1 /* 2 * Copyright (C) 2007 Oracle. 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 <asm/div64.h> 27 #include "compat.h" 28 #include "ctree.h" 29 #include "extent_map.h" 30 #include "disk-io.h" 31 #include "transaction.h" 32 #include "print-tree.h" 33 #include "volumes.h" 34 #include "async-thread.h" 35 36 struct map_lookup { 37 u64 type; 38 int io_align; 39 int io_width; 40 int stripe_len; 41 int sector_size; 42 int num_stripes; 43 int sub_stripes; 44 struct btrfs_bio_stripe stripes[]; 45 }; 46 47 static int init_first_rw_device(struct btrfs_trans_handle *trans, 48 struct btrfs_root *root, 49 struct btrfs_device *device); 50 static int btrfs_relocate_sys_chunks(struct btrfs_root *root); 51 52 #define map_lookup_size(n) (sizeof(struct map_lookup) + \ 53 (sizeof(struct btrfs_bio_stripe) * (n))) 54 55 static DEFINE_MUTEX(uuid_mutex); 56 static LIST_HEAD(fs_uuids); 57 58 void btrfs_lock_volumes(void) 59 { 60 mutex_lock(&uuid_mutex); 61 } 62 63 void btrfs_unlock_volumes(void) 64 { 65 mutex_unlock(&uuid_mutex); 66 } 67 68 static void lock_chunks(struct btrfs_root *root) 69 { 70 mutex_lock(&root->fs_info->chunk_mutex); 71 } 72 73 static void unlock_chunks(struct btrfs_root *root) 74 { 75 mutex_unlock(&root->fs_info->chunk_mutex); 76 } 77 78 static void free_fs_devices(struct btrfs_fs_devices *fs_devices) 79 { 80 struct btrfs_device *device; 81 WARN_ON(fs_devices->opened); 82 while (!list_empty(&fs_devices->devices)) { 83 device = list_entry(fs_devices->devices.next, 84 struct btrfs_device, dev_list); 85 list_del(&device->dev_list); 86 kfree(device->name); 87 kfree(device); 88 } 89 kfree(fs_devices); 90 } 91 92 int btrfs_cleanup_fs_uuids(void) 93 { 94 struct btrfs_fs_devices *fs_devices; 95 96 while (!list_empty(&fs_uuids)) { 97 fs_devices = list_entry(fs_uuids.next, 98 struct btrfs_fs_devices, list); 99 list_del(&fs_devices->list); 100 free_fs_devices(fs_devices); 101 } 102 return 0; 103 } 104 105 static noinline struct btrfs_device *__find_device(struct list_head *head, 106 u64 devid, u8 *uuid) 107 { 108 struct btrfs_device *dev; 109 110 list_for_each_entry(dev, head, dev_list) { 111 if (dev->devid == devid && 112 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) { 113 return dev; 114 } 115 } 116 return NULL; 117 } 118 119 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid) 120 { 121 struct btrfs_fs_devices *fs_devices; 122 123 list_for_each_entry(fs_devices, &fs_uuids, list) { 124 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0) 125 return fs_devices; 126 } 127 return NULL; 128 } 129 130 static void requeue_list(struct btrfs_pending_bios *pending_bios, 131 struct bio *head, struct bio *tail) 132 { 133 134 struct bio *old_head; 135 136 old_head = pending_bios->head; 137 pending_bios->head = head; 138 if (pending_bios->tail) 139 tail->bi_next = old_head; 140 else 141 pending_bios->tail = tail; 142 } 143 144 /* 145 * we try to collect pending bios for a device so we don't get a large 146 * number of procs sending bios down to the same device. This greatly 147 * improves the schedulers ability to collect and merge the bios. 148 * 149 * But, it also turns into a long list of bios to process and that is sure 150 * to eventually make the worker thread block. The solution here is to 151 * make some progress and then put this work struct back at the end of 152 * the list if the block device is congested. This way, multiple devices 153 * can make progress from a single worker thread. 154 */ 155 static noinline int run_scheduled_bios(struct btrfs_device *device) 156 { 157 struct bio *pending; 158 struct backing_dev_info *bdi; 159 struct btrfs_fs_info *fs_info; 160 struct btrfs_pending_bios *pending_bios; 161 struct bio *tail; 162 struct bio *cur; 163 int again = 0; 164 unsigned long num_run; 165 unsigned long num_sync_run; 166 unsigned long batch_run = 0; 167 unsigned long limit; 168 unsigned long last_waited = 0; 169 int force_reg = 0; 170 171 bdi = blk_get_backing_dev_info(device->bdev); 172 fs_info = device->dev_root->fs_info; 173 limit = btrfs_async_submit_limit(fs_info); 174 limit = limit * 2 / 3; 175 176 /* we want to make sure that every time we switch from the sync 177 * list to the normal list, we unplug 178 */ 179 num_sync_run = 0; 180 181 loop: 182 spin_lock(&device->io_lock); 183 184 loop_lock: 185 num_run = 0; 186 187 /* take all the bios off the list at once and process them 188 * later on (without the lock held). But, remember the 189 * tail and other pointers so the bios can be properly reinserted 190 * into the list if we hit congestion 191 */ 192 if (!force_reg && device->pending_sync_bios.head) { 193 pending_bios = &device->pending_sync_bios; 194 force_reg = 1; 195 } else { 196 pending_bios = &device->pending_bios; 197 force_reg = 0; 198 } 199 200 pending = pending_bios->head; 201 tail = pending_bios->tail; 202 WARN_ON(pending && !tail); 203 204 /* 205 * if pending was null this time around, no bios need processing 206 * at all and we can stop. Otherwise it'll loop back up again 207 * and do an additional check so no bios are missed. 208 * 209 * device->running_pending is used to synchronize with the 210 * schedule_bio code. 211 */ 212 if (device->pending_sync_bios.head == NULL && 213 device->pending_bios.head == NULL) { 214 again = 0; 215 device->running_pending = 0; 216 } else { 217 again = 1; 218 device->running_pending = 1; 219 } 220 221 pending_bios->head = NULL; 222 pending_bios->tail = NULL; 223 224 spin_unlock(&device->io_lock); 225 226 /* 227 * if we're doing the regular priority list, make sure we unplug 228 * for any high prio bios we've sent down 229 */ 230 if (pending_bios == &device->pending_bios && num_sync_run > 0) { 231 num_sync_run = 0; 232 blk_run_backing_dev(bdi, NULL); 233 } 234 235 while (pending) { 236 237 rmb(); 238 /* we want to work on both lists, but do more bios on the 239 * sync list than the regular list 240 */ 241 if ((num_run > 32 && 242 pending_bios != &device->pending_sync_bios && 243 device->pending_sync_bios.head) || 244 (num_run > 64 && pending_bios == &device->pending_sync_bios && 245 device->pending_bios.head)) { 246 spin_lock(&device->io_lock); 247 requeue_list(pending_bios, pending, tail); 248 goto loop_lock; 249 } 250 251 cur = pending; 252 pending = pending->bi_next; 253 cur->bi_next = NULL; 254 atomic_dec(&fs_info->nr_async_bios); 255 256 if (atomic_read(&fs_info->nr_async_bios) < limit && 257 waitqueue_active(&fs_info->async_submit_wait)) 258 wake_up(&fs_info->async_submit_wait); 259 260 BUG_ON(atomic_read(&cur->bi_cnt) == 0); 261 262 if (cur->bi_rw & REQ_SYNC) 263 num_sync_run++; 264 265 submit_bio(cur->bi_rw, cur); 266 num_run++; 267 batch_run++; 268 if (need_resched()) { 269 if (num_sync_run) { 270 blk_run_backing_dev(bdi, NULL); 271 num_sync_run = 0; 272 } 273 cond_resched(); 274 } 275 276 /* 277 * we made progress, there is more work to do and the bdi 278 * is now congested. Back off and let other work structs 279 * run instead 280 */ 281 if (pending && bdi_write_congested(bdi) && batch_run > 8 && 282 fs_info->fs_devices->open_devices > 1) { 283 struct io_context *ioc; 284 285 ioc = current->io_context; 286 287 /* 288 * the main goal here is that we don't want to 289 * block if we're going to be able to submit 290 * more requests without blocking. 291 * 292 * This code does two great things, it pokes into 293 * the elevator code from a filesystem _and_ 294 * it makes assumptions about how batching works. 295 */ 296 if (ioc && ioc->nr_batch_requests > 0 && 297 time_before(jiffies, ioc->last_waited + HZ/50UL) && 298 (last_waited == 0 || 299 ioc->last_waited == last_waited)) { 300 /* 301 * we want to go through our batch of 302 * requests and stop. So, we copy out 303 * the ioc->last_waited time and test 304 * against it before looping 305 */ 306 last_waited = ioc->last_waited; 307 if (need_resched()) { 308 if (num_sync_run) { 309 blk_run_backing_dev(bdi, NULL); 310 num_sync_run = 0; 311 } 312 cond_resched(); 313 } 314 continue; 315 } 316 spin_lock(&device->io_lock); 317 requeue_list(pending_bios, pending, tail); 318 device->running_pending = 1; 319 320 spin_unlock(&device->io_lock); 321 btrfs_requeue_work(&device->work); 322 goto done; 323 } 324 } 325 326 if (num_sync_run) { 327 num_sync_run = 0; 328 blk_run_backing_dev(bdi, NULL); 329 } 330 /* 331 * IO has already been through a long path to get here. Checksumming, 332 * async helper threads, perhaps compression. We've done a pretty 333 * good job of collecting a batch of IO and should just unplug 334 * the device right away. 335 * 336 * This will help anyone who is waiting on the IO, they might have 337 * already unplugged, but managed to do so before the bio they 338 * cared about found its way down here. 339 */ 340 blk_run_backing_dev(bdi, NULL); 341 342 cond_resched(); 343 if (again) 344 goto loop; 345 346 spin_lock(&device->io_lock); 347 if (device->pending_bios.head || device->pending_sync_bios.head) 348 goto loop_lock; 349 spin_unlock(&device->io_lock); 350 351 done: 352 return 0; 353 } 354 355 static void pending_bios_fn(struct btrfs_work *work) 356 { 357 struct btrfs_device *device; 358 359 device = container_of(work, struct btrfs_device, work); 360 run_scheduled_bios(device); 361 } 362 363 static noinline int device_list_add(const char *path, 364 struct btrfs_super_block *disk_super, 365 u64 devid, struct btrfs_fs_devices **fs_devices_ret) 366 { 367 struct btrfs_device *device; 368 struct btrfs_fs_devices *fs_devices; 369 u64 found_transid = btrfs_super_generation(disk_super); 370 char *name; 371 372 fs_devices = find_fsid(disk_super->fsid); 373 if (!fs_devices) { 374 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); 375 if (!fs_devices) 376 return -ENOMEM; 377 INIT_LIST_HEAD(&fs_devices->devices); 378 INIT_LIST_HEAD(&fs_devices->alloc_list); 379 list_add(&fs_devices->list, &fs_uuids); 380 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE); 381 fs_devices->latest_devid = devid; 382 fs_devices->latest_trans = found_transid; 383 mutex_init(&fs_devices->device_list_mutex); 384 device = NULL; 385 } else { 386 device = __find_device(&fs_devices->devices, devid, 387 disk_super->dev_item.uuid); 388 } 389 if (!device) { 390 if (fs_devices->opened) 391 return -EBUSY; 392 393 device = kzalloc(sizeof(*device), GFP_NOFS); 394 if (!device) { 395 /* we can safely leave the fs_devices entry around */ 396 return -ENOMEM; 397 } 398 device->devid = devid; 399 device->work.func = pending_bios_fn; 400 memcpy(device->uuid, disk_super->dev_item.uuid, 401 BTRFS_UUID_SIZE); 402 spin_lock_init(&device->io_lock); 403 device->name = kstrdup(path, GFP_NOFS); 404 if (!device->name) { 405 kfree(device); 406 return -ENOMEM; 407 } 408 INIT_LIST_HEAD(&device->dev_alloc_list); 409 410 mutex_lock(&fs_devices->device_list_mutex); 411 list_add(&device->dev_list, &fs_devices->devices); 412 mutex_unlock(&fs_devices->device_list_mutex); 413 414 device->fs_devices = fs_devices; 415 fs_devices->num_devices++; 416 } else if (!device->name || strcmp(device->name, path)) { 417 name = kstrdup(path, GFP_NOFS); 418 if (!name) 419 return -ENOMEM; 420 kfree(device->name); 421 device->name = name; 422 if (device->missing) { 423 fs_devices->missing_devices--; 424 device->missing = 0; 425 } 426 } 427 428 if (found_transid > fs_devices->latest_trans) { 429 fs_devices->latest_devid = devid; 430 fs_devices->latest_trans = found_transid; 431 } 432 *fs_devices_ret = fs_devices; 433 return 0; 434 } 435 436 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig) 437 { 438 struct btrfs_fs_devices *fs_devices; 439 struct btrfs_device *device; 440 struct btrfs_device *orig_dev; 441 442 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); 443 if (!fs_devices) 444 return ERR_PTR(-ENOMEM); 445 446 INIT_LIST_HEAD(&fs_devices->devices); 447 INIT_LIST_HEAD(&fs_devices->alloc_list); 448 INIT_LIST_HEAD(&fs_devices->list); 449 mutex_init(&fs_devices->device_list_mutex); 450 fs_devices->latest_devid = orig->latest_devid; 451 fs_devices->latest_trans = orig->latest_trans; 452 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid)); 453 454 mutex_lock(&orig->device_list_mutex); 455 list_for_each_entry(orig_dev, &orig->devices, dev_list) { 456 device = kzalloc(sizeof(*device), GFP_NOFS); 457 if (!device) 458 goto error; 459 460 device->name = kstrdup(orig_dev->name, GFP_NOFS); 461 if (!device->name) { 462 kfree(device); 463 goto error; 464 } 465 466 device->devid = orig_dev->devid; 467 device->work.func = pending_bios_fn; 468 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid)); 469 spin_lock_init(&device->io_lock); 470 INIT_LIST_HEAD(&device->dev_list); 471 INIT_LIST_HEAD(&device->dev_alloc_list); 472 473 list_add(&device->dev_list, &fs_devices->devices); 474 device->fs_devices = fs_devices; 475 fs_devices->num_devices++; 476 } 477 mutex_unlock(&orig->device_list_mutex); 478 return fs_devices; 479 error: 480 mutex_unlock(&orig->device_list_mutex); 481 free_fs_devices(fs_devices); 482 return ERR_PTR(-ENOMEM); 483 } 484 485 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices) 486 { 487 struct btrfs_device *device, *next; 