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 "compat.h" 30 #include "ctree.h" 31 #include "extent_map.h" 32 #include "disk-io.h" 33 #include "transaction.h" 34 #include "print-tree.h" 35 #include "volumes.h" 36 #include "async-thread.h" 37 #include "check-integrity.h" 38 #include "rcu-string.h" 39 #include "dev-replace.h" 40 41 static u64 btrfs_get_seconds_since_1970(void); 42 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 43 int scrub_ret); 44 static void btrfs_dev_replace_update_device_in_mapping_tree( 45 struct btrfs_fs_info *fs_info, 46 struct btrfs_device *srcdev, 47 struct btrfs_device *tgtdev); 48 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 49 char *srcdev_name, 50 struct btrfs_device **device); 51 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 52 static int btrfs_dev_replace_kthread(void *data); 53 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 54 55 56 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 57 { 58 struct btrfs_key key; 59 struct btrfs_root *dev_root = fs_info->dev_root; 60 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 61 struct extent_buffer *eb; 62 int slot; 63 int ret = 0; 64 struct btrfs_path *path = NULL; 65 int item_size; 66 struct btrfs_dev_replace_item *ptr; 67 u64 src_devid; 68 69 path = btrfs_alloc_path(); 70 if (!path) { 71 ret = -ENOMEM; 72 goto out; 73 } 74 75 key.objectid = 0; 76 key.type = BTRFS_DEV_REPLACE_KEY; 77 key.offset = 0; 78 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 79 if (ret) { 80 no_valid_dev_replace_entry_found: 81 ret = 0; 82 dev_replace->replace_state = 83 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 84 dev_replace->cont_reading_from_srcdev_mode = 85 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 86 dev_replace->replace_state = 0; 87 dev_replace->time_started = 0; 88 dev_replace->time_stopped = 0; 89 atomic64_set(&dev_replace->num_write_errors, 0); 90 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 91 dev_replace->cursor_left = 0; 92 dev_replace->committed_cursor_left = 0; 93 dev_replace->cursor_left_last_write_of_item = 0; 94 dev_replace->cursor_right = 0; 95 dev_replace->srcdev = NULL; 96 dev_replace->tgtdev = NULL; 97 dev_replace->is_valid = 0; 98 dev_replace->item_needs_writeback = 0; 99 goto out; 100 } 101 slot = path->slots[0]; 102 eb = path->nodes[0]; 103 item_size = btrfs_item_size_nr(eb, slot); 104 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 105 106 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 107 pr_warn("btrfs: dev_replace entry found has unexpected size, ignore entry\n"); 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 pr_warn("btrfs: cannot mount because device replace operation is ongoing and\n" "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?\n", 151 (unsigned long long)src_devid); 152 } 153 if (!dev_replace->tgtdev && 154 !btrfs_test_opt(dev_root, DEGRADED)) { 155 ret = -EIO; 156 pr_warn("btrfs: cannot mount because device replace operation is ongoing and\n" "tgtdev (devid %llu) is missing, need to run btrfs dev scan?\n", 157 (unsigned long long)BTRFS_DEV_REPLACE_DEVID); 158 } 159 if (dev_replace->tgtdev) { 160 if (dev_replace->srcdev) { 161 dev_replace->tgtdev->total_bytes = 162 dev_replace->srcdev->total_bytes; 163 dev_replace->tgtdev->disk_total_bytes = 164 dev_replace->srcdev->disk_total_bytes; 165 dev_replace->tgtdev->bytes_used = 166 dev_replace->srcdev->bytes_used; 167 } 168 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; 169 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 170 dev_replace->tgtdev); 171 } 172 break; 173 } 174 175 out: 176 if (path) 177 btrfs_free_path(path); 178 return ret; 179 } 180 181 /* 182 * called from commit_transaction. Writes changed device replace state to 183 * disk. 184 */ 185 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 186 struct btrfs_fs_info *fs_info) 187 { 188 int ret; 189 struct btrfs_root *dev_root = fs_info->dev_root; 190 struct btrfs_path *path; 191 struct btrfs_key key; 192 struct extent_buffer *eb; 193 struct btrfs_dev_replace_item *ptr; 194 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 195 196 btrfs_dev_replace_lock(dev_replace); 197 if (!dev_replace->is_valid || 198 !dev_replace->item_needs_writeback) { 199 btrfs_dev_replace_unlock(dev_replace); 200 return 0; 201 } 202 btrfs_dev_replace_unlock(dev_replace); 203 204 key.objectid = 0; 205 key.type = BTRFS_DEV_REPLACE_KEY; 206 key.offset = 0; 207 208 path = btrfs_alloc_path(); 209 if (!path) { 210 ret = -ENOMEM; 211 goto out; 212 } 213 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 214 if (ret < 0) { 215 pr_warn("btrfs: error %d while searching for dev_replace item!