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 u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 48 static int btrfs_dev_replace_kthread(void *data); 49 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 50 51 52 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 53 { 54 struct btrfs_key key; 55 struct btrfs_root *dev_root = fs_info->dev_root; 56 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 57 struct extent_buffer *eb; 58 int slot; 59 int ret = 0; 60 struct btrfs_path *path = NULL; 61 int item_size; 62 struct btrfs_dev_replace_item *ptr; 63 u64 src_devid; 64 65 path = btrfs_alloc_path(); 66 if (!path) { 67 ret = -ENOMEM; 68 goto out; 69 } 70 71 key.objectid = 0; 72 key.type = BTRFS_DEV_REPLACE_KEY; 73 key.offset = 0; 74 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 75 if (ret) { 76 no_valid_dev_replace_entry_found: 77 ret = 0; 78 dev_replace->replace_state = 79 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 80 dev_replace->cont_reading_from_srcdev_mode = 81 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 82 dev_replace->replace_state = 0; 83 dev_replace->time_started = 0; 84 dev_replace->time_stopped = 0; 85 atomic64_set(&dev_replace->num_write_errors, 0); 86 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 87 dev_replace->cursor_left = 0; 88 dev_replace->committed_cursor_left = 0; 89 dev_replace->cursor_left_last_write_of_item = 0; 90 dev_replace->cursor_right = 0; 91 dev_replace->srcdev = NULL; 92 dev_replace->tgtdev = NULL; 93 dev_replace->is_valid = 0; 94 dev_replace->item_needs_writeback = 0; 95 goto out; 96 } 97 slot = path->slots[0]; 98 eb = path->nodes[0]; 99 item_size = btrfs_item_size_nr(eb, slot); 100 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 101 102 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 103 btrfs_warn(fs_info, 104 "dev_replace entry found has unexpected size, ignore entry"); 105 goto no_valid_dev_replace_entry_found; 106 } 107 108 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 109 dev_replace->cont_reading_from_srcdev_mode = 110 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 111 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 112 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 113 dev_replace->time_stopped = 114 btrfs_dev_replace_time_stopped(eb, ptr); 115 atomic64_set(&dev_replace->num_write_errors, 116 btrfs_dev_replace_num_write_errors(eb, ptr)); 117 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 118 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 119 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 120 dev_replace->committed_cursor_left = dev_replace->cursor_left; 121 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 122 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 123 dev_replace->is_valid = 1; 124 125 dev_replace->item_needs_writeback = 0; 126 switch (dev_replace->replace_state) { 127 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 128 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 129 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 130 dev_replace->srcdev = NULL; 131 dev_replace->tgtdev = NULL; 132 break; 133 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 134 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 135 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 136 NULL, NULL); 137 dev_replace->tgtdev = btrfs_find_device(fs_info, 138 BTRFS_DEV_REPLACE_DEVID, 139 NULL, NULL); 140 /* 141 * allow 'btrfs dev replace_cancel' if src/tgt device is 142 * missing 143 */ 144 if (!dev_replace->srcdev && 145 !btrfs_test_opt(fs_info, DEGRADED)) { 146 ret = -EIO; 147 btrfs_warn(fs_info, 148 "cannot mount because device replace operation is ongoing and"); 149 btrfs_warn(fs_info, 150 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 151 src_devid); 152 } 153 if (!dev_replace->tgtdev && 154 !btrfs_test_opt(fs_info, DEGRADED)) { 155 ret = -EIO; 156 btrfs_warn(fs_info, 157 "cannot mount because device replace operation is ongoing and"); 158 btrfs_warn(fs_info, 159 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 160 BTRFS_DEV_REPLACE_DEVID); 161 } 162 if (dev_replace->tgtdev) { 163 if (dev_replace->srcdev) { 164 dev_replace->tgtdev->total_bytes = 165 dev_replace->srcdev->total_bytes; 166 dev_replace->tgtdev->disk_total_bytes = 167 dev_replace->srcdev->disk_total_bytes; 168 dev_replace->tgtdev->commit_total_bytes = 169 dev_replace->srcdev->commit_total_bytes; 170 dev_replace->tgtdev->bytes_used = 171 dev_replace->srcdev->bytes_used; 172 dev_replace->tgtdev->commit_bytes_used = 173 dev_replace->srcdev->commit_bytes_used; 174 } 175 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 176 &dev_replace->tgtdev->dev_state); 177 btrfs_init_dev_replace_tgtdev_for_resume(fs_info, 178 dev_replace->tgtdev); 