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 int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 48 char *srcdev_name, 49 struct btrfs_device **device); 50 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 51 static int btrfs_dev_replace_kthread(void *data); 52 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 53 54 55 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 56 { 57 struct btrfs_key key; 58 struct btrfs_root *dev_root = fs_info->dev_root; 59 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 60 struct extent_buffer *eb; 61 int slot; 62 int ret = 0; 63 struct btrfs_path *path = NULL; 64 int item_size; 65 struct btrfs_dev_replace_item *ptr; 66 u64 src_devid; 67 68 path = btrfs_alloc_path(); 69 if (!path) { 70 ret = -ENOMEM; 71 goto out; 72 } 73 74 key.objectid = 0; 75 key.type = BTRFS_DEV_REPLACE_KEY; 76 key.offset = 0; 77 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 78 if (ret) { 79 no_valid_dev_replace_entry_found: 80 ret = 0; 81 dev_replace->replace_state = 82 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 83 dev_replace->cont_reading_from_srcdev_mode = 84 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 85 dev_replace->replace_state = 0; 86 dev_replace->time_started = 0; 87 dev_replace->time_stopped = 0; 88 atomic64_set(&dev_replace->num_write_errors, 0); 89 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 90 dev_replace->cursor_left = 0; 91 dev_replace->committed_cursor_left = 0; 92 dev_replace->cursor_left_last_write_of_item = 0; 93 dev_replace->cursor_right = 0; 94 dev_replace->srcdev = NULL; 95 dev_replace->tgtdev = NULL; 96 dev_replace->is_valid = 0; 97 dev_replace->item_needs_writeback = 0; 98 goto out; 99 } 100 slot = path->slots[0]; 101 eb = path->nodes[0]; 102 item_size = btrfs_item_size_nr(eb, slot); 103 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 104 105 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 106 btrfs_warn(fs_info, 107 "dev_replace entry found has unexpected size, ignore entry"); 108 goto no_valid_dev_replace_entry_found; 109 } 110 111 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 112 dev_replace->cont_reading_from_srcdev_mode = 113 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 114 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 115 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 116 dev_replace->time_stopped = 117 btrfs_dev_replace_time_stopped(eb, ptr); 118 atomic64_set(&dev_replace->num_write_errors, 119 btrfs_dev_replace_num_write_errors(eb, ptr)); 120 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 121 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 122 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 123 dev_replace->committed_cursor_left = dev_replace->cursor_left; 124 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 125 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 126 dev_replace->is_valid = 1; 127 128 dev_replace->item_needs_writeback = 0; 129 switch (dev_replace->replace_state) { 130 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 131 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 132 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 133 dev_replace->srcdev = NULL; 134 dev_replace->tgtdev = NULL; 135 break; 136 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 137 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 138 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 139 NULL, NULL); 140 dev_replace->tgtdev = btrfs_find_device(fs_info, 141 BTRFS_DEV_REPLACE_DEVID, 142 NULL, NULL); 143 /* 144 * allow 'btrfs dev replace_cancel' if src/tgt device is 145 * missing 146 */ 147 if (!dev_replace->srcdev && 148 !btrfs_test_opt(dev_root, DEGRADED)) { 149 ret = -EIO; 150 btrfs_warn(fs_info, 151 "cannot mount because device replace operation is ongoing and"); 152 btrfs_warn(fs_info, 153 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 154 src_devid); 155 } 156 if (!dev_replace->tgtdev && 157 !btrfs_test_opt(dev_root, DEGRADED)) { 158 ret = -EIO; 159 btrfs_warn(fs_info, 160 "cannot mount because device replace operation is ongoing and"); 161 btrfs_warn(fs_info, 162 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 163 BTRFS_DEV_REPLACE_DEVID); 164 } 165 if (dev_replace->tgtdev) { 