488 489 mutex_lock(&uuid_mutex); 490 again: 491 mutex_lock(&fs_devices->device_list_mutex); 492 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { 493 if (device->in_fs_metadata) 494 continue; 495 496 if (device->bdev) { 497 blkdev_put(device->bdev, device->mode); 498 device->bdev = NULL; 499 fs_devices->open_devices--; 500 } 501 if (device->writeable) { 502 list_del_init(&device->dev_alloc_list); 503 device->writeable = 0; 504 fs_devices->rw_devices--; 505 } 506 list_del_init(&device->dev_list); 507 fs_devices->num_devices--; 508 kfree(device->name); 509 kfree(device); 510 } 511 mutex_unlock(&fs_devices->device_list_mutex); 512 513 if (fs_devices->seed) { 514 fs_devices = fs_devices->seed; 515 goto again; 516 } 517 518 mutex_unlock(&uuid_mutex); 519 return 0; 520 } 521 522 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) 523 { 524 struct btrfs_device *device; 525 526 if (--fs_devices->opened > 0) 527 return 0; 528 529 list_for_each_entry(device, &fs_devices->devices, dev_list) { 530 if (device->bdev) { 531 blkdev_put(device->bdev, device->mode); 532 fs_devices->open_devices--; 533 } 534 if (device->writeable) { 535 list_del_init(&device->dev_alloc_list); 536 fs_devices->rw_devices--; 537 } 538 539 device->bdev = NULL; 540 device->writeable = 0; 541 device->in_fs_metadata = 0; 542 } 543 WARN_ON(fs_devices->open_devices); 544 WARN_ON(fs_devices->rw_devices); 545 fs_devices->opened = 0; 546 fs_devices->seeding = 0; 547 548 return 0; 549 } 550 551 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) 552 { 553 struct btrfs_fs_devices *seed_devices = NULL; 554 int ret; 555 556 mutex_lock(&uuid_mutex); 557 ret = __btrfs_close_devices(fs_devices); 558 if (!fs_devices->opened) { 559 seed_devices = fs_devices->seed; 560 fs_devices->seed = NULL; 561 } 562 mutex_unlock(&uuid_mutex); 563 564 while (seed_devices) { 565 fs_devices = seed_devices; 566 seed_devices = fs_devices->seed; 567 __btrfs_close_devices(fs_devices); 568 free_fs_devices(fs_devices); 569 } 570 return ret; 571 } 572 573 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, 574 fmode_t flags, void *holder) 575 { 576 struct block_device *bdev; 577 struct list_head *head = &fs_devices->devices; 578 struct btrfs_device *device; 579 struct block_device *latest_bdev = NULL; 580 struct buffer_head *bh; 581 struct btrfs_super_block *disk_super; 582 u64 latest_devid = 0; 583 u64 latest_transid = 0; 584 u64 devid; 585 int seeding = 1; 586 int ret = 0; 587 588 flags |= FMODE_EXCL; 589 590 list_for_each_entry(device, head, dev_list) { 591 if (device->bdev) 592 continue; 593 if (!device->name) 594 continue; 595 596 bdev = blkdev_get_by_path(device->name, flags, holder); 597 if (IS_ERR(bdev)) { 598 printk(KERN_INFO "open %s failed\n", device->name); 599 goto error; 600 } 601 set_blocksize(bdev, 4096); 602 603 bh = btrfs_read_dev_super(bdev); 604 if (!bh) { 605 ret = -EINVAL; 606 goto error_close; 607 } 608 609 disk_super = (struct btrfs_super_block *)bh->b_data; 610 devid = btrfs_stack_device_id(&disk_super->dev_item); 611 if (devid != device->devid) 612 goto error_brelse; 613 614 if (memcmp(device->uuid, disk_super->dev_item.uuid, 615 BTRFS_UUID_SIZE)) 616 goto error_brelse; 617 618 device->generation = btrfs_super_generation(disk_super); 619 if (!latest_transid || device->generation > latest_transid) { 620 latest_devid = devid; 621 latest_transid = device->generation; 622 latest_bdev = bdev; 623 } 624 625 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) { 626 device->writeable = 0; 627 } else { 628 device->writeable = !bdev_read_only(bdev); 629 seeding = 0; 630 } 631 632 device->bdev = bdev; 633 device->in_fs_metadata = 0; 634 device->mode = flags; 635 636 if (!blk_queue_nonrot(bdev_get_queue(bdev))) 637 fs_devices->rotating = 1; 638 639 fs_devices->open_devices++; 640 if (device->writeable) { 641 fs_devices->rw_devices++; 642 list_add(&device->dev_alloc_list, 643 &fs_devices->alloc_list); 644 } 645 continue; 646 647 error_brelse: 648 brelse(bh); 649 error_close: 650 blkdev_put(bdev, flags); 651 error: 652 continue; 653 } 654 if (fs_devices->open_devices == 0) { 655 ret = -EIO; 656 goto out; 657 } 658 fs_devices->seeding = seeding; 659 fs_devices->opened = 1; 660 fs_devices->latest_bdev = latest_bdev; 661 fs_devices->latest_devid = latest_devid; 662 fs_devices->latest_trans = latest_transid; 663 fs_devices->total_rw_bytes = 0; 664 out: 665 return ret; 666 } 667 668 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, 669 fmode_t flags, void *holder) 670 { 671 int ret; 672 673 mutex_lock(&uuid_mutex); 674 if (fs_devices->opened) { 675 fs_devices->opened++; 676 ret = 0; 677 } else { 678 ret = __btrfs_open_devices(fs_devices, flags, holder); 679 } 680 mutex_unlock(&uuid_mutex); 681 return ret; 682 } 683 684 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, 685 struct btrfs_fs_devices **fs_devices_ret) 686 { 687 struct btrfs_super_block *disk_super; 688 struct block_device *bdev; 689 struct buffer_head *bh; 690 int ret; 691 u64 devid; 692 u64 transid; 693 694 mutex_lock(&uuid_mutex); 695 696 flags |= FMODE_EXCL; 697 bdev = blkdev_get_by_path(path, flags, holder); 698 699 if (IS_ERR(bdev)) { 700 ret = PTR_ERR(bdev); 701 goto error; 702 } 703 704 ret = set_blocksize(bdev, 4096); 705 if (ret) 706 goto error_close; 707 bh = btrfs_read_dev_super(bdev); 708 if (!bh) { 709 ret = -EINVAL; 710 goto error_close; 711 } 712 disk_super = (struct btrfs_super_block *)bh->b_data; 713 devid = btrfs_stack_device_id(&disk_super->dev_item); 714 transid = btrfs_super_generation(disk_super); 715 if (disk_super->label[0]) 716 printk(KERN_INFO "device label %s ", disk_super->label); 717 else { 718 /* FIXME, make a readl uuid parser */ 719 printk(KERN_INFO "device fsid %llx-%llx ", 720 *(unsigned long long *)disk_super->fsid, 721 *(unsigned long long *)(disk_super->fsid + 8)); 722 } 723 printk(KERN_CONT "devid %llu transid %llu %s\n", 724 (unsigned long long)devid, (unsigned long long)transid, path); 725 ret = device_list_add(path, disk_super, devid, fs_devices_ret); 726 727 brelse(bh); 728 error_close: 729 blkdev_put(bdev, flags); 730 error: 731 mutex_unlock(&uuid_mutex); 732 return ret; 733 } 734 735 /* helper to account the used device space in the range */ 736 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start, 737 u64 end, u64 *length) 738 { 739 struct btrfs_key key; 740 struct btrfs_root *root = device->dev_root; 741 struct btrfs_dev_extent *dev_extent; 742 struct btrfs_path *path; 743 u64 extent_end; 744 int ret; 745 int slot; 746 struct extent_buffer *l; 747 748 *length = 0; 749 750 if (start >= device->total_bytes) 751 return 0; 752 753 path = btrfs_alloc_path(); 754 if (!path) 755 return -ENOMEM; 756 path->reada = 2; 757 758 key.objectid = device->devid; 759 key.offset = start; 760 key.type = BTRFS_DEV_EXTENT_KEY; 761 762 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 763 if (ret < 0) 764 goto out; 765 if (ret > 0) { 766 ret = btrfs_previous_item(root, path, key.objectid, key.type); 767 if (ret < 0) 768 goto out; 769 } 770 771 while (1) { 772 l = path->nodes[0]; 773 slot = path->slots[0]; 774 if (slot >= btrfs_header_nritems(l)) { 775 ret = btrfs_next_leaf(root, path); 776 if (ret == 0) 777 continue; 778 if (ret < 0) 779 goto out; 780 781 break; 782 } 783 btrfs_item_key_to_cpu(l, &key, slot); 784 785 if (key.objectid < device->devid) 786 goto next; 787 788 if (key.objectid > device->devid) 789 break; 790 791 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) 792 goto next; 793 794 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 795 extent_end = key.offset + btrfs_dev_extent_length(l, 796 dev_extent); 797 if (key.offset <= start && extent_end > end) { 798 *length = end - start + 1; 799 break; 800 } else if (key.offset <= start && extent_end > start) 801 *length += extent_end - start; 802 else if (key.offset > start && extent_end <= end) 803 *length += extent_end - key.offset; 804 else if (key.offset > start && key.offset <= end) { 805 *length += end - key.offset + 1; 806 break; 807 } else if (key.offset > end) 808 break; 809 810 next: 811 path->slots[0]++; 812 } 813 ret = 0; 814 out: 815 btrfs_free_path(path); 816 return ret; 817 } 818 819 /* 820 * find_free_dev_extent - find free space in the specified device 821 * @trans: transaction handler 822 * @device: the device which we search the free space in 823 * @num_bytes: the size of the free space that we need 824 * @start: store the start of the free space. 825 * @len: the size of the free space. that we find, or the size of the max 826 * free space if we don't find suitable free space 827 * 828 * this uses a pretty simple search, the expectation is that it is 829 * called very infrequently and that a given device has a small number 830 * of extents 831 * 832 * @start is used to store the start of the free space if we find. But if we 833 * don't find suitable free space, it will be used to store the start position 834 * of the max free space. 835 * 836 * @len is used to store the size of the free space that we find. 837 * But if we don't find suitable free space, it is used to store the size of 838 * the max free space. 839 */ 840 int find_free_dev_extent(struct btrfs_trans_handle *trans, 841 struct btrfs_device *device, u64 num_bytes, 842 u64 *start, u64 *len) 843 { 844 struct btrfs_key key; 845 struct btrfs_root *root = device->dev_root; 846 struct btrfs_dev_extent *dev_extent; 847 struct btrfs_path *path; 848 u64 hole_size; 849 u64 max_hole_start; 850 u64 max_hole_size; 851 u64 extent_end; 852 u64 search_start; 853 u64 search_end = device->total_bytes; 854 int ret; 855 int slot; 856 struct extent_buffer *l; 857 858 /* FIXME use last free of some kind */ 859 860 /* we don't want to overwrite the superblock on the drive, 861 * so we make sure to start at an offset of at least 1MB 862 */ 863 search_start = 1024 * 1024; 864 865 if (root->fs_info->alloc_start + num_bytes <= search_end) 866 search_start = max(root->fs_info->alloc_start, search_start); 867 868 max_hole_start = search_start; 869 max_hole_size = 0; 870 871 if (search_start >= search_end) { 872 ret = -ENOSPC; 873 goto error; 874 } 875 876 path = btrfs_alloc_path(); 877 if (!path) { 878 ret = -ENOMEM; 879 goto error; 880 } 881 path->reada = 2; 882 883 key.objectid = device->devid; 884 key.offset = search_start; 885 key.type = BTRFS_DEV_EXTENT_KEY; 886 887 ret = btrfs_search_slot(trans, root, &key, path, 0, 0); 888 if (ret < 0) 889 goto out; 890 if (ret > 0) { 891 ret = btrfs_previous_item(root, path, key.objectid, key.type); 892 if (ret < 0) 893 goto out; 894 } 895 896 while (1) { 897 l = path->nodes[0]; 898 slot = path->slots[0]; 899 if (slot >= btrfs_header_nritems(l)) { 900 ret = btrfs_next_leaf(root, path); 901 if (ret == 0) 902 continue; 903 if (ret < 0) 904 goto out; 905 906 break; 907 } 908 btrfs_item_key_to_cpu(l, &key, slot); 909 910 if (key.objectid < device->devid) 911 goto next; 912 913 if (key.objectid > device->devid) 914 break; 915 916 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) 917 goto next; 918 919 if (key.offset > search_start) { 920 hole_size = key.offset - search_start; 921 922 if (hole_size > max_hole_size) { 923 max_hole_start = search_start; 924 max_hole_size = hole_size; 925 } 926 927 /* 928 * If this free space is greater than which we need, 929 * it must be the max free space that we have found 930 * until now, so max_hole_start must point to the start 931 * of this free space and the length of this free space 932 * is stored in max_hole_size. Thus, we return 933 * max_hole_start and max_hole_size and go back to the 934 * caller. 