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->bytes_used = 172 dev_replace->srcdev->bytes_used; 173 } 174 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; 175 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 176 dev_replace->tgtdev); 177 } 178 break; 179 } 180 181 out: 182 if (path) 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); 203 if (!dev_replace->is_valid || 204 !dev_replace->item_needs_writeback) { 205 btrfs_dev_replace_unlock(dev_replace); 206 return 0; 207 } 208 btrfs_dev_replace_unlock(dev_replace); 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); 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); 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, 306 struct btrfs_ioctl_dev_replace_args *args) 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 if (btrfs_fs_incompat(fs_info, RAID56)) { 316 btrfs_warn(fs_info, "dev_replace cannot yet handle RAID5/RAID6"); 317 return -EOPNOTSUPP; 318 } 319 320 switch (args->start.cont_reading_from_srcdev_mode) { 321 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 322 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 323 break; 324 default: 325 return -EINVAL; 326 } 327 328 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 329 args->start.tgtdev_name[0] == '\0') 330 return -EINVAL; 331 332 mutex_lock(&fs_info->volume_mutex); 333 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 334 &tgt_device); 335 if (ret) { 336 btrfs_err(fs_info, "target device %s is invalid!", 337 args->start.tgtdev_name); 338 mutex_unlock(&fs_info->volume_mutex); 339 return -EINVAL; 340 } 341 342 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 343 args->start.srcdev_name, 344 &src_device); 345 mutex_unlock(&fs_info->volume_mutex); 346 if (ret) { 347 ret = -EINVAL; 348 goto leave_no_lock; 349 } 350 351 if (tgt_device->total_bytes < src_device->total_bytes) { 352 btrfs_err(fs_info, "target device is smaller than source device!"); 353 ret = -EINVAL; 354 goto leave_no_lock; 355 } 356 357 btrfs_dev_replace_lock(dev_replace); 358 switch (dev_replace->replace_state) { 359 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 360 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 361 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 362 break; 363 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 364 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 365 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 366 goto leave; 367 } 368 369 dev_replace->cont_reading_from_srcdev_mode = 370 args->start.cont_reading_from_srcdev_mode; 371 WARN_ON(!src_device); 372 dev_replace->srcdev = src_device; 373 WARN_ON(!tgt_device); 374 dev_replace->tgtdev = tgt_device; 375 376 printk_in_rcu(KERN_INFO 377 "BTRFS: dev_replace from %s (devid %llu) to %s started\n", 378 src_device->missing ? "<missing disk>" : 379 rcu_str_deref(src_device->name), 380 src_device->devid, 381 rcu_str_deref(tgt_device->name)); 382 383 tgt_device->total_bytes = src_device->total_bytes; 384 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 385 tgt_device->bytes_used = src_device->bytes_used; 386 387 /* 388 * from now on, the writes to the srcdev are all duplicated to 389 * go to the tgtdev as well (refer to btrfs_map_block()). 390 */ 391 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 392 dev_replace->time_started = get_seconds(); 393 dev_replace->cursor_left = 0; 394 dev_replace->committed_cursor_left = 0; 395 dev_replace->cursor_left_last_write_of_item = 0; 396 dev_replace->cursor_right = 0; 397 dev_replace->is_valid = 1; 398 dev_replace->item_needs_writeback = 1; 399 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 400 btrfs_dev_replace_unlock(dev_replace); 401 402 btrfs_wait_ordered_roots(root->fs_info, -1); 403 404 /* force writing the updated state information to disk */ 405 trans = btrfs_start_transaction(root, 0); 406 if (IS_ERR(trans)) { 407 ret = PTR_ERR(trans); 408 btrfs_dev_replace_lock(dev_replace); 409 goto leave; 410 } 411 412 ret = btrfs_commit_transaction(trans, root); 413 WARN_ON(ret); 414 415 /* the disk copy procedure reuses the scrub code */ 416 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 417 src_device->total_bytes, 418 &dev_replace->scrub_progress, 0, 1); 419 420 ret = btrfs_dev_replace_finishing(root->fs_info, ret); 421 WARN_ON(ret); 422 423 return 0; 424 425 leave: 426 dev_replace->srcdev = NULL; 427 dev_replace->tgtdev = NULL; 428 btrfs_dev_replace_unlock(dev_replace); 429 leave_no_lock: 430 if (tgt_device) 431 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 432 return ret; 433 } 434 435 /* 436 * blocked until all flighting bios are finished. 437 */ 438 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 439 { 440 s64 writers; 441 DEFINE_WAIT(wait); 442 443 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 444 do { 445 prepare_to_wait(&fs_info->replace_wait, &wait, 446 TASK_UNINTERRUPTIBLE); 447 writers = percpu_counter_sum(&fs_info->bio_counter); 448 if (writers) 449 schedule(); 450 finish_wait(&fs_info->replace_wait, &wait); 451 } while (writers); 452 } 453 454 /* 455 * we have removed target device, it is safe to allow new bios request. 