179 } 180 break; 181 } 182 183 out: 184 btrfs_free_path(path); 185 return ret; 186 } 187 188 /* 189 * called from commit_transaction. Writes changed device replace state to 190 * disk. 191 */ 192 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 193 struct btrfs_fs_info *fs_info) 194 { 195 int ret; 196 struct btrfs_root *dev_root = fs_info->dev_root; 197 struct btrfs_path *path; 198 struct btrfs_key key; 199 struct extent_buffer *eb; 200 struct btrfs_dev_replace_item *ptr; 201 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 202 203 btrfs_dev_replace_lock(dev_replace, 0); 204 if (!dev_replace->is_valid || 205 !dev_replace->item_needs_writeback) { 206 btrfs_dev_replace_unlock(dev_replace, 0); 207 return 0; 208 } 209 btrfs_dev_replace_unlock(dev_replace, 0); 210 211 key.objectid = 0; 212 key.type = BTRFS_DEV_REPLACE_KEY; 213 key.offset = 0; 214 215 path = btrfs_alloc_path(); 216 if (!path) { 217 ret = -ENOMEM; 218 goto out; 219 } 220 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 221 if (ret < 0) { 222 btrfs_warn(fs_info, 223 "error %d while searching for dev_replace item!", 224 ret); 225 goto out; 226 } 227 228 if (ret == 0 && 229 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 230 /* 231 * need to delete old one and insert a new one. 232 * Since no attempt is made to recover any old state, if the 233 * dev_replace state is 'running', the data on the target 234 * drive is lost. 235 * It would be possible to recover the state: just make sure 236 * that the beginning of the item is never changed and always 237 * contains all the essential information. Then read this 238 * minimal set of information and use it as a base for the 239 * new state. 240 */ 241 ret = btrfs_del_item(trans, dev_root, path); 242 if (ret != 0) { 243 btrfs_warn(fs_info, 244 "delete too small dev_replace item failed %d!", 245 ret); 246 goto out; 247 } 248 ret = 1; 249 } 250 251 if (ret == 1) { 252 /* need to insert a new item */ 253 btrfs_release_path(path); 254 ret = btrfs_insert_empty_item(trans, dev_root, path, 255 &key, sizeof(*ptr)); 256 if (ret < 0) { 257 btrfs_warn(fs_info, 258 "insert dev_replace item failed %d!", ret); 259 goto out; 260 } 261 } 262 263 eb = path->nodes[0]; 264 ptr = btrfs_item_ptr(eb, path->slots[0], 265 struct btrfs_dev_replace_item); 266 267 btrfs_dev_replace_lock(dev_replace, 1); 268 if (dev_replace->srcdev) 269 btrfs_set_dev_replace_src_devid(eb, ptr, 270 dev_replace->srcdev->devid); 271 else 272 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 273 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 274 dev_replace->cont_reading_from_srcdev_mode); 275 btrfs_set_dev_replace_replace_state(eb, ptr, 276 dev_replace->replace_state); 277 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 278 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 279 btrfs_set_dev_replace_num_write_errors(eb, ptr, 280 atomic64_read(&dev_replace->num_write_errors)); 281 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 282 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 283 dev_replace->cursor_left_last_write_of_item = 284 dev_replace->cursor_left; 285 btrfs_set_dev_replace_cursor_left(eb, ptr, 286 dev_replace->cursor_left_last_write_of_item); 287 btrfs_set_dev_replace_cursor_right(eb, ptr, 288 dev_replace->cursor_right); 289 dev_replace->item_needs_writeback = 0; 290 btrfs_dev_replace_unlock(dev_replace, 1); 291 292 btrfs_mark_buffer_dirty(eb); 293 294 out: 295 btrfs_free_path(path); 296 297 return ret; 298 } 299 300 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 301 { 302 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 303 304 dev_replace->committed_cursor_left = 305 dev_replace->cursor_left_last_write_of_item; 306 } 307 308 static char* btrfs_dev_name(struct btrfs_device *device) 309 { 310 if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 311 return "<missing disk>"; 312 else 313 return rcu_str_deref(device->name); 314 } 315 316 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 317 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 318 int read_src) 319 { 320 struct btrfs_root *root = fs_info->dev_root; 321 struct btrfs_trans_handle *trans; 322 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 323 int ret; 324 struct btrfs_device *tgt_device = NULL; 325 struct btrfs_device *src_device = NULL; 326 327 /* the disk copy procedure reuses the scrub code */ 328 mutex_lock(&fs_info->volume_mutex); 329 ret = btrfs_find_device_by_devspec(fs_info, srcdevid, 330 srcdev_name, &src_device); 331 if (ret) { 332 mutex_unlock(&fs_info->volume_mutex); 333 return ret; 334 } 335 336 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 337 src_device, &tgt_device); 338 mutex_unlock(&fs_info->volume_mutex); 339 if (ret) 340 return ret; 341 342 /* 343 * Here we commit the transaction to make sure commit_total_bytes 344 * of all the devices are updated. 