935 */ 936 if (hole_size >= num_bytes) { 937 ret = 0; 938 goto out; 939 } 940 } 941 942 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 943 extent_end = key.offset + btrfs_dev_extent_length(l, 944 dev_extent); 945 if (extent_end > search_start) 946 search_start = extent_end; 947 next: 948 path->slots[0]++; 949 cond_resched(); 950 } 951 952 hole_size = search_end- search_start; 953 if (hole_size > max_hole_size) { 954 max_hole_start = search_start; 955 max_hole_size = hole_size; 956 } 957 958 /* See above. */ 959 if (hole_size < num_bytes) 960 ret = -ENOSPC; 961 else 962 ret = 0; 963 964 out: 965 btrfs_free_path(path); 966 error: 967 *start = max_hole_start; 968 if (len) 969 *len = max_hole_size; 970 return ret; 971 } 972 973 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans, 974 struct btrfs_device *device, 975 u64 start) 976 { 977 int ret; 978 struct btrfs_path *path; 979 struct btrfs_root *root = device->dev_root; 980 struct btrfs_key key; 981 struct btrfs_key found_key; 982 struct extent_buffer *leaf = NULL; 983 struct btrfs_dev_extent *extent = NULL; 984 985 path = btrfs_alloc_path(); 986 if (!path) 987 return -ENOMEM; 988 989 key.objectid = device->devid; 990 key.offset = start; 991 key.type = BTRFS_DEV_EXTENT_KEY; 992 993 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 994 if (ret > 0) { 995 ret = btrfs_previous_item(root, path, key.objectid, 996 BTRFS_DEV_EXTENT_KEY); 997 BUG_ON(ret); 998 leaf = path->nodes[0]; 999 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1000 extent = btrfs_item_ptr(leaf, path->slots[0], 1001 struct btrfs_dev_extent); 1002 BUG_ON(found_key.offset > start || found_key.offset + 1003 btrfs_dev_extent_length(leaf, extent) < start); 1004 ret = 0; 1005 } else if (ret == 0) { 1006 leaf = path->nodes[0]; 1007 extent = btrfs_item_ptr(leaf, path->slots[0], 1008 struct btrfs_dev_extent); 1009 } 1010 BUG_ON(ret); 1011 1012 if (device->bytes_used > 0) 1013 device->bytes_used -= btrfs_dev_extent_length(leaf, extent); 1014 ret = btrfs_del_item(trans, root, path); 1015 BUG_ON(ret); 1016 1017 btrfs_free_path(path); 1018 return ret; 1019 } 1020 1021 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans, 1022 struct btrfs_device *device, 1023 u64 chunk_tree, u64 chunk_objectid, 1024 u64 chunk_offset, u64 start, u64 num_bytes) 1025 { 1026 int ret; 1027 struct btrfs_path *path; 1028 struct btrfs_root *root = device->dev_root; 1029 struct btrfs_dev_extent *extent; 1030 struct extent_buffer *leaf; 1031 struct btrfs_key key; 1032 1033 WARN_ON(!device->in_fs_metadata); 1034 path = btrfs_alloc_path(); 1035 if (!path) 1036 return -ENOMEM; 1037 1038 key.objectid = device->devid; 1039 key.offset = start; 1040 key.type = BTRFS_DEV_EXTENT_KEY; 1041 ret = btrfs_insert_empty_item(trans, root, path, &key, 1042 sizeof(*extent)); 1043 BUG_ON(ret); 1044 1045 leaf = path->nodes[0]; 1046 extent = btrfs_item_ptr(leaf, path->slots[0], 1047 struct btrfs_dev_extent); 1048 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree); 1049 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid); 1050 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset); 1051 1052 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, 1053 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent), 1054 BTRFS_UUID_SIZE); 1055 1056 btrfs_set_dev_extent_length(leaf, extent, num_bytes); 1057 btrfs_mark_buffer_dirty(leaf); 1058 btrfs_free_path(path); 1059 return ret; 1060 } 1061 1062 static noinline int find_next_chunk(struct btrfs_root *root, 1063 u64 objectid, u64 *offset) 1064 { 1065 struct btrfs_path *path; 1066 int ret; 1067 struct btrfs_key key; 1068 struct btrfs_chunk *chunk; 1069 struct btrfs_key found_key; 1070 1071 path = btrfs_alloc_path(); 1072 BUG_ON(!path); 1073 1074 key.objectid = objectid; 1075 key.offset = (u64)-1; 1076 key.type = BTRFS_CHUNK_ITEM_KEY; 1077 1078 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1079 if (ret < 0) 1080 goto error; 1081 1082 BUG_ON(ret == 0); 1083 1084 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY); 1085 if (ret) { 1086 *offset = 0; 1087 } else { 1088 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 1089 path->slots[0]); 1090 if (found_key.objectid != objectid) 1091 *offset = 0; 1092 else { 1093 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], 1094 struct btrfs_chunk); 1095 *offset = found_key.offset + 1096 btrfs_chunk_length(path->nodes[0], chunk); 1097 } 1098 } 1099 ret = 0; 1100 error: 1101 btrfs_free_path(path); 1102 return ret; 1103 } 1104 1105 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid) 1106 { 1107 int ret; 1108 struct btrfs_key key; 1109 struct btrfs_key found_key; 1110 struct btrfs_path *path; 1111 1112 root = root->fs_info->chunk_root; 1113 1114 path = btrfs_alloc_path(); 1115 if (!path) 1116 return -ENOMEM; 1117 1118 key.objectid = BTRFS_DEV_ITEMS_OBJECTID; 1119 key.type = BTRFS_DEV_ITEM_KEY; 1120 key.offset = (u64)-1; 1121 1122 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1123 if (ret < 0) 1124 goto error; 1125 1126 BUG_ON(ret == 0); 1127 1128 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID, 1129 BTRFS_DEV_ITEM_KEY); 1130 if (ret) { 1131 *objectid = 1; 1132 } else { 1133 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 1134 path->slots[0]); 1135 *objectid = found_key.offset + 1; 1136 } 1137 ret = 0; 1138 error: 1139 btrfs_free_path(path); 1140 return ret; 1141 } 1142 1143 /* 1144 * the device information is stored in the chunk root 1145 * the btrfs_device struct should be fully filled in 1146 */ 1147 int btrfs_add_device(struct btrfs_trans_handle *trans, 1148 struct btrfs_root *root, 1149 struct btrfs_device *device) 1150 { 1151 int ret; 1152 struct btrfs_path *path; 1153 struct btrfs_dev_item *dev_item; 1154 struct extent_buffer *leaf; 1155 struct btrfs_key key; 1156 unsigned long ptr; 1157 1158 root = root->fs_info->chunk_root; 1159 1160 path = btrfs_alloc_path(); 1161 if (!path) 1162 return -ENOMEM; 1163 1164 key.objectid = BTRFS_DEV_ITEMS_OBJECTID; 1165 key.type = BTRFS_DEV_ITEM_KEY; 1166 key.offset = device->devid; 1167 1168 ret = btrfs_insert_empty_item(trans, root, path, &key, 1169 sizeof(*dev_item)); 1170 if (ret) 1171 goto out; 1172 1173 leaf = path->nodes[0]; 1174 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); 1175 1176 btrfs_set_device_id(leaf, dev_item, device->devid); 1177 btrfs_set_device_generation(leaf, dev_item, 0); 1178 btrfs_set_device_type(leaf, dev_item, device->type); 1179 btrfs_set_device_io_align(leaf, dev_item, device->io_align); 1180 btrfs_set_device_io_width(leaf, dev_item, device->io_width); 1181 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); 1182 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); 1183 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); 1184 btrfs_set_device_group(leaf, dev_item, 0); 1185 btrfs_set_device_seek_speed(leaf, dev_item, 0); 1186 btrfs_set_device_bandwidth(leaf, dev_item, 0); 1187 btrfs_set_device_start_offset(leaf, dev_item, 0); 1188 1189 ptr = (unsigned long)btrfs_device_uuid(dev_item); 1190 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); 1191 ptr = (unsigned long)btrfs_device_fsid(dev_item); 1192 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE); 1193 btrfs_mark_buffer_dirty(leaf); 1194 1195 ret = 0; 1196 out: 1197 btrfs_free_path(path); 1198 return ret; 1199 } 1200 1201 static int btrfs_rm_dev_item(struct btrfs_root *root, 1202 struct btrfs_device *device) 1203 { 1204 int ret; 1205 struct btrfs_path *path; 1206 struct btrfs_key key; 1207 struct btrfs_trans_handle *trans; 1208 1209 root = root->fs_info->chunk_root; 1210 1211 path = btrfs_alloc_path(); 1212 if (!path) 1213 return -ENOMEM; 1214 1215 trans = btrfs_start_transaction(root, 0); 1216 key.objectid = BTRFS_DEV_ITEMS_OBJECTID; 1217 key.type = BTRFS_DEV_ITEM_KEY; 1218 key.offset = device->devid; 1219 lock_chunks(root); 1220 1221 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 1222 if (ret < 0) 1223 goto out; 1224 1225 if (ret > 0) { 1226 ret = -ENOENT; 1227 goto out; 1228 } 1229 1230 ret = btrfs_del_item(trans, root, path); 1231 if (ret) 1232 goto out; 1233 out: 1234 btrfs_free_path(path); 1235 unlock_chunks(root); 1236 btrfs_commit_transaction(trans, root); 1237 return ret; 1238 } 1239 1240 int btrfs_rm_device(struct btrfs_root *root, char *device_path) 1241 { 1242 struct btrfs_device *device; 1243 struct btrfs_device *next_device; 1244 struct block_device *bdev; 1245 struct buffer_head *bh = NULL; 1246 struct btrfs_super_block *disk_super; 1247 u64 all_avail; 1248 u64 devid; 1249 u64 num_devices; 1250 u8 *dev_uuid; 1251 int ret = 0; 1252 1253 mutex_lock(&uuid_mutex); 1254 mutex_lock(&root->fs_info->volume_mutex); 1255 1256 all_avail = root->fs_info->avail_data_alloc_bits | 1257 root->fs_info->avail_system_alloc_bits | 1258 root->fs_info->avail_metadata_alloc_bits; 1259 1260 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && 1261 root->fs_info->fs_devices->num_devices <= 4) { 1262 printk(KERN_ERR "btrfs: unable to go below four devices " 1263 "on raid10\n"); 1264 ret = -EINVAL; 1265 goto out; 1266 } 1267 1268 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && 1269 root->fs_info->fs_devices->num_devices <= 2) { 1270 printk(KERN_ERR "btrfs: unable to go below two " 1271 "devices on raid1\n"); 1272 ret = -EINVAL; 1273 goto out; 1274 } 1275 1276 if (strcmp(device_path, "missing") == 0) { 1277 struct list_head *devices; 1278 struct btrfs_device *tmp; 1279 1280 device = NULL; 1281 devices = &root->fs_info->fs_devices->devices; 1282 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 1283 list_for_each_entry(tmp, devices, dev_list) { 1284 if (tmp->in_fs_metadata && !tmp->bdev) { 1285 device = tmp; 1286 break; 1287 } 1288 } 1289 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1290 bdev = NULL; 1291 bh = NULL; 1292 disk_super = NULL; 1293 if (!device) { 1294 printk(KERN_ERR "btrfs: no missing devices found to " 1295 "remove\n"); 1296 goto out; 1297 } 1298 } else { 1299 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL, 1300 root->fs_info->bdev_holder); 1301 if (IS_ERR(bdev)) { 1302 ret = PTR_ERR(bdev); 1303 goto out; 1304 } 1305 1306 set_blocksize(bdev, 4096); 1307 bh = btrfs_read_dev_super(bdev); 1308 if (!bh) { 1309 ret = -EINVAL; 1310 goto error_close; 1311 } 1312 disk_super = (struct btrfs_super_block *)bh->b_data; 1313 devid = btrfs_stack_device_id(&disk_super->dev_item); 1314 dev_uuid = disk_super->dev_item.uuid; 1315 device = btrfs_find_device(root, devid, dev_uuid, 1316 disk_super->fsid); 1317 if (!device) { 1318 ret = -ENOENT; 1319 goto error_brelse; 1320 } 1321 } 1322 1323 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) { 1324 printk(KERN_ERR "btrfs: unable to remove the only writeable " 1325 "device\n"); 1326 ret = -EINVAL; 1327 goto error_brelse; 1328 } 1329 1330 if (device->writeable) { 1331 list_del_init(&device->dev_alloc_list); 1332 root->fs_info->fs_devices->rw_devices--; 1333 } 1334 1335 ret = btrfs_shrink_device(device, 0); 1336 if (ret) 1337 goto error_brelse; 1338 1339 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device); 1340 if (ret) 1341 goto error_brelse; 1342 1343 device->in_fs_metadata = 0; 1344 1345 /* 1346 * the device list mutex makes sure that we don't change 1347 * the device list while someone else is writing out all 1348 * the device supers. 1349 */ 1350 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 1351 list_del_init(&device->dev_list); 1352 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1353 1354 device->fs_devices->num_devices--; 1355 1356 if (device->missing) 1357 root->fs_info->fs_devices->missing_devices--; 1358 1359 next_device = list_entry(root->fs_info->fs_devices->devices.next, 1360 struct btrfs_device, dev_list); 1361 if (device->bdev == root->fs_info->sb->s_bdev) 1362 root->fs_info->sb->s_bdev = next_device->bdev; 1363 if (device->bdev == root->fs_info->fs_devices->latest_bdev) 1364 root->fs_info->fs_devices->latest_bdev = next_device->bdev; 1365 1366 if (device->bdev) { 1367 blkdev_put(device->bdev, device->mode); 1368 device->bdev = NULL; 1369 device->fs_devices->open_devices--; 1370 } 1371 1372 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1; 1373 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices); 1374 1375 if (device->fs_devices->open_devices == 0) { 1376 struct btrfs_fs_devices *fs_devices; 1377 fs_devices = root->fs_info->fs_devices; 1378 while (fs_devices) { 1379 if (fs_devices->seed == device->fs_devices) 1380 break; 1381 fs_devices = fs_devices->seed; 1382 } 1383 fs_devices->seed = device->fs_devices->seed; 1384 device->fs_devices->seed = NULL; 1385 __btrfs_close_devices(device->fs_devices); 1386 free_fs_devices(device->fs_devices); 1387 } 1388 1389 /* 1390 * at this point, the device is zero sized. We want to 1391 * remove it from the devices list and zero out the old super 1392 */ 1393 if (device->writeable) { 1394 /* make sure this device isn't detected as part of 1395 * the FS anymore 1396 */ 1397 memset(&disk_super->magic, 0, sizeof(disk_super->magic)); 1398 set_buffer_dirty(bh); 1399 sync_dirty_buffer(bh); 1400 } 1401 1402 kfree(device->name); 1403 kfree(device); 1404 ret = 0; 1405 1406 error_brelse: 1407 brelse(bh); 1408 error_close: 1409 if (bdev) 1410 blkdev_put(bdev, FMODE_READ | FMODE_EXCL); 1411 out: 1412 mutex_unlock(&root->fs_info->volume_mutex); 1413 mutex_unlock(&uuid_mutex); 1414 return ret; 1415 } 1416 1417 /* 1418 * does all the dirty work required for changing file system's UUID. 1419 */ 1420 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans, 1421 struct btrfs_root *root) 1422 { 1423 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 1424 struct btrfs_fs_devices *old_devices; 1425 struct btrfs_fs_devices *seed_devices; 1426 struct btrfs_super_block *disk_super = &root->fs_info->super_copy; 1427 struct btrfs_device *device; 1428 u64 super_flags; 1429 1430 BUG_ON(!mutex_is_locked(&uuid_mutex)); 1431 if (!fs_devices->seeding) 1432 return -EINVAL; 1433 1434 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); 1435 if (!seed_devices) 1436 return -ENOMEM; 1437 1438 old_devices = clone_fs_devices(fs_devices); 1439 if (IS_ERR(old_devices)) { 1440 kfree(seed_devices); 1441 return PTR_ERR(old_devices); 1442 } 1443 1444 list_add(&old_devices->list, &fs_uuids); 1445 1446 memcpy(seed_devices, fs_devices, sizeof(*seed_devices)); 1447 seed_devices->opened = 1; 1448 INIT_LIST_HEAD(&seed_devices->devices); 1449 INIT_LIST_HEAD(&seed_devices->alloc_list); 1450 mutex_init(&seed_devices->device_list_mutex); 1451 list_splice_init(&fs_devices->devices, &seed_devices->devices); 1452 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list); 1453 list_for_each_entry(device, &seed_devices->devices, dev_list) { 1454 device->fs_devices = seed_devices; 1455 } 1456 1457 fs_devices->seeding = 0; 1458 fs_devices->num_devices = 0; 1459 fs_devices->open_devices = 0; 1460 fs_devices->seed = seed_devices; 1461 1462 generate_random_uuid(fs_devices->fsid); 1463 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); 1464 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); 1465 super_flags = btrfs_super_flags(disk_super) & 1466 ~BTRFS_SUPER_FLAG_SEEDING; 1467 btrfs_set_super_flags(disk_super, super_flags); 1468 1469 return 0; 1470 } 1471 1472 /* 1473 * strore the expected generation for seed devices in device items. 