builtin-fsck.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "commit.h"
   4 #include "tree.h"
   5 #include "blob.h"
   6 #include "tag.h"
   7 #include "refs.h"
   8 #include "pack.h"
   9 #include "cache-tree.h"
  10 #include "tree-walk.h"
  11 #include "fsck.h"
  12 #include "parse-options.h"
  13
  14 #define REACHABLE 0x0001
  15 #define SEEN      0x0002
  16
  17 static int show_root;
  18 static int show_tags;
  19 static int show_unreachable;
  20 static int include_reflogs = 1;
  21 static int check_full;
  22 static int check_strict;
  23 static int keep_cache_objects;
  24 static unsigned char head_sha1[20];
  25 static int errors_found;
  26 static int write_lost_and_found;
  27 static int verbose;
  28 #define ERROR_OBJECT 01
  29 #define ERROR_REACHABLE 02
  30
  31 #ifdef NO_D_INO_IN_DIRENT
  32 #define SORT_DIRENT 0
  33 #define DIRENT_SORT_HINT(de) 0
  34 #else
  35 #define SORT_DIRENT 1
  36 #define DIRENT_SORT_HINT(de) ((de)->d_ino)
  37 #endif
  38
  39 static void objreport(struct object *obj, const char *severity,
  40                       const char *err, va_list params)
  41 {
  42         fprintf(stderr, "%s in %s %s: ",
  43                 severity, typename(obj->type), sha1_to_hex(obj->sha1));
  44         vfprintf(stderr, err, params);
  45         fputs("\n", stderr);
  46 }
  47
  48 static int objerror(struct object *obj, const char *err, ...)
  49 {
  50         va_list params;
  51         va_start(params, err);
  52         errors_found |= ERROR_OBJECT;
  53         objreport(obj, "error", err, params);
  54         va_end(params);
  55         return -1;
  56 }
  57
  58 static int objwarning(struct object *obj, const char *err, ...)
  59 {
  60         va_list params;
  61         va_start(params, err);
  62         objreport(obj, "warning", err, params);
  63         va_end(params);
  64         return -1;
  65 }
  66
  67 static int mark_object(struct object *obj, int type, void *data)
  68 {
  69         struct tree *tree = NULL;
  70         struct object *parent = data;
  71         int result;
  72
  73         if (!obj) {
  74                 printf("broken link from %7s %s\n",
  75                            typename(parent->type), sha1_to_hex(parent->sha1));
  76                 printf("broken link from %7s %s\n",
  77                            (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
  78                 errors_found |= ERROR_REACHABLE;
  79                 return 1;
  80         }
  81
  82         if (type != OBJ_ANY && obj->type != type)
  83                 objerror(parent, "wrong object type in link");
  84
  85         if (obj->flags & REACHABLE)
  86                 return 0;
  87         obj->flags |= REACHABLE;
  88         if (!obj->parsed) {
  89                 if (parent && !has_sha1_file(obj->sha1)) {
  90                         printf("broken link from %7s %s\n",
  91                                  typename(parent->type), sha1_to_hex(parent->sha1));
  92                         printf("              to %7s %s\n",
  93                                  typename(obj->type), sha1_to_hex(obj->sha1));
  94                         errors_found |= ERROR_REACHABLE;
  95                 }
  96                 return 1;
  97         }
  98
  99         if (obj->type == OBJ_TREE) {
 100                 obj->parsed = 0;
 101                 tree = (struct tree *)obj;
 102                 if (parse_tree(tree) < 0)
 103                         return 1; /* error already displayed */
 104         }
 105         result = fsck_walk(obj, mark_object, obj);
 106         if (tree) {
 107                 free(tree->buffer);
 108                 tree->buffer = NULL;
 109         }
 110         if (result < 0)
 111                 result = 1;
 112
 113         return result;
 114 }
 115
 116 static void mark_object_reachable(struct object *obj)
 117 {
 118         mark_object(obj, OBJ_ANY, 0);
 119 }
 120
 121 static int mark_used(struct object *obj, int type, void *data)
 122 {
 123         if (!obj)
 124                 return 1;
 125         obj->used = 1;
 126         return 0;
 127 }
 128
 129 /*
 130  * Check a single reachable object
 131  */
 132 static void check_reachable_object(struct object *obj)
 133 {
 134         /*
 135          * We obviously want the object to be parsed,
 136          * except if it was in a pack-file and we didn't
 137          * do a full fsck
 138          */
 139         if (!obj->parsed) {
 140                 if (has_sha1_pack(obj->sha1, NULL))
 141                         return; /* it is in pack - forget about it */
 142                 printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 143                 errors_found |= ERROR_REACHABLE;
 144                 return;
 145         }
 146 }
 147
 148 /*
 149  * Check a single unreachable object
 150  */
 151 static void check_unreachable_object(struct object *obj)
 152 {
 153         /*
 154          * Missing unreachable object? Ignore it. It's not like
 155          * we miss it (since it can't be reached), nor do we want
 156          * to complain about it being unreachable (since it does
 157          * not exist).
