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