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 btrfs_free_path(path); 187 return ret; 188 } 189 190 /* 191 * called from commit_transaction. Writes changed device replace state to 192 * disk. 193 */ 194 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 195 struct btrfs_fs_info *fs_info) 196 { 197 int ret; 198 struct btrfs_root *dev_root = fs_info->dev_root; 199 struct btrfs_path *path; 200 struct btrfs_key key; 201 struct extent_buffer *eb; 202 struct btrfs_dev_replace_item *ptr; 203 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 204 205 btrfs_dev_replace_lock(dev_replace, 0); 206 if (!dev_replace->is_valid || 207 !dev_replace->item_needs_writeback) { 208 btrfs_dev_replace_unlock(dev_replace, 0); 209 return 0; 210 } 211 btrfs_dev_replace_unlock(dev_replace, 0); 212 213 key.objectid = 0; 214 key.type = BTRFS_DEV_REPLACE_KEY; 215 key.offset = 0; 216 217 path = btrfs_alloc_path(); 218 if (!path) { 219 ret = -ENOMEM; 220 goto out; 221 } 222 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); 223 if (ret < 0) { 224 btrfs_warn(fs_info, "error %d while searching for dev_replace item!", 225 ret); 226 goto out; 227 } 228 229 if (ret == 0 && 230 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { 231 /* 232 * need to delete old one and insert a new one. 233 * Since no attempt is made to recover any old state, if the 234 * dev_replace state is 'running', the data on the target 235 * drive is lost. 236 * It would be possible to recover the state: just make sure 237 * that the beginning of the item is never changed and always 238 * contains all the essential information. Then read this 239 * minimal set of information and use it as a base for the 240 * new state. 241 */ 242 ret = btrfs_del_item(trans, dev_root, path); 243 if (ret != 0) { 244 btrfs_warn(fs_info, "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, "insert dev_replace item failed %d!", 258 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 int btrfs_dev_replace_start(struct btrfs_root *root, 309 struct btrfs_ioctl_dev_replace_args *args) 310 { 311 struct btrfs_trans_handle *trans; 312 struct btrfs_fs_info *fs_info = root->fs_info; 313 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 314 int ret; 315 struct btrfs_device *tgt_device = NULL; 316 struct btrfs_device *src_device = NULL; 317 318 switch (args->start.cont_reading_from_srcdev_mode) { 319 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: 320 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: 321 break; 322 default: 323 return -EINVAL; 324 } 325 326 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || 327 args->start.tgtdev_name[0] == '\0') 328 return -EINVAL; 329 330 /* the disk copy procedure reuses the scrub code */ 331 mutex_lock(&fs_info->volume_mutex); 332 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, 333 args->start.srcdev_name, 334 &src_device); 335 if (ret) { 336 mutex_unlock(&fs_info->volume_mutex); 337 return ret; 338 } 339 340 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, 341 src_device, &tgt_device); 342 mutex_unlock(&fs_info->volume_mutex); 343 if (ret) 344 return ret; 345 346 /* 347 * Here we commit the transaction to make sure commit_total_bytes 348 * of all the devices are updated. 349 */ 350 trans = btrfs_attach_transaction(root); 351 if (!IS_ERR(trans)) { 352 ret = btrfs_commit_transaction(trans, root); 353 if (ret) 354 return ret; 355 } else if (PTR_ERR(trans) != -ENOENT) { 356 return PTR_ERR(trans); 357 } 358 359 btrfs_dev_replace_lock(dev_replace, 1); 360 switch (dev_replace->replace_state) { 361 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 362 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 363 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 364 break; 365 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 366 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 367 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; 368 goto leave; 369 } 370 371 dev_replace->cont_reading_from_srcdev_mode = 372 args->start.cont_reading_from_srcdev_mode; 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(root->fs_info, 379 "dev_replace from %s (devid %llu) to %s started", 380 src_device->missing ? "<missing disk>" : 381 rcu_str_deref(src_device->name), 382 src_device->devid, 383 rcu_str_deref(tgt_device->name)); 384 385 /* 386 * from now on, the writes to the srcdev are all duplicated to 387 * go to the tgtdev as well (refer to btrfs_map_block()). 