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 -EINVAL; 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 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 435 int scrub_ret) 436 { 437 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 438 struct btrfs_device *tgt_device; 439 struct btrfs_device *src_device; 440 struct btrfs_root *root = fs_info->tree_root; 441 u8 uuid_tmp[BTRFS_UUID_SIZE]; 442 struct btrfs_trans_handle *trans; 443 int ret = 0; 444 445 /* don't allow cancel or unmount to disturb the finishing procedure */ 446 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 447 448 btrfs_dev_replace_lock(dev_replace); 449 /* was the operation canceled, or is it finished? */ 450 if (dev_replace->replace_state != 451 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 452 btrfs_dev_replace_unlock(dev_replace); 453 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 454 return 0; 455 } 456 457 tgt_device = dev_replace->tgtdev; 458 src_device = dev_replace->srcdev; 459 btrfs_dev_replace_unlock(dev_replace); 460 461 /* replace old device with new one in mapping tree */ 462 if (!scrub_ret) 463 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 464 src_device, 465 tgt_device); 466 467 /* 468 * flush all outstanding I/O and inode extent mappings before the 469 * copy operation is declared as being finished 470 */ 471 ret = btrfs_start_delalloc_roots(root->fs_info, 0); 472 if (ret) { 473 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 474 return ret; 475 } 476 btrfs_wait_ordered_roots(root->fs_info, -1); 477 478 trans = btrfs_start_transaction(root, 0); 479 if (IS_ERR(trans)) { 480 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 481 return PTR_ERR(trans); 482 } 483 ret = btrfs_commit_transaction(trans, root); 484 WARN_ON(ret); 485 486 /* keep away write_all_supers() during the finishing procedure */ 487 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 488 btrfs_dev_replace_lock(dev_replace); 489 dev_replace->replace_state = 490 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 491 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 492 dev_replace->tgtdev = NULL; 493 dev_replace->srcdev = NULL; 494 dev_replace->time_stopped = get_seconds(); 495 dev_replace->item_needs_writeback = 1; 496 497 if (scrub_ret) { 498 printk_in_rcu(KERN_ERR 499 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 500 src_device->missing ? "<missing disk>" : 501 rcu_str_deref(src_device->name), 502 src_device->devid, 503 rcu_str_deref(tgt_device->name), scrub_ret); 504 btrfs_dev_replace_unlock(dev_replace); 505 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 506 if (tgt_device) 507 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 508 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 509 510 return 0; 511 } 512 513 printk_in_rcu(KERN_INFO 514 "BTRFS: dev_replace from %s (devid %llu) to %s) finished\n", 515 src_device->missing ? "<missing disk>" : 516 rcu_str_deref(src_device->name), 517 src_device->devid, 518 rcu_str_deref(tgt_device->name)); 519 tgt_device->is_tgtdev_for_dev_replace = 0; 520 tgt_device->devid = src_device->devid; 521 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 522 tgt_device->bytes_used = src_device->bytes_used; 523 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 524 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 525 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 526 tgt_device->total_bytes = src_device->total_bytes; 527 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 528 tgt_device->bytes_used = src_device->bytes_used; 529 if (fs_info->sb->s_bdev == src_device->bdev) 530 fs_info->sb->s_bdev = tgt_device->bdev; 531 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 532 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 533 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 534 535 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 536 537 /* 538 * this is again a consistent state where no dev_replace procedure 539 * is running, the target device is part of the filesystem, the 540 * source device is not part of the filesystem anymore and its 1st 541 * superblock is scratched out so that it is no longer marked to 542 * belong to this filesystem. 543 */ 544 btrfs_dev_replace_unlock(dev_replace); 545 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 546 547 /* write back the superblocks */ 548 trans = btrfs_start_transaction(root, 0); 549 if (!IS_ERR(trans)) 550 btrfs_commit_transaction(trans, root); 551 552 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 553 554 return 0; 555 } 556 557 static void btrfs_dev_replace_update_device_in_mapping_tree( 558 struct btrfs_fs_info *fs_info, 559 struct btrfs_device *srcdev, 560 struct btrfs_device *tgtdev) 561 { 562 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 563 struct extent_map *em; 564 struct map_lookup *map; 565 u64 start = 0; 566 int i; 567 568 write_lock(&em_tree->lock); 569 do { 570 em = lookup_extent_mapping(em_tree, start, (u64)-1); 571 if (!em) 572 break; 573 map = (struct map_lookup *)em->bdev; 574 for (i = 0; i < map->num_stripes; i++) 575 if (srcdev == map->stripes[i].dev) 576 map->stripes[i].dev = tgtdev; 577 start = em->start + em->len; 578 free_extent_map(em); 579 } while (start); 580 write_unlock(&em_tree->lock); 581 } 582 583 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 584 char *srcdev_name, 585 struct btrfs_device **device) 586 { 587 int ret; 588 589 if (srcdevid) { 590 ret = 0; 591 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 592 NULL); 593 if (!