builtin/fsck.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "config.h"
   4 #include "commit.h"
   5 #include "tree.h"
   6 #include "blob.h"
   7 #include "tag.h"
   8 #include "refs.h"
   9 #include "pack.h"
  10 #include "cache-tree.h"
  11 #include "tree-walk.h"
  12 #include "fsck.h"
  13 #include "parse-options.h"
  14 #include "dir.h"
  15 #include "progress.h"
  16 #include "streaming.h"
  17 #include "decorate.h"
  18 #include "packfile.h"
  19
  20 #define REACHABLE 0x0001
  21 #define SEEN      0x0002
  22 #define HAS_OBJ   0x0004
  23 /* This flag is set if something points to this object. */
  24 #define USED      0x0008
  25
  26 static int show_root;
  27 static int show_tags;
  28 static int show_unreachable;
  29 static int include_reflogs = 1;
  30 static int check_full = 1;
  31 static int connectivity_only;
  32 static int check_strict;
  33 static int keep_cache_objects;
  34 static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
  35 static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
  36 static struct object_id head_oid;
  37 static const char *head_points_at;
  38 static int errors_found;
  39 static int write_lost_and_found;
  40 static int verbose;
  41 static int show_progress = -1;
  42 static int show_dangling = 1;
  43 static int name_objects;
  44 #define ERROR_OBJECT 01
  45 #define ERROR_REACHABLE 02
  46 #define ERROR_PACK 04
  47 #define ERROR_REFS 010
  48
  49 static const char *describe_object(struct object *obj)
  50 {
  51         static struct strbuf buf = STRBUF_INIT;
  52         char *name = name_objects ?
  53                 lookup_decoration(fsck_walk_options.object_names, obj) : NULL;
  54
  55         strbuf_reset(&buf);
  56         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
  57         if (name)
  58                 strbuf_addf(&buf, " (%s)", name);
  59
  60         return buf.buf;
  61 }
  62
  63 static const char *printable_type(struct object *obj)
  64 {
  65         const char *ret;
  66
  67         if (obj->type == OBJ_NONE) {
  68                 enum object_type type = sha1_object_info(obj->oid.hash, NULL);
  69                 if (type > 0)
  70                         object_as_type(obj, type, 0);
  71         }
  72
  73         ret = typename(obj->type);
  74         if (!ret)
  75                 ret = "unknown";
  76
  77         return ret;
  78 }
  79
  80 static int fsck_config(const char *var, const char *value, void *cb)
  81 {
  82         if (strcmp(var, "fsck.skiplist") == 0) {
  83                 const char *path;
  84                 struct strbuf sb = STRBUF_INIT;
  85
  86                 if (git_config_pathname(&path, var, value))
  87                         return 1;
  88                 strbuf_addf(&sb, "skiplist=%s", path);
  89                 free((char *)path);
  90                 fsck_set_msg_types(&fsck_obj_options, sb.buf);
  91                 strbuf_release(&sb);
  92                 return 0;
  93         }
  94
  95         if (skip_prefix(var, "fsck.", &var)) {
  96                 fsck_set_msg_type(&fsck_obj_options, var, value);
  97                 return 0;
  98         }
  99
 100         return git_default_config(var, value, cb);
 101 }
 102
 103 static void objreport(struct object *obj, const char *msg_type,
 104                         const char *err)
 105 {
 106         fprintf(stderr, "%s in %s %s: %s\n",
 107                 msg_type, printable_type(obj), describe_object(obj), err);
 108 }
 109
 110 static int objerror(struct object *obj, const char *err)
 111 {
 112         errors_found |= ERROR_OBJECT;
 113         objreport(obj, "error", err);
 114         return -1;
 115 }
 116
 117 static int fsck_error_func(struct fsck_options *o,
 118         struct object *obj, int type, const char *message)
 119 {
 120         objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
 121         return (type == FSCK_WARN) ? 0 : 1;
 122 }
 123
 124 static struct object_array pending;
 125
 126 static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
 127 {
 128         struct object *parent = data;
 129
 130         /*
 131          * The only case data is NULL or type is OBJ_ANY is when
 132          * mark_object_reachable() calls us.  All the callers of
 133          * that function has non-NULL obj hence ...
