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 40 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 41 int scrub_ret); 42 static void btrfs_dev_replace_update_device_in_mapping_tree( 43 struct btrfs_fs_info *fs_info, 44 struct btrfs_device *srcdev, 45 struct btrfs_device *tgtdev); 46 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 47 char *srcdev_name, 48 struct btrfs_device **device); 49 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 50 static int btrfs_dev_replace_kthread(void *data); 51 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 52 53 54 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 55 { 56 struct btrfs_key key; 57 struct btrfs_root *dev_root = fs_info->dev_root; 58 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 59 struct extent_buffer *eb; 60 int slot; 61 int ret = 0; 62 struct btrfs_path *path = NULL; 63 int item_size; 64 struct btrfs_dev_replace_item *ptr; 65 u64 src_devid; 66 67 path = btrfs_alloc_path(); 68 if (!path) { 69 ret = -ENOMEM; 70 goto out; 71 } 72 73 key.objectid = 0; 74 key.type = BTRFS_DEV_REPLACE_KEY; 75 key.offset = 0; 76 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 77 if (ret) { 78 no_valid_dev_replace_entry_found: 79 ret = 0; 80 dev_replace->replace_state = 81 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 82 dev_replace->cont_reading_from_srcdev_mode = 83 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 84 dev_replace->replace_state = 0; 85 dev_replace->time_started = 0; 86 dev_replace->time_stopped = 0; 87 atomic64_set(&dev_replace->num_write_errors, 0); 88 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 89 dev_replace->cursor_left = 0; 90 dev_replace->committed_cursor_left = 0; 91 dev_replace->cursor_left_last_write_of_item = 0; 92 dev_replace->cursor_right = 0; 93 dev_replace->srcdev = NULL; 94 dev_replace->tgtdev = NULL; 95 dev_replace->is_valid = 0; 96 dev_replace->item_needs_writeback = 0; 97 goto out; 98 } 99 slot = path->slots[0]; 100 eb = path->nodes[0]; 101 item_size = btrfs_item_size_nr(eb, slot); 102 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 103 104 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 105 btrfs_warn(fs_info, 106 "dev_replace entry found has unexpected size, ignore entry"); 107 goto no_valid_dev_replace_entry_found; 108 } 109 110 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 111 dev_replace->cont_reading_from_srcdev_mode = 112 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 113 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 114 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 115 dev_replace->time_stopped = 116 btrfs_dev_replace_time_stopped(eb, ptr); 117 atomic64_set(&dev_replace->num_write_errors, 118 btrfs_dev_replace_num_write_errors(eb, ptr)); 119 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 120 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 121 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 122 dev_replace->committed_cursor_left = dev_replace->cursor_left; 123 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 124 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 125 dev_replace->is_valid = 1; 126 127 dev_replace->item_needs_writeback = 0; 128 switch (dev_replace->replace_state) { 129 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 130 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 131 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 132 dev_replace->srcdev = NULL; 133 dev_replace->tgtdev = NULL; 134 break; 135 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 136 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 137 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 138 NULL, NULL); 139 dev_replace->tgtdev = btrfs_find_device(fs_info, 140 BTRFS_DEV_REPLACE_DEVID, 141 NULL, NULL); 142 /* 143 * allow 'btrfs dev replace_cancel' if src/tgt device is 144 * missing 145 */ 146 if (!dev_replace->srcdev && 147 !btrfs_test_opt(dev_root, DEGRADED)) { 148 ret = -EIO; 149 btrfs_warn(fs_info, 150 "cannot mount because device replace operation is ongoing and"); 151 btrfs_warn(fs_info, 152 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 153 src_devid); 154 } 155 if (!dev_replace->tgtdev && 156 !btrfs_test_opt(dev_root, DEGRADED)) { 157 ret = -EIO; 158 btrfs_warn(fs_info, 159 "cannot mount because device replace operation is ongoing and"); 160 btrfs_warn(fs_info, 161 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 162 BTRFS_DEV_REPLACE_DEVID); 163 } 164 if (dev_replace->tgtdev) { 165 if (dev_replace->srcdev) { 166 dev_replace->tgtdev->total_bytes = 167 dev_replace->srcdev->total_bytes; 168 dev_replace->tgtdev->disk_total_bytes = 169 dev_replace->srcdev->disk_total_bytes; 170 dev_replace->tgtdev->bytes_used = 171 dev_replace->srcdev->bytes_used; 172 } 173 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; 174 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 175 dev_replace->tgtdev); 