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->replace_state = 0; 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, src_devid, 116 NULL, NULL); 117 dev_replace->tgtdev = btrfs_find_device(fs_info, 118 BTRFS_DEV_REPLACE_DEVID, 119 NULL, NULL); 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 filemap_write_and_wait(bdev->bd_inode->i_mapping); 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 mutex_lock(&fs_info->fs_devices->device_list_mutex); 242 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); 243 device->generation = 0; 244 device->io_width = fs_info->sectorsize; 245 device->io_align = fs_info->sectorsize; 246 device->sector_size = fs_info->sectorsize; 247 device->total_bytes = btrfs_device_get_total_bytes(srcdev); 248 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); 249 device->bytes_used = btrfs_device_get_bytes_used(srcdev); 250 device->commit_total_bytes = srcdev->commit_total_bytes; 251 device->commit_bytes_used = device->bytes_used; 252 device->fs_info = fs_info; 253 device->bdev = bdev; 254 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); 255 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); 256 device->mode = FMODE_EXCL; 257 device->dev_stats_valid = 1; 258 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); 259 device->fs_devices = fs_info->fs_devices; 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 struct btrfs_fs_info *fs_info) 279 { 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 btrfs_dev_replace_read_lock(dev_replace); 289 if (!dev_replace->is_valid || 290 !dev_replace->item_needs_writeback) { 291 btrfs_dev_replace_read_unlock(dev_replace); 292 return 0; 293 } 294 btrfs_dev_replace_read_unlock(dev_replace); 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 btrfs_dev_replace_write_lock(dev_replace); 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 btrfs_dev_replace_write_unlock(dev_replace); 376 377 btrfs_mark_buffer_dirty(eb); 378 379 out: 380 btrfs_free_path(path); 381 382 return ret; 383 } 384 385 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 386 { 387 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 388 389 dev_replace->committed_cursor_left = 390 dev_replace->cursor_left_last_write_of_item; 391 } 392 393 static char* btrfs_dev_name(struct btrfs_device *device) 394 { 395 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 396 return "<missing disk>"; 397 else 398 return rcu_str_deref(device->name); 399 } 400 401 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 402 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 403 int read_src) 404 { 405 struct btrfs_root *root = fs_info->dev_root; 406 struct btrfs_trans_handle *trans; 407 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 408 int ret; 409 struct btrfs_device *tgt_device = NULL; 410 struct btrfs_device *src_device = NULL; 411 412 ret = btrfs_find_device_by_devspec(fs_info, srcdevid, 413 srcdev_name, &src_device); 414 if (ret) 415 return ret; 416 417 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 418 src_device, &tgt_device); 419 if (ret) 420 return ret; 421 422 /* 423 * Here we commit the transaction to make sure commit_total_bytes 424 * of all the devices are updated. 425 */ 426 trans = btrfs_attach_transaction(root); 427 if (!IS_ERR(trans)) { 428 ret = btrfs_commit_transaction(trans); 429 if (ret) 430 return ret; 431 } else if (PTR_ERR(trans) != -ENOENT) { 432 return PTR_ERR(trans); 433 } 434 435 btrfs_dev_replace_write_lock(dev_replace); 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 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 444 goto leave; 445 } 446 447 dev_replace->cont_reading_from_srcdev_mode = read_src; 448 WARN_ON(!src_device); 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 btrfs_dev_replace_write_unlock(dev_replace); 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 btrfs_dev_replace_write_lock(dev_replace); 485 goto leave; 486 } 487 488 ret = btrfs_commit_transaction(trans); 489 WARN_ON(ret); 490 491 /* the disk copy procedure reuses the scrub code */ 492 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 493 btrfs_device_get_total_bytes(src_device), 494 &dev_replace->scrub_progress, 0, 1); 495 496 ret = btrfs_dev_replace_finishing(fs_info, ret); 497 if (ret == -EINPROGRESS) { 498 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 499 } else { 500 WARN_ON(ret); 501 } 502 503 return ret; 504 505 leave: 506 dev_replace->srcdev = NULL; 507 dev_replace->tgtdev = NULL; 508 btrfs_dev_replace_write_unlock(dev_replace); 509 btrfs_destroy_dev_replace_tgtdev(fs_info, 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 = 0; 538 539 return ret; 540 } 541 542 /* 543 * blocked until all in-flight bios operations are finished. 544 */ 545 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 546 { 547 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 548 wait_event(fs_info->replace_wait, !percpu_counter_sum( 549 &fs_info->bio_counter)); 550 } 551 552 /* 553 * we have removed target device, it is safe to allow new bios request. 