 134          */
 135         if (!obj) {
 136                 /* ... these references to parent->fld are safe here */
 137                 printf("broken link from %7s %s\n",
 138                            printable_type(parent), describe_object(parent));
 139                 printf("broken link from %7s %s\n",
 140                            (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
 141                 errors_found |= ERROR_REACHABLE;
 142                 return 1;
 143         }
 144
 145         if (type != OBJ_ANY && obj->type != type)
 146                 /* ... and the reference to parent is safe here */
 147                 objerror(parent, "wrong object type in link");
 148
 149         if (obj->flags & REACHABLE)
 150                 return 0;
 151         obj->flags |= REACHABLE;
 152
 153         if (is_promisor_object(&obj->oid))
 154                 /*
 155                  * Further recursion does not need to be performed on this
 156                  * object since it is a promisor object (so it does not need to
 157                  * be added to "pending").
 158                  */
 159                 return 0;
 160
 161         if (!(obj->flags & HAS_OBJ)) {
 162                 if (parent && !has_object_file(&obj->oid)) {
 163                         printf("broken link from %7s %s\n",
 164                                  printable_type(parent), describe_object(parent));
 165                         printf("              to %7s %s\n",
 166                                  printable_type(obj), describe_object(obj));
 167                         errors_found |= ERROR_REACHABLE;
 168                 }
 169                 return 1;
 170         }
 171
 172         add_object_array(obj, NULL, &pending);
 173         return 0;
 174 }
 175
 176 static void mark_object_reachable(struct object *obj)
 177 {
 178         mark_object(obj, OBJ_ANY, NULL, NULL);
 179 }
 180
 181 static int traverse_one_object(struct object *obj)
 182 {
 183         return fsck_walk(obj, obj, &fsck_walk_options);
 184 }
 185
 186 static int traverse_reachable(void)
 187 {
 188         struct progress *progress = NULL;
 189         unsigned int nr = 0;
 190         int result = 0;
 191         if (show_progress)
 192                 progress = start_delayed_progress(_("Checking connectivity"), 0);
 193         while (pending.nr) {
 194                 result |= traverse_one_object(object_array_pop(&pending));
 195                 display_progress(progress, ++nr);
 196         }
 197         stop_progress(&progress);
 198         return !!result;
 199 }
 200
 201 static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
 202 {
 203         if (!obj)
 204                 return 1;
 205         obj->flags |= USED;
 206         return 0;
 207 }
 208
 209 /*
 210  * Check a single reachable object
 211  */
 212 static void check_reachable_object(struct object *obj)
 213 {
 214         /*
 215          * We obviously want the object to be parsed,
 216          * except if it was in a pack-file and we didn't
 217          * do a full fsck
 218          */
 219         if (!(obj->flags & HAS_OBJ)) {
 220                 if (is_promisor_object(&obj->oid))
 221                         return;
 222                 if (has_sha1_pack(obj->oid.hash))
 223                         return; /* it is in pack - forget about it */
 224                 printf("missing %s %s\n", printable_type(obj),
 225                         describe_object(obj));
 226                 errors_found |= ERROR_REACHABLE;
 227                 return;
 228         }
 229 }
 230
 231 /*
 232  * Check a single unreachable object
 233  */
 234 static void check_unreachable_object(struct object *obj)
 235 {
 236         /*
 237          * Missing unreachable object? Ignore it. It's not like
 238          * we miss it (since it can't be reached), nor do we want
 239          * to complain about it being unreachable (since it does
 240          * not exist).
 241          */
 242         if (!(obj->flags & HAS_OBJ))
 243                 return;
 244
 245         /*
 246          * Unreachable object that exists? Show it if asked to,
 247          * since this is something that is prunable.
 248          */
 249         if (show_unreachable) {
 250                 printf("unreachable %s %s\n", printable_type(obj),
 251                         describe_object(obj));
 252                 return;
 253         }
 254
 255         /*
 256          * "!USED" means that nothing at all points to it, including
 257          * other unreachable objects. In other words, it's the "tip"
 258          * of some set of unreachable objects, usually a commit that
 259          * got dropped.
 260          *
 261          * Such starting points are more interesting than some random
 262          * set of unreachable objects, so we show them even if the user
 263          * hasn't asked for _all_ unreachable objects. If you have
 264          * deleted a branch by mistake, this is a prime candidate to
 265          * start looking at, for example.