1474 */ 1475 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans, 1476 struct btrfs_root *root) 1477 { 1478 struct btrfs_path *path; 1479 struct extent_buffer *leaf; 1480 struct btrfs_dev_item *dev_item; 1481 struct btrfs_device *device; 1482 struct btrfs_key key; 1483 u8 fs_uuid[BTRFS_UUID_SIZE]; 1484 u8 dev_uuid[BTRFS_UUID_SIZE]; 1485 u64 devid; 1486 int ret; 1487 1488 path = btrfs_alloc_path(); 1489 if (!path) 1490 return -ENOMEM; 1491 1492 root = root->fs_info->chunk_root; 1493 key.objectid = BTRFS_DEV_ITEMS_OBJECTID; 1494 key.offset = 0; 1495 key.type = BTRFS_DEV_ITEM_KEY; 1496 1497 while (1) { 1498 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 1499 if (ret < 0) 1500 goto error; 1501 1502 leaf = path->nodes[0]; 1503 next_slot: 1504 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1505 ret = btrfs_next_leaf(root, path); 1506 if (ret > 0) 1507 break; 1508 if (ret < 0) 1509 goto error; 1510 leaf = path->nodes[0]; 1511 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 1512 btrfs_release_path(root, path); 1513 continue; 1514 } 1515 1516 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 1517 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID || 1518 key.type != BTRFS_DEV_ITEM_KEY) 1519 break; 1520 1521 dev_item = btrfs_item_ptr(leaf, path->slots[0], 1522 struct btrfs_dev_item); 1523 devid = btrfs_device_id(leaf, dev_item); 1524 read_extent_buffer(leaf, dev_uuid, 1525 (unsigned long)btrfs_device_uuid(dev_item), 1526 BTRFS_UUID_SIZE); 1527 read_extent_buffer(leaf, fs_uuid, 1528 (unsigned long)btrfs_device_fsid(dev_item), 1529 BTRFS_UUID_SIZE); 1530 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); 1531 BUG_ON(!device); 1532 1533 if (device->fs_devices->seeding) { 1534 btrfs_set_device_generation(leaf, dev_item, 1535 device->generation); 1536 btrfs_mark_buffer_dirty(leaf); 1537 } 1538 1539 path->slots[0]++; 1540 goto next_slot; 1541 } 1542 ret = 0; 1543 error: 1544 btrfs_free_path(path); 1545 return ret; 1546 } 1547 1548 int btrfs_init_new_device(struct btrfs_root *root, char *device_path) 1549 { 1550 struct btrfs_trans_handle *trans; 1551 struct btrfs_device *device; 1552 struct block_device *bdev; 1553 struct list_head *devices; 1554 struct super_block *sb = root->fs_info->sb; 1555 u64 total_bytes; 1556 int seeding_dev = 0; 1557 int ret = 0; 1558 1559 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding) 1560 return -EINVAL; 1561 1562 bdev = blkdev_get_by_path(device_path, FMODE_EXCL, 1563 root->fs_info->bdev_holder); 1564 if (IS_ERR(bdev)) 1565 return PTR_ERR(bdev); 1566 1567 if (root->fs_info->fs_devices->seeding) { 1568 seeding_dev = 1; 1569 down_write(&sb->s_umount); 1570 mutex_lock(&uuid_mutex); 1571 } 1572 1573 filemap_write_and_wait(bdev->bd_inode->i_mapping); 1574 mutex_lock(&root->fs_info->volume_mutex); 1575 1576 devices = &root->fs_info->fs_devices->devices; 1577 /* 1578 * we have the volume lock, so we don't need the extra 1579 * device list mutex while reading the list here. 1580 */ 1581 list_for_each_entry(device, devices, dev_list) { 1582 if (device->bdev == bdev) { 1583 ret = -EEXIST; 1584 goto error; 1585 } 1586 } 1587 1588 device = kzalloc(sizeof(*device), GFP_NOFS); 1589 if (!device) { 1590 /* we can safely leave the fs_devices entry around */ 1591 ret = -ENOMEM; 1592 goto error; 1593 } 1594 1595 device->name = kstrdup(device_path, GFP_NOFS); 1596 if (!device->name) { 1597 kfree(device); 1598 ret = -ENOMEM; 1599 goto error; 1600 } 1601 1602 ret = find_next_devid(root, &device->devid); 1603 if (ret) { 1604 kfree(device); 1605 goto error; 1606 } 1607 1608 trans = btrfs_start_transaction(root, 0); 1609 lock_chunks(root); 1610 1611 device->writeable = 1; 1612 device->work.func = pending_bios_fn; 1613 generate_random_uuid(device->uuid); 1614 spin_lock_init(&device->io_lock); 1615 device->generation = trans->transid; 1616 device->io_width = root->sectorsize; 1617 device->io_align = root->sectorsize; 1618 device->sector_size = root->sectorsize; 1619 device->total_bytes = i_size_read(bdev->bd_inode); 1620 device->disk_total_bytes = device->total_bytes; 1621 device->dev_root = root->fs_info->dev_root; 1622 device->bdev = bdev; 1623 device->in_fs_metadata = 1; 1624 device->mode = 0; 1625 set_blocksize(device->bdev, 4096); 1626 1627 if (seeding_dev) { 1628 sb->s_flags &= ~MS_RDONLY; 1629 ret = btrfs_prepare_sprout(trans, root); 1630 BUG_ON(ret); 1631 } 1632 1633 device->fs_devices = root->fs_info->fs_devices; 1634 1635 /* 1636 * we don't want write_supers to jump in here with our device 1637 * half setup 1638 */ 1639 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 1640 list_add(&device->dev_list, &root->fs_info->fs_devices->devices); 1641 list_add(&device->dev_alloc_list, 1642 &root->fs_info->fs_devices->alloc_list); 1643 root->fs_info->fs_devices->num_devices++; 1644 root->fs_info->fs_devices->open_devices++; 1645 root->fs_info->fs_devices->rw_devices++; 1646 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes; 1647 1648 if (!blk_queue_nonrot(bdev_get_queue(bdev))) 1649 root->fs_info->fs_devices->rotating = 1; 1650 1651 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); 1652 btrfs_set_super_total_bytes(&root->fs_info->super_copy, 1653 total_bytes + device->total_bytes); 1654 1655 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy); 1656 btrfs_set_super_num_devices(&root->fs_info->super_copy, 1657 total_bytes + 1); 1658 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 1659 1660 if (seeding_dev) { 1661 ret = init_first_rw_device(trans, root, device); 1662 BUG_ON(ret); 1663 ret = btrfs_finish_sprout(trans, root); 1664 BUG_ON(ret); 1665 } else { 1666 ret = btrfs_add_device(trans, root, device); 1667 } 1668 1669 /* 1670 * we've got more storage, clear any full flags on the space 1671 * infos 1672 */ 1673 btrfs_clear_space_info_full(root->fs_info); 1674 1675 unlock_chunks(root); 1676 btrfs_commit_transaction(trans, root); 1677 1678 if (seeding_dev) { 1679 mutex_unlock(&uuid_mutex); 1680 up_write(&sb->s_umount); 1681 1682 ret = btrfs_relocate_sys_chunks(root); 1683 BUG_ON(ret); 1684 } 1685 out: 1686 mutex_unlock(&root->fs_info->volume_mutex); 1687 return ret; 1688 error: 1689 blkdev_put(bdev, FMODE_EXCL); 1690 if (seeding_dev) { 1691 mutex_unlock(&uuid_mutex); 1692 up_write(&sb->s_umount); 1693 } 1694 goto out; 1695 } 1696 1697 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, 1698 struct btrfs_device *device) 1699 { 1700 int ret; 1701 struct btrfs_path *path; 1702 struct btrfs_root *root; 1703 struct btrfs_dev_item *dev_item; 1704 struct extent_buffer *leaf; 1705 struct btrfs_key key; 1706 1707 root = device->dev_root->fs_info->chunk_root; 1708 1709 path = btrfs_alloc_path(); 1710 if (!path) 1711 return -ENOMEM; 1712 1713 key.objectid = BTRFS_DEV_ITEMS_OBJECTID; 1714 key.type = BTRFS_DEV_ITEM_KEY; 1715 key.offset = device->devid; 1716 1717 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 1718 if (ret < 0) 1719 goto out; 1720 1721 if (ret > 0) { 1722 ret = -ENOENT; 1723 goto out; 1724 } 1725 1726 leaf = path->nodes[0]; 1727 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); 1728 1729 btrfs_set_device_id(leaf, dev_item, device->devid); 1730 btrfs_set_device_type(leaf, dev_item, device->type); 1731 btrfs_set_device_io_align(leaf, dev_item, device->io_align); 1732 btrfs_set_device_io_width(leaf, dev_item, device->io_width); 1733 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); 1734 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes); 1735 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); 1736 btrfs_mark_buffer_dirty(leaf); 1737 1738 out: 1739 btrfs_free_path(path); 1740 return ret; 1741 } 1742 1743 static int __btrfs_grow_device(struct btrfs_trans_handle *trans, 1744 struct btrfs_device *device, u64 new_size) 1745 { 1746 struct btrfs_super_block *super_copy = 1747 &device->dev_root->fs_info->super_copy; 1748 u64 old_total = btrfs_super_total_bytes(super_copy); 1749 u64 diff = new_size - device->total_bytes; 1750 1751 if (!device->writeable) 1752 return -EACCES; 1753 if (new_size <= device->total_bytes) 1754 return -EINVAL; 1755 1756 btrfs_set_super_total_bytes(super_copy, old_total + diff); 1757 device->fs_devices->total_rw_bytes += diff; 1758 1759 device->total_bytes = new_size; 1760 device->disk_total_bytes = new_size; 1761 btrfs_clear_space_info_full(device->dev_root->fs_info); 1762 1763 return btrfs_update_device(trans, device); 1764 } 1765 1766 int btrfs_grow_device(struct btrfs_trans_handle *trans, 1767 struct btrfs_device *device, u64 new_size) 1768 { 1769 int ret; 1770 lock_chunks(device->dev_root); 1771 ret = __btrfs_grow_device(trans, device, new_size); 1772 unlock_chunks(device->dev_root); 1773 return ret; 1774 } 1775 1776 static int btrfs_free_chunk(struct btrfs_trans_handle *trans, 1777 struct btrfs_root *root, 1778 u64 chunk_tree, u64 chunk_objectid, 1779 u64 chunk_offset) 1780 { 1781 int ret; 1782 struct btrfs_path *path; 1783 struct btrfs_key key; 1784 1785 root = root->fs_info->chunk_root; 1786 path = btrfs_alloc_path(); 1787 if (!path) 1788 return -ENOMEM; 1789 1790 key.objectid = chunk_objectid; 1791 key.offset = chunk_offset; 1792 key.type = BTRFS_CHUNK_ITEM_KEY; 1793 1794 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 1795 BUG_ON(ret); 1796 1797 ret = btrfs_del_item(trans, root, path); 1798 BUG_ON(ret); 1799 1800 btrfs_free_path(path); 1801 return 0; 1802 } 1803 1804 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64 1805 chunk_offset) 1806 { 1807 struct btrfs_super_block *super_copy = &root->fs_info->super_copy; 1808 struct btrfs_disk_key *disk_key; 1809 struct btrfs_chunk *chunk; 1810 u8 *ptr; 1811 int ret = 0; 1812 u32 num_stripes; 1813 u32 array_size; 1814 u32 len = 0; 1815 u32 cur; 1816 struct btrfs_key key; 1817 1818 array_size = btrfs_super_sys_array_size(super_copy); 1819 1820 ptr = super_copy->sys_chunk_array; 1821 cur = 0; 1822 1823 while (cur < array_size) { 1824 disk_key = (struct btrfs_disk_key *)ptr; 1825 btrfs_disk_key_to_cpu(&key, disk_key); 1826 1827 len = sizeof(*disk_key); 1828 1829 if (key.type == BTRFS_CHUNK_ITEM_KEY) { 1830 chunk = (struct btrfs_chunk *)(ptr + len); 1831 num_stripes = btrfs_stack_chunk_num_stripes(chunk); 1832 len += btrfs_chunk_item_size(num_stripes); 1833 } else { 1834 ret = -EIO; 1835 break; 1836 } 1837 if (key.objectid == chunk_objectid && 1838 key.offset == chunk_offset) { 1839 memmove(ptr, ptr + len, array_size - (cur + len)); 1840 array_size -= len; 1841 btrfs_set_super_sys_array_size(super_copy, array_size); 1842 } else { 1843 ptr += len; 1844 cur += len; 1845 } 1846 } 1847 return ret; 1848 } 1849 1850 static int btrfs_relocate_chunk(struct btrfs_root *root, 1851 u64 chunk_tree, u64 chunk_objectid, 1852 u64 chunk_offset) 1853 { 1854 struct extent_map_tree *em_tree; 1855 struct btrfs_root *extent_root; 1856 struct btrfs_trans_handle *trans; 1857 struct extent_map *em; 1858 struct map_lookup *map; 1859 int ret; 1860 int i; 1861 1862 root = root->fs_info->chunk_root; 1863 extent_root = root->fs_info->extent_root; 1864 em_tree = &root->fs_info->mapping_tree.map_tree; 1865 1866 ret = btrfs_can_relocate(extent_root, chunk_offset); 1867 if (ret) 1868 return -ENOSPC; 1869 1870 /* step one, relocate all the extents inside this chunk */ 1871 ret = btrfs_relocate_block_group(extent_root, chunk_offset); 1872 if (ret) 1873 return ret; 1874 1875 trans = btrfs_start_transaction(root, 0); 1876 BUG_ON(!trans); 1877 1878 lock_chunks(root); 1879 1880 /* 1881 * step two, delete the device extents and the 1882 * chunk tree entries 1883 */ 1884 read_lock(&em_tree->lock); 1885 em = lookup_extent_mapping(em_tree, chunk_offset, 1); 1886 read_unlock(&em_tree->lock); 1887 1888 BUG_ON(em->start > chunk_offset || 1889 em->start + em->len < chunk_offset); 1890 map = (struct map_lookup *)em->bdev; 1891 1892 for (i = 0; i < map->num_stripes; i++) { 1893 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev, 1894 map->stripes[i].physical); 1895 BUG_ON(ret); 1896 1897 if (map->stripes[i].dev) { 1898 ret = btrfs_update_device(trans, map->stripes[i].dev); 1899 BUG_ON(ret); 1900 } 1901 } 1902 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid, 1903 chunk_offset); 1904 1905 BUG_ON(ret); 1906 1907 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { 1908 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset); 1909 