176 } 177 break; 178 } 179 180 out: 181 if (path) 182 btrfs_free_path(path); 183 return ret; 184 } 185 186 /* 187 * called from commit_transaction. Writes changed device replace state to 188 * disk. 189 */ 190 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 191 struct btrfs_fs_info *fs_info) 192 { 193 int ret; 194 struct btrfs_root *dev_root = fs_info->dev_root; 195 struct btrfs_path *path; 196 struct btrfs_key key; 197 struct extent_buffer *eb; 198 struct btrfs_dev_replace_item *ptr; 199 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 200 201 btrfs_dev_replace_lock(dev_replace); 202 if (!dev_replace->is_valid || 203 !dev_replace->item_needs_writeback) { 204 btrfs_dev_replace_unlock(dev_replace); 205 return 0; 206 } 207 btrfs_dev_replace_unlock(dev_replace); 208 209 key.objectid = 0; 210 key.type = BTRFS_DEV_REPLACE_KEY; 211 key.offset = 0; 212 213 path = btrfs_alloc_path(); 214 if (!path) { 215 ret = -ENOMEM; 216 goto out; 217 } 218 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 219 if (ret < 0) { 220 btrfs_warn(fs_info, "error %d while searching for dev_replace item!", 221 ret); 222 goto out; 223 } 224 225 if (ret == 0 && 226 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 227 /* 228 * need to delete old one and insert a new one. 229 * Since no attempt is made to recover any old state, if the 230 * dev_replace state is 'running', the data on the target 231 * drive is lost. 232 * It would be possible to recover the state: just make sure 233 * that the beginning of the item is never changed and always 234 * contains all the essential information. Then read this 235 * minimal set of information and use it as a base for the 236 * new state. 237 */ 238 ret = btrfs_del_item(trans, dev_root, path); 239 if (ret != 0) { 240 btrfs_warn(fs_info, "delete too small dev_replace item failed %d!", 241 ret); 242 goto out; 243 } 244 ret = 1; 245 } 246 247 if (ret == 1) { 248 /* need to insert a new item */ 249 btrfs_release_path(path); 250 ret = btrfs_insert_empty_item(trans, dev_root, path, 251 &key, sizeof(*ptr)); 252 if (ret < 0) { 253 btrfs_warn(fs_info, "insert dev_replace item failed %d!", 254 ret); 255 goto out; 256 } 257 } 258 259 eb = path->nodes[0]; 260 ptr = btrfs_item_ptr(eb, path->slots[0], 261 struct btrfs_dev_replace_item); 262 263 btrfs_dev_replace_lock(dev_replace); 264 if (dev_replace->srcdev) 265 btrfs_set_dev_replace_src_devid(eb, ptr, 266 dev_replace->srcdev->devid); 267 else 268 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 269 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 270 dev_replace->cont_reading_from_srcdev_mode); 271 btrfs_set_dev_replace_replace_state(eb, ptr, 272 dev_replace->replace_state); 273 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 274 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 275 btrfs_set_dev_replace_num_write_errors(eb, ptr, 276 atomic64_read(&dev_replace->num_write_errors)); 277 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 278 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 279 dev_replace->cursor_left_last_write_of_item = 280 dev_replace->cursor_left; 281 btrfs_set_dev_replace_cursor_left(eb, ptr, 282 dev_replace->cursor_left_last_write_of_item); 283 btrfs_set_dev_replace_cursor_right(eb, ptr, 284 dev_replace->cursor_right); 285 dev_replace->item_needs_writeback = 0; 286 btrfs_dev_replace_unlock(dev_replace); 287 288 btrfs_mark_buffer_dirty(eb); 289 290 out: 291 btrfs_free_path(path); 292 293 return ret; 294 } 295 296 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 297 { 298 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 299 300 dev_replace->committed_cursor_left = 301 dev_replace->cursor_left_last_write_of_item; 302 } 303 304 int btrfs_dev_replace_start(struct btrfs_root *root, 305 struct btrfs_ioctl_dev_replace_args *args) 306 { 307 struct btrfs_trans_handle *trans; 308 struct btrfs_fs_info *fs_info = root->fs_info; 309 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 310 int ret; 311 struct btrfs_device *tgt_device = NULL; 312 struct btrfs_device *src_device = NULL; 313 314 if (btrfs_fs_incompat(fs_info, RAID56)) { 315 btrfs_warn(fs_info, "dev_replace cannot yet handle RAID5/RAID6"); 316 return -EOPNOTSUPP; 317 } 318 319 switch (args->start.cont_reading_from_srcdev_mode) { 320 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 321 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 322 break; 323 default: 324 return -EINVAL; 325 } 326 327 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 328 args->start.tgtdev_name[0] == '\0') 329 return -EINVAL; 330 331 mutex_lock(&fs_info->volume_mutex); 332 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 333 &tgt_device); 334 if (ret) { 335 btrfs_err(fs_info, "target device %s is invalid!", 336 args->start.tgtdev_name); 337 mutex_unlock(&fs_info->volume_mutex); 338 return -EINVAL; 339 } 340 341 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 