 266          */
 267         if (!(obj->flags & USED)) {
 268                 if (show_dangling)
 269                         printf("dangling %s %s\n", printable_type(obj),
 270                                describe_object(obj));
 271                 if (write_lost_and_found) {
 272                         char *filename = git_pathdup("lost-found/%s/%s",
 273                                 obj->type == OBJ_COMMIT ? "commit" : "other",
 274                                 describe_object(obj));
 275                         FILE *f;
 276
 277                         if (safe_create_leading_directories_const(filename)) {
 278                                 error("Could not create lost-found");
 279                                 free(filename);
 280                                 return;
 281                         }
 282                         f = xfopen(filename, "w");
 283                         if (obj->type == OBJ_BLOB) {
 284                                 if (stream_blob_to_fd(fileno(f), &obj->oid, NULL, 1))
 285                                         die_errno("Could not write '%s'", filename);
 286                         } else
 287                                 fprintf(f, "%s\n", describe_object(obj));
 288                         if (fclose(f))
 289                                 die_errno("Could not finish '%s'",
 290                                           filename);
 291                         free(filename);
 292                 }
 293                 return;
 294         }
 295
 296         /*
 297          * Otherwise? It's there, it's unreachable, and some other unreachable
 298          * object points to it. Ignore it - it's not interesting, and we showed
 299          * all the interesting cases above.
 300          */
 301 }
 302
 303 static void check_object(struct object *obj)
 304 {
 305         if (verbose)
 306                 fprintf(stderr, "Checking %s\n", describe_object(obj));
 307
 308         if (obj->flags & REACHABLE)
 309                 check_reachable_object(obj);
 310         else
 311                 check_unreachable_object(obj);
 312 }
 313
 314 static void check_connectivity(void)
 315 {
 316         int i, max;
 317
 318         /* Traverse the pending reachable objects */
 319         traverse_reachable();
 320
 321         /* Look up all the requirements, warn about missing objects.. */
 322         max = get_max_object_index();
 323         if (verbose)
 324                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
 325
 326         for (i = 0; i < max; i++) {
 327                 struct object *obj = get_indexed_object(i);
 328
 329                 if (obj)
 330                         check_object(obj);
 331         }
 332 }
 333
 334 static int fsck_obj(struct object *obj)
 335 {
 336         int err;
 337
 338         if (obj->flags & SEEN)
 339                 return 0;
 340         obj->flags |= SEEN;
 341
 342         if (verbose)
 343                 fprintf(stderr, "Checking %s %s\n",
 344                         printable_type(obj), describe_object(obj));
 345
 346         if (fsck_walk(obj, NULL, &fsck_obj_options))
 347                 objerror(obj, "broken links");
 348         err = fsck_object(obj, NULL, 0, &fsck_obj_options);
 349         if (err)
 350                 goto out;
 351
 352         if (obj->type == OBJ_COMMIT) {
 353                 struct commit *commit = (struct commit *) obj;
 354
 355                 if (!commit->parents && show_root)
 356                         printf("root %s\n", describe_object(&commit->object));
 357         }
 358
 359         if (obj->type == OBJ_TAG) {
 360                 struct tag *tag = (struct tag *) obj;
 361
 362                 if (show_tags && tag->tagged) {
 363                         printf("tagged %s %s", printable_type(tag->tagged),
 364                                 describe_object(tag->tagged));
 365                         printf(" (%s) in %s\n", tag->tag,
 366                                 describe_object(&tag->object));
 367                 }
 368         }
 369
 370 out:
 371         if (obj->type == OBJ_TREE)
 372                 free_tree_buffer((struct tree *)obj);
 373         if (obj->type == OBJ_COMMIT)
 374                 free_commit_buffer((struct commit *)obj);
 375         return err;
 376 }
 377
 378 static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
 379                            unsigned long size, void *buffer, int *eaten)
 380 {
 381         /*
 382          * Note, buffer may be NULL if type is OBJ_BLOB. See
 383          * verify_packfile(), data_valid variable for details.
