cmds-check.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/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <getopt.h>
  29 #include <uuid/uuid.h>
  30 #include "kerncompat.h"
  31 #include "ctree.h"
  32 #include "volumes.h"
  33 #include "repair.h"
  34 #include "disk-io.h"
  35 #include "print-tree.h"
  36 #include "transaction.h"
  37 #include "list.h"
  38 #include "version.h"
  39 #include "utils.h"
  40 #include "commands.h"
  41 #include "free-space-cache.h"
  42
  43 static u64 bytes_used = 0;
  44 static u64 total_csum_bytes = 0;
  45 static u64 total_btree_bytes = 0;
  46 static u64 total_fs_tree_bytes = 0;
  47 static u64 total_extent_tree_bytes = 0;
  48 static u64 btree_space_waste = 0;
  49 static u64 data_bytes_allocated = 0;
  50 static u64 data_bytes_referenced = 0;
  51 static int found_old_backref = 0;
  52 static LIST_HEAD(duplicate_extents);
  53
  54 struct extent_backref {
  55         struct list_head list;
  56         unsigned int is_data:1;
  57         unsigned int found_extent_tree:1;
  58         unsigned int full_backref:1;
  59         unsigned int found_ref:1;
  60 };
  61
  62 struct data_backref {
  63         struct extent_backref node;
  64         union {
  65                 u64 parent;
  66                 u64 root;
  67         };
  68         u64 owner;
  69         u64 offset;
  70         u64 disk_bytenr;
  71         u64 bytes;
  72         u64 ram_bytes;
  73         u32 num_refs;
  74         u32 found_ref;
  75 };
  76
  77 struct tree_backref {
  78         struct extent_backref node;
  79         union {
  80                 u64 parent;
  81                 u64 root;
  82         };
  83 };
  84
  85 struct extent_record {
  86         struct list_head backrefs;
  87         struct list_head dups;
  88         struct list_head list;
  89         struct cache_extent cache;
  90         struct btrfs_disk_key parent_key;
  91         u64 start;
  92         u64 max_size;
  93         u64 nr;
  94         u64 refs;
  95         u64 extent_item_refs;
  96         u64 generation;
  97         u64 info_objectid;
  98         u8 info_level;
  99         unsigned int content_checked:1;
 100         unsigned int owner_ref_checked:1;
 101         unsigned int is_root:1;
 102         unsigned int metadata:1;
 103         unsigned int found_rec:1;
 104         unsigned int has_duplicate:1;
 105 };
 106
 107 struct inode_backref {
 108         struct list_head list;
 109         unsigned int found_dir_item:1;
 110         unsigned int found_dir_index:1;
 111         unsigned int found_inode_ref:1;
 112         unsigned int filetype:8;
 113         int errors;
 114         unsigned int ref_type;
 115         u64 dir;
 116         u64 index;
 117         u16 namelen;
 118         char name[0];
 119 };
 120
 121 #define REF_ERR_NO_DIR_ITEM             (1 << 0)
 122 #define REF_ERR_NO_DIR_INDEX            (1 << 1)
 123 #define REF_ERR_NO_INODE_REF            (1 << 2)
 124 #define REF_ERR_DUP_DIR_ITEM            (1 << 3)
 125 #define REF_ERR_DUP_DIR_INDEX           (1 << 4)
 126 #define REF_ERR_DUP_INODE_REF           (1 << 5)
 127 #define REF_ERR_INDEX_UNMATCH           (1 << 6)
 128 #define REF_ERR_FILETYPE_UNMATCH        (1 << 7)
 129 #define REF_ERR_NAME_TOO_LONG           (1 << 8) // 100
 130 #define REF_ERR_NO_ROOT_REF             (1 << 9)
 131 #define REF_ERR_NO_ROOT_BACKREF         (1 << 10)
 132 #define REF_ERR_DUP_ROOT_REF            (1 << 11)
 133 #define REF_ERR_DUP_ROOT_BACKREF        (1 << 12)
 134
 135 struct inode_record {
 136         struct list_head backrefs;
 137         unsigned int checked:1;
 138         unsigned int merging:1;
 139         unsigned int found_inode_item:1;
 140         unsigned int found_dir_item:1;
 141         unsigned int found_file_extent:1;
 142         unsigned int found_csum_item:1;
 143         unsigned int some_csum_missing:1;
 144         unsigned int nodatasum:1;
 145         int errors;
 146
 147         u64 ino;
 148         u32 nlink;
 149         u32 imode;
 150         u64 isize;
 151         u64 nbytes;
 152
 153         u32 found_link;
 154         u64 found_size;
 155         u64 extent_start;
 156         u64 extent_end;
 157         u64 first_extent_gap;
 158
 159         u32 refs;
 160 };
 161
 162 #define I_ERR_NO_INODE_ITEM             (1 << 0)
 163 #define I_ERR_NO_ORPHAN_ITEM            (1 << 1)
 164 #define I_ERR_DUP_INODE_ITEM            (1 << 2)
 165 #define I_ERR_DUP_DIR_INDEX             (1 << 3)
 166 #define I_ERR_ODD_DIR_ITEM              (1 << 4)
 167 #define I_ERR_ODD_FILE_EXTENT           (1 << 5)
 168 #define I_ERR_BAD_FILE_EXTENT           (1 << 6)
 169 #define I_ERR_FILE_EXTENT_OVERLAP       (1 << 7)
 170 #define I_ERR_FILE_EXTENT_DISCOUNT      (1 << 8) // 100
 171 #define I_ERR_DIR_ISIZE_WRONG           (1 << 9)
 172 #define I_ERR_FILE_NBYTES_WRONG         (1 << 10) // 400
 173 #define I_ERR_ODD_CSUM_ITEM             (1 << 11)
 174 #define I_ERR_SOME_CSUM_MISSING         (1 << 12)
 175 #define I_ERR_LINK_COUNT_WRONG          (1 << 13)
 176
 177 struct root_backref {
 178         struct list_head list;
 179         unsigned int found_dir_item:1;
 180         unsigned int found_dir_index:1;
 181         unsigned int found_back_ref:1;
 182         unsigned int found_forward_ref:1;
 183         unsigned int reachable:1;
 184         int errors;
 185         u64 ref_root;
 186         u64 dir;
 187         u64 index;
 188         u16 namelen;
 189         char name[0];
 190 };
 191
 192 struct root_record {
 193         struct list_head backrefs;
 194         struct cache_extent cache;
 195         unsigned int found_root_item:1;
 196         u64 objectid;
 197         u32 found_ref;
 198 };
 199
 200 struct ptr_node {
 201         struct cache_extent cache;
 202         void *data;
 203 };
 204
 205 struct shared_node {
 206         struct cache_extent cache;
 207         struct cache_tree root_cache;
 208         struct cache_tree inode_cache;
 209         struct inode_record *current;
 210         u32 refs;
 211 };
 212
 213 struct block_info {
 214         u64 start;
 215         u32 size;
 216 };
 217
 218 struct walk_control {
 219         struct cache_tree shared;
 220         struct shared_node *nodes[BTRFS_MAX_LEVEL];
 221         int active_node;
 222         int root_level;
 223 };
 224
 225 static u8 imode_to_type(u32 imode)
 226 {
 227 #define S_SHIFT 12
 228         static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
 229                 [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
 230                 [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
 231                 [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
 232                 [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
 233                 [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
 234                 [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
 235                 [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
 236         };
 237
 238         return btrfs_type_by_mode[(imode & S_IFMT) >> S_SHIFT];
 239 #undef S_SHIFT
 240 }
 241
 242 static struct inode_record *clone_inode_rec(struct inode_record *orig_rec)
 243 {
 244         struct inode_record *rec;
 245         struct inode_backref *backref;
 246         struct inode_backref *orig;
 247         size_t size;
 248
 249         rec = malloc(sizeof(*rec));
 250         memcpy(rec, orig_rec, sizeof(*rec));
 251         rec->refs = 1;
 252         INIT_LIST_HEAD(&rec->backrefs);
 253
 254         list_for_each_entry(orig, &orig_rec->backrefs, list) {
 255                 size = sizeof(*orig) + orig->namelen + 1;
 256                 backref = malloc(size);
 257                 memcpy(backref, orig, size);
 258                 list_add_tail(&backref->list, &rec->backrefs);
 259         }
 260         return rec;
 261 }
 262
 263 static struct inode_record *get_inode_rec(struct cache_tree *inode_cache,
 264                                           u64 ino, int mod)
 265 {
 266         struct ptr_node *node;
 267         struct cache_extent *cache;
 268         struct inode_record *rec = NULL;
 269         int ret;
 270
 271         cache = find_cache_extent(inode_cache, ino, 1);
 272         if (cache) {
 273                 node = container_of(cache, struct ptr_node, cache);
 274                 rec = node->data;
 275                 if (mod && rec->refs > 1) {
 276                         node->data = clone_inode_rec(rec);
 277                         rec->refs--;
 278                         rec = node->data;
 279                 }
 280         } else if (mod) {
 281                 rec = calloc(1, sizeof(*rec));
 282                 rec->ino = ino;
 283                 rec->extent_start = (u64)-1;
 284                 rec->first_extent_gap = (u64)-1;
 285                 rec->refs = 1;
 286                 INIT_LIST_HEAD(&rec->backrefs);
 287
 288                 node = malloc(sizeof(*node));
 289                 node->cache.start = ino;
 290                 node->cache.size = 1;
 291                 node->data = rec;
 292
 293                 if (ino == BTRFS_FREE_INO_OBJECTID)
 294                         rec->found_link = 1;
 295
 296                 ret = insert_existing_cache_extent(inode_cache, &node->cache);
 297                 BUG_ON(ret);
 298         }
 299         return rec;
 300 }
 301
 302 static void free_inode_rec(struct inode_record *rec)
 303 {
 304         struct inode_backref *backref;
 305
 306         if (--rec->refs > 0)
 307                 return;
 308
 309         while (!list_empty(&rec->backrefs)) {
 310                 backref = list_entry(rec->backrefs.next,
 311                                      struct inode_backref, list);
 312                 list_del(&backref->list);
 313                 free(backref);
 314         }
 315         free(rec);
 316 }
 317
 318 static int can_free_inode_rec(struct inode_record *rec)
 319 {
 320         if (!rec->errors && rec->checked && rec->found_inode_item &&
 321             rec->nlink == rec->found_link && list_empty(&rec->backrefs))
 322                 return 1;
 323         return 0;
 324 }
 325
 326 static void maybe_free_inode_rec(struct cache_tree *inode_cache,
 327                                  struct inode_record *rec)
 328 {
 329         struct cache_extent *cache;
 330         struct inode_backref *tmp, *backref;
 331         struct ptr_node *node;
 332         unsigned char filetype;
 333
 334         if (!rec->found_inode_item)
 335                 return;
 336
 337         filetype = imode_to_type(rec->imode);
 338         list_for_each_entry_safe(backref, tmp, &rec->backrefs, list) {
 339                 if (backref->found_dir_item && backref->found_dir_index) {
 340                         if (backref->filetype != filetype)
 341                                 backref->errors |= REF_ERR_FILETYPE_UNMATCH;
 342                         if (!backref->errors && backref->found_inode_ref) {
 343                                 list_del(&backref->list);
 344                                 free(backref);
 345                         }
 346                 }
 347         }
 348
 349         if (!rec->checked || rec->merging)
 350                 return;
 351
 352         if (S_ISDIR(rec->imode)) {
 353                 if (rec->found_size != rec->isize)
 354                         rec->errors |= I_ERR_DIR_ISIZE_WRONG;
 355                 if (rec->found_file_extent)
 356                         rec->errors |= I_ERR_ODD_FILE_EXTENT;
 357         } else if (S_ISREG(rec->imode) || S_ISLNK(rec->imode)) {
 358                 if (rec->found_dir_item)
 359                         rec->errors |= I_ERR_ODD_DIR_ITEM;
 360                 if (rec->found_size != rec->nbytes)
 361                         rec->errors |= I_ERR_FILE_NBYTES_WRONG;
 362                 if (rec->extent_start == (u64)-1 || rec->extent_start > 0)
 363                         rec->first_extent_gap = 0;
 364                 if (rec->nlink > 0 && (rec->extent_end < rec->isize ||
 365                     rec->first_extent_gap < rec->isize))
 366                         rec->errors |= I_ERR_FILE_EXTENT_DISCOUNT;
 367         }
 368
 369         if (S_ISREG(rec->imode) || S_ISLNK(rec->imode)) {
 370                 if (rec->found_csum_item && rec->nodatasum)
 371                         rec->errors |= I_ERR_ODD_CSUM_ITEM;
 372                 if (rec->some_csum_missing && !rec->nodatasum)
 373                         rec->errors |= I_ERR_SOME_CSUM_MISSING;
 374         }
 375
 376         BUG_ON(rec->refs != 1);
 377         if (can_free_inode_rec(rec)) {
 378                 cache = find_cache_extent(inode_cache, rec->ino, 1);
 379                 node = container_of(cache, struct ptr_node, cache);
 380                 BUG_ON(node->data != rec);
 381                 remove_cache_extent(inode_cache, &node->cache);
 382                 free(node);
 383                 free_inode_rec(rec);
 384         }
 385 }
 386
 387 static int check_orphan_item(struct btrfs_root *root, u64 ino)
 388 {
 389         struct btrfs_path path;
 390         struct btrfs_key key;
 391         int ret;
 392
 393         key.objectid = BTRFS_ORPHAN_OBJECTID;
 394         key.type = BTRFS_ORPHAN_ITEM_KEY;
 395         key.offset = ino;
 396
 397         btrfs_init_path(&path);
 398         ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
 399         btrfs_release_path(root, &path);
 400         if (ret > 0)
 401                 ret = -ENOENT;
 402         return ret;
 403 }
 404
 405 static int process_inode_item(struct extent_buffer *eb,
 406                               int slot, struct btrfs_key *key,
 407                               struct shared_node *active_node)
 408 {
 409         struct inode_record *rec;
 410         struct btrfs_inode_item *item;
 411
 412         rec = active_node->current;
 413         BUG_ON(rec->ino != key->objectid || rec->refs > 1);
 414         if (rec->found_inode_item) {
 415                 rec->errors |= I_ERR_DUP_INODE_ITEM;
 416                 return 1;
 417         }
 418         item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
 419         rec->nlink = btrfs_inode_nlink(eb, item);
 420         rec->isize = btrfs_inode_size(eb, item);
 421         rec->nbytes = btrfs_inode_nbytes(eb, item);
 422         rec->imode = btrfs_inode_mode(eb, item);
 423         if (btrfs_inode_flags(eb, item) & BTRFS_INODE_NODATASUM)
 424                 rec->nodatasum = 1;
 425         rec->found_inode_item = 1;
 426         if (rec->nlink == 0)
 427                 rec->errors |= I_ERR_NO_ORPHAN_ITEM;
 428         maybe_free_inode_rec(&active_node->inode_cache, rec);
 429         return 0;
 430 }
 431
 432 static struct inode_backref *get_inode_backref(struct inode_record *rec,
 433                                                 const char *name,
 434                                                 int namelen, u64 dir)
 435 {
 436         struct inode_backref *backref;
 437
 438         list_for_each_entry(backref, &rec->backrefs, list) {
 439                 if (backref->dir != dir || backref->namelen != namelen)
 440                         continue;
 441                 if (memcmp(name, backref->name, namelen))
 442                         continue;
 443                 return backref;
 444         }
 445
 446         backref = malloc(sizeof(*backref) + namelen + 1);
 447         memset(backref, 0, sizeof(*backref));
 448         backref->dir = dir;
 449         backref->namelen = namelen;
 450         memcpy(backref->name, name, namelen);
 451         backref->name[namelen] = '\0';
 452         list_add_tail(&backref->list, &rec->backrefs);
 453         return backref;
 454 }
 455
 456 static int add_inode_backref(struct cache_tree *inode_cache,
 457                              u64 ino, u64 dir, u64 index,
 458                              const char *name, int namelen,
 459                              int filetype, int itemtype, int errors)
 460 {
 461         struct inode_record *rec;
 462         struct inode_backref *backref;
 463
 464         rec = get_inode_rec(inode_cache, ino, 1);
 465         backref = get_inode_backref(rec, name, namelen, dir);
 466         if (errors)
 467                 backref->errors |= errors;
 468         if (itemtype == BTRFS_DIR_INDEX_KEY) {
 469                 if (backref->found_dir_index)
 470                         backref->errors |= REF_ERR_DUP_DIR_INDEX;
 471                 if (backref->found_inode_ref && backref->index != index)
 472                         backref->errors |= REF_ERR_INDEX_UNMATCH;
 473                 if (backref->found_dir_item && backref->filetype != filetype)
 474                         backref->errors |= REF_ERR_FILETYPE_UNMATCH;
 475
 476                 backref->index = index;
 477                 backref->filetype = filetype;
 478                 backref->found_dir_index = 1;
 479         } else if (itemtype == BTRFS_DIR_ITEM_KEY) {
 480                 rec->found_link++;
 481                 if (backref->found_dir_item)
 482                         backref->errors |= REF_ERR_DUP_DIR_ITEM;
 483                 if (backref->found_dir_index && backref->filetype != filetype)
 484                         backref->errors |= REF_ERR_FILETYPE_UNMATCH;
 485
 486                 backref->filetype = filetype;
 487                 backref->found_dir_item = 1;
 488         } else if ((itemtype == BTRFS_INODE_REF_KEY) ||
 489                    (itemtype == BTRFS_INODE_EXTREF_KEY)) {
 490                 if (backref->found_inode_ref)
 491                         backref->errors |= REF_ERR_DUP_INODE_REF;
 492                 if (backref->found_dir_index && backref->index != index)
 493                         backref->errors |= REF_ERR_INDEX_UNMATCH;
 494
 495                 backref->ref_type = itemtype;
 496                 backref->index = index;
 497                 backref->found_inode_ref = 1;
 498         } else {
 499                 BUG_ON(1);
 500         }
 501
 502         maybe_free_inode_rec(inode_cache, rec);
 503         return 0;
 504 }
 505
 506 static int merge_inode_recs(struct inode_record *src, struct inode_record *dst,
 507                             struct cache_tree *dst_cache)
 508 {
 509         struct inode_backref *backref;
 510         u32 dir_count = 0;
 511
 512         dst->merging = 1;
 513         list_for_each_entry(backref, &src->backrefs, list) {
 514                 if (backref->found_dir_index) {
 515                         add_inode_backref(dst_cache, dst->ino, backref->dir,
 516                                         backref->index, backref->name,
 517                                         backref->namelen, backref->filetype,
 518                                         BTRFS_DIR_INDEX_KEY, backref->errors);
 519                 }
 520                 if (backref->found_dir_item) {
 521                         dir_count++;
 522                         add_inode_backref(dst_cache, dst->ino,
 523                                         backref->dir, 0, backref->name,
 524                                         backref->namelen, backref->filetype,
 525                                         BTRFS_DIR_ITEM_KEY, backref->errors);
 526                 }
 527                 if (backref->found_inode_ref) {
 528                         add_inode_backref(dst_cache, dst->ino,
 529                                         backref->dir, backref->index,
 530                                         backref->name, backref->namelen, 0,
 531                                         backref->ref_type, backref->errors);
 532                 }
 533         }
 534
 535         if (src->found_dir_item)
 536                 dst->found_dir_item = 1;
 537         if (src->found_file_extent)
 538                 dst->found_file_extent = 1;
 539         if (src->found_csum_item)
 540                 dst->found_csum_item = 1;
 541         if (src->some_csum_missing)
 542                 dst->some_csum_missing = 1;
 543         if (dst->first_extent_gap > src->first_extent_gap)
 544                 dst->first_extent_gap = src->first_extent_gap;
 545
 546         BUG_ON(src->found_link < dir_count);
 547         dst->found_link += src->found_link - dir_count;
 548         dst->found_size += src->found_size;
 549         if (src->extent_start != (u64)-1) {
 550                 if (dst->extent_start == (u64)-1) {
 551                         dst->extent_start = src->extent_start;
 552                         dst->extent_end = src->extent_end;
 553                 } else {
 554                         if (dst->extent_end > src->extent_start)
 555                                 dst->errors |= I_ERR_FILE_EXTENT_OVERLAP;
 556                         else if (dst->extent_end < src->extent_start &&
 557                                  dst->extent_end < dst->first_extent_gap)
 558                                 dst->first_extent_gap = dst->extent_end;
 559                         if (dst->extent_end < src->extent_end)
 560                                 dst->extent_end = src->extent_end;
 561                 }
 562         }
 563
 564         dst->errors |= src->errors;
 565         if (src->found_inode_item) {
 566                 if (!dst->found_inode_item) {
 567                         dst->nlink = src->nlink;
 568                         dst->isize = src->isize;
 569                         dst->nbytes = src->nbytes;
 570                         dst->imode = src->imode;
 571                         dst->nodatasum = src->nodatasum;
 572                         dst->found_inode_item = 1;
 573                 } else {
 574                         dst->errors |= I_ERR_DUP_INODE_ITEM;
 575                 }
 576         }
 577         dst->merging = 0;
 578
 579         return 0;
 580 }
 581
 582 static int splice_shared_node(struct shared_node *src_node,
 583                               struct shared_node *dst_node)
 584 {
 585         struct cache_extent *cache;
 586         struct ptr_node *node, *ins;
 587         struct cache_tree *src, *dst;
 588         struct inode_record *rec, *conflict;
 589         u64 current_ino = 0;
 590         int splice = 0;
 591         int ret;
 592
 593         if (--src_node->refs == 0)
 594                 splice = 1;
 595         if (src_node->current)
 596                 current_ino = src_node->current->ino;
 597
 598         src = &src_node->root_cache;
 599         dst = &dst_node->root_cache;
 600 again:
 601         cache = find_first_cache_extent(src, 0);
 602         while (cache) {
 603                 node = container_of(cache, struct ptr_node, cache);
 604                 rec = node->data;
 605                 cache = next_cache_extent(cache);
 606
 607                 if (splice) {
 608                         remove_cache_extent(src, &node->cache);
 609                         ins = node;
 610                 } else {
 611                         ins = malloc(sizeof(*ins));
 612                         ins->cache.start = node->cache.start;
 613                         ins->cache.size = node->cache.size;
 614                         ins->data = rec;
 615                         rec->refs++;
 616                 }
 617                 ret = insert_existing_cache_extent(dst, &ins->cache);
 618                 if (ret == -EEXIST) {
 619                         conflict = get_inode_rec(dst, rec->ino, 1);
 620                         merge_inode_recs(rec, conflict, dst);
 621                         if (rec->checked) {
 622                                 conflict->checked = 1;
 623                                 if (dst_node->current == conflict)
 624                                         dst_node->current = NULL;
 625                         }
 626                         maybe_free_inode_rec(dst, conflict);
 627                         free_inode_rec(rec);
 628                         free(ins);
 629                 } else {
 630                         BUG_ON(ret);
 631                 }
 632         }
 633
 634         if (src == &src_node->root_cache) {
 635                 src = &src_node->inode_cache;
 636                 dst = &dst_node->inode_cache;
 637                 goto again;
 638         }
 639
 640         if (current_ino > 0 && (!dst_node->current ||
 641             current_ino > dst_node->current->ino)) {
 642                 if (dst_node->current) {
 643                         dst_node->current->checked = 1;
 644                         maybe_free_inode_rec(dst, dst_node->current);
 645                 }
 646                 dst_node->current = get_inode_rec(dst, current_ino, 1);
 647         }
 648         return 0;
 649 }
 650
 651 static void free_inode_recs(struct cache_tree *inode_cache)
 652 {
 653         struct cache_extent *cache;
 654         struct ptr_node *node;
 655         struct inode_record *rec;
 656
 657         while (1) {
 658                 cache = find_first_cache_extent(inode_cache, 0);
 659                 if (!cache)
 660                         break;
 661                 node = container_of(cache, struct ptr_node, cache);
 662                 rec = node->data;
 663                 remove_cache_extent(inode_cache, &node->cache);
 664                 free(node);
 665                 free_inode_rec(rec);
 666         }
 667 }
 668
 669 static struct shared_node *find_shared_node(struct cache_tree *shared,
 670                                             u64 bytenr)
 671 {
 672         struct cache_extent *cache;
 673         struct shared_node *node;
 674