342 args->start.srcdev_name, 343 &src_device); 344 mutex_unlock(&fs_info->volume_mutex); 345 if (ret) { 346 ret = -EINVAL; 347 goto leave_no_lock; 348 } 349 350 if (tgt_device->total_bytes < src_device->total_bytes) { 351 btrfs_err(fs_info, "target device is smaller than source device!"); 352 ret = -EINVAL; 353 goto leave_no_lock; 354 } 355 356 btrfs_dev_replace_lock(dev_replace); 357 switch (dev_replace->replace_state) { 358 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 359 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 360 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 361 break; 362 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 363 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 364 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 365 goto leave; 366 } 367 368 dev_replace->cont_reading_from_srcdev_mode = 369 args->start.cont_reading_from_srcdev_mode; 370 WARN_ON(!src_device); 371 dev_replace->srcdev = src_device; 372 WARN_ON(!tgt_device); 373 dev_replace->tgtdev = tgt_device; 374 375 printk_in_rcu(KERN_INFO 376 "BTRFS: dev_replace from %s (devid %llu) to %s started\n", 377 src_device->missing ? "<missing disk>" : 378 rcu_str_deref(src_device->name), 379 src_device->devid, 380 rcu_str_deref(tgt_device->name)); 381 382 tgt_device->total_bytes = src_device->total_bytes; 383 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 384 tgt_device->bytes_used = src_device->bytes_used; 385 386 /* 387 * from now on, the writes to the srcdev are all duplicated to 388 * go to the tgtdev as well (refer to btrfs_map_block()). 389 */ 390 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 391 dev_replace->time_started = get_seconds(); 392 dev_replace->cursor_left = 0; 393 dev_replace->committed_cursor_left = 0; 394 dev_replace->cursor_left_last_write_of_item = 0; 395 dev_replace->cursor_right = 0; 396 dev_replace->is_valid = 1; 397 dev_replace->item_needs_writeback = 1; 398 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 399 btrfs_dev_replace_unlock(dev_replace); 400 401 btrfs_wait_ordered_roots(root->fs_info, -1); 402 403 /* force writing the updated state information to disk */ 404 trans = btrfs_start_transaction(root, 0); 405 if (IS_ERR(trans)) { 406 ret = PTR_ERR(trans); 407 btrfs_dev_replace_lock(dev_replace); 408 goto leave; 409 } 410 411 ret = btrfs_commit_transaction(trans, root); 412 WARN_ON(ret); 413 414 /* the disk copy procedure reuses the scrub code */ 415 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 416 src_device->total_bytes, 417 &dev_replace->scrub_progress, 0, 1); 418 419 ret = btrfs_dev_replace_finishing(root->fs_info, ret); 420 WARN_ON(ret); 421 422 return 0; 423 424 leave: 425 dev_replace->srcdev = NULL; 426 dev_replace->tgtdev = NULL; 427 btrfs_dev_replace_unlock(dev_replace); 428 leave_no_lock: 429 if (tgt_device) 430 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 431 return ret; 432 } 433 434 /* 435 * blocked until all flighting bios are finished. 436 */ 437 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 438 { 439 s64 writers; 440 DEFINE_WAIT(wait); 441 442 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 443 do { 444 prepare_to_wait(&fs_info->replace_wait, &wait, 445 TASK_UNINTERRUPTIBLE); 446 writers = percpu_counter_sum(&fs_info->bio_counter); 447 if (writers) 448 schedule(); 449 finish_wait(&fs_info->replace_wait, &wait); 450 } while (writers); 451 } 452 453 /* 454 * we have removed target device, it is safe to allow new bios request. 455 */ 456 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 457 { 458 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 459 if (waitqueue_active(&fs_info->replace_wait)) 460 wake_up(&fs_info->replace_wait); 461 } 462 463 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 464 int scrub_ret) 465 { 466 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 467 struct btrfs_device *tgt_device; 468 struct btrfs_device *src_device; 469 struct btrfs_root *root = fs_info->tree_root; 470 u8 uuid_tmp[BTRFS_UUID_SIZE]; 471 struct btrfs_trans_handle *trans; 472 int ret = 0; 473 474 /* don't allow cancel or unmount to disturb the finishing procedure */ 475 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 476 477 btrfs_dev_replace_lock(dev_replace); 478 /* was the operation canceled, or is it finished? */ 479 if (dev_replace->replace_state != 480 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 481 btrfs_dev_replace_unlock(dev_replace); 482 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 483 return 0; 484 } 485 486 tgt_device = dev_replace->tgtdev; 487 src_device = dev_replace->srcdev; 488 btrfs_dev_replace_unlock(dev_replace); 489 490 /* 491 * flush all outstanding I/O and inode extent mappings before the 492 * copy operation is declared as being finished 493 */ 494 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 495 if (ret) { 496 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 