166 if (dev_replace->srcdev) { 167 dev_replace->tgtdev->total_bytes = 168 dev_replace->srcdev->total_bytes; 169 dev_replace->tgtdev->disk_total_bytes = 170 dev_replace->srcdev->disk_total_bytes; 171 dev_replace->tgtdev->commit_total_bytes = 172 dev_replace->srcdev->commit_total_bytes; 173 dev_replace->tgtdev->bytes_used = 174 dev_replace->srcdev->bytes_used; 175 dev_replace->tgtdev->commit_bytes_used = 176 dev_replace->srcdev->commit_bytes_used; 177 } 178 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; 179 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 180 dev_replace->tgtdev); 181 } 182 break; 183 } 184 185 out: 186 if (path) 187 btrfs_free_path(path); 188 return ret; 189 } 190 191 /* 192 * called from commit_transaction. Writes changed device replace state to 193 * disk. 194 */ 195 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 196 struct btrfs_fs_info *fs_info) 197 { 198 int ret; 199 struct btrfs_root *dev_root = fs_info->dev_root; 200 struct btrfs_path *path; 201 struct btrfs_key key; 202 struct extent_buffer *eb; 203 struct btrfs_dev_replace_item *ptr; 204 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 205 206 btrfs_dev_replace_lock(dev_replace); 207 if (!dev_replace->is_valid || 208 !dev_replace->item_needs_writeback) { 209 btrfs_dev_replace_unlock(dev_replace); 210 return 0; 211 } 212 btrfs_dev_replace_unlock(dev_replace); 213 214 key.objectid = 0; 215 key.type = BTRFS_DEV_REPLACE_KEY; 216 key.offset = 0; 217 218 path = btrfs_alloc_path(); 219 if (!path) { 220 ret = -ENOMEM; 221 goto out; 222 } 223 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 224 if (ret < 0) { 225 btrfs_warn(fs_info, "error %d while searching for dev_replace item!", 226 ret); 227 goto out; 228 } 229 230 if (ret == 0 && 231 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 232 /* 233 * need to delete old one and insert a new one. 234 * Since no attempt is made to recover any old state, if the 235 * dev_replace state is 'running', the data on the target 236 * drive is lost. 237 * It would be possible to recover the state: just make sure 238 * that the beginning of the item is never changed and always 239 * contains all the essential information. Then read this 240 * minimal set of information and use it as a base for the 241 * new state. 242 */ 243 ret = btrfs_del_item(trans, dev_root, path); 244 if (ret != 0) { 245 btrfs_warn(fs_info, "delete too small dev_replace item failed %d!", 246 ret); 247 goto out; 248 } 249 ret = 1; 250 } 251 252 if (ret == 1) { 253 /* need to insert a new item */ 254 btrfs_release_path(path); 255 ret = btrfs_insert_empty_item(trans, dev_root, path, 256 &key, sizeof(*ptr)); 257 if (ret < 0) { 258 btrfs_warn(fs_info, "insert dev_replace item failed %d!", 259 ret); 260 goto out; 261 } 262 } 263 264 eb = path->nodes[0]; 265 ptr = btrfs_item_ptr(eb, path->slots[0], 266 struct btrfs_dev_replace_item); 267 268 btrfs_dev_replace_lock(dev_replace); 269 if (dev_replace->srcdev) 270 btrfs_set_dev_replace_src_devid(eb, ptr, 271 dev_replace->srcdev->devid); 272 else 273 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 274 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 275 dev_replace->cont_reading_from_srcdev_mode); 276 btrfs_set_dev_replace_replace_state(eb, ptr, 277 dev_replace->replace_state); 278 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 279 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 280 btrfs_set_dev_replace_num_write_errors(eb, ptr, 281 atomic64_read(&dev_replace->num_write_errors)); 282 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 283 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 284 dev_replace->cursor_left_last_write_of_item = 285 dev_replace->cursor_left; 286 btrfs_set_dev_replace_cursor_left(eb, ptr, 287 dev_replace->cursor_left_last_write_of_item); 288 btrfs_set_dev_replace_cursor_right(eb, ptr, 289 dev_replace->cursor_right); 290 dev_replace->item_needs_writeback = 0; 291 btrfs_dev_replace_unlock(dev_replace); 292 293 btrfs_mark_buffer_dirty(eb); 294 295 out: 296 btrfs_free_path(path); 297 298 return ret; 299 } 300 301 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 302 { 303 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 304 305 dev_replace->committed_cursor_left = 