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

   1 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   2 #include "builtin.h"
   3 #include "cache.h"
   4 #include "repository.h"
   5 #include "config.h"
   6 #include "commit.h"
   7 #include "tree.h"
   8 #include "blob.h"
   9 #include "tag.h"
  10 #include "refs.h"
  11 #include "pack.h"
  12 #include "cache-tree.h"
  13 #include "tree-walk.h"
  14 #include "fsck.h"
  15 #include "parse-options.h"
  16 #include "dir.h"
  17 #include "progress.h"
  18 #include "streaming.h"
  19 #include "decorate.h"
  20 #include "packfile.h"
  21 #include "object-store.h"
  22 #include "run-command.h"
  23 #include "worktree.h"
  24
  25 #define REACHABLE 0x0001
  26 #define SEEN      0x0002
  27 #define HAS_OBJ   0x0004
  28 /* This flag is set if something points to this object. */
  29 #define USED      0x0008
  30
  31 static int show_root;
  32 static int show_tags;
  33 static int show_unreachable;
  34 static int include_reflogs = 1;
  35 static int check_full = 1;
  36 static int connectivity_only;
  37 static int check_strict;
  38 static int keep_cache_objects;
  39 static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
  40 static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
  41 static int errors_found;
  42 static int write_lost_and_found;
  43 static int verbose;
  44 static int show_progress = -1;
  45 static int show_dangling = 1;
  46 static int name_objects;
  47 #define ERROR_OBJECT 01
  48 #define ERROR_REACHABLE 02
  49 #define ERROR_PACK 04
  50 #define ERROR_REFS 010
  51 #define ERROR_COMMIT_GRAPH 020
  52
  53 static const char *describe_object(struct object *obj)
  54 {
  55         static struct strbuf bufs[] = {
  56                 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
  57         };
  58         static int b = 0;
  59         struct strbuf *buf;
  60         char *name = NULL;
  61
  62         if (name_objects)
  63                 name = lookup_decoration(fsck_walk_options.object_names, obj);
  64
  65         buf = bufs + b;
  66         b = (b + 1) % ARRAY_SIZE(bufs);
  67         strbuf_reset(buf);
  68         strbuf_addstr(buf, oid_to_hex(&obj->oid));
  69         if (name)
  70                 strbuf_addf(buf, " (%s)", name);
  71
  72         return buf->buf;
  73 }
  74
  75 static const char *printable_type(struct object *obj)
  76 {
  77         const char *ret;
  78
  79         if (obj->type == OBJ_NONE) {
  80                 enum object_type type = oid_object_info(the_repository,
  81                                                         &obj->oid, NULL);
  82                 if (type > 0)
  83                         object_as_type(the_repository, obj, type, 0);
  84         }
  85
  86         ret = type_name(obj->type);
  87         if (!ret)
  88                 ret = _("unknown");
  89
  90         return ret;
  91 }
  92
  93 static int fsck_config(const char *var, const char *value, void *cb)
  94 {
  95         if (strcmp(var, "fsck.skiplist") == 0) {
  96                 const char *path;
  97                 struct strbuf sb = STRBUF_INIT;
  98
  99                 if (git_config_pathname(&path, var, value))
 100                         return 1;
 101                 strbuf_addf(&sb, "skiplist=%s", path);
 102                 free((char *)path);
 103                 fsck_set_msg_types(&fsck_obj_options, sb.buf);
 104                 strbuf_release(&sb);
 105                 return 0;
 106         }
 107
 108         if (skip_prefix(var, "fsck.", &var)) {
 109                 fsck_set_msg_type(&fsck_obj_options, var, value);
 110                 return 0;
 111         }
 112
 113         return git_default_config(var, value, cb);
 114 }
 115
 116 static int objerror(struct object *obj, const char *err)
 117 {
 118         errors_found |= ERROR_OBJECT;
 119         /* TRANSLATORS: e.g. error in tree 01bfda: <more explanation> */
 120         fprintf_ln(stderr, _("error in %s %s: %s"),
 121                    printable_type(obj), describe_object(obj), err);
 122         return -1;
 123 }
 124
 125 static int fsck_error_func(struct fsck_options *o,
 126         struct object *obj, int type, const char *message)
 127 {
 128         switch (type) {
 129         case FSCK_WARN:
 130                 /* TRANSLATORS: e.g. warning in tree 01bfda: <more explanation> */
 131                 fprintf_ln(stderr, _("warning in %s %s: %s"),
 132                            printable_type(obj), describe_object(obj), message);
 133                 return 0;
 134         case FSCK_ERROR:
 135                 /* TRANSLATORS: e.g. error in tree 01bfda: <more explanation> */
 136                 fprintf_ln(stderr, _("error in %s %s: %s"),
 137                            printable_type(obj), describe_object(obj), message);
 138                 return 1;
 139         default:
 140                 BUG("%d (FSCK_IGNORE?) should never trigger this callback", type);
 141         }
 142 }
 143
 144 static struct object_array pending;
 145
 146 static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
 147 {
 148         struct object *parent = data;
 149
 150         /*
 151          * The only case data is NULL or type is OBJ_ANY is when
 152          * mark_object_reachable() calls us.  All the callers of
 153          * that function has non-NULL obj hence ...
