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/buffer_head.h> 10 #include <linux/blkdev.h> 11 #include <linux/random.h> 12 #include <linux/iocontext.h> 13 #include <linux/capability.h> 14 #include <linux/kthread.h> 15 #include <linux/math64.h> 16 #include <asm/div64.h> 17 #include "ctree.h" 18 #include "extent_map.h" 19 #include "disk-io.h" 20 #include "transaction.h" 21 #include "print-tree.h" 22 #include "volumes.h" 23 #include "async-thread.h" 24 #include "check-integrity.h" 25 #include "rcu-string.h" 26 #include "dev-replace.h" 27 #include "sysfs.h" 28 29 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 30 int scrub_ret); 31 static void btrfs_dev_replace_update_device_in_mapping_tree( 32 struct btrfs_fs_info *fs_info, 33 struct btrfs_device *srcdev, 34 struct btrfs_device *tgtdev); 35 static int btrfs_dev_replace_kthread(void *data); 36 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 37 38 39 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 40 { 41 struct btrfs_key key; 42 struct btrfs_root *dev_root = fs_info->dev_root; 43 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 44 struct extent_buffer *eb; 45 int slot; 46 int ret = 0; 47 struct btrfs_path *path = NULL; 48 int item_size; 49 struct btrfs_dev_replace_item *ptr; 50 u64 src_devid; 51 52 path = btrfs_alloc_path(); 53 if (!path) { 54 ret = -ENOMEM; 55 goto out; 56 } 57 58 key.objectid = 0; 59 key.type = BTRFS_DEV_REPLACE_KEY; 60 key.offset = 0; 61 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 62 if (ret) { 63 no_valid_dev_replace_entry_found: 64 ret = 0; 65 dev_replace->replace_state = 66 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 67 dev_replace->cont_reading_from_srcdev_mode = 68 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 69 dev_replace->replace_state = 0; 70 dev_replace->time_started = 0; 71 dev_replace->time_stopped = 0; 72 atomic64_set(&dev_replace->num_write_errors, 0); 73 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 74 dev_replace->cursor_left = 0; 75 dev_replace->committed_cursor_left = 0; 76 dev_replace->cursor_left_last_write_of_item = 0; 77 dev_replace->cursor_right = 0; 78 dev_replace->srcdev = NULL; 79 dev_replace->tgtdev = NULL; 80 dev_replace->is_valid = 0; 81 dev_replace->item_needs_writeback = 0; 82 goto out; 83 } 84 slot = path->slots[0]; 85 eb = path->nodes[0]; 86 item_size = btrfs_item_size_nr(eb, slot); 87 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 88 89 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 90 btrfs_warn(fs_info, 91 "dev_replace entry found has unexpected size, ignore entry"); 92 goto no_valid_dev_replace_entry_found; 93 } 94 95 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 96 dev_replace->cont_reading_from_srcdev_mode = 97 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 98 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 99 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 100 dev_replace->time_stopped = 101 btrfs_dev_replace_time_stopped(eb, ptr); 102 atomic64_set(&dev_replace->num_write_errors, 103 btrfs_dev_replace_num_write_errors(eb, ptr)); 104 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 105 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 106 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 107 dev_replace->committed_cursor_left = dev_replace->cursor_left; 108 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 109 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 110 dev_replace->is_valid = 1; 111 112 dev_replace->item_needs_writeback = 0; 113 switch (dev_replace->replace_state) { 114 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 115 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 116 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 117 dev_replace->srcdev = NULL; 118 dev_replace->tgtdev = NULL; 119 break; 120 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 121 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 122 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 123 NULL, NULL); 124 dev_replace->tgtdev = btrfs_find_device(fs_info, 125 BTRFS_DEV_REPLACE_DEVID, 126 NULL, NULL); 127 /* 128 * allow 'btrfs dev replace_cancel' if src/tgt device is 129 * missing 130 */ 131 if (!dev_replace->srcdev && 132 !btrfs_test_opt(fs_info, DEGRADED)) { 133 ret = -EIO; 134 btrfs_warn(fs_info, 135 "cannot mount because device replace operation is ongoing and"); 136 btrfs_warn(fs_info, 137 