 158          */
 159         if (!obj->parsed)
 160                 return;
 161
 162         /*
 163          * Unreachable object that exists? Show it if asked to,
 164          * since this is something that is prunable.
 165          */
 166         if (show_unreachable) {
 167                 printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 168                 return;
 169         }
 170
 171         /*
 172          * "!used" means that nothing at all points to it, including
 173          * other unreachable objects. In other words, it's the "tip"
 174          * of some set of unreachable objects, usually a commit that
 175          * got dropped.
 176          *
 177          * Such starting points are more interesting than some random
 178          * set of unreachable objects, so we show them even if the user
 179          * hasn't asked for _all_ unreachable objects. If you have
 180          * deleted a branch by mistake, this is a prime candidate to
 181          * start looking at, for example.
 182          */
 183         if (!obj->used) {
 184                 printf("dangling %s %s\n", typename(obj->type),
 185                        sha1_to_hex(obj->sha1));
 186                 if (write_lost_and_found) {
 187                         char *filename = git_path("lost-found/%s/%s",
 188                                 obj->type == OBJ_COMMIT ? "commit" : "other",
 189                                 sha1_to_hex(obj->sha1));
 190                         FILE *f;
 191
 192                         if (safe_create_leading_directories(filename)) {
 193                                 error("Could not create lost-found");
 194                                 return;
 195                         }
 196                         if (!(f = fopen(filename, "w")))
 197                                 die("Could not open %s", filename);
 198                         if (obj->type == OBJ_BLOB) {
 199                                 enum object_type type;
 200                                 unsigned long size;
 201                                 char *buf = read_sha1_file(obj->sha1,
 202                                                 &type, &size);
 203                                 if (buf) {
 204                                         fwrite(buf, size, 1, f);
 205                                         free(buf);
 206                                 }
 207                         } else
 208                                 fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
 209                         fclose(f);
 210                 }
 211                 return;
 212         }
 213
 214         /*
 215          * Otherwise? It's there, it's unreachable, and some other unreachable
 216          * object points to it. Ignore it - it's not interesting, and we showed
 217          * all the interesting cases above.
 218          */
 219 }
 220
 221 static void check_object(struct object *obj)
 222 {
 223         if (verbose)
 224                 fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
 225
 226         if (obj->flags & REACHABLE)
 227                 check_reachable_object(obj);
 228         else
 229                 check_unreachable_object(obj);
 230 }
 231
 232 static void check_connectivity(void)
 233 {
 234         int i, max;
 235
 236         /* Look up all the requirements, warn about missing objects.. */
 237         max = get_max_object_index();
 238         if (verbose)
 239                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
 240
 241         for (i = 0; i < max; i++) {
 242                 struct object *obj = get_indexed_object(i);
 243
 244                 if (obj)
 245                         check_object(obj);
 246         }
 247 }
 248
 249 /*
 250  * The entries in a tree are ordered in the _path_ order,
 251  * which means that a directory entry is ordered by adding
 252  * a slash to the end of it.