345 */ 346 trans = btrfs_attach_transaction(root); 347 if (!IS_ERR(trans)) { 348 ret = btrfs_commit_transaction(trans); 349 if (ret) 350 return ret; 351 } else if (PTR_ERR(trans) != -ENOENT) { 352 return PTR_ERR(trans); 353 } 354 355 btrfs_dev_replace_lock(dev_replace, 1); 356 switch (dev_replace->replace_state) { 357 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 358 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 359 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 360 break; 361 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 362 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 363 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 364 goto leave; 365 } 366 367 dev_replace->cont_reading_from_srcdev_mode = read_src; 368 WARN_ON(!src_device); 369 dev_replace->srcdev = src_device; 370 WARN_ON(!tgt_device); 371 dev_replace->tgtdev = tgt_device; 372 373 btrfs_info_in_rcu(fs_info, 374 "dev_replace from %s (devid %llu) to %s started", 375 btrfs_dev_name(src_device), 376 src_device->devid, 377 rcu_str_deref(tgt_device->name)); 378 379 /* 380 * from now on, the writes to the srcdev are all duplicated to 381 * go to the tgtdev as well (refer to btrfs_map_block()). 382 */ 383 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 384 dev_replace->time_started = get_seconds(); 385 dev_replace->cursor_left = 0; 386 dev_replace->committed_cursor_left = 0; 387 dev_replace->cursor_left_last_write_of_item = 0; 388 dev_replace->cursor_right = 0; 389 dev_replace->is_valid = 1; 390 dev_replace->item_needs_writeback = 1; 391 atomic64_set(&dev_replace->num_write_errors, 0); 392 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 393 btrfs_dev_replace_unlock(dev_replace, 1); 394 395 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 396 if (ret) 397 btrfs_err(fs_info, "kobj add dev failed %d", ret); 398 399 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 400 401 /* force writing the updated state information to disk */ 402 trans = btrfs_start_transaction(root, 0); 403 if (IS_ERR(trans)) { 404 ret = PTR_ERR(trans); 405 btrfs_dev_replace_lock(dev_replace, 1); 406 goto leave; 407 } 408 409 ret = btrfs_commit_transaction(trans); 410 WARN_ON(ret); 411 412 /* the disk copy procedure reuses the scrub code */ 413 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 414 btrfs_device_get_total_bytes(src_device), 415 &dev_replace->scrub_progress, 0, 1); 416 417 ret = btrfs_dev_replace_finishing(fs_info, ret); 418 if (ret == -EINPROGRESS) { 419 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 420 } else { 421 WARN_ON(ret); 422 } 423 424 return ret; 425 426 leave: 427 dev_replace->srcdev = NULL; 428 dev_replace->tgtdev = NULL; 429 btrfs_dev_replace_unlock(dev_replace, 1); 430 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 431 return ret; 432 } 433 434 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 435 struct btrfs_ioctl_dev_replace_args *args) 436 { 437 int ret; 438 439 switch (args->start.cont_reading_from_srcdev_mode) { 440 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 441 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 442 break; 443 default: 444 return -EINVAL; 445 } 446 447 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 448 args->start.tgtdev_name[0] == '\0') 449 return -EINVAL; 450 451 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 452 args->start.srcdevid, 453 args->start.srcdev_name, 454 args->start.cont_reading_from_srcdev_mode); 455 args->result = ret; 456 /* don't warn if EINPROGRESS, someone else might be running scrub */ 457 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS) 458 ret = 0; 459 460 return ret; 461 } 462 463 /* 464 * blocked until all in-flight bios operations are finished. 465 */ 466 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 467 { 468 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 469 wait_event(fs_info->replace_wait, !percpu_counter_sum( 470 &fs_info->bio_counter)); 471 } 472 473 /* 474 * we have removed target device, it is safe to allow new bios request. 