 384          */
 385         struct object *obj;
 386         obj = parse_object_buffer(oid, type, size, buffer, eaten);
 387         if (!obj) {
 388                 errors_found |= ERROR_OBJECT;
 389                 return error("%s: object corrupt or missing", oid_to_hex(oid));
 390         }
 391         obj->flags &= ~(REACHABLE | SEEN);
 392         obj->flags |= HAS_OBJ;
 393         return fsck_obj(obj);
 394 }
 395
 396 static int default_refs;
 397
 398 static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
 399         timestamp_t timestamp)
 400 {
 401         struct object *obj;
 402
 403         if (!is_null_oid(oid)) {
 404                 obj = lookup_object(oid->hash);
 405                 if (obj && (obj->flags & HAS_OBJ)) {
 406                         if (timestamp && name_objects)
 407                                 add_decoration(fsck_walk_options.object_names,
 408                                         obj,
 409                                         xstrfmt("%s@{%"PRItime"}", refname, timestamp));
 410                         obj->flags |= USED;
 411                         mark_object_reachable(obj);
 412                 } else if (!is_promisor_object(oid)) {
 413                         error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
 414                         errors_found |= ERROR_REACHABLE;
 415                 }
 416         }
 417 }
 418
 419 static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
 420                 const char *email, timestamp_t timestamp, int tz,
 421                 const char *message, void *cb_data)
 422 {
 423         const char *refname = cb_data;
 424
 425         if (verbose)
 426                 fprintf(stderr, "Checking reflog %s->%s\n",
 427                         oid_to_hex(ooid), oid_to_hex(noid));
 428
 429         fsck_handle_reflog_oid(refname, ooid, 0);
 430         fsck_handle_reflog_oid(refname, noid, timestamp);
 431         return 0;
 432 }
 433
 434 static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
 435                               int flag, void *cb_data)
 436 {
 437         for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
 438         return 0;
 439 }
 440
 441 static int fsck_handle_ref(const char *refname, const struct object_id *oid,
 442                            int flag, void *cb_data)
 443 {
 444         struct object *obj;
 445
 446         obj = parse_object(oid);
 447         if (!obj) {
 448                 if (is_promisor_object(oid)) {
 449                         /*
 450                          * Increment default_refs anyway, because this is a
 451                          * valid ref.
 452                          */
 453                          default_refs++;
 454                          return 0;
 455                 }
 456                 error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
 457                 errors_found |= ERROR_REACHABLE;
 458                 /* We'll continue with the rest despite the error.. */
 459                 return 0;
 460         }
 461         if (obj->type != OBJ_COMMIT && is_branch(refname)) {
 462                 error("%s: not a commit", refname);
 463                 errors_found |= ERROR_REFS;
 464         }
 465         default_refs++;
 466         obj->flags |= USED;
 467         if (name_objects)
 468                 add_decoration(fsck_walk_options.object_names,
 469                         obj, xstrdup(refname));
 470         mark_object_reachable(obj);
 471
 472         return 0;
 473 }
 474
 475 static void get_default_heads(void)
 476 {
 477         if (head_points_at && !is_null_oid(&head_oid))
 478                 fsck_handle_ref("HEAD", &head_oid, 0, NULL);
 479         for_each_rawref(fsck_handle_ref, NULL);
 480         if (include_reflogs)
 481                 for_each_reflog(fsck_handle_reflog, NULL);
 482
 483         /*
 484          * Not having any default heads isn't really fatal, but
 485          * it does mean that "--unreachable" no longer makes any
 486          * sense (since in this case everything will obviously
 487          * be unreachable by definition.
 488          *
 489          * Showing dangling objects is valid, though (as those
 490          * dangling objects are likely lost heads).
 491          *
 492          * So we just print a warning about it, and clear the
 493          * "show_unreachable" flag.
 494          */
 495         if (!default_refs) {
 496                 fprintf(stderr, "notice: No default references\n");
 497                 show_unreachable = 0;
 498         }
 499 }
 500
 501 static struct object *parse_loose_object(const struct object_id *oid,
 502                                          const char *path)
 503 {
 504         struct object *obj;
 505         void *contents;
 506         enum object_type type;
 507         unsigned long size;
 508         int eaten;
 509
 510         if (read_loose_object(path, oid->hash, &type, &size, &contents) < 0)
 511                 return NULL;
 512
 513         if (!contents && type != OBJ_BLOB)
 514                 die("BUG: read_loose_object streamed a non-blob");
 515
 516         obj = parse_object_buffer(oid, type, size, contents, &eaten);
 517
 518         if (!eaten)
 519                 free(contents);
 520         return obj;
 521 }
 522
 523 static int fsck_loose(const struct object_id *oid, const char *path, void *data)
 524 {
 525         struct object *obj = parse_loose_object(oid, path);
 526
 527         if (!obj) {
 528                 errors_found |= ERROR_OBJECT;
 529                 error("%s: object corrupt or missing: %s",
 530                       oid_to_hex(oid), path);
