1 /* 2 * Copyright (C) 2009 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 19 #include <linux/sched.h> 20 #include <linux/pagemap.h> 21 #include <linux/writeback.h> 22 #include <linux/blkdev.h> 23 #include <linux/rbtree.h> 24 #include "ctree.h" 25 #include "disk-io.h" 26 #include "transaction.h" 27 #include "volumes.h" 28 #include "locking.h" 29 #include "btrfs_inode.h" 30 #include "async-thread.h" 31 32 /* 33 * backref_node, mapping_node and tree_block start with this 34 */ 35 struct tree_entry { 36 struct rb_node rb_node; 37 u64 bytenr; 38 }; 39 40 /* 41 * present a tree block in the backref cache 42 */ 43 struct backref_node { 44 struct rb_node rb_node; 45 u64 bytenr; 46 /* objectid tree block owner */ 47 u64 owner; 48 /* list of upper level blocks reference this block */ 49 struct list_head upper; 50 /* list of child blocks in the cache */ 51 struct list_head lower; 52 /* NULL if this node is not tree root */ 53 struct btrfs_root *root; 54 /* extent buffer got by COW the block */ 55 struct extent_buffer *eb; 56 /* level of tree block */ 57 unsigned int level:8; 58 /* 1 if the block is root of old snapshot */ 59 unsigned int old_root:1; 60 /* 1 if no child blocks in the cache */ 61 unsigned int lowest:1; 62 /* is the extent buffer locked */ 63 unsigned int locked:1; 64 /* has the block been processed */ 65 unsigned int processed:1; 66 /* have backrefs of this block been checked */ 67 unsigned int checked:1; 68 }; 69 70 /* 71 * present a block pointer in the backref cache 72 */ 73 struct backref_edge { 74 struct list_head list[2]; 75 struct backref_node *node[2]; 76 u64 blockptr; 77 }; 78 79 #define LOWER 0 80 #define UPPER 1 81 82 struct backref_cache { 83 /* red black tree of all backref nodes in the cache */ 84 struct rb_root rb_root; 85 /* list of backref nodes with no child block in the cache */ 86 struct list_head pending[BTRFS_MAX_LEVEL]; 87 spinlock_t lock; 88 }; 89 90 /* 91 * map address of tree root to tree 92 */ 93 struct mapping_node { 94 struct rb_node rb_node; 95 u64 bytenr; 96 void *data; 97 }; 98 99 struct mapping_tree { 100 struct rb_root rb_root; 101 spinlock_t lock; 102 }; 103 104 /* 105 * present a tree block to process 106 */ 107 struct tree_block { 108 struct rb_node rb_node; 109 u64 bytenr; 110 struct btrfs_key key; 111 unsigned int level:8; 112 unsigned int key_ready:1; 113 }; 114 115 /* inode vector */ 116 #define INODEVEC_SIZE 16 117 118 struct inodevec { 119 struct list_head list; 120 struct inode *inode[INODEVEC_SIZE]; 121 int nr; 122 }; 123 124 struct reloc_control { 125 /* block group to relocate */ 126 struct btrfs_block_group_cache *block_group; 127 /* extent tree */ 128 struct btrfs_root *extent_root; 129 /* inode for moving data */ 130 struct inode *data_inode; 131 struct btrfs_workers workers; 132 /* tree blocks have been processed */ 133 struct extent_io_tree processed_blocks; 134 /* map start of tree root to corresponding reloc tree */ 135 struct mapping_tree reloc_root_tree; 136 /* list of reloc trees */ 137 struct list_head reloc_roots; 138 u64 search_start; 139 u64 extents_found; 140 u64 extents_skipped; 141 int stage; 142 int create_reloc_root; 143 unsigned int found_file_extent:1; 144 unsigned int found_old_snapshot:1; 145 }; 146 147 /* stages of data relocation */ 148 #define MOVE_DATA_EXTENTS 0 149 #define UPDATE_DATA_PTRS 1 150 151 /* 152 * merge reloc tree to corresponding fs tree in worker threads 153 */ 154 struct async_merge { 155 struct btrfs_work work; 156 struct reloc_control *rc; 157 struct btrfs_root *root; 158 struct completion *done; 159 atomic_t *num_pending; 160 }; 161 162 static void mapping_tree_init(struct mapping_tree *tree) 163 { 164 tree->rb_root.rb_node = NULL; 165 spin_lock_init(&tree->lock); 166 } 167 168 static void backref_cache_init(struct backref_cache *cache) 169 { 170 int i; 171 cache->rb_root.rb_node = NULL; 172 for (i = 0; i < BTRFS_MAX_LEVEL; i++) 173 INIT_LIST_HEAD(&cache->pending[i]); 174 spin_lock_init(&cache->lock); 175 } 176 177 static void backref_node_init(struct backref_node *node) 178 { 179 memset(node, 0, sizeof(*node)); 180 INIT_LIST_HEAD(&node->upper); 181 INIT_LIST_HEAD(&node->lower); 182 RB_CLEAR_NODE(&node->rb_node); 183 } 184 185 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, 186 struct rb_node *node) 187 { 188 struct rb_node **p = &root->rb_node; 189 struct rb_node *parent = NULL; 190 struct tree_entry *entry; 191 192 while (*p) { 193 parent = *p; 194 entry = rb_entry(parent, struct tree_entry, rb_node); 195 196 if (bytenr < entry->bytenr) 197 p = &(*p)->rb_left; 198 else if (bytenr > entry->bytenr) 199 p = &(*p)->rb_right; 200 else 201 return parent; 202 } 203 204 rb_link_node(node, parent, p); 205 rb_insert_color(node, root); 206 return NULL; 207 } 208 209 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) 210 { 211 struct rb_node *n = root->rb_node; 212 struct tree_entry *entry; 213 214 while (n) { 215 entry = rb_entry(n, struct tree_entry, rb_node); 216 217 if (bytenr < entry->bytenr) 218 n = n->rb_left; 219 else if (bytenr > entry->bytenr) 220 n = n->rb_right; 221 else 222 return n; 223 } 224 return NULL; 225 } 226 227 /* 228 * walk up backref nodes until reach node presents tree root 229 */ 230 static struct backref_node *walk_up_backref(struct backref_node *node, 231 struct backref_edge *edges[], 232 int *index) 233 { 234 struct backref_edge *edge; 235 int idx = *index; 236 237 while (!list_empty(&node->upper)) { 238 edge = list_entry(node->upper.next, 239 struct backref_edge, list[LOWER]); 240 edges[idx++] = edge; 241 node = edge->node[UPPER]; 242 } 243 *index = idx; 244 return node; 245 } 246 247 /* 248 * walk down backref nodes to find start of next reference path 249 */ 250 static struct backref_node *walk_down_backref(struct backref_edge *edges[], 251 int *index) 252 { 253 struct backref_edge *edge; 254 struct backref_node *lower; 255 int idx = *index; 256 257 while (idx > 0) { 258 edge = edges[idx - 1]; 259 lower = edge->node[LOWER]; 260 if (list_is_last(&edge->list[LOWER], &lower->upper)) { 261 idx--; 262 continue; 263 } 264 edge = list_entry(edge->list[LOWER].next, 265 struct backref_edge, list[LOWER]); 266 edges[idx - 1] = edge; 267 *index = idx; 268 return edge->node[UPPER]; 269 } 270 *index = 0; 271 return NULL; 272 } 273 274 static void drop_node_buffer(struct backref_node *node) 275 { 276 if (node->eb) { 277 if (node->locked) { 278 btrfs_tree_unlock(node->eb); 279 node->locked = 0; 280 } 281 free_extent_buffer(node->eb); 282 node->eb = NULL; 283 } 284 } 285 286 static void drop_backref_node(struct backref_cache *tree, 287 struct backref_node *node) 288 { 289 BUG_ON(!node->lowest); 290 BUG_ON(!list_empty(&node->upper)); 291 292 drop_node_buffer(node); 293 list_del(&node->lower); 294 295 rb_erase(&node->rb_node, &tree->rb_root); 296 kfree(node); 297 } 298 299 /* 300 * remove a backref node from the backref cache 301 */ 302 static void remove_backref_node(struct backref_cache *cache, 303 struct backref_node *node) 304 { 305 struct backref_node *upper; 306 struct backref_edge *edge; 307 308 if (!node) 309 return; 310 311 BUG_ON(!node->lowest); 312 while (!list_empty(&node->upper)) { 313 edge = list_entry(node->upper.next, struct backref_edge, 314 list[LOWER]); 315 upper = edge->node[UPPER]; 316 list_del(&edge->list[LOWER]); 317 list_del(&edge->list[UPPER]); 318 kfree(edge); 319 /* 320 * add the node to pending list if no other 321 * child block cached. 322 */ 323 if (list_empty(&upper->lower)) { 324 list_add_tail(&upper->lower, 325 &cache->pending[upper->level]); 326 upper->lowest = 1; 327 } 328 } 329 drop_backref_node(cache, node); 330 } 331 332 /* 333 * find reloc tree by address of tree root 334 */ 335 static struct btrfs_root *find_reloc_root(struct reloc_control *rc, 336 u64 bytenr) 337 { 338 struct rb_node *rb_node; 339 struct mapping_node *node; 340 struct btrfs_root *root = NULL; 341 342 spin_lock(&rc->reloc_root_tree.lock); 343 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr); 344 if (rb_node) { 345 node = rb_entry(rb_node, struct mapping_node, rb_node); 346 root = (struct btrfs_root *)node->data; 347 } 348 spin_unlock(&rc->reloc_root_tree.lock); 349 return root; 350 } 351 352 static int is_cowonly_root(u64 root_objectid) 353 { 354 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || 355 root_objectid == BTRFS_EXTENT_TREE_OBJECTID || 356 root_objectid == BTRFS_CHUNK_TREE_OBJECTID || 357 root_objectid == BTRFS_DEV_TREE_OBJECTID || 358 root_objectid == BTRFS_TREE_LOG_OBJECTID || 359 root_objectid == BTRFS_CSUM_TREE_OBJECTID) 360 return 1; 361 return 0; 362 } 363 364 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, 365 u64 root_objectid) 366 { 367 struct btrfs_key key; 368 369 key.objectid = root_objectid; 370 key.type = BTRFS_ROOT_ITEM_KEY; 371 if (is_cowonly_root(root_objectid)) 372 key.offset = 0; 373 else 374 key.offset = (u64)-1; 375 376 return btrfs_read_fs_root_no_name(fs_info, &key); 377 } 378 379 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 380 static noinline_for_stack 381 struct btrfs_root *find_tree_root(struct reloc_control *rc, 382 struct extent_buffer *leaf, 383 struct btrfs_extent_ref_v0 *ref0) 384 { 385 struct btrfs_root *root; 386 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0); 387 u64 generation = btrfs_ref_generation_v0(leaf, ref0); 388 389 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID); 390 391 root = read_fs_root(rc->extent_root->fs_info, root_objectid); 392 BUG_ON(IS_ERR(root)); 393 394 if (root->ref_cows && 395 generation != btrfs_root_generation(&root->root_item)) 396 return NULL; 397 398 return root; 399 } 400 #endif 401 402 static noinline_for_stack 403 int find_inline_backref(struct extent_buffer *leaf, int slot, 404 unsigned long *ptr, unsigned long *end) 405 { 406 struct btrfs_extent_item *ei; 407 struct btrfs_tree_block_info *bi; 408 u32 item_size; 409 410 item_size = btrfs_item_size_nr(leaf, slot); 411 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 412 if (item_size < sizeof(*ei)) { 413 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); 414 return 1; 415 } 416 #endif 417 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); 418 WARN_ON(!(btrfs_extent_flags(leaf, ei) & 419 BTRFS_EXTENT_FLAG_TREE_BLOCK)); 420 421 if (item_size <= sizeof(*ei) + sizeof(*bi)) { 422 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); 423 return 1; 424 } 425 426 bi = (struct btrfs_tree_block_info *)(ei + 1); 427 *ptr = (unsigned long)(bi + 1); 428 *end = (unsigned long)ei + item_size; 429 return 0; 430 } 431 432 /* 433 * build backref tree for a given tree block. root of the backref tree 434 * corresponds the tree block, leaves of the backref tree correspond 435 * roots of b-trees that reference the tree block. 436 * 437 * the basic idea of this function is check backrefs of a given block 438 * to find upper level blocks that refernece the block, and then check 439 * bakcrefs of these upper level blocks recursively. the recursion stop 440 * when tree root is reached or backrefs for the block is cached. 441 * 442 * NOTE: if we find backrefs for a block are cached, we know backrefs 443 * for all upper level blocks that directly/indirectly reference the 444 * block are also cached. 