 154          */
 155         if (!obj) {
 156                 /* ... these references to parent->fld are safe here */
 157                 printf_ln(_("broken link from %7s %s"),
 158                           printable_type(parent), describe_object(parent));
 159                 printf_ln(_("broken link from %7s %s"),
 160                           (type == OBJ_ANY ? _("unknown") : type_name(type)),
 161                           _("unknown"));
 162                 errors_found |= ERROR_REACHABLE;
 163                 return 1;
 164         }
 165
 166         if (type != OBJ_ANY && obj->type != type)
 167                 /* ... and the reference to parent is safe here */
 168                 objerror(parent, _("wrong object type in link"));
 169
 170         if (obj->flags & REACHABLE)
 171                 return 0;
 172         obj->flags |= REACHABLE;
 173
 174         if (is_promisor_object(&obj->oid))
 175                 /*
 176                  * Further recursion does not need to be performed on this
 177                  * object since it is a promisor object (so it does not need to
 178                  * be added to "pending").
 179                  */
 180                 return 0;
 181
 182         if (!(obj->flags & HAS_OBJ)) {
 183                 if (parent && !has_object_file(&obj->oid)) {
 184                         printf_ln(_("broken link from %7s %s\n"
 185                                     "              to %7s %s"),
 186                                   printable_type(parent),
 187                                   describe_object(parent),
 188                                   printable_type(obj),
 189                                   describe_object(obj));
 190                         errors_found |= ERROR_REACHABLE;
 191                 }
 192                 return 1;
 193         }
 194
 195         add_object_array(obj, NULL, &pending);
 196         return 0;
 197 }
 198
 199 static void mark_object_reachable(struct object *obj)
 200 {
 201         mark_object(obj, OBJ_ANY, NULL, NULL);
 202 }
 203
 204 static int traverse_one_object(struct object *obj)
 205 {
 206         int result = fsck_walk(obj, obj, &fsck_walk_options);
 207
 208         if (obj->type == OBJ_TREE) {
 209                 struct tree *tree = (struct tree *)obj;
 210                 free_tree_buffer(tree);
 211         }
 212         return result;
 213 }
 214
 215 static int traverse_reachable(void)
 216 {
 217         struct progress *progress = NULL;
 218         unsigned int nr = 0;
 219         int result = 0;
 220         if (show_progress)
 221                 progress = start_delayed_progress(_("Checking connectivity"), 0);
 222         while (pending.nr) {
 223                 result |= traverse_one_object(object_array_pop(&pending));
 224                 display_progress(progress, ++nr);
 225         }
 226         stop_progress(&progress);
 227         return !!result;
 228 }
 229
 230 static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
 231 {
 232         if (!obj)
 233                 return 1;
 234         obj->flags |= USED;
 235         return 0;
 236 }
 237
 238 static void mark_unreachable_referents(const struct object_id *oid)
 239 {
 240         struct fsck_options options = FSCK_OPTIONS_DEFAULT;
 241         struct object *obj = lookup_object(the_repository, oid);
 242
 243         if (!obj || !(obj->flags & HAS_OBJ))
 244                 return; /* not part of our original set */
 245         if (obj->flags & REACHABLE)
 246                 return; /* reachable objects already traversed */
 247
 248         /*
 249          * Avoid passing OBJ_NONE to fsck_walk, which will parse the object
 250          * (and we want to avoid parsing blobs).
