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_kthread(void *data); 48 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); 49 50 51 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 52 { 53 struct btrfs_key key; 54 struct btrfs_root *dev_root = fs_info->dev_root; 55 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 56 struct extent_buffer *eb; 57 int slot; 58 int ret = 0; 59 struct btrfs_path *path = NULL; 60 int item_size; 61 struct btrfs_dev_replace_item *ptr; 62 u64 src_devid; 63 64 path = btrfs_alloc_path(); 65 if (!path) { 66 ret = -ENOMEM; 67 goto out; 68 } 69 70 key.objectid = 0; 71 key.type = BTRFS_DEV_REPLACE_KEY; 72 key.offset = 0; 73 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); 74 if (ret) { 75 no_valid_dev_replace_entry_found: 76 ret = 0; 77 dev_replace->replace_state = 78 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; 79 dev_replace->cont_reading_from_srcdev_mode = 80 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; 81 dev_replace->replace_state = 0; 82 dev_replace->time_started = 0; 83 dev_replace->time_stopped = 0; 84 atomic64_set(&dev_replace->num_write_errors, 0); 85 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 86 dev_replace->cursor_left = 0; 87 dev_replace->committed_cursor_left = 0; 88 dev_replace->cursor_left_last_write_of_item = 0; 89 dev_replace->cursor_right = 0; 90 dev_replace->srcdev = NULL; 91 dev_replace->tgtdev = NULL; 92 dev_replace->is_valid = 0; 93 dev_replace->item_needs_writeback = 0; 94 goto out; 95 } 96 slot = path->slots[0]; 97 eb = path->nodes[0]; 98 item_size = btrfs_item_size_nr(eb, slot); 99 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); 100 101 if (item_size != sizeof(struct btrfs_dev_replace_item)) { 102 btrfs_warn(fs_info, 103 "dev_replace entry found has unexpected size, ignore entry"); 104 goto no_valid_dev_replace_entry_found; 105 } 106 107 src_devid = btrfs_dev_replace_src_devid(eb, ptr); 108 dev_replace->cont_reading_from_srcdev_mode = 109 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); 110 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); 111 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); 112 dev_replace->time_stopped = 113 btrfs_dev_replace_time_stopped(eb, ptr); 114 atomic64_set(&dev_replace->num_write_errors, 115 btrfs_dev_replace_num_write_errors(eb, ptr)); 116 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 117 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); 118 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); 119 dev_replace->committed_cursor_left = dev_replace->cursor_left; 120 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; 121 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); 122 dev_replace->is_valid = 1; 123 124 dev_replace->item_needs_writeback = 0; 125 switch (dev_replace->replace_state) { 126 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 127 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 128 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 129 dev_replace->srcdev = NULL; 130 dev_replace->tgtdev = NULL; 131 break; 132 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 133 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 134 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, 135 NULL, NULL); 136 dev_replace->tgtdev = btrfs_find_device(fs_info, 137 BTRFS_DEV_REPLACE_DEVID, 138 NULL, NULL); 139 /* 140 * allow 'btrfs dev replace_cancel' if src/tgt device is 141 * missing 142 */ 143 if (!dev_replace->srcdev && 144 !btrfs_test_opt(fs_info, DEGRADED)) { 145 ret = -EIO; 146 btrfs_warn(fs_info, 147 "cannot mount because device replace operation is ongoing and"); 148 btrfs_warn(fs_info, 149 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 150 src_devid); 151 } 152 if (!dev_replace->tgtdev && 153 !btrfs_test_opt(fs_info, DEGRADED)) { 154 ret = -EIO; 155 btrfs_warn(fs_info, 156 "cannot mount because device replace operation is ongoing and"); 157 btrfs_warn(fs_info, 158 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", 159 BTRFS_DEV_REPLACE_DEVID); 160 } 161 if (dev_replace->tgtdev) { 162 if (dev_replace->srcdev) { 163 dev_replace->tgtdev->total_bytes = 164 dev_replace->srcdev->total_bytes; 165 dev_replace->tgtdev->disk_total_bytes = 166 