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/pagemap.h> 20 #include <linux/writeback.h> 21 #include <linux/blkdev.h> 22 #include <linux/sort.h> 23 #include <linux/rcupdate.h> 24 #include "compat.h" 25 #include "hash.h" 26 #include "crc32c.h" 27 #include "ctree.h" 28 #include "disk-io.h" 29 #include "print-tree.h" 30 #include "transaction.h" 31 #include "volumes.h" 32 #include "locking.h" 33 #include "ref-cache.h" 34 #include "free-space-cache.h" 35 36 #define PENDING_EXTENT_INSERT 0 37 #define PENDING_EXTENT_DELETE 1 38 #define PENDING_BACKREF_UPDATE 2 39 40 struct pending_extent_op { 41 int type; 42 u64 bytenr; 43 u64 num_bytes; 44 u64 parent; 45 u64 orig_parent; 46 u64 generation; 47 u64 orig_generation; 48 int level; 49 struct list_head list; 50 int del; 51 }; 52 53 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, 54 struct btrfs_root *root, u64 parent, 55 u64 root_objectid, u64 ref_generation, 56 u64 owner, struct btrfs_key *ins, 57 int ref_mod); 58 static int update_reserved_extents(struct btrfs_root *root, 59 u64 bytenr, u64 num, int reserve); 60 static int update_block_group(struct btrfs_trans_handle *trans, 61 struct btrfs_root *root, 62 u64 bytenr, u64 num_bytes, int alloc, 63 int mark_free); 64 static noinline int __btrfs_free_extent(struct btrfs_trans_handle *trans, 65 struct btrfs_root *root, 66 u64 bytenr, u64 num_bytes, u64 parent, 67 u64 root_objectid, u64 ref_generation, 68 u64 owner_objectid, int pin, 69 int ref_to_drop); 70 71 static int do_chunk_alloc(struct btrfs_trans_handle *trans, 72 struct btrfs_root *extent_root, u64 alloc_bytes, 73 u64 flags, int force); 74 75 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) 76 { 77 return (cache->flags & bits) == bits; 78 } 79 80 /* 81 * this adds the block group to the fs_info rb tree for the block group 82 * cache 83 */ 84 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info, 85 struct btrfs_block_group_cache *block_group) 86 { 87 struct rb_node **p; 88 struct rb_node *parent = NULL; 89 struct btrfs_block_group_cache *cache; 90 91 spin_lock(&info->block_group_cache_lock); 92 p = &info->block_group_cache_tree.rb_node; 93 94 while (*p) { 95 parent = *p; 96 cache = rb_entry(parent, struct btrfs_block_group_cache, 97 cache_node); 98 if (block_group->key.objectid < cache->key.objectid) { 99 p = &(*p)->rb_left; 100 } else if (block_group->key.objectid > cache->key.objectid) { 101 p = &(*p)->rb_right; 102 } else { 103 spin_unlock(&info->block_group_cache_lock); 104 return -EEXIST; 105 } 106 } 107 108 rb_link_node(&block_group->cache_node, parent, p); 109 rb_insert_color(&block_group->cache_node, 110 &info->block_group_cache_tree); 111 spin_unlock(&info->block_group_cache_lock); 112 113 return 0; 114 } 115 116 /* 117 * This will return the block group at or after bytenr if contains is 0, else 118 * it will return the block group that contains the bytenr 119 */ 120 static struct btrfs_block_group_cache * 121 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr, 122 int contains) 123 { 124 struct btrfs_block_group_cache *cache, *ret = NULL; 125 struct rb_node *n; 126 u64 end, start; 127 128 spin_lock(&info->block_group_cache_lock); 129 n = info->block_group_cache_tree.rb_node; 130 131 while (n) { 132 cache = rb_entry(n, struct btrfs_block_group_cache, 133 cache_node); 134 end = cache->key.objectid + cache->key.offset - 1; 135 start = cache->key.objectid; 136 137 if (bytenr < start) { 138 if (!contains && (!ret || start < ret->key.objectid)) 139 ret = cache; 140 n = n->rb_left; 141 } else if (bytenr > start) { 142 if (contains && bytenr <= end) { 143 ret = cache; 144 break; 145 } 146 n = n->rb_right; 147 } else { 148 ret = cache; 149 break; 150 } 151 } 152 if (ret) 153 atomic_inc(&ret->count); 154 spin_unlock(&info->block_group_cache_lock); 155 156 return ret; 157 } 158 159 /* 160 * this is only called by cache_block_group, since we could have freed extents 161 * we need to check the pinned_extents for any extents that can't be used yet 162 * since their free space will be released as soon as the transaction commits. 163 */ 164 static int add_new_free_space(struct btrfs_block_group_cache *block_group, 165 struct btrfs_fs_info *info, u64 start, u64 end) 166 { 167 u64 extent_start, extent_end, size; 168 int ret; 169 170 while (start < end) { 171 ret = find_first_extent_bit(&info->pinned_extents, start, 172 &extent_start, &extent_end, 173 EXTENT_DIRTY); 174 if (ret) 175 break; 176 177 if (extent_start == start) { 178 start = extent_end + 1; 179 } else if (extent_start > start && extent_start < end) { 180 size = extent_start - start; 181 ret = btrfs_add_free_space(block_group, start, 182 size); 183 BUG_ON(ret); 184 start = extent_end + 1; 185 } else { 186 break; 187 } 188 } 189 190 if (start < end) { 191 size = end - start; 192 ret = btrfs_add_free_space(block_group, start, size); 193 BUG_ON(ret); 194 } 195 196 return 0; 197 } 198 199 static int remove_sb_from_cache(struct btrfs_root *root, 200 struct btrfs_block_group_cache *cache) 201 { 202 u64 bytenr; 203 u64 *logical; 204 int stripe_len; 205 int i, nr, ret; 206 207 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { 208 bytenr = btrfs_sb_offset(i); 209 ret = btrfs_rmap_block(&root->fs_info->mapping_tree, 210 cache->key.objectid, bytenr, 0, 211 &logical, &nr, &stripe_len); 212 BUG_ON(ret); 213 while (nr--) { 214 btrfs_remove_free_space(cache, logical[nr], 215 stripe_len); 216 } 217 kfree(logical); 218 } 219 return 0; 220 } 221 222 static int cache_block_group(struct btrfs_root *root, 223 struct btrfs_block_group_cache *block_group) 224 { 225 struct btrfs_path *path; 226 int ret = 0; 227 struct btrfs_key key; 228 struct extent_buffer *leaf; 229 int slot; 230 u64 last; 231 232 if (!block_group) 233 return 0; 234 235 root = root->fs_info->extent_root; 236 237 if (block_group->cached) 238 return 0; 239 240 path = btrfs_alloc_path(); 241 if (!path) 242 return -ENOMEM; 243 244 path->reada = 2; 245 /* 246 * we get into deadlocks with paths held by callers of this function. 247 * since the alloc_mutex is protecting things right now, just 248 * skip the locking here 249 */ 250 path->skip_locking = 1; 251 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET); 252 key.objectid = last; 253 key.offset = 0; 254 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); 255 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 256 if (ret < 0) 257 goto err; 258 259 while (1) { 260 leaf = path->nodes[0]; 261 slot = path->slots[0]; 262 if (slot >= btrfs_header_nritems(leaf)) { 263 ret = btrfs_next_leaf(root, path); 264 if (ret < 0) 265 goto err; 266 if (ret == 0) 267 continue; 268 else 269 break; 270 } 271 btrfs_item_key_to_cpu(leaf, &key, slot); 272 if (key.objectid < block_group->key.objectid) 273 goto next; 274 275 if (key.objectid >= block_group->key.objectid + 276 block_group->key.offset) 277 break; 278 279 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) { 280 add_new_free_space(block_group, root->fs_info, last, 281 key.objectid); 282 283 last = key.objectid + key.offset; 284 } 285 next: 286 path->slots[0]++; 287 } 288 289 add_new_free_space(block_group, root->fs_info, last, 290 block_group->key.objectid + 291 block_group->key.offset); 292 293 block_group->cached = 1; 294 remove_sb_from_cache(root, block_group); 295 ret = 0; 296 err: 297 btrfs_free_path(path); 298 return ret; 299 } 300 301 /* 302 * return the block group that starts at or after bytenr 303 */ 304 static struct btrfs_block_group_cache * 305 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr) 306 { 307 struct btrfs_block_group_cache *cache; 308 309 cache = block_group_cache_tree_search(info, bytenr, 0); 310 311 return cache; 312 } 313 314 /* 315 * return the block group that contains teh given bytenr 316 */ 317 struct btrfs_block_group_cache *btrfs_lookup_block_group( 318 struct btrfs_fs_info *info, 319 u64 bytenr) 320 { 321 struct btrfs_block_group_cache *cache; 322 323 cache = block_group_cache_tree_search(info, bytenr, 1); 324 325 return cache; 326 } 327 328 void btrfs_put_block_group(struct btrfs_block_group_cache *cache) 329 { 330 if (atomic_dec_and_test(&cache->count)) 331 kfree(cache); 332 } 333 334 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, 335 u64 flags) 336 { 337 struct list_head *head = &info->space_info; 338 struct btrfs_space_info *found; 339 340 rcu_read_lock(); 341 list_for_each_entry_rcu(found, head, list) { 342 if (found->flags == flags) { 343 rcu_read_unlock(); 344 return found; 345 } 346 } 347 rcu_read_unlock(); 348 return NULL; 349 } 350 351 /* 352 * after adding space to the filesystem, we need to clear the full flags 353 * on all the space infos. 354 */ 355 void btrfs_clear_space_info_full(struct btrfs_fs_info *info) 356 { 357 struct list_head *head = &info->space_info; 358 struct btrfs_space_info *found; 359 360 rcu_read_lock(); 361 list_for_each_entry_rcu(found, head, list) 362 found->full = 0; 363 rcu_read_unlock(); 364 } 365 366 static u64 div_factor(u64 num, int factor) 367 { 368 if (factor == 10) 369 return num; 370 num *= factor; 371 do_div(num, 10); 372 return num; 373 } 374 375 u64 btrfs_find_block_group(struct btrfs_root *root, 376 u64 search_start, u64 search_hint, int owner) 377 { 378 struct btrfs_block_group_cache *cache; 379 u64 used; 380 u64 last = max(search_hint, search_start); 381 u64 group_start = 0; 382 int full_search = 0; 383 int factor = 9; 384 int wrapped = 0; 385 again: 386 while (1) { 387 cache = btrfs_lookup_first_block_group(root->fs_info, last); 388 if (!cache) 389 break; 390 391 spin_lock(&cache->lock); 392 last = cache->key.objectid + cache->key.offset; 393 used = btrfs_block_group_used(&cache->item); 394 395 if ((full_search || !cache->ro) && 396 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) { 397 if (used + cache->pinned + cache->reserved < 398 div_factor(cache->key.offset, factor)) { 399 group_start = cache->key.objectid; 400 spin_unlock(&cache->lock); 401 btrfs_put_block_group(cache); 402 goto found; 403 } 404 } 405 spin_unlock(&cache->lock); 406 btrfs_put_block_group(cache); 407 cond_resched(); 408 } 409 if (!wrapped) { 410 last = search_start; 411 wrapped = 1; 412 goto again; 413 } 414 if (!full_search && factor < 10) { 415 last = search_start; 416 full_search = 1; 417 factor = 10; 418 goto again; 419 } 420 found: 421 return group_start; 422 } 423 424 /* simple helper to search for an existing extent at a given offset */ 425 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len) 426 { 427 int ret; 428 struct btrfs_key key; 429 struct btrfs_path *path; 430 431 path = btrfs_alloc_path(); 432 BUG_ON(!path); 433 key.objectid = start; 434 key.offset = len; 435 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); 436 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, 437 0, 0); 438 btrfs_free_path(path); 439 return ret; 440 } 441 442 /* 443 * Back reference rules. Back refs have three main goals: 444 * 445 * 1) differentiate between all holders of references to an extent so that 446 * when a reference is dropped we can make sure it was a valid reference 447 * before freeing the extent. 448 * 449 * 2) Provide enough information to quickly find the holders of an extent 450 * if we notice a given block is corrupted or bad. 451 * 452 * 3) Make it easy to migrate blocks for FS shrinking or storage pool 453 * maintenance. This is actually the same as #2, but with a slightly 454 * different use case. 455 * 456 * File extents can be referenced by: 457 * 458 * - multiple snapshots, subvolumes, or different generations in one subvol 459 * - different files inside a single subvolume 460 * - different offsets inside a file (bookend extents in file.c) 461 * 462 * The extent ref structure has fields for: 463 * 464 * - Objectid of the subvolume root 465 * - Generation number of the tree holding the reference 466 * - objectid of the file holding the reference 467 * - number of references holding by parent node (alway 1 for tree blocks) 468 * 469 * Btree leaf may hold multiple references to a file extent. In most cases, 470 * these references are from same file and the corresponding offsets inside 471 * the file are close together. 472 * 473 * When a file extent is allocated the fields are filled in: 474 * (root_key.objectid, trans->transid, inode objectid, 1) 475 * 476 * When a leaf is cow'd new references are added for every file extent found 477 * in the leaf. It looks similar to the create case, but trans->transid will 478 * be different when the block is cow'd. 479 * 480 * (root_key.objectid, trans->transid, inode objectid, 481 * number of references in the leaf) 482 * 483 * When a file extent is removed either during snapshot deletion or 484 * file truncation, we find the corresponding back reference and check 485 * the following fields: 486 * 487 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf), 488 * inode objectid) 489 * 490 * Btree extents can be referenced by: 491 * 492 * - Different subvolumes 493 * - Different generations of the same subvolume 494 * 495 * When a tree block is created, back references are inserted: 496 * 497 * (root->root_key.objectid, trans->transid, level, 1) 498 * 499 * When a tree block is cow'd, new back references are added for all the 500 * blocks it points to. If the tree block isn't in reference counted root, 501 * the old back references are removed. These new back references are of 502 * the form (trans->transid will have increased since creation): 503 * 504 * (root->root_key.objectid, trans->transid, level, 1) 505 * 506 * When a backref is in deleting, the following fields are checked: 507 * 508 * if backref was for a tree root: 509 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level) 510 * else 511 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level) 512 * 513 * Back Reference Key composing: 514 * 515 * The key objectid corresponds to the first byte in the extent, the key 516 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first 517 * byte of parent extent. If a extent is tree root, the key offset is set 518 * to the key objectid. 519 */ 520 521 static noinline int lookup_extent_backref(struct btrfs_trans_handle *trans, 522 struct btrfs_root *root, 523 struct btrfs_path *path, 524 u64 bytenr, u64 parent, 525 u64 ref_root, u64 ref_generation, 526 u64 owner_objectid, int del) 527 { 528 struct btrfs_key key; 529 struct btrfs_extent_ref *ref; 530 struct extent_buffer *leaf; 531 u64 ref_objectid; 532 int ret; 533 534 key.objectid = bytenr; 535 key.type = BTRFS_EXTENT_REF_KEY; 536 key.offset = parent; 537 538 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1); 539 if (ret < 0) 540 goto out; 541 if (ret > 0) { 542 ret = -ENOENT; 543 goto out; 544 } 545 546 leaf = path->nodes[0]; 547 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); 548 ref_objectid = btrfs_ref_objectid(leaf, ref); 549 if (btrfs_ref_root(leaf, ref) != ref_root || 550 btrfs_ref_generation(leaf, ref) != ref_generation || 551 (ref_objectid != owner_objectid && 552 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) { 553 ret = -EIO; 554 WARN_ON(1); 555 goto out; 556 } 557 ret = 0; 558 out: 559 return ret; 560 } 561 562 static noinline int insert_extent_backref(struct btrfs_trans_handle *trans, 563 struct btrfs_root *root, 564 struct btrfs_path *path, 565 u64 bytenr, u64 parent, 566 u64 ref_root, u64 ref_generation, 567 u64 owner_objectid, 568 int refs_to_add) 569 { 570 struct btrfs_key key; 571 struct extent_buffer *leaf; 572 struct btrfs_extent_ref *ref; 573 u32 num_refs; 574 int ret; 575 576 key.objectid = bytenr; 577 key.type = BTRFS_EXTENT_REF_KEY; 578 key.offset = parent; 579 580 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref)); 581 if (ret == 0) { 582 leaf = path->nodes[0]; 583 ref = btrfs_item_ptr(leaf, path->slots[0], 584 struct btrfs_extent_ref); 585 btrfs_set_ref_root(leaf, ref, ref_root); 586 btrfs_set_ref_generation(leaf, ref, ref_generation); 587 btrfs_set_ref_objectid(leaf, ref, owner_objectid); 588 btrfs_set_ref_num_refs(leaf, ref, refs_to_add); 589 } else if (ret == -EEXIST) { 590 u64 existing_owner; 591 592 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID); 593 leaf = path->nodes[0]; 594 ref = btrfs_item_ptr(leaf, path->slots[0], 595 struct btrfs_extent_ref); 596 if (btrfs_ref_root(leaf, ref) != ref_root || 597 btrfs_ref_generation(leaf, ref) != ref_generation) { 598 ret = -EIO; 599 WARN_ON(1); 600 goto out; 601 } 602 603 num_refs = btrfs_ref_num_refs(leaf, ref); 604 BUG_ON(num_refs == 0); 605 btrfs_set_ref_num_refs(leaf, ref, num_refs + refs_to_add); 606 607 existing_owner = btrfs_ref_objectid(leaf, ref); 608 if (existing_owner != owner_objectid && 609 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) { 610 btrfs_set_ref_objectid(leaf, ref, 611 BTRFS_MULTIPLE_OBJECTIDS); 612 } 613 ret = 0; 614 } else { 615 goto out; 616 } 617 btrfs_unlock_up_safe(path, 1); 618 btrfs_mark_buffer_dirty(path->nodes[0]); 619 out: 620 btrfs_release_path(root, path); 621 return ret; 622 } 623 624 static noinline int remove_extent_backref(struct btrfs_trans_handle *trans, 625 struct btrfs_root *root, 626 struct btrfs_path *path, 627 int refs_to_drop) 628 { 629 struct extent_buffer *leaf; 630 struct btrfs_extent_ref *ref; 631 u32 num_refs; 632 int ret = 0; 633 634 leaf = path->nodes[0]; 635 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); 636 num_refs = btrfs_ref_num_refs(leaf, ref); 637 BUG_ON(num_refs < refs_to_drop); 638 num_refs -= refs_to_drop; 639 if (num_refs == 0) { 640 ret = btrfs_del_item(trans, root, path); 641 } else { 642 btrfs_set_ref_num_refs(leaf, ref, num_refs); 643 btrfs_mark_buffer_dirty(leaf); 644 } 645 btrfs_release_path(root, path); 646 return ret; 647 } 648 649 #ifdef BIO_RW_DISCARD 650 static void btrfs_issue_discard(struct block_device *bdev, 651 u64 start, u64 len) 652 { 653 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL); 654 } 655 #endif 656 657 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, 658 u64 num_bytes) 659 { 660 #ifdef BIO_RW_DISCARD 661 int ret; 662 u64 map_length = num_bytes; 663 struct btrfs_multi_bio *multi = NULL; 664 665 /* Tell the block device(s) that the sectors can be discarded */ 666 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ, 667 bytenr, &map_length, &multi, 0); 668 if (!ret) { 669 struct btrfs_bio_stripe *stripe = multi->stripes; 670 int i; 671 672 if (map_length > num_bytes) 673 map_length = num_bytes; 674 675 for (i = 0; i < multi->num_stripes; i++, stripe++) { 676 btrfs_issue_discard(stripe->dev->bdev, 677 stripe->physical, 678 map_length); 679 } 680 kfree(multi); 681 } 682 683 return ret; 684 #else 685 return 0; 686 #endif 687 } 688 689 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans, 690 struct btrfs_root *root, u64 bytenr, 691 u64 num_bytes, 692 u64 orig_parent, u64 parent, 693 u64 orig_root, u64 ref_root, 694 u64 orig_generation, u64 ref_generation, 695 u64 owner_objectid) 696 { 697 int ret; 698 int pin = owner_objectid < BTRFS_FIRST_FREE_OBJECTID; 699 700 ret = btrfs_update_delayed_ref(trans, bytenr, num_bytes, 701 orig_parent, parent, orig_root, 702 ref_root, orig_generation, 703 ref_generation, owner_objectid, pin); 704 BUG_ON(ret); 705 return ret; 706 } 707 708 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans, 709 struct btrfs_root *root, u64 bytenr, 710 u64 num_bytes, u64 orig_parent, u64 parent, 711 u64 ref_root, u64 ref_generation, 712 u64 owner_objectid) 713 { 714 int ret; 715 if (ref_root == BTRFS_TREE_LOG_OBJECTID && 716 owner_objectid < BTRFS_FIRST_FREE_OBJECTID) 717 return 0; 718 719 ret = __btrfs_update_extent_ref(trans, root, bytenr, num_bytes, 720 orig_parent, parent, ref_root, 721 ref_root, ref_generation, 722 ref_generation, owner_objectid); 723 return ret; 724 } 725 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, 726 struct btrfs_root *root, u64 bytenr, 727 u64 num_bytes, 728 u64 orig_parent, u64 parent, 729 u64 orig_root, u64 ref_root, 730 u64 orig_generation, u64 ref_generation, 731 u64 owner_objectid) 732 { 733 int ret; 734 735 ret = btrfs_add_delayed_ref(trans, bytenr, num_bytes, parent, ref_root, 736 ref_generation, owner_objectid, 737 BTRFS_ADD_DELAYED_REF, 0); 738 BUG_ON(ret); 739 return ret; 740 } 741 742 static noinline_for_stack int add_extent_ref(struct btrfs_trans_handle *trans, 743 struct btrfs_root *root, u64 bytenr, 744 u64 num_bytes, u64 parent, u64 ref_root, 745 u64 ref_generation, u64 owner_objectid, 746 int refs_to_add) 747 { 748 struct btrfs_path *path; 749 int ret; 750 struct btrfs_key key; 751 struct extent_buffer *l; 752 struct btrfs_extent_item *item; 753 u32 refs; 754 755 path = btrfs_alloc_path(); 756 if (!path) 757 return -ENOMEM; 758 759 path->reada = 1; 760 path->leave_spinning = 1; 761 key.objectid = bytenr; 762 key.type = BTRFS_EXTENT_ITEM_KEY; 763 key.offset = num_bytes; 764 765 /* first find the extent item and update its reference count */ 766 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, 767 path, 0, 1); 768 if (ret < 0) { 769 btrfs_set_path_blocking(path); 770 return ret; 771 } 772 773 if (ret > 0) { 774 WARN_ON(1); 775 btrfs_free_path(path); 776 return -EIO; 777 } 778 l = path->nodes[0]; 779 780 btrfs_item_key_to_cpu(l, &key, path->slots[0]); 781 if (key.objectid != bytenr) { 782 btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]); 783 printk(KERN_ERR "btrfs wanted %llu found %llu\n", 784 (unsigned long long)bytenr, 785 (unsigned long long)key.objectid); 786 BUG(); 787 } 788 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY); 789 790 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); 791 792 refs = btrfs_extent_refs(l, item); 