btrfsck.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #define _XOPEN_SOURCE 500
  20 #define _GNU_SOURCE 1
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <sys/stat.h>
  26 #include <getopt.h>
  27 #include "kerncompat.h"
  28 #include "ctree.h"
  29 #include "volumes.h"
  30 #include "repair.h"
  31 #include "disk-io.h"
  32 #include "print-tree.h"
  33 #include "transaction.h"
  34 #include "list.h"
  35 #include "version.h"
  36 #include "utils.h"
  37
  38 static u64 bytes_used = 0;
  39 static u64 total_csum_bytes = 0;
  40 static u64 total_btree_bytes = 0;
  41 static u64 total_fs_tree_bytes = 0;
  42 static u64 btree_space_waste = 0;
  43 static u64 data_bytes_allocated = 0;
  44 static u64 data_bytes_referenced = 0;
  45 static int found_old_backref = 0;
  46
  47 struct extent_backref {
  48         struct list_head list;
  49         unsigned int is_data:1;
  50         unsigned int found_extent_tree:1;
  51         unsigned int full_backref:1;
  52         unsigned int found_ref:1;
  53 };
  54
  55 struct data_backref {
  56         struct extent_backref node;
  57         union {
  58                 u64 parent;
  59                 u64 root;
  60         };
  61         u64 owner;
  62         u64 offset;
  63         u32 num_refs;
  64         u32 found_ref;
  65 };
  66
  67 struct tree_backref {
  68         struct extent_backref node;
  69         union {
  70                 u64 parent;
  71                 u64 root;
  72         };
  73 };
  74
  75 struct extent_record {
  76         struct list_head backrefs;
  77         struct cache_extent cache;
  78         struct btrfs_disk_key parent_key;
  79         u64 start;
  80         u64 max_size;
  81         u64 nr;
  82         u64 refs;
  83         u64 extent_item_refs;
  84         u64 generation;
  85         u64 info_objectid;
  86         u8 info_level;
  87         unsigned int content_checked:1;
  88         unsigned int owner_ref_checked:1;
  89         unsigned int is_root:1;
  90 };
  91
  92 struct inode_backref {
  93         struct list_head list;
  94         unsigned int found_dir_item:1;
  95         unsigned int found_dir_index:1;
  96         unsigned int found_inode_ref:1;
  97         unsigned int filetype:8;
  98         int errors;
  99         u64 dir;
 100         u64 index;
 101         u16 namelen;
 102         char name[0];
 103 };
 104
 105 #define REF_ERR_NO_DIR_ITEM             (1 << 0)
 106 #define REF_ERR_NO_DIR_INDEX            (1 << 1)
 107 #define REF_ERR_NO_INODE_REF            (1 << 2)
 108 #define REF_ERR_DUP_DIR_ITEM            (1 << 3)
 109 #define REF_ERR_DUP_DIR_INDEX           (1 << 4)
 110 #define REF_ERR_DUP_INODE_REF           (1 << 5)
 111 #define REF_ERR_INDEX_UNMATCH           (1 << 6)
 112 #define REF_ERR_FILETYPE_UNMATCH        (1 << 7)
 113 #define REF_ERR_NAME_TOO_LONG           (1 << 8) // 100
 114 #define REF_ERR_NO_ROOT_REF             (1 << 9)
 115 #define REF_ERR_NO_ROOT_BACKREF         (1 << 10)
 116 #define REF_ERR_DUP_ROOT_REF            (1 << 11)
 117 #define REF_ERR_DUP_ROOT_BACKREF        (1 << 12)
 118
 119 struct inode_record {
 120         struct list_head backrefs;
 121         unsigned int checked:1;
 122         unsigned int merging:1;
 123         unsigned int found_inode_item:1;
 124         unsigned int found_dir_item:1;
 125         unsigned int found_file_extent:1;
 126         unsigned int found_csum_item:1;
 127         unsigned int some_csum_missing:1;
 128         unsigned int nodatasum:1;
 129         int errors;
 130
 131         u64 ino;
 132         u32 nlink;
 133         u32 imode;
 134         u64 isize;
 135         u64 nbytes;
 136
 137         u32 found_link;
 138         u64 found_size;
 139         u64 extent_start;
 140         u64 extent_end;
 141         u64 first_extent_gap;
 142
 143         u32 refs;
 144 };
 145
 146 #define I_ERR_NO_INODE_ITEM             (1 << 0)
 147 #define I_ERR_NO_ORPHAN_ITEM            (1 << 1)
 148 #define I_ERR_DUP_INODE_ITEM            (1 << 2)
 149 #define I_ERR_DUP_DIR_INDEX             (1 << 3)
 150 #define I_ERR_ODD_DIR_ITEM              (1 << 4)
 151 #define I_ERR_ODD_FILE_EXTENT           (1 << 5)
 152 #define I_ERR_BAD_FILE_EXTENT           (1 << 6)
 153 #define I_ERR_FILE_EXTENT_OVERLAP       (1 << 7)
 154 #define I_ERR_FILE_EXTENT_DISCOUNT      (1 << 8) // 100
 155 #define I_ERR_DIR_ISIZE_WRONG           (1 << 9)
 156 #define I_ERR_FILE_NBYTES_WRONG         (1 << 10) // 400
 157 #define I_ERR_ODD_CSUM_ITEM             (1 << 11)
 158 #define I_ERR_SOME_CSUM_MISSING         (1 << 12)
 159 #define I_ERR_LINK_COUNT_WRONG          (1 << 13)
 160
 161 struct root_backref {
 162         struct list_head list;
 163         unsigned int found_dir_item:1;
 164         unsigned int found_dir_index:1;
 165         unsigned int found_back_ref:1;
 166         unsigned int found_forward_ref:1;
 167         unsigned int reachable:1;
 168         int errors;
 169         u64 ref_root;
 170         u64 dir;
 171         u64 index;
 172         u16 namelen;
 173         char name[0];
 174 };
 175
 176 struct root_record {
 177         struct list_head backrefs;
 178         struct cache_extent cache;
 179         unsigned int found_root_item:1;
 180         u64 objectid;
 181         u32 found_ref;
 182 };
 183
 184 struct ptr_node {
 185         struct cache_extent cache;
 186         void *data;
 187 };
 188
 189 struct shared_node {
 190         struct cache_extent cache;
 191         struct cache_tree root_cache;
 192         struct cache_tree inode_cache;
 193         struct inode_record *current;
 194         u32 refs;
 195 };
 196
 197 struct block_info {
 198         u64 start;
 199         u32 size;
 200 };
 201
 202 struct walk_control {
 203         struct cache_tree shared;
 204         struct shared_node *nodes[BTRFS_MAX_LEVEL];
 205         int active_node;
 206         int root_level;
 207 };
 208
 209 static u8 imode_to_type(u32 imode)
 210 {
 211 #define S_SHIFT 12
 212         static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
 213                 [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
 214                 [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
 215                 [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
 216                 [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
 217                 [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
 218                 [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
 219                 [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
 220         };
 221
 222         return btrfs_type_by_mode[(imode & S_IFMT) >> S_SHIFT];
 223 #undef S_SHIFT
 224 }
 225
 226 static struct inode_record *clone_inode_rec(struct inode_record *orig_rec)
 227 {
 228         struct inode_record *rec;
 229         struct inode_backref *backref;
 230         struct inode_backref *orig;
 231         size_t size;
 232
 233         rec = malloc(sizeof(*rec));
 234         memcpy(rec, orig_rec, sizeof(*rec));
 235         rec->refs = 1;
 236         INIT_LIST_HEAD(&rec->backrefs);
 237
 238         list_for_each_entry(orig, &orig_rec->backrefs, list) {
 239                 size = sizeof(*orig) + orig->namelen + 1;
 240                 backref = malloc(size);
 241                 memcpy(backref, orig, size);
 242                 list_add_tail(&backref->list, &rec->backrefs);
 243         }
 244         return rec;
 245 }
 246
 247 static struct inode_record *get_inode_rec(struct cache_tree *inode_cache,
 248                                           u64 ino, int mod)
 249 {
 250         struct ptr_node *node;
 251         struct cache_extent *cache;
 252         struct inode_record *rec = NULL;
 253         int ret;
 254
 255         cache = find_cache_extent(inode_cache, ino, 1);
 256         if (cache) {
 257                 node = container_of(cache, struct ptr_node, cache);
 258                 rec = node->data;
 259                 if (mod && rec->refs > 1) {
 260                         node->data = clone_inode_rec(rec);
 261                         rec->refs--;
 262                         rec = node->data;
 263                 }
 264         } else if (mod) {
 265                 rec = calloc(1, sizeof(*rec));
 266                 rec->ino = ino;
 267                 rec->extent_start = (u64)-1;
 268                 rec->first_extent_gap = (u64)-1;
 269                 rec->refs = 1;
 270                 INIT_LIST_HEAD(&rec->backrefs);
 271
 272                 node = malloc(sizeof(*node));
 273                 node->cache.start = ino;
 274                 node->cache.size = 1;
 275                 node->data = rec;
 276
 277                 if (ino == BTRFS_FREE_INO_OBJECTID)
 278                         rec->found_link = 1;
 279
 280                 ret = insert_existing_cache_extent(inode_cache, &node->cache);
 281                 BUG_ON(ret);
 282         }
 283         return rec;
 284 }
 285
 286 static void free_inode_rec(struct inode_record *rec)
 287 {
 288         struct inode_backref *backref;
 289
 290         if (--rec->refs > 0)
 291                 return;
 292
 293         while (!list_empty(&rec->backrefs)) {
 294                 backref = list_entry(rec->backrefs.next,
 295                                      struct inode_backref, list);
 296                 list_del(&backref->list);
 297                 free(backref);
 298         }
 299         free(rec);
 300 }
 301
 302 static int can_free_inode_rec(struct inode_record *rec)
 303 {
 304         if (!rec->errors && rec->checked && rec->found_inode_item &&
 305             rec->nlink == rec->found_link && list_empty(&rec->backrefs))
 306                 return 1;
 307         return 0;
 308 }
 309
 310 static void maybe_free_inode_rec(struct cache_tree *inode_cache,
 311                                  struct inode_record *rec)
 312 {
 313         struct cache_extent *cache;
 314         struct inode_backref *tmp, *backref;
 315         struct ptr_node *node;
 316         unsigned char filetype;
 317
 318         if (!rec->found_inode_item)
 319                 return;
 320
 321         filetype = imode_to_type(rec->imode);
 322         list_for_each_entry_safe(backref, tmp, &rec->backrefs, list) {
 323                 if (backref->found_dir_item && backref->found_dir_index) {
 324                         if (backref->filetype != filetype)
 325                                 backref->errors |= REF_ERR_FILETYPE_UNMATCH;
 326                         if (!backref->errors && backref->found_inode_ref) {
 327                                 list_del(&backref->list);
 328                                 free(backref);
 329                         }
 330                 }
 331         }
 332
 333         if (!rec->checked || rec->merging)
 334                 return;
 335
 336         if (S_ISDIR(rec->imode)) {
 337                 if (rec->found_size != rec->isize)
 338                         rec->errors |= I_ERR_DIR_ISIZE_WRONG;
 339                 if (rec->found_file_extent)
 340                         rec->errors |= I_ERR_ODD_FILE_EXTENT;
 341         } else if (S_ISREG(rec->imode) || S_ISLNK(rec->imode)) {
 342                 if (rec->found_dir_item)
 343                         rec->errors |= I_ERR_ODD_DIR_ITEM;
 344                 if (rec->found_size != rec->nbytes)
 345                         rec->errors |= I_ERR_FILE_NBYTES_WRONG;
 346                 if (rec->extent_start == (u64)-1 || rec->extent_start > 0)
 347                         rec->first_extent_gap = 0;
 348                 if (rec->nlink > 0 && (rec->extent_end < rec->isize ||
 349                     rec->first_extent_gap < rec->isize))
 350                         rec->errors |= I_ERR_FILE_EXTENT_DISCOUNT;
 351         }
 352
 353         if (S_ISREG(rec->imode) || S_ISLNK(rec->imode)) {
 354                 if (rec->found_csum_item && rec->nodatasum)
 355                         rec->errors |= I_ERR_ODD_CSUM_ITEM;
 356                 if (rec->some_csum_missing && !rec->nodatasum)
 357                         rec->errors |= I_ERR_SOME_CSUM_MISSING;
 358         }
 359
 360         BUG_ON(rec->refs != 1);
 361         if (can_free_inode_rec(rec)) {
 362                 cache = find_cache_extent(inode_cache, rec->ino, 1);
 363                 node = container_of(cache, struct ptr_node, cache);
 364                 BUG_ON(node->data != rec);
 365                 remove_cache_extent(inode_cache, &node->cache);
 366                 free(node);
 367                 free_inode_rec(rec);
 368         }
 369 }
 370
 371 static int check_orphan_item(struct btrfs_root *root, u64 ino)
 372 {
 373         struct btrfs_path path;
 374         struct btrfs_key key;
 375         int ret;
 376
 377         key.objectid = BTRFS_ORPHAN_OBJECTID;
 378         key.type = BTRFS_ORPHAN_ITEM_KEY;
 379         key.offset = ino;
 380
 381         btrfs_init_path(&path);
 382         ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
 383         btrfs_release_path(root, &path);
 384         if (ret > 0)
 385                 ret = -ENOENT;
 386         return ret;
 387 }
 388
 389 static int process_inode_item(struct extent_buffer *eb,
 390                               int slot, struct btrfs_key *key,
 391                               struct shared_node *active_node)
 392 {
 393         struct inode_record *rec;
 394         struct btrfs_inode_item *item;
 395
 396         rec = active_node->current;
 397         BUG_ON(rec->ino != key->objectid || rec->refs > 1);
 398         if (rec->found_inode_item) {
 399                 rec->errors |= I_ERR_DUP_INODE_ITEM;
 400                 return 1;
 401         }
 402         item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
 403         rec->nlink = btrfs_inode_nlink(eb, item);
 404         rec->isize = btrfs_inode_size(eb, item);
 405         rec->nbytes = btrfs_inode_nbytes(eb, item);
 406         rec->imode = btrfs_inode_mode(eb, item);
 407         if (btrfs_inode_flags(eb, item) & BTRFS_INODE_NODATASUM)
 408                 rec->nodatasum = 1;
 409         rec->found_inode_item = 1;
 410         if (rec->nlink == 0)
 411                 rec->errors |= I_ERR_NO_ORPHAN_ITEM;
 412         maybe_free_inode_rec(&active_node->inode_cache, rec);
 413         return 0;
 414 }
 415
 416 static struct inode_backref *get_inode_backref(struct inode_record *rec,
 417                                                 const char *name,
 418                                                 int namelen, u64 dir)
 419 {
 420         struct inode_backref *backref;
 421
 422         list_for_each_entry(backref, &rec->backrefs, list) {
 423                 if (backref->dir != dir || backref->namelen != namelen)
 424                         continue;
 425                 if (memcmp(name, backref->name, namelen))
 426                         continue;
 427                 return backref;
 428         }
 429
 430         backref = malloc(sizeof(*backref) + namelen + 1);
 431         memset(backref, 0, sizeof(*backref));
 432         backref->dir = dir;
 433         backref->namelen = namelen;
 434         memcpy(backref->name, name, namelen);
 435         backref->name[namelen] = '\0';
 436         list_add_tail(&backref->list, &rec->backrefs);
 437         return backref;
 438 }
 439
 440 static int add_inode_backref(struct cache_tree *inode_cache,
 441                              u64 ino, u64 dir, u64 index,
 442                              const char *name, int namelen,
 443                              int filetype, int itemtype, int errors)
 444 {
 445         struct inode_record *rec;
 446         struct inode_backref *backref;
 447
 448         rec = get_inode_rec(inode_cache, ino, 1);
 449         backref = get_inode_backref(rec, name, namelen, dir);
 450         if (errors)
 451                 backref->errors |= errors;
 452         if (itemtype == BTRFS_DIR_INDEX_KEY) {
 453                 if (backref->found_dir_index)
 454                         backref->errors |= REF_ERR_DUP_DIR_INDEX;
 455                 if (backref->found_inode_ref && backref->index != index)
 456                         backref->errors |= REF_ERR_INDEX_UNMATCH;
 457                 if (backref->found_dir_item && backref->filetype != filetype)
 458                         backref->errors |= REF_ERR_FILETYPE_UNMATCH;
 459
 460                 backref->index = index;
 461                 backref->filetype = filetype;
 462                 backref->found_dir_index = 1;
 463         } else if (itemtype == BTRFS_DIR_ITEM_KEY) {
 464                 rec->found_link++;
 465                 if (backref->found_dir_item)
 466                         backref->errors |= REF_ERR_DUP_DIR_ITEM;
 467                 if (backref->found_dir_index && backref->filetype != filetype)
 468                         backref->errors |= REF_ERR_FILETYPE_UNMATCH;
 469
 470                 backref->filetype = filetype;
 471                 backref->found_dir_item = 1;
 472         } else if (itemtype == BTRFS_INODE_REF_KEY) {
 473                 if (backref->found_inode_ref)
 474                         backref->errors |= REF_ERR_DUP_INODE_REF;
 475                 if (backref->found_dir_index && backref->index != index)
 476                         backref->errors |= REF_ERR_INDEX_UNMATCH;
 477
 478                 backref->index = index;
 479                 backref->found_inode_ref = 1;
 480         } else {
 481                 BUG_ON(1);
 482         }
 483
 484         maybe_free_inode_rec(inode_cache, rec);
 485         return 0;
 486 }
 487
 488 static int merge_inode_recs(struct inode_record *src, struct inode_record *dst,
 489                             struct cache_tree *dst_cache)
 490 {
 491         struct inode_backref *backref;
 492         u32 dir_count = 0;
 493
 494         dst->merging = 1;
 495         list_for_each_entry(backref, &src->backrefs, list) {
 496                 if (backref->found_dir_index) {
 497                         add_inode_backref(dst_cache, dst->ino, backref->dir,
 498                                         backref->index, backref->name,
 499                                         backref->namelen, backref->filetype,
 500                                         BTRFS_DIR_INDEX_KEY, backref->errors);
 501                 }
 502                 if (backref->found_dir_item) {
 503                         dir_count++;
 504                         add_inode_backref(dst_cache, dst->ino,
 505                                         backref->dir, 0, backref->name,
