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; 505 506 return ret; 507 508 leave: 509 btrfs_destroy_dev_replace_tgtdev(tgt_device); 510 return ret; 511 } 512 513 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 514 struct btrfs_ioctl_dev_replace_args *args) 515 { 516 int ret; 517 518 switch (args->start.cont_reading_from_srcdev_mode) { 519 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 520 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 521 break; 522 default: 523 return -EINVAL; 524 } 525 526 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 527 args->start.tgtdev_name[0] == '\0') 528 return -EINVAL; 529 530 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 531 args->start.srcdevid, 532 args->start.srcdev_name, 533 args->start.cont_reading_from_srcdev_mode); 534 args->result = ret; 535 /* don't warn if EINPROGRESS, someone else might be running scrub */ 536 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 537 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 538 return 0; 539 540 return ret; 541 } 542 543 /* 544 * blocked until all in-flight bios operations are finished. 545 */ 546 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 547 { 548 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 549 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 550 &fs_info->dev_replace.bio_counter)); 551 } 552 553 /* 554 * we have removed target device, it is safe to allow new bios request. 555 */ 556 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 557 { 558 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 559 wake_up(&fs_info->dev_replace.replace_wait); 560 } 561 562 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 563 int scrub_ret) 564 { 565 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 566 struct btrfs_device *tgt_device; 567 struct btrfs_device *src_device; 568 struct btrfs_root *root = fs_info->tree_root; 569 u8 uuid_tmp[BTRFS_UUID_SIZE]; 570 struct btrfs_trans_handle *trans; 571 int ret = 0; 572 573 /* don't allow cancel or unmount to disturb the finishing procedure */ 574 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 575 576 down_read(&dev_replace->rwsem); 577 /* was the operation canceled, or is it finished? */ 578 if (dev_replace->replace_state != 579 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 580 up_read(&dev_replace->rwsem); 581 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 582 return 0; 583 } 584 585 tgt_device = dev_replace->tgtdev; 586 src_device = dev_replace->srcdev; 587 up_read(&dev_replace->rwsem); 588 589 /* 590 * flush all outstanding I/O and inode extent mappings before the 591 * copy operation is declared as being finished 592 */ 593 ret = btrfs_start_delalloc_roots(fs_info, -1); 594 if (ret) { 595 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 596 return ret; 597 } 598 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 599 600 /* 601 * We have to use this loop approach because at this point src_device 602 * has to be available for transaction commit to complete, yet new 603 * chunks shouldn't be allocated on the device. 604 */ 605 while (1) { 606 trans = btrfs_start_transaction(root, 0); 607 if (IS_ERR(trans)) { 608 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 609 return PTR_ERR(trans); 610 } 611 ret = btrfs_commit_transaction(trans); 612 WARN_ON(ret); 613 614 /* Prevent write_all_supers() during the finishing procedure */ 615 mutex_lock(&fs_info->fs_devices->device_list_mutex); 616 /* Prevent new chunks being allocated on the source device */ 617 mutex_lock(&fs_info->chunk_mutex); 618 619 if (!list_empty(&src_device->post_commit_list)) { 620 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 621 mutex_unlock(&fs_info->chunk_mutex); 622 } else { 623 break; 624 } 625 } 626 627 down_write(&dev_replace->rwsem); 628 dev_replace->replace_state = 629 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 630 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 631 dev_replace->tgtdev = NULL; 632 dev_replace->srcdev = NULL; 633 dev_replace->time_stopped = ktime_get_real_seconds(); 634 dev_replace->item_needs_writeback = 1; 635 636 /* replace old device with new one in mapping tree */ 637 if (!scrub_ret) { 638 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 639 src_device, 640 tgt_device); 641 } else { 642 if (scrub_ret != -ECANCELED) 643 btrfs_err_in_rcu(fs_info, 644 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 645 btrfs_dev_name(src_device), 646 src_device->devid, 647 rcu_str_deref(tgt_device->name), scrub_ret); 648 up_write(&dev_replace->rwsem); 649 mutex_unlock(&fs_info->chunk_mutex); 650 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 651 btrfs_rm_dev_replace_blocked(fs_info); 652 if (tgt_device) 653 btrfs_destroy_dev_replace_tgtdev(tgt_device); 654 btrfs_rm_dev_replace_unblocked(fs_info); 655 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 656 657 return scrub_ret; 658 } 659 660 btrfs_info_in_rcu(fs_info, 661 "dev_replace from %s (devid %llu) to %s finished", 662 btrfs_dev_name(src_device), 663 src_device->devid, 664 rcu_str_deref(tgt_device->name)); 665 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 666 tgt_device->devid = src_device->devid; 667 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 668 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 669 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 670 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 671 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 672 btrfs_device_set_disk_total_bytes(tgt_device, 673 src_device->disk_total_bytes); 674 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 675 tgt_device->commit_bytes_used = src_device->bytes_used; 676 677 btrfs_assign_next_active_device(src_device, tgt_device); 678 679 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 680 fs_info->fs_devices->rw_devices++; 681 682 up_write(&dev_replace->rwsem); 683 btrfs_rm_dev_replace_blocked(fs_info); 684 685 btrfs_rm_dev_replace_remove_srcdev(src_device); 686 687 btrfs_rm_dev_replace_unblocked(fs_info); 688 689 /* 690 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will 691 * update on-disk dev stats value during commit transaction 692 */ 693 atomic_inc(&tgt_device->dev_stats_ccnt); 694 695 /* 696 * this is again a consistent state where no dev_replace procedure 697 * is running, the target device is part of the filesystem, the 698 * source device is not part of the filesystem anymore and its 1st 699 * superblock is scratched out so that it is no longer marked to 700 * belong to this filesystem. 