445 */ 446 static struct backref_node *build_backref_tree(struct reloc_control *rc, 447 struct backref_cache *cache, 448 struct btrfs_key *node_key, 449 int level, u64 bytenr) 450 { 451 struct btrfs_path *path1; 452 struct btrfs_path *path2; 453 struct extent_buffer *eb; 454 struct btrfs_root *root; 455 struct backref_node *cur; 456 struct backref_node *upper; 457 struct backref_node *lower; 458 struct backref_node *node = NULL; 459 struct backref_node *exist = NULL; 460 struct backref_edge *edge; 461 struct rb_node *rb_node; 462 struct btrfs_key key; 463 unsigned long end; 464 unsigned long ptr; 465 LIST_HEAD(list); 466 int ret; 467 int err = 0; 468 469 path1 = btrfs_alloc_path(); 470 path2 = btrfs_alloc_path(); 471 if (!path1 || !path2) { 472 err = -ENOMEM; 473 goto out; 474 } 475 476 node = kmalloc(sizeof(*node), GFP_NOFS); 477 if (!node) { 478 err = -ENOMEM; 479 goto out; 480 } 481 482 backref_node_init(node); 483 node->bytenr = bytenr; 484 node->owner = 0; 485 node->level = level; 486 node->lowest = 1; 487 cur = node; 488 again: 489 end = 0; 490 ptr = 0; 491 key.objectid = cur->bytenr; 492 key.type = BTRFS_EXTENT_ITEM_KEY; 493 key.offset = (u64)-1; 494 495 path1->search_commit_root = 1; 496 path1->skip_locking = 1; 497 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1, 498 0, 0); 499 if (ret < 0) { 500 err = ret; 501 goto out; 502 } 503 BUG_ON(!ret || !path1->slots[0]); 504 505 path1->slots[0]--; 506 507 WARN_ON(cur->checked); 508 if (!list_empty(&cur->upper)) { 509 /* 510 * the backref was added previously when processsing 511 * backref of type BTRFS_TREE_BLOCK_REF_KEY 512 */ 513 BUG_ON(!list_is_singular(&cur->upper)); 514 edge = list_entry(cur->upper.next, struct backref_edge, 515 list[LOWER]); 516 BUG_ON(!list_empty(&edge->list[UPPER])); 517 exist = edge->node[UPPER]; 518 /* 519 * add the upper level block to pending list if we need 520 * check its backrefs 521 */ 522 if (!exist->checked) 523 list_add_tail(&edge->list[UPPER], &list); 524 } else { 525 exist = NULL; 526 } 527 528 while (1) { 529 cond_resched(); 530 eb = path1->nodes[0]; 531 532 if (ptr >= end) { 533 if (path1->slots[0] >= btrfs_header_nritems(eb)) { 534 ret = btrfs_next_leaf(rc->extent_root, path1); 535 if (ret < 0) { 536 err = ret; 537 goto out; 538 } 539 if (ret > 0) 540 break; 541 eb = path1->nodes[0]; 542 } 543 544 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); 545 if (key.objectid != cur->bytenr) { 546 WARN_ON(exist); 547 break; 548 } 549 550 if (key.type == BTRFS_EXTENT_ITEM_KEY) { 551 ret = find_inline_backref(eb, path1->slots[0], 552 &ptr, &end); 553 if (ret) 554 goto next; 555 } 556 } 557 558 if (ptr < end) { 559 /* update key for inline back ref */ 560 struct btrfs_extent_inline_ref *iref; 561 iref = (struct btrfs_extent_inline_ref *)ptr; 562 key.type = btrfs_extent_inline_ref_type(eb, iref); 563 key.offset = btrfs_extent_inline_ref_offset(eb, iref); 564 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY && 565 key.type != BTRFS_SHARED_BLOCK_REF_KEY); 566 } 567 568 if (exist && 569 ((key.type == BTRFS_TREE_BLOCK_REF_KEY && 570 exist->owner == key.offset) || 571 (key.type == BTRFS_SHARED_BLOCK_REF_KEY && 572 exist->bytenr == key.offset))) { 573 exist = NULL; 574 goto next; 575 } 576 577 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 578 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY || 579 key.type == BTRFS_EXTENT_REF_V0_KEY) { 580 if (key.objectid == key.offset && 581 key.type == BTRFS_EXTENT_REF_V0_KEY) { 582 struct btrfs_extent_ref_v0 *ref0; 583 ref0 = btrfs_item_ptr(eb, path1->slots[0], 584 struct btrfs_extent_ref_v0); 585 root = find_tree_root(rc, eb, ref0); 586 if (root) 587 cur->root = root; 588 else 589 cur->old_root = 1; 590 break; 591 } 592 #else 593 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); 594 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { 595 #endif 596 if (key.objectid == key.offset) { 597 /* 598 * only root blocks of reloc trees use 599 * backref of this type. 600 */ 601 root = find_reloc_root(rc, cur->bytenr); 602 BUG_ON(!root); 603 cur->root = root; 604 break; 605 } 606 607 edge = kzalloc(sizeof(*edge), GFP_NOFS); 608 if (!edge) { 609 err = -ENOMEM; 610 goto out; 611 } 612 rb_node = tree_search(&cache->rb_root, key.offset); 613 if (!rb_node) { 614 upper = kmalloc(sizeof(*upper), GFP_NOFS); 615 if (!upper) { 616 kfree(edge); 617 err = -ENOMEM; 618 goto out; 619 } 620 backref_node_init(upper); 621 upper->bytenr = key.offset; 622 upper->owner = 0; 623 upper->level = cur->level + 1; 624 /* 625 * backrefs for the upper level block isn't 626 * cached, add the block to pending list 627 */ 628 list_add_tail(&edge->list[UPPER], &list); 629 } else { 630 upper = rb_entry(rb_node, struct backref_node, 631 rb_node); 632 INIT_LIST_HEAD(&edge->list[UPPER]); 633 } 634 list_add(&edge->list[LOWER], &cur->upper); 635 edge->node[UPPER] = upper; 636 edge->node[LOWER] = cur; 637 638 goto next; 639 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { 640 goto next; 641 } 642 643 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */ 644 root = read_fs_root(rc->extent_root->fs_info, key.offset); 645 if (IS_ERR(root)) { 646 err = PTR_ERR(root); 647 goto out; 648 } 649 650 if (btrfs_root_level(&root->root_item) == cur->level) { 651 /* tree root */ 652 BUG_ON(btrfs_root_bytenr(&root->root_item) != 653 cur->bytenr); 654 cur->root = root; 655 break; 656 } 657 658 level = cur->level + 1; 659 660 /* 661 * searching the tree to find upper level blocks 662 * reference the block. 663 */ 664 path2->search_commit_root = 1; 665 path2->skip_locking = 1; 666 path2->lowest_level = level; 667 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0); 668 path2->lowest_level = 0; 669 if (ret < 0) { 670 err = ret; 671 goto out; 672 } 673 if (ret > 0 && path2->slots[level] > 0) 674 path2->slots[level]--; 675 676 eb = path2->nodes[level]; 677 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) != 678 cur->bytenr); 679 680 lower = cur; 681 for (; level < BTRFS_MAX_LEVEL; level++) { 682 if (!path2->nodes[level]) { 683 BUG_ON(btrfs_root_bytenr(&root->root_item) != 684 lower->bytenr); 685 lower->root = root; 686 break; 687 } 688 689 edge = kzalloc(sizeof(*edge), GFP_NOFS); 690 if (!edge) { 691 err = -ENOMEM; 692 goto out; 693 } 694 695 eb = path2->nodes[level]; 696 rb_node = tree_search(&cache->rb_root, eb->start); 697 if (!rb_node) { 698 upper = kmalloc(sizeof(*upper), GFP_NOFS); 699 if (!upper) { 700 kfree(edge); 701 err = -ENOMEM; 702 goto out; 703 } 704 backref_node_init(upper); 705 upper->bytenr = eb->start; 706 upper->owner = btrfs_header_owner(eb); 707 upper->level = lower->level + 1; 708 709 /* 710 * if we know the block isn't shared 711 * we can void checking its backrefs. 712 */ 713 if (btrfs_block_can_be_shared(root, eb)) 714 upper->checked = 0; 715 else 716 upper->checked = 1; 717 718 /* 719 * add the block to pending list if we 720 * need check its backrefs. only block 721 * at 'cur->level + 1' is added to the 722 * tail of pending list. this guarantees 723 * we check backrefs from lower level 724 * blocks to upper level blocks. 725 */ 726 if (!upper->checked && 727 level == cur->level + 1) { 728 list_add_tail(&edge->list[UPPER], 729 &list); 730 } else 731 INIT_LIST_HEAD(&edge->list[UPPER]); 732 } else { 733 upper = rb_entry(rb_node, struct backref_node, 734 rb_node); 735 BUG_ON(!upper->checked); 736 INIT_LIST_HEAD(&edge->list[UPPER]); 737 } 738 list_add_tail(&edge->list[LOWER], &lower->upper); 739 edge->node[UPPER] = upper; 740 edge->node[LOWER] = lower; 741 742 if (rb_node) 743 break; 744 lower = upper; 745 upper = NULL; 746 } 747 btrfs_release_path(root, path2); 748 next: 749 if (ptr < end) { 750 ptr += btrfs_extent_inline_ref_size(key.type); 751 if (ptr >= end) { 752 WARN_ON(ptr > end); 753 ptr = 0; 754 end = 0; 755 } 756 } 757 if (ptr >= end) 758 path1->slots[0]++; 759 } 760 btrfs_release_path(rc->extent_root, path1); 761 762 cur->checked = 1; 763 WARN_ON(exist); 764 765 /* the pending list isn't empty, take the first block to process */ 766 if (!list_empty(&list)) { 767 edge = list_entry(list.next, struct backref_edge, list[UPPER]); 768 list_del_init(&edge->list[UPPER]); 769 cur = edge->node[UPPER]; 770 goto again; 771 } 772 773 /* 774 * everything goes well, connect backref nodes and insert backref nodes 775 * into the cache. 776 */ 777 BUG_ON(!node->checked); 778 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); 779 BUG_ON(rb_node); 780 781 list_for_each_entry(edge, &node->upper, list[LOWER]) 782 list_add_tail(&edge->list[UPPER], &list); 783 784 while (!list_empty(&list)) { 785 edge = list_entry(list.next, struct backref_edge, list[UPPER]); 786 list_del_init(&edge->list[UPPER]); 787 upper = edge->node[UPPER]; 788 789 if (!RB_EMPTY_NODE(&upper->rb_node)) { 790 if (upper->lowest) { 791 list_del_init(&upper->lower); 792 upper->lowest = 0; 793 } 794 795 list_add_tail(&edge->list[UPPER], &upper->lower); 796 continue; 797 } 798 799 BUG_ON(!upper->checked); 800 rb_node = tree_insert(&cache->rb_root, upper->bytenr, 801 &upper->rb_node); 802 BUG_ON(rb_node); 803 804 list_add_tail(&edge->list[UPPER], &upper->lower); 805 806 list_for_each_entry(edge, &upper->upper, list[LOWER]) 807 list_add_tail(&edge->list[UPPER], &list); 808 } 809 out: 810 btrfs_free_path(path1); 811 btrfs_free_path(path2); 812 if (err) { 813 INIT_LIST_HEAD(&list); 814 upper = node; 815 while (upper) { 816 if (RB_EMPTY_NODE(&upper->rb_node)) { 817 list_splice_tail(&upper->upper, &list); 818 kfree(upper); 819 } 820 821 if (list_empty(&list)) 822 break; 823 824 edge = list_entry(list.next, struct backref_edge, 825 list[LOWER]); 826 upper = edge->node[UPPER]; 827 kfree(edge); 828 } 829 return ERR_PTR(err); 830 } 831 return node; 832 } 833 834 /* 835 * helper to add 'address of tree root -> reloc tree' mapping 836 */ 837 static int __add_reloc_root(struct btrfs_root *root) 838 { 839 struct rb_node *rb_node; 840 struct mapping_node *node; 841 struct reloc_control *rc = root->fs_info->reloc_ctl; 842 843 node = kmalloc(sizeof(*node), GFP_NOFS); 844 BUG_ON(!node); 845 846 node->bytenr = root->node->start; 847 node->data = root; 848 849 spin_lock(&rc->reloc_root_tree.lock); 850 rb_node = tree_insert(&rc->reloc_root_tree.rb_root, 851 node->bytenr, &node->rb_node); 852 spin_unlock(&rc->reloc_root_tree.lock); 853 BUG_ON(rb_node); 854 855 list_add_tail(&root->root_list, &rc->reloc_roots); 856 return 0; 857 } 858 859 /* 860 * helper to update/delete the 'address of tree root -> reloc tree' 861 * mapping 862 */ 863 static int __update_reloc_root(struct btrfs_root *root, int del) 864 { 865 struct rb_node *rb_node; 866 struct mapping_node *node = NULL; 867 struct reloc_control *rc = root->fs_info->reloc_ctl; 868 869 spin_lock(&rc->reloc_root_tree.lock); 870 rb_node = tree_search(&rc->reloc_root_tree.rb_root, 871 root->commit_root->start); 872 if (rb_node) { 873 node = rb_entry(rb_node, struct mapping_node, rb_node); 874 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); 875 } 876 spin_unlock(&rc->reloc_root_tree.lock); 877 878 BUG_ON((struct btrfs_root *)node->data != root); 879 880 if (!del) { 881 spin_lock(&rc->reloc_root_tree.lock); 882 node->bytenr = root->node->start; 883 rb_node = tree_insert(&rc->reloc_root_tree.rb_root, 884 node->bytenr, &node->rb_node); 885 spin_unlock(&rc->reloc_root_tree.lock); 886 BUG_ON(rb_node); 887 } else { 888 list_del_init(&root->root_list); 889 kfree(node); 890 } 891 return 0; 892 } 893 894 /* 895 * create reloc tree for a given fs tree. reloc tree is just a 896 * snapshot of the fs tree with special root objectid. 897 */ 898 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, 899 struct btrfs_root *root) 900 { 901 struct btrfs_root *reloc_root; 902 struct extent_buffer *eb; 903 struct btrfs_root_item *root_item; 904 struct btrfs_key root_key; 905 int ret; 906 907 if (root->reloc_root) { 908 reloc_root = root->reloc_root; 909 reloc_root->last_trans = trans->transid; 910 return 0; 911 } 912 913 if (!root->fs_info->reloc_ctl || 914 !root->fs_info->reloc_ctl->create_reloc_root || 915 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 916 return 0; 917 918 root_item = kmalloc(sizeof(*root_item), GFP_NOFS); 919 BUG_ON(!root_item); 920 921 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; 922 root_key.type = BTRFS_ROOT_ITEM_KEY; 923 root_key.offset = root->root_key.objectid; 924 925 ret = btrfs_copy_root(trans, root, root->commit_root, &eb, 926 BTRFS_TREE_RELOC_OBJECTID); 927 BUG_ON(ret); 928 929 btrfs_set_root_last_snapshot(&root->root_item, trans->transid - 1); 930 memcpy(root_item, &root->root_item, sizeof(*root_item)); 931 btrfs_set_root_refs(root_item, 1); 932 btrfs_set_root_bytenr(root_item, eb->start); 933 btrfs_set_root_level(root_item, btrfs_header_level(eb)); 934 btrfs_set_root_generation(root_item, trans->transid); 935 memset(&root_item->drop_progress, 0, sizeof(struct btrfs_disk_key)); 936 root_item->drop_level = 0; 937 938 btrfs_tree_unlock(eb); 939 free_extent_buffer(eb); 940 941 ret = btrfs_insert_root(trans, root->fs_info->tree_root, 942 &root_key, root_item); 943 BUG_ON(ret); 944 kfree(root_item); 945 946 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, 947 &root_key); 948 BUG_ON(IS_ERR(reloc_root)); 949 reloc_root->last_trans = trans->transid; 950 951 __add_reloc_root(reloc_root); 952 root->reloc_root = reloc_root; 953 return 0; 954 } 955 956 /* 957 * update root item of reloc tree 958 */ 959 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, 960 struct btrfs_root *root) 961 { 962 struct btrfs_root *reloc_root; 