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(dev_root, 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(dev_root, 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, "error %d while searching for dev_replace item!", 222 ret); 223 goto out; 224 } 225 226 if (ret == 0 && 227 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 228 /* 229 * need to delete old one and insert a new one. 230 * Since no attempt is made to recover any old state, if the 231 * dev_replace state is 'running', the data on the target 232 * drive is lost. 233 * It would be possible to recover the state: just make sure 234 * that the beginning of the item is never changed and always 235 * contains all the essential information. Then read this 236 * minimal set of information and use it as a base for the 237 * new state. 238 */ 239 ret = btrfs_del_item(trans, dev_root, path); 240 if (ret != 0) { 241 btrfs_warn(fs_info, "delete too small dev_replace item failed %d!", 242 ret); 243 goto out; 244 } 245 ret = 1; 246 } 247 248 if (ret == 1) { 249 /* need to insert a new item */ 250 btrfs_release_path(path); 251 ret = btrfs_insert_empty_item(trans, dev_root, path, 252 &key, sizeof(*ptr)); 253 if (ret < 0) { 254 btrfs_warn(fs_info, "insert dev_replace item failed %d!", 255 ret); 256 goto out; 257 } 258 } 259 260 eb = path->nodes[0]; 261 ptr = btrfs_item_ptr(eb, path->slots[0], 262 struct btrfs_dev_replace_item); 263 264 btrfs_dev_replace_lock(dev_replace, 1); 265 if (dev_replace->srcdev) 266 btrfs_set_dev_replace_src_devid(eb, ptr, 267 dev_replace->srcdev->devid); 268 else 269 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 270 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 271 dev_replace->cont_reading_from_srcdev_mode); 272 btrfs_set_dev_replace_replace_state(eb, ptr, 273 dev_replace->replace_state); 274 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 275 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 276 btrfs_set_dev_replace_num_write_errors(eb, ptr, 277 atomic64_read(&dev_replace->num_write_errors)); 278 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 279 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 280 dev_replace->cursor_left_last_write_of_item = 281 dev_replace->cursor_left; 282 btrfs_set_dev_replace_cursor_left(eb, ptr, 283 dev_replace->cursor_left_last_write_of_item); 284 btrfs_set_dev_replace_cursor_right(eb, ptr, 285 dev_replace->cursor_right); 286 dev_replace->item_needs_writeback = 0; 287 btrfs_dev_replace_unlock(dev_replace, 1); 288 289 btrfs_mark_buffer_dirty(eb); 290 291 out: 292 btrfs_free_path(path); 293 294 return ret; 295 } 296 297 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 298 { 299 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 300 301 dev_replace->committed_cursor_left = 302 dev_replace->cursor_left_last_write_of_item; 303 } 304 305 int btrfs_dev_replace_start(struct btrfs_root *root, char *tgtdev_name, 306 u64 srcdevid, char *srcdev_name, int read_src) 307 { 308 struct btrfs_trans_handle *trans; 309 struct btrfs_fs_info *fs_info = root->fs_info; 310 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 311 int ret; 312 struct btrfs_device *tgt_device = NULL; 313 struct btrfs_device *src_device = NULL; 314 315 /* the disk copy procedure reuses the scrub code */ 316 mutex_lock(&fs_info->volume_mutex); 317 ret = btrfs_find_device_by_devspec(root, srcdevid, 318 srcdev_name, &src_device); 319 if (ret) { 320 mutex_unlock(&fs_info->volume_mutex); 321 return ret; 322 } 323 324 ret = btrfs_init_dev_replace_tgtdev(root, tgtdev_name, 325 src_device, &tgt_device); 326 mutex_unlock(&fs_info->volume_mutex); 327 if (ret) 328 return ret; 329 330 /* 331 * Here we commit the transaction to make sure commit_total_bytes 332 * of all the devices are updated. 333 */ 334 trans = btrfs_attach_transaction(root); 335 if (!IS_ERR(trans)) { 336 ret = btrfs_commit_transaction(trans, root); 337 if (ret) 338 return ret; 339 } else if (PTR_ERR(trans) != -ENOENT) { 340 return PTR_ERR(trans); 341 } 342 343 btrfs_dev_replace_lock(dev_replace, 1); 344 switch (dev_replace->replace_state) { 345 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 346 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 347 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 348 break; 349 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 350 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 351 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 352 goto leave; 353 } 354 355 dev_replace->cont_reading_from_srcdev_mode = read_src; 356 WARN_ON(!src_device); 357 dev_replace->srcdev = src_device; 358 WARN_ON(!tgt_device); 359 dev_replace->tgtdev = tgt_device; 360 361 btrfs_info_in_rcu(fs_info, 362 "dev_replace from %s (devid %llu) to %s started", 363 src_device->missing ? "<missing disk>" : 364 rcu_str_deref(src_device->name), 365 src_device->devid, 366 rcu_str_deref(tgt_device->name)); 367 368 /* 369 * from now on, the writes to the srcdev are all duplicated to 370 * go to the tgtdev as well (refer to btrfs_map_block()). 