793 btrfs_set_extent_refs(l, item, refs + refs_to_add); 794 btrfs_unlock_up_safe(path, 1); 795 796 btrfs_mark_buffer_dirty(path->nodes[0]); 797 798 btrfs_release_path(root->fs_info->extent_root, path); 799 800 path->reada = 1; 801 path->leave_spinning = 1; 802 803 /* now insert the actual backref */ 804 ret = insert_extent_backref(trans, root->fs_info->extent_root, 805 path, bytenr, parent, 806 ref_root, ref_generation, 807 owner_objectid, refs_to_add); 808 BUG_ON(ret); 809 btrfs_free_path(path); 810 return 0; 811 } 812 813 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, 814 struct btrfs_root *root, 815 u64 bytenr, u64 num_bytes, u64 parent, 816 u64 ref_root, u64 ref_generation, 817 u64 owner_objectid) 818 { 819 int ret; 820 if (ref_root == BTRFS_TREE_LOG_OBJECTID && 821 owner_objectid < BTRFS_FIRST_FREE_OBJECTID) 822 return 0; 823 824 ret = __btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0, parent, 825 0, ref_root, 0, ref_generation, 826 owner_objectid); 827 return ret; 828 } 829 830 static int drop_delayed_ref(struct btrfs_trans_handle *trans, 831 struct btrfs_root *root, 832 struct btrfs_delayed_ref_node *node) 833 { 834 int ret = 0; 835 struct btrfs_delayed_ref *ref = btrfs_delayed_node_to_ref(node); 836 837 BUG_ON(node->ref_mod == 0); 838 ret = __btrfs_free_extent(trans, root, node->bytenr, node->num_bytes, 839 node->parent, ref->root, ref->generation, 840 ref->owner_objectid, ref->pin, node->ref_mod); 841 842 return ret; 843 } 844 845 /* helper function to actually process a single delayed ref entry */ 846 static noinline int run_one_delayed_ref(struct btrfs_trans_handle *trans, 847 struct btrfs_root *root, 848 struct btrfs_delayed_ref_node *node, 849 int insert_reserved) 850 { 851 int ret; 852 struct btrfs_delayed_ref *ref; 853 854 if (node->parent == (u64)-1) { 855 struct btrfs_delayed_ref_head *head; 856 /* 857 * we've hit the end of the chain and we were supposed 858 * to insert this extent into the tree. But, it got 859 * deleted before we ever needed to insert it, so all 860 * we have to do is clean up the accounting 861 */ 862 if (insert_reserved) { 863 update_reserved_extents(root, node->bytenr, 864 node->num_bytes, 0); 865 } 866 head = btrfs_delayed_node_to_head(node); 867 mutex_unlock(&head->mutex); 868 return 0; 869 } 870 871 ref = btrfs_delayed_node_to_ref(node); 872 if (ref->action == BTRFS_ADD_DELAYED_REF) { 873 if (insert_reserved) { 874 struct btrfs_key ins; 875 876 ins.objectid = node->bytenr; 877 ins.offset = node->num_bytes; 878 ins.type = BTRFS_EXTENT_ITEM_KEY; 879 880 /* record the full extent allocation */ 881 ret = __btrfs_alloc_reserved_extent(trans, root, 882 node->parent, ref->root, 883 ref->generation, ref->owner_objectid, 884 &ins, node->ref_mod); 885 update_reserved_extents(root, node->bytenr, 886 node->num_bytes, 0); 887 } else { 888 /* just add one backref */ 889 ret = add_extent_ref(trans, root, node->bytenr, 890 node->num_bytes, 891 node->parent, ref->root, ref->generation, 892 ref->owner_objectid, node->ref_mod); 893 } 894 BUG_ON(ret); 895 } else if (ref->action == BTRFS_DROP_DELAYED_REF) { 896 WARN_ON(insert_reserved); 897 ret = drop_delayed_ref(trans, root, node); 898 } 899 return 0; 900 } 901 902 static noinline struct btrfs_delayed_ref_node * 903 select_delayed_ref(struct btrfs_delayed_ref_head *head) 904 { 905 struct rb_node *node; 906 struct btrfs_delayed_ref_node *ref; 907 int action = BTRFS_ADD_DELAYED_REF; 908 again: 909 /* 910 * select delayed ref of type BTRFS_ADD_DELAYED_REF first. 911 * this prevents ref count from going down to zero when 912 * there still are pending delayed ref. 913 */ 914 node = rb_prev(&head->node.rb_node); 915 while (1) { 916 if (!node) 917 break; 918 ref = rb_entry(node, struct btrfs_delayed_ref_node, 919 rb_node); 920 if (ref->bytenr != head->node.bytenr) 921 break; 922 if (btrfs_delayed_node_to_ref(ref)->action == action) 923 return ref; 924 node = rb_prev(node); 925 } 926 if (action == BTRFS_ADD_DELAYED_REF) { 927 action = BTRFS_DROP_DELAYED_REF; 928 goto again; 929 } 930 return NULL; 931 } 932 933 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans, 934 struct btrfs_root *root, 935 struct list_head *cluster) 936 { 937 struct btrfs_delayed_ref_root *delayed_refs; 938 struct btrfs_delayed_ref_node *ref; 939 struct btrfs_delayed_ref_head *locked_ref = NULL; 940 int ret; 941 int count = 0; 942 int must_insert_reserved = 0; 943 944 delayed_refs = &trans->transaction->delayed_refs; 945 while (1) { 946 if (!locked_ref) { 947 /* pick a new head ref from the cluster list */ 948 if (list_empty(cluster)) 949 break; 950 951 locked_ref = list_entry(cluster->next, 952 struct btrfs_delayed_ref_head, cluster); 953 954 /* grab the lock that says we are going to process 955 * all the refs for this head */ 956 ret = btrfs_delayed_ref_lock(trans, locked_ref); 957 958 /* 959 * we may have dropped the spin lock to get the head 960 * mutex lock, and that might have given someone else 961 * time to free the head. If that's true, it has been 962 * removed from our list and we can move on. 963 */ 964 if (ret == -EAGAIN) { 965 locked_ref = NULL; 966 count++; 967 continue; 968 } 969 } 970 971 /* 972 * record the must insert reserved flag before we 973 * drop the spin lock. 974 */ 975 must_insert_reserved = locked_ref->must_insert_reserved; 976 locked_ref->must_insert_reserved = 0; 977 978 /* 979 * locked_ref is the head node, so we have to go one 980 * node back for any delayed ref updates 981 */ 982 ref = select_delayed_ref(locked_ref); 983 if (!ref) { 984 /* All delayed refs have been processed, Go ahead 985 * and send the head node to run_one_delayed_ref, 986 * so that any accounting fixes can happen 987 */ 988 ref = &locked_ref->node; 989 list_del_init(&locked_ref->cluster); 990 locked_ref = NULL; 991 } 992 993 ref->in_tree = 0; 994 rb_erase(&ref->rb_node, &delayed_refs->root); 995 delayed_refs->num_entries--; 996 spin_unlock(&delayed_refs->lock); 997 998 ret = run_one_delayed_ref(trans, root, ref, 999 must_insert_reserved); 1000 BUG_ON(ret); 1001 btrfs_put_delayed_ref(ref); 1002 1003 count++; 1004 cond_resched(); 1005 spin_lock(&delayed_refs->lock); 1006 } 1007 return count; 1008 } 1009 1010 /* 1011 * this starts processing the delayed reference count updates and 1012 * extent insertions we have queued up so far. count can be 1013 * 0, which means to process everything in the tree at the start 1014 * of the run (but not newly added entries), or it can be some target 1015 * number you'd like to process. 1016 */ 1017 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, 1018 struct btrfs_root *root, unsigned long count) 1019 { 1020 struct rb_node *node; 1021 struct btrfs_delayed_ref_root *delayed_refs; 1022 struct btrfs_delayed_ref_node *ref; 1023 struct list_head cluster; 1024 int ret; 1025 int run_all = count == (unsigned long)-1; 1026 int run_most = 0; 1027 1028 if (root == root->fs_info->extent_root) 1029 root = root->fs_info->tree_root; 1030 1031 delayed_refs = &trans->transaction->delayed_refs; 1032 INIT_LIST_HEAD(&cluster); 1033 again: 1034 spin_lock(&delayed_refs->lock); 1035 if (count == 0) { 1036 count = delayed_refs->num_entries * 2; 1037 run_most = 1; 1038 } 1039 while (1) { 1040 if (!(run_all || run_most) && 1041 delayed_refs->num_heads_ready < 64) 1042 break; 1043 1044 /* 1045 * go find something we can process in the rbtree. We start at 1046 * the beginning of the tree, and then build a cluster 1047 * of refs to process starting at the first one we are able to 1048 * lock 1049 */ 1050 ret = btrfs_find_ref_cluster(trans, &cluster, 1051 delayed_refs->run_delayed_start); 1052 if (ret) 1053 break; 1054 1055 ret = run_clustered_refs(trans, root, &cluster); 1056 BUG_ON(ret < 0); 1057 1058 count -= min_t(unsigned long, ret, count); 1059 1060 if (count == 0) 1061 break; 1062 } 1063 1064 if (run_all) { 1065 node = rb_first(&delayed_refs->root); 1066 if (!node) 1067 goto out; 1068 count = (unsigned long)-1; 1069 1070 while (node) { 1071 ref = rb_entry(node, struct btrfs_delayed_ref_node, 1072 rb_node); 1073 if (btrfs_delayed_ref_is_head(ref)) { 1074 struct btrfs_delayed_ref_head *head; 1075 1076 head = btrfs_delayed_node_to_head(ref); 1077 atomic_inc(&ref->refs); 1078 1079 spin_unlock(&delayed_refs->lock); 1080 mutex_lock(&head->mutex); 1081 mutex_unlock(&head->mutex); 1082 1083 btrfs_put_delayed_ref(ref); 1084 cond_resched(); 1085 goto again; 1086 } 1087 node = rb_next(node); 1088 } 1089 spin_unlock(&delayed_refs->lock); 1090 schedule_timeout(1); 1091 goto again; 1092 } 1093 out: 1094 spin_unlock(&delayed_refs->lock); 1095 return 0; 1096 } 1097 1098 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans, 1099 struct btrfs_root *root, u64 objectid, u64 bytenr) 1100 { 1101 struct btrfs_root *extent_root = root->fs_info->extent_root; 1102 struct btrfs_path *path; 1103 struct extent_buffer *leaf; 1104 struct btrfs_extent_ref *ref_item; 1105 struct btrfs_key key; 1106 struct btrfs_key found_key; 1107 u64 ref_root; 1108 u64 last_snapshot; 1109 u32 nritems; 1110 int ret; 1111 1112 key.objectid = bytenr; 1113 key.offset = (u64)-1; 1114 key.type = BTRFS_EXTENT_ITEM_KEY; 1115 1116 path = btrfs_alloc_path(); 1117 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); 1118 if (ret < 0) 1119 goto out; 1120 BUG_ON(ret == 0); 1121 1122 ret = -ENOENT; 1123 if (path->slots[0] == 0) 1124 goto out; 1125 1126 path->slots[0]--; 1127 leaf = path->nodes[0]; 1128 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1129 1130 if (found_key.objectid != bytenr || 1131 found_key.type != BTRFS_EXTENT_ITEM_KEY) 1132 goto out; 1133 1134 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 1135 while (1) { 1136 leaf = path->nodes[0]; 1137 nritems = btrfs_header_nritems(leaf); 1138 if (path->slots[0] >= nritems) { 1139 ret = btrfs_next_leaf(extent_root, path); 1140 if (ret < 0) 1141 goto out; 1142 if (ret == 0) 1143 continue; 1144 break; 1145 } 1146 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1147 if (found_key.objectid != bytenr) 1148 break; 1149 1150 if (found_key.type != BTRFS_EXTENT_REF_KEY) { 1151 path->slots[0]++; 1152 continue; 1153 } 1154 1155 ref_item = btrfs_item_ptr(leaf, path->slots[0], 1156 struct btrfs_extent_ref); 1157 ref_root = btrfs_ref_root(leaf, ref_item); 1158 if ((ref_root != root->root_key.objectid && 1159 ref_root != BTRFS_TREE_LOG_OBJECTID) || 1160 objectid != btrfs_ref_objectid(leaf, ref_item)) { 1161 ret = 1; 1162 goto out; 1163 } 1164 if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) { 1165 ret = 1; 1166 goto out; 1167 } 1168 1169 path->slots[0]++; 1170 } 1171 ret = 0; 1172 out: 1173 btrfs_free_path(path); 1174 return ret; 1175 } 1176 1177 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, 1178 struct extent_buffer *buf, u32 nr_extents) 1179 { 1180 struct btrfs_key key; 1181 struct btrfs_file_extent_item *fi; 1182 u64 root_gen; 1183 u32 nritems; 1184 int i; 1185 int level; 1186 int ret = 0; 1187 int shared = 0; 1188 1189 if (!root->ref_cows) 1190 return 0; 1191 1192 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { 1193 shared = 0; 1194 root_gen = root->root_key.offset; 1195 } else { 1196 shared = 1; 1197 root_gen = trans->transid - 1; 1198 } 1199 1200 level = btrfs_header_level(buf); 1201 nritems = btrfs_header_nritems(buf); 1202 1203 if (level == 0) { 1204 struct btrfs_leaf_ref *ref; 1205 struct btrfs_extent_info *info; 1206 1207 ref = btrfs_alloc_leaf_ref(root, nr_extents); 1208 if (!ref) { 1209 ret = -ENOMEM; 1210 goto out; 1211 } 1212 1213 ref->root_gen = root_gen; 1214 ref->bytenr = buf->start; 1215 ref->owner = btrfs_header_owner(buf); 1216 ref->generation = btrfs_header_generation(buf); 1217 ref->nritems = nr_extents; 1218 info = ref->extents; 1219 1220 for (i = 0; nr_extents > 0 && i < nritems; i++) { 1221 u64 disk_bytenr; 1222 btrfs_item_key_to_cpu(buf, &key, i); 1223 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) 1224 continue; 1225 fi = btrfs_item_ptr(buf, i, 1226 struct btrfs_file_extent_item); 1227 if (btrfs_file_extent_type(buf, fi) == 1228 BTRFS_FILE_EXTENT_INLINE) 1229 continue; 1230 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); 1231 if (disk_bytenr == 0) 1232 continue; 1233 1234 info->bytenr = disk_bytenr; 1235 info->num_bytes = 1236 btrfs_file_extent_disk_num_bytes(buf, fi); 1237 info->objectid = key.objectid; 1238 info->offset = key.offset; 1239 info++; 1240 } 1241 1242 ret = btrfs_add_leaf_ref(root, ref, shared); 1243 if (ret == -EEXIST && shared) { 1244 struct btrfs_leaf_ref *old; 1245 old = btrfs_lookup_leaf_ref(root, ref->bytenr); 1246 BUG_ON(!old); 1247 btrfs_remove_leaf_ref(root, old); 1248 btrfs_free_leaf_ref(root, old); 1249 ret = btrfs_add_leaf_ref(root, ref, shared); 1250 } 1251 WARN_ON(ret); 1252 btrfs_free_leaf_ref(root, ref); 1253 } 1254 out: 1255 return ret; 1256 } 1257 1258 /* when a block goes through cow, we update the reference counts of 1259 * everything that block points to. The internal pointers of the block 1260 * can be in just about any order, and it is likely to have clusters of 1261 * things that are close together and clusters of things that are not. 1262 * 1263 * To help reduce the seeks that come with updating all of these reference 1264 * counts, sort them by byte number before actual updates are done. 1265 * 1266 * struct refsort is used to match byte number to slot in the btree block. 1267 * we sort based on the byte number and then use the slot to actually 1268 * find the item. 1269 * 1270 * struct refsort is smaller than strcut btrfs_item and smaller than 1271 * struct btrfs_key_ptr. Since we're currently limited to the page size 1272 * for a btree block, there's no way for a kmalloc of refsorts for a 1273 * single node to be bigger than a page. 1274 */ 1275 struct refsort { 1276 u64 bytenr; 1277 u32 slot; 1278 }; 1279 1280 /* 1281 * for passing into sort() 1282 */ 1283 static int refsort_cmp(const void *a_void, const void *b_void) 1284 { 1285 const struct refsort *a = a_void; 1286 const struct refsort *b = b_void; 1287 1288 if (a->bytenr < b->bytenr) 1289 return -1; 1290 if (a->bytenr > b->bytenr) 1291 return 1; 1292 return 0; 1293 } 1294 1295 1296 noinline int btrfs_inc_ref(struct btrfs_trans_handle *trans, 1297 struct btrfs_root *root, 1298 struct extent_buffer *orig_buf, 1299 struct extent_buffer *buf, u32 *nr_extents) 1300 { 1301 u64 bytenr; 1302 u64 ref_root; 1303 u64 orig_root; 1304 u64 ref_generation; 1305 u64 orig_generation; 1306 struct refsort *sorted; 1307 u32 nritems; 1308 u32 nr_file_extents = 0; 1309 struct btrfs_key key; 1310 struct btrfs_file_extent_item *fi; 1311 int i; 1312 int level; 1313 int ret = 0; 1314 int faili = 0; 1315 int refi = 0; 1316 int slot; 1317 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *, 1318 u64, u64, u64, u64, u64, u64, u64, u64, u64); 1319 1320 ref_root = btrfs_header_owner(buf); 1321 ref_generation = btrfs_header_generation(buf); 1322 orig_root = btrfs_header_owner(orig_buf); 1323 orig_generation = btrfs_header_generation(orig_buf); 1324 1325 nritems = btrfs_header_nritems(buf); 1326 level = btrfs_header_level(buf); 1327 1328 sorted = kmalloc(sizeof(struct refsort) * nritems, GFP_NOFS); 1329 BUG_ON(!sorted); 1330 1331 if (root->ref_cows) { 1332 process_func = __btrfs_inc_extent_ref; 1333 } else { 1334 if (level == 0 && 1335 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) 1336 goto out; 1337 if (level != 0 && 1338 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) 1339 goto out; 1340 process_func = __btrfs_update_extent_ref; 1341 } 1342 1343 /* 1344 * we make two passes through the items. In the first pass we 1345 * only record the byte number and slot. Then we sort based on 1346 * byte number and do the actual work based on the sorted results 1347 */ 1348 for (i = 0; i < nritems; i++) { 1349 cond_resched(); 1350 if (level == 0) { 1351 btrfs_item_key_to_cpu(buf, &key, i); 1352 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) 1353 continue; 1354 fi = btrfs_item_ptr(buf, i, 1355 struct btrfs_file_extent_item); 1356 if (btrfs_file_extent_type(buf, fi) == 1357 BTRFS_FILE_EXTENT_INLINE) 1358 continue; 1359 bytenr = btrfs_file_extent_disk_bytenr(buf, fi); 1360 if (bytenr == 0) 1361 continue; 1362 1363 nr_file_extents++; 1364 sorted[refi].bytenr = bytenr; 1365 sorted[refi].slot = i; 1366 refi++; 1367 } else { 1368 bytenr = btrfs_node_blockptr(buf, i); 1369 sorted[refi].bytenr = bytenr; 1370 sorted[refi].slot = i; 1371 refi++; 1372 } 1373 } 1374 /* 1375 * if refi == 0, we didn't actually put anything into the sorted 1376 * array and we're done 1377 */ 1378 if (refi == 0) 1379 goto out; 1380 1381 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL); 1382 1383 for (i = 0; i < refi; i++) { 1384 cond_resched(); 1385 slot = sorted[i].slot; 1386 bytenr = sorted[i].bytenr; 1387 1388 if (level == 0) { 1389 btrfs_item_key_to_cpu(buf, &key, slot); 1390 fi = btrfs_item_ptr(buf, slot, 1391 struct btrfs_file_extent_item); 1392 1393 bytenr = btrfs_file_extent_disk_bytenr(buf, fi); 1394 if (bytenr == 0) 1395 continue; 1396 1397 ret = process_func(trans, root, bytenr, 1398 btrfs_file_extent_disk_num_bytes(buf, fi), 1399 orig_buf->start, buf->start, 1400 orig_root, ref_root, 1401 orig_generation, ref_generation, 1402 key.objectid); 1403 1404 if (ret) { 1405 faili = slot; 1406 WARN_ON(1); 1407 goto fail; 1408 } 1409 } else { 1410 ret = process_func(trans, root, bytenr, buf->len, 1411 orig_buf->start, buf->start, 1412 orig_root, ref_root, 1413 orig_generation, ref_generation, 1414 level - 1); 1415 if (ret) { 1416 faili = slot; 1417 WARN_ON(1); 1418 goto fail; 1419 } 1420 } 1421 } 1422 out: 1423 kfree(sorted); 1424 if (nr_extents) { 1425 if (level == 0) 1426 *nr_extents = nr_file_extents; 1427 else 1428 *nr_extents = nritems; 1429 } 1430 return 0; 1431 fail: 1432 kfree(sorted); 1433 WARN_ON(1); 1434 return ret; 1435 } 1436 1437 int btrfs_update_ref(struct btrfs_trans_handle *trans, 1438 struct btrfs_root *root, struct extent_buffer *orig_buf, 1439 struct extent_buffer *buf, int start_slot, int nr) 1440 1441 { 1442 u64 bytenr; 1443 u64 ref_root; 1444 u64 orig_root; 1445 u64 ref_generation; 1446 u64 orig_generation; 1447 struct btrfs_key key; 1448 struct btrfs_file_extent_item *fi; 1449 int i; 1450 int ret; 1451 int slot; 1452 int level; 1453 1454 BUG_ON(start_slot < 0); 1455 BUG_ON(start_slot + nr > btrfs_header_nritems(buf)); 1456 1457 ref_root = btrfs_header_owner(buf); 1458 ref_generation = btrfs_header_generation(buf); 1459 orig_root = btrfs_header_owner(orig_buf); 1460 orig_generation = btrfs_header_generation(orig_buf); 1461 level = btrfs_header_level(buf); 1462 1463 if (!root->ref_cows) { 1464 if (level == 0 && 1465 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) 1466 return 0; 1467 if (level != 0 && 1468 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) 1469 return 0; 1470 } 1471 1472 for (i = 0, slot = start_slot; i < nr; i++, slot++) { 1473 cond_resched(); 1474 if (level == 0) { 1475 btrfs_item_key_to_cpu(buf, &key, slot); 1476 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) 1477 continue; 1478 fi = btrfs_item_ptr(buf, slot, 1479 struct btrfs_file_extent_item); 1480 if (btrfs_file_extent_type(buf, fi) == 1481 BTRFS_FILE_EXTENT_INLINE) 1482 continue; 1483 bytenr = btrfs_file_extent_disk_bytenr(buf, fi); 1484 if (bytenr == 0) 1485 continue; 1486 ret = __btrfs_update_extent_ref(trans, root, bytenr, 1487 btrfs_file_extent_disk_num_bytes(buf, fi), 1488 orig_buf->start, buf->start, 1489 orig_root, ref_root, orig_generation, 1490 ref_generation, key.objectid); 1491 if (ret) 1492 goto fail; 1493 } else { 1494 bytenr = btrfs_node_blockptr(buf, slot); 1495 ret = __btrfs_update_extent_ref(trans, root, bytenr, 1496 buf->len, orig_buf->start, 1497 buf->start, orig_root, ref_root, 1498 orig_generation, ref_generation, 1499 level - 1); 1500 if (ret) 1501 goto fail; 1502 } 1503 } 1504 return 0; 1505 fail: 1506 WARN_ON(1); 1507 return -1; 1508 } 1509 1510 static int write_one_cache_group(struct btrfs_trans_handle *trans, 1511 struct btrfs_root *root, 1512 struct btrfs_path *path, 1513 struct btrfs_block_group_cache *cache) 1514 { 1515 int ret; 1516 struct btrfs_root *extent_root = root->fs_info->extent_root; 1517 unsigned long bi; 1518 struct extent_buffer *leaf; 1519 1520 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); 1521 if (ret < 0) 1522 goto fail; 1523 BUG_ON(ret); 1524 1525 leaf = path->nodes[0]; 1526 bi = btrfs_item_ptr_offset(leaf, path->slots[0]); 1527 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); 1528 btrfs_mark_buffer_dirty(leaf); 1529 btrfs_release_path(extent_root, path); 1530 fail: 1531 if (ret) 1532 return ret; 1533 return 0; 1534 1535 } 1536 1537 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, 1538 struct btrfs_root *root) 1539 { 1540 struct btrfs_block_group_cache *cache, *entry; 1541 struct rb_node *n; 1542 int err = 0; 1543 int werr = 0; 1544 struct btrfs_path *path; 1545 u64 last = 0; 1546 1547 path = btrfs_alloc_path(); 1548 if (!path) 1549 return -ENOMEM; 1550 1551 while (1) { 1552 cache = NULL; 1553 spin_lock(&root->fs_info->block_group_cache_lock); 1554 for (n = rb_first(&root->fs_info->block_group_cache_tree); 1555 n; n = rb_next(n)) { 1556 entry = rb_entry(n, struct btrfs_block_group_cache, 1557 cache_node); 1558 if (entry->dirty) { 1559 cache = entry; 1560 break; 1561 } 1562 } 1563 spin_unlock(&root->fs_info->block_group_cache_lock); 1564 1565 if (!cache) 1566 break; 1567 1568 cache->dirty = 0; 1569 last += cache->key.offset; 1570 1571 err = write_one_cache_group(trans, root, 1572 path, cache); 1573 /* 1574 * if we fail to