git.oblomov.eu Git - git/blob - builtin-fsck.c

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