963 struct btrfs_root_item *root_item; 964 int del = 0; 965 int ret; 966 967 if (!root->reloc_root) 968 return 0; 969 970 reloc_root = root->reloc_root; 971 root_item = &reloc_root->root_item; 972 973 if (btrfs_root_refs(root_item) == 0) { 974 root->reloc_root = NULL; 975 del = 1; 976 } 977 978 __update_reloc_root(reloc_root, del); 979 980 if (reloc_root->commit_root != reloc_root->node) { 981 btrfs_set_root_node(root_item, reloc_root->node); 982 free_extent_buffer(reloc_root->commit_root); 983 reloc_root->commit_root = btrfs_root_node(reloc_root); 984 } 985 986 ret = btrfs_update_root(trans, root->fs_info->tree_root, 987 &reloc_root->root_key, root_item); 988 BUG_ON(ret); 989 return 0; 990 } 991 992 /* 993 * helper to find first cached inode with inode number >= objectid 994 * in a subvolume 995 */ 996 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid) 997 { 998 struct rb_node *node; 999 struct rb_node *prev; 1000 struct btrfs_inode *entry; 1001 struct inode *inode; 1002 1003 spin_lock(&root->inode_lock); 1004 again: 1005 node = root->inode_tree.rb_node; 1006 prev = NULL; 1007 while (node) { 1008 prev = node; 1009 entry = rb_entry(node, struct btrfs_inode, rb_node); 1010 1011 if (objectid < entry->vfs_inode.i_ino) 1012 node = node->rb_left; 1013 else if (objectid > entry->vfs_inode.i_ino) 1014 node = node->rb_right; 1015 else 1016 break; 1017 } 1018 if (!node) { 1019 while (prev) { 1020 entry = rb_entry(prev, struct btrfs_inode, rb_node); 1021 if (objectid <= entry->vfs_inode.i_ino) { 1022 node = prev; 1023 break; 1024 } 1025 prev = rb_next(prev); 1026 } 1027 } 1028 while (node) { 1029 entry = rb_entry(node, struct btrfs_inode, rb_node); 1030 inode = igrab(&entry->vfs_inode); 1031 if (inode) { 1032 spin_unlock(&root->inode_lock); 1033 return inode; 1034 } 1035 1036 objectid = entry->vfs_inode.i_ino + 1; 1037 if (cond_resched_lock(&root->inode_lock)) 1038 goto again; 1039 1040 node = rb_next(node); 1041 } 1042 spin_unlock(&root->inode_lock); 1043 return NULL; 1044 } 1045 1046 static int in_block_group(u64 bytenr, 1047 struct btrfs_block_group_cache *block_group) 1048 { 1049 if (bytenr >= block_group->key.objectid && 1050 bytenr < block_group->key.objectid + block_group->key.offset) 1051 return 1; 1052 return 0; 1053 } 1054 1055 /* 1056 * get new location of data 1057 */ 1058 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, 1059 u64 bytenr, u64 num_bytes) 1060 { 1061 struct btrfs_root *root = BTRFS_I(reloc_inode)->root; 1062 struct btrfs_path *path; 1063 struct btrfs_file_extent_item *fi; 1064 struct extent_buffer *leaf; 1065 int ret; 1066 1067 path = btrfs_alloc_path(); 1068 if (!path) 1069 return -ENOMEM; 1070 1071 bytenr -= BTRFS_I(reloc_inode)->index_cnt; 1072 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino, 1073 bytenr, 0); 1074 if (ret < 0) 1075 goto out; 1076 if (ret > 0) { 1077 ret = -ENOENT; 1078 goto out; 1079 } 1080 1081 leaf = path->nodes[0]; 1082 fi = btrfs_item_ptr(leaf, path->slots[0], 1083 struct btrfs_file_extent_item); 1084 1085 BUG_ON(btrfs_file_extent_offset(leaf, fi) || 1086 btrfs_file_extent_compression(leaf, fi) || 1087 btrfs_file_extent_encryption(leaf, fi) || 1088 btrfs_file_extent_other_encoding(leaf, fi)); 1089 1090 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) { 1091 ret = 1; 1092 goto out; 1093 } 1094 1095 if (new_bytenr) 1096 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1097 ret = 0; 1098 out: 1099 btrfs_free_path(path); 1100 return ret; 1101 } 1102 1103 /* 1104 * update file extent items in the tree leaf to point to 1105 * the new locations. 1106 */ 1107 static int replace_file_extents(struct btrfs_trans_handle *trans, 1108 struct reloc_control *rc, 1109 struct btrfs_root *root, 1110 struct extent_buffer *leaf, 1111 struct list_head *inode_list) 1112 { 1113 struct btrfs_key key; 1114 struct btrfs_file_extent_item *fi; 1115 struct inode *inode = NULL; 1116 struct inodevec *ivec = NULL; 1117 u64 parent; 1118 u64 bytenr; 1119 u64 new_bytenr; 1120 u64 num_bytes; 1121 u64 end; 1122 u32 nritems; 1123 u32 i; 1124 int ret; 1125 int first = 1; 1126 int dirty = 0; 1127 1128 if (rc->stage != UPDATE_DATA_PTRS) 1129 return 0; 1130 1131 /* reloc trees always use full backref */ 1132 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 1133 parent = leaf->start; 1134 else 1135 parent = 0; 1136 1137 nritems = btrfs_header_nritems(leaf); 1138 for (i = 0; i < nritems; i++) { 1139 cond_resched(); 1140 btrfs_item_key_to_cpu(leaf, &key, i); 1141 if (key.type != BTRFS_EXTENT_DATA_KEY) 1142 continue; 1143 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); 1144 if (btrfs_file_extent_type(leaf, fi) == 1145 BTRFS_FILE_EXTENT_INLINE) 1146 continue; 1147 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1148 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); 1149 if (bytenr == 0) 1150 continue; 1151 if (!in_block_group(bytenr, rc->block_group)) 1152 continue; 1153 1154 /* 1155 * if we are modifying block in fs tree, wait for readpage 1156 * to complete and drop the extent cache 1157 */ 1158 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { 1159 if (!ivec || ivec->nr == INODEVEC_SIZE) { 1160 ivec = kmalloc(sizeof(*ivec), GFP_NOFS); 1161 BUG_ON(!ivec); 1162 ivec->nr = 0; 1163 list_add_tail(&ivec->list, inode_list); 1164 } 1165 if (first) { 1166 inode = find_next_inode(root, key.objectid); 1167 if (inode) 1168 ivec->inode[ivec->nr++] = inode; 1169 first = 0; 1170 } else if (inode && inode->i_ino < key.objectid) { 1171 inode = find_next_inode(root, key.objectid); 1172 if (inode) 1173 ivec->inode[ivec->nr++] = inode; 1174 } 1175 if (inode && inode->i_ino == key.objectid) { 1176 end = key.offset + 1177 btrfs_file_extent_num_bytes(leaf, fi); 1178 WARN_ON(!IS_ALIGNED(key.offset, 1179 root->sectorsize)); 1180 WARN_ON(!IS_ALIGNED(end, root->sectorsize)); 1181 end--; 1182 ret = try_lock_extent(&BTRFS_I(inode)->io_tree, 1183 key.offset, end, 1184 GFP_NOFS); 1185 if (!ret) 1186 continue; 1187 1188 btrfs_drop_extent_cache(inode, key.offset, end, 1189 1); 1190 unlock_extent(&BTRFS_I(inode)->io_tree, 1191 key.offset, end, GFP_NOFS); 1192 } 1193 } 1194 1195 ret = get_new_location(rc->data_inode, &new_bytenr, 1196 bytenr, num_bytes); 1197 if (ret > 0) 1198 continue; 1199 BUG_ON(ret < 0); 1200 1201 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr); 1202 dirty = 1; 1203 1204 key.offset -= btrfs_file_extent_offset(leaf, fi); 1205 ret = btrfs_inc_extent_ref(trans, root, new_bytenr, 1206 num_bytes, parent, 1207 btrfs_header_owner(leaf), 1208 key.objectid, key.offset); 1209 BUG_ON(ret); 1210 1211 ret = btrfs_free_extent(trans, root, bytenr, num_bytes, 1212 parent, btrfs_header_owner(leaf), 1213 key.objectid, key.offset); 1214 BUG_ON(ret); 1215 } 1216 if (dirty) 1217 btrfs_mark_buffer_dirty(leaf); 1218 return 0; 1219 } 1220 1221 static noinline_for_stack 1222 int memcmp_node_keys(struct extent_buffer *eb, int slot, 1223 struct btrfs_path *path, int level) 1224 { 1225 struct btrfs_disk_key key1; 1226 struct btrfs_disk_key key2; 1227 btrfs_node_key(eb, &key1, slot); 1228 btrfs_node_key(path->nodes[level], &key2, path->slots[level]); 1229 return memcmp(&key1, &key2, sizeof(key1)); 1230 } 1231 1232 /* 1233 * try to replace tree blocks in fs tree with the new blocks 1234 * in reloc tree. tree blocks haven't been modified since the 1235 * reloc tree was create can be replaced. 1236 * 1237 * if a block was replaced, level of the block + 1 is returned. 1238 * if no block got replaced, 0 is returned. if there are other 1239 * errors, a negative error number is returned. 1240 */ 1241 static int replace_path(struct btrfs_trans_handle *trans, 1242 struct btrfs_root *dest, struct btrfs_root *src, 1243 struct btrfs_path *path, struct btrfs_key *next_key, 1244 struct extent_buffer **leaf, 1245 int lowest_level, int max_level) 1246 { 1247 struct extent_buffer *eb; 1248 struct extent_buffer *parent; 1249 struct btrfs_key key; 1250 u64 old_bytenr; 1251 u64 new_bytenr; 1252 u64 old_ptr_gen; 1253 u64 new_ptr_gen; 1254 u64 last_snapshot; 1255 u32 blocksize; 1256 int level; 1257 int ret; 1258 int slot; 1259 1260 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); 1261 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID); 1262 BUG_ON(lowest_level > 1 && leaf); 1263 1264 last_snapshot = btrfs_root_last_snapshot(&src->root_item); 1265 1266 slot = path->slots[lowest_level]; 1267 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot); 1268 1269 eb = btrfs_lock_root_node(dest); 1270 btrfs_set_lock_blocking(eb); 1271 level = btrfs_header_level(eb); 1272 1273 if (level < lowest_level) { 1274 btrfs_tree_unlock(eb); 1275 free_extent_buffer(eb); 1276 return 0; 1277 } 1278 1279 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb); 1280 BUG_ON(ret); 1281 btrfs_set_lock_blocking(eb); 1282 1283 if (next_key) { 1284 next_key->objectid = (u64)-1; 1285 next_key->type = (u8)-1; 1286 next_key->offset = (u64)-1; 1287 } 1288 1289 parent = eb; 1290 while (1) { 1291 level = btrfs_header_level(parent); 1292 BUG_ON(level < lowest_level); 1293 1294 ret = btrfs_bin_search(parent, &key, level, &slot); 1295 if (ret && slot > 0) 1296 slot--; 1297 1298 if (next_key && slot + 1 < btrfs_header_nritems(parent)) 1299 btrfs_node_key_to_cpu(parent, next_key, slot + 1); 1300 1301 old_bytenr = btrfs_node_blockptr(parent, slot); 1302 blocksize = btrfs_level_size(dest, level - 1); 1303 old_ptr_gen = btrfs_node_ptr_generation(parent, slot); 1304 1305 if (level <= max_level) { 1306 eb = path->nodes[level]; 1307 new_bytenr = btrfs_node_blockptr(eb, 1308 path->slots[level]); 1309 new_ptr_gen = btrfs_node_ptr_generation(eb, 1310 path->slots[level]); 1311 } else { 1312 new_bytenr = 0; 1313 new_ptr_gen = 0; 1314 } 1315 1316 if (new_bytenr > 0 && new_bytenr == old_bytenr) { 1317 WARN_ON(1); 1318 ret = level; 1319 break; 1320 } 1321 1322 if (new_bytenr == 0 || old_ptr_gen > last_snapshot || 1323 memcmp_node_keys(parent, slot, path, level)) { 1324 if (level <= lowest_level && !leaf) { 1325 ret = 0; 1326 break; 1327 } 1328 1329 eb = read_tree_block(dest, old_bytenr, blocksize, 1330 old_ptr_gen); 1331 btrfs_tree_lock(eb); 1332 ret = btrfs_cow_block(trans, dest, eb, parent, 1333 slot, &eb); 1334 BUG_ON(ret); 1335 btrfs_set_lock_blocking(eb); 1336 1337 if (level <= lowest_level) { 1338 *leaf = eb; 1339 ret = 0; 1340 break; 1341 } 1342 1343 btrfs_tree_unlock(parent); 1344 free_extent_buffer(parent); 1345 1346 parent = eb; 1347 continue; 1348 } 1349 1350 btrfs_node_key_to_cpu(path->nodes[level], &key, 1351 path->slots[level]); 1352 btrfs_release_path(src, path); 1353 1354 path->lowest_level = level; 1355 ret = btrfs_search_slot(trans, src, &key, path, 0, 1); 1356 path->lowest_level = 0; 1357 BUG_ON(ret); 1358 1359 /* 1360 * swap blocks in fs tree and reloc tree. 1361 */ 1362 btrfs_set_node_blockptr(parent, slot, new_bytenr); 1363 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen); 1364 btrfs_mark_buffer_dirty(parent); 1365 1366 btrfs_set_node_blockptr(path->nodes[level], 1367 path->slots[level], old_bytenr); 1368 btrfs_set_node_ptr_generation(path->nodes[level], 1369 path->slots[level], old_ptr_gen); 1370 btrfs_mark_buffer_dirty(path->nodes[level]); 1371 1372 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize, 1373 path->nodes[level]->start, 1374 src->root_key.objectid, level - 1, 0); 1375 BUG_ON(ret); 1376 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize, 1377 0, dest->root_key.objectid, level - 1, 1378 0); 1379 BUG_ON(ret); 1380 1381 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize, 1382 path->nodes[level]->start, 1383 src->root_key.objectid, level - 1, 0); 1384 BUG_ON(ret); 1385 1386 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize, 1387 0, dest->root_key.objectid, level - 1, 1388 0); 1389 BUG_ON(ret); 1390 1391 btrfs_unlock_up_safe(path, 0); 1392 1393 ret = level; 1394 break; 1395 } 1396 btrfs_tree_unlock(parent); 1397 free_extent_buffer(parent); 1398 return ret; 1399 } 1400 1401 /* 1402 * helper to find next relocated block in reloc tree 1403 */ 1404 static noinline_for_stack 1405 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, 1406 int *level) 1407 { 1408 struct extent_buffer *eb; 1409 int i; 1410 u64 last_snapshot; 1411 u32 nritems; 1412 1413 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 1414 1415 for (i = 0; i < *level; i++) { 1416 free_extent_buffer(path->nodes[i]); 1417 path->nodes[i] = NULL; 