 531                 return 0; /* keep checking other objects */
 532         }
 533
 534         obj->flags &= ~(REACHABLE | SEEN);
 535         obj->flags |= HAS_OBJ;
 536         if (fsck_obj(obj))
 537                 errors_found |= ERROR_OBJECT;
 538         return 0;
 539 }
 540
 541 static int fsck_cruft(const char *basename, const char *path, void *data)
 542 {
 543         if (!starts_with(basename, "tmp_obj_"))
 544                 fprintf(stderr, "bad sha1 file: %s\n", path);
 545         return 0;
 546 }
 547
 548 static int fsck_subdir(unsigned int nr, const char *path, void *progress)
 549 {
 550         display_progress(progress, nr + 1);
 551         return 0;
 552 }
 553
 554 static void fsck_object_dir(const char *path)
 555 {
 556         struct progress *progress = NULL;
 557
 558         if (verbose)
 559                 fprintf(stderr, "Checking object directory\n");
 560
 561         if (show_progress)
 562                 progress = start_progress(_("Checking object directories"), 256);
 563
 564         for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
 565                                       progress);
 566         display_progress(progress, 256);
 567         stop_progress(&progress);
 568 }
 569
 570 static int fsck_head_link(void)
 571 {
 572         int null_is_error = 0;
 573
 574         if (verbose)
 575                 fprintf(stderr, "Checking HEAD link\n");
 576
 577         head_points_at = resolve_ref_unsafe("HEAD", 0, head_oid.hash, NULL);
 578         if (!head_points_at) {
 579                 errors_found |= ERROR_REFS;
 580                 return error("Invalid HEAD");
 581         }
 582         if (!strcmp(head_points_at, "HEAD"))
 583                 /* detached HEAD */
 584                 null_is_error = 1;
 585         else if (!starts_with(head_points_at, "refs/heads/")) {
 586                 errors_found |= ERROR_REFS;
 587                 return error("HEAD points to something strange (%s)",
 588                              head_points_at);
 589         }
 590         if (is_null_oid(&head_oid)) {
 591                 if (null_is_error) {
 592                         errors_found |= ERROR_REFS;
 593                         return error("HEAD: detached HEAD points at nothing");
 594                 }
 595                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
 596                         head_points_at + 11);
 597         }
 598         return 0;
 599 }
 600
 601 static int fsck_cache_tree(struct cache_tree *it)
 602 {
 603         int i;
 604         int err = 0;
 605
 606         if (verbose)
 607                 fprintf(stderr, "Checking cache tree\n");
 608
 609         if (0 <= it->entry_count) {
 610                 struct object *obj = parse_object(&it->oid);
 611                 if (!obj) {
 612                         error("%s: invalid sha1 pointer in cache-tree",
 613                               oid_to_hex(&it->oid));
 614                         errors_found |= ERROR_REFS;
 615                         return 1;
 616                 }
 617                 obj->flags |= USED;
 618                 if (name_objects)
 619                         add_decoration(fsck_walk_options.object_names,
 620                                 obj, xstrdup(":"));
 621                 mark_object_reachable(obj);
 622                 if (obj->type != OBJ_TREE)
 623                         err |= objerror(obj, "non-tree in cache-tree");
 624         }
 625         for (i = 0; i < it->subtree_nr; i++)
 626                 err |= fsck_cache_tree(it->down[i]->cache_tree);
 627         return err;
 628 }
 629
 630 static void mark_object_for_connectivity(const struct object_id *oid)
 631 {
 632         struct object *obj = lookup_unknown_object(oid->hash);
 633         obj->flags |= HAS_OBJ;
 634 }
 635
 636 static int mark_loose_for_connectivity(const struct object_id *oid,
 637                                        const char *path,
 638                                        void *data)
 639 {
 640         mark_object_for_connectivity(oid);
 641         return 0;
 642 }
 643
 644 static int mark_packed_for_connectivity(const struct object_id *oid,
 645                                         struct packed_git *pack,
 646                                         uint32_t pos,
 647                                         void *data)
 648 {
 649         mark_object_for_connectivity(oid);
 650         return 0;
 651 }
 652
 653 static char const * const fsck_usage[] = {
 654         N_("git fsck [<options>] [<object>...]"),
 655         NULL
 656 };
 657
 658 static struct option fsck_opts[] = {
 659         OPT__VERBOSE(&verbose, N_("be verbose")),
 660         OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
 661         OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
 662         OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
 663         OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
 664         OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
 665         OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
 666         OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
 667         OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
 668         OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
 669         OPT_BOOL(0, "lost-found", &write_lost_and_found,
 670                                 N_("write dangling objects in .git/lost-found")),
 671         OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
 672         OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
 673         OPT_END(),
 674 };
 675
 676 int cmd_fsck(int argc, const char **argv, const char *prefix)
 677 {
 678         int i;
