1 /* 2 * Copyright (C) STRATO AG 2012. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 #include <linux/sched.h> 19 #include <linux/bio.h> 20 #include <linux/slab.h> 21 #include <linux/buffer_head.h> 22 #include <linux/blkdev.h> 23 #include <linux/random.h> 24 #include <linux/iocontext.h> 25 #include <linux/capability.h> 26 #include <linux/kthread.h> 27 #include <linux/math64.h> 28 #include <asm/div64.h> 29 #include "ctree.h" 30 #include "extent_map.h" 31 #include "disk-io.h" 32 #include "transaction.h" 33 #include "print-tree.h" 34 #include "volumes.h" 35 #include "async-thread.h" 36 #include "check-integrity.h" 37 #include "rcu-string.h" 38 #include "dev-replace.h" 39 #include "sysfs.h" 40 41 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 42 int scrub_ret); 43 static void btrfs_dev_replace_update_device_in_mapping_tree( 44 struct btrfs_fs_info *fs_info, 45 struct btrfs_device *srcdev, 46 struct btrfs_device *tgtdev); 47 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 48 static int btrfs_dev_replace_kthread(void *data); 49 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 50 51 52 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 53 { 54 struct btrfs_key key; 55 struct btrfs_root *dev_root = fs_info->dev_root; 56 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 57 struct extent_buffer *eb; 58 int slot; 59 int ret = 0; 60 struct btrfs_path *path = NULL; 61 int item_size; 62 struct btrfs_dev_replace_item *ptr; 63 u64 src_devid; 64 65 path = btrfs_alloc_path(); 66 if (!path) { 67 ret = -ENOMEM; 68 goto out; 69 } 70 71 key.objectid = 0; 72 key.type = BTRFS_DEV_REPLACE_KEY; 73 key.offset = 0; 74 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 75 if (ret) { 76 no_valid_dev_replace_entry_found: 77 ret = 0; 78 dev_replace->replace_state = 79 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 80 dev_replace->cont_reading_from_srcdev_mode = 81 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 82 dev_replace->replace_state = 0; 83 dev_replace->time_started = 0; 84 dev_replace->time_stopped = 0; 85 atomic64_set(&dev_replace->num_write_errors, 0); 86 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 87 dev_replace->cursor_left = 0; 88 dev_replace->committed_cursor_left = 0; 89 dev_replace->cursor_left_last_write_of_item = 0; 90 dev_replace->cursor_right = 0; 91 dev_replace->srcdev = NULL; 92 dev_replace->tgtdev = NULL; 93 dev_replace->is_valid = 0; 94 dev_replace->item_needs_writeback = 0; 95 goto out; 96 } 97 slot = path->slots[0]; 98 eb = path->nodes[0]; 99 item_size = btrfs_item_size_nr(eb, slot); 100 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 101 102 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 103 btrfs_warn(fs_info, 104 "dev_replace entry found has unexpected size, ignore entry"); 105 goto no_valid_dev_replace_entry_found; 106 } 107 108 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 109 dev_replace->cont_reading_from_srcdev_mode = 110 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 111 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 112 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 113 dev_replace->time_stopped = 114 btrfs_dev_replace_time_stopped(eb, ptr); 115 atomic64_set(&dev_replace->num_write_errors, 116 btrfs_dev_replace_num_write_errors(eb, ptr)); 117 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 118 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 119 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 120 dev_replace->committed_cursor_left = dev_replace->cursor_left; 121 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 122 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 123 dev_replace->is_valid = 1; 124 125 dev_replace->item_needs_writeback = 0; 126 switch (dev_replace->replace_state) { 127 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 128 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 129 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 130 dev_replace->srcdev = NULL; 131 dev_replace->tgtdev = NULL; 132 break; 133 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 134 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 135 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 136 NULL, NULL); 137 dev_replace->tgtdev = btrfs_find_device(fs_info, 138 BTRFS_DEV_REPLACE_DEVID, 139 NULL, NULL); 140 /* 141 * allow 'btrfs dev replace_cancel' if src/tgt