\n", 216 ret); 217 goto out; 218 } 219 220 if (ret == 0 && 221 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 222 /* 223 * need to delete old one and insert a new one. 224 * Since no attempt is made to recover any old state, if the 225 * dev_replace state is 'running', the data on the target 226 * drive is lost. 227 * It would be possible to recover the state: just make sure 228 * that the beginning of the item is never changed and always 229 * contains all the essential information. Then read this 230 * minimal set of information and use it as a base for the 231 * new state. 232 */ 233 ret = btrfs_del_item(trans, dev_root, path); 234 if (ret != 0) { 235 pr_warn("btrfs: delete too small dev_replace item failed %d!\n", 236 ret); 237 goto out; 238 } 239 ret = 1; 240 } 241 242 if (ret == 1) { 243 /* need to insert a new item */ 244 btrfs_release_path(path); 245 ret = btrfs_insert_empty_item(trans, dev_root, path, 246 &key, sizeof(*ptr)); 247 if (ret < 0) { 248 pr_warn("btrfs: insert dev_replace item failed %d!\n", 249 ret); 250 goto out; 251 } 252 } 253 254 eb = path->nodes[0]; 255 ptr = btrfs_item_ptr(eb, path->slots[0], 256 struct btrfs_dev_replace_item); 257 258 btrfs_dev_replace_lock(dev_replace); 259 if (dev_replace->srcdev) 260 btrfs_set_dev_replace_src_devid(eb, ptr, 261 dev_replace->srcdev->devid); 262 else 263 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 264 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 265 dev_replace->cont_reading_from_srcdev_mode); 266 btrfs_set_dev_replace_replace_state(eb, ptr, 267 dev_replace->replace_state); 268 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 269 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 270 btrfs_set_dev_replace_num_write_errors(eb, ptr, 271 atomic64_read(&dev_replace->num_write_errors)); 272 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 273 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 274 dev_replace->cursor_left_last_write_of_item = 275 dev_replace->cursor_left; 276 btrfs_set_dev_replace_cursor_left(eb, ptr, 277 dev_replace->cursor_left_last_write_of_item); 278 btrfs_set_dev_replace_cursor_right(eb, ptr, 279 dev_replace->cursor_right); 280 dev_replace->item_needs_writeback = 0; 281 btrfs_dev_replace_unlock(dev_replace); 282 283 btrfs_mark_buffer_dirty(eb); 284 285 out: 286 btrfs_free_path(path); 287 288 return ret; 289 } 290 291 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 292 { 293 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 294 295 dev_replace->committed_cursor_left = 296 dev_replace->cursor_left_last_write_of_item; 297 } 298 299 static u64 btrfs_get_seconds_since_1970(void) 300 { 301 struct timespec t = CURRENT_TIME_SEC; 302 303 return t.tv_sec; 304 } 305 306 int btrfs_dev_replace_start(struct btrfs_root *root, 307 struct btrfs_ioctl_dev_replace_args *args) 308 { 309 struct btrfs_trans_handle *trans; 310 struct btrfs_fs_info *fs_info = root->fs_info; 311 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 312 int ret; 313 struct btrfs_device *tgt_device = NULL; 314 struct btrfs_device *src_device = NULL; 315 316 if (btrfs_fs_incompat(fs_info, RAID56)) { 317 pr_warn("btrfs: dev_replace cannot yet handle RAID5/RAID6\n"); 318 return -EINVAL; 319 } 320 321 switch (args->start.cont_reading_from_srcdev_mode) { 322 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 323 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 324 break; 325 default: 326 return -EINVAL; 327 } 328 329 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 330 args->start.tgtdev_name[0] == '\0') 331 return -EINVAL; 332 333 mutex_lock(&fs_info->volume_mutex); 334 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 335 &tgt_device); 336 if (ret) { 337 pr_err("btrfs: target device %s is invalid!\n", 338 args->start.tgtdev_name); 339 mutex_unlock(&fs_info->volume_mutex); 340 return -EINVAL; 341 } 342 343 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 344 args->start.srcdev_name, 345 &src_device); 346 mutex_unlock(&fs_info->volume_mutex); 347 if (ret) { 348 ret = -EINVAL; 349 goto leave_no_lock; 350 } 351 352 if (tgt_device->total_bytes < src_device->total_bytes) { 353 pr_err("btrfs: target device is smaller than source device!