371 */ 372 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 373 dev_replace->time_started = get_seconds(); 374 dev_replace->cursor_left = 0; 375 dev_replace->committed_cursor_left = 0; 376 dev_replace->cursor_left_last_write_of_item = 0; 377 dev_replace->cursor_right = 0; 378 dev_replace->is_valid = 1; 379 dev_replace->item_needs_writeback = 1; 380 atomic64_set(&dev_replace->num_write_errors, 0); 381 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 382 btrfs_dev_replace_unlock(dev_replace, 1); 383 384 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 385 if (ret) 386 btrfs_err(fs_info, "kobj add dev failed %d\n", ret); 387 388 btrfs_wait_ordered_roots(fs_info, -1); 389 390 /* force writing the updated state information to disk */ 391 trans = btrfs_start_transaction(root, 0); 392 if (IS_ERR(trans)) { 393 ret = PTR_ERR(trans); 394 btrfs_dev_replace_lock(dev_replace, 1); 395 goto leave; 396 } 397 398 ret = btrfs_commit_transaction(trans, root); 399 WARN_ON(ret); 400 401 /* the disk copy procedure reuses the scrub code */ 402 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 403 btrfs_device_get_total_bytes(src_device), 404 &dev_replace->scrub_progress, 0, 1); 405 406 ret = btrfs_dev_replace_finishing(fs_info, ret); 407 if (ret == -EINPROGRESS) { 408 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 409 } else { 410 WARN_ON(ret); 411 } 412 413 return ret; 414 415 leave: 416 dev_replace->srcdev = NULL; 417 dev_replace->tgtdev = NULL; 418 btrfs_dev_replace_unlock(dev_replace, 1); 419 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 420 return ret; 421 } 422 423 int btrfs_dev_replace_by_ioctl(struct btrfs_root *root, 424 struct btrfs_ioctl_dev_replace_args *args) 425 { 426 int ret; 427 428 switch (args->start.cont_reading_from_srcdev_mode) { 429 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 430 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 431 break; 432 default: 433 return -EINVAL; 434 } 435 436 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 437 args->start.tgtdev_name[0] == '\0') 438 return -EINVAL; 439 440 ret = btrfs_dev_replace_start(root, args->start.tgtdev_name, 441 args->start.srcdevid, 442 args->start.srcdev_name, 443 args->start.cont_reading_from_srcdev_mode); 444 args->result = ret; 445 /* don't warn if EINPROGRESS, someone else might be running scrub */ 446 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS) 447 ret = 0; 448 449 return ret; 450 } 451 452 /* 453 * blocked until all flighting bios are finished. 454 */ 455 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 456 { 457 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 458 wait_event(fs_info->replace_wait, !percpu_counter_sum( 459 &fs_info->bio_counter)); 460 } 461 462 /* 463 * we have removed target device, it is safe to allow new bios request. 464 */ 465 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 466 { 467 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 468 wake_up(&fs_info->replace_wait); 469 } 470 471 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 472 int scrub_ret) 473 { 474 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 475 struct btrfs_device *tgt_device; 476 struct btrfs_device *src_device; 477 struct btrfs_root *root = fs_info->tree_root; 478 u8 uuid_tmp[BTRFS_UUID_SIZE]; 479 struct btrfs_trans_handle *trans; 480 int ret = 0; 481 482 /* don't allow cancel or unmount to disturb the finishing procedure */ 483 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 484 485 btrfs_dev_replace_lock(dev_replace, 0); 486 /* was the operation canceled, or is it finished? */ 487 if (dev_replace->replace_state != 488 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 489 btrfs_dev_replace_unlock(dev_replace, 0); 490 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 491 return 0; 492 } 493 494 tgt_device = dev_replace->tgtdev; 495 src_device = dev_replace->srcdev; 496 btrfs_dev_replace_unlock(dev_replace, 0); 497 498 /* 499 * flush all outstanding I/O and inode extent mappings before the 500 * copy operation is declared as being finished 501 */ 502 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 503 if (ret) { 504 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 505 return ret; 506 } 507 btrfs_wait_ordered_roots(root->fs_info, -1); 508 509 trans = btrfs_start_transaction(root, 0); 510 if (IS_ERR(trans)) { 511 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 512 return PTR_ERR(trans); 513 } 514 ret = btrfs_commit_transaction(trans, root); 515 WARN_ON(ret); 516 517 mutex_lock(&uuid_mutex); 518 /* keep away write_all_supers() during the finishing procedure */ 519 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 