701 */ 702 mutex_unlock(&fs_info->chunk_mutex); 703 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 704 705 /* replace the sysfs entry */ 706 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 707 btrfs_rm_dev_replace_free_srcdev(src_device); 708 709 /* write back the superblocks */ 710 trans = btrfs_start_transaction(root, 0); 711 if (!IS_ERR(trans)) 712 btrfs_commit_transaction(trans); 713 714 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 715 716 return 0; 717 } 718 719 static void btrfs_dev_replace_update_device_in_mapping_tree( 720 struct btrfs_fs_info *fs_info, 721 struct btrfs_device *srcdev, 722 struct btrfs_device *tgtdev) 723 { 724 struct extent_map_tree *em_tree = &fs_info->mapping_tree; 725 struct extent_map *em; 726 struct map_lookup *map; 727 u64 start = 0; 728 int i; 729 730 write_lock(&em_tree->lock); 731 do { 732 em = lookup_extent_mapping(em_tree, start, (u64)-1); 733 if (!em) 734 break; 735 map = em->map_lookup; 736 for (i = 0; i < map->num_stripes; i++) 737 if (srcdev == map->stripes[i].dev) 738 map->stripes[i].dev = tgtdev; 739 start = em->start + em->len; 740 free_extent_map(em); 741 } while (start); 742 write_unlock(&em_tree->lock); 743 } 744 745 /* 746 * Read progress of device replace status according to the state and last 747 * stored position. The value format is the same as for 748 * btrfs_dev_replace::progress_1000 749 */ 750 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 751 { 752 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 753 u64 ret = 0; 754 755 switch (dev_replace->replace_state) { 756 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 757 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 758 ret = 0; 759 break; 760 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 761 ret = 1000; 762 break; 763 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 764 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 765 ret = div64_u64(dev_replace->cursor_left, 766 div_u64(btrfs_device_get_total_bytes( 767 dev_replace->srcdev), 1000)); 768 break; 769 } 770 771 return ret; 772 } 773 774 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 775 struct btrfs_ioctl_dev_replace_args *args) 776 { 777 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 778 779 down_read(&dev_replace->rwsem); 780 /* even if !dev_replace_is_valid, the values are good enough for 781 * the replace_status ioctl */ 782 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 783 args->status.replace_state = dev_replace->replace_state; 784 args->status.time_started = dev_replace->time_started; 785 args->status.time_stopped = dev_replace->time_stopped; 786 args->status.num_write_errors = 787 atomic64_read(&dev_replace->num_write_errors); 788 args->status.num_uncorrectable_read_errors = 789 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 790 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 791 up_read(&dev_replace->rwsem); 792 } 793 794 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 795 { 796 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 797 struct btrfs_device *tgt_device = NULL; 798 struct btrfs_device *src_device = NULL; 799 struct btrfs_trans_handle *trans; 800 struct btrfs_root *root = fs_info->tree_root; 801 int result; 802 int ret; 803 804 if (sb_rdonly(fs_info->sb)) 805 return -EROFS; 806 807 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 808 down_write(&dev_replace->rwsem); 809 switch (dev_replace->replace_state) { 810 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 811 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 812 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 813 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 814 up_write(&dev_replace->rwsem); 815 break; 816 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 817 tgt_device = dev_replace->tgtdev; 818 src_device = dev_replace->srcdev; 819 up_write(&dev_replace->rwsem); 820 ret = btrfs_scrub_cancel(fs_info); 821 if (ret < 0) { 822 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 823 } else { 824 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 825 /* 826 * btrfs_dev_replace_finishing() will handle the 827 * cleanup part 828 */ 829 btrfs_info_in_rcu(fs_info, 830 "dev_replace from %s (devid %llu) to %s canceled", 831 btrfs_dev_name(src_device), src_device->devid, 832 btrfs_dev_name(tgt_device)); 833 } 834 break; 835 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 836 /* 837 * Scrub doing the replace isn't running so we need to do the 838 * cleanup step of btrfs_dev_replace_finishing() here 839 */ 840 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 841 tgt_device = dev_replace->tgtdev; 842 src_device = dev_replace->srcdev; 843 dev_replace->tgtdev = NULL; 844 dev_replace->srcdev = NULL; 845 dev_replace->replace_state = 846 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 847 dev_replace->time_stopped = ktime_get_real_seconds(); 848 dev_replace->item_needs_writeback = 1; 849 850 up_write(&dev_replace->rwsem); 851 852 /* Scrub for replace must not be running in suspended state */ 853 ret = btrfs_scrub_cancel(fs_info); 854 ASSERT(ret != -ENOTCONN); 855 856 trans = btrfs_start_transaction(root, 0); 857 if (IS_ERR(trans)) { 858 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 