builtin-fsck.con commit Merge branch 'maint-1.6.0' into maint-1.6.1 (8e4f767)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "commit.h"
   4#include "tree.h"
   5#include "blob.h"
   6#include "tag.h"
   7#include "refs.h"
   8#include "pack.h"
   9#include "cache-tree.h"
  10#include "tree-walk.h"
  11#include "fsck.h"
  12#include "parse-options.h"
  13
  14#define REACHABLE 0x0001
  15#define SEEN      0x0002
  16
  17static int show_root;
  18static int show_tags;
  19static int show_unreachable;
  20static int include_reflogs = 1;
  21static int check_full;
  22static int check_strict;
  23static int keep_cache_objects;
  24static unsigned char head_sha1[20];
  25static int errors_found;
  26static int write_lost_and_found;
  27static int verbose;
  28#define ERROR_OBJECT 01
  29#define ERROR_REACHABLE 02
  30
  31#ifdef NO_D_INO_IN_DIRENT
  32#define SORT_DIRENT 0
  33#define DIRENT_SORT_HINT(de) 0
  34#else
  35#define SORT_DIRENT 1
  36#define DIRENT_SORT_HINT(de) ((de)->d_ino)
  37#endif
  38
  39static void objreport(struct object *obj, const char *severity,
  40                      const char *err, va_list params)
  41{
  42        fprintf(stderr, "%s in %s %s: ",
  43                severity, typename(obj->type), sha1_to_hex(obj->sha1));
  44        vfprintf(stderr, err, params);
  45        fputs("\n", stderr);
  46}
  47
  48static int objerror(struct object *obj, const char *err, ...)
  49{
  50        va_list params;
  51        va_start(params, err);
  52        errors_found |= ERROR_OBJECT;
  53        objreport(obj, "error", err, params);
  54        va_end(params);
  55        return -1;
  56}
  57
  58static int fsck_error_func(struct object *obj, int type, const char *err, ...)
  59{
  60        va_list params;
  61        va_start(params, err);
  62        objreport(obj, (type == FSCK_WARN) ? "warning" : "error", err, params);
  63        va_end(params);
  64        return (type == FSCK_WARN) ? 0 : 1;
  65}
  66
  67static struct object_array pending;
  68
  69static int mark_object(struct object *obj, int type, void *data)
  70{
  71        struct object *parent = data;
  72
  73        if (!obj) {
  74                printf("broken link from %7s %s\n",
  75                           typename(parent->type), sha1_to_hex(parent->sha1));
  76                printf("broken link from %7s %s\n",
  77                           (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
  78                errors_found |= ERROR_REACHABLE;
  79                return 1;
  80        }
  81
  82        if (type != OBJ_ANY && obj->type != type)
  83                objerror(parent, "wrong object type in link");
  84
  85        if (obj->flags & REACHABLE)
  86                return 0;
  87        obj->flags |= REACHABLE;
  88        if (!obj->parsed) {
  89                if (parent && !has_sha1_file(obj->sha1)) {
  90                        printf("broken link from %7s %s\n",
  91                                 typename(parent->type), sha1_to_hex(parent->sha1));
  92                        printf("              to %7s %s\n",
  93                                 typename(obj->type), sha1_to_hex(obj->sha1));
  94                        errors_found |= ERROR_REACHABLE;
  95                }
  96                return 1;
  97        }
  98
  99        add_object_array(obj, (void *) parent, &pending);
 100        return 0;
 101}
 102
 103static void mark_object_reachable(struct object *obj)
 104{
 105        mark_object(obj, OBJ_ANY, 0);
 106}
 107
 108static int traverse_one_object(struct object *obj, struct object *parent)
 109{
 110        int result;
 111        struct tree *tree = NULL;
 112
 113        if (obj->type == OBJ_TREE) {
 114                obj->parsed = 0;
 115                tree = (struct tree *)obj;
 116                if (parse_tree(tree) < 0)
 117                        return 1; /* error already displayed */
 118        }
 119        result = fsck_walk(obj, mark_object, obj);
 120        if (tree) {
 121                free(tree->buffer);
 122                tree->buffer = NULL;
 123        }
 124        return result;
 125}
 126
 127static int traverse_reachable(void)
 128{
 129        int result = 0;
 130        while (pending.nr) {
 131                struct object_array_entry *entry;
 132                struct object *obj, *parent;
 133
 134                entry = pending.objects + --pending.nr;
 135                obj = entry->item;
 136                parent = (struct object *) entry->name;
