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 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 /* 332 * Here we commit the transaction to make sure commit_total_bytes 333 * of all the devices are updated. 334 */ 335 trans = btrfs_attach_transaction(root); 336 if (!IS_ERR(trans)) { 337 ret = btrfs_commit_transaction(trans, root); 338 if (ret) 339 return ret; 340 } else if (PTR_ERR(trans) != -ENOENT) { 341 return PTR_ERR(trans); 342 } 343 344 /* the disk copy procedure reuses the scrub code */ 345 mutex_lock(&fs_info->volume_mutex); 346 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 347 args->start.srcdev_name, 348 &src_device); 349 if (ret) { 350 mutex_unlock(&fs_info->volume_mutex); 351 return ret; 352 } 353 354 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 355 src_device, &tgt_device); 356 mutex_unlock(&fs_info->volume_mutex); 357 if (ret) 358 return ret; 359 360 btrfs_dev_replace_lock(dev_replace); 361 switch (dev_replace->replace_state) { 362 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 363 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 364 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 365 break; 366 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 367 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 368 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 369 goto leave; 370 } 371 372 dev_replace->cont_reading_from_srcdev_mode = 373 args->start.cont_reading_from_srcdev_mode; 374 WARN_ON(!src_device); 375 dev_replace->srcdev = src_device; 376 WARN_ON(!tgt_device); 377 dev_replace->tgtdev = tgt_device; 378 379 printk_in_rcu(KERN_INFO 380 "BTRFS: dev_replace from %s (devid %llu) to %s started\n", 381 src_device->missing ? "<missing disk>" : 382 rcu_str_deref(src_device->name), 383 src_device->devid, 384 rcu_str_deref(tgt_device->name)); 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 btrfs_device_get_total_bytes(src_device), 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 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 429 return ret; 430 } 431 432 /* 433 * blocked until all flighting bios are finished. 434 */ 435 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 436 { 437 s64 writers; 438 DEFINE_WAIT(wait); 439 440 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 441 do { 442 prepare_to_wait(&fs_info->replace_wait, &wait, 443 TASK_UNINTERRUPTIBLE); 444 writers = percpu_counter_sum(&fs_info->bio_counter); 445 if (writers) 446 schedule(); 447 finish_wait(&fs_info->replace_wait, &wait); 448 } while (writers); 449 } 450 451 /* 452 * we have removed target device, it is safe to allow new bios request. 453 */ 454 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 455 { 456 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 457 if (waitqueue_active(&fs_info->replace_wait)) 458 wake_up(&fs_info->replace_wait); 459 } 460 461 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 462 int scrub_ret) 463 { 464 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 465 struct btrfs_device *tgt_device; 466 struct btrfs_device *src_device; 467 struct btrfs_root *root = fs_info->tree_root; 468 u8 uuid_tmp[BTRFS_UUID_SIZE]; 469 struct btrfs_trans_handle *trans; 470 int ret = 0; 471 472 /* don't allow cancel or unmount to disturb the finishing procedure */ 473 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 474 475 btrfs_dev_replace_lock(dev_replace); 476 /* was the operation canceled, or is it finished? */ 477 if (dev_replace->replace_state != 478 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 479 btrfs_dev_replace_unlock(dev_replace); 480 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 481 return 0; 482 } 483 484 tgt_device = dev_replace->tgtdev; 485 src_device = dev_replace->srcdev; 486 btrfs_dev_replace_unlock(dev_replace); 487 488 /* 489 * flush all outstanding I/O and inode extent mappings before the 490 * copy operation is declared as being finished 491 */ 492 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 493 if (ret) { 494 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 495 return ret; 496 } 497 btrfs_wait_ordered_roots(root->fs_info, -1); 498 499 trans = btrfs_start_transaction(root, 0); 500 if (IS_ERR(trans)) { 501 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 502 return PTR_ERR(trans); 503 } 504 ret = btrfs_commit_transaction(trans, root); 505 WARN_ON(ret); 506 507 mutex_lock(&uuid_mutex); 508 /* keep away write_all_supers() during the finishing procedure */ 509 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 510 mutex_lock(&root->fs_info->chunk_mutex); 511 btrfs_dev_replace_lock(dev_replace); 512 dev_replace->replace_state = 513 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 514 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 515 dev_replace->tgtdev = NULL; 516 dev_replace->srcdev = NULL; 517 dev_replace->time_stopped = get_seconds(); 518 dev_replace->item_needs_writeback = 1; 519 520 /* replace old device with new one in mapping tree */ 521 if (!scrub_ret) { 522 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 523 src_device, 524 tgt_device); 525 } else { 526 printk_in_rcu(KERN_ERR 527 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 528 src_device->missing ? "<missing disk>" : 529 rcu_str_deref(src_device->name), 530 src_device->devid, 531 rcu_str_deref(tgt_device->name), scrub_ret); 532 btrfs_dev_replace_unlock(dev_replace); 533 mutex_unlock(&root->fs_info->chunk_mutex); 534 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 535 mutex_unlock(&uuid_mutex); 536 if (tgt_device) 537 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 538 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 539 540 return 0; 541 } 542 543 printk_in_rcu(KERN_INFO 544 "BTRFS: dev_replace from %s (devid %llu) to %s finished\n", 545 src_device->missing ? "<missing disk>" : 546 rcu_str_deref(src_device->name), 547 src_device->devid, 548 rcu_str_deref(tgt_device->name)); 549 tgt_device->is_tgtdev_for_dev_replace = 0; 550 tgt_device->devid = src_device->devid; 551 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 552 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 553 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 554 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 555 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 556 btrfs_device_set_disk_total_bytes(tgt_device, 557 src_device->disk_total_bytes); 558 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 559 ASSERT(list_empty(&src_device->resized_list)); 560 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 561 tgt_device->commit_bytes_used = src_device->bytes_used; 562 if (fs_info->sb->s_bdev == src_device->bdev) 563 fs_info->sb->s_bdev = tgt_device->bdev; 564 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 565 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 566 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 567 fs_info->fs_devices->rw_devices++; 568 569 /* replace the sysfs entry */ 570 btrfs_kobj_rm_device(fs_info, src_device); 571 btrfs_kobj_add_device(fs_info, tgt_device); 572 573 btrfs_dev_replace_unlock(dev_replace); 574 575 btrfs_rm_dev_replace_blocked(fs_info); 576 577 btrfs_rm_dev_replace_srcdev(fs_info, src_device); 578 579 btrfs_rm_dev_replace_unblocked(fs_info); 580 581 /* 582 * this is again a consistent state where no dev_replace procedure 583 * is running, the target device is part of the filesystem, the 584 * source device is not part of the filesystem anymore and its 1st 585 * superblock is scratched out so that it is no longer marked to 586 * belong to this filesystem. 587 */ 588 mutex_unlock(&root->fs_info->chunk_mutex); 589 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 590 mutex_unlock(&uuid_mutex); 591 592 /* write back the superblocks */ 593 trans = btrfs_start_transaction(root, 0); 594 if (!IS_ERR(trans)) 595 btrfs_commit_transaction(trans, root); 596 597 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 598 599 return 0; 600 } 601 602 static void btrfs_dev_replace_update_device_in_mapping_tree( 603 struct btrfs_fs_info *fs_info, 604 struct btrfs_device *srcdev, 605 struct btrfs_device *tgtdev) 606 { 607 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 608 struct extent_map *em; 609 struct map_lookup *map; 610 u64 start = 0; 611 int i; 612 613 write_lock(&em_tree->lock); 614 do { 615 em = lookup_extent_mapping(em_tree, start, (u64)-1); 616 if (!em) 617 break; 618 map = (struct map_lookup *)em->bdev; 619 for (i = 0; i < map->num_stripes; i++) 620 if (srcdev == map->stripes[i].dev) 621 map->stripes[i].dev = tgtdev; 622 start = em->start + em->len; 623 free_extent_map(em); 624 } while (start); 625 write_unlock(&em_tree->lock); 626 } 627 628 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 629 char *srcdev_name, 630 struct btrfs_device **device) 631 { 632 int ret; 633 634 if (srcdevid) { 635 ret = 0; 636 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 637 NULL); 638 if (!