 506                                         backref->namelen, backref->filetype,
 507                                         BTRFS_DIR_ITEM_KEY, backref->errors);
 508                 }
 509                 if (backref->found_inode_ref) {
 510                         add_inode_backref(dst_cache, dst->ino,
 511                                         backref->dir, backref->index,
 512                                         backref->name, backref->namelen, 0,
 513                                         BTRFS_INODE_REF_KEY, backref->errors);
 514                 }
 515         }
 516
 517         if (src->found_dir_item)
 518                 dst->found_dir_item = 1;
 519         if (src->found_file_extent)
 520                 dst->found_file_extent = 1;
 521         if (src->found_csum_item)
 522                 dst->found_csum_item = 1;
 523         if (src->some_csum_missing)
 524                 dst->some_csum_missing = 1;
 525         if (dst->first_extent_gap > src->first_extent_gap)
 526                 dst->first_extent_gap = src->first_extent_gap;
 527
 528         BUG_ON(src->found_link < dir_count);
 529         dst->found_link += src->found_link - dir_count;
 530         dst->found_size += src->found_size;
 531         if (src->extent_start != (u64)-1) {
 532                 if (dst->extent_start == (u64)-1) {
 533                         dst->extent_start = src->extent_start;
 534                         dst->extent_end = src->extent_end;
 535                 } else {
 536                         if (dst->extent_end > src->extent_start)
 537                                 dst->errors |= I_ERR_FILE_EXTENT_OVERLAP;
 538                         else if (dst->extent_end < src->extent_start &&
 539                                  dst->extent_end < dst->first_extent_gap)
 540                                 dst->first_extent_gap = dst->extent_end;
 541                         if (dst->extent_end < src->extent_end)
 542                                 dst->extent_end = src->extent_end;
 543                 }
 544         }
 545
 546         dst->errors |= src->errors;
 547         if (src->found_inode_item) {
 548                 if (!dst->found_inode_item) {
 549                         dst->nlink = src->nlink;
 550                         dst->isize = src->isize;
 551                         dst->nbytes = src->nbytes;
 552                         dst->imode = src->imode;
 553                         dst->nodatasum = src->nodatasum;
 554                         dst->found_inode_item = 1;
 555                 } else {
 556                         dst->errors |= I_ERR_DUP_INODE_ITEM;
 557                 }
 558         }
 559         dst->merging = 0;
 560
 561         return 0;
 562 }
 563
 564 static int splice_shared_node(struct shared_node *src_node,
 565                               struct shared_node *dst_node)
 566 {
 567         struct cache_extent *cache;
 568         struct ptr_node *node, *ins;
 569         struct cache_tree *src, *dst;
 570         struct inode_record *rec, *conflict;
 571         u64 current_ino = 0;
 572         int splice = 0;
 573         int ret;
 574
 575         if (--src_node->refs == 0)
 576                 splice = 1;
 577         if (src_node->current)
 578                 current_ino = src_node->current->ino;
 579
 580         src = &src_node->root_cache;
 581         dst = &dst_node->root_cache;
 582 again:
 583         cache = find_first_cache_extent(src, 0);
 584         while (cache) {
 585                 node = container_of(cache, struct ptr_node, cache);
 586                 rec = node->data;
 587                 cache = next_cache_extent(cache);
 588
 589                 if (splice) {
 590                         remove_cache_extent(src, &node->cache);
 591                         ins = node;
 592                 } else {
 593                         ins = malloc(sizeof(*ins));
 594                         ins->cache.start = node->cache.start;
 595                         ins->cache.size = node->cache.size;
 596                         ins->data = rec;
 597                         rec->refs++;
 598                 }
 599                 ret = insert_existing_cache_extent(dst, &ins->cache);
 600                 if (ret == -EEXIST) {
 601                         conflict = get_inode_rec(dst, rec->ino, 1);
 602                         merge_inode_recs(rec, conflict, dst);
 603                         if (rec->checked) {
 604                                 conflict->checked = 1;
 605                                 if (dst_node->current == conflict)
 606                                         dst_node->current = NULL;
 607                         }
 608                         maybe_free_inode_rec(dst, conflict);
 609                         free_inode_rec(rec);
 610                         free(ins);
 611                 } else {
 612                         BUG_ON(ret);
 613                 }
 614         }
 615
 616         if (src == &src_node->root_cache) {
 617                 src = &src_node->inode_cache;
 618                 dst = &dst_node->inode_cache;
 619                 goto again;
 620         }
 621
 622         if (current_ino > 0 && (!dst_node->current ||
 623             current_ino > dst_node->current->ino)) {
 624                 if (dst_node->current) {
 625                         dst_node->current->checked = 1;
 626                         maybe_free_inode_rec(dst, dst_node->current);
 627                 }
 628                 dst_node->current = get_inode_rec(dst, current_ino, 1);
 629         }
 630         return 0;
 631 }
 632
 633 static void free_inode_recs(struct cache_tree *inode_cache)
 634 {
 635         struct cache_extent *cache;
 636         struct ptr_node *node;
 637         struct inode_record *rec;
 638
 639         while (1) {
 640                 cache = find_first_cache_extent(inode_cache, 0);
 641                 if (!cache)
 642                         break;
 643                 node = container_of(cache, struct ptr_node, cache);
 644                 rec = node->data;
 645                 remove_cache_extent(inode_cache, &node->cache);
 646                 free(node);
 647                 free_inode_rec(rec);
 648         }
 649 }
 650
 651 static struct shared_node *find_shared_node(struct cache_tree *shared,
 652                                             u64 bytenr)
 653 {
 654         struct cache_extent *cache;
 655         struct shared_node *node;
 656
 657         cache = find_cache_extent(shared, bytenr, 1);
 658         if (cache) {
 659                 node = container_of(cache, struct shared_node, cache);
 660                 return node;
 661         }
 662         return NULL;
 663 }
 664
 665 static int add_shared_node(struct cache_tree *shared, u64 bytenr, u32 refs)
 666 {
 667         int ret;
 668         struct shared_node *node;
 669
 670         node = calloc(1, sizeof(*node));
 671         node->cache.start = bytenr;
 672         node->cache.size = 1;
 673         cache_tree_init(&node->root_cache);
 674         cache_tree_init(&node->inode_cache);
 675         node->refs = refs;
 676
 677         ret = insert_existing_cache_extent(shared, &node->cache);
 678         BUG_ON(ret);
 679         return 0;
 680 }
 681
 682 static int enter_shared_node(struct btrfs_root *root, u64 bytenr, u32 refs,
 683                              struct walk_control *wc, int level)
 684 {
 685         struct shared_node *node;
 686         struct shared_node *dest;
 687
 688         if (level == wc->active_node)
 689                 return 0;
 690
 691         BUG_ON(wc->active_node <= level);
 692         node = find_shared_node(&wc->shared, bytenr);
 693         if (!node) {
 694                 add_shared_node(&wc->shared, bytenr, refs);
 695                 node = find_shared_node(&wc->shared, bytenr);
 696                 wc->nodes[level] = node;
 697                 wc->active_node = level;
 698                 return 0;
 699         }
 700
 701         if (wc->root_level == wc->active_node &&
 702             btrfs_root_refs(&root->root_item) == 0) {
 703                 if (--node->refs == 0) {
 704                         free_inode_recs(&node->root_cache);
 705                         free_inode_recs(&node->inode_cache);
 706                         remove_cache_extent(&wc->shared, &node->cache);
 707                         free(node);
 708                 }
 709                 return 1;
 710         }
 711
 712         dest = wc->nodes[wc->active_node];
 713         splice_shared_node(node, dest);
 714         if (node->refs == 0) {
 715                 remove_cache_extent(&wc->shared, &node->cache);
 716                 free(node);
 717         }
 718         return 1;
 719 }
 720
 721 static int leave_shared_node(struct btrfs_root *root,
 722                              struct walk_control *wc, int level)
 723 {
 724         struct shared_node *node;
 725         struct shared_node *dest;
 726         int i;
 727
 728         if (level == wc->root_level)
 729                 return 0;
 730
 731         for (i = level + 1; i < BTRFS_MAX_LEVEL; i++) {
 732                 if (wc->nodes[i])
 733                         break;
 734         }
 735         BUG_ON(i >= BTRFS_MAX_LEVEL);
 736
 737         node = wc->nodes[wc->active_node];
 738         wc->nodes[wc->active_node] = NULL;
 739         wc->active_node = i;
 740
 741         dest = wc->nodes[wc->active_node];
 742         if (wc->active_node < wc->root_level ||
 743             btrfs_root_refs(&root->root_item) > 0) {
 744                 BUG_ON(node->refs <= 1);
 745                 splice_shared_node(node, dest);
 746         } else {
 747                 BUG_ON(node->refs < 2);
 748                 node->refs--;
 749         }
 750         return 0;
 751 }
 752
 753 static int is_child_root(struct btrfs_root *root, u64 parent_root_id,
 754                          u64 child_root_id)
 755 {
 756         struct btrfs_path path;
 757         struct btrfs_key key;
 758         struct extent_buffer *leaf;
 759         int has_parent = 0;
 760         int ret;
 761
 762         btrfs_init_path(&path);
 763
 764         key.objectid = parent_root_id;
 765         key.type = BTRFS_ROOT_REF_KEY;
 766         key.offset = child_root_id;
 767         ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, &path,
 768                                 0, 0);
 769         BUG_ON(ret < 0);
 770         btrfs_release_path(root, &path);
 771         if (!ret)
 772                 return 1;
 773
 774         key.objectid = child_root_id;
 775         key.type = BTRFS_ROOT_BACKREF_KEY;
 776         key.offset = 0;
 777         ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, &path,
 778                                 0, 0);
 779         BUG_ON(ret <= 0);
 780
 781         while (1) {
 782                 leaf = path.nodes[0];
 783                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
 784                         ret = btrfs_next_leaf(root->fs_info->tree_root, &path);
 785                         BUG_ON(ret < 0);
 786
 787                         if (ret > 0)
 788                                 break;
 789                 }
 790
 791                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
 792                 if (key.objectid != child_root_id ||
 793                     key.type != BTRFS_ROOT_BACKREF_KEY)
 794                         break;
 795
 796                 has_parent = 1;
 797
 798                 if (key.offset == parent_root_id) {
 799                         btrfs_release_path(root, &path);
 800                         return 1;
 801                 }
 802
 803                 path.slots[0]++;
 804         }
 805
 806         btrfs_release_path(root, &path);
 807         return has_parent? 0 : -1;
 808 }
 809
 810 static int process_dir_item(struct btrfs_root *root,
 811                             struct extent_buffer *eb,
 812                             int slot, struct btrfs_key *key,
 813                             struct shared_node *active_node)
 814 {
 815         u32 total;
 816         u32 cur = 0;
 817         u32 len;
 818         u32 name_len;
 819         u32 data_len;
 820         int error;
 821         int nritems = 0;
 822         int filetype;
 823         struct btrfs_dir_item *di;
 824         struct inode_record *rec;
 825         struct cache_tree *root_cache;
 826         struct cache_tree *inode_cache;
 827         struct btrfs_key location;
 828         char namebuf[BTRFS_NAME_LEN];
 829
 830         root_cache = &active_node->root_cache;
 831         inode_cache = &active_node->inode_cache;
 832         rec = active_node->current;
 833         rec->found_dir_item = 1;
 834
 835         di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
 836         total = btrfs_item_size_nr(eb, slot);
 837         while (cur < total) {
 838                 nritems++;
 839                 btrfs_dir_item_key_to_cpu(eb, di, &location);
 840                 name_len = btrfs_dir_name_len(eb, di);
 841                 data_len = btrfs_dir_data_len(eb, di);
 842                 filetype = btrfs_dir_type(eb, di);
 843
 844                 rec->found_size += name_len;
 845                 if (name_len <= BTRFS_NAME_LEN) {
 846                         len = name_len;
 847                         error = 0;
 848                 } else {
 849                         len = BTRFS_NAME_LEN;
 850                         error = REF_ERR_NAME_TOO_LONG;
 851                 }
 852                 read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), len);
 853
 854                 if (location.type == BTRFS_INODE_ITEM_KEY) {
 855                         add_inode_backref(inode_cache, location.objectid,
 856                                           key->objectid, key->offset, namebuf,
 857                                           len, filetype, key->type, error);
 858                 } else if (location.type == BTRFS_ROOT_ITEM_KEY) {
 859                         u64 parent = root->objectid;
 860
 861                         if (is_child_root(root, parent, location.objectid))
 862                                 add_inode_backref(root_cache, location.objectid,
 863                                                   key->objectid, key->offset,
 864                                                   namebuf, len, filetype,
 865                                                   key->type, error);
 866                 } else {
 867                         fprintf(stderr, "warning line %d\n", __LINE__);
 868                 }
 869
 870                 len = sizeof(*di) + name_len + data_len;
 871                 di = (struct btrfs_dir_item *)((char *)di + len);
 872                 cur += len;
 873         }
 874         if (key->type == BTRFS_DIR_INDEX_KEY && nritems > 1)
 875                 rec->errors |= I_ERR_DUP_DIR_INDEX;
 876
 877         return 0;
 878 }
 879
 880 static int process_inode_ref(struct extent_buffer *eb,
 881                              int slot, struct btrfs_key *key,
 882                              struct shared_node *active_node)
 883 {
 884         u32 total;
 885         u32 cur = 0;
 886         u32 len;
 887         u32 name_len;
 888         u64 index;
 889         int error;
 890         struct cache_tree *inode_cache;
 891         struct btrfs_inode_ref *ref;
 892         char namebuf[BTRFS_NAME_LEN];
 893
 894         inode_cache = &active_node->inode_cache;
 895
 896         ref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
 897         total = btrfs_item_size_nr(eb, slot);
 898         while (cur < total) {
 899                 name_len = btrfs_inode_ref_name_len(eb, ref);
 900                 index = btrfs_inode_ref_index(eb, ref);
 901                 if (name_len <= BTRFS_NAME_LEN) {
 902                         len = name_len;
 903                         error = 0;
 904                 } else {
 905                         len = BTRFS_NAME_LEN;
 906                         error = REF_ERR_NAME_TOO_LONG;
 907                 }
 908                 read_extent_buffer(eb, namebuf, (unsigned long)(ref + 1), len);
 909                 add_inode_backref(inode_cache, key->objectid, key->offset,
 910                                   index, namebuf, len, 0, key->type, error);
 911
 912                 len = sizeof(*ref) + name_len;
 913                 ref = (struct btrfs_inode_ref *)((char *)ref + len);
 914                 cur += len;
 915         }
 916         return 0;
 917 }
 918
 919 static u64 count_csum_range(struct btrfs_root *root, u64 start, u64 len)
 920 {
 921         struct btrfs_key key;
 922         struct btrfs_path path;
 923         struct extent_buffer *leaf;
 924         int ret ;
 925         size_t size;
 926         u64 found = 0;
 927         u64 csum_end;
 928         u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
 929
 930         btrfs_init_path(&path);
 931
 932         key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
 933         key.offset = start;
 934         key.type = BTRFS_EXTENT_CSUM_KEY;
 935
 936         ret = btrfs_search_slot(NULL, root->fs_info->csum_root,
 937                                 &key, &path, 0, 0);
 938         BUG_ON(ret < 0);
 939         if (ret > 0 && path.slots[0] > 0) {
 940                 leaf = path.nodes[0];
 941                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0] - 1);
 942                 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
 943                     key.type == BTRFS_EXTENT_CSUM_KEY)
 944                         path.slots[0]--;
 945         }
 946
 947         while (len > 0) {
 948                 leaf = path.nodes[0];
 949                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
 950                         ret = btrfs_next_leaf(root->fs_info->csum_root, &path);
 951                         BUG_ON(ret < 0);
 952                         if (ret > 0)
 953                                 break;
 954                         leaf = path.nodes[0];
 955                 }
 956
 957                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
 958                 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
 959                     key.type != BTRFS_EXTENT_CSUM_KEY)
 960                         break;
 961
 962                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
 963                 if (key.offset >= start + len)
 964                         break;
 965
 966                 if (key.offset > start)
 967                         start = key.offset;