 251          */
 252         if (obj->type == OBJ_NONE) {
 253                 enum object_type type = oid_object_info(the_repository,
 254                                                         &obj->oid, NULL);
 255                 if (type > 0)
 256                         object_as_type(the_repository, obj, type, 0);
 257         }
 258
 259         options.walk = mark_used;
 260         fsck_walk(obj, NULL, &options);
 261 }
 262
 263 static int mark_loose_unreachable_referents(const struct object_id *oid,
 264                                             const char *path,
 265                                             void *data)
 266 {
 267         mark_unreachable_referents(oid);
 268         return 0;
 269 }
 270
 271 static int mark_packed_unreachable_referents(const struct object_id *oid,
 272                                              struct packed_git *pack,
 273                                              uint32_t pos,
 274                                              void *data)
 275 {
 276         mark_unreachable_referents(oid);
 277         return 0;
 278 }
 279
 280 /*
 281  * Check a single reachable object
 282  */
 283 static void check_reachable_object(struct object *obj)
 284 {
 285         /*
 286          * We obviously want the object to be parsed,
 287          * except if it was in a pack-file and we didn't
 288          * do a full fsck
 289          */
 290         if (!(obj->flags & HAS_OBJ)) {
 291                 if (is_promisor_object(&obj->oid))
 292                         return;
 293                 if (has_object_pack(&obj->oid))
 294                         return; /* it is in pack - forget about it */
 295                 printf_ln(_("missing %s %s"), printable_type(obj),
 296                           describe_object(obj));
 297                 errors_found |= ERROR_REACHABLE;
 298                 return;
 299         }
 300 }
 301
 302 /*
 303  * Check a single unreachable object
 304  */
 305 static void check_unreachable_object(struct object *obj)
 306 {
 307         /*
 308          * Missing unreachable object? Ignore it. It's not like
 309          * we miss it (since it can't be reached), nor do we want
 310          * to complain about it being unreachable (since it does
 311          * not exist).
 312          */
 313         if (!(obj->flags & HAS_OBJ))
 314                 return;
 315
 316         /*
 317          * Unreachable object that exists? Show it if asked to,
 318          * since this is something that is prunable.
 319          */
 320         if (show_unreachable) {
 321                 printf_ln(_("unreachable %s %s"), printable_type(obj),
 322                           describe_object(obj));
 323                 return;
 324         }
 325
 326         /*
 327          * "!USED" means that nothing at all points to it, including
 328          * other unreachable objects. In other words, it's the "tip"
 329          * of some set of unreachable objects, usually a commit that
 330          * got dropped.
 331          *
 332          * Such starting points are more interesting than some random
 333          * set of unreachable objects, so we show them even if the user
 334          * hasn't asked for _all_ unreachable objects. If you have
 335          * deleted a branch by mistake, this is a prime candidate to
 336          * start looking at, for example.
 337          */
 338         if (!(obj->flags & USED)) {
 339                 if (show_dangling)
 340                         printf_ln(_("dangling %s %s"), printable_type(obj),
 341                                   describe_object(obj));
 342                 if (write_lost_and_found) {
 343                         char *filename = git_pathdup("lost-found/%s/%s",
 344                                 obj->type == OBJ_COMMIT ? "commit" : "other",
 345                                 describe_object(obj));
 346                         FILE *f;
 347
 348                         if (safe_create_leading_directories_const(filename)) {
 349                                 error(_("could not create lost-found"));
 350                                 free(filename);
 351                                 return;
 352                         }
 353                         f = xfopen(filename, "w");
 354                         if (obj->type == OBJ_BLOB) {
 355                                 if (stream_blob_to_fd(fileno(f), &obj->oid, NULL, 1))
 356                                         die_errno(_("could not write '%s'"), filename);
 357                         } else
 358                                 fprintf(f, "%s\n", describe_object(obj));
 359                         if (fclose(f))
 360                                 die_errno(_("could not finish '%s'"),
 361                                           filename);
 362                         free(filename);
 363                 }
 364                 return;
 365         }
 366
 367         /*
 368          * Otherwise? It's there, it's unreachable, and some other unreachable
 369          * object points to it. Ignore it - it's not interesting, and we showed
 370          * all the interesting cases above.