306 dev_replace->cursor_left_last_write_of_item; 307 } 308 309 int btrfs_dev_replace_start(struct btrfs_root *root, 310 struct btrfs_ioctl_dev_replace_args *args) 311 { 312 struct btrfs_trans_handle *trans; 313 struct btrfs_fs_info *fs_info = root->fs_info; 314 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 315 int ret; 316 struct btrfs_device *tgt_device = NULL; 317 struct btrfs_device *src_device = NULL; 318 319 if (btrfs_fs_incompat(fs_info, RAID56)) { 320 btrfs_warn(fs_info, "dev_replace cannot yet handle RAID5/RAID6"); 321 return -EOPNOTSUPP; 322 } 323 324 switch (args->start.cont_reading_from_srcdev_mode) { 325 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 326 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 327 break; 328 default: 329 return -EINVAL; 330 } 331 332 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 333 args->start.tgtdev_name[0] == '\0') 334 return -EINVAL; 335 336 /* 337 * Here we commit the transaction to make sure commit_total_bytes 338 * of all the devices are updated. 339 */ 340 trans = btrfs_attach_transaction(root); 341 if (!IS_ERR(trans)) { 342 ret = btrfs_commit_transaction(trans, root); 343 if (ret) 344 return ret; 345 } else if (PTR_ERR(trans) != -ENOENT) { 346 return PTR_ERR(trans); 347 } 348 349 /* the disk copy procedure reuses the scrub code */ 350 mutex_lock(&fs_info->volume_mutex); 351 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 352 args->start.srcdev_name, 353 &src_device); 354 if (ret) { 355 mutex_unlock(&fs_info->volume_mutex); 356 return ret; 357 } 358 359 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 360 src_device, &tgt_device); 361 mutex_unlock(&fs_info->volume_mutex); 362 if (ret) 363 return ret; 364 365 btrfs_dev_replace_lock(dev_replace); 366 switch (dev_replace->replace_state) { 367 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 368 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 369 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 370 break; 371 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 372 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 373 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 374 goto leave; 375 } 376 377 dev_replace->cont_reading_from_srcdev_mode = 378 args->start.cont_reading_from_srcdev_mode; 379 WARN_ON(!src_device); 380 dev_replace->srcdev = src_device; 381 WARN_ON(!tgt_device); 382 dev_replace->tgtdev = tgt_device; 383 384 printk_in_rcu(KERN_INFO 385 "BTRFS: dev_replace from %s (devid %llu) to %s started\n", 386 src_device->missing ? "<missing disk>" : 387 rcu_str_deref(src_device->name), 388 src_device->devid, 389 rcu_str_deref(tgt_device->name)); 390 391 /* 392 * from now on, the writes to the srcdev are all duplicated to 393 * go to the tgtdev as well (refer to btrfs_map_block()). 394 */ 395 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 396 dev_replace->time_started = get_seconds(); 397 dev_replace->cursor_left = 0; 398 dev_replace->committed_cursor_left = 0; 399 dev_replace->cursor_left_last_write_of_item = 0; 400 dev_replace->cursor_right = 0; 401 dev_replace->is_valid = 1; 402 dev_replace->item_needs_writeback = 1; 403 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 404 btrfs_dev_replace_unlock(dev_replace); 405 406 btrfs_wait_ordered_roots(root->fs_info, -1); 407 408 /* force writing the updated state information to disk */ 409 trans = btrfs_start_transaction(root, 0); 410 if (IS_ERR(trans)) { 411 ret = PTR_ERR(trans); 412 btrfs_dev_replace_lock(dev_replace); 413 goto leave; 414 } 415 416 ret = btrfs_commit_transaction(trans, root); 417 WARN_ON(ret); 418 419 /* the disk copy procedure reuses the scrub code */ 420 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 421 btrfs_device_get_total_bytes(src_device), 422 &dev_replace->scrub_progress, 0, 1); 423 424 ret = btrfs_dev_replace_finishing(root->fs_info, ret); 425 WARN_ON(ret); 426 427 return 0; 428 429 leave: 430 dev_replace->srcdev = NULL; 431 dev_replace->tgtdev = NULL; 432 btrfs_dev_replace_unlock(dev_replace); 433 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 434 return ret; 435 } 436 437 /* 438 * blocked until all flighting bios are finished. 