497 return ret; 498 } 499 btrfs_wait_ordered_roots(root->fs_info, -1); 500 501 trans = btrfs_start_transaction(root, 0); 502 if (IS_ERR(trans)) { 503 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 504 return PTR_ERR(trans); 505 } 506 ret = btrfs_commit_transaction(trans, root); 507 WARN_ON(ret); 508 509 /* keep away write_all_supers() during the finishing procedure */ 510 mutex_lock(&root->fs_info->chunk_mutex); 511 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 512 btrfs_dev_replace_lock(dev_replace); 513 dev_replace->replace_state = 514 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 515 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 516 dev_replace->tgtdev = NULL; 517 dev_replace->srcdev = NULL; 518 dev_replace->time_stopped = get_seconds(); 519 dev_replace->item_needs_writeback = 1; 520 521 /* replace old device with new one in mapping tree */ 522 if (!scrub_ret) { 523 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 524 src_device, 525 tgt_device); 526 } else { 527 printk_in_rcu(KERN_ERR 528 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 529 src_device->missing ? "<missing disk>" : 530 rcu_str_deref(src_device->name), 531 src_device->devid, 532 rcu_str_deref(tgt_device->name), scrub_ret); 533 btrfs_dev_replace_unlock(dev_replace); 534 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 535 mutex_unlock(&root->fs_info->chunk_mutex); 536 if (tgt_device) 537 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 538 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 539 540 return 0; 541 } 542 543 printk_in_rcu(KERN_INFO 544 "BTRFS: dev_replace from %s (devid %llu) to %s) finished\n", 545 src_device->missing ? "<missing disk>" : 546 rcu_str_deref(src_device->name), 547 src_device->devid, 548 rcu_str_deref(tgt_device->name)); 549 tgt_device->is_tgtdev_for_dev_replace = 0; 550 tgt_device->devid = src_device->devid; 551 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 552 tgt_device->bytes_used = src_device->bytes_used; 553 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 554 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 555 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 556 tgt_device->total_bytes = src_device->total_bytes; 557 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 558 tgt_device->bytes_used = src_device->bytes_used; 559 if (fs_info->sb->s_bdev == src_device->bdev) 560 fs_info->sb->s_bdev = tgt_device->bdev; 561 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 562 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 563 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 564 565 btrfs_rm_dev_replace_blocked(fs_info); 566 567 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 568 569 btrfs_rm_dev_replace_unblocked(fs_info); 570 571 /* 572 * this is again a consistent state where no dev_replace procedure 573 * is running, the target device is part of the filesystem, the 574 * source device is not part of the filesystem anymore and its 1st 575 * superblock is scratched out so that it is no longer marked to 576 * belong to this filesystem. 577 */ 578 btrfs_dev_replace_unlock(dev_replace); 579 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 580 mutex_unlock(&root->fs_info->chunk_mutex); 581 582 /* write back the superblocks */ 583 trans = btrfs_start_transaction(root, 0); 584 if (!IS_ERR(trans)) 585 btrfs_commit_transaction(trans, root); 586 587 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 588 589 return 0; 590 } 591 592 static void btrfs_dev_replace_update_device_in_mapping_tree( 593 struct btrfs_fs_info *fs_info, 594 struct btrfs_device *srcdev, 595 struct btrfs_device *tgtdev) 596 { 597 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 598 struct extent_map *em; 599 struct map_lookup *map; 600 u64 start = 0; 601 int i; 602 603 write_lock(&em_tree->lock); 604 do { 605 em = lookup_extent_mapping(em_tree, start, (u64)-1); 606 if (!em) 607 break; 608 map = (struct map_lookup *)em->bdev; 609 for (i = 0; i < map->num_stripes; i++) 610 if (srcdev == map->stripes[i].dev) 611 map->stripes[i].dev = tgtdev; 612 start = em->start + em->len; 613 free_extent_map(em); 614 } while (start); 615 write_unlock(&em_tree->lock); 616 } 617 618 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 619 char *srcdev_name, 620 struct btrfs_device **device) 621 { 622 int ret; 623 624 if (srcdevid) { 625 ret = 0; 626 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 627 NULL); 628 if (!