 675         cache = find_cache_extent(shared, bytenr, 1);
 676         if (cache) {
 677                 node = container_of(cache, struct shared_node, cache);
 678                 return node;
 679         }
 680         return NULL;
 681 }
 682
 683 static int add_shared_node(struct cache_tree *shared, u64 bytenr, u32 refs)
 684 {
 685         int ret;
 686         struct shared_node *node;
 687
 688         node = calloc(1, sizeof(*node));
 689         node->cache.start = bytenr;
 690         node->cache.size = 1;
 691         cache_tree_init(&node->root_cache);
 692         cache_tree_init(&node->inode_cache);
 693         node->refs = refs;
 694
 695         ret = insert_existing_cache_extent(shared, &node->cache);
 696         BUG_ON(ret);
 697         return 0;
 698 }
 699
 700 static int enter_shared_node(struct btrfs_root *root, u64 bytenr, u32 refs,
 701                              struct walk_control *wc, int level)
 702 {
 703         struct shared_node *node;
 704         struct shared_node *dest;
 705
 706         if (level == wc->active_node)
 707                 return 0;
 708
 709         BUG_ON(wc->active_node <= level);
 710         node = find_shared_node(&wc->shared, bytenr);
 711         if (!node) {
 712                 add_shared_node(&wc->shared, bytenr, refs);
 713                 node = find_shared_node(&wc->shared, bytenr);
 714                 wc->nodes[level] = node;
 715                 wc->active_node = level;
 716                 return 0;
 717         }
 718
 719         if (wc->root_level == wc->active_node &&
 720             btrfs_root_refs(&root->root_item) == 0) {
 721                 if (--node->refs == 0) {
 722                         free_inode_recs(&node->root_cache);
 723                         free_inode_recs(&node->inode_cache);
 724                         remove_cache_extent(&wc->shared, &node->cache);
 725                         free(node);
 726                 }
 727                 return 1;
 728         }
 729
 730         dest = wc->nodes[wc->active_node];
 731         splice_shared_node(node, dest);
 732         if (node->refs == 0) {
 733                 remove_cache_extent(&wc->shared, &node->cache);
 734                 free(node);
 735         }
 736         return 1;
 737 }
 738
 739 static int leave_shared_node(struct btrfs_root *root,
 740                              struct walk_control *wc, int level)
 741 {
 742         struct shared_node *node;
 743         struct shared_node *dest;
 744         int i;
 745
 746         if (level == wc->root_level)
 747                 return 0;
 748
 749         for (i = level + 1; i < BTRFS_MAX_LEVEL; i++) {
 750                 if (wc->nodes[i])
 751                         break;
 752         }
 753         BUG_ON(i >= BTRFS_MAX_LEVEL);
 754
 755         node = wc->nodes[wc->active_node];
 756         wc->nodes[wc->active_node] = NULL;
 757         wc->active_node = i;
 758
 759         dest = wc->nodes[wc->active_node];
 760         if (wc->active_node < wc->root_level ||
 761             btrfs_root_refs(&root->root_item) > 0) {
 762                 BUG_ON(node->refs <= 1);
 763                 splice_shared_node(node, dest);
 764         } else {
 765                 BUG_ON(node->refs < 2);
 766                 node->refs--;
 767         }
 768         return 0;
 769 }
 770
 771 static int is_child_root(struct btrfs_root *root, u64 parent_root_id,
 772                          u64 child_root_id)
 773 {
 774         struct btrfs_path path;
 775         struct btrfs_key key;
 776         struct extent_buffer *leaf;
 777         int has_parent = 0;
 778         int ret;
 779
 780         btrfs_init_path(&path);
 781
 782         key.objectid = parent_root_id;
 783         key.type = BTRFS_ROOT_REF_KEY;
 784         key.offset = child_root_id;
 785         ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, &path,
 786                                 0, 0);
 787         BUG_ON(ret < 0);
 788         btrfs_release_path(root, &path);
 789         if (!ret)
 790                 return 1;
 791
 792         key.objectid = child_root_id;
 793         key.type = BTRFS_ROOT_BACKREF_KEY;
 794         key.offset = 0;
 795         ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, &path,
 796                                 0, 0);
 797         BUG_ON(ret <= 0);
 798
 799         while (1) {
 800                 leaf = path.nodes[0];
 801                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
 802                         ret = btrfs_next_leaf(root->fs_info->tree_root, &path);
 803                         BUG_ON(ret < 0);
 804
 805                         if (ret > 0)
 806                                 break;
 807                         leaf = path.nodes[0];
 808                 }
 809
 810                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
 811                 if (key.objectid != child_root_id ||
 812                     key.type != BTRFS_ROOT_BACKREF_KEY)
 813                         break;
 814
 815                 has_parent = 1;
 816
 817                 if (key.offset == parent_root_id) {
 818                         btrfs_release_path(root, &path);
 819                         return 1;
 820                 }
 821
 822                 path.slots[0]++;
 823         }
 824
 825         btrfs_release_path(root, &path);
 826         return has_parent? 0 : -1;
 827 }
 828
 829 static int process_dir_item(struct btrfs_root *root,
 830                             struct extent_buffer *eb,
 831                             int slot, struct btrfs_key *key,
 832                             struct shared_node *active_node)
 833 {
 834         u32 total;
 835         u32 cur = 0;
 836         u32 len;
 837         u32 name_len;
 838         u32 data_len;
 839         int error;
 840         int nritems = 0;
 841         int filetype;
 842         struct btrfs_dir_item *di;
 843         struct inode_record *rec;
 844         struct cache_tree *root_cache;
 845         struct cache_tree *inode_cache;
 846         struct btrfs_key location;
 847         char namebuf[BTRFS_NAME_LEN];
 848
 849         root_cache = &active_node->root_cache;
 850         inode_cache = &active_node->inode_cache;
 851         rec = active_node->current;
 852         rec->found_dir_item = 1;
 853
 854         di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
 855         total = btrfs_item_size_nr(eb, slot);
 856         while (cur < total) {
 857                 nritems++;
 858                 btrfs_dir_item_key_to_cpu(eb, di, &location);
 859                 name_len = btrfs_dir_name_len(eb, di);
 860                 data_len = btrfs_dir_data_len(eb, di);
 861                 filetype = btrfs_dir_type(eb, di);
 862
 863                 rec->found_size += name_len;
 864                 if (name_len <= BTRFS_NAME_LEN) {
 865                         len = name_len;
 866                         error = 0;
 867                 } else {
 868                         len = BTRFS_NAME_LEN;
 869                         error = REF_ERR_NAME_TOO_LONG;
 870                 }
 871                 read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), len);
 872
 873                 if (location.type == BTRFS_INODE_ITEM_KEY) {
 874                         add_inode_backref(inode_cache, location.objectid,
 875                                           key->objectid, key->offset, namebuf,
 876                                           len, filetype, key->type, error);
 877                 } else if (location.type == BTRFS_ROOT_ITEM_KEY) {
 878                         add_inode_backref(root_cache, location.objectid,
 879                                           key->objectid, key->offset,
 880                                           namebuf, len, filetype,
 881                                           key->type, error);
 882                 } else {
 883                         fprintf(stderr, "warning line %d\n", __LINE__);
 884                 }
 885
 886                 len = sizeof(*di) + name_len + data_len;
 887                 di = (struct btrfs_dir_item *)((char *)di + len);
 888                 cur += len;
 889         }
 890         if (key->type == BTRFS_DIR_INDEX_KEY && nritems > 1)
 891                 rec->errors |= I_ERR_DUP_DIR_INDEX;
 892
 893         return 0;
 894 }
 895
 896 static int process_inode_ref(struct extent_buffer *eb,
 897                              int slot, struct btrfs_key *key,
 898                              struct shared_node *active_node)
 899 {
 900         u32 total;
 901         u32 cur = 0;
 902         u32 len;
 903         u32 name_len;
 904         u64 index;
 905         int error;
 906         struct cache_tree *inode_cache;
 907         struct btrfs_inode_ref *ref;
 908         char namebuf[BTRFS_NAME_LEN];
 909
 910         inode_cache = &active_node->inode_cache;
 911
 912         ref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
 913         total = btrfs_item_size_nr(eb, slot);
 914         while (cur < total) {
 915                 name_len = btrfs_inode_ref_name_len(eb, ref);
 916                 index = btrfs_inode_ref_index(eb, ref);
 917                 if (name_len <= BTRFS_NAME_LEN) {
 918                         len = name_len;
 919                         error = 0;
 920                 } else {
 921                         len = BTRFS_NAME_LEN;
 922                         error = REF_ERR_NAME_TOO_LONG;
 923                 }
 924                 read_extent_buffer(eb, namebuf, (unsigned long)(ref + 1), len);
 925                 add_inode_backref(inode_cache, key->objectid, key->offset,
 926                                   index, namebuf, len, 0, key->type, error);
 927
 928                 len = sizeof(*ref) + name_len;
 929                 ref = (struct btrfs_inode_ref *)((char *)ref + len);
 930                 cur += len;
 931         }
 932         return 0;
 933 }
 934
 935 static int process_inode_extref(struct extent_buffer *eb,
 936                                 int slot, struct btrfs_key *key,
 937                                 struct shared_node *active_node)
 938 {
 939         u32 total;
 940         u32 cur = 0;
 941         u32 len;
 942         u32 name_len;
 943         u64 index;
 944         u64 parent;
 945         int error;
 946         struct cache_tree *inode_cache;
 947         struct btrfs_inode_extref *extref;
 948         char namebuf[BTRFS_NAME_LEN];
 949
 950         inode_cache = &active_node->inode_cache;
 951
 952         extref = btrfs_item_ptr(eb, slot, struct btrfs_inode_extref);
 953         total = btrfs_item_size_nr(eb, slot);
 954         while (cur < total) {
 955                 name_len = btrfs_inode_extref_name_len(eb, extref);
 956                 index = btrfs_inode_extref_index(eb, extref);
 957                 parent = btrfs_inode_extref_parent(eb, extref);
 958                 if (name_len <= BTRFS_NAME_LEN) {
 959                         len = name_len;
 960                         error = 0;
 961                 } else {
 962                         len = BTRFS_NAME_LEN;
 963                         error = REF_ERR_NAME_TOO_LONG;
 964                 }
 965                 read_extent_buffer(eb, namebuf,
 966                                    (unsigned long)(extref + 1), len);
 967                 add_inode_backref(inode_cache, key->objectid, parent,
 968                                   index, namebuf, len, 0, key->type, error);
 969
 970                 len = sizeof(*extref) + name_len;
 971                 extref = (struct btrfs_inode_extref *)((char *)extref + len);
 972                 cur += len;
 973         }
 974         return 0;
 975
 976 }
 977
 978 static u64 count_csum_range(struct btrfs_root *root, u64 start, u64 len)
 979 {
 980         struct btrfs_key key;
 981         struct btrfs_path path;
 982         struct extent_buffer *leaf;
 983         int ret ;
 984         size_t size;
 985         u64 found = 0;
 986         u64 csum_end;
 987         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 988
 989         btrfs_init_path(&path);
 990
 991         key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
 992         key.offset = start;
 993         key.type = BTRFS_EXTENT_CSUM_KEY;
 994
 995         ret = btrfs_search_slot(NULL, root->fs_info->csum_root,
 996                                 &key, &path, 0, 0);
 997         BUG_ON(ret < 0);
 998         if (ret > 0 && path.slots[0] > 0) {
 999                 leaf = path.nodes[0];
1000                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0] - 1);
1001                 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
1002                     key.type == BTRFS_EXTENT_CSUM_KEY)
1003                         path.slots[0]--;
1004         }
1005
1006         while (len > 0) {
1007                 leaf = path.nodes[0];
1008                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
1009                         ret = btrfs_next_leaf(root->fs_info->csum_root, &path);
1010                         BUG_ON(ret < 0);
1011                         if (ret > 0)
1012                                 break;
1013                         leaf = path.nodes[0];
1014                 }
1015
1016                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
1017                 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1018                     key.type != BTRFS_EXTENT_CSUM_KEY)
1019                         break;
1020
1021                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
1022                 if (key.offset >= start + len)
1023                         break;
1024
1025                 if (key.offset > start)
1026                         start = key.offset;
1027
1028                 size = btrfs_item_size_nr(leaf, path.slots[0]);
1029                 csum_end = key.offset + (size / csum_size) * root->sectorsize;
1030                 if (csum_end > start) {
1031                         size = min(csum_end - start, len);
1032                         len -= size;
1033                         start += size;
1034                         found += size;
1035                 }
1036
1037                 path.slots[0]++;
1038         }
1039         btrfs_release_path(root->fs_info->csum_root, &path);
1040         return found;
1041 }
1042
1043 static int process_file_extent(struct btrfs_root *root,
1044                                 struct extent_buffer *eb,
1045                                 int slot, struct btrfs_key *key,
1046                                 struct shared_node *active_node)
1047 {
1048         struct inode_record *rec;
1049         struct btrfs_file_extent_item *fi;
1050         u64 num_bytes = 0;
1051         u64 disk_bytenr = 0;
1052         u64 extent_offset = 0;
1053         u64 mask = root->sectorsize - 1;
1054         int extent_type;
1055
1056         rec = active_node->current;
1057         BUG_ON(rec->ino != key->objectid || rec->refs > 1);
1058         rec->found_file_extent = 1;
1059
1060         if (rec->extent_start == (u64)-1) {
1061                 rec->extent_start = key->offset;
1062                 rec->extent_end = key->offset;
1063         }
1064
1065         if (rec->extent_end > key->offset)
1066                 rec->errors |= I_ERR_FILE_EXTENT_OVERLAP;
1067         else if (rec->extent_end < key->offset &&
1068                  rec->extent_end < rec->first_extent_gap)
1069                 rec->first_extent_gap = rec->extent_end;
1070
1071         fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
1072         extent_type = btrfs_file_extent_type(eb, fi);
1073
1074         if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1075                 num_bytes = btrfs_file_extent_inline_len(eb, fi);
1076                 if (num_bytes == 0)
1077                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1078                 rec->found_size += num_bytes;
1079                 num_bytes = (num_bytes + mask) & ~mask;
1080         } else if (extent_type == BTRFS_FILE_EXTENT_REG ||
1081                    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1082                 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1083                 disk_bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1084                 extent_offset = btrfs_file_extent_offset(eb, fi);
1085                 if (num_bytes == 0 || (num_bytes & mask))
1086                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1087                 if (num_bytes + extent_offset >
1088                     btrfs_file_extent_ram_bytes(eb, fi))
1089                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1090                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC &&
1091                     (btrfs_file_extent_compression(eb, fi) ||
1092                      btrfs_file_extent_encryption(eb, fi) ||
1093                      btrfs_file_extent_other_encoding(eb, fi)))
1094                         rec->errors |= I_ERR_BAD_FILE_EXTENT;
1095                 if (disk_bytenr > 0)
1096                         rec->found_size += num_bytes;
1097         } else {
1098                 rec->errors |= I_ERR_BAD_FILE_EXTENT;
1099         }
1100         rec->extent_end = key->offset + num_bytes;
1101
1102         if (disk_bytenr > 0) {
1103                 u64 found;
1104                 if (btrfs_file_extent_compression(eb, fi))
1105                         num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1106                 else
1107                         disk_bytenr += extent_offset;
1108
1109                 found = count_csum_range(root, disk_bytenr, num_bytes);
1110                 if (extent_type == BTRFS_FILE_EXTENT_REG) {
1111                         if (found > 0)
1112                                 rec->found_csum_item = 1;
1113                         if (found < num_bytes)
1114                                 rec->some_csum_missing = 1;
1115                 } else if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1116                         if (found > 0)
1117                                 rec->errors |= I_ERR_ODD_CSUM_ITEM;
1118                 }
1119         }
1120         return 0;
1121 }
1122
1123 static int process_one_leaf(struct btrfs_root *root, struct extent_buffer *eb,
1124                             struct walk_control *wc)
1125 {
1126         struct btrfs_key key;
1127         u32 nritems;
1128         int i;
1129         int ret = 0;
1130         struct cache_tree *inode_cache;
1131         struct shared_node *active_node;
1132
1133         if (wc->root_level == wc->active_node &&
1134             btrfs_root_refs(&root->root_item) == 0)
1135                 return 0;
1136
1137         active_node = wc->nodes[wc->active_node];
1138         inode_cache = &active_node->inode_cache;
1139         nritems = btrfs_header_nritems(eb);
1140         for (i = 0; i < nritems; i++) {
1141                 btrfs_item_key_to_cpu(eb, &key, i);
1142
1143                 if (key.objectid == BTRFS_FREE_SPACE_OBJECTID)
1144                         continue;
1145
1146                 if (active_node->current == NULL ||
1147                     active_node->current->ino < key.objectid) {
1148                         if (active_node->current) {
1149                                 active_node->current->checked = 1;
1150                                 maybe_free_inode_rec(inode_cache,
1151                                                      active_node->current);
1152                         }
1153                         active_node->current = get_inode_rec(inode_cache,
1154                                                              key.objectid, 1);
1155                 }
1156                 switch (key.type) {
1157                 case BTRFS_DIR_ITEM_KEY:
1158                 case BTRFS_DIR_INDEX_KEY:
1159                         ret = process_dir_item(root, eb, i, &key, active_node);
1160                         break;
1161                 case BTRFS_INODE_REF_KEY:
1162                         ret = process_inode_ref(eb, i, &key, active_node);
1163                         break;
1164                 case BTRFS_INODE_EXTREF_KEY:
1165                         ret = process_inode_extref(eb, i, &key, active_node);
1166                         break;
1167                 case BTRFS_INODE_ITEM_KEY:
1168                         ret = process_inode_item(eb, i, &key, active_node);
1169                         break;
1170                 case BTRFS_EXTENT_DATA_KEY:
1171                         ret = process_file_extent(root, eb, i, &key,
1172                                                   active_node);
1173                         break;
1174                 default:
1175                         break;
1176                 };
1177         }
1178         return ret;
1179 }
1180
1181 static void reada_walk_down(struct btrfs_root *root,
1182                             struct extent_buffer *node, int slot)
1183 {
1184         u64 bytenr;
1185         u64 ptr_gen;
1186         u32 nritems;
1187         u32 blocksize;
1188         int i;
1189         int ret;
1190         int level;
1191
1192         level = btrfs_header_level(node);
1193         if (level != 1)
1194                 return;
1195
1196         nritems = btrfs_header_nritems(node);
1197         blocksize = btrfs_level_size(root, level - 1);
1198         for (i = slot; i < nritems; i++) {
1199                 bytenr = btrfs_node_blockptr(node, i);
1200                 ptr_gen = btrfs_node_ptr_generation(node, i);
1201                 ret = readahead_tree_block(root, bytenr, blocksize, ptr_gen);
1202                 if (ret)
1203                         break;
1204         }
1205 }
1206
1207 static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path,
1208                           struct walk_control *wc, int *level)
1209 {
1210         u64 bytenr;
1211         u64 ptr_gen;
1212         struct extent_buffer *next;
1213         struct extent_buffer *cur;
1214         u32 blocksize;
1215         int ret;
1216         u64 refs;
1217
1218         WARN_ON(*level < 0);
1219         WARN_ON(*level >= BTRFS_MAX_LEVEL);
1220         ret = btrfs_lookup_extent_info(NULL, root,
1221                                        path->nodes[*level]->start,
1222                                        *level, 1, &refs, NULL);
1223         if (ret < 0)
1224                 goto out;
1225
1226         if (refs > 1) {
1227                 ret = enter_shared_node(root, path->nodes[*level]->start,
1228                                         refs, wc, *level);
1229                 if (ret > 0)
1230                         goto out;
1231         }
1232
1233         while (*level >= 0) {
1234                 WARN_ON(*level < 0);
1235                 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1236                 cur = path->nodes[*level];
1237
1238                 if (btrfs_header_level(cur) != *level)
1239                         WARN_ON(1);
1240
1241                 if (path->slots[*level] >= btrfs_header_nritems(cur))
1242                         break;
1243                 if (*level == 0) {
1244                         ret = process_one_leaf(root, cur, wc);
1245                         break;
1246                 }
1247                 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1248                 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1249                 blocksize = btrfs_level_size(root, *level - 1);
1250                 ret = btrfs_lookup_extent_info(NULL, root, bytenr, *level - 1,
1251                                                1, &refs, NULL);
1252                 if (ret < 0)
1253                         refs = 0;
1254
1255                 if (refs > 1) {
1256                         ret = enter_shared_node(root, bytenr, refs,
1257                                                 wc, *level - 1);
1258                         if (ret > 0) {
1259                                 path->slots[*level]++;
1260                                 continue;
1261                         }
1262                 }
1263
1264                 next = btrfs_find_tree_block(root, bytenr, blocksize);
1265                 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
1266                         free_extent_buffer(next);
1267                         reada_walk_down(root, cur, path->slots[*level]);
1268                         next = read_tree_block(root, bytenr, blocksize,
1269                                                ptr_gen);
1270                 }
1271
1272                 *level = *level - 1;
1273                 free_extent_buffer(path->nodes[*level]);
1274                 path->nodes[*level] = next;
1275                 path->slots[*level] = 0;
1276         }
1277 out:
1278         path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
1279         return 0;
1280 }
1281
1282 static int walk_up_tree(struct btrfs_root *root, struct btrfs_path *path,
1283                         struct walk_control *wc, int *level)
1284 {
1285         int i;
1286         struct extent_buffer *leaf;
1287
1288         for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1289                 leaf = path->nodes[i];
1290                 if (path->slots[i] + 1 < btrfs_header_nritems(leaf)) {
1291                         path->slots[i]++;
1292                         *level = i;
1293                         return 0;
1294                 } else {
1295                         free_extent_buffer(path->nodes[*level]);
1296                         path->nodes[*level] = NULL;