388 */ 389 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 390 dev_replace->time_started = get_seconds(); 391 dev_replace->cursor_left = 0; 392 dev_replace->committed_cursor_left = 0; 393 dev_replace->cursor_left_last_write_of_item = 0; 394 dev_replace->cursor_right = 0; 395 dev_replace->is_valid = 1; 396 dev_replace->item_needs_writeback = 1; 397 atomic64_set(&dev_replace->num_write_errors, 0); 398 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); 399 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 400 btrfs_dev_replace_unlock(dev_replace, 1); 401 402 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); 403 if (ret) 404 btrfs_err(root->fs_info, "kobj add dev failed %d\n", ret); 405 406 btrfs_wait_ordered_roots(root->fs_info, -1); 407 408 /* force writing the updated state information to disk */ 409 trans = btrfs_start_transaction(root, 0); 410 if (IS_ERR(trans)) { 411 ret = PTR_ERR(trans); 412 btrfs_dev_replace_lock(dev_replace, 1); 413 goto leave; 414 } 415 416 ret = btrfs_commit_transaction(trans, root); 417 WARN_ON(ret); 418 419 /* the disk copy procedure reuses the scrub code */ 420 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, 421 btrfs_device_get_total_bytes(src_device), 422 &dev_replace->scrub_progress, 0, 1); 423 424 ret = btrfs_dev_replace_finishing(root->fs_info, ret); 425 /* don't warn if EINPROGRESS, someone else might be running scrub */ 426 if (ret == -EINPROGRESS) { 427 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; 428 ret = 0; 429 } else { 430 WARN_ON(ret); 431 } 432 433 return ret; 434 435 leave: 436 dev_replace->srcdev = NULL; 437 dev_replace->tgtdev = NULL; 438 btrfs_dev_replace_unlock(dev_replace, 1); 439 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 440 return ret; 441 } 442 443 /* 444 * blocked until all in-flight bios operations are finished. 445 */ 446 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) 447 { 448 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 449 wait_event(fs_info->replace_wait, !percpu_counter_sum( 450 &fs_info->bio_counter)); 451 } 452 453 /* 454 * we have removed target device, it is safe to allow new bios request. 455 */ 456 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) 457 { 458 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); 459 wake_up(&fs_info->replace_wait); 460 } 461 462 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 463 int scrub_ret) 464 { 465 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 466 struct btrfs_device *tgt_device; 467 struct btrfs_device *src_device; 468 struct btrfs_root *root = fs_info->tree_root; 469 u8 uuid_tmp[BTRFS_UUID_SIZE]; 470 struct btrfs_trans_handle *trans; 471 int ret = 0; 472 473 /* don't allow cancel or unmount to disturb the finishing procedure */ 474 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 475 476 btrfs_dev_replace_lock(dev_replace, 0); 477 /* was the operation canceled, or is it finished? */ 478 if (dev_replace->replace_state != 479 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { 480 btrfs_dev_replace_unlock(dev_replace, 0); 481 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 482 return 0; 483 } 484 485 tgt_device = dev_replace->tgtdev; 486 src_device = dev_replace->srcdev; 487 btrfs_dev_replace_unlock(dev_replace, 0); 488 489 /* 490 * flush all outstanding I/O and inode extent mappings before the 491 * copy operation is declared as being finished 492 */ 493 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1); 494 if (ret) { 495 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 496 return ret; 497 } 498 btrfs_wait_ordered_roots(root->fs_info, -1); 499 500 trans = btrfs_start_transaction(root, 0); 501 if (IS_ERR(trans)) { 502 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 503 return PTR_ERR(trans); 504 } 505 ret = btrfs_commit_transaction(trans, root); 506 WARN_ON(ret); 507 508 mutex_lock(&uuid_mutex); 509 /* keep away write_all_supers() during the finishing procedure */ 510 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 511 mutex_lock(&root->fs_info->chunk_mutex); 512 btrfs_dev_replace_lock(dev_replace, 1); 513 dev_replace->replace_state = 514 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 515 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; 516 dev_replace->tgtdev = NULL; 517 dev_replace->srcdev = NULL; 518 dev_replace->time_stopped = get_seconds(); 519 dev_replace->item_needs_writeback = 1; 520 521 /* replace old device with new one in mapping tree */ 522 if (!scrub_ret) { 523 btrfs_dev_replace_update_device_in_mapping_tree(fs_info, 524 src_device, 525 tgt_device); 526 } else { 527 btrfs_err_in_rcu(root->fs_info, 528 "btrfs_scrub_dev(%s, %llu, %s) failed %d", 529 src_device->missing ? "<missing disk>" : 530 rcu_str_deref(src_device->name), 531 src_device->devid, 532 rcu_str_deref(tgt_device->name), scrub_ret); 533 btrfs_dev_replace_unlock(dev_replace, 1); 534 mutex_unlock(&root->fs_info->chunk_mutex); 535 