475 */ 476 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 477 { 478 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 479 wake_up(&fs_info->replace_wait); 480 } 481 482 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 483 int scrub_ret) 484 { 485 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 486 struct btrfs_device *tgt_device; 487 struct btrfs_device *src_device; 488 struct btrfs_root *root = fs_info->tree_root; 489 u8 uuid_tmp[BTRFS_UUID_SIZE]; 490 struct btrfs_trans_handle *trans; 491 int ret = 0; 492 493 /* don't allow cancel or unmount to disturb the finishing procedure */ 494 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 495 496 btrfs_dev_replace_lock(dev_replace, 0); 497 /* was the operation canceled, or is it finished? */ 498 if (dev_replace->replace_state != 499 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 500 btrfs_dev_replace_unlock(dev_replace, 0); 501 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 502 return 0; 503 } 504 505 tgt_device = dev_replace->tgtdev; 506 src_device = dev_replace->srcdev; 507 btrfs_dev_replace_unlock(dev_replace, 0); 508 509 /* 510 * flush all outstanding I/O and inode extent mappings before the 511 * copy operation is declared as being finished 512 */ 513 ret = btrfs_start_delalloc_roots(fs_info, 0, -1); 514 if (ret) { 515 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 516 return ret; 517 } 518 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 519 520 trans = btrfs_start_transaction(root, 0); 521 if (IS_ERR(trans)) { 522 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 523 return PTR_ERR(trans); 524 } 525 ret = btrfs_commit_transaction(trans); 526 WARN_ON(ret); 527 528 mutex_lock(&uuid_mutex); 529 /* keep away write_all_supers() during the finishing procedure */ 530 mutex_lock(&fs_info->fs_devices->device_list_mutex); 531 mutex_lock(&fs_info->chunk_mutex); 532 btrfs_dev_replace_lock(dev_replace, 1); 533 dev_replace->replace_state = 534 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 535 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 536 dev_replace->tgtdev = NULL; 537 dev_replace->srcdev = NULL; 538 dev_replace->time_stopped = get_seconds(); 539 dev_replace->item_needs_writeback = 1; 540 541 /* replace old device with new one in mapping tree */ 542 if (!scrub_ret) { 543 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 544 src_device, 545 tgt_device); 546 } else { 547 btrfs_err_in_rcu(fs_info, 548 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 549 btrfs_dev_name(src_device), 550 src_device->devid, 551 rcu_str_deref(tgt_device->name), scrub_ret); 552 btrfs_dev_replace_unlock(dev_replace, 1); 553 mutex_unlock(&fs_info->chunk_mutex); 554 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 555 mutex_unlock(&uuid_mutex); 556 btrfs_rm_dev_replace_blocked(fs_info); 557 if (tgt_device) 558 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 559 btrfs_rm_dev_replace_unblocked(fs_info); 560 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 561 562 return scrub_ret; 563 } 564 565 btrfs_info_in_rcu(fs_info, 566 "dev_replace from %s (devid %llu) to %s finished", 567 btrfs_dev_name(src_device), 568 src_device->devid, 569 rcu_str_deref(tgt_device->name)); 570 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 571 tgt_device->devid = src_device->devid; 572 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 573 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 574 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 575 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 576 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 577 btrfs_device_set_disk_total_bytes(tgt_device, 578 src_device->disk_total_bytes); 579 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 580 ASSERT(list_empty(&src_device->resized_list)); 581 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 582 tgt_device->commit_bytes_used = src_device->bytes_used; 583 584 btrfs_assign_next_active_device(fs_info, src_device, tgt_device); 585 586 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 587 fs_info->fs_devices->rw_devices++; 588 589 btrfs_dev_replace_unlock(dev_replace, 1); 590 591 btrfs_rm_dev_replace_blocked(fs_info); 592 593 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 594 595 btrfs_rm_dev_replace_unblocked(fs_info); 596 597 /* 598 * this is again a consistent state where no dev_replace procedure 599 * is running, the target device is part of the filesystem, the 600 * source device is not part of the filesystem anymore and its 1st 601 * superblock is scratched out so that it is no longer marked to 602 * belong to this filesystem. 603 */ 604 mutex_unlock(&fs_info->chunk_mutex); 605 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 606 mutex_unlock(&uuid_mutex); 607 608 /* replace the sysfs entry */ 609 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 610 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 611 612 /* write back the superblocks */ 613 trans = btrfs_start_transaction(root, 0); 614 if (!IS_ERR(trans)) 615 btrfs_commit_transaction(trans); 616 617 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 618 619 return 0; 620 } 621 622 static void btrfs_dev_replace_update_device_in_mapping_tree( 623 struct btrfs_fs_info *fs_info, 624 struct btrfs_device *srcdev, 625 struct btrfs_device *tgtdev) 626 { 627 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 