\n"); 354 ret = -EINVAL; 355 goto leave_no_lock; 356 } 357 358 btrfs_dev_replace_lock(dev_replace); 359 switch (dev_replace->replace_state) { 360 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 361 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 362 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 363 break; 364 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 365 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 366 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 367 goto leave; 368 } 369 370 dev_replace->cont_reading_from_srcdev_mode = 371 args->start.cont_reading_from_srcdev_mode; 372 WARN_ON(!src_device); 373 dev_replace->srcdev = src_device; 374 WARN_ON(!tgt_device); 375 dev_replace->tgtdev = tgt_device; 376 377 printk_in_rcu(KERN_INFO 378 "btrfs: dev_replace from %s (devid %llu) to %s) started\n", 379 src_device->missing ? "<missing disk>" : 380 rcu_str_deref(src_device->name), 381 src_device->devid, 382 rcu_str_deref(tgt_device->name)); 383 384 tgt_device->total_bytes = src_device->total_bytes; 385 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 386 tgt_device->bytes_used = src_device->bytes_used; 387 388 /* 389 * from now on, the writes to the srcdev are all duplicated to 390 * go to the tgtdev as well (refer to btrfs_map_block()). 391 */ 392 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 393 dev_replace->time_started = btrfs_get_seconds_since_1970(); 394 dev_replace->cursor_left = 0; 395 dev_replace->committed_cursor_left = 0; 396 dev_replace->cursor_left_last_write_of_item = 0; 397 dev_replace->cursor_right = 0; 398 dev_replace->is_valid = 1; 399 dev_replace->item_needs_writeback = 1; 400 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 401 btrfs_dev_replace_unlock(dev_replace); 402 403 btrfs_wait_all_ordered_extents(root->fs_info, 0); 404 405 /* force writing the updated state information to disk */ 406 trans = btrfs_start_transaction(root, 0); 407 if (IS_ERR(trans)) { 408 ret = PTR_ERR(trans); 409 btrfs_dev_replace_lock(dev_replace); 410 goto leave; 411 } 412 413 ret = btrfs_commit_transaction(trans, root); 414 WARN_ON(ret); 415 416 /* the disk copy procedure reuses the scrub code */ 417 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 418 src_device->total_bytes, 419 &dev_replace->scrub_progress, 0, 1); 420 421 ret = btrfs_dev_replace_finishing(root->fs_info, ret); 422 WARN_ON(ret); 423 424 return 0; 425 426 leave: 427 dev_replace->srcdev = NULL; 428 dev_replace->tgtdev = NULL; 429 btrfs_dev_replace_unlock(dev_replace); 430 leave_no_lock: 431 if (tgt_device) 432 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 433 return ret; 434 } 435 436 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 437 int scrub_ret) 438 { 439 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 440 struct btrfs_device *tgt_device; 441 struct btrfs_device *src_device; 442 struct btrfs_root *root = fs_info->tree_root; 443 u8 uuid_tmp[BTRFS_UUID_SIZE]; 444 struct btrfs_trans_handle *trans; 445 int ret = 0; 446 447 /* don't allow cancel or unmount to disturb the finishing procedure */ 448 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 449 450 btrfs_dev_replace_lock(dev_replace); 451 /* was the operation canceled, or is it finished? */ 452 if (dev_replace->replace_state != 453 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 454 btrfs_dev_replace_unlock(dev_replace); 455 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 456 return 0; 457 } 458 459 tgt_device = dev_replace->tgtdev; 460 src_device = dev_replace->srcdev; 461 btrfs_dev_replace_unlock(dev_replace); 462 463 /* replace old device with new one in mapping tree */ 464 if (!scrub_ret) 465 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 466 src_device, 467 tgt_device); 468 469 /* 470 * flush all outstanding I/O and inode extent mappings before the 471 * copy operation is declared as being finished 472 */ 473 ret = btrfs_start_all_delalloc_inodes(root->fs_info, 0); 474 if (ret) { 475 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 476 return ret; 477 } 478 btrfs_wait_all_ordered_extents(root->fs_info, 0); 479 480 trans = btrfs_start_transaction(root, 0); 481 if (IS_ERR(trans)) { 482 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 483 return PTR_ERR(trans); 484 } 485 ret = btrfs_commit_transaction(trans, root); 486 WARN_ON(ret); 487 488 /* keep away write_all_supers() during the finishing procedure */ 489 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 490 btrfs_dev_replace_lock(dev_replace); 491 dev_replace->replace_state = 492 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 493 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 494 dev_replace->tgtdev = NULL; 495 dev_replace->srcdev = NULL; 496 dev_replace->time_stopped = btrfs_get_seconds_since_1970(); 497 dev_replace->item_needs_writeback = 1; 498 499 if (scrub_ret) { 500 printk_in_rcu(KERN_ERR 501 "btrfs: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 502 src_device->missing ? "<missing disk>" : 503 rcu_str_deref(src_device->name), 504 src_device->devid, 505 rcu_str_deref(tgt_device->name), scrub_ret); 506 btrfs_dev_replace_unlock(dev_replace); 507 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 508 if (tgt_device) 509 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 510 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 511 512 return 0; 513 } 514 515 printk_in_rcu(KERN_INFO 516 "btrfs: dev_replace from %s (devid %llu) to %s) finished\n", 517 src_device->missing ? "<missing disk>" : 518 rcu_str_deref(src_device->name), 519 src_device->devid, 520 rcu_str_deref(tgt_device->name)); 521 tgt_device->is_tgtdev_for_dev_replace = 0; 522 tgt_device->devid = src_device->devid; 523 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 524 tgt_device->bytes_used = src_device->bytes_used; 525 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 526 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 527 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 528 tgt_device->total_bytes = src_device->total_bytes; 529 tgt_device->disk_total_bytes = src_device->disk_total_bytes; 530 tgt_device->bytes_used = src_device->bytes_used; 531 if (fs_info->sb->s_bdev == src_device->bdev) 532 fs_info->sb->s_bdev = tgt_device->bdev; 533 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 534 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 535 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 536 537 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 538 if (src_device->bdev) { 539 /* zero out the old super */ 540 btrfs_scratch_superblock(src_device); 541 } 542 /* 543 * this is again a consistent state where no dev_replace procedure 544 * is running, the target device is part of the filesystem, the 545 * source device is not part of the filesystem anymore and its 1st 546 * superblock is scratched out so that it is no longer marked to 547 * belong to this filesystem. 548 */ 549 btrfs_dev_replace_unlock(dev_replace); 550 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 551 552 /* write back the superblocks */ 553 trans = btrfs_start_transaction(root, 0); 554 if (!IS_ERR(trans)) 555 btrfs_commit_transaction(trans, root); 556 557 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 558 559 return 0; 560 } 561 562 static void btrfs_dev_replace_update_device_in_mapping_tree( 563 struct btrfs_fs_info *fs_info, 564 struct btrfs_device *srcdev, 565 struct btrfs_device *tgtdev) 566 { 567 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 568 struct extent_map *em; 569 struct map_lookup *map; 570 u64 start = 0; 571 int i; 572 573 write_lock(&em_tree->lock); 574 do { 575 em = lookup_extent_mapping(em_tree, start, (u64)-1); 576 if (!em) 577 break; 578 map = (struct map_lookup *)em->bdev; 579 for (i = 0; i < map->num_stripes; i++) 580 if (srcdev == map->stripes[i].dev) 581 map->stripes[i].dev = tgtdev; 582 start = em->start + em->len; 583 free_extent_map(em); 584 } while (start); 585 write_unlock(&em_tree->lock); 586 } 587 588 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 589 char *srcdev_name, 590 struct btrfs_device **device) 591 { 592 int ret; 593 594 if (srcdevid) { 595 ret = 0; 596 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 597 NULL); 598 if (!