6c9d59885309fc252c5f454a5586c7633adcb603
   1#include "builtin.h"
   2#include "cache.h"
   3#include "commit.h"
   4#include "tree.h"
   5#include "blob.h"
   6#include "tag.h"
   7#include "refs.h"
   8#include "pack.h"
   9#include "cache-tree.h"
  10#include "tree-walk.h"
  11#include "fsck.h"
  12#include "parse-options.h"
  13#include "dir.h"
  14#include "progress.h"
  15#include "streaming.h"
  16
  17#define REACHABLE 0x0001
  18#define SEEN      0x0002
  19#define HAS_OBJ   0x0004
  20
  21static int show_root;
  22static int show_tags;
  23static int show_unreachable;
  24static int include_reflogs = 1;
  25static int check_full = 1;
  26static int connectivity_only;
  27static int check_strict;
  28static int keep_cache_objects;
  29static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
  30static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
  31static struct object_id head_oid;
  32static const char *head_points_at;
  33static int errors_found;
  34static int write_lost_and_found;
  35static int verbose;
  36static int show_progress = -1;
  37static int show_dangling = 1;
  38#define ERROR_OBJECT 01
  39#define ERROR_REACHABLE 02
  40#define ERROR_PACK 04
  41#define ERROR_REFS 010
  42
  43static const char *describe_object(struct object *obj)
  44{
  45        return oid_to_hex(&obj->oid);
  46}
  47
  48static int fsck_config(const char *var, const char *value, void *cb)
  49{
  50        if (strcmp(var, "fsck.skiplist") == 0) {
  51                const char *path;
  52                struct strbuf sb = STRBUF_INIT;
  53
  54                if (git_config_pathname(&path, var, value))
  55                        return 1;
  56                strbuf_addf(&sb, "skiplist=%s", path);
  57                free((char *)path);
  58                fsck_set_msg_types(&fsck_obj_options, sb.buf);
  59                strbuf_release(&sb);
  60                return 0;
  61        }
  62
  63        if (skip_prefix(var, "fsck.", &var)) {
  64                fsck_set_msg_type(&fsck_obj_options, var, value);
  65                return 0;
  66        }
  67
  68        return git_default_config(var, value, cb);
  69}
  70
  71static void objreport(struct object *obj, const char *msg_type,
  72                        const char *err)
  73{
  74        fprintf(stderr, "%s in %s %s: %s\n",
  75                msg_type, typename(obj->type), describe_object(obj), err);
  76}
  77
  78static int objerror(struct object *obj, const char *err)
  79{
  80        errors_found |= ERROR_OBJECT;
  81        objreport(obj, "error", err);
  82        return -1;
  83}
  84
  85static int fsck_error_func(struct fsck_options *o,
  86        struct object *obj, int type, const char *message)
  87{
  88        objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
  89        return (type == FSCK_WARN) ? 0 : 1;
  90}
  91
  92static struct object_array pending;
  93
  94static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
  95{
  96        struct object *parent = data;
  97
  98        /*
  99         * The only case data is NULL or type is OBJ_ANY is when
 100         * mark_object_reachable() calls us.  All the callers of
 101         * that function has non-NULL obj hence ...
 102         */
 103        if (!obj) {
 104                /* ... these references to parent->fld are safe here */
 105                printf("broken link from %7s %s\n",
 106                           typename(parent->type), describe_object(parent));
 107                printf("broken link from %7s %s\n",
 108                           (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
 109                errors_found |= ERROR_REACHABLE;
 110                return 1;
 111        }
 112
 113        if (type != OBJ_ANY && obj->type != type)
 114                /* ... and the reference to parent is safe here */
 115                objerror(parent, "wrong object type in link");
 116
 117        if (obj->flags & REACHABLE)
 118                return 0;
 119        obj->flags |= REACHABLE;
 120        if (!(obj->flags & HAS_OBJ)) {
 121                if (parent && !has_object_file(&obj->oid)) {
 122                        printf("broken link from %7s %s\n",
 123                                 typename(parent->type), describe_object(parent));
 124                        printf("              to %7s %s\n",
 125                                 typename(obj->type), describe_object(obj));
 126                        errors_found |= ERROR_REACHABLE;
 127                }
 128                return 1;
 129        }
 130
 131        add_object_array(obj, NULL, &pending);
 132        return 0;
 133}
 134
 135static void mark_object_reachable(struct object *obj)
 136{
 137        mark_object(obj, OBJ_ANY, NULL, NULL);
 138}
 139
 140static int traverse_one_object(struct object *obj)
 141{
 142        int result;
 143        struct tree *tree = NULL;
 144
 145        if (obj->type == OBJ_TREE) {
 146                tree = (struct tree *)obj;
 147                if (parse_tree(tree) < 0)
 148                        return 1; /* error already displayed */