*device) 629 ret = -ENOENT; 630 } else { 631 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 632 device); 633 } 634 return ret; 635 } 636 637 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 638 struct btrfs_ioctl_dev_replace_args *args) 639 { 640 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 641 642 btrfs_dev_replace_lock(dev_replace); 643 /* even if !dev_replace_is_valid, the values are good enough for 644 * the replace_status ioctl */ 645 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 646 args->status.replace_state = dev_replace->replace_state; 647 args->status.time_started = dev_replace->time_started; 648 args->status.time_stopped = dev_replace->time_stopped; 649 args->status.num_write_errors = 650 atomic64_read(&dev_replace->num_write_errors); 651 args->status.num_uncorrectable_read_errors = 652 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 653 switch (dev_replace->replace_state) { 654 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 655 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 656 args->status.progress_1000 = 0; 657 break; 658 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 659 args->status.progress_1000 = 1000; 660 break; 661 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 662 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 663 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 664 div64_u64(dev_replace->srcdev->total_bytes, 1000)); 665 break; 666 } 667 btrfs_dev_replace_unlock(dev_replace); 668 } 669 670 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 671 struct btrfs_ioctl_dev_replace_args *args) 672 { 673 args->result = __btrfs_dev_replace_cancel(fs_info); 674 return 0; 675 } 676 677 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 678 { 679 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 680 struct btrfs_device *tgt_device = NULL; 681 struct btrfs_trans_handle *trans; 682 struct btrfs_root *root = fs_info->tree_root; 683 u64 result; 684 int ret; 685 686 if (fs_info->sb->s_flags & MS_RDONLY) 687 return -EROFS; 688 689 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 690 btrfs_dev_replace_lock(dev_replace); 691 switch (dev_replace->replace_state) { 692 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 693 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 694 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 695 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 696 btrfs_dev_replace_unlock(dev_replace); 697 goto leave; 698 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 699 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 700 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 701 tgt_device = dev_replace->tgtdev; 702 dev_replace->tgtdev = NULL; 703 dev_replace->srcdev = NULL; 704 break; 705 } 706 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 707 dev_replace->time_stopped = get_seconds(); 708 dev_replace->item_needs_writeback = 1; 709 btrfs_dev_replace_unlock(dev_replace); 710 btrfs_scrub_cancel(fs_info); 711 712 trans = btrfs_start_transaction(root, 0); 713 if (IS_ERR(trans)) { 714 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 715 return PTR_ERR(trans); 716 } 717 ret = btrfs_commit_transaction(trans, root); 718 WARN_ON(ret); 719 if (tgt_device) 720 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 721 722 leave: 723 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 724 return result; 725 } 726 727 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 728 { 729 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 730 731 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 732 btrfs_dev_replace_lock(dev_replace); 733 switch (dev_replace->replace_state) { 734 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 735 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 736 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 737 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 738 break; 739 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 740 dev_replace->replace_state = 741 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 742 dev_replace->time_stopped = get_seconds(); 743 dev_replace->item_needs_writeback = 1; 744 btrfs_info(fs_info, "suspending dev_replace for unmount"); 745 break; 746 } 747 748 btrfs_dev_replace_unlock(dev_replace); 749 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 750 } 751 752 /* resume dev_replace procedure that was interrupted by unmount */ 753 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 754 { 755 struct task_struct *task; 756 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 757 758 btrfs_dev_replace_lock(dev_replace); 759 switch (dev_replace->replace_state) { 760 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 761 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 762 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 763 btrfs_dev_replace_unlock(dev_replace); 764 return 0; 765 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 766 break; 767 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 768 dev_replace->replace_state = 769 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 770 break; 771 } 772 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 773 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 774 btrfs_info(fs_info, 775 "you may cancel the operation after 'mount -o degraded'"); 