*device) 639 ret = -ENOENT; 640 } else { 641 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 642 device); 643 } 644 return ret; 645 } 646 647 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 648 struct btrfs_ioctl_dev_replace_args *args) 649 { 650 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 651 struct btrfs_device *srcdev; 652 653 btrfs_dev_replace_lock(dev_replace); 654 /* even if !dev_replace_is_valid, the values are good enough for 655 * the replace_status ioctl */ 656 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 657 args->status.replace_state = dev_replace->replace_state; 658 args->status.time_started = dev_replace->time_started; 659 args->status.time_stopped = dev_replace->time_stopped; 660 args->status.num_write_errors = 661 atomic64_read(&dev_replace->num_write_errors); 662 args->status.num_uncorrectable_read_errors = 663 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 664 switch (dev_replace->replace_state) { 665 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 666 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 667 args->status.progress_1000 = 0; 668 break; 669 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 670 args->status.progress_1000 = 1000; 671 break; 672 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 673 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 674 srcdev = dev_replace->srcdev; 675 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 676 div64_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 677 break; 678 } 679 btrfs_dev_replace_unlock(dev_replace); 680 } 681 682 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 683 struct btrfs_ioctl_dev_replace_args *args) 684 { 685 args->result = __btrfs_dev_replace_cancel(fs_info); 686 return 0; 687 } 688 689 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 690 { 691 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 692 struct btrfs_device *tgt_device = NULL; 693 struct btrfs_trans_handle *trans; 694 struct btrfs_root *root = fs_info->tree_root; 695 u64 result; 696 int ret; 697 698 if (fs_info->sb->s_flags & MS_RDONLY) 699 return -EROFS; 700 701 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 702 btrfs_dev_replace_lock(dev_replace); 703 switch (dev_replace->replace_state) { 704 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 705 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 706 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 707 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 708 btrfs_dev_replace_unlock(dev_replace); 709 goto leave; 710 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 711 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 712 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 713 tgt_device = dev_replace->tgtdev; 714 dev_replace->tgtdev = NULL; 715 dev_replace->srcdev = NULL; 716 break; 717 } 718 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 719 dev_replace->time_stopped = get_seconds(); 720 dev_replace->item_needs_writeback = 1; 721 btrfs_dev_replace_unlock(dev_replace); 722 btrfs_scrub_cancel(fs_info); 723 724 trans = btrfs_start_transaction(root, 0); 725 if (IS_ERR(trans)) { 726 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 727 return PTR_ERR(trans); 728 } 729 ret = btrfs_commit_transaction(trans, root); 730 WARN_ON(ret); 731 if (tgt_device) 732 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 733 734 leave: 735 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 736 return result; 737 } 738 739 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 740 { 741 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 742 743 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 744 btrfs_dev_replace_lock(dev_replace); 745 switch (dev_replace->replace_state) { 746 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 747 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 748 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 749 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 750 break; 751 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 752 dev_replace->replace_state = 753 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 754 dev_replace->time_stopped = get_seconds(); 755 dev_replace->item_needs_writeback = 1; 756 btrfs_info(fs_info, "suspending dev_replace for unmount"); 757 break; 758 } 759 760 btrfs_dev_replace_unlock(dev_replace); 761 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 762 } 763 764 /* resume dev_replace procedure that was interrupted by unmount */ 765 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 766 { 767 struct task_struct *task; 768 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 769 770 btrfs_dev_replace_lock(dev_replace); 771 switch (dev_replace->replace_state) { 772 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 773 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 774 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 775 btrfs_dev_replace_unlock(dev_replace); 776 return 0; 777 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 778 break; 779 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 780 dev_replace->replace_state = 781 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 782 break; 783 } 784 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 785 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 786 btrfs_info(fs_info, 787 "you may cancel the operation after 'mount -o degraded'"); 788 btrfs_dev_replace_unlock(dev_replace); 789 return 0; 790 } 791 btrfs_dev_replace_unlock(dev_replace); 792 