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 25 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 26 int scrub_ret); 27 static void btrfs_dev_replace_update_device_in_mapping_tree( 28 struct btrfs_fs_info *fs_info, 29 struct btrfs_device *srcdev, 30 struct btrfs_device *tgtdev); 31 static int btrfs_dev_replace_kthread(void *data); 32 33 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 34 { 35 struct btrfs_key key; 36 struct btrfs_root *dev_root = fs_info->dev_root; 37 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 38 struct extent_buffer *eb; 39 int slot; 40 int ret = 0; 41 struct btrfs_path *path = NULL; 42 int item_size; 43 struct btrfs_dev_replace_item *ptr; 44 u64 src_devid; 45 46 path = btrfs_alloc_path(); 47 if (!path) { 48 ret = -ENOMEM; 49 goto out; 50 } 51 52 key.objectid = 0; 53 key.type = BTRFS_DEV_REPLACE_KEY; 54 key.offset = 0; 55 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 56 if (ret) { 57 no_valid_dev_replace_entry_found: 58 ret = 0; 59 dev_replace->replace_state = 60 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 61 dev_replace->cont_reading_from_srcdev_mode = 62 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 63 dev_replace->time_started = 0; 64 dev_replace->time_stopped = 0; 65 atomic64_set(&dev_replace->num_write_errors, 0); 66 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 67 dev_replace->cursor_left = 0; 68 dev_replace->committed_cursor_left = 0; 69 dev_replace->cursor_left_last_write_of_item = 0; 70 dev_replace->cursor_right = 0; 71 dev_replace->srcdev = NULL; 72 dev_replace->tgtdev = NULL; 73 dev_replace->is_valid = 0; 74 dev_replace->item_needs_writeback = 0; 75 goto out; 76 } 77 slot = path->slots[0]; 78 eb = path->nodes[0]; 79 item_size = btrfs_item_size_nr(eb, slot); 80 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 81 82 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 83 btrfs_warn(fs_info, 84 "dev_replace entry found has unexpected size, ignore entry"); 85 goto no_valid_dev_replace_entry_found; 86 } 87 88 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 89 dev_replace->cont_reading_from_srcdev_mode = 90 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 91 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 92 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 93 dev_replace->time_stopped = 94 btrfs_dev_replace_time_stopped(eb, ptr); 95 atomic64_set(&dev_replace->num_write_errors, 96 btrfs_dev_replace_num_write_errors(eb, ptr)); 97 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 98 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 99 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 100 dev_replace->committed_cursor_left = dev_replace->cursor_left; 101 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 102 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 103 dev_replace->is_valid = 1; 104 105 dev_replace->item_needs_writeback = 0; 106 switch (dev_replace->replace_state) { 107 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 108 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 109 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 110 dev_replace->srcdev = NULL; 111 dev_replace->tgtdev = NULL; 112 break; 113 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 114 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 115 dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices, 116 src_devid, NULL, NULL, true); 117 dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices, 118 BTRFS_DEV_REPLACE_DEVID, 119 NULL, NULL, true); 120 /* 121 * allow 'btrfs dev replace_cancel' if src/tgt device is 122 * missing 123 */ 124 if (!dev_replace->srcdev && 125 !btrfs_test_opt(fs_info, DEGRADED)) { 126 ret = -EIO; 127 btrfs_warn(fs_info, 128 "cannot mount because device replace operation is ongoing and"); 129 btrfs_warn(fs_info, 130 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 131 src_devid); 132 } 133 if (!dev_replace->tgtdev && 134 !btrfs_test_opt(fs_info, DEGRADED)) { 135 ret = -EIO; 136 btrfs_warn(fs_info, 137 "cannot mount because device replace operation is ongoing and"); 138 btrfs_warn(fs_info, 139 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 140 BTRFS_DEV_REPLACE_DEVID); 141 } 142 if (dev_replace->tgtdev) { 143 if (dev_replace->srcdev) { 144 dev_replace->tgtdev->total_bytes = 145 dev_replace->srcdev->total_bytes; 146 dev_replace->tgtdev->disk_total_bytes = 147 dev_replace->srcdev->disk_total_bytes; 148 dev_replace->tgtdev->commit_total_bytes = 149 dev_replace->srcdev->commit_total_bytes; 150 dev_replace->tgtdev->bytes_used = 151 dev_replace->srcdev->bytes_used; 152 dev_replace->tgtdev->commit_bytes_used = 153 dev_replace->srcdev->commit_bytes_used; 154 } 155 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 