dev_replace->srcdev->disk_total_bytes; 167 dev_replace->tgtdev->commit_total_bytes = 168 dev_replace->srcdev->commit_total_bytes; 169 dev_replace->tgtdev->bytes_used = 170 dev_replace->srcdev->bytes_used; 171 dev_replace->tgtdev->commit_bytes_used = 172 dev_replace->srcdev->commit_bytes_used; 173 } 174 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, 175 &dev_replace->tgtdev->dev_state); 176 177 WARN_ON(fs_info->fs_devices->rw_devices == 0); 178 dev_replace->tgtdev->io_width = fs_info->sectorsize; 179 dev_replace->tgtdev->io_align = fs_info->sectorsize; 180 dev_replace->tgtdev->sector_size = fs_info->sectorsize; 181 dev_replace->tgtdev->fs_info = fs_info; 182 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 183 &dev_replace->tgtdev->dev_state); 184 } 185 break; 186 } 187 188 out: 189 btrfs_free_path(path); 190 return ret; 191 } 192 193 /* 194 * called from commit_transaction. Writes changed device replace state to 195 * disk. 196 */ 197 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 198 struct btrfs_fs_info *fs_info) 199 { 200 int ret; 201 struct btrfs_root *dev_root = fs_info->dev_root; 202 struct btrfs_path *path; 203 struct btrfs_key key; 204 struct extent_buffer *eb; 205 struct btrfs_dev_replace_item *ptr; 206 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 207 208 btrfs_dev_replace_lock(dev_replace, 0); 209 if (!dev_replace->is_valid || 210 !dev_replace->item_needs_writeback) { 211 btrfs_dev_replace_unlock(dev_replace, 0); 212 return 0; 213 } 214 btrfs_dev_replace_unlock(dev_replace, 0); 215 216 key.objectid = 0; 217 key.type = BTRFS_DEV_REPLACE_KEY; 218 key.offset = 0; 219 220 path = btrfs_alloc_path(); 221 if (!path) { 222 ret = -ENOMEM; 223 goto out; 224 } 225 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 226 if (ret < 0) { 227 btrfs_warn(fs_info, 228 "error %d while searching for dev_replace item!", 229 ret); 230 goto out; 231 } 232 233 if (ret == 0 && 234 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 235 /* 236 * need to delete old one and insert a new one. 237 * Since no attempt is made to recover any old state, if the 238 * dev_replace state is 'running', the data on the target 239 * drive is lost. 240 * It would be possible to recover the state: just make sure 241 * that the beginning of the item is never changed and always 242 * contains all the essential information. Then read this 243 * minimal set of information and use it as a base for the 244 * new state. 245 */ 246 ret = btrfs_del_item(trans, dev_root, path); 247 if (ret != 0) { 248 btrfs_warn(fs_info, 249 "delete too small dev_replace item failed %d!", 250 ret); 251 goto out; 252 } 253 ret = 1; 254 } 255 256 if (ret == 1) { 257 /* need to insert a new item */ 258 btrfs_release_path(path); 259 ret = btrfs_insert_empty_item(trans, dev_root, path, 260 &key, sizeof(*ptr)); 261 if (ret < 0) { 262 btrfs_warn(fs_info, 263 "insert dev_replace item failed %d!", ret); 264 goto out; 265 } 266 } 267 268 eb = path->nodes[0]; 269 ptr = btrfs_item_ptr(eb, path->slots[0], 270 struct btrfs_dev_replace_item); 271 272 btrfs_dev_replace_lock(dev_replace, 1); 273 if (dev_replace->srcdev) 274 btrfs_set_dev_replace_src_devid(eb, ptr, 275 dev_replace->srcdev->devid); 276 else 277 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); 278 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, 279 dev_replace->cont_reading_from_srcdev_mode); 280 btrfs_set_dev_replace_replace_state(eb, ptr, 281 dev_replace->replace_state); 282 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); 283 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); 284 btrfs_set_dev_replace_num_write_errors(eb, ptr, 285 atomic64_read(&dev_replace->num_write_errors)); 286 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, 287 atomic64_read(&dev_replace->num_uncorrectable_read_errors)); 288 dev_replace->cursor_left_last_write_of_item = 289 dev_replace->cursor_left; 290 btrfs_set_dev_replace_cursor_left(eb, ptr, 291 dev_replace->cursor_left_last_write_of_item); 292 btrfs_set_dev_replace_cursor_right(eb, ptr, 293 dev_replace->cursor_right); 294 dev_replace->item_needs_writeback = 0; 295 btrfs_dev_replace_unlock(dev_replace, 1); 296 297 btrfs_mark_buffer_dirty(eb); 298 299 out: 300 btrfs_free_path(path); 