device is 142 * missing 143 */ 144 if (!dev_replace->srcdev && 145 !btrfs_test_opt(fs_info, DEGRADED)) { 146 ret = -EIO; 147 btrfs_warn(fs_info, 148 "cannot mount because device replace operation is ongoing and"); 149 btrfs_warn(fs_info, 150 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 151 src_devid); 152 } 153 if (!dev_replace->tgtdev && 154 !btrfs_test_opt(fs_info, DEGRADED)) { 155 ret = -EIO; 156 btrfs_warn(fs_info, 157 "cannot mount because device replace operation is ongoing and"); 158 btrfs_warn(fs_info, 159 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 160 BTRFS_DEV_REPLACE_DEVID); 161 } 162 if (dev_replace->tgtdev) { 163 if (dev_replace->srcdev) { 164 dev_replace->tgtdev->total_bytes = 165 dev_replace->srcdev->total_bytes; 166 dev_replace->tgtdev->disk_total_bytes = 167 dev_replace->srcdev->disk_total_bytes; 168 dev_replace->tgtdev->commit_total_bytes = 169 dev_replace->srcdev->commit_total_bytes; 170 dev_replace->tgtdev->bytes_used = 171 dev_replace->srcdev->bytes_used; 172 dev_replace->tgtdev->commit_bytes_used = 173 dev_replace->srcdev->commit_bytes_used; 174 } 175 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; 176 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 177 dev_replace->tgtdev); 178 } 179 break; 180 } 181 182 out: 183 btrfs_free_path(path); 184 return ret; 185 } 186 187 /* 188 * called from commit_transaction. Writes changed device replace state to 189 * disk. 190 */ 191 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 192 struct btrfs_fs_info *fs_info) 193 { 194 int ret; 195 struct btrfs_root *dev_root = fs_info->dev_root; 196 struct btrfs_path *path; 197 struct btrfs_key key; 198 struct extent_buffer *eb; 199 struct btrfs_dev_replace_item *ptr; 200 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 201 202 btrfs_dev_replace_lock(dev_replace, 0); 203 if (!dev_replace->is_valid || 204 !dev_replace->item_needs_writeback) { 205 btrfs_dev_replace_unlock(dev_replace, 0); 206 return 0; 207 } 208 btrfs_dev_replace_unlock(dev_replace, 0); 209 210 key.objectid = 0; 211 key.type = BTRFS_DEV_REPLACE_KEY; 212 key.offset = 0; 213 214 path = btrfs_alloc_path(); 215 if (!path) { 216 ret = -ENOMEM; 217 goto out; 218 } 219 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 220 if (ret < 0) { 221 btrfs_warn(fs_info, 222 "error %d while searching for dev_replace item!", 223 ret); 224 goto out; 225 } 226 227 if (ret == 0 && 228 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 229 /* 230 * need to delete old one and insert a new one. 231 * Since no attempt is made to recover any old state, if the 232 * dev_replace state is 'running', the data on the target 233 * drive is lost. 234 * It would be possible to recover the state: just make sure 235 * that the beginning of the item is never changed and always 236 * contains all the essential information. Then read this 237 * minimal set of information and use it as a base for the 238 * new state. 239 */ 240 ret = btrfs_del_item(trans, dev_root, path); 241 if (ret != 0) { 242 btrfs_warn(fs_info, 243 "delete too small dev_replace item failed %d!", 244 ret); 245 goto out; 246 } 247 ret = 1; 248 } 249 250 if (ret == 1) { 251 /* need to insert a new item */ 252 btrfs_release_path(path); 253 ret = btrfs_insert_empty_item(trans, dev_root, path, 254 &key, sizeof(*ptr)); 255 if (ret < 0) { 256 btrfs_warn(fs_info, 257 "insert dev_replace item failed %d!", ret); 258 goto out; 259 } 260 } 261 262 eb = path->nodes[0]; 263 ptr = btrfs_item_ptr(eb, path->slots[0], 264 struct btrfs_dev_replace_item); 265 266 btrfs_dev_replace_lock(dev_replace, 1); 267 if (dev_replace->srcdev) 268 btrfs_set_dev_replace_src_devid(eb, ptr, 269 dev_replace->srcdev->devid); 270 else 271 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 272 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 273 dev_replace->cont_reading_from_srcdev_mode); 274 btrfs_set_dev_replace_replace_state(eb, ptr, 275 dev_replace->replace_state); 276 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 277 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 278 btrfs_set_dev_replace_num_write_errors(eb, ptr, 279 atomic64_read(&dev_replace->num_write_errors)); 280 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 281 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 282 dev_replace->cursor_left_last_write_of_item = 283 dev_replace->cursor_left; 284 