1297                         BUG_ON(*level > wc->active_node);
1298                         if (*level == wc->active_node)
1299                                 leave_shared_node(root, wc, *level);
1300                         *level = i + 1;
1301                 }
1302         }
1303         return 1;
1304 }
1305
1306 static int check_root_dir(struct inode_record *rec)
1307 {
1308         struct inode_backref *backref;
1309         int ret = -1;
1310
1311         if (!rec->found_inode_item || rec->errors)
1312                 goto out;
1313         if (rec->nlink != 1 || rec->found_link != 0)
1314                 goto out;
1315         if (list_empty(&rec->backrefs))
1316                 goto out;
1317         backref = list_entry(rec->backrefs.next, struct inode_backref, list);
1318         if (!backref->found_inode_ref)
1319                 goto out;
1320         if (backref->index != 0 || backref->namelen != 2 ||
1321             memcmp(backref->name, "..", 2))
1322                 goto out;
1323         if (backref->found_dir_index || backref->found_dir_item)
1324                 goto out;
1325         ret = 0;
1326 out:
1327         return ret;
1328 }
1329
1330 static int check_inode_recs(struct btrfs_root *root,
1331                             struct cache_tree *inode_cache)
1332 {
1333         struct cache_extent *cache;
1334         struct ptr_node *node;
1335         struct inode_record *rec;
1336         struct inode_backref *backref;
1337         int ret;
1338         u64 error = 0;
1339         u64 root_dirid = btrfs_root_dirid(&root->root_item);
1340
1341         if (btrfs_root_refs(&root->root_item) == 0) {
1342                 if (!cache_tree_empty(inode_cache))
1343                         fprintf(stderr, "warning line %d\n", __LINE__);
1344                 return 0;
1345         }
1346
1347         rec = get_inode_rec(inode_cache, root_dirid, 0);
1348         if (rec) {
1349                 ret = check_root_dir(rec);
1350                 if (ret) {
1351                         fprintf(stderr, "root %llu root dir %llu error\n",
1352                                 (unsigned long long)root->root_key.objectid,
1353                                 (unsigned long long)root_dirid);
1354                         error++;
1355                 }
1356         } else {
1357                 fprintf(stderr, "root %llu root dir %llu not found\n",
1358                         (unsigned long long)root->root_key.objectid,
1359                         (unsigned long long)root_dirid);
1360         }
1361
1362         while (1) {
1363                 cache = find_first_cache_extent(inode_cache, 0);
1364                 if (!cache)
1365                         break;
1366                 node = container_of(cache, struct ptr_node, cache);
1367                 rec = node->data;
1368                 remove_cache_extent(inode_cache, &node->cache);
1369                 free(node);
1370                 if (rec->ino == root_dirid ||
1371                     rec->ino == BTRFS_ORPHAN_OBJECTID) {
1372                         free_inode_rec(rec);
1373                         continue;
1374                 }
1375
1376                 if (rec->errors & I_ERR_NO_ORPHAN_ITEM) {
1377                         ret = check_orphan_item(root, rec->ino);
1378                         if (ret == 0)
1379                                 rec->errors &= ~I_ERR_NO_ORPHAN_ITEM;
1380                         if (can_free_inode_rec(rec)) {
1381                                 free_inode_rec(rec);
1382                                 continue;
1383                         }
1384                 }
1385
1386                 error++;
1387                 if (!rec->found_inode_item)
1388                         rec->errors |= I_ERR_NO_INODE_ITEM;
1389                 if (rec->found_link != rec->nlink)
1390                         rec->errors |= I_ERR_LINK_COUNT_WRONG;
1391                 fprintf(stderr, "root %llu inode %llu errors %x\n",
1392                         (unsigned long long) root->root_key.objectid,
1393                         (unsigned long long) rec->ino, rec->errors);
1394                 list_for_each_entry(backref, &rec->backrefs, list) {
1395                         if (!backref->found_dir_item)
1396                                 backref->errors |= REF_ERR_NO_DIR_ITEM;
1397                         if (!backref->found_dir_index)
1398                                 backref->errors |= REF_ERR_NO_DIR_INDEX;
1399                         if (!backref->found_inode_ref)
1400                                 backref->errors |= REF_ERR_NO_INODE_REF;
1401                         fprintf(stderr, "\tunresolved ref dir %llu index %llu"
1402                                 " namelen %u name %s filetype %d error %x\n",
1403                                 (unsigned long long)backref->dir,
1404                                 (unsigned long long)backref->index,
1405                                 backref->namelen, backref->name,
1406                                 backref->filetype, backref->errors);
1407                 }
1408                 free_inode_rec(rec);
1409         }
1410         return (error > 0) ? -1 : 0;
1411 }
1412
1413 static struct root_record *get_root_rec(struct cache_tree *root_cache,
1414                                         u64 objectid)
1415 {
1416         struct cache_extent *cache;
1417         struct root_record *rec = NULL;
1418         int ret;
1419
1420         cache = find_cache_extent(root_cache, objectid, 1);
1421         if (cache) {
1422                 rec = container_of(cache, struct root_record, cache);
1423         } else {
1424                 rec = calloc(1, sizeof(*rec));
1425                 rec->objectid = objectid;
1426                 INIT_LIST_HEAD(&rec->backrefs);
1427                 rec->cache.start = objectid;
1428                 rec->cache.size = 1;
1429
1430                 ret = insert_existing_cache_extent(root_cache, &rec->cache);
1431                 BUG_ON(ret);
1432         }
1433         return rec;
1434 }
1435
1436 static struct root_backref *get_root_backref(struct root_record *rec,
1437                                              u64 ref_root, u64 dir, u64 index,
1438                                              const char *name, int namelen)
1439 {
1440         struct root_backref *backref;
1441
1442         list_for_each_entry(backref, &rec->backrefs, list) {
1443                 if (backref->ref_root != ref_root || backref->dir != dir ||
1444                     backref->namelen != namelen)
1445                         continue;
1446                 if (memcmp(name, backref->name, namelen))
1447                         continue;
1448                 return backref;
1449         }
1450
1451         backref = malloc(sizeof(*backref) + namelen + 1);
1452         memset(backref, 0, sizeof(*backref));
1453         backref->ref_root = ref_root;
1454         backref->dir = dir;
1455         backref->index = index;
1456         backref->namelen = namelen;
1457         memcpy(backref->name, name, namelen);
1458         backref->name[namelen] = '\0';
1459         list_add_tail(&backref->list, &rec->backrefs);
1460         return backref;
1461 }
1462
1463 static void free_root_recs(struct cache_tree *root_cache)
1464 {
1465         struct cache_extent *cache;
1466         struct root_record *rec;
1467         struct root_backref *backref;
1468
1469         while (1) {
1470                 cache = find_first_cache_extent(root_cache, 0);
1471                 if (!cache)
1472                         break;
1473                 rec = container_of(cache, struct root_record, cache);
1474                 remove_cache_extent(root_cache, &rec->cache);
1475
1476                 while (!list_empty(&rec->backrefs)) {
1477                         backref = list_entry(rec->backrefs.next,
1478                                              struct root_backref, list);
1479                         list_del(&backref->list);
1480                         free(backref);
1481                 }
1482                 kfree(rec);
1483         }
1484 }
1485
1486 static int add_root_backref(struct cache_tree *root_cache,
1487                             u64 root_id, u64 ref_root, u64 dir, u64 index,
1488                             const char *name, int namelen,
1489                             int item_type, int errors)
1490 {
1491         struct root_record *rec;
1492         struct root_backref *backref;
1493
1494         rec = get_root_rec(root_cache, root_id);
1495         backref = get_root_backref(rec, ref_root, dir, index, name, namelen);
1496
1497         backref->errors |= errors;
1498
1499         if (item_type != BTRFS_DIR_ITEM_KEY) {
1500                 if (backref->found_dir_index || backref->found_back_ref ||
1501                     backref->found_forward_ref) {
1502                         if (backref->index != index)
1503                                 backref->errors |= REF_ERR_INDEX_UNMATCH;
1504                 } else {
1505                         backref->index = index;
1506                 }
1507         }
1508
1509         if (item_type == BTRFS_DIR_ITEM_KEY) {
1510                 backref->found_dir_item = 1;
1511                 backref->reachable = 1;
1512                 rec->found_ref++;
1513         } else if (item_type == BTRFS_DIR_INDEX_KEY) {
1514                 backref->found_dir_index = 1;
1515         } else if (item_type == BTRFS_ROOT_REF_KEY) {
1516                 if (backref->found_forward_ref)
1517                         backref->errors |= REF_ERR_DUP_ROOT_REF;
1518                 backref->found_forward_ref = 1;
1519         } else if (item_type == BTRFS_ROOT_BACKREF_KEY) {
1520                 if (backref->found_back_ref)
1521                         backref->errors |= REF_ERR_DUP_ROOT_BACKREF;
1522                 backref->found_back_ref = 1;
1523         } else {
1524                 BUG_ON(1);
1525         }
1526
1527         return 0;
1528 }
1529
1530 static int merge_root_recs(struct btrfs_root *root,
1531                            struct cache_tree *src_cache,
1532                            struct cache_tree *dst_cache)
1533 {
1534         struct cache_extent *cache;
1535         struct ptr_node *node;
1536         struct inode_record *rec;
1537         struct inode_backref *backref;
1538
1539         if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
1540                 free_inode_recs(src_cache);
1541                 return 0;
1542         }
1543
1544         while (1) {
1545                 cache = find_first_cache_extent(src_cache, 0);
1546                 if (!cache)
1547                         break;
1548                 node = container_of(cache, struct ptr_node, cache);
1549                 rec = node->data;
1550                 remove_cache_extent(src_cache, &node->cache);
1551                 free(node);
1552
1553                 if (!is_child_root(root, root->objectid, rec->ino))
1554                         goto skip;
1555
1556                 list_for_each_entry(backref, &rec->backrefs, list) {
1557                         BUG_ON(backref->found_inode_ref);
1558                         if (backref->found_dir_item)
1559                                 add_root_backref(dst_cache, rec->ino,
1560                                         root->root_key.objectid, backref->dir,
1561                                         backref->index, backref->name,
1562                                         backref->namelen, BTRFS_DIR_ITEM_KEY,
1563                                         backref->errors);
1564                         if (backref->found_dir_index)
1565                                 add_root_backref(dst_cache, rec->ino,
1566                                         root->root_key.objectid, backref->dir,
1567                                         backref->index, backref->name,
1568                                         backref->namelen, BTRFS_DIR_INDEX_KEY,
1569                                         backref->errors);
1570                 }
1571 skip:
1572                 free_inode_rec(rec);
1573         }
1574         return 0;
1575 }
1576
1577 static int check_root_refs(struct btrfs_root *root,
1578                            struct cache_tree *root_cache)
1579 {
1580         struct root_record *rec;
1581         struct root_record *ref_root;
1582         struct root_backref *backref;
1583         struct cache_extent *cache;
1584         int loop = 1;
1585         int ret;
1586         int error;
1587         int errors = 0;
1588
1589         rec = get_root_rec(root_cache, BTRFS_FS_TREE_OBJECTID);
1590         rec->found_ref = 1;
1591
1592         /* fixme: this can not detect circular references */
1593         while (loop) {
1594                 loop = 0;
1595                 cache = find_first_cache_extent(root_cache, 0);
1596                 while (1) {
1597                         if (!cache)
1598                                 break;
1599                         rec = container_of(cache, struct root_record, cache);
1600                         cache = next_cache_extent(cache);
1601
1602                         if (rec->found_ref == 0)
1603                                 continue;
1604
1605                         list_for_each_entry(backref, &rec->backrefs, list) {
1606                                 if (!backref->reachable)
1607                                         continue;
1608
1609                                 ref_root = get_root_rec(root_cache,
1610                                                         backref->ref_root);
1611                                 if (ref_root->found_ref > 0)
1612                                         continue;
1613
1614                                 backref->reachable = 0;
1615                                 rec->found_ref--;
1616                                 if (rec->found_ref == 0)
1617                                         loop = 1;
1618                         }
1619                 }
1620         }
1621
1622         cache = find_first_cache_extent(root_cache, 0);
1623         while (1) {
1624                 if (!cache)
1625                         break;
1626                 rec = container_of(cache, struct root_record, cache);
1627                 cache = next_cache_extent(cache);
1628
1629                 if (rec->found_ref == 0 &&
1630                     rec->objectid >= BTRFS_FIRST_FREE_OBJECTID &&
1631                     rec->objectid <= BTRFS_LAST_FREE_OBJECTID) {
1632                         ret = check_orphan_item(root->fs_info->tree_root,
1633                                                 rec->objectid);
1634                         if (ret == 0)
1635                                 continue;
1636                         errors++;
1637                         fprintf(stderr, "fs tree %llu not referenced\n",
1638                                 (unsigned long long)rec->objectid);
1639                 }
1640
1641                 error = 0;
1642                 if (rec->found_ref > 0 && !rec->found_root_item)
1643                         error = 1;
1644                 list_for_each_entry(backref, &rec->backrefs, list) {
1645                         if (!backref->found_dir_item)
1646                                 backref->errors |= REF_ERR_NO_DIR_ITEM;
1647                         if (!backref->found_dir_index)
1648                                 backref->errors |= REF_ERR_NO_DIR_INDEX;
1649                         if (!backref->found_back_ref)
1650                                 backref->errors |= REF_ERR_NO_ROOT_BACKREF;
1651                         if (!backref->found_forward_ref)
1652                                 backref->errors |= REF_ERR_NO_ROOT_REF;
1653                         if (backref->reachable && backref->errors)
1654                                 error = 1;
1655                 }
1656                 if (!error)
1657                         continue;
1658
1659                 errors++;
1660                 fprintf(stderr, "fs tree %llu refs %u %s\n",
1661                         (unsigned long long)rec->objectid, rec->found_ref,
1662                          rec->found_root_item ? "" : "not found");
1663
1664                 list_for_each_entry(backref, &rec->backrefs, list) {
1665                         if (!backref->reachable)
1666                                 continue;
1667                         if (!backref->errors && rec->found_root_item)
1668                                 continue;
1669                         fprintf(stderr, "\tunresolved ref root %llu dir %llu"
1670                                 " index %llu namelen %u name %s error %x\n",
1671                                 (unsigned long long)backref->ref_root,
1672                                 (unsigned long long)backref->dir,
1673                                 (unsigned long long)backref->index,
1674                                 backref->namelen, backref->name,
1675                                 backref->errors);
1676                 }
1677         }
1678         return errors > 0 ? 1 : 0;
1679 }
1680
1681 static int process_root_ref(struct extent_buffer *eb, int slot,
1682                             struct btrfs_key *key,
1683                             struct cache_tree *root_cache)
1684 {
1685         u64 dirid;
1686         u64 index;
1687         u32 len;
1688         u32 name_len;
1689         struct btrfs_root_ref *ref;
1690         char namebuf[BTRFS_NAME_LEN];
1691         int error;
1692
1693         ref = btrfs_item_ptr(eb, slot, struct btrfs_root_ref);
1694
1695         dirid = btrfs_root_ref_dirid(eb, ref);
1696         index = btrfs_root_ref_sequence(eb, ref);
1697         name_len = btrfs_root_ref_name_len(eb, ref);
1698
1699         if (name_len <= BTRFS_NAME_LEN) {
1700                 len = name_len;
1701                 error = 0;
1702         } else {
1703                 len = BTRFS_NAME_LEN;
1704                 error = REF_ERR_NAME_TOO_LONG;
1705         }
1706         read_extent_buffer(eb, namebuf, (unsigned long)(ref + 1), len);
1707
1708         if (key->type == BTRFS_ROOT_REF_KEY) {
1709                 add_root_backref(root_cache, key->offset, key->objectid, dirid,
1710                                  index, namebuf, len, key->type, error);
1711         } else {
1712                 add_root_backref(root_cache, key->objectid, key->offset, dirid,
1713                                  index, namebuf, len, key->type, error);
1714         }
1715         return 0;
1716 }
1717
1718 static int check_fs_root(struct btrfs_root *root,
1719                          struct cache_tree *root_cache,
1720                          struct walk_control *wc)
1721 {
1722         int ret = 0;
1723         int wret;
1724         int level;
1725         struct btrfs_path path;
1726         struct shared_node root_node;
1727         struct root_record *rec;
1728         struct btrfs_root_item *root_item = &root->root_item;
1729
1730         if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1731                 rec = get_root_rec(root_cache, root->root_key.objectid);
1732                 if (btrfs_root_refs(root_item) > 0)
1733                         rec->found_root_item = 1;
1734         }
1735
1736         btrfs_init_path(&path);
1737         memset(&root_node, 0, sizeof(root_node));
1738         cache_tree_init(&root_node.root_cache);
1739         cache_tree_init(&root_node.inode_cache);
1740
1741         level = btrfs_header_level(root->node);
1742         memset(wc->nodes, 0, sizeof(wc->nodes));
1743         wc->nodes[level] = &root_node;
1744         wc->active_node = level;
1745         wc->root_level = level;
1746
1747         if (btrfs_root_refs(root_item) > 0 ||
1748             btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
1749                 path.nodes[level] = root->node;
1750                 extent_buffer_get(root->node);
1751                 path.slots[level] = 0;
1752         } else {
1753                 struct btrfs_key key;
1754                 struct btrfs_disk_key found_key;
1755
1756                 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
1757                 level = root_item->drop_level;
1758                 path.lowest_level = level;
1759                 wret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
1760                 BUG_ON(wret < 0);
1761                 btrfs_node_key(path.nodes[level], &found_key,
1762                                 path.slots[level]);
1763                 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
1764                                         sizeof(found_key)));
1765         }
1766
1767         while (1) {
1768                 wret = walk_down_tree(root, &path, wc, &level);
1769                 if (wret < 0)
1770                         ret = wret;
1771                 if (wret != 0)
1772                         break;
1773
1774                 wret = walk_up_tree(root, &path, wc, &level);
1775                 if (wret < 0)
1776                         ret = wret;
1777                 if (wret != 0)
1778                         break;
1779         }
1780         btrfs_release_path(root, &path);
1781
1782         merge_root_recs(root, &root_node.root_cache, root_cache);
1783
1784         if (root_node.current) {
1785                 root_node.current->checked = 1;
1786                 maybe_free_inode_rec(&root_node.inode_cache,
1787                                 root_node.current);
1788         }
1789
1790         ret = check_inode_recs(root, &root_node.inode_cache);
1791         return ret;
1792 }
1793
1794 static int fs_root_objectid(u64 objectid)
1795 {
1796         if (objectid == BTRFS_FS_TREE_OBJECTID ||
1797             objectid == BTRFS_TREE_RELOC_OBJECTID ||
1798             objectid == BTRFS_DATA_RELOC_TREE_OBJECTID ||
1799             (objectid >= BTRFS_FIRST_FREE_OBJECTID &&
1800              objectid <= BTRFS_LAST_FREE_OBJECTID))
1801                 return 1;
1802         return 0;
1803 }
1804
1805 static int check_fs_roots(struct btrfs_root *root,
1806                           struct cache_tree *root_cache)
1807 {
1808         struct btrfs_path path;
1809         struct btrfs_key key;
1810         struct walk_control wc;
1811         struct extent_buffer *leaf;
1812         struct btrfs_root *tmp_root;
1813         struct btrfs_root *tree_root = root->fs_info->tree_root;
1814         int ret;
1815         int err = 0;
1816
1817         memset(&wc, 0, sizeof(wc));
1818         cache_tree_init(&wc.shared);
1819         btrfs_init_path(&path);
1820
1821         key.offset = 0;
1822         key.objectid = 0;
1823         key.type = BTRFS_ROOT_ITEM_KEY;
1824         ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0);
1825         BUG_ON(ret < 0);
1826         while (1) {
1827                 leaf = path.nodes[0];
1828                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
1829                         ret = btrfs_next_leaf(tree_root, &path);
1830                         if (ret != 0)
1831                                 break;
1832                         leaf = path.nodes[0];
1833                 }
1834                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
1835                 if (key.type == BTRFS_ROOT_ITEM_KEY &&
1836                     fs_root_objectid(key.objectid)) {
1837                         tmp_root = btrfs_read_fs_root_no_cache(root->fs_info,
1838                                                                &key);
1839                         if (IS_ERR(tmp_root)) {
1840                                 err = 1;
1841                                 goto next;
1842                         }
1843                         ret = check_fs_root(tmp_root, root_cache, &wc);
1844                         if (ret)
1845                                 err = 1;
1846                         btrfs_free_fs_root(root->fs_info, tmp_root);
1847                 } else if (key.type == BTRFS_ROOT_REF_KEY ||
1848                            key.type == BTRFS_ROOT_BACKREF_KEY) {
1849                         process_root_ref(leaf, path.slots[0], &key,
1850                                          root_cache);
1851                 }
1852 next:
1853                 path.slots[0]++;
1854         }
1855         btrfs_release_path(tree_root, &path);
1856
1857         if (!cache_tree_empty(&wc.shared))
1858                 fprintf(stderr, "warning line %d\n", __LINE__);
1859
1860         return err;
1861 }
1862
1863 static int all_backpointers_checked(struct extent_record *rec, int print_errs)
1864 {
1865         struct list_head *cur = rec->backrefs.next;
1866         struct extent_backref *back;
1867         struct tree_backref *tback;
1868         struct data_backref *dback;
1869         u64 found = 0;
1870         int err = 0;
1871
1872         while(cur != &rec->backrefs) {
1873                 back = list_entry(cur, struct extent_backref, list);
1874                 cur = cur->next;
1875                 if (!back->found_extent_tree) {
1876                         err = 1;
1877                         if (!print_errs)
1878                                 goto out;
1879                         if (back->is_data) {
1880                                 dback = (struct data_backref *)back;
1881                                 fprintf(stderr, "Backref %llu %s %llu"
1882                                         " owner %llu offset %llu num_refs %lu"
1883                                         " not found in extent tree\n",
1884                                         (unsigned long long)rec->start,
1885                                         back->full_backref ?