BUG_ON(ret); 1910 } 1911 1912 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset); 1913 BUG_ON(ret); 1914 1915 write_lock(&em_tree->lock); 1916 remove_extent_mapping(em_tree, em); 1917 write_unlock(&em_tree->lock); 1918 1919 kfree(map); 1920 em->bdev = NULL; 1921 1922 /* once for the tree */ 1923 free_extent_map(em); 1924 /* once for us */ 1925 free_extent_map(em); 1926 1927 unlock_chunks(root); 1928 btrfs_end_transaction(trans, root); 1929 return 0; 1930 } 1931 1932 static int btrfs_relocate_sys_chunks(struct btrfs_root *root) 1933 { 1934 struct btrfs_root *chunk_root = root->fs_info->chunk_root; 1935 struct btrfs_path *path; 1936 struct extent_buffer *leaf; 1937 struct btrfs_chunk *chunk; 1938 struct btrfs_key key; 1939 struct btrfs_key found_key; 1940 u64 chunk_tree = chunk_root->root_key.objectid; 1941 u64 chunk_type; 1942 bool retried = false; 1943 int failed = 0; 1944 int ret; 1945 1946 path = btrfs_alloc_path(); 1947 if (!path) 1948 return -ENOMEM; 1949 1950 again: 1951 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; 1952 key.offset = (u64)-1; 1953 key.type = BTRFS_CHUNK_ITEM_KEY; 1954 1955 while (1) { 1956 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); 1957 if (ret < 0) 1958 goto error; 1959 BUG_ON(ret == 0); 1960 1961 ret = btrfs_previous_item(chunk_root, path, key.objectid, 1962 key.type); 1963 if (ret < 0) 1964 goto error; 1965 if (ret > 0) 1966 break; 1967 1968 leaf = path->nodes[0]; 1969 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1970 1971 chunk = btrfs_item_ptr(leaf, path->slots[0], 1972 struct btrfs_chunk); 1973 chunk_type = btrfs_chunk_type(leaf, chunk); 1974 btrfs_release_path(chunk_root, path); 1975 1976 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) { 1977 ret = btrfs_relocate_chunk(chunk_root, chunk_tree, 1978 found_key.objectid, 1979 found_key.offset); 1980 if (ret == -ENOSPC) 1981 failed++; 1982 else if (ret) 1983 BUG(); 1984 } 1985 1986 if (found_key.offset == 0) 1987 break; 1988 key.offset = found_key.offset - 1; 1989 } 1990 ret = 0; 1991 if (failed && !retried) { 1992 failed = 0; 1993 retried = true; 1994 goto again; 1995 } else if (failed && retried) { 1996 WARN_ON(1); 1997 ret = -ENOSPC; 1998 } 1999 error: 2000 btrfs_free_path(path); 2001 return ret; 2002 } 2003 2004 static u64 div_factor(u64 num, int factor) 2005 { 2006 if (factor == 10) 2007 return num; 2008 num *= factor; 2009 do_div(num, 10); 2010 return num; 2011 } 2012 2013 int btrfs_balance(struct btrfs_root *dev_root) 2014 { 2015 int ret; 2016 struct list_head *devices = &dev_root->fs_info->fs_devices->devices; 2017 struct btrfs_device *device; 2018 u64 old_size; 2019 u64 size_to_free; 2020 struct btrfs_path *path; 2021 struct btrfs_key key; 2022 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root; 2023 struct btrfs_trans_handle *trans; 2024 struct btrfs_key found_key; 2025 2026 if (dev_root->fs_info->sb->s_flags & MS_RDONLY) 2027 return -EROFS; 2028 2029 if (!capable(CAP_SYS_ADMIN)) 2030 return -EPERM; 2031 2032 mutex_lock(&dev_root->fs_info->volume_mutex); 2033 dev_root = dev_root->fs_info->dev_root; 2034 2035 /* step one make some room on all the devices */ 2036 list_for_each_entry(device, devices, dev_list) { 2037 old_size = device->total_bytes; 2038 size_to_free = div_factor(old_size, 1); 2039 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024); 2040 if (!device->writeable || 2041 device->total_bytes - device->bytes_used > size_to_free) 2042 continue; 2043 2044 ret = btrfs_shrink_device(device, old_size - size_to_free); 2045 if (ret == -ENOSPC) 2046 break; 2047 BUG_ON(ret); 2048 2049 trans = btrfs_start_transaction(dev_root, 0); 2050 BUG_ON(!trans); 2051 2052 ret = btrfs_grow_device(trans, device, old_size); 2053 BUG_ON(ret); 2054 2055 btrfs_end_transaction(trans, dev_root); 2056 } 2057 2058 /* step two, relocate all the chunks */ 2059 path = btrfs_alloc_path(); 2060 BUG_ON(!path); 2061 2062 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; 2063 key.offset = (u64)-1; 2064 key.type = BTRFS_CHUNK_ITEM_KEY; 2065 2066 while (1) { 2067 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); 2068 if (ret < 0) 2069 goto error; 2070 2071 /* 2072 * this shouldn't happen, it means the last relocate 2073 * failed 2074 */ 2075 if (ret == 0) 2076 break; 2077 2078 ret = btrfs_previous_item(chunk_root, path, 0, 2079 BTRFS_CHUNK_ITEM_KEY); 2080 if (ret) 2081 break; 2082 2083 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 2084 path->slots[0]); 2085 if (found_key.objectid != key.objectid) 2086 break; 2087 2088 /* chunk zero is special */ 2089 if (found_key.offset == 0) 2090 break; 2091 2092 btrfs_release_path(chunk_root, path); 2093 ret = btrfs_relocate_chunk(chunk_root, 2094 chunk_root->root_key.objectid, 2095 found_key.objectid, 2096 found_key.offset); 2097 BUG_ON(ret && ret != -ENOSPC); 2098 key.offset = found_key.offset - 1; 2099 } 2100 ret = 0; 2101 error: 2102 btrfs_free_path(path); 2103 mutex_unlock(&dev_root->fs_info->volume_mutex); 2104 return ret; 2105 } 2106 2107 /* 2108 * shrinking a device means finding all of the device extents past 2109 * the new size, and then following the back refs to the chunks. 2110 * The chunk relocation code actually frees the device extent 2111 */ 2112 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) 2113 { 2114 struct btrfs_trans_handle *trans; 2115 struct btrfs_root *root = device->dev_root; 2116 struct btrfs_dev_extent *dev_extent = NULL; 2117 struct btrfs_path *path; 2118 u64 length; 2119 u64 chunk_tree; 2120 u64 chunk_objectid; 2121 u64 chunk_offset; 2122 int ret; 2123 int slot; 2124 int failed = 0; 2125 bool retried = false; 2126 struct extent_buffer *l; 2127 struct btrfs_key key; 2128 struct btrfs_super_block *super_copy = &root->fs_info->super_copy; 2129 u64 old_total = btrfs_super_total_bytes(super_copy); 2130 u64 old_size = device->total_bytes; 2131 u64 diff = device->total_bytes - new_size; 2132 2133 if (new_size >= device->total_bytes) 2134 return -EINVAL; 2135 2136 path = btrfs_alloc_path(); 2137 if (!path) 2138 return -ENOMEM; 2139 2140 path->reada = 2; 2141 2142 lock_chunks(root); 2143 2144 device->total_bytes = new_size; 2145 if (device->writeable) 2146 device->fs_devices->total_rw_bytes -= diff; 2147 unlock_chunks(root); 2148 2149 again: 2150 key.objectid = device->devid; 2151 key.offset = (u64)-1; 2152 key.type = BTRFS_DEV_EXTENT_KEY; 2153 2154 while (1) { 2155 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2156 if (ret < 0) 2157 goto done; 2158 2159 ret = btrfs_previous_item(root, path, 0, key.type); 2160 if (ret < 0) 2161 goto done; 2162 if (ret) { 2163 ret = 0; 2164 btrfs_release_path(root, path); 2165 break; 2166 } 2167 2168 l = path->nodes[0]; 2169 slot = path->slots[0]; 2170 btrfs_item_key_to_cpu(l, &key, path->slots[0]); 2171 2172 if (key.objectid != device->devid) { 2173 btrfs_release_path(root, path); 2174 break; 2175 } 2176 2177 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); 2178 length = btrfs_dev_extent_length(l, dev_extent); 2179 2180 if (key.offset + length <= new_size) { 2181 btrfs_release_path(root, path); 2182 break; 2183 } 2184 2185 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); 2186 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); 2187 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); 2188 btrfs_release_path(root, path); 2189 2190 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid, 2191 chunk_offset); 2192 if (ret && ret != -ENOSPC) 2193 goto done; 2194 if (ret == -ENOSPC) 2195 failed++; 2196 key.offset -= 1; 2197 } 2198 2199 if (failed && !retried) { 2200 failed = 0; 2201 retried = true; 2202 goto again; 2203 } else if (failed && retried) { 2204 ret = -ENOSPC; 2205 lock_chunks(root); 2206 2207 device->total_bytes = old_size; 2208 if (device->writeable) 2209 device->fs_devices->total_rw_bytes += diff; 2210 unlock_chunks(root); 2211 goto done; 2212 } 2213 2214 /* Shrinking succeeded, else we would be at "done". */ 2215 trans = btrfs_start_transaction(root, 0); 2216 lock_chunks(root); 2217 2218 device->disk_total_bytes = new_size; 2219 /* Now btrfs_update_device() will change the on-disk size. */ 2220 ret = btrfs_update_device(trans, device); 2221 if (ret) { 2222 unlock_chunks(root); 2223 btrfs_end_transaction(trans, root); 2224 goto done; 2225 } 2226 WARN_ON(diff > old_total); 2227 btrfs_set_super_total_bytes(super_copy, old_total - diff); 2228 unlock_chunks(root); 2229 btrfs_end_transaction(trans, root); 2230 done: 2231 btrfs_free_path(path); 2232 return ret; 2233 } 2234 2235 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans, 2236 struct btrfs_root *root, 2237 struct btrfs_key *key, 2238 struct btrfs_chunk *chunk, int item_size) 2239 { 2240 struct btrfs_super_block *super_copy = &root->fs_info->super_copy; 2241 struct btrfs_disk_key disk_key; 2242 u32 array_size; 2243 u8 *ptr; 2244 2245 array_size = btrfs_super_sys_array_size(super_copy); 2246 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) 2247 return -EFBIG; 2248 2249 ptr = super_copy->sys_chunk_array + array_size; 2250 btrfs_cpu_key_to_disk(&disk_key, key); 2251 memcpy(ptr, &disk_key, sizeof(disk_key)); 2252 ptr += sizeof(disk_key); 2253 memcpy(ptr, chunk, item_size); 2254 item_size += sizeof(disk_key); 2255 btrfs_set_super_sys_array_size(super_copy, array_size + item_size); 2256 return 0; 2257 } 2258 2259 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size, 2260 int num_stripes, int sub_stripes) 2261 { 2262 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP)) 2263 return calc_size; 2264 else if (type & BTRFS_BLOCK_GROUP_RAID10) 2265 return calc_size * (num_stripes / sub_stripes); 2266 else 2267 return calc_size * num_stripes; 2268 } 2269 2270 /* Used to sort the devices by max_avail(descending sort) */ 2271 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2) 2272 { 2273 if (((struct btrfs_device_info *)dev_info1)->max_avail > 2274 ((struct btrfs_device_info *)dev_info2)->max_avail) 2275 return -1; 2276 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 2277 ((struct btrfs_device_info *)dev_info2)->max_avail) 2278 return 1; 2279 else 2280 return 0; 2281 } 2282 2283 static int __btrfs_calc_nstripes(struct btrfs_fs_devices *fs_devices, u64 type, 2284 int *num_stripes, int *min_stripes, 2285 int *sub_stripes) 2286 { 2287 *num_stripes = 1; 2288 *min_stripes = 1; 2289 *sub_stripes = 0; 2290 2291 if (type & (BTRFS_BLOCK_GROUP_RAID0)) { 2292 *num_stripes = fs_devices->rw_devices; 2293 *min_stripes = 2; 2294 } 2295 if (type & (BTRFS_BLOCK_GROUP_DUP)) { 2296 *num_stripes = 2; 2297 *min_stripes = 2; 2298 } 2299 if (type & (BTRFS_BLOCK_GROUP_RAID1)) { 2300 if (fs_devices->rw_devices < 2) 2301 return -ENOSPC; 2302 *num_stripes = 2; 2303 *min_stripes = 2; 2304 } 2305 if (type & (BTRFS_BLOCK_GROUP_RAID10)) { 2306 *num_stripes = fs_devices->rw_devices; 2307 if (*num_stripes < 4) 2308 return -ENOSPC; 2309 *num_stripes &= ~(u32)1; 2310 *sub_stripes = 2; 2311 *min_stripes = 4; 2312 } 2313 2314 return 0; 2315 } 2316 2317 static u64 __btrfs_calc_stripe_size(struct btrfs_fs_devices *fs_devices, 2318 u64 proposed_size, u64 type, 2319 int num_stripes, int small_stripe) 2320 { 2321 int min_stripe_size = 1 * 1024 * 1024; 2322 u64 calc_size = proposed_size; 2323 u64 max_chunk_size = calc_size; 2324 int ncopies = 1; 2325 2326 if (type & (BTRFS_BLOCK_GROUP_RAID1 | 2327 BTRFS_BLOCK_GROUP_DUP | 2328 BTRFS_BLOCK_GROUP_RAID10)) 2329 ncopies = 2; 2330 2331 if (type & BTRFS_BLOCK_GROUP_DATA) { 2332 max_chunk_size = 10 * calc_size; 2333 min_stripe_size = 64 * 1024 * 1024; 2334 } else if (type & BTRFS_BLOCK_GROUP_METADATA) { 2335 max_chunk_size = 256 * 1024 * 1024; 2336 min_stripe_size = 32 * 1024 * 1024; 2337 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { 2338 calc_size = 8 * 1024 * 1024; 2339 max_chunk_size = calc_size * 2; 2340 min_stripe_size = 1 * 1024 * 1024; 2341 } 2342 2343 /* we don't want a chunk larger than 10% of writeable space */ 2344 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1), 2345 max_chunk_size); 2346 2347 if (calc_size * num_stripes > max_chunk_size * ncopies) { 2348 calc_size = max_chunk_size * ncopies; 2349 do_div(calc_size, num_stripes); 2350 do_div(calc_size, BTRFS_STRIPE_LEN); 2351 calc_size *= BTRFS_STRIPE_LEN; 2352 } 2353 2354 /* we don't want tiny stripes */ 2355 if (!small_stripe) 2356 calc_size = max_t(u64, min_stripe_size, calc_size); 2357 2358 /* 2359 * we're about to do_div by the BTRFS_STRIPE_LEN so lets make sure 2360 * we end up with something bigger than a stripe 2361 */ 2362 calc_size = max_t(u64, calc_size, BTRFS_STRIPE_LEN); 2363 2364 do_div(calc_size, BTRFS_STRIPE_LEN); 2365 calc_size *= BTRFS_STRIPE_LEN; 2366 2367 return calc_size; 2368 } 2369 2370 static struct map_lookup *__shrink_map_lookup_stripes(struct map_lookup *map, 2371 int num_stripes) 2372 { 2373 struct map_lookup *new; 2374 size_t len = map_lookup_size(num_stripes); 2375 2376 BUG_ON(map->num_stripes < num_stripes); 2377 2378 if (map->num_stripes == num_stripes) 2379 return map; 2380 2381 new = kmalloc(len, GFP_NOFS); 2382 if (!new) { 2383 /* just change map->num_stripes */ 2384 map->num_stripes = num_stripes; 2385 return map; 2386 } 2387 2388 memcpy(new, map, len); 2389 new->num_stripes = num_stripes; 2390 kfree(map); 2391 return new; 2392 } 2393 2394 /* 2395 * helper to allocate device space from btrfs_device_info, in which we stored 2396 * max free space information of every device. It is used when we can not 2397 * allocate chunks by default size. 2398 * 2399 * By this helper, we can allocate a new chunk as larger as possible. 