*device) 599 ret = -ENOENT; 600 } else { 601 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 602 device); 603 } 604 return ret; 605 } 606 607 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 608 struct btrfs_ioctl_dev_replace_args *args) 609 { 610 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 611 612 btrfs_dev_replace_lock(dev_replace); 613 /* even if !dev_replace_is_valid, the values are good enough for 614 * the replace_status ioctl */ 615 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 616 args->status.replace_state = dev_replace->replace_state; 617 args->status.time_started = dev_replace->time_started; 618 args->status.time_stopped = dev_replace->time_stopped; 619 args->status.num_write_errors = 620 atomic64_read(&dev_replace->num_write_errors); 621 args->status.num_uncorrectable_read_errors = 622 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 623 switch (dev_replace->replace_state) { 624 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 625 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 626 args->status.progress_1000 = 0; 627 break; 628 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 629 args->status.progress_1000 = 1000; 630 break; 631 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 632 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 633 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 634 div64_u64(dev_replace->srcdev->total_bytes, 1000)); 635 break; 636 } 637 btrfs_dev_replace_unlock(dev_replace); 638 } 639 640 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 641 struct btrfs_ioctl_dev_replace_args *args) 642 { 643 args->result = __btrfs_dev_replace_cancel(fs_info); 644 return 0; 645 } 646 647 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 648 { 649 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 650 struct btrfs_device *tgt_device = NULL; 651 struct btrfs_trans_handle *trans; 652 struct btrfs_root *root = fs_info->tree_root; 653 u64 result; 654 int ret; 655 656 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 657 btrfs_dev_replace_lock(dev_replace); 658 switch (dev_replace->replace_state) { 659 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 660 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 661 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 662 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 663 btrfs_dev_replace_unlock(dev_replace); 664 goto leave; 665 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 666 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 667 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 668 tgt_device = dev_replace->tgtdev; 669 dev_replace->tgtdev = NULL; 670 dev_replace->srcdev = NULL; 671 break; 672 } 673 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 674 dev_replace->time_stopped = btrfs_get_seconds_since_1970(); 675 dev_replace->item_needs_writeback = 1; 676 btrfs_dev_replace_unlock(dev_replace); 677 btrfs_scrub_cancel(fs_info); 678 679 trans = btrfs_start_transaction(root, 0); 680 if (IS_ERR(trans)) { 681 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 682 return PTR_ERR(trans); 683 } 684 ret = btrfs_commit_transaction(trans, root); 685 WARN_ON(ret); 686 if (tgt_device) 687 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 688 689 leave: 690 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 691 return result; 692 } 693 694 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 695 { 696 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 697 698 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 699 btrfs_dev_replace_lock(dev_replace); 700 switch (dev_replace->replace_state) { 701 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 702 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 703 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 704 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 705 break; 706 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 707 dev_replace->replace_state = 708 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 709 dev_replace->time_stopped = btrfs_get_seconds_since_1970(); 710 dev_replace->item_needs_writeback = 1; 711 pr_info("btrfs: suspending dev_replace for unmount\n"); 712 break; 713 } 714 715 btrfs_dev_replace_unlock(dev_replace); 716 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 717 } 718 719 /* resume dev_replace procedure that was interrupted by unmount */ 720 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 721 { 722 struct task_struct *task; 723 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 724 725 btrfs_dev_replace_lock(dev_replace); 726 switch (dev_replace->replace_state) { 727 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 728 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 729 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 730 btrfs_dev_replace_unlock(dev_replace); 731 return 0; 732 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 733 break; 734 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 735 dev_replace->replace_state = 736 