 137                result |= traverse_one_object(obj, parent);
 138        }
 139        return !!result;
 140}
 141
 142static int mark_used(struct object *obj, int type, void *data)
 143{
 144        if (!obj)
 145                return 1;
 146        obj->used = 1;
 147        return 0;
 148}
 149
 150/*
 151 * Check a single reachable object
 152 */
 153static void check_reachable_object(struct object *obj)
 154{
 155        /*
 156         * We obviously want the object to be parsed,
 157         * except if it was in a pack-file and we didn't
 158         * do a full fsck
 159         */
 160        if (!obj->parsed) {
 161                if (has_sha1_pack(obj->sha1, NULL))
 162                        return; /* it is in pack - forget about it */
 163                printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 164                errors_found |= ERROR_REACHABLE;
 165                return;
 166        }
 167}
 168
 169/*
 170 * Check a single unreachable object
 171 */
 172static void check_unreachable_object(struct object *obj)
 173{
 174        /*
 175         * Missing unreachable object? Ignore it. It's not like
 176         * we miss it (since it can't be reached), nor do we want
 177         * to complain about it being unreachable (since it does
 178         * not exist).
 179         */
 180        if (!obj->parsed)
 181                return;
 182
 183        /*
 184         * Unreachable object that exists? Show it if asked to,
 185         * since this is something that is prunable.
 186         */
 187        if (show_unreachable) {
 188                printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 189                return;
 190        }
 191
 192        /*
 193         * "!used" means that nothing at all points to it, including
 194         * other unreachable objects. In other words, it's the "tip"
 195         * of some set of unreachable objects, usually a commit that
 196         * got dropped.
 197         *
 198         * Such starting points are more interesting than some random
 199         * set of unreachable objects, so we show them even if the user
 200         * hasn't asked for _all_ unreachable objects. If you have
 201         * deleted a branch by mistake, this is a prime candidate to
 202         * start looking at, for example.
 203         */
 204        if (!obj->used) {
 205                printf("dangling %s %s\n", typename(obj->type),
 206                       sha1_to_hex(obj->sha1));
 207                if (write_lost_and_found) {
 208                        char *filename = git_path("lost-found/%s/%s",
 209                                obj->type == OBJ_COMMIT ? "commit" : "other",
 210                                sha1_to_hex(obj->sha1));
 211                        FILE *f;
 212
 213                        if (safe_create_leading_directories(filename)) {
 214                                error("Could not create lost-found");
 215                                return;
 216                        }
 217                        if (!(f = fopen(filename, "w")))
 218                                die("Could not open %s", filename);
 219                        if (obj->type == OBJ_BLOB) {
 220                                enum object_type type;
 221                                unsigned long size;
 222                                char *buf = read_sha1_file(obj->sha1,
 223                                                &type, &size);
 224                                if (buf) {
 225                                        if (fwrite(buf, size, 1, f) != 1)
 226                                                die("Could not write %s: %s",
 227                                                    filename, strerror(errno));
 228                                        free(buf);
 229                                }
 230                        } else
 231                                fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
 232                        if (fclose(f))
 233                                die("Could not finish %s: %s",
 234                                    filename, strerror(errno));
 235                }
 236                return;
 237        }
 238
 239        /*
 240         * Otherwise? It's there, it's unreachable, and some other unreachable
 241         * object points to it. Ignore it - it's not interesting, and we showed
 242         * all the interesting cases above.