520 mutex_lock(&root->fs_info->chunk_mutex); 521 btrfs_dev_replace_lock(dev_replace, 1); 522 dev_replace->replace_state = 523 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 524 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 525 dev_replace->tgtdev = NULL; 526 dev_replace->srcdev = NULL; 527 dev_replace->time_stopped = get_seconds(); 528 dev_replace->item_needs_writeback = 1; 529 530 /* replace old device with new one in mapping tree */ 531 if (!scrub_ret) { 532 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 533 src_device, 534 tgt_device); 535 } else { 536 btrfs_err_in_rcu(root->fs_info, 537 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 538 src_device->missing ? "<missing disk>" : 539 rcu_str_deref(src_device->name), 540 src_device->devid, 541 rcu_str_deref(tgt_device->name), scrub_ret); 542 btrfs_dev_replace_unlock(dev_replace, 1); 543 mutex_unlock(&root->fs_info->chunk_mutex); 544 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 545 mutex_unlock(&uuid_mutex); 546 if (tgt_device) 547 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 548 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 549 550 return scrub_ret; 551 } 552 553 btrfs_info_in_rcu(root->fs_info, 554 "dev_replace from %s (devid %llu) to %s finished", 555 src_device->missing ? "<missing disk>" : 556 rcu_str_deref(src_device->name), 557 src_device->devid, 558 rcu_str_deref(tgt_device->name)); 559 tgt_device->is_tgtdev_for_dev_replace = 0; 560 tgt_device->devid = src_device->devid; 561 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 562 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 563 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 564 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 565 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 566 btrfs_device_set_disk_total_bytes(tgt_device, 567 src_device->disk_total_bytes); 568 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 569 ASSERT(list_empty(&src_device->resized_list)); 570 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 571 tgt_device->commit_bytes_used = src_device->bytes_used; 572 if (fs_info->sb->s_bdev && 573 (fs_info->sb->s_bdev == src_device->bdev)) 574 fs_info->sb->s_bdev = tgt_device->bdev; 575 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 576 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 577 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 578 fs_info->fs_devices->rw_devices++; 579 580 btrfs_dev_replace_unlock(dev_replace, 1); 581 582 btrfs_rm_dev_replace_blocked(fs_info); 583 584 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 585 586 btrfs_rm_dev_replace_unblocked(fs_info); 587 588 /* 589 * this is again a consistent state where no dev_replace procedure 590 * is running, the target device is part of the filesystem, the 591 * source device is not part of the filesystem anymore and its 1st 592 * superblock is scratched out so that it is no longer marked to 593 * belong to this filesystem. 594 */ 595 mutex_unlock(&root->fs_info->chunk_mutex); 596 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 597 mutex_unlock(&uuid_mutex); 598 599 /* replace the sysfs entry */ 600 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 601 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 602 603 /* write back the superblocks */ 604 trans = btrfs_start_transaction(root, 0); 605 if (!IS_ERR(trans)) 606 btrfs_commit_transaction(trans, root); 607 608 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 609 610 return 0; 611 } 612 613 static void btrfs_dev_replace_update_device_in_mapping_tree( 614 struct btrfs_fs_info *fs_info, 615 struct btrfs_device *srcdev, 616 struct btrfs_device *tgtdev) 617 { 618 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 619 struct extent_map *em; 620 struct map_lookup *map; 621 u64 start = 0; 622 int i; 623 624 write_lock(&em_tree->lock); 625 do { 626 em = lookup_extent_mapping(em_tree, start, (u64)-1); 627 if (!em) 628 break; 629 map = em->map_lookup; 630 for (i = 0; i < map->num_stripes; i++) 631 if (srcdev == map->stripes[i].dev) 632 map->stripes[i].dev = tgtdev; 633 start = em->start + em->len; 634 free_extent_map(em); 635 } while (start); 636 write_unlock(&em_tree->lock); 637 } 638 639 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 640 struct btrfs_ioctl_dev_replace_args *args) 641 { 642 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 643 struct btrfs_device *srcdev; 644 645 btrfs_dev_replace_lock(dev_replace, 0); 646 /* even if !dev_replace_is_valid, the values are good enough for 647 * the replace_status ioctl */ 648 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 649 args->status.replace_state = dev_replace->replace_state; 650 args->status.time_started = dev_replace->time_started; 651 args->status.time_stopped = dev_replace->time_stopped; 652 args->status.num_write_errors = 653 