301 302 return ret; 303 } 304 305 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) 306 { 307 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 308 309 dev_replace->committed_cursor_left = 310 dev_replace->cursor_left_last_write_of_item; 311 } 312 313 static char* btrfs_dev_name(struct btrfs_device *device) 314 { 315 if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) 316 return "<missing disk>"; 317 else 318 return rcu_str_deref(device->name); 319 } 320 321 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 322 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, 323 int read_src) 324 { 325 struct btrfs_root *root = fs_info->dev_root; 326 struct btrfs_trans_handle *trans; 327 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 328 int ret; 329 struct btrfs_device *tgt_device = NULL; 330 struct btrfs_device *src_device = NULL; 331 332 /* the disk copy procedure reuses the scrub code */ 333 mutex_lock(&fs_info->volume_mutex); 334 ret = btrfs_find_device_by_devspec(fs_info, srcdevid, 335 srcdev_name, &src_device); 336 if (ret) { 337 mutex_unlock(&fs_info->volume_mutex); 338 return ret; 339 } 340 341 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, 342 src_device, &tgt_device); 343 mutex_unlock(&fs_info->volume_mutex); 344 if (ret) 345 return ret; 346 347 /* 348 * Here we commit the transaction to make sure commit_total_bytes 349 * of all the devices are updated. 350 */ 351 trans = btrfs_attach_transaction(root); 352 if (!IS_ERR(trans)) { 353 ret = btrfs_commit_transaction(trans); 354 if (ret) 355 return ret; 356 } else if (PTR_ERR(trans) != -ENOENT) { 357 return PTR_ERR(trans); 358 } 359 360 btrfs_dev_replace_lock(dev_replace, 1); 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 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 369 goto leave; 370 } 371 372 dev_replace->cont_reading_from_srcdev_mode = read_src; 373 WARN_ON(!src_device); 374 dev_replace->srcdev = src_device; 375 WARN_ON(!tgt_device); 376 dev_replace->tgtdev = tgt_device; 377 378 btrfs_info_in_rcu(fs_info, 379 "dev_replace from %s (devid %llu) to %s started", 380 btrfs_dev_name(src_device), 381 src_device->devid, 382 rcu_str_deref(tgt_device->name)); 383 384 /* 385 * from now on, the writes to the srcdev are all duplicated to 386 * go to the tgtdev as well (refer to btrfs_map_block()). 387 */ 388 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 389 dev_replace->time_started = get_seconds(); 390 dev_replace->cursor_left = 0; 391 dev_replace->committed_cursor_left = 0; 392 dev_replace->cursor_left_last_write_of_item = 0; 393 dev_replace->cursor_right = 0; 394 dev_replace->is_valid = 1; 395 dev_replace->item_needs_writeback = 1; 396 atomic64_set(&dev_replace->num_write_errors, 0); 397 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 398 btrfs_dev_replace_unlock(dev_replace, 1); 399 400 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 401 if (ret) 402 btrfs_err(fs_info, "kobj add dev failed %d", ret); 403 404 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 405 406 /* force writing the updated state information to disk */ 407 trans = btrfs_start_transaction(root, 0); 408 if (IS_ERR(trans)) { 409 ret = PTR_ERR(trans); 410 btrfs_dev_replace_lock(dev_replace, 1); 411 goto leave; 412 } 413 414 ret = btrfs_commit_transaction(trans); 415 WARN_ON(ret); 416 417 /* the disk copy procedure reuses the scrub code */ 418 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 419 btrfs_device_get_total_bytes(src_device), 420 &dev_replace->scrub_progress, 0, 1); 421 422 ret = btrfs_dev_replace_finishing(fs_info, ret); 423 if (ret == -EINPROGRESS) { 424 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 425 } else { 426 WARN_ON(ret); 427 } 428 429 return ret; 430 431 leave: 432 dev_replace->srcdev = NULL; 433 dev_replace->tgtdev = NULL; 434 btrfs_dev_replace_unlock(dev_replace, 1); 435 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 436 return ret; 437 } 438 439 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, 440 struct btrfs_ioctl_dev_replace_args *args) 441 { 442 int ret; 443 444 switch (args->start.cont_reading_from_srcdev_mode) { 445 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 446 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 447 break; 448 default: 449 return -EINVAL; 450 } 451 452 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 453 args->start.tgtdev_name[0] == '\0') 454 return -EINVAL; 455 456 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, 457 args->start.srcdevid, 458 args->start.srcdev_name, 459 args->start.cont_reading_from_srcdev_mode); 460 args->result = ret; 461 /* don't warn if EINPROGRESS, someone else might be running scrub */ 462 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS) 463 ret = 0; 464 465 return ret; 466 } 467 468 /* 469 * blocked until all in-flight bios operations are finished. 