write the cache group, we want 1575 * to keep it marked dirty in hopes that a later 1576 * write will work 1577 */ 1578 if (err) { 1579 werr = err; 1580 continue; 1581 } 1582 } 1583 btrfs_free_path(path); 1584 return werr; 1585 } 1586 1587 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr) 1588 { 1589 struct btrfs_block_group_cache *block_group; 1590 int readonly = 0; 1591 1592 block_group = btrfs_lookup_block_group(root->fs_info, bytenr); 1593 if (!block_group || block_group->ro) 1594 readonly = 1; 1595 if (block_group) 1596 btrfs_put_block_group(block_group); 1597 return readonly; 1598 } 1599 1600 static int update_space_info(struct btrfs_fs_info *info, u64 flags, 1601 u64 total_bytes, u64 bytes_used, 1602 struct btrfs_space_info **space_info) 1603 { 1604 struct btrfs_space_info *found; 1605 1606 found = __find_space_info(info, flags); 1607 if (found) { 1608 spin_lock(&found->lock); 1609 found->total_bytes += total_bytes; 1610 found->bytes_used += bytes_used; 1611 found->full = 0; 1612 spin_unlock(&found->lock); 1613 *space_info = found; 1614 return 0; 1615 } 1616 found = kzalloc(sizeof(*found), GFP_NOFS); 1617 if (!found) 1618 return -ENOMEM; 1619 1620 INIT_LIST_HEAD(&found->block_groups); 1621 init_rwsem(&found->groups_sem); 1622 spin_lock_init(&found->lock); 1623 found->flags = flags; 1624 found->total_bytes = total_bytes; 1625 found->bytes_used = bytes_used; 1626 found->bytes_pinned = 0; 1627 found->bytes_reserved = 0; 1628 found->bytes_readonly = 0; 1629 found->bytes_delalloc = 0; 1630 found->full = 0; 1631 found->force_alloc = 0; 1632 *space_info = found; 1633 list_add_rcu(&found->list, &info->space_info); 1634 return 0; 1635 } 1636 1637 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) 1638 { 1639 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 | 1640 BTRFS_BLOCK_GROUP_RAID1 | 1641 BTRFS_BLOCK_GROUP_RAID10 | 1642 BTRFS_BLOCK_GROUP_DUP); 1643 if (extra_flags) { 1644 if (flags & BTRFS_BLOCK_GROUP_DATA) 1645 fs_info->avail_data_alloc_bits |= extra_flags; 1646 if (flags & BTRFS_BLOCK_GROUP_METADATA) 1647 fs_info->avail_metadata_alloc_bits |= extra_flags; 1648 if (flags & BTRFS_BLOCK_GROUP_SYSTEM) 1649 fs_info->avail_system_alloc_bits |= extra_flags; 1650 } 1651 } 1652 1653 static void set_block_group_readonly(struct btrfs_block_group_cache *cache) 1654 { 1655 spin_lock(&cache->space_info->lock); 1656 spin_lock(&cache->lock); 1657 if (!cache->ro) { 1658 cache->space_info->bytes_readonly += cache->key.offset - 1659 btrfs_block_group_used(&cache->item); 1660 cache->ro = 1; 1661 } 1662 spin_unlock(&cache->lock); 1663 spin_unlock(&cache->space_info->lock); 1664 } 1665 1666 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) 1667 { 1668 u64 num_devices = root->fs_info->fs_devices->rw_devices; 1669 1670 if (num_devices == 1) 1671 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0); 1672 if (num_devices < 4) 1673 flags &= ~BTRFS_BLOCK_GROUP_RAID10; 1674 1675 if ((flags & BTRFS_BLOCK_GROUP_DUP) && 1676 (flags & (BTRFS_BLOCK_GROUP_RAID1 | 1677 BTRFS_BLOCK_GROUP_RAID10))) { 1678 flags &= ~BTRFS_BLOCK_GROUP_DUP; 1679 } 1680 1681 if ((flags & BTRFS_BLOCK_GROUP_RAID1) && 1682 (flags & BTRFS_BLOCK_GROUP_RAID10)) { 1683 flags &= ~BTRFS_BLOCK_GROUP_RAID1; 1684 } 1685 1686 if ((flags & BTRFS_BLOCK_GROUP_RAID0) && 1687 ((flags & BTRFS_BLOCK_GROUP_RAID1) | 1688 (flags & BTRFS_BLOCK_GROUP_RAID10) | 1689 (flags & BTRFS_BLOCK_GROUP_DUP))) 1690 flags &= ~BTRFS_BLOCK_GROUP_RAID0; 1691 return flags; 1692 } 1693 1694 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data) 1695 { 1696 struct btrfs_fs_info *info = root->fs_info; 1697 u64 alloc_profile; 1698 1699 if (data) { 1700 alloc_profile = info->avail_data_alloc_bits & 1701 info->data_alloc_profile; 1702 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile; 1703 } else if (root == root->fs_info->chunk_root) { 1704 alloc_profile = info->avail_system_alloc_bits & 1705 info->system_alloc_profile; 1706 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile; 1707 } else { 1708 alloc_profile = info->avail_metadata_alloc_bits & 1709 info->metadata_alloc_profile; 1710 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; 1711 } 1712 1713 return btrfs_reduce_alloc_profile(root, data); 1714 } 1715 1716 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode) 1717 { 1718 u64 alloc_target; 1719 1720 alloc_target = btrfs_get_alloc_profile(root, 1); 1721 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info, 1722 alloc_target); 1723 } 1724 1725 /* 1726 * for now this just makes sure we have at least 5% of our metadata space free 1727 * for use. 1728 */ 1729 int btrfs_check_metadata_free_space(struct btrfs_root *root) 1730 { 1731 struct btrfs_fs_info *info = root->fs_info; 1732 struct btrfs_space_info *meta_sinfo; 1733 u64 alloc_target, thresh; 1734 int committed = 0, ret; 1735 1736 /* get the space info for where the metadata will live */ 1737 alloc_target = btrfs_get_alloc_profile(root, 0); 1738 meta_sinfo = __find_space_info(info, alloc_target); 1739 1740 again: 1741 spin_lock(&meta_sinfo->lock); 1742 if (!meta_sinfo->full) 1743 thresh = meta_sinfo->total_bytes * 80; 1744 else 1745 thresh = meta_sinfo->total_bytes * 95; 1746 1747 do_div(thresh, 100); 1748 1749 if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved + 1750 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) { 1751 struct btrfs_trans_handle *trans; 1752 if (!meta_sinfo->full) { 1753 meta_sinfo->force_alloc = 1; 1754 spin_unlock(&meta_sinfo->lock); 1755 1756 trans = btrfs_start_transaction(root, 1); 1757 if (!trans) 1758 return -ENOMEM; 1759 1760 ret = do_chunk_alloc(trans, root->fs_info->extent_root, 1761 2 * 1024 * 1024, alloc_target, 0); 1762 btrfs_end_transaction(trans, root); 1763 goto again; 1764 } 1765 spin_unlock(&meta_sinfo->lock); 1766 1767 if (!committed) { 1768 committed = 1; 1769 trans = btrfs_join_transaction(root, 1); 1770 if (!trans) 1771 return -ENOMEM; 1772 ret = btrfs_commit_transaction(trans, root); 1773 if (ret) 1774 return ret; 1775 goto again; 1776 } 1777 return -ENOSPC; 1778 } 1779 spin_unlock(&meta_sinfo->lock); 1780 1781 return 0; 1782 } 1783 1784 /* 1785 * This will check the space that the inode allocates from to make sure we have 1786 * enough space for bytes. 1787 */ 1788 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode, 1789 u64 bytes) 1790 { 1791 struct btrfs_space_info *data_sinfo; 1792 int ret = 0, committed = 0; 1793 1794 /* make sure bytes are sectorsize aligned */ 1795 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); 1796 1797 data_sinfo = BTRFS_I(inode)->space_info; 1798 again: 1799 /* make sure we have enough space to handle the data first */ 1800 spin_lock(&data_sinfo->lock); 1801 if (data_sinfo->total_bytes - data_sinfo->bytes_used - 1802 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved - 1803 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly - 1804 data_sinfo->bytes_may_use < bytes) { 1805 struct btrfs_trans_handle *trans; 1806 1807 /* 1808 * if we don't have enough free bytes in this space then we need 1809 * to alloc a new chunk. 1810 */ 1811 if (!data_sinfo->full) { 1812 u64 alloc_target; 1813 1814 data_sinfo->force_alloc = 1; 1815 spin_unlock(&data_sinfo->lock); 1816 1817 alloc_target = btrfs_get_alloc_profile(root, 1); 1818 trans = btrfs_start_transaction(root, 1); 1819 if (!trans) 1820 return -ENOMEM; 1821 1822 ret = do_chunk_alloc(trans, root->fs_info->extent_root, 1823 bytes + 2 * 1024 * 1024, 1824 alloc_target, 0); 1825 btrfs_end_transaction(trans, root); 1826 if (ret) 1827 return ret; 1828 goto again; 1829 } 1830 spin_unlock(&data_sinfo->lock); 1831 1832 /* commit the current transaction and try again */ 1833 if (!committed) { 1834 committed = 1; 1835 trans = btrfs_join_transaction(root, 1); 1836 if (!trans) 1837 return -ENOMEM; 1838 ret = btrfs_commit_transaction(trans, root); 1839 if (ret) 1840 return ret; 1841 goto again; 1842 } 1843 1844 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes" 1845 ", %llu bytes_used, %llu bytes_reserved, " 1846 "%llu bytes_pinned, %llu bytes_readonly, %llu may use" 1847 "%llu total\n", (unsigned long long)bytes, 1848 (unsigned long long)data_sinfo->bytes_delalloc, 1849 (unsigned long long)data_sinfo->bytes_used, 1850 (unsigned long long)data_sinfo->bytes_reserved, 1851 (unsigned long long)data_sinfo->bytes_pinned, 1852 (unsigned long long)data_sinfo->bytes_readonly, 1853 (unsigned long long)data_sinfo->bytes_may_use, 1854 (unsigned long long)data_sinfo->total_bytes); 1855 return -ENOSPC; 1856 } 1857 data_sinfo->bytes_may_use += bytes; 1858 BTRFS_I(inode)->reserved_bytes += bytes; 1859 spin_unlock(&data_sinfo->lock); 1860 1861 return btrfs_check_metadata_free_space(root); 1862 } 1863 1864 /* 1865 * if there was an error for whatever reason after calling 1866 * btrfs_check_data_free_space, call this so we can cleanup the counters. 1867 */ 1868 void btrfs_free_reserved_data_space(struct btrfs_root *root, 1869 struct inode *inode, u64 bytes) 1870 { 1871 struct btrfs_space_info *data_sinfo; 1872 1873 /* make sure bytes are sectorsize aligned */ 1874 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); 1875 1876 data_sinfo = BTRFS_I(inode)->space_info; 1877 spin_lock(&data_sinfo->lock); 1878 data_sinfo->bytes_may_use -= bytes; 1879 BTRFS_I(inode)->reserved_bytes -= bytes; 1880 spin_unlock(&data_sinfo->lock); 1881 } 1882 1883 /* called when we are adding a delalloc extent to the inode's io_tree */ 1884 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode, 1885 u64 bytes) 1886 { 1887 struct btrfs_space_info *data_sinfo; 1888 1889 /* get the space info for where this inode will be storing its data */ 1890 data_sinfo = BTRFS_I(inode)->space_info; 1891 1892 /* make sure we have enough space to handle the data first */ 1893 spin_lock(&data_sinfo->lock); 1894 data_sinfo->bytes_delalloc += bytes; 1895 1896 /* 1897 * we are adding a delalloc extent without calling 1898 * btrfs_check_data_free_space first. This happens on a weird 1899 * writepage condition, but shouldn't hurt our accounting 1900 */ 1901 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) { 1902 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes; 1903 BTRFS_I(inode)->reserved_bytes = 0; 1904 } else { 1905 data_sinfo->bytes_may_use -= bytes; 1906 BTRFS_I(inode)->reserved_bytes -= bytes; 1907 } 1908 1909 spin_unlock(&data_sinfo->lock); 1910 } 1911 1912 /* called when we are clearing an delalloc extent from the inode's io_tree */ 1913 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode, 1914 u64 bytes) 1915 { 1916 struct btrfs_space_info *info; 1917 1918 info = BTRFS_I(inode)->space_info; 1919 1920 spin_lock(&info->lock); 1921 info->bytes_delalloc -= bytes; 1922 spin_unlock(&info->lock); 1923 } 1924 1925 static void force_metadata_allocation(struct btrfs_fs_info *info) 1926 { 1927 struct list_head *head = &info->space_info; 1928 struct btrfs_space_info *found; 1929 1930 rcu_read_lock(); 1931 list_for_each_entry_rcu(found, head, list) { 1932 if (found->flags & BTRFS_BLOCK_GROUP_METADATA) 1933 found->force_alloc = 1; 1934 } 1935 rcu_read_unlock(); 1936 } 1937 1938 static int do_chunk_alloc(struct btrfs_trans_handle *trans, 1939 struct btrfs_root *extent_root, u64 alloc_bytes, 1940 u64 flags, int force) 1941 { 1942 struct btrfs_space_info *space_info; 1943 struct btrfs_fs_info *fs_info = extent_root->fs_info; 1944 u64 thresh; 1945 int ret = 0; 1946 1947 mutex_lock(&fs_info->chunk_mutex); 1948 1949 flags = btrfs_reduce_alloc_profile(extent_root, flags); 1950 1951 space_info = __find_space_info(extent_root->fs_info, flags); 1952 if (!space_info) { 1953 ret = update_space_info(extent_root->fs_info, flags, 1954 0, 0, &space_info); 1955 BUG_ON(ret); 1956 } 1957 BUG_ON(!space_info); 1958 1959 spin_lock(&space_info->lock); 1960 if (space_info->force_alloc) { 1961 force = 1; 1962 space_info->force_alloc = 0; 1963 } 1964 if (space_info->full) { 1965 spin_unlock(&space_info->lock); 1966 goto out; 1967 } 1968 1969 thresh = space_info->total_bytes - space_info->bytes_readonly; 1970 thresh = div_factor(thresh, 6); 1971 if (!force && 1972 (space_info->bytes_used + space_info->bytes_pinned + 1973 space_info->bytes_reserved + alloc_bytes) < thresh) { 1974 spin_unlock(&space_info->lock); 1975 goto out; 1976 } 1977 spin_unlock(&space_info->lock); 1978 1979 /* 1980 * if we're doing a data chunk, go ahead and make sure that 1981 * we keep a reasonable number of metadata chunks allocated in the 1982 * FS as well. 1983 */ 1984 if (flags & BTRFS_BLOCK_GROUP_DATA) { 1985 fs_info->data_chunk_allocations++; 1986 if (!(fs_info->data_chunk_allocations % 1987 fs_info->metadata_ratio)) 1988 force_metadata_allocation(fs_info); 1989 } 1990 1991 ret = btrfs_alloc_chunk(trans, extent_root, flags); 1992 if (ret) 1993 space_info->full = 1; 1994 out: 1995 mutex_unlock(&extent_root->fs_info->chunk_mutex); 1996 return ret; 1997 } 1998 1999 static int update_block_group(struct btrfs_trans_handle *trans, 2000 struct btrfs_root *root, 2001 u64 bytenr, u64 num_bytes, int alloc, 2002 int mark_free) 2003 { 2004 struct btrfs_block_group_cache *cache; 2005 struct btrfs_fs_info *info = root->fs_info; 2006 u64 total = num_bytes; 2007 u64 old_val; 2008 u64 byte_in_group; 2009 2010 while (total) { 2011 cache = btrfs_lookup_block_group(info, bytenr); 2012 if (!cache) 2013 return -1; 2014 byte_in_group = bytenr - cache->key.objectid; 2015 WARN_ON(byte_in_group > cache->key.offset); 2016 2017 spin_lock(&cache->space_info->lock); 2018 spin_lock(&cache->lock); 2019 cache->dirty = 1; 2020 old_val = btrfs_block_group_used(&cache->item); 2021 num_bytes = min(total, cache->key.offset - byte_in_group); 2022 if (alloc) { 2023 old_val += num_bytes; 2024 cache->space_info->bytes_used += num_bytes; 2025 if (cache->ro) 2026 cache->space_info->bytes_readonly -= num_bytes; 2027 btrfs_set_block_group_used(&cache->item, old_val); 2028 spin_unlock(&cache->lock); 2029 spin_unlock(&cache->space_info->lock); 2030 } else { 2031 old_val -= num_bytes; 2032 cache->space_info->bytes_used -= num_bytes; 2033 if (cache->ro) 2034 cache->space_info->bytes_readonly += num_bytes; 2035 btrfs_set_block_group_used(&cache->item, old_val); 2036 spin_unlock(&cache->lock); 2037 spin_unlock(&cache->space_info->lock); 2038 if (mark_free) { 2039 int ret; 2040 2041 ret = btrfs_discard_extent(root, bytenr, 2042 num_bytes); 2043 WARN_ON(ret); 2044 2045 ret = btrfs_add_free_space(cache, bytenr, 2046 num_bytes); 2047 WARN_ON(ret); 2048 } 2049 } 2050 btrfs_put_block_group(cache); 2051 total -= num_bytes; 2052 bytenr += num_bytes; 2053 } 2054 return 0; 2055 } 2056 2057 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) 2058 { 2059 struct btrfs_block_group_cache *cache; 2060 u64 bytenr; 2061 2062 cache = btrfs_lookup_first_block_group(root->fs_info, search_start); 2063 if (!cache) 2064 return 0; 2065 2066 bytenr = cache->key.objectid; 2067 btrfs_put_block_group(cache); 2068 2069 return bytenr; 2070 } 2071 2072 int btrfs_update_pinned_extents(struct btrfs_root *root, 2073 u64 bytenr, u64 num, int pin) 2074 { 2075 u64 len; 2076 struct btrfs_block_group_cache *cache; 2077 struct btrfs_fs_info *fs_info = root->fs_info; 2078 2079 if (pin) { 2080 set_extent_dirty(&fs_info->pinned_extents, 2081 bytenr, bytenr + num - 1, GFP_NOFS); 2082 } else { 2083 clear_extent_dirty(&fs_info->pinned_extents, 2084 bytenr, bytenr + num - 1, GFP_NOFS); 2085 } 2086 2087 while (num > 0) { 2088 cache = btrfs_lookup_block_group(fs_info, bytenr); 2089 BUG_ON(!cache); 2090 len = min(num, cache->key.offset - 2091 (bytenr - cache->key.objectid)); 2092 if (pin) { 2093 spin_lock(&cache->space_info->lock); 2094 spin_lock(&cache->lock); 2095 cache->pinned += len; 2096 cache->space_info->bytes_pinned += len; 2097 spin_unlock(&cache->lock); 2098 spin_unlock(&cache->space_info->lock); 2099 fs_info->total_pinned += len; 2100 } else { 2101 spin_lock(&cache->space_info->lock); 2102 spin_lock(&cache->lock); 2103 cache->pinned -= len; 2104 cache->space_info->bytes_pinned -= len; 2105 spin_unlock(&cache->lock); 2106 spin_unlock(&cache->space_info->lock); 2107 fs_info->total_pinned -= len; 2108 if (cache->cached) 2109 btrfs_add_free_space(cache, bytenr, len); 2110 } 2111 btrfs_put_block_group(cache); 2112 bytenr += len; 2113 num -= len; 2114 } 2115 return 0; 2116 } 2117 2118 static int update_reserved_extents(struct btrfs_root *root, 2119 u64 bytenr, u64 num, int reserve) 2120 { 2121 u64 len; 2122 struct btrfs_block_group_cache *cache; 2123 struct btrfs_fs_info *fs_info = root->fs_info; 2124 2125 while (num > 0) { 2126 cache = btrfs_lookup_block_group(fs_info, bytenr); 2127 BUG_ON(!cache); 2128 len = min(num, cache->key.offset - 2129 (bytenr - cache->key.objectid)); 2130 2131 spin_lock(&cache->space_info->lock); 2132 spin_lock(&cache->lock); 2133 if (reserve) { 2134 cache->reserved += len; 2135 cache->space_info->bytes_reserved += len; 2136 } else { 2137 cache->reserved -= len; 2138 cache->space_info->bytes_reserved -= len; 2139 } 2140 spin_unlock(&cache->lock); 2141 spin_unlock(&cache->space_info->lock); 2142 btrfs_put_block_group(cache); 2143 bytenr += len; 2144 num -= len; 2145 } 2146 return 0; 2147 } 2148 2149 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy) 2150 { 2151 u64 last = 0; 2152 u64 start; 2153 u64 end; 2154 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents; 2155 int ret; 2156 2157 while (1) { 2158 ret = find_first_extent_bit(pinned_extents, last, 2159 &start, &end, EXTENT_DIRTY); 2160 if (ret) 2161 break; 2162 set_extent_dirty(copy, start, end, GFP_NOFS); 2163 last = end + 1; 2164 } 2165 return 0; 2166 } 2167 2168 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, 2169 struct btrfs_root *root, 2170 struct extent_io_tree *unpin) 2171 { 2172 u64 start; 2173 u64 end; 2174 int ret; 2175 2176 while (1) { 2177 ret = find_first_extent_bit(unpin, 0, &start, &end, 2178 EXTENT_DIRTY); 2179 if (ret) 2180 break; 2181 2182 ret = btrfs_discard_extent(root, start, end + 1 - start); 2183 2184 /* unlocks the pinned mutex */ 2185 btrfs_update_pinned_extents(root, start, end + 1 - start, 0); 2186 clear_extent_dirty(unpin, start, end, GFP_NOFS); 2187 2188 cond_resched(); 2189 } 2190 return ret; 2191 } 2192 2193 static int pin_down_bytes(struct btrfs_trans_handle *trans, 2194 struct btrfs_root *root, 2195 struct btrfs_path *path, 2196 u64 bytenr, u64 num_bytes, int is_data, 2197 struct extent_buffer **must_clean) 2198 { 2199 int err = 0; 2200 struct extent_buffer *buf; 2201 2202 if (is_data) 2203 goto pinit; 2204 2205 buf = btrfs_find_tree_block(root, bytenr, num_bytes); 2206 if (!buf) 2207 goto pinit; 2208 2209 /* we can reuse a block if it hasn't been written 2210 * and it is from this transaction. We can't 2211 * reuse anything from the tree log root because 2212 * it has tiny sub-transactions. 