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 138 src_devid); 139 } 140 if (!dev_replace->tgtdev && 141 !btrfs_test_opt(fs_info, DEGRADED)) { 142 ret = -EIO; 143 btrfs_warn(fs_info, 144 "cannot mount because device replace operation is ongoing and"); 145 btrfs_warn(fs_info, 146 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 147 BTRFS_DEV_REPLACE_DEVID); 148 } 149 if (dev_replace->tgtdev) { 150 if (dev_replace->srcdev) { 151 dev_replace->tgtdev->total_bytes = 152 dev_replace->srcdev->total_bytes; 153 dev_replace->tgtdev->disk_total_bytes = 154 dev_replace->srcdev->disk_total_bytes; 155 dev_replace->tgtdev->commit_total_bytes = 156 dev_replace->srcdev->commit_total_bytes; 157 dev_replace->tgtdev->bytes_used = 158 dev_replace->srcdev->bytes_used; 159 dev_replace->tgtdev->commit_bytes_used = 160 dev_replace->srcdev->commit_bytes_used; 161 } 162 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 163 &dev_replace->tgtdev->dev_state); 164 165 WARN_ON(fs_info->fs_devices->rw_devices == 0); 166 dev_replace->tgtdev->io_width = fs_info->sectorsize; 167 dev_replace->tgtdev->io_align = fs_info->sectorsize; 168 dev_replace->tgtdev->sector_size = fs_info->sectorsize; 169 dev_replace->tgtdev->fs_info = fs_info; 170 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 171 &dev_replace->tgtdev->dev_state); 172 } 173 break; 174 } 175 176 out: 177 btrfs_free_path(path); 178 return ret; 179 } 180 181 /* 182 * called from commit_transaction. Writes changed device replace state to 183 * disk. 184 */ 185 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 186 struct btrfs_fs_info *fs_info) 187 { 188 int ret; 189 struct btrfs_root *dev_root = fs_info->dev_root; 190 struct btrfs_path *path; 191 struct btrfs_key key; 192 struct extent_buffer *eb; 193 struct btrfs_dev_replace_item *ptr; 194 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 195 196 btrfs_dev_replace_read_lock(dev_replace); 197 if (!dev_replace->is_valid || 198 !dev_replace->item_needs_writeback) { 199 btrfs_dev_replace_read_unlock(dev_replace); 200 return 0; 201 } 202 btrfs_dev_replace_read_unlock(dev_replace); 203 204 key.objectid = 0; 205 key.type = BTRFS_DEV_REPLACE_KEY; 206 key.offset = 0; 207 208 path = btrfs_alloc_path(); 209 if (!path) { 210 ret = -ENOMEM; 211 goto out; 212 } 213 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 214 if (ret < 0) { 215 btrfs_warn(fs_info, 216 "error %d while searching for dev_replace item!", 217 ret); 218 goto out; 219 } 220 221 if (ret == 0 && 222 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 223 /* 224 * need to delete old one and insert a new one. 225 * Since no attempt is made to recover any old state, if the 226 * dev_replace state is 'running', the data on the target 227 * drive is lost. 228 * It would be possible to recover the state: just make sure 229 * that the beginning of the item is never changed and always 230 * contains all the essential information. Then read this 231 * minimal set of information and use it as a base for the 232 * new state. 233 */ 234 ret = btrfs_del_item(trans, dev_root, path); 235 if (ret != 0) { 236 btrfs_warn(fs_info, 237 "delete too small dev_replace item failed %d!", 238 ret); 239 goto out; 240 } 241 ret = 1; 242 } 243 244 if (ret == 1) { 245 /* need to insert a new item */ 246 btrfs_release_path(path); 247 ret = btrfs_insert_empty_item(trans, dev_root, path, 248 &key, sizeof(*ptr)); 249 if (ret < 0) { 250 btrfs_warn(fs_info, 251 "insert dev_replace item failed %d!", ret); 252 goto out; 253 } 254 } 255 256 eb = path->nodes[0]; 257 ptr = btrfs_item_ptr(eb, path->slots[0], 258 struct btrfs_dev_replace_item); 259 260 btrfs_dev_replace_write_lock(dev_replace); 261 if (dev_replace->srcdev) 262 btrfs_set_dev_replace_src_devid(eb, ptr, 263 dev_replace->srcdev->devid); 264 else 265 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 266 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 267 dev_replace->cont_reading_from_srcdev_mode); 268 btrfs_set_dev_replace_replace_state(eb, ptr, 269 dev_replace->replace_state); 270 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 271 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 272 btrfs_set_dev_replace_num_write_errors(eb, ptr, 273 atomic64_read(&dev_replace->num_write_errors)); 274 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 275 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 276 dev_replace->cursor_left_last_write_of_item = 277 dev_replace->cursor_left; 