156 &dev_replace->tgtdev->dev_state); 157 158 WARN_ON(fs_info->fs_devices->rw_devices == 0); 159 dev_replace->tgtdev->io_width = fs_info->sectorsize; 160 dev_replace->tgtdev->io_align = fs_info->sectorsize; 161 dev_replace->tgtdev->sector_size = fs_info->sectorsize; 162 dev_replace->tgtdev->fs_info = fs_info; 163 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 164 &dev_replace->tgtdev->dev_state); 165 } 166 break; 167 } 168 169 out: 170 btrfs_free_path(path); 171 return ret; 172 } 173 174 /* 175 * Initialize a new device for device replace target from a given source dev 176 * and path. 177 * 178 * Return 0 and new device in @device_out, otherwise return < 0 179 */ 180 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, 181 const char *device_path, 182 struct btrfs_device *srcdev, 183 struct btrfs_device **device_out) 184 { 185 struct btrfs_device *device; 186 struct block_device *bdev; 187 struct list_head *devices; 188 struct rcu_string *name; 189 u64 devid = BTRFS_DEV_REPLACE_DEVID; 190 int ret = 0; 191 192 *device_out = NULL; 193 if (fs_info->fs_devices->seeding) { 194 btrfs_err(fs_info, "the filesystem is a seed filesystem!"); 195 return -EINVAL; 196 } 197 198 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, 199 fs_info->bdev_holder); 200 if (IS_ERR(bdev)) { 201 btrfs_err(fs_info, "target device %s is invalid!", device_path); 202 return PTR_ERR(bdev); 203 } 204 205 sync_blockdev(bdev); 206 207 devices = &fs_info->fs_devices->devices; 208 list_for_each_entry(device, devices, dev_list) { 209 if (device->bdev == bdev) { 210 btrfs_err(fs_info, 211 "target device is in the filesystem!"); 212 ret = -EEXIST; 213 goto error; 214 } 215 } 216 217 218 if (i_size_read(bdev->bd_inode) < 219 btrfs_device_get_total_bytes(srcdev)) { 220 btrfs_err(fs_info, 221 "target device is smaller than source device!"); 222 ret = -EINVAL; 223 goto error; 224 } 225 226 227 device = btrfs_alloc_device(NULL, &devid, NULL); 228 if (IS_ERR(device)) { 229 ret = PTR_ERR(device); 230 goto error; 231 } 232 233 name = rcu_string_strdup(device_path, GFP_KERNEL); 234 if (!name) { 235 btrfs_free_device(device); 236 ret = -ENOMEM; 237 goto error; 238 } 239 rcu_assign_pointer(device->name, name); 240 241 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 242 device->generation = 0; 243 device->io_width = fs_info->sectorsize; 244 device->io_align = fs_info->sectorsize; 245 device->sector_size = fs_info->sectorsize; 246 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 247 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 248 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 249 device->commit_total_bytes = srcdev->commit_total_bytes; 250 device->commit_bytes_used = device->bytes_used; 251 device->fs_info = fs_info; 252 device->bdev = bdev; 253 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 254 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 255 device->mode = FMODE_EXCL; 256 device->dev_stats_valid = 1; 257 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 258 device->fs_devices = fs_info->fs_devices; 259 260 mutex_lock(&fs_info->fs_devices->device_list_mutex); 261 list_add(&device->dev_list, &fs_info->fs_devices->devices); 262 fs_info->fs_devices->num_devices++; 263 fs_info->fs_devices->open_devices++; 264 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 265 266 *device_out = device; 267 return 0; 268 269 error: 270 blkdev_put(bdev, FMODE_EXCL); 271 return ret; 272 } 273 274 /* 275 * called from commit_transaction. Writes changed device replace state to 276 * disk. 277 */ 278 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 279 { 280 struct btrfs_fs_info *fs_info = trans->fs_info; 281 int ret; 282 struct btrfs_root *dev_root = fs_info->dev_root; 283 struct btrfs_path *path; 284 struct btrfs_key key; 285 struct extent_buffer *eb; 286 struct btrfs_dev_replace_item *ptr; 287 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 288 289 down_read(&dev_replace->rwsem); 290 if (!dev_replace->is_valid || 291 !dev_replace->item_needs_writeback) { 292 up_read(&dev_replace->rwsem); 293 return 0; 294 } 295 up_read(&dev_replace->rwsem); 296 297 key.objectid = 0; 298 key.type = BTRFS_DEV_REPLACE_KEY; 299 key.offset = 0; 300 301 path = btrfs_alloc_path(); 302 if (!path) { 303 ret = -ENOMEM; 304 goto out; 305 } 306 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 307 if (ret < 0) { 308 btrfs_warn(fs_info, 309 "error %d while searching for dev_replace item!", 310 ret); 311 goto out; 312 } 313 314 if (ret == 0 && 315 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 316 /* 317 * need to delete old one and insert a new one. 318 * Since no attempt is made to recover any old state, if the 319 * dev_replace state is 'running', the data on the target 320 * drive is lost. 321 * It would be possible to recover the state: just make sure 322 * that the beginning of the item is never changed and always 323 * contains all the essential information. Then read this 324 * minimal set of information and use it as a base for the 325 * new state. 