1418 } 1419 1420 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) { 1421 eb = path->nodes[i]; 1422 nritems = btrfs_header_nritems(eb); 1423 while (path->slots[i] + 1 < nritems) { 1424 path->slots[i]++; 1425 if (btrfs_node_ptr_generation(eb, path->slots[i]) <= 1426 last_snapshot) 1427 continue; 1428 1429 *level = i; 1430 return 0; 1431 } 1432 free_extent_buffer(path->nodes[i]); 1433 path->nodes[i] = NULL; 1434 } 1435 return 1; 1436 } 1437 1438 /* 1439 * walk down reloc tree to find relocated block of lowest level 1440 */ 1441 static noinline_for_stack 1442 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, 1443 int *level) 1444 { 1445 struct extent_buffer *eb = NULL; 1446 int i; 1447 u64 bytenr; 1448 u64 ptr_gen = 0; 1449 u64 last_snapshot; 1450 u32 blocksize; 1451 u32 nritems; 1452 1453 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 1454 1455 for (i = *level; i > 0; i--) { 1456 eb = path->nodes[i]; 1457 nritems = btrfs_header_nritems(eb); 1458 while (path->slots[i] < nritems) { 1459 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]); 1460 if (ptr_gen > last_snapshot) 1461 break; 1462 path->slots[i]++; 1463 } 1464 if (path->slots[i] >= nritems) { 1465 if (i == *level) 1466 break; 1467 *level = i + 1; 1468 return 0; 1469 } 1470 if (i == 1) { 1471 *level = i; 1472 return 0; 1473 } 1474 1475 bytenr = btrfs_node_blockptr(eb, path->slots[i]); 1476 blocksize = btrfs_level_size(root, i - 1); 1477 eb = read_tree_block(root, bytenr, blocksize, ptr_gen); 1478 BUG_ON(btrfs_header_level(eb) != i - 1); 1479 path->nodes[i - 1] = eb; 1480 path->slots[i - 1] = 0; 1481 } 1482 return 1; 1483 } 1484 1485 /* 1486 * invalidate extent cache for file extents whose key in range of 1487 * [min_key, max_key) 1488 */ 1489 static int invalidate_extent_cache(struct btrfs_root *root, 1490 struct btrfs_key *min_key, 1491 struct btrfs_key *max_key) 1492 { 1493 struct inode *inode = NULL; 1494 u64 objectid; 1495 u64 start, end; 1496 1497 objectid = min_key->objectid; 1498 while (1) { 1499 cond_resched(); 1500 iput(inode); 1501 1502 if (objectid > max_key->objectid) 1503 break; 1504 1505 inode = find_next_inode(root, objectid); 1506 if (!inode) 1507 break; 1508 1509 if (inode->i_ino > max_key->objectid) { 1510 iput(inode); 1511 break; 1512 } 1513 1514 objectid = inode->i_ino + 1; 1515 if (!S_ISREG(inode->i_mode)) 1516 continue; 1517 1518 if (unlikely(min_key->objectid == inode->i_ino)) { 1519 if (min_key->type > BTRFS_EXTENT_DATA_KEY) 1520 continue; 1521 if (min_key->type < BTRFS_EXTENT_DATA_KEY) 1522 start = 0; 1523 else { 1524 start = min_key->offset; 1525 WARN_ON(!IS_ALIGNED(start, root->sectorsize)); 1526 } 1527 } else { 1528 start = 0; 1529 } 1530 1531 if (unlikely(max_key->objectid == inode->i_ino)) { 1532 if (max_key->type < BTRFS_EXTENT_DATA_KEY) 1533 continue; 1534 if (max_key->type > BTRFS_EXTENT_DATA_KEY) { 1535 end = (u64)-1; 1536 } else { 1537 if (max_key->offset == 0) 1538 continue; 1539 end = max_key->offset; 1540 WARN_ON(!IS_ALIGNED(end, root->sectorsize)); 1541 end--; 1542 } 1543 } else { 1544 end = (u64)-1; 1545 } 1546 1547 /* the lock_extent waits for readpage to complete */ 1548 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 1549 btrfs_drop_extent_cache(inode, start, end, 1); 1550 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 1551 } 1552 return 0; 1553 } 1554 1555 static int find_next_key(struct btrfs_path *path, int level, 1556 struct btrfs_key *key) 1557 1558 { 1559 while (level < BTRFS_MAX_LEVEL) { 1560 if (!path->nodes[level]) 1561 break; 1562 if (path->slots[level] + 1 < 1563 btrfs_header_nritems(path->nodes[level])) { 1564 btrfs_node_key_to_cpu(path->nodes[level], key, 1565 path->slots[level] + 1); 1566 return 0; 1567 } 1568 level++; 1569 } 1570 return 1; 1571 } 1572 1573 /* 1574 * merge the relocated tree blocks in reloc tree with corresponding 1575 * fs tree. 1576 */ 1577 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, 1578 struct btrfs_root *root) 1579 { 1580 LIST_HEAD(inode_list); 1581 struct btrfs_key key; 1582 struct btrfs_key next_key; 1583 struct btrfs_trans_handle *trans; 1584 struct btrfs_root *reloc_root; 1585 struct btrfs_root_item *root_item; 1586 struct btrfs_path *path; 1587 struct extent_buffer *leaf = NULL; 1588 unsigned long nr; 1589 int level; 1590 int max_level; 1591 int replaced = 0; 1592 int ret; 1593 int err = 0; 1594 1595 path = btrfs_alloc_path(); 1596 if (!path) 1597 return -ENOMEM; 1598 1599 reloc_root = root->reloc_root; 1600 root_item = &reloc_root->root_item; 1601 1602 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { 1603 level = btrfs_root_level(root_item); 1604 extent_buffer_get(reloc_root->node); 1605 path->nodes[level] = reloc_root->node; 1606 path->slots[level] = 0; 1607 } else { 1608 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); 1609 1610 level = root_item->drop_level; 1611 BUG_ON(level == 0); 1612 path->lowest_level = level; 1613 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0); 1614 path->lowest_level = 0; 1615 if (ret < 0) { 1616 btrfs_free_path(path); 1617 return ret; 1618 } 1619 1620 btrfs_node_key_to_cpu(path->nodes[level], &next_key, 1621 path->slots[level]); 1622 WARN_ON(memcmp(&key, &next_key, sizeof(key))); 1623 1624 btrfs_unlock_up_safe(path, 0); 1625 } 1626 1627 if (level == 0 && rc->stage == UPDATE_DATA_PTRS) { 1628 trans = btrfs_start_transaction(root, 1); 1629 1630 leaf = path->nodes[0]; 1631 btrfs_item_key_to_cpu(leaf, &key, 0); 1632 btrfs_release_path(reloc_root, path); 1633 1634 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 1635 if (ret < 0) { 1636 err = ret; 1637 goto out; 1638 } 1639 1640 leaf = path->nodes[0]; 1641 btrfs_unlock_up_safe(path, 1); 1642 ret = replace_file_extents(trans, rc, root, leaf, 1643 &inode_list); 1644 if (ret < 0) 1645 err = ret; 1646 goto out; 1647 } 1648 1649 memset(&next_key, 0, sizeof(next_key)); 1650 1651 while (1) { 1652 leaf = NULL; 1653 replaced = 0; 1654 trans = btrfs_start_transaction(root, 1); 1655 max_level = level; 1656 1657 ret = walk_down_reloc_tree(reloc_root, path, &level); 1658 if (ret < 0) { 1659 err = ret; 1660 goto out; 1661 } 1662 if (ret > 0) 1663 break; 1664 1665 if (!find_next_key(path, level, &key) && 1666 btrfs_comp_cpu_keys(&next_key, &key) >= 0) { 1667 ret = 0; 1668 } else if (level == 1 && rc->stage == UPDATE_DATA_PTRS) { 1669 ret = replace_path(trans, root, reloc_root, 1670 path, &next_key, &leaf, 1671 level, max_level); 1672 } else { 1673 ret = replace_path(trans, root, reloc_root, 1674 path, &next_key, NULL, 1675 level, max_level); 1676 } 1677 if (ret < 0) { 1678 err = ret; 1679 goto out; 1680 } 1681 1682 if (ret > 0) { 1683 level = ret; 1684 btrfs_node_key_to_cpu(path->nodes[level], &key, 1685 path->slots[level]); 1686 replaced = 1; 1687 } else if (leaf) { 1688 /* 1689 * no block got replaced, try replacing file extents 1690 */ 1691 btrfs_item_key_to_cpu(leaf, &key, 0); 1692 ret = replace_file_extents(trans, rc, root, leaf, 1693 &inode_list); 1694 btrfs_tree_unlock(leaf); 1695 free_extent_buffer(leaf); 1696 BUG_ON(ret < 0); 1697 } 1698 1699 ret = walk_up_reloc_tree(reloc_root, path, &level); 1700 if (ret > 0) 1701 break; 1702 1703 BUG_ON(level == 0); 1704 /* 1705 * save the merging progress in the drop_progress. 1706 * this is OK since root refs == 1 in this case. 1707 */ 1708 btrfs_node_key(path->nodes[level], &root_item->drop_progress, 1709 path->slots[level]); 1710 root_item->drop_level = level; 1711 1712 nr = trans->blocks_used; 1713 btrfs_end_transaction(trans, root); 1714 1715 btrfs_btree_balance_dirty(root, nr); 1716 1717 if (replaced && rc->stage == UPDATE_DATA_PTRS) 1718 invalidate_extent_cache(root, &key, &next_key); 1719 } 1720 1721 /* 1722 * handle the case only one block in the fs tree need to be 1723 * relocated and the block is tree root. 1724 */ 1725 leaf = btrfs_lock_root_node(root); 1726 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf); 1727 btrfs_tree_unlock(leaf); 1728 free_extent_buffer(leaf); 1729 if (ret < 0) 1730 err = ret; 1731 out: 1732 btrfs_free_path(path); 1733 1734 if (err == 0) { 1735 memset(&root_item->drop_progress, 0, 1736 sizeof(root_item->drop_progress)); 1737 root_item->drop_level = 0; 1738 btrfs_set_root_refs(root_item, 0); 1739 } 1740 1741 nr = trans->blocks_used; 1742 btrfs_end_transaction(trans, root); 1743 1744 btrfs_btree_balance_dirty(root, nr); 1745 1746 /* 1747 * put inodes while we aren't holding the tree locks 1748 */ 1749 while (!list_empty(&inode_list)) { 1750 struct inodevec *ivec; 1751 ivec = list_entry(inode_list.next, struct inodevec, list); 1752 list_del(&ivec->list); 1753 while (ivec->nr > 0) { 1754 ivec->nr--; 1755 iput(ivec->inode[ivec->nr]); 1756 } 1757 kfree(ivec); 1758 } 1759 1760 if (replaced && rc->stage == UPDATE_DATA_PTRS) 1761 invalidate_extent_cache(root, &key, &next_key); 1762 1763 return err; 1764 } 1765 1766 /* 1767 * callback for the work threads. 1768 * this function merges reloc tree with corresponding fs tree, 1769 * and then drops the reloc tree. 1770 */ 1771 static void merge_func(struct btrfs_work *work) 1772 { 1773 struct btrfs_trans_handle *trans; 1774 struct btrfs_root *root; 1775 struct btrfs_root *reloc_root; 1776 struct async_merge *async; 1777 1778 async = container_of(work, struct async_merge, work); 1779 reloc_root = async->root; 1780 1781 if (btrfs_root_refs(&reloc_root->root_item) > 0) { 1782 root = read_fs_root(reloc_root->fs_info, 1783 reloc_root->root_key.offset); 1784 BUG_ON(IS_ERR(root)); 1785 BUG_ON(root->reloc_root != reloc_root); 1786 1787 merge_reloc_root(async->rc, root); 1788 1789 trans = btrfs_start_transaction(root, 1); 1790 btrfs_update_reloc_root(trans, root); 1791 btrfs_end_transaction(trans, root); 1792 } 1793 1794 btrfs_drop_snapshot(reloc_root, 0); 1795 1796 if (atomic_dec_and_test(async->num_pending)) 1797 complete(async->done); 1798 1799 kfree(async); 1800 } 1801 1802 static int merge_reloc_roots(struct reloc_control *rc) 1803 { 1804 struct async_merge *async; 1805 struct btrfs_root *root; 1806 struct completion done; 1807 atomic_t num_pending; 1808 1809 init_completion(&done); 1810 atomic_set(&num_pending, 1); 1811 1812 while (!list_empty(&rc->reloc_roots)) { 1813 root = list_entry(rc->reloc_roots.next, 1814 struct btrfs_root, root_list); 1815 list_del_init(&root->root_list); 1816 1817 async = kmalloc(sizeof(*async), GFP_NOFS); 1818 BUG_ON(!async); 1819 async->work.func = merge_func; 1820 async->work.flags = 0; 1821 async->rc = rc; 1822 async->root = root; 1823 async->done = &done; 1824 async->num_pending = &num_pending; 1825 atomic_inc(&num_pending); 1826 btrfs_queue_worker(&rc->workers, &async->work); 1827 } 1828 1829 if (!atomic_dec_and_test(&num_pending)) 1830 wait_for_completion(&done); 1831 1832 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); 1833 return 0; 1834 } 1835 1836 static void free_block_list(struct rb_root *blocks) 1837 { 1838 struct tree_block *block; 1839 struct rb_node *rb_node; 1840 while ((rb_node = rb_first(blocks))) { 1841 block = rb_entry(rb_node, struct tree_block, rb_node); 1842 rb_erase(rb_node, blocks); 1843 kfree(block); 1844 } 1845 } 1846 1847 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans, 1848 struct btrfs_root *reloc_root) 1849 { 1850 struct btrfs_root *root; 1851 1852 if (reloc_root->last_trans == trans->transid) 1853 return 0; 1854 1855 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset); 1856 BUG_ON(IS_ERR(root)); 1857 BUG_ON(root->reloc_root != reloc_root); 1858 1859 return btrfs_record_root_in_trans(trans, root); 1860 } 1861 1862 /* 1863 * select one tree from trees that references the block. 1864 * for blocks in refernce counted trees, we preper reloc tree. 1865 * if no reloc tree found and reloc_only is true, NULL is returned. 