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 /* don't warn if EINPROGRESS, someone else might be running scrub */ 421 if (ret == -EINPROGRESS) { 422 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 423 ret = 0; 424 } else { 425 WARN_ON(ret); 426 } 427 428 return ret; 429 430 leave: 431 dev_replace->srcdev = NULL; 432 dev_replace->tgtdev = NULL; 433 btrfs_dev_replace_unlock(dev_replace); 434 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 435 return ret; 436 } 437 438 /* 439 * blocked until all flighting bios are finished. 440 */ 441 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 442 { 443 s64 writers; 444 DEFINE_WAIT(wait); 445 446 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 447 do { 448 prepare_to_wait(&fs_info->replace_wait, &wait, 449 TASK_UNINTERRUPTIBLE); 450 writers = percpu_counter_sum(&fs_info->bio_counter); 451 if (writers) 452 schedule(); 453 finish_wait(&fs_info->replace_wait, &wait); 454 } while (writers); 455 } 456 457 /* 458 * we have removed target device, it is safe to allow new bios request. 459 */ 460 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 461 { 462 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 463 if (waitqueue_active(&fs_info->replace_wait)) 464 wake_up(&fs_info->replace_wait); 465 } 466 467 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 468 int scrub_ret) 469 { 470 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 471 struct btrfs_device *tgt_device; 472 struct btrfs_device *src_device; 473 struct btrfs_root *root = fs_info->tree_root; 474 u8 uuid_tmp[BTRFS_UUID_SIZE]; 475 struct btrfs_trans_handle *trans; 476 int ret = 0; 477 478 /* don't allow cancel or unmount to disturb the finishing procedure */ 479 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 480 481 btrfs_dev_replace_lock(dev_replace); 482 /* was the operation canceled, or is it finished? */ 483 if (dev_replace->replace_state != 484 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 485 btrfs_dev_replace_unlock(dev_replace); 486 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 487 return 0; 488 } 489 490 tgt_device = dev_replace->tgtdev; 491 src_device = dev_replace->srcdev; 492 btrfs_dev_replace_unlock(dev_replace); 493 494 /* 495 * flush all outstanding I/O and inode extent mappings before the 496 * copy operation is declared as being finished 497 */ 498 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 499 if (ret) { 500 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 501 return ret; 502 } 503 btrfs_wait_ordered_roots(root->fs_info, -1); 504 505 trans = btrfs_start_transaction(root, 0); 506 if (IS_ERR(trans)) { 507 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 508 return PTR_ERR(trans); 509 } 510 ret = btrfs_commit_transaction(trans, root); 511 WARN_ON(ret); 512 513 mutex_lock(&uuid_mutex); 514 /* keep away write_all_supers() during the finishing procedure */ 515 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 516 mutex_lock(&root->fs_info->chunk_mutex); 517 btrfs_dev_replace_lock(dev_replace); 518 dev_replace->replace_state = 519 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 520 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 521 dev_replace->tgtdev = NULL; 522 dev_replace->srcdev = NULL; 523 dev_replace->time_stopped = get_seconds(); 524 dev_replace->item_needs_writeback = 1; 525 526 /* replace old device with new one in mapping tree */ 527 if (!scrub_ret) { 528 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 529 src_device, 530 tgt_device); 531 } else { 532 printk_in_rcu(KERN_ERR 533 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", 534 src_device->missing ? "<missing disk>" : 535 rcu_str_deref(src_device->name), 536 src_device->devid, 537 rcu_str_deref(tgt_device->name), scrub_ret); 538 btrfs_dev_replace_unlock(dev_replace); 539 mutex_unlock(&root->fs_info->chunk_mutex); 540 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 541 mutex_unlock(&uuid_mutex); 542 if (tgt_device) 543 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 544 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 545 546 return scrub_ret; 547 } 548 549 printk_in_rcu(KERN_INFO 550 "BTRFS: dev_replace from %s (devid %llu) to %s finished\n", 551 src_device->missing ? "<missing disk>" : 552 rcu_str_deref(src_device->name), 553 src_device->devid, 554 rcu_str_deref(tgt_device->name)); 555 tgt_device->is_tgtdev_for_dev_replace = 0; 556 tgt_device->devid = src_device->devid; 