439 */ 440 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 441 { 442 s64 writers; 443 DEFINE_WAIT(wait); 444 445 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 446 do { 447 prepare_to_wait(&fs_info->replace_wait, &wait, 448 TASK_UNINTERRUPTIBLE); 449 writers = percpu_counter_sum(&fs_info->bio_counter); 450 if (writers) 451 schedule(); 452 finish_wait(&fs_info->replace_wait, &wait); 453 } while (writers); 454 } 455 456 /* 457 * we have removed target device, it is safe to allow new bios request. 458 */ 459 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 460 { 461 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 462 if (waitqueue_active(&fs_info->replace_wait)) 463 wake_up(&fs_info->replace_wait); 464 } 465 466 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 467 int scrub_ret) 468 { 469 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 470 struct btrfs_device *tgt_device; 471 struct btrfs_device *src_device; 472 struct btrfs_root *root = fs_info->tree_root; 473 u8 uuid_tmp[BTRFS_UUID_SIZE]; 474 struct btrfs_trans_handle *trans; 475 int ret = 0; 476 477 /* don't allow cancel or unmount to disturb the finishing procedure */ 478 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 479 480 btrfs_dev_replace_lock(dev_replace); 481 /* was the operation canceled, or is it finished? */ 482 if (dev_replace->replace_state != 483 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 484 btrfs_dev_replace_unlock(dev_replace); 485 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 486 return 0; 487 } 488 489 tgt_device = dev_replace->tgtdev; 490 src_device = dev_replace->srcdev; 491 btrfs_dev_replace_unlock(dev_replace); 492 493 /* 494 * flush all outstanding I/O and inode extent mappings before the 495 * copy operation is declared as being finished 496 */ 497 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 498 if (ret) { 499 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 500 return ret; 501 } 502 btrfs_wait_ordered_roots(root->fs_info, -1); 503 504 trans = btrfs_start_transaction(root, 0); 505 if (IS_ERR(trans)) { 506 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 507 return PTR_ERR(trans); 508 } 509 ret = btrfs_commit_transaction(trans, root); 510 WARN_ON(ret); 511 512 /* keep away write_all_supers() during the finishing procedure */ 513 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 514 mutex_lock(&root->fs_info->chunk_mutex); 515 btrfs_dev_replace_lock(dev_replace); 516 dev_replace->replace_state = 517 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 518 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 519 dev_replace->tgtdev = NULL; 520 dev_replace->srcdev = NULL; 521 dev_replace->time_stopped = get_seconds(); 522 dev_replace->item_needs_writeback = 1; 523 524 /* replace old device with new one in mapping tree */ 525 if (!scrub_ret) { 526 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 527 src_device, 528 tgt_device); 529 } else { 530 printk_in_rcu(KERN_ERR 531 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 532 src_device->missing ? "<missing disk>" : 533 rcu_str_deref(src_device->name), 534 src_device->devid, 535 rcu_str_deref(tgt_device->name), scrub_ret); 536 btrfs_dev_replace_unlock(dev_replace); 537 mutex_unlock(&root->fs_info->chunk_mutex); 538 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 539 if (tgt_device) 540 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 541 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 542 543 return 0; 544 } 545 546 printk_in_rcu(KERN_INFO 547 "BTRFS: dev_replace from %s (devid %llu) to %s finished\n", 548 src_device->missing ? "<missing disk>" : 549 rcu_str_deref(src_device->name), 550 src_device->devid, 551 rcu_str_deref(tgt_device->name)); 552 tgt_device->is_tgtdev_for_dev_replace = 0; 553 tgt_device->devid = src_device->devid; 554 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 555 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 556 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 557 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 558 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 559 btrfs_device_set_disk_total_bytes(tgt_device, 560 src_device->disk_total_bytes); 561 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 562 ASSERT(list_empty(&src_device->resized_list)); 563 