btrfs_set_dev_replace_cursor_left(eb, ptr, 285 dev_replace->cursor_left_last_write_of_item); 286 btrfs_set_dev_replace_cursor_right(eb, ptr, 287 dev_replace->cursor_right); 288 dev_replace->item_needs_writeback = 0; 289 btrfs_dev_replace_unlock(dev_replace, 1); 290 291 btrfs_mark_buffer_dirty(eb); 292 293 out: 294 btrfs_free_path(path); 295 296 return ret; 297 } 298 299 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 300 { 301 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 302 303 dev_replace->committed_cursor_left = 304 dev_replace->cursor_left_last_write_of_item; 305 } 306 307 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 308 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 309 int read_src) 310 { 311 struct btrfs_root *root = fs_info->dev_root; 312 struct btrfs_trans_handle *trans; 313 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 314 int ret; 315 struct btrfs_device *tgt_device = NULL; 316 struct btrfs_device *src_device = NULL; 317 318 /* the disk copy procedure reuses the scrub code */ 319 mutex_lock(&fs_info->volume_mutex); 320 ret = btrfs_find_device_by_devspec(fs_info, srcdevid, 321 srcdev_name, &src_device); 322 if (ret) { 323 mutex_unlock(&fs_info->volume_mutex); 324 return ret; 325 } 326 327 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 328 src_device, &tgt_device); 329 mutex_unlock(&fs_info->volume_mutex); 330 if (ret) 331 return ret; 332 333 /* 334 * Here we commit the transaction to make sure commit_total_bytes 335 * of all the devices are updated. 336 */ 337 trans = btrfs_attach_transaction(root); 338 if (!IS_ERR(trans)) { 339 ret = btrfs_commit_transaction(trans); 340 if (ret) 341 return ret; 342 } else if (PTR_ERR(trans) != -ENOENT) { 343 return PTR_ERR(trans); 344 } 345 346 btrfs_dev_replace_lock(dev_replace, 1); 347 switch (dev_replace->replace_state) { 348 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 349 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 350 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 351 break; 352 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 353 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 354 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 355 goto leave; 356 } 357 358 dev_replace->cont_reading_from_srcdev_mode = read_src; 359 WARN_ON(!src_device); 360 dev_replace->srcdev = src_device; 361 WARN_ON(!tgt_device); 362 dev_replace->tgtdev = tgt_device; 363 364 btrfs_info_in_rcu(fs_info, 365 "dev_replace from %s (devid %llu) to %s started", 366 src_device->missing ? "<missing disk>" : 367 rcu_str_deref(src_device->name), 368 src_device->devid, 369 rcu_str_deref(tgt_device->name)); 370 371 /* 372 * from now on, the writes to the srcdev are all duplicated to 373 * go to the tgtdev as well (refer to btrfs_map_block()). 374 */ 375 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 376 dev_replace->time_started = get_seconds(); 377 dev_replace->cursor_left = 0; 378 dev_replace->committed_cursor_left = 0; 379 dev_replace->cursor_left_last_write_of_item = 0; 380 dev_replace->cursor_right = 0; 381 dev_replace->is_valid = 1; 382 dev_replace->item_needs_writeback = 1; 383 atomic64_set(&dev_replace->num_write_errors, 0); 384 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 385 btrfs_dev_replace_unlock(dev_replace, 1); 386 387 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 388 if (ret) 389 btrfs_err(fs_info, "kobj add dev failed %d", ret); 390 391 btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1); 392 393 /* force writing the updated state information to disk */ 394 trans = btrfs_start_transaction(root, 0); 395 if (IS_ERR(trans)) { 396 ret = PTR_ERR(trans); 397 btrfs_dev_replace_lock(dev_replace, 1); 398 goto leave; 399 } 400 401 ret = btrfs_commit_transaction(trans); 402 WARN_ON(ret); 403 404 /* the disk copy procedure reuses the scrub code */ 405 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 406 btrfs_device_get_total_bytes(src_device), 407 &dev_replace->scrub_progress, 0, 1); 408 409 ret = btrfs_dev_replace_finishing(fs_info, ret); 410 if (ret == -EINPROGRESS) { 411 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 412 } else { 413 WARN_ON(ret); 414 } 415 416 return ret; 417 418 leave: 419 dev_replace->srcdev = NULL; 420 dev_replace->tgtdev = NULL; 421 btrfs_dev_replace_unlock(dev_replace, 1); 422 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 