 968
 969                 size = btrfs_item_size_nr(leaf, path.slots[0]);
 970                 csum_end = key.offset + (size / csum_size) * root->sectorsize;
 971                 if (csum_end > start) {
 972                         size = min(csum_end - start, len);
 973                         len -= size;
 974                         start += size;
 975                         found += size;
 976                 }
 977
 978                 path.slots[0]++;
 979         }
 980         btrfs_release_path(root->fs_info->csum_root, &path);
 981         return found;
 982 }
 983
 984 static int process_file_extent(struct btrfs_root *root,
 985                                 struct extent_buffer *eb,
 986                                 int slot, struct btrfs_key *key,
 987                                 struct shared_node *active_node)
 988 {
 989         struct inode_record *rec;
 990         struct btrfs_file_extent_item *fi;
 991         u64 num_bytes = 0;
 992         u64 disk_bytenr = 0;
 993         u64 extent_offset = 0;
 994         u64 mask = root->sectorsize - 1;
 995         int extent_type;
 996
 997         rec = active_node->current;
 998         BUG_ON(rec->ino != key->objectid || rec->refs > 1);
 999         rec->found_file_extent = 1;
1000
1001         if (rec->extent_start == (u64)-1) {
1002                 rec->extent_start = key->offset;
1003                 rec->extent_end = key->offset;
1004         }
1005
1006         if (rec->extent_end > key->offset)
1007                 rec->errors |= I_ERR_FILE_EXTENT_OVERLAP;
1008         else if (rec->extent_end < key->offset &&
1009                  rec->extent_end < rec->first_extent_gap)
1010                 rec->first_extent_gap = rec->extent_end;
1011
1012         fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
1013         extent_type = btrfs_file_extent_type(eb, fi);
1014
1015         if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1016                 num_bytes = btrfs_file_extent_inline_len(eb, fi);
1017                 if (num_bytes == 0)
1018                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1019                 rec->found_size += num_bytes;
1020                 num_bytes = (num_bytes + mask) & ~mask;
1021         } else if (extent_type == BTRFS_FILE_EXTENT_REG ||
1022                    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1023                 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1024                 disk_bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1025                 extent_offset = btrfs_file_extent_offset(eb, fi);
1026                 if (num_bytes == 0 || (num_bytes & mask))
1027                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1028                 if (num_bytes + extent_offset >
1029                     btrfs_file_extent_ram_bytes(eb, fi))
1030                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1031                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC &&
1032                     (btrfs_file_extent_compression(eb, fi) ||
1033                      btrfs_file_extent_encryption(eb, fi) ||
1034                      btrfs_file_extent_other_encoding(eb, fi)))
1035                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1036                 if (disk_bytenr > 0)
1037                         rec->found_size += num_bytes;
1038         } else {
1039                 rec->errors |= I_ERR_BAD_FILE_EXTENT;
1040         }
1041         rec->extent_end = key->offset + num_bytes;
1042
1043         if (disk_bytenr > 0) {
1044                 u64 found;
1045                 if (btrfs_file_extent_compression(eb, fi))
1046                         num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1047                 else
1048                         disk_bytenr += extent_offset;
1049
1050                 found = count_csum_range(root, disk_bytenr, num_bytes);
1051                 if (extent_type == BTRFS_FILE_EXTENT_REG) {
1052                         if (found > 0)
1053                                 rec->found_csum_item = 1;
1054                         if (found < num_bytes)
1055                                 rec->some_csum_missing = 1;
1056                 } else if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1057                         if (found > 0)
1058                                 rec->errors |= I_ERR_ODD_CSUM_ITEM;
1059                 }
1060         }
1061         return 0;
1062 }
1063
1064 static int process_one_leaf(struct btrfs_root *root, struct extent_buffer *eb,
1065                             struct walk_control *wc)
1066 {
1067         struct btrfs_key key;
1068         u32 nritems;
1069         int i;
1070         int ret = 0;
1071         struct cache_tree *inode_cache;
1072         struct shared_node *active_node;
1073
1074         if (wc->root_level == wc->active_node &&
1075             btrfs_root_refs(&root->root_item) == 0)
1076                 return 0;
1077
1078         active_node = wc->nodes[wc->active_node];
1079         inode_cache = &active_node->inode_cache;
1080         nritems = btrfs_header_nritems(eb);
1081         for (i = 0; i < nritems; i++) {
1082                 btrfs_item_key_to_cpu(eb, &key, i);
1083
1084                 if (key.objectid == BTRFS_FREE_SPACE_OBJECTID)
1085                         continue;
1086
1087                 if (active_node->current == NULL ||
1088                     active_node->current->ino < key.objectid) {
1089                         if (active_node->current) {
1090                                 active_node->current->checked = 1;
1091                                 maybe_free_inode_rec(inode_cache,
1092                                                      active_node->current);
1093                         }
1094                         active_node->current = get_inode_rec(inode_cache,
1095                                                              key.objectid, 1);
1096                 }
1097                 switch (key.type) {
1098                 case BTRFS_DIR_ITEM_KEY:
1099                 case BTRFS_DIR_INDEX_KEY:
1100                         ret = process_dir_item(root, eb, i, &key, active_node);
1101                         break;
1102                 case BTRFS_INODE_REF_KEY:
1103                         ret = process_inode_ref(eb, i, &key, active_node);
1104                         break;
1105                 case BTRFS_INODE_ITEM_KEY:
1106                         ret = process_inode_item(eb, i, &key, active_node);
1107                         break;
1108                 case BTRFS_EXTENT_DATA_KEY:
1109                         ret = process_file_extent(root, eb, i, &key,
1110                                                   active_node);
1111                         break;
1112                 default:
1113                         break;
1114                 };
1115         }
1116         return ret;
1117 }
1118
1119 static void reada_walk_down(struct btrfs_root *root,
1120                             struct extent_buffer *node, int slot)
1121 {
1122         u64 bytenr;
1123         u64 ptr_gen;
1124         u32 nritems;
1125         u32 blocksize;
1126         int i;
1127         int ret;
1128         int level;
1129
1130         level = btrfs_header_level(node);
1131         if (level != 1)
1132                 return;
1133
1134         nritems = btrfs_header_nritems(node);
1135         blocksize = btrfs_level_size(root, level - 1);
1136         for (i = slot; i < nritems; i++) {
1137                 bytenr = btrfs_node_blockptr(node, i);
1138                 ptr_gen = btrfs_node_ptr_generation(node, i);
1139                 ret = readahead_tree_block(root, bytenr, blocksize, ptr_gen);
1140                 if (ret)
1141                         break;
1142         }
1143 }
1144
1145 static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path,
1146                           struct walk_control *wc, int *level)
1147 {
1148         u64 bytenr;
1149         u64 ptr_gen;
1150         struct extent_buffer *next;
1151         struct extent_buffer *cur;
1152         u32 blocksize;
1153         int ret;
1154         u64 refs;
1155
1156         WARN_ON(*level < 0);
1157         WARN_ON(*level >= BTRFS_MAX_LEVEL);
1158         ret = btrfs_lookup_extent_info(NULL, root,
1159                                        path->nodes[*level]->start,
1160                                        path->nodes[*level]->len, &refs, NULL);
1161         if (ret < 0)
1162                 goto out;
1163
1164         if (refs > 1) {
1165                 ret = enter_shared_node(root, path->nodes[*level]->start,
1166                                         refs, wc, *level);
1167                 if (ret > 0)
1168                         goto out;
1169         }
1170
1171         while (*level >= 0) {
1172                 WARN_ON(*level < 0);
1173                 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1174                 cur = path->nodes[*level];
1175
1176                 if (btrfs_header_level(cur) != *level)
1177                         WARN_ON(1);
1178
1179                 if (path->slots[*level] >= btrfs_header_nritems(cur))
1180                         break;
1181                 if (*level == 0) {
1182                         ret = process_one_leaf(root, cur, wc);
1183                         break;
1184                 }
1185                 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1186                 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1187                 blocksize = btrfs_level_size(root, *level - 1);
1188                 ret = btrfs_lookup_extent_info(NULL, root, bytenr, blocksize,
1189                                                &refs, NULL);
1190                 if (ret < 0)
1191                         refs = 0;
1192
1193                 if (refs > 1) {
1194                         ret = enter_shared_node(root, bytenr, refs,
1195                                                 wc, *level - 1);
1196                         if (ret > 0) {
1197                                 path->slots[*level]++;
1198                                 continue;
1199                         }
1200                 }
1201
1202                 next = btrfs_find_tree_block(root, bytenr, blocksize);
1203                 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
1204                         free_extent_buffer(next);
1205                         reada_walk_down(root, cur, path->slots[*level]);
1206                         next = read_tree_block(root, bytenr, blocksize,
1207                                                ptr_gen);
1208                 }
1209
1210                 *level = *level - 1;
1211                 free_extent_buffer(path->nodes[*level]);
1212                 path->nodes[*level] = next;
1213                 path->slots[*level] = 0;
1214         }
1215 out:
1216         path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
1217         return 0;
1218 }
1219
1220 static int walk_up_tree(struct btrfs_root *root, struct btrfs_path *path,
1221                         struct walk_control *wc, int *level)
1222 {
1223         int i;
1224         struct extent_buffer *leaf;
1225
1226         for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1227                 leaf = path->nodes[i];
1228                 if (path->slots[i] + 1 < btrfs_header_nritems(leaf)) {
1229                         path->slots[i]++;
1230                         *level = i;
1231                         return 0;
1232                 } else {
1233                         free_extent_buffer(path->nodes[*level]);
1234                         path->nodes[*level] = NULL;
1235                         BUG_ON(*level > wc->active_node);
1236                         if (*level == wc->active_node)
1237                                 leave_shared_node(root, wc, *level);
1238                         *level = i + 1;
1239                 }
1240         }
1241         return 1;
1242 }
1243
1244 static int check_root_dir(struct inode_record *rec)
1245 {
1246         struct inode_backref *backref;
1247         int ret = -1;
1248
1249         if (!rec->found_inode_item || rec->errors)
1250                 goto out;
1251         if (rec->nlink != 1 || rec->found_link != 0)
1252                 goto out;
1253         if (list_empty(&rec->backrefs))
1254                 goto out;
1255         backref = list_entry(rec->backrefs.next, struct inode_backref, list);
1256         if (!backref->found_inode_ref)
1257                 goto out;
1258         if (backref->index != 0 || backref->namelen != 2 ||
1259             memcmp(backref->name, "..", 2))
1260                 goto out;
1261         if (backref->found_dir_index || backref->found_dir_item)
1262                 goto out;
1263         ret = 0;
1264 out:
1265         return ret;
1266 }
1267
1268 static int check_inode_recs(struct btrfs_root *root,
1269                             struct cache_tree *inode_cache)
1270 {
1271         struct cache_extent *cache;
1272         struct ptr_node *node;
1273         struct inode_record *rec;
1274         struct inode_backref *backref;
1275         int ret;
1276         u64 error = 0;
1277         u64 root_dirid = btrfs_root_dirid(&root->root_item);
1278
1279         if (btrfs_root_refs(&root->root_item) == 0) {
1280                 if (!cache_tree_empty(inode_cache))
1281                         fprintf(stderr, "warning line %d\n", __LINE__);
1282                 return 0;
1283         }
1284
1285         rec = get_inode_rec(inode_cache, root_dirid, 0);
1286         if (rec) {
1287                 ret = check_root_dir(rec);
1288                 if (ret) {
1289                         fprintf(stderr, "root %llu root dir %llu error\n",
1290                                 (unsigned long long)root->root_key.objectid,
1291                                 (unsigned long long)root_dirid);
1292                         error++;
1293                 }
1294         } else {
1295                 fprintf(stderr, "root %llu root dir %llu not found\n",
1296                         (unsigned long long)root->root_key.objectid,
1297                         (unsigned long long)root_dirid);
1298         }
1299
1300         while (1) {
1301                 cache = find_first_cache_extent(inode_cache, 0);
1302                 if (!cache)
1303                         break;
1304                 node = container_of(cache, struct ptr_node, cache);
1305                 rec = node->data;
1306                 remove_cache_extent(inode_cache, &node->cache);
1307                 free(node);
1308                 if (rec->ino == root_dirid ||
1309                     rec->ino == BTRFS_ORPHAN_OBJECTID) {
1310                         free_inode_rec(rec);
1311                         continue;
1312                 }
1313
1314                 if (rec->errors & I_ERR_NO_ORPHAN_ITEM) {
1315                         ret = check_orphan_item(root, rec->ino);
1316                         if (ret == 0)
1317                                 rec->errors &= ~I_ERR_NO_ORPHAN_ITEM;
1318                         if (can_free_inode_rec(rec)) {
1319                                 free_inode_rec(rec);
1320                                 continue;
1321                         }
1322                 }
1323
1324                 error++;
1325                 if (!rec->found_inode_item)
1326                         rec->errors |= I_ERR_NO_INODE_ITEM;
1327                 if (rec->found_link != rec->nlink)
1328                         rec->errors |= I_ERR_LINK_COUNT_WRONG;
1329                 fprintf(stderr, "root %llu inode %llu errors %x\n",
1330                         (unsigned long long) root->root_key.objectid,
1331                         (unsigned long long) rec->ino, rec->errors);
1332                 list_for_each_entry(backref, &rec->backrefs, list) {
1333                         if (!backref->found_dir_item)
1334                                 backref->errors |= REF_ERR_NO_DIR_ITEM;
1335                         if (!backref->found_dir_index)
1336                                 backref->errors |= REF_ERR_NO_DIR_INDEX;
1337                         if (!backref->found_inode_ref)
1338                                 backref->errors |= REF_ERR_NO_INODE_REF;
1339                         fprintf(stderr, "\tunresolved ref dir %llu index %llu"
1340                                 " namelen %u name %s filetype %d error %x\n",
1341                                 (unsigned long long)backref->dir,
1342                                 (unsigned long long)backref->index,
1343                                 backref->namelen, backref->name,
1344                                 backref->filetype, backref->errors);
1345                 }
1346                 free_inode_rec(rec);
1347         }
1348         return (error > 0) ? -1 : 0;
1349 }
1350
1351 static struct root_record *get_root_rec(struct cache_tree *root_cache,
1352                                         u64 objectid)
1353 {
1354         struct cache_extent *cache;
1355         struct root_record *rec = NULL;
1356         int ret;
1357
1358         cache = find_cache_extent(root_cache, objectid, 1);
1359         if (cache) {
1360                 rec = container_of(cache, struct root_record, cache);
1361         } else {
1362                 rec = calloc(1, sizeof(*rec));
1363                 rec->objectid = objectid;
1364                 INIT_LIST_HEAD(&rec->backrefs);
1365                 rec->cache.start = objectid;
1366                 rec->cache.size = 1;
1367
1368                 ret = insert_existing_cache_extent(root_cache, &rec->cache);
1369                 BUG_ON(ret);
1370         }
1371         return rec;
1372 }
1373
1374 static struct root_backref *get_root_backref(struct root_record *rec,
1375                                              u64 ref_root, u64 dir, u64 index,
1376                                              const char *name, int namelen)
1377 {
1378         struct root_backref *backref;
1379
1380         list_for_each_entry(backref, &rec->backrefs, list) {
1381                 if (backref->ref_root != ref_root || backref->dir != dir ||
1382                     backref->namelen != namelen)
1383                         continue;
1384                 if (memcmp(name, backref->name, namelen))
1385                         continue;
1386                 return backref;
1387         }
1388
1389         backref = malloc(sizeof(*backref) + namelen + 1);
1390         memset(backref, 0, sizeof(*backref));
