1 /* 2 * Copyright (C) STRATO AG 2012. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 #include <linux/sched.h> 19 #include <linux/bio.h> 20 #include <linux/slab.h> 21 #include <linux/buffer_head.h> 22 #include <linux/blkdev.h> 23 #include <linux/random.h> 24 #include <linux/iocontext.h> 25 #include <linux/capability.h> 26 #include <linux/kthread.h> 27 #include <linux/math64.h> 28 #include <asm/div64.h> 29 #include "ctree.h" 30 #include "extent_map.h" 31 #include "disk-io.h" 32 #include "transaction.h" 33 #include "print-tree.h" 34 #include "volumes.h" 35 #include "async-thread.h" 36 #include "check-integrity.h" 37 #include "rcu-string.h" 38 #include "dev-replace.h" 39 #include "sysfs.h" 40 41 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 42 int scrub_ret); 43 static void btrfs_dev_replace_update_device_in_mapping_tree( 44 struct btrfs_fs_info *fs_info, 45 struct btrfs_device *srcdev, 46 struct btrfs_device *tgtdev); 47 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 48 char *srcdev_name, 49 struct btrfs_device **device); 50 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 51 static int btrfs_dev_replace_kthread(void *data); 52 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 53 54 55 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 56 { 57 struct btrfs_key key; 58 struct btrfs_root *dev_root = fs_info->dev_root; 59 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 60 struct extent_buffer *eb; 61 int slot; 62 int ret = 0; 63 struct btrfs_path *path = NULL; 64 int item_size; 65 struct btrfs_dev_replace_item *ptr; 66 u64 src_devid; 67 68 path = btrfs_alloc_path(); 69 if (!path) { 70 ret = -ENOMEM; 71 goto out; 72 } 73 74 key.objectid = 0; 75 key.type = BTRFS_DEV_REPLACE_KEY; 76 key.offset = 0; 77 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 78 if (ret) { 79 no_valid_dev_replace_entry_found: 80 ret = 0; 81 dev_replace->replace_state = 82 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 83 dev_replace->cont_reading_from_srcdev_mode = 84 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 85 dev_replace->replace_state = 0; 86 dev_replace->time_started = 0; 87 dev_replace->time_stopped = 0; 88 atomic64_set(&dev_replace->num_write_errors, 0); 89 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 90 dev_replace->cursor_left = 0; 91 dev_replace->committed_cursor_left = 0; 92 dev_replace->cursor_left_last_write_of_item = 0; 93 dev_replace->cursor_right = 0; 94 dev_replace->srcdev = NULL; 95 dev_replace->tgtdev = NULL; 96 dev_replace->is_valid = 0; 97 dev_replace->item_needs_writeback = 0; 98 goto out; 99 } 100 slot = path->slots[0]; 101 eb = path->nodes[0]; 102 item_size = btrfs_item_size_nr(eb, slot); 103 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 104 105 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 106 btrfs_warn(fs_info, 107 "dev_replace entry found has unexpected size, ignore entry"); 108 goto no_valid_dev_replace_entry_found; 109 } 110 111 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 112 dev_replace->cont_reading_from_srcdev_mode = 113 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 114 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 115 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 116 dev_replace->time_stopped = 117 btrfs_dev_replace_time_stopped(eb, ptr); 118 atomic64_set(&dev_replace->num_write_errors, 119 btrfs_dev_replace_num_write_errors(eb, ptr)); 120 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 121 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 122 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 123 dev_replace->committed_cursor_left = dev_replace->cursor_left; 124 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 125 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 126 dev_replace->is_valid = 1; 127 128 dev_replace->item_needs_writeback = 0; 129 switch (dev_replace->replace_state) { 130 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 131 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 132 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 133 dev_replace->srcdev = NULL; 134 dev_replace->tgtdev = NULL; 135 break; 136 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 137 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 138 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 139 NULL, NULL); 140 dev_replace->tgtdev = btrfs_find_device(fs_info, 141 