 149        }
 150        result = fsck_walk(obj, obj, &fsck_walk_options);
 151        if (tree)
 152                free_tree_buffer(tree);
 153        return result;
 154}
 155
 156static int traverse_reachable(void)
 157{
 158        struct progress *progress = NULL;
 159        unsigned int nr = 0;
 160        int result = 0;
 161        if (show_progress)
 162                progress = start_progress_delay(_("Checking connectivity"), 0, 0, 2);
 163        while (pending.nr) {
 164                struct object_array_entry *entry;
 165                struct object *obj;
 166
 167                entry = pending.objects + --pending.nr;
 168                obj = entry->item;
 169                result |= traverse_one_object(obj);
 170                display_progress(progress, ++nr);
 171        }
 172        stop_progress(&progress);
 173        return !!result;
 174}
 175
 176static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
 177{
 178        if (!obj)
 179                return 1;
 180        obj->used = 1;
 181        return 0;
 182}
 183
 184/*
 185 * Check a single reachable object
 186 */
 187static void check_reachable_object(struct object *obj)
 188{
 189        /*
 190         * We obviously want the object to be parsed,
 191         * except if it was in a pack-file and we didn't
 192         * do a full fsck
 193         */
 194        if (!(obj->flags & HAS_OBJ)) {
 195                if (has_sha1_pack(obj->oid.hash))
 196                        return; /* it is in pack - forget about it */
 197                if (connectivity_only && has_object_file(&obj->oid))
 198                        return;
 199                printf("missing %s %s\n", typename(obj->type),
 200                        describe_object(obj));
 201                errors_found |= ERROR_REACHABLE;
 202                return;
 203        }
 204}
 205
 206/*
 207 * Check a single unreachable object
 208 */
 209static void check_unreachable_object(struct object *obj)
 210{
 211        /*
 212         * Missing unreachable object? Ignore it. It's not like
 213         * we miss it (since it can't be reached), nor do we want
 214         * to complain about it being unreachable (since it does
 215         * not exist).
 216         */
 217        if (!obj->parsed)
 218                return;
 219
 220        /*
 221         * Unreachable object that exists? Show it if asked to,
 222         * since this is something that is prunable.
 223         */
 224        if (show_unreachable) {
 225                printf("unreachable %s %s\n", typename(obj->type),
 226                        describe_object(obj));
 227                return;
 228        }
 229
 230        /*
 231         * "!used" means that nothing at all points to it, including
 232         * other unreachable objects. In other words, it's the "tip"
 233         * of some set of unreachable objects, usually a commit that
 234         * got dropped.
 235         *
 236         * Such starting points are more interesting than some random
 237         * set of unreachable objects, so we show them even if the user
 238         * hasn't asked for _all_ unreachable objects. If you have
 239         * deleted a branch by mistake, this is a prime candidate to
 240         * start looking at, for example.
 241         */
 242        if (!obj->used) {
 243                if (show_dangling)
 244                        printf("dangling %s %s\n", typename(obj->type),
 245                               describe_object(obj));
 246                if (write_lost_and_found) {
 247                        char *filename = git_pathdup("lost-found/%s/%s",
 248                                obj->type == OBJ_COMMIT ? "commit" : "other",
 249                                describe_object(obj));
 250                        FILE *f;
 251
 252                        if (safe_create_leading_directories_const(filename)) {
 253                                error("Could not create lost-found");
 254                                free(filename);
 255                                return;
 256                        }
 257                        if (!(f = fopen(filename, "w")))
 258                                die_errno("Could not open '%s'", filename);
 259                        if (obj->type == OBJ_BLOB) {
 260                                if (stream_blob_to_fd(fileno(f), obj->oid.hash, NULL, 1))
 261                                        die_errno("Could not write '%s'", filename);
 262                        } else
 263                                fprintf(f, "%s\n", describe_object(obj));
 264                        if (fclose(f))
 265                                die_errno("Could not finish '%s'",
 266                                          filename);
 267                        free(filename);
 268                }
 269                return;
 270        }
 271
 272        /*
 273         * Otherwise? It's there, it's unreachable, and some other unreachable
 274         * object points to it. Ignore it - it's not interesting, and we showed
 275         * all the interesting cases above.