423 return ret; 424 } 425 426 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 427 struct btrfs_ioctl_dev_replace_args *args) 428 { 429 int ret; 430 431 switch (args->start.cont_reading_from_srcdev_mode) { 432 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 433 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 434 break; 435 default: 436 return -EINVAL; 437 } 438 439 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 440 args->start.tgtdev_name[0] == '\0') 441 return -EINVAL; 442 443 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 444 args->start.srcdevid, 445 args->start.srcdev_name, 446 args->start.cont_reading_from_srcdev_mode); 447 args->result = ret; 448 /* don't warn if EINPROGRESS, someone else might be running scrub */ 449 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS) 450 ret = 0; 451 452 return ret; 453 } 454 455 /* 456 * blocked until all in-flight bios operations are finished. 457 */ 458 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 459 { 460 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 461 wait_event(fs_info->replace_wait, !percpu_counter_sum( 462 &fs_info->bio_counter)); 463 } 464 465 /* 466 * we have removed target device, it is safe to allow new bios request. 467 */ 468 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 469 { 470 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 471 wake_up(&fs_info->replace_wait); 472 } 473 474 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 475 int scrub_ret) 476 { 477 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 478 struct btrfs_device *tgt_device; 479 struct btrfs_device *src_device; 480 struct btrfs_root *root = fs_info->tree_root; 481 u8 uuid_tmp[BTRFS_UUID_SIZE]; 482 struct btrfs_trans_handle *trans; 483 int ret = 0; 484 485 /* don't allow cancel or unmount to disturb the finishing procedure */ 486 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 487 488 btrfs_dev_replace_lock(dev_replace, 0); 489 /* was the operation canceled, or is it finished? */ 490 if (dev_replace->replace_state != 491 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 492 btrfs_dev_replace_unlock(dev_replace, 0); 493 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 494 return 0; 495 } 496 497 tgt_device = dev_replace->tgtdev; 498 src_device = dev_replace->srcdev; 499 btrfs_dev_replace_unlock(dev_replace, 0); 500 501 /* 502 * flush all outstanding I/O and inode extent mappings before the 503 * copy operation is declared as being finished 504 */ 505 ret = btrfs_start_delalloc_roots(fs_info, 0, -1); 506 if (ret) { 507 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 508 return ret; 509 } 510 btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1); 511 512 trans = btrfs_start_transaction(root, 0); 513 if (IS_ERR(trans)) { 514 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 515 return PTR_ERR(trans); 516 } 517 ret = btrfs_commit_transaction(trans); 518 WARN_ON(ret); 519 520 mutex_lock(&uuid_mutex); 521 /* keep away write_all_supers() during the finishing procedure */ 522 mutex_lock(&fs_info->fs_devices->device_list_mutex); 523 mutex_lock(&fs_info->chunk_mutex); 524 btrfs_dev_replace_lock(dev_replace, 1); 525 dev_replace->replace_state = 526 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 527 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 528 dev_replace->tgtdev = NULL; 529 dev_replace->srcdev = NULL; 530 dev_replace->time_stopped = get_seconds(); 531 dev_replace->item_needs_writeback = 1; 532 533 /* replace old device with new one in mapping tree */ 534 if (!scrub_ret) { 535 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 536 src_device, 537 tgt_device); 538 } else { 539 btrfs_err_in_rcu(fs_info, 540 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 541 src_device->missing ? "<missing disk>" : 542 rcu_str_deref(src_device->name), 543 src_device->devid, 544 rcu_str_deref(tgt_device->name), scrub_ret); 545 btrfs_dev_replace_unlock(dev_replace, 1); 546 mutex_unlock(&fs_info->chunk_mutex); 547 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 548 mutex_unlock(&uuid_mutex); 549 if (tgt_device) 550 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 551 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 552 553 return scrub_ret; 554 } 555 556 btrfs_info_in_rcu(fs_info, 557 "dev_replace from %s (devid %llu) to %s finished", 558 src_device->missing ? "<missing disk>" : 559 rcu_str_deref(src_device->name), 560 src_device->devid, 561 rcu_str_deref(tgt_device->name)); 562 tgt_device->is_tgtdev_for_dev_replace = 0; 563 tgt_device->devid = src_device->devid; 564 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 565 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 566 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 567 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 568 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 569 btrfs_device_set_disk_total_bytes(tgt_device, 570 src_device->disk_total_bytes); 571 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 572 ASSERT(list_empty(&src_device->resized_list)); 573 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 574 tgt_device->commit_bytes_used = src_device->bytes_used; 575 576 btrfs_assign_next_active_device(fs_info, src_device, tgt_device); 577 578 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 579 fs_info->fs_devices->rw_devices++; 580 581 btrfs_dev_replace_unlock(dev_replace, 1); 582 583 btrfs_rm_dev_replace_blocked(fs_info); 584 585 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 586 587 btrfs_rm_dev_replace_unblocked(fs_info); 588 589 /* 590 * this is again a consistent state where no dev_replace procedure 591 * is running, the target device is part of the filesystem, the 592 * source device is not part of the filesystem anymore and its 1st 593 * superblock is scratched out so that it is no longer marked to 594 * belong to this filesystem. 595 */ 596 mutex_unlock(&fs_info->chunk_mutex); 597 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 598 mutex_unlock(&uuid_mutex); 599 600 /* replace the sysfs entry */ 601 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 602 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 603 604 /* write back the superblocks */ 605 trans = btrfs_start_transaction(root, 0); 606 if (!IS_ERR(trans)) 607 btrfs_commit_transaction(trans); 608 609 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 610 611 return 0; 612 } 613 614 static void btrfs_dev_replace_update_device_in_mapping_tree( 615 struct btrfs_fs_info *fs_info, 616 struct btrfs_device *srcdev, 617 struct btrfs_device *tgtdev) 618 { 619 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 620 struct extent_map *em; 621 struct map_lookup *map; 622 u64 start = 0; 623 int i; 624 625 write_lock(&em_tree->lock); 626 do { 627 em = lookup_extent_mapping(em_tree, start, (u64)-1); 628 if (!em) 629 break; 630 map = em->map_lookup; 631 for (i = 0; i < map->num_stripes; i++) 632 if (srcdev == map->stripes[i].dev) 633 map->stripes[i].dev = tgtdev; 634 start = em->start + em->len; 635 free_extent_map(em); 636 } while (start); 637 write_unlock(&em_tree->lock); 638 } 639 640 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 641 struct btrfs_ioctl_dev_replace_args *args) 642 { 643 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 644 struct btrfs_device *srcdev; 645 646 btrfs_dev_replace_lock(dev_replace, 0); 647 /* even if !dev_replace_is_valid, the values are good enough for 648 * the replace_status ioctl */ 649 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 650 args->status.replace_state = dev_replace->replace_state; 651 args->status.time_started = dev_replace->time_started; 652 args->status.time_stopped = dev_replace->time_stopped; 653 args->status.num_write_errors = 654 atomic64_read(&dev_replace->num_write_errors); 655 args->status.num_uncorrectable_read_errors = 656 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 657 switch (dev_replace->replace_state) { 658 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 659 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 660 args->status.progress_1000 = 0; 661 break; 662 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 663 args->status.progress_1000 = 1000; 664 break; 665 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 666 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 667 srcdev = dev_replace->srcdev; 668 args->status.progress_1000 = div_u64(dev_replace->cursor_left, 669 div_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 670 break; 671 } 672 btrfs_dev_replace_unlock(dev_replace, 0); 673 } 674 675 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 676 struct btrfs_ioctl_dev_replace_args *args) 677 { 678 args->result = __btrfs_dev_replace_cancel(fs_info); 