*device) 594 ret = -ENOENT; 595 } else { 596 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 597 device); 598 } 599 return ret; 600 } 601 602 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 603 struct btrfs_ioctl_dev_replace_args *args) 604 { 605 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 606 607 btrfs_dev_replace_lock(dev_replace); 608 /* even if !dev_replace_is_valid, the values are good enough for 609 * the replace_status ioctl */ 610 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 611 args->status.replace_state = dev_replace->replace_state; 612 args->status.time_started = dev_replace->time_started; 613 args->status.time_stopped = dev_replace->time_stopped; 614 args->status.num_write_errors = 615 atomic64_read(&dev_replace->num_write_errors); 616 args->status.num_uncorrectable_read_errors = 617 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 618 switch (dev_replace->replace_state) { 619 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 620 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 621 args->status.progress_1000 = 0; 622 break; 623 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 624 args->status.progress_1000 = 1000; 625 break; 626 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 627 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 628 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 629 div64_u64(dev_replace->srcdev->total_bytes, 1000)); 630 break; 631 } 632 btrfs_dev_replace_unlock(dev_replace); 633 } 634 635 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 636 struct btrfs_ioctl_dev_replace_args *args) 637 { 638 args->result = __btrfs_dev_replace_cancel(fs_info); 639 return 0; 640 } 641 642 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 643 { 644 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 645 struct btrfs_device *tgt_device = NULL; 646 struct btrfs_trans_handle *trans; 647 struct btrfs_root *root = fs_info->tree_root; 648 u64 result; 649 int ret; 650 651 if (fs_info->sb->s_flags & MS_RDONLY) 652 return -EROFS; 653 654 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 655 btrfs_dev_replace_lock(dev_replace); 656 switch (dev_replace->replace_state) { 657 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 658 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 659 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 660 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 661 btrfs_dev_replace_unlock(dev_replace); 662 goto leave; 663 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 664 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 665 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 666 tgt_device = dev_replace->tgtdev; 667 dev_replace->tgtdev = NULL; 668 dev_replace->srcdev = NULL; 669 break; 670 } 671 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 672 dev_replace->time_stopped = get_seconds(); 673 dev_replace->item_needs_writeback = 1; 674 btrfs_dev_replace_unlock(dev_replace); 675 btrfs_scrub_cancel(fs_info); 676 677 trans = btrfs_start_transaction(root, 0); 678 if (IS_ERR(trans)) { 679 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 680 return PTR_ERR(trans); 681 } 682 ret = btrfs_commit_transaction(trans, root); 683 WARN_ON(ret); 684 if (tgt_device) 685 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 686 687 leave: 688 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 689 return result; 690 } 691 692 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 693 { 694 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 695 696 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 697 btrfs_dev_replace_lock(dev_replace); 698 switch (dev_replace->replace_state) { 699 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 700 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 701 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 702 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 703 break; 704 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 705 dev_replace->replace_state = 706 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 707 dev_replace->time_stopped = get_seconds(); 708 dev_replace->item_needs_writeback = 1; 709 btrfs_info(fs_info, "suspending dev_replace for unmount"); 710 break; 711 } 712 713 btrfs_dev_replace_unlock(dev_replace); 714 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 715 } 716 717 /* resume dev_replace procedure that was interrupted by unmount */ 718 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 719 { 720 struct task_struct *task; 721 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 722 723 btrfs_dev_replace_lock(dev_replace); 724 switch (dev_replace->replace_state) { 725 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 726 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 727 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 728 btrfs_dev_replace_unlock(dev_replace); 729 return 0; 730 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 731 break; 732 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 733 dev_replace->replace_state = 734 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 735 break; 736 } 737 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 738 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 739 btrfs_info(fs_info, 740 "you may cancel the operation after 'mount -o degraded'"); 741 btrfs_dev_replace_unlock(dev_replace); 742 return 0; 743 } 744 btrfs_dev_replace_unlock(dev_replace); 745 746 WARN_ON(atomic_xchg( 747 &fs_info->mutually_exclusive_operation_running, 1)); 748 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 749 return PTR_ERR_OR_ZERO(task); 750 } 751 752 static int btrfs_dev_replace_kthread(void *data) 753 { 754 struct btrfs_fs_info *fs_info = data; 755 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 756 struct btrfs_ioctl_dev_replace_args *status_args; 757 u64 progress; 758 759 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 760 if (status_args) { 761 btrfs_dev_replace_status(fs_info, status_args); 762 progress = status_args->status.progress_1000; 763 kfree(status_args); 764 do_div(progress, 10); 765 printk_in_rcu(KERN_INFO 766 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 767 dev_replace->srcdev->missing ? "<missing disk>" : 768 rcu_str_deref(dev_replace->srcdev->name), 769 dev_replace->srcdev->devid, 770 dev_replace->tgtdev ? 771 rcu_str_deref(dev_replace->tgtdev->name) : 772 "<missing target disk>", 773 (unsigned int)progress); 774 } 775 btrfs_dev_replace_continue_on_mount(fs_info); 776 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 777 778 return 0; 779 } 780 781 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 782 { 783 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 784 int ret; 785 786 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 787 dev_replace->committed_cursor_left, 788 dev_replace->srcdev->total_bytes, 789 &dev_replace->scrub_progress, 0, 1); 790 ret = btrfs_dev_replace_finishing(fs_info, ret); 791 WARN_ON(ret); 792 return 0; 793 } 794 795 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 796 { 797 if (!dev_replace->is_valid) 798 return 0; 799 800 switch (dev_replace->replace_state) { 801 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 802 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 803 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 804 return 0; 805 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 806 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 807 /* 808 * return true even if tgtdev is missing (this is 809 * something that can happen if the dev_replace 810 * procedure is suspended by an umount and then 811 * the tgtdev is missing (or "btrfs dev scan") was 812 * not called and the the filesystem is remounted 813 * in degraded state. This does not stop the 814 * dev_replace procedure. It needs to be canceled 815 * manually if the cancelation is wanted. 816 */ 817 break; 818 } 819 return 1; 820 } 821 822 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 823 { 824 /* the beginning is just an optimization for the typical case */ 825 if (atomic_read(&dev_replace->nesting_level) == 0) { 826 acquire_lock: 827 /* this is not a nested case where the same thread 828 * is trying to acqurire the same lock twice */ 829 mutex_lock(&dev_replace->lock); 830 mutex_lock(&dev_replace->lock_management_lock); 831 dev_replace->lock_owner = current->pid; 832 atomic_inc(&dev_replace->nesting_level); 833 mutex_unlock(&dev_replace->lock_management_lock); 834 return; 835 } 836 837 mutex_lock(&dev_replace->lock_management_lock); 838 if (atomic_read(&dev_replace->nesting_level) > 0 && 839 dev_replace->lock_owner == current->pid) { 840 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 841 atomic_inc(&dev_replace->nesting_level); 842 mutex_unlock(&dev_replace->lock_management_lock); 843 return; 844 } 845 846 mutex_unlock(&dev_replace->lock_management_lock); 847 goto acquire_lock; 848 } 849 850 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 851 { 852 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 853 mutex_lock(&dev_replace->lock_management_lock); 854 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 855 WARN_ON(dev_replace->lock_owner != current->pid); 856 atomic_dec(&dev_replace->nesting_level); 857 if (atomic_read(&dev_replace->nesting_level) == 0) { 858 dev_replace->lock_owner = 0; 859 mutex_unlock(&dev_replace->lock_management_lock); 860 mutex_unlock(&dev_replace->lock); 861 } else { 862 mutex_unlock(&dev_replace->lock_management_lock); 863 } 864 } 865