326 */ 327 ret = btrfs_del_item(trans, dev_root, path); 328 if (ret != 0) { 329 btrfs_warn(fs_info, 330 "delete too small dev_replace item failed %d!", 331 ret); 332 goto out; 333 } 334 ret = 1; 335 } 336 337 if (ret == 1) { 338 /* need to insert a new item */ 339 btrfs_release_path(path); 340 ret = btrfs_insert_empty_item(trans, dev_root, path, 341 &key, sizeof(*ptr)); 342 if (ret < 0) { 343 btrfs_warn(fs_info, 344 "insert dev_replace item failed %d!", ret); 345 goto out; 346 } 347 } 348 349 eb = path->nodes[0]; 350 ptr = btrfs_item_ptr(eb, path->slots[0], 351 struct btrfs_dev_replace_item); 352 353 down_write(&dev_replace->rwsem); 354 if (dev_replace->srcdev) 355 btrfs_set_dev_replace_src_devid(eb, ptr, 356 dev_replace->srcdev->devid); 357 else 358 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 359 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 360 dev_replace->cont_reading_from_srcdev_mode); 361 btrfs_set_dev_replace_replace_state(eb, ptr, 362 dev_replace->replace_state); 363 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 364 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 365 btrfs_set_dev_replace_num_write_errors(eb, ptr, 366 atomic64_read(&dev_replace->num_write_errors)); 367 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 368 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 369 dev_replace->cursor_left_last_write_of_item = 370 dev_replace->cursor_left; 371 btrfs_set_dev_replace_cursor_left(eb, ptr, 372 dev_replace->cursor_left_last_write_of_item); 373 btrfs_set_dev_replace_cursor_right(eb, ptr, 374 dev_replace->cursor_right); 375 dev_replace->item_needs_writeback = 0; 376 up_write(&dev_replace->rwsem); 377 378 btrfs_mark_buffer_dirty(eb); 379 380 out: 381 btrfs_free_path(path); 382 383 return ret; 384 } 385 386 static char* btrfs_dev_name(struct btrfs_device *device) 387 { 388 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 389 return "<missing disk>"; 390 else 391 return rcu_str_deref(device->name); 392 } 393 394 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 395 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 396 int read_src) 397 { 398 struct btrfs_root *root = fs_info->dev_root; 399 struct btrfs_trans_handle *trans; 400 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 401 int ret; 402 struct btrfs_device *tgt_device = NULL; 403 struct btrfs_device *src_device = NULL; 404 405 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, 406 srcdev_name); 407 if (IS_ERR(src_device)) 408 return PTR_ERR(src_device); 409 410 if (btrfs_pinned_by_swapfile(fs_info, src_device)) { 411 btrfs_warn_in_rcu(fs_info, 412 "cannot replace device %s (devid %llu) due to active swapfile", 413 btrfs_dev_name(src_device), src_device->devid); 414 return -ETXTBSY; 415 } 416 417 /* 418 * Here we commit the transaction to make sure commit_total_bytes 419 * of all the devices are updated. 420 */ 421 trans = btrfs_attach_transaction(root); 422 if (!IS_ERR(trans)) { 423 ret = btrfs_commit_transaction(trans); 424 if (ret) 425 return ret; 426 } else if (PTR_ERR(trans) != -ENOENT) { 427 return PTR_ERR(trans); 428 } 429 430 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 431 src_device, &tgt_device); 432 if (ret) 433 return ret; 434 435 down_write(&dev_replace->rwsem); 436 switch (dev_replace->replace_state) { 437 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 438 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 439 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 440 break; 441 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 442 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 443 ASSERT(0); 444 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 445 up_write(&dev_replace->rwsem); 446 goto leave; 447 } 448 449 dev_replace->cont_reading_from_srcdev_mode = read_src; 450 dev_replace->srcdev = src_device; 451 dev_replace->tgtdev = tgt_device; 452 453 btrfs_info_in_rcu(fs_info, 454 "dev_replace from %s (devid %llu) to %s started", 455 btrfs_dev_name(src_device), 456 src_device->devid, 457 rcu_str_deref(tgt_device->name)); 458 459 /* 460 * from now on, the writes to the srcdev are all duplicated to 461 * go to the tgtdev as well (refer to btrfs_map_block()). 