1866 */ 1867 static struct btrfs_root *__select_one_root(struct btrfs_trans_handle *trans, 1868 struct backref_node *node, 1869 struct backref_edge *edges[], 1870 int *nr, int reloc_only) 1871 { 1872 struct backref_node *next; 1873 struct btrfs_root *root; 1874 int index; 1875 int loop = 0; 1876 again: 1877 index = 0; 1878 next = node; 1879 while (1) { 1880 cond_resched(); 1881 next = walk_up_backref(next, edges, &index); 1882 root = next->root; 1883 if (!root) { 1884 BUG_ON(!node->old_root); 1885 goto skip; 1886 } 1887 1888 /* no other choice for non-refernce counted tree */ 1889 if (!root->ref_cows) { 1890 BUG_ON(reloc_only); 1891 break; 1892 } 1893 1894 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { 1895 record_reloc_root_in_trans(trans, root); 1896 break; 1897 } 1898 1899 if (loop) { 1900 btrfs_record_root_in_trans(trans, root); 1901 break; 1902 } 1903 1904 if (reloc_only || next != node) { 1905 if (!root->reloc_root) 1906 btrfs_record_root_in_trans(trans, root); 1907 root = root->reloc_root; 1908 /* 1909 * if the reloc tree was created in current 1910 * transation, there is no node in backref tree 1911 * corresponds to the root of the reloc tree. 1912 */ 1913 if (btrfs_root_last_snapshot(&root->root_item) == 1914 trans->transid - 1) 1915 break; 1916 } 1917 skip: 1918 root = NULL; 1919 next = walk_down_backref(edges, &index); 1920 if (!next || next->level <= node->level) 1921 break; 1922 } 1923 1924 if (!root && !loop && !reloc_only) { 1925 loop = 1; 1926 goto again; 1927 } 1928 1929 if (root) 1930 *nr = index; 1931 else 1932 *nr = 0; 1933 1934 return root; 1935 } 1936 1937 static noinline_for_stack 1938 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, 1939 struct backref_node *node) 1940 { 1941 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 1942 int nr; 1943 return __select_one_root(trans, node, edges, &nr, 0); 1944 } 1945 1946 static noinline_for_stack 1947 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, 1948 struct backref_node *node, 1949 struct backref_edge *edges[], int *nr) 1950 { 1951 return __select_one_root(trans, node, edges, nr, 1); 1952 } 1953 1954 static void grab_path_buffers(struct btrfs_path *path, 1955 struct backref_node *node, 1956 struct backref_edge *edges[], int nr) 1957 { 1958 int i = 0; 1959 while (1) { 1960 drop_node_buffer(node); 1961 node->eb = path->nodes[node->level]; 1962 BUG_ON(!node->eb); 1963 if (path->locks[node->level]) 1964 node->locked = 1; 1965 path->nodes[node->level] = NULL; 1966 path->locks[node->level] = 0; 1967 1968 if (i >= nr) 1969 break; 1970 1971 edges[i]->blockptr = node->eb->start; 1972 node = edges[i]->node[UPPER]; 1973 i++; 1974 } 1975 } 1976 1977 /* 1978 * relocate a block tree, and then update pointers in upper level 1979 * blocks that reference the block to point to the new location. 1980 * 1981 * if called by link_to_upper, the block has already been relocated. 1982 * in that case this function just updates pointers. 1983 */ 1984 static int do_relocation(struct btrfs_trans_handle *trans, 1985 struct backref_node *node, 1986 struct btrfs_key *key, 1987 struct btrfs_path *path, int lowest) 1988 { 1989 struct backref_node *upper; 1990 struct backref_edge *edge; 1991 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 1992 struct btrfs_root *root; 1993 struct extent_buffer *eb; 1994 u32 blocksize; 1995 u64 bytenr; 1996 u64 generation; 1997 int nr; 1998 int slot; 1999 int ret; 2000 int err = 0; 2001 2002 BUG_ON(lowest && node->eb); 2003 2004 path->lowest_level = node->level + 1; 2005 list_for_each_entry(edge, &node->upper, list[LOWER]) { 2006 cond_resched(); 2007 if (node->eb && node->eb->start == edge->blockptr) 2008 continue; 2009 2010 upper = edge->node[UPPER]; 2011 root = select_reloc_root(trans, upper, edges, &nr); 2012 if (!root) 2013 continue; 2014 2015 if (upper->eb && !upper->locked) 2016 drop_node_buffer(upper); 2017 2018 if (!upper->eb) { 2019 ret = btrfs_search_slot(trans, root, key, path, 0, 1); 2020 if (ret < 0) { 2021 err = ret; 2022 break; 2023 } 2024 BUG_ON(ret > 0); 2025 2026 slot = path->slots[upper->level]; 2027 2028 btrfs_unlock_up_safe(path, upper->level + 1); 2029 grab_path_buffers(path, upper, edges, nr); 2030 2031 btrfs_release_path(NULL, path); 2032 } else { 2033 ret = btrfs_bin_search(upper->eb, key, upper->level, 2034 &slot); 2035 BUG_ON(ret); 2036 } 2037 2038 bytenr = btrfs_node_blockptr(upper->eb, slot); 2039 if (!lowest) { 2040 if (node->eb->start == bytenr) { 2041 btrfs_tree_unlock(upper->eb); 2042 upper->locked = 0; 2043 continue; 2044 } 2045 } else { 2046 BUG_ON(node->bytenr != bytenr); 2047 } 2048 2049 blocksize = btrfs_level_size(root, node->level); 2050 generation = btrfs_node_ptr_generation(upper->eb, slot); 2051 eb = read_tree_block(root, bytenr, blocksize, generation); 2052 btrfs_tree_lock(eb); 2053 btrfs_set_lock_blocking(eb); 2054 2055 if (!node->eb) { 2056 ret = btrfs_cow_block(trans, root, eb, upper->eb, 2057 slot, &eb); 2058 if (ret < 0) { 2059 err = ret; 2060 break; 2061 } 2062 btrfs_set_lock_blocking(eb); 2063 node->eb = eb; 2064 node->locked = 1; 2065 } else { 2066 btrfs_set_node_blockptr(upper->eb, slot, 2067 node->eb->start); 2068 btrfs_set_node_ptr_generation(upper->eb, slot, 2069 trans->transid); 2070 btrfs_mark_buffer_dirty(upper->eb); 2071 2072 ret = btrfs_inc_extent_ref(trans, root, 2073 node->eb->start, blocksize, 2074 upper->eb->start, 2075 btrfs_header_owner(upper->eb), 2076 node->level, 0); 2077 BUG_ON(ret); 2078 2079 ret = btrfs_drop_subtree(trans, root, eb, upper->eb); 2080 BUG_ON(ret); 2081 } 2082 if (!lowest) { 2083 btrfs_tree_unlock(upper->eb); 2084 upper->locked = 0; 2085 } 2086 } 2087 path->lowest_level = 0; 2088 return err; 2089 } 2090 2091 static int link_to_upper(struct btrfs_trans_handle *trans, 2092 struct backref_node *node, 2093 struct btrfs_path *path) 2094 { 2095 struct btrfs_key key; 2096 if (!node->eb || list_empty(&node->upper)) 2097 return 0; 2098 2099 btrfs_node_key_to_cpu(node->eb, &key, 0); 2100 return do_relocation(trans, node, &key, path, 0); 2101 } 2102 2103 static int finish_pending_nodes(struct btrfs_trans_handle *trans, 2104 struct backref_cache *cache, 2105 struct btrfs_path *path) 2106 { 2107 struct backref_node *node; 2108 int level; 2109 int ret; 2110 int err = 0; 2111 2112 for (level = 0; level < BTRFS_MAX_LEVEL; level++) { 2113 while (!list_empty(&cache->pending[level])) { 2114 node = list_entry(cache->pending[level].next, 2115 struct backref_node, lower); 2116 BUG_ON(node->level != level); 2117 2118 ret = link_to_upper(trans, node, path); 2119 if (ret < 0) 2120 err = ret; 2121 /* 2122 * this remove the node from the pending list and 2123 * may add some other nodes to the level + 1 2124 * pending list 2125 */ 2126 remove_backref_node(cache, node); 2127 } 2128 } 2129 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root)); 2130 return err; 2131 } 2132 2133 static void mark_block_processed(struct reloc_control *rc, 2134 struct backref_node *node) 2135 { 2136 u32 blocksize; 2137 if (node->level == 0 || 2138 in_block_group(node->bytenr, rc->block_group)) { 2139 blocksize = btrfs_level_size(rc->extent_root, node->level); 2140 set_extent_bits(&rc->processed_blocks, node->bytenr, 2141 node->bytenr + blocksize - 1, EXTENT_DIRTY, 2142 GFP_NOFS); 2143 } 2144 node->processed = 1; 2145 } 2146 2147 /* 2148 * mark a block and all blocks directly/indirectly reference the block 2149 * as processed. 2150 */ 2151 static void update_processed_blocks(struct reloc_control *rc, 2152 struct backref_node *node) 2153 { 2154 struct backref_node *next = node; 2155 struct backref_edge *edge; 2156 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 2157 int index = 0; 2158 2159 while (next) { 2160 cond_resched(); 2161 while (1) { 2162 if (next->processed) 2163 break; 2164 2165 mark_block_processed(rc, next); 2166 2167 if (list_empty(&next->upper)) 2168 break; 2169 2170 edge = list_entry(next->upper.next, 2171 struct backref_edge, list[LOWER]); 2172 edges[index++] = edge; 2173 next = edge->node[UPPER]; 2174 } 2175 next = walk_down_backref(edges, &index); 2176 } 2177 } 2178 2179 static int tree_block_processed(u64 bytenr, u32 blocksize, 2180 struct reloc_control *rc) 2181 { 2182 if (test_range_bit(&rc->processed_blocks, bytenr, 2183 bytenr + blocksize - 1, EXTENT_DIRTY, 1)) 2184 return 1; 2185 return 0; 2186 } 2187 2188 /* 2189 * check if there are any file extent pointers in the leaf point to 2190 * data require processing 2191 */ 2192 static int check_file_extents(struct reloc_control *rc, 2193 u64 bytenr, u32 blocksize, u64 ptr_gen) 2194 { 2195 struct btrfs_key found_key; 2196 struct btrfs_file_extent_item *fi; 2197 struct extent_buffer *leaf; 2198 u32 nritems; 2199 int i; 2200 int ret = 0; 2201 2202 leaf = read_tree_block(rc->extent_root, bytenr, blocksize, ptr_gen); 2203 2204 nritems = btrfs_header_nritems(leaf); 2205 for (i = 0; i < nritems; i++) { 2206 cond_resched(); 2207 btrfs_item_key_to_cpu(leaf, &found_key, i); 2208 if (found_key.type != BTRFS_EXTENT_DATA_KEY) 2209 continue; 2210 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); 2211 if (btrfs_file_extent_type(leaf, fi) == 2212 BTRFS_FILE_EXTENT_INLINE) 2213 continue; 2214 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 2215 if (bytenr == 0) 2216 continue; 2217 if (in_block_group(bytenr, rc->block_group)) { 2218 ret = 1; 2219 break; 2220 } 2221 } 2222 free_extent_buffer(leaf); 2223 return ret; 2224 } 2225 2226 /* 2227 * scan child blocks of a given block to find blocks require processing 2228 */ 2229 static int add_child_blocks(struct btrfs_trans_handle *trans, 2230 struct reloc_control *rc, 2231 struct backref_node *node, 2232 struct rb_root *blocks) 2233 { 2234 struct tree_block *block; 2235 struct rb_node *rb_node; 2236 u64 bytenr; 2237 u64 ptr_gen; 2238 u32 blocksize; 2239 u32 nritems; 2240 int i; 2241 int err = 0; 2242 2243 nritems = btrfs_header_nritems(node->eb); 2244 blocksize = btrfs_level_size(rc->extent_root, node->level - 1); 2245 for (i = 0; i < nritems; i++) { 2246 cond_resched(); 2247 bytenr = btrfs_node_blockptr(node->eb, i); 2248 ptr_gen = btrfs_node_ptr_generation(node->eb, i); 2249 if (ptr_gen == trans->transid) 2250 continue; 2251 if (!in_block_group(bytenr, rc->block_group) && 2252 (node->level > 1 || rc->stage == MOVE_DATA_EXTENTS)) 2253 continue; 2254 if (tree_block_processed(bytenr, blocksize, rc)) 2255 continue; 2256 2257 readahead_tree_block(rc->extent_root, 2258 bytenr, blocksize, ptr_gen); 2259 } 2260 2261 for (i = 0; i < nritems; i++) { 2262 cond_resched(); 2263 bytenr = btrfs_node_blockptr(node->eb, i); 2264 ptr_gen = btrfs_node_ptr_generation(node->eb, i); 2265 if (ptr_gen == trans->transid) 2266 continue; 2267 if (!in_block_group(bytenr, rc->block_group) && 2268 (node->level > 1 || rc->stage == MOVE_DATA_EXTENTS)) 2269 continue; 2270 if (tree_block_processed(bytenr, blocksize, rc)) 2271 continue; 2272 if (!in_block_group(bytenr, rc->block_group) && 2273 !check_file_extents(rc, bytenr, blocksize, ptr_gen)) 2274 continue; 2275 2276 block = kmalloc(sizeof(*block), GFP_NOFS); 2277 if (!block) { 2278 err = -ENOMEM; 2279 break; 2280 } 2281 block->bytenr = bytenr; 2282 btrfs_node_key_to_cpu(node->eb, &block->key, i); 2283 block->level = node->level - 1; 2284 block->key_ready = 1; 2285 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); 2286 BUG_ON(rb_node); 2287 } 2288 if (err) 2289 free_block_list(blocks); 2290 return err; 2291 } 2292 2293 /* 2294 * find adjacent blocks require processing 2295 */ 2296 static noinline_for_stack 2297 int add_adjacent_blocks(struct btrfs_trans_handle *trans, 2298 struct reloc_control *rc, 2299 struct backref_cache *cache, 2300 struct rb_root *blocks, int level, 2301 struct backref_node **upper) 2302 { 2303 struct backref_node *node; 2304 int ret = 0; 2305 2306 WARN_ON(!list_empty(&cache->pending[level])); 2307 2308 if (list_empty(&cache->pending[level + 1])) 2309 return 1; 2310 2311 node = list_entry(cache->pending[level + 1].next, 2312 struct backref_node, lower); 2313 if (node->eb) 2314 ret = add_child_blocks(trans, rc, node, blocks); 2315 2316 *upper = node; 2317 return ret; 2318 } 2319 2320 static int get_tree_block_key(struct reloc_control *rc, 2321 struct tree_block *block) 2322 { 2323 struct extent_buffer *eb; 2324 2325 BUG_ON(block->key_ready); 2326 eb = read_tree_block(rc->extent_root, block->bytenr, 2327 block->key.objectid, block->key.offset); 2328 WARN_ON(btrfs_header_level(eb) != block->level); 2329 if (block->level == 0) 2330 btrfs_item_key_to_cpu(eb, &block->key, 0); 2331 else 2332 btrfs_node_key_to_cpu(eb, &block->key, 0); 2333 free_extent_buffer(eb); 2334 block->key_ready = 1; 2335 return 0; 2336 } 2337 2338 static int reada_tree_block(struct reloc_control *rc, 2339 struct tree_block *block) 2340 { 2341 BUG_ON(block->key_ready); 2342 readahead_tree_block(rc->extent_root, block->bytenr, 2343 block->key.objectid, block->key.offset); 2344 return 0; 2345 } 2346 2347 /* 2348 * helper function to relocate a tree block 2349 */ 2350 static int relocate_tree_block(struct