557 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 558 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 559 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 560 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 561 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 562 btrfs_device_set_disk_total_bytes(tgt_device, 563 src_device->disk_total_bytes); 564 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 565 ASSERT(list_empty(&src_device->resized_list)); 566 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 567 tgt_device->commit_bytes_used = src_device->bytes_used; 568 if (fs_info->sb->s_bdev == src_device->bdev) 569 fs_info->sb->s_bdev = tgt_device->bdev; 570 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 571 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 572 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 573 fs_info->fs_devices->rw_devices++; 574 575 btrfs_dev_replace_unlock(dev_replace); 576 577 btrfs_rm_dev_replace_blocked(fs_info); 578 579 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 580 581 btrfs_rm_dev_replace_unblocked(fs_info); 582 583 /* 584 * this is again a consistent state where no dev_replace procedure 585 * is running, the target device is part of the filesystem, the 586 * source device is not part of the filesystem anymore and its 1st 587 * superblock is scratched out so that it is no longer marked to 588 * belong to this filesystem. 589 */ 590 mutex_unlock(&root->fs_info->chunk_mutex); 591 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 592 mutex_unlock(&uuid_mutex); 593 594 /* replace the sysfs entry */ 595 btrfs_kobj_rm_device(fs_info, src_device); 596 btrfs_kobj_add_device(fs_info, tgt_device); 597 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 598 599 /* write back the superblocks */ 600 trans = btrfs_start_transaction(root, 0); 601 if (!IS_ERR(trans)) 602 btrfs_commit_transaction(trans, root); 603 604 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 605 606 return 0; 607 } 608 609 static void btrfs_dev_replace_update_device_in_mapping_tree( 610 struct btrfs_fs_info *fs_info, 611 struct btrfs_device *srcdev, 612 struct btrfs_device *tgtdev) 613 { 614 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 615 struct extent_map *em; 616 struct map_lookup *map; 617 u64 start = 0; 618 int i; 619 620 write_lock(&em_tree->lock); 621 do { 622 em = lookup_extent_mapping(em_tree, start, (u64)-1); 623 if (!em) 624 break; 625 map = (struct map_lookup *)em->bdev; 626 for (i = 0; i < map->num_stripes; i++) 627 if (srcdev == map->stripes[i].dev) 628 map->stripes[i].dev = tgtdev; 629 start = em->start + em->len; 630 free_extent_map(em); 631 } while (start); 632 write_unlock(&em_tree->lock); 633 } 634 635 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 636 char *srcdev_name, 637 struct btrfs_device **device) 638 { 639 int ret; 640 641 if (srcdevid) { 642 ret = 0; 643 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 644 NULL); 645 if (!*device) 646 ret = -ENOENT; 647 } else { 648 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 649 device); 650 } 651 return ret; 652 } 653 654 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 655 struct btrfs_ioctl_dev_replace_args *args) 656 { 657 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 658 struct btrfs_device *srcdev; 659 660 btrfs_dev_replace_lock(dev_replace); 661 /* even if !dev_replace_is_valid, the values are good enough for 662 * the replace_status ioctl */ 663 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 664 args->status.replace_state = dev_replace->replace_state; 665 args->status.time_started = dev_replace->time_started; 666 args->status.time_stopped = dev_replace->time_stopped; 667 args->status.num_write_errors = 668 atomic64_read(&dev_replace->num_write_errors); 669 args->status.num_uncorrectable_read_errors = 670 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 671 switch (dev_replace->replace_state) { 672 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 673 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 674 args->status.progress_1000 = 0; 675 break; 676 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 677 args->status.progress_1000 = 1000; 678 break; 679 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 680 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 681 srcdev = dev_replace->srcdev; 682 args->status.progress_1000 = div64_u64(dev_replace->cursor_left, 683 