1391         backref->ref_root = ref_root;
1392         backref->dir = dir;
1393         backref->index = index;
1394         backref->namelen = namelen;
1395         memcpy(backref->name, name, namelen);
1396         backref->name[namelen] = '\0';
1397         list_add_tail(&backref->list, &rec->backrefs);
1398         return backref;
1399 }
1400
1401 static void free_root_recs(struct cache_tree *root_cache)
1402 {
1403         struct cache_extent *cache;
1404         struct root_record *rec;
1405         struct root_backref *backref;
1406
1407         while (1) {
1408                 cache = find_first_cache_extent(root_cache, 0);
1409                 if (!cache)
1410                         break;
1411                 rec = container_of(cache, struct root_record, cache);
1412                 remove_cache_extent(root_cache, &rec->cache);
1413
1414                 while (!list_empty(&rec->backrefs)) {
1415                         backref = list_entry(rec->backrefs.next,
1416                                              struct root_backref, list);
1417                         list_del(&backref->list);
1418                         free(backref);
1419                 }
1420                 kfree(rec);
1421         }
1422 }
1423
1424 static int add_root_backref(struct cache_tree *root_cache,
1425                             u64 root_id, u64 ref_root, u64 dir, u64 index,
1426                             const char *name, int namelen,
1427                             int item_type, int errors)
1428 {
1429         struct root_record *rec;
1430         struct root_backref *backref;
1431
1432         rec = get_root_rec(root_cache, root_id);
1433         backref = get_root_backref(rec, ref_root, dir, index, name, namelen);
1434
1435         backref->errors |= errors;
1436
1437         if (item_type != BTRFS_DIR_ITEM_KEY) {
1438                 if (backref->found_dir_index || backref->found_back_ref ||
1439                     backref->found_forward_ref) {
1440                         if (backref->index != index)
1441                                 backref->errors |= REF_ERR_INDEX_UNMATCH;
1442                 } else {
1443                         backref->index = index;
1444                 }
1445         }
1446
1447         if (item_type == BTRFS_DIR_ITEM_KEY) {
1448                 backref->found_dir_item = 1;
1449                 backref->reachable = 1;
1450                 rec->found_ref++;
1451         } else if (item_type == BTRFS_DIR_INDEX_KEY) {
1452                 backref->found_dir_index = 1;
1453         } else if (item_type == BTRFS_ROOT_REF_KEY) {
1454                 if (backref->found_forward_ref)
1455                         backref->errors |= REF_ERR_DUP_ROOT_REF;
1456                 backref->found_forward_ref = 1;
1457         } else if (item_type == BTRFS_ROOT_BACKREF_KEY) {
1458                 if (backref->found_back_ref)
1459                         backref->errors |= REF_ERR_DUP_ROOT_BACKREF;
1460                 backref->found_back_ref = 1;
1461         } else {
1462                 BUG_ON(1);
1463         }
1464
1465         return 0;
1466 }
1467
1468 static int merge_root_recs(struct btrfs_root *root,
1469                            struct cache_tree *src_cache,
1470                            struct cache_tree *dst_cache)
1471 {
1472         struct cache_extent *cache;
1473         struct ptr_node *node;
1474         struct inode_record *rec;
1475         struct inode_backref *backref;
1476
1477         if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
1478                 free_inode_recs(src_cache);
1479                 return 0;
1480         }
1481
1482         while (1) {
1483                 cache = find_first_cache_extent(src_cache, 0);
1484                 if (!cache)
1485                         break;
1486                 node = container_of(cache, struct ptr_node, cache);
1487                 rec = node->data;
1488                 remove_cache_extent(src_cache, &node->cache);
1489                 free(node);
1490
1491                 list_for_each_entry(backref, &rec->backrefs, list) {
1492                         BUG_ON(backref->found_inode_ref);
1493                         if (backref->found_dir_item)
1494                                 add_root_backref(dst_cache, rec->ino,
1495                                         root->root_key.objectid, backref->dir,
1496                                         backref->index, backref->name,
1497                                         backref->namelen, BTRFS_DIR_ITEM_KEY,
1498                                         backref->errors);
1499                         if (backref->found_dir_index)
1500                                 add_root_backref(dst_cache, rec->ino,
1501                                         root->root_key.objectid, backref->dir,
1502                                         backref->index, backref->name,
1503                                         backref->namelen, BTRFS_DIR_INDEX_KEY,
1504                                         backref->errors);
1505                 }
1506                 free_inode_rec(rec);
1507         }
1508         return 0;
1509 }
1510
1511 static int check_root_refs(struct btrfs_root *root,
1512                            struct cache_tree *root_cache)
1513 {
1514         struct root_record *rec;
1515         struct root_record *ref_root;
1516         struct root_backref *backref;
1517         struct cache_extent *cache;
1518         int loop = 1;
1519         int ret;
1520         int error;
1521         int errors = 0;
1522
1523         rec = get_root_rec(root_cache, BTRFS_FS_TREE_OBJECTID);
1524         rec->found_ref = 1;
1525
1526         /* fixme: this can not detect circular references */
1527         while (loop) {
1528                 loop = 0;
1529                 cache = find_first_cache_extent(root_cache, 0);
1530                 while (1) {
1531                         if (!cache)
1532                                 break;
1533                         rec = container_of(cache, struct root_record, cache);
1534                         cache = next_cache_extent(cache);
1535
1536                         if (rec->found_ref == 0)
1537                                 continue;
1538
1539                         list_for_each_entry(backref, &rec->backrefs, list) {
1540                                 if (!backref->reachable)
1541                                         continue;
1542
1543                                 ref_root = get_root_rec(root_cache,
1544                                                         backref->ref_root);
1545                                 if (ref_root->found_ref > 0)
1546                                         continue;
1547
1548                                 backref->reachable = 0;
1549                                 rec->found_ref--;
1550                                 if (rec->found_ref == 0)
1551                                         loop = 1;
1552                         }
1553                 }
1554         }
1555
1556         cache = find_first_cache_extent(root_cache, 0);
1557         while (1) {
1558                 if (!cache)
1559                         break;
1560                 rec = container_of(cache, struct root_record, cache);
1561                 cache = next_cache_extent(cache);
1562
1563                 if (rec->found_ref == 0 &&
1564                     rec->objectid >= BTRFS_FIRST_FREE_OBJECTID &&
1565                     rec->objectid <= BTRFS_LAST_FREE_OBJECTID) {
1566                         ret = check_orphan_item(root->fs_info->tree_root,
1567                                                 rec->objectid);
1568                         if (ret == 0)
1569                                 continue;
1570                         errors++;
1571                         fprintf(stderr, "fs tree %llu not referenced\n",
1572                                 (unsigned long long)rec->objectid);
1573                 }
1574
1575                 error = 0;
1576                 if (rec->found_ref > 0 && !rec->found_root_item)
1577                         error = 1;
1578                 list_for_each_entry(backref, &rec->backrefs, list) {
1579                         if (!backref->found_dir_item)
1580                                 backref->errors |= REF_ERR_NO_DIR_ITEM;
1581                         if (!backref->found_dir_index)
1582                                 backref->errors |= REF_ERR_NO_DIR_INDEX;
1583                         if (!backref->found_back_ref)
1584                                 backref->errors |= REF_ERR_NO_ROOT_BACKREF;
1585                         if (!backref->found_forward_ref)
1586                                 backref->errors |= REF_ERR_NO_ROOT_REF;
1587                         if (backref->reachable && backref->errors)
1588                                 error = 1;
1589                 }
1590                 if (!error)
1591                         continue;
1592
1593                 errors++;
1594                 fprintf(stderr, "fs tree %llu refs %u %s\n",
1595                         (unsigned long long)rec->objectid, rec->found_ref,
1596                          rec->found_root_item ? "" : "not found");
1597
1598                 list_for_each_entry(backref, &rec->backrefs, list) {
1599                         if (!backref->reachable)
1600                                 continue;
1601                         if (!backref->errors && rec->found_root_item)
1602                                 continue;
1603                         fprintf(stderr, "\tunresolved ref root %llu dir %llu"
1604                                 " index %llu namelen %u name %s error %x\n",
1605                                 (unsigned long long)backref->ref_root,
1606                                 (unsigned long long)backref->dir,
1607                                 (unsigned long long)backref->index,
1608                                 backref->namelen, backref->name,
1609                                 backref->errors);
1610                 }
1611         }
1612         return errors > 0 ? 1 : 0;
1613 }
1614
1615 static int process_root_ref(struct extent_buffer *eb, int slot,
1616                             struct btrfs_key *key,
1617                             struct cache_tree *root_cache)
1618 {
1619         u64 dirid;
1620         u64 index;
1621         u32 len;
1622         u32 name_len;
1623         struct btrfs_root_ref *ref;
1624         char namebuf[BTRFS_NAME_LEN];
1625         int error;
1626
1627         ref = btrfs_item_ptr(eb, slot, struct btrfs_root_ref);
1628
1629         dirid = btrfs_root_ref_dirid(eb, ref);
1630         index = btrfs_root_ref_sequence(eb, ref);
1631         name_len = btrfs_root_ref_name_len(eb, ref);
1632
1633         if (name_len <= BTRFS_NAME_LEN) {
1634                 len = name_len;
1635                 error = 0;
1636         } else {
1637                 len = BTRFS_NAME_LEN;
1638                 error = REF_ERR_NAME_TOO_LONG;
1639         }
1640         read_extent_buffer(eb, namebuf, (unsigned long)(ref + 1), len);
1641
1642         if (key->type == BTRFS_ROOT_REF_KEY) {
1643                 add_root_backref(root_cache, key->offset, key->objectid, dirid,
1644                                  index, namebuf, len, key->type, error);
1645         } else {
1646                 add_root_backref(root_cache, key->objectid, key->offset, dirid,
1647                                  index, namebuf, len, key->type, error);
1648         }
1649         return 0;
1650 }
1651
1652 static int check_fs_root(struct btrfs_root *root,
1653                          struct cache_tree *root_cache,
1654                          struct walk_control *wc)
1655 {
1656         int ret = 0;
1657         int wret;
1658         int level;
1659         struct btrfs_path path;
1660         struct shared_node root_node;
1661         struct root_record *rec;
1662         struct btrfs_root_item *root_item = &root->root_item;
1663
1664         if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1665                 rec = get_root_rec(root_cache, root->root_key.objectid);
1666                 if (btrfs_root_refs(root_item) > 0)
1667                         rec->found_root_item = 1;
1668         }
1669
1670         btrfs_init_path(&path);
1671         memset(&root_node, 0, sizeof(root_node));
1672         cache_tree_init(&root_node.root_cache);
1673         cache_tree_init(&root_node.inode_cache);
1674
1675         level = btrfs_header_level(root->node);
1676         memset(wc->nodes, 0, sizeof(wc->nodes));
1677         wc->nodes[level] = &root_node;
1678         wc->active_node = level;
1679         wc->root_level = level;
1680
1681         if (btrfs_root_refs(root_item) > 0 ||
1682             btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
1683                 path.nodes[level] = root->node;
1684                 extent_buffer_get(root->node);
1685                 path.slots[level] = 0;
1686         } else {
1687                 struct btrfs_key key;
1688                 struct btrfs_disk_key found_key;
1689
1690                 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
1691                 level = root_item->drop_level;
1692                 path.lowest_level = level;
1693                 wret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
1694                 BUG_ON(wret < 0);
1695                 btrfs_node_key(path.nodes[level], &found_key,
1696                                 path.slots[level]);
1697                 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
1698                                         sizeof(found_key)));
1699         }
1700
1701         while (1) {
1702                 wret = walk_down_tree(root, &path, wc, &level);
1703                 if (wret < 0)
1704                         ret = wret;
1705                 if (wret != 0)
1706                         break;
1707
1708                 wret = walk_up_tree(root, &path, wc, &level);
1709                 if (wret < 0)
1710                         ret = wret;
1711                 if (wret != 0)
1712                         break;
1713         }
1714         btrfs_release_path(root, &path);
1715
1716         merge_root_recs(root, &root_node.root_cache, root_cache);
1717
1718         if (root_node.current) {
1719                 root_node.current->checked = 1;
1720                 maybe_free_inode_rec(&root_node.inode_cache,
1721                                 root_node.current);
1722         }
1723
1724         ret = check_inode_recs(root, &root_node.inode_cache);
1725         return ret;
1726 }
1727
1728 static int fs_root_objectid(u64 objectid)
1729 {
1730         if (objectid == BTRFS_FS_TREE_OBJECTID ||
1731             objectid == BTRFS_TREE_RELOC_OBJECTID ||
1732             objectid == BTRFS_DATA_RELOC_TREE_OBJECTID ||
1733             (objectid >= BTRFS_FIRST_FREE_OBJECTID &&
1734              objectid <= BTRFS_LAST_FREE_OBJECTID))
1735                 return 1;
1736         return 0;
1737 }
1738
1739 static int check_fs_roots(struct btrfs_root *root,
1740                           struct cache_tree *root_cache)
1741 {
1742         struct btrfs_path path;
1743         struct btrfs_key key;
1744         struct walk_control wc;
1745         struct extent_buffer *leaf;
1746         struct btrfs_root *tmp_root;
1747         struct btrfs_root *tree_root = root->fs_info->tree_root;
1748         int ret;
1749         int err = 0;
1750
1751         memset(&wc, 0, sizeof(wc));
1752         cache_tree_init(&wc.shared);
1753         btrfs_init_path(&path);
1754
1755         key.offset = 0;
1756         key.objectid = 0;
1757         key.type = BTRFS_ROOT_ITEM_KEY;
1758         ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0);
1759         BUG_ON(ret < 0);
1760         while (1) {
1761                 leaf = path.nodes[0];
1762                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
1763                         ret = btrfs_next_leaf(tree_root, &path);
1764                         if (ret != 0)
1765                                 break;
1766                         leaf = path.nodes[0];
1767                 }
1768                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
1769                 if (key.type == BTRFS_ROOT_ITEM_KEY &&
1770                     fs_root_objectid(key.objectid)) {
1771                         tmp_root = btrfs_read_fs_root_no_cache(root->fs_info,
1772                                                                &key);
1773                         ret = check_fs_root(tmp_root, root_cache, &wc);
1774                         if (ret)
1775                                 err = 1;
1776                         btrfs_free_fs_root(root->fs_info, tmp_root);
1777                 } else if (key.type == BTRFS_ROOT_REF_KEY ||
1778                            key.type == BTRFS_ROOT_BACKREF_KEY) {
1779                         process_root_ref(leaf, path.slots[0], &key,
1780                                          root_cache);
1781                 }
1782                 path.slots[0]++;
1783         }
1784         btrfs_release_path(tree_root, &path);
1785
1786         if (!cache_tree_empty(&wc.shared))
1787                 fprintf(stderr, "warning line %d\n", __LINE__);
1788
1789         return err;
1790 }
1791
1792 static int all_backpointers_checked(struct extent_record *rec, int print_errs)
1793 {
1794         struct list_head *cur = rec->backrefs.next;
1795         struct extent_backref *back;
1796         struct tree_backref *tback;
1797         struct data_backref *dback;
1798         u64 found = 0;
1799         int err = 0;
1800
1801         while(cur != &rec->backrefs) {
1802                 back = list_entry(cur, struct extent_backref, list);
1803                 cur = cur->next;
1804                 if (!back->found_extent_tree) {
1805                         err = 1;
1806                         if (!print_errs)
1807                                 goto out;
1808                         if (back->is_data) {
1809                                 dback = (struct data_backref *)back;
1810                                 fprintf(stderr, "Backref %llu %s %llu"
1811                                         " owner %llu offset %llu num_refs %lu"
1812                                         " not found in extent tree\n",
1813                                         (unsigned long long)rec->start,
1814                                         back->full_backref ?
1815                                         "parent" : "root",
1816                                         back->full_backref ?