554 */ 555 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 556 { 557 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 558 wake_up(&fs_info->replace_wait); 559 } 560 561 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 562 int scrub_ret) 563 { 564 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 565 struct btrfs_device *tgt_device; 566 struct btrfs_device *src_device; 567 struct btrfs_root *root = fs_info->tree_root; 568 u8 uuid_tmp[BTRFS_UUID_SIZE]; 569 struct btrfs_trans_handle *trans; 570 int ret = 0; 571 572 /* don't allow cancel or unmount to disturb the finishing procedure */ 573 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 574 575 btrfs_dev_replace_read_lock(dev_replace); 576 /* was the operation canceled, or is it finished? */ 577 if (dev_replace->replace_state != 578 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 579 btrfs_dev_replace_read_unlock(dev_replace); 580 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 581 return 0; 582 } 583 584 tgt_device = dev_replace->tgtdev; 585 src_device = dev_replace->srcdev; 586 btrfs_dev_replace_read_unlock(dev_replace); 587 588 /* 589 * flush all outstanding I/O and inode extent mappings before the 590 * copy operation is declared as being finished 591 */ 592 ret = btrfs_start_delalloc_roots(fs_info, -1); 593 if (ret) { 594 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 595 return ret; 596 } 597 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 598 599 trans = btrfs_start_transaction(root, 0); 600 if (IS_ERR(trans)) { 601 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 602 return PTR_ERR(trans); 603 } 604 ret = btrfs_commit_transaction(trans); 605 WARN_ON(ret); 606 607 /* keep away write_all_supers() during the finishing procedure */ 608 mutex_lock(&fs_info->fs_devices->device_list_mutex); 609 mutex_lock(&fs_info->chunk_mutex); 610 btrfs_dev_replace_write_lock(dev_replace); 611 dev_replace->replace_state = 612 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 613 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 614 dev_replace->tgtdev = NULL; 615 dev_replace->srcdev = NULL; 616 dev_replace->time_stopped = ktime_get_real_seconds(); 617 dev_replace->item_needs_writeback = 1; 618 619 /* replace old device with new one in mapping tree */ 620 if (!scrub_ret) { 621 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 622 src_device, 623 tgt_device); 624 } else { 625 btrfs_err_in_rcu(fs_info, 626 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 627 btrfs_dev_name(src_device), 628 src_device->devid, 629 rcu_str_deref(tgt_device->name), scrub_ret); 630 btrfs_dev_replace_write_unlock(dev_replace); 631 mutex_unlock(&fs_info->chunk_mutex); 632 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 633 btrfs_rm_dev_replace_blocked(fs_info); 634 if (tgt_device) 635 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 636 btrfs_rm_dev_replace_unblocked(fs_info); 637 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 638 639 return scrub_ret; 640 } 641 642 btrfs_info_in_rcu(fs_info, 643 "dev_replace from %s (devid %llu) to %s finished", 644 btrfs_dev_name(src_device), 645 src_device->devid, 646 rcu_str_deref(tgt_device->name)); 647 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 648 tgt_device->devid = src_device->devid; 649 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 650 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 651 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 652 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 653 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 654 btrfs_device_set_disk_total_bytes(tgt_device, 655 src_device->disk_total_bytes); 656 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 657 ASSERT(list_empty(&src_device->resized_list)); 658 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 659 tgt_device->commit_bytes_used = src_device->bytes_used; 660 661 btrfs_assign_next_active_device(src_device, tgt_device); 662 663 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 664 fs_info->fs_devices->rw_devices++; 665 666 btrfs_dev_replace_write_unlock(dev_replace); 667 668 btrfs_rm_dev_replace_blocked(fs_info); 669 670 btrfs_rm_dev_replace_remove_srcdev(src_device); 671 672 btrfs_rm_dev_replace_unblocked(fs_info); 673 674 /* 675 * this is again a consistent state where no dev_replace procedure 676 * is running, the target device is part of the filesystem, the 677 * source device is not part of the filesystem anymore and its 1st 678 * superblock is scratched out so that it is no longer marked to 679 * belong to this filesystem. 680 */ 681 mutex_unlock(&fs_info->chunk_mutex); 682 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 683 684 /* replace the sysfs entry */ 685 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 686 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 687 688 /* write back the superblocks */ 689 trans = btrfs_start_transaction(root, 0); 690 if (!IS_ERR(trans)) 691 btrfs_commit_transaction(trans); 692 693 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 694 695 return 0; 696 } 697 698 static void btrfs_dev_replace_update_device_in_mapping_tree( 699 struct btrfs_fs_info *fs_info, 700 struct btrfs_device *srcdev, 701 struct btrfs_device *tgtdev) 702 { 703 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 704 struct extent_map *em; 705 struct map_lookup *map; 706 u64 start = 0; 707 int i; 708 709 write_lock(&em_tree->lock); 710 do { 711 em = lookup_extent_mapping(em_tree, start, (u64)-1); 712 if (!em) 713 break; 714 map = em->map_lookup; 715 for (i = 0; i < map->num_stripes; i++) 716 if (srcdev == map->stripes[i].dev) 717 map->stripes[i].dev = tgtdev; 718 