BTRFS_DEV_REPLACE_DEVID, 142 NULL, NULL); 143 /* 144 * allow 'btrfs dev replace_cancel' if src/tgt device is 145 * missing 146 */ 147 if (!dev_replace->srcdev && 148 !btrfs_test_opt(dev_root, DEGRADED)) { 149 ret = -EIO; 150 btrfs_warn(fs_info, 151 "cannot mount because device replace operation is ongoing and"); 152 btrfs_warn(fs_info, 153 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 154 src_devid); 155 } 156 if (!dev_replace->tgtdev && 157 !btrfs_test_opt(dev_root, DEGRADED)) { 158 ret = -EIO; 159 btrfs_warn(fs_info, 160 "cannot mount because device replace operation is ongoing and"); 161 btrfs_warn(fs_info, 162 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 163 BTRFS_DEV_REPLACE_DEVID); 164 } 165 if (dev_replace->tgtdev) { 166 if (dev_replace->srcdev) { 167 dev_replace->tgtdev->total_bytes = 168 dev_replace->srcdev->total_bytes; 169 dev_replace->tgtdev->disk_total_bytes = 170 dev_replace->srcdev->disk_total_bytes; 171 dev_replace->tgtdev->commit_total_bytes = 172 dev_replace->srcdev->commit_total_bytes; 173 dev_replace->tgtdev->bytes_used = 174 dev_replace->srcdev->bytes_used; 175 dev_replace->tgtdev->commit_bytes_used = 176 dev_replace->srcdev->commit_bytes_used; 177 } 178 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; 179 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 180 dev_replace->tgtdev); 181 } 182 break; 183 } 184 185 out: 186 if (path) 187 btrfs_free_path(path); 188 return ret; 189 } 190 191 /* 192 * called from commit_transaction. Writes changed device replace state to 193 * disk. 194 */ 195 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 196 struct btrfs_fs_info *fs_info) 197 { 198 int ret; 199 struct btrfs_root *dev_root = fs_info->dev_root; 200 struct btrfs_path *path; 201 struct btrfs_key key; 202 struct extent_buffer *eb; 203 struct btrfs_dev_replace_item *ptr; 204 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 205 206 btrfs_dev_replace_lock(dev_replace); 207 if (!dev_replace->is_valid || 208 !dev_replace->item_needs_writeback) { 209 btrfs_dev_replace_unlock(dev_replace); 210 return 0; 211 } 212 btrfs_dev_replace_unlock(dev_replace); 213 214 key.objectid = 0; 215 key.type = BTRFS_DEV_REPLACE_KEY; 216 key.offset = 0; 217 218 path = btrfs_alloc_path(); 219 if (!path) { 220 ret = -ENOMEM; 221 goto out; 222 } 223 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 224 if (ret < 0) { 225 btrfs_warn(fs_info, "error %d while searching for dev_replace item!", 226 ret); 227 goto out; 228 } 229 230 if (ret == 0 && 231 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 232 /* 233 * need to delete old one and insert a new one. 234 * Since no attempt is made to recover any old state, if the 235 * dev_replace state is 'running', the data on the target 236 * drive is lost. 237 * It would be possible to recover the state: just make sure 238 * that the beginning of the item is never changed and always 239 * contains all the essential information. Then read this 240 * minimal set of information and use it as a base for the 241 * new state. 242 */ 243 ret = btrfs_del_item(trans, dev_root, path); 244 if (ret != 0) { 245 btrfs_warn(fs_info, "delete too small dev_replace item failed %d!", 246 ret); 247 goto out; 248 } 249 ret = 1; 250 } 251 252 if (ret == 1) { 253 /* need to insert a new item */ 254 btrfs_release_path(path); 255 ret = btrfs_insert_empty_item(trans, dev_root, path, 256 &key, sizeof(*ptr)); 257 if (ret < 0) { 258 btrfs_warn(fs_info, "insert dev_replace item failed %d!", 259 ret); 260 goto out; 261 } 262 } 263 264 eb = path->nodes[0]; 265 ptr = btrfs_item_ptr(eb, path->slots[0], 266 struct btrfs_dev_replace_item); 267 268 btrfs_dev_replace_lock(dev_replace); 269 if (dev_replace->srcdev) 270 btrfs_set_dev_replace_src_devid(eb, ptr, 271 dev_replace->srcdev->devid); 272 else 273 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 274 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 275 dev_replace->cont_reading_from_srcdev_mode); 276 btrfs_set_dev_replace_replace_state(eb, ptr, 277 dev_replace->replace_state); 278 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 279 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 280 btrfs_set_dev_replace_num_write_errors(eb, ptr, 281 atomic64_read(&dev_replace->num_write_errors)); 282 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 283 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 284 