div64_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 684 break; 685 } 686 btrfs_dev_replace_unlock(dev_replace); 687 } 688 689 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 690 struct btrfs_ioctl_dev_replace_args *args) 691 { 692 args->result = __btrfs_dev_replace_cancel(fs_info); 693 return 0; 694 } 695 696 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 697 { 698 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 699 struct btrfs_device *tgt_device = NULL; 700 struct btrfs_trans_handle *trans; 701 struct btrfs_root *root = fs_info->tree_root; 702 u64 result; 703 int ret; 704 705 if (fs_info->sb->s_flags & MS_RDONLY) 706 return -EROFS; 707 708 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 709 btrfs_dev_replace_lock(dev_replace); 710 switch (dev_replace->replace_state) { 711 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 712 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 713 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 714 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 715 btrfs_dev_replace_unlock(dev_replace); 716 goto leave; 717 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 718 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 719 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 720 tgt_device = dev_replace->tgtdev; 721 dev_replace->tgtdev = NULL; 722 dev_replace->srcdev = NULL; 723 break; 724 } 725 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 726 dev_replace->time_stopped = get_seconds(); 727 dev_replace->item_needs_writeback = 1; 728 btrfs_dev_replace_unlock(dev_replace); 729 btrfs_scrub_cancel(fs_info); 730 731 trans = btrfs_start_transaction(root, 0); 732 if (IS_ERR(trans)) { 733 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 734 return PTR_ERR(trans); 735 } 736 ret = btrfs_commit_transaction(trans, root); 737 WARN_ON(ret); 738 if (tgt_device) 739 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 740 741 leave: 742 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 743 return result; 744 } 745 746 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 747 { 748 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 749 750 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 751 btrfs_dev_replace_lock(dev_replace); 752 switch (dev_replace->replace_state) { 753 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 754 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 755 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 756 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 757 break; 758 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 759 dev_replace->replace_state = 760 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 761 dev_replace->time_stopped = get_seconds(); 762 dev_replace->item_needs_writeback = 1; 763 btrfs_info(fs_info, "suspending dev_replace for unmount"); 764 break; 765 } 766 767 btrfs_dev_replace_unlock(dev_replace); 768 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 769 } 770 771 /* resume dev_replace procedure that was interrupted by unmount */ 772 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 773 { 774 struct task_struct *task; 775 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 776 777 btrfs_dev_replace_lock(dev_replace); 778 switch (dev_replace->replace_state) { 779 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 780 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 781 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 782 btrfs_dev_replace_unlock(dev_replace); 783 return 0; 784 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 785 break; 786 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 787 dev_replace->replace_state = 788 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 789 break; 790 } 791 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 792 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 793 btrfs_info(fs_info, 794 "you may cancel the operation after 'mount -o degraded'"); 795 btrfs_dev_replace_unlock(dev_replace); 796 return 0; 797 } 798 btrfs_dev_replace_unlock(dev_replace); 799 800 WARN_ON(atomic_xchg( 801 &fs_info->mutually_exclusive_operation_running, 1)); 802 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 803 return PTR_ERR_OR_ZERO(task); 804 } 805 806 static int btrfs_dev_replace_kthread(void *data) 807 { 808 struct btrfs_fs_info *fs_info = data; 809 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 810 struct btrfs_ioctl_dev_replace_args *status_args; 811 u64 progress; 812 813 status_args = kzalloc(sizeof(*status_args), GFP_NOFS); 814 if (status_args) { 815 btrfs_dev_replace_status(fs_info, status_args); 816 progress = status_args->status.progress_1000; 817 kfree(status_args); 818 do_div(progress, 10); 819 printk_in_rcu(KERN_INFO 820 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", 821 dev_replace->srcdev->missing ? "<missing disk>" : 822 rcu_str_deref(dev_replace->srcdev->name), 823 dev_replace->srcdev->devid, 824 dev_replace->tgtdev ? 