456 */ 457 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 458 { 459 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 460 if (waitqueue_active(&fs_info->replace_wait)) 461 wake_up(&fs_info->replace_wait); 462 } 463 464 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 465 int scrub_ret) 466 { 467 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 468 struct btrfs_device *tgt_device; 469 struct btrfs_device *src_device; 470 struct btrfs_root *root = fs_info->tree_root; 471 u8 uuid_tmp[BTRFS_UUID_SIZE]; 472 struct btrfs_trans_handle *trans; 473 int ret = 0; 474 475 /* don't allow cancel or unmount to disturb the finishing procedure */ 476 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 477 478 btrfs_dev_replace_lock(dev_replace); 479 /* was the operation canceled, or is it finished? */ 480 if (dev_replace->replace_state != 481 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 482 btrfs_dev_replace_unlock(dev_replace); 483 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 484 return 0; 485 } 486 487 tgt_device = dev_replace->tgtdev; 488 src_device = dev_replace->srcdev; 489 btrfs_dev_replace_unlock(dev_replace); 490 491 /* 492 * flush all outstanding I/O and inode extent mappings before the 493 * copy operation is declared as being finished 494 */ 495 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 496 if (ret) { 497 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 498 return ret; 499 } 500 btrfs_wait_ordered_roots(root->fs_info, -1); 501 502 trans = btrfs_start_transaction(root, 0); 503 if (IS_ERR(trans)) { 504 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 505 return PTR_ERR(trans); 506 } 507 ret = btrfs_commit_transaction(trans, root); 508 WARN_ON(ret); 509 510 /* keep away write_all_supers() during the finishing procedure */ 511 mutex_lock(&root->fs_info->chunk_mutex); 512 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 513 btrfs_dev_replace_lock(dev_replace); 514 dev_replace->replace_state = 515 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 516 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 517 dev_replace->tgtdev = NULL; 518 dev_replace->srcdev = NULL; 519 dev_replace->time_stopped = get_seconds(); 520 dev_replace->item_needs_writeback = 1; 521 522 /* replace old device with new one in mapping tree */ 523 if (!scrub_ret) { 524 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 525 src_device, 526 tgt_device); 527 } else { 528 printk_in_rcu(KERN_ERR 529 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 530 src_device->missing ? "<missing disk>" : 531 rcu_str_deref(src_device->name), 532 src_device->devid, 533 rcu_str_deref(tgt_device->name), scrub_ret); 534 btrfs_dev_replace_unlock(dev_replace); 535 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 536 mutex_unlock(&root->fs_info->chunk_mutex); 537 if (tgt_device) 538 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 539 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 540 541 return 0; 542 } 543 544 printk_in_rcu(KERN_INFO 545 "BTRFS: dev_replace from %s (devid %llu) to %s finished\n", 546 src_device->missing ? "<missing disk>" : 547 rcu_str_deref(src_device->name), 548 src_device->devid, 549 rcu_str_deref(tgt_device->name)); 550 tgt_device->is_tgtdev_for_dev_replace = 0; 551 tgt_device->devid = src_device->devid; 552 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 553 tgt_device->bytes_used = src_device->bytes_used; 554 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 555 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 556 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 557 tgt_device->total_bytes = src_device->total_bytes; 558 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 559 tgt_device->bytes_used = src_device->bytes_used; 560 if (fs_info->sb->s_bdev == src_device->bdev) 561 fs_info->sb->s_bdev = tgt_device->bdev; 562 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 563 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 564 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 565 if (src_device->fs_devices->seeding) 566 fs_info->fs_devices->rw_devices++; 567 568 /* replace the sysfs entry */ 569 btrfs_kobj_rm_device(fs_info, src_device); 570 btrfs_kobj_add_device(fs_info, tgt_device); 571 572 btrfs_dev_replace_unlock(dev_replace); 573 574 btrfs_rm_dev_replace_blocked(fs_info); 575 576 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 577 578 btrfs_rm_dev_replace_unblocked(fs_info); 579 580 /* 581 * this is again a consistent state where no dev_replace procedure 582 * is running, the target device is part of the filesystem, the 583 * source device is not part of the filesystem anymore and its 1st 584 * superblock is scratched out so that it is no longer marked to 585 * belong to this filesystem. 586 */ 587 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 588 mutex_unlock(&root->fs_info->chunk_mutex); 589 590 /* write back the superblocks */ 591 trans = btrfs_start_transaction(root, 0); 592 if (!IS_ERR(trans)) 593 btrfs_commit_transaction(trans, root); 594 595 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 596 597 return 0; 598 } 599 600 static void btrfs_dev_replace_update_device_in_mapping_tree( 601 struct btrfs_fs_info *fs_info, 602 struct btrfs_device *srcdev, 603 struct btrfs_device *tgtdev) 604 { 605 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 606 struct extent_map *em; 607 struct map_lookup *map; 608 u64 start = 0; 609 int i; 610 611 write_lock(&em_tree->lock); 612 do { 613 em = lookup_extent_mapping(em_tree, start, (u64)-1); 614 if (!em) 615 break; 616 map = (struct map_lookup *)em->bdev; 617 for (i = 0; i < map->num_stripes; i++) 618 if (srcdev == map->stripes[i].dev) 619 map->stripes[i].dev = tgtdev; 620 start = em->start + em->len; 621 free_extent_map(em); 622 } while (start); 623 write_unlock(&em_tree->lock); 624 } 625 626 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 627 char *srcdev_name, 628 struct btrfs_device **device) 629 { 630 int ret; 631 632 if (srcdevid) { 633 ret = 0; 634 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 635 NULL); 636 if (!