dev_replace->cursor_left_last_write_of_item = 285 dev_replace->cursor_left; 286 btrfs_set_dev_replace_cursor_left(eb, ptr, 287 dev_replace->cursor_left_last_write_of_item); 288 btrfs_set_dev_replace_cursor_right(eb, ptr, 289 dev_replace->cursor_right); 290 dev_replace->item_needs_writeback = 0; 291 btrfs_dev_replace_unlock(dev_replace); 292 293 btrfs_mark_buffer_dirty(eb); 294 295 out: 296 btrfs_free_path(path); 297 298 return ret; 299 } 300 301 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 302 { 303 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 304 305 dev_replace->committed_cursor_left = 306 dev_replace->cursor_left_last_write_of_item; 307 } 308 309 int btrfs_dev_replace_start(struct btrfs_root *root, 310 struct btrfs_ioctl_dev_replace_args *args) 311 { 312 struct btrfs_trans_handle *trans; 313 struct btrfs_fs_info *fs_info = root->fs_info; 314 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 315 int ret; 316 struct btrfs_device *tgt_device = NULL; 317 struct btrfs_device *src_device = NULL; 318 319 if (btrfs_fs_incompat(fs_info, RAID56)) { 320 btrfs_warn(fs_info, "dev_replace cannot yet handle RAID5/RAID6"); 321 return -EOPNOTSUPP; 322 } 323 324 switch (args->start.cont_reading_from_srcdev_mode) { 325 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 326 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 327 break; 328 default: 329 return -EINVAL; 330 } 331 332 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 333 args->start.tgtdev_name[0] == '\0') 334 return -EINVAL; 335 336 /* 337 * Here we commit the transaction to make sure commit_total_bytes 338 * of all the devices are updated. 339 */ 340 trans = btrfs_attach_transaction(root); 341 if (!IS_ERR(trans)) { 342 ret = btrfs_commit_transaction(trans, root); 343 if (ret) 344 return ret; 345 } else if (PTR_ERR(trans) != -ENOENT) { 346 return PTR_ERR(trans); 347 } 348 349 /* the disk copy procedure reuses the scrub code */ 350 mutex_lock(&fs_info->volume_mutex); 351 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 352 args->start.srcdev_name, 353 &src_device); 354 if (ret) { 355 mutex_unlock(&fs_info->volume_mutex); 356 return ret; 357 } 358 359 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 360 src_device, &tgt_device); 361 mutex_unlock(&fs_info->volume_mutex); 362 if (ret) 363 return ret; 364 365 btrfs_dev_replace_lock(dev_replace); 366 switch (dev_replace->replace_state) { 367 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 368 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 369 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 370 break; 371 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 372 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 373 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 374 goto leave; 375 } 376 377 dev_replace->cont_reading_from_srcdev_mode = 378 args->start.cont_reading_from_srcdev_mode; 379 WARN_ON(!src_device); 380 dev_replace->srcdev = src_device; 381 WARN_ON(!tgt_device); 382 dev_replace->tgtdev = tgt_device; 383 384 printk_in_rcu(KERN_INFO 385 "BTRFS: dev_replace from %s (devid %llu) to %s started\n", 386 src_device->missing ? "<missing disk>" : 387 rcu_str_deref(src_device->name), 388 src_device->devid, 389 rcu_str_deref(tgt_device->name)); 390 391 /* 392 * from now on, the writes to the srcdev are all duplicated to 393 * go to the tgtdev as well (refer to btrfs_map_block()). 394 */ 395 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 396 dev_replace->time_started = get_seconds(); 397 dev_replace->cursor_left = 0; 398 dev_replace->committed_cursor_left = 0; 399 dev_replace->cursor_left_last_write_of_item = 0; 400 dev_replace->cursor_right = 0; 401 dev_replace->is_valid = 1; 402 dev_replace->item_needs_writeback = 1; 403 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 404 btrfs_dev_replace_unlock(dev_replace); 405 406 btrfs_wait_ordered_roots(root->fs_info, -1); 407 408 /* force writing the updated state information to disk */ 409 trans = btrfs_start_transaction(root, 0); 410 if (IS_ERR(trans)) { 411 ret = PTR_ERR(trans); 412 btrfs_dev_replace_lock(dev_replace); 413 goto leave; 414 } 415 416 ret = btrfs_commit_transaction(trans, root); 417 WARN_ON(ret); 418 419 /* the disk copy procedure reuses the scrub code */ 420 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 421 btrfs_device_get_total_bytes(src_device), 422 &dev_replace->scrub_progress, 0, 1); 423 424 ret = btrfs_dev_replace_finishing(root->fs_info, ret); 425 WARN_ON(ret); 426 427 return 0; 428 429 leave: 430 dev_replace->srcdev = NULL; 431 dev_replace->tgtdev = NULL; 432 btrfs_dev_replace_unlock(dev_replace); 433 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 434 return ret; 435 } 436 437 /* 438 * blocked until all flighting bios are finished. 