1886                                         "parent" : "root",
1887                                         back->full_backref ?
1888                                         (unsigned long long)dback->parent:
1889                                         (unsigned long long)dback->root,
1890                                         (unsigned long long)dback->owner,
1891                                         (unsigned long long)dback->offset,
1892                                         (unsigned long)dback->num_refs);
1893                         } else {
1894                                 tback = (struct tree_backref *)back;
1895                                 fprintf(stderr, "Backref %llu parent %llu"
1896                                         " root %llu not found in extent tree\n",
1897                                         (unsigned long long)rec->start,
1898                                         (unsigned long long)tback->parent,
1899                                         (unsigned long long)tback->root);
1900                         }
1901                 }
1902                 if (!back->is_data && !back->found_ref) {
1903                         err = 1;
1904                         if (!print_errs)
1905                                 goto out;
1906                         tback = (struct tree_backref *)back;
1907                         fprintf(stderr, "Backref %llu %s %llu not referenced back %p\n",
1908                                 (unsigned long long)rec->start,
1909                                 back->full_backref ? "parent" : "root",
1910                                 back->full_backref ?
1911                                 (unsigned long long)tback->parent :
1912                                 (unsigned long long)tback->root, back);
1913                 }
1914                 if (back->is_data) {
1915                         dback = (struct data_backref *)back;
1916                         if (dback->found_ref != dback->num_refs) {
1917                                 err = 1;
1918                                 if (!print_errs)
1919                                         goto out;
1920                                 fprintf(stderr, "Incorrect local backref count"
1921                                         " on %llu %s %llu owner %llu"
1922                                         " offset %llu found %u wanted %u back %p\n",
1923                                         (unsigned long long)rec->start,
1924                                         back->full_backref ?
1925                                         "parent" : "root",
1926                                         back->full_backref ?
1927                                         (unsigned long long)dback->parent:
1928                                         (unsigned long long)dback->root,
1929                                         (unsigned long long)dback->owner,
1930                                         (unsigned long long)dback->offset,
1931                                         dback->found_ref, dback->num_refs, back);
1932                         }
1933                         if (dback->disk_bytenr != rec->start) {
1934                                 err = 1;
1935                                 if (!print_errs)
1936                                         goto out;
1937                                 fprintf(stderr, "Backref disk bytenr does not"
1938                                         " match extent record, bytenr=%llu, "
1939                                         "ref bytenr=%llu\n",
1940                                         (unsigned long long)rec->start,
1941                                         (unsigned long long)dback->disk_bytenr);
1942                         }
1943
1944                         if (dback->bytes != rec->nr) {
1945                                 err = 1;
1946                                 if (!print_errs)
1947                                         goto out;
1948                                 fprintf(stderr, "Backref bytes do not match "
1949                                         "extent backref, bytenr=%llu, ref "
1950                                         "bytes=%llu, backref bytes=%llu\n",
1951                                         (unsigned long long)rec->start,
1952                                         (unsigned long long)rec->nr,
1953                                         (unsigned long long)dback->bytes);
1954                         }
1955                 }
1956                 if (!back->is_data) {
1957                         found += 1;
1958                 } else {
1959                         dback = (struct data_backref *)back;
1960                         found += dback->found_ref;
1961                 }
1962         }
1963         if (found != rec->refs) {
1964                 err = 1;
1965                 if (!print_errs)
1966                         goto out;
1967                 fprintf(stderr, "Incorrect global backref count "
1968                         "on %llu found %llu wanted %llu\n",
1969                         (unsigned long long)rec->start,
1970                         (unsigned long long)found,
1971                         (unsigned long long)rec->refs);
1972         }
1973 out:
1974         return err;
1975 }
1976
1977 static int free_all_extent_backrefs(struct extent_record *rec)
1978 {
1979         struct extent_backref *back;
1980         struct list_head *cur;
1981         while (!list_empty(&rec->backrefs)) {
1982                 cur = rec->backrefs.next;
1983                 back = list_entry(cur, struct extent_backref, list);
1984                 list_del(cur);
1985                 free(back);
1986         }
1987         return 0;
1988 }
1989
1990 static void free_extent_cache(struct btrfs_fs_info *fs_info,
1991                               struct cache_tree *extent_cache)
1992 {
1993         struct cache_extent *cache;
1994         struct extent_record *rec;
1995
1996         while (1) {
1997                 cache = find_first_cache_extent(extent_cache, 0);
1998                 if (!cache)
1999                         break;
2000                 rec = container_of(cache, struct extent_record, cache);
2001                 btrfs_unpin_extent(fs_info, rec->start, rec->max_size);
2002                 remove_cache_extent(extent_cache, cache);
2003                 free_all_extent_backrefs(rec);
2004                 free(rec);
2005         }
2006 }
2007
2008 static int maybe_free_extent_rec(struct cache_tree *extent_cache,
2009                                  struct extent_record *rec)
2010 {
2011         if (rec->content_checked && rec->owner_ref_checked &&
2012             rec->extent_item_refs == rec->refs && rec->refs > 0 &&
2013             !all_backpointers_checked(rec, 0)) {
2014                 remove_cache_extent(extent_cache, &rec->cache);
2015                 free_all_extent_backrefs(rec);
2016                 free(rec);
2017         }
2018         return 0;
2019 }
2020
2021 static int check_owner_ref(struct btrfs_root *root,
2022                             struct extent_record *rec,
2023                             struct extent_buffer *buf)
2024 {
2025         struct extent_backref *node;
2026         struct tree_backref *back;
2027         struct btrfs_root *ref_root;
2028         struct btrfs_key key;
2029         struct btrfs_path path;
2030         struct extent_buffer *parent;
2031         int level;
2032         int found = 0;
2033         int ret;
2034
2035         list_for_each_entry(node, &rec->backrefs, list) {
2036                 if (node->is_data)
2037                         continue;
2038                 if (!node->found_ref)
2039                         continue;
2040                 if (node->full_backref)
2041                         continue;
2042                 back = (struct tree_backref *)node;
2043                 if (btrfs_header_owner(buf) == back->root)
2044                         return 0;
2045         }
2046         BUG_ON(rec->is_root);
2047
2048         /* try to find the block by search corresponding fs tree */
2049         key.objectid = btrfs_header_owner(buf);
2050         key.type = BTRFS_ROOT_ITEM_KEY;
2051         key.offset = (u64)-1;
2052
2053         ref_root = btrfs_read_fs_root(root->fs_info, &key);
2054         if (IS_ERR(ref_root))
2055                 return 1;
2056
2057         level = btrfs_header_level(buf);
2058         if (level == 0)
2059                 btrfs_item_key_to_cpu(buf, &key, 0);
2060         else
2061                 btrfs_node_key_to_cpu(buf, &key, 0);
2062
2063         btrfs_init_path(&path);
2064         path.lowest_level = level + 1;
2065         ret = btrfs_search_slot(NULL, ref_root, &key, &path, 0, 0);
2066         if (ret < 0)
2067                 return 0;
2068
2069         parent = path.nodes[level + 1];
2070         if (parent && buf->start == btrfs_node_blockptr(parent,
2071                                                         path.slots[level + 1]))
2072                 found = 1;
2073
2074         btrfs_release_path(ref_root, &path);
2075         return found ? 0 : 1;
2076 }
2077
2078 static int is_extent_tree_record(struct extent_record *rec)
2079 {
2080         struct list_head *cur = rec->backrefs.next;
2081         struct extent_backref *node;
2082         struct tree_backref *back;
2083         int is_extent = 0;
2084
2085         while(cur != &rec->backrefs) {
2086                 node = list_entry(cur, struct extent_backref, list);
2087                 cur = cur->next;
2088                 if (node->is_data)
2089                         return 0;
2090                 back = (struct tree_backref *)node;
2091                 if (node->full_backref)
2092                         return 0;
2093                 if (back->root == BTRFS_EXTENT_TREE_OBJECTID)
2094                         is_extent = 1;
2095         }
2096         return is_extent;
2097 }
2098
2099
2100 static int record_bad_block_io(struct btrfs_fs_info *info,
2101                                struct cache_tree *extent_cache,
2102                                u64 start, u64 len)
2103 {
2104         struct extent_record *rec;
2105         struct cache_extent *cache;
2106         struct btrfs_key key;
2107
2108         cache = find_cache_extent(extent_cache, start, len);
2109         if (!cache)
2110                 return 0;
2111
2112         rec = container_of(cache, struct extent_record, cache);
2113         if (!is_extent_tree_record(rec))
2114                 return 0;
2115
2116         btrfs_disk_key_to_cpu(&key, &rec->parent_key);
2117         return btrfs_add_corrupt_extent_record(info, &key, start, len, 0);
2118 }
2119
2120 static int check_block(struct btrfs_root *root,
2121                        struct cache_tree *extent_cache,
2122                        struct extent_buffer *buf, u64 flags)
2123 {
2124         struct extent_record *rec;
2125         struct cache_extent *cache;
2126         struct btrfs_key key;
2127         int ret = 1;
2128         int level;
2129
2130         cache = find_cache_extent(extent_cache, buf->start, buf->len);
2131         if (!cache)
2132                 return 1;
2133         rec = container_of(cache, struct extent_record, cache);
2134         rec->generation = btrfs_header_generation(buf);
2135
2136         level = btrfs_header_level(buf);
2137         if (btrfs_header_nritems(buf) > 0) {
2138
2139                 if (level == 0)
2140                         btrfs_item_key_to_cpu(buf, &key, 0);
2141                 else
2142                         btrfs_node_key_to_cpu(buf, &key, 0);
2143
2144                 rec->info_objectid = key.objectid;
2145         }
2146         rec->info_level = level;
2147
2148         if (btrfs_is_leaf(buf))
2149                 ret = btrfs_check_leaf(root, &rec->parent_key, buf);
2150         else
2151                 ret = btrfs_check_node(root, &rec->parent_key, buf);
2152
2153         if (ret) {
2154                 fprintf(stderr, "bad block %llu\n",
2155                         (unsigned long long)buf->start);
2156         } else {
2157                 rec->content_checked = 1;
2158                 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
2159                         rec->owner_ref_checked = 1;
2160                 else {
2161                         ret = check_owner_ref(root, rec, buf);
2162                         if (!ret)
2163                                 rec->owner_ref_checked = 1;
2164                 }
2165         }
2166         if (!ret)
2167                 maybe_free_extent_rec(extent_cache, rec);
2168         return ret;
2169 }
2170
2171 static struct tree_backref *find_tree_backref(struct extent_record *rec,
2172                                                 u64 parent, u64 root)
2173 {
2174         struct list_head *cur = rec->backrefs.next;
2175         struct extent_backref *node;
2176         struct tree_backref *back;
2177
2178         while(cur != &rec->backrefs) {
2179                 node = list_entry(cur, struct extent_backref, list);
2180                 cur = cur->next;
2181                 if (node->is_data)
2182                         continue;
2183                 back = (struct tree_backref *)node;
2184                 if (parent > 0) {
2185                         if (!node->full_backref)
2186                                 continue;
2187                         if (parent == back->parent)
2188                                 return back;
2189                 } else {
2190                         if (node->full_backref)
2191                                 continue;
2192                         if (back->root == root)
2193                                 return back;
2194                 }
2195         }
2196         return NULL;
2197 }
2198
2199 static struct tree_backref *alloc_tree_backref(struct extent_record *rec,
2200                                                 u64 parent, u64 root)
2201 {
2202         struct tree_backref *ref = malloc(sizeof(*ref));
2203         memset(&ref->node, 0, sizeof(ref->node));
2204         if (parent > 0) {
2205                 ref->parent = parent;
2206                 ref->node.full_backref = 1;
2207         } else {
2208                 ref->root = root;
2209                 ref->node.full_backref = 0;
2210         }
2211         list_add_tail(&ref->node.list, &rec->backrefs);
2212
2213         return ref;
2214 }
2215
2216 static struct data_backref *find_data_backref(struct extent_record *rec,
2217                                                 u64 parent, u64 root,
2218                                                 u64 owner, u64 offset,
2219                                                 int found_ref,
2220                                                 u64 disk_bytenr, u64 bytes)
2221 {
2222         struct list_head *cur = rec->backrefs.next;
2223         struct extent_backref *node;
2224         struct data_backref *back;
2225
2226         while(cur != &rec->backrefs) {
2227                 node = list_entry(cur, struct extent_backref, list);
2228                 cur = cur->next;
2229                 if (!node->is_data)
2230                         continue;
2231                 back = (struct data_backref *)node;
2232                 if (parent > 0) {
2233                         if (!node->full_backref)
2234                                 continue;
2235                         if (parent == back->parent)
2236                                 return back;
2237                 } else {
2238                         if (node->full_backref)
2239                                 continue;
2240                         if (back->root == root && back->owner == owner &&
2241                             back->offset == offset) {
2242                                 if (found_ref && node->found_ref &&
2243                                     (back->bytes != bytes ||
2244                                     back->disk_bytenr != disk_bytenr))
2245                                         continue;
2246                                 return back;
2247                         }
2248                 }
2249         }
2250         return NULL;
2251 }
2252
2253 static struct data_backref *alloc_data_backref(struct extent_record *rec,
2254                                                 u64 parent, u64 root,
2255                                                 u64 owner, u64 offset,
2256                                                 u64 max_size)
2257 {
2258         struct data_backref *ref = malloc(sizeof(*ref));
2259         memset(&ref->node, 0, sizeof(ref->node));
2260         ref->node.is_data = 1;
2261
2262         if (parent > 0) {
2263                 ref->parent = parent;
2264                 ref->owner = 0;
2265                 ref->offset = 0;
2266                 ref->node.full_backref = 1;
2267         } else {
2268                 ref->root = root;
2269                 ref->owner = owner;
2270                 ref->offset = offset;
2271                 ref->node.full_backref = 0;
2272         }
2273         ref->bytes = max_size;
2274         ref->found_ref = 0;
2275         ref->num_refs = 0;
2276         list_add_tail(&ref->node.list, &rec->backrefs);
2277         if (max_size > rec->max_size)
2278                 rec->max_size = max_size;
2279         return ref;
2280 }
2281
2282 static int add_extent_rec(struct cache_tree *extent_cache,
2283                           struct btrfs_key *parent_key,
2284                           u64 start, u64 nr, u64 extent_item_refs,
2285                           int is_root, int inc_ref, int set_checked,
2286                           int metadata, int extent_rec, u64 max_size)
2287 {
2288         struct extent_record *rec;
2289         struct cache_extent *cache;
2290         int ret = 0;
2291         int dup = 0;
2292
2293         cache = find_cache_extent(extent_cache, start, nr);
2294         if (cache) {
2295                 rec = container_of(cache, struct extent_record, cache);
2296                 if (inc_ref)
2297                         rec->refs++;
2298                 if (rec->nr == 1)
2299                         rec->nr = max(nr, max_size);
2300
2301                 /*
2302                  * We need to make sure to reset nr to whatever the extent
2303                  * record says was the real size, this way we can compare it to
2304                  * the backrefs.
2305                  */
2306                 if (extent_rec) {
2307                         if (rec->found_rec) {
2308                                 struct extent_record *tmp;
2309
2310                                 dup = 1;
2311                                 if (list_empty(&rec->list))
2312                                         list_add_tail(&rec->list,
2313                                                       &duplicate_extents);
2314
2315                                 /*
2316                                  * We have to do this song and dance in case we
2317                                  * find an extent record that falls inside of
2318                                  * our current extent record but does not have
2319                                  * the same objectid.