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 536 mutex_unlock(&uuid_mutex); 537 if (tgt_device) 538 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 539 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 540 541 return scrub_ret; 542 } 543 544 btrfs_info_in_rcu(root->fs_info, 545 "dev_replace from %s (devid %llu) to %s finished", 546 src_device->missing ? "<missing disk>" : 547 rcu_str_deref(src_device->name), 548 src_device->devid, 549 rcu_str_deref(tgt_device->name)); 550 tgt_device->is_tgtdev_for_dev_replace = 0; 551 tgt_device->devid = src_device->devid; 552 src_device->devid = BTRFS_DEV_REPLACE_DEVID; 553 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); 554 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); 555 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); 556 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); 557 btrfs_device_set_disk_total_bytes(tgt_device, 558 src_device->disk_total_bytes); 559 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); 560 ASSERT(list_empty(&src_device->resized_list)); 561 tgt_device->commit_total_bytes = src_device->commit_total_bytes; 562 tgt_device->commit_bytes_used = src_device->bytes_used; 563 if (fs_info->sb->s_bdev == src_device->bdev) 564 fs_info->sb->s_bdev = tgt_device->bdev; 565 if (fs_info->fs_devices->latest_bdev == src_device->bdev) 566 fs_info->fs_devices->latest_bdev = tgt_device->bdev; 567 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); 568 fs_info->fs_devices->rw_devices++; 569 570 btrfs_dev_replace_unlock(dev_replace, 1); 571 572 btrfs_rm_dev_replace_blocked(fs_info); 573 574 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device); 575 576 btrfs_rm_dev_replace_unblocked(fs_info); 577 578 /* 579 * this is again a consistent state where no dev_replace procedure 580 * is running, the target device is part of the filesystem, the 581 * source device is not part of the filesystem anymore and its 1st 582 * superblock is scratched out so that it is no longer marked to 583 * belong to this filesystem. 584 */ 585 mutex_unlock(&root->fs_info->chunk_mutex); 586 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 587 mutex_unlock(&uuid_mutex); 588 589 /* replace the sysfs entry */ 590 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); 591 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device); 592 593 /* write back the superblocks */ 594 trans = btrfs_start_transaction(root, 0); 595 if (!IS_ERR(trans)) 596 btrfs_commit_transaction(trans, root); 597 598 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 599 600 return 0; 601 } 602 603 static void btrfs_dev_replace_update_device_in_mapping_tree( 604 struct btrfs_fs_info *fs_info, 605 struct btrfs_device *srcdev, 606 struct btrfs_device *tgtdev) 607 { 608 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; 609 struct extent_map *em; 610 struct map_lookup *map; 611 u64 start = 0; 612 int i; 613 614 write_lock(&em_tree->lock); 615 do { 616 em = lookup_extent_mapping(em_tree, start, (u64)-1); 617 if (!em) 618 break; 619 map = em->map_lookup; 620 for (i = 0; i < map->num_stripes; i++) 621 if (srcdev == map->stripes[i].dev) 622 map->stripes[i].dev = tgtdev; 623 start = em->start + em->len; 624 free_extent_map(em); 625 } while (start); 626 write_unlock(&em_tree->lock); 627 } 628 629 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, 630 char *srcdev_name, 631 struct btrfs_device **device) 632 { 633 int ret; 634 635 if (srcdevid) { 636 ret = 0; 637 *device = btrfs_find_device(root->fs_info, srcdevid, NULL, 638 NULL); 639 if (!*device) 640 ret = -ENOENT; 641 } else { 642 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, 643 device); 644 } 645 return ret; 646 } 647 648 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 649 struct btrfs_ioctl_dev_replace_args *args) 650 { 651 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 652 struct btrfs_device *srcdev; 653 654 btrfs_dev_replace_lock(dev_replace, 0); 655 /* even if !dev_replace_is_valid, the values are good enough for 656 * the replace_status ioctl */ 657 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 658 args->status.replace_state = dev_replace->replace_state; 659 args->status.time_started = dev_replace->time_started; 660 args->status.time_stopped = dev_replace->time_stopped; 661 args->status.num_write_errors = 662 atomic64_read(&dev_replace->num_write_errors); 663 args->status.num_uncorrectable_read_errors = 664 atomic64_read(&dev_replace->num_uncorrectable_read_errors); 665 switch (dev_replace->replace_state) { 666 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 667 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 668 args->status.progress_1000 = 0; 669 