439 */ 440 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 441 { 442 s64 writers; 443 DEFINE_WAIT(wait); 444 445 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 446 do { 447 prepare_to_wait(&fs_info->replace_wait, &wait, 448 TASK_UNINTERRUPTIBLE); 449 writers = percpu_counter_sum(&fs_info->bio_counter); 450 if (writers) 451 schedule(); 452 finish_wait(&fs_info->replace_wait, &wait); 453 } while (writers); 454 } 455 456 /* 457 * we have removed target device, it is safe to allow new bios request. 458 */ 459 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 460 { 461 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 462 if (waitqueue_active(&fs_info->replace_wait)) 463 wake_up(&fs_info->replace_wait); 464 } 465 466 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 467 int scrub_ret) 468 { 469 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 470 struct btrfs_device *tgt_device; 471 struct btrfs_device *src_device; 472 struct btrfs_root *root = fs_info->tree_root; 473 u8 uuid_tmp[BTRFS_UUID_SIZE]; 474 struct btrfs_trans_handle *trans; 475 int ret = 0; 476 477 /* don't allow cancel or unmount to disturb the finishing procedure */ 478 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 479 480 btrfs_dev_replace_lock(dev_replace); 481 /* was the operation canceled, or is it finished? */ 482 if (dev_replace->replace_state != 483 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 484 btrfs_dev_replace_unlock(dev_replace); 485 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 486 return 0; 487 } 488 489 tgt_device = dev_replace->tgtdev; 490 src_device = dev_replace->srcdev; 491 btrfs_dev_replace_unlock(dev_replace); 492 493 /* 494 * flush all outstanding I/O and inode extent mappings before the 495 * copy operation is declared as being finished 496 */ 497 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 498 if (ret) { 499 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 500 return ret; 501 } 502 btrfs_wait_ordered_roots(root->fs_info, -1); 503 504 trans = btrfs_start_transaction(root, 0); 505 if (IS_ERR(trans)) { 506 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 507 return PTR_ERR(trans); 508 } 509 ret = btrfs_commit_transaction(trans, root); 510 WARN_ON(ret); 511 512 mutex_lock(&uuid_mutex); 513 /* keep away write_all_supers() during the finishing procedure */ 514 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 515 mutex_lock(&root->fs_info->chunk_mutex); 516 btrfs_dev_replace_lock(dev_replace); 517 dev_replace->replace_state = 518 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 519 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 520 dev_replace->tgtdev = NULL; 521 dev_replace->srcdev = NULL; 522 dev_replace->time_stopped = get_seconds(); 523 dev_replace->item_needs_writeback = 1; 524 525 /* replace old device with new one in mapping tree */ 526 if (!scrub_ret) { 527 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 528 src_device, 529 tgt_device); 530 } else { 531 printk_in_rcu(KERN_ERR 532 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 533 src_device->missing ? "<missing disk>" : 534 rcu_str_deref(src_device->name), 535 src_device->devid, 536 rcu_str_deref(tgt_device->name), scrub_ret); 537 btrfs_dev_replace_unlock(dev_replace); 538 mutex_unlock(&root->fs_info->chunk_mutex); 539 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 540 mutex_unlock(&uuid_mutex); 541 if (tgt_device) 542 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 543 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 544 545 return 0; 546 } 547 548 printk_in_rcu(KERN_INFO 549 "BTRFS: dev_replace from %s (devid %llu) to %s finished\n", 550 src_device->missing ? "<missing disk>" : 551 rcu_str_deref(src_device->name), 552 src_device->devid, 553 rcu_str_deref(tgt_device->name)); 554 tgt_device->is_tgtdev_for_dev_replace = 0; 555 tgt_device->devid = src_device->devid; 556 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 557 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 558 