2400 */ 2401 static int __btrfs_alloc_tiny_space(struct btrfs_trans_handle *trans, 2402 struct btrfs_fs_devices *fs_devices, 2403 struct btrfs_device_info *devices, 2404 int nr_device, u64 type, 2405 struct map_lookup **map_lookup, 2406 int min_stripes, u64 *stripe_size) 2407 { 2408 int i, index, sort_again = 0; 2409 int min_devices = min_stripes; 2410 u64 max_avail, min_free; 2411 struct map_lookup *map = *map_lookup; 2412 int ret; 2413 2414 if (nr_device < min_stripes) 2415 return -ENOSPC; 2416 2417 btrfs_descending_sort_devices(devices, nr_device); 2418 2419 max_avail = devices[0].max_avail; 2420 if (!max_avail) 2421 return -ENOSPC; 2422 2423 for (i = 0; i < nr_device; i++) { 2424 /* 2425 * if dev_offset = 0, it means the free space of this device 2426 * is less than what we need, and we didn't search max avail 2427 * extent on this device, so do it now. 2428 */ 2429 if (!devices[i].dev_offset) { 2430 ret = find_free_dev_extent(trans, devices[i].dev, 2431 max_avail, 2432 &devices[i].dev_offset, 2433 &devices[i].max_avail); 2434 if (ret != 0 && ret != -ENOSPC) 2435 return ret; 2436 sort_again = 1; 2437 } 2438 } 2439 2440 /* we update the max avail free extent of each devices, sort again */ 2441 if (sort_again) 2442 btrfs_descending_sort_devices(devices, nr_device); 2443 2444 if (type & BTRFS_BLOCK_GROUP_DUP) 2445 min_devices = 1; 2446 2447 if (!devices[min_devices - 1].max_avail) 2448 return -ENOSPC; 2449 2450 max_avail = devices[min_devices - 1].max_avail; 2451 if (type & BTRFS_BLOCK_GROUP_DUP) 2452 do_div(max_avail, 2); 2453 2454 max_avail = __btrfs_calc_stripe_size(fs_devices, max_avail, type, 2455 min_stripes, 1); 2456 if (type & BTRFS_BLOCK_GROUP_DUP) 2457 min_free = max_avail * 2; 2458 else 2459 min_free = max_avail; 2460 2461 if (min_free > devices[min_devices - 1].max_avail) 2462 return -ENOSPC; 2463 2464 map = __shrink_map_lookup_stripes(map, min_stripes); 2465 *stripe_size = max_avail; 2466 2467 index = 0; 2468 for (i = 0; i < min_stripes; i++) { 2469 map->stripes[i].dev = devices[index].dev; 2470 map->stripes[i].physical = devices[index].dev_offset; 2471 if (type & BTRFS_BLOCK_GROUP_DUP) { 2472 i++; 2473 map->stripes[i].dev = devices[index].dev; 2474 map->stripes[i].physical = devices[index].dev_offset + 2475 max_avail; 2476 } 2477 index++; 2478 } 2479 *map_lookup = map; 2480 2481 return 0; 2482 } 2483 2484 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, 2485 struct btrfs_root *extent_root, 2486 struct map_lookup **map_ret, 2487 u64 *num_bytes, u64 *stripe_size, 2488 u64 start, u64 type) 2489 { 2490 struct btrfs_fs_info *info = extent_root->fs_info; 2491 struct btrfs_device *device = NULL; 2492 struct btrfs_fs_devices *fs_devices = info->fs_devices; 2493 struct list_head *cur; 2494 struct map_lookup *map; 2495 struct extent_map_tree *em_tree; 2496 struct extent_map *em; 2497 struct btrfs_device_info *devices_info; 2498 struct list_head private_devs; 2499 u64 calc_size = 1024 * 1024 * 1024; 2500 u64 min_free; 2501 u64 avail; 2502 u64 dev_offset; 2503 int num_stripes; 2504 int min_stripes; 2505 int sub_stripes; 2506 int min_devices; /* the min number of devices we need */ 2507 int i; 2508 int ret; 2509 int index; 2510 2511 if ((type & BTRFS_BLOCK_GROUP_RAID1) && 2512 (type & BTRFS_BLOCK_GROUP_DUP)) { 2513 WARN_ON(1); 2514 type &= ~BTRFS_BLOCK_GROUP_DUP; 2515 } 2516 if (list_empty(&fs_devices->alloc_list)) 2517 return -ENOSPC; 2518 2519 ret = __btrfs_calc_nstripes(fs_devices, type, &num_stripes, 2520 &min_stripes, &sub_stripes); 2521 if (ret) 2522 return ret; 2523 2524 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices, 2525 GFP_NOFS); 2526 if (!devices_info) 2527 return -ENOMEM; 2528 2529 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); 2530 if (!map) { 2531 ret = -ENOMEM; 2532 goto error; 2533 } 2534 map->num_stripes = num_stripes; 2535 2536 cur = fs_devices->alloc_list.next; 2537 index = 0; 2538 i = 0; 2539 2540 calc_size = __btrfs_calc_stripe_size(fs_devices, calc_size, type, 2541 num_stripes, 0); 2542 2543 if (type & BTRFS_BLOCK_GROUP_DUP) { 2544 min_free = calc_size * 2; 2545 min_devices = 1; 2546 } else { 2547 min_free = calc_size; 2548 min_devices = min_stripes; 2549 } 2550 2551 INIT_LIST_HEAD(&private_devs); 2552 while (index < num_stripes) { 2553 device = list_entry(cur, struct btrfs_device, dev_alloc_list); 2554 BUG_ON(!device->writeable); 2555 if (device->total_bytes > device->bytes_used) 2556 avail = device->total_bytes - device->bytes_used; 2557 else 2558 avail = 0; 2559 cur = cur->next; 2560 2561 if (device->in_fs_metadata && avail >= min_free) { 2562 ret = find_free_dev_extent(trans, device, min_free, 2563 &devices_info[i].dev_offset, 2564 &devices_info[i].max_avail); 2565 if (ret == 0) { 2566 list_move_tail(&device->dev_alloc_list, 2567 &private_devs); 2568 map->stripes[index].dev = device; 2569 map->stripes[index].physical = 2570 devices_info[i].dev_offset; 2571 index++; 2572 if (type & BTRFS_BLOCK_GROUP_DUP) { 2573 map->stripes[index].dev = device; 2574 map->stripes[index].physical = 2575 devices_info[i].dev_offset + 2576 calc_size; 2577 index++; 2578 } 2579 } else if (ret != -ENOSPC) 2580 goto error; 2581 2582 devices_info[i].dev = device; 2583 i++; 2584 } else if (device->in_fs_metadata && 2585 avail >= BTRFS_STRIPE_LEN) { 2586 devices_info[i].dev = device; 2587 devices_info[i].max_avail = avail; 2588 i++; 2589 } 2590 2591 if (cur == &fs_devices->alloc_list) 2592 break; 2593 } 2594 2595 list_splice(&private_devs, &fs_devices->alloc_list); 2596 if (index < num_stripes) { 2597 if (index >= min_stripes) { 2598 num_stripes = index; 2599 if (type & (BTRFS_BLOCK_GROUP_RAID10)) { 2600 num_stripes /= sub_stripes; 2601 num_stripes *= sub_stripes; 2602 } 2603 2604 map = __shrink_map_lookup_stripes(map, num_stripes); 2605 } else if (i >= min_devices) { 2606 ret = __btrfs_alloc_tiny_space(trans, fs_devices, 2607 devices_info, i, type, 2608 &map, min_stripes, 2609 &calc_size); 2610 if (ret) 2611 goto error; 2612 } else { 2613 ret = -ENOSPC; 2614 goto error; 2615 } 2616 } 2617 map->sector_size = extent_root->sectorsize; 2618 map->stripe_len = BTRFS_STRIPE_LEN; 2619 map->io_align = BTRFS_STRIPE_LEN; 2620 map->io_width = BTRFS_STRIPE_LEN; 2621 map->type = type; 2622 map->sub_stripes = sub_stripes; 2623 2624 *map_ret = map; 2625 *stripe_size = calc_size; 2626 *num_bytes = chunk_bytes_by_type(type, calc_size, 2627 map->num_stripes, sub_stripes); 2628 2629 em = alloc_extent_map(GFP_NOFS); 2630 if (!em) { 2631 ret = -ENOMEM; 2632 goto error; 2633 } 2634 em->bdev = (struct block_device *)map; 2635 em->start = start; 2636 em->len = *num_bytes; 2637 em->block_start = 0; 2638 em->block_len = em->len; 2639 2640 em_tree = &extent_root->fs_info->mapping_tree.map_tree; 2641 write_lock(&em_tree->lock); 2642 ret = add_extent_mapping(em_tree, em); 2643 write_unlock(&em_tree->lock); 2644 BUG_ON(ret); 2645 free_extent_map(em); 2646 2647 ret = btrfs_make_block_group(trans, extent_root, 0, type, 2648 BTRFS_FIRST_CHUNK_TREE_OBJECTID, 2649 start, *num_bytes); 2650 BUG_ON(ret); 2651 2652 index = 0; 2653 while (index < map->num_stripes) { 2654 device = map->stripes[index].dev; 2655 dev_offset = map->stripes[index].physical; 2656 2657 ret = btrfs_alloc_dev_extent(trans, device, 2658 info->chunk_root->root_key.objectid, 2659 BTRFS_FIRST_CHUNK_TREE_OBJECTID, 2660 start, dev_offset, calc_size); 2661 BUG_ON(ret); 2662 index++; 2663 } 2664 2665 kfree(devices_info); 2666 return 0; 2667 2668 error: 2669 kfree(map); 2670 kfree(devices_info); 2671 return ret; 2672 } 2673 2674 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans, 2675 struct btrfs_root *extent_root, 2676 struct map_lookup *map, u64 chunk_offset, 2677 u64 chunk_size, u64 stripe_size) 2678 { 2679 u64 dev_offset; 2680 struct btrfs_key key; 2681 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; 2682 struct btrfs_device *device; 2683 struct btrfs_chunk *chunk; 2684 struct btrfs_stripe *stripe; 2685 size_t item_size = btrfs_chunk_item_size(map->num_stripes); 2686 int index = 0; 2687 int ret; 2688 2689 chunk = kzalloc(item_size, GFP_NOFS); 2690 if (!chunk) 2691 return -ENOMEM; 2692 2693 index = 0; 2694 while (index < map->num_stripes) { 2695 device = map->stripes[index].dev; 2696 device->bytes_used += stripe_size; 2697 ret = btrfs_update_device(trans, device); 2698 BUG_ON(ret); 2699 index++; 2700 } 2701 2702 index = 0; 2703 stripe = &chunk->stripe; 2704 while (index < map->num_stripes) { 2705 device = map->stripes[index].dev; 2706 dev_offset = map->stripes[index].physical; 2707 2708 btrfs_set_stack_stripe_devid(stripe, device->devid); 2709 btrfs_set_stack_stripe_offset(stripe, dev_offset); 2710 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE); 2711 stripe++; 2712 index++; 2713 } 2714 2715 btrfs_set_stack_chunk_length(chunk, chunk_size); 2716 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid); 2717 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len); 2718 btrfs_set_stack_chunk_type(chunk, map->type); 2719 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes); 2720 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len); 2721 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len); 2722 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize); 2723 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes); 2724 2725 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; 2726 key.type = BTRFS_CHUNK_ITEM_KEY; 2727 key.offset = chunk_offset; 2728 2729 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size); 2730 BUG_ON(ret); 2731 2732 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { 2733 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk, 2734 item_size); 2735 BUG_ON(ret); 2736 } 2737 kfree(chunk); 2738 return 0; 2739 } 2740 2741 /* 2742 * Chunk allocation falls into two parts. The first part does works 2743 * that make the new allocated chunk useable, but not do any operation 2744 * that modifies the chunk tree. The second part does the works that 2745 * require modifying the chunk tree. This division is important for the 2746 * bootstrap process of adding storage to a seed btrfs. 2747 */ 2748 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, 2749 struct btrfs_root *extent_root, u64 type) 2750 { 2751 u64 chunk_offset; 2752 u64 chunk_size; 2753 u64 stripe_size; 2754 struct map_lookup *map; 2755 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; 2756 int ret; 2757 2758 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID, 2759 &chunk_offset); 2760 if (ret) 2761 return ret; 2762 2763 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size, 2764 &stripe_size, chunk_offset, type); 2765 if (ret) 2766 return ret; 2767 2768 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, 2769 chunk_size, stripe_size); 2770 BUG_ON(ret); 2771 return 0; 2772 } 2773 2774 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans, 2775 struct btrfs_root *root, 2776 struct btrfs_device *device) 2777 { 2778 u64 chunk_offset; 2779 u64 sys_chunk_offset; 2780 u64 chunk_size; 2781 u64 sys_chunk_size; 2782 u64 stripe_size; 2783 u64 sys_stripe_size; 2784 u64 alloc_profile; 2785 struct map_lookup *map; 2786 struct map_lookup *sys_map; 2787 struct btrfs_fs_info *fs_info = root->fs_info; 2788 struct btrfs_root *extent_root = fs_info->extent_root; 2789 int ret; 2790 2791 ret = find_next_chunk(fs_info->chunk_root, 2792 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset); 2793 BUG_ON(ret); 2794 2795 alloc_profile = BTRFS_BLOCK_GROUP_METADATA | 2796 (fs_info->metadata_alloc_profile & 2797 fs_info->avail_metadata_alloc_bits); 2798 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile); 2799 2800 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size, 2801 &stripe_size, chunk_offset, alloc_profile); 2802 BUG_ON(ret); 2803 2804 sys_chunk_offset = chunk_offset + chunk_size; 2805 2806 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM | 2807 (fs_info->system_alloc_profile & 2808 fs_info->avail_system_alloc_bits); 2809 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile); 2810 2811 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map, 2812 &sys_chunk_size, &sys_stripe_size, 2813 sys_chunk_offset, alloc_profile); 2814 BUG_ON(ret); 2815 2816 ret = btrfs_add_device(trans, fs_info->chunk_root, device); 2817 BUG_ON(ret); 2818 2819 /* 2820 * Modifying chunk tree needs allocating new blocks from both 2821 * system block group and metadata block group. So we only can 2822 * do operations require modifying the chunk tree after both 2823 * block groups were created. 