 371          */
 372 }
 373
 374 static void check_object(struct object *obj)
 375 {
 376         if (verbose)
 377                 fprintf_ln(stderr, _("Checking %s"), describe_object(obj));
 378
 379         if (obj->flags & REACHABLE)
 380                 check_reachable_object(obj);
 381         else
 382                 check_unreachable_object(obj);
 383 }
 384
 385 static void check_connectivity(void)
 386 {
 387         int i, max;
 388
 389         /* Traverse the pending reachable objects */
 390         traverse_reachable();
 391
 392         /*
 393          * With --connectivity-only, we won't have actually opened and marked
 394          * unreachable objects with USED. Do that now to make --dangling, etc
 395          * accurate.
 396          */
 397         if (connectivity_only && (show_dangling || write_lost_and_found)) {
 398                 /*
 399                  * Even though we already have a "struct object" for each of
 400                  * these in memory, we must not iterate over the internal
 401                  * object hash as we do below. Our loop would potentially
 402                  * resize the hash, making our iteration invalid.
 403                  *
 404                  * Instead, we'll just go back to the source list of objects,
 405                  * and ignore any that weren't present in our earlier
 406                  * traversal.
 407                  */
 408                 for_each_loose_object(mark_loose_unreachable_referents, NULL, 0);
 409                 for_each_packed_object(mark_packed_unreachable_referents, NULL, 0);
 410         }
 411
 412         /* Look up all the requirements, warn about missing objects.. */
 413         max = get_max_object_index();
 414         if (verbose)
 415                 fprintf_ln(stderr, _("Checking connectivity (%d objects)"), max);
 416
 417         for (i = 0; i < max; i++) {
 418                 struct object *obj = get_indexed_object(i);
 419
 420                 if (obj)
 421                         check_object(obj);
 422         }
 423 }
 424
 425 static int fsck_obj(struct object *obj, void *buffer, unsigned long size)
 426 {
 427         int err;
 428
 429         if (obj->flags & SEEN)
 430                 return 0;
 431         obj->flags |= SEEN;
 432
 433         if (verbose)
 434                 fprintf_ln(stderr, _("Checking %s %s"),
 435                            printable_type(obj), describe_object(obj));
 436
 437         if (fsck_walk(obj, NULL, &fsck_obj_options))
 438                 objerror(obj, _("broken links"));
 439         err = fsck_object(obj, buffer, size, &fsck_obj_options);
 440         if (err)
 441                 goto out;
 442
 443         if (obj->type == OBJ_COMMIT) {
 444                 struct commit *commit = (struct commit *) obj;
 445
 446                 if (!commit->parents && show_root)
 447                         printf_ln(_("root %s"),
 448                                   describe_object(&commit->object));
 449         }
 450
 451         if (obj->type == OBJ_TAG) {
 452                 struct tag *tag = (struct tag *) obj;
 453
 454                 if (show_tags && tag->tagged) {
 455                         printf_ln(_("tagged %s %s (%s) in %s"),
 456                                   printable_type(tag->tagged),
 457                                   describe_object(tag->tagged),
 458                                   tag->tag,
 459                                   describe_object(&tag->object));
 460                 }
 461         }
 462
 463 out:
 464         if (obj->type == OBJ_TREE)
 465                 free_tree_buffer((struct tree *)obj);
 466         if (obj->type == OBJ_COMMIT)
 467                 free_commit_buffer(the_repository->parsed_objects,
 468                                    (struct commit *)obj);
 469         return err;
 470 }
 471
 472 static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
 473                            unsigned long size, void *buffer, int *eaten)
 474 {
 475         /*
 476          * Note, buffer may be NULL if type is OBJ_BLOB. See
 477          * verify_packfile(), data_valid variable for details.