679 return 0; 680 } 681 682 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 683 { 684 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 685 struct btrfs_device *tgt_device = NULL; 686 struct btrfs_trans_handle *trans; 687 struct btrfs_root *root = fs_info->tree_root; 688 u64 result; 689 int ret; 690 691 if (fs_info->sb->s_flags & MS_RDONLY) 692 return -EROFS; 693 694 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 695 btrfs_dev_replace_lock(dev_replace, 1); 696 switch (dev_replace->replace_state) { 697 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 698 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 699 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 700 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 701 btrfs_dev_replace_unlock(dev_replace, 1); 702 goto leave; 703 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 704 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 705 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 706 tgt_device = dev_replace->tgtdev; 707 dev_replace->tgtdev = NULL; 708 dev_replace->srcdev = NULL; 709 break; 710 } 711 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 712 dev_replace->time_stopped = get_seconds(); 713 dev_replace->item_needs_writeback = 1; 714 btrfs_dev_replace_unlock(dev_replace, 1); 715 btrfs_scrub_cancel(fs_info); 716 717 trans = btrfs_start_transaction(root, 0); 718 if (IS_ERR(trans)) { 719 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 720 return PTR_ERR(trans); 721 } 722 ret = btrfs_commit_transaction(trans); 723 WARN_ON(ret); 724 if (tgt_device) 725 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 726 727 leave: 728 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 729 return result; 730 } 731 732 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 733 { 734 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 735 736 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 737 btrfs_dev_replace_lock(dev_replace, 1); 738 switch (dev_replace->replace_state) { 739 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 740 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 741 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 742 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 743 break; 744 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 745 dev_replace->replace_state = 746 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 747 dev_replace->time_stopped = get_seconds(); 748 dev_replace->item_needs_writeback = 1; 749 btrfs_info(fs_info, "suspending dev_replace for unmount"); 750 break; 751 } 752 753 btrfs_dev_replace_unlock(dev_replace, 1); 754 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 755 } 756 757 /* resume dev_replace procedure that was interrupted by unmount */ 758 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 759 { 760 struct task_struct *task; 761 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 762 763 btrfs_dev_replace_lock(dev_replace, 1); 764 switch (dev_replace->replace_state) { 765 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 766 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 767 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 768 btrfs_dev_replace_unlock(dev_replace, 1); 769 return 0; 770 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 771 break; 772 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 773 dev_replace->replace_state = 774 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 775 break; 776 } 777 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 778 btrfs_info(fs_info, 779 "cannot continue dev_replace, tgtdev is missing"); 780 btrfs_info(fs_info, 781 "you may cancel the operation after 'mount -o degraded'"); 782 btrfs_dev_replace_unlock(dev_replace, 1); 783 return 0; 784 } 785 btrfs_dev_replace_unlock(dev_replace, 1); 786 787 WARN_ON(atomic_xchg( 788 &fs_info->mutually_exclusive_operation_running, 1)); 789 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 790 return PTR_ERR_OR_ZERO(task); 791 } 792 793 static int btrfs_dev_replace_kthread(void *data) 794 { 795 struct btrfs_fs_info *fs_info = data; 796 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 797 struct btrfs_ioctl_dev_replace_args *status_args; 798 u64 progress; 799 800 status_args = kzalloc(sizeof(*status_args), GFP_KERNEL); 801 if (status_args) { 802 btrfs_dev_replace_status(fs_info, status_args); 803 progress = status_args->status.progress_1000; 804 kfree(status_args); 805 progress = div_u64(progress, 10); 806 btrfs_info_in_rcu(fs_info, 807 "continuing dev_replace from %s (devid %llu) to %s @%u%%", 808 dev_replace->srcdev->missing ? "<missing disk>" : 809 rcu_str_deref(dev_replace->srcdev->name), 810 dev_replace->srcdev->devid, 811 dev_replace->tgtdev ? 