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 "ctree.h" 13 #include "extent_map.h" 14 #include "disk-io.h" 15 #include "transaction.h" 16 #include "print-tree.h" 17 #include "volumes.h" 18 #include "async-thread.h" 19 #include "check-integrity.h" 20 #include "rcu-string.h" 21 #include "dev-replace.h" 22 #include "sysfs.h" 23 24 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 25 int scrub_ret); 26 static void btrfs_dev_replace_update_device_in_mapping_tree( 27 struct btrfs_fs_info *fs_info, 28 struct btrfs_device *srcdev, 29 struct btrfs_device *tgtdev); 30 static int btrfs_dev_replace_kthread(void *data); 31 32 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 33 { 34 struct btrfs_key key; 35 struct btrfs_root *dev_root = fs_info->dev_root; 36 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 37 struct extent_buffer *eb; 38 int slot; 39 int ret = 0; 40 struct btrfs_path *path = NULL; 41 int item_size; 42 struct btrfs_dev_replace_item *ptr; 43 u64 src_devid; 44 45 path = btrfs_alloc_path(); 46 if (!path) { 47 ret = -ENOMEM; 48 goto out; 49 } 50 51 key.objectid = 0; 52 key.type = BTRFS_DEV_REPLACE_KEY; 53 key.offset = 0; 54 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 55 if (ret) { 56 no_valid_dev_replace_entry_found: 57 ret = 0; 58 dev_replace->replace_state = 59 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 60 dev_replace->cont_reading_from_srcdev_mode = 61 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 62 dev_replace->time_started = 0; 63 dev_replace->time_stopped = 0; 64 atomic64_set(&dev_replace->num_write_errors, 0); 65 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 66 dev_replace->cursor_left = 0; 67 dev_replace->committed_cursor_left = 0; 68 dev_replace->cursor_left_last_write_of_item = 0; 69 dev_replace->cursor_right = 0; 70 dev_replace->srcdev = NULL; 71 dev_replace->tgtdev = NULL; 72 dev_replace->is_valid = 0; 73 dev_replace->item_needs_writeback = 0; 74 goto out; 75 } 76 slot = path->slots[0]; 77 eb = path->nodes[0]; 78 item_size = btrfs_item_size_nr(eb, slot); 79 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 80 81 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 82 btrfs_warn(fs_info, 83 "dev_replace entry found has unexpected size, ignore entry"); 84 goto no_valid_dev_replace_entry_found; 85 } 86 87 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 88 dev_replace->cont_reading_from_srcdev_mode = 89 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 90 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 91 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 92 dev_replace->time_stopped = 93 btrfs_dev_replace_time_stopped(eb, ptr); 94 atomic64_set(&dev_replace->num_write_errors, 95 btrfs_dev_replace_num_write_errors(eb, ptr)); 96 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 97 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 98 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 99 dev_replace->committed_cursor_left = dev_replace->cursor_left; 100 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 101 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 102 dev_replace->is_valid = 1; 103 104 dev_replace->item_needs_writeback = 0; 105 switch (dev_replace->replace_state) { 106 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 107 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 108 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 109 dev_replace->srcdev = NULL; 110 dev_replace->tgtdev = NULL; 111 break; 112 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 113 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 114 dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices, 115 src_devid, NULL, NULL, true); 116 dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices, 117 BTRFS_DEV_REPLACE_DEVID, 118 NULL, NULL, true); 119 /* 120 * allow 'btrfs dev replace_cancel' if src/tgt device is 121 * missing 122 */ 123 if (!dev_replace->srcdev && 124 !btrfs_test_opt(fs_info, DEGRADED)) { 125 ret = -EIO; 126 btrfs_warn(fs_info, 127 "cannot mount because device replace operation is ongoing and"); 128 btrfs_warn(fs_info, 129 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 130 src_devid); 131 } 132 if (!dev_replace->tgtdev && 133 !btrfs_test_opt(fs_info, DEGRADED)) { 134 ret = -EIO; 135 btrfs_warn(fs_info, 136 "cannot mount because device