 478          */
 479         struct object *obj;
 480         obj = parse_object_buffer(the_repository, oid, type, size, buffer,
 481                                   eaten);
 482         if (!obj) {
 483                 errors_found |= ERROR_OBJECT;
 484                 return error(_("%s: object corrupt or missing"),
 485                              oid_to_hex(oid));
 486         }
 487         obj->flags &= ~(REACHABLE | SEEN);
 488         obj->flags |= HAS_OBJ;
 489         return fsck_obj(obj, buffer, size);
 490 }
 491
 492 static int default_refs;
 493
 494 static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
 495         timestamp_t timestamp)
 496 {
 497         struct object *obj;
 498
 499         if (!is_null_oid(oid)) {
 500                 obj = lookup_object(the_repository, oid);
 501                 if (obj && (obj->flags & HAS_OBJ)) {
 502                         if (timestamp && name_objects)
 503                                 add_decoration(fsck_walk_options.object_names,
 504                                         obj,
 505                                         xstrfmt("%s@{%"PRItime"}", refname, timestamp));
 506                         obj->flags |= USED;
 507                         mark_object_reachable(obj);
 508                 } else if (!is_promisor_object(oid)) {
 509                         error(_("%s: invalid reflog entry %s"),
 510                               refname, oid_to_hex(oid));
 511                         errors_found |= ERROR_REACHABLE;
 512                 }
 513         }
 514 }
 515
 516 static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
 517                 const char *email, timestamp_t timestamp, int tz,
 518                 const char *message, void *cb_data)
 519 {
 520         const char *refname = cb_data;
 521
 522         if (verbose)
 523                 fprintf_ln(stderr, _("Checking reflog %s->%s"),
 524                            oid_to_hex(ooid), oid_to_hex(noid));
 525
 526         fsck_handle_reflog_oid(refname, ooid, 0);
 527         fsck_handle_reflog_oid(refname, noid, timestamp);
 528         return 0;
 529 }
 530
 531 static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
 532                               int flag, void *cb_data)
 533 {
 534         struct strbuf refname = STRBUF_INIT;
 535
 536         strbuf_worktree_ref(cb_data, &refname, logname);
 537         for_each_reflog_ent(refname.buf, fsck_handle_reflog_ent, refname.buf);
 538         strbuf_release(&refname);
 539         return 0;
 540 }
 541
 542 static int fsck_handle_ref(const char *refname, const struct object_id *oid,
 543                            int flag, void *cb_data)
 544 {
 545         struct object *obj;
 546
 547         obj = parse_object(the_repository, oid);
 548         if (!obj) {
 549                 if (is_promisor_object(oid)) {
 550                         /*
 551                          * Increment default_refs anyway, because this is a
 552                          * valid ref.
 553                          */
 554                          default_refs++;
 555                          return 0;
 556                 }
 557                 error(_("%s: invalid sha1 pointer %s"),
 558                       refname, oid_to_hex(oid));
 559                 errors_found |= ERROR_REACHABLE;
 560                 /* We'll continue with the rest despite the error.. */
 561                 return 0;
 562         }
 563         if (obj->type != OBJ_COMMIT && is_branch(refname)) {
 564                 error(_("%s: not a commit"), refname);
 565                 errors_found |= ERROR_REFS;
 566         }
 567         default_refs++;
 568         obj->flags |= USED;
 569         if (name_objects)
 570                 add_decoration(fsck_walk_options.object_names,
 571                         obj, xstrdup(refname));
 572         mark_object_reachable(obj);
 573
 574         return 0;
 575 }
 576
 577 static int fsck_head_link(const char *head_ref_name,
 578                           const char **head_points_at,
 579                           struct object_id *head_oid);
 580
 581 static void get_default_heads(void)
 582 {
 583         struct worktree **worktrees, **p;
 584         const char *head_points_at;
 585         struct object_id head_oid;
 586
 587         for_each_rawref(fsck_handle_ref, NULL);
 588
 589         worktrees = get_worktrees(0);
 590         for (p = worktrees; *p; p++) {
 591                 struct worktree *wt = *p;
 592                 struct strbuf ref = STRBUF_INIT;
 593
 594                 strbuf_worktree_ref(wt, &ref, "HEAD");
 595                 fsck_head_link(ref.buf, &head_points_at, &head_oid);
 596                 if (head_points_at && !is_null_oid(&head_oid))
 597                         fsck_handle_ref(ref.buf, &head_oid, 0, NULL);
 598                 strbuf_release(&ref);
 599
 600                 if (include_reflogs)
 601                         refs_for_each_reflog(get_worktree_ref_store(wt),
 602                                              fsck_handle_reflog, wt);
 603         }
 604         free_worktrees(worktrees);
 605
 606         /*
 607          * Not having any default heads isn't really fatal, but
 608          * it does mean that "--unreachable" no longer makes any
 609          * sense (since in this case everything will obviously
 610          * be unreachable by definition.
 611          *
 612          * Showing dangling objects is valid, though (as those
 613          * dangling objects are likely lost heads).