1817                                         (unsigned long long)dback->parent:
1818                                         (unsigned long long)dback->root,
1819                                         (unsigned long long)dback->owner,
1820                                         (unsigned long long)dback->offset,
1821                                         (unsigned long)dback->num_refs);
1822                         } else {
1823                                 tback = (struct tree_backref *)back;
1824                                 fprintf(stderr, "Backref %llu parent %llu"
1825                                         " root %llu not found in extent tree\n",
1826                                         (unsigned long long)rec->start,
1827                                         (unsigned long long)tback->parent,
1828                                         (unsigned long long)tback->root);
1829                         }
1830                 }
1831                 if (!back->is_data && !back->found_ref) {
1832                         err = 1;
1833                         if (!print_errs)
1834                                 goto out;
1835                         tback = (struct tree_backref *)back;
1836                         fprintf(stderr, "Backref %llu %s %llu not referenced back %p\n",
1837                                 (unsigned long long)rec->start,
1838                                 back->full_backref ? "parent" : "root",
1839                                 back->full_backref ?
1840                                 (unsigned long long)tback->parent :
1841                                 (unsigned long long)tback->root, back);
1842                 }
1843                 if (back->is_data) {
1844                         dback = (struct data_backref *)back;
1845                         if (dback->found_ref != dback->num_refs) {
1846                                 err = 1;
1847                                 if (!print_errs)
1848                                         goto out;
1849                                 fprintf(stderr, "Incorrect local backref count"
1850                                         " on %llu %s %llu owner %llu"
1851                                         " offset %llu found %u wanted %u back %p\n",
1852                                         (unsigned long long)rec->start,
1853                                         back->full_backref ?
1854                                         "parent" : "root",
1855                                         back->full_backref ?
1856                                         (unsigned long long)dback->parent:
1857                                         (unsigned long long)dback->root,
1858                                         (unsigned long long)dback->owner,
1859                                         (unsigned long long)dback->offset,
1860                                         dback->found_ref, dback->num_refs, back);
1861                         }
1862                 }
1863                 if (!back->is_data) {
1864                         found += 1;
1865                 } else {
1866                         dback = (struct data_backref *)back;
1867                         found += dback->found_ref;
1868                 }
1869         }
1870         if (found != rec->refs) {
1871                 err = 1;
1872                 if (!print_errs)
1873                         goto out;
1874                 fprintf(stderr, "Incorrect global backref count "
1875                         "on %llu found %llu wanted %llu\n",
1876                         (unsigned long long)rec->start,
1877                         (unsigned long long)found,
1878                         (unsigned long long)rec->refs);
1879         }
1880 out:
1881         return err;
1882 }
1883
1884 static int free_all_extent_backrefs(struct extent_record *rec)
1885 {
1886         struct extent_backref *back;
1887         struct list_head *cur;
1888         while (!list_empty(&rec->backrefs)) {
1889                 cur = rec->backrefs.next;
1890                 back = list_entry(cur, struct extent_backref, list);
1891                 list_del(cur);
1892                 free(back);
1893         }
1894         return 0;
1895 }
1896
1897 static int maybe_free_extent_rec(struct cache_tree *extent_cache,
1898                                  struct extent_record *rec)
1899 {
1900         if (rec->content_checked && rec->owner_ref_checked &&
1901             rec->extent_item_refs == rec->refs && rec->refs > 0 &&
1902             !all_backpointers_checked(rec, 0)) {
1903                 remove_cache_extent(extent_cache, &rec->cache);
1904                 free_all_extent_backrefs(rec);
1905                 free(rec);
1906         }
1907         return 0;
1908 }
1909
1910 static int check_owner_ref(struct btrfs_root *root,
1911                             struct extent_record *rec,
1912                             struct extent_buffer *buf)
1913 {
1914         struct extent_backref *node;
1915         struct tree_backref *back;
1916         struct btrfs_root *ref_root;
1917         struct btrfs_key key;
1918         struct btrfs_path path;
1919         int level;
1920         int found = 0;
1921
1922         list_for_each_entry(node, &rec->backrefs, list) {
1923                 if (node->is_data)
1924                         continue;
1925                 if (!node->found_ref)
1926                         continue;
1927                 if (node->full_backref)
1928                         continue;
1929                 back = (struct tree_backref *)node;
1930                 if (btrfs_header_owner(buf) == back->root)
1931                         return 0;
1932         }
1933         BUG_ON(rec->is_root);
1934
1935         /* try to find the block by search corresponding fs tree */
1936         key.objectid = btrfs_header_owner(buf);
1937         key.type = BTRFS_ROOT_ITEM_KEY;
1938         key.offset = (u64)-1;
1939
1940         ref_root = btrfs_read_fs_root(root->fs_info, &key);
1941         BUG_ON(IS_ERR(ref_root));
1942
1943         level = btrfs_header_level(buf);
1944         if (level == 0)
1945                 btrfs_item_key_to_cpu(buf, &key, 0);
1946         else
1947                 btrfs_node_key_to_cpu(buf, &key, 0);
1948
1949         btrfs_init_path(&path);
1950         path.lowest_level = level + 1;
1951         btrfs_search_slot(NULL, ref_root, &key, &path, 0, 0);
1952
1953         if (buf->start == btrfs_node_blockptr(path.nodes[level + 1],
1954                                               path.slots[level + 1]))
1955                 rec->owner_ref_checked = 1;
1956
1957         btrfs_release_path(ref_root, &path);
1958         return found ? 0 : 1;
1959 }
1960
1961 static int is_extent_tree_record(struct extent_record *rec)
1962 {
1963         struct list_head *cur = rec->backrefs.next;
1964         struct extent_backref *node;
1965         struct tree_backref *back;
1966         int is_extent = 0;
1967
1968         while(cur != &rec->backrefs) {
1969                 node = list_entry(cur, struct extent_backref, list);
1970                 cur = cur->next;
1971                 if (node->is_data)
1972                         return 0;
1973                 back = (struct tree_backref *)node;
1974                 if (node->full_backref)
1975                         return 0;
1976                 if (back->root == BTRFS_EXTENT_TREE_OBJECTID)
1977                         is_extent = 1;
1978         }
1979         return is_extent;
1980 }
1981
1982
1983 static int record_bad_block_io(struct btrfs_fs_info *info,
1984                                struct cache_tree *extent_cache,
1985                                u64 start, u64 len)
1986 {
1987         struct extent_record *rec;
1988         struct cache_extent *cache;
1989         struct btrfs_key key;
1990
1991         cache = find_cache_extent(extent_cache, start, len);
1992         if (!cache)
1993                 return 0;
1994
1995         rec = container_of(cache, struct extent_record, cache);
1996         if (!is_extent_tree_record(rec))
1997                 return 0;
1998
1999         btrfs_disk_key_to_cpu(&key, &rec->parent_key);
2000         return btrfs_add_corrupt_extent_record(info, &key, start, len, 0);
2001 }
2002
2003 static int check_block(struct btrfs_root *root,
2004                        struct cache_tree *extent_cache,
2005                        struct extent_buffer *buf, u64 flags)
2006 {
2007         struct extent_record *rec;
2008         struct cache_extent *cache;
2009         struct btrfs_key key;
2010         int ret = 1;
2011         int level;
2012
2013         cache = find_cache_extent(extent_cache, buf->start, buf->len);
2014         if (!cache)
2015                 return 1;
2016         rec = container_of(cache, struct extent_record, cache);
2017         rec->generation = btrfs_header_generation(buf);
2018
2019         level = btrfs_header_level(buf);
2020         if (btrfs_header_nritems(buf) > 0) {
2021
2022                 if (level == 0)
2023                         btrfs_item_key_to_cpu(buf, &key, 0);
2024                 else
2025                         btrfs_node_key_to_cpu(buf, &key, 0);
2026
2027                 rec->info_objectid = key.objectid;
2028         }
2029         rec->info_level = level;
2030
2031         if (btrfs_is_leaf(buf))
2032                 ret = btrfs_check_leaf(root, &rec->parent_key, buf);
2033         else
2034                 ret = btrfs_check_node(root, &rec->parent_key, buf);
2035
2036         if (ret) {
2037                 fprintf(stderr, "bad block %llu\n",
2038                         (unsigned long long)buf->start);
2039         } else {
2040                 rec->content_checked = 1;
2041                 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
2042                         rec->owner_ref_checked = 1;
2043                 else {
2044                         ret = check_owner_ref(root, rec, buf);
2045                         if (!ret)
2046                                 rec->owner_ref_checked = 1;
2047                 }
2048         }
2049         if (!ret)
2050                 maybe_free_extent_rec(extent_cache, rec);
2051         return ret;
2052 }
2053
2054 static struct tree_backref *find_tree_backref(struct extent_record *rec,
2055                                                 u64 parent, u64 root)
2056 {
2057         struct list_head *cur = rec->backrefs.next;
2058         struct extent_backref *node;
2059         struct tree_backref *back;
2060
2061         while(cur != &rec->backrefs) {
2062                 node = list_entry(cur, struct extent_backref, list);
2063                 cur = cur->next;
2064                 if (node->is_data)
2065                         continue;
2066                 back = (struct tree_backref *)node;
2067                 if (parent > 0) {
2068                         if (!node->full_backref)
2069                                 continue;
2070                         if (parent == back->parent)
2071                                 return back;
2072                 } else {
2073                         if (node->full_backref)
2074                                 continue;
2075                         if (back->root == root)
2076                                 return back;
2077                 }
2078         }
2079         return NULL;
2080 }
2081
2082 static struct tree_backref *alloc_tree_backref(struct extent_record *rec,
2083                                                 u64 parent, u64 root)
2084 {
2085         struct tree_backref *ref = malloc(sizeof(*ref));
2086         memset(&ref->node, 0, sizeof(ref->node));
2087         if (parent > 0) {
2088                 ref->parent = parent;
2089                 ref->node.full_backref = 1;
2090         } else {
2091                 ref->root = root;
2092                 ref->node.full_backref = 0;
2093         }
2094         list_add_tail(&ref->node.list, &rec->backrefs);
2095
2096         return ref;
2097 }
2098
2099 static struct data_backref *find_data_backref(struct extent_record *rec,
2100                                                 u64 parent, u64 root,
2101                                                 u64 owner, u64 offset)
2102 {
2103         struct list_head *cur = rec->backrefs.next;
2104         struct extent_backref *node;
2105         struct data_backref *back;
2106
2107         while(cur != &rec->backrefs) {
2108                 node = list_entry(cur, struct extent_backref, list);
2109                 cur = cur->next;
2110                 if (!node->is_data)
2111                         continue;
2112                 back = (struct data_backref *)node;
2113                 if (parent > 0) {
2114                         if (!node->full_backref)
2115                                 continue;
2116                         if (parent == back->parent)
2117                                 return back;
2118                 } else {
2119                         if (node->full_backref)
2120                                 continue;
2121                         if (back->root == root && back->owner == owner &&
2122                             back->offset == offset)
2123                                 return back;
2124                 }
2125         }
2126         return NULL;
2127 }
2128
2129 static struct data_backref *alloc_data_backref(struct extent_record *rec,
2130                                                 u64 parent, u64 root,
2131                                                 u64 owner, u64 offset,
2132                                                 u64 max_size)
2133 {
2134         struct data_backref *ref = malloc(sizeof(*ref));
2135         memset(&ref->node, 0, sizeof(ref->node));
2136         ref->node.is_data = 1;
2137
2138         if (parent > 0) {
2139                 ref->parent = parent;
2140                 ref->owner = 0;
2141                 ref->offset = 0;
2142                 ref->node.full_backref = 1;
2143         } else {
2144                 ref->root = root;
2145                 ref->owner = owner;
2146                 ref->offset = offset;
2147                 ref->node.full_backref = 0;
2148         }
2149         ref->found_ref = 0;
2150         ref->num_refs = 0;
2151         list_add_tail(&ref->node.list, &rec->backrefs);
2152         if (max_size > rec->max_size)
2153                 rec->max_size = max_size;
2154         return ref;
2155 }
2156
2157 static int add_extent_rec(struct cache_tree *extent_cache,
2158                           struct btrfs_key *parent_key,
2159                           u64 start, u64 nr, u64 extent_item_refs,
2160                           int is_root, int inc_ref, int set_checked,
2161                           u64 max_size)
2162 {
2163         struct extent_record *rec;
2164         struct cache_extent *cache;
2165         int ret = 0;
2166
2167         cache = find_cache_extent(extent_cache, start, nr);
2168         if (cache) {
2169                 rec = container_of(cache, struct extent_record, cache);
2170                 if (inc_ref)
2171                         rec->refs++;
2172                 if (rec->nr == 1)
2173                         rec->nr = max(nr, max_size);
2174
2175                 if (start != rec->start) {
2176                         fprintf(stderr, "warning, start mismatch %llu %llu\n",
2177                                 (unsigned long long)rec->start,
2178                                 (unsigned long long)start);
2179                         ret = 1;
2180                 }
2181                 if (extent_item_refs) {
2182                         if (rec->extent_item_refs) {
2183                                 fprintf(stderr, "block %llu rec "
2184                                         "extent_item_refs %llu, passed %llu\n",
2185                                         (unsigned long long)start,
2186                                         (unsigned long long)
2187                                                         rec->extent_item_refs,
2188                                         (unsigned long long)extent_item_refs);
2189                         }
2190                         rec->extent_item_refs = extent_item_refs;
2191                 }
2192                 if (is_root)
2193                         rec->is_root = 1;
2194                 if (set_checked) {
2195                         rec->content_checked = 1;
2196                         rec->owner_ref_checked = 1;
2197                 }
2198
2199                 if (parent_key)
2200                         btrfs_cpu_key_to_disk(&rec->parent_key, parent_key);
2201
2202                 if (rec->max_size < max_size)
2203                         rec->max_size = max_size;
2204
2205                 maybe_free_extent_rec(extent_cache, rec);
2206                 return ret;
2207         }
2208         rec = malloc(sizeof(*rec));
2209         rec->start = start;
2210         rec->max_size = max_size;
2211         rec->nr = max(nr, max_size);
2212         rec->content_checked = 0;
2213         rec->owner_ref_checked = 0;
2214         INIT_LIST_HEAD(&rec->backrefs);
2215
2216         if (is_root)
2217                 rec->is_root = 1;
2218         else
2219                 rec->is_root = 0;
2220
2221         if (inc_ref)
2222                 rec->refs = 1;
2223         else
2224                 rec->refs = 0;
2225
2226         if (extent_item_refs)
2227                 rec->extent_item_refs = extent_item_refs;
2228         else
2229                 rec->extent_item_refs = 0;
2230
2231         if (parent_key)
2232                 btrfs_cpu_key_to_disk(&rec->parent_key, parent_key);
2233         else
2234                 memset(&rec->parent_key, 0, sizeof(*parent_key));
2235
2236         rec->cache.start = start;
2237         rec->cache.size = nr;
2238         ret = insert_existing_cache_extent(extent_cache, &rec->cache);
2239         BUG_ON(ret);
2240         bytes_used += nr;
2241         if (set_checked) {
2242                 rec->content_checked = 1;
2243                 rec->owner_ref_checked = 1;
2244         }
2245         return ret;
2246 }
2247
2248 static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr,
2249                             u64 parent, u64 root, int found_ref)
2250 {
2251         struct extent_record *rec;
2252         struct tree_backref *back;
2253         struct cache_extent *cache;
2254
2255         cache = find_cache_extent(extent_cache, bytenr, 1);
2256         if (!cache) {
2257                 add_extent_rec(extent_cache, NULL, bytenr, 1, 0, 0, 0, 0, 0);
2258                 cache = find_cache_extent(extent_cache, bytenr, 1);
2259                 if (!cache)
2260                         abort();
2261         }
2262
2263         rec = container_of(cache, struct extent_record, cache);
2264         if (rec->start != bytenr) {
2265                 abort();
2266         }
2267
2268         back = find_tree_backref(rec, parent, root);
2269         if (!back)
2270                 back = alloc_tree_backref(rec, parent, root);
2271
2272         if (found_ref) {
2273                 if (back->node.found_ref) {
2274                         fprintf(stderr, "Extent back ref already exists "
2275                                 "for %llu parent %llu root %llu \n",
2276                                 (unsigned long long)bytenr,
2277                                 (unsigned long long)parent,
2278                                 (unsigned long long)root);
2279                 }
2280                 back->node.found_ref = 1;
2281         } else {
2282                 if (back->node.found_extent_tree) {
2283                         fprintf(stderr, "Extent back ref already exists "
2284                                 "for %llu parent %llu root %llu \n",
2285                                 (unsigned long long)bytenr,
2286                                 (unsigned long long)parent,
2287                                 (unsigned long long)root);
2288                 }
2289                 back->node.found_extent_tree = 1;
2290         }
2291         return 0;
2292 }
2293
2294 static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
2295                             u64 parent, u64 root, u64 owner, u64 offset,
2296                             u32 num_refs, int found_ref, u64 max_size)
2297 {
2298         struct extent_record *rec;
2299         struct data_backref *back;
2300         struct cache_extent *cache;
2301
2302         cache = find_cache_extent(extent_cache, bytenr, 1);
2303         if (!cache) {
2304                 add_extent_rec(extent_cache, NULL, bytenr, 1, 0, 0, 0, 0,
2305                                max_size);
2306                 cache = find_cache_extent(extent_cache, bytenr, 1);
2307                 if (!cache)
2308                         abort();
2309         }
2310
2311         rec = container_of(cache, struct extent_record, cache);
2312         if (rec->start != bytenr) {
2313                 abort();
2314         }
2315         if (rec->max_size < max_size)
2316                 rec->max_size = max_size;
2317
2318         back = find_data_backref(rec, parent, root, owner, offset);
2319         if (!back)