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 559 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 560 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 561 btrfs_device_set_disk_total_bytes(tgt_device, 562 src_device->disk_total_bytes); 563 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 564 ASSERT(list_empty(&src_device->resized_list)); 565 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 566 tgt_device->commit_bytes_used = src_device->bytes_used; 567 if (fs_info->sb->s_bdev == src_device->bdev) 568 fs_info->sb->s_bdev = tgt_device->bdev; 569 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 570 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 571 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 572 if (src_device->fs_devices->seeding) 573 fs_info->fs_devices->rw_devices++; 574 575 /* replace the sysfs entry */ 576 btrfs_kobj_rm_device(fs_info, src_device); 577 btrfs_kobj_add_device(fs_info, tgt_device); 578 579 btrfs_dev_replace_unlock(dev_replace); 580 581 btrfs_rm_dev_replace_blocked(fs_info); 582 583 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 584 585 btrfs_rm_dev_replace_unblocked(fs_info); 586 587 /* 588 * this is again a consistent state where no dev_replace procedure 589 * is running, the target device is part of the filesystem, the 590 * source device is not part of the filesystem anymore and its 1st 591 * superblock is scratched out so that it is no longer marked to 592 * belong to this filesystem. 593 */ 594 mutex_unlock(&root->fs_info->chunk_mutex); 595 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 596 mutex_unlock(&uuid_mutex); 597 598 /* write back the superblocks */ 599 trans = btrfs_start_transaction(root, 0); 600 if (!IS_ERR(trans)) 601 btrfs_commit_transaction(trans, root); 602 603 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 604 605 return 0; 606 } 607 608 static void btrfs_dev_replace_update_device_in_mapping_tree( 609 struct btrfs_fs_info *fs_info, 610 struct btrfs_device *srcdev, 611 struct btrfs_device *tgtdev) 612 { 613 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 614 struct extent_map *em; 615 struct map_lookup *map; 616 u64 start = 0; 617 int i; 618 619 write_lock(&em_tree->lock); 620 do { 621 em = lookup_extent_mapping(em_tree, start, (u64)-1); 622 if (!em) 623 break; 624 map = (struct map_lookup *)em->bdev; 625 for (i = 0; i < map->num_stripes; i++) 626 if (srcdev == map->stripes[i].dev) 627 map->stripes[i].dev = tgtdev; 628 start = em->start + em->len; 629 free_extent_map(em); 630 } while (start); 631 write_unlock(&em_tree->lock); 632 } 633 634 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 635 char *srcdev_name, 636 struct btrfs_device **device) 637 { 638 int ret; 639 640 if (srcdevid) { 641 ret = 0; 642 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 643 NULL); 644 if (!*device) 645 ret = -ENOENT; 646 } else { 647 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 648 device); 649 } 650 return ret; 651 } 652 653 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 654 struct btrfs_ioctl_dev_replace_args *args) 655 { 656 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 657 struct btrfs_device *srcdev; 658 659 btrfs_dev_replace_lock(dev_replace); 660 /* even if !dev_replace_is_valid, the values are good enough for 661 * the replace_status ioctl */ 662 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 663 args->status.replace_state = dev_replace->replace_state; 664 args->status.time_started = dev_replace->time_started; 665 args->status.time_stopped = dev_replace->time_stopped; 666 args->status.num_write_errors = 667 atomic64_read(&dev_replace->num_write_errors); 668 args->status.num_uncorrectable_read_errors = 669 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 670 switch (dev_replace->replace_state) { 671 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 672 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 673 args->status.progress_1000 = 0; 674 break; 675 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 676 args->status.progress_1000 = 1000; 677 break; 678 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 679 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 680 srcdev = dev_replace->srcdev; 681 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 682 div64_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 683 break; 684 } 685 btrfs_dev_replace_unlock(dev_replace); 