 253  *
 254  * So a directory called "a" is ordered _after_ a file
 255  * called "a.c", because "a/" sorts after "a.c".
 256  */
 257 #define TREE_UNORDERED (-1)
 258 #define TREE_HAS_DUPS  (-2)
 259
 260 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 261 {
 262         int len1 = strlen(name1);
 263         int len2 = strlen(name2);
 264         int len = len1 < len2 ? len1 : len2;
 265         unsigned char c1, c2;
 266         int cmp;
 267
 268         cmp = memcmp(name1, name2, len);
 269         if (cmp < 0)
 270                 return 0;
 271         if (cmp > 0)
 272                 return TREE_UNORDERED;
 273
 274         /*
 275          * Ok, the first <len> characters are the same.
 276          * Now we need to order the next one, but turn
 277          * a '\0' into a '/' for a directory entry.
 278          */
 279         c1 = name1[len];
 280         c2 = name2[len];
 281         if (!c1 && !c2)
 282                 /*
 283                  * git-write-tree used to write out a nonsense tree that has
 284                  * entries with the same name, one blob and one tree.  Make
 285                  * sure we do not have duplicate entries.
 286                  */
 287                 return TREE_HAS_DUPS;
 288         if (!c1 && S_ISDIR(mode1))
 289                 c1 = '/';
 290         if (!c2 && S_ISDIR(mode2))
 291                 c2 = '/';
 292         return c1 < c2 ? 0 : TREE_UNORDERED;
 293 }
 294
 295 static int fsck_tree(struct tree *item)
 296 {
 297         int retval;
 298         int has_full_path = 0;
 299         int has_empty_name = 0;
 300         int has_zero_pad = 0;
 301         int has_bad_modes = 0;
 302         int has_dup_entries = 0;
 303         int not_properly_sorted = 0;
 304         struct tree_desc desc;
 305         unsigned o_mode;
 306         const char *o_name;
 307         const unsigned char *o_sha1;
 308
 309         if (verbose)
 310                 fprintf(stderr, "Checking tree %s\n",
 311                                 sha1_to_hex(item->object.sha1));
 312
 313         init_tree_desc(&desc, item->buffer, item->size);
 314
 315         o_mode = 0;
 316         o_name = NULL;
 317         o_sha1 = NULL;
 318         while (desc.size) {
 319                 unsigned mode;
 320                 const char *name;
 321                 const unsigned char *sha1;
 322
 323                 sha1 = tree_entry_extract(&desc, &name, &mode);
 324
 325                 if (strchr(name, '/'))
 326                         has_full_path = 1;
 327                 if (!*name)
 328                         has_empty_name = 1;
 329                 has_zero_pad |= *(char *)desc.buffer == '0';
 330                 update_tree_entry(&desc);
 331
 332                 switch (mode) {
 333                 /*
 334                  * Standard modes..
 335                  */
 336                 case S_IFREG | 0755:
 337                 case S_IFREG | 0644:
 338                 case S_IFLNK:
 339                 case S_IFDIR:
 340                 case S_IFGITLINK:
 341                         break;
 342                 /*
 343                  * This is nonstandard, but we had a few of these
 344                  * early on when we honored the full set of mode
 345                  * bits..