2320                 back = alloc_data_backref(rec, parent, root, owner, offset,
2321                                           max_size);
2322
2323         if (found_ref) {
2324                 BUG_ON(num_refs != 1);
2325                 back->node.found_ref = 1;
2326                 back->found_ref += 1;
2327         } else {
2328                 if (back->node.found_extent_tree) {
2329                         fprintf(stderr, "Extent back ref already exists "
2330                                 "for %llu parent %llu root %llu"
2331                                 "owner %llu offset %llu num_refs %lu\n",
2332                                 (unsigned long long)bytenr,
2333                                 (unsigned long long)parent,
2334                                 (unsigned long long)root,
2335                                 (unsigned long long)owner,
2336                                 (unsigned long long)offset,
2337                                 (unsigned long)num_refs);
2338                 }
2339                 back->num_refs = num_refs;
2340                 back->node.found_extent_tree = 1;
2341         }
2342         return 0;
2343 }
2344
2345 static int add_pending(struct cache_tree *pending,
2346                        struct cache_tree *seen, u64 bytenr, u32 size)
2347 {
2348         int ret;
2349         ret = insert_cache_extent(seen, bytenr, size);
2350         if (ret)
2351                 return ret;
2352         insert_cache_extent(pending, bytenr, size);
2353         return 0;
2354 }
2355
2356 static int pick_next_pending(struct cache_tree *pending,
2357                         struct cache_tree *reada,
2358                         struct cache_tree *nodes,
2359                         u64 last, struct block_info *bits, int bits_nr,
2360                         int *reada_bits)
2361 {
2362         unsigned long node_start = last;
2363         struct cache_extent *cache;
2364         int ret;
2365
2366         cache = find_first_cache_extent(reada, 0);
2367         if (cache) {
2368                 bits[0].start = cache->start;
2369                 bits[1].size = cache->size;
2370                 *reada_bits = 1;
2371                 return 1;
2372         }
2373         *reada_bits = 0;
2374         if (node_start > 32768)
2375                 node_start -= 32768;
2376
2377         cache = find_first_cache_extent(nodes, node_start);
2378         if (!cache)
2379                 cache = find_first_cache_extent(nodes, 0);
2380
2381         if (!cache) {
2382                  cache = find_first_cache_extent(pending, 0);
2383                  if (!cache)
2384                          return 0;
2385                  ret = 0;
2386                  do {
2387                          bits[ret].start = cache->start;
2388                          bits[ret].size = cache->size;
2389                          cache = next_cache_extent(cache);
2390                          ret++;
2391                  } while (cache && ret < bits_nr);
2392                  return ret;
2393         }
2394
2395         ret = 0;
2396         do {
2397                 bits[ret].start = cache->start;
2398                 bits[ret].size = cache->size;
2399                 cache = next_cache_extent(cache);
2400                 ret++;
2401         } while (cache && ret < bits_nr);
2402
2403         if (bits_nr - ret > 8) {
2404                 u64 lookup = bits[0].start + bits[0].size;
2405                 struct cache_extent *next;
2406                 next = find_first_cache_extent(pending, lookup);
2407                 while(next) {
2408                         if (next->start - lookup > 32768)
2409                                 break;
2410                         bits[ret].start = next->start;
2411                         bits[ret].size = next->size;
2412                         lookup = next->start + next->size;
2413                         ret++;
2414                         if (ret == bits_nr)
2415                                 break;
2416                         next = next_cache_extent(next);
2417                         if (!next)
2418                                 break;
2419                 }
2420         }
2421         return ret;
2422 }
2423
2424 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2425 static int process_extent_ref_v0(struct cache_tree *extent_cache,
2426                                  struct extent_buffer *leaf, int slot)
2427 {
2428         struct btrfs_extent_ref_v0 *ref0;
2429         struct btrfs_key key;
2430
2431         btrfs_item_key_to_cpu(leaf, &key, slot);
2432         ref0 = btrfs_item_ptr(leaf, slot, struct btrfs_extent_ref_v0);
2433         if (btrfs_ref_objectid_v0(leaf, ref0) < BTRFS_FIRST_FREE_OBJECTID) {
2434                 add_tree_backref(extent_cache, key.objectid, key.offset, 0, 0);
2435         } else {
2436                 add_data_backref(extent_cache, key.objectid, key.offset, 0,
2437                                  0, 0, btrfs_ref_count_v0(leaf, ref0), 0, 0);
2438         }
2439         return 0;
2440 }
2441 #endif
2442
2443 static int process_extent_item(struct cache_tree *extent_cache,
2444                                struct extent_buffer *eb, int slot)
2445 {
2446         struct btrfs_extent_item *ei;
2447         struct btrfs_extent_inline_ref *iref;
2448         struct btrfs_extent_data_ref *dref;
2449         struct btrfs_shared_data_ref *sref;
2450         struct btrfs_key key;
2451         unsigned long end;
2452         unsigned long ptr;
2453         int type;
2454         u32 item_size = btrfs_item_size_nr(eb, slot);
2455         u64 refs = 0;
2456         u64 offset;
2457
2458         btrfs_item_key_to_cpu(eb, &key, slot);
2459
2460         if (item_size < sizeof(*ei)) {
2461 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2462                 struct btrfs_extent_item_v0 *ei0;
2463                 BUG_ON(item_size != sizeof(*ei0));
2464                 ei0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_item_v0);
2465                 refs = btrfs_extent_refs_v0(eb, ei0);
2466 #else
2467                 BUG();
2468 #endif
2469                 return add_extent_rec(extent_cache, NULL, key.objectid,
2470                                       key.offset, refs, 0, 0, 0, key.offset);
2471         }
2472
2473         ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
2474         refs = btrfs_extent_refs(eb, ei);
2475
2476         add_extent_rec(extent_cache, NULL, key.objectid, key.offset,
2477                        refs, 0, 0, 0, key.offset);
2478
2479         ptr = (unsigned long)(ei + 1);
2480         if (btrfs_extent_flags(eb, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK)
2481                 ptr += sizeof(struct btrfs_tree_block_info);
2482
2483         end = (unsigned long)ei + item_size;
2484         while (ptr < end) {
2485                 iref = (struct btrfs_extent_inline_ref *)ptr;
2486                 type = btrfs_extent_inline_ref_type(eb, iref);
2487                 offset = btrfs_extent_inline_ref_offset(eb, iref);
2488                 switch (type) {
2489                 case BTRFS_TREE_BLOCK_REF_KEY:
2490                         add_tree_backref(extent_cache, key.objectid,
2491                                          0, offset, 0);
2492                         break;
2493                 case BTRFS_SHARED_BLOCK_REF_KEY:
2494                         add_tree_backref(extent_cache, key.objectid,
2495                                          offset, 0, 0);
2496                         break;
2497                 case BTRFS_EXTENT_DATA_REF_KEY:
2498                         dref = (struct btrfs_extent_data_ref *)(&iref->offset);
2499                         add_data_backref(extent_cache, key.objectid, 0,
2500                                         btrfs_extent_data_ref_root(eb, dref),
2501                                         btrfs_extent_data_ref_objectid(eb,
2502                                                                        dref),
2503                                         btrfs_extent_data_ref_offset(eb, dref),
2504                                         btrfs_extent_data_ref_count(eb, dref),
2505                                         0, key.offset);
2506                         break;
2507                 case BTRFS_SHARED_DATA_REF_KEY:
2508                         sref = (struct btrfs_shared_data_ref *)(iref + 1);
2509                         add_data_backref(extent_cache, key.objectid, offset,
2510                                         0, 0, 0,
2511                                         btrfs_shared_data_ref_count(eb, sref),
2512                                         0, key.offset);
2513                         break;
2514                 default:
2515                         fprintf(stderr, "corrupt extent record: key %Lu %u %Lu\n",
2516                                 key.objectid, key.type, key.offset);
2517                         goto out;
2518                 }
2519                 ptr += btrfs_extent_inline_ref_size(type);
2520         }
2521         WARN_ON(ptr > end);
2522 out:
2523         return 0;
2524 }
2525
2526 static int run_next_block(struct btrfs_root *root,
2527                           struct block_info *bits,
2528                           int bits_nr,
2529                           u64 *last,
2530                           struct cache_tree *pending,
2531                           struct cache_tree *seen,
2532                           struct cache_tree *reada,
2533                           struct cache_tree *nodes,
2534                           struct cache_tree *extent_cache)
2535 {
2536         struct extent_buffer *buf;
2537         u64 bytenr;
2538         u32 size;
2539         u64 parent;
2540         u64 owner;
2541         u64 flags;
2542         int ret;
2543         int i;
2544         int nritems;
2545         struct btrfs_key key;
2546         struct cache_extent *cache;
2547         int reada_bits;
2548
2549         ret = pick_next_pending(pending, reada, nodes, *last, bits,
2550                                 bits_nr, &reada_bits);
2551         if (ret == 0) {
2552                 return 1;
2553         }
2554         if (!reada_bits) {
2555                 for(i = 0; i < ret; i++) {
2556                         insert_cache_extent(reada, bits[i].start,
2557                                             bits[i].size);
2558
2559                         /* fixme, get the parent transid */
2560                         readahead_tree_block(root, bits[i].start,
2561                                              bits[i].size, 0);
2562                 }
2563         }
2564         *last = bits[0].start;
2565         bytenr = bits[0].start;
2566         size = bits[0].size;
2567
2568         cache = find_cache_extent(pending, bytenr, size);
2569         if (cache) {
2570                 remove_cache_extent(pending, cache);
2571                 free(cache);
2572         }
2573         cache = find_cache_extent(reada, bytenr, size);
2574         if (cache) {
2575                 remove_cache_extent(reada, cache);
2576                 free(cache);
2577         }
2578         cache = find_cache_extent(nodes, bytenr, size);
2579         if (cache) {
2580                 remove_cache_extent(nodes, cache);
2581                 free(cache);
2582         }
2583
2584         /* fixme, get the real parent transid */
2585         buf = read_tree_block(root, bytenr, size, 0);
2586         if (!extent_buffer_uptodate(buf)) {
2587                 record_bad_block_io(root->fs_info,
2588                                     extent_cache, bytenr, size);
2589                 free_extent_buffer(buf);
2590                 goto out;
2591         }
2592
2593         nritems = btrfs_header_nritems(buf);
2594
2595         ret = btrfs_lookup_extent_info(NULL, root, bytenr, size, NULL, &flags);
2596         if (ret < 0)
2597                 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
2598
2599         if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
2600                 parent = bytenr;
2601                 owner = 0;
2602         } else {
2603                 parent = 0;
2604                 owner = btrfs_header_owner(buf);
2605         }
2606
2607         ret = check_block(root, extent_cache, buf, flags);
2608         if (ret)
2609                 goto out;
2610
2611         if (btrfs_is_leaf(buf)) {
2612                 btree_space_waste += btrfs_leaf_free_space(root, buf);
2613                 for (i = 0; i < nritems; i++) {
2614                         struct btrfs_file_extent_item *fi;
2615                         btrfs_item_key_to_cpu(buf, &key, i);
2616                         if (key.type == BTRFS_EXTENT_ITEM_KEY) {
2617                                 process_extent_item(extent_cache, buf, i);
2618                                 continue;
2619                         }
2620                         if (key.type == BTRFS_EXTENT_CSUM_KEY) {
2621                                 total_csum_bytes +=
2622                                         btrfs_item_size_nr(buf, i);
2623                                 continue;
2624                         }
2625                         if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
2626                                 continue;
2627                         }
2628                         if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
2629 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2630                                 process_extent_ref_v0(extent_cache, buf, i);
2631 #else
2632                                 BUG();
2633 #endif
2634                                 continue;
2635                         }
2636
2637                         if (key.type == BTRFS_TREE_BLOCK_REF_KEY) {
2638                                 add_tree_backref(extent_cache, key.objectid, 0,
2639                                                  key.offset, 0);
2640                                 continue;
2641                         }
2642                         if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
2643                                 add_tree_backref(extent_cache, key.objectid,
2644                                                  key.offset, 0, 0);
2645                                 continue;
2646                         }
2647                         if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
2648                                 struct btrfs_extent_data_ref *ref;
2649                                 ref = btrfs_item_ptr(buf, i,
2650                                                 struct btrfs_extent_data_ref);
2651                                 add_data_backref(extent_cache,
2652                                         key.objectid, 0,
2653                                         btrfs_extent_data_ref_root(buf, ref),
2654                                         btrfs_extent_data_ref_objectid(buf,
2655                                                                        ref),
2656                                         btrfs_extent_data_ref_offset(buf, ref),
2657                                         btrfs_extent_data_ref_count(buf, ref),
2658                                         0, root->sectorsize);
2659                                 continue;
2660                         }
2661                         if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
2662                                 struct btrfs_shared_data_ref *ref;
2663                                 ref = btrfs_item_ptr(buf, i,
2664                                                 struct btrfs_shared_data_ref);
2665                                 add_data_backref(extent_cache,
2666                                         key.objectid, key.offset, 0, 0, 0,
2667                                         btrfs_shared_data_ref_count(buf, ref),
2668                                         0, root->sectorsize);
2669                                 continue;
2670                         }
2671                         if (key.type != BTRFS_EXTENT_DATA_KEY)
2672                                 continue;
2673                         fi = btrfs_item_ptr(buf, i,
2674                                             struct btrfs_file_extent_item);
2675                         if (btrfs_file_extent_type(buf, fi) ==
2676                             BTRFS_FILE_EXTENT_INLINE)
2677                                 continue;
2678                         if (btrfs_file_extent_disk_bytenr(buf, fi) == 0)
2679                                 continue;
2680
2681                         data_bytes_allocated +=
2682                                 btrfs_file_extent_disk_num_bytes(buf, fi);
2683                         if (data_bytes_allocated < root->sectorsize) {
2684                                 abort();
2685                         }
2686                         data_bytes_referenced +=
2687                                 btrfs_file_extent_num_bytes(buf, fi);
2688                         ret = add_extent_rec(extent_cache, NULL,
2689                                    btrfs_file_extent_disk_bytenr(buf, fi),
2690                                    btrfs_file_extent_disk_num_bytes(buf, fi),
2691                                    0, 0, 1, 1,
2692                                    btrfs_file_extent_disk_num_bytes(buf, fi));
2693                         add_data_backref(extent_cache,
2694                                 btrfs_file_extent_disk_bytenr(buf, fi),
2695                                 parent, owner, key.objectid, key.offset -
2696                                 btrfs_file_extent_offset(buf, fi), 1, 1,
2697                                 btrfs_file_extent_disk_num_bytes(buf, fi));
2698                         BUG_ON(ret);
2699                 }
2700         } else {
2701                 int level;
2702                 struct btrfs_key first_key;
2703
2704                 first_key.objectid = 0;
2705
2706                 if (nritems > 0)
2707                         btrfs_item_key_to_cpu(buf, &first_key, 0);
2708                 level = btrfs_header_level(buf);
2709                 for (i = 0; i < nritems; i++) {
2710                         u64 ptr = btrfs_node_blockptr(buf, i);
2711                         u32 size = btrfs_level_size(root, level - 1);
2712                         btrfs_node_key_to_cpu(buf, &key, i);
2713                         ret = add_extent_rec(extent_cache, &key,
2714                                              ptr, size, 0, 0, 1, 0, size);
2715                         BUG_ON(ret);
2716
2717                         add_tree_backref(extent_cache, ptr, parent, owner, 1);
2718
2719                         if (level > 1) {
2720                                 add_pending(nodes, seen, ptr, size);
2721                         } else {
2722                                 add_pending(pending, seen, ptr, size);
2723                         }
2724                 }
2725                 btree_space_waste += (BTRFS_NODEPTRS_PER_BLOCK(root) -
2726                                       nritems) * sizeof(struct btrfs_key_ptr);
2727         }
2728         total_btree_bytes += buf->len;
2729         if (fs_root_objectid(btrfs_header_owner(buf)))
2730                 total_fs_tree_bytes += buf->len;
2731         if (!found_old_backref &&
2732             btrfs_header_owner(buf) == BTRFS_TREE_RELOC_OBJECTID &&
2733             btrfs_header_backref_rev(buf) == BTRFS_MIXED_BACKREF_REV &&
2734             !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))
2735                 found_old_backref = 1;
2736 out:
2737         free_extent_buffer(buf);
2738         return 0;
2739 }
2740
2741 static int add_root_to_pending(struct extent_buffer *buf,
2742                                struct block_info *bits,
2743                                int bits_nr,
2744                                struct cache_tree *extent_cache,
2745                                struct cache_tree *pending,
2746                                struct cache_tree *seen,
2747                                struct cache_tree *reada,
2748                                struct cache_tree *nodes,
2749                                struct btrfs_key *root_key)
2750 {
2751         if (btrfs_header_level(buf) > 0)
2752                 add_pending(nodes, seen, buf->start, buf->len);
2753         else
2754                 add_pending(pending, seen, buf->start, buf->len);
2755         add_extent_rec(extent_cache, NULL, buf->start, buf->len,
2756                        0, 1, 1, 0, buf->len);
2757
2758         if (root_key->objectid == BTRFS_TREE_RELOC_OBJECTID ||
2759             btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
2760                 add_tree_backref(extent_cache, buf->start, buf->start,
2761                                  0, 1);
2762         else
2763                 add_tree_backref(extent_cache, buf->start, 0,
2764                                  root_key->objectid, 1);
2765         return 0;
2766 }
2767
2768 /* as we fix the tree, we might be deleting blocks that
2769  * we're tracking for repair.  This hook makes sure we
2770  * remove any backrefs for blocks as we are fixing them.