replace operation is ongoing and"); 137 btrfs_warn(fs_info, 138 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 139 BTRFS_DEV_REPLACE_DEVID); 140 } 141 if (dev_replace->tgtdev) { 142 if (dev_replace->srcdev) { 143 dev_replace->tgtdev->total_bytes = 144 dev_replace->srcdev->total_bytes; 145 dev_replace->tgtdev->disk_total_bytes = 146 dev_replace->srcdev->disk_total_bytes; 147 dev_replace->tgtdev->commit_total_bytes = 148 dev_replace->srcdev->commit_total_bytes; 149 dev_replace->tgtdev->bytes_used = 150 dev_replace->srcdev->bytes_used; 151 dev_replace->tgtdev->commit_bytes_used = 152 dev_replace->srcdev->commit_bytes_used; 153 } 154 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 155 &dev_replace->tgtdev->dev_state); 156 157 WARN_ON(fs_info->fs_devices->rw_devices == 0); 158 dev_replace->tgtdev->io_width = fs_info->sectorsize; 159 dev_replace->tgtdev->io_align = fs_info->sectorsize; 160 dev_replace->tgtdev->sector_size = fs_info->sectorsize; 161 dev_replace->tgtdev->fs_info = fs_info; 162 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 163 &dev_replace->tgtdev->dev_state); 164 } 165 break; 166 } 167 168 out: 169 btrfs_free_path(path); 170 return ret; 171 } 172 173 /* 174 * Initialize a new device for device replace target from a given source dev 175 * and path. 176 * 177 * Return 0 and new device in @device_out, otherwise return < 0 178 */ 179 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, 180 const char *device_path, 181 struct btrfs_device *srcdev, 182 struct btrfs_device **device_out) 183 { 184 struct btrfs_device *device; 185 struct block_device *bdev; 186 struct list_head *devices; 187 struct rcu_string *name; 188 u64 devid = BTRFS_DEV_REPLACE_DEVID; 189 int ret = 0; 190 191 *device_out = NULL; 192 if (fs_info->fs_devices->seeding) { 193 btrfs_err(fs_info, "the filesystem is a seed filesystem!"); 194 return -EINVAL; 195 } 196 197 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, 198 fs_info->bdev_holder); 199 if (IS_ERR(bdev)) { 200 btrfs_err(fs_info, "target device %s is invalid!", device_path); 201 return PTR_ERR(bdev); 202 } 203 204 sync_blockdev(bdev); 205 206 devices = &fs_info->fs_devices->devices; 207 list_for_each_entry(device, devices, dev_list) { 208 if (device->bdev == bdev) { 209 btrfs_err(fs_info, 210 "target device is in the filesystem!"); 211 ret = -EEXIST; 212 goto error; 213 } 214 } 215 216 217 if (i_size_read(bdev->bd_inode) < 218 btrfs_device_get_total_bytes(srcdev)) { 219 btrfs_err(fs_info, 220 "target device is smaller than source device!"); 221 ret = -EINVAL; 222 goto error; 223 } 224 225 226 device = btrfs_alloc_device(NULL, &devid, NULL); 227 if (IS_ERR(device)) { 228 ret = PTR_ERR(device); 229 goto error; 230 } 231 232 name = rcu_string_strdup(device_path, GFP_KERNEL); 233 if (!name) { 234 btrfs_free_device(device); 235 ret = -ENOMEM; 236 goto error; 237 } 238 rcu_assign_pointer(device->name, name); 239 240 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 241 device->generation = 0; 242 device->io_width = fs_info->sectorsize; 243 device->io_align = fs_info->sectorsize; 244 device->sector_size = fs_info->sectorsize; 245 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 246 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 247 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 248 device->commit_total_bytes = srcdev->commit_total_bytes; 249 device->commit_bytes_used = device->bytes_used; 250 device->fs_info = fs_info; 251 device->bdev = bdev; 252 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 253 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 254 device->mode = FMODE_EXCL; 255 device->dev_stats_valid = 1; 256 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 257 device->fs_devices = fs_info->fs_devices; 258 259 mutex_lock(&fs_info->fs_devices->device_list_mutex); 260 list_add(&device->dev_list, &fs_info->fs_devices->devices); 261 fs_info->fs_devices->num_devices++; 262 fs_info->fs_devices->open_devices++; 263 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 264 265 *device_out = device; 266 return 0; 267 268 error: 269 blkdev_put(bdev, FMODE_EXCL); 270 return ret; 271 } 272 273 /* 274 * called from commit_transaction. Writes changed device replace state to 275 * disk. 276 */ 277 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 278 { 279 struct btrfs_fs_info *fs_info = trans->fs_info; 280 int ret; 281 struct btrfs_root *dev_root = fs_info->dev_root; 282 struct btrfs_path *path; 283 struct btrfs_key key; 284 struct extent_buffer *eb; 285 struct btrfs_dev_replace_item *ptr; 286 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 287 288 down_read(&dev_replace->rwsem); 289 if (!dev_replace->is_valid || 290 !dev_replace->item_needs_writeback) { 291 up_read(&dev_replace->rwsem); 292 return 0; 293 } 294 up_read(&dev_replace->rwsem); 295 296 key.objectid = 0; 297 key.type = BTRFS_DEV_REPLACE_KEY; 298 key.offset = 0; 299 300 path = btrfs_alloc_path(); 301 if (!path) { 302 ret = -ENOMEM; 303 goto out; 304 } 305 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 306 if (ret < 0) { 307 btrfs_warn(fs_info, 308 "error %d while searching for dev_replace item!", 309 ret); 310 goto out; 311 } 312 313 if (ret == 0 && 314 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 315 /* 316 * need to delete old one and insert a new one. 317 * Since no attempt is made to recover any old state, if the 318 * dev_replace state is 'running', the data on the target 319 * drive is lost. 320 * It would be possible to recover the state: just make sure 321 * that the beginning of the item is never changed and always 322 * contains all the essential information. Then read this 323 * minimal set of information and use it as a base for the 324 * new state. 325 */ 326 ret = btrfs_del_item(trans, dev_root, path); 327 if (ret != 0) { 328 btrfs_warn(fs_info, 329 "delete too small dev_replace item failed %d!", 330 ret); 331 goto out; 332 } 333 ret = 1; 334 } 335 336 if (ret == 1) { 337 /* need to insert a new item */ 338 btrfs_release_path(path); 339 ret = btrfs_insert_empty_item(trans, dev_root, path, 340 &key, sizeof(*ptr)); 341 if (ret < 0) { 342 btrfs_warn(fs_info, 343 "insert dev_replace item failed %d!", ret); 344 goto out; 345 } 346 } 347 348 eb = path->nodes[0]; 349 ptr = btrfs_item_ptr(eb, path->slots[0], 350 struct btrfs_dev_replace_item); 351 352 down_write(&dev_replace->rwsem); 353 if (dev_replace->srcdev) 354 btrfs_set_dev_replace_src_devid(eb, ptr, 355 dev_replace->srcdev->devid); 356 else 357 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 358 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 359 dev_replace->cont_reading_from_srcdev_mode); 360 btrfs_set_dev_replace_replace_state(eb, ptr, 361 dev_replace->replace_state); 362 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 363 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 364 btrfs_set_dev_replace_num_write_errors(eb, ptr, 365 atomic64_read(&dev_replace->num_write_errors)); 366 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 367 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 368 dev_replace->cursor_left_last_write_of_item = 369 dev_replace->cursor_left; 370 btrfs_set_dev_replace_cursor_left(eb, ptr, 371 dev_replace->cursor_left_last_write_of_item); 372 btrfs_set_dev_replace_cursor_right(eb, ptr, 373 dev_replace->cursor_right); 374 dev_replace->item_needs_writeback = 0; 375 up_write(&dev_replace->rwsem); 376 377 btrfs_mark_buffer_dirty(eb); 378 379 out: 380 btrfs_free_path(path); 381 382 return ret; 383 } 384 385 static char* btrfs_dev_name(struct btrfs_device *device) 386 { 387 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 388 return "<missing disk>"; 389 else 390 return rcu_str_deref(device->name); 391 } 392 393 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 394 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 395 int read_src) 396 { 397 struct btrfs_root *root = fs_info->dev_root; 398 struct btrfs_trans_handle *trans; 399 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 400 int ret; 401 struct btrfs_device *tgt_device = NULL; 402 struct btrfs_device *src_device = NULL; 403 404 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, 405 srcdev_name); 406 if (IS_ERR(src_device)) 407 return PTR_ERR(src_device); 408 409 if (btrfs_pinned_by_swapfile(fs_info, src_device)) { 410 btrfs_warn_in_rcu(fs_info, 411 "cannot replace device %s (devid %llu) due to active swapfile", 412 btrfs_dev_name(src_device), src_device->devid); 413 return -ETXTBSY; 414 } 415 416 /* 417 * Here we commit the transaction to make sure commit_total_bytes 418 * of all the devices are updated. 