470 */ 471 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 472 { 473 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 474 wait_event(fs_info->replace_wait, !percpu_counter_sum( 475 &fs_info->bio_counter)); 476 } 477 478 /* 479 * we have removed target device, it is safe to allow new bios request. 480 */ 481 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 482 { 483 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 484 wake_up(&fs_info->replace_wait); 485 } 486 487 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 488 int scrub_ret) 489 { 490 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 491 struct btrfs_device *tgt_device; 492 struct btrfs_device *src_device; 493 struct btrfs_root *root = fs_info->tree_root; 494 u8 uuid_tmp[BTRFS_UUID_SIZE]; 495 struct btrfs_trans_handle *trans; 496 int ret = 0; 497 498 /* don't allow cancel or unmount to disturb the finishing procedure */ 499 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 500 501 btrfs_dev_replace_lock(dev_replace, 0); 502 /* was the operation canceled, or is it finished? */ 503 if (dev_replace->replace_state != 504 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 505 btrfs_dev_replace_unlock(dev_replace, 0); 506 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 507 return 0; 508 } 509 510 tgt_device = dev_replace->tgtdev; 511 src_device = dev_replace->srcdev; 512 btrfs_dev_replace_unlock(dev_replace, 0); 513 514 /* 515 * flush all outstanding I/O and inode extent mappings before the 516 * copy operation is declared as being finished 517 */ 518 ret = btrfs_start_delalloc_roots(fs_info, 0, -1); 519 if (ret) { 520 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 521 return ret; 522 } 523 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 524 525 trans = btrfs_start_transaction(root, 0); 526 if (IS_ERR(trans)) { 527 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 528 return PTR_ERR(trans); 529 } 530 ret = btrfs_commit_transaction(trans); 531 WARN_ON(ret); 532 533 mutex_lock(&uuid_mutex); 534 /* keep away write_all_supers() during the finishing procedure */ 535 mutex_lock(&fs_info->fs_devices->device_list_mutex); 536 mutex_lock(&fs_info->chunk_mutex); 537 btrfs_dev_replace_lock(dev_replace, 1); 538 dev_replace->replace_state = 539 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 540 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 541 dev_replace->tgtdev = NULL; 542 dev_replace->srcdev = NULL; 543 dev_replace->time_stopped = get_seconds(); 544 dev_replace->item_needs_writeback = 1; 545 546 /* replace old device with new one in mapping tree */ 547 if (!scrub_ret) { 548 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 549 src_device, 550 tgt_device); 551 } else { 552 btrfs_err_in_rcu(fs_info, 553 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 554 btrfs_dev_name(src_device), 555 src_device->devid, 556 rcu_str_deref(tgt_device->name), scrub_ret); 557 btrfs_dev_replace_unlock(dev_replace, 1); 558 mutex_unlock(&fs_info->chunk_mutex); 559 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 560 mutex_unlock(&uuid_mutex); 561 btrfs_rm_dev_replace_blocked(fs_info); 562 if (tgt_device) 563 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 564 btrfs_rm_dev_replace_unblocked(fs_info); 565 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 566 567 return scrub_ret; 568 } 569 570 btrfs_info_in_rcu(fs_info, 571 "dev_replace from %s (devid %llu) to %s finished", 572 btrfs_dev_name(src_device), 573 src_device->devid, 574 rcu_str_deref(tgt_device->name)); 575 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); 576 