462 */ 463 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 464 dev_replace->time_started = ktime_get_real_seconds(); 465 dev_replace->cursor_left = 0; 466 dev_replace->committed_cursor_left = 0; 467 dev_replace->cursor_left_last_write_of_item = 0; 468 dev_replace->cursor_right = 0; 469 dev_replace->is_valid = 1; 470 dev_replace->item_needs_writeback = 1; 471 atomic64_set(&dev_replace->num_write_errors, 0); 472 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 473 up_write(&dev_replace->rwsem); 474 475 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 476 if (ret) 477 btrfs_err(fs_info, "kobj add dev failed %d", ret); 478 479 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 480 481 /* Commit dev_replace state and reserve 1 item for it. */ 482 trans = btrfs_start_transaction(root, 1); 483 if (IS_ERR(trans)) { 484 ret = PTR_ERR(trans); 485 down_write(&dev_replace->rwsem); 486 dev_replace->replace_state = 487 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 488 dev_replace->srcdev = NULL; 489 dev_replace->tgtdev = NULL; 490 up_write(&dev_replace->rwsem); 491 goto leave; 492 } 493 494 ret = btrfs_commit_transaction(trans); 495 WARN_ON(ret); 496 497 /* the disk copy procedure reuses the scrub code */ 498 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 499 btrfs_device_get_total_bytes(src_device), 500 &dev_replace->scrub_progress, 0, 1); 501 502 ret = btrfs_dev_replace_finishing(fs_info, ret); 503 if (ret == -EINPROGRESS) { 504 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 505 } else if (ret != -ECANCELED) { 506 WARN_ON(ret); 507 } 508 509 return ret; 510 511 leave: 512 btrfs_destroy_dev_replace_tgtdev(tgt_device); 513 return ret; 514 } 515 516 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 517 struct btrfs_ioctl_dev_replace_args *args) 518 { 519 int ret; 520 521 switch (args->start.cont_reading_from_srcdev_mode) { 522 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 523 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 524 break; 525 default: 526 return -EINVAL; 527 } 528 529 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 530 args->start.tgtdev_name[0] == '\0') 531 return -EINVAL; 532 533 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 534 args->start.srcdevid, 535 args->start.srcdev_name, 536 args->start.cont_reading_from_srcdev_mode); 537 args->result = ret; 538 /* don't warn if EINPROGRESS, someone else might be running scrub */ 539 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 540 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 541 return 0; 542 543 return ret; 544 } 545 546 /* 547 * blocked until all in-flight bios operations are finished. 548 */ 549 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 550 { 551 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 552 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 553 &fs_info->dev_replace.bio_counter)); 554 } 555 556 /* 557 * we have removed target device, it is safe to allow new bios request. 558 */ 559 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 560 { 561 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 562 wake_up(&fs_info->dev_replace.replace_wait); 563 } 564 565 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 566 int scrub_ret) 567 { 568 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 569 struct btrfs_device *tgt_device; 570 struct btrfs_device *src_device; 571 struct btrfs_root *root = fs_info->tree_root; 572 u8 uuid_tmp[BTRFS_UUID_SIZE]; 573 struct btrfs_trans_handle *trans; 574 int ret = 0; 575 576 /* don't allow cancel or unmount to disturb the finishing procedure */ 577 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 578 579 down_read(&dev_replace->rwsem); 580 /* was the operation canceled, or is it finished? */ 581 if (dev_replace->replace_state != 582 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 583 up_read(&dev_replace->rwsem); 584 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 585 return 0; 586 } 587 588 tgt_device = dev_replace->tgtdev; 589 src_device = dev_replace->srcdev; 590 up_read(&dev_replace->rwsem); 591 592 /* 593 * flush all outstanding I/O and inode extent mappings before the 594 * copy operation is declared as being finished 595 */ 596 ret = btrfs_start_delalloc_roots(fs_info, -1); 597 if (ret) { 598 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 599 return ret; 600 } 601 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 602 603 /* 604 * We have to use this loop approach because at this point src_device 605 * has to be available for transaction commit to complete, yet new 606 * chunks shouldn't be allocated on the device. 