278 btrfs_set_dev_replace_cursor_left(eb, ptr, 279 dev_replace->cursor_left_last_write_of_item); 280 btrfs_set_dev_replace_cursor_right(eb, ptr, 281 dev_replace->cursor_right); 282 dev_replace->item_needs_writeback = 0; 283 btrfs_dev_replace_write_unlock(dev_replace); 284 285 btrfs_mark_buffer_dirty(eb); 286 287 out: 288 btrfs_free_path(path); 289 290 return ret; 291 } 292 293 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 294 { 295 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 296 297 dev_replace->committed_cursor_left = 298 dev_replace->cursor_left_last_write_of_item; 299 } 300 301 static char* btrfs_dev_name(struct btrfs_device *device) 302 { 303 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 304 return "<missing disk>"; 305 else 306 return rcu_str_deref(device->name); 307 } 308 309 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 310 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 311 int read_src) 312 { 313 struct btrfs_root *root = fs_info->dev_root; 314 struct btrfs_trans_handle *trans; 315 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 316 int ret; 317 struct btrfs_device *tgt_device = NULL; 318 struct btrfs_device *src_device = NULL; 319 320 /* the disk copy procedure reuses the scrub code */ 321 mutex_lock(&fs_info->volume_mutex); 322 ret = btrfs_find_device_by_devspec(fs_info, srcdevid, 323 srcdev_name, &src_device); 324 if (ret) { 325 mutex_unlock(&fs_info->volume_mutex); 326 return ret; 327 } 328 329 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 330 src_device, &tgt_device); 331 mutex_unlock(&fs_info->volume_mutex); 332 if (ret) 333 return ret; 334 335 /* 336 * Here we commit the transaction to make sure commit_total_bytes 337 * of all the devices are updated. 338 */ 339 trans = btrfs_attach_transaction(root); 340 if (!IS_ERR(trans)) { 341 ret = btrfs_commit_transaction(trans); 342 if (ret) 343 return ret; 344 } else if (PTR_ERR(trans) != -ENOENT) { 345 return PTR_ERR(trans); 346 } 347 348 btrfs_dev_replace_write_lock(dev_replace); 349 switch (dev_replace->replace_state) { 350 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 351 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 352 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 353 break; 354 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 355 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 356 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 357 goto leave; 358 } 359 360 dev_replace->cont_reading_from_srcdev_mode = read_src; 361 WARN_ON(!src_device); 362 dev_replace->srcdev = src_device; 363 WARN_ON(!tgt_device); 364 dev_replace->tgtdev = tgt_device; 365 366 btrfs_info_in_rcu(fs_info, 367 "dev_replace from %s (devid %llu) to %s started", 368 btrfs_dev_name(src_device), 369 src_device->devid, 370 rcu_str_deref(tgt_device->name)); 371 372 /* 373 * from now on, the writes to the srcdev are all duplicated to 374 * go to the tgtdev as well (refer to btrfs_map_block()). 375 */ 376 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 377 dev_replace->time_started = get_seconds(); 378 dev_replace->cursor_left = 0; 379 dev_replace->committed_cursor_left = 0; 380 dev_replace->cursor_left_last_write_of_item = 0; 381 dev_replace->cursor_right = 0; 382 dev_replace->is_valid = 1; 383 dev_replace->item_needs_writeback = 1; 384 atomic64_set(&dev_replace->num_write_errors, 0); 385 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 386 btrfs_dev_replace_write_unlock(dev_replace); 387 388 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 389 if (ret) 390 btrfs_err(fs_info, "kobj add dev failed %d", ret); 391 392 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 393 394 /* force writing the updated state information to disk */ 395 trans = btrfs_start_transaction(root, 0); 396 if (IS_ERR(trans)) { 397 ret = PTR_ERR(trans); 398 btrfs_dev_replace_write_lock(dev_replace); 399 goto leave; 400 } 401 402 ret = btrfs_commit_transaction(trans); 403 WARN_ON(ret); 404 405 /* the disk copy procedure reuses the scrub code */ 406 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 407 btrfs_device_get_total_bytes(src_device), 408 &dev_replace->scrub_progress, 0, 1); 409 410 ret = btrfs_dev_replace_finishing(fs_info, ret); 411 if (ret == -EINPROGRESS) { 412 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 413 } else { 414 WARN_ON(ret); 415 } 416 417 return ret; 418 419 leave: 420 dev_replace->srcdev = NULL; 421 