2771  */
2772 static int free_extent_hook(struct btrfs_trans_handle *trans,
2773                             struct btrfs_root *root,
2774                             u64 bytenr, u64 num_bytes, u64 parent,
2775                             u64 root_objectid, u64 owner, u64 offset,
2776                             int refs_to_drop)
2777 {
2778         struct extent_record *rec;
2779         struct cache_extent *cache;
2780         int is_data;
2781         struct cache_tree *extent_cache = root->fs_info->fsck_extent_cache;
2782
2783         is_data = owner >= BTRFS_FIRST_FREE_OBJECTID;
2784         cache = find_cache_extent(extent_cache, bytenr, num_bytes);
2785         if (!cache)
2786                 return 0;
2787
2788         rec = container_of(cache, struct extent_record, cache);
2789         if (is_data) {
2790                 struct data_backref *back;
2791                 back = find_data_backref(rec, parent, root_objectid, owner,
2792                                          offset);
2793                 if (!back)
2794                         goto out;
2795                 if (back->node.found_ref) {
2796                         back->found_ref -= refs_to_drop;
2797                         if (rec->refs)
2798                                 rec->refs -= refs_to_drop;
2799                 }
2800                 if (back->node.found_extent_tree) {
2801                         back->num_refs -= refs_to_drop;
2802                         if (rec->extent_item_refs)
2803                                 rec->extent_item_refs -= refs_to_drop;
2804                 }
2805                 if (back->found_ref == 0)
2806                         back->node.found_ref = 0;
2807                 if (back->num_refs == 0)
2808                         back->node.found_extent_tree = 0;
2809
2810                 if (!back->node.found_extent_tree && back->node.found_ref) {
2811                         list_del(&back->node.list);
2812                         free(back);
2813                 }
2814         } else {
2815                 struct tree_backref *back;
2816                 back = find_tree_backref(rec, parent, root_objectid);
2817                 if (!back)
2818                         goto out;
2819                 if (back->node.found_ref) {
2820                         if (rec->refs)
2821                                 rec->refs--;
2822                         back->node.found_ref = 0;
2823                 }
2824                 if (back->node.found_extent_tree) {
2825                         if (rec->extent_item_refs)
2826                                 rec->extent_item_refs--;
2827                         back->node.found_extent_tree = 0;
2828                 }
2829                 if (!back->node.found_extent_tree && back->node.found_ref) {
2830                         list_del(&back->node.list);
2831                         free(back);
2832                 }
2833         }
2834         maybe_free_extent_rec(extent_cache, rec);
2835 out:
2836         return 0;
2837 }
2838
2839 static int delete_extent_records(struct btrfs_trans_handle *trans,
2840                                  struct btrfs_root *root,
2841                                  struct btrfs_path *path,
2842                                  u64 bytenr, u64 new_len)
2843 {
2844         struct btrfs_key key;
2845         struct btrfs_key found_key;
2846         struct extent_buffer *leaf;
2847         int ret;
2848         int slot;
2849
2850
2851         key.objectid = bytenr;
2852         key.type = (u8)-1;
2853         key.offset = (u64)-1;
2854
2855         while(1) {
2856                 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
2857                                         &key, path, 0, 1);
2858                 if (ret < 0)
2859                         break;
2860
2861                 if (ret > 0) {
2862                         ret = 0;
2863                         if (path->slots[0] == 0)
2864                                 break;
2865                         path->slots[0]--;
2866                 }
2867                 ret = 0;
2868
2869                 leaf = path->nodes[0];
2870                 slot = path->slots[0];
2871
2872                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2873                 if (found_key.objectid != bytenr)
2874                         break;
2875
2876                 if (found_key.type != BTRFS_EXTENT_ITEM_KEY &&
2877                     found_key.type != BTRFS_TREE_BLOCK_REF_KEY &&
2878                     found_key.type != BTRFS_EXTENT_DATA_REF_KEY &&
2879                     found_key.type != BTRFS_EXTENT_REF_V0_KEY &&
2880                     found_key.type != BTRFS_SHARED_BLOCK_REF_KEY &&
2881                     found_key.type != BTRFS_SHARED_DATA_REF_KEY) {
2882                         btrfs_release_path(NULL, path);
2883                         if (found_key.type == 0) {
2884                                 if (found_key.offset == 0)
2885                                         break;
2886                                 key.offset = found_key.offset - 1;
2887                                 key.type = found_key.type;
2888                         }
2889                         key.type = found_key.type - 1;
2890                         key.offset = (u64)-1;
2891                         continue;
2892                 }
2893
2894                 fprintf(stderr, "repair deleting extent record: key %Lu %u %Lu\n",
2895                         found_key.objectid, found_key.type, found_key.offset);
2896
2897                 ret = btrfs_del_item(trans, root->fs_info->extent_root, path);
2898                 if (ret)
2899                         break;
2900                 btrfs_release_path(NULL, path);
2901
2902                 if (found_key.type == BTRFS_EXTENT_ITEM_KEY) {
2903                         ret = btrfs_update_block_group(trans, root, bytenr,
2904                                                        found_key.offset, 0, 0);
2905                         if (ret)
2906                                 break;
2907                 }
2908         }
2909
2910         btrfs_release_path(NULL, path);
2911         return ret;
2912 }
2913
2914 /*
2915  * for a single backref, this will allocate a new extent
2916  * and add the backref to it.
2917  */
2918 static int record_extent(struct btrfs_trans_handle *trans,
2919                          struct btrfs_fs_info *info,
2920                          struct btrfs_path *path,
2921                          struct extent_record *rec,
2922                          struct extent_backref *back,
2923                          int allocated, u64 flags)
2924 {
2925         int ret;
2926         struct btrfs_root *extent_root = info->extent_root;
2927         struct extent_buffer *leaf;
2928         struct btrfs_key ins_key;
2929         struct btrfs_extent_item *ei;
2930         struct tree_backref *tback;
2931         struct data_backref *dback;
2932         struct btrfs_tree_block_info *bi;
2933
2934         if (!back->is_data)
2935                 rec->max_size = max_t(u64, rec->max_size,
2936                                     info->extent_root->leafsize);
2937
2938         if (!allocated) {
2939                 u32 item_size = sizeof(*ei);
2940
2941                 if (!back->is_data)
2942                         item_size += sizeof(*bi);
2943
2944                 ins_key.objectid = rec->start;
2945                 ins_key.offset = rec->max_size;
2946                 ins_key.type = BTRFS_EXTENT_ITEM_KEY;
2947
2948                 ret = btrfs_insert_empty_item(trans, extent_root, path,
2949                                         &ins_key, item_size);
2950                 if (ret)
2951                         goto fail;
2952
2953                 leaf = path->nodes[0];
2954                 ei = btrfs_item_ptr(leaf, path->slots[0],
2955                                     struct btrfs_extent_item);
2956
2957                 btrfs_set_extent_refs(leaf, ei, 0);
2958                 btrfs_set_extent_generation(leaf, ei, rec->generation);
2959
2960                 if (back->is_data) {
2961                         btrfs_set_extent_flags(leaf, ei,
2962                                                BTRFS_EXTENT_FLAG_DATA);
2963                 } else {
2964                         struct btrfs_disk_key copy_key;;
2965
2966                         tback = (struct tree_backref *)back;
2967                         bi = (struct btrfs_tree_block_info *)(ei + 1);
2968                         memset_extent_buffer(leaf, 0, (unsigned long)bi,
2969                                              sizeof(*bi));
2970                         memset(&copy_key, 0, sizeof(copy_key));
2971
2972                         copy_key.objectid = le64_to_cpu(rec->info_objectid);
2973                         btrfs_set_tree_block_level(leaf, bi, rec->info_level);
2974                         btrfs_set_tree_block_key(leaf, bi, &copy_key);
2975
2976                         btrfs_set_extent_flags(leaf, ei,
2977                                                BTRFS_EXTENT_FLAG_TREE_BLOCK | flags);
2978                 }
2979
2980                 btrfs_mark_buffer_dirty(leaf);
2981                 ret = btrfs_update_block_group(trans, extent_root, rec->start,
2982                                                rec->max_size, 1, 0);
2983                 if (ret)
2984                         goto fail;
2985                 btrfs_release_path(NULL, path);
2986         }
2987
2988         if (back->is_data) {
2989                 u64 parent;
2990                 int i;
2991
2992                 dback = (struct data_backref *)back;
2993                 if (back->full_backref)
2994                         parent = dback->parent;
2995                 else
2996                         parent = 0;
2997
2998                 for (i = 0; i < dback->found_ref; i++) {
2999                         /* if parent != 0, we're doing a full backref
3000                          * passing BTRFS_FIRST_FREE_OBJECTID as the owner
3001                          * just makes the backref allocator create a data
3002                          * backref
3003                          */
3004                         ret = btrfs_inc_extent_ref(trans, info->extent_root,
3005                                                    rec->start, rec->max_size,
3006                                                    parent,
3007                                                    dback->root,
3008                                                    parent ?
3009                                                    BTRFS_FIRST_FREE_OBJECTID :
3010                                                    dback->owner,
3011                                                    dback->offset);
3012                         if (ret)
3013                                 break;
3014                 }
3015                 fprintf(stderr, "adding new data backref"
3016                                 " on %llu %s %llu owner %llu"
3017                                 " offset %llu found %d\n",
3018                                 (unsigned long long)rec->start,
3019                                 back->full_backref ?
3020                                 "parent" : "root",
3021                                 back->full_backref ?
3022                                 (unsigned long long)parent :
3023                                 (unsigned long long)dback->root,
3024                                 (unsigned long long)dback->owner,
3025                                 (unsigned long long)dback->offset,
3026                                 dback->found_ref);
3027         } else {
3028                 u64 parent;
3029
3030                 tback = (struct tree_backref *)back;
3031                 if (back->full_backref)
3032                         parent = tback->parent;
3033                 else
3034                         parent = 0;
3035
3036                 ret = btrfs_inc_extent_ref(trans, info->extent_root,
3037                                            rec->start, rec->max_size,
3038                                            parent, tback->root, 0, 0);
3039                 fprintf(stderr, "adding new tree backref on "
3040                         "start %llu len %llu parent %llu root %llu\n",
3041                         rec->start, rec->max_size, tback->parent, tback->root);
3042         }
3043         if (ret)
3044                 goto fail;
3045 fail:
3046         btrfs_release_path(NULL, path);
3047         return ret;
3048 }
3049
3050 /*
3051  * when an incorrect extent item is found, this will delete
3052  * all of the existing entries for it and recreate them
3053  * based on what the tree scan found.