break; 670 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 671 args->status.progress_1000 = 1000; 672 break; 673 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 674 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 675 srcdev = dev_replace->srcdev; 676 args->status.progress_1000 = div_u64(dev_replace->cursor_left, 677 div_u64(btrfs_device_get_total_bytes(srcdev), 1000)); 678 break; 679 } 680 btrfs_dev_replace_unlock(dev_replace, 0); 681 } 682 683 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, 684 struct btrfs_ioctl_dev_replace_args *args) 685 { 686 args->result = __btrfs_dev_replace_cancel(fs_info); 687 return 0; 688 } 689 690 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 691 { 692 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 693 struct btrfs_device *tgt_device = NULL; 694 struct btrfs_trans_handle *trans; 695 struct btrfs_root *root = fs_info->tree_root; 696 u64 result; 697 int ret; 698 699 if (fs_info->sb->s_flags & MS_RDONLY) 700 return -EROFS; 701 702 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 703 btrfs_dev_replace_lock(dev_replace, 1); 704 switch (dev_replace->replace_state) { 705 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 706 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 707 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 708 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; 709 btrfs_dev_replace_unlock(dev_replace, 1); 710 goto leave; 711 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 712 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 713 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; 714 tgt_device = dev_replace->tgtdev; 715 dev_replace->tgtdev = NULL; 716 dev_replace->srcdev = NULL; 717 break; 718 } 719 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; 720 dev_replace->time_stopped = get_seconds(); 721 dev_replace->item_needs_writeback = 1; 722 btrfs_dev_replace_unlock(dev_replace, 1); 723 btrfs_scrub_cancel(fs_info); 724 725 trans = btrfs_start_transaction(root, 0); 726 if (IS_ERR(trans)) { 727 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 728 return PTR_ERR(trans); 729 } 730 ret = btrfs_commit_transaction(trans, root); 731 WARN_ON(ret); 732 if (tgt_device) 733 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); 734 735 leave: 736 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 737 return result; 738 } 739 740 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 741 { 742 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 743 744 mutex_lock(&dev_replace->lock_finishing_cancel_unmount); 745 btrfs_dev_replace_lock(dev_replace, 1); 746 switch (dev_replace->replace_state) { 747 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 748 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 749 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 750 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 751 break; 752 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 753 dev_replace->replace_state = 754 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; 755 dev_replace->time_stopped = get_seconds(); 756 dev_replace->item_needs_writeback = 1; 757 btrfs_info(fs_info, "suspending dev_replace for unmount"); 758 break; 759 } 760 761 btrfs_dev_replace_unlock(dev_replace, 1); 762 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); 763 } 764 765 /* resume dev_replace procedure that was interrupted by unmount */ 766 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 767 { 768 struct task_struct *task; 769 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 770 771 btrfs_dev_replace_lock(dev_replace, 1); 772 switch (dev_replace->replace_state) { 773 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 774 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 775 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 776 btrfs_dev_replace_unlock(dev_replace, 1); 777 return 0; 778 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 779 break; 780 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 781 dev_replace->replace_state = 782 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; 783 break; 784 } 785 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { 786 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); 787 btrfs_info(fs_info, 788 "you may cancel the operation after 'mount -o degraded'"); 789 btrfs_dev_replace_unlock(dev_replace, 1); 790 return 0; 791 } 792 btrfs_dev_replace_unlock(dev_replace, 1); 793 794 WARN_ON(atomic_xchg( 795 &fs_info->mutually_exclusive_operation_running, 1)); 796 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); 797 return PTR_ERR_OR_ZERO(task); 798 } 799 800 static int btrfs_dev_replace_kthread(void *data) 801 { 802 struct btrfs_fs_info *fs_info = data; 803 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 804 struct btrfs_ioctl_dev_replace_args *status_args; 805 u64 progress; 806 807 status_args = kzalloc(sizeof(*status_args), GFP_KERNEL); 808 if (status_args) { 809 btrfs_dev_replace_status(fs_info, status_args); 810 progress = status_args->status.progress_1000; 811 kfree(status_args); 812 progress = div_u64(progress, 10); 813 btrfs_info_in_rcu(fs_info, 814 "continuing dev_replace from %s (devid %llu) to %s @%u%%", 815 dev_replace->srcdev->missing ? "<missing disk>" : 816 rcu_str_deref(dev_replace->srcdev->name), 817 dev_replace->srcdev->devid, 818 dev_replace->tgtdev ? 