 346                  */
 347                 case S_IFREG | 0664:
 348                         if (!check_strict)
 349                                 break;
 350                 default:
 351                         has_bad_modes = 1;
 352                 }
 353
 354                 if (o_name) {
 355                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 356                         case TREE_UNORDERED:
 357                                 not_properly_sorted = 1;
 358                                 break;
 359                         case TREE_HAS_DUPS:
 360                                 has_dup_entries = 1;
 361                                 break;
 362                         default:
 363                                 break;
 364                         }
 365                 }
 366
 367                 o_mode = mode;
 368                 o_name = name;
 369                 o_sha1 = sha1;
 370         }
 371         free(item->buffer);
 372         item->buffer = NULL;
 373
 374         retval = 0;
 375         if (has_full_path) {
 376                 objwarning(&item->object, "contains full pathnames");
 377         }
 378         if (has_empty_name) {
 379                 objwarning(&item->object, "contains empty pathname");
 380         }
 381         if (has_zero_pad) {
 382                 objwarning(&item->object, "contains zero-padded file modes");
 383         }
 384         if (has_bad_modes) {
 385                 objwarning(&item->object, "contains bad file modes");
 386         }
 387         if (has_dup_entries) {
 388                 retval = objerror(&item->object, "contains duplicate file entries");
 389         }
 390         if (not_properly_sorted) {
 391                 retval = objerror(&item->object, "not properly sorted");
 392         }
 393         return retval;
 394 }
 395
 396 static int fsck_commit(struct commit *commit)
 397 {
 398         char *buffer = commit->buffer;
 399         unsigned char tree_sha1[20], sha1[20];
 400         struct commit_graft *graft;
 401         int parents = 0;
 402
 403         if (verbose)
 404                 fprintf(stderr, "Checking commit %s\n",
 405                         sha1_to_hex(commit->object.sha1));
 406
 407         if (memcmp(buffer, "tree ", 5))
 408                 return objerror(&commit->object, "invalid format - expected 'tree' line");
 409         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
 410                 return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
 411         buffer += 46;
 412         while (!memcmp(buffer, "parent ", 7)) {
 413                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
 414                         return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
 415                 buffer += 48;
 416                 parents++;
 417         }
 418         graft = lookup_commit_graft(commit->object.sha1);
 419         if (graft) {
 420                 struct commit_list *p = commit->parents;
 421                 parents = 0;
 422                 while (p) {
 423                         p = p->next;
 424                         parents++;
 425                 }
 426                 if (graft->nr_parent == -1 && !parents)
 427                         ; /* shallow commit */
 428                 else if (graft->nr_parent != parents)
 429                         return objerror(&commit->object, "graft objects missing");
 430         } else {
 431                 struct commit_list *p = commit->parents;
 432                 while (p && parents) {
 433                         p = p->next;
 434                         parents--;
 435                 }
 436                 if (p || parents)
 437                         return objerror(&commit->object, "parent objects missing");
 438         }
 439         if (memcmp(buffer, "author ", 7))
 440                 return objerror(&commit->object, "invalid format - expected 'author' line");
 441         free(commit->buffer);
 442         commit->buffer = NULL;
 443         if (!commit->tree)
 444                 return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
 445         if (!commit->parents && show_root)
 446                 printf("root %s\n", sha1_to_hex(commit->object.sha1));
 447         if (!commit->date)
 448                 printf("bad commit date in %s\n",
 449                        sha1_to_hex(commit->object.sha1));
 450         return 0;
 451 }
 452
 453 static int fsck_tag(struct tag *tag)
 454 {
 455         struct object *tagged = tag->tagged;
 456
 457         if (verbose)
 458                 fprintf(stderr, "Checking tag %s\n",
 459                         sha1_to_hex(tag->object.sha1));
 460
 461         if (!tagged) {
 462                 return objerror(&tag->object, "could not load tagged object");
 463         }
 464         if (!show_tags)
 465                 return 0;
 466
 467         printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
 468         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 469         return 0;
 470 }
 471
 472 static int fsck_sha1(const unsigned char *sha1)
 473 {
 474         struct object *obj = parse_object(sha1);
 475         if (!obj) {
 476                 errors_found |= ERROR_OBJECT;
 477                 return error("%s: object corrupt or missing",
 478                              sha1_to_hex(sha1));
 479         }
 480         if (obj->flags & SEEN)
 481                 return 0;
 482         obj->flags |= SEEN;
 483         if (fsck_walk(obj, mark_used, 0))
 484                 objerror(obj, "broken links");
 485         if (obj->type == OBJ_BLOB)
 486                 return 0;
 487         if (obj->type == OBJ_TREE)
 488                 return fsck_tree((struct tree *) obj);
 489         if (obj->type == OBJ_COMMIT)
 490                 return fsck_commit((struct commit *) obj);
 491         if (obj->type == OBJ_TAG)
 492                 return fsck_tag((struct tag *) obj);
 493
 494         /* By now, parse_object() would've returned NULL instead. */
 495         return objerror(obj, "unknown type '%d' (internal fsck error)",
 496                         obj->type);
 497 }
 498
 499 /*
 500  * This is the sorting chunk size: make it reasonably
 501  * big so that we can sort well..