 614          *
 615          * So we just print a warning about it, and clear the
 616          * "show_unreachable" flag.
 617          */
 618         if (!default_refs) {
 619                 fprintf_ln(stderr, _("notice: No default references"));
 620                 show_unreachable = 0;
 621         }
 622 }
 623
 624 static int fsck_loose(const struct object_id *oid, const char *path, void *data)
 625 {
 626         struct object *obj;
 627         enum object_type type;
 628         unsigned long size;
 629         void *contents;
 630         int eaten;
 631
 632         if (read_loose_object(path, oid, &type, &size, &contents) < 0) {
 633                 errors_found |= ERROR_OBJECT;
 634                 error(_("%s: object corrupt or missing: %s"),
 635                       oid_to_hex(oid), path);
 636                 return 0; /* keep checking other objects */
 637         }
 638
 639         if (!contents && type != OBJ_BLOB)
 640                 BUG("read_loose_object streamed a non-blob");
 641
 642         obj = parse_object_buffer(the_repository, oid, type, size,
 643                                   contents, &eaten);
 644
 645         if (!obj) {
 646                 errors_found |= ERROR_OBJECT;
 647                 error(_("%s: object could not be parsed: %s"),
 648                       oid_to_hex(oid), path);
 649                 if (!eaten)
 650                         free(contents);
 651                 return 0; /* keep checking other objects */
 652         }
 653
 654         obj->flags &= ~(REACHABLE | SEEN);
 655         obj->flags |= HAS_OBJ;
 656         if (fsck_obj(obj, contents, size))
 657                 errors_found |= ERROR_OBJECT;
 658
 659         if (!eaten)
 660                 free(contents);
 661         return 0; /* keep checking other objects, even if we saw an error */
 662 }
 663
 664 static int fsck_cruft(const char *basename, const char *path, void *data)
 665 {
 666         if (!starts_with(basename, "tmp_obj_"))
 667                 fprintf_ln(stderr, _("bad sha1 file: %s"), path);
 668         return 0;
 669 }
 670
 671 static int fsck_subdir(unsigned int nr, const char *path, void *progress)
 672 {
 673         display_progress(progress, nr + 1);
 674         return 0;
 675 }
 676
 677 static void fsck_object_dir(const char *path)
 678 {
 679         struct progress *progress = NULL;
 680
 681         if (verbose)
 682                 fprintf_ln(stderr, _("Checking object directory"));
 683
 684         if (show_progress)
 685                 progress = start_progress(_("Checking object directories"), 256);
 686
 687         for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
 688                                       progress);
 689         display_progress(progress, 256);
 690         stop_progress(&progress);
 691 }
 692
 693 static int fsck_head_link(const char *head_ref_name,
 694                           const char **head_points_at,
 695                           struct object_id *head_oid)
 696 {
 697         int null_is_error = 0;
 698
 699         if (verbose)
 700                 fprintf_ln(stderr, _("Checking %s link"), head_ref_name);
 701
 702         *head_points_at = resolve_ref_unsafe(head_ref_name, 0, head_oid, NULL);
 703         if (!*head_points_at) {
 704                 errors_found |= ERROR_REFS;
 705                 return error(_("invalid %s"), head_ref_name);
 706         }
 707         if (!strcmp(*head_points_at, head_ref_name))
 708                 /* detached HEAD */
 709                 null_is_error = 1;
 710         else if (!starts_with(*head_points_at, "refs/heads/")) {
 711                 errors_found |= ERROR_REFS;
 712                 return error(_("%s points to something strange (%s)"),
 713                              head_ref_name, *head_points_at);
 714         }
 715         if (is_null_oid(head_oid)) {
 716                 if (null_is_error) {
 717                         errors_found |= ERROR_REFS;
 718                         return error(_("%s: detached HEAD points at nothing"),
 719                                      head_ref_name);
 720                 }
 721                 fprintf_ln(stderr,
 722                            _("notice: %s points to an unborn branch (%s)"),
 723                            head_ref_name, *head_points_at + 11);
 724         }
 725         return 0;
 726 }
 727
 728 static int fsck_cache_tree(struct cache_tree *it)
 729 {
 730         int i;
 731         int err = 0;
 732
 733         if (verbose)
 734                 fprintf_ln(stderr, _("Checking cache tree"));
 735
 736         if (0 <= it->entry_count) {
 737                 struct object *obj = parse_object(the_repository, &it->oid);
 738                 if (!obj) {
 739                         error(_("%s: invalid sha1 pointer in cache-tree"),
 740                               oid_to_hex(&it->oid));
 741                         errors_found |= ERROR_REFS;
 742                         return 1;
 743                 }
 744                 obj->flags |= USED;
 745                 if (name_objects)
 746                         add_decoration(fsck_walk_options.object_names,