2213 */ 2214 if (btrfs_buffer_uptodate(buf, 0) && 2215 btrfs_try_tree_lock(buf)) { 2216 u64 header_owner = btrfs_header_owner(buf); 2217 u64 header_transid = btrfs_header_generation(buf); 2218 if (header_owner != BTRFS_TREE_LOG_OBJECTID && 2219 header_owner != BTRFS_TREE_RELOC_OBJECTID && 2220 header_owner != BTRFS_DATA_RELOC_TREE_OBJECTID && 2221 header_transid == trans->transid && 2222 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { 2223 *must_clean = buf; 2224 return 1; 2225 } 2226 btrfs_tree_unlock(buf); 2227 } 2228 free_extent_buffer(buf); 2229 pinit: 2230 btrfs_set_path_blocking(path); 2231 /* unlocks the pinned mutex */ 2232 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1); 2233 2234 BUG_ON(err < 0); 2235 return 0; 2236 } 2237 2238 /* 2239 * remove an extent from the root, returns 0 on success 2240 */ 2241 static int __free_extent(struct btrfs_trans_handle *trans, 2242 struct btrfs_root *root, 2243 u64 bytenr, u64 num_bytes, u64 parent, 2244 u64 root_objectid, u64 ref_generation, 2245 u64 owner_objectid, int pin, int mark_free, 2246 int refs_to_drop) 2247 { 2248 struct btrfs_path *path; 2249 struct btrfs_key key; 2250 struct btrfs_fs_info *info = root->fs_info; 2251 struct btrfs_root *extent_root = info->extent_root; 2252 struct extent_buffer *leaf; 2253 int ret; 2254 int extent_slot = 0; 2255 int found_extent = 0; 2256 int num_to_del = 1; 2257 struct btrfs_extent_item *ei; 2258 u32 refs; 2259 2260 key.objectid = bytenr; 2261 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); 2262 key.offset = num_bytes; 2263 path = btrfs_alloc_path(); 2264 if (!path) 2265 return -ENOMEM; 2266 2267 path->reada = 1; 2268 path->leave_spinning = 1; 2269 ret = lookup_extent_backref(trans, extent_root, path, 2270 bytenr, parent, root_objectid, 2271 ref_generation, owner_objectid, 1); 2272 if (ret == 0) { 2273 struct btrfs_key found_key; 2274 extent_slot = path->slots[0]; 2275 while (extent_slot > 0) { 2276 extent_slot--; 2277 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 2278 extent_slot); 2279 if (found_key.objectid != bytenr) 2280 break; 2281 if (found_key.type == BTRFS_EXTENT_ITEM_KEY && 2282 found_key.offset == num_bytes) { 2283 found_extent = 1; 2284 break; 2285 } 2286 if (path->slots[0] - extent_slot > 5) 2287 break; 2288 } 2289 if (!found_extent) { 2290 ret = remove_extent_backref(trans, extent_root, path, 2291 refs_to_drop); 2292 BUG_ON(ret); 2293 btrfs_release_path(extent_root, path); 2294 path->leave_spinning = 1; 2295 ret = btrfs_search_slot(trans, extent_root, 2296 &key, path, -1, 1); 2297 if (ret) { 2298 printk(KERN_ERR "umm, got %d back from search" 2299 ", was looking for %llu\n", ret, 2300 (unsigned long long)bytenr); 2301 btrfs_print_leaf(extent_root, path->nodes[0]); 2302 } 2303 BUG_ON(ret); 2304 extent_slot = path->slots[0]; 2305 } 2306 } else { 2307 btrfs_print_leaf(extent_root, path->nodes[0]); 2308 WARN_ON(1); 2309 printk(KERN_ERR "btrfs unable to find ref byte nr %llu " 2310 "parent %llu root %llu gen %llu owner %llu\n", 2311 (unsigned long long)bytenr, 2312 (unsigned long long)parent, 2313 (unsigned long long)root_objectid, 2314 (unsigned long long)ref_generation, 2315 (unsigned long long)owner_objectid); 2316 } 2317 2318 leaf = path->nodes[0]; 2319 ei = btrfs_item_ptr(leaf, extent_slot, 2320 struct btrfs_extent_item); 2321 refs = btrfs_extent_refs(leaf, ei); 2322 2323 /* 2324 * we're not allowed to delete the extent item if there 2325 * are other delayed ref updates pending 2326 */ 2327 2328 BUG_ON(refs < refs_to_drop); 2329 refs -= refs_to_drop; 2330 btrfs_set_extent_refs(leaf, ei, refs); 2331 btrfs_mark_buffer_dirty(leaf); 2332 2333 if (refs == 0 && found_extent && 2334 path->slots[0] == extent_slot + 1) { 2335 struct btrfs_extent_ref *ref; 2336 ref = btrfs_item_ptr(leaf, path->slots[0], 2337 struct btrfs_extent_ref); 2338 BUG_ON(btrfs_ref_num_refs(leaf, ref) != refs_to_drop); 2339 /* if the back ref and the extent are next to each other 2340 * they get deleted below in one shot 2341 */ 2342 path->slots[0] = extent_slot; 2343 num_to_del = 2; 2344 } else if (found_extent) { 2345 /* otherwise delete the extent back ref */ 2346 ret = remove_extent_backref(trans, extent_root, path, 2347 refs_to_drop); 2348 BUG_ON(ret); 2349 /* if refs are 0, we need to setup the path for deletion */ 2350 if (refs == 0) { 2351 btrfs_release_path(extent_root, path); 2352 path->leave_spinning = 1; 2353 ret = btrfs_search_slot(trans, extent_root, &key, path, 2354 -1, 1); 2355 BUG_ON(ret); 2356 } 2357 } 2358 2359 if (refs == 0) { 2360 u64 super_used; 2361 u64 root_used; 2362 struct extent_buffer *must_clean = NULL; 2363 2364 if (pin) { 2365 ret = pin_down_bytes(trans, root, path, 2366 bytenr, num_bytes, 2367 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID, 2368 &must_clean); 2369 if (ret > 0) 2370 mark_free = 1; 2371 BUG_ON(ret < 0); 2372 } 2373 2374 /* block accounting for super block */ 2375 spin_lock(&info->delalloc_lock); 2376 super_used = btrfs_super_bytes_used(&info->super_copy); 2377 btrfs_set_super_bytes_used(&info->super_copy, 2378 super_used - num_bytes); 2379 2380 /* block accounting for root item */ 2381 root_used = btrfs_root_used(&root->root_item); 2382 btrfs_set_root_used(&root->root_item, 2383 root_used - num_bytes); 2384 spin_unlock(&info->delalloc_lock); 2385 2386 /* 2387 * it is going to be very rare for someone to be waiting 2388 * on the block we're freeing. del_items might need to 2389 * schedule, so rather than get fancy, just force it 2390 * to blocking here 2391 */ 2392 if (must_clean) 2393 btrfs_set_lock_blocking(must_clean); 2394 2395 ret = btrfs_del_items(trans, extent_root, path, path->slots[0], 2396 num_to_del); 2397 BUG_ON(ret); 2398 btrfs_release_path(extent_root, path); 2399 2400 if (must_clean) { 2401 clean_tree_block(NULL, root, must_clean); 2402 btrfs_tree_unlock(must_clean); 2403 free_extent_buffer(must_clean); 2404 } 2405 2406 if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { 2407 ret = btrfs_del_csums(trans, root, bytenr, num_bytes); 2408 BUG_ON(ret); 2409 } else { 2410 invalidate_mapping_pages(info->btree_inode->i_mapping, 2411 bytenr >> PAGE_CACHE_SHIFT, 2412 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT); 2413 } 2414 2415 ret = update_block_group(trans, root, bytenr, num_bytes, 0, 2416 mark_free); 2417 BUG_ON(ret); 2418 } 2419 btrfs_free_path(path); 2420 return ret; 2421 } 2422 2423 /* 2424 * remove an extent from the root, returns 0 on success 2425 */ 2426 static int __btrfs_free_extent(struct btrfs_trans_handle *trans, 2427 struct btrfs_root *root, 2428 u64 bytenr, u64 num_bytes, u64 parent, 2429 u64 root_objectid, u64 ref_generation, 2430 u64 owner_objectid, int pin, 2431 int refs_to_drop) 2432 { 2433 WARN_ON(num_bytes < root->sectorsize); 2434 2435 /* 2436 * if metadata always pin 2437 * if data pin when any transaction has committed this 2438 */ 2439 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID || 2440 ref_generation != trans->transid) 2441 pin = 1; 2442 2443 if (ref_generation != trans->transid) 2444 pin = 1; 2445 2446 return __free_extent(trans, root, bytenr, num_bytes, parent, 2447 root_objectid, ref_generation, 2448 owner_objectid, pin, pin == 0, refs_to_drop); 2449 } 2450 2451 /* 2452 * when we free an extent, it is possible (and likely) that we free the last 2453 * delayed ref for that extent as well. This searches the delayed ref tree for 2454 * a given extent, and if there are no other delayed refs to be processed, it 2455 * removes it from the tree. 2456 */ 2457 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, 2458 struct btrfs_root *root, u64 bytenr) 2459 { 2460 struct btrfs_delayed_ref_head *head; 2461 struct btrfs_delayed_ref_root *delayed_refs; 2462 struct btrfs_delayed_ref_node *ref; 2463 struct rb_node *node; 2464 int ret; 2465 2466 delayed_refs = &trans->transaction->delayed_refs; 2467 spin_lock(&delayed_refs->lock); 2468 head = btrfs_find_delayed_ref_head(trans, bytenr); 2469 if (!head) 2470 goto out; 2471 2472 node = rb_prev(&head->node.rb_node); 2473 if (!node) 2474 goto out; 2475 2476 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); 2477 2478 /* there are still entries for this ref, we can't drop it */ 2479 if (ref->bytenr == bytenr) 2480 goto out; 2481 2482 /* 2483 * waiting for the lock here would deadlock. If someone else has it 2484 * locked they are already in the process of dropping it anyway 2485 */ 2486 if (!mutex_trylock(&head->mutex)) 2487 goto out; 2488 2489 /* 2490 * at this point we have a head with no other entries. Go 2491 * ahead and process it. 2492 */ 2493 head->node.in_tree = 0; 2494 rb_erase(&head->node.rb_node, &delayed_refs->root); 2495 2496 delayed_refs->num_entries--; 2497 2498 /* 2499 * we don't take a ref on the node because we're removing it from the 2500 * tree, so we just steal the ref the tree was holding. 2501 */ 2502 delayed_refs->num_heads--; 2503 if (list_empty(&head->cluster)) 2504 delayed_refs->num_heads_ready--; 2505 2506 list_del_init(&head->cluster); 2507 spin_unlock(&delayed_refs->lock); 2508 2509 ret = run_one_delayed_ref(trans, root->fs_info->tree_root, 2510 &head->node, head->must_insert_reserved); 2511 BUG_ON(ret); 2512 btrfs_put_delayed_ref(&head->node); 2513 return 0; 2514 out: 2515 spin_unlock(&delayed_refs->lock); 2516 return 0; 2517 } 2518 2519 int btrfs_free_extent(struct btrfs_trans_handle *trans, 2520 struct btrfs_root *root, 2521 u64 bytenr, u64 num_bytes, u64 parent, 2522 u64 root_objectid, u64 ref_generation, 2523 u64 owner_objectid, int pin) 2524 { 2525 int ret; 2526 2527 /* 2528 * tree log blocks never actually go into the extent allocation 2529 * tree, just update pinning info and exit early. 2530 * 2531 * data extents referenced by the tree log do need to have 2532 * their reference counts bumped. 2533 */ 2534 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID && 2535 owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { 2536 /* unlocks the pinned mutex */ 2537 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1); 2538 update_reserved_extents(root, bytenr, num_bytes, 0); 2539 ret = 0; 2540 } else { 2541 ret = btrfs_add_delayed_ref(trans, bytenr, num_bytes, parent, 2542 root_objectid, ref_generation, 2543 owner_objectid, 2544 BTRFS_DROP_DELAYED_REF, 1); 2545 BUG_ON(ret); 2546 ret = check_ref_cleanup(trans, root, bytenr); 2547 BUG_ON(ret); 2548 } 2549 return ret; 2550 } 2551 2552 static u64 stripe_align(struct btrfs_root *root, u64 val) 2553 { 2554 u64 mask = ((u64)root->stripesize - 1); 2555 u64 ret = (val + mask) & ~mask; 2556 return ret; 2557 } 2558 2559 /* 2560 * walks the btree of allocated extents and find a hole of a given size. 2561 * The key ins is changed to record the hole: 2562 * ins->objectid == block start 2563 * ins->flags = BTRFS_EXTENT_ITEM_KEY 2564 * ins->offset == number of blocks 2565 * Any available blocks before search_start are skipped. 2566 */ 2567 static noinline int find_free_extent(struct btrfs_trans_handle *trans, 2568 struct btrfs_root *orig_root, 2569 u64 num_bytes, u64 empty_size, 2570 u64 search_start, u64 search_end, 2571 u64 hint_byte, struct btrfs_key *ins, 2572 u64 exclude_start, u64 exclude_nr, 2573 int data) 2574 { 2575 int ret = 0; 2576 struct btrfs_root *root = orig_root->fs_info->extent_root; 2577 struct btrfs_free_cluster *last_ptr = NULL; 2578 struct btrfs_block_group_cache *block_group = NULL; 2579 int empty_cluster = 2 * 1024 * 1024; 2580 int allowed_chunk_alloc = 0; 2581 struct btrfs_space_info *space_info; 2582 int last_ptr_loop = 0; 2583 int loop = 0; 2584 2585 WARN_ON(num_bytes < root->sectorsize); 2586 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); 2587 ins->objectid = 0; 2588 ins->offset = 0; 2589 2590 space_info = __find_space_info(root->fs_info, data); 2591 2592 if (orig_root->ref_cows || empty_size) 2593 allowed_chunk_alloc = 1; 2594 2595 if (data & BTRFS_BLOCK_GROUP_METADATA) { 2596 last_ptr = &root->fs_info->meta_alloc_cluster; 2597 if (!btrfs_test_opt(root, SSD)) 2598 empty_cluster = 64 * 1024; 2599 } 2600 2601 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) { 2602 last_ptr = &root->fs_info->data_alloc_cluster; 2603 } 2604 2605 if (last_ptr) { 2606 spin_lock(&last_ptr->lock); 2607 if (last_ptr->block_group) 2608 hint_byte = last_ptr->window_start; 2609 spin_unlock(&last_ptr->lock); 2610 } 2611 2612 search_start = max(search_start, first_logical_byte(root, 0)); 2613 search_start = max(search_start, hint_byte); 2614 2615 if (!last_ptr) { 2616 empty_cluster = 0; 2617 loop = 1; 2618 } 2619 2620 if (search_start == hint_byte) { 2621 block_group = btrfs_lookup_block_group(root->fs_info, 2622 search_start); 2623 if (block_group && block_group_bits(block_group, data)) { 2624 down_read(&space_info->groups_sem); 2625 goto have_block_group; 2626 } else if (block_group) { 2627 btrfs_put_block_group(block_group); 2628 } 2629 } 2630 2631 search: 2632 down_read(&space_info->groups_sem); 2633 list_for_each_entry(block_group, &space_info->block_groups, list) { 2634 u64 offset; 2635 2636 atomic_inc(&block_group->count); 2637 search_start = block_group->key.objectid; 2638 2639 have_block_group: 2640 if (unlikely(!block_group->cached)) { 2641 mutex_lock(&block_group->cache_mutex); 2642 ret = cache_block_group(root, block_group); 2643 mutex_unlock(&block_group->cache_mutex); 2644 if (ret) { 2645 btrfs_put_block_group(block_group); 2646 break; 2647 } 2648 } 2649 2650 if (unlikely(block_group->ro)) 2651 goto loop; 2652 2653 if (last_ptr) { 2654 /* 2655 * the refill lock keeps out other 2656 * people trying to start a new cluster 2657 */ 2658 spin_lock(&last_ptr->refill_lock); 2659 offset = btrfs_alloc_from_cluster(block_group, last_ptr, 2660 num_bytes, search_start); 2661 if (offset) { 2662 /* we have a block, we're done */ 2663 spin_unlock(&last_ptr->refill_lock); 2664 goto checks; 2665 } 2666 2667 spin_lock(&last_ptr->lock); 2668 /* 2669 * whoops, this cluster doesn't actually point to 2670 * this block group. Get a ref on the block 2671 * group is does point to and try again 2672 */ 2673 if (!last_ptr_loop && last_ptr->block_group && 2674 last_ptr->block_group != block_group) { 2675 2676 btrfs_put_block_group(block_group); 2677 block_group = last_ptr->block_group; 2678 atomic_inc(&block_group->count); 2679 spin_unlock(&last_ptr->lock); 2680 spin_unlock(&last_ptr->refill_lock); 2681 2682 last_ptr_loop = 1; 2683 search_start = block_group->key.objectid; 2684 goto have_block_group; 2685 } 2686 spin_unlock(&last_ptr->lock); 2687 2688 /* 2689 * this cluster didn't work out, free it and 2690 * start over 2691 */ 2692 btrfs_return_cluster_to_free_space(NULL, last_ptr); 2693 2694 last_ptr_loop = 0; 2695 2696 /* allocate a cluster in this block group */ 2697 ret = btrfs_find_space_cluster(trans, 2698 block_group, last_ptr, 2699 offset, num_bytes, 2700 empty_cluster + empty_size); 2701 if (ret == 0) { 2702 /* 2703 * now pull our allocation out of this 2704 * cluster 2705 */ 2706 offset = btrfs_alloc_from_cluster(block_group, 2707 last_ptr, num_bytes, 2708 search_start); 2709 if (offset) { 2710 /* we found one, proceed */ 2711 spin_unlock(&last_ptr->refill_lock); 2712 goto checks; 2713 } 2714 } 2715 /* 2716 * at this point we either didn't find a cluster 2717 * or we weren't able to allocate a block from our 2718 * cluster. Free the cluster we've been trying 2719 * to use, and go to the next block group 2720 */ 2721 if (loop < 2) { 2722 btrfs_return_cluster_to_free_space(NULL, 2723 last_ptr); 2724 spin_unlock(&last_ptr->refill_lock); 2725 goto loop; 2726 } 2727 spin_unlock(&last_ptr->refill_lock); 2728 } 2729 2730 offset = btrfs_find_space_for_alloc(block_group, search_start, 2731 num_bytes, empty_size); 2732 if (!offset) 2733 goto loop; 2734 checks: 2735 search_start = stripe_align(root, offset); 2736 2737 /* move on to the next group */ 2738 if (search_start + num_bytes >= search_end) { 2739 btrfs_add_free_space(block_group, offset, num_bytes); 2740 goto loop; 2741 } 2742 2743 /* move on to the next group */ 2744 if (search_start + num_bytes > 2745 block_group->key.objectid + block_group->key.offset) { 2746 btrfs_add_free_space(block_group, offset, num_bytes); 2747 goto loop; 2748 } 2749 2750 if (exclude_nr > 0 && 2751 (search_start + num_bytes > exclude_start && 2752 search_start < exclude_start + exclude_nr)) { 2753 search_start = exclude_start + exclude_nr; 2754 2755 btrfs_add_free_space(block_group, offset, num_bytes); 2756 /* 2757 * if search_start is still in this block group 2758 * then we just re-search this block group 2759 */ 2760 if (search_start >= block_group->key.objectid && 2761 search_start < (block_group->key.objectid + 2762 block_group->key.offset)) 2763 goto have_block_group; 2764 goto loop; 2765 } 2766 2767 ins->objectid = search_start; 2768 ins->offset = num_bytes; 2769 2770 if (offset < search_start) 2771 btrfs_add_free_space(block_group, offset, 2772 search_start - offset); 2773 BUG_ON(offset > search_start); 2774 2775 /* we are all good, lets return */ 2776 break; 2777 loop: 2778 btrfs_put_block_group(block_group); 2779 } 2780 up_read(&space_info->groups_sem); 2781 2782 /* loop == 0, try to find a clustered alloc in every block group 2783 * loop == 1, try again after forcing a chunk allocation 2784 * loop == 2, set empty_size and empty_cluster to 0 and try again 2785 */ 2786 if (!ins->objectid && loop < 3 && 2787 (empty_size || empty_cluster || allowed_chunk_alloc)) { 2788 if (loop >= 2) { 2789 empty_size = 0; 2790 empty_cluster = 0; 2791 } 2792 2793 if (allowed_chunk_alloc) { 2794 ret = do_chunk_alloc(trans, root, num_bytes + 2795 2 * 1024 * 1024, data, 1); 2796 allowed_chunk_alloc = 0; 2797 } else { 2798 space_info->force_alloc = 1; 2799 } 2800 2801 if (loop < 3) { 2802 loop++; 2803 goto search; 2804 } 2805 ret = -ENOSPC; 2806 } else if (!ins->objectid) { 2807 ret = -ENOSPC; 2808 } 2809 2810 /* we found what we needed */ 2811 if (ins->objectid) { 2812 if (!(data & BTRFS_BLOCK_GROUP_DATA)) 2813 trans->block_group = block_group->key.objectid; 2814 2815 btrfs_put_block_group(block_group); 2816 ret = 0; 2817 } 2818 2819 return ret; 2820 } 2821 2822 static void dump_space_info(struct btrfs_space_info *info, u64 bytes) 2823 { 2824 struct btrfs_block_group_cache *cache; 2825 2826 printk(KERN_INFO "space_info has %llu free, is %sfull\n", 2827 (unsigned long long)(info->total_bytes - info->bytes_used - 2828 info->bytes_pinned - info->bytes_reserved), 2829 (info->full) ? "" : "not "); 2830 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu," 2831 " may_use=%llu, used=%llu\n", 2832 (unsigned long long)info->total_bytes, 2833 (unsigned long long)info->bytes_pinned, 2834 (unsigned long long)info->bytes_delalloc, 2835 (unsigned long long)info->bytes_may_use, 2836 (unsigned long long)info->bytes_used); 2837 2838 down_read(&info->groups_sem); 2839 list_for_each_entry(cache, &info->block_groups, list) { 2840 spin_lock(&cache->lock); 2841 printk(KERN_INFO "block group %llu has %llu bytes, %llu used " 2842 "%llu pinned %llu reserved\n", 2843 (unsigned long long)cache->key.objectid, 2844 (unsigned long long)cache->key.offset, 2845 (unsigned long long)btrfs_block_group_used(&cache->item), 2846 (unsigned long long)cache->pinned, 2847 (unsigned long long)cache->reserved); 2848 btrfs_dump_free_space(cache, bytes); 2849 spin_unlock(&cache->lock); 2850 } 2851 up_read(&info->groups_sem); 2852 } 2853 2854 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, 2855 struct btrfs_root *root, 2856 u64 num_bytes, u64 min_alloc_size, 2857 u64 empty_size, u64 hint_byte, 2858 u64 search_end, struct btrfs_key *ins, 2859 u64 data) 2860 { 2861 int ret; 2862 u64 search_start = 0; 2863 struct btrfs_fs_info *info = root->fs_info; 2864 2865 data = btrfs_get_alloc_profile(root, data); 2866 again: 2867 /* 2868 * the only place that sets empty_size is btrfs_realloc_node, which 2869 * is not called recursively on allocations 2870 */ 2871 if (empty_size || root->ref_cows) { 2872 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) { 2873 ret = do_chunk_alloc(trans, root->fs_info->extent_root, 2874 2 * 1024 * 1024, 2875 BTRFS_BLOCK_GROUP_METADATA | 2876 (info->metadata_alloc_profile & 2877 info->avail_metadata_alloc_bits), 0); 2878 } 2879 ret = do_chunk_alloc(trans, root->fs_info->extent_root, 2880 num_bytes + 2 * 1024 * 1024, data, 0); 2881 } 2882 2883 WARN_ON(num_bytes < root->sectorsize); 2884 ret = find_free_extent(trans, root, num_bytes, empty_size, 2885 search_start, search_end, hint_byte, ins, 2886 trans->alloc_exclude_start, 2887 trans->alloc_exclude_nr, data); 2888 2889 if (ret == -ENOSPC && num_bytes > min_alloc_size) { 2890 num_bytes = num_bytes >> 1; 2891 num_bytes = num_bytes & ~(root->sectorsize - 1); 2892 num_bytes = max(num_bytes, min_alloc_size); 2893 do_chunk_alloc(trans, root->fs_info->extent_root, 2894 num_bytes, data, 1); 2895 goto again; 2896 } 2897 if (ret) { 2898 struct btrfs_space_info *sinfo; 2899 2900 sinfo = __find_space_info(root->fs_info, data); 2901 printk(KERN_ERR "btrfs allocation failed flags %llu, " 2902 "wanted %llu\n", (unsigned long long)data, 2903 (unsigned long long)num_bytes); 2904 dump_space_info(sinfo, num_bytes); 2905 BUG(); 2906 } 2907 2908 return ret; 2909 } 2910 2911 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) 2912 { 2913 struct btrfs_block_group_cache *cache; 2914 int ret = 0; 2915 2916 cache = btrfs_lookup_block_group(root->fs_info, start); 2917 if (!cache) { 2918 printk(KERN_ERR "Unable to find block group for %llu\n", 2919 (unsigned long long)start); 2920 return -ENOSPC; 2921 } 2922 2923 ret = btrfs_discard_extent(root, start, len); 2924 2925 btrfs_add_free_space(cache, start, len); 2926 btrfs_put_block_group(cache); 2927 update_reserved_extents(root, start, len, 0); 2928 2929 return ret; 2930 } 2931 2932 int btrfs_reserve_extent(struct btrfs_trans_handle *trans, 2933 struct btrfs_root *root, 2934 u64 num_bytes, u64 min_alloc_size, 2935 u64 empty_size, u64 hint_byte, 2936 u64 search_end, struct btrfs_key *ins, 2937 u64 data) 2938 { 2939 int ret; 2940 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, 2941 empty_size, hint_byte, search_end, ins, 2942 data); 2943 update_reserved_extents(root, ins->objectid, ins->offset, 1); 2944 return ret; 2945 } 2946 2947 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, 2948 struct btrfs_root *root, u64 parent, 2949 u64 root_objectid, u64 ref_generation, 2950 u64 owner, struct btrfs_key *ins, 2951 int ref_mod) 2952 { 2953 int ret; 2954 u64 super_used; 2955 u64 root_used; 2956 u64 num_bytes = ins->offset; 2957 u32 sizes[2]; 2958 struct btrfs_fs_info *info = root->fs_info; 2959 struct btrfs_root *extent_root = info->extent_root; 2960 struct btrfs_extent_item *extent_item; 2961 struct btrfs_extent_ref *ref; 2962 struct btrfs_path *path; 2963 struct btrfs_key keys[2]; 2964 2965 if (parent == 0) 2966 parent = ins->objectid; 2967 2968 /* block accounting for super block */ 2969 spin_lock(&info->delalloc_lock); 2970 super_used = btrfs_super_bytes_used(&info->super_copy); 2971 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes); 2972 2973 /* block accounting for root item */ 2974 root_used = btrfs_root_used(&root->root_item); 2975 btrfs_set_root_used(&root->root_item, root_used + num_bytes); 2976 spin_unlock(&info->delalloc_lock); 2977 2978 memcpy(&keys[0], ins, sizeof(*ins)); 2979 keys[1].objectid = ins->objectid; 2980 keys[1].type = BTRFS_EXTENT_REF_KEY; 2981 keys[1].offset = parent; 2982 sizes[0] = sizeof(*extent_item); 2983 sizes[1] = sizeof(*ref); 2984 2985 path = btrfs_alloc_path(); 2986 BUG_ON(!path); 2987 2988 path->leave_spinning = 1; 2989 ret = btrfs_insert_empty_items(trans, extent_root, path, keys, 2990 sizes, 2); 2991 BUG_ON(ret); 2992 2993 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 2994 struct btrfs_extent_item); 2995 btrfs_set_extent_refs(path->nodes[0], extent_item, ref_mod); 2996 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 2997 struct btrfs_extent_ref); 2998 2999 btrfs_set_ref_root(path->nodes[0], ref, root_objectid); 3000 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation); 3001 btrfs_set_ref_objectid(path->nodes[0], ref, owner); 3002 btrfs_set_ref_num_refs(path->nodes[0], ref, ref_mod); 3003 3004 btrfs_mark_buffer_dirty(path->nodes[0]); 3005 3006 trans->alloc_exclude_start = 0; 3007 trans->alloc_exclude_nr = 0; 3008 btrfs_free_path(path); 3009 3010 if (ret) 3011 goto out; 3012 3013 ret = update_block_group(trans, root, ins->objectid, 3014 ins->offset, 1, 0); 3015 if (ret) { 3016 printk(KERN_ERR "btrfs update block group failed for %llu " 3017 "%llu\n", (unsigned long long)ins->objectid, 3018 (unsigned long long)ins->offset); 3019 BUG(); 3020 } 3021 out: 3022 return ret; 3023 } 3024 3025 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, 3026 struct btrfs_root *root, u64 parent, 3027 u64 root_objectid, u64 ref_generation, 3028 u64 owner, struct btrfs_key *ins) 3029 { 3030 int ret; 3031 3032 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) 3033 return 0; 3034 3035 ret = btrfs_add_delayed_ref(trans, ins->objectid, 3036 ins->offset, parent, root_objectid, 3037 ref_generation, owner, 3038 BTRFS_ADD_DELAYED_EXTENT, 0); 3039 BUG_ON(ret); 3040 return ret; 3041 } 3042 3043 /* 3044 * this is used by the tree logging recovery code. It records that 3045 * an extent has been allocated and makes sure to clear the free 3046 * space cache bits as well 3047 */ 3048 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans, 3049 struct btrfs_root *root, u64 parent, 3050 u64 root_objectid, u64 ref_generation, 3051 u64 owner, struct btrfs_key *ins) 3052 { 3053 int ret; 3054 struct btrfs_block_group_cache *block_group; 3055 3056 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); 3057 mutex_lock(&block_group->cache_mutex); 3058 cache_block_group(root, block_group); 3059 mutex_unlock(&block_group->cache_mutex); 3060 3061 ret = btrfs_remove_free_space(block_group, ins->objectid, 3062 ins->offset); 3063 BUG_ON(ret); 3064 btrfs_put_block_group(block_group); 3065 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid, 3066 ref_generation, owner, ins, 1); 3067 return ret; 3068 } 3069 3070 /* 3071 * finds a free extent and does all the dirty work required for allocation 3072 * returns the key for the extent through ins, and a tree buffer for 3073 * the first block of the extent through buf. 3074 * 3075 * returns 0 if everything worked, non-zero otherwise. 