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 564 tgt_device->commit_bytes_used = src_device->bytes_used; 565 if (fs_info->sb->s_bdev == src_device->bdev) 566 fs_info->sb->s_bdev = tgt_device->bdev; 567 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 568 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 569 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 570 if (src_device->fs_devices->seeding) 571 fs_info->fs_devices->rw_devices++; 572 573 /* replace the sysfs entry */ 574 btrfs_kobj_rm_device(fs_info, src_device); 575 btrfs_kobj_add_device(fs_info, tgt_device); 576 577 btrfs_dev_replace_unlock(dev_replace); 578 579 btrfs_rm_dev_replace_blocked(fs_info); 580 581 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 582 583 btrfs_rm_dev_replace_unblocked(fs_info); 584 585 /* 586 * this is again a consistent state where no dev_replace procedure 587 * is running, the target device is part of the filesystem, the 588 * source device is not part of the filesystem anymore and its 1st 589 * superblock is scratched out so that it is no longer marked to 590 * belong to this filesystem. 591 */ 592 mutex_unlock(&root->fs_info->chunk_mutex); 593 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 594 595 /* write back the superblocks */ 596 trans = btrfs_start_transaction(root, 0); 597 if (!IS_ERR(trans)) 598 btrfs_commit_transaction(trans, root); 599 600 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 601 602 return 0; 603 } 604 605 static void btrfs_dev_replace_update_device_in_mapping_tree( 606 struct btrfs_fs_info *fs_info, 607 struct btrfs_device *srcdev, 608 struct btrfs_device *tgtdev) 609 { 610 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 611 struct extent_map *em; 612 struct map_lookup *map; 613 u64 start = 0; 614 int i; 615 616 write_lock(&em_tree->lock); 617 do { 618 em = lookup_extent_mapping(em_tree, start, (u64)-1); 619 if (!em) 620 break; 621 map = (struct map_lookup *)em->bdev; 622 for (i = 0; i < map->num_stripes; i++) 623 if (srcdev == map->stripes[i].dev) 624 map->stripes[i].dev = tgtdev; 625 start = em->start + em->len; 626 free_extent_map(em); 627 } while (start); 628 write_unlock(&em_tree->lock); 629 } 630 631 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 632 char *srcdev_name, 633 struct btrfs_device **device) 634 { 635 int ret; 636 637 if (srcdevid) { 638 ret = 0; 639 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 640 NULL); 641 if (!*device) 642 ret = -ENOENT; 643 } else { 644 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 645 device); 646 } 647 return ret; 648 } 649 650 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 651 struct btrfs_ioctl_dev_replace_args *args) 652 { 653 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 654 struct btrfs_device *srcdev; 655 656 btrfs_dev_replace_lock(dev_replace); 657 /* even if !dev_replace_is_valid, the values are good enough for 658 * the replace_status ioctl */ 659 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 660 args->status.replace_state = dev_replace->replace_state; 661 args->status.time_started = dev_replace->time_started; 662 args->status.time_stopped = dev_replace->time_stopped; 663 args->status.num_write_errors = 664 atomic64_read(&dev_replace->num_write_errors); 665 args->status.num_uncorrectable_read_errors = 666 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 667 switch (dev_replace->replace_state) { 668 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 669 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 670 args->status.progress_1000 = 0; 671 break; 672 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 673 args->status.progress_1000 = 1000; 674 break; 675 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 676 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 677 srcdev = dev_replace->srcdev; 678 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 679 div64_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 680 break; 681 } 682 btrfs_dev_replace_unlock(dev_replace); 683 } 684 685 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 686 struct btrfs_ioctl_dev_replace_args *args) 687 { 688 args->result = __btrfs_dev_replace_cancel(fs_info); 689 return 0; 690 } 691 692 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 693 { 694 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 695 struct btrfs_device *tgt_device = NULL; 696 struct btrfs_trans_handle *trans; 697 struct btrfs_root *root = fs_info->tree_root; 698 u64 result; 699 int ret; 700 701 if (fs_info->sb->s_flags & MS_RDONLY) 702 return -EROFS; 703 704 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 705 btrfs_dev_replace_lock(dev_replace); 706 switch (dev_replace->replace_state) { 707 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 708 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 709 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 710 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 711 btrfs_dev_replace_unlock(dev_replace); 712 goto leave; 713 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 714 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 715 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 716 tgt_device = dev_replace->tgtdev; 717 dev_replace->tgtdev = NULL; 718 dev_replace->srcdev = NULL; 719 break; 720 } 721 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 722 dev_replace->time_stopped = get_seconds(); 723 dev_replace->item_needs_writeback = 1; 724 btrfs_dev_replace_unlock(dev_replace); 725 btrfs_scrub_cancel(fs_info); 726 727 trans = btrfs_start_transaction(root, 0); 728 if (IS_ERR(trans)) { 729 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 730 return PTR_ERR(trans); 731 } 732 ret = btrfs_commit_transaction(trans, root); 733 WARN_ON(ret); 734 if (tgt_device) 735 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 736 737 leave: 738 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 739 return result; 740 } 741 742 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 743 { 744 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 745 746 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 747 btrfs_dev_replace_lock(dev_replace); 748 switch (dev_replace->replace_state) { 749 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 750 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 751 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 752 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 753 break; 754 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 755 dev_replace->replace_state = 756 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 757 dev_replace->time_stopped = get_seconds(); 758 dev_replace->item_needs_writeback = 1; 759 btrfs_info(fs_info, "suspending dev_replace for unmount"); 760 break; 761 } 762 763 btrfs_dev_replace_unlock(dev_replace); 764 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 765 } 766 767 /* resume dev_replace procedure that was interrupted by unmount */ 768 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 769 { 770 struct task_struct *task; 771 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 772 773 btrfs_dev_replace_lock(dev_replace); 774 switch (dev_replace->replace_state) { 775 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 776 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 777 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 778 btrfs_dev_replace_unlock(dev_replace); 779 return 0; 780 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 781 break; 782 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 783 dev_replace->replace_state = 784 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 785 break; 786 } 787 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 788 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 789 btrfs_info(fs_info, 790 "you may cancel the operation after 'mount -o degraded'"); 791 btrfs_dev_replace_unlock(dev_replace); 792 return 0; 793 } 794 btrfs_dev_replace_unlock(dev_replace); 795 796 WARN_ON(atomic_xchg( 797 &fs_info->mutually_exclusive_operation_running, 1)); 798 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 799 return PTR_ERR_OR_ZERO(task); 800 } 801 802 static int btrfs_dev_replace_kthread(void *data) 803 { 804 struct btrfs_fs_info *fs_info = data; 805 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 806 struct btrfs_ioctl_dev_replace_args *status_args; 807 u64 progress; 808 809 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 810 if (status_args) { 811 btrfs_dev_replace_status(fs_info, status_args); 812 progress = status_args->status.progress_1000; 813 kfree(status_args); 814 do_div(progress, 10); 815 printk_in_rcu(KERN_INFO 816 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 817 dev_replace->srcdev->missing ? "<missing disk>" : 818 rcu_str_deref(dev_replace->srcdev->name), 819 dev_replace->srcdev->devid, 820 dev_replace->tgtdev ? 