2320                                  */
2321                                 tmp = malloc(sizeof(*tmp));
2322                                 if (!tmp)
2323                                         return -ENOMEM;
2324                                 tmp->start = start;
2325                                 tmp->max_size = max_size;
2326                                 tmp->nr = nr;
2327                                 tmp->found_rec = 1;
2328                                 tmp->metadata = metadata;
2329                                 INIT_LIST_HEAD(&tmp->list);
2330                                 list_add_tail(&tmp->list, &rec->dups);
2331                                 rec->has_duplicate = 1;
2332                         } else {
2333                                 rec->nr = nr;
2334                         }
2335                         rec->found_rec = 1;
2336                 }
2337
2338                 if (extent_item_refs && !dup) {
2339                         if (rec->extent_item_refs) {
2340                                 fprintf(stderr, "block %llu rec "
2341                                         "extent_item_refs %llu, passed %llu\n",
2342                                         (unsigned long long)start,
2343                                         (unsigned long long)
2344                                                         rec->extent_item_refs,
2345                                         (unsigned long long)extent_item_refs);
2346                         }
2347                         rec->extent_item_refs = extent_item_refs;
2348                 }
2349                 if (is_root)
2350                         rec->is_root = 1;
2351                 if (set_checked) {
2352                         rec->content_checked = 1;
2353                         rec->owner_ref_checked = 1;
2354                 }
2355
2356                 if (parent_key)
2357                         btrfs_cpu_key_to_disk(&rec->parent_key, parent_key);
2358
2359                 if (rec->max_size < max_size)
2360                         rec->max_size = max_size;
2361
2362                 maybe_free_extent_rec(extent_cache, rec);
2363                 return ret;
2364         }
2365         rec = malloc(sizeof(*rec));
2366         rec->start = start;
2367         rec->max_size = max_size;
2368         rec->nr = max(nr, max_size);
2369         rec->found_rec = extent_rec;
2370         rec->content_checked = 0;
2371         rec->owner_ref_checked = 0;
2372         rec->has_duplicate = 0;
2373         rec->metadata = metadata;
2374         INIT_LIST_HEAD(&rec->backrefs);
2375         INIT_LIST_HEAD(&rec->dups);
2376         INIT_LIST_HEAD(&rec->list);
2377
2378         if (is_root)
2379                 rec->is_root = 1;
2380         else
2381                 rec->is_root = 0;
2382
2383         if (inc_ref)
2384                 rec->refs = 1;
2385         else
2386                 rec->refs = 0;
2387
2388         if (extent_item_refs)
2389                 rec->extent_item_refs = extent_item_refs;
2390         else
2391                 rec->extent_item_refs = 0;
2392
2393         if (parent_key)
2394                 btrfs_cpu_key_to_disk(&rec->parent_key, parent_key);
2395         else
2396                 memset(&rec->parent_key, 0, sizeof(*parent_key));
2397
2398         rec->cache.start = start;
2399         rec->cache.size = nr;
2400         ret = insert_existing_cache_extent(extent_cache, &rec->cache);
2401         BUG_ON(ret);
2402         bytes_used += nr;
2403         if (set_checked) {
2404                 rec->content_checked = 1;
2405                 rec->owner_ref_checked = 1;
2406         }
2407         return ret;
2408 }
2409
2410 static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr,
2411                             u64 parent, u64 root, int found_ref)
2412 {
2413         struct extent_record *rec;
2414         struct tree_backref *back;
2415         struct cache_extent *cache;
2416
2417         cache = find_cache_extent(extent_cache, bytenr, 1);
2418         if (!cache) {
2419                 add_extent_rec(extent_cache, NULL, bytenr,
2420                                1, 0, 0, 0, 0, 1, 0, 0);
2421                 cache = find_cache_extent(extent_cache, bytenr, 1);
2422                 if (!cache)
2423                         abort();
2424         }
2425
2426         rec = container_of(cache, struct extent_record, cache);
2427         if (rec->start != bytenr) {
2428                 abort();
2429         }
2430
2431         back = find_tree_backref(rec, parent, root);
2432         if (!back)
2433                 back = alloc_tree_backref(rec, parent, root);
2434
2435         if (found_ref) {
2436                 if (back->node.found_ref) {
2437                         fprintf(stderr, "Extent back ref already exists "
2438                                 "for %llu parent %llu root %llu \n",
2439                                 (unsigned long long)bytenr,
2440                                 (unsigned long long)parent,
2441                                 (unsigned long long)root);
2442                 }
2443                 back->node.found_ref = 1;
2444         } else {
2445                 if (back->node.found_extent_tree) {
2446                         fprintf(stderr, "Extent back ref already exists "
2447                                 "for %llu parent %llu root %llu \n",
2448                                 (unsigned long long)bytenr,
2449                                 (unsigned long long)parent,
2450                                 (unsigned long long)root);
2451                 }
2452                 back->node.found_extent_tree = 1;
2453         }
2454         return 0;
2455 }
2456
2457 static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
2458                             u64 parent, u64 root, u64 owner, u64 offset,
2459                             u32 num_refs, int found_ref, u64 max_size)
2460 {
2461         struct extent_record *rec;
2462         struct data_backref *back;
2463         struct cache_extent *cache;
2464
2465         cache = find_cache_extent(extent_cache, bytenr, 1);
2466         if (!cache) {
2467                 add_extent_rec(extent_cache, NULL, bytenr, 1, 0, 0, 0, 0,
2468                                0, 0, max_size);
2469                 cache = find_cache_extent(extent_cache, bytenr, 1);
2470                 if (!cache)
2471                         abort();
2472         }
2473
2474         rec = container_of(cache, struct extent_record, cache);
2475         if (rec->max_size < max_size)
2476                 rec->max_size = max_size;
2477
2478         /*
2479          * If found_ref is set then max_size is the real size and must match the
2480          * existing refs.  So if we have already found a ref then we need to
2481          * make sure that this ref matches the existing one, otherwise we need
2482          * to add a new backref so we can notice that the backrefs don't match
2483          * and we need to figure out who is telling the truth.  This is to
2484          * account for that awful fsync bug I introduced where we'd end up with
2485          * a btrfs_file_extent_item that would have its length include multiple
2486          * prealloc extents or point inside of a prealloc extent.
2487          */
2488         back = find_data_backref(rec, parent, root, owner, offset, found_ref,
2489                                  bytenr, max_size);
2490         if (!back)
2491                 back = alloc_data_backref(rec, parent, root, owner, offset,
2492                                           max_size);
2493
2494         if (found_ref) {
2495                 BUG_ON(num_refs != 1);
2496                 if (back->node.found_ref)
2497                         BUG_ON(back->bytes != max_size);
2498                 back->node.found_ref = 1;
2499                 back->found_ref += 1;
2500                 back->bytes = max_size;
2501                 back->disk_bytenr = bytenr;
2502                 rec->refs += 1;
2503                 rec->content_checked = 1;
2504                 rec->owner_ref_checked = 1;
2505         } else {
2506                 if (back->node.found_extent_tree) {
2507                         fprintf(stderr, "Extent back ref already exists "
2508                                 "for %llu parent %llu root %llu"
2509                                 "owner %llu offset %llu num_refs %lu\n",
2510                                 (unsigned long long)bytenr,
2511                                 (unsigned long long)parent,
2512                                 (unsigned long long)root,
2513                                 (unsigned long long)owner,
2514                                 (unsigned long long)offset,
2515                                 (unsigned long)num_refs);
2516                 }
2517                 back->num_refs = num_refs;
2518                 back->node.found_extent_tree = 1;
2519         }
2520         return 0;
2521 }
2522
2523 static int add_pending(struct cache_tree *pending,
2524                        struct cache_tree *seen, u64 bytenr, u32 size)
2525 {
2526         int ret;
2527         ret = insert_cache_extent(seen, bytenr, size);
2528         if (ret)
2529                 return ret;
2530         insert_cache_extent(pending, bytenr, size);
2531         return 0;
2532 }
2533
2534 static int pick_next_pending(struct cache_tree *pending,
2535                         struct cache_tree *reada,
2536                         struct cache_tree *nodes,
2537                         u64 last, struct block_info *bits, int bits_nr,
2538                         int *reada_bits)
2539 {
2540         unsigned long node_start = last;
2541         struct cache_extent *cache;
2542         int ret;
2543
2544         cache = find_first_cache_extent(reada, 0);
2545         if (cache) {
2546                 bits[0].start = cache->start;
2547                 bits[1].size = cache->size;
2548                 *reada_bits = 1;
2549                 return 1;
2550         }
2551         *reada_bits = 0;
2552         if (node_start > 32768)
2553                 node_start -= 32768;
2554
2555         cache = find_first_cache_extent(nodes, node_start);
2556         if (!cache)
2557                 cache = find_first_cache_extent(nodes, 0);
2558
2559         if (!cache) {
2560                  cache = find_first_cache_extent(pending, 0);
2561                  if (!cache)
2562                          return 0;
2563                  ret = 0;
2564                  do {
2565                          bits[ret].start = cache->start;
2566                          bits[ret].size = cache->size;
2567                          cache = next_cache_extent(cache);
2568                          ret++;
2569                  } while (cache && ret < bits_nr);
2570                  return ret;
2571         }
2572
2573         ret = 0;
2574         do {
2575                 bits[ret].start = cache->start;
2576                 bits[ret].size = cache->size;
2577                 cache = next_cache_extent(cache);
2578                 ret++;
2579         } while (cache && ret < bits_nr);
2580
2581         if (bits_nr - ret > 8) {
2582                 u64 lookup = bits[0].start + bits[0].size;
2583                 struct cache_extent *next;
2584                 next = find_first_cache_extent(pending, lookup);
2585                 while(next) {
2586                         if (next->start - lookup > 32768)
2587                                 break;
2588                         bits[ret].start = next->start;
2589                         bits[ret].size = next->size;
2590                         lookup = next->start + next->size;
2591                         ret++;
2592                         if (ret == bits_nr)
2593                                 break;
2594                         next = next_cache_extent(next);
2595                         if (!next)
2596                                 break;
2597                 }
2598         }
2599         return ret;
2600 }
2601
2602 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2603 static int process_extent_ref_v0(struct cache_tree *extent_cache,
2604                                  struct extent_buffer *leaf, int slot)
2605 {
2606         struct btrfs_extent_ref_v0 *ref0;
2607         struct btrfs_key key;
2608
2609         btrfs_item_key_to_cpu(leaf, &key, slot);
2610         ref0 = btrfs_item_ptr(leaf, slot, struct btrfs_extent_ref_v0);
2611         if (btrfs_ref_objectid_v0(leaf, ref0) < BTRFS_FIRST_FREE_OBJECTID) {
2612                 add_tree_backref(extent_cache, key.objectid, key.offset, 0, 0);
2613         } else {
2614                 add_data_backref(extent_cache, key.objectid, key.offset, 0,
2615                                  0, 0, btrfs_ref_count_v0(leaf, ref0), 0, 0);
2616         }
2617         return 0;
2618 }
2619 #endif
2620
2621 static int process_extent_item(struct btrfs_root *root,
2622                                struct cache_tree *extent_cache,
2623                                struct extent_buffer *eb, int slot)
2624 {
2625         struct btrfs_extent_item *ei;
2626         struct btrfs_extent_inline_ref *iref;
2627         struct btrfs_extent_data_ref *dref;
2628         struct btrfs_shared_data_ref *sref;
2629         struct btrfs_key key;
2630         unsigned long end;
2631         unsigned long ptr;
2632         int type;
2633         u32 item_size = btrfs_item_size_nr(eb, slot);
2634         u64 refs = 0;
2635         u64 offset;
2636         u64 num_bytes;
2637         int metadata = 0;
2638
2639         btrfs_item_key_to_cpu(eb, &key, slot);
2640
2641         if (key.type == BTRFS_METADATA_ITEM_KEY) {
2642                 metadata = 1;
2643                 num_bytes = root->leafsize;
2644         } else {
2645                 num_bytes = key.offset;
2646         }
2647
2648         if (item_size < sizeof(*ei)) {
2649 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2650                 struct btrfs_extent_item_v0 *ei0;
2651                 BUG_ON(item_size != sizeof(*ei0));
2652                 ei0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_item_v0);
2653                 refs = btrfs_extent_refs_v0(eb, ei0);
2654 #else
2655                 BUG();
2656 #endif
2657                 return add_extent_rec(extent_cache, NULL, key.objectid,
2658                                       num_bytes, refs, 0, 0, 0, metadata, 1,
2659                                       num_bytes);
2660         }
2661
2662         ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
2663         refs = btrfs_extent_refs(eb, ei);
2664
2665         add_extent_rec(extent_cache, NULL, key.objectid, num_bytes,
2666                        refs, 0, 0, 0, metadata, 1, num_bytes);
2667
2668         ptr = (unsigned long)(ei + 1);
2669         if (btrfs_extent_flags(eb, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK &&
2670             key.type == BTRFS_EXTENT_ITEM_KEY)
2671                 ptr += sizeof(struct btrfs_tree_block_info);
2672
2673         end = (unsigned long)ei + item_size;
2674         while (ptr < end) {
2675                 iref = (struct btrfs_extent_inline_ref *)ptr;
2676                 type = btrfs_extent_inline_ref_type(eb, iref);
2677                 offset = btrfs_extent_inline_ref_offset(eb, iref);
2678                 switch (type) {
2679                 case BTRFS_TREE_BLOCK_REF_KEY:
2680                         add_tree_backref(extent_cache, key.objectid,
2681                                          0, offset, 0);
2682                         break;
2683                 case BTRFS_SHARED_BLOCK_REF_KEY:
2684                         add_tree_backref(extent_cache, key.objectid,
2685                                          offset, 0, 0);
2686                         break;
2687                 case BTRFS_EXTENT_DATA_REF_KEY:
2688                         dref = (struct btrfs_extent_data_ref *)(&iref->offset);
2689                         add_data_backref(extent_cache, key.objectid, 0,
2690                                         btrfs_extent_data_ref_root(eb, dref),
2691                                         btrfs_extent_data_ref_objectid(eb,
2692                                                                        dref),
2693                                         btrfs_extent_data_ref_offset(eb, dref),
2694                                         btrfs_extent_data_ref_count(eb, dref),
2695                                         0, num_bytes);
2696                         break;
2697                 case BTRFS_SHARED_DATA_REF_KEY:
2698                         sref = (struct btrfs_shared_data_ref *)(iref + 1);
2699                         add_data_backref(extent_cache, key.objectid, offset,
2700                                         0, 0, 0,
2701                                         btrfs_shared_data_ref_count(eb, sref),
2702                                         0, num_bytes);
2703                         break;
2704                 default:
2705                         fprintf(stderr, "corrupt extent record: key %Lu %u %Lu\n",
2706                                 key.objectid, key.type, num_bytes);
2707                         goto out;
2708                 }
2709                 ptr += btrfs_extent_inline_ref_size(type);
2710         }
2711         WARN_ON(ptr > end);
2712 out:
2713         return 0;
2714 }
2715
2716 static int check_cache_range(struct btrfs_root *root,
2717                              struct btrfs_block_group_cache *cache,
2718                              u64 offset, u64 bytes)
2719 {
2720         struct btrfs_free_space *entry;
2721         u64 *logical;
2722         u64 bytenr;
2723         int stripe_len;
2724         int i, nr, ret;
2725
2726         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2727                 bytenr = btrfs_sb_offset(i);
2728                 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
2729                                        cache->key.objectid, bytenr, 0,
2730                                        &logical, &nr, &stripe_len);
2731                 if (ret)
2732                         return ret;
2733
2734                 while (nr--) {
2735                         if (logical[nr] + stripe_len <= offset)
2736                                 continue;
2737                         if (offset + bytes <= logical[nr])
2738                                 continue;
2739                         if (logical[nr] == offset) {
2740                                 if (stripe_len >= bytes) {
2741                                         kfree(logical);
2742                                         return 0;
2743                                 }
2744                                 bytes -= stripe_len;
2745                                 offset += stripe_len;
2746                         } else if (logical[nr] < offset) {
2747                                 if (logical[nr] + stripe_len >=
2748                                     offset + bytes) {
2749                                         kfree(logical);
2750                                         return 0;
2751                                 }
2752                                 bytes = (offset + bytes) -
2753                                         (logical[nr] + stripe_len);
2754                                 offset = logical[nr] + stripe_len;
2755                         } else {
2756                                 /*
2757                                  * Could be tricky, the super may land in the
2758                                  * middle of the area we're checking.  First
2759                                  * check the easiest case, it's at the end.
2760                                  */
2761                                 if (logical[nr] + stripe_len >=
2762                                     bytes + offset) {
2763                                         bytes = logical[nr] - offset;
2764                                         continue;
2765                                 }
2766
2767                                 /* Check the left side */
2768                                 ret = check_cache_range(root, cache,
2769                                                         offset,
2770                                                         logical[nr] - offset);
2771                                 if (ret) {
2772                                         kfree(logical);
2773                                         return ret;
2774                                 }
2775
2776                                 /* Now we continue with the right side */
2777                                 bytes = (offset + bytes) -
2778                                         (logical[nr] + stripe_len);
2779                                 offset = logical[nr] + stripe_len;
2780                         }
2781                 }
2782
2783                 kfree(logical);
2784         }
2785
2786         entry = btrfs_find_free_space(cache->free_space_ctl, offset, bytes);
2787         if (!entry) {
2788                 fprintf(stderr, "There is no free space entry for %Lu-%Lu\n",
2789                         offset, offset+bytes);
2790                 return -EINVAL;
2791         }
2792
2793         if (entry->offset != offset) {
2794                 fprintf(stderr, "Wanted offset %Lu, found %Lu\n", offset,
2795                         entry->offset);
2796                 return -EINVAL;
2797         }
2798
2799         if (entry->bytes != bytes) {
2800                 fprintf(stderr, "Wanted bytes %Lu, found %Lu for off %Lu\n",
2801                         bytes, entry->bytes, offset);
2802                 return -EINVAL;
2803         }
2804
2805         unlink_free_space(cache->free_space_ctl, entry);
2806         free(entry);
2807         return 0;
2808 }
2809
2810 static int verify_space_cache(struct btrfs_root *root,
2811                               struct btrfs_block_group_cache *cache)
2812 {
2813         struct btrfs_path *path;
2814         struct extent_buffer *leaf;
2815         struct btrfs_key key;
2816         u64 last;
2817         int ret = 0;
2818
2819         path = btrfs_alloc_path();
2820         if (!path)
2821                 return -ENOMEM;
2822
2823         root = root->fs_info->extent_root;
2824
2825         last = max_t(u64, cache->key.objectid, BTRFS_SUPER_INFO_OFFSET);
2826
2827         key.objectid = last;
2828         key.offset = 0;
2829         key.type = BTRFS_EXTENT_ITEM_KEY;
2830
2831         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2832         if (ret < 0)
2833                 return ret;
2834         ret = 0;
2835         while (1) {
2836                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2837                         ret = btrfs_next_leaf(root, path);
2838                         if (ret < 0)
2839                                 return ret;
2840                         if (ret > 0) {
2841                                 ret = 0;
2842                                 break;
2843                         }
2844                 }
2845                 leaf = path->nodes[0];
2846                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2847                 if (key.objectid >= cache->key.offset + cache->key.objectid)
2848                         break;
2849                 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2850                     key.type != BTRFS_METADATA_ITEM_KEY) {
2851                         path->slots[0]++;
2852                         continue;
2853                 }
2854
2855                 if (last == key.objectid) {
2856                         last = key.objectid + key.offset;
2857                         path->slots[0]++;
2858                         continue;
2859                 }
2860
2861                 ret = check_cache_range(root, cache, last,
2862                                         key.objectid - last);
2863                 if (ret)
2864                         break;
2865                 if (key.type == BTRFS_EXTENT_ITEM_KEY)
2866                         last = key.objectid + key.offset;
2867                 else
2868                         last = key.objectid + root->leafsize;
2869                 path->slots[0]++;
2870         }
2871
2872         if (last < cache->key.objectid + cache->key.offset)
2873                 ret = check_cache_range(root, cache, last,
2874                                         cache->key.objectid +
2875                                         cache->key.offset - last);
2876         btrfs_free_path(path);
2877
2878         if (!ret &&
2879             !RB_EMPTY_ROOT(&cache->free_space_ctl->free_space_offset)) {
2880                 fprintf(stderr, "There are still entries left in the space "
2881                         "cache\n");
2882                 ret = -EINVAL;
2883         }
2884
2885         return ret;
2886 }
2887
2888 static int check_space_cache(struct btrfs_root *root)
2889 {
2890         struct btrfs_block_group_cache *cache;
2891         u64 start = BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE;
2892         int ret;
2893         int error = 0;
2894
2895         if (btrfs_super_generation(root->fs_info->super_copy) !=
2896             btrfs_super_cache_generation(root->fs_info->super_copy)) {
2897                 printf("cache and super generation don't match, space cache "
2898                        "will be invalidated\n");
2899                 return 0;
2900         }
2901
2902         while (1) {
2903                 cache = btrfs_lookup_first_block_group(root->fs_info, start);
2904                 if (!cache)
2905                         break;
2906
2907                 start = cache->key.objectid + cache->key.offset;
2908                 if (!cache->free_space_ctl) {
2909                         int sectorsize;
2910
2911                         if (cache->flags & (BTRFS_BLOCK_GROUP_METADATA |
2912                                             BTRFS_BLOCK_GROUP_SYSTEM))
2913                                 sectorsize = root->leafsize;
2914                         else
2915                                 sectorsize = root->sectorsize;
2916
2917                         if (btrfs_init_free_space_ctl(cache, sectorsize)) {
2918                                 ret = -ENOMEM;
2919                                 break;
2920                         }
2921                 } else {
2922                         btrfs_remove_free_space_cache(cache);
2923                 }
2924
2925                 ret = load_free_space_cache(root->fs_info, cache);
2926                 if (!ret)
2927                         continue;
2928
2929                 ret = verify_space_cache(root, cache);
2930                 if (ret) {
2931                         fprintf(stderr, "cache appears valid but isnt %Lu\n",
2932                                 cache->key.objectid);
2933                         error++;
2934                 }
2935         }
2936
2937         return error ? -EINVAL : 0;
2938 }
2939
2940 static int check_extent_exists(struct btrfs_root *root, u64 bytenr,
2941                                u64 num_bytes)
2942 {
2943         struct btrfs_path *path;
2944         struct extent_buffer *leaf;
2945         struct btrfs_key key;
2946         int ret;
2947
2948         path = btrfs_alloc_path();
2949         if (!path) {
2950                 fprintf(stderr, "Error allocing path\n");
2951                 return -ENOMEM;
2952         }
2953
2954         key.objectid = bytenr;
2955         key.type = BTRFS_EXTENT_ITEM_KEY;
2956         key.offset = 0;
2957
2958
2959 again:
2960         ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
2961                                 0, 0);
2962         if (ret < 0) {
2963                 fprintf(stderr, "Error looking up extent record %d\n", ret);
2964                 btrfs_free_path(path);
2965                 return ret;
2966         } else if (ret) {
2967                 if (path->slots[0])
2968                         path->slots[0]--;
2969                 else
2970                         btrfs_prev_leaf(root, path);
2971         }
2972
2973         btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2974
2975         /*
2976          * Block group items come before extent items if they have the same
2977          * bytenr, so walk back one more just in case.  Dear future traveler,
2978          * first congrats on mastering time travel.  Now if it's not too much
2979          * trouble could you go back to 2006 and tell Chris to make the
2980          * BLOCK_GROUP_ITEM_KEY lower than the EXTENT_ITEM_KEY please?
2981          */
2982         if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
2983                 if (path->slots[0])
2984                         path->slots[0]--;
2985                 else
2986                         btrfs_prev_leaf(root, path);
2987         }
2988
2989         while (num_bytes) {
2990                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2991                         ret = btrfs_next_leaf(root, path);
2992                         if (ret < 0) {
2993                                 fprintf(stderr, "Error going to next leaf "
2994                                         "%d\n", ret);
2995                                 btrfs_free_path(path);
2996                                 return ret;
2997                         } else if (ret) {
2998                                 break;
2999                         }
3000                 }
3001                 leaf = path->nodes[0];
3002                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3003                 if (key.type != BTRFS_EXTENT_ITEM_KEY) {
3004                         path->slots[0]++;
3005                         continue;
3006                 }
3007                 if (key.objectid + key.offset < bytenr) {
3008                         path->slots[0]++;
3009                         continue;
3010                 }
3011                 if (key.objectid > bytenr + num_bytes)
3012                         break;
3013
3014                 if (key.objectid == bytenr) {
3015                         if (key.offset >= num_bytes) {
3016                                 num_bytes = 0;
3017                                 break;
3018                         }
3019                         num_bytes -= key.offset;
3020                         bytenr += key.offset;
3021                 } else if (key.objectid < bytenr) {
3022                         if (key.objectid + key.offset >= bytenr + num_bytes) {
3023                                 num_bytes = 0;
3024                                 break;
3025                         }
3026                         num_bytes = (bytenr + num_bytes) -
3027                                 (key.objectid + key.offset);
3028                         bytenr = key.objectid + key.offset;
3029                 } else {
3030                         if (key.objectid + key.offset < bytenr + num_bytes) {
3031                                 u64 new_start = key.objectid + key.offset;
3032                                 u64 new_bytes = bytenr + num_bytes - new_start;
3033
3034                                 /*
3035                                  * Weird case, the extent is in the middle of
3036                                  * our range, we'll have to search one side
3037                                  * and then the other.  Not sure if this happens
3038                                  * in real life, but no harm in coding it up
3039                                  * anyway just in case.