3076 */ 3077 int btrfs_alloc_extent(struct btrfs_trans_handle *trans, 3078 struct btrfs_root *root, 3079 u64 num_bytes, u64 parent, u64 min_alloc_size, 3080 u64 root_objectid, u64 ref_generation, 3081 u64 owner_objectid, u64 empty_size, u64 hint_byte, 3082 u64 search_end, struct btrfs_key *ins, u64 data) 3083 { 3084 int ret; 3085 ret = __btrfs_reserve_extent(trans, root, num_bytes, 3086 min_alloc_size, empty_size, hint_byte, 3087 search_end, ins, data); 3088 BUG_ON(ret); 3089 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { 3090 ret = btrfs_add_delayed_ref(trans, ins->objectid, 3091 ins->offset, parent, root_objectid, 3092 ref_generation, owner_objectid, 3093 BTRFS_ADD_DELAYED_EXTENT, 0); 3094 BUG_ON(ret); 3095 } 3096 update_reserved_extents(root, ins->objectid, ins->offset, 1); 3097 return ret; 3098 } 3099 3100 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, 3101 struct btrfs_root *root, 3102 u64 bytenr, u32 blocksize, 3103 int level) 3104 { 3105 struct extent_buffer *buf; 3106 3107 buf = btrfs_find_create_tree_block(root, bytenr, blocksize); 3108 if (!buf) 3109 return ERR_PTR(-ENOMEM); 3110 btrfs_set_header_generation(buf, trans->transid); 3111 btrfs_set_buffer_lockdep_class(buf, level); 3112 btrfs_tree_lock(buf); 3113 clean_tree_block(trans, root, buf); 3114 3115 btrfs_set_lock_blocking(buf); 3116 btrfs_set_buffer_uptodate(buf); 3117 3118 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { 3119 set_extent_dirty(&root->dirty_log_pages, buf->start, 3120 buf->start + buf->len - 1, GFP_NOFS); 3121 } else { 3122 set_extent_dirty(&trans->transaction->dirty_pages, buf->start, 3123 buf->start + buf->len - 1, GFP_NOFS); 3124 } 3125 trans->blocks_used++; 3126 /* this returns a buffer locked for blocking */ 3127 return buf; 3128 } 3129 3130 /* 3131 * helper function to allocate a block for a given tree 3132 * returns the tree buffer or NULL. 3133 */ 3134 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, 3135 struct btrfs_root *root, 3136 u32 blocksize, u64 parent, 3137 u64 root_objectid, 3138 u64 ref_generation, 3139 int level, 3140 u64 hint, 3141 u64 empty_size) 3142 { 3143 struct btrfs_key ins; 3144 int ret; 3145 struct extent_buffer *buf; 3146 3147 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize, 3148 root_objectid, ref_generation, level, 3149 empty_size, hint, (u64)-1, &ins, 0); 3150 if (ret) { 3151 BUG_ON(ret > 0); 3152 return ERR_PTR(ret); 3153 } 3154 3155 buf = btrfs_init_new_buffer(trans, root, ins.objectid, 3156 blocksize, level); 3157 return buf; 3158 } 3159 3160 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans, 3161 struct btrfs_root *root, struct extent_buffer *leaf) 3162 { 3163 u64 leaf_owner; 3164 u64 leaf_generation; 3165 struct refsort *sorted; 3166 struct btrfs_key key; 3167 struct btrfs_file_extent_item *fi; 3168 int i; 3169 int nritems; 3170 int ret; 3171 int refi = 0; 3172 int slot; 3173 3174 BUG_ON(!btrfs_is_leaf(leaf)); 3175 nritems = btrfs_header_nritems(leaf); 3176 leaf_owner = btrfs_header_owner(leaf); 3177 leaf_generation = btrfs_header_generation(leaf); 3178 3179 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS); 3180 /* we do this loop twice. The first time we build a list 3181 * of the extents we have a reference on, then we sort the list 3182 * by bytenr. The second time around we actually do the 3183 * extent freeing. 3184 */ 3185 for (i = 0; i < nritems; i++) { 3186 u64 disk_bytenr; 3187 cond_resched(); 3188 3189 btrfs_item_key_to_cpu(leaf, &key, i); 3190 3191 /* only extents have references, skip everything else */ 3192 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) 3193 continue; 3194 3195 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); 3196 3197 /* inline extents live in the btree, they don't have refs */ 3198 if (btrfs_file_extent_type(leaf, fi) == 3199 BTRFS_FILE_EXTENT_INLINE) 3200 continue; 3201 3202 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 3203 3204 /* holes don't have refs */ 3205 if (disk_bytenr == 0) 3206 continue; 3207 3208 sorted[refi].bytenr = disk_bytenr; 3209 sorted[refi].slot = i; 3210 refi++; 3211 } 3212 3213 if (refi == 0) 3214 goto out; 3215 3216 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL); 3217 3218 for (i = 0; i < refi; i++) { 3219 u64 disk_bytenr; 3220 3221 disk_bytenr = sorted[i].bytenr; 3222 slot = sorted[i].slot; 3223 3224 cond_resched(); 3225 3226 btrfs_item_key_to_cpu(leaf, &key, slot); 3227 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) 3228 continue; 3229 3230 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 3231 3232 ret = btrfs_free_extent(trans, root, disk_bytenr, 3233 btrfs_file_extent_disk_num_bytes(leaf, fi), 3234 leaf->start, leaf_owner, leaf_generation, 3235 key.objectid, 0); 3236 BUG_ON(ret); 3237 3238 atomic_inc(&root->fs_info->throttle_gen); 3239 wake_up(&root->fs_info->transaction_throttle); 3240 cond_resched(); 3241 } 3242 out: 3243 kfree(sorted); 3244 return 0; 3245 } 3246 3247 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans, 3248 struct btrfs_root *root, 3249 struct btrfs_leaf_ref *ref) 3250 { 3251 int i; 3252 int ret; 3253 struct btrfs_extent_info *info; 3254 struct refsort *sorted; 3255 3256 if (ref->nritems == 0) 3257 return 0; 3258 3259 sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS); 3260 for (i = 0; i < ref->nritems; i++) { 3261 sorted[i].bytenr = ref->extents[i].bytenr; 3262 sorted[i].slot = i; 3263 } 3264 sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL); 3265 3266 /* 3267 * the items in the ref were sorted when the ref was inserted 3268 * into the ref cache, so this is already in order 3269 */ 3270 for (i = 0; i < ref->nritems; i++) { 3271 info = ref->extents + sorted[i].slot; 3272 ret = btrfs_free_extent(trans, root, info->bytenr, 3273 info->num_bytes, ref->bytenr, 3274 ref->owner, ref->generation, 3275 info->objectid, 0); 3276 3277 atomic_inc(&root->fs_info->throttle_gen); 3278 wake_up(&root->fs_info->transaction_throttle); 3279 cond_resched(); 3280 3281 BUG_ON(ret); 3282 info++; 3283 } 3284 3285 kfree(sorted); 3286 return 0; 3287 } 3288 3289 static int drop_snap_lookup_refcount(struct btrfs_trans_handle *trans, 3290 struct btrfs_root *root, u64 start, 3291 u64 len, u32 *refs) 3292 { 3293 int ret; 3294 3295 ret = btrfs_lookup_extent_ref(trans, root, start, len, refs); 3296 BUG_ON(ret); 3297 3298 #if 0 /* some debugging code in case we see problems here */ 3299 /* if the refs count is one, it won't get increased again. But 3300 * if the ref count is > 1, someone may be decreasing it at 3301 * the same time we are. 3302 */ 3303 if (*refs != 1) { 3304 struct extent_buffer *eb = NULL; 3305 eb = btrfs_find_create_tree_block(root, start, len); 3306 if (eb) 3307 btrfs_tree_lock(eb); 3308 3309 mutex_lock(&root->fs_info->alloc_mutex); 3310 ret = lookup_extent_ref(NULL, root, start, len, refs); 3311 BUG_ON(ret); 3312 mutex_unlock(&root->fs_info->alloc_mutex); 3313 3314 if (eb) { 3315 btrfs_tree_unlock(eb); 3316 free_extent_buffer(eb); 3317 } 3318 if (*refs == 1) { 3319 printk(KERN_ERR "btrfs block %llu went down to one " 3320 "during drop_snap\n", (unsigned long long)start); 3321 } 3322 3323 } 3324 #endif 3325 3326 cond_resched(); 3327 return ret; 3328 } 3329 3330 /* 3331 * this is used while deleting old snapshots, and it drops the refs 3332 * on a whole subtree starting from a level 1 node. 3333 * 3334 * The idea is to sort all the leaf pointers, and then drop the 3335 * ref on all the leaves in order. Most of the time the leaves 3336 * will have ref cache entries, so no leaf IOs will be required to 3337 * find the extents they have references on. 3338 * 3339 * For each leaf, any references it has are also dropped in order 3340 * 3341 * This ends up dropping the references in something close to optimal 3342 * order for reading and modifying the extent allocation tree. 3343 */ 3344 static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans, 3345 struct btrfs_root *root, 3346 struct btrfs_path *path) 3347 { 3348 u64 bytenr; 3349 u64 root_owner; 3350 u64 root_gen; 3351 struct extent_buffer *eb = path->nodes[1]; 3352 struct extent_buffer *leaf; 3353 struct btrfs_leaf_ref *ref; 3354 struct refsort *sorted = NULL; 3355 int nritems = btrfs_header_nritems(eb); 3356 int ret; 3357 int i; 3358 int refi = 0; 3359 int slot = path->slots[1]; 3360 u32 blocksize = btrfs_level_size(root, 0); 3361 u32 refs; 3362 3363 if (nritems == 0) 3364 goto out; 3365 3366 root_owner = btrfs_header_owner(eb); 3367 root_gen = btrfs_header_generation(eb); 3368 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS); 3369 3370 /* 3371 * step one, sort all the leaf pointers so we don't scribble 3372 * randomly into the extent allocation tree 3373 */ 3374 for (i = slot; i < nritems; i++) { 3375 sorted[refi].bytenr = btrfs_node_blockptr(eb, i); 3376 sorted[refi].slot = i; 3377 refi++; 3378 } 3379 3380 /* 3381 * nritems won't be zero, but if we're picking up drop_snapshot 3382 * after a crash, slot might be > 0, so double check things 3383 * just in case. 3384 */ 3385 if (refi == 0) 3386 goto out; 3387 3388 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL); 3389 3390 /* 3391 * the first loop frees everything the leaves point to 3392 */ 3393 for (i = 0; i < refi; i++) { 3394 u64 ptr_gen; 3395 3396 bytenr = sorted[i].bytenr; 3397 3398 /* 3399 * check the reference count on this leaf. If it is > 1 3400 * we just decrement it below and don't update any 3401 * of the refs the leaf points to. 3402 */ 3403 ret = drop_snap_lookup_refcount(trans, root, bytenr, 3404 blocksize, &refs); 3405 BUG_ON(ret); 3406 if (refs != 1) 3407 continue; 3408 3409 ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot); 3410 3411 /* 3412 * the leaf only had one reference, which means the 3413 * only thing pointing to this leaf is the snapshot 3414 * we're deleting. It isn't possible for the reference 3415 * count to increase again later 3416 * 3417 * The reference cache is checked for the leaf, 3418 * and if found we'll be able to drop any refs held by 3419 * the leaf without needing to read it in. 3420 */ 3421 ref = btrfs_lookup_leaf_ref(root, bytenr); 3422 if (ref && ref->generation != ptr_gen) { 3423 btrfs_free_leaf_ref(root, ref); 3424 ref = NULL; 3425 } 3426 if (ref) { 3427 ret = cache_drop_leaf_ref(trans, root, ref); 3428 BUG_ON(ret); 3429 btrfs_remove_leaf_ref(root, ref); 3430 btrfs_free_leaf_ref(root, ref); 3431 } else { 3432 /* 3433 * the leaf wasn't in the reference cache, so 3434 * we have to read it. 3435 */ 3436 leaf = read_tree_block(root, bytenr, blocksize, 3437 ptr_gen); 3438 ret = btrfs_drop_leaf_ref(trans, root, leaf); 3439 BUG_ON(ret); 3440 free_extent_buffer(leaf); 3441 } 3442 atomic_inc(&root->fs_info->throttle_gen); 3443 wake_up(&root->fs_info->transaction_throttle); 3444 cond_resched(); 3445 } 3446 3447 /* 3448 * run through the loop again to free the refs on the leaves. 3449 * This is faster than doing it in the loop above because 3450 * the leaves are likely to be clustered together. We end up 3451 * working in nice chunks on the extent allocation tree. 3452 */ 3453 for (i = 0; i < refi; i++) { 3454 bytenr = sorted[i].bytenr; 3455 ret = btrfs_free_extent(trans, root, bytenr, 3456 blocksize, eb->start, 3457 root_owner, root_gen, 0, 1); 3458 BUG_ON(ret); 3459 3460 atomic_inc(&root->fs_info->throttle_gen); 3461 wake_up(&root->fs_info->transaction_throttle); 3462 cond_resched(); 3463 } 3464 out: 3465 kfree(sorted); 3466 3467 /* 3468 * update the path to show we've processed the entire level 1 3469 * node. This will get saved into the root's drop_snapshot_progress 3470 * field so these drops are not repeated again if this transaction 3471 * commits. 3472 */ 3473 path->slots[1] = nritems; 3474 return 0; 3475 } 3476 3477 /* 3478 * helper function for drop_snapshot, this walks down the tree dropping ref 3479 * counts as it goes. 3480 */ 3481 static noinline int walk_down_tree(struct btrfs_trans_handle *trans, 3482 struct btrfs_root *root, 3483 struct btrfs_path *path, int *level) 3484 { 3485 u64 root_owner; 3486 u64 root_gen; 3487 u64 bytenr; 3488 u64 ptr_gen; 3489 struct extent_buffer *next; 3490 struct extent_buffer *cur; 3491 struct extent_buffer *parent; 3492 u32 blocksize; 3493 int ret; 3494 u32 refs; 3495 3496 WARN_ON(*level < 0); 3497 WARN_ON(*level >= BTRFS_MAX_LEVEL); 3498 ret = drop_snap_lookup_refcount(trans, root, path->nodes[*level]->start, 3499 path->nodes[*level]->len, &refs); 3500 BUG_ON(ret); 3501 if (refs > 1) 3502 goto out; 3503 3504 /* 3505 * walk down to the last node level and free all the leaves 3506 */ 3507 while (*level >= 0) { 3508 WARN_ON(*level < 0); 3509 WARN_ON(*level >= BTRFS_MAX_LEVEL); 3510 cur = path->nodes[*level]; 3511 3512 if (btrfs_header_level(cur) != *level) 3513 WARN_ON(1); 3514 3515 if (path->slots[*level] >= 3516 btrfs_header_nritems(cur)) 3517 break; 3518 3519 /* the new code goes down to level 1 and does all the 3520 * leaves pointed to that node in bulk. So, this check 3521 * for level 0 will always be false. 3522 * 3523 * But, the disk format allows the drop_snapshot_progress 3524 * field in the root to leave things in a state where 3525 * a leaf will need cleaning up here. If someone crashes 3526 * with the old code and then boots with the new code, 3527 * we might find a leaf here. 3528 */ 3529 if (*level == 0) { 3530 ret = btrfs_drop_leaf_ref(trans, root, cur); 3531 BUG_ON(ret); 3532 break; 3533 } 3534 3535 /* 3536 * once we get to level one, process the whole node 3537 * at once, including everything below it. 3538 */ 3539 if (*level == 1) { 3540 ret = drop_level_one_refs(trans, root, path); 3541 BUG_ON(ret); 3542 break; 3543 } 3544 3545 bytenr = btrfs_node_blockptr(cur, path->slots[*level]); 3546 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); 3547 blocksize = btrfs_level_size(root, *level - 1); 3548 3549 ret = drop_snap_lookup_refcount(trans, root, bytenr, 3550 blocksize, &refs); 3551 BUG_ON(ret); 3552 3553 /* 3554 * if there is more than one reference, we don't need 3555 * to read that node to drop any references it has. We 3556 * just drop the ref we hold on that node and move on to the 3557 * next slot in this level. 3558 */ 3559 if (refs != 1) { 3560 parent = path->nodes[*level]; 3561 root_owner = btrfs_header_owner(parent); 3562 root_gen = btrfs_header_generation(parent); 3563 path->slots[*level]++; 3564 3565 ret = btrfs_free_extent(trans, root, bytenr, 3566 blocksize, parent->start, 3567 root_owner, root_gen, 3568 *level - 1, 1); 3569 BUG_ON(ret); 3570 3571 atomic_inc(&root->fs_info->throttle_gen); 3572 wake_up(&root->fs_info->transaction_throttle); 3573 cond_resched(); 3574 3575 continue; 3576 } 3577 3578 /* 3579 * we need to keep freeing things in the next level down. 3580 * read the block and loop around to process it 3581 */ 3582 next = read_tree_block(root, bytenr, blocksize, ptr_gen); 3583 WARN_ON(*level <= 0); 3584 if (path->nodes[*level-1]) 3585 free_extent_buffer(path->nodes[*level-1]); 3586 path->nodes[*level-1] = next; 3587 *level = btrfs_header_level(next); 3588 path->slots[*level] = 0; 3589 cond_resched(); 3590 } 3591 out: 3592 WARN_ON(*level < 0); 3593 WARN_ON(*level >= BTRFS_MAX_LEVEL); 3594 3595 if (path->nodes[*level] == root->node) { 3596 parent = path->nodes[*level]; 3597 bytenr = path->nodes[*level]->start; 3598 } else { 3599 parent = path->nodes[*level + 1]; 3600 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]); 3601 } 3602 3603 blocksize = btrfs_level_size(root, *level); 3604 root_owner = btrfs_header_owner(parent); 3605 root_gen = btrfs_header_generation(parent); 3606 3607 /* 3608 * cleanup and free the reference on the last node 3609 * we processed 3610 */ 3611 ret = btrfs_free_extent(trans, root, bytenr, blocksize, 3612 parent->start, root_owner, root_gen, 3613 *level, 1); 3614 free_extent_buffer(path->nodes[*level]); 3615 path->nodes[*level] = NULL; 3616 3617 *level += 1; 3618 BUG_ON(ret); 3619 3620 cond_resched(); 3621 return 0; 3622 } 3623 3624 /* 3625 * helper function for drop_subtree, this function is similar to 3626 * walk_down_tree. The main difference is that it checks reference 3627 * counts while tree blocks are locked. 3628 */ 3629 static noinline int walk_down_subtree(struct btrfs_trans_handle *trans, 3630 struct btrfs_root *root, 3631 struct btrfs_path *path, int *level) 3632 { 3633 struct extent_buffer *next; 3634 struct extent_buffer *cur; 3635 struct extent_buffer *parent; 3636 u64 bytenr; 3637 u64 ptr_gen; 3638 u32 blocksize; 3639 u32 refs; 3640 int ret; 3641 3642 cur = path->nodes[*level]; 3643 ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len, 3644 &refs); 3645 BUG_ON(ret); 3646 if (refs > 1) 3647 goto out; 3648 3649 while (*level >= 0) { 3650 cur = path->nodes[*level]; 3651 if (*level == 0) { 3652 ret = btrfs_drop_leaf_ref(trans, root, cur); 3653 BUG_ON(ret); 3654 clean_tree_block(trans, root, cur); 3655 break; 3656 } 3657 if (path->slots[*level] >= btrfs_header_nritems(cur)) { 3658 clean_tree_block(trans, root, cur); 3659 break; 3660 } 3661 3662 bytenr = btrfs_node_blockptr(cur, path->slots[*level]); 3663 blocksize = btrfs_level_size(root, *level - 1); 3664 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); 3665 3666 next = read_tree_block(root, bytenr, blocksize, ptr_gen); 3667 btrfs_tree_lock(next); 3668 btrfs_set_lock_blocking(next); 3669 3670 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize, 3671 &refs); 3672 BUG_ON(ret); 3673 if (refs > 1) { 3674 parent = path->nodes[*level]; 3675 ret = btrfs_free_extent(trans, root, bytenr, 3676 blocksize, parent->start, 3677 btrfs_header_owner(parent), 3678 btrfs_header_generation(parent), 3679 *level - 1, 1); 3680 BUG_ON(ret); 3681 path->slots[*level]++; 3682 btrfs_tree_unlock(next); 3683 free_extent_buffer(next); 3684 continue; 3685 } 3686 3687 *level = btrfs_header_level(next); 3688 path->nodes[*level] = next; 3689 path->slots[*level] = 0; 3690 path->locks[*level] = 1; 3691 cond_resched(); 3692 } 3693 out: 3694 parent = path->nodes[*level + 1]; 3695 bytenr = path->nodes[*level]->start; 3696 blocksize = path->nodes[*level]->len; 3697 3698 ret = btrfs_free_extent(trans, root, bytenr, blocksize, 3699 parent->start, btrfs_header_owner(parent), 3700 btrfs_header_generation(parent), *level, 1); 3701 BUG_ON(ret); 3702 3703 if (path->locks[*level]) { 3704 btrfs_tree_unlock(path->nodes[*level]); 3705 path->locks[*level] = 0; 3706 } 3707 free_extent_buffer(path->nodes[*level]); 3708 path->nodes[*level] = NULL; 3709 *level += 1; 3710 cond_resched(); 3711 return 0; 3712 } 3713 3714 /* 3715 * helper for dropping snapshots. This walks back up the tree in the path 3716 * to find the first node higher up where we haven't yet gone through 3717 * all the slots 3718 */ 3719 static noinline int walk_up_tree(struct btrfs_trans_handle *trans, 3720 struct btrfs_root *root, 3721 struct btrfs_path *path, 3722 int *level, int max_level) 3723 { 3724 u64 root_owner; 3725 u64 root_gen; 3726 struct btrfs_root_item *root_item = &root->root_item; 3727 int i; 3728 int slot; 3729 int ret; 3730 3731 for (i = *level; i < max_level && path->nodes[i]; i++) { 3732 slot = path->slots[i]; 3733 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { 3734 struct extent_buffer *node; 3735 struct btrfs_disk_key disk_key; 3736 3737 /* 3738 * there is more work to do in this level. 