tgt_device->devid = src_device->devid; 577 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 578 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 579 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 580 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 581 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 582 btrfs_device_set_disk_total_bytes(tgt_device, 583 src_device->disk_total_bytes); 584 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 585 ASSERT(list_empty(&src_device->resized_list)); 586 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 587 tgt_device->commit_bytes_used = src_device->bytes_used; 588 589 btrfs_assign_next_active_device(fs_info, src_device, tgt_device); 590 591 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 592 fs_info->fs_devices->rw_devices++; 593 594 btrfs_dev_replace_unlock(dev_replace, 1); 595 596 btrfs_rm_dev_replace_blocked(fs_info); 597 598 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 599 600 btrfs_rm_dev_replace_unblocked(fs_info); 601 602 /* 603 * this is again a consistent state where no dev_replace procedure 604 * is running, the target device is part of the filesystem, the 605 * source device is not part of the filesystem anymore and its 1st 606 * superblock is scratched out so that it is no longer marked to 607 * belong to this filesystem. 608 */ 609 mutex_unlock(&fs_info->chunk_mutex); 610 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 611 mutex_unlock(&uuid_mutex); 612 613 /* replace the sysfs entry */ 614 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 615 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 616 617 /* write back the superblocks */ 618 trans = btrfs_start_transaction(root, 0); 619 if (!IS_ERR(trans)) 620 btrfs_commit_transaction(trans); 621 622 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 623 624 return 0; 625 } 626 627 static void btrfs_dev_replace_update_device_in_mapping_tree( 628 struct btrfs_fs_info *fs_info, 629 struct btrfs_device *srcdev, 630 struct btrfs_device *tgtdev) 631 { 632 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 633 struct extent_map *em; 634 struct map_lookup *map; 635 u64 start = 0; 636 int i; 637 638 write_lock(&em_tree->lock); 639 do { 640 em = lookup_extent_mapping(em_tree, start, (u64)-1); 641 if (!em) 642 break; 643 map = em->map_lookup; 644 for (i = 0; i < map->num_stripes; i++) 645 if (srcdev == map->stripes[i].dev) 646 map->stripes[i].dev = tgtdev; 647 start = em->start + em->len; 648 free_extent_map(em); 649 } while (start); 650 write_unlock(&em_tree->lock); 651 } 652 653 /* 654 * Read progress of device replace status according to the state and last 655 * stored position. The value format is the same as for 656 * btrfs_dev_replace::progress_1000 657 */ 658 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) 659 { 660 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 661 u64 ret = 0; 662 663 switch (dev_replace->replace_state) { 664 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 665 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 666 ret = 0; 667 break; 668 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 669 ret = 1000; 670 break; 671 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 672 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 673 ret = div64_u64(dev_replace->cursor_left, 674 div_u64(btrfs_device_get_total_bytes( 675 dev_replace->srcdev), 1000)); 676 break; 677 } 678 679 return ret; 680 } 681 682 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 683 struct btrfs_ioctl_dev_replace_args *args) 684 { 685 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 686 687 btrfs_dev_replace_lock(dev_replace, 0); 688 /* even if !dev_replace_is_valid, the values are good enough for 689 * the replace_status ioctl */ 690 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 691 args->status.replace_state = dev_replace->replace_state; 692 args->status.time_started = dev_replace->time_started; 693 args->status.time_stopped = dev_replace->time_stopped; 694 args->status.num_write_errors = 695 atomic64_read(&dev_replace->num_write_errors); 696 args->status.num_uncorrectable_read_errors = 697 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 698 