2824 */ 2825 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, 2826 chunk_size, stripe_size); 2827 BUG_ON(ret); 2828 2829 ret = __finish_chunk_alloc(trans, extent_root, sys_map, 2830 sys_chunk_offset, sys_chunk_size, 2831 sys_stripe_size); 2832 BUG_ON(ret); 2833 return 0; 2834 } 2835 2836 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) 2837 { 2838 struct extent_map *em; 2839 struct map_lookup *map; 2840 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; 2841 int readonly = 0; 2842 int i; 2843 2844 read_lock(&map_tree->map_tree.lock); 2845 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); 2846 read_unlock(&map_tree->map_tree.lock); 2847 if (!em) 2848 return 1; 2849 2850 if (btrfs_test_opt(root, DEGRADED)) { 2851 free_extent_map(em); 2852 return 0; 2853 } 2854 2855 map = (struct map_lookup *)em->bdev; 2856 for (i = 0; i < map->num_stripes; i++) { 2857 if (!map->stripes[i].dev->writeable) { 2858 readonly = 1; 2859 break; 2860 } 2861 } 2862 free_extent_map(em); 2863 return readonly; 2864 } 2865 2866 void btrfs_mapping_init(struct btrfs_mapping_tree *tree) 2867 { 2868 extent_map_tree_init(&tree->map_tree, GFP_NOFS); 2869 } 2870 2871 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree) 2872 { 2873 struct extent_map *em; 2874 2875 while (1) { 2876 write_lock(&tree->map_tree.lock); 2877 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1); 2878 if (em) 2879 remove_extent_mapping(&tree->map_tree, em); 2880 write_unlock(&tree->map_tree.lock); 2881 if (!em) 2882 break; 2883 kfree(em->bdev); 2884 /* once for us */ 2885 free_extent_map(em); 2886 /* once for the tree */ 2887 free_extent_map(em); 2888 } 2889 } 2890 2891 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len) 2892 { 2893 struct extent_map *em; 2894 struct map_lookup *map; 2895 struct extent_map_tree *em_tree = &map_tree->map_tree; 2896 int ret; 2897 2898 read_lock(&em_tree->lock); 2899 em = lookup_extent_mapping(em_tree, logical, len); 2900 read_unlock(&em_tree->lock); 2901 BUG_ON(!em); 2902 2903 BUG_ON(em->start > logical || em->start + em->len < logical); 2904 map = (struct map_lookup *)em->bdev; 2905 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) 2906 ret = map->num_stripes; 2907 else if (map->type & BTRFS_BLOCK_GROUP_RAID10) 2908 ret = map->sub_stripes; 2909 else 2910 ret = 1; 2911 free_extent_map(em); 2912 return ret; 2913 } 2914 2915 static int find_live_mirror(struct map_lookup *map, int first, int num, 2916 int optimal) 2917 { 2918 int i; 2919 if (map->stripes[optimal].dev->bdev) 2920 return optimal; 2921 for (i = first; i < first + num; i++) { 2922 if (map->stripes[i].dev->bdev) 2923 return i; 2924 } 2925 /* we couldn't find one that doesn't fail. Just return something 2926 * and the io error handling code will clean up eventually 2927 */ 2928 return optimal; 2929 } 2930 2931 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, 2932 u64 logical, u64 *length, 2933 struct btrfs_multi_bio **multi_ret, 2934 int mirror_num, struct page *unplug_page) 2935 { 2936 struct extent_map *em; 2937 struct map_lookup *map; 2938 struct extent_map_tree *em_tree = &map_tree->map_tree; 2939 u64 offset; 2940 u64 stripe_offset; 2941 u64 stripe_nr; 2942 int stripes_allocated = 8; 2943 int stripes_required = 1; 2944 int stripe_index; 2945 int i; 2946 int num_stripes; 2947 int max_errors = 0; 2948 struct btrfs_multi_bio *multi = NULL; 2949 2950 if (multi_ret && !(rw & REQ_WRITE)) 2951 stripes_allocated = 1; 2952 again: 2953 if (multi_ret) { 2954 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated), 2955 GFP_NOFS); 2956 if (!multi) 2957 return -ENOMEM; 2958 2959 atomic_set(&multi->error, 0); 2960 } 2961 2962 read_lock(&em_tree->lock); 2963 em = lookup_extent_mapping(em_tree, logical, *length); 2964 read_unlock(&em_tree->lock); 2965 2966 if (!em && unplug_page) { 2967 kfree(multi); 2968 return 0; 2969 } 2970 2971 if (!em) { 2972 printk(KERN_CRIT "unable to find logical %llu len %llu\n", 2973 (unsigned long long)logical, 2974 (unsigned long long)*length); 2975 BUG(); 2976 } 2977 2978 BUG_ON(em->start > logical || em->start + em->len < logical); 2979 map = (struct map_lookup *)em->bdev; 2980 offset = logical - em->start; 2981 2982 if (mirror_num > map->num_stripes) 2983 mirror_num = 0; 2984 2985 /* if our multi bio struct is too small, back off and try again */ 2986 if (rw & REQ_WRITE) { 2987 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | 2988 BTRFS_BLOCK_GROUP_DUP)) { 2989 stripes_required = map->num_stripes; 2990 max_errors = 1; 2991 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 2992 stripes_required = map->sub_stripes; 2993 max_errors = 1; 2994 } 2995 } 2996 if (multi_ret && (rw & REQ_WRITE) && 2997 stripes_allocated < stripes_required) { 2998 stripes_allocated = map->num_stripes; 2999 free_extent_map(em); 3000 kfree(multi); 3001 goto again; 3002 } 3003 stripe_nr = offset; 3004 /* 3005 * stripe_nr counts the total number of stripes we have to stride 3006 * to get to this block 3007 */ 3008 do_div(stripe_nr, map->stripe_len); 3009 3010 stripe_offset = stripe_nr * map->stripe_len; 3011 BUG_ON(offset < stripe_offset); 3012 3013 /* stripe_offset is the offset of this block in its stripe*/ 3014 stripe_offset = offset - stripe_offset; 3015 3016 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | 3017 BTRFS_BLOCK_GROUP_RAID10 | 3018 BTRFS_BLOCK_GROUP_DUP)) { 3019 /* we limit the length of each bio to what fits in a stripe */ 3020 *length = min_t(u64, em->len - offset, 3021 map->stripe_len - stripe_offset); 3022 } else { 3023 *length = em->len - offset; 3024 } 3025 3026 if (!multi_ret && !unplug_page) 3027 goto out; 3028 3029 num_stripes = 1; 3030 stripe_index = 0; 3031 if (map->type & BTRFS_BLOCK_GROUP_RAID1) { 3032 if (unplug_page || (rw & REQ_WRITE)) 3033 num_stripes = map->num_stripes; 3034 else if (mirror_num) 3035 stripe_index = mirror_num - 1; 3036 else { 3037 stripe_index = find_live_mirror(map, 0, 3038 map->num_stripes, 3039 current->pid % map->num_stripes); 3040 } 3041 3042 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { 3043 if (rw & REQ_WRITE) 3044 num_stripes = map->num_stripes; 3045 else if (mirror_num) 3046 stripe_index = mirror_num - 1; 3047 3048 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 3049 int factor = map->num_stripes / map->sub_stripes; 3050 3051 stripe_index = do_div(stripe_nr, factor); 3052 stripe_index *= map->sub_stripes; 3053 3054 if (unplug_page || (rw & REQ_WRITE)) 3055 num_stripes = map->sub_stripes; 3056 else if (mirror_num) 3057 stripe_index += mirror_num - 1; 3058 else { 3059 stripe_index = find_live_mirror(map, stripe_index, 3060 map->sub_stripes, stripe_index + 3061 current->pid % map->sub_stripes); 3062 } 3063 } else { 3064 /* 3065 * after this do_div call, stripe_nr is the number of stripes 3066 * on this device we have to walk to find the data, and 3067 * stripe_index is the number of our device in the stripe array 3068 */ 3069 stripe_index = do_div(stripe_nr, map->num_stripes); 3070 } 3071 BUG_ON(stripe_index >= map->num_stripes); 3072 3073 for (i = 0; i < num_stripes; i++) { 3074 if (unplug_page) { 3075 struct btrfs_device *device; 3076 struct backing_dev_info *bdi; 3077 3078 device = map->stripes[stripe_index].dev; 3079 if (device->bdev) { 3080 bdi = blk_get_backing_dev_info(device->bdev); 3081 if (bdi->unplug_io_fn) 3082 bdi->unplug_io_fn(bdi, unplug_page); 3083 } 3084 } else { 3085 multi->stripes[i].physical = 3086 map->stripes[stripe_index].physical + 3087 stripe_offset + stripe_nr * map->stripe_len; 3088 multi->stripes[i].dev = map->stripes[stripe_index].dev; 3089 } 3090 stripe_index++; 3091 } 3092 if (multi_ret) { 3093 *multi_ret = multi; 3094 multi->num_stripes = num_stripes; 3095 multi->max_errors = max_errors; 3096 } 3097 out: 3098 free_extent_map(em); 3099 return 0; 3100 } 3101 3102 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, 3103 u64 logical, u64 *length, 3104 struct btrfs_multi_bio **multi_ret, int mirror_num) 3105 { 3106 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret, 3107 mirror_num, NULL); 3108 } 3109 3110 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree, 3111 u64 chunk_start, u64 physical, u64 devid, 3112 u64 **logical, int *naddrs, int *stripe_len) 3113 { 3114 struct extent_map_tree *em_tree = &map_tree->map_tree; 3115 struct extent_map *em; 3116 struct map_lookup *map; 3117 u64 *buf; 3118 u64 bytenr; 3119 u64 length; 3120 u64 stripe_nr; 3121 int i, j, nr = 0; 3122 3123 read_lock(&em_tree->lock); 3124 em = lookup_extent_mapping(em_tree, chunk_start, 1); 3125 read_unlock(&em_tree->lock); 3126 3127 BUG_ON(!em || em->start != chunk_start); 3128 map = (struct map_lookup *)em->bdev; 3129 3130 length = em->len; 3131 if (map->type & BTRFS_BLOCK_GROUP_RAID10) 3132 do_div(length, map->num_stripes / map->sub_stripes); 3133 else if (map->type & BTRFS_BLOCK_GROUP_RAID0) 3134 do_div(length, map->num_stripes); 3135 3136 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS); 3137 BUG_ON(!buf); 3138 3139 for (i = 0; i < map->num_stripes; i++) { 3140 if (devid && map->stripes[i].dev->devid != devid) 3141 continue; 3142 if (map->stripes[i].physical > physical || 3143 map->stripes[i].physical + length <= physical) 3144 continue; 3145 3146 stripe_nr = physical - map->stripes[i].physical; 3147 do_div(stripe_nr, map->stripe_len); 3148 3149 if (map->type & BTRFS_BLOCK_GROUP_RAID10) { 3150 stripe_nr = stripe_nr * map->num_stripes + i; 3151 do_div(stripe_nr, map->sub_stripes); 3152 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) { 3153 stripe_nr = stripe_nr * map->num_stripes + i; 3154 } 3155 bytenr = chunk_start + stripe_nr * map->stripe_len; 3156 WARN_ON(nr >= map->num_stripes); 3157 for (j = 0; j < nr; j++) { 3158 if (buf[j] == bytenr) 3159 break; 3160 } 3161 if (j == nr) { 3162 WARN_ON(nr >= map->num_stripes); 3163 buf[nr++] = bytenr; 3164 } 3165 } 3166 3167 *logical = buf; 3168 *naddrs = nr; 3169 *stripe_len = map->stripe_len; 3170 3171 free_extent_map(em); 3172 return 0; 3173 } 3174 3175 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree, 3176 u64 logical, struct page *page) 3177 { 3178 u64 length = PAGE_CACHE_SIZE; 3179 return __btrfs_map_block(map_tree, READ, logical, &length, 3180 NULL, 0, page); 3181 } 3182 3183 static void end_bio_multi_stripe(struct bio *bio, int err) 3184 { 3185 struct btrfs_multi_bio *multi = bio->bi_private; 3186 int is_orig_bio = 0; 3187 3188 if (err) 3189 atomic_inc(&multi->error); 3190 3191 if (bio == multi->orig_bio) 3192 is_orig_bio = 1; 3193 3194 if (atomic_dec_and_test(&multi->stripes_pending)) { 3195 if (!is_orig_bio) { 3196 bio_put(bio); 3197 bio = multi->orig_bio; 3198 } 3199 bio->bi_private = multi->private; 3200 bio->bi_end_io = multi->end_io; 3201 /* only send an error to the higher layers if it is 3202 * beyond the tolerance of the multi-bio 3203 */ 3204 if (atomic_read(&multi->error) > multi->max_errors) { 3205 err = -EIO; 3206 } else if (err) { 3207 /* 3208 * this bio is actually up to date, we didn't 3209 * go over the max number of errors 3210 */ 3211 set_bit(BIO_UPTODATE, &bio->bi_flags); 3212 err = 0; 3213 } 3214 kfree(multi); 3215 3216 bio_endio(bio, err); 3217 } else if (!is_orig_bio) { 3218 bio_put(bio); 3219 } 3220 } 3221 3222 struct async_sched { 3223 struct bio *bio; 3224 int rw; 3225 struct btrfs_fs_info *info; 3226 struct btrfs_work work; 3227 }; 3228 3229 /* 3230 * see run_scheduled_bios for a description of why bios are collected for 3231 * async submit. 3232 * 3233 * This will add one bio to the pending list for a device and make sure 3234 * the work struct is scheduled. 3235 */ 3236 static noinline int schedule_bio(struct btrfs_root *root, 3237 struct btrfs_device *device, 3238 int rw, struct bio *bio) 3239 { 3240 int should_queue = 1; 3241 struct btrfs_pending_bios *pending_bios; 3242 3243 /* don't bother with additional async steps for reads, right now */ 3244 if (!