859 return PTR_ERR(trans); 860 } 861 ret = btrfs_commit_transaction(trans); 862 WARN_ON(ret); 863 864 btrfs_info_in_rcu(fs_info, 865 "suspended dev_replace from %s (devid %llu) to %s canceled", 866 btrfs_dev_name(src_device), src_device->devid, 867 btrfs_dev_name(tgt_device)); 868 869 if (tgt_device) 870 btrfs_destroy_dev_replace_tgtdev(tgt_device); 871 break; 872 default: 873 up_write(&dev_replace->rwsem); 874 result = -EINVAL; 875 } 876 877 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 878 return result; 879 } 880 881 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 882 { 883 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 884 885 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 886 down_write(&dev_replace->rwsem); 887 888 switch (dev_replace->replace_state) { 889 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 890 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 891 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 892 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 893 break; 894 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 895 dev_replace->replace_state = 896 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 897 dev_replace->time_stopped = ktime_get_real_seconds(); 898 dev_replace->item_needs_writeback = 1; 899 btrfs_info(fs_info, "suspending dev_replace for unmount"); 900 break; 901 } 902 903 up_write(&dev_replace->rwsem); 904 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 905 } 906 907 /* resume dev_replace procedure that was interrupted by unmount */ 908 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 909 { 910 struct task_struct *task; 911 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 912 913 down_write(&dev_replace->rwsem); 914 915 switch (dev_replace->replace_state) { 916 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 917 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 918 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 919 up_write(&dev_replace->rwsem); 920 return 0; 921 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 922 break; 923 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 924 dev_replace->replace_state = 925 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 926 break; 927 } 928 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 929 btrfs_info(fs_info, 930 "cannot continue dev_replace, tgtdev is missing"); 931 btrfs_info(fs_info, 932 "you may cancel the operation after 'mount -o degraded'"); 933 dev_replace->replace_state = 934 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 935 up_write(&dev_replace->rwsem); 936 return 0; 937 } 938 up_write(&dev_replace->rwsem); 939 940 /* 941 * This could collide with a paused balance, but the exclusive op logic 942 * should never allow both to start and pause. We don't want to allow 943 * dev-replace to start anyway. 944 */ 945 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { 946 down_write(&dev_replace->rwsem); 947 dev_replace->replace_state = 948 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 949 up_write(&dev_replace->rwsem); 950 btrfs_info(fs_info, 951 "cannot resume dev-replace, other exclusive operation running"); 952 return 0; 953 } 954 955 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 956 return PTR_ERR_OR_ZERO(task); 957 } 958 959 static int btrfs_dev_replace_kthread(void *data) 960 { 961 struct btrfs_fs_info *fs_info = data; 962 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 963 u64 progress; 964 int ret; 965 966 progress = btrfs_dev_replace_progress(fs_info); 967 progress = div_u64(progress, 10); 968 btrfs_info_in_rcu(fs_info, 969 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 970 btrfs_dev_name(dev_replace->srcdev), 971 dev_replace->srcdev->devid, 972 btrfs_dev_name(dev_replace->tgtdev), 973 (unsigned int)progress); 974 975 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 976 dev_replace->committed_cursor_left, 977 btrfs_device_get_total_bytes(dev_replace->srcdev), 978 &dev_replace->scrub_progress, 0, 1); 979 ret = btrfs_dev_replace_finishing(fs_info, ret); 980 WARN_ON(ret && ret != -ECANCELED); 981 982 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); 983 return 0; 984 } 985 986 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 987 { 988 if (!dev_replace->is_valid) 989 return 0; 990 991 switch (dev_replace->replace_state) { 992 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 993 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 994 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 995 return 0; 996 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 997 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 998 /* 999 * return true even if tgtdev is missing (this is 1000 * something that can happen if the dev_replace 1001 * procedure is suspended by an umount and then 1002 * the tgtdev is missing (or "btrfs dev scan") was 1003 * not called and the filesystem is remounted 1004 * in degraded state. This does not stop the 1005 * dev_replace procedure. It needs to be canceled 1006 * manually if the cancellation is wanted. 1007 */ 1008 break; 1009 } 1010 return 1; 1011 } 1012 1013 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1014 { 1015 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1016 } 1017 1018 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1019 { 1020 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); 1021 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); 1022 } 1023 1024 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1025 { 1026 while (1) { 1027 percpu_counter_inc(&fs_info->dev_replace.bio_counter); 1028 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1029 &fs_info->fs_state))) 1030 break; 1031 1032 btrfs_bio_counter_dec(fs_info); 1033 wait_event(fs_info->dev_replace.replace_wait, 1034 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1035 &fs_info->fs_state)); 1036 } 1037 } 1038