start = em->start + em->len; 719 free_extent_map(em); 720 } while (start); 721 write_unlock(&em_tree->lock); 722 } 723 724 /* 725 * Read progress of device replace status according to the state and last 726 * stored position. The value format is the same as for 727 * btrfs_dev_replace::progress_1000 728 */ 729 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 730 { 731 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 732 u64 ret = 0; 733 734 switch (dev_replace->replace_state) { 735 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 736 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 737 ret = 0; 738 break; 739 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 740 ret = 1000; 741 break; 742 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 743 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 744 ret = div64_u64(dev_replace->cursor_left, 745 div_u64(btrfs_device_get_total_bytes( 746 dev_replace->srcdev), 1000)); 747 break; 748 } 749 750 return ret; 751 } 752 753 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 754 struct btrfs_ioctl_dev_replace_args *args) 755 { 756 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 757 758 btrfs_dev_replace_read_lock(dev_replace); 759 /* even if !dev_replace_is_valid, the values are good enough for 760 * the replace_status ioctl */ 761 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 762 args->status.replace_state = dev_replace->replace_state; 763 args->status.time_started = dev_replace->time_started; 764 args->status.time_stopped = dev_replace->time_stopped; 765 args->status.num_write_errors = 766 atomic64_read(&dev_replace->num_write_errors); 767 args->status.num_uncorrectable_read_errors = 768 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 769 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 770 btrfs_dev_replace_read_unlock(dev_replace); 771 } 772 773 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 774 { 775 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 776 struct btrfs_device *tgt_device = NULL; 777 struct btrfs_device *src_device = NULL; 778 struct btrfs_trans_handle *trans; 779 struct btrfs_root *root = fs_info->tree_root; 780 int result; 781 int ret; 782 783 if (sb_rdonly(fs_info->sb)) 784 return -EROFS; 785 786 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 787 btrfs_dev_replace_write_lock(dev_replace); 788 switch (dev_replace->replace_state) { 789 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 790 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 791 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 792 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 793 btrfs_dev_replace_write_unlock(dev_replace); 794 goto leave; 795 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 796 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 797 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 798 tgt_device = dev_replace->tgtdev; 799 src_device = dev_replace->srcdev; 800 dev_replace->tgtdev = NULL; 801 dev_replace->srcdev = NULL; 802 break; 803 } 804 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 805 dev_replace->time_stopped = ktime_get_real_seconds(); 806 dev_replace->item_needs_writeback = 1; 807 btrfs_dev_replace_write_unlock(dev_replace); 808 btrfs_scrub_cancel(fs_info); 809 810 trans = btrfs_start_transaction(root, 0); 811 if (IS_ERR(trans)) { 812 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 813 return PTR_ERR(trans); 814 } 815 ret = btrfs_commit_transaction(trans); 816 WARN_ON(ret); 817 818 btrfs_info_in_rcu(fs_info, 819 "dev_replace from %s (devid %llu) to %s canceled", 820 btrfs_dev_name(src_device), src_device->devid, 821 btrfs_dev_name(tgt_device)); 822 823 if (tgt_device) 824 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 825 826 leave: 827 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 828 return result; 829 } 830 831 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 832 { 833 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 834 835 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 836 btrfs_dev_replace_write_lock(dev_replace); 837 switch (dev_replace->replace_state) { 838 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 839 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 840 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 841 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 842 break; 843 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 844 dev_replace->replace_state = 845 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 846 dev_replace->time_stopped = ktime_get_real_seconds(); 847 dev_replace->item_needs_writeback = 1; 848 btrfs_info(fs_info, "suspending dev_replace for unmount"); 849 break; 850 } 851 852 btrfs_dev_replace_write_unlock(dev_replace); 853 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 854 } 855 856 /* resume dev_replace procedure that was interrupted by unmount */ 857 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 858 { 859 struct task_struct *task; 860 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 861 862 btrfs_dev_replace_write_lock(dev_replace); 863 switch (dev_replace->replace_state) { 864 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 865 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 866 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 867 btrfs_dev_replace_write_unlock(dev_replace); 868 return 0; 869 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 870 break; 871 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 872 dev_replace->replace_state = 873 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 874 break; 875 } 876 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 877 btrfs_info(fs_info, 878 "cannot continue dev_replace, tgtdev is missing"); 879 btrfs_info(fs_info, 880 "you may cancel the operation after 'mount -o degraded'"); 881 btrfs_dev_replace_write_unlock(dev_replace); 882 return 0; 883 } 884 btrfs_dev_replace_write_unlock(dev_replace); 885 886 /* 887 * This could collide with a paused balance, but the exclusive op logic 888 * should never allow both to start and pause. We don't want to allow 889 * dev-replace to start anyway. 