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 737 break; 738 } 739 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 740 pr_info("btrfs: cannot continue dev_replace, tgtdev is missing\n" 741 "btrfs: you may cancel the operation after 'mount -o degraded'\n"); 742 btrfs_dev_replace_unlock(dev_replace); 743 return 0; 744 } 745 btrfs_dev_replace_unlock(dev_replace); 746 747 WARN_ON(atomic_xchg( 748 &fs_info->mutually_exclusive_operation_running, 1)); 749 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 750 return PTR_RET(task); 751 } 752 753 static int btrfs_dev_replace_kthread(void *data) 754 { 755 struct btrfs_fs_info *fs_info = data; 756 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 757 struct btrfs_ioctl_dev_replace_args *status_args; 758 u64 progress; 759 760 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 761 if (status_args) { 762 btrfs_dev_replace_status(fs_info, status_args); 763 progress = status_args->status.progress_1000; 764 kfree(status_args); 765 do_div(progress, 10); 766 printk_in_rcu(KERN_INFO 767 "btrfs: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 768 dev_replace->srcdev->missing ? "<missing disk>" : 769 rcu_str_deref(dev_replace->srcdev->name), 770 dev_replace->srcdev->devid, 771 dev_replace->tgtdev ? 772 rcu_str_deref(dev_replace->tgtdev->name) : 773 "<missing target disk>", 774 (unsigned int)progress); 775 } 776 btrfs_dev_replace_continue_on_mount(fs_info); 777 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 778 779 return 0; 780 } 781 782 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 783 { 784 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 785 int ret; 786 787 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 788 dev_replace->committed_cursor_left, 789 dev_replace->srcdev->total_bytes, 790 &dev_replace->scrub_progress, 0, 1); 791 ret = btrfs_dev_replace_finishing(fs_info, ret); 792 WARN_ON(ret); 793 return 0; 794 } 795 796 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 797 { 798 if (!dev_replace->is_valid) 799 return 0; 800 801 switch (dev_replace->replace_state) { 802 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 803 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 804 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 805 return 0; 806 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 807 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 808 /* 809 * return true even if tgtdev is missing (this is 810 * something that can happen if the dev_replace 811 * procedure is suspended by an umount and then 812 * the tgtdev is missing (or "btrfs dev scan") was 813 * not called and the the filesystem is remounted 814 * in degraded state. This does not stop the 815 * dev_replace procedure. It needs to be canceled 816 * manually if the cancelation is wanted. 817 */ 818 break; 819 } 820 return 1; 821 } 822 823 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 824 { 825 /* the beginning is just an optimization for the typical case */ 826 if (atomic_read(&dev_replace->nesting_level) == 0) { 827 acquire_lock: 828 /* this is not a nested case where the same thread 829 * is trying to acqurire the same lock twice */ 830 mutex_lock(&dev_replace->lock); 831 mutex_lock(&dev_replace->lock_management_lock); 832 dev_replace->lock_owner = current->pid; 833 atomic_inc(&dev_replace->nesting_level); 834 mutex_unlock(&dev_replace->lock_management_lock); 835 return; 836 } 837 838 mutex_lock(&dev_replace->lock_management_lock); 839 if (atomic_read(&dev_replace->nesting_level) > 0 && 840 dev_replace->lock_owner == current->pid) { 841 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 842 atomic_inc(&dev_replace->nesting_level); 843 mutex_unlock(&dev_replace->lock_management_lock); 844 return; 845 } 846 847 mutex_unlock(&dev_replace->lock_management_lock); 848 goto acquire_lock; 849 } 850 851 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 852 { 853 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 854 mutex_lock(&dev_replace->lock_management_lock); 855 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 856 WARN_ON(dev_replace->lock_owner != current->pid); 857 atomic_dec(&dev_replace->nesting_level); 858 if (atomic_read(&dev_replace->nesting_level) == 0) { 859 dev_replace->lock_owner = 0; 860 mutex_unlock(&dev_replace->lock_management_lock); 861 mutex_unlock(&dev_replace->lock); 862 } else { 863 mutex_unlock(&dev_replace->lock_management_lock); 864 } 865 } 866