 276         */
 277}
 278
 279static void check_object(struct object *obj)
 280{
 281        if (verbose)
 282                fprintf(stderr, "Checking %s\n", describe_object(obj));
 283
 284        if (obj->flags & REACHABLE)
 285                check_reachable_object(obj);
 286        else
 287                check_unreachable_object(obj);
 288}
 289
 290static void check_connectivity(void)
 291{
 292        int i, max;
 293
 294        /* Traverse the pending reachable objects */
 295        traverse_reachable();
 296
 297        /* Look up all the requirements, warn about missing objects.. */
 298        max = get_max_object_index();
 299        if (verbose)
 300                fprintf(stderr, "Checking connectivity (%d objects)\n", max);
 301
 302        for (i = 0; i < max; i++) {
 303                struct object *obj = get_indexed_object(i);
 304
 305                if (obj)
 306                        check_object(obj);
 307        }
 308}
 309
 310static int fsck_obj(struct object *obj)
 311{
 312        if (obj->flags & SEEN)
 313                return 0;
 314        obj->flags |= SEEN;
 315
 316        if (verbose)
 317                fprintf(stderr, "Checking %s %s\n",
 318                        typename(obj->type), describe_object(obj));
 319
 320        if (fsck_walk(obj, NULL, &fsck_obj_options))
 321                objerror(obj, "broken links");
 322        if (fsck_object(obj, NULL, 0, &fsck_obj_options))
 323                return -1;
 324
 325        if (obj->type == OBJ_TREE) {
 326                struct tree *item = (struct tree *) obj;
 327
 328                free_tree_buffer(item);
 329        }
 330
 331        if (obj->type == OBJ_COMMIT) {
 332                struct commit *commit = (struct commit *) obj;
 333
 334                free_commit_buffer(commit);
 335
 336                if (!commit->parents && show_root)
 337                        printf("root %s\n", describe_object(&commit->object));
 338        }
 339
 340        if (obj->type == OBJ_TAG) {
 341                struct tag *tag = (struct tag *) obj;
 342
 343                if (show_tags && tag->tagged) {
 344                        printf("tagged %s %s", typename(tag->tagged->type),
 345                                describe_object(tag->tagged));
 346                        printf(" (%s) in %s\n", tag->tag,
 347                                describe_object(&tag->object));
 348                }
 349        }
 350
 351        return 0;
 352}
 353
 354static int fsck_sha1(const unsigned char *sha1)
 355{
 356        struct object *obj = parse_object(sha1);
 357        if (!obj) {
 358                errors_found |= ERROR_OBJECT;
 359                return error("%s: object corrupt or missing",
 360                             sha1_to_hex(sha1));
 361        }
 362        obj->flags |= HAS_OBJ;
 363        return fsck_obj(obj);
 364}
 365
 366static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
 367                           unsigned long size, void *buffer, int *eaten)
 368{
 369        struct object *obj;
 370        obj = parse_object_buffer(sha1, type, size, buffer, eaten);
 371        if (!obj) {
 372                errors_found |= ERROR_OBJECT;
 373                return error("%s: object corrupt or missing", sha1_to_hex(sha1));
 374        }
 375        obj->flags = HAS_OBJ;
 376        return fsck_obj(obj);
 377}
 378
 379static int default_refs;
 380
 381static void fsck_handle_reflog_sha1(const char *refname, unsigned char *sha1)
 382{
 383        struct object *obj;
 384
 385        if (!is_null_sha1(sha1)) {
 386                obj = lookup_object(sha1);
 387                if (obj) {
 388                        obj->used = 1;
 389                        mark_object_reachable(obj);
 390                } else {
 391                        error("%s: invalid reflog entry %s", refname, sha1_to_hex(sha1));
 392                        errors_found |= ERROR_REACHABLE;
 393                }
 394        }
 395}
 396
 397static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 398                const char *email, unsigned long timestamp, int tz,
 399                const char *message, void *cb_data)
 400{
 401        const char *refname = cb_data;
 402
 403        if (verbose)
 404                fprintf(stderr, "Checking reflog %s->%s\n",
 405                        sha1_to_hex(osha1), sha1_to_hex(nsha1));
 406
 407        fsck_handle_reflog_sha1(refname, osha1);
 408        fsck_handle_reflog_sha1(refname, nsha1);
 409        return 0;
 410}
 411
 412static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
 413                              int flag, void *cb_data)
 414{
 415        for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
 416        return 0;
 417}
 418
 419static int fsck_handle_ref(const char *refname, const struct object_id *oid,
 420                           int flag, void *cb_data)
 421{
 422        struct object *obj;
 423
 424        obj = parse_object(oid->hash);
 425        if (!obj) {
 426                error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
 427                errors_found |= ERROR_REACHABLE;
 428                /* We'll continue with the rest despite the error.. */
 429                return 0;
 430        }
 431        if (obj->type != OBJ_COMMIT && is_branch(refname)) {
 432                error("%s: not a commit", refname);
 433                errors_found |= ERROR_REFS;
 434        }
 435        default_refs++;
 436        obj->used = 1;
 437        mark_object_reachable(obj);
 438
 439        return 0;
 440}
 441
 442static void get_default_heads(void)
 443{
 444        if (head_points_at && !is_null_oid(&head_oid))
 445                fsck_handle_ref("HEAD", &head_oid, 0, NULL);
 446        for_each_rawref(fsck_handle_ref, NULL);
 447        if (include_reflogs)
 448                for_each_reflog(fsck_handle_reflog, NULL);
 449
 450        /*
 451         * Not having any default heads isn't really fatal, but
 452         * it does mean that "--unreachable" no longer makes any
 453         * sense (since in this case everything will obviously
 454         * be unreachable by definition.