890 */ 891 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { 892 btrfs_info(fs_info, 893 "cannot resume dev-replace, other exclusive operation running"); 894 return 0; 895 } 896 897 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 898 return PTR_ERR_OR_ZERO(task); 899 } 900 901 static int btrfs_dev_replace_kthread(void *data) 902 { 903 struct btrfs_fs_info *fs_info = data; 904 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 905 u64 progress; 906 int ret; 907 908 progress = btrfs_dev_replace_progress(fs_info); 909 progress = div_u64(progress, 10); 910 btrfs_info_in_rcu(fs_info, 911 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 912 btrfs_dev_name(dev_replace->srcdev), 913 dev_replace->srcdev->devid, 914 btrfs_dev_name(dev_replace->tgtdev), 915 (unsigned int)progress); 916 917 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 918 dev_replace->committed_cursor_left, 919 btrfs_device_get_total_bytes(dev_replace->srcdev), 920 &dev_replace->scrub_progress, 0, 1); 921 ret = btrfs_dev_replace_finishing(fs_info, ret); 922 WARN_ON(ret); 923 924 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); 925 return 0; 926 } 927 928 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 929 { 930 if (!dev_replace->is_valid) 931 return 0; 932 933 switch (dev_replace->replace_state) { 934 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 935 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 936 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 937 return 0; 938 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 939 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 940 /* 941 * return true even if tgtdev is missing (this is 942 * something that can happen if the dev_replace 943 * procedure is suspended by an umount and then 944 * the tgtdev is missing (or "btrfs dev scan") was 945 * not called and the the filesystem is remounted 946 * in degraded state. This does not stop the 947 * dev_replace procedure. It needs to be canceled 948 * manually if the cancellation is wanted. 949 */ 950 break; 951 } 952 return 1; 953 } 954 955 void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace) 956 { 957 read_lock(&dev_replace->lock); 958 atomic_inc(&dev_replace->read_locks); 959 } 960 961 void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace) 962 { 963 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 964 atomic_dec(&dev_replace->read_locks); 965 read_unlock(&dev_replace->lock); 966 } 967 968 void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace) 969 { 970 again: 971 wait_event(dev_replace->read_lock_wq, 972 atomic_read(&dev_replace->blocking_readers) == 0); 973 write_lock(&dev_replace->lock); 974 if (atomic_read(&dev_replace->blocking_readers)) { 975 write_unlock(&dev_replace->lock); 976 goto again; 977 } 978 } 979 980 void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace) 981 { 982 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 983 write_unlock(&dev_replace->lock); 984 } 985 986 /* inc blocking cnt and release read lock */ 987 void btrfs_dev_replace_set_lock_blocking( 988 struct btrfs_dev_replace *dev_replace) 989 { 990 /* only set blocking for read lock */ 991 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 992 atomic_inc(&dev_replace->blocking_readers); 993 read_unlock(&dev_replace->lock); 994 } 995 996 /* acquire read lock and dec blocking cnt */ 997 void btrfs_dev_replace_clear_lock_blocking( 998 struct btrfs_dev_replace *dev_replace) 999 { 1000 /* only set blocking for read lock */ 1001 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 1002 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 1003 read_lock(&dev_replace->lock); 1004 /* Barrier implied by atomic_dec_and_test */ 1005 if (atomic_dec_and_test(&dev_replace->blocking_readers)) 1006 cond_wake_up_nomb(&dev_replace->read_lock_wq); 1007 } 1008 1009 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 1010 { 1011 percpu_counter_inc(&fs_info->bio_counter); 1012 } 1013 1014 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 1015 { 1016 percpu_counter_sub(&fs_info->bio_counter, amount); 1017 cond_wake_up_nomb(&fs_info->replace_wait); 1018 } 1019 1020 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 1021 { 1022 while (1) { 1023 percpu_counter_inc(&fs_info->bio_counter); 1024 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1025 &fs_info->fs_state))) 1026 break; 1027 1028 btrfs_bio_counter_dec(fs_info); 1029 wait_event(fs_info->replace_wait, 1030 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 1031 &fs_info->fs_state)); 1032 } 1033 } 1034