 679         struct alternate_object_database *alt;
 680
 681         /* fsck knows how to handle missing promisor objects */
 682         fetch_if_missing = 0;
 683
 684         errors_found = 0;
 685         check_replace_refs = 0;
 686
 687         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
 688
 689         fsck_walk_options.walk = mark_object;
 690         fsck_obj_options.walk = mark_used;
 691         fsck_obj_options.error_func = fsck_error_func;
 692         if (check_strict)
 693                 fsck_obj_options.strict = 1;
 694
 695         if (show_progress == -1)
 696                 show_progress = isatty(2);
 697         if (verbose)
 698                 show_progress = 0;
 699
 700         if (write_lost_and_found) {
 701                 check_full = 1;
 702                 include_reflogs = 0;
 703         }
 704
 705         if (name_objects)
 706                 fsck_walk_options.object_names =
 707                         xcalloc(1, sizeof(struct decoration));
 708
 709         git_config(fsck_config, NULL);
 710
 711         fsck_head_link();
 712         if (connectivity_only) {
 713                 for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
 714                 for_each_packed_object(mark_packed_for_connectivity, NULL, 0);
 715         } else {
 716                 fsck_object_dir(get_object_directory());
 717
 718                 prepare_alt_odb();
 719                 for (alt = alt_odb_list; alt; alt = alt->next)
 720                         fsck_object_dir(alt->path);
 721
 722                 if (check_full) {
 723                         struct packed_git *p;
 724                         uint32_t total = 0, count = 0;
 725                         struct progress *progress = NULL;
 726
 727                         prepare_packed_git();
 728
 729                         if (show_progress) {
 730                                 for (p = packed_git; p; p = p->next) {
 731                                         if (open_pack_index(p))
 732                                                 continue;
 733                                         total += p->num_objects;
 734                                 }
 735
 736                                 progress = start_progress(_("Checking objects"), total);
 737                         }
 738                         for (p = packed_git; p; p = p->next) {
 739                                 /* verify gives error messages itself */
 740                                 if (verify_pack(p, fsck_obj_buffer,
 741                                                 progress, count))
 742                                         errors_found |= ERROR_PACK;
 743                                 count += p->num_objects;
 744                         }
 745                         stop_progress(&progress);
 746                 }
 747         }
 748
 749         for (i = 0; i < argc; i++) {
 750                 const char *arg = argv[i];
 751                 struct object_id oid;
 752                 if (!get_oid(arg, &oid)) {
 753                         struct object *obj = lookup_object(oid.hash);
 754
 755                         if (!obj || !(obj->flags & HAS_OBJ)) {
 756                                 if (is_promisor_object(&oid))
 757                                         continue;
 758                                 error("%s: object missing", oid_to_hex(&oid));
 759                                 errors_found |= ERROR_OBJECT;
 760                                 continue;
 761                         }
 762
 763                         obj->flags |= USED;
 764                         if (name_objects)
 765                                 add_decoration(fsck_walk_options.object_names,
 766                                         obj, xstrdup(arg));
 767                         mark_object_reachable(obj);
 768                         continue;
 769                 }
 770                 error("invalid parameter: expected sha1, got '%s'", arg);
 771                 errors_found |= ERROR_OBJECT;
 772         }
 773
 774         /*
 775          * If we've not been given any explicit head information, do the
 776          * default ones from .git/refs. We also consider the index file
 777          * in this case (ie this implies --cache).
 778          */
 779         if (!argc) {
 780                 get_default_heads();
 781                 keep_cache_objects = 1;
 782         }
 783
 784         if (keep_cache_objects) {
 785                 verify_index_checksum = 1;
 786                 read_cache();
 787                 for (i = 0; i < active_nr; i++) {
 788                         unsigned int mode;
 789                         struct blob *blob;
 790                         struct object *obj;
 791
 792                         mode = active_cache[i]->ce_mode;
 793                         if (S_ISGITLINK(mode))
 794                                 continue;
 795                         blob = lookup_blob(&active_cache[i]->oid);
 796                         if (!blob)
 797                                 continue;
 798                         obj = &blob->object;
 799                         obj->flags |= USED;
 800                         if (name_objects)
 801                                 add_decoration(fsck_walk_options.object_names,
 802                                         obj,
 803                                         xstrfmt(":%s", active_cache[i]->name));
 804                         mark_object_reachable(obj);
 805                 }
 806                 if (active_cache_tree)
 807                         fsck_cache_tree(active_cache_tree);
 808         }
 809
 810         check_connectivity();
 811         return errors_found;
 812 }