825 rcu_str_deref(dev_replace->tgtdev->name) : 826 "<missing target disk>", 827 (unsigned int)progress); 828 } 829 btrfs_dev_replace_continue_on_mount(fs_info); 830 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 831 832 return 0; 833 } 834 835 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 836 { 837 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 838 int ret; 839 840 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 841 dev_replace->committed_cursor_left, 842 btrfs_device_get_total_bytes(dev_replace->srcdev), 843 &dev_replace->scrub_progress, 0, 1); 844 ret = btrfs_dev_replace_finishing(fs_info, ret); 845 WARN_ON(ret); 846 return 0; 847 } 848 849 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 850 { 851 if (!dev_replace->is_valid) 852 return 0; 853 854 switch (dev_replace->replace_state) { 855 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 856 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 857 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 858 return 0; 859 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 860 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 861 /* 862 * return true even if tgtdev is missing (this is 863 * something that can happen if the dev_replace 864 * procedure is suspended by an umount and then 865 * the tgtdev is missing (or "btrfs dev scan") was 866 * not called and the the filesystem is remounted 867 * in degraded state. This does not stop the 868 * dev_replace procedure. It needs to be canceled 869 * manually if the cancelation is wanted. 870 */ 871 break; 872 } 873 return 1; 874 } 875 876 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) 877 { 878 /* the beginning is just an optimization for the typical case */ 879 if (atomic_read(&dev_replace->nesting_level) == 0) { 880 acquire_lock: 881 /* this is not a nested case where the same thread 882 * is trying to acqurire the same lock twice */ 883 mutex_lock(&dev_replace->lock); 884 mutex_lock(&dev_replace->lock_management_lock); 885 dev_replace->lock_owner = current->pid; 886 atomic_inc(&dev_replace->nesting_level); 887 mutex_unlock(&dev_replace->lock_management_lock); 888 return; 889 } 890 891 mutex_lock(&dev_replace->lock_management_lock); 892 if (atomic_read(&dev_replace->nesting_level) > 0 && 893 dev_replace->lock_owner == current->pid) { 894 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 895 atomic_inc(&dev_replace->nesting_level); 896 mutex_unlock(&dev_replace->lock_management_lock); 897 return; 898 } 899 900 mutex_unlock(&dev_replace->lock_management_lock); 901 goto acquire_lock; 902 } 903 904 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) 905 { 906 WARN_ON(!mutex_is_locked(&dev_replace->lock)); 907 mutex_lock(&dev_replace->lock_management_lock); 908 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); 909 WARN_ON(dev_replace->lock_owner != current->pid); 910 atomic_dec(&dev_replace->nesting_level); 911 if (atomic_read(&dev_replace->nesting_level) == 0) { 912 dev_replace->lock_owner = 0; 913 mutex_unlock(&dev_replace->lock_management_lock); 914 mutex_unlock(&dev_replace->lock); 915 } else { 916 mutex_unlock(&dev_replace->lock_management_lock); 917 } 918 } 919 920 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 921 { 922 percpu_counter_inc(&fs_info->bio_counter); 923 } 924 925 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 926 { 927 percpu_counter_sub(&fs_info->bio_counter, amount); 928 929 if (waitqueue_active(&fs_info->replace_wait)) 930 wake_up(&fs_info->replace_wait); 931 } 932 933 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 934 { 935 DEFINE_WAIT(wait); 936 again: 937 percpu_counter_inc(&fs_info->bio_counter); 938 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) { 939 btrfs_bio_counter_dec(fs_info); 940 wait_event(fs_info->replace_wait, 941 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 942 &fs_info->fs_state)); 943 goto again; 944 } 945 946 } 947