 243         */
 244}
 245
 246static void check_object(struct object *obj)
 247{
 248        if (verbose)
 249                fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
 250
 251        if (obj->flags & REACHABLE)
 252                check_reachable_object(obj);
 253        else
 254                check_unreachable_object(obj);
 255}
 256
 257static void check_connectivity(void)
 258{
 259        int i, max;
 260
 261        /* Traverse the pending reachable objects */
 262        traverse_reachable();
 263
 264        /* Look up all the requirements, warn about missing objects.. */
 265        max = get_max_object_index();
 266        if (verbose)
 267                fprintf(stderr, "Checking connectivity (%d objects)\n", max);
 268
 269        for (i = 0; i < max; i++) {
 270                struct object *obj = get_indexed_object(i);
 271
 272                if (obj)
 273                        check_object(obj);
 274        }
 275}
 276
 277static int fsck_sha1(const unsigned char *sha1)
 278{
 279        struct object *obj = parse_object(sha1);
 280        if (!obj) {
 281                errors_found |= ERROR_OBJECT;
 282                return error("%s: object corrupt or missing",
 283                             sha1_to_hex(sha1));
 284        }
 285        if (obj->flags & SEEN)
 286                return 0;
 287        obj->flags |= SEEN;
 288
 289        if (verbose)
 290                fprintf(stderr, "Checking %s %s\n",
 291                        typename(obj->type), sha1_to_hex(obj->sha1));
 292
 293        if (fsck_walk(obj, mark_used, 0))
 294                objerror(obj, "broken links");
 295        if (fsck_object(obj, check_strict, fsck_error_func))
 296                return -1;
 297
 298        if (obj->type == OBJ_TREE) {
 299                struct tree *item = (struct tree *) obj;
 300
 301                free(item->buffer);
 302                item->buffer = NULL;
 303        }
 304
 305        if (obj->type == OBJ_COMMIT) {
 306                struct commit *commit = (struct commit *) obj;
 307
 308                free(commit->buffer);
 309                commit->buffer = NULL;
 310
 311                if (!commit->parents && show_root)
 312                        printf("root %s\n", sha1_to_hex(commit->object.sha1));
 313        }
 314
 315        if (obj->type == OBJ_TAG) {
 316                struct tag *tag = (struct tag *) obj;
 317
 318                if (show_tags && tag->tagged) {
 319                        printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
 320                        printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 321                }
 322        }
 323
 324        return 0;
 325}
 326
 327/*
 328 * This is the sorting chunk size: make it reasonably
 329 * big so that we can sort well..
 330 */
 331#define MAX_SHA1_ENTRIES (1024)
 332
 333struct sha1_entry {
 334        unsigned long ino;
 335        unsigned char sha1[20];
 336};
 337
 338static struct {
 339        unsigned long nr;
 340        struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 341} sha1_list;
 342
 343static int ino_compare(const void *_a, const void *_b)
 344{
 345        const struct sha1_entry *a = _a, *b = _b;
 346        unsigned long ino1 = a->ino, ino2 = b->ino;
 347        return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 348}
 349
 350static void fsck_sha1_list(void)
 351{
 352        int i, nr = sha1_list.nr;
 353
 354        if (SORT_DIRENT)
 355                qsort(sha1_list.entry, nr,
 356                      sizeof(struct sha1_entry *), ino_compare);
 357        for (i = 0; i < nr; i++) {
 358                struct sha1_entry *entry = sha1_list.entry[i];
 359                unsigned char *sha1 = entry->sha1;
 360
 361                sha1_list.entry[i] = NULL;
 362                fsck_sha1(sha1);
 363                free(entry);
 364        }
 365        sha1_list.nr = 0;
 366}
 367
 368static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 369{
 370        struct sha1_entry *entry = xmalloc(sizeof(*entry));
 371        int nr;
 372
 373        entry->ino = ino;
 374        hashcpy(entry->sha1, sha1);
 375        nr = sha1_list.nr;
 376        if (nr == MAX_SHA1_ENTRIES) {
 377                fsck_sha1_list();
 378                nr = 0;
 379        }
 380        sha1_list.entry[nr] = entry;
 381        sha1_list.nr = ++nr;
 382}
 383
 384static void fsck_dir(int i, char *path)
 385{
 386        DIR *dir = opendir(path);
 387        struct dirent *de;
 388
 389        if (!dir)
 390                return;
 391
 392        if (verbose)
 393                fprintf(stderr, "Checking directory %s\n", path);
 394
 395        while ((de = readdir(dir)) != NULL) {
 396                char name[100];
 397                unsigned char sha1[20];
 398                int len = strlen(de->d_name);
 399
 400                switch (len) {
 401                case 2:
 402                        if (de->d_name[1] != '.')
 403                                break;
 404                case 1:
 405                        if (de->d_name[0] != '.')