3739 * Update the drop_progress marker to reflect 3740 * the work we've done so far, and then bump 3741 * the slot number 3742 */ 3743 node = path->nodes[i]; 3744 path->slots[i]++; 3745 *level = i; 3746 WARN_ON(*level == 0); 3747 btrfs_node_key(node, &disk_key, path->slots[i]); 3748 memcpy(&root_item->drop_progress, 3749 &disk_key, sizeof(disk_key)); 3750 root_item->drop_level = i; 3751 return 0; 3752 } else { 3753 struct extent_buffer *parent; 3754 3755 /* 3756 * this whole node is done, free our reference 3757 * on it and go up one level 3758 */ 3759 if (path->nodes[*level] == root->node) 3760 parent = path->nodes[*level]; 3761 else 3762 parent = path->nodes[*level + 1]; 3763 3764 root_owner = btrfs_header_owner(parent); 3765 root_gen = btrfs_header_generation(parent); 3766 3767 clean_tree_block(trans, root, path->nodes[*level]); 3768 ret = btrfs_free_extent(trans, root, 3769 path->nodes[*level]->start, 3770 path->nodes[*level]->len, 3771 parent->start, root_owner, 3772 root_gen, *level, 1); 3773 BUG_ON(ret); 3774 if (path->locks[*level]) { 3775 btrfs_tree_unlock(path->nodes[*level]); 3776 path->locks[*level] = 0; 3777 } 3778 free_extent_buffer(path->nodes[*level]); 3779 path->nodes[*level] = NULL; 3780 *level = i + 1; 3781 } 3782 } 3783 return 1; 3784 } 3785 3786 /* 3787 * drop the reference count on the tree rooted at 'snap'. This traverses 3788 * the tree freeing any blocks that have a ref count of zero after being 3789 * decremented. 3790 */ 3791 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root 3792 *root) 3793 { 3794 int ret = 0; 3795 int wret; 3796 int level; 3797 struct btrfs_path *path; 3798 int i; 3799 int orig_level; 3800 int update_count; 3801 struct btrfs_root_item *root_item = &root->root_item; 3802 3803 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex)); 3804 path = btrfs_alloc_path(); 3805 BUG_ON(!path); 3806 3807 level = btrfs_header_level(root->node); 3808 orig_level = level; 3809 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { 3810 path->nodes[level] = root->node; 3811 extent_buffer_get(root->node); 3812 path->slots[level] = 0; 3813 } else { 3814 struct btrfs_key key; 3815 struct btrfs_disk_key found_key; 3816 struct extent_buffer *node; 3817 3818 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); 3819 level = root_item->drop_level; 3820 path->lowest_level = level; 3821 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3822 if (wret < 0) { 3823 ret = wret; 3824 goto out; 3825 } 3826 node = path->nodes[level]; 3827 btrfs_node_key(node, &found_key, path->slots[level]); 3828 WARN_ON(memcmp(&found_key, &root_item->drop_progress, 3829 sizeof(found_key))); 3830 /* 3831 * unlock our path, this is safe because only this 3832 * function is allowed to delete this snapshot 3833 */ 3834 for (i = 0; i < BTRFS_MAX_LEVEL; i++) { 3835 if (path->nodes[i] && path->locks[i]) { 3836 path->locks[i] = 0; 3837 btrfs_tree_unlock(path->nodes[i]); 3838 } 3839 } 3840 } 3841 while (1) { 3842 unsigned long update; 3843 wret = walk_down_tree(trans, root, path, &level); 3844 if (wret > 0) 3845 break; 3846 if (wret < 0) 3847 ret = wret; 3848 3849 wret = walk_up_tree(trans, root, path, &level, 3850 BTRFS_MAX_LEVEL); 3851 if (wret > 0) 3852 break; 3853 if (wret < 0) 3854 ret = wret; 3855 if (trans->transaction->in_commit || 3856 trans->transaction->delayed_refs.flushing) { 3857 ret = -EAGAIN; 3858 break; 3859 } 3860 atomic_inc(&root->fs_info->throttle_gen); 3861 wake_up(&root->fs_info->transaction_throttle); 3862 for (update_count = 0; update_count < 16; update_count++) { 3863 update = trans->delayed_ref_updates; 3864 trans->delayed_ref_updates = 0; 3865 if (update) 3866 btrfs_run_delayed_refs(trans, root, update); 3867 else 3868 break; 3869 } 3870 } 3871 for (i = 0; i <= orig_level; i++) { 3872 if (path->nodes[i]) { 3873 free_extent_buffer(path->nodes[i]); 3874 path->nodes[i] = NULL; 3875 } 3876 } 3877 out: 3878 btrfs_free_path(path); 3879 return ret; 3880 } 3881 3882 int btrfs_drop_subtree(struct btrfs_trans_handle *trans, 3883 struct btrfs_root *root, 3884 struct extent_buffer *node, 3885 struct extent_buffer *parent) 3886 { 3887 struct btrfs_path *path; 3888 int level; 3889 int parent_level; 3890 int ret = 0; 3891 int wret; 3892 3893 path = btrfs_alloc_path(); 3894 BUG_ON(!path); 3895 3896 btrfs_assert_tree_locked(parent); 3897 parent_level = btrfs_header_level(parent); 3898 extent_buffer_get(parent); 3899 path->nodes[parent_level] = parent; 3900 path->slots[parent_level] = btrfs_header_nritems(parent); 3901 3902 btrfs_assert_tree_locked(node); 3903 level = btrfs_header_level(node); 3904 extent_buffer_get(node); 3905 path->nodes[level] = node; 3906 path->slots[level] = 0; 3907 3908 while (1) { 3909 wret = walk_down_subtree(trans, root, path, &level); 3910 if (wret < 0) 3911 ret = wret; 3912 if (wret != 0) 3913 break; 3914 3915 wret = walk_up_tree(trans, root, path, &level, parent_level); 3916 if (wret < 0) 3917 ret = wret; 3918 if (wret != 0) 3919 break; 3920 } 3921 3922 btrfs_free_path(path); 3923 return ret; 3924 } 3925 3926 static unsigned long calc_ra(unsigned long start, unsigned long last, 3927 unsigned long nr) 3928 { 3929 return min(last, start + nr - 1); 3930 } 3931 3932 static noinline int relocate_inode_pages(struct inode *inode, u64 start, 3933 u64 len) 3934 { 3935 u64 page_start; 3936 u64 page_end; 3937 unsigned long first_index; 3938 unsigned long last_index; 3939 unsigned long i; 3940 struct page *page; 3941 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 3942 struct file_ra_state *ra; 3943 struct btrfs_ordered_extent *ordered; 3944 unsigned int total_read = 0; 3945 unsigned int total_dirty = 0; 3946 int ret = 0; 3947 3948 ra = kzalloc(sizeof(*ra), GFP_NOFS); 3949 3950 mutex_lock(&inode->i_mutex); 3951 first_index = start >> PAGE_CACHE_SHIFT; 3952 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; 3953 3954 /* make sure the dirty trick played by the caller work */ 3955 ret = invalidate_inode_pages2_range(inode->i_mapping, 3956 first_index, last_index); 3957 if (ret) 3958 goto out_unlock; 3959 3960 file_ra_state_init(ra, inode->i_mapping); 3961 3962 for (i = first_index ; i <= last_index; i++) { 3963 if (total_read % ra->ra_pages == 0) { 3964 btrfs_force_ra(inode->i_mapping, ra, NULL, i, 3965 calc_ra(i, last_index, ra->ra_pages)); 3966 } 3967 total_read++; 3968 again: 3969 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) 3970 BUG_ON(1); 3971 page = grab_cache_page(inode->i_mapping, i); 3972 if (!page) { 3973 ret = -ENOMEM; 3974 goto out_unlock; 3975 } 3976 if (!PageUptodate(page)) { 3977 btrfs_readpage(NULL, page); 3978 lock_page(page); 3979 if (!PageUptodate(page)) { 3980 unlock_page(page); 3981 page_cache_release(page); 3982 ret = -EIO; 3983 goto out_unlock; 3984 } 3985 } 3986 wait_on_page_writeback(page); 3987 3988 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 3989 page_end = page_start + PAGE_CACHE_SIZE - 1; 3990 lock_extent(io_tree, page_start, page_end, GFP_NOFS); 3991 3992 ordered = btrfs_lookup_ordered_extent(inode, page_start); 3993 if (ordered) { 3994 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 3995 unlock_page(page); 3996 page_cache_release(page); 3997 btrfs_start_ordered_extent(inode, ordered, 1); 3998 btrfs_put_ordered_extent(ordered); 3999 goto again; 4000 } 4001 set_page_extent_mapped(page); 4002 4003 if (i == first_index) 4004 set_extent_bits(io_tree, page_start, page_end, 4005 EXTENT_BOUNDARY, GFP_NOFS); 4006 btrfs_set_extent_delalloc(inode, page_start, page_end); 4007 4008 set_page_dirty(page); 4009 total_dirty++; 4010 4011 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 4012 unlock_page(page); 4013 page_cache_release(page); 4014 } 4015 4016 out_unlock: 4017 kfree(ra); 4018 mutex_unlock(&inode->i_mutex); 4019 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty); 4020 return ret; 4021 } 4022 4023 static noinline int relocate_data_extent(struct inode *reloc_inode, 4024 struct btrfs_key *extent_key, 4025 u64 offset) 4026 { 4027 struct btrfs_root *root = BTRFS_I(reloc_inode)->root; 4028 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree; 4029 struct extent_map *em; 4030 u64 start = extent_key->objectid - offset; 4031 u64 end = start + extent_key->offset - 1; 4032 4033 em = alloc_extent_map(GFP_NOFS); 4034 BUG_ON(!em || IS_ERR(em)); 4035 4036 em->start = start; 4037 em->len = extent_key->offset; 4038 em->block_len = extent_key->offset; 4039 em->block_start = extent_key->objectid; 4040 em->bdev = root->fs_info->fs_devices->latest_bdev; 4041 set_bit(EXTENT_FLAG_PINNED, &em->flags); 4042 4043 /* setup extent map to cheat btrfs_readpage */ 4044 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS); 4045 while (1) { 4046 int ret; 4047 spin_lock(&em_tree->lock); 4048 ret = add_extent_mapping(em_tree, em); 4049 spin_unlock(&em_tree->lock); 4050 if (ret != -EEXIST) { 4051 free_extent_map(em); 4052 break; 4053 } 4054 btrfs_drop_extent_cache(reloc_inode, start, end, 0); 4055 } 4056 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS); 4057 4058 return relocate_inode_pages(reloc_inode, start, extent_key->offset); 4059 } 4060 4061 struct btrfs_ref_path { 4062 u64 extent_start; 4063 u64 nodes[BTRFS_MAX_LEVEL]; 4064 u64 root_objectid; 4065 u64 root_generation; 4066 u64 owner_objectid; 4067 u32 num_refs; 4068 int lowest_level; 4069 int current_level; 4070 int shared_level; 4071 4072 struct btrfs_key node_keys[BTRFS_MAX_LEVEL]; 4073 u64 new_nodes[BTRFS_MAX_LEVEL]; 4074 }; 4075 4076 struct disk_extent { 4077 u64 ram_bytes; 4078 u64 disk_bytenr; 4079 u64 disk_num_bytes; 4080 u64 offset; 4081 u64 num_bytes; 4082 u8 compression; 4083 u8 encryption; 4084 u16 other_encoding; 4085 }; 4086 4087 static int is_cowonly_root(u64 root_objectid) 4088 { 4089 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || 4090 root_objectid == BTRFS_EXTENT_TREE_OBJECTID || 4091 root_objectid == BTRFS_CHUNK_TREE_OBJECTID || 4092 root_objectid == BTRFS_DEV_TREE_OBJECTID || 4093 root_objectid == BTRFS_TREE_LOG_OBJECTID || 4094 root_objectid == BTRFS_CSUM_TREE_OBJECTID) 4095 return 1; 4096 return 0; 4097 } 4098 4099 static noinline int __next_ref_path(struct btrfs_trans_handle *trans, 4100 struct btrfs_root *extent_root, 4101 struct btrfs_ref_path *ref_path, 4102 int first_time) 4103 { 4104 struct extent_buffer *leaf; 4105 struct btrfs_path *path; 4106 struct btrfs_extent_ref *ref; 4107 struct btrfs_key key; 4108 struct btrfs_key found_key; 4109 u64 bytenr; 4110 u32 nritems; 4111 int level; 4112 int ret = 1; 4113 4114 path = btrfs_alloc_path(); 4115 if (!path) 4116 return -ENOMEM; 4117 4118 if (first_time) { 4119 ref_path->lowest_level = -1; 4120 ref_path->current_level = -1; 4121 ref_path->shared_level = -1; 4122 goto walk_up; 4123 } 4124 walk_down: 4125 level = ref_path->current_level - 1; 4126 while (level >= -1) { 4127 u64 parent; 4128 if (level < ref_path->lowest_level) 4129 break; 4130 4131 if (level >= 0) 4132 bytenr = ref_path->nodes[level]; 4133 else 4134 bytenr = ref_path->extent_start; 4135 BUG_ON(bytenr == 0); 4136 4137 parent = ref_path->nodes[level + 1]; 4138 ref_path->nodes[level + 1] = 0; 4139 ref_path->current_level = level; 4140 BUG_ON(parent == 0); 4141 4142 key.objectid = bytenr; 4143 key.offset = parent + 1; 4144 key.type = BTRFS_EXTENT_REF_KEY; 4145 4146 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); 4147 if (ret < 0) 4148 goto out; 4149 BUG_ON(ret == 0); 4150 4151 leaf = path->nodes[0]; 4152 nritems = btrfs_header_nritems(leaf); 4153 if (path->slots[0] >= nritems) { 4154 ret = btrfs_next_leaf(extent_root, path); 4155 if (ret < 0) 4156 goto out; 4157 if (ret > 0) 4158 goto next; 4159 leaf = path->nodes[0]; 4160 } 4161 4162 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4163 if (found_key.objectid == bytenr && 4164 found_key.type == BTRFS_EXTENT_REF_KEY) { 4165 if (level < ref_path->shared_level) 4166 ref_path->shared_level = level; 4167 goto found; 4168 } 4169 next: 4170 level--; 4171 btrfs_release_path(extent_root, path); 4172 cond_resched(); 4173 } 4174 /* reached lowest level */ 4175 ret = 1; 4176 goto out; 4177 walk_up: 4178 level = ref_path->current_level; 4179 while (level < BTRFS_MAX_LEVEL - 1) { 4180 u64 ref_objectid; 4181 4182 if (level >= 0) 4183 bytenr = ref_path->nodes[level]; 4184 else 4185 bytenr = ref_path->extent_start; 4186 4187 BUG_ON(bytenr == 0); 4188 4189 key.objectid = bytenr; 4190 key.offset = 0; 4191 key.type = BTRFS_EXTENT_REF_KEY; 4192 4193 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); 4194 if (ret < 0) 4195 goto out; 4196 4197 leaf = path->nodes[0]; 4198 nritems = btrfs_header_nritems(leaf); 4199 if (path->slots[0] >= nritems) { 4200 ret = btrfs_next_leaf(extent_root, path); 4201 if (ret < 0) 4202 goto out; 4203 if (ret > 0) { 4204 /* the extent was freed by someone */ 4205 if (ref_path->lowest_level == level) 4206 goto out; 4207 btrfs_release_path(extent_root, path); 4208 goto walk_down; 4209 } 4210 leaf = path->nodes[0]; 4211 } 4212 4213 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4214 if (found_key.objectid != bytenr || 4215 found_key.type != BTRFS_EXTENT_REF_KEY) { 4216 /* the extent was freed by someone */ 4217 if (ref_path->lowest_level == level) { 4218 ret = 1; 4219 goto out; 4220 } 4221 btrfs_release_path(extent_root, path); 4222 goto walk_down; 4223 } 4224 found: 4225 ref = btrfs_item_ptr(leaf, path->slots[0], 4226 struct btrfs_extent_ref); 4227 ref_objectid = btrfs_ref_objectid(leaf, ref); 4228 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) { 4229 if (first_time) { 4230 level = (int)ref_objectid; 4231 BUG_ON(level >= BTRFS_MAX_LEVEL); 4232 ref_path->lowest_level = level; 4233 ref_path->current_level = level; 4234 ref_path->nodes[level] = bytenr; 4235 } else { 4236 WARN_ON(ref_objectid != level); 4237 } 4238 } else { 4239 WARN_ON(level != -1); 4240 } 4241 first_time = 0; 4242 4243 if (ref_path->lowest_level == level) { 4244 ref_path->owner_objectid = ref_objectid; 4245 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref); 4246 } 4247 4248 /* 4249 * the block is tree root or the block isn't in reference 4250 * counted tree. 4251 */ 4252 if (found_key.objectid == found_key.offset || 4253 is_cowonly_root(btrfs_ref_root(leaf, ref))) { 4254 ref_path->root_objectid = btrfs_ref_root(leaf, ref); 4255 ref_path->root_generation = 4256 btrfs_ref_generation(leaf, ref); 4257 if (level < 0) { 4258 /* special reference from the tree log */ 4259 ref_path->nodes[0] = found_key.offset; 4260 ref_path->current_level = 0; 4261 } 4262 ret = 0; 4263 goto out; 4264 } 4265 4266 level++; 4267 BUG_ON(ref_path->nodes[level] != 0); 4268 ref_path->nodes[level] = found_key.offset; 4269 ref_path->current_level = level; 4270 4271 /* 4272 * the reference was created in the running transaction, 4273 * no need to continue walking up. 4274 */ 4275 if (btrfs_ref_generation(leaf, ref) == trans->transid) { 4276 ref_path->root_objectid = btrfs_ref_root(leaf, ref); 4277 ref_path->root_generation = 4278 btrfs_ref_generation(leaf, ref); 4279 ret = 0; 4280 goto out; 4281 } 4282 4283 btrfs_release_path(extent_root, path); 4284 cond_resched(); 4285 } 4286 /* reached max tree level, but no tree root found. */ 4287 BUG(); 4288 out: 4289 btrfs_free_path(path); 4290 return ret; 4291 } 4292 4293 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans, 4294 struct btrfs_root *extent_root, 4295 struct btrfs_ref_path *ref_path, 4296 u64 extent_start) 4297 { 4298 memset(ref_path, 0, sizeof(*ref_path)); 4299 ref_path->extent_start = extent_start; 4300 4301 return __next_ref_path(trans, extent_root, ref_path, 1); 4302 } 4303 4304 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans, 4305 struct btrfs_root *extent_root, 4306 struct btrfs_ref_path *ref_path) 4307 { 4308 return __next_ref_path(trans, extent_root, ref_path, 0); 4309 } 4310 4311 static noinline int get_new_locations(struct inode *reloc_inode, 4312 struct btrfs_key *extent_key, 4313 u64 offset, int no_fragment, 4314 struct disk_extent **extents, 4315 int *nr_extents) 4316 { 4317 struct btrfs_root *root = BTRFS_I(reloc_inode)->root; 4318 struct btrfs_path *path; 4319 struct btrfs_file_extent_item *fi; 4320 struct extent_buffer *leaf; 4321 struct disk_extent *exts = *extents; 4322 struct btrfs_key found_key; 4323 u64 cur_pos; 4324 u64 last_byte; 4325 u32 nritems; 4326 int nr = 0; 4327 int max = *nr_extents; 4328 int ret; 4329 4330 WARN_ON(!no_fragment && *extents); 4331 if (!exts) { 4332 max = 1; 4333 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS); 4334 if (!exts) 4335 return -ENOMEM; 4336 } 4337 4338 path = btrfs_alloc_path(); 4339 BUG_ON(!path); 4340 4341 cur_pos = extent_key->objectid - offset; 4342 last_byte = extent_key->objectid + extent_key->offset; 4343 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino, 4344 cur_pos, 0); 4345 if (ret < 0) 4346 goto out; 4347 if (ret > 0) { 4348 ret = -ENOENT; 4349 goto out; 4350 } 4351 4352 while (1) { 4353 leaf = path->nodes[0]; 4354 nritems = btrfs_header_nritems(leaf); 4355 if (path->slots[0] >= nritems) { 4356 ret = btrfs_next_leaf(root, path); 4357 if (ret < 0) 4358 goto out; 4359 if (ret > 0) 4360 break; 4361 leaf = path->nodes[0]; 4362 } 4363 4364 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4365 if (found_key.offset != cur_pos || 4366 found_key.type != BTRFS_EXTENT_DATA_KEY || 4367 found_key.objectid != reloc_inode->i_ino) 4368 break; 4369 4370 fi = btrfs_item_ptr(leaf, path->slots[0], 4371 struct btrfs_file_extent_item); 4372 if (btrfs_file_extent_type(leaf, fi) != 4373 BTRFS_FILE_EXTENT_REG || 4374 btrfs_file_extent_disk_bytenr(leaf, fi) == 0) 4375 break; 4376 4377 if (nr == max) { 4378 struct disk_extent *old = exts; 4379 max *= 2; 4380 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS); 4381 memcpy(exts, old, sizeof(*exts) * nr); 4382 if (old != *extents) 4383 kfree(old); 4384 } 4385 4386 exts[nr].disk_bytenr = 4387 btrfs_file_extent_disk_bytenr(leaf, fi); 4388 exts[nr].disk_num_bytes = 4389 btrfs_file_extent_disk_num_bytes(leaf, fi); 4390 exts[nr].offset = btrfs_file_extent_offset(leaf, fi); 4391 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi); 4392 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 4393 exts[nr].compression = btrfs_file_extent_compression(leaf, fi); 4394 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi); 4395 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf, 4396 fi); 4397 BUG_ON(exts[nr].offset > 0); 4398 BUG_ON(exts[nr].compression || exts[nr].encryption); 4399 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes); 4400 4401 cur_pos += exts[nr].num_bytes; 4402 nr++; 4403 4404 if (cur_pos + offset >= last_byte) 4405 break; 4406 4407 if (no_fragment) { 4408 ret = 1; 4409 goto out; 4410 } 4411 path->slots[0]++; 4412 } 4413 4414 BUG_ON(cur_pos + offset > last_byte); 4415 if (cur_pos + offset < last_byte) { 4416 ret = -ENOENT; 4417 goto out; 4418 } 4419 ret = 0; 4420 out: 4421 btrfs_free_path(path); 4422 if (ret) { 4423 if (exts != *extents) 4424 kfree(exts); 4425 } else { 4426 *extents = exts; 4427 *nr_extents = nr; 4428 } 4429 return ret; 4430 } 4431 4432 static noinline int replace_one_extent(struct btrfs_trans_handle *trans, 4433 struct btrfs_root *root, 4434 struct btrfs_path *path, 4435 struct btrfs_key *extent_key, 4436 struct btrfs_key *leaf_key, 4437 struct btrfs_ref_path *ref_path, 4438 struct disk_extent *new_extents, 4439 int nr_extents) 4440 { 4441 struct extent_buffer *leaf; 4442 struct btrfs_file_extent_item *fi; 4443 struct inode *inode = NULL; 4444 struct btrfs_key key; 4445 u64 lock_start = 0; 4446 u64 lock_end = 0; 4447 u64 num_bytes; 4448 u64 ext_offset; 4449 u64 search_end = (u64)-1; 4450 u32 nritems; 4451 int nr_scaned = 0; 4452 int extent_locked = 0; 4453 int extent_type; 4454 int ret; 4455 4456 memcpy(&key, leaf_key, sizeof(key)); 4457 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { 4458 if (key.objectid < ref_path->owner_objectid || 4459 (key.objectid == ref_path->owner_objectid && 4460 key.type < BTRFS_EXTENT_DATA_KEY)) { 4461 key.objectid = ref_path->owner_objectid; 4462 key.type = BTRFS_EXTENT_DATA_KEY; 4463 key.offset = 0; 4464 } 4465 } 4466 4467 while (1) { 4468 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 4469 if (ret < 0) 4470 goto out; 4471 4472 leaf = path->nodes[0]; 4473 nritems = btrfs_header_nritems(leaf); 4474 next: 4475 if (extent_locked && ret > 0) { 4476 /* 4477 * the file extent item was modified by someone 4478 * before the extent got locked. 