btrfs_trans_handle *trans, 2351 struct reloc_control *rc, 2352 struct backref_node *node, 2353 struct btrfs_key *key, 2354 struct btrfs_path *path) 2355 { 2356 struct btrfs_root *root; 2357 int ret; 2358 2359 root = select_one_root(trans, node); 2360 if (unlikely(!root)) { 2361 rc->found_old_snapshot = 1; 2362 update_processed_blocks(rc, node); 2363 return 0; 2364 } 2365 2366 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { 2367 ret = do_relocation(trans, node, key, path, 1); 2368 if (ret < 0) 2369 goto out; 2370 if (node->level == 0 && rc->stage == UPDATE_DATA_PTRS) { 2371 ret = replace_file_extents(trans, rc, root, 2372 node->eb, NULL); 2373 if (ret < 0) 2374 goto out; 2375 } 2376 drop_node_buffer(node); 2377 } else if (!root->ref_cows) { 2378 path->lowest_level = node->level; 2379 ret = btrfs_search_slot(trans, root, key, path, 0, 1); 2380 btrfs_release_path(root, path); 2381 if (ret < 0) 2382 goto out; 2383 } else if (root != node->root) { 2384 WARN_ON(node->level > 0 || rc->stage != UPDATE_DATA_PTRS); 2385 } 2386 2387 update_processed_blocks(rc, node); 2388 ret = 0; 2389 out: 2390 drop_node_buffer(node); 2391 return ret; 2392 } 2393 2394 /* 2395 * relocate a list of blocks 2396 */ 2397 static noinline_for_stack 2398 int relocate_tree_blocks(struct btrfs_trans_handle *trans, 2399 struct reloc_control *rc, struct rb_root *blocks) 2400 { 2401 struct backref_cache *cache; 2402 struct backref_node *node; 2403 struct btrfs_path *path; 2404 struct tree_block *block; 2405 struct rb_node *rb_node; 2406 int level = -1; 2407 int ret; 2408 int err = 0; 2409 2410 path = btrfs_alloc_path(); 2411 if (!path) 2412 return -ENOMEM; 2413 2414 cache = kmalloc(sizeof(*cache), GFP_NOFS); 2415 if (!cache) { 2416 btrfs_free_path(path); 2417 return -ENOMEM; 2418 } 2419 2420 backref_cache_init(cache); 2421 2422 rb_node = rb_first(blocks); 2423 while (rb_node) { 2424 block = rb_entry(rb_node, struct tree_block, rb_node); 2425 if (level == -1) 2426 level = block->level; 2427 else 2428 BUG_ON(level != block->level); 2429 if (!block->key_ready) 2430 reada_tree_block(rc, block); 2431 rb_node = rb_next(rb_node); 2432 } 2433 2434 rb_node = rb_first(blocks); 2435 while (rb_node) { 2436 block = rb_entry(rb_node, struct tree_block, rb_node); 2437 if (!block->key_ready) 2438 get_tree_block_key(rc, block); 2439 rb_node = rb_next(rb_node); 2440 } 2441 2442 rb_node = rb_first(blocks); 2443 while (rb_node) { 2444 block = rb_entry(rb_node, struct tree_block, rb_node); 2445 2446 node = build_backref_tree(rc, cache, &block->key, 2447 block->level, block->bytenr); 2448 if (IS_ERR(node)) { 2449 err = PTR_ERR(node); 2450 goto out; 2451 } 2452 2453 ret = relocate_tree_block(trans, rc, node, &block->key, 2454 path); 2455 if (ret < 0) { 2456 err = ret; 2457 goto out; 2458 } 2459 remove_backref_node(cache, node); 2460 rb_node = rb_next(rb_node); 2461 } 2462 2463 if (level > 0) 2464 goto out; 2465 2466 free_block_list(blocks); 2467 2468 /* 2469 * now backrefs of some upper level tree blocks have been cached, 2470 * try relocating blocks referenced by these upper level blocks. 2471 */ 2472 while (1) { 2473 struct backref_node *upper = NULL; 2474 if (trans->transaction->in_commit || 2475 trans->transaction->delayed_refs.flushing) 2476 break; 2477 2478 ret = add_adjacent_blocks(trans, rc, cache, blocks, level, 2479 &upper); 2480 if (ret < 0) 2481 err = ret; 2482 if (ret != 0) 2483 break; 2484 2485 rb_node = rb_first(blocks); 2486 while (rb_node) { 2487 block = rb_entry(rb_node, struct tree_block, rb_node); 2488 if (trans->transaction->in_commit || 2489 trans->transaction->delayed_refs.flushing) 2490 goto out; 2491 BUG_ON(!block->key_ready); 2492 node = build_backref_tree(rc, cache, &block->key, 2493 level, block->bytenr); 2494 if (IS_ERR(node)) { 2495 err = PTR_ERR(node); 2496 goto out; 2497 } 2498 2499 ret = relocate_tree_block(trans, rc, node, 2500 &block->key, path); 2501 if (ret < 0) { 2502 err = ret; 2503 goto out; 2504 } 2505 remove_backref_node(cache, node); 2506 rb_node = rb_next(rb_node); 2507 } 2508 free_block_list(blocks); 2509 2510 if (upper) { 2511 ret = link_to_upper(trans, upper, path); 2512 if (ret < 0) { 2513 err = ret; 2514 break; 2515 } 2516 remove_backref_node(cache, upper); 2517 } 2518 } 2519 out: 2520 free_block_list(blocks); 2521 2522 ret = finish_pending_nodes(trans, cache, path); 2523 if (ret < 0) 2524 err = ret; 2525 2526 kfree(cache); 2527 btrfs_free_path(path); 2528 return err; 2529 } 2530 2531 static noinline_for_stack 2532 int relocate_inode_pages(struct inode *inode, u64 start, u64 len) 2533 { 2534 u64 page_start; 2535 u64 page_end; 2536 unsigned long i; 2537 unsigned long first_index; 2538 unsigned long last_index; 2539 unsigned int total_read = 0; 2540 unsigned int total_dirty = 0; 2541 struct page *page; 2542 struct file_ra_state *ra; 2543 struct btrfs_ordered_extent *ordered; 2544 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2545 int ret = 0; 2546 2547 ra = kzalloc(sizeof(*ra), GFP_NOFS); 2548 if (!ra) 2549 return -ENOMEM; 2550 2551 mutex_lock(&inode->i_mutex); 2552 first_index = start >> PAGE_CACHE_SHIFT; 2553 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; 2554 2555 /* make sure the dirty trick played by the caller work */ 2556 while (1) { 2557 ret = invalidate_inode_pages2_range(inode->i_mapping, 2558 first_index, last_index); 2559 if (ret != -EBUSY) 2560 break; 2561 schedule_timeout(HZ/10); 2562 } 2563 if (ret) 2564 goto out_unlock; 2565 2566 file_ra_state_init(ra, inode->i_mapping); 2567 2568 for (i = first_index ; i <= last_index; i++) { 2569 if (total_read % ra->ra_pages == 0) { 2570 btrfs_force_ra(inode->i_mapping, ra, NULL, i, 2571 min(last_index, ra->ra_pages + i - 1)); 2572 } 2573 total_read++; 2574 again: 2575 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) 2576 BUG_ON(1); 2577 page = grab_cache_page(inode->i_mapping, i); 2578 if (!page) { 2579 ret = -ENOMEM; 2580 goto out_unlock; 2581 } 2582 if (!PageUptodate(page)) { 2583 btrfs_readpage(NULL, page); 2584 lock_page(page); 2585 if (!PageUptodate(page)) { 2586 unlock_page(page); 2587 page_cache_release(page); 2588 ret = -EIO; 2589 goto out_unlock; 2590 } 2591 } 2592 wait_on_page_writeback(page); 2593 2594 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 2595 page_end = page_start + PAGE_CACHE_SIZE - 1; 2596 lock_extent(io_tree, page_start, page_end, GFP_NOFS); 2597 2598 ordered = btrfs_lookup_ordered_extent(inode, page_start); 2599 if (ordered) { 2600 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 2601 unlock_page(page); 2602 page_cache_release(page); 2603 btrfs_start_ordered_extent(inode, ordered, 1); 2604 btrfs_put_ordered_extent(ordered); 2605 goto again; 2606 } 2607 set_page_extent_mapped(page); 2608 2609 if (i == first_index) 2610 set_extent_bits(io_tree, page_start, page_end, 2611 EXTENT_BOUNDARY, GFP_NOFS); 2612 btrfs_set_extent_delalloc(inode, page_start, page_end); 2613 2614 set_page_dirty(page); 2615 total_dirty++; 2616 2617 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 2618 unlock_page(page); 2619 page_cache_release(page); 2620 } 2621 out_unlock: 2622 mutex_unlock(&inode->i_mutex); 2623 kfree(ra); 2624 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty); 2625 return ret; 2626 } 2627 2628 static noinline_for_stack 2629 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key) 2630 { 2631 struct btrfs_root *root = BTRFS_I(inode)->root; 2632 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 2633 struct extent_map *em; 2634 u64 start = extent_key->objectid - BTRFS_I(inode)->index_cnt; 2635 u64 end = start + extent_key->offset - 1; 2636 2637 em = alloc_extent_map(GFP_NOFS); 2638 em->start = start; 2639 em->len = extent_key->offset; 2640 em->block_len = extent_key->offset; 2641 em->block_start = extent_key->objectid; 2642 em->bdev = root->fs_info->fs_devices->latest_bdev; 2643 set_bit(EXTENT_FLAG_PINNED, &em->flags); 2644 2645 /* setup extent map to cheat btrfs_readpage */ 2646 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 2647 while (1) { 2648 int ret; 2649 spin_lock(&em_tree->lock); 2650 ret = add_extent_mapping(em_tree, em); 2651 spin_unlock(&em_tree->lock); 2652 if (ret != -EEXIST) { 2653 free_extent_map(em); 2654 break; 2655 } 2656 btrfs_drop_extent_cache(inode, start, end, 0); 2657 } 2658 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 2659 2660 return relocate_inode_pages(inode, start, extent_key->offset); 2661 } 2662 2663 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 2664 static int get_ref_objectid_v0(struct reloc_control *rc, 2665 struct btrfs_path *path, 2666 struct btrfs_key *extent_key, 2667 u64 *ref_objectid, int *path_change) 2668 { 2669 struct btrfs_key key; 2670 struct extent_buffer *leaf; 2671 struct btrfs_extent_ref_v0 *ref0; 2672 int ret; 2673 int slot; 2674 2675 leaf = path->nodes[0]; 2676 slot = path->slots[0]; 2677 while (1) { 2678 if (slot >= btrfs_header_nritems(leaf)) { 2679 ret = btrfs_next_leaf(rc->extent_root, path); 2680 if (ret < 0) 2681 return ret; 2682 BUG_ON(ret > 0); 2683 leaf = path->nodes[0]; 2684 slot = path->slots[0]; 2685 if (path_change) 2686 *path_change = 1; 2687 } 2688 btrfs_item_key_to_cpu(leaf, &key, slot); 2689 if (key.objectid != extent_key->objectid) 2690 return -ENOENT; 2691 2692 if (key.type != BTRFS_EXTENT_REF_V0_KEY) { 2693 slot++; 2694 continue; 2695 } 2696 ref0 = btrfs_item_ptr(leaf, slot, 2697 struct btrfs_extent_ref_v0); 2698 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0); 2699 break; 2700 } 2701 return 0; 2702 } 2703 #endif 2704 2705 /* 2706 * helper to add a tree block to the list. 2707 * the major work is getting the generation and level of the block 2708 */ 2709 static int add_tree_block(struct reloc_control *rc, 2710 struct btrfs_key *extent_key, 2711 struct btrfs_path *path, 2712 struct rb_root *blocks) 2713 { 2714 struct extent_buffer *eb; 2715 struct btrfs_extent_item *ei; 2716 struct btrfs_tree_block_info *bi; 2717 struct tree_block *block; 2718 struct rb_node *rb_node; 2719 u32 item_size; 2720 int level = -1; 2721 int generation; 2722 2723 eb = path->nodes[0]; 2724 item_size = btrfs_item_size_nr(eb, path->slots[0]); 2725 2726 if (item_size >= sizeof(*ei) + sizeof(*bi)) { 2727 ei = btrfs_item_ptr(eb, path->slots[0], 2728 struct btrfs_extent_item); 2729 bi = (struct btrfs_tree_block_info *)(ei + 1); 2730 generation = btrfs_extent_generation(eb, ei); 2731 level = btrfs_tree_block_level(eb, bi); 2732 } else { 2733 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 2734 u64 ref_owner; 2735 int ret; 2736 2737 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0)); 2738 ret = get_ref_objectid_v0(rc, path, extent_key, 2739 &ref_owner, NULL); 2740 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL); 2741 level = (int)ref_owner; 2742 /* FIXME: get real generation */ 2743 generation = 0; 2744 #else 2745 BUG(); 2746 #endif 2747 } 2748 2749 btrfs_release_path(rc->extent_root, path); 2750 2751 BUG_ON(level == -1); 2752 2753 block = kmalloc(sizeof(*block), GFP_NOFS); 2754 if (!block) 2755 return -ENOMEM; 2756 2757 block->bytenr = extent_key->objectid; 2758 block->key.objectid = extent_key->offset; 2759 block->key.offset = generation; 2760 block->level = level; 2761 block->key_ready = 0; 2762 2763 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); 2764 BUG_ON(rb_node); 2765 2766 return 0; 2767 } 2768 2769 /* 2770 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY 2771 */ 2772 static int __add_tree_block(struct reloc_control *rc, 2773 u64 bytenr, u32 blocksize, 2774 struct rb_root *blocks) 2775 { 2776 struct btrfs_path *path; 2777 struct btrfs_key key; 2778 int ret; 2779 2780 if (tree_block_processed(bytenr, blocksize, rc)) 2781 return 0; 2782 2783 if (tree_search(blocks, bytenr)) 2784 return 0; 2785 2786 path = btrfs_alloc_path(); 2787 if (!path) 2788 return -ENOMEM; 2789 2790 key.objectid = bytenr; 2791 key.type = BTRFS_EXTENT_ITEM_KEY; 2792 key.offset = blocksize; 2793 2794 path->search_commit_root = 1; 2795 path->skip_locking = 1; 2796 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0); 2797 if (ret < 0) 2798 goto out; 2799 BUG_ON(ret); 2800 2801 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 2802 ret = add_tree_block(rc, &key, path, blocks); 2803 out: 2804 btrfs_free_path(path); 2805 return ret; 2806 } 2807 2808 /* 2809 * helper to check if the block use full backrefs for pointers in it 2810 */ 