776 btrfs_dev_replace_unlock(dev_replace); 777 return 0; 778 } 779 btrfs_dev_replace_unlock(dev_replace); 780 781 WARN_ON(atomic_xchg( 782 &fs_info->mutually_exclusive_operation_running, 1)); 783 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 784 return PTR_ERR_OR_ZERO(task); 785 } 786 787 static int btrfs_dev_replace_kthread(void *data) 788 { 789 struct btrfs_fs_info *fs_info = data; 790 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 791 struct btrfs_ioctl_dev_replace_args *status_args; 792 u64 progress; 793 794 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 795 if (status_args) { 796 btrfs_dev_replace_status(fs_info, status_args); 797 progress = status_args->status.progress_1000; 798 kfree(status_args); 799 do_div(progress, 10); 800 printk_in_rcu(KERN_INFO 801 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 802 dev_replace->srcdev->missing ? "<missing disk>" : 803 rcu_str_deref(dev_replace->srcdev->name), 804 dev_replace->srcdev->devid, 805 dev_replace->tgtdev ? 806 rcu_str_deref(dev_replace->tgtdev->name) : 807 "<missing target disk>", 808 (unsigned int)progress); 809 } 810 btrfs_dev_replace_continue_on_mount(fs_info); 811 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 812 813 return 0; 814 } 815 816 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 817 { 818 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 819 int ret; 820 821 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 822 dev_replace->committed_cursor_left, 823 dev_replace->srcdev->total_bytes, 824 &dev_replace->scrub_progress, 0, 1); 825 ret = btrfs_dev_replace_finishing(fs_info, ret); 826 WARN_ON(ret); 827 return 0; 828 } 829 830 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 831 { 832 if (!dev_replace->is_valid) 833 return 0; 834 835 switch (dev_replace->replace_state) { 836 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 837 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 838 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 839 return 0; 840 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 841 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 842 /* 843 * return true even if tgtdev is missing (this is 844 * something that can happen if the dev_replace 845 * procedure is suspended by an umount and then 846 * the tgtdev is missing (or "btrfs dev scan") was 847 * not called and the the filesystem is remounted 848 * in degraded state. This does not stop the 849 * dev_replace procedure. It needs to be canceled 850 * manually if the cancelation is wanted. 851 */ 852 break; 853 } 854 return 1; 855 } 856 857 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 858 { 859 /* the beginning is just an optimization for the typical case */ 860 if (atomic_read(&dev_replace->nesting_level) == 0) { 861 acquire_lock: 862 /* this is not a nested case where the same thread 863 * is trying to acqurire the same lock twice */ 864 mutex_lock(&dev_replace->lock); 865 mutex_lock(&dev_replace->lock_management_lock); 866 dev_replace->lock_owner = current->pid; 867 atomic_inc(&dev_replace->nesting_level); 868 mutex_unlock(&dev_replace->lock_management_lock); 869 return; 870 } 871 872 mutex_lock(&dev_replace->lock_management_lock); 873 if (atomic_read(&dev_replace->nesting_level) > 0 && 874 dev_replace->lock_owner == current->pid) { 875 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 876 atomic_inc(&dev_replace->nesting_level); 877 mutex_unlock(&dev_replace->lock_management_lock); 878 return; 879 } 880 881 mutex_unlock(&dev_replace->lock_management_lock); 882 goto acquire_lock; 883 } 884 885 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 886 { 887 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 888 mutex_lock(&dev_replace->lock_management_lock); 889 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 890 WARN_ON(dev_replace->lock_owner != current->pid); 891 atomic_dec(&dev_replace->nesting_level); 892 if (atomic_read(&dev_replace->nesting_level) == 0) { 893 dev_replace->lock_owner = 0; 894 mutex_unlock(&dev_replace->lock_management_lock); 895 mutex_unlock(&dev_replace->lock); 896 } else { 897 mutex_unlock(&dev_replace->lock_management_lock); 898 } 899 } 900 901 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 902 { 903 percpu_counter_inc(&fs_info->bio_counter); 904 } 905 906 void btrfs_bio_counter_dec(struct btrfs_fs_info *fs_info) 907 { 908 percpu_counter_dec(&fs_info->bio_counter); 909 910 if (waitqueue_active(&fs_info->replace_wait)) 911 wake_up(&fs_info->replace_wait); 912 } 913 914 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 915 { 916 DEFINE_WAIT(wait); 917 again: 918 percpu_counter_inc(&fs_info->bio_counter); 919 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) { 920 btrfs_bio_counter_dec(fs_info); 921 wait_event(fs_info->replace_wait, 922 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 923 &fs_info->fs_state)); 924 goto again; 925 } 926 927 } 928