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); 699 btrfs_dev_replace_unlock(dev_replace, 0); 700 } 701 702 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 703 { 704 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 705 struct btrfs_device *tgt_device = NULL; 706 struct btrfs_trans_handle *trans; 707 struct btrfs_root *root = fs_info->tree_root; 708 int result; 709 int ret; 710 711 if (sb_rdonly(fs_info->sb)) 712 return -EROFS; 713 714 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 715 btrfs_dev_replace_lock(dev_replace, 1); 716 switch (dev_replace->replace_state) { 717 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 718 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 719 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 720 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 721 btrfs_dev_replace_unlock(dev_replace, 1); 722 goto leave; 723 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 724 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 725 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 726 tgt_device = dev_replace->tgtdev; 727 dev_replace->tgtdev = NULL; 728 dev_replace->srcdev = NULL; 729 break; 730 } 731 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 732 dev_replace->time_stopped = get_seconds(); 733 dev_replace->item_needs_writeback = 1; 734 btrfs_dev_replace_unlock(dev_replace, 1); 735 btrfs_scrub_cancel(fs_info); 736 737 trans = btrfs_start_transaction(root, 0); 738 if (IS_ERR(trans)) { 739 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 740 return PTR_ERR(trans); 741 } 742 ret = btrfs_commit_transaction(trans); 743 WARN_ON(ret); 744 if (tgt_device) 745 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 746 747 leave: 748 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 749 return result; 750 } 751 752 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 753 { 754 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 755 756 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 757 btrfs_dev_replace_lock(dev_replace, 1); 758 switch (dev_replace->replace_state) { 759 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 760 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 761 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 762 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 763 break; 764 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 765 dev_replace->replace_state = 766 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 767 dev_replace->time_stopped = get_seconds(); 768 dev_replace->item_needs_writeback = 1; 769 btrfs_info(fs_info, "suspending dev_replace for unmount"); 770 break; 771 } 772 773 btrfs_dev_replace_unlock(dev_replace, 1); 774 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 775 } 776 777 /* resume dev_replace procedure that was interrupted by unmount */ 778 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 779 { 780 struct task_struct *task; 781 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 782 783 btrfs_dev_replace_lock(dev_replace, 1); 784 switch (dev_replace->replace_state) { 785 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 786 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 787 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 788 btrfs_dev_replace_unlock(dev_replace, 1); 789 return 0; 790 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 791 break; 792 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 793 dev_replace->replace_state = 794 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 795 break; 796 } 797 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 798 btrfs_info(fs_info, 799 "cannot continue dev_replace, tgtdev is missing"); 800 btrfs_info(fs_info, 801 "you may cancel the operation after 'mount -o degraded'"); 802 btrfs_dev_replace_unlock(dev_replace, 1); 803 return 0; 804 } 805 btrfs_dev_replace_unlock(dev_replace, 1); 806 807 WARN_ON(test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)); 808 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 809 return PTR_ERR_OR_ZERO(task); 810 } 811 812 static int btrfs_dev_replace_kthread(void *data) 813 { 814 struct btrfs_fs_info *fs_info = data; 815 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 816 u64 progress; 817 818 