2811 static int block_use_full_backref(struct reloc_control *rc, 2812 struct extent_buffer *eb) 2813 { 2814 struct btrfs_path *path; 2815 struct btrfs_extent_item *ei; 2816 struct btrfs_key key; 2817 u64 flags; 2818 int ret; 2819 2820 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) || 2821 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV) 2822 return 1; 2823 2824 path = btrfs_alloc_path(); 2825 BUG_ON(!path); 2826 2827 key.objectid = eb->start; 2828 key.type = BTRFS_EXTENT_ITEM_KEY; 2829 key.offset = eb->len; 2830 2831 path->search_commit_root = 1; 2832 path->skip_locking = 1; 2833 ret = btrfs_search_slot(NULL, rc->extent_root, 2834 &key, path, 0, 0); 2835 BUG_ON(ret); 2836 2837 ei = btrfs_item_ptr(path->nodes[0], path->slots[0], 2838 struct btrfs_extent_item); 2839 flags = btrfs_extent_flags(path->nodes[0], ei); 2840 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)); 2841 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) 2842 ret = 1; 2843 else 2844 ret = 0; 2845 btrfs_free_path(path); 2846 return ret; 2847 } 2848 2849 /* 2850 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY 2851 * this function scans fs tree to find blocks reference the data extent 2852 */ 2853 static int find_data_references(struct reloc_control *rc, 2854 struct btrfs_key *extent_key, 2855 struct extent_buffer *leaf, 2856 struct btrfs_extent_data_ref *ref, 2857 struct rb_root *blocks) 2858 { 2859 struct btrfs_path *path; 2860 struct tree_block *block; 2861 struct btrfs_root *root; 2862 struct btrfs_file_extent_item *fi; 2863 struct rb_node *rb_node; 2864 struct btrfs_key key; 2865 u64 ref_root; 2866 u64 ref_objectid; 2867 u64 ref_offset; 2868 u32 ref_count; 2869 u32 nritems; 2870 int err = 0; 2871 int added = 0; 2872 int counted; 2873 int ret; 2874 2875 path = btrfs_alloc_path(); 2876 if (!path) 2877 return -ENOMEM; 2878 2879 ref_root = btrfs_extent_data_ref_root(leaf, ref); 2880 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref); 2881 ref_offset = btrfs_extent_data_ref_offset(leaf, ref); 2882 ref_count = btrfs_extent_data_ref_count(leaf, ref); 2883 2884 root = read_fs_root(rc->extent_root->fs_info, ref_root); 2885 if (IS_ERR(root)) { 2886 err = PTR_ERR(root); 2887 goto out; 2888 } 2889 2890 key.objectid = ref_objectid; 2891 key.offset = ref_offset; 2892 key.type = BTRFS_EXTENT_DATA_KEY; 2893 2894 path->search_commit_root = 1; 2895 path->skip_locking = 1; 2896 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2897 if (ret < 0) { 2898 err = ret; 2899 goto out; 2900 } 2901 2902 leaf = path->nodes[0]; 2903 nritems = btrfs_header_nritems(leaf); 2904 /* 2905 * the references in tree blocks that use full backrefs 2906 * are not counted in 2907 */ 2908 if (block_use_full_backref(rc, leaf)) 2909 counted = 0; 2910 else 2911 counted = 1; 2912 rb_node = tree_search(blocks, leaf->start); 2913 if (rb_node) { 2914 if (counted) 2915 added = 1; 2916 else 2917 path->slots[0] = nritems; 2918 } 2919 2920 while (ref_count > 0) { 2921 while (path->slots[0] >= nritems) { 2922 ret = btrfs_next_leaf(root, path); 2923 if (ret < 0) { 2924 err = ret; 2925 goto out; 2926 } 2927 if (ret > 0) { 2928 WARN_ON(1); 2929 goto out; 2930 } 2931 2932 leaf = path->nodes[0]; 2933 nritems = btrfs_header_nritems(leaf); 2934 added = 0; 2935 2936 if (block_use_full_backref(rc, leaf)) 2937 counted = 0; 2938 else 2939 counted = 1; 2940 rb_node = tree_search(blocks, leaf->start); 2941 if (rb_node) { 2942 if (counted) 2943 added = 1; 2944 else 2945 path->slots[0] = nritems; 2946 } 2947 } 2948 2949 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 2950 if (key.objectid != ref_objectid || 2951 key.type != BTRFS_EXTENT_DATA_KEY) { 2952 WARN_ON(1); 2953 break; 2954 } 2955 2956 fi = btrfs_item_ptr(leaf, path->slots[0], 2957 struct btrfs_file_extent_item); 2958 2959 if (btrfs_file_extent_type(leaf, fi) == 2960 BTRFS_FILE_EXTENT_INLINE) 2961 goto next; 2962 2963 if (btrfs_file_extent_disk_bytenr(leaf, fi) != 2964 extent_key->objectid) 2965 goto next; 2966 2967 key.offset -= btrfs_file_extent_offset(leaf, fi); 2968 if (key.offset != ref_offset) 2969 goto next; 2970 2971 if (counted) 2972 ref_count--; 2973 if (added) 2974 goto next; 2975 2976 if (!tree_block_processed(leaf->start, leaf->len, rc)) { 2977 block = kmalloc(sizeof(*block), GFP_NOFS); 2978 if (!block) { 2979 err = -ENOMEM; 2980 break; 2981 } 2982 block->bytenr = leaf->start; 2983 btrfs_item_key_to_cpu(leaf, &block->key, 0); 2984 block->level = 0; 2985 block->key_ready = 1; 2986 rb_node = tree_insert(blocks, block->bytenr, 2987 &block->rb_node); 2988 BUG_ON(rb_node); 2989 } 2990 if (counted) 2991 added = 1; 2992 else 2993 path->slots[0] = nritems; 2994 next: 2995 path->slots[0]++; 2996 2997 } 2998 out: 2999 btrfs_free_path(path); 3000 return err; 3001 } 3002 3003 /* 3004 * hepler to find all tree blocks that reference a given data extent 3005 */ 3006 static noinline_for_stack 3007 int add_data_references(struct reloc_control *rc, 3008 struct btrfs_key *extent_key, 3009 struct btrfs_path *path, 3010 struct rb_root *blocks) 3011 { 3012 struct btrfs_key key; 3013 struct extent_buffer *eb; 3014 struct btrfs_extent_data_ref *dref; 3015 struct btrfs_extent_inline_ref *iref; 3016 unsigned long ptr; 3017 unsigned long end; 3018 u32 blocksize; 3019 int ret; 3020 int err = 0; 3021 3022 ret = get_new_location(rc->data_inode, NULL, extent_key->objectid, 3023 extent_key->offset); 3024 BUG_ON(ret < 0); 3025 if (ret > 0) { 3026 /* the relocated data is fragmented */ 3027 rc->extents_skipped++; 3028 btrfs_release_path(rc->extent_root, path); 3029 return 0; 3030 } 3031 3032 blocksize = btrfs_level_size(rc->extent_root, 0); 3033 3034 eb = path->nodes[0]; 3035 ptr = btrfs_item_ptr_offset(eb, path->slots[0]); 3036 end = ptr + btrfs_item_size_nr(eb, path->slots[0]); 3037 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 3038 if (ptr + sizeof(struct btrfs_extent_item_v0) == end) 3039 ptr = end; 3040 else 3041 #endif 3042 ptr += sizeof(struct btrfs_extent_item); 3043 3044 while (ptr < end) { 3045 iref = (struct btrfs_extent_inline_ref *)ptr; 3046 key.type = btrfs_extent_inline_ref_type(eb, iref); 3047 if (key.type == BTRFS_SHARED_DATA_REF_KEY) { 3048 key.offset = btrfs_extent_inline_ref_offset(eb, iref); 3049 ret = __add_tree_block(rc, key.offset, blocksize, 3050 blocks); 3051 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { 3052 dref = (struct btrfs_extent_data_ref *)(&iref->offset); 3053 ret = find_data_references(rc, extent_key, 3054 eb, dref, blocks); 3055 } else { 3056 BUG(); 3057 } 3058 ptr += btrfs_extent_inline_ref_size(key.type); 3059 } 3060 WARN_ON(ptr > end); 3061 3062 while (1) { 3063 cond_resched(); 3064 eb = path->nodes[0]; 3065 if (path->slots[0] >= btrfs_header_nritems(eb)) { 3066 ret = btrfs_next_leaf(rc->extent_root, path); 3067 if (ret < 0) { 3068 err = ret; 3069 break; 3070 } 3071 if (ret > 0) 3072 break; 3073 eb = path->nodes[0]; 3074 } 3075 3076 btrfs_item_key_to_cpu(eb, &key, path->slots[0]); 3077 if (key.objectid != extent_key->objectid) 3078 break; 3079 3080 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 3081 if (key.type == BTRFS_SHARED_DATA_REF_KEY || 3082 key.type == BTRFS_EXTENT_REF_V0_KEY) { 3083 #else 3084 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); 3085 if (key.type == BTRFS_SHARED_DATA_REF_KEY) { 3086 #endif 3087 ret = __add_tree_block(rc, key.offset, blocksize, 3088 blocks); 3089 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { 3090 dref = btrfs_item_ptr(eb, path->slots[0], 3091 struct btrfs_extent_data_ref); 3092 ret = find_data_references(rc, extent_key, 3093 eb, dref, blocks); 3094 } else { 3095 ret = 0; 3096 } 3097 if (ret) { 3098 err = ret; 3099 break; 3100 } 3101 path->slots[0]++; 3102 } 3103 btrfs_release_path(rc->extent_root, path); 3104 if (err) 3105 free_block_list(blocks); 3106 return err; 3107 } 3108 3109 /* 3110 * hepler to find next unprocessed extent 3111 */ 3112 static noinline_for_stack 3113 int find_next_extent(struct btrfs_trans_handle *trans, 3114 struct reloc_control *rc, struct btrfs_path *path) 3115 { 3116 struct btrfs_key key; 3117 struct extent_buffer *leaf; 3118 u64 start, end, last; 3119 int ret; 3120 3121 last = rc->block_group->key.objectid + rc->block_group->key.offset; 3122 while (1) { 3123 cond_resched(); 3124 if (rc->search_start >= last) { 3125 ret = 1; 3126 break; 3127 } 3128 3129 key.objectid = rc->search_start; 3130 key.type = BTRFS_EXTENT_ITEM_KEY; 3131 key.offset = 0; 3132 3133 path->search_commit_root = 1; 3134 path->skip_locking = 1; 3135 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 3136 0, 0); 3137 if (ret < 0) 3138 break; 3139 next: 3140 leaf = path->nodes[0]; 3141 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 3142 ret = btrfs_next_leaf(rc->extent_root, path); 3143 if (ret != 0) 3144 break; 3145 leaf = path->nodes[0]; 3146 } 3147 3148 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3149 if (key.objectid >= last) { 3150 ret = 1; 3151 break; 3152 } 3153 3154 if (key.type != BTRFS_EXTENT_ITEM_KEY || 3155 key.objectid + key.offset <= rc->search_start) { 3156 path->slots[0]++; 3157 goto next; 3158 } 3159 3160 ret = find_first_extent_bit(&rc->processed_blocks, 3161 key.objectid, &start, &end, 3162 EXTENT_DIRTY); 3163 3164 if (ret == 0 && start <= key.objectid) { 3165 btrfs_release_path(rc->extent_root, path); 3166 rc->search_start = end + 1; 3167 } else { 3168 rc->search_start = key.objectid + key.offset; 3169 return 0; 3170 } 3171 } 3172 btrfs_release_path(rc->extent_root, path); 3173 return ret; 3174 } 3175 3176 static void set_reloc_control(struct reloc_control *rc) 3177 { 3178 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; 3179 mutex_lock(&fs_info->trans_mutex); 3180 fs_info->reloc_ctl = rc; 3181 mutex_unlock(&fs_info->trans_mutex); 3182 } 3183 3184 static void unset_reloc_control(struct reloc_control *rc) 3185 { 3186 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; 3187 mutex_lock(&fs_info->trans_mutex); 3188 fs_info->reloc_ctl = NULL; 3189 mutex_unlock(&fs_info->trans_mutex); 3190 } 3191 3192 static int check_extent_flags(u64 flags) 3193 { 3194 if ((flags & BTRFS_EXTENT_FLAG_DATA) && 3195 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) 3196 return 1; 3197 if (!(flags & BTRFS_EXTENT_FLAG_DATA) && 3198 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) 3199 return 1; 3200 if ((flags & BTRFS_EXTENT_FLAG_DATA) && 3201 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) 3202 return 1; 3203 return 0; 3204 } 3205 3206 static noinline_for_stack int relocate_block_group(struct reloc_control *rc) 3207 { 3208 struct rb_root blocks = RB_ROOT; 3209 struct btrfs_key key; 3210 struct btrfs_trans_handle *trans = NULL; 3211 struct btrfs_path *path; 3212 struct btrfs_extent_item *ei; 3213 unsigned long nr; 3214 u64 flags; 3215 u32 item_size; 3216 int ret; 3217 int err = 0; 3218 3219 path = btrfs_alloc_path(); 3220 if (!path) 3221 return -ENOMEM; 3222 3223 rc->search_start = rc->block_group->key.objectid; 3224 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY, 3225 GFP_NOFS); 3226 3227 rc->create_reloc_root = 1; 3228 set_reloc_control(rc); 3229 3230 trans = btrfs_start_transaction(rc->extent_root, 1); 3231 btrfs_commit_transaction(trans, rc->extent_root); 3232 3233 while (1) { 3234 trans = btrfs_start_transaction(rc->extent_root, 1); 3235 3236 ret = find_next_extent(trans, rc, path); 3237 if (ret < 0) 3238 err = ret; 3239 if (ret != 0) 3240 break; 3241 3242 rc->extents_found++; 3243 3244 ei = btrfs_item_ptr(path->nodes[0], path->slots[0], 3245 struct btrfs_extent_item); 3246 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 3247 item_size = btrfs_item_size_nr(path->nodes[0], 3248 path->slots[0]); 3249 if (item_size >= sizeof(*ei)) { 3250 flags = btrfs_extent_flags(path->nodes[0], ei); 3251 ret = check_extent_flags(flags); 3252 BUG_ON(ret); 3253 3254 } else { 3255 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 3256 u64 ref_owner; 3257 int path_change = 0; 3258 3259 BUG_ON(item_size != 3260 sizeof(struct btrfs_extent_item_v0)); 3261 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner, 3262 &path_change); 3263 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID) 3264 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK; 3265 else 3266 flags = BTRFS_EXTENT_FLAG_DATA; 3267 3268 if (path_change) { 3269 btrfs_release_path(rc->extent_root, path); 3270 3271 