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