268 1269 progress = btrfs_dev_replace_progress(fs_info); 1270 progress = div_u64(progress, 10); 1271 btrfs_info_in_rcu(fs_info, 1272 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 1273 btrfs_dev_name(dev_replace->srcdev), 1274 dev_replace->srcdev->devid, 1275 btrfs_dev_name(dev_replace->tgtdev), 1276 (unsigned int)progress); 1277 1278 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 1279 dev_replace->committed_cursor_left, 1280 btrfs_device_get_total_bytes(dev_replace->srcdev), 1281 &dev_replace->scrub_progress, 0, 1); 1282 ret = btrfs_dev_replace_finishing(fs_info, ret); 1283 WARN_ON(ret && ret != -ECANCELED); 1284 1285 btrfs_exclop_finish(fs_info); 1286 return 0; 1287 } 1288 1289 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 1290 { 1291 if (!dev_replace->is_valid) 1292 return 0; 1293 1294 switch (dev_replace->replace_state) { 1295 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 1296 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 1297 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 1298 return 0; 1299 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1300 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1301 /* 1302 * return true even if tgtdev is missing (this is 1303 * something that can happen if the dev_replace 1304 * procedure is suspended by an umount and then 1305 * the tgtdev is missing (or "btrfs dev scan") was 1306 * not called and the filesystem is remounted 1307 * in degraded state. This does not stop the 1308 * dev_replace procedure. It needs to be canceled 1309 * manually if the cancellation is wanted. 1310 */ 1311 break; 1312 } 1313 return 1; 1314 } 1315 1316 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1317 { 1318 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1319 } 1320 1321 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1322 { 1323 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); 1324 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); 1325 } 1326 1327 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1328 { 1329 while (1) { 1330 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1331 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1332 &fs_info->fs_state))) 1333 break; 1334 1335 btrfs_bio_counter_dec(fs_info); 1336 wait_event(fs_info->dev_replace.replace_wait, 1337 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1338 &fs_info->fs_state)); 1339 } 1340 } 1341