atomic64_read(&dev_replace->num_write_errors); 654 args->status.num_uncorrectable_read_errors = 655 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 656 switch (dev_replace->replace_state) { 657 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 658 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 659 args->status.progress_1000 = 0; 660 break; 661 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 662 args->status.progress_1000 = 1000; 663 break; 664 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 665 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 666 srcdev = dev_replace->srcdev; 667 args->status.progress_1000 = div_u64(dev_replace->cursor_left, 668 div_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 669 break; 670 } 671 btrfs_dev_replace_unlock(dev_replace, 0); 672 } 673 674 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 675 struct btrfs_ioctl_dev_replace_args *args) 676 { 677 args->result = __btrfs_dev_replace_cancel(fs_info); 678 return 0; 679 } 680 681 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 682 { 683 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 684 struct btrfs_device *tgt_device = NULL; 685 struct btrfs_trans_handle *trans; 686 struct btrfs_root *root = fs_info->tree_root; 687 u64 result; 688 int ret; 689 690 if (fs_info->sb->s_flags & MS_RDONLY) 691 return -EROFS; 692 693 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 694 btrfs_dev_replace_lock(dev_replace, 1); 695 switch (dev_replace->replace_state) { 696 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 697 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 698 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 699 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 700 btrfs_dev_replace_unlock(dev_replace, 1); 701 goto leave; 702 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 703 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 704 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 705 tgt_device = dev_replace->tgtdev; 706 dev_replace->tgtdev = NULL; 707 dev_replace->srcdev = NULL; 708 break; 709 } 710 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 711 dev_replace->time_stopped = get_seconds(); 712 dev_replace->item_needs_writeback = 1; 713 btrfs_dev_replace_unlock(dev_replace, 1); 714 btrfs_scrub_cancel(fs_info); 715 716 trans = btrfs_start_transaction(root, 0); 717 if (IS_ERR(trans)) { 718 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 719 return PTR_ERR(trans); 720 } 721 ret = btrfs_commit_transaction(trans, root); 722 WARN_ON(ret); 723 if (tgt_device) 724 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 725 726 leave: 727 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 728 return result; 729 } 730 731 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 732 { 733 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 734 735 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 736 btrfs_dev_replace_lock(dev_replace, 1); 737 switch (dev_replace->replace_state) { 738 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 739 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 740 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 741 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 742 break; 743 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 744 dev_replace->replace_state = 745 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 746 dev_replace->time_stopped = get_seconds(); 747 dev_replace->item_needs_writeback = 1; 748 btrfs_info(fs_info, "suspending dev_replace for unmount"); 749 break; 750 } 751 752 btrfs_dev_replace_unlock(dev_replace, 1); 753 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 754 } 755 756 /* resume dev_replace procedure that was interrupted by unmount */ 757 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 758 { 759 struct task_struct *task; 760 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 761 762 btrfs_dev_replace_lock(dev_replace, 1); 763 switch (dev_replace->replace_state) { 764 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 765 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 766 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 767 btrfs_dev_replace_unlock(dev_replace, 1); 768 return 0; 769 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 770 break; 771 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 772 dev_replace->replace_state = 773 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 774 break; 775 } 776 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 777 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 778 btrfs_info(fs_info, 779 "you may cancel the operation after 'mount -o degraded'"); 780 btrfs_dev_replace_unlock(dev_replace, 1); 781 return 0; 782 } 783 btrfs_dev_replace_unlock(dev_replace, 1); 784 785 WARN_ON(atomic_xchg( 786 &fs_info->mutually_exclusive_operation_running, 