 406                                break;
 407                        continue;
 408                case 38:
 409                        sprintf(name, "%02x", i);
 410                        memcpy(name+2, de->d_name, len+1);
 411                        if (get_sha1_hex(name, sha1) < 0)
 412                                break;
 413                        add_sha1_list(sha1, DIRENT_SORT_HINT(de));
 414                        continue;
 415                }
 416                if (!prefixcmp(de->d_name, "tmp_obj_"))
 417                        continue;
 418                fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 419        }
 420        closedir(dir);
 421}
 422
 423static int default_refs;
 424
 425static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 426                const char *email, unsigned long timestamp, int tz,
 427                const char *message, void *cb_data)
 428{
 429        struct object *obj;
 430
 431        if (verbose)
 432                fprintf(stderr, "Checking reflog %s->%s\n",
 433                        sha1_to_hex(osha1), sha1_to_hex(nsha1));
 434
 435        if (!is_null_sha1(osha1)) {
 436                obj = lookup_object(osha1);
 437                if (obj) {
 438                        obj->used = 1;
 439                        mark_object_reachable(obj);
 440                }
 441        }
 442        obj = lookup_object(nsha1);
 443        if (obj) {
 444                obj->used = 1;
 445                mark_object_reachable(obj);
 446        }
 447        return 0;
 448}
 449
 450static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
 451{
 452        for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
 453        return 0;
 454}
 455
 456static int is_branch(const char *refname)
 457{
 458        return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
 459}
 460
 461static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 462{
 463        struct object *obj;
 464
 465        obj = parse_object(sha1);
 466        if (!obj) {
 467                error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
 468                /* We'll continue with the rest despite the error.. */
 469                return 0;
 470        }
 471        if (obj->type != OBJ_COMMIT && is_branch(refname))
 472                error("%s: not a commit", refname);
 473        default_refs++;
 474        obj->used = 1;
 475        mark_object_reachable(obj);
 476
 477        return 0;
 478}
 479
 480static void get_default_heads(void)
 481{
 482        for_each_ref(fsck_handle_ref, NULL);
 483        if (include_reflogs)
 484                for_each_reflog(fsck_handle_reflog, NULL);
 485
 486        /*
 487         * Not having any default heads isn't really fatal, but
 488         * it does mean that "--unreachable" no longer makes any
 489         * sense (since in this case everything will obviously
 490         * be unreachable by definition.
 491         *
 492         * Showing dangling objects is valid, though (as those
 493         * dangling objects are likely lost heads).
 494         *
 495         * So we just print a warning about it, and clear the
 496         * "show_unreachable" flag.
 497         */
 498        if (!default_refs) {
 499                fprintf(stderr, "notice: No default references\n");
 500                show_unreachable = 0;
 501        }
 502}
 503
 504static void fsck_object_dir(const char *path)
 505{
 506        int i;
 507
 508        if (verbose)
 509                fprintf(stderr, "Checking object directory\n");
 510
 511        for (i = 0; i < 256; i++) {
 512                static char dir[4096];
 513                sprintf(dir, "%s/%02x", path, i);
 514                fsck_dir(i, dir);
 515        }
 516        fsck_sha1_list();
 517}
 518
 519static int fsck_head_link(void)
 520{
 521        unsigned char sha1[20];
 522        int flag;
 523        int null_is_error = 0;
 524        const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag);
 525
 526        if (verbose)
 527                fprintf(stderr, "Checking HEAD link\n");
 528
 529        if (!head_points_at)
 530                return error("Invalid HEAD");
 531        if (!strcmp(head_points_at, "HEAD"))
 532                /* detached HEAD */
 533                null_is_error = 1;
 534        else if (prefixcmp(head_points_at, "refs/heads/"))
 535                return error("HEAD points to something strange (%s)",
 536                             head_points_at);
 537        if (is_null_sha1(sha1)) {
 538                if (null_is_error)
 539                        return error("HEAD: detached HEAD points at nothing");
 540                fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
 541                        head_points_at + 11);
 542        }
 543        return 0;
 544}
 545
 546static int fsck_cache_tree(struct cache_tree *it)
 547{
 548        int i;
 549        int err = 0;
 550
 551        if (verbose)
 552                fprintf(stderr, "Checking cache tree\n");
 553
 554        if (0 <= it->entry_count) {
 555                struct object *obj = parse_object(it->sha1);