607 */ 608 while (1) { 609 trans = btrfs_start_transaction(root, 0); 610 if (IS_ERR(trans)) { 611 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 612 return PTR_ERR(trans); 613 } 614 ret = btrfs_commit_transaction(trans); 615 WARN_ON(ret); 616 617 /* Prevent write_all_supers() during the finishing procedure */ 618 mutex_lock(&fs_info->fs_devices->device_list_mutex); 619 /* Prevent new chunks being allocated on the source device */ 620 mutex_lock(&fs_info->chunk_mutex); 621 622 if (!list_empty(&src_device->post_commit_list)) { 623 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 624 mutex_unlock(&fs_info->chunk_mutex); 625 } else { 626 break; 627 } 628 } 629 630 down_write(&dev_replace->rwsem); 631 dev_replace->replace_state = 632 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 633 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 634 dev_replace->tgtdev = NULL; 635 dev_replace->srcdev = NULL; 636 dev_replace->time_stopped = ktime_get_real_seconds(); 637 dev_replace->item_needs_writeback = 1; 638 639 /* replace old device with new one in mapping tree */ 640 if (!scrub_ret) { 641 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 642 src_device, 643 tgt_device); 644 } else { 645 if (scrub_ret != -ECANCELED) 646 btrfs_err_in_rcu(fs_info, 647 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 648 btrfs_dev_name(src_device), 649 src_device->devid, 650 rcu_str_deref(tgt_device->name), scrub_ret); 651 up_write(&dev_replace->rwsem); 652 mutex_unlock(&fs_info->chunk_mutex); 653 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 654 btrfs_rm_dev_replace_blocked(fs_info); 655 if (tgt_device) 656 btrfs_destroy_dev_replace_tgtdev(tgt_device); 657 btrfs_rm_dev_replace_unblocked(fs_info); 658 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 659 660 return scrub_ret; 661 } 662 663 btrfs_info_in_rcu(fs_info, 664 "dev_replace from %s (devid %llu) to %s finished", 665 btrfs_dev_name(src_device), 666 src_device->devid, 667 rcu_str_deref(tgt_device->name)); 668 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 669 tgt_device->devid = src_device->devid; 670 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 671 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 672 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 673 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 674 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 675 btrfs_device_set_disk_total_bytes(tgt_device, 676 src_device->disk_total_bytes); 677 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 678 tgt_device->commit_bytes_used = src_device->bytes_used; 679 680 btrfs_assign_next_active_device(src_device, tgt_device); 681 682 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 683 fs_info->fs_devices->rw_devices++; 684 685 up_write(&dev_replace->rwsem); 686 btrfs_rm_dev_replace_blocked(fs_info); 687 688 btrfs_rm_dev_replace_remove_srcdev(src_device); 689 690 btrfs_rm_dev_replace_unblocked(fs_info); 691 692 /* 693 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will 694 * update on-disk dev stats value during commit transaction 695 */ 696 atomic_inc(&tgt_device->dev_stats_ccnt); 697 698 /* 699 * this is again a consistent state where no dev_replace procedure 700 * is running, the target device is part of the filesystem, the 701 * source device is not part of the filesystem anymore and its 1st 702 * superblock is scratched out so that it is no longer marked to 703 * belong to this filesystem. 704 */ 705 mutex_unlock(&fs_info->chunk_mutex); 706 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 707 708 /* replace the sysfs entry */ 709 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 710 btrfs_rm_dev_replace_free_srcdev(src_device); 711 712 /* write back the superblocks */ 713 trans = btrfs_start_transaction(root, 0); 714 if (!IS_ERR(trans)) 715 btrfs_commit_transaction(trans); 716 717 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 718 719 return 0; 720 } 721 722 static void btrfs_dev_replace_update_device_in_mapping_tree( 723 struct btrfs_fs_info *fs_info, 724 struct btrfs_device *srcdev, 725 struct btrfs_device *tgtdev) 726 { 727 struct extent_map_tree *em_tree = &fs_info->mapping_tree; 728 struct extent_map *em; 729 struct map_lookup *map; 730 u64 start = 0; 731 int i; 732 733 write_lock(&em_tree->lock); 734 do { 735 em = lookup_extent_mapping(em_tree, start, (u64)-1); 736 if (!em) 737 break; 738 map = em->map_lookup; 739 for (i = 0; i < map->num_stripes; i++) 740 if (srcdev == map->stripes[i].dev) 741 map->stripes[i].dev = tgtdev; 742 start = em->start + em->len; 743 free_extent_map(em); 744 } while (start); 745 write_unlock(&em_tree->lock); 746 } 747 748 /* 749 * Read progress of device replace status according to the state and last 750 * stored position. The value format is the same as for 751 * btrfs_dev_replace::progress_1000 752 */ 753 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 754 { 755 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 756 u64 ret = 0; 757 758 switch (dev_replace->replace_state) { 759 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 760 