1)); 787 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 788 return PTR_ERR_OR_ZERO(task); 789 } 790 791 static int btrfs_dev_replace_kthread(void *data) 792 { 793 struct btrfs_fs_info *fs_info = data; 794 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 795 struct btrfs_ioctl_dev_replace_args *status_args; 796 u64 progress; 797 798 status_args = kzalloc(sizeof(*status_args), GFP_KERNEL); 799 if (status_args) { 800 btrfs_dev_replace_status(fs_info, status_args); 801 progress = status_args->status.progress_1000; 802 kfree(status_args); 803 progress = div_u64(progress, 10); 804 btrfs_info_in_rcu(fs_info, 805 "continuing dev_replace from %s (devid %llu) to %s @%u%%", 806 dev_replace->srcdev->missing ? "<missing disk>" : 807 rcu_str_deref(dev_replace->srcdev->name), 808 dev_replace->srcdev->devid, 809 dev_replace->tgtdev ? 810 rcu_str_deref(dev_replace->tgtdev->name) : 811 "<missing target disk>", 812 (unsigned int)progress); 813 } 814 btrfs_dev_replace_continue_on_mount(fs_info); 815 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 816 817 return 0; 818 } 819 820 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 821 { 822 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 823 int ret; 824 825 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 826 dev_replace->committed_cursor_left, 827 btrfs_device_get_total_bytes(dev_replace->srcdev), 828 &dev_replace->scrub_progress, 0, 1); 829 ret = btrfs_dev_replace_finishing(fs_info, ret); 830 WARN_ON(ret); 831 return 0; 832 } 833 834 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 835 { 836 if (!dev_replace->is_valid) 837 return 0; 838 839 switch (dev_replace->replace_state) { 840 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 841 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 842 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 843 return 0; 844 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 845 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 846 /* 847 * return true even if tgtdev is missing (this is 848 * something that can happen if the dev_replace 849 * procedure is suspended by an umount and then 850 * the tgtdev is missing (or "btrfs dev scan") was 851 * not called and the the filesystem is remounted 852 * in degraded state. This does not stop the 853 * dev_replace procedure. It needs to be canceled 854 * manually if the cancellation is wanted. 855 */ 856 break; 857 } 858 return 1; 859 } 860 861 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw) 862 { 863 if (rw == 1) { 864 /* write */ 865 again: 866 wait_event(dev_replace->read_lock_wq, 867 atomic_read(&dev_replace->blocking_readers) == 0); 868 write_lock(&dev_replace->lock); 869 if (atomic_read(&dev_replace->blocking_readers)) { 870 write_unlock(&dev_replace->lock); 871 goto again; 872 } 873 } else { 874 read_lock(&dev_replace->lock); 875 atomic_inc(&dev_replace->read_locks); 876 } 877 } 878 879 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw) 880 { 881 if (rw == 1) { 882 /* write */ 883 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 884 write_unlock(&dev_replace->lock); 885 } else { 886 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 887 atomic_dec(&dev_replace->read_locks); 888 read_unlock(&dev_replace->lock); 889 } 890 } 891 892 /* inc blocking cnt and release read lock */ 893 void btrfs_dev_replace_set_lock_blocking( 894 struct btrfs_dev_replace *dev_replace) 895 { 896 /* only set blocking for read lock */ 897 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 898 atomic_inc(&dev_replace->blocking_readers); 899 read_unlock(&dev_replace->lock); 900 } 901 902 /* acquire read lock and dec blocking cnt */ 903 void btrfs_dev_replace_clear_lock_blocking( 904 struct btrfs_dev_replace *dev_replace) 905 { 906 /* only set blocking for read lock */ 907 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 908 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 909 read_lock(&dev_replace->lock); 910 if (atomic_dec_and_test(&dev_replace->blocking_readers) && 911 waitqueue_active(&dev_replace->read_lock_wq)) 912 wake_up(&dev_replace->read_lock_wq); 913 } 914 915 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 916 { 917 percpu_counter_inc(&fs_info->bio_counter); 918 } 919 920 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 921 { 922 percpu_counter_sub(&fs_info->bio_counter, amount); 923 924 if (waitqueue_active(&fs_info->replace_wait)) 925 wake_up(&fs_info->replace_wait); 926 } 927 928 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 929 { 930 while (1) { 931 percpu_counter_inc(&fs_info->bio_counter); 932 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 933 &fs_info->fs_state))) 934 break; 935 936 btrfs_bio_counter_dec(fs_info); 937 wait_event(fs_info->replace_wait, 938 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 939 &fs_info->fs_state)); 940 } 941 } 942