419 */ 420 trans = btrfs_attach_transaction(root); 421 if (!IS_ERR(trans)) { 422 ret = btrfs_commit_transaction(trans); 423 if (ret) 424 return ret; 425 } else if (PTR_ERR(trans) != -ENOENT) { 426 return PTR_ERR(trans); 427 } 428 429 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 430 src_device, &tgt_device); 431 if (ret) 432 return ret; 433 434 down_write(&dev_replace->rwsem); 435 switch (dev_replace->replace_state) { 436 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 437 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 438 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 439 break; 440 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 441 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 442 ASSERT(0); 443 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 444 up_write(&dev_replace->rwsem); 445 goto leave; 446 } 447 448 dev_replace->cont_reading_from_srcdev_mode = read_src; 449 dev_replace->srcdev = src_device; 450 dev_replace->tgtdev = tgt_device; 451 452 btrfs_info_in_rcu(fs_info, 453 "dev_replace from %s (devid %llu) to %s started", 454 btrfs_dev_name(src_device), 455 src_device->devid, 456 rcu_str_deref(tgt_device->name)); 457 458 /* 459 * from now on, the writes to the srcdev are all duplicated to 460 * go to the tgtdev as well (refer to btrfs_map_block()). 461 */ 462 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 463 dev_replace->time_started = ktime_get_real_seconds(); 464 dev_replace->cursor_left = 0; 465 dev_replace->committed_cursor_left = 0; 466 dev_replace->cursor_left_last_write_of_item = 0; 467 dev_replace->cursor_right = 0; 468 dev_replace->is_valid = 1; 469 dev_replace->item_needs_writeback = 1; 470 atomic64_set(&dev_replace->num_write_errors, 0); 471 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 472 up_write(&dev_replace->rwsem); 473 474 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 475 if (ret) 476 btrfs_err(fs_info, "kobj add dev failed %d", ret); 477 478 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 479 480 /* force writing the updated state information to disk */ 481 trans = btrfs_start_transaction(root, 0); 482 if (IS_ERR(trans)) { 483 ret = PTR_ERR(trans); 484 down_write(&dev_replace->rwsem); 485 dev_replace->replace_state = 486 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; 487 dev_replace->srcdev = NULL; 488 dev_replace->tgtdev = NULL; 489 up_write(&dev_replace->rwsem); 490 goto leave; 491 } 492 493 ret = btrfs_commit_transaction(trans); 494 WARN_ON(ret); 495 496 /* the disk copy procedure reuses the scrub code */ 497 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 498 btrfs_device_get_total_bytes(src_device), 499 &dev_replace->scrub_progress, 0, 1); 500 501 ret = btrfs_dev_replace_finishing(fs_info, ret); 502 if (ret == -EINPROGRESS) { 503 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 504 } else if (ret != -ECANCELED) { 505 WARN_ON(ret); 506 } 507 508 return ret; 509 510 leave: 511 btrfs_destroy_dev_replace_tgtdev(tgt_device); 512 return ret; 513 } 514 515 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 516 struct btrfs_ioctl_dev_replace_args *args) 517 { 518 int ret; 519 520 switch (args->start.cont_reading_from_srcdev_mode) { 521 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 522 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 523 break; 524 default: 525 return -EINVAL; 526 } 527 528 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 529 args->start.tgtdev_name[0] == '\0') 530 return -EINVAL; 531 532 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 533 args->start.srcdevid, 534 args->start.srcdev_name, 535 args->start.cont_reading_from_srcdev_mode); 536 args->result = ret; 537 /* don't warn if EINPROGRESS, someone else might be running scrub */ 538 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || 539 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) 540 return 0; 541 542 return ret; 543 } 544 545 /* 546 * blocked until all in-flight bios operations are finished. 547 */ 548 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 549 { 550 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 551 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( 552 &fs_info->dev_replace.bio_counter)); 553 } 554 555 /* 556 * we have removed target device, it is safe to allow new bios request. 