 502  */
 503 #define MAX_SHA1_ENTRIES (1024)
 504
 505 struct sha1_entry {
 506         unsigned long ino;
 507         unsigned char sha1[20];
 508 };
 509
 510 static struct {
 511         unsigned long nr;
 512         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 513 } sha1_list;
 514
 515 static int ino_compare(const void *_a, const void *_b)
 516 {
 517         const struct sha1_entry *a = _a, *b = _b;
 518         unsigned long ino1 = a->ino, ino2 = b->ino;
 519         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 520 }
 521
 522 static void fsck_sha1_list(void)
 523 {
 524         int i, nr = sha1_list.nr;
 525
 526         if (SORT_DIRENT)
 527                 qsort(sha1_list.entry, nr,
 528                       sizeof(struct sha1_entry *), ino_compare);
 529         for (i = 0; i < nr; i++) {
 530                 struct sha1_entry *entry = sha1_list.entry[i];
 531                 unsigned char *sha1 = entry->sha1;
 532
 533                 sha1_list.entry[i] = NULL;
 534                 fsck_sha1(sha1);
 535                 free(entry);
 536         }
 537         sha1_list.nr = 0;
 538 }
 539
 540 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 541 {
 542         struct sha1_entry *entry = xmalloc(sizeof(*entry));
 543         int nr;
 544
 545         entry->ino = ino;
 546         hashcpy(entry->sha1, sha1);
 547         nr = sha1_list.nr;
 548         if (nr == MAX_SHA1_ENTRIES) {
 549                 fsck_sha1_list();
 550                 nr = 0;
 551         }
 552         sha1_list.entry[nr] = entry;
 553         sha1_list.nr = ++nr;
 554 }
 555
 556 static void fsck_dir(int i, char *path)
 557 {
 558         DIR *dir = opendir(path);
 559         struct dirent *de;
 560
 561         if (!dir)
 562                 return;
 563
 564         if (verbose)
 565                 fprintf(stderr, "Checking directory %s\n", path);
 566
 567         while ((de = readdir(dir)) != NULL) {
 568                 char name[100];
 569                 unsigned char sha1[20];
 570                 int len = strlen(de->d_name);
 571
 572                 switch (len) {
 573                 case 2:
 574                         if (de->d_name[1] != '.')
 575                                 break;
 576                 case 1:
 577                         if (de->d_name[0] != '.')