4479 */ 4480 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, 4481 lock_end, GFP_NOFS); 4482 extent_locked = 0; 4483 } 4484 4485 if (path->slots[0] >= nritems) { 4486 if (++nr_scaned > 2) 4487 break; 4488 4489 BUG_ON(extent_locked); 4490 ret = btrfs_next_leaf(root, path); 4491 if (ret < 0) 4492 goto out; 4493 if (ret > 0) 4494 break; 4495 leaf = path->nodes[0]; 4496 nritems = btrfs_header_nritems(leaf); 4497 } 4498 4499 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4500 4501 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { 4502 if ((key.objectid > ref_path->owner_objectid) || 4503 (key.objectid == ref_path->owner_objectid && 4504 key.type > BTRFS_EXTENT_DATA_KEY) || 4505 key.offset >= search_end) 4506 break; 4507 } 4508 4509 if (inode && key.objectid != inode->i_ino) { 4510 BUG_ON(extent_locked); 4511 btrfs_release_path(root, path); 4512 mutex_unlock(&inode->i_mutex); 4513 iput(inode); 4514 inode = NULL; 4515 continue; 4516 } 4517 4518 if (key.type != BTRFS_EXTENT_DATA_KEY) { 4519 path->slots[0]++; 4520 ret = 1; 4521 goto next; 4522 } 4523 fi = btrfs_item_ptr(leaf, path->slots[0], 4524 struct btrfs_file_extent_item); 4525 extent_type = btrfs_file_extent_type(leaf, fi); 4526 if ((extent_type != BTRFS_FILE_EXTENT_REG && 4527 extent_type != BTRFS_FILE_EXTENT_PREALLOC) || 4528 (btrfs_file_extent_disk_bytenr(leaf, fi) != 4529 extent_key->objectid)) { 4530 path->slots[0]++; 4531 ret = 1; 4532 goto next; 4533 } 4534 4535 num_bytes = btrfs_file_extent_num_bytes(leaf, fi); 4536 ext_offset = btrfs_file_extent_offset(leaf, fi); 4537 4538 if (search_end == (u64)-1) { 4539 search_end = key.offset - ext_offset + 4540 btrfs_file_extent_ram_bytes(leaf, fi); 4541 } 4542 4543 if (!extent_locked) { 4544 lock_start = key.offset; 4545 lock_end = lock_start + num_bytes - 1; 4546 } else { 4547 if (lock_start > key.offset || 4548 lock_end + 1 < key.offset + num_bytes) { 4549 unlock_extent(&BTRFS_I(inode)->io_tree, 4550 lock_start, lock_end, GFP_NOFS); 4551 extent_locked = 0; 4552 } 4553 } 4554 4555 if (!inode) { 4556 btrfs_release_path(root, path); 4557 4558 inode = btrfs_iget_locked(root->fs_info->sb, 4559 key.objectid, root); 4560 if (inode->i_state & I_NEW) { 4561 BTRFS_I(inode)->root = root; 4562 BTRFS_I(inode)->location.objectid = 4563 key.objectid; 4564 BTRFS_I(inode)->location.type = 4565 BTRFS_INODE_ITEM_KEY; 4566 BTRFS_I(inode)->location.offset = 0; 4567 btrfs_read_locked_inode(inode); 4568 unlock_new_inode(inode); 4569 } 4570 /* 4571 * some code call btrfs_commit_transaction while 4572 * holding the i_mutex, so we can't use mutex_lock 4573 * here. 4574 */ 4575 if (is_bad_inode(inode) || 4576 !mutex_trylock(&inode->i_mutex)) { 4577 iput(inode); 4578 inode = NULL; 4579 key.offset = (u64)-1; 4580 goto skip; 4581 } 4582 } 4583 4584 if (!extent_locked) { 4585 struct btrfs_ordered_extent *ordered; 4586 4587 btrfs_release_path(root, path); 4588 4589 lock_extent(&BTRFS_I(inode)->io_tree, lock_start, 4590 lock_end, GFP_NOFS); 4591 ordered = btrfs_lookup_first_ordered_extent(inode, 4592 lock_end); 4593 if (ordered && 4594 ordered->file_offset <= lock_end && 4595 ordered->file_offset + ordered->len > lock_start) { 4596 unlock_extent(&BTRFS_I(inode)->io_tree, 4597 lock_start, lock_end, GFP_NOFS); 4598 btrfs_start_ordered_extent(inode, ordered, 1); 4599 btrfs_put_ordered_extent(ordered); 4600 key.offset += num_bytes; 4601 goto skip; 4602 } 4603 if (ordered) 4604 btrfs_put_ordered_extent(ordered); 4605 4606 extent_locked = 1; 4607 continue; 4608 } 4609 4610 if (nr_extents == 1) { 4611 /* update extent pointer in place */ 4612 btrfs_set_file_extent_disk_bytenr(leaf, fi, 4613 new_extents[0].disk_bytenr); 4614 btrfs_set_file_extent_disk_num_bytes(leaf, fi, 4615 new_extents[0].disk_num_bytes); 4616 btrfs_mark_buffer_dirty(leaf); 4617 4618 btrfs_drop_extent_cache(inode, key.offset, 4619 key.offset + num_bytes - 1, 0); 4620 4621 ret = btrfs_inc_extent_ref(trans, root, 4622 new_extents[0].disk_bytenr, 4623 new_extents[0].disk_num_bytes, 4624 leaf->start, 4625 root->root_key.objectid, 4626 trans->transid, 4627 key.objectid); 4628 BUG_ON(ret); 4629 4630 ret = btrfs_free_extent(trans, root, 4631 extent_key->objectid, 4632 extent_key->offset, 4633 leaf->start, 4634 btrfs_header_owner(leaf), 4635 btrfs_header_generation(leaf), 4636 key.objectid, 0); 4637 BUG_ON(ret); 4638 4639 btrfs_release_path(root, path); 4640 key.offset += num_bytes; 4641 } else { 4642 BUG_ON(1); 4643 #if 0 4644 u64 alloc_hint; 4645 u64 extent_len; 4646 int i; 4647 /* 4648 * drop old extent pointer at first, then insert the 4649 * new pointers one bye one 4650 */ 4651 btrfs_release_path(root, path); 4652 ret = btrfs_drop_extents(trans, root, inode, key.offset, 4653 key.offset + num_bytes, 4654 key.offset, &alloc_hint); 4655 BUG_ON(ret); 4656 4657 for (i = 0; i < nr_extents; i++) { 4658 if (ext_offset >= new_extents[i].num_bytes) { 4659 ext_offset -= new_extents[i].num_bytes; 4660 continue; 4661 } 4662 extent_len = min(new_extents[i].num_bytes - 4663 ext_offset, num_bytes); 4664 4665 ret = btrfs_insert_empty_item(trans, root, 4666 path, &key, 4667 sizeof(*fi)); 4668 BUG_ON(ret); 4669 4670 leaf = path->nodes[0]; 4671 fi = btrfs_item_ptr(leaf, path->slots[0], 4672 struct btrfs_file_extent_item); 4673 btrfs_set_file_extent_generation(leaf, fi, 4674 trans->transid); 4675 btrfs_set_file_extent_type(leaf, fi, 4676 BTRFS_FILE_EXTENT_REG); 4677 btrfs_set_file_extent_disk_bytenr(leaf, fi, 4678 new_extents[i].disk_bytenr); 4679 btrfs_set_file_extent_disk_num_bytes(leaf, fi, 4680 new_extents[i].disk_num_bytes); 4681 btrfs_set_file_extent_ram_bytes(leaf, fi, 4682 new_extents[i].ram_bytes); 4683 4684 btrfs_set_file_extent_compression(leaf, fi, 4685 new_extents[i].compression); 4686 btrfs_set_file_extent_encryption(leaf, fi, 4687 new_extents[i].encryption); 4688 btrfs_set_file_extent_other_encoding(leaf, fi, 4689 new_extents[i].other_encoding); 4690 4691 btrfs_set_file_extent_num_bytes(leaf, fi, 4692 extent_len); 4693 ext_offset += new_extents[i].offset; 4694 btrfs_set_file_extent_offset(leaf, fi, 4695 ext_offset); 4696 btrfs_mark_buffer_dirty(leaf); 4697 4698 btrfs_drop_extent_cache(inode, key.offset, 4699 key.offset + extent_len - 1, 0); 4700 4701 ret = btrfs_inc_extent_ref(trans, root, 4702 new_extents[i].disk_bytenr, 4703 new_extents[i].disk_num_bytes, 4704 leaf->start, 4705 root->root_key.objectid, 4706 trans->transid, key.objectid); 4707 BUG_ON(ret); 4708 btrfs_release_path(root, path); 4709 4710 inode_add_bytes(inode, extent_len); 4711 4712 ext_offset = 0; 4713 num_bytes -= extent_len; 4714 key.offset += extent_len; 4715 4716 if (num_bytes == 0) 4717 break; 4718 } 4719 BUG_ON(i >= nr_extents); 4720 #endif 4721 } 4722 4723 if (extent_locked) { 4724 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, 4725 lock_end, GFP_NOFS); 4726 extent_locked = 0; 4727 } 4728 skip: 4729 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS && 4730 key.offset >= search_end) 4731 break; 4732 4733 cond_resched(); 4734 } 4735 ret = 0; 4736 out: 4737 btrfs_release_path(root, path); 4738 if (inode) { 4739 mutex_unlock(&inode->i_mutex); 4740 if (extent_locked) { 4741 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, 4742 lock_end, GFP_NOFS); 4743 } 4744 iput(inode); 4745 } 4746 return ret; 4747 } 4748 4749 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans, 4750 struct btrfs_root *root, 4751 struct extent_buffer *buf, u64 orig_start) 4752 { 4753 int level; 4754 int ret; 4755 4756 BUG_ON(btrfs_header_generation(buf) != trans->transid); 4757 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); 4758 4759 level = btrfs_header_level(buf); 4760 if (level == 0) { 4761 struct btrfs_leaf_ref *ref; 4762 struct btrfs_leaf_ref *orig_ref; 4763 4764 orig_ref = btrfs_lookup_leaf_ref(root, orig_start); 4765 if (!orig_ref) 4766 return -ENOENT; 4767 4768 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems); 4769 if (!ref) { 4770 btrfs_free_leaf_ref(root, orig_ref); 4771 return -ENOMEM; 4772 } 4773 4774 ref->nritems = orig_ref->nritems; 4775 memcpy(ref->extents, orig_ref->extents, 4776 sizeof(ref->extents[0]) * ref->nritems); 4777 4778 btrfs_free_leaf_ref(root, orig_ref); 4779 4780 ref->root_gen = trans->transid; 4781 ref->bytenr = buf->start; 4782 ref->owner = btrfs_header_owner(buf); 4783 ref->generation = btrfs_header_generation(buf); 4784 4785 ret = btrfs_add_leaf_ref(root, ref, 0); 4786 WARN_ON(ret); 4787 btrfs_free_leaf_ref(root, ref); 4788 } 4789 return 0; 4790 } 4791 4792 static noinline int invalidate_extent_cache(struct btrfs_root *root, 4793 struct extent_buffer *leaf, 4794 struct btrfs_block_group_cache *group, 4795 struct btrfs_root *target_root) 4796 { 4797 struct btrfs_key key; 4798 struct inode *inode = NULL; 4799 struct btrfs_file_extent_item *fi; 4800 u64 num_bytes; 4801 u64 skip_objectid = 0; 4802 u32 nritems; 4803 u32 i; 4804 4805 nritems = btrfs_header_nritems(leaf); 4806 for (i = 0; i < nritems; i++) { 4807 btrfs_item_key_to_cpu(leaf, &key, i); 4808 if (key.objectid == skip_objectid || 4809 key.type != BTRFS_EXTENT_DATA_KEY) 4810 continue; 4811 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); 4812 if (btrfs_file_extent_type(leaf, fi) == 4813 BTRFS_FILE_EXTENT_INLINE) 4814 continue; 4815 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) 4816 continue; 4817 if (!inode || inode->i_ino != key.objectid) { 4818 iput(inode); 4819 inode = btrfs_ilookup(target_root->fs_info->sb, 4820 key.objectid, target_root, 1); 4821 } 4822 if (!inode) { 4823 skip_objectid = key.objectid; 4824 continue; 4825 } 4826 num_bytes = btrfs_file_extent_num_bytes(leaf, fi); 4827 4828 lock_extent(&BTRFS_I(inode)->io_tree, key.offset, 4829 key.offset + num_bytes - 1, GFP_NOFS); 4830 btrfs_drop_extent_cache(inode, key.offset, 4831 key.offset + num_bytes - 1, 1); 4832 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset, 4833 key.offset + num_bytes - 1, GFP_NOFS); 4834 cond_resched(); 4835 } 4836 iput(inode); 4837 return 0; 4838 } 4839 4840 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans, 4841 struct btrfs_root *root, 4842 struct extent_buffer *leaf, 4843 struct btrfs_block_group_cache *group, 4844 struct inode *reloc_inode) 4845 { 4846 struct btrfs_key key; 4847 struct btrfs_key extent_key; 4848 struct btrfs_file_extent_item *fi; 4849 struct btrfs_leaf_ref *ref; 4850 struct disk_extent *new_extent; 4851 u64 bytenr; 4852 u64 num_bytes; 4853 u32 nritems; 4854 u32 i; 4855 int ext_index; 4856 int nr_extent; 4857 int ret; 4858 4859 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS); 4860 BUG_ON(!new_extent); 4861 4862 ref = btrfs_lookup_leaf_ref(root, leaf->start); 4863 BUG_ON(!ref); 4864 4865 ext_index = -1; 4866 nritems = btrfs_header_nritems(leaf); 4867 for (i = 0; i < nritems; i++) { 4868 btrfs_item_key_to_cpu(leaf, &key, i); 4869 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) 4870 continue; 4871 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); 4872 if (btrfs_file_extent_type(leaf, fi) == 4873 BTRFS_FILE_EXTENT_INLINE) 4874 continue; 4875 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 4876 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); 4877 if (bytenr == 0) 4878 continue; 4879 4880 ext_index++; 4881 if (bytenr >= group->key.objectid + group->key.offset || 4882 bytenr + num_bytes <= group->key.objectid) 4883 continue; 4884 4885 extent_key.objectid = bytenr; 4886 extent_key.offset = num_bytes; 4887 extent_key.type = BTRFS_EXTENT_ITEM_KEY; 4888 nr_extent = 1; 4889 ret = get_new_locations(reloc_inode, &extent_key, 4890 group->key.objectid, 1, 4891 &new_extent, &nr_extent); 4892 if (ret > 0) 4893 continue; 4894 BUG_ON(ret < 0); 4895 4896 BUG_ON(ref->extents[ext_index].bytenr != bytenr); 4897 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes); 4898 ref->extents[ext_index].bytenr = new_extent->disk_bytenr; 4899 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes; 4900 4901 btrfs_set_file_extent_disk_bytenr(leaf, fi, 4902 new_extent->disk_bytenr); 4903 btrfs_set_file_extent_disk_num_bytes(leaf, fi, 4904 new_extent->disk_num_bytes); 4905 btrfs_mark_buffer_dirty(leaf); 4906 4907 ret = btrfs_inc_extent_ref(trans, root, 4908 new_extent->disk_bytenr, 4909 new_extent->disk_num_bytes, 4910 leaf->start, 4911 root->root_key.objectid, 4912 trans->transid, key.objectid); 4913 BUG_ON(ret); 4914 4915 ret = btrfs_free_extent(trans, root, 4916 bytenr, num_bytes, leaf->start, 4917 btrfs_header_owner(leaf), 4918 btrfs_header_generation(leaf), 4919 key.objectid, 0); 4920 BUG_ON(ret); 4921 cond_resched(); 4922 } 4923 kfree(new_extent); 4924 BUG_ON(ext_index + 1 != ref->nritems); 4925 btrfs_free_leaf_ref(root, ref); 4926 return 0; 4927 } 4928 4929 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans, 4930 struct btrfs_root *root) 4931 { 4932 struct btrfs_root *reloc_root; 4933 int ret; 4934 4935 if (root->reloc_root) { 4936 reloc_root = root->reloc_root; 4937 root->reloc_root = NULL; 4938 list_add(&reloc_root->dead_list, 4939 &root->fs_info->dead_reloc_roots); 4940 4941 btrfs_set_root_bytenr(&reloc_root->root_item, 4942 reloc_root->node->start); 4943 btrfs_set_root_level(&root->root_item, 4944 btrfs_header_level(reloc_root->node)); 4945 memset(&reloc_root->root_item.drop_progress, 0, 4946 sizeof(struct btrfs_disk_key)); 4947 reloc_root->root_item.drop_level = 0; 4948 4949 ret = btrfs_update_root(trans, root->fs_info->tree_root, 4950 &reloc_root->root_key, 4951 &reloc_root->root_item); 4952 BUG_ON(ret); 4953 } 4954 return 0; 4955 } 4956 4957 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root) 4958 { 4959 struct btrfs_trans_handle *trans; 4960 struct btrfs_root *reloc_root; 4961 struct btrfs_root *prev_root = NULL; 4962 struct list_head dead_roots; 4963 int ret; 4964 unsigned long nr; 4965 4966 INIT_LIST_HEAD(&dead_roots); 4967 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots); 4968 4969 while (!list_empty(&dead_roots)) { 4970 reloc_root = list_entry(dead_roots.prev, 4971 struct btrfs_root, dead_list); 4972 list_del_init(&reloc_root->dead_list); 4973 4974 BUG_ON(reloc_root->commit_root != NULL); 4975 while (1) { 4976 trans = btrfs_join_transaction(root, 1); 4977 BUG_ON(!trans); 4978 4979 mutex_lock(&root->fs_info->drop_mutex); 4980 ret = btrfs_drop_snapshot(trans, reloc_root); 4981 if (ret != -EAGAIN) 4982 break; 4983 mutex_unlock(&root->fs_info->drop_mutex); 4984 4985 nr = trans->blocks_used; 4986 ret = btrfs_end_transaction(trans, root); 4987 BUG_ON(ret); 4988 btrfs_btree_balance_dirty(root, nr); 4989 } 4990 4991 free_extent_buffer(reloc_root->node); 4992 4993 ret = btrfs_del_root(trans, root->fs_info->tree_root, 4994 &reloc_root->root_key); 4995 BUG_ON(ret); 4996 mutex_unlock(&root->fs_info->drop_mutex); 4997 4998 nr = trans->blocks_used; 4999 ret = btrfs_end_transaction(trans, root); 5000 BUG_ON(ret); 5001 btrfs_btree_balance_dirty(root, nr); 5002 5003 kfree(prev_root); 5004 prev_root = reloc_root; 5005 } 5006 if (prev_root) { 5007 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0); 5008 kfree(prev_root); 5009 } 5010 return 0; 5011 } 5012 5013 int btrfs_add_dead_reloc_root(struct btrfs_root *root) 5014 { 5015 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots); 5016 return 0; 5017 } 5018 5019 int btrfs_cleanup_reloc_trees(struct btrfs_root *root) 5020 { 5021 struct btrfs_root *reloc_root; 5022 struct btrfs_trans_handle *trans; 5023 struct btrfs_key location; 5024 int found; 5025 int ret; 5026 5027 mutex_lock(&root->fs_info->tree_reloc_mutex); 5028 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL); 5029 BUG_ON(ret); 5030 found = !list_empty(&root->fs_info->dead_reloc_roots); 5031 mutex_unlock(&root->fs_info->tree_reloc_mutex); 5032 5033 if (found) { 5034 trans = btrfs_start_transaction(root, 1); 5035 BUG_ON(!trans); 5036 ret = btrfs_commit_transaction(trans, root); 5037 BUG_ON(ret); 5038 } 5039 5040 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; 5041 location.offset = (u64)-1; 5042 location.type = BTRFS_ROOT_ITEM_KEY; 5043 5044 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 5045 BUG_ON(!reloc_root); 5046 btrfs_orphan_cleanup(reloc_root); 5047 return 0; 5048 } 5049 5050 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans, 5051 struct btrfs_root *root) 5052 { 5053 struct btrfs_root *reloc_root; 5054 struct extent_buffer *eb; 5055 struct btrfs_root_item *root_item; 5056 struct btrfs_key root_key; 5057 int ret; 5058 5059 BUG_ON(!root->ref_cows); 5060 if (root->reloc_root) 5061 return 0; 5062 5063 root_item = kmalloc(sizeof(*root_item), GFP_NOFS); 5064 BUG_ON(!root_item); 5065 5066 ret = btrfs_copy_root(trans, root, root->commit_root, 5067 &eb, BTRFS_TREE_RELOC_OBJECTID); 5068 BUG_ON(ret); 5069 5070 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; 5071 root_key.offset = root->root_key.objectid; 5072 root_key.type = BTRFS_ROOT_ITEM_KEY; 5073 5074 memcpy(root_item, &root->root_item, sizeof(root_item)); 5075 btrfs_set_root_refs(root_item, 0); 5076 btrfs_set_root_bytenr(root_item, eb->start); 5077 btrfs_set_root_level(root_item, btrfs_header_level(eb)); 5078 btrfs_set_root_generation(root_item, trans->transid); 5079 5080 btrfs_tree_unlock(eb); 5081 free_extent_buffer(eb); 5082 5083 ret = btrfs_insert_root(trans, root->fs_info->tree_root, 5084 &root_key, root_item); 5085 BUG_ON(ret); 5086 kfree(root_item); 5087 5088 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, 5089 &root_key); 5090 BUG_ON(!reloc_root); 5091 reloc_root->last_trans = trans->transid; 5092 reloc_root->commit_root = NULL; 5093 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree; 5094 5095 root->reloc_root = reloc_root; 5096 return 0; 5097 } 5098 5099 /* 5100 * Core function of space balance. 5101 * 5102 * The idea is using reloc trees to relocate tree blocks in reference 5103 * counted roots. There is one reloc tree for each subvol, and all 5104 * reloc trees share same root key objectid. Reloc trees are snapshots 5105 * of the latest committed roots of subvols (root->commit_root). 5106 * 5107 * To relocate a tree block referenced by a subvol, there are two steps. 5108 * COW the block through subvol's reloc tree, then update block pointer 5109 * in the subvol to point to the new block. Since all reloc trees share 5110 * same root key objectid, doing special handing for tree blocks owned 5111 * by them is easy. Once a tree block has been COWed in one reloc tree, 5112 * we can use the resulting new block directly when the same block is 5113 * required to COW again through other reloc trees. By this way, relocated 5114 * tree blocks are shared between reloc trees, so they are also shared 5115 * between subvols. 5116 */ 5117 static noinline int relocate_one_path(struct btrfs_trans_handle *trans, 5118 struct btrfs_root *root, 5119 struct btrfs_path *path, 5120 struct btrfs_key *first_key, 5121 struct btrfs_ref_path *ref_path, 5122 struct btrfs_block_group_cache *group, 5123 struct inode *reloc_inode) 5124 { 5125 struct btrfs_root *reloc_root; 5126 struct extent_buffer *eb = NULL; 5127 struct btrfs_key *keys; 5128 u64 *nodes; 5129 int level; 5130 int shared_level; 5131 int lowest_level = 0; 5132 int ret; 5133 5134 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) 5135 lowest_level = ref_path->owner_objectid; 5136 5137 if (!root->ref_cows) { 5138 path->lowest_level = lowest_level; 5139 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1); 5140 BUG_ON(ret < 0); 5141 path->lowest_level = 0; 5142 btrfs_release_path(root, path); 5143 return 0; 5144 } 5145 5146 mutex_lock(&root->fs_info->tree_reloc_mutex); 5147 ret = init_reloc_tree(trans, root); 5148 BUG_ON(ret); 5149 reloc_root = root->reloc_root; 5150 5151 shared_level = ref_path->shared_level; 5152 ref_path->shared_level = BTRFS_MAX_LEVEL - 1; 5153 5154 keys = ref_path->node_keys; 5155 nodes = ref_path->new_nodes; 5156 memset(&keys[shared_level + 1], 0, 5157 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1)); 5158 memset(&nodes[shared_level + 1], 0, 5159 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1)); 5160 5161 if (nodes[lowest_level] == 0) { 5162 path->lowest_level = lowest_level; 5163 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 5164 0, 1); 5165 BUG_ON(ret); 5166 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) { 5167 eb = path->nodes[level]; 5168 if (!eb || eb == reloc_root->node) 5169 break; 5170 nodes[level] = eb->start; 5171 if (level == 0) 5172 btrfs_item_key_to_cpu(eb, &keys[level], 0); 5173 else 5174 btrfs_node_key_to_cpu(eb, &keys[level], 0); 5175 } 5176 if (nodes[0] && 5177 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { 5178 eb = path->nodes[0]; 5179 ret = replace_extents_in_leaf(trans, reloc_root, eb, 5180 group, reloc_inode); 5181 BUG_ON(ret); 5182 } 5183 btrfs_release_path(reloc_root, path); 5184 } else { 5185 ret = btrfs_merge_path(trans, reloc_root, keys, nodes, 5186 lowest_level); 5187 BUG_ON(ret); 5188 } 5189 5190 /* 5191 * replace tree blocks in the fs tree with tree blocks in 5192 * the reloc tree. 5193 */ 5194 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level); 5195 BUG_ON(ret < 0); 5196 5197 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { 5198 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 5199 0, 0); 5200 BUG_ON(ret); 5201 extent_buffer_get(path->nodes[0]); 5202 eb = path->nodes[0]; 5203 btrfs_release_path(reloc_root, path); 5204 ret = invalidate_extent_cache(reloc_root, eb, group, root); 5205 BUG_ON(ret); 5206 free_extent_buffer(eb); 5207 } 5208 5209 mutex_unlock(&root->fs_info->tree_reloc_mutex); 5210 path->lowest_level = 0; 5211 return 0; 5212 } 5213 5214 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans, 5215 struct btrfs_root *root, 5216 struct btrfs_path *path, 5217 struct btrfs_key *first_key, 5218 struct btrfs_ref_path *ref_path) 5219 { 5220 int ret; 5221 5222 ret = relocate_one_path(trans, root, path, first_key, 5223 ref_path, NULL, NULL); 5224 BUG_ON(ret); 5225 5226 return 0; 5227 } 5228 5229 static noinline int del_extent_zero(struct btrfs_trans_handle *trans, 5230 struct btrfs_root *extent_root, 5231 struct btrfs_path *path, 5232 struct btrfs_key *extent_key) 5233 { 5234 int ret; 5235 5236 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); 5237 if (ret) 5238 goto out; 5239 ret = btrfs_del_item(trans, extent_root, path); 5240 out: 5241 btrfs_release_path(extent_root, path); 5242 return ret; 5243 } 5244 5245 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info, 5246 struct btrfs_ref_path *ref_path) 5247 { 5248 struct btrfs_key root_key; 5249 5250 root_key.objectid = ref_path->root_objectid; 5251 root_key.type = BTRFS_ROOT_ITEM_KEY; 5252 if (is_cowonly_root(ref_path->root_objectid)) 5253 root_key.offset = 0; 5254 else 5255 root_key.offset = (u64)-1; 5256 5257 return btrfs_read_fs_root_no_name(fs_info, &root_key); 5258 } 5259 5260 static noinline int relocate_one_extent(struct btrfs_root *extent_root, 5261 struct btrfs_path *path, 5262 struct btrfs_key *extent_key, 5263 struct btrfs_block_group_cache *group, 5264 struct inode *reloc_inode, int pass) 5265 { 5266 struct btrfs_trans_handle *trans; 5267 struct btrfs_root *found_root; 5268 struct btrfs_ref_path *ref_path = NULL; 5269 struct disk_extent *new_extents = NULL; 5270 int nr_extents = 0; 5271 int loops; 5272 int ret; 5273 int level; 5274 struct btrfs_key first_key; 5275 u64 prev_block = 0; 5276 5277 5278 trans = btrfs_start_transaction(extent_root, 1); 5279 BUG_ON(!trans); 5280 5281 if (extent_key->objectid == 0) { 5282 ret = del_extent_zero(trans, extent_root, path, extent_key); 5283 goto out; 5284 } 5285 5286 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS); 5287 if (!ref_path) { 5288 ret = -ENOMEM; 5289 goto out; 5290 } 5291 5292 for (loops = 0; ; loops++) { 5293 if (loops == 0) { 5294 ret = btrfs_first_ref_path(trans, extent_root, ref_path, 5295 extent_key->objectid); 5296 } else { 5297 ret = btrfs_next_ref_path(trans, extent_root, ref_path); 5298 } 5299 if (ret < 0) 5300 goto out; 5301 if (ret > 0) 5302 break; 5303 5304 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID || 5305 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID) 5306 continue; 5307 5308 found_root = read_ref_root(extent_root->fs_info, ref_path); 5309 BUG_ON(!found_root); 5310 /* 5311 * for reference counted tree, only process reference paths 5312 * rooted at the latest committed root. 5313 */ 5314 if (found_root->ref_cows && 5315 ref_path->root_generation != found_root->root_key.offset) 5316 continue; 5317 5318 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { 5319 if (pass == 0) { 5320 /* 5321 * copy data extents to new locations 5322 */ 5323 u64 group_start = group->key.objectid; 5324 ret = relocate_data_extent(reloc_inode, 5325 extent_key, 5326 group_start); 5327 if (ret < 0) 5328 goto out; 5329 break; 5330 } 5331 level = 0; 5332 } else { 5333 level = ref_path->owner_objectid; 5334 } 5335 5336 if (prev_block != ref_path->nodes[level]) { 5337 struct extent_buffer *eb; 5338 u64 block_start = ref_path->nodes[level]; 5339 u64 block_size = btrfs_level_size(found_root, level); 5340 5341 eb = read_tree_block(found_root, block_start, 5342 block_size, 0); 5343 btrfs_tree_lock(eb); 5344 BUG_ON(level != btrfs_header_level(eb)); 5345 5346 if (level == 0) 5347 btrfs_item_key_to_cpu(eb, &first_key, 0); 5348 else 5349 btrfs_node_key_to_cpu(eb, &first_key, 0); 5350 5351 btrfs_tree_unlock(eb); 5352 free_extent_buffer(eb); 5353 prev_block = block_start; 5354 } 5355 5356 mutex_lock(&extent_root->fs_info->trans_mutex); 5357 btrfs_record_root_in_trans(found_root); 5358 mutex_unlock(&extent_root->fs_info->trans_mutex); 5359 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { 5360 /* 5361 * try to update data extent references while 5362 * keeping metadata shared between snapshots. 