*device) 637 ret = -ENOENT; 638 } else { 639 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 640 device); 641 } 642 return ret; 643 } 644 645 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 646 struct btrfs_ioctl_dev_replace_args *args) 647 { 648 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 649 650 btrfs_dev_replace_lock(dev_replace); 651 /* even if !dev_replace_is_valid, the values are good enough for 652 * the replace_status ioctl */ 653 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 654 args->status.replace_state = dev_replace->replace_state; 655 args->status.time_started = dev_replace->time_started; 656 args->status.time_stopped = dev_replace->time_stopped; 657 args->status.num_write_errors = 658 atomic64_read(&dev_replace->num_write_errors); 659 args->status.num_uncorrectable_read_errors = 660 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 661 switch (dev_replace->replace_state) { 662 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 663 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 664 args->status.progress_1000 = 0; 665 break; 666 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 667 args->status.progress_1000 = 1000; 668 break; 669 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 670 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 671 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 672 div64_u64(dev_replace->srcdev->total_bytes, 1000)); 673 break; 674 } 675 btrfs_dev_replace_unlock(dev_replace); 676 } 677 678 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 679 struct btrfs_ioctl_dev_replace_args *args) 680 { 681 args->result = __btrfs_dev_replace_cancel(fs_info); 682 return 0; 683 } 684 685 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 686 { 687 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 688 struct btrfs_device *tgt_device = NULL; 689 struct btrfs_trans_handle *trans; 690 struct btrfs_root *root = fs_info->tree_root; 691 u64 result; 692 int ret; 693 694 if (fs_info->sb->s_flags & MS_RDONLY) 695 return -EROFS; 696 697 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 698 btrfs_dev_replace_lock(dev_replace); 699 switch (dev_replace->replace_state) { 700 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 701 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 702 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 703 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 704 btrfs_dev_replace_unlock(dev_replace); 705 goto leave; 706 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 707 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 708 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 709 tgt_device = dev_replace->tgtdev; 710 dev_replace->tgtdev = NULL; 711 dev_replace->srcdev = NULL; 712 break; 713 } 714 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 715 dev_replace->time_stopped = get_seconds(); 716 dev_replace->item_needs_writeback = 1; 717 btrfs_dev_replace_unlock(dev_replace); 718 btrfs_scrub_cancel(fs_info); 719 720 trans = btrfs_start_transaction(root, 0); 721 if (IS_ERR(trans)) { 722 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 723 return PTR_ERR(trans); 724 } 725 ret = btrfs_commit_transaction(trans, root); 726 WARN_ON(ret); 727 if (tgt_device) 728 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 729 730 leave: 731 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 732 return result; 733 } 734 735 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 736 { 737 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 738 739 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 740 btrfs_dev_replace_lock(dev_replace); 741 switch (dev_replace->replace_state) { 742 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 743 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 744 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 745 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 746 break; 747 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 748 dev_replace->replace_state = 749 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 750 dev_replace->time_stopped = get_seconds(); 751 dev_replace->item_needs_writeback = 1; 752 btrfs_info(fs_info, "suspending dev_replace for unmount"); 753 break; 754 } 755 756 btrfs_dev_replace_unlock(dev_replace); 757 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 758 } 759 760 /* resume dev_replace procedure that was interrupted by unmount */ 761 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 762 { 763 struct task_struct *task; 764 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 765 766 btrfs_dev_replace_lock(dev_replace); 767 switch (dev_replace->replace_state) { 768 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 769 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 770 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 771 btrfs_dev_replace_unlock(dev_replace); 