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