3040                                  */
3041                                 btrfs_release_path(root, path);
3042                                 ret = check_extent_exists(root, new_start,
3043                                                           new_bytes);
3044                                 if (ret) {
3045                                         fprintf(stderr, "Right section didn't "
3046                                                 "have a record\n");
3047                                         break;
3048                                 }
3049                                 num_bytes = key.objectid - bytenr;
3050                                 goto again;
3051                         }
3052                         num_bytes = key.objectid - bytenr;
3053                 }
3054                 path->slots[0]++;
3055         }
3056         ret = 0;
3057
3058         if (num_bytes) {
3059                 fprintf(stderr, "There are no extents for csum range "
3060                         "%Lu-%Lu\n", bytenr, bytenr+num_bytes);
3061                 ret = 1;
3062         }
3063
3064         btrfs_free_path(path);
3065         return ret;
3066 }
3067
3068 static int check_csums(struct btrfs_root *root)
3069 {
3070         struct btrfs_path *path;
3071         struct extent_buffer *leaf;
3072         struct btrfs_key key;
3073         u64 offset = 0, num_bytes = 0;
3074         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
3075         int errors = 0;
3076         int ret;
3077
3078         root = root->fs_info->csum_root;
3079
3080         key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3081         key.type = BTRFS_EXTENT_CSUM_KEY;
3082         key.offset = 0;
3083
3084         path = btrfs_alloc_path();
3085         if (!path)
3086                 return -ENOMEM;
3087
3088         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3089         if (ret < 0) {
3090                 fprintf(stderr, "Error searching csum tree %d\n", ret);
3091                 btrfs_free_path(path);
3092                 return ret;
3093         }
3094
3095         if (ret > 0 && path->slots[0])
3096                 path->slots[0]--;
3097         ret = 0;
3098
3099         while (1) {
3100                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3101                         ret = btrfs_next_leaf(root, path);
3102                         if (ret < 0) {
3103                                 fprintf(stderr, "Error going to next leaf "
3104                                         "%d\n", ret);
3105                                 break;
3106                         }
3107                         if (ret)
3108                                 break;
3109                 }
3110                 leaf = path->nodes[0];
3111
3112                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3113                 if (key.type != BTRFS_EXTENT_CSUM_KEY) {
3114                         path->slots[0]++;
3115                         continue;
3116                 }
3117
3118                 if (!num_bytes) {
3119                         offset = key.offset;
3120                 } else if (key.offset != offset + num_bytes) {
3121                         ret = check_extent_exists(root, offset, num_bytes);
3122                         if (ret) {
3123                                 fprintf(stderr, "Csum exists for %Lu-%Lu but "
3124                                         "there is no extent record\n",
3125                                         offset, offset+num_bytes);
3126                                 errors++;
3127                         }
3128                         offset = key.offset;
3129                         num_bytes = 0;
3130                 }
3131
3132                 num_bytes += (btrfs_item_size_nr(leaf, path->slots[0]) /
3133                               csum_size) * root->sectorsize;
3134                 path->slots[0]++;
3135         }
3136
3137         btrfs_free_path(path);
3138         return errors;
3139 }
3140
3141 static int run_next_block(struct btrfs_root *root,
3142                           struct block_info *bits,
3143                           int bits_nr,
3144                           u64 *last,
3145                           struct cache_tree *pending,
3146                           struct cache_tree *seen,
3147                           struct cache_tree *reada,
3148                           struct cache_tree *nodes,
3149                           struct cache_tree *extent_cache)
3150 {
3151         struct extent_buffer *buf;
3152         u64 bytenr;
3153         u32 size;
3154         u64 parent;
3155         u64 owner;
3156         u64 flags;
3157         int ret;
3158         int i;
3159         int nritems;
3160         struct btrfs_key key;
3161         struct cache_extent *cache;
3162         int reada_bits;
3163
3164         ret = pick_next_pending(pending, reada, nodes, *last, bits,
3165                                 bits_nr, &reada_bits);
3166         if (ret == 0) {
3167                 return 1;
3168         }
3169         if (!reada_bits) {
3170                 for(i = 0; i < ret; i++) {
3171                         insert_cache_extent(reada, bits[i].start,
3172                                             bits[i].size);
3173
3174                         /* fixme, get the parent transid */
3175                         readahead_tree_block(root, bits[i].start,
3176                                              bits[i].size, 0);
3177                 }
3178         }
3179         *last = bits[0].start;
3180         bytenr = bits[0].start;
3181         size = bits[0].size;
3182
3183         cache = find_cache_extent(pending, bytenr, size);
3184         if (cache) {
3185                 remove_cache_extent(pending, cache);
3186                 free(cache);
3187         }
3188         cache = find_cache_extent(reada, bytenr, size);
3189         if (cache) {
3190                 remove_cache_extent(reada, cache);
3191                 free(cache);
3192         }
3193         cache = find_cache_extent(nodes, bytenr, size);
3194         if (cache) {
3195                 remove_cache_extent(nodes, cache);
3196                 free(cache);
3197         }
3198
3199         /* fixme, get the real parent transid */
3200         buf = read_tree_block(root, bytenr, size, 0);
3201         if (!extent_buffer_uptodate(buf)) {
3202                 record_bad_block_io(root->fs_info,
3203                                     extent_cache, bytenr, size);
3204                 goto out;
3205         }
3206
3207         nritems = btrfs_header_nritems(buf);
3208
3209         ret = btrfs_lookup_extent_info(NULL, root, bytenr,
3210                                        btrfs_header_level(buf), 1, NULL,
3211                                        &flags);
3212         if (ret < 0)
3213                 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
3214
3215         if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
3216                 parent = bytenr;
3217                 owner = 0;
3218         } else {
3219                 parent = 0;
3220                 owner = btrfs_header_owner(buf);
3221         }
3222
3223         ret = check_block(root, extent_cache, buf, flags);
3224         if (ret)
3225                 goto out;
3226
3227         if (btrfs_is_leaf(buf)) {
3228                 btree_space_waste += btrfs_leaf_free_space(root, buf);
3229                 for (i = 0; i < nritems; i++) {
3230                         struct btrfs_file_extent_item *fi;
3231                         btrfs_item_key_to_cpu(buf, &key, i);
3232                         if (key.type == BTRFS_EXTENT_ITEM_KEY) {
3233                                 process_extent_item(root, extent_cache, buf,
3234                                                     i);
3235                                 continue;
3236                         }
3237                         if (key.type == BTRFS_METADATA_ITEM_KEY) {
3238                                 process_extent_item(root, extent_cache, buf,
3239                                                     i);
3240                                 continue;
3241                         }
3242                         if (key.type == BTRFS_EXTENT_CSUM_KEY) {
3243                                 total_csum_bytes +=
3244                                         btrfs_item_size_nr(buf, i);
3245                                 continue;
3246                         }
3247                         if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
3248                                 continue;
3249                         }
3250                         if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
3251 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3252                                 process_extent_ref_v0(extent_cache, buf, i);
3253 #else
3254                                 BUG();
3255 #endif
3256                                 continue;
3257                         }
3258
3259                         if (key.type == BTRFS_TREE_BLOCK_REF_KEY) {
3260                                 add_tree_backref(extent_cache, key.objectid, 0,
3261                                                  key.offset, 0);
3262                                 continue;
3263                         }
3264                         if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
3265                                 add_tree_backref(extent_cache, key.objectid,
3266                                                  key.offset, 0, 0);
3267                                 continue;
3268                         }
3269                         if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3270                                 struct btrfs_extent_data_ref *ref;
3271                                 ref = btrfs_item_ptr(buf, i,
3272                                                 struct btrfs_extent_data_ref);
3273                                 add_data_backref(extent_cache,
3274                                         key.objectid, 0,
3275                                         btrfs_extent_data_ref_root(buf, ref),
3276                                         btrfs_extent_data_ref_objectid(buf,
3277                                                                        ref),
3278                                         btrfs_extent_data_ref_offset(buf, ref),
3279                                         btrfs_extent_data_ref_count(buf, ref),
3280                                         0, root->sectorsize);
3281                                 continue;
3282                         }
3283                         if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3284                                 struct btrfs_shared_data_ref *ref;
3285                                 ref = btrfs_item_ptr(buf, i,
3286                                                 struct btrfs_shared_data_ref);
3287                                 add_data_backref(extent_cache,
3288                                         key.objectid, key.offset, 0, 0, 0,
3289                                         btrfs_shared_data_ref_count(buf, ref),
3290                                         0, root->sectorsize);
3291                                 continue;
3292                         }
3293                         if (key.type != BTRFS_EXTENT_DATA_KEY)
3294                                 continue;
3295                         fi = btrfs_item_ptr(buf, i,
3296                                             struct btrfs_file_extent_item);
3297                         if (btrfs_file_extent_type(buf, fi) ==
3298                             BTRFS_FILE_EXTENT_INLINE)
3299                                 continue;
3300                         if (btrfs_file_extent_disk_bytenr(buf, fi) == 0)
3301                                 continue;
3302
3303                         data_bytes_allocated +=
3304                                 btrfs_file_extent_disk_num_bytes(buf, fi);
3305                         if (data_bytes_allocated < root->sectorsize) {
3306                                 abort();
3307                         }
3308                         data_bytes_referenced +=
3309                                 btrfs_file_extent_num_bytes(buf, fi);
3310                         add_data_backref(extent_cache,
3311                                 btrfs_file_extent_disk_bytenr(buf, fi),
3312                                 parent, owner, key.objectid, key.offset -
3313                                 btrfs_file_extent_offset(buf, fi), 1, 1,
3314                                 btrfs_file_extent_disk_num_bytes(buf, fi));
3315                         BUG_ON(ret);
3316                 }
3317         } else {
3318                 int level;
3319                 struct btrfs_key first_key;
3320
3321                 first_key.objectid = 0;
3322
3323                 if (nritems > 0)
3324                         btrfs_item_key_to_cpu(buf, &first_key, 0);
3325                 level = btrfs_header_level(buf);
3326                 for (i = 0; i < nritems; i++) {
3327                         u64 ptr = btrfs_node_blockptr(buf, i);
3328                         u32 size = btrfs_level_size(root, level - 1);
3329                         btrfs_node_key_to_cpu(buf, &key, i);
3330                         ret = add_extent_rec(extent_cache, &key,
3331                                              ptr, size, 0, 0, 1, 0, 1, 0,
3332                                              size);
3333                         BUG_ON(ret);
3334
3335                         add_tree_backref(extent_cache, ptr, parent, owner, 1);
3336
3337                         if (level > 1) {
3338                                 add_pending(nodes, seen, ptr, size);
3339                         } else {
3340                                 add_pending(pending, seen, ptr, size);
3341                         }
3342                 }
3343                 btree_space_waste += (BTRFS_NODEPTRS_PER_BLOCK(root) -
3344                                       nritems) * sizeof(struct btrfs_key_ptr);
3345         }
3346         total_btree_bytes += buf->len;
3347         if (fs_root_objectid(btrfs_header_owner(buf)))
3348                 total_fs_tree_bytes += buf->len;
3349         if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID)
3350                 total_extent_tree_bytes += buf->len;
3351         if (!found_old_backref &&
3352             btrfs_header_owner(buf) == BTRFS_TREE_RELOC_OBJECTID &&
3353             btrfs_header_backref_rev(buf) == BTRFS_MIXED_BACKREF_REV &&
3354             !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))
3355                 found_old_backref = 1;
3356 out:
3357         free_extent_buffer(buf);
3358         return 0;
3359 }
3360
3361 static int add_root_to_pending(struct extent_buffer *buf,
3362                                struct cache_tree *extent_cache,
3363                                struct cache_tree *pending,
3364                                struct cache_tree *seen,
3365                                struct cache_tree *nodes,
3366                                struct btrfs_key *root_key)
3367 {
3368         if (btrfs_header_level(buf) > 0)
3369                 add_pending(nodes, seen, buf->start, buf->len);
3370         else
3371                 add_pending(pending, seen, buf->start, buf->len);
3372         add_extent_rec(extent_cache, NULL, buf->start, buf->len,
3373                        0, 1, 1, 0, 1, 0, buf->len);
3374
3375         if (root_key->objectid == BTRFS_TREE_RELOC_OBJECTID ||
3376             btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
3377                 add_tree_backref(extent_cache, buf->start, buf->start,
3378                                  0, 1);
3379         else
3380                 add_tree_backref(extent_cache, buf->start, 0,
3381                                  root_key->objectid, 1);
3382         return 0;
3383 }
3384
3385 /* as we fix the tree, we might be deleting blocks that
3386  * we're tracking for repair.  This hook makes sure we
3387  * remove any backrefs for blocks as we are fixing them.
3388  */
3389 static int free_extent_hook(struct btrfs_trans_handle *trans,
3390                             struct btrfs_root *root,
3391                             u64 bytenr, u64 num_bytes, u64 parent,
3392                             u64 root_objectid, u64 owner, u64 offset,
3393                             int refs_to_drop)
3394 {
3395         struct extent_record *rec;
3396         struct cache_extent *cache;
3397         int is_data;
3398         struct cache_tree *extent_cache = root->fs_info->fsck_extent_cache;
3399
3400         is_data = owner >= BTRFS_FIRST_FREE_OBJECTID;
3401         cache = find_cache_extent(extent_cache, bytenr, num_bytes);
3402         if (!cache)
3403                 return 0;
3404
3405         rec = container_of(cache, struct extent_record, cache);
3406         if (is_data) {
3407                 struct data_backref *back;
3408                 back = find_data_backref(rec, parent, root_objectid, owner,
3409                                          offset, 1, bytenr, num_bytes);
3410                 if (!back)
3411                         goto out;
3412                 if (back->node.found_ref) {
3413                         back->found_ref -= refs_to_drop;
3414                         if (rec->refs)
3415                                 rec->refs -= refs_to_drop;
3416                 }
3417                 if (back->node.found_extent_tree) {
3418                         back->num_refs -= refs_to_drop;
3419                         if (rec->extent_item_refs)
3420                                 rec->extent_item_refs -= refs_to_drop;
3421                 }
3422                 if (back->found_ref == 0)
3423                         back->node.found_ref = 0;
3424                 if (back->num_refs == 0)
3425                         back->node.found_extent_tree = 0;
3426
3427                 if (!back->node.found_extent_tree && back->node.found_ref) {
3428                         list_del(&back->node.list);
3429                         free(back);
3430                 }
3431         } else {
3432                 struct tree_backref *back;
3433                 back = find_tree_backref(rec, parent, root_objectid);
3434                 if (!back)
3435                         goto out;
3436                 if (back->node.found_ref) {
3437                         if (rec->refs)
3438                                 rec->refs--;
3439                         back->node.found_ref = 0;
3440                 }
3441                 if (back->node.found_extent_tree) {
3442                         if (rec->extent_item_refs)
3443                                 rec->extent_item_refs--;
3444                         back->node.found_extent_tree = 0;
3445                 }
3446                 if (!back->node.found_extent_tree && back->node.found_ref) {
3447                         list_del(&back->node.list);
3448                         free(back);
3449                 }
3450         }
3451         maybe_free_extent_rec(extent_cache, rec);
3452 out:
3453         return 0;
3454 }
3455
3456 static int delete_extent_records(struct btrfs_trans_handle *trans,
3457                                  struct btrfs_root *root,
3458                                  struct btrfs_path *path,
3459                                  u64 bytenr, u64 new_len)
3460 {
3461         struct btrfs_key key;
3462         struct btrfs_key found_key;
3463         struct extent_buffer *leaf;
3464         int ret;
3465         int slot;
3466
3467
3468         key.objectid = bytenr;
3469         key.type = (u8)-1;
3470         key.offset = (u64)-1;
3471
3472         while(1) {
3473                 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
3474                                         &key, path, 0, 1);
3475                 if (ret < 0)
3476                         break;
3477
3478                 if (ret > 0) {
3479                         ret = 0;
3480                         if (path->slots[0] == 0)
3481                                 break;
3482                         path->slots[0]--;
3483                 }
3484                 ret = 0;
3485
3486                 leaf = path->nodes[0];
3487                 slot = path->slots[0];
3488
3489                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3490                 if (found_key.objectid != bytenr)
3491                         break;
3492
3493                 if (found_key.type != BTRFS_EXTENT_ITEM_KEY &&
3494                     found_key.type != BTRFS_METADATA_ITEM_KEY &&
3495                     found_key.type != BTRFS_TREE_BLOCK_REF_KEY &&
3496                     found_key.type != BTRFS_EXTENT_DATA_REF_KEY &&
3497                     found_key.type != BTRFS_EXTENT_REF_V0_KEY &&
3498                     found_key.type != BTRFS_SHARED_BLOCK_REF_KEY &&
3499                     found_key.type != BTRFS_SHARED_DATA_REF_KEY) {
3500                         btrfs_release_path(NULL, path);
3501                         if (found_key.type == 0) {
3502                                 if (found_key.offset == 0)
3503                                         break;
3504                                 key.offset = found_key.offset - 1;
3505                                 key.type = found_key.type;
3506                         }
3507                         key.type = found_key.type - 1;
3508                         key.offset = (u64)-1;
3509                         continue;
3510                 }
3511
3512                 fprintf(stderr, "repair deleting extent record: key %Lu %u %Lu\n",
3513                         found_key.objectid, found_key.type, found_key.offset);
3514
3515                 ret = btrfs_del_item(trans, root->fs_info->extent_root, path);
3516                 if (ret)
3517                         break;
3518                 btrfs_release_path(NULL, path);
3519
3520                 if (found_key.type == BTRFS_EXTENT_ITEM_KEY ||
3521                     found_key.type == BTRFS_METADATA_ITEM_KEY) {
3522                         u64 bytes = (found_key.type == BTRFS_EXTENT_ITEM_KEY) ?
3523                                 found_key.offset : root->leafsize;
3524
3525                         ret = btrfs_update_block_group(trans, root, bytenr,
3526                                                        bytes, 0, 0);
3527                         if (ret)
3528                                 break;
3529                 }
3530         }
3531
3532         btrfs_release_path(NULL, path);
3533         return ret;
3534 }
3535
3536 /*
3537  * for a single backref, this will allocate a new extent
3538  * and add the backref to it.
3539  */
3540 static int record_extent(struct btrfs_trans_handle *trans,
3541                          struct btrfs_fs_info *info,
3542                          struct btrfs_path *path,
3543                          struct extent_record *rec,
3544                          struct extent_backref *back,
3545                          int allocated, u64 flags)
3546 {
3547         int ret;
3548         struct btrfs_root *extent_root = info->extent_root;
3549         struct extent_buffer *leaf;
3550         struct btrfs_key ins_key;
3551         struct btrfs_extent_item *ei;
3552         struct tree_backref *tback;
3553         struct data_backref *dback;
3554         struct btrfs_tree_block_info *bi;
3555
3556         if (!back->is_data)
3557                 rec->max_size = max_t(u64, rec->max_size,
3558                                     info->extent_root->leafsize);
3559
3560         if (!allocated) {
3561                 u32 item_size = sizeof(*ei);
3562
3563                 if (!back->is_data)
3564                         item_size += sizeof(*bi);
3565
3566                 ins_key.objectid = rec->start;
3567                 ins_key.offset = rec->max_size;
3568                 ins_key.type = BTRFS_EXTENT_ITEM_KEY;
3569
3570                 ret = btrfs_insert_empty_item(trans, extent_root, path,
3571                                         &ins_key, item_size);
3572                 if (ret)
3573                         goto fail;
3574
3575                 leaf = path->nodes[0];
3576                 ei = btrfs_item_ptr(leaf, path->slots[0],
3577                                     struct btrfs_extent_item);
3578
3579                 btrfs_set_extent_refs(leaf, ei, 0);
3580                 btrfs_set_extent_generation(leaf, ei, rec->generation);
3581
3582                 if (back->is_data) {
3583                         btrfs_set_extent_flags(leaf, ei,
3584                                                BTRFS_EXTENT_FLAG_DATA);
3585                 } else {
3586                         struct btrfs_disk_key copy_key;;
3587
3588                         tback = (struct tree_backref *)back;
3589                         bi = (struct btrfs_tree_block_info *)(ei + 1);
3590                         memset_extent_buffer(leaf, 0, (unsigned long)bi,
3591                                              sizeof(*bi));
3592                         memset(&copy_key, 0, sizeof(copy_key));
3593
3594                         copy_key.objectid = le64_to_cpu(rec->info_objectid);
3595                         btrfs_set_tree_block_level(leaf, bi, rec->info_level);
3596                         btrfs_set_tree_block_key(leaf, bi, &copy_key);
3597
3598                         btrfs_set_extent_flags(leaf, ei,
3599                                                BTRFS_EXTENT_FLAG_TREE_BLOCK | flags);
3600                 }
3601
3602                 btrfs_mark_buffer_dirty(leaf);
3603                 ret = btrfs_update_block_group(trans, extent_root, rec->start,
3604                                                rec->max_size, 1, 0);
3605                 if (ret)
3606                         goto fail;
3607                 btrfs_release_path(NULL, path);
3608         }
3609
3610         if (back->is_data) {
3611                 u64 parent;
3612                 int i;
3613
3614                 dback = (struct data_backref *)back;
3615                 if (back->full_backref)
3616                         parent = dback->parent;
3617                 else
3618                         parent = 0;
3619
3620                 for (i = 0; i < dback->found_ref; i++) {
3621                         /* if parent != 0, we're doing a full backref
3622                          * passing BTRFS_FIRST_FREE_OBJECTID as the owner
3623                          * just makes the backref allocator create a data
3624                          * backref
3625                          */
3626                         ret = btrfs_inc_extent_ref(trans, info->extent_root,
3627                                                    rec->start, rec->max_size,
3628                                                    parent,
3629                                                    dback->root,
3630                                                    parent ?