 578                                 break;
 579                         continue;
 580                 case 38:
 581                         sprintf(name, "%02x", i);
 582                         memcpy(name+2, de->d_name, len+1);
 583                         if (get_sha1_hex(name, sha1) < 0)
 584                                 break;
 585                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
 586                         continue;
 587                 }
 588                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 589         }
 590         closedir(dir);
 591 }
 592
 593 static int default_refs;
 594
 595 static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 596                 const char *email, unsigned long timestamp, int tz,
 597                 const char *message, void *cb_data)
 598 {
 599         struct object *obj;
 600
 601         if (verbose)
 602                 fprintf(stderr, "Checking reflog %s->%s\n",
 603                         sha1_to_hex(osha1), sha1_to_hex(nsha1));
 604
 605         if (!is_null_sha1(osha1)) {
 606                 obj = lookup_object(osha1);
 607                 if (obj) {
 608                         obj->used = 1;
 609                         mark_object_reachable(obj);
 610                 }
 611         }
 612         obj = lookup_object(nsha1);
 613         if (obj) {
 614                 obj->used = 1;
 615                 mark_object_reachable(obj);
 616         }
 617         return 0;
 618 }
 619
 620 static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
 621 {
 622         for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
 623         return 0;
 624 }
 625
 626 static int is_branch(const char *refname)
 627 {
 628         return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
 629 }
 630
 631 static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 632 {
 633         struct object *obj;
 634
 635         obj = parse_object(sha1);
 636         if (!obj) {
 637                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
 638                 /* We'll continue with the rest despite the error.. */
 639                 return 0;
 640         }
 641         if (obj->type != OBJ_COMMIT && is_branch(refname))
 642                 error("%s: not a commit", refname);
 643         default_refs++;
 644         obj->used = 1;
 645         mark_object_reachable(obj);
 646
 647         return 0;
 648 }
 649
 650 static void get_default_heads(void)
 651 {
 652         for_each_ref(fsck_handle_ref, NULL);
 653         if (include_reflogs)
 654                 for_each_reflog(fsck_handle_reflog, NULL);
 655
 656         /*
 657          * Not having any default heads isn't really fatal, but
 658          * it does mean that "--unreachable" no longer makes any
 659          * sense (since in this case everything will obviously
 660          * be unreachable by definition.
 661          *
 662          * Showing dangling objects is valid, though (as those
 663          * dangling objects are likely lost heads).
 664          *
 665          * So we just print a warning about it, and clear the
 666          * "show_unreachable" flag.
 667          */
 668         if (!default_refs) {
 669                 fprintf(stderr, "notice: No default references\n");
 670                 show_unreachable = 0;
 671         }
 672 }
 673
 674 static void fsck_object_dir(const char *path)
 675 {
 676         int i;
 677
 678         if (verbose)
 679                 fprintf(stderr, "Checking object directory\n");
 680
 681         for (i = 0; i < 256; i++) {
 682                 static char dir[4096];
 683                 sprintf(dir, "%s/%02x", path, i);
 684                 fsck_dir(i, dir);
 685         }
 686         fsck_sha1_list();
 687 }
 688
 689 static int fsck_head_link(void)
 690 {
 691         unsigned char sha1[20];
 692         int flag;
 693         int null_is_error = 0;
 694         const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag);
 695
 696         if (verbose)
 697                 fprintf(stderr, "Checking HEAD link\n");
 698
 699         if (!head_points_at)
 700                 return error("Invalid HEAD");
 701         if (!strcmp(head_points_at, "HEAD"))
 702                 /* detached HEAD */
 703                 null_is_error = 1;
 704         else if (prefixcmp(head_points_at, "refs/heads/"))
 705                 return error("HEAD points to something strange (%s)",
 706                              head_points_at);
 707         if (is_null_sha1(sha1)) {
 708                 if (null_is_error)
 709                         return error("HEAD: detached HEAD points at nothing");
 710                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
 711                         head_points_at + 11);
 712         }
 713         return 0;
 714 }
 715
 716 static int fsck_cache_tree(struct cache_tree *it)
 717 {
 718         int i;
 719         int err = 0;
 720
 721         if (verbose)
 722                 fprintf(stderr, "Checking cache tree\n");
 723
 724         if (0 <= it->entry_count) {
 725                 struct object *obj = parse_object(it->sha1);
 726                 if (!obj) {