557 */ 558 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 559 { 560 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 561 wake_up(&fs_info->dev_replace.replace_wait); 562 } 563 564 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 565 int scrub_ret) 566 { 567 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 568 struct btrfs_device *tgt_device; 569 struct btrfs_device *src_device; 570 struct btrfs_root *root = fs_info->tree_root; 571 u8 uuid_tmp[BTRFS_UUID_SIZE]; 572 struct btrfs_trans_handle *trans; 573 int ret = 0; 574 575 /* don't allow cancel or unmount to disturb the finishing procedure */ 576 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 577 578 down_read(&dev_replace->rwsem); 579 /* was the operation canceled, or is it finished? */ 580 if (dev_replace->replace_state != 581 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 582 up_read(&dev_replace->rwsem); 583 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 584 return 0; 585 } 586 587 tgt_device = dev_replace->tgtdev; 588 src_device = dev_replace->srcdev; 589 up_read(&dev_replace->rwsem); 590 591 /* 592 * flush all outstanding I/O and inode extent mappings before the 593 * copy operation is declared as being finished 594 */ 595 ret = btrfs_start_delalloc_roots(fs_info, -1); 596 if (ret) { 597 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 598 return ret; 599 } 600 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 601 602 /* 603 * We have to use this loop approach because at this point src_device 604 * has to be available for transaction commit to complete, yet new 605 * chunks shouldn't be allocated on the device. 606 */ 607 while (1) { 608 trans = btrfs_start_transaction(root, 0); 609 if (IS_ERR(trans)) { 610 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 611 return PTR_ERR(trans); 612 } 613 ret = btrfs_commit_transaction(trans); 614 WARN_ON(ret); 615 616 /* Prevent write_all_supers() during the finishing procedure */ 617 mutex_lock(&fs_info->fs_devices->device_list_mutex); 618 /* Prevent new chunks being allocated on the source device */ 619 mutex_lock(&fs_info->chunk_mutex); 620 621 if (!list_empty(&src_device->post_commit_list)) { 622 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 623 mutex_unlock(&fs_info->chunk_mutex); 624 } else { 625 break; 626 } 627 } 628 629 down_write(&dev_replace->rwsem); 630 dev_replace->replace_state = 631 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 632 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 633 dev_replace->tgtdev = NULL; 634 dev_replace->srcdev = NULL; 635 dev_replace->time_stopped = ktime_get_real_seconds(); 636 dev_replace->item_needs_writeback = 1; 637 638 /* replace old device with new one in mapping tree */ 639 if (!scrub_ret) { 640 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 641 src_device, 642 tgt_device); 643 } else { 644 if (scrub_ret != -ECANCELED) 645 btrfs_err_in_rcu(fs_info, 646 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 647 btrfs_dev_name(src_device), 648 src_device->devid, 649 rcu_str_deref(tgt_device->name), scrub_ret); 650 up_write(&dev_replace->rwsem); 651 mutex_unlock(&fs_info->chunk_mutex); 652 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 653 btrfs_rm_dev_replace_blocked(fs_info); 654 if (tgt_device) 655 btrfs_destroy_dev_replace_tgtdev(tgt_device); 656 btrfs_rm_dev_replace_unblocked(fs_info); 657 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 658 659 return scrub_ret; 660 } 661 662 btrfs_info_in_rcu(fs_info, 663 "dev_replace from %s (devid %llu) to %s finished", 664 btrfs_dev_name(src_device), 665 src_device->devid, 666 rcu_str_deref(tgt_device->name)); 667 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 668 tgt_device->devid = src_device->devid; 669 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 670 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 671 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 672 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 673 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 674 btrfs_device_set_disk_total_bytes(tgt_device, 675 src_device->disk_total_bytes); 676 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 677 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 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.map_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 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