dev_replace->tgtdev = NULL; 422 btrfs_dev_replace_write_unlock(dev_replace); 423 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 424 return ret; 425 } 426 427 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 428 struct btrfs_ioctl_dev_replace_args *args) 429 { 430 int ret; 431 432 switch (args->start.cont_reading_from_srcdev_mode) { 433 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 434 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 435 break; 436 default: 437 return -EINVAL; 438 } 439 440 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 441 args->start.tgtdev_name[0] == '\0') 442 return -EINVAL; 443 444 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 445 args->start.srcdevid, 446 args->start.srcdev_name, 447 args->start.cont_reading_from_srcdev_mode); 448 args->result = ret; 449 /* don't warn if EINPROGRESS, someone else might be running scrub */ 450 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS) 451 ret = 0; 452 453 return ret; 454 } 455 456 /* 457 * blocked until all in-flight bios operations are finished. 458 */ 459 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 460 { 461 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 462 wait_event(fs_info->replace_wait, !percpu_counter_sum( 463 &fs_info->bio_counter)); 464 } 465 466 /* 467 * we have removed target device, it is safe to allow new bios request. 468 */ 469 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 470 { 471 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 472 wake_up(&fs_info->replace_wait); 473 } 474 475 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 476 int scrub_ret) 477 { 478 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 479 struct btrfs_device *tgt_device; 480 struct btrfs_device *src_device; 481 struct btrfs_root *root = fs_info->tree_root; 482 u8 uuid_tmp[BTRFS_UUID_SIZE]; 483 struct btrfs_trans_handle *trans; 484 int ret = 0; 485 486 /* don't allow cancel or unmount to disturb the finishing procedure */ 487 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 488 489 btrfs_dev_replace_read_lock(dev_replace); 490 /* was the operation canceled, or is it finished? */ 491 if (dev_replace->replace_state != 492 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 493 btrfs_dev_replace_read_unlock(dev_replace); 494 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 495 return 0; 496 } 497 498 tgt_device = dev_replace->tgtdev; 499 src_device = dev_replace->srcdev; 500 btrfs_dev_replace_read_unlock(dev_replace); 501 502 /* 503 * flush all outstanding I/O and inode extent mappings before the 504 * copy operation is declared as being finished 505 */ 506 ret = btrfs_start_delalloc_roots(fs_info, 0, -1); 507 if (ret) { 508 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 509 return ret; 510 } 511 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 512 513 trans = btrfs_start_transaction(root, 0); 514 if (IS_ERR(trans)) { 515 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 516 return PTR_ERR(trans); 517 } 518 ret = btrfs_commit_transaction(trans); 519 WARN_ON(ret); 520 521 mutex_lock(&uuid_mutex); 522 /* keep away write_all_supers() during the finishing procedure */ 523 mutex_lock(&fs_info->fs_devices->device_list_mutex); 524 mutex_lock(&fs_info->chunk_mutex); 525 btrfs_dev_replace_write_lock(dev_replace); 526 dev_replace->replace_state = 527 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 528 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 529 dev_replace->tgtdev = NULL; 530 dev_replace->srcdev = NULL; 531 dev_replace->time_stopped = get_seconds(); 532 dev_replace->item_needs_writeback = 1; 533 534 /* replace old device with new one in mapping tree */ 535 if (!scrub_ret) { 536 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 537 src_device, 538 tgt_device); 539 } else { 540 btrfs_err_in_rcu(fs_info, 541 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 542 btrfs_dev_name(src_device), 543 src_device->devid, 544 rcu_str_deref(tgt_device->name), scrub_ret); 545 btrfs_dev_replace_write_unlock(dev_replace); 546 mutex_unlock(&fs_info->chunk_mutex); 547 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 548 mutex_unlock(&uuid_mutex); 549 btrfs_rm_dev_replace_blocked(fs_info); 550 if (tgt_device) 551 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 552 btrfs_rm_dev_replace_unblocked(fs_info); 553 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 554 555 return scrub_ret; 556 } 