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