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 761 ret = 0; 762 break; 763 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 764 ret = 1000; 765 break; 766 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 767 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 768 ret = div64_u64(dev_replace->cursor_left, 769 div_u64(btrfs_device_get_total_bytes( 770 dev_replace->srcdev), 1000)); 771 break; 772 } 773 774 return ret; 775 } 776 777 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 778 struct btrfs_ioctl_dev_replace_args *args) 779 { 780 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 781 782 down_read(&dev_replace->rwsem); 783 /* even if !dev_replace_is_valid, the values are good enough for 784 * the replace_status ioctl */ 785 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 786 args->status.replace_state = dev_replace->replace_state; 787 args->status.time_started = dev_replace->time_started; 788 args->status.time_stopped = dev_replace->time_stopped; 789 args->status.num_write_errors = 790 atomic64_read(&dev_replace->num_write_errors); 791 args->status.num_uncorrectable_read_errors = 792 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 793 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 794 up_read(&dev_replace->rwsem); 795 } 796 797 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 798 { 799 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 800 struct btrfs_device *tgt_device = NULL; 801 struct btrfs_device *src_device = NULL; 802 struct btrfs_trans_handle *trans; 803 struct btrfs_root *root = fs_info->tree_root; 804 int result; 805 int ret; 806 807 if (sb_rdonly(fs_info->sb)) 808 return -EROFS; 809 810 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 811 down_write(&dev_replace->rwsem); 812 switch (dev_replace->replace_state) { 813 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 814 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 815 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 816 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 817 up_write(&dev_replace->rwsem); 818 break; 819 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 820 tgt_device = dev_replace->tgtdev; 821 src_device = dev_replace->srcdev; 822 up_write(&dev_replace->rwsem); 823 ret = btrfs_scrub_cancel(fs_info); 824 if (ret < 0) { 825 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 826 } else { 827 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 828 /* 829 * btrfs_dev_replace_finishing() will handle the 830 * cleanup part 831 */ 832 btrfs_info_in_rcu(fs_info, 833 "dev_replace from %s (devid %llu) to %s canceled", 834 btrfs_dev_name(src_device), src_device->devid, 835 btrfs_dev_name(tgt_device)); 836 } 837 break; 838 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 839 /* 840 * Scrub doing the replace isn't running so we need to do the 841 * cleanup step of btrfs_dev_replace_finishing() here 842 */ 843 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 844 tgt_device = dev_replace->tgtdev; 845 src_device = dev_replace->srcdev; 846 dev_replace->tgtdev = NULL; 847 dev_replace->srcdev = NULL; 848 dev_replace->replace_state = 849 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 850 dev_replace->time_stopped = ktime_get_real_seconds(); 851 dev_replace->item_needs_writeback = 1; 852 853 up_write(&dev_replace->rwsem); 854 855 /* Scrub for replace must not be running in suspended state */ 856 ret = btrfs_scrub_cancel(fs_info); 857 ASSERT(ret != -ENOTCONN); 858 859 trans = btrfs_start_transaction(root, 0); 860 if (IS_ERR(trans)) { 861 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 862 return PTR_ERR(trans); 863 } 864 ret = btrfs_commit_transaction(trans); 865 WARN_ON(ret); 866 867 btrfs_info_in_rcu(fs_info, 868 "suspended dev_replace from %s (devid %llu) to %s canceled", 869 btrfs_dev_name(src_device), src_device->devid, 870 btrfs_dev_name(tgt_device)); 871 872 if (tgt_device) 873 btrfs_destroy_dev_replace_tgtdev(tgt_device); 874 break; 875 default: 876 up_write(&dev_replace->rwsem); 877 result = -EINVAL; 878 } 879 880 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 881 return result; 882 } 883 884 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 885 { 886 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 887 888 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 889 down_write(&dev_replace->rwsem); 890 891 switch (dev_replace->replace_state) { 892 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 893 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 894 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 895 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 896 break; 897 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 898 dev_replace->replace_state = 899 