 727                         error("%s: invalid sha1 pointer in cache-tree",
 728                               sha1_to_hex(it->sha1));
 729                         return 1;
 730                 }
 731                 mark_object_reachable(obj);
 732                 obj->used = 1;
 733                 if (obj->type != OBJ_TREE)
 734                         err |= objerror(obj, "non-tree in cache-tree");
 735         }
 736         for (i = 0; i < it->subtree_nr; i++)
 737                 err |= fsck_cache_tree(it->down[i]->cache_tree);
 738         return err;
 739 }
 740
 741 static char const * const fsck_usage[] = {
 742         "git-fsck [options] [<object>...]",
 743         NULL
 744 };
 745
 746 static struct option fsck_opts[] = {
 747         OPT__VERBOSE(&verbose),
 748         OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
 749         OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
 750         OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
 751         OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
 752         OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
 753         OPT_BOOLEAN(0, "full", &check_full, "also consider alternate objects"),
 754         OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
 755         OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
 756                                 "write dangling objects in .git/lost-found"),
 757         OPT_END(),
 758 };
 759
 760 int cmd_fsck(int argc, const char **argv, const char *prefix)
 761 {
 762         int i, heads;
 763
 764         errors_found = 0;
 765
 766         argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0);
 767         if (write_lost_and_found) {
 768                 check_full = 1;
 769                 include_reflogs = 0;
 770         }
 771
 772         fsck_head_link();
 773         fsck_object_dir(get_object_directory());
 774         if (check_full) {
 775                 struct alternate_object_database *alt;
 776                 struct packed_git *p;
 777                 prepare_alt_odb();
 778                 for (alt = alt_odb_list; alt; alt = alt->next) {
 779                         char namebuf[PATH_MAX];
 780                         int namelen = alt->name - alt->base;
 781                         memcpy(namebuf, alt->base, namelen);
 782                         namebuf[namelen - 1] = 0;
 783                         fsck_object_dir(namebuf);
 784                 }
 785                 prepare_packed_git();
 786                 for (p = packed_git; p; p = p->next)
 787                         /* verify gives error messages itself */
 788                         verify_pack(p, 0);
 789
 790                 for (p = packed_git; p; p = p->next) {
 791                         uint32_t j, num;
 792                         if (open_pack_index(p))
 793                                 continue;
 794                         num = p->num_objects;
 795                         for (j = 0; j < num; j++)
 796                                 fsck_sha1(nth_packed_object_sha1(p, j));
 797                 }
 798         }
 799
 800         heads = 0;
 801         for (i = 1; i < argc; i++) {
 802                 const char *arg = argv[i];
 803                 if (!get_sha1(arg, head_sha1)) {
 804                         struct object *obj = lookup_object(head_sha1);
 805
 806                         /* Error is printed by lookup_object(). */
 807                         if (!obj)
 808                                 continue;
 809
 810                         obj->used = 1;
 811                         mark_object_reachable(obj);
 812                         heads++;
 813                         continue;
 814                 }
 815                 error("invalid parameter: expected sha1, got '%s'", arg);
 816         }
 817
 818         /*
 819          * If we've not been given any explicit head information, do the
 820          * default ones from .git/refs. We also consider the index file
 821          * in this case (ie this implies --cache).
 822          */
 823         if (!heads) {
 824                 get_default_heads();
 825                 keep_cache_objects = 1;
 826         }
 827
 828         if (keep_cache_objects) {
 829                 read_cache();
 830                 for (i = 0; i < active_nr; i++) {
 831                         unsigned int mode;
 832                         struct blob *blob;
 833                         struct object *obj;
 834
 835                         mode = ntohl(active_cache[i]->ce_mode);
 836                         if (S_ISGITLINK(mode))
 837                                 continue;
 838                         blob = lookup_blob(active_cache[i]->sha1);
 839                         if (!blob)
 840                                 continue;
 841                         obj = &blob->object;
 842                         obj->used = 1;
 843                         mark_object_reachable(obj);
 844                 }
 845                 if (active_cache_tree)
 846                         fsck_cache_tree(active_cache_tree);
 847         }
 848
 849         check_connectivity();
 850         return errors_found;
 851 }