 747                                 obj, xstrdup(":"));
 748                 mark_object_reachable(obj);
 749                 if (obj->type != OBJ_TREE)
 750                         err |= objerror(obj, _("non-tree in cache-tree"));
 751         }
 752         for (i = 0; i < it->subtree_nr; i++)
 753                 err |= fsck_cache_tree(it->down[i]->cache_tree);
 754         return err;
 755 }
 756
 757 static void mark_object_for_connectivity(const struct object_id *oid)
 758 {
 759         struct object *obj = lookup_unknown_object(oid);
 760         obj->flags |= HAS_OBJ;
 761 }
 762
 763 static int mark_loose_for_connectivity(const struct object_id *oid,
 764                                        const char *path,
 765                                        void *data)
 766 {
 767         mark_object_for_connectivity(oid);
 768         return 0;
 769 }
 770
 771 static int mark_packed_for_connectivity(const struct object_id *oid,
 772                                         struct packed_git *pack,
 773                                         uint32_t pos,
 774                                         void *data)
 775 {
 776         mark_object_for_connectivity(oid);
 777         return 0;
 778 }
 779
 780 static char const * const fsck_usage[] = {
 781         N_("git fsck [<options>] [<object>...]"),
 782         NULL
 783 };
 784
 785 static struct option fsck_opts[] = {
 786         OPT__VERBOSE(&verbose, N_("be verbose")),
 787         OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
 788         OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
 789         OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
 790         OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
 791         OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
 792         OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
 793         OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
 794         OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
 795         OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
 796         OPT_BOOL(0, "lost-found", &write_lost_and_found,
 797                                 N_("write dangling objects in .git/lost-found")),
 798         OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
 799         OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
 800         OPT_END(),
 801 };
 802
 803 int cmd_fsck(int argc, const char **argv, const char *prefix)
 804 {
 805         int i;
 806         struct object_directory *odb;
 807
 808         /* fsck knows how to handle missing promisor objects */
 809         fetch_if_missing = 0;
 810
 811         errors_found = 0;
 812         read_replace_refs = 0;
 813
 814         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
 815
 816         fsck_walk_options.walk = mark_object;
 817         fsck_obj_options.walk = mark_used;
 818         fsck_obj_options.error_func = fsck_error_func;
 819         if (check_strict)
 820                 fsck_obj_options.strict = 1;
 821
 822         if (show_progress == -1)
 823                 show_progress = isatty(2);
 824         if (verbose)
 825                 show_progress = 0;
 826
 827         if (write_lost_and_found) {
 828                 check_full = 1;
 829                 include_reflogs = 0;
 830         }
 831
 832         if (name_objects)
 833                 fsck_walk_options.object_names =
 834                         xcalloc(1, sizeof(struct decoration));
 835
 836         git_config(fsck_config, NULL);
 837
 838         if (connectivity_only) {
 839                 for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
 840                 for_each_packed_object(mark_packed_for_connectivity, NULL, 0);
 841         } else {
 842                 prepare_alt_odb(the_repository);
 843                 for (odb = the_repository->objects->odb; odb; odb = odb->next)
 844                         fsck_object_dir(odb->path);
 845
 846                 if (check_full) {
 847                         struct packed_git *p;
 848                         uint32_t total = 0, count = 0;
 849                         struct progress *progress = NULL;
 850
 851                         if (show_progress) {
 852                                 for (p = get_all_packs(the_repository); p;
 853                                      p = p->next) {
 854                                         if (open_pack_index(p))
 855                                                 continue;
 856                                         total += p->num_objects;
 857                                 }
 858
 859                                 progress = start_progress(_("Checking objects"), total);
 860                         }
 861                         for (p = get_all_packs(the_repository); p;
 862                              p = p->next) {
 863                                 /* verify gives error messages itself */
 864                                 if (verify_pack(the_repository,
 865                                                 p, fsck_obj_buffer,
 866                                                 progress, count))