821 rcu_str_deref(dev_replace->tgtdev->name) : 822 "<missing target disk>", 823 (unsigned int)progress); 824 } 825 btrfs_dev_replace_continue_on_mount(fs_info); 826 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 827 828 return 0; 829 } 830 831 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 832 { 833 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 834 int ret; 835 836 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 837 dev_replace->committed_cursor_left, 838 btrfs_device_get_total_bytes(dev_replace->srcdev), 839 &dev_replace->scrub_progress, 0, 1); 840 ret = btrfs_dev_replace_finishing(fs_info, ret); 841 WARN_ON(ret); 842 return 0; 843 } 844 845 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 846 { 847 if (!dev_replace->is_valid) 848 return 0; 849 850 switch (dev_replace->replace_state) { 851 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 852 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 853 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 854 return 0; 855 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 856 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 857 /* 858 * return true even if tgtdev is missing (this is 859 * something that can happen if the dev_replace 860 * procedure is suspended by an umount and then 861 * the tgtdev is missing (or "btrfs dev scan") was 862 * not called and the the filesystem is remounted 863 * in degraded state. This does not stop the 864 * dev_replace procedure. It needs to be canceled 865 * manually if the cancelation is wanted. 866 */ 867 break; 868 } 869 return 1; 870 } 871 872 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 873 { 874 /* the beginning is just an optimization for the typical case */ 875 if (atomic_read(&dev_replace->nesting_level) == 0) { 876 acquire_lock: 877 /* this is not a nested case where the same thread 878 * is trying to acqurire the same lock twice */ 879 mutex_lock(&dev_replace->lock); 880 mutex_lock(&dev_replace->lock_management_lock); 881 dev_replace->lock_owner = current->pid; 882 atomic_inc(&dev_replace->nesting_level); 883 mutex_unlock(&dev_replace->lock_management_lock); 884 return; 885 } 886 887 mutex_lock(&dev_replace->lock_management_lock); 888 if (atomic_read(&dev_replace->nesting_level) > 0 && 889 dev_replace->lock_owner == current->pid) { 890 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 891 atomic_inc(&dev_replace->nesting_level); 892 mutex_unlock(&dev_replace->lock_management_lock); 893 return; 894 } 895 896 mutex_unlock(&dev_replace->lock_management_lock); 897 goto acquire_lock; 898 } 899 900 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 901 { 902 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 903 mutex_lock(&dev_replace->lock_management_lock); 904 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 905 WARN_ON(dev_replace->lock_owner != current->pid); 906 atomic_dec(&dev_replace->nesting_level); 907 if (atomic_read(&dev_replace->nesting_level) == 0) { 908 dev_replace->lock_owner = 0; 909 mutex_unlock(&dev_replace->lock_management_lock); 910 mutex_unlock(&dev_replace->lock); 911 } else { 912 mutex_unlock(&dev_replace->lock_management_lock); 913 } 914 } 915 916 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 917 { 918 percpu_counter_inc(&fs_info->bio_counter); 919 } 920 921 void btrfs_bio_counter_dec(struct btrfs_fs_info *fs_info) 922 { 923 percpu_counter_dec(&fs_info->bio_counter); 924 925 if (waitqueue_active(&fs_info->replace_wait)) 926 wake_up(&fs_info->replace_wait); 927 } 928 929 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 930 { 931 DEFINE_WAIT(wait); 932 again: 933 percpu_counter_inc(&fs_info->bio_counter); 934 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) { 935 btrfs_bio_counter_dec(fs_info); 936 wait_event(fs_info->replace_wait, 937 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 938 &fs_info->fs_state)); 939 goto again; 940 } 941 942 } 943