812 rcu_str_deref(dev_replace->tgtdev->name) : 813 "<missing target disk>", 814 (unsigned int)progress); 815 } 816 btrfs_dev_replace_continue_on_mount(fs_info); 817 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 818 819 return 0; 820 } 821 822 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 823 { 824 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 825 int ret; 826 827 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 828 dev_replace->committed_cursor_left, 829 btrfs_device_get_total_bytes(dev_replace->srcdev), 830 &dev_replace->scrub_progress, 0, 1); 831 ret = btrfs_dev_replace_finishing(fs_info, ret); 832 WARN_ON(ret); 833 return 0; 834 } 835 836 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 837 { 838 if (!dev_replace->is_valid) 839 return 0; 840 841 switch (dev_replace->replace_state) { 842 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 843 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 844 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 845 return 0; 846 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 847 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 848 /* 849 * return true even if tgtdev is missing (this is 850 * something that can happen if the dev_replace 851 * procedure is suspended by an umount and then 852 * the tgtdev is missing (or "btrfs dev scan") was 853 * not called and the the filesystem is remounted 854 * in degraded state. This does not stop the 855 * dev_replace procedure. It needs to be canceled 856 * manually if the cancellation is wanted. 857 */ 858 break; 859 } 860 return 1; 861 } 862 863 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw) 864 { 865 if (rw == 1) { 866 /* write */ 867 again: 868 wait_event(dev_replace->read_lock_wq, 869 atomic_read(&dev_replace->blocking_readers) == 0); 870 write_lock(&dev_replace->lock); 871 if (atomic_read(&dev_replace->blocking_readers)) { 872 write_unlock(&dev_replace->lock); 873 goto again; 874 } 875 } else { 876 read_lock(&dev_replace->lock); 877 atomic_inc(&dev_replace->read_locks); 878 } 879 } 880 881 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw) 882 { 883 if (rw == 1) { 884 /* write */ 885 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 886 write_unlock(&dev_replace->lock); 887 } else { 888 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 889 atomic_dec(&dev_replace->read_locks); 890 read_unlock(&dev_replace->lock); 891 } 892 } 893 894 /* inc blocking cnt and release read lock */ 895 void btrfs_dev_replace_set_lock_blocking( 896 struct btrfs_dev_replace *dev_replace) 897 { 898 /* only set blocking for read lock */ 899 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 900 atomic_inc(&dev_replace->blocking_readers); 901 read_unlock(&dev_replace->lock); 902 } 903 904 /* acquire read lock and dec blocking cnt */ 905 void btrfs_dev_replace_clear_lock_blocking( 906 struct btrfs_dev_replace *dev_replace) 907 { 908 /* only set blocking for read lock */ 909 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 910 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 911 read_lock(&dev_replace->lock); 912 if (atomic_dec_and_test(&dev_replace->blocking_readers) && 913 waitqueue_active(&dev_replace->read_lock_wq)) 914 wake_up(&dev_replace->read_lock_wq); 915 } 916 917 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 918 { 919 percpu_counter_inc(&fs_info->bio_counter); 920 } 921 922 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 923 { 924 percpu_counter_sub(&fs_info->bio_counter, amount); 925 926 if (waitqueue_active(&fs_info->replace_wait)) 927 wake_up(&fs_info->replace_wait); 928 } 929 930 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 931 { 932 while (1) { 933 percpu_counter_inc(&fs_info->bio_counter); 934 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 935 &fs_info->fs_state))) 936 break; 937 938 btrfs_bio_counter_dec(fs_info); 939 wait_event(fs_info->replace_wait, 940 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 941 &fs_info->fs_state)); 942 } 943 } 944