628 struct extent_map *em; 629 struct map_lookup *map; 630 u64 start = 0; 631 int i; 632 633 write_lock(&em_tree->lock); 634 do { 635 em = lookup_extent_mapping(em_tree, start, (u64)-1); 636 if (!em) 637 break; 638 map = em->map_lookup; 639 for (i = 0; i < map->num_stripes; i++) 640 if (srcdev == map->stripes[i].dev) 641 map->stripes[i].dev = tgtdev; 642 start = em->start + em->len; 643 free_extent_map(em); 644 } while (start); 645 write_unlock(&em_tree->lock); 646 } 647 648 /* 649 * Read progress of device replace status according to the state and last 650 * stored position. The value format is the same as for 651 * btrfs_dev_replace::progress_1000 652 */ 653 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 654 { 655 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 656 u64 ret = 0; 657 658 switch (dev_replace->replace_state) { 659 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 660 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 661 ret = 0; 662 break; 663 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 664 ret = 1000; 665 break; 666 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 667 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 668 ret = div64_u64(dev_replace->cursor_left, 669 div_u64(btrfs_device_get_total_bytes( 670 dev_replace->srcdev), 1000)); 671 break; 672 } 673 674 return ret; 675 } 676 677 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 678 struct btrfs_ioctl_dev_replace_args *args) 679 { 680 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 681 682 btrfs_dev_replace_lock(dev_replace, 0); 683 /* even if !dev_replace_is_valid, the values are good enough for 684 * the replace_status ioctl */ 685 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 686 args->status.replace_state = dev_replace->replace_state; 687 args->status.time_started = dev_replace->time_started; 688 args->status.time_stopped = dev_replace->time_stopped; 689 args->status.num_write_errors = 690 atomic64_read(&dev_replace->num_write_errors); 691 args->status.num_uncorrectable_read_errors = 692 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 693 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 694 btrfs_dev_replace_unlock(dev_replace, 0); 695 } 696 697 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 698 struct btrfs_ioctl_dev_replace_args *args) 699 { 700 args->result = __btrfs_dev_replace_cancel(fs_info); 701 return 0; 702 } 703 704 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 705 { 706 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 707 struct btrfs_device *tgt_device = NULL; 708 struct btrfs_trans_handle *trans; 709 struct btrfs_root *root = fs_info->tree_root; 710 u64 result; 711 int ret; 712 713 if (sb_rdonly(fs_info->sb)) 714 return -EROFS; 715 716 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 717 btrfs_dev_replace_lock(dev_replace, 1); 718 switch (dev_replace->replace_state) { 719 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 720 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 721 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 722 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 723 btrfs_dev_replace_unlock(dev_replace, 1); 724 goto leave; 725 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 726 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 727 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 728 tgt_device = dev_replace->tgtdev; 729 dev_replace->tgtdev = NULL; 730 dev_replace->srcdev = NULL; 731 break; 732 } 733 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 734 dev_replace->time_stopped = get_seconds(); 735 dev_replace->item_needs_writeback = 1; 736 btrfs_dev_replace_unlock(dev_replace, 1); 737 btrfs_scrub_cancel(fs_info); 738 739 trans = btrfs_start_transaction(root, 0); 740 if (IS_ERR(trans)) { 741 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 742 return PTR_ERR(trans); 743 } 744 ret = btrfs_commit_transaction(trans); 745 WARN_ON(ret); 746 if (tgt_device) 747 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 748 749 leave: 750 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 751 return result; 752 } 753 754 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 755 { 756 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 757 758 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 759 btrfs_dev_replace_lock(dev_replace, 1); 760 switch (dev_replace->replace_state) { 761 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 762 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 763 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 764 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 765 break; 766 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 767 dev_replace->replace_state = 768 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 