progress = btrfs_dev_replace_progress(fs_info); 819 progress = div_u64(progress, 10); 820 btrfs_info_in_rcu(fs_info, 821 "continuing dev_replace from %s (devid %llu) to target %s @%u%%", 822 btrfs_dev_name(dev_replace->srcdev), 823 dev_replace->srcdev->devid, 824 btrfs_dev_name(dev_replace->tgtdev), 825 (unsigned int)progress); 826 827 btrfs_dev_replace_continue_on_mount(fs_info); 828 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); 829 830 return 0; 831 } 832 833 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 834 { 835 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 836 int ret; 837 838 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 839 dev_replace->committed_cursor_left, 840 btrfs_device_get_total_bytes(dev_replace->srcdev), 841 &dev_replace->scrub_progress, 0, 1); 842 ret = btrfs_dev_replace_finishing(fs_info, ret); 843 WARN_ON(ret); 844 return 0; 845 } 846 847 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 848 { 849 if (!dev_replace->is_valid) 850 return 0; 851 852 switch (dev_replace->replace_state) { 853 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 854 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 855 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 856 return 0; 857 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 858 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 859 /* 860 * return true even if tgtdev is missing (this is 861 * something that can happen if the dev_replace 862 * procedure is suspended by an umount and then 863 * the tgtdev is missing (or "btrfs dev scan") was 864 * not called and the the filesystem is remounted 865 * in degraded state. This does not stop the 866 * dev_replace procedure. It needs to be canceled 867 * manually if the cancellation is wanted. 868 */ 869 break; 870 } 871 return 1; 872 } 873 874 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw) 875 { 876 if (rw == 1) { 877 /* write */ 878 again: 879 wait_event(dev_replace->read_lock_wq, 880 atomic_read(&dev_replace->blocking_readers) == 0); 881 write_lock(&dev_replace->lock); 882 if (atomic_read(&dev_replace->blocking_readers)) { 883 write_unlock(&dev_replace->lock); 884 goto again; 885 } 886 } else { 887 read_lock(&dev_replace->lock); 888 atomic_inc(&dev_replace->read_locks); 889 } 890 } 891 892 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw) 893 { 894 if (rw == 1) { 895 /* write */ 896 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 897 write_unlock(&dev_replace->lock); 898 } else { 899 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 900 atomic_dec(&dev_replace->read_locks); 901 read_unlock(&dev_replace->lock); 902 } 903 } 904 905 /* inc blocking cnt and release read lock */ 906 void btrfs_dev_replace_set_lock_blocking( 907 struct btrfs_dev_replace *dev_replace) 908 { 909 /* only set blocking for read lock */ 910 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 911 atomic_inc(&dev_replace->blocking_readers); 912 read_unlock(&dev_replace->lock); 913 } 914 915 /* acquire read lock and dec blocking cnt */ 916 void btrfs_dev_replace_clear_lock_blocking( 917 struct btrfs_dev_replace *dev_replace) 918 { 919 /* only set blocking for read lock */ 920 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 921 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 922 read_lock(&dev_replace->lock); 923 if (atomic_dec_and_test(&dev_replace->blocking_readers) && 924 waitqueue_active(&dev_replace->read_lock_wq)) 925 wake_up(&dev_replace->read_lock_wq); 926 } 927 928 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 929 { 930 percpu_counter_inc(&fs_info->bio_counter); 931 } 932 933 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 934 { 935 percpu_counter_sub(&fs_info->bio_counter, amount); 936 937 if (waitqueue_active(&fs_info->replace_wait)) 938 wake_up(&fs_info->replace_wait); 939 } 940 941 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 942 { 943 while (1) { 944 percpu_counter_inc(&fs_info->bio_counter); 945 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 946 &fs_info->fs_state))) 947 break; 948 949 btrfs_bio_counter_dec(fs_info); 950 wait_event(fs_info->replace_wait, 951 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 952 &fs_info->fs_state)); 953 } 954 } 955