 455         *
 456         * Showing dangling objects is valid, though (as those
 457         * dangling objects are likely lost heads).
 458         *
 459         * So we just print a warning about it, and clear the
 460         * "show_unreachable" flag.
 461         */
 462        if (!default_refs) {
 463                fprintf(stderr, "notice: No default references\n");
 464                show_unreachable = 0;
 465        }
 466}
 467
 468static int fsck_loose(const unsigned char *sha1, const char *path, void *data)
 469{
 470        if (fsck_sha1(sha1))
 471                errors_found |= ERROR_OBJECT;
 472        return 0;
 473}
 474
 475static int fsck_cruft(const char *basename, const char *path, void *data)
 476{
 477        if (!starts_with(basename, "tmp_obj_"))
 478                fprintf(stderr, "bad sha1 file: %s\n", path);
 479        return 0;
 480}
 481
 482static int fsck_subdir(int nr, const char *path, void *progress)
 483{
 484        display_progress(progress, nr + 1);
 485        return 0;
 486}
 487
 488static void fsck_object_dir(const char *path)
 489{
 490        struct progress *progress = NULL;
 491
 492        if (verbose)
 493                fprintf(stderr, "Checking object directory\n");
 494
 495        if (show_progress)
 496                progress = start_progress(_("Checking object directories"), 256);
 497
 498        for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
 499                                      progress);
 500        display_progress(progress, 256);
 501        stop_progress(&progress);
 502}
 503
 504static int fsck_head_link(void)
 505{
 506        int null_is_error = 0;
 507
 508        if (verbose)
 509                fprintf(stderr, "Checking HEAD link\n");
 510
 511        head_points_at = resolve_ref_unsafe("HEAD", 0, head_oid.hash, NULL);
 512        if (!head_points_at) {
 513                errors_found |= ERROR_REFS;
 514                return error("Invalid HEAD");
 515        }
 516        if (!strcmp(head_points_at, "HEAD"))
 517                /* detached HEAD */
 518                null_is_error = 1;
 519        else if (!starts_with(head_points_at, "refs/heads/")) {
 520                errors_found |= ERROR_REFS;
 521                return error("HEAD points to something strange (%s)",
 522                             head_points_at);
 523        }
 524        if (is_null_oid(&head_oid)) {
 525                if (null_is_error) {
 526                        errors_found |= ERROR_REFS;
 527                        return error("HEAD: detached HEAD points at nothing");
 528                }
 529                fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
 530                        head_points_at + 11);
 531        }
 532        return 0;
 533}
 534
 535static int fsck_cache_tree(struct cache_tree *it)
 536{
 537        int i;
 538        int err = 0;
 539
 540        if (verbose)
 541                fprintf(stderr, "Checking cache tree\n");
 542
 543        if (0 <= it->entry_count) {
 544                struct object *obj = parse_object(it->sha1);
 545                if (!obj) {
 546                        error("%s: invalid sha1 pointer in cache-tree",
 547                              sha1_to_hex(it->sha1));
 548                        errors_found |= ERROR_REFS;
 549                        return 1;
 550                }
 551                obj->used = 1;
 552                mark_object_reachable(obj);
 553                if (obj->type != OBJ_TREE)
 554                        err |= objerror(obj, "non-tree in cache-tree");
 555        }
 556        for (i = 0; i < it->subtree_nr; i++)
 557                err |= fsck_cache_tree(it->down[i]->cache_tree);
 558        return err;
 559}
 560
 561static char const * const fsck_usage[] = {
 562        N_("git fsck [<options>] [<object>...]"),
 563        NULL
 564};
 565
 566static struct option fsck_opts[] = {
 567        OPT__VERBOSE(&verbose, N_("be verbose")),
 568        OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
 569        OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
 570        OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
 571        OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
 572        OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
 573        OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
 574        OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
 575        OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
 576        OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
 577        OPT_BOOL(0, "lost-found", &write_lost_and_found,
 578                                N_("write dangling objects in .git/lost-found")),
 579        OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