 556                if (!obj) {
 557                        error("%s: invalid sha1 pointer in cache-tree",
 558                              sha1_to_hex(it->sha1));
 559                        return 1;
 560                }
 561                mark_object_reachable(obj);
 562                obj->used = 1;
 563                if (obj->type != OBJ_TREE)
 564                        err |= objerror(obj, "non-tree in cache-tree");
 565        }
 566        for (i = 0; i < it->subtree_nr; i++)
 567                err |= fsck_cache_tree(it->down[i]->cache_tree);
 568        return err;
 569}
 570
 571static char const * const fsck_usage[] = {
 572        "git fsck [options] [<object>...]",
 573        NULL
 574};
 575
 576static struct option fsck_opts[] = {
 577        OPT__VERBOSE(&verbose),
 578        OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
 579        OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
 580        OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
 581        OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
 582        OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
 583        OPT_BOOLEAN(0, "full", &check_full, "also consider alternate objects"),
 584        OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
 585        OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
 586                                "write dangling objects in .git/lost-found"),
 587        OPT_END(),
 588};
 589
 590int cmd_fsck(int argc, const char **argv, const char *prefix)
 591{
 592        int i, heads;
 593
 594        errors_found = 0;
 595
 596        argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0);
 597        if (write_lost_and_found) {
 598                check_full = 1;
 599                include_reflogs = 0;
 600        }
 601
 602        fsck_head_link();
 603        fsck_object_dir(get_object_directory());
 604        if (check_full) {
 605                struct alternate_object_database *alt;
 606                struct packed_git *p;
 607                prepare_alt_odb();
 608                for (alt = alt_odb_list; alt; alt = alt->next) {
 609                        char namebuf[PATH_MAX];
 610                        int namelen = alt->name - alt->base;
 611                        memcpy(namebuf, alt->base, namelen);
 612                        namebuf[namelen - 1] = 0;
 613                        fsck_object_dir(namebuf);
 614                }
 615                prepare_packed_git();
 616                for (p = packed_git; p; p = p->next)
 617                        /* verify gives error messages itself */
 618                        verify_pack(p);
 619
 620                for (p = packed_git; p; p = p->next) {
 621                        uint32_t j, num;
 622                        if (open_pack_index(p))
 623                                continue;
 624                        num = p->num_objects;
 625                        for (j = 0; j < num; j++)
 626                                fsck_sha1(nth_packed_object_sha1(p, j));
 627                }
 628        }
 629
 630        heads = 0;
 631        for (i = 0; i < argc; i++) {
 632                const char *arg = argv[i];
 633                if (!get_sha1(arg, head_sha1)) {
 634                        struct object *obj = lookup_object(head_sha1);
 635
 636                        /* Error is printed by lookup_object(). */
 637                        if (!obj)
 638                                continue;
 639
 640                        obj->used = 1;
 641                        mark_object_reachable(obj);
 642                        heads++;
 643                        continue;
 644                }
 645                error("invalid parameter: expected sha1, got '%s'", arg);
 646        }
 647
 648        /*
 649         * If we've not been given any explicit head information, do the
 650         * default ones from .git/refs. We also consider the index file
 651         * in this case (ie this implies --cache).
 652         */
 653        if (!heads) {
 654                get_default_heads();
 655                keep_cache_objects = 1;
 656        }
 657
 658        if (keep_cache_objects) {
 659                read_cache();
 660                for (i = 0; i < active_nr; i++) {
 661                        unsigned int mode;
 662                        struct blob *blob;
 663                        struct object *obj;
 664
 665                        mode = active_cache[i]->ce_mode;
 666                        if (S_ISGITLINK(mode))
 667                                continue;
 668                        blob = lookup_blob(active_cache[i]->sha1);
 669                        if (!blob)
 670                                continue;
 671                        obj = &blob->object;
 672                        obj->used = 1;
 673                        mark_object_reachable(obj);
 674                }
 675                if (active_cache_tree)
 676                        fsck_cache_tree(active_cache_tree);
 677        }
 678
 679        check_connectivity();
 680        return errors_found;
 681}