3631                                                    BTRFS_FIRST_FREE_OBJECTID :
3632                                                    dback->owner,
3633                                                    dback->offset);
3634                         if (ret)
3635                                 break;
3636                 }
3637                 fprintf(stderr, "adding new data backref"
3638                                 " on %llu %s %llu owner %llu"
3639                                 " offset %llu found %d\n",
3640                                 (unsigned long long)rec->start,
3641                                 back->full_backref ?
3642                                 "parent" : "root",
3643                                 back->full_backref ?
3644                                 (unsigned long long)parent :
3645                                 (unsigned long long)dback->root,
3646                                 (unsigned long long)dback->owner,
3647                                 (unsigned long long)dback->offset,
3648                                 dback->found_ref);
3649         } else {
3650                 u64 parent;
3651
3652                 tback = (struct tree_backref *)back;
3653                 if (back->full_backref)
3654                         parent = tback->parent;
3655                 else
3656                         parent = 0;
3657
3658                 ret = btrfs_inc_extent_ref(trans, info->extent_root,
3659                                            rec->start, rec->max_size,
3660                                            parent, tback->root, 0, 0);
3661                 fprintf(stderr, "adding new tree backref on "
3662                         "start %llu len %llu parent %llu root %llu\n",
3663                         rec->start, rec->max_size, tback->parent, tback->root);
3664         }
3665         if (ret)
3666                 goto fail;
3667 fail:
3668         btrfs_release_path(NULL, path);
3669         return ret;
3670 }
3671
3672 struct extent_entry {
3673         u64 bytenr;
3674         u64 bytes;
3675         int count;
3676         struct list_head list;
3677 };
3678
3679 static struct extent_entry *find_entry(struct list_head *entries,
3680                                        u64 bytenr, u64 bytes)
3681 {
3682         struct extent_entry *entry = NULL;
3683
3684         list_for_each_entry(entry, entries, list) {
3685                 if (entry->bytenr == bytenr && entry->bytes == bytes)
3686                         return entry;
3687         }
3688
3689         return NULL;
3690 }
3691
3692 static struct extent_entry *find_most_right_entry(struct list_head *entries)
3693 {
3694         struct extent_entry *entry, *best = NULL, *prev = NULL;
3695
3696         list_for_each_entry(entry, entries, list) {
3697                 if (!prev) {
3698                         prev = entry;
3699                         continue;
3700                 }
3701
3702                 /*
3703                  * If our current entry == best then we can't be sure our best
3704                  * is really the best, so we need to keep searching.
3705                  */
3706                 if (best && best->count == entry->count) {
3707                         prev = entry;
3708                         best = NULL;
3709                         continue;
3710                 }
3711
3712                 /* Prev == entry, not good enough, have to keep searching */
3713                 if (prev->count == entry->count)
3714                         continue;
3715
3716                 if (!best)
3717                         best = (prev->count > entry->count) ? prev : entry;
3718                 else if (best->count < entry->count)
3719                         best = entry;
3720                 prev = entry;
3721         }
3722
3723         return best;
3724 }
3725
3726 static int repair_ref(struct btrfs_trans_handle *trans,
3727                       struct btrfs_fs_info *info, struct btrfs_path *path,
3728                       struct data_backref *dback, struct extent_entry *entry)
3729 {
3730         struct btrfs_root *root;
3731         struct btrfs_file_extent_item *fi;
3732         struct extent_buffer *leaf;
3733         struct btrfs_key key;
3734         u64 bytenr, bytes;
3735         int ret;
3736
3737         key.objectid = dback->root;
3738         key.type = BTRFS_ROOT_ITEM_KEY;
3739         key.offset = (u64)-1;
3740         root = btrfs_read_fs_root(info, &key);
3741         if (IS_ERR(root)) {
3742                 fprintf(stderr, "Couldn't find root for our ref\n");
3743                 return -EINVAL;
3744         }
3745
3746         /*
3747          * The backref points to the original offset of the extent if it was
3748          * split, so we need to search down to the offset we have and then walk
3749          * forward until we find the backref we're looking for.
3750          */
3751         key.objectid = dback->owner;
3752         key.type = BTRFS_EXTENT_DATA_KEY;
3753         key.offset = dback->offset;
3754         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3755         if (ret < 0) {
3756                 fprintf(stderr, "Error looking up ref %d\n", ret);
3757                 return ret;
3758         }
3759
3760         while (1) {
3761                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3762                         ret = btrfs_next_leaf(root, path);
3763                         if (ret) {
3764                                 fprintf(stderr, "Couldn't find our ref, next\n");
3765                                 return -EINVAL;
3766                         }
3767                 }
3768                 leaf = path->nodes[0];
3769                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3770                 if (key.objectid != dback->owner ||
3771                     key.type != BTRFS_EXTENT_DATA_KEY) {
3772                         fprintf(stderr, "Couldn't find our ref, search\n");
3773                         return -EINVAL;
3774                 }
3775                 fi = btrfs_item_ptr(leaf, path->slots[0],
3776                                     struct btrfs_file_extent_item);
3777                 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
3778                 bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
3779
3780                 if (bytenr == dback->disk_bytenr && bytes == dback->bytes)
3781                         break;
3782                 path->slots[0]++;
3783         }
3784
3785         btrfs_release_path(root, path);
3786
3787         /*
3788          * Have to make sure that this root gets updated when we commit the
3789          * transaction
3790          */
3791         root->track_dirty = 1;
3792         if (root->last_trans != trans->transid) {
3793                 root->last_trans = trans->transid;
3794                 root->commit_root = root->node;
3795                 extent_buffer_get(root->node);
3796         }
3797
3798         /*
3799          * Ok we have the key of the file extent we want to fix, now we can cow
3800          * down to the thing and fix it.
3801          */
3802         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3803         if (ret < 0) {
3804                 fprintf(stderr, "Error cowing down to ref [%Lu, %u, %Lu]: %d\n",
3805                         key.objectid, key.type, key.offset, ret);
3806                 return ret;
3807         }
3808         if (ret > 0) {
3809                 fprintf(stderr, "Well that's odd, we just found this key "
3810                         "[%Lu, %u, %Lu]\n", key.objectid, key.type,
3811                         key.offset);
3812                 return -EINVAL;
3813         }
3814         leaf = path->nodes[0];
3815         fi = btrfs_item_ptr(leaf, path->slots[0],
3816                             struct btrfs_file_extent_item);
3817
3818         if (btrfs_file_extent_compression(leaf, fi) &&
3819             dback->disk_bytenr != entry->bytenr) {
3820                 fprintf(stderr, "Ref doesn't match the record start and is "
3821                         "compressed, please take a btrfs-image of this file "
3822                         "system and send it to a btrfs developer so they can "
3823                         "complete this functionality for bytenr %Lu\n",
3824                         dback->disk_bytenr);
3825                 return -EINVAL;
3826         }
3827
3828         if (dback->disk_bytenr > entry->bytenr) {
3829                 u64 off_diff, offset;
3830
3831                 off_diff = dback->disk_bytenr - entry->bytenr;
3832                 offset = btrfs_file_extent_offset(leaf, fi);
3833                 if (dback->disk_bytenr + offset +
3834                     btrfs_file_extent_num_bytes(leaf, fi) >
3835                     entry->bytenr + entry->bytes) {
3836                         fprintf(stderr, "Ref is past the entry end, please "
3837                                 "take a btrfs-image of this file system and "
3838                                 "send it to a btrfs developer, ref %Lu\n",
3839                                 dback->disk_bytenr);
3840                         return -EINVAL;
3841                 }
3842                 offset += off_diff;
3843                 btrfs_set_file_extent_disk_bytenr(leaf, fi, entry->bytenr);
3844                 btrfs_set_file_extent_offset(leaf, fi, offset);
3845         } else if (dback->disk_bytenr < entry->bytenr) {
3846                 u64 offset;
3847
3848                 offset = btrfs_file_extent_offset(leaf, fi);
3849                 if (dback->disk_bytenr + offset < entry->bytenr) {
3850                         fprintf(stderr, "Ref is before the entry start, please"
3851                                 " take a btrfs-image of this file system and "
3852                                 "send it to a btrfs developer, ref %Lu\n",
3853                                 dback->disk_bytenr);
3854                         return -EINVAL;
3855                 }
3856
3857                 offset += dback->disk_bytenr;
3858                 offset -= entry->bytenr;
3859                 btrfs_set_file_extent_disk_bytenr(leaf, fi, entry->bytenr);
3860                 btrfs_set_file_extent_offset(leaf, fi, offset);
3861         }
3862
3863         btrfs_set_file_extent_disk_num_bytes(leaf, fi, entry->bytes);
3864
3865         /*
3866          * Chances are if disk_num_bytes were wrong then so is ram_bytes, but
3867          * only do this if we aren't using compression, otherwise it's a
3868          * trickier case.
3869          */
3870         if (!btrfs_file_extent_compression(leaf, fi))
3871                 btrfs_set_file_extent_ram_bytes(leaf, fi, entry->bytes);
3872         else
3873                 printf("ram bytes may be wrong?\n");
3874         btrfs_mark_buffer_dirty(leaf);
3875         btrfs_release_path(root, path);
3876         return 0;
3877 }
3878
3879 static int verify_backrefs(struct btrfs_trans_handle *trans,
3880                            struct btrfs_fs_info *info, struct btrfs_path *path,
3881                            struct extent_record *rec)
3882 {
3883         struct extent_backref *back;
3884         struct data_backref *dback;
3885         struct extent_entry *entry, *best = NULL;
3886         LIST_HEAD(entries);
3887         int nr_entries = 0;
3888         int ret = 0;
3889
3890         /*
3891          * Metadata is easy and the backrefs should always agree on bytenr and
3892          * size, if not we've got bigger issues.
3893          */
3894         if (rec->metadata)
3895                 return 0;
3896
3897         list_for_each_entry(back, &rec->backrefs, list) {
3898                 dback = (struct data_backref *)back;
3899                 /*
3900                  * We only pay attention to backrefs that we found a real
3901                  * backref for.
3902                  */
3903                 if (dback->found_ref == 0)
3904                         continue;
3905                 if (back->full_backref)
3906                         continue;
3907
3908                 /*
3909                  * For now we only catch when the bytes don't match, not the
3910                  * bytenr.  We can easily do this at the same time, but I want
3911                  * to have a fs image to test on before we just add repair
3912                  * functionality willy-nilly so we know we won't screw up the
3913                  * repair.
3914                  */
3915
3916                 entry = find_entry(&entries, dback->disk_bytenr,
3917                                    dback->bytes);
3918                 if (!entry) {
3919                         entry = malloc(sizeof(struct extent_entry));
3920                         if (!entry) {
3921                                 ret = -ENOMEM;
3922                                 goto out;
3923                         }
3924                         memset(entry, 0, sizeof(*entry));
3925                         entry->bytenr = dback->disk_bytenr;
3926                         entry->bytes = dback->bytes;
3927                         list_add_tail(&entry->list, &entries);
3928                         nr_entries++;
3929                 }
3930                 entry->count++;
3931         }
3932
3933         /* Yay all the backrefs agree, carry on good sir */
3934         if (nr_entries <= 1)
3935                 goto out;
3936
3937         fprintf(stderr, "attempting to repair backref discrepency for bytenr "
3938                 "%Lu\n", rec->start);
3939
3940         /*
3941          * First we want to see if the backrefs can agree amongst themselves who
3942          * is right, so figure out which one of the entries has the highest
3943          * count.
3944          */
3945         best = find_most_right_entry(&entries);
3946
3947         /*
3948          * Ok so we may have an even split between what the backrefs think, so
3949          * this is where we use the extent ref to see what it thinks.
3950          */
3951         if (!best) {
3952                 entry = find_entry(&entries, rec->start, rec->nr);
3953                 if (!entry) {
3954                         fprintf(stderr, "Backrefs don't agree with eachother "
3955                                 "and extent record doesn't agree with anybody,"
3956                                 " so we can't fix bytenr %Lu bytes %Lu\n",
3957                                 rec->start, rec->nr);
3958                         ret = -EINVAL;
3959                         goto out;
3960                 }
3961                 entry->count++;
3962                 best = find_most_right_entry(&entries);
3963                 if (!best) {
3964                         fprintf(stderr, "Backrefs and extent record evenly "
3965                                 "split on who is right, this is going to "
3966                                 "require user input to fix bytenr %Lu bytes "
3967                                 "%Lu\n", rec->start, rec->nr);
3968                         ret = -EINVAL;
3969                         goto out;
3970                 }
3971         }
3972
3973         /*
3974          * I don't think this can happen currently as we'll abort() if we catch
3975          * this case higher up, but in case somebody removes that we still can't
3976          * deal with it properly here yet, so just bail out of that's the case.
3977          */
3978         if (best->bytenr != rec->start) {
3979                 fprintf(stderr, "Extent start and backref starts don't match, "
3980                         "please use btrfs-image on this file system and send "
3981                         "it to a btrfs developer so they can make fsck fix "
3982                         "this particular case.  bytenr is %Lu, bytes is %Lu\n",
3983                         rec->start, rec->nr);
3984                 ret = -EINVAL;
3985                 goto out;
3986         }
3987
3988         /*
3989          * Ok great we all agreed on an extent record, let's go find the real
3990          * references and fix up the ones that don't match.
3991          */
3992         list_for_each_entry(back, &rec->backrefs, list) {
3993                 dback = (struct data_backref *)back;
3994
3995                 /*
3996                  * Still ignoring backrefs that don't have a real ref attached
3997                  * to them.
3998                  */
3999                 if (dback->found_ref == 0)
4000                         continue;
4001                 if (back->full_backref)
4002                         continue;
4003
4004                 if (dback->bytes == best->bytes &&
4005                     dback->disk_bytenr == best->bytenr)
4006                         continue;
4007
4008                 ret = repair_ref(trans, info, path, dback, best);
4009                 if (ret)
4010                         goto out;
4011         }
4012
4013         /*
4014          * Ok we messed with the actual refs, which means we need to drop our
4015          * entire cache and go back and rescan.  I know this is a huge pain and
4016          * adds a lot of extra work, but it's the only way to be safe.  Once all
4017          * the backrefs agree we may not need to do anything to the extent
4018          * record itself.
4019          */
4020         ret = -EAGAIN;
4021 out:
4022         while (!list_empty(&entries)) {
4023                 entry = list_entry(entries.next, struct extent_entry, list);
4024                 list_del_init(&entry->list);
4025                 free(entry);
4026         }
4027         return ret;
4028 }
4029
4030 static int delete_duplicate_records(struct btrfs_trans_handle *trans,
4031                                     struct btrfs_root *root,
4032                                     struct extent_record *rec)
4033 {
4034         LIST_HEAD(delete_list);
4035         struct btrfs_path *path;
4036         struct extent_record *tmp, *good, *n;
4037         int ret = 0;
4038         struct btrfs_key key;
4039
4040         path = btrfs_alloc_path();
4041         if (!path) {
4042                 ret = -ENOMEM;
4043                 goto out;
4044         }
4045
4046         good = rec;
4047         /* Find the record that covers all of the duplicates. */
4048         list_for_each_entry(tmp, &rec->dups, list) {
4049                 if (good->start < tmp->start)
4050                         continue;
4051                 if (good->nr > tmp->nr)
4052                         continue;
4053
4054                 if (tmp->start + tmp->nr < good->start + good->nr) {
4055                         fprintf(stderr, "Ok we have overlapping extents that "
4056                                 "aren't completely covered by eachother, this "
4057                                 "is going to require more careful thought.  "
4058                                 "The extents are [%Lu-%Lu] and [%Lu-%Lu]\n",
4059                                 tmp->start, tmp->nr, good->start, good->nr);
4060                         abort();
4061                 }
4062                 good = tmp;
4063         }
4064
4065         if (good != rec)
4066                 list_add_tail(&rec->list, &delete_list);
4067
4068         list_for_each_entry_safe(tmp, n, &rec->dups, list) {
4069                 if (tmp == good)
4070                         continue;
4071                 list_move_tail(&tmp->list, &delete_list);
4072         }
4073
4074         root = root->fs_info->extent_root;
4075         list_for_each_entry(tmp, &delete_list, list) {
4076                 key.objectid = tmp->start;
4077                 key.type = BTRFS_EXTENT_ITEM_KEY;
4078                 key.offset = tmp->nr;
4079
4080                 /* Shouldn't happen but just in case */
4081                 if (tmp->metadata) {
4082                         fprintf(stderr, "Well this shouldn't happen, extent "
4083                                 "record overlaps but is metadata? "
4084                                 "[%Lu, %Lu]\n", tmp->start, tmp->nr);
4085                         abort();
4086                 }
4087
4088                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4089                 if (ret) {
4090                         if (ret > 0)
4091                                 ret = -EINVAL;
4092                         goto out;
4093                 }
4094                 ret = btrfs_del_item(trans, root, path);
4095                 if (ret)
4096                         goto out;
4097                 btrfs_release_path(root, path);
4098         }
4099
4100 out:
4101         while (!list_empty(&delete_list)) {
4102                 tmp = list_entry(delete_list.next, struct extent_record, list);
4103                 list_del_init(&tmp->list);
4104                 if (tmp == rec)
4105                         continue;
4106                 free(tmp);
4107         }
4108
4109         while (!list_empty(&rec->dups)) {
4110                 tmp = list_entry(rec->dups.next, struct extent_record, list);
4111                 list_del_init(&tmp->list);
4112                 free(tmp);
4113         }
4114
4115         btrfs_free_path(path);
4116
4117         return ret;
4118 }
4119
4120 /*
4121  * when an incorrect extent item is found, this will delete
4122  * all of the existing entries for it and recreate them
4123  * based on what the tree scan found.