772 return 0; 773 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 774 break; 775 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 776 dev_replace->replace_state = 777 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 778 break; 779 } 780 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 781 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 782 btrfs_info(fs_info, 783 "you may cancel the operation after 'mount -o degraded'"); 784 btrfs_dev_replace_unlock(dev_replace); 785 return 0; 786 } 787 btrfs_dev_replace_unlock(dev_replace); 788 789 WARN_ON(atomic_xchg( 790 &fs_info->mutually_exclusive_operation_running, 1)); 791 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 792 return PTR_ERR_OR_ZERO(task); 793 } 794 795 static int btrfs_dev_replace_kthread(void *data) 796 { 797 struct btrfs_fs_info *fs_info = data; 798 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 799 struct btrfs_ioctl_dev_replace_args *status_args; 800 u64 progress; 801 802 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 803 if (status_args) { 804 btrfs_dev_replace_status(fs_info, status_args); 805 progress = status_args->status.progress_1000; 806 kfree(status_args); 807 do_div(progress, 10); 808 printk_in_rcu(KERN_INFO 809 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 810 dev_replace->srcdev->missing ? "<missing disk>" : 811 rcu_str_deref(dev_replace->srcdev->name), 812 dev_replace->srcdev->devid, 813 dev_replace->tgtdev ? 814 rcu_str_deref(dev_replace->tgtdev->name) : 815 "<missing target disk>", 816 (unsigned int)progress); 817 } 818 btrfs_dev_replace_continue_on_mount(fs_info); 819 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 820 821 return 0; 822 } 823 824 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 825 { 826 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 827 int ret; 828 829 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 830 dev_replace->committed_cursor_left, 831 dev_replace->srcdev->total_bytes, 832 &dev_replace->scrub_progress, 0, 1); 833 ret = btrfs_dev_replace_finishing(fs_info, ret); 834 WARN_ON(ret); 835 return 0; 836 } 837 838 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 839 { 840 if (!dev_replace->is_valid) 841 return 0; 842 843 switch (dev_replace->replace_state) { 844 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 845 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 846 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 847 return 0; 848 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 849 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 850 /* 851 * return true even if tgtdev is missing (this is 852 * something that can happen if the dev_replace 853 * procedure is suspended by an umount and then 854 * the tgtdev is missing (or "btrfs dev scan") was 855 * not called and the the filesystem is remounted 856 * in degraded state. This does not stop the 857 * dev_replace procedure. It needs to be canceled 858 * manually if the cancelation is wanted. 859 */ 860 break; 861 } 862 return 1; 863 } 864 865 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 866 { 867 /* the beginning is just an optimization for the typical case */ 868 if (atomic_read(&dev_replace->nesting_level) == 0) { 869 acquire_lock: 870 /* this is not a nested case where the same thread 871 * is trying to acqurire the same lock twice */ 872 mutex_lock(&dev_replace->lock); 873 mutex_lock(&dev_replace->lock_management_lock); 874 dev_replace->lock_owner = current->pid; 875 atomic_inc(&dev_replace->nesting_level); 876 mutex_unlock(&dev_replace->lock_management_lock); 877 return; 878 } 879 880 mutex_lock(&dev_replace->lock_management_lock); 881 if (atomic_read(&dev_replace->nesting_level) > 0 && 882 dev_replace->lock_owner == current->pid) { 883 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 884 atomic_inc(&dev_replace->nesting_level); 885 mutex_unlock(&dev_replace->lock_management_lock); 886 return; 887 } 888 889 mutex_unlock(&dev_replace->lock_management_lock); 890 goto acquire_lock; 891 } 892 893 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 894 { 895 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 896 mutex_lock(&dev_replace->lock_management_lock); 897 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 898 WARN_ON(dev_replace->lock_owner != current->pid); 899 atomic_dec(&dev_replace->nesting_level); 900 if (atomic_read(&dev_replace->nesting_level) == 0) { 901 dev_replace->lock_owner = 0; 902 mutex_unlock(&dev_replace->lock_management_lock); 903 mutex_unlock(&dev_replace->lock); 904 } else { 905 mutex_unlock(&dev_replace->lock_management_lock); 906 } 907 } 908 909 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 910 { 911 percpu_counter_inc(&fs_info->bio_counter); 912 } 913 914 void btrfs_bio_counter_dec(struct btrfs_fs_info *fs_info) 915 { 916 percpu_counter_dec(&fs_info->bio_counter); 917 918 if (waitqueue_active(&fs_info->replace_wait)) 919 wake_up(&fs_info->replace_wait); 920 } 921 922 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 923 { 924 DEFINE_WAIT(wait); 925 again: 926 percpu_counter_inc(&fs_info->bio_counter); 927 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) { 928 btrfs_bio_counter_dec(fs_info); 929 wait_event(fs_info->replace_wait, 930 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 931 &fs_info->fs_state)); 932 goto again; 933 } 934 935 } 936