819 rcu_str_deref(dev_replace->tgtdev->name) : 820 "<missing target disk>", 821 (unsigned int)progress); 822 } 823 btrfs_dev_replace_continue_on_mount(fs_info); 824 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 825 826 return 0; 827 } 828 829 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) 830 { 831 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; 832 int ret; 833 834 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, 835 dev_replace->committed_cursor_left, 836 btrfs_device_get_total_bytes(dev_replace->srcdev), 837 &dev_replace->scrub_progress, 0, 1); 838 ret = btrfs_dev_replace_finishing(fs_info, ret); 839 WARN_ON(ret); 840 return 0; 841 } 842 843 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 844 { 845 if (!dev_replace->is_valid) 846 return 0; 847 848 switch (dev_replace->replace_state) { 849 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: 850 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: 851 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: 852 return 0; 853 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: 854 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: 855 /* 856 * return true even if tgtdev is missing (this is 857 * something that can happen if the dev_replace 858 * procedure is suspended by an umount and then 859 * the tgtdev is missing (or "btrfs dev scan") was 860 * not called and the the filesystem is remounted 861 * in degraded state. This does not stop the 862 * dev_replace procedure. It needs to be canceled 863 * manually if the cancellation is wanted. 864 */ 865 break; 866 } 867 return 1; 868 } 869 870 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw) 871 { 872 if (rw == 1) { 873 /* write */ 874 again: 875 wait_event(dev_replace->read_lock_wq, 876 atomic_read(&dev_replace->blocking_readers) == 0); 877 write_lock(&dev_replace->lock); 878 if (atomic_read(&dev_replace->blocking_readers)) { 879 write_unlock(&dev_replace->lock); 880 goto again; 881 } 882 } else { 883 read_lock(&dev_replace->lock); 884 atomic_inc(&dev_replace->read_locks); 885 } 886 } 887 888 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw) 889 { 890 if (rw == 1) { 891 /* write */ 892 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); 893 write_unlock(&dev_replace->lock); 894 } else { 895 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 896 atomic_dec(&dev_replace->read_locks); 897 read_unlock(&dev_replace->lock); 898 } 899 } 900 901 /* inc blocking cnt and release read lock */ 902 void btrfs_dev_replace_set_lock_blocking( 903 struct btrfs_dev_replace *dev_replace) 904 { 905 /* only set blocking for read lock */ 906 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 907 atomic_inc(&dev_replace->blocking_readers); 908 read_unlock(&dev_replace->lock); 909 } 910 911 /* acquire read lock and dec blocking cnt */ 912 void btrfs_dev_replace_clear_lock_blocking( 913 struct btrfs_dev_replace *dev_replace) 914 { 915 /* only set blocking for read lock */ 916 ASSERT(atomic_read(&dev_replace->read_locks) > 0); 917 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); 918 read_lock(&dev_replace->lock); 919 if (atomic_dec_and_test(&dev_replace->blocking_readers) && 920 waitqueue_active(&dev_replace->read_lock_wq)) 921 wake_up(&dev_replace->read_lock_wq); 922 } 923 924 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) 925 { 926 percpu_counter_inc(&fs_info->bio_counter); 927 } 928 929 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) 930 { 931 percpu_counter_sub(&fs_info->bio_counter, amount); 932 933 if (waitqueue_active(&fs_info->replace_wait)) 934 wake_up(&fs_info->replace_wait); 935 } 936 937 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) 938 { 939 while (1) { 940 percpu_counter_inc(&fs_info->bio_counter); 941 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, 942 &fs_info->fs_state))) 943 break; 944 945 btrfs_bio_counter_dec(fs_info); 946 wait_event(fs_info->replace_wait, 947 !test_bit(BTRFS_FS_STATE_DEV_REPLACING, 948 &fs_info->fs_state)); 949 } 950 } 951