557 558 btrfs_info_in_rcu(fs_info, 559 "dev_replace from %s (devid %llu) to %s finished", 560 btrfs_dev_name(src_device), 561 src_device->devid, 562 rcu_str_deref(tgt_device->name)); 563 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 564 tgt_device->devid = src_device->devid; 565 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 566 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 567 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 568 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 569 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 570 btrfs_device_set_disk_total_bytes(tgt_device, 571 src_device->disk_total_bytes); 572 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 573 ASSERT(list_empty(&src_device->resized_list)); 574 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 575 tgt_device->commit_bytes_used = src_device->bytes_used; 576 577 btrfs_assign_next_active_device(fs_info, src_device, tgt_device); 578 579 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 580 fs_info->fs_devices->rw_devices++; 581 582 btrfs_dev_replace_write_unlock(dev_replace); 583 584 btrfs_rm_dev_replace_blocked(fs_info); 585 586 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 587 588 btrfs_rm_dev_replace_unblocked(fs_info); 589 590 /* 591 * this is again a consistent state where no dev_replace procedure 592 * is running, the target device is part of the filesystem, the 593 * source device is not part of the filesystem anymore and its 1st 594 * superblock is scratched out so that it is no longer marked to 595 * belong to this filesystem. 596 */ 597 mutex_unlock(&fs_info->chunk_mutex); 598 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 599 mutex_unlock(&uuid_mutex); 600 601 /* replace the sysfs entry */ 602 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 603 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 604 605 /* write back the superblocks */ 606 trans = btrfs_start_transaction(root, 0); 607 if (!IS_ERR(trans)) 608 btrfs_commit_transaction(trans); 609 610 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 611 612 return 0; 613 } 614 615 static void btrfs_dev_replace_update_device_in_mapping_tree( 616 struct btrfs_fs_info *fs_info, 617 struct btrfs_device *srcdev, 618 struct btrfs_device *tgtdev) 619 { 620 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 621 struct extent_map *em; 622 struct map_lookup *map; 623 u64 start = 0; 624 int i; 625 626 write_lock(&em_tree->lock); 627 do { 628 em = lookup_extent_mapping(em_tree, start, (u64)-1); 629 if (!em) 630 break; 631 map = em->map_lookup; 632 for (i = 0; i < map->num_stripes; i++) 633 if (srcdev == map->stripes[i].dev) 634 map->stripes[i].dev = tgtdev; 635 start = em->start + em->len; 636 free_extent_map(em); 637 } while (start); 638 write_unlock(&em_tree->lock); 639 } 640 641 /* 642 * Read progress of device replace status according to the state and last 643 * stored position. The value format is the same as for 644 * btrfs_dev_replace::progress_1000 645 */ 646 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 647 { 648 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 649 u64 ret = 0; 650 651 switch (dev_replace->replace_state) { 652 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 653 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 654 ret = 0; 655 break; 656 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 657 ret = 1000; 658 break; 659 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 660 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 661 ret = div64_u64(dev_replace->cursor_left, 662 div_u64(btrfs_device_get_total_bytes( 663 dev_replace->srcdev), 1000)); 664 break; 665 } 666 667 return ret; 668 } 669 670 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 671 struct btrfs_ioctl_dev_replace_args *args) 672 { 673 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 674 675 btrfs_dev_replace_read_lock(dev_replace); 676 /* even if !dev_replace_is_valid, the values are good enough for 677 * the replace_status ioctl */ 678 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 679 args->status.replace_state = dev_replace->replace_state; 680 args->status.time_started = dev_replace->time_started; 681 args->status.time_stopped = dev_replace->time_stopped; 682 args->status.num_write_errors = 683 atomic64_read(&dev_replace->num_write_errors); 684 args->status.num_uncorrectable_read_errors = 685 