769 dev_replace->time_stopped = get_seconds(); 770 dev_replace->item_needs_writeback = 1; 771 btrfs_info(fs_info, "suspending dev_replace for unmount"); 772 break; 773 } 774 775 btrfs_dev_replace_unlock(dev_replace, 1); 776 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 777 } 778 779 /* resume dev_replace procedure that was interrupted by unmount */ 780 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 781 { 782 struct task_struct *task; 783 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 784 785 btrfs_dev_replace_lock(dev_replace, 1); 786 switch (dev_replace->replace_state) { 787 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 788 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 789 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 790 btrfs_dev_replace_unlock(dev_replace, 1); 791 return 0; 792 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 793 break; 794 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 795 dev_replace->replace_state = 796 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 797 break; 798 } 799 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 800 btrfs_info(fs_info, 801 "cannot continue dev_replace, tgtdev is missing"); 802 btrfs_info(fs_info, 803 "you may cancel the operation after 'mount -o degraded'"); 804 btrfs_dev_replace_unlock(dev_replace, 1); 805 return 0; 806 } 807 btrfs_dev_replace_unlock(dev_replace, 1); 808 809 WARN_ON(test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)); 810 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 811 return PTR_ERR_OR_ZERO(task); 812 } 813 814 static int btrfs_dev_replace_kthread(void *data) 815 { 816 struct btrfs_fs_info *fs_info = data; 817 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 818 u64 progress; 819 820 progress = btrfs_dev_replace_progress(fs_info); 821 progress = div_u64(progress, 10); 822 btrfs_info_in_rcu(fs_info, 823 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 824 btrfs_dev_name(dev_replace->srcdev), 825 dev_replace->srcdev->devid, 826 btrfs_dev_name(dev_replace->tgtdev), 827 (unsigned int)progress); 828 829 btrfs_dev_replace_continue_on_mount(fs_info); 830 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); 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 cancellation is wanted. 870 */ 871 break; 872 } 873 return 1; 874 } 875 876 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw) 877 { 878 if (rw == 1) { 879 /* write */ 880 again: 881 wait_event(dev_replace->read_lock_wq, 882 atomic_read(&dev_replace->blocking_readers) == 0); 883 write_lock(&dev_replace->lock); 884 if (atomic_read(&dev_replace->blocking_readers)) { 885 write_unlock(&dev_replace->lock); 886 goto again; 887 } 888 } else { 889 read_lock(&dev_replace->lock); 890 atomic_inc(&dev_replace->read_locks); 891 } 892 } 893 894 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw) 895 { 896 if (rw == 1) { 897 /* write */ 898 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 899 write_unlock(&dev_replace->lock); 900 } else { 901 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 902 atomic_dec(&dev_replace->read_locks); 903 read_unlock(&dev_replace->lock); 904 } 905 } 906 907 /* inc blocking cnt and release read lock */ 908 void btrfs_dev_replace_set_lock_blocking( 909 struct btrfs_dev_replace *dev_replace) 910 { 911 /* only set blocking for read lock */ 912 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 913 atomic_inc(&dev_replace->blocking_readers); 914 read_unlock(&dev_replace->lock); 915 } 916 917 /* acquire read lock and dec blocking cnt */ 918 void btrfs_dev_replace_clear_lock_blocking( 919 struct btrfs_dev_replace *dev_replace) 920 { 921 /* only set blocking for read lock */ 922 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 923 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 924 read_lock(&dev_replace->lock); 925 if (atomic_dec_and_test(&dev_replace->blocking_readers) && 926 waitqueue_active(&dev_replace->read_lock_wq)) 927 wake_up(&dev_replace->read_lock_wq); 928 } 929 930 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 931 { 932 percpu_counter_inc(&fs_info->bio_counter); 933 } 934 935 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 936 { 937 percpu_counter_sub(&fs_info->bio_counter, amount); 938 939 if (waitqueue_active(&fs_info->replace_wait)) 940 wake_up(&fs_info->replace_wait); 941 } 942 943 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 944 { 945 while (1) { 946 percpu_counter_inc(&fs_info->bio_counter); 947 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 948 &fs_info->fs_state))) 949 break; 950 951 btrfs_bio_counter_dec(fs_info); 952 wait_event(fs_info->replace_wait, 953 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 954 &fs_info->fs_state)); 955 } 956 } 957