4124  */
4125 static int fixup_extent_refs(struct btrfs_trans_handle *trans,
4126                              struct btrfs_fs_info *info,
4127                              struct extent_record *rec)
4128 {
4129         int ret;
4130         struct btrfs_path *path;
4131         struct list_head *cur = rec->backrefs.next;
4132         struct cache_extent *cache;
4133         struct extent_backref *back;
4134         int allocated = 0;
4135         u64 flags = 0;
4136
4137         /* remember our flags for recreating the extent */
4138         ret = btrfs_lookup_extent_info(NULL, info->extent_root, rec->start,
4139                                        rec->max_size, rec->metadata, NULL,
4140                                        &flags);
4141         if (ret < 0)
4142                 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
4143
4144         path = btrfs_alloc_path();
4145
4146         /* step one, make sure all of the backrefs agree */
4147         ret = verify_backrefs(trans, info, path, rec);
4148         if (ret < 0)
4149                 goto out;
4150
4151         /* step two, delete all the existing records */
4152         ret = delete_extent_records(trans, info->extent_root, path,
4153                                     rec->start, rec->max_size);
4154
4155         if (ret < 0)
4156                 goto out;
4157
4158         /* was this block corrupt?  If so, don't add references to it */
4159         cache = find_cache_extent(info->corrupt_blocks, rec->start, rec->max_size);
4160         if (cache) {
4161                 ret = 0;
4162                 goto out;
4163         }
4164
4165         /* step three, recreate all the refs we did find */
4166         while(cur != &rec->backrefs) {
4167                 back = list_entry(cur, struct extent_backref, list);
4168                 cur = cur->next;
4169
4170                 /*
4171                  * if we didn't find any references, don't create a
4172                  * new extent record
4173                  */
4174                 if (!back->found_ref)
4175                         continue;
4176
4177                 ret = record_extent(trans, info, path, rec, back, allocated, flags);
4178                 allocated = 1;
4179
4180                 if (ret)
4181                         goto out;
4182         }
4183 out:
4184         btrfs_free_path(path);
4185         return ret;
4186 }
4187
4188 /* right now we only prune from the extent allocation tree */
4189 static int prune_one_block(struct btrfs_trans_handle *trans,
4190                            struct btrfs_fs_info *info,
4191                            struct btrfs_corrupt_block *corrupt)
4192 {
4193         int ret;
4194         struct btrfs_path path;
4195         struct extent_buffer *eb;
4196         u64 found;
4197         int slot;
4198         int nritems;
4199         int level = corrupt->level + 1;
4200
4201         btrfs_init_path(&path);
4202 again:
4203         /* we want to stop at the parent to our busted block */
4204         path.lowest_level = level;
4205
4206         ret = btrfs_search_slot(trans, info->extent_root,
4207                                 &corrupt->key, &path, -1, 1);
4208
4209         if (ret < 0)
4210                 goto out;
4211
4212         eb = path.nodes[level];
4213         if (!eb) {
4214                 ret = -ENOENT;
4215                 goto out;
4216         }
4217
4218         /*
4219          * hopefully the search gave us the block we want to prune,
4220          * lets try that first
4221          */
4222         slot = path.slots[level];
4223         found =  btrfs_node_blockptr(eb, slot);
4224         if (found == corrupt->cache.start)
4225                 goto del_ptr;
4226
4227         nritems = btrfs_header_nritems(eb);
4228
4229         /* the search failed, lets scan this node and hope we find it */
4230         for (slot = 0; slot < nritems; slot++) {
4231                 found =  btrfs_node_blockptr(eb, slot);
4232                 if (found == corrupt->cache.start)
4233                         goto del_ptr;
4234         }
4235         /*
4236          * we couldn't find the bad block.  TODO, search all the nodes for pointers
4237          * to this block
4238          */
4239         if (eb == info->extent_root->node) {
4240                 ret = -ENOENT;
4241                 goto out;
4242         } else {
4243                 level++;
4244                 btrfs_release_path(NULL, &path);
4245                 goto again;
4246         }
4247
4248 del_ptr:
4249         printk("deleting pointer to block %Lu\n", corrupt->cache.start);
4250         ret = btrfs_del_ptr(trans, info->extent_root, &path, level, slot);
4251
4252 out:
4253         btrfs_release_path(NULL, &path);
4254         return ret;
4255 }
4256
4257 static int prune_corrupt_blocks(struct btrfs_trans_handle *trans,
4258                                 struct btrfs_fs_info *info)
4259 {
4260         struct cache_extent *cache;
4261         struct btrfs_corrupt_block *corrupt;
4262
4263         cache = find_first_cache_extent(info->corrupt_blocks, 0);
4264         while (1) {
4265                 if (!cache)
4266                         break;
4267                 corrupt = container_of(cache, struct btrfs_corrupt_block, cache);
4268                 prune_one_block(trans, info, corrupt);
4269                 cache = next_cache_extent(cache);
4270         }
4271         return 0;
4272 }
4273
4274 static void free_corrupt_blocks(struct btrfs_fs_info *info)
4275 {
4276         struct cache_extent *cache;
4277         struct btrfs_corrupt_block *corrupt;
4278
4279         while (1) {
4280                 cache = find_first_cache_extent(info->corrupt_blocks, 0);
4281                 if (!cache)
4282                         break;
4283                 corrupt = container_of(cache, struct btrfs_corrupt_block, cache);
4284                 remove_cache_extent(info->corrupt_blocks, cache);
4285                 free(corrupt);
4286         }
4287 }
4288
4289 static int check_block_group(struct btrfs_trans_handle *trans,
4290                               struct btrfs_fs_info *info,
4291                               struct map_lookup *map,
4292                               int *reinit)
4293 {
4294         struct btrfs_key key;
4295         struct btrfs_path path;
4296         int ret;
4297
4298         key.objectid = map->ce.start;
4299         key.offset = map->ce.size;
4300         key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
4301
4302         btrfs_init_path(&path);
4303         ret = btrfs_search_slot(NULL, info->extent_root,
4304                                 &key, &path, 0, 0);
4305         btrfs_release_path(NULL, &path);
4306         if (ret <= 0)
4307                 goto out;
4308
4309         ret = btrfs_make_block_group(trans, info->extent_root, 0, map->type,
4310                                BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4311                                key.objectid, key.offset);
4312         *reinit = 1;
4313 out:
4314         return ret;
4315 }
4316
4317 static int check_block_groups(struct btrfs_trans_handle *trans,
4318                               struct btrfs_fs_info *info, int *reinit)
4319 {
4320         struct cache_extent *ce;
4321         struct map_lookup *map;
4322         struct btrfs_mapping_tree *map_tree = &info->mapping_tree;
4323
4324         /* this isn't quite working */
4325         return 0;
4326
4327         ce = find_first_cache_extent(&map_tree->cache_tree, 0);
4328         while (1) {
4329                 if (!ce)
4330                         break;
4331                 map = container_of(ce, struct map_lookup, ce);
4332                 check_block_group(trans, info, map, reinit);
4333                 ce = next_cache_extent(ce);
4334         }
4335         return 0;
4336 }
4337
4338 static void reset_cached_block_groups(struct btrfs_fs_info *fs_info)
4339 {
4340         struct btrfs_block_group_cache *cache;
4341         u64 start, end;
4342         int ret;
4343
4344         while (1) {
4345                 ret = find_first_extent_bit(&fs_info->free_space_cache, 0,
4346                                             &start, &end, EXTENT_DIRTY);
4347                 if (ret)
4348                         break;
4349                 clear_extent_dirty(&fs_info->free_space_cache, start, end,
4350                                    GFP_NOFS);
4351         }
4352
4353         start = 0;
4354         while (1) {
4355                 cache = btrfs_lookup_first_block_group(fs_info, start);
4356                 if (!cache)
4357                         break;
4358                 if (cache->cached)
4359                         cache->cached = 0;
4360                 start = cache->key.objectid + cache->key.offset;
4361         }
4362 }
4363
4364 static int check_extent_refs(struct btrfs_trans_handle *trans,
4365                              struct btrfs_root *root,
4366                              struct cache_tree *extent_cache, int repair)
4367 {
4368         struct extent_record *rec, *n;
4369         struct cache_extent *cache;
4370         int err = 0;
4371         int ret = 0;
4372         int fixed = 0;
4373         int reinit = 0;
4374         int had_dups = 0;
4375
4376         if (repair) {
4377                 /*
4378                  * if we're doing a repair, we have to make sure
4379                  * we don't allocate from the problem extents.
4380                  * In the worst case, this will be all the
4381                  * extents in the FS
4382                  */
4383                 cache = find_first_cache_extent(extent_cache, 0);
4384                 while(cache) {
4385                         rec = container_of(cache, struct extent_record, cache);
4386                         btrfs_pin_extent(root->fs_info,
4387                                          rec->start, rec->max_size);
4388                         cache = next_cache_extent(cache);
4389                 }
4390
4391                 /* pin down all the corrupted blocks too */
4392                 cache = find_first_cache_extent(root->fs_info->corrupt_blocks, 0);
4393                 while(cache) {
4394                         rec = container_of(cache, struct extent_record, cache);
4395                         btrfs_pin_extent(root->fs_info,
4396                                          rec->start, rec->max_size);
4397                         cache = next_cache_extent(cache);
4398                 }
4399                 prune_corrupt_blocks(trans, root->fs_info);
4400                 check_block_groups(trans, root->fs_info, &reinit);
4401                 if (reinit)
4402                         btrfs_read_block_groups(root->fs_info->extent_root);
4403                 reset_cached_block_groups(root->fs_info);
4404         }
4405
4406         /*
4407          * We need to delete any duplicate entries we find first otherwise we
4408          * could mess up the extent tree when we have backrefs that actually
4409          * belong to a different extent item and not the weird duplicate one.
4410          */
4411         list_for_each_entry_safe(rec, n, &duplicate_extents, list) {
4412                 if (!repair)
4413                         break;
4414                 list_del_init(&rec->list);
4415                 had_dups = 1;
4416                 ret = delete_duplicate_records(trans, root, rec);
4417                 if (ret)
4418                         return ret;
4419         }
4420
4421         if (had_dups)
4422                 return -EAGAIN;
4423
4424         while(1) {
4425                 fixed = 0;
4426                 cache = find_first_cache_extent(extent_cache, 0);
4427                 if (!cache)
4428                         break;
4429                 rec = container_of(cache, struct extent_record, cache);
4430                 if (rec->has_duplicate) {
4431                         fprintf(stderr, "extent item %llu has multiple extent "
4432                                 "items\n", (unsigned long long)rec->start);
4433                         err = 1;
4434                 }
4435
4436                 if (rec->refs != rec->extent_item_refs) {
4437                         fprintf(stderr, "ref mismatch on [%llu %llu] ",
4438                                 (unsigned long long)rec->start,
4439                                 (unsigned long long)rec->nr);
4440                         fprintf(stderr, "extent item %llu, found %llu\n",
4441                                 (unsigned long long)rec->extent_item_refs,
4442                                 (unsigned long long)rec->refs);
4443                         if (!fixed && repair) {
4444                                 ret = fixup_extent_refs(trans, root->fs_info, rec);
4445                                 if (ret)
4446                                         goto repair_abort;
4447                                 fixed = 1;
4448                         }
4449                         err = 1;
4450
4451                 }
4452                 if (all_backpointers_checked(rec, 1)) {
4453                         fprintf(stderr, "backpointer mismatch on [%llu %llu]\n",
4454                                 (unsigned long long)rec->start,
4455                                 (unsigned long long)rec->nr);
4456
4457                         if (!fixed && repair) {
4458                                 ret = fixup_extent_refs(trans, root->fs_info, rec);
4459                                 if (ret)
4460                                         goto repair_abort;
4461                                 fixed = 1;
4462                         }
4463
4464                         err = 1;
4465                 }
4466                 if (!rec->owner_ref_checked) {
4467                         fprintf(stderr, "owner ref check failed [%llu %llu]\n",
4468                                 (unsigned long long)rec->start,
4469                                 (unsigned long long)rec->nr);
4470                         if (!fixed && repair) {
4471                                 ret = fixup_extent_refs(trans, root->fs_info, rec);
4472                                 if (ret)
4473                                         goto repair_abort;
4474                                 fixed = 1;
4475                         }
4476                         err = 1;
4477                 }
4478
4479                 remove_cache_extent(extent_cache, cache);
4480                 free_all_extent_backrefs(rec);
4481                 free(rec);
4482         }
4483 repair_abort:
4484         if (repair) {
4485                 if (ret && ret != -EAGAIN) {
4486                         fprintf(stderr, "failed to repair damaged filesystem, aborting\n");
4487                         exit(1);
4488                 } else if (!ret) {
4489                         btrfs_fix_block_accounting(trans, root);
4490                 }
4491                 if (err)
4492                         fprintf(stderr, "repaired damaged extent references\n");
4493                 return ret;
4494         }
4495         return err;
4496 }
4497
4498 static void free_cache_tree(struct cache_tree *tree)
4499 {
4500         struct cache_extent *cache;
4501
4502         while (1) {
4503                 cache = find_first_cache_extent(tree, 0);
4504                 if (!cache)
4505                         break;
4506                 remove_cache_extent(tree, cache);
4507                 free(cache);
4508         }
4509 }
4510
4511 static int check_extents(struct btrfs_root *root, int repair)
4512 {
4513         struct cache_tree extent_cache;
4514         struct cache_tree seen;
4515         struct cache_tree pending;
4516         struct cache_tree reada;
4517         struct cache_tree nodes;
4518         struct cache_tree corrupt_blocks;
4519         struct btrfs_path path;
4520         struct btrfs_key key;
4521         struct btrfs_key found_key;
4522         int ret;
4523         u64 last = 0;
4524         struct block_info *bits;
4525         int bits_nr;
4526         struct extent_buffer *leaf;
4527         struct btrfs_trans_handle *trans = NULL;
4528         int slot;
4529         struct btrfs_root_item ri;
4530
4531         cache_tree_init(&extent_cache);
4532         cache_tree_init(&seen);
4533         cache_tree_init(&pending);
4534         cache_tree_init(&nodes);
4535         cache_tree_init(&reada);
4536         cache_tree_init(&corrupt_blocks);
4537
4538         if (repair) {
4539                 trans = btrfs_start_transaction(root, 1);
4540                 if (IS_ERR(trans)) {
4541                         fprintf(stderr, "Error starting transaction\n");
4542                         return PTR_ERR(trans);
4543                 }
4544                 root->fs_info->fsck_extent_cache = &extent_cache;
4545                 root->fs_info->free_extent_hook = free_extent_hook;
4546                 root->fs_info->corrupt_blocks = &corrupt_blocks;
4547         }
4548
4549         bits_nr = 1024;
4550         bits = malloc(bits_nr * sizeof(struct block_info));
4551         if (!bits) {
4552                 perror("malloc");
4553                 exit(1);
4554         }
4555
4556 again:
4557         add_root_to_pending(root->fs_info->tree_root->node,
4558                             &extent_cache, &pending, &seen, &nodes,
4559                             &root->fs_info->tree_root->root_key);
4560
4561         add_root_to_pending(root->fs_info->chunk_root->node,
4562                             &extent_cache, &pending, &seen, &nodes,
4563                             &root->fs_info->chunk_root->root_key);
4564
4565         btrfs_init_path(&path);
4566         key.offset = 0;
4567         key.objectid = 0;
4568         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
4569         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
4570                                         &key, &path, 0, 0);
4571         BUG_ON(ret < 0);
4572         while(1) {
4573                 leaf = path.nodes[0];
4574                 slot = path.slots[0];
4575                 if (slot >= btrfs_header_nritems(path.nodes[0])) {
4576                         ret = btrfs_next_leaf(root, &path);
4577                         if (ret != 0)
4578                                 break;
4579                         leaf = path.nodes[0];
4580                         slot = path.slots[0];
4581                 }
4582                 btrfs_item_key_to_cpu(leaf, &found_key, path.slots[0]);
4583                 if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
4584                         unsigned long offset;
4585                         struct extent_buffer *buf;
4586
4587                         offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
4588                         read_extent_buffer(leaf, &ri, offset, sizeof(ri));
4589                         buf = read_tree_block(root->fs_info->tree_root,
4590                                               btrfs_root_bytenr(&ri),
4591                                               btrfs_level_size(root,
4592                                                btrfs_root_level(&ri)), 0);
4593                         add_root_to_pending(buf, &extent_cache, &pending,
4594                                             &seen, &nodes, &found_key);
4595                         free_extent_buffer(buf);
4596                 }
4597                 path.slots[0]++;
4598         }
4599         btrfs_release_path(root, &path);
4600         while(1) {
4601                 ret = run_next_block(root, bits, bits_nr, &last, &pending,
4602                                      &seen, &reada, &nodes, &extent_cache);
4603                 if (ret != 0)
4604                         break;
4605         }
4606         ret = check_extent_refs(trans, root, &extent_cache, repair);
4607
4608         if (ret == -EAGAIN) {
4609                 ret = btrfs_commit_transaction(trans, root);
4610                 if (ret)
4611                         goto out;
4612
4613                 trans = btrfs_start_transaction(root, 1);
4614                 if (IS_ERR(trans)) {
4615                         ret = PTR_ERR(trans);
4616                         goto out;
4617                 }
4618
4619                 free_corrupt_blocks(root->fs_info);
4620                 free_cache_tree(&seen);
4621                 free_cache_tree(&pending);
4622                 free_cache_tree(&reada);
4623                 free_cache_tree(&nodes);
4624                 free_extent_cache(root->fs_info, &extent_cache);
4625                 goto again;
4626         }
4627
4628         if (trans) {
4629                 int err;
4630
4631                 err = btrfs_commit_transaction(trans, root);
4632                 if (!ret)
4633                         ret = err;
4634         }
4635 out:
4636         if (repair) {
4637                 free_corrupt_blocks(root->fs_info);
4638                 root->fs_info->fsck_extent_cache = NULL;
4639                 root->fs_info->free_extent_hook = NULL;
4640                 root->fs_info->corrupt_blocks = NULL;
4641         }
4642         free(bits);
4643         return ret;
4644 }
4645
4646 static struct option long_options[] = {
4647         { "super", 1, NULL, 's' },
4648         { "repair", 0, NULL, 0 },
4649         { "init-csum-tree", 0, NULL, 0 },
4650         { "init-extent-tree", 0, NULL, 0 },
4651         { 0, 0, 0, 0}
4652 };
4653
4654 const char * const cmd_check_usage[] = {
4655         "btrfs check [options] <device>",
4656         "Check an unmounted btrfs filesystem.",
4657         "",
4658         "-s|--super <superblock>     use this superblock copy",
4659         "--repair                    try to repair the filesystem",
4660         "--init-csum-tree            create a new CRC tree",
4661         "--init-extent-tree          create a new extent tree",
4662         NULL
4663 };
4664
4665 int cmd_check(int argc, char **argv)
4666 {
4667         struct cache_tree root_cache;
4668         struct btrfs_root *root;
4669         struct btrfs_fs_info *info;
4670         u64 bytenr = 0;
4671         char uuidbuf[37];
4672         int ret;
4673         int num;
4674         int repair = 0;
4675         int option_index = 0;
4676         int init_csum_tree = 0;
4677         int rw = 0;
4678
4679         while(1) {
4680                 int c;
4681                 c = getopt_long(argc, argv, "as:", long_options,
4682                                 &option_index);
4683                 if (c < 0)
4684                         break;
4685                 switch(c) {
4686                         case 'a': /* ignored */ break;
4687                         case 's':
4688                                 num = atol(optarg);
4689                                 bytenr = btrfs_sb_offset(num);
4690                                 printf("using SB copy %d, bytenr %llu\n", num,
4691                                        (unsigned long long)bytenr);
4692                                 break;
4693                         case '?':
4694                         case 'h':
4695                                 usage(cmd_check_usage);
4696                 }
4697                 if (option_index == 1) {
4698                         printf("enabling repair mode\n");
4699                         repair = 1;
4700                         rw = 1;
4701                 } else if (option_index == 2) {
4702                         printf("Creating a new CRC tree\n");
4703                         init_csum_tree = 1;
4704                         rw = 1;
4705                 }
4706
4707         }
4708         argc = argc - optind;
4709
4710         if (argc != 1)
4711                 usage(cmd_check_usage);
4712
4713         radix_tree_init();
4714         cache_tree_init(&root_cache);
4715
4716         if((ret = check_mounted(argv[optind])) < 0) {
4717                 fprintf(stderr, "Could not check mount status: %s\n", strerror(-ret));
4718                 return ret;
4719         } else if(ret) {
4720                 fprintf(stderr, "%s is currently mounted. Aborting.\n", argv[optind]);
4721                 return -EBUSY;
4722         }
4723
4724         info = open_ctree_fs_info(argv[optind], bytenr, 0, rw, 1);
4725         if (!info) {
4726                 fprintf(stderr, "Couldn't open file system\n");
4727                 return -EIO;
4728         }
4729
4730         uuid_unparse(info->super_copy->fsid, uuidbuf);
4731         printf("Checking filesystem on %s\nUUID: %s\n", argv[optind], uuidbuf);
4732
4733         if (!extent_buffer_uptodate(info->tree_root->node) ||
4734             !extent_buffer_uptodate(info->dev_root->node) ||
4735             !extent_buffer_uptodate(info->extent_root->node) ||
4736             !extent_buffer_uptodate(info->chunk_root->node)) {
4737                 fprintf(stderr, "Critical roots corrupted, unable to fsck the FS\n");
4738                 return -EIO;
4739         }
4740
4741         root = info->fs_root;
4742
4743         fprintf(stderr, "checking extents\n");
4744         if (init_csum_tree) {
4745                 struct btrfs_trans_handle *trans;
4746
4747                 fprintf(stderr, "Reinit crc root\n");
4748                 trans = btrfs_start_transaction(info->csum_root, 1);
4749                 if (IS_ERR(trans)) {
4750                         fprintf(stderr, "Error starting transaction\n");
4751                         return PTR_ERR(trans);
4752                 }
4753
4754                 ret = btrfs_fsck_reinit_root(trans, info->csum_root);
4755                 if (ret) {
4756                         fprintf(stderr, "crc root initialization failed\n");
4757                         return -EIO;
4758                 }
4759
4760                 ret = btrfs_commit_transaction(trans, root);
4761                 if (ret)
4762                         exit(1);
4763                 goto out;
4764         }
4765         ret = check_extents(root, repair);
4766         if (ret)
4767                 fprintf(stderr, "Errors found in extent allocation tree\n");
4768
4769         fprintf(stderr, "checking free space cache\n");
4770         ret = check_space_cache(root);
4771         if (ret)
4772                 goto out;
4773
4774         fprintf(stderr, "checking fs roots\n");
4775         ret = check_fs_roots(root, &root_cache);
4776         if (ret)
4777                 goto out;
4778
4779         fprintf(stderr, "checking csums\n");
4780         ret = check_csums(root);
4781         if (ret)
4782                 goto out;
4783
4784         fprintf(stderr, "checking root refs\n");
4785         ret = check_root_refs(root, &root_cache);
4786 out:
4787         free_root_recs(&root_cache);
4788         close_ctree(root);
4789
4790         if (found_old_backref) { /*
4791                  * there was a disk format change when mixed
4792                  * backref was in testing tree. The old format
4793                  * existed about one week.
4794                  */
4795                 printf("\n * Found old mixed backref format. "
4796                        "The old format is not supported! *"
4797                        "\n * Please mount the FS in readonly mode, "
4798                        "backup data and re-format the FS. *\n\n");
4799                 ret = 1;
4800         }
4801         printf("found %llu bytes used err is %d\n",
4802                (unsigned long long)bytes_used, ret);
4803         printf("total csum bytes: %llu\n",(unsigned long long)total_csum_bytes);
4804         printf("total tree bytes: %llu\n",
4805                (unsigned long long)total_btree_bytes);
4806         printf("total fs tree bytes: %llu\n",
4807                (unsigned long long)total_fs_tree_bytes);
4808         printf("total extent tree bytes: %llu\n",
4809                (unsigned long long)total_extent_tree_bytes);
4810         printf("btree space waste bytes: %llu\n",
4811                (unsigned long long)btree_space_waste);
4812         printf("file data blocks allocated: %llu\n referenced %llu\n",
4813                 (unsigned long long)data_bytes_allocated,
4814                 (unsigned long long)data_bytes_referenced);
4815         printf("%s\n", BTRFS_BUILD_VERSION);
4816         return ret;
4817 }