(rw & REQ_WRITE)) { 3245 bio_get(bio); 3246 submit_bio(rw, bio); 3247 bio_put(bio); 3248 return 0; 3249 } 3250 3251 /* 3252 * nr_async_bios allows us to reliably return congestion to the 3253 * higher layers. Otherwise, the async bio makes it appear we have 3254 * made progress against dirty pages when we've really just put it 3255 * on a queue for later 3256 */ 3257 atomic_inc(&root->fs_info->nr_async_bios); 3258 WARN_ON(bio->bi_next); 3259 bio->bi_next = NULL; 3260 bio->bi_rw |= rw; 3261 3262 spin_lock(&device->io_lock); 3263 if (bio->bi_rw & REQ_SYNC) 3264 pending_bios = &device->pending_sync_bios; 3265 else 3266 pending_bios = &device->pending_bios; 3267 3268 if (pending_bios->tail) 3269 pending_bios->tail->bi_next = bio; 3270 3271 pending_bios->tail = bio; 3272 if (!pending_bios->head) 3273 pending_bios->head = bio; 3274 if (device->running_pending) 3275 should_queue = 0; 3276 3277 spin_unlock(&device->io_lock); 3278 3279 if (should_queue) 3280 btrfs_queue_worker(&root->fs_info->submit_workers, 3281 &device->work); 3282 return 0; 3283 } 3284 3285 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio, 3286 int mirror_num, int async_submit) 3287 { 3288 struct btrfs_mapping_tree *map_tree; 3289 struct btrfs_device *dev; 3290 struct bio *first_bio = bio; 3291 u64 logical = (u64)bio->bi_sector << 9; 3292 u64 length = 0; 3293 u64 map_length; 3294 struct btrfs_multi_bio *multi = NULL; 3295 int ret; 3296 int dev_nr = 0; 3297 int total_devs = 1; 3298 3299 length = bio->bi_size; 3300 map_tree = &root->fs_info->mapping_tree; 3301 map_length = length; 3302 3303 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi, 3304 mirror_num); 3305 BUG_ON(ret); 3306 3307 total_devs = multi->num_stripes; 3308 if (map_length < length) { 3309 printk(KERN_CRIT "mapping failed logical %llu bio len %llu " 3310 "len %llu\n", (unsigned long long)logical, 3311 (unsigned long long)length, 3312 (unsigned long long)map_length); 3313 BUG(); 3314 } 3315 multi->end_io = first_bio->bi_end_io; 3316 multi->private = first_bio->bi_private; 3317 multi->orig_bio = first_bio; 3318 atomic_set(&multi->stripes_pending, multi->num_stripes); 3319 3320 while (dev_nr < total_devs) { 3321 if (total_devs > 1) { 3322 if (dev_nr < total_devs - 1) { 3323 bio = bio_clone(first_bio, GFP_NOFS); 3324 BUG_ON(!bio); 3325 } else { 3326 bio = first_bio; 3327 } 3328 bio->bi_private = multi; 3329 bio->bi_end_io = end_bio_multi_stripe; 3330 } 3331 bio->bi_sector = multi->stripes[dev_nr].physical >> 9; 3332 dev = multi->stripes[dev_nr].dev; 3333 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) { 3334 bio->bi_bdev = dev->bdev; 3335 if (async_submit) 3336 schedule_bio(root, dev, rw, bio); 3337 else 3338 submit_bio(rw, bio); 3339 } else { 3340 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev; 3341 bio->bi_sector = logical >> 9; 3342 bio_endio(bio, -EIO); 3343 } 3344 dev_nr++; 3345 } 3346 if (total_devs == 1) 3347 kfree(multi); 3348 return 0; 3349 } 3350 3351 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid, 3352 u8 *uuid, u8 *fsid) 3353 { 3354 struct btrfs_device *device; 3355 struct btrfs_fs_devices *cur_devices; 3356 3357 cur_devices = root->fs_info->fs_devices; 3358 while (cur_devices) { 3359 if (!fsid || 3360 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) { 3361 device = __find_device(&cur_devices->devices, 3362 devid, uuid); 3363 if (device) 3364 return device; 3365 } 3366 cur_devices = cur_devices->seed; 3367 } 3368 return NULL; 3369 } 3370 3371 static struct btrfs_device *add_missing_dev(struct btrfs_root *root, 3372 u64 devid, u8 *dev_uuid) 3373 { 3374 struct btrfs_device *device; 3375 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 3376 3377 device = kzalloc(sizeof(*device), GFP_NOFS); 3378 if (!device) 3379 return NULL; 3380 list_add(&device->dev_list, 3381 &fs_devices->devices); 3382 device->dev_root = root->fs_info->dev_root; 3383 device->devid = devid; 3384 device->work.func = pending_bios_fn; 3385 device->fs_devices = fs_devices; 3386 device->missing = 1; 3387 fs_devices->num_devices++; 3388 fs_devices->missing_devices++; 3389 spin_lock_init(&device->io_lock); 3390 INIT_LIST_HEAD(&device->dev_alloc_list); 3391 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE); 3392 return device; 3393 } 3394 3395 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key, 3396 struct extent_buffer *leaf, 3397 struct btrfs_chunk *chunk) 3398 { 3399 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; 3400 struct map_lookup *map; 3401 struct extent_map *em; 3402 u64 logical; 3403 u64 length; 3404 u64 devid; 3405 u8 uuid[BTRFS_UUID_SIZE]; 3406 int num_stripes; 3407 int ret; 3408 int i; 3409 3410 logical = key->offset; 3411 length = btrfs_chunk_length(leaf, chunk); 3412 3413 read_lock(&map_tree->map_tree.lock); 3414 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1); 3415 read_unlock(&map_tree->map_tree.lock); 3416 3417 /* already mapped? */ 3418 if (em && em->start <= logical && em->start + em->len > logical) { 3419 free_extent_map(em); 3420 return 0; 3421 } else if (em) { 3422 free_extent_map(em); 3423 } 3424 3425 em = alloc_extent_map(GFP_NOFS); 3426 if (!em) 3427 return -ENOMEM; 3428 num_stripes = btrfs_chunk_num_stripes(leaf, chunk); 3429 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); 3430 if (!map) { 3431 free_extent_map(em); 3432 return -ENOMEM; 3433 } 3434 3435 em->bdev = (struct block_device *)map; 3436 em->start = logical; 3437 em->len = length; 3438 em->block_start = 0; 3439 em->block_len = em->len; 3440 3441 map->num_stripes = num_stripes; 3442 map->io_width = btrfs_chunk_io_width(leaf, chunk); 3443 map->io_align = btrfs_chunk_io_align(leaf, chunk); 3444 map->sector_size = btrfs_chunk_sector_size(leaf, chunk); 3445 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk); 3446 map->type = btrfs_chunk_type(leaf, chunk); 3447 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk); 3448 for (i = 0; i < num_stripes; i++) { 3449 map->stripes[i].physical = 3450 btrfs_stripe_offset_nr(leaf, chunk, i); 3451 devid = btrfs_stripe_devid_nr(leaf, chunk, i); 3452 read_extent_buffer(leaf, uuid, (unsigned long) 3453 btrfs_stripe_dev_uuid_nr(chunk, i), 3454 BTRFS_UUID_SIZE); 3455 map->stripes[i].dev = btrfs_find_device(root, devid, uuid, 3456 NULL); 3457 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) { 3458 kfree(map); 3459 free_extent_map(em); 3460 return -EIO; 3461 } 3462 if (!map->stripes[i].dev) { 3463 map->stripes[i].dev = 3464 add_missing_dev(root, devid, uuid); 3465 if (!map->stripes[i].dev) { 3466 kfree(map); 3467 free_extent_map(em); 3468 return -EIO; 3469 } 3470 } 3471 map->stripes[i].dev->in_fs_metadata = 1; 3472 } 3473 3474 write_lock(&map_tree->map_tree.lock); 3475 ret = add_extent_mapping(&map_tree->map_tree, em); 3476 write_unlock(&map_tree->map_tree.lock); 3477 BUG_ON(ret); 3478 free_extent_map(em); 3479 3480 return 0; 3481 } 3482 3483 static int fill_device_from_item(struct extent_buffer *leaf, 3484 struct btrfs_dev_item *dev_item, 3485 struct btrfs_device *device) 3486 { 3487 unsigned long ptr; 3488 3489 device->devid = btrfs_device_id(leaf, dev_item); 3490 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item); 3491 device->total_bytes = device->disk_total_bytes; 3492 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); 3493 device->type = btrfs_device_type(leaf, dev_item); 3494 device->io_align = btrfs_device_io_align(leaf, dev_item); 3495 device->io_width = btrfs_device_io_width(leaf, dev_item); 3496 device->sector_size = btrfs_device_sector_size(leaf, dev_item); 3497 3498 ptr = (unsigned long)btrfs_device_uuid(dev_item); 3499 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); 3500 3501 return 0; 3502 } 3503 3504 static int open_seed_devices(struct btrfs_root *root, u8 *fsid) 3505 { 3506 struct btrfs_fs_devices *fs_devices; 3507 int ret; 3508 3509 mutex_lock(&uuid_mutex); 3510 3511 fs_devices = root->fs_info->fs_devices->seed; 3512 while (fs_devices) { 3513 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) { 3514 ret = 0; 3515 goto out; 3516 } 3517 fs_devices = fs_devices->seed; 3518 } 3519 3520 fs_devices = find_fsid(fsid); 3521 if (!fs_devices) { 3522 ret = -ENOENT; 3523 goto out; 3524 } 3525 3526 fs_devices = clone_fs_devices(fs_devices); 3527 if (IS_ERR(fs_devices)) { 3528 ret = PTR_ERR(fs_devices); 3529 goto out; 3530 } 3531 3532 ret = __btrfs_open_devices(fs_devices, FMODE_READ, 3533 root->fs_info->bdev_holder); 3534 if (ret) 3535 goto out; 3536 3537 if (!fs_devices->seeding) { 3538 __btrfs_close_devices(fs_devices); 3539 free_fs_devices(fs_devices); 3540 ret = -EINVAL; 3541 goto out; 3542 } 3543 3544 fs_devices->seed = root->fs_info->fs_devices->seed; 3545 root->fs_info->fs_devices->seed = fs_devices; 3546 out: 3547 mutex_unlock(&uuid_mutex); 3548 return ret; 3549 } 3550 3551 static int read_one_dev(struct btrfs_root *root, 3552 struct extent_buffer *leaf, 3553 struct btrfs_dev_item *dev_item) 3554 { 3555 struct btrfs_device *device; 3556 u64 devid; 3557 int ret; 3558 u8 fs_uuid[BTRFS_UUID_SIZE]; 3559 u8 dev_uuid[BTRFS_UUID_SIZE]; 3560 3561 devid = btrfs_device_id(leaf, dev_item); 3562 read_extent_buffer(leaf, dev_uuid, 3563 (unsigned long)btrfs_device_uuid(dev_item), 3564 BTRFS_UUID_SIZE); 3565 read_extent_buffer(leaf, fs_uuid, 3566 (unsigned long)btrfs_device_fsid(dev_item), 3567 BTRFS_UUID_SIZE); 3568 3569 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) { 3570 ret = open_seed_devices(root, fs_uuid); 3571 if (ret && !btrfs_test_opt(root, DEGRADED)) 3572 return ret; 3573 } 3574 3575 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); 3576 if (!device || !device->bdev) { 3577 if (!btrfs_test_opt(root, DEGRADED)) 3578 return -EIO; 3579 3580 if (!device) { 3581 printk(KERN_WARNING "warning devid %llu missing\n", 3582 (unsigned long long)devid); 3583 device = add_missing_dev(root, devid, dev_uuid); 3584 if (!device) 3585 return -ENOMEM; 3586 } else if (!device->missing) { 3587 /* 3588 * this happens when a device that was properly setup 3589 * in the device info lists suddenly goes bad. 3590 * device->bdev is NULL, and so we have to set 3591 * device->missing to one here 3592 */ 3593 root->fs_info->fs_devices->missing_devices++; 3594 device->missing = 1; 3595 } 3596 } 3597 3598 if (device->fs_devices != root->fs_info->fs_devices) { 3599 BUG_ON(device->writeable); 3600 if (device->generation != 3601 btrfs_device_generation(leaf, dev_item)) 3602 return -EINVAL; 3603 } 3604 3605 fill_device_from_item(leaf, dev_item, device); 3606 device->dev_root = root->fs_info->dev_root; 3607 device->in_fs_metadata = 1; 3608 if (device->writeable) 3609 device->fs_devices->total_rw_bytes += device->total_bytes; 3610 ret = 0; 3611 return ret; 3612 } 3613 3614 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf) 3615 { 3616 struct btrfs_dev_item *dev_item; 3617 3618 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block, 3619 dev_item); 3620 return read_one_dev(root, buf, dev_item); 3621 } 3622 3623 int btrfs_read_sys_array(struct btrfs_root *root) 3624 { 3625 struct btrfs_super_block *super_copy = &root->fs_info->super_copy; 3626 struct extent_buffer *sb; 3627 struct btrfs_disk_key *disk_key; 3628 struct btrfs_chunk *chunk; 3629 u8 *ptr; 3630 unsigned long sb_ptr; 3631 int ret = 0; 3632 u32 num_stripes; 3633 u32 array_size; 3634 u32 len = 0; 3635 u32 cur; 3636 struct btrfs_key key; 3637 3638 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET, 3639 BTRFS_SUPER_INFO_SIZE); 3640 if (!sb) 3641 return -ENOMEM; 3642 btrfs_set_buffer_uptodate(sb); 3643 btrfs_set_buffer_lockdep_class(sb, 0); 3644 3645 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); 3646 array_size = btrfs_super_sys_array_size(super_copy); 3647 3648 ptr = super_copy->sys_chunk_array; 3649 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array); 3650 cur = 0; 3651 3652 while (cur < array_size) { 3653 disk_key = (struct btrfs_disk_key *)ptr; 3654 btrfs_disk_key_to_cpu(&key, disk_key); 3655 3656 len = sizeof(*disk_key); ptr += len; 3657 sb_ptr += len; 3658 cur += len; 3659 3660 if (key.type == BTRFS_CHUNK_ITEM_KEY) { 3661 chunk = (struct btrfs_chunk *)sb_ptr; 3662 ret = read_one_chunk(root, &key, sb, chunk); 3663 if (ret) 3664 break; 3665 num_stripes = btrfs_chunk_num_stripes(sb, chunk); 3666 len = btrfs_chunk_item_size(num_stripes); 3667 } else { 3668 ret = -EIO; 3669 break; 3670 } 3671 ptr += len; 3672 sb_ptr += len; 3673 cur += len; 3674 } 3675 free_extent_buffer(sb); 3676 return ret; 3677 } 3678 3679 int btrfs_read_chunk_tree(struct btrfs_root *root) 3680 { 3681 struct btrfs_path *path; 3682 struct extent_buffer *leaf; 3683 struct btrfs_key key; 3684 struct btrfs_key found_key; 3685 int ret; 3686 int slot; 3687 3688 root = root->fs_info->chunk_root; 3689 3690 path = btrfs_alloc_path(); 3691 if (!path) 3692 return -ENOMEM; 3693 3694 /* first we search for all of the device items, and then we 3695 * read in all of the chunk items. This way we can create chunk 3696 * mappings that reference all of the devices that are afound 3697 */ 3698 key.objectid = BTRFS_DEV_ITEMS_OBJECTID; 3699 key.offset = 0; 3700 key.type = 0; 3701 again: 3702 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3703 if (ret < 0) 3704 goto error; 3705 while (1) { 3706 leaf = path->nodes[0]; 3707 slot = path->slots[0]; 3708 if (slot >= btrfs_header_nritems(leaf)) { 3709 ret = btrfs_next_leaf(root, path); 3710 if (ret == 0) 3711 continue; 3712 if (ret < 0) 3713 goto error; 3714 break; 3715 } 3716 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3717 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { 3718 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) 3719 break; 3720 if (found_key.type == BTRFS_DEV_ITEM_KEY) { 3721 struct btrfs_dev_item *dev_item; 3722 dev_item = btrfs_item_ptr(leaf, slot, 3723 struct btrfs_dev_item); 3724 ret = read_one_dev(root, leaf, dev_item); 3725 if (ret) 3726 goto error; 3727 } 3728 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { 3729 struct btrfs_chunk *chunk; 3730 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); 3731 ret = read_one_chunk(root, &found_key, leaf, chunk); 3732 if (ret) 3733 goto error; 3734 } 3735 path->slots[0]++; 3736 } 3737 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { 3738 key.objectid = 0; 3739 btrfs_release_path(root, path); 3740 goto again; 3741 } 3742 ret = 0; 3743 error: 3744 btrfs_free_path(path); 3745 return ret; 3746 } 3747