path->search_commit_root = 1; 3272 path->skip_locking = 1; 3273 ret = btrfs_search_slot(NULL, rc->extent_root, 3274 &key, path, 0, 0); 3275 if (ret < 0) { 3276 err = ret; 3277 break; 3278 } 3279 BUG_ON(ret > 0); 3280 } 3281 #else 3282 BUG(); 3283 #endif 3284 } 3285 3286 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 3287 ret = add_tree_block(rc, &key, path, &blocks); 3288 } else if (rc->stage == UPDATE_DATA_PTRS && 3289 (flags & BTRFS_EXTENT_FLAG_DATA)) { 3290 ret = add_data_references(rc, &key, path, &blocks); 3291 } else { 3292 btrfs_release_path(rc->extent_root, path); 3293 ret = 0; 3294 } 3295 if (ret < 0) { 3296 err = 0; 3297 break; 3298 } 3299 3300 if (!RB_EMPTY_ROOT(&blocks)) { 3301 ret = relocate_tree_blocks(trans, rc, &blocks); 3302 if (ret < 0) { 3303 err = ret; 3304 break; 3305 } 3306 } 3307 3308 nr = trans->blocks_used; 3309 btrfs_end_transaction_throttle(trans, rc->extent_root); 3310 trans = NULL; 3311 btrfs_btree_balance_dirty(rc->extent_root, nr); 3312 3313 if (rc->stage == MOVE_DATA_EXTENTS && 3314 (flags & BTRFS_EXTENT_FLAG_DATA)) { 3315 rc->found_file_extent = 1; 3316 ret = relocate_data_extent(rc->data_inode, &key); 3317 if (ret < 0) { 3318 err = ret; 3319 break; 3320 } 3321 } 3322 } 3323 btrfs_free_path(path); 3324 3325 if (trans) { 3326 nr = trans->blocks_used; 3327 btrfs_end_transaction(trans, rc->extent_root); 3328 btrfs_btree_balance_dirty(rc->extent_root, nr); 3329 } 3330 3331 rc->create_reloc_root = 0; 3332 smp_mb(); 3333 3334 if (rc->extents_found > 0) { 3335 trans = btrfs_start_transaction(rc->extent_root, 1); 3336 btrfs_commit_transaction(trans, rc->extent_root); 3337 } 3338 3339 merge_reloc_roots(rc); 3340 3341 unset_reloc_control(rc); 3342 3343 /* get rid of pinned extents */ 3344 trans = btrfs_start_transaction(rc->extent_root, 1); 3345 btrfs_commit_transaction(trans, rc->extent_root); 3346 3347 return err; 3348 } 3349 3350 static int __insert_orphan_inode(struct btrfs_trans_handle *trans, 3351 struct btrfs_root *root, 3352 u64 objectid, u64 size) 3353 { 3354 struct btrfs_path *path; 3355 struct btrfs_inode_item *item; 3356 struct extent_buffer *leaf; 3357 int ret; 3358 3359 path = btrfs_alloc_path(); 3360 if (!path) 3361 return -ENOMEM; 3362 3363 ret = btrfs_insert_empty_inode(trans, root, path, objectid); 3364 if (ret) 3365 goto out; 3366 3367 leaf = path->nodes[0]; 3368 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); 3369 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); 3370 btrfs_set_inode_generation(leaf, item, 1); 3371 btrfs_set_inode_size(leaf, item, size); 3372 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); 3373 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS); 3374 btrfs_mark_buffer_dirty(leaf); 3375 btrfs_release_path(root, path); 3376 out: 3377 btrfs_free_path(path); 3378 return ret; 3379 } 3380 3381 /* 3382 * helper to create inode for data relocation. 3383 * the inode is in data relocation tree and its link count is 0 3384 */ 3385 static struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info, 3386 struct btrfs_block_group_cache *group) 3387 { 3388 struct inode *inode = NULL; 3389 struct btrfs_trans_handle *trans; 3390 struct btrfs_root *root; 3391 struct btrfs_key key; 3392 unsigned long nr; 3393 u64 objectid = BTRFS_FIRST_FREE_OBJECTID; 3394 int err = 0; 3395 3396 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID); 3397 if (IS_ERR(root)) 3398 return ERR_CAST(root); 3399 3400 trans = btrfs_start_transaction(root, 1); 3401 BUG_ON(!trans); 3402 3403 err = btrfs_find_free_objectid(trans, root, objectid, &objectid); 3404 if (err) 3405 goto out; 3406 3407 err = __insert_orphan_inode(trans, root, objectid, group->key.offset); 3408 BUG_ON(err); 3409 3410 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0, 3411 group->key.offset, 0, group->key.offset, 3412 0, 0, 0); 3413 BUG_ON(err); 3414 3415 key.objectid = objectid; 3416 key.type = BTRFS_INODE_ITEM_KEY; 3417 key.offset = 0; 3418 inode = btrfs_iget(root->fs_info->sb, &key, root); 3419 BUG_ON(IS_ERR(inode) || is_bad_inode(inode)); 3420 BTRFS_I(inode)->index_cnt = group->key.objectid; 3421 3422 err = btrfs_orphan_add(trans, inode); 3423 out: 3424 nr = trans->blocks_used; 3425 btrfs_end_transaction(trans, root); 3426 3427 btrfs_btree_balance_dirty(root, nr); 3428 if (err) { 3429 if (inode) 3430 iput(inode); 3431 inode = ERR_PTR(err); 3432 } 3433 return inode; 3434 } 3435 3436 /* 3437 * function to relocate all extents in a block group. 3438 */ 3439 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start) 3440 { 3441 struct btrfs_fs_info *fs_info = extent_root->fs_info; 3442 struct reloc_control *rc; 3443 int ret; 3444 int err = 0; 3445 3446 rc = kzalloc(sizeof(*rc), GFP_NOFS); 3447 if (!rc) 3448 return -ENOMEM; 3449 3450 mapping_tree_init(&rc->reloc_root_tree); 3451 extent_io_tree_init(&rc->processed_blocks, NULL, GFP_NOFS); 3452 INIT_LIST_HEAD(&rc->reloc_roots); 3453 3454 rc->block_group = btrfs_lookup_block_group(fs_info, group_start); 3455 BUG_ON(!rc->block_group); 3456 3457 btrfs_init_workers(&rc->workers, "relocate", 3458 fs_info->thread_pool_size); 3459 3460 rc->extent_root = extent_root; 3461 btrfs_prepare_block_group_relocation(extent_root, rc->block_group); 3462 3463 rc->data_inode = create_reloc_inode(fs_info, rc->block_group); 3464 if (IS_ERR(rc->data_inode)) { 3465 err = PTR_ERR(rc->data_inode); 3466 rc->data_inode = NULL; 3467 goto out; 3468 } 3469 3470 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n", 3471 (unsigned long long)rc->block_group->key.objectid, 3472 (unsigned long long)rc->block_group->flags); 3473 3474 btrfs_start_delalloc_inodes(fs_info->tree_root); 3475 btrfs_wait_ordered_extents(fs_info->tree_root, 0); 3476 3477 while (1) { 3478 mutex_lock(&fs_info->cleaner_mutex); 3479 btrfs_clean_old_snapshots(fs_info->tree_root); 3480 mutex_unlock(&fs_info->cleaner_mutex); 3481 3482 rc->extents_found = 0; 3483 rc->extents_skipped = 0; 3484 3485 ret = relocate_block_group(rc); 3486 if (ret < 0) { 3487 err = ret; 3488 break; 3489 } 3490 3491 if (rc->extents_found == 0) 3492 break; 3493 3494 printk(KERN_INFO "btrfs: found %llu extents\n", 3495 (unsigned long long)rc->extents_found); 3496 3497 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) { 3498 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1); 3499 invalidate_mapping_pages(rc->data_inode->i_mapping, 3500 0, -1); 3501 rc->stage = UPDATE_DATA_PTRS; 3502 } else if (rc->stage == UPDATE_DATA_PTRS && 3503 rc->extents_skipped >= rc->extents_found) { 3504 iput(rc->data_inode); 3505 rc->data_inode = create_reloc_inode(fs_info, 3506 rc->block_group); 3507 if (IS_ERR(rc->data_inode)) { 3508 err = PTR_ERR(rc->data_inode); 3509 rc->data_inode = NULL; 3510 break; 3511 } 3512 rc->stage = MOVE_DATA_EXTENTS; 3513 rc->found_file_extent = 0; 3514 } 3515 } 3516 3517 filemap_fdatawrite_range(fs_info->btree_inode->i_mapping, 3518 rc->block_group->key.objectid, 3519 rc->block_group->key.objectid + 3520 rc->block_group->key.offset - 1); 3521 3522 WARN_ON(rc->block_group->pinned > 0); 3523 WARN_ON(rc->block_group->reserved > 0); 3524 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0); 3525 out: 3526 iput(rc->data_inode); 3527 btrfs_stop_workers(&rc->workers); 3528 btrfs_put_block_group(rc->block_group); 3529 kfree(rc); 3530 return err; 3531 } 3532 3533 /* 3534 * recover relocation interrupted by system crash. 3535 * 3536 * this function resumes merging reloc trees with corresponding fs trees. 3537 * this is important for keeping the sharing of tree blocks 3538 */ 3539 int btrfs_recover_relocation(struct btrfs_root *root) 3540 { 3541 LIST_HEAD(reloc_roots); 3542 struct btrfs_key key; 3543 struct btrfs_root *fs_root; 3544 struct btrfs_root *reloc_root; 3545 struct btrfs_path *path; 3546 struct extent_buffer *leaf; 3547 struct reloc_control *rc = NULL; 3548 struct btrfs_trans_handle *trans; 3549 int ret; 3550 int err = 0; 3551 3552 path = btrfs_alloc_path(); 3553 if (!path) 3554 return -ENOMEM; 3555 3556 key.objectid = BTRFS_TREE_RELOC_OBJECTID; 3557 key.type = BTRFS_ROOT_ITEM_KEY; 3558 key.offset = (u64)-1; 3559 3560 while (1) { 3561 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, 3562 path, 0, 0); 3563 if (ret < 0) { 3564 err = ret; 3565 goto out; 3566 } 3567 if (ret > 0) { 3568 if (path->slots[0] == 0) 3569 break; 3570 path->slots[0]--; 3571 } 3572 leaf = path->nodes[0]; 3573 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3574 btrfs_release_path(root->fs_info->tree_root, path); 3575 3576 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID || 3577 key.type != BTRFS_ROOT_ITEM_KEY) 3578 break; 3579 3580 reloc_root = btrfs_read_fs_root_no_radix(root, &key); 3581 if (IS_ERR(reloc_root)) { 3582 err = PTR_ERR(reloc_root); 3583 goto out; 3584 } 3585 3586 list_add(&reloc_root->root_list, &reloc_roots); 3587 3588 if (btrfs_root_refs(&reloc_root->root_item) > 0) { 3589 fs_root = read_fs_root(root->fs_info, 3590 reloc_root->root_key.offset); 3591 if (IS_ERR(fs_root)) { 3592 err = PTR_ERR(fs_root); 3593 goto out; 3594 } 3595 } 3596 3597 if (key.offset == 0) 3598 break; 3599 3600 key.offset--; 3601 } 3602 btrfs_release_path(root->fs_info->tree_root, path); 3603 3604 if (list_empty(&reloc_roots)) 3605 goto out; 3606 3607 rc = kzalloc(sizeof(*rc), GFP_NOFS); 3608 if (!rc) { 3609 err = -ENOMEM; 3610 goto out; 3611 } 3612 3613 mapping_tree_init(&rc->reloc_root_tree); 3614 INIT_LIST_HEAD(&rc->reloc_roots); 3615 btrfs_init_workers(&rc->workers, "relocate", 3616 root->fs_info->thread_pool_size); 3617 rc->extent_root = root->fs_info->extent_root; 3618 3619 set_reloc_control(rc); 3620 3621 while (!list_empty(&reloc_roots)) { 3622 reloc_root = list_entry(reloc_roots.next, 3623 struct btrfs_root, root_list); 3624 list_del(&reloc_root->root_list); 3625 3626 if (btrfs_root_refs(&reloc_root->root_item) == 0) { 3627 list_add_tail(&reloc_root->root_list, 3628 &rc->reloc_roots); 3629 continue; 3630 } 3631 3632 fs_root = read_fs_root(root->fs_info, 3633 reloc_root->root_key.offset); 3634 BUG_ON(IS_ERR(fs_root)); 3635 3636 __add_reloc_root(reloc_root); 3637 fs_root->reloc_root = reloc_root; 3638 } 3639 3640 trans = btrfs_start_transaction(rc->extent_root, 1); 3641 btrfs_commit_transaction(trans, rc->extent_root); 3642 3643 merge_reloc_roots(rc); 3644 3645 unset_reloc_control(rc); 3646 3647 trans = btrfs_start_transaction(rc->extent_root, 1); 3648 btrfs_commit_transaction(trans, rc->extent_root); 3649 out: 3650 if (rc) { 3651 btrfs_stop_workers(&rc->workers); 3652 kfree(rc); 3653 } 3654 while (!list_empty(&reloc_roots)) { 3655 reloc_root = list_entry(reloc_roots.next, 3656 struct btrfs_root, root_list); 3657 list_del(&reloc_root->root_list); 3658 free_extent_buffer(reloc_root->node); 3659 free_extent_buffer(reloc_root->commit_root); 3660 kfree(reloc_root); 3661 } 3662 btrfs_free_path(path); 3663 3664 if (err == 0) { 3665 /* cleanup orphan inode in data relocation tree */ 3666 fs_root = read_fs_root(root->fs_info, 3667 BTRFS_DATA_RELOC_TREE_OBJECTID); 3668 if (IS_ERR(fs_root)) 3669 err = PTR_ERR(fs_root); 3670 } 3671 return err; 3672 } 3673 3674 /* 3675 * helper to add ordered checksum for data relocation. 3676 * 3677 * cloning checksum properly handles the nodatasum extents. 3678 * it also saves CPU time to re-calculate the checksum. 3679 */ 3680 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) 3681 { 3682 struct btrfs_ordered_sum *sums; 3683 struct btrfs_sector_sum *sector_sum; 3684 struct btrfs_ordered_extent *ordered; 3685 struct btrfs_root *root = BTRFS_I(inode)->root; 3686 size_t offset; 3687 int ret; 3688 u64 disk_bytenr; 3689 LIST_HEAD(list); 3690 3691 ordered = btrfs_lookup_ordered_extent(inode, file_pos); 3692 BUG_ON(ordered->file_offset != file_pos || ordered->len != len); 3693 3694 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt; 3695 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr, 3696 disk_bytenr + len - 1, &list); 3697 3698 while (!list_empty(&list)) { 3699 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 3700 list_del_init(&sums->list); 3701 3702 sector_sum = sums->sums; 3703 sums->bytenr = ordered->start; 3704 3705 offset = 0; 3706 while (offset < sums->len) { 3707 sector_sum->bytenr += ordered->start - disk_bytenr; 3708 sector_sum++; 3709 offset += root->sectorsize; 3710 } 3711 3712 btrfs_add_ordered_sum(inode, ordered, sums); 3713 } 3714 btrfs_put_ordered_extent(ordered); 3715 return 0; 3716 } 3717