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 900 dev_replace->time_stopped = ktime_get_real_seconds(); 901 dev_replace->item_needs_writeback = 1; 902 btrfs_info(fs_info, "suspending dev_replace for unmount"); 903 break; 904 } 905 906 up_write(&dev_replace->rwsem); 907 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 908 } 909 910 /* resume dev_replace procedure that was interrupted by unmount */ 911 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 912 { 913 struct task_struct *task; 914 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 915 916 down_write(&dev_replace->rwsem); 917 918 switch (dev_replace->replace_state) { 919 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 920 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 921 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 922 up_write(&dev_replace->rwsem); 923 return 0; 924 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 925 break; 926 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 927 dev_replace->replace_state = 928 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 929 break; 930 } 931 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 932 btrfs_info(fs_info, 933 "cannot continue dev_replace, tgtdev is missing"); 934 btrfs_info(fs_info, 935 "you may cancel the operation after 'mount -o degraded'"); 936 dev_replace->replace_state = 937 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 938 up_write(&dev_replace->rwsem); 939 return 0; 940 } 941 up_write(&dev_replace->rwsem); 942 943 /* 944 * This could collide with a paused balance, but the exclusive op logic 945 * should never allow both to start and pause. We don't want to allow 946 * dev-replace to start anyway. 947 */ 948 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { 949 down_write(&dev_replace->rwsem); 950 dev_replace->replace_state = 951 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 952 up_write(&dev_replace->rwsem); 953 btrfs_info(fs_info, 954 "cannot resume dev-replace, other exclusive operation running"); 955 return 0; 956 } 957 958 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 959 return PTR_ERR_OR_ZERO(task); 960 } 961 962 static int btrfs_dev_replace_kthread(void *data) 963 { 964 struct btrfs_fs_info *fs_info = data; 965 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 966 u64 progress; 967 int ret; 968 969 progress = btrfs_dev_replace_progress(fs_info); 970 progress = div_u64(progress, 10); 971 btrfs_info_in_rcu(fs_info, 972 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 973 btrfs_dev_name(dev_replace->srcdev), 974 dev_replace->srcdev->devid, 975 btrfs_dev_name(dev_replace->tgtdev), 976 (unsigned int)progress); 977 978 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 979 dev_replace->committed_cursor_left, 980 btrfs_device_get_total_bytes(dev_replace->srcdev), 981 &dev_replace->scrub_progress, 0, 1); 982 ret = btrfs_dev_replace_finishing(fs_info, ret); 983 WARN_ON(ret && ret != -ECANCELED); 984 985 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); 986 return 0; 987 } 988 989 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 990 { 991 if (!dev_replace->is_valid) 992 return 0; 993 994 switch (dev_replace->replace_state) { 995 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 996 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 997 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 998 return 0; 999 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 1000 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 1001 /* 1002 * return true even if tgtdev is missing (this is 1003 * something that can happen if the dev_replace 1004 * procedure is suspended by an umount and then 1005 * the tgtdev is missing (or "btrfs dev scan") was 1006 * not called and the filesystem is remounted 1007 * in degraded state. This does not stop the 1008 * dev_replace procedure. It needs to be canceled 1009 * manually if the cancellation is wanted. 1010 */ 1011 break; 1012 } 1013 return 1; 1014 } 1015 1016 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1017 { 1018 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1019 } 1020 1021 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1022 { 1023 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); 1024 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); 1025 } 1026 1027 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1028 { 1029 while (1) { 1030 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1031 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1032 &fs_info->fs_state))) 1033 break; 1034 1035 btrfs_bio_counter_dec(fs_info); 1036 wait_event(fs_info->dev_replace.replace_wait, 1037 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1038 &fs_info->fs_state)); 1039 } 1040 } 1041