3054  */
3055 static int fixup_extent_refs(struct btrfs_trans_handle *trans,
3056                              struct btrfs_fs_info *info,
3057                              struct extent_record *rec)
3058 {
3059         int ret;
3060         struct btrfs_path *path;
3061         struct list_head *cur = rec->backrefs.next;
3062         struct cache_extent *cache;
3063         struct extent_backref *back;
3064         int allocated = 0;
3065         u64 flags = 0;
3066
3067         /* remember our flags for recreating the extent */
3068         ret = btrfs_lookup_extent_info(NULL, info->extent_root, rec->start,
3069                                        rec->max_size, NULL, &flags);
3070         if (ret < 0)
3071                 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
3072
3073         path = btrfs_alloc_path();
3074
3075         /* step one, delete all the existing records */
3076         ret = delete_extent_records(trans, info->extent_root, path,
3077                                     rec->start, rec->max_size);
3078
3079         if (ret < 0)
3080                 goto out;
3081
3082         /* was this block corrupt?  If so, don't add references to it */
3083         cache = find_cache_extent(info->corrupt_blocks, rec->start, rec->max_size);
3084         if (cache) {
3085                 ret = 0;
3086                 goto out;
3087         }
3088
3089         /* step two, recreate all the refs we did find */
3090         while(cur != &rec->backrefs) {
3091                 back = list_entry(cur, struct extent_backref, list);
3092                 cur = cur->next;
3093
3094                 /*
3095                  * if we didn't find any references, don't create a
3096                  * new extent record
3097                  */
3098                 if (!back->found_ref)
3099                         continue;
3100
3101                 ret = record_extent(trans, info, path, rec, back, allocated, flags);
3102                 allocated = 1;
3103
3104                 if (ret)
3105                         goto out;
3106         }
3107 out:
3108         btrfs_free_path(path);
3109         return ret;
3110 }
3111
3112 /* right now we only prune from the extent allocation tree */
3113 static int prune_one_block(struct btrfs_trans_handle *trans,
3114                            struct btrfs_fs_info *info,
3115                            struct btrfs_corrupt_block *corrupt)
3116 {
3117         int ret;
3118         struct btrfs_path path;
3119         struct extent_buffer *eb;
3120         u64 found;
3121         int slot;
3122         int nritems;
3123         int level = corrupt->level + 1;
3124
3125         btrfs_init_path(&path);
3126 again:
3127         /* we want to stop at the parent to our busted block */
3128         path.lowest_level = level;
3129
3130         ret = btrfs_search_slot(trans, info->extent_root,
3131                                 &corrupt->key, &path, -1, 1);
3132
3133         if (ret < 0)
3134                 goto out;
3135
3136         eb = path.nodes[level];
3137         if (!eb) {
3138                 ret = -ENOENT;
3139                 goto out;
3140         }
3141
3142         /*
3143          * hopefully the search gave us the block we want to prune,
3144          * lets try that first
3145          */
3146         slot = path.slots[level];
3147         found =  btrfs_node_blockptr(eb, slot);
3148         if (found == corrupt->cache.start)
3149                 goto del_ptr;
3150
3151         nritems = btrfs_header_nritems(eb);
3152
3153         /* the search failed, lets scan this node and hope we find it */
3154         for (slot = 0; slot < nritems; slot++) {
3155                 found =  btrfs_node_blockptr(eb, slot);
3156                 if (found == corrupt->cache.start)
3157                         goto del_ptr;
3158         }
3159         /*
3160          * we couldn't find the bad block.  TODO, search all the nodes for pointers
3161          * to this block
3162          */
3163         if (eb == info->extent_root->node) {
3164                 ret = -ENOENT;
3165                 goto out;
3166         } else {
3167                 level++;
3168                 btrfs_release_path(NULL, &path);
3169                 goto again;
3170         }
3171
3172 del_ptr:
3173         printk("deleting pointer to block %Lu\n", corrupt->cache.start);
3174         ret = btrfs_del_ptr(trans, info->extent_root, &path, level, slot);
3175
3176 out:
3177         btrfs_release_path(NULL, &path);
3178         return ret;
3179 }
3180
3181 static int prune_corrupt_blocks(struct btrfs_trans_handle *trans,
3182                                 struct btrfs_fs_info *info)
3183 {
3184         struct cache_extent *cache;
3185         struct btrfs_corrupt_block *corrupt;
3186
3187         cache = find_first_cache_extent(info->corrupt_blocks, 0);
3188         while (1) {
3189                 if (!cache)
3190                         break;
3191                 corrupt = container_of(cache, struct btrfs_corrupt_block, cache);
3192                 prune_one_block(trans, info, corrupt);
3193                 cache = next_cache_extent(cache);
3194         }
3195         return 0;
3196 }
3197
3198 static void free_corrupt_blocks(struct btrfs_fs_info *info)
3199 {
3200         struct cache_extent *cache;
3201         struct btrfs_corrupt_block *corrupt;
3202
3203         while (1) {
3204                 cache = find_first_cache_extent(info->corrupt_blocks, 0);
3205                 if (!cache)
3206                         break;
3207                 corrupt = container_of(cache, struct btrfs_corrupt_block, cache);
3208                 remove_cache_extent(info->corrupt_blocks, cache);
3209                 free(corrupt);
3210         }
3211 }
3212
3213 static int check_block_group(struct btrfs_trans_handle *trans,
3214                               struct btrfs_fs_info *info,
3215                               struct map_lookup *map,
3216                               int *reinit)
3217 {
3218         struct btrfs_key key;
3219         struct btrfs_path path;
3220         int ret;
3221
3222         key.objectid = map->ce.start;
3223         key.offset = map->ce.size;
3224         key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3225
3226         btrfs_init_path(&path);
3227         ret = btrfs_search_slot(NULL, info->extent_root,
3228                                 &key, &path, 0, 0);
3229         btrfs_release_path(NULL, &path);
3230         if (ret <= 0)
3231                 goto out;
3232
3233         ret = btrfs_make_block_group(trans, info->extent_root, 0, map->type,
3234                                BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3235                                key.objectid, key.offset);
3236         *reinit = 1;
3237 out:
3238         return ret;
3239 }
3240
3241 static int check_block_groups(struct btrfs_trans_handle *trans,
3242                               struct btrfs_fs_info *info, int *reinit)
3243 {
3244         struct cache_extent *ce;
3245         struct map_lookup *map;
3246         struct btrfs_mapping_tree *map_tree = &info->mapping_tree;
3247
3248         /* this isn't quite working */
3249         return 0;
3250
3251         ce = find_first_cache_extent(&map_tree->cache_tree, 0);
3252         while (1) {
3253                 if (!ce)
3254                         break;
3255                 map = container_of(ce, struct map_lookup, ce);
3256                 check_block_group(trans, info, map, reinit);
3257                 ce = next_cache_extent(ce);
3258         }
3259         return 0;
3260 }
3261
3262 static int check_extent_refs(struct btrfs_trans_handle *trans,
3263                              struct btrfs_root *root,
3264                              struct cache_tree *extent_cache, int repair)
3265 {
3266         struct extent_record *rec;
3267         struct cache_extent *cache;
3268         int err = 0;
3269         int ret = 0;
3270         int fixed = 0;
3271         int reinit = 0;
3272
3273         if (repair) {
3274                 /*
3275                  * if we're doing a repair, we have to make sure
3276                  * we don't allocate from the problem extents.
3277                  * In the worst case, this will be all the
3278                  * extents in the FS
3279                  */
3280                 cache = find_first_cache_extent(extent_cache, 0);
3281                 while(cache) {
3282                         rec = container_of(cache, struct extent_record, cache);
3283                         btrfs_pin_extent(root->fs_info,
3284                                          rec->start, rec->max_size);
3285                         cache = next_cache_extent(cache);
3286                 }
3287
3288                 /* pin down all the corrupted blocks too */
3289                 cache = find_first_cache_extent(root->fs_info->corrupt_blocks, 0);
3290                 while(cache) {
3291                         rec = container_of(cache, struct extent_record, cache);
3292                         btrfs_pin_extent(root->fs_info,
3293                                          rec->start, rec->max_size);
3294                         cache = next_cache_extent(cache);
3295                 }
3296                 prune_corrupt_blocks(trans, root->fs_info);
3297                 check_block_groups(trans, root->fs_info, &reinit);
3298                 if (reinit)
3299                         btrfs_read_block_groups(root->fs_info->extent_root);
3300         }
3301         while(1) {
3302                 fixed = 0;
3303                 cache = find_first_cache_extent(extent_cache, 0);
3304                 if (!cache)
3305                         break;
3306                 rec = container_of(cache, struct extent_record, cache);
3307                 if (rec->refs != rec->extent_item_refs) {
3308                         fprintf(stderr, "ref mismatch on [%llu %llu] ",
3309                                 (unsigned long long)rec->start,
3310                                 (unsigned long long)rec->nr);
3311                         fprintf(stderr, "extent item %llu, found %llu\n",
3312                                 (unsigned long long)rec->extent_item_refs,
3313                                 (unsigned long long)rec->refs);
3314                         if (!fixed && repair) {
3315                                 ret = fixup_extent_refs(trans, root->fs_info, rec);
3316                                 if (ret)
3317                                         goto repair_abort;
3318                                 fixed = 1;
3319                         }
3320                         err = 1;
3321
3322                 }
3323                 if (all_backpointers_checked(rec, 1)) {
3324                         fprintf(stderr, "backpointer mismatch on [%llu %llu]\n",
3325                                 (unsigned long long)rec->start,
3326                                 (unsigned long long)rec->nr);
3327
3328                         if (!fixed && repair) {
3329                                 ret = fixup_extent_refs(trans, root->fs_info, rec);
3330                                 if (ret)
3331                                         goto repair_abort;
3332                                 fixed = 1;
3333                         }
3334
3335                         err = 1;
3336                 }
3337                 if (!rec->owner_ref_checked) {
3338                         fprintf(stderr, "owner ref check failed [%llu %llu]\n",
3339                                 (unsigned long long)rec->start,
3340                                 (unsigned long long)rec->nr);
3341                         if (!fixed && repair) {
3342                                 ret = fixup_extent_refs(trans, root->fs_info, rec);
3343                                 if (ret)
3344                                         goto repair_abort;
3345                                 fixed = 1;
3346                         }
3347                         err = 1;
3348                 }
3349
3350                 remove_cache_extent(extent_cache, cache);
3351                 free_all_extent_backrefs(rec);
3352                 free(rec);
3353         }
3354 repair_abort:
3355         if (repair) {
3356                 if (ret) {
3357                         fprintf(stderr, "failed to repair damaged filesystem, aborting\n");
3358                         exit(1);
3359                 } else {
3360                         btrfs_fix_block_accounting(trans, root);
3361                 }
3362                 if (err)
3363                         fprintf(stderr, "repaired damaged extent references\n");
3364                 return ret;
3365         }
3366         return err;
3367 }
3368
3369 static int check_extents(struct btrfs_trans_handle *trans,
3370                          struct btrfs_root *root, int repair)
3371 {
3372         struct cache_tree extent_cache;
3373         struct cache_tree seen;
3374         struct cache_tree pending;
3375         struct cache_tree reada;
3376         struct cache_tree nodes;
3377         struct cache_tree corrupt_blocks;
3378         struct btrfs_path path;
3379         struct btrfs_key key;
3380         struct btrfs_key found_key;
3381         int ret;
3382         u64 last = 0;
3383         struct block_info *bits;
3384         int bits_nr;
3385         struct extent_buffer *leaf;
3386         int slot;
3387         struct btrfs_root_item ri;
3388
3389         cache_tree_init(&extent_cache);
3390         cache_tree_init(&seen);
3391         cache_tree_init(&pending);
3392         cache_tree_init(&nodes);
3393         cache_tree_init(&reada);
3394         cache_tree_init(&corrupt_blocks);
3395
3396         if (repair) {
3397                 root->fs_info->fsck_extent_cache = &extent_cache;
3398                 root->fs_info->free_extent_hook = free_extent_hook;
3399                 root->fs_info->corrupt_blocks = &corrupt_blocks;
3400         }
3401
3402         bits_nr = 1024;
3403         bits = malloc(bits_nr * sizeof(struct block_info));
3404         if (!bits) {
3405                 perror("malloc");
3406                 exit(1);
3407         }
3408
3409         add_root_to_pending(root->fs_info->tree_root->node, bits, bits_nr,
3410                             &extent_cache, &pending, &seen, &reada, &nodes,
3411                             &root->fs_info->tree_root->root_key);
3412
3413         add_root_to_pending(root->fs_info->chunk_root->node, bits, bits_nr,
3414                             &extent_cache, &pending, &seen, &reada, &nodes,
3415                             &root->fs_info->chunk_root->root_key);
3416
3417         btrfs_init_path(&path);
3418         key.offset = 0;
3419         key.objectid = 0;
3420         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
3421         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
3422                                         &key, &path, 0, 0);
3423         BUG_ON(ret < 0);
3424         while(1) {
3425                 leaf = path.nodes[0];
3426                 slot = path.slots[0];
3427                 if (slot >= btrfs_header_nritems(path.nodes[0])) {
3428                         ret = btrfs_next_leaf(root, &path);
3429                         if (ret != 0)
3430                                 break;
3431                         leaf = path.nodes[0];
3432                         slot = path.slots[0];
3433                 }
3434                 btrfs_item_key_to_cpu(leaf, &found_key, path.slots[0]);
3435                 if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
3436                         unsigned long offset;
3437                         struct extent_buffer *buf;
3438
3439                         offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
3440                         read_extent_buffer(leaf, &ri, offset, sizeof(ri));
3441                         buf = read_tree_block(root->fs_info->tree_root,
3442                                               btrfs_root_bytenr(&ri),
3443                                               btrfs_level_size(root,
3444                                                btrfs_root_level(&ri)), 0);
3445                         add_root_to_pending(buf, bits, bits_nr, &extent_cache,
3446                                             &pending, &seen, &reada, &nodes,
3447                                             &found_key);
3448                         free_extent_buffer(buf);
3449                 }
3450                 path.slots[0]++;
3451         }
3452         btrfs_release_path(root, &path);
3453         while(1) {
3454                 ret = run_next_block(root, bits, bits_nr, &last, &pending,
3455                                      &seen, &reada, &nodes, &extent_cache);
3456                 if (ret != 0)
3457                         break;
3458         }
3459         ret = check_extent_refs(trans, root, &extent_cache, repair);
3460
3461         if (repair) {
3462                 free_corrupt_blocks(root->fs_info);
3463                 root->fs_info->fsck_extent_cache = NULL;
3464                 root->fs_info->free_extent_hook = NULL;
3465                 root->fs_info->corrupt_blocks = NULL;
3466         }
3467
3468         return ret;
3469 }
3470
3471 static void print_usage(void)
3472 {
3473         fprintf(stderr, "usage: btrfsck dev\n");
3474         fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
3475         exit(1);
3476 }
3477
3478 static struct option long_options[] = {
3479         { "super", 1, NULL, 's' },
3480         { "repair", 0, NULL, 0 },
3481         { "init-csum-tree", 0, NULL, 0 },
3482         { "init-extent-tree", 0, NULL, 0 },
3483         { 0, 0, 0, 0}
3484 };
3485
3486 int main(int ac, char **av)
3487 {
3488         struct cache_tree root_cache;
3489         struct btrfs_root *root;
3490         struct btrfs_fs_info *info;
3491         struct btrfs_trans_handle *trans = NULL;
3492         u64 bytenr = 0;
3493         int ret;
3494         int num;
3495         int repair = 0;
3496         int option_index = 0;
3497         int init_csum_tree = 0;
3498         int rw = 0;
3499
3500         while(1) {
3501                 int c;
3502                 c = getopt_long(ac, av, "s:", long_options,
3503                                 &option_index);
3504                 if (c < 0)
3505                         break;
3506                 switch(c) {
3507                         case 's':
3508                                 num = atol(optarg);
3509                                 bytenr = btrfs_sb_offset(num);
3510                                 printf("using SB copy %d, bytenr %llu\n", num,
3511                                        (unsigned long long)bytenr);
3512                                 break;
3513                         case '?':
3514                                 print_usage();
3515                 }
3516                 if (option_index == 1) {
3517                         printf("enabling repair mode\n");
3518                         repair = 1;
3519                         rw = 1;
3520                 } else if (option_index == 2) {
3521                         printf("Creating a new CRC tree\n");
3522                         init_csum_tree = 1;
3523                         rw = 1;
3524                 }
3525
3526         }
3527         ac = ac - optind;
3528
3529         if (ac != 1)
3530                 print_usage();
3531
3532         radix_tree_init();
3533         cache_tree_init(&root_cache);
3534
3535         if((ret = check_mounted(av[optind])) < 0) {
3536                 fprintf(stderr, "Could not check mount status: %s\n", strerror(-ret));
3537                 return ret;
3538         } else if(ret) {
3539                 fprintf(stderr, "%s is currently mounted. Aborting.\n", av[optind]);
3540                 return -EBUSY;
3541         }
3542
3543         info = open_ctree_fs_info(av[optind], bytenr, rw, 1);
3544
3545         if (info == NULL)
3546                 return 1;
3547
3548         if (!extent_buffer_uptodate(info->tree_root->node) ||
3549             !extent_buffer_uptodate(info->dev_root->node) ||
3550             !extent_buffer_uptodate(info->extent_root->node) ||
3551             !extent_buffer_uptodate(info->chunk_root->node)) {
3552                 fprintf(stderr, "Critical roots corrupted, unable to fsck the FS\n");
3553                 return -EIO;
3554         }
3555
3556         root = info->fs_root;
3557
3558         fprintf(stderr, "checking extents\n");
3559         if (rw)
3560                 trans = btrfs_start_transaction(root, 1);
3561
3562         if (init_csum_tree) {
3563                 fprintf(stderr, "Reinit crc root\n");
3564                 ret = btrfs_fsck_reinit_root(trans, info->csum_root);
3565                 if (ret) {
3566                         fprintf(stderr, "crc root initialization failed\n");
3567                         return -EIO;
3568                 }
3569                 goto out;
3570         }
3571         ret = check_extents(trans, root, repair);
3572         if (ret)
3573                 fprintf(stderr, "Errors found in extent allocation tree\n");
3574
3575         fprintf(stderr, "checking fs roots\n");
3576         ret = check_fs_roots(root, &root_cache);
3577         if (ret)
3578                 goto out;
3579
3580         fprintf(stderr, "checking root refs\n");
3581         ret = check_root_refs(root, &root_cache);
3582 out:
3583         free_root_recs(&root_cache);
3584         if (rw) {
3585                 ret = btrfs_commit_transaction(trans, root);
3586                 if (ret)
3587                         exit(1);
3588         }
3589         close_ctree(root);
3590
3591         if (found_old_backref) { /*
3592                  * there was a disk format change when mixed
3593                  * backref was in testing tree. The old format
3594                  * existed about one week.
3595                  */
3596                 printf("\n * Found old mixed backref format. "
3597                        "The old format is not supported! *"
3598                        "\n * Please mount the FS in readonly mode, "
3599                        "backup data and re-format the FS. *\n\n");
3600                 ret = 1;
3601         }
3602         printf("found %llu bytes used err is %d\n",
3603                (unsigned long long)bytes_used, ret);
3604         printf("total csum bytes: %llu\n",(unsigned long long)total_csum_bytes);
3605         printf("total tree bytes: %llu\n",
3606                (unsigned long long)total_btree_bytes);
3607         printf("total fs tree bytes: %llu\n",
3608                (unsigned long long)total_fs_tree_bytes);
3609         printf("btree space waste bytes: %llu\n",
3610                (unsigned long long)btree_space_waste);
3611         printf("file data blocks allocated: %llu\n referenced %llu\n",
3612                 (unsigned long long)data_bytes_allocated,
3613                 (unsigned long long)data_bytes_referenced);
3614         printf("%s\n", BTRFS_BUILD_VERSION);
3615         return ret;
3616 }