793 WARN_ON(atomic_xchg( 794 &fs_info->mutually_exclusive_operation_running, 1)); 795 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 796 return PTR_ERR_OR_ZERO(task); 797 } 798 799 static int btrfs_dev_replace_kthread(void *data) 800 { 801 struct btrfs_fs_info *fs_info = data; 802 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 803 struct btrfs_ioctl_dev_replace_args *status_args; 804 u64 progress; 805 806 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 807 if (status_args) { 808 btrfs_dev_replace_status(fs_info, status_args); 809 progress = status_args->status.progress_1000; 810 kfree(status_args); 811 do_div(progress, 10); 812 printk_in_rcu(KERN_INFO 813 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 814 dev_replace->srcdev->missing ? "<missing disk>" : 815 rcu_str_deref(dev_replace->srcdev->name), 816 dev_replace->srcdev->devid, 817 dev_replace->tgtdev ? 818 rcu_str_deref(dev_replace->tgtdev->name) : 819 "<missing target disk>", 820 (unsigned int)progress); 821 } 822 btrfs_dev_replace_continue_on_mount(fs_info); 823 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 824 825 return 0; 826 } 827 828 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 829 { 830 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 831 int ret; 832 833 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 834 dev_replace->committed_cursor_left, 835 btrfs_device_get_total_bytes(dev_replace->srcdev), 836 &dev_replace->scrub_progress, 0, 1); 837 ret = btrfs_dev_replace_finishing(fs_info, ret); 838 WARN_ON(ret); 839 return 0; 840 } 841 842 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 843 { 844 if (!dev_replace->is_valid) 845 return 0; 846 847 switch (dev_replace->replace_state) { 848 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 849 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 850 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 851 return 0; 852 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 853 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 854 /* 855 * return true even if tgtdev is missing (this is 856 * something that can happen if the dev_replace 857 * procedure is suspended by an umount and then 858 * the tgtdev is missing (or "btrfs dev scan") was 859 * not called and the the filesystem is remounted 860 * in degraded state. This does not stop the 861 * dev_replace procedure. It needs to be canceled 862 * manually if the cancelation is wanted. 863 */ 864 break; 865 } 866 return 1; 867 } 868 869 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 870 { 871 /* the beginning is just an optimization for the typical case */ 872 if (atomic_read(&dev_replace->nesting_level) == 0) { 873 acquire_lock: 874 /* this is not a nested case where the same thread 875 * is trying to acqurire the same lock twice */ 876 mutex_lock(&dev_replace->lock); 877 mutex_lock(&dev_replace->lock_management_lock); 878 dev_replace->lock_owner = current->pid; 879 atomic_inc(&dev_replace->nesting_level); 880 mutex_unlock(&dev_replace->lock_management_lock); 881 return; 882 } 883 884 mutex_lock(&dev_replace->lock_management_lock); 885 if (atomic_read(&dev_replace->nesting_level) > 0 && 886 dev_replace->lock_owner == current->pid) { 887 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 888 atomic_inc(&dev_replace->nesting_level); 889 mutex_unlock(&dev_replace->lock_management_lock); 890 return; 891 } 892 893 mutex_unlock(&dev_replace->lock_management_lock); 894 goto acquire_lock; 895 } 896 897 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 898 { 899 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 900 mutex_lock(&dev_replace->lock_management_lock); 901 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 902 WARN_ON(dev_replace->lock_owner != current->pid); 903 atomic_dec(&dev_replace->nesting_level); 904 if (atomic_read(&dev_replace->nesting_level) == 0) { 905 dev_replace->lock_owner = 0; 906 mutex_unlock(&dev_replace->lock_management_lock); 907 mutex_unlock(&dev_replace->lock); 908 } else { 909 mutex_unlock(&dev_replace->lock_management_lock); 910 } 911 } 912 913 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 914 { 915 percpu_counter_inc(&fs_info->bio_counter); 916 } 917 918 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 919 { 920 percpu_counter_sub(&fs_info->bio_counter, amount); 921 922 if (waitqueue_active(&fs_info->replace_wait)) 923 wake_up(&fs_info->replace_wait); 924 } 925 926 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 927 { 928 DEFINE_WAIT(wait); 929 again: 930 percpu_counter_inc(&fs_info->bio_counter); 931 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) { 932 btrfs_bio_counter_dec(fs_info); 933 wait_event(fs_info->replace_wait, 934 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 935 &fs_info->fs_state)); 936 goto again; 937 } 938 939 } 940