 867                                         errors_found |= ERROR_PACK;
 868                                 count += p->num_objects;
 869                         }
 870                         stop_progress(&progress);
 871                 }
 872
 873                 if (fsck_finish(&fsck_obj_options))
 874                         errors_found |= ERROR_OBJECT;
 875         }
 876
 877         for (i = 0; i < argc; i++) {
 878                 const char *arg = argv[i];
 879                 struct object_id oid;
 880                 if (!get_oid(arg, &oid)) {
 881                         struct object *obj = lookup_object(the_repository,
 882                                                            &oid);
 883
 884                         if (!obj || !(obj->flags & HAS_OBJ)) {
 885                                 if (is_promisor_object(&oid))
 886                                         continue;
 887                                 error(_("%s: object missing"), oid_to_hex(&oid));
 888                                 errors_found |= ERROR_OBJECT;
 889                                 continue;
 890                         }
 891
 892                         obj->flags |= USED;
 893                         if (name_objects)
 894                                 add_decoration(fsck_walk_options.object_names,
 895                                         obj, xstrdup(arg));
 896                         mark_object_reachable(obj);
 897                         continue;
 898                 }
 899                 error(_("invalid parameter: expected sha1, got '%s'"), arg);
 900                 errors_found |= ERROR_OBJECT;
 901         }
 902
 903         /*
 904          * If we've not been given any explicit head information, do the
 905          * default ones from .git/refs. We also consider the index file
 906          * in this case (ie this implies --cache).
 907          */
 908         if (!argc) {
 909                 get_default_heads();
 910                 keep_cache_objects = 1;
 911         }
 912
 913         if (keep_cache_objects) {
 914                 verify_index_checksum = 1;
 915                 verify_ce_order = 1;
 916                 read_cache();
 917                 for (i = 0; i < active_nr; i++) {
 918                         unsigned int mode;
 919                         struct blob *blob;
 920                         struct object *obj;
 921
 922                         mode = active_cache[i]->ce_mode;
 923                         if (S_ISGITLINK(mode))
 924                                 continue;
 925                         blob = lookup_blob(the_repository,
 926                                            &active_cache[i]->oid);
 927                         if (!blob)
 928                                 continue;
 929                         obj = &blob->object;
 930                         obj->flags |= USED;
 931                         if (name_objects)
 932                                 add_decoration(fsck_walk_options.object_names,
 933                                         obj,
 934                                         xstrfmt(":%s", active_cache[i]->name));
 935                         mark_object_reachable(obj);
 936                 }
 937                 if (active_cache_tree)
 938                         fsck_cache_tree(active_cache_tree);
 939         }
 940
 941         check_connectivity();
 942
 943         if (!git_config_get_bool("core.commitgraph", &i) && i) {
 944                 struct child_process commit_graph_verify = CHILD_PROCESS_INIT;
 945                 const char *verify_argv[] = { "commit-graph", "verify", NULL, NULL, NULL };
 946
 947                 prepare_alt_odb(the_repository);
 948                 for (odb = the_repository->objects->odb; odb; odb = odb->next) {
 949                         child_process_init(&commit_graph_verify);
 950                         commit_graph_verify.argv = verify_argv;
 951                         commit_graph_verify.git_cmd = 1;
 952                         verify_argv[2] = "--object-dir";
 953                         verify_argv[3] = odb->path;
 954                         if (run_command(&commit_graph_verify))
 955                                 errors_found |= ERROR_COMMIT_GRAPH;
 956                 }
 957         }
 958
 959         if (!git_config_get_bool("core.multipackindex", &i) && i) {
 960                 struct child_process midx_verify = CHILD_PROCESS_INIT;
 961                 const char *midx_argv[] = { "multi-pack-index", "verify", NULL, NULL, NULL };
 962
 963                 prepare_alt_odb(the_repository);
 964                 for (odb = the_repository->objects->odb; odb; odb = odb->next) {
 965                         child_process_init(&midx_verify);
 966                         midx_verify.argv = midx_argv;
 967                         midx_verify.git_cmd = 1;
 968                         midx_argv[2] = "--object-dir";
 969                         midx_argv[3] = odb->path;
 970                         if (run_command(&midx_verify))
 971                                 errors_found |= ERROR_COMMIT_GRAPH;
 972                 }
 973         }
 974
 975         return errors_found;
 976 }