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 686 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 687 btrfs_dev_replace_read_unlock(dev_replace); 688 } 689 690 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 691 { 692 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 693 struct btrfs_device *tgt_device = NULL; 694 struct btrfs_device *src_device = NULL; 695 struct btrfs_trans_handle *trans; 696 struct btrfs_root *root = fs_info->tree_root; 697 int result; 698 int ret; 699 700 if (sb_rdonly(fs_info->sb)) 701 return -EROFS; 702 703 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 704 btrfs_dev_replace_write_lock(dev_replace); 705 switch (dev_replace->replace_state) { 706 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 707 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 708 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 709 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 710 btrfs_dev_replace_write_unlock(dev_replace); 711 goto leave; 712 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 713 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 714 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 715 tgt_device = dev_replace->tgtdev; 716 src_device = dev_replace->srcdev; 717 dev_replace->tgtdev = NULL; 718 dev_replace->srcdev = NULL; 719 break; 720 } 721 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 722 dev_replace->time_stopped = get_seconds(); 723 dev_replace->item_needs_writeback = 1; 724 btrfs_dev_replace_write_unlock(dev_replace); 725 btrfs_scrub_cancel(fs_info); 726 727 trans = btrfs_start_transaction(root, 0); 728 if (IS_ERR(trans)) { 729 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 730 return PTR_ERR(trans); 731 } 732 ret = btrfs_commit_transaction(trans); 733 WARN_ON(ret); 734 735 btrfs_info_in_rcu(fs_info, 736 "dev_replace from %s (devid %llu) to %s canceled", 737 btrfs_dev_name(src_device), src_device->devid, 738 btrfs_dev_name(tgt_device)); 739 740 if (tgt_device) 741 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 742 743 leave: 744 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 745 return result; 746 } 747 748 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 749 { 750 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 751 752 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 753 btrfs_dev_replace_write_lock(dev_replace); 754 switch (dev_replace->replace_state) { 755 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 756 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 757 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 758 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 759 break; 760 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 761 dev_replace->replace_state = 762 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 763 dev_replace->time_stopped = get_seconds(); 764 dev_replace->item_needs_writeback = 1; 765 btrfs_info(fs_info, "suspending dev_replace for unmount"); 766 break; 767 } 768 769 btrfs_dev_replace_write_unlock(dev_replace); 770 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 771 } 772 773 /* resume dev_replace procedure that was interrupted by unmount */ 774 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 775 { 776 struct task_struct *task; 777 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 778 779 btrfs_dev_replace_write_lock(dev_replace); 780 switch (dev_replace->replace_state) { 781 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 782 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 783 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 784 btrfs_dev_replace_write_unlock(dev_replace); 785 return 0; 786 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 787 break; 788 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 789 dev_replace->replace_state = 790 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 791 break; 792 } 793 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 794 btrfs_info(fs_info, 795 "cannot continue dev_replace, tgtdev is missing"); 796 btrfs_info(fs_info, 797 "you may cancel the operation after 'mount -o degraded'"); 798 btrfs_dev_replace_write_unlock(dev_replace); 799 return 0; 800 } 801 btrfs_dev_replace_write_unlock(dev_replace); 802 803 WARN_ON(test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)); 804 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 805 return PTR_ERR_OR_ZERO(task); 806 } 807 808 static int btrfs_dev_replace_kthread(void *data) 809 { 810 struct btrfs_fs_info *fs_info = data; 811 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 812 u64 progress; 813 814 progress = btrfs_dev_replace_progress(fs_info); 815 progress = div_u64(progress, 10); 816 btrfs_info_in_rcu(fs_info, 817 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 818 btrfs_dev_name(dev_replace->srcdev), 819 dev_replace->srcdev->devid, 820 btrfs_dev_name(dev_replace->tgtdev), 821 (unsigned int)progress); 822 823 btrfs_dev_replace_continue_on_mount(fs_info); 824 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); 825 826 return 0; 827 } 828 829 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 830 { 831 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 832 int ret; 833 834 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 835 dev_replace->committed_cursor_left, 836 btrfs_device_get_total_bytes(dev_replace->srcdev), 837 &dev_replace->scrub_progress, 0, 1); 838 ret = btrfs_dev_replace_finishing(fs_info, ret); 839 WARN_ON(ret); 840 return 0; 841 } 842 843 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 844 { 845 if (!dev_replace->is_valid) 846 return 0; 847 848 switch (dev_replace->replace_state) { 849 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 850 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 851 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 852 return 0; 853 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 854 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 855 /* 856 * return true even if tgtdev is missing (this is 857 * something that can happen if the dev_replace 858 * procedure is suspended by an umount and then 859 * the tgtdev is missing (or "btrfs dev scan") was 860 * not called and the the filesystem is remounted 861 * in degraded state. This does not stop the 862 * dev_replace procedure. It needs to be canceled 863 * manually if the cancellation is wanted. 864 */ 865 break; 866 } 867 return 1; 868 } 869 870 void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace) 871 { 872 read_lock(&dev_replace->lock); 873 atomic_inc(&dev_replace->read_locks); 874 } 875 876 void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace) 877 { 878 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 879 atomic_dec(&dev_replace->read_locks); 880 read_unlock(&dev_replace->lock); 881 } 882 883 void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace) 884 { 885 again: 886 wait_event(dev_replace->read_lock_wq, 887 atomic_read(&dev_replace->blocking_readers) == 0); 888 write_lock(&dev_replace->lock); 889 if (atomic_read(&dev_replace->blocking_readers)) { 890 write_unlock(&dev_replace->lock); 891 goto again; 892 } 893 } 894 895 void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace) 896 { 897 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 898 write_unlock(&dev_replace->lock); 899 } 900 901 /* inc blocking cnt and release read lock */ 902 void btrfs_dev_replace_set_lock_blocking( 903 struct btrfs_dev_replace *dev_replace) 904 { 905 /* only set blocking for read lock */ 906 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 907 atomic_inc(&dev_replace->blocking_readers); 908 read_unlock(&dev_replace->lock); 909 } 910 911 /* acquire read lock and dec blocking cnt */ 912 void btrfs_dev_replace_clear_lock_blocking( 913 struct btrfs_dev_replace *dev_replace) 914 { 915 /* only set blocking for read lock */ 916 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 917 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 918 read_lock(&dev_replace->lock); 919 if (atomic_dec_and_test(&dev_replace->blocking_readers) && 920 waitqueue_active(&dev_replace->read_lock_wq)) 921 wake_up(&dev_replace->read_lock_wq); 922 } 923 924 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 925 { 926 percpu_counter_inc(&fs_info->bio_counter); 927 } 928 929 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 930 { 931 percpu_counter_sub(&fs_info->bio_counter, amount); 932 933 if (waitqueue_active(&fs_info->replace_wait)) 934 wake_up(&fs_info->replace_wait); 935 } 936 937 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 938 { 939 while (1) { 940 percpu_counter_inc(&fs_info->bio_counter); 941 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 942 &fs_info->fs_state))) 943 break; 944 945 btrfs_bio_counter_dec(fs_info); 946 wait_event(fs_info->replace_wait, 947 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 948 &fs_info->fs_state)); 949 } 950 } 951