5363 */ 5364 if (pass == 1) { 5365 ret = relocate_one_path(trans, found_root, 5366 path, &first_key, ref_path, 5367 group, reloc_inode); 5368 if (ret < 0) 5369 goto out; 5370 continue; 5371 } 5372 /* 5373 * use fallback method to process the remaining 5374 * references. 5375 */ 5376 if (!new_extents) { 5377 u64 group_start = group->key.objectid; 5378 new_extents = kmalloc(sizeof(*new_extents), 5379 GFP_NOFS); 5380 nr_extents = 1; 5381 ret = get_new_locations(reloc_inode, 5382 extent_key, 5383 group_start, 1, 5384 &new_extents, 5385 &nr_extents); 5386 if (ret) 5387 goto out; 5388 } 5389 ret = replace_one_extent(trans, found_root, 5390 path, extent_key, 5391 &first_key, ref_path, 5392 new_extents, nr_extents); 5393 } else { 5394 ret = relocate_tree_block(trans, found_root, path, 5395 &first_key, ref_path); 5396 } 5397 if (ret < 0) 5398 goto out; 5399 } 5400 ret = 0; 5401 out: 5402 btrfs_end_transaction(trans, extent_root); 5403 kfree(new_extents); 5404 kfree(ref_path); 5405 return ret; 5406 } 5407 5408 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) 5409 { 5410 u64 num_devices; 5411 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 | 5412 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; 5413 5414 num_devices = root->fs_info->fs_devices->rw_devices; 5415 if (num_devices == 1) { 5416 stripped |= BTRFS_BLOCK_GROUP_DUP; 5417 stripped = flags & ~stripped; 5418 5419 /* turn raid0 into single device chunks */ 5420 if (flags & BTRFS_BLOCK_GROUP_RAID0) 5421 return stripped; 5422 5423 /* turn mirroring into duplication */ 5424 if (flags & (BTRFS_BLOCK_GROUP_RAID1 | 5425 BTRFS_BLOCK_GROUP_RAID10)) 5426 return stripped | BTRFS_BLOCK_GROUP_DUP; 5427 return flags; 5428 } else { 5429 /* they already had raid on here, just return */ 5430 if (flags & stripped) 5431 return flags; 5432 5433 stripped |= BTRFS_BLOCK_GROUP_DUP; 5434 stripped = flags & ~stripped; 5435 5436 /* switch duplicated blocks with raid1 */ 5437 if (flags & BTRFS_BLOCK_GROUP_DUP) 5438 return stripped | BTRFS_BLOCK_GROUP_RAID1; 5439 5440 /* turn single device chunks into raid0 */ 5441 return stripped | BTRFS_BLOCK_GROUP_RAID0; 5442 } 5443 return flags; 5444 } 5445 5446 static int __alloc_chunk_for_shrink(struct btrfs_root *root, 5447 struct btrfs_block_group_cache *shrink_block_group, 5448 int force) 5449 { 5450 struct btrfs_trans_handle *trans; 5451 u64 new_alloc_flags; 5452 u64 calc; 5453 5454 spin_lock(&shrink_block_group->lock); 5455 if (btrfs_block_group_used(&shrink_block_group->item) > 0) { 5456 spin_unlock(&shrink_block_group->lock); 5457 5458 trans = btrfs_start_transaction(root, 1); 5459 spin_lock(&shrink_block_group->lock); 5460 5461 new_alloc_flags = update_block_group_flags(root, 5462 shrink_block_group->flags); 5463 if (new_alloc_flags != shrink_block_group->flags) { 5464 calc = 5465 btrfs_block_group_used(&shrink_block_group->item); 5466 } else { 5467 calc = shrink_block_group->key.offset; 5468 } 5469 spin_unlock(&shrink_block_group->lock); 5470 5471 do_chunk_alloc(trans, root->fs_info->extent_root, 5472 calc + 2 * 1024 * 1024, new_alloc_flags, force); 5473 5474 btrfs_end_transaction(trans, root); 5475 } else 5476 spin_unlock(&shrink_block_group->lock); 5477 return 0; 5478 } 5479 5480 static int __insert_orphan_inode(struct btrfs_trans_handle *trans, 5481 struct btrfs_root *root, 5482 u64 objectid, u64 size) 5483 { 5484 struct btrfs_path *path; 5485 struct btrfs_inode_item *item; 5486 struct extent_buffer *leaf; 5487 int ret; 5488 5489 path = btrfs_alloc_path(); 5490 if (!path) 5491 return -ENOMEM; 5492 5493 path->leave_spinning = 1; 5494 ret = btrfs_insert_empty_inode(trans, root, path, objectid); 5495 if (ret) 5496 goto out; 5497 5498 leaf = path->nodes[0]; 5499 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); 5500 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); 5501 btrfs_set_inode_generation(leaf, item, 1); 5502 btrfs_set_inode_size(leaf, item, size); 5503 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); 5504 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS); 5505 btrfs_mark_buffer_dirty(leaf); 5506 btrfs_release_path(root, path); 5507 out: 5508 btrfs_free_path(path); 5509 return ret; 5510 } 5511 5512 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info, 5513 struct btrfs_block_group_cache *group) 5514 { 5515 struct inode *inode = NULL; 5516 struct btrfs_trans_handle *trans; 5517 struct btrfs_root *root; 5518 struct btrfs_key root_key; 5519 u64 objectid = BTRFS_FIRST_FREE_OBJECTID; 5520 int err = 0; 5521 5522 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; 5523 root_key.type = BTRFS_ROOT_ITEM_KEY; 5524 root_key.offset = (u64)-1; 5525 root = btrfs_read_fs_root_no_name(fs_info, &root_key); 5526 if (IS_ERR(root)) 5527 return ERR_CAST(root); 5528 5529 trans = btrfs_start_transaction(root, 1); 5530 BUG_ON(!trans); 5531 5532 err = btrfs_find_free_objectid(trans, root, objectid, &objectid); 5533 if (err) 5534 goto out; 5535 5536 err = __insert_orphan_inode(trans, root, objectid, group->key.offset); 5537 BUG_ON(err); 5538 5539 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0, 5540 group->key.offset, 0, group->key.offset, 5541 0, 0, 0); 5542 BUG_ON(err); 5543 5544 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root); 5545 if (inode->i_state & I_NEW) { 5546 BTRFS_I(inode)->root = root; 5547 BTRFS_I(inode)->location.objectid = objectid; 5548 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; 5549 BTRFS_I(inode)->location.offset = 0; 5550 btrfs_read_locked_inode(inode); 5551 unlock_new_inode(inode); 5552 BUG_ON(is_bad_inode(inode)); 5553 } else { 5554 BUG_ON(1); 5555 } 5556 BTRFS_I(inode)->index_cnt = group->key.objectid; 5557 5558 err = btrfs_orphan_add(trans, inode); 5559 out: 5560 btrfs_end_transaction(trans, root); 5561 if (err) { 5562 if (inode) 5563 iput(inode); 5564 inode = ERR_PTR(err); 5565 } 5566 return inode; 5567 } 5568 5569 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) 5570 { 5571 5572 struct btrfs_ordered_sum *sums; 5573 struct btrfs_sector_sum *sector_sum; 5574 struct btrfs_ordered_extent *ordered; 5575 struct btrfs_root *root = BTRFS_I(inode)->root; 5576 struct list_head list; 5577 size_t offset; 5578 int ret; 5579 u64 disk_bytenr; 5580 5581 INIT_LIST_HEAD(&list); 5582 5583 ordered = btrfs_lookup_ordered_extent(inode, file_pos); 5584 BUG_ON(ordered->file_offset != file_pos || ordered->len != len); 5585 5586 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt; 5587 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr, 5588 disk_bytenr + len - 1, &list); 5589 5590 while (!list_empty(&list)) { 5591 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 5592 list_del_init(&sums->list); 5593 5594 sector_sum = sums->sums; 5595 sums->bytenr = ordered->start; 5596 5597 offset = 0; 5598 while (offset < sums->len) { 5599 sector_sum->bytenr += ordered->start - disk_bytenr; 5600 sector_sum++; 5601 offset += root->sectorsize; 5602 } 5603 5604 btrfs_add_ordered_sum(inode, ordered, sums); 5605 } 5606 btrfs_put_ordered_extent(ordered); 5607 return 0; 5608 } 5609 5610 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start) 5611 { 5612 struct btrfs_trans_handle *trans; 5613 struct btrfs_path *path; 5614 struct btrfs_fs_info *info = root->fs_info; 5615 struct extent_buffer *leaf; 5616 struct inode *reloc_inode; 5617 struct btrfs_block_group_cache *block_group; 5618 struct btrfs_key key; 5619 u64 skipped; 5620 u64 cur_byte; 5621 u64 total_found; 5622 u32 nritems; 5623 int ret; 5624 int progress; 5625 int pass = 0; 5626 5627 root = root->fs_info->extent_root; 5628 5629 block_group = btrfs_lookup_block_group(info, group_start); 5630 BUG_ON(!block_group); 5631 5632 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n", 5633 (unsigned long long)block_group->key.objectid, 5634 (unsigned long long)block_group->flags); 5635 5636 path = btrfs_alloc_path(); 5637 BUG_ON(!path); 5638 5639 reloc_inode = create_reloc_inode(info, block_group); 5640 BUG_ON(IS_ERR(reloc_inode)); 5641 5642 __alloc_chunk_for_shrink(root, block_group, 1); 5643 set_block_group_readonly(block_group); 5644 5645 btrfs_start_delalloc_inodes(info->tree_root); 5646 btrfs_wait_ordered_extents(info->tree_root, 0); 5647 again: 5648 skipped = 0; 5649 total_found = 0; 5650 progress = 0; 5651 key.objectid = block_group->key.objectid; 5652 key.offset = 0; 5653 key.type = 0; 5654 cur_byte = key.objectid; 5655 5656 trans = btrfs_start_transaction(info->tree_root, 1); 5657 btrfs_commit_transaction(trans, info->tree_root); 5658 5659 mutex_lock(&root->fs_info->cleaner_mutex); 5660 btrfs_clean_old_snapshots(info->tree_root); 5661 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1); 5662 mutex_unlock(&root->fs_info->cleaner_mutex); 5663 5664 trans = btrfs_start_transaction(info->tree_root, 1); 5665 btrfs_commit_transaction(trans, info->tree_root); 5666 5667 while (1) { 5668 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5669 if (ret < 0) 5670 goto out; 5671 next: 5672 leaf = path->nodes[0]; 5673 nritems = btrfs_header_nritems(leaf); 5674 if (path->slots[0] >= nritems) { 5675 ret = btrfs_next_leaf(root, path); 5676 if (ret < 0) 5677 goto out; 5678 if (ret == 1) { 5679 ret = 0; 5680 break; 5681 } 5682 leaf = path->nodes[0]; 5683 nritems = btrfs_header_nritems(leaf); 5684 } 5685 5686 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 5687 5688 if (key.objectid >= block_group->key.objectid + 5689 block_group->key.offset) 5690 break; 5691 5692 if (progress && need_resched()) { 5693 btrfs_release_path(root, path); 5694 cond_resched(); 5695 progress = 0; 5696 continue; 5697 } 5698 progress = 1; 5699 5700 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY || 5701 key.objectid + key.offset <= cur_byte) { 5702 path->slots[0]++; 5703 goto next; 5704 } 5705 5706 total_found++; 5707 cur_byte = key.objectid + key.offset; 5708 btrfs_release_path(root, path); 5709 5710 __alloc_chunk_for_shrink(root, block_group, 0); 5711 ret = relocate_one_extent(root, path, &key, block_group, 5712 reloc_inode, pass); 5713 BUG_ON(ret < 0); 5714 if (ret > 0) 5715 skipped++; 5716 5717 key.objectid = cur_byte; 5718 key.type = 0; 5719 key.offset = 0; 5720 } 5721 5722 btrfs_release_path(root, path); 5723 5724 if (pass == 0) { 5725 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1); 5726 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1); 5727 } 5728 5729 if (total_found > 0) { 5730 printk(KERN_INFO "btrfs found %llu extents in pass %d\n", 5731 (unsigned long long)total_found, pass); 5732 pass++; 5733 if (total_found == skipped && pass > 2) { 5734 iput(reloc_inode); 5735 reloc_inode = create_reloc_inode(info, block_group); 5736 pass = 0; 5737 } 5738 goto again; 5739 } 5740 5741 /* delete reloc_inode */ 5742 iput(reloc_inode); 5743 5744 /* unpin extents in this range */ 5745 trans = btrfs_start_transaction(info->tree_root, 1); 5746 btrfs_commit_transaction(trans, info->tree_root); 5747 5748 spin_lock(&block_group->lock); 5749 WARN_ON(block_group->pinned > 0); 5750 WARN_ON(block_group->reserved > 0); 5751 WARN_ON(btrfs_block_group_used(&block_group->item) > 0); 5752 spin_unlock(&block_group->lock); 5753 btrfs_put_block_group(block_group); 5754 ret = 0; 5755 out: 5756 btrfs_free_path(path); 5757 return ret; 5758 } 5759 5760 static int find_first_block_group(struct btrfs_root *root, 5761 struct btrfs_path *path, struct btrfs_key *key) 5762 { 5763 int ret = 0; 5764 struct btrfs_key found_key; 5765 struct extent_buffer *leaf; 5766 int slot; 5767 5768 ret = btrfs_search_slot(NULL, root, key, path, 0, 0); 5769 if (ret < 0) 5770 goto out; 5771 5772 while (1) { 5773 slot = path->slots[0]; 5774 leaf = path->nodes[0]; 5775 if (slot >= btrfs_header_nritems(leaf)) { 5776 ret = btrfs_next_leaf(root, path); 5777 if (ret == 0) 5778 continue; 5779 if (ret < 0) 5780 goto out; 5781 break; 5782 } 5783 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5784 5785 if (found_key.objectid >= key->objectid && 5786 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { 5787 ret = 0; 5788 goto out; 5789 } 5790 path->slots[0]++; 5791 } 5792 ret = -ENOENT; 5793 out: 5794 return ret; 5795 } 5796 5797 int btrfs_free_block_groups(struct btrfs_fs_info *info) 5798 { 5799 struct btrfs_block_group_cache *block_group; 5800 struct btrfs_space_info *space_info; 5801 struct rb_node *n; 5802 5803 spin_lock(&info->block_group_cache_lock); 5804 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { 5805 block_group = rb_entry(n, struct btrfs_block_group_cache, 5806 cache_node); 5807 rb_erase(&block_group->cache_node, 5808 &info->block_group_cache_tree); 5809 spin_unlock(&info->block_group_cache_lock); 5810 5811 btrfs_remove_free_space_cache(block_group); 5812 down_write(&block_group->space_info->groups_sem); 5813 list_del(&block_group->list); 5814 up_write(&block_group->space_info->groups_sem); 5815 5816 WARN_ON(atomic_read(&block_group->count) != 1); 5817 kfree(block_group); 5818 5819 spin_lock(&info->block_group_cache_lock); 5820 } 5821 spin_unlock(&info->block_group_cache_lock); 5822 5823 /* now that all the block groups are freed, go through and 5824 * free all the space_info structs. This is only called during 5825 * the final stages of unmount, and so we know nobody is 5826 * using them. We call synchronize_rcu() once before we start, 5827 * just to be on the safe side. 5828 */ 5829 synchronize_rcu(); 5830 5831 while(!list_empty(&info->space_info)) { 5832 space_info = list_entry(info->space_info.next, 5833 struct btrfs_space_info, 5834 list); 5835 5836 list_del(&space_info->list); 5837 kfree(space_info); 5838 } 5839 return 0; 5840 } 5841 5842 int btrfs_read_block_groups(struct btrfs_root *root) 5843 { 5844 struct btrfs_path *path; 5845 int ret; 5846 struct btrfs_block_group_cache *cache; 5847 struct btrfs_fs_info *info = root->fs_info; 5848 struct btrfs_space_info *space_info; 5849 struct btrfs_key key; 5850 struct btrfs_key found_key; 5851 struct extent_buffer *leaf; 5852 5853 root = info->extent_root; 5854 key.objectid = 0; 5855 key.offset = 0; 5856 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); 5857 path = btrfs_alloc_path(); 5858 if (!path) 5859 return -ENOMEM; 5860 5861 while (1) { 5862 ret = find_first_block_group(root, path, &key); 5863 if (ret > 0) { 5864 ret = 0; 5865 goto error; 5866 } 5867 if (ret != 0) 5868 goto error; 5869 5870 leaf = path->nodes[0]; 5871 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5872 cache = kzalloc(sizeof(*cache), GFP_NOFS); 5873 if (!cache) { 5874 ret = -ENOMEM; 5875 break; 5876 } 5877 5878 atomic_set(&cache->count, 1); 5879 spin_lock_init(&cache->lock); 5880 spin_lock_init(&cache->tree_lock); 5881 mutex_init(&cache->cache_mutex); 5882 INIT_LIST_HEAD(&cache->list); 5883 INIT_LIST_HEAD(&cache->cluster_list); 5884 read_extent_buffer(leaf, &cache->item, 5885 btrfs_item_ptr_offset(leaf, path->slots[0]), 5886 sizeof(cache->item)); 5887 memcpy(&cache->key, &found_key, sizeof(found_key)); 5888 5889 key.objectid = found_key.objectid + found_key.offset; 5890 btrfs_release_path(root, path); 5891 cache->flags = btrfs_block_group_flags(&cache->item); 5892 5893 ret = update_space_info(info, cache->flags, found_key.offset, 5894 btrfs_block_group_used(&cache->item), 5895 &space_info); 5896 BUG_ON(ret); 5897 cache->space_info = space_info; 5898 down_write(&space_info->groups_sem); 5899 list_add_tail(&cache->list, &space_info->block_groups); 5900 up_write(&space_info->groups_sem); 5901 5902 ret = btrfs_add_block_group_cache(root->fs_info, cache); 5903 BUG_ON(ret); 5904 5905 set_avail_alloc_bits(root->fs_info, cache->flags); 5906 if (btrfs_chunk_readonly(root, cache->key.objectid)) 5907 set_block_group_readonly(cache); 5908 } 5909 ret = 0; 5910 error: 5911 btrfs_free_path(path); 5912 return ret; 5913 } 5914 5915 int btrfs_make_block_group(struct btrfs_trans_handle *trans, 5916 struct btrfs_root *root, u64 bytes_used, 5917 u64 type, u64 chunk_objectid, u64 chunk_offset, 5918 u64 size) 5919 { 5920 int ret; 5921 struct btrfs_root *extent_root; 5922 struct btrfs_block_group_cache *cache; 5923 5924 extent_root = root->fs_info->extent_root; 5925 5926 root->fs_info->last_trans_log_full_commit = trans->transid; 5927 5928 cache = kzalloc(sizeof(*cache), GFP_NOFS); 5929 if (!cache) 5930 return -ENOMEM; 5931 5932 cache->key.objectid = chunk_offset; 5933 cache->key.offset = size; 5934 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; 5935 atomic_set(&cache->count, 1); 5936 spin_lock_init(&cache->lock); 5937 spin_lock_init(&cache->tree_lock); 5938 mutex_init(&cache->cache_mutex); 5939 INIT_LIST_HEAD(&cache->list); 5940 INIT_LIST_HEAD(&cache->cluster_list); 5941 5942 btrfs_set_block_group_used(&cache->item, bytes_used); 5943 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); 5944 cache->flags = type; 5945 btrfs_set_block_group_flags(&cache->item, type); 5946 5947 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, 5948 &cache->space_info); 5949 BUG_ON(ret); 5950 down_write(&cache->space_info->groups_sem); 5951 list_add_tail(&cache->list, &cache->space_info->block_groups); 5952 up_write(&cache->space_info->groups_sem); 5953 5954 ret = btrfs_add_block_group_cache(root->fs_info, cache); 5955 BUG_ON(ret); 5956 5957 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, 5958 sizeof(cache->item)); 5959 BUG_ON(ret); 5960 5961 set_avail_alloc_bits(extent_root->fs_info, type); 5962 5963 return 0; 5964 } 5965 5966 int btrfs_remove_block_group(struct btrfs_trans_handle *trans, 5967 struct btrfs_root *root, u64 group_start) 5968 { 5969 struct btrfs_path *path; 5970 struct btrfs_block_group_cache *block_group; 5971 struct btrfs_key key; 5972 int ret; 5973 5974 root = root->fs_info->extent_root; 5975 5976 block_group = btrfs_lookup_block_group(root->fs_info, group_start); 5977 BUG_ON(!block_group); 5978 BUG_ON(!block_group->ro); 5979 5980 memcpy(&key, &block_group->key, sizeof(key)); 5981 5982 path = btrfs_alloc_path(); 5983 BUG_ON(!path); 5984 5985 spin_lock(&root->fs_info->block_group_cache_lock); 5986 rb_erase(&block_group->cache_node, 5987 &root->fs_info->block_group_cache_tree); 5988 spin_unlock(&root->fs_info->block_group_cache_lock); 5989 btrfs_remove_free_space_cache(block_group); 5990 down_write(&block_group->space_info->groups_sem); 5991 list_del(&block_group->list); 5992 up_write(&block_group->space_info->groups_sem); 5993 5994 spin_lock(&block_group->space_info->lock); 5995 block_group->space_info->total_bytes -= block_group->key.offset; 5996 block_group->space_info->bytes_readonly -= block_group->key.offset; 5997 spin_unlock(&block_group->space_info->lock); 5998 block_group->space_info->full = 0; 5999 6000 btrfs_put_block_group(block_group); 6001 btrfs_put_block_group(block_group); 6002 6003 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 6004 if (ret > 0) 6005 ret = -EIO; 6006 if (ret < 0) 6007 goto out; 6008 6009 ret = btrfs_del_item(trans, root, path); 6010 out: 6011 btrfs_free_path(path); 6012 return ret; 6013 } 6014