686 } 687 688 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 689 struct btrfs_ioctl_dev_replace_args *args) 690 { 691 args->result = __btrfs_dev_replace_cancel(fs_info); 692 return 0; 693 } 694 695 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 696 { 697 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 698 struct btrfs_device *tgt_device = NULL; 699 struct btrfs_trans_handle *trans; 700 struct btrfs_root *root = fs_info->tree_root; 701 u64 result; 702 int ret; 703 704 if (fs_info->sb->s_flags & MS_RDONLY) 705 return -EROFS; 706 707 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 708 btrfs_dev_replace_lock(dev_replace); 709 switch (dev_replace->replace_state) { 710 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 711 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 712 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 713 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 714 btrfs_dev_replace_unlock(dev_replace); 715 goto leave; 716 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 717 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 718 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 719 tgt_device = dev_replace->tgtdev; 720 dev_replace->tgtdev = NULL; 721 dev_replace->srcdev = NULL; 722 break; 723 } 724 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 725 dev_replace->time_stopped = get_seconds(); 726 dev_replace->item_needs_writeback = 1; 727 btrfs_dev_replace_unlock(dev_replace); 728 btrfs_scrub_cancel(fs_info); 729 730 trans = btrfs_start_transaction(root, 0); 731 if (IS_ERR(trans)) { 732 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 733 return PTR_ERR(trans); 734 } 735 ret = btrfs_commit_transaction(trans, root); 736 WARN_ON(ret); 737 if (tgt_device) 738 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 739 740 leave: 741 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 742 return result; 743 } 744 745 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 746 { 747 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 748 749 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 750 btrfs_dev_replace_lock(dev_replace); 751 switch (dev_replace->replace_state) { 752 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 753 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 754 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 755 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 756 break; 757 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 758 dev_replace->replace_state = 759 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 760 dev_replace->time_stopped = get_seconds(); 761 dev_replace->item_needs_writeback = 1; 762 btrfs_info(fs_info, "suspending dev_replace for unmount"); 763 break; 764 } 765 766 btrfs_dev_replace_unlock(dev_replace); 767 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 768 } 769 770 /* resume dev_replace procedure that was interrupted by unmount */ 771 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 772 { 773 struct task_struct *task; 774 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 775 776 btrfs_dev_replace_lock(dev_replace); 777 switch (dev_replace->replace_state) { 778 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 779 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 780 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 781 btrfs_dev_replace_unlock(dev_replace); 782 return 0; 783 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 784 break; 785 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 786 dev_replace->replace_state = 787 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 788 break; 789 } 790 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 791 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 792 btrfs_info(fs_info, 793 "you may cancel the operation after 'mount -o degraded'"); 794 btrfs_dev_replace_unlock(dev_replace); 795 return 0; 796 } 797 btrfs_dev_replace_unlock(dev_replace); 798 799 WARN_ON(atomic_xchg( 800 &fs_info->mutually_exclusive_operation_running, 1)); 801 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 802 return PTR_ERR_OR_ZERO(task); 803 } 804 805 static int btrfs_dev_replace_kthread(void *data) 806 { 807 struct btrfs_fs_info *fs_info = data; 808 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 809 struct btrfs_ioctl_dev_replace_args *status_args; 810 u64 progress; 811 812 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 813 if (status_args) { 814 btrfs_dev_replace_status(fs_info, status_args); 815 progress = status_args->status.progress_1000; 816 kfree(status_args); 817 do_div(progress, 10); 818 printk_in_rcu(KERN_INFO 819 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 820 dev_replace->srcdev->missing ? "<missing disk>" : 821 rcu_str_deref(dev_replace->srcdev->name), 822 dev_replace->srcdev->devid, 823 dev_replace->tgtdev ? 