 580        OPT_END(),
 581};
 582
 583int cmd_fsck(int argc, const char **argv, const char *prefix)
 584{
 585        int i, heads;
 586        struct alternate_object_database *alt;
 587
 588        errors_found = 0;
 589        check_replace_refs = 0;
 590
 591        argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
 592
 593        fsck_walk_options.walk = mark_object;
 594        fsck_obj_options.walk = mark_used;
 595        fsck_obj_options.error_func = fsck_error_func;
 596        if (check_strict)
 597                fsck_obj_options.strict = 1;
 598
 599        if (show_progress == -1)
 600                show_progress = isatty(2);
 601        if (verbose)
 602                show_progress = 0;
 603
 604        if (write_lost_and_found) {
 605                check_full = 1;
 606                include_reflogs = 0;
 607        }
 608
 609        git_config(fsck_config, NULL);
 610
 611        fsck_head_link();
 612        if (!connectivity_only) {
 613                fsck_object_dir(get_object_directory());
 614
 615                prepare_alt_odb();
 616                for (alt = alt_odb_list; alt; alt = alt->next) {
 617                        /* directory name, minus trailing slash */
 618                        size_t namelen = alt->name - alt->base - 1;
 619                        struct strbuf name = STRBUF_INIT;
 620                        strbuf_add(&name, alt->base, namelen);
 621                        fsck_object_dir(name.buf);
 622                        strbuf_release(&name);
 623                }
 624        }
 625
 626        if (check_full) {
 627                struct packed_git *p;
 628                uint32_t total = 0, count = 0;
 629                struct progress *progress = NULL;
 630
 631                prepare_packed_git();
 632
 633                if (show_progress) {
 634                        for (p = packed_git; p; p = p->next) {
 635                                if (open_pack_index(p))
 636                                        continue;
 637                                total += p->num_objects;
 638                        }
 639
 640                        progress = start_progress(_("Checking objects"), total);
 641                }
 642                for (p = packed_git; p; p = p->next) {
 643                        /* verify gives error messages itself */
 644                        if (verify_pack(p, fsck_obj_buffer,
 645                                        progress, count))
 646                                errors_found |= ERROR_PACK;
 647                        count += p->num_objects;
 648                }
 649                stop_progress(&progress);
 650        }
 651
 652        heads = 0;
 653        for (i = 0; i < argc; i++) {
 654                const char *arg = argv[i];
 655                unsigned char sha1[20];
 656                if (!get_sha1(arg, sha1)) {
 657                        struct object *obj = lookup_object(sha1);
 658
 659                        /* Error is printed by lookup_object(). */
 660                        if (!obj)
 661                                continue;
 662
 663                        obj->used = 1;
 664                        mark_object_reachable(obj);
 665                        heads++;
 666                        continue;
 667                }
 668                error("invalid parameter: expected sha1, got '%s'", arg);
 669        }
 670
 671        /*
 672         * If we've not been given any explicit head information, do the
 673         * default ones from .git/refs. We also consider the index file
 674         * in this case (ie this implies --cache).
 675         */
 676        if (!heads) {
 677                get_default_heads();
 678                keep_cache_objects = 1;
 679        }
 680
 681        if (keep_cache_objects) {
 682                read_cache();
 683                for (i = 0; i < active_nr; i++) {
 684                        unsigned int mode;
 685                        struct blob *blob;
 686                        struct object *obj;
 687
 688                        mode = active_cache[i]->ce_mode;
 689                        if (S_ISGITLINK(mode))
 690                                continue;
 691                        blob = lookup_blob(active_cache[i]->sha1);
 692                        if (!blob)
 693                                continue;
 694                        obj = &blob->object;
 695                        obj->used = 1;
 696                        mark_object_reachable(obj);
 697                }
 698                if (active_cache_tree)
 699                        fsck_cache_tree(active_cache_tree);
 700        }
 701
 702        check_connectivity();
 703        return errors_found;
 704}