824 rcu_str_deref(dev_replace->tgtdev->name) : 825 "<missing target disk>", 826 (unsigned int)progress); 827 } 828 btrfs_dev_replace_continue_on_mount(fs_info); 829 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 830 831 return 0; 832 } 833 834 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 835 { 836 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 837 int ret; 838 839 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 840 dev_replace->committed_cursor_left, 841 btrfs_device_get_total_bytes(dev_replace->srcdev), 842 &dev_replace->scrub_progress, 0, 1); 843 ret = btrfs_dev_replace_finishing(fs_info, ret); 844 WARN_ON(ret); 845 return 0; 846 } 847 848 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 849 { 850 if (!dev_replace->is_valid) 851 return 0; 852 853 switch (dev_replace->replace_state) { 854 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 855 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 856 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 857 return 0; 858 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 859 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 860 /* 861 * return true even if tgtdev is missing (this is 862 * something that can happen if the dev_replace 863 * procedure is suspended by an umount and then 864 * the tgtdev is missing (or "btrfs dev scan") was 865 * not called and the the filesystem is remounted 866 * in degraded state. This does not stop the 867 * dev_replace procedure. It needs to be canceled 868 * manually if the cancelation is wanted. 869 */ 870 break; 871 } 872 return 1; 873 } 874 875 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 876 { 877 /* the beginning is just an optimization for the typical case */ 878 if (atomic_read(&dev_replace->nesting_level) == 0) { 879 acquire_lock: 880 /* this is not a nested case where the same thread 881 * is trying to acqurire the same lock twice */ 882 mutex_lock(&dev_replace->lock); 883 mutex_lock(&dev_replace->lock_management_lock); 884 dev_replace->lock_owner = current->pid; 885 atomic_inc(&dev_replace->nesting_level); 886 mutex_unlock(&dev_replace->lock_management_lock); 887 return; 888 } 889 890 mutex_lock(&dev_replace->lock_management_lock); 891 if (atomic_read(&dev_replace->nesting_level) > 0 && 892 dev_replace->lock_owner == current->pid) { 893 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 894 atomic_inc(&dev_replace->nesting_level); 895 mutex_unlock(&dev_replace->lock_management_lock); 896 return; 897 } 898 899 mutex_unlock(&dev_replace->lock_management_lock); 900 goto acquire_lock; 901 } 902 903 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 904 { 905 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 906 mutex_lock(&dev_replace->lock_management_lock); 907 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 908 WARN_ON(dev_replace->lock_owner != current->pid); 909 atomic_dec(&dev_replace->nesting_level); 910 if (atomic_read(&dev_replace->nesting_level) == 0) { 911 dev_replace->lock_owner = 0; 912 mutex_unlock(&dev_replace->lock_management_lock); 913 mutex_unlock(&dev_replace->lock); 914 } else { 915 mutex_unlock(&dev_replace->lock_management_lock); 916 } 917 } 918 919 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 920 { 921 percpu_counter_inc(&fs_info->bio_counter); 922 } 923 924 void btrfs_bio_counter_dec(struct btrfs_fs_info *fs_info) 925 { 926 percpu_counter_dec(&fs_info->bio_counter); 927 928 if (waitqueue_active(&fs_info->replace_wait)) 929 wake_up(&fs_info->replace_wait); 930 } 931 932 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 933 { 934 DEFINE_WAIT(wait); 935 again: 936 percpu_counter_inc(&fs_info->bio_counter); 937 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) { 938 btrfs_bio_counter_dec(fs_info); 939 wait_event(fs_info->replace_wait, 940 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 941 &fs_info->fs_state)); 942 goto again; 943 } 944 945 } 946