builtin-fsck.con commit Improve error output of git-rebase (9b752a6)
   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 int mark_object(struct object *obj, int type, void *data)
  68{
  69        struct tree *tree = NULL;
  70        struct object *parent = data;
  71        int result;
  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        if (obj->type == OBJ_TREE) {
 100                obj->parsed = 0;
 101                tree = (struct tree *)obj;
 102                if (parse_tree(tree) < 0)
 103                        return 1; /* error already displayed */
 104        }
 105        result = fsck_walk(obj, mark_object, obj);
 106        if (tree) {
 107                free(tree->buffer);
 108                tree->buffer = NULL;
 109        }
 110        if (result < 0)
 111                result = 1;
 112
 113        return result;
 114}
 115
 116static void mark_object_reachable(struct object *obj)
 117{
 118        mark_object(obj, OBJ_ANY, 0);
 119}
 120
 121static int mark_used(struct object *obj, int type, void *data)
 122{
 123        if (!obj)
 124                return 1;
 125        obj->used = 1;
 126        return 0;
 127}
 128
 129/*
 130 * Check a single reachable object
 131 */
 132static void check_reachable_object(struct object *obj)
 133{
 134        /*
 135         * We obviously want the object to be parsed,
 136         * except if it was in a pack-file and we didn't
 137         * do a full fsck
 138         */
 139        if (!obj->parsed) {
 140                if (has_sha1_pack(obj->sha1, NULL))
 141                        return; /* it is in pack - forget about it */
 142                printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 143                errors_found |= ERROR_REACHABLE;
 144                return;
 145        }
 146}
 147
 148/*
 149 * Check a single unreachable object
 150 */
 151static void check_unreachable_object(struct object *obj)
 152{
 153        /*
 154         * Missing unreachable object? Ignore it. It's not like
 155         * we miss it (since it can't be reached), nor do we want
 156         * to complain about it being unreachable (since it does
 157         * not exist).
 158         */
 159        if (!obj->parsed)
 160                return;
 161
 162        /*
 163         * Unreachable object that exists? Show it if asked to,
 164         * since this is something that is prunable.
 165         */
 166        if (show_unreachable) {
 167                printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 168                return;
 169        }
 170
 171        /*
 172         * "!used" means that nothing at all points to it, including
 173         * other unreachable objects. In other words, it's the "tip"
 174         * of some set of unreachable objects, usually a commit that
 175         * got dropped.
 176         *
 177         * Such starting points are more interesting than some random
 178         * set of unreachable objects, so we show them even if the user
 179         * hasn't asked for _all_ unreachable objects. If you have
 180         * deleted a branch by mistake, this is a prime candidate to
 181         * start looking at, for example.
 182         */
 183        if (!obj->used) {
 184                printf("dangling %s %s\n", typename(obj->type),
 185                       sha1_to_hex(obj->sha1));
 186                if (write_lost_and_found) {
 187                        char *filename = git_path("lost-found/%s/%s",
 188                                obj->type == OBJ_COMMIT ? "commit" : "other",
 189                                sha1_to_hex(obj->sha1));
 190                        FILE *f;
 191
 192                        if (safe_create_leading_directories(filename)) {
 193                                error("Could not create lost-found");
 194                                return;
 195                        }
 196                        if (!(f = fopen(filename, "w")))
 197                                die("Could not open %s", filename);
 198                        if (obj->type == OBJ_BLOB) {
 199                                enum object_type type;
 200                                unsigned long size;
 201                                char *buf = read_sha1_file(obj->sha1,
 202                                                &type, &size);
 203                                if (buf) {
 204                                        fwrite(buf, size, 1, f);
 205                                        free(buf);
 206                                }
 207                        } else
 208                                fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
 209                        fclose(f);
 210                }
 211                return;
 212        }
 213
 214        /*
 215         * Otherwise? It's there, it's unreachable, and some other unreachable
 216         * object points to it. Ignore it - it's not interesting, and we showed
 217         * all the interesting cases above.
 218         */
 219}
 220
 221static void check_object(struct object *obj)
 222{
 223        if (verbose)
 224                fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
 225
 226        if (obj->flags & REACHABLE)
 227                check_reachable_object(obj);
 228        else
 229                check_unreachable_object(obj);
 230}
 231
 232static void check_connectivity(void)
 233{
 234        int i, max;
 235
 236        /* Look up all the requirements, warn about missing objects.. */
 237        max = get_max_object_index();
 238        if (verbose)
 239                fprintf(stderr, "Checking connectivity (%d objects)\n", max);
 240
 241        for (i = 0; i < max; i++) {
 242                struct object *obj = get_indexed_object(i);
 243
 244                if (obj)
 245                        check_object(obj);
 246        }
 247}
 248
 249static int fsck_sha1(const unsigned char *sha1)
 250{
 251        struct object *obj = parse_object(sha1);
 252        if (!obj) {
 253                errors_found |= ERROR_OBJECT;
 254                return error("%s: object corrupt or missing",
 255                             sha1_to_hex(sha1));
 256        }
 257        if (obj->flags & SEEN)
 258                return 0;
 259        obj->flags |= SEEN;
 260
 261        if (verbose)
 262                fprintf(stderr, "Checking %s %s\n",
 263                        typename(obj->type), sha1_to_hex(obj->sha1));
 264
 265        if (fsck_walk(obj, mark_used, 0))
 266                objerror(obj, "broken links");
 267        if (fsck_object(obj, check_strict, fsck_error_func))
 268                return -1;
 269
 270        if (obj->type == OBJ_TREE) {
 271                struct tree *item = (struct tree *) obj;
 272
 273                free(item->buffer);
 274                item->buffer = NULL;
 275        }
 276
 277        if (obj->type == OBJ_COMMIT) {
 278                struct commit *commit = (struct commit *) obj;
 279
 280                free(commit->buffer);
 281                commit->buffer = NULL;
 282
 283                if (!commit->parents && show_root)
 284                        printf("root %s\n", sha1_to_hex(commit->object.sha1));
 285        }
 286
 287        if (obj->type == OBJ_TAG) {
 288                struct tag *tag = (struct tag *) obj;
 289
 290                if (show_tags && tag->tagged) {
 291                        printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
 292                        printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 293                }
 294        }
 295
 296        return 0;
 297}
 298
 299/*
 300 * This is the sorting chunk size: make it reasonably
 301 * big so that we can sort well..
 302 */
 303#define MAX_SHA1_ENTRIES (1024)
 304
 305struct sha1_entry {
 306        unsigned long ino;
 307        unsigned char sha1[20];
 308};
 309
 310static struct {
 311        unsigned long nr;
 312        struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 313} sha1_list;
 314
 315static int ino_compare(const void *_a, const void *_b)
 316{
 317        const struct sha1_entry *a = _a, *b = _b;
 318        unsigned long ino1 = a->ino, ino2 = b->ino;
 319        return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 320}
 321
 322static void fsck_sha1_list(void)
 323{
 324        int i, nr = sha1_list.nr;
 325
 326        if (SORT_DIRENT)
 327                qsort(sha1_list.entry, nr,
 328                      sizeof(struct sha1_entry *), ino_compare);
 329        for (i = 0; i < nr; i++) {
 330                struct sha1_entry *entry = sha1_list.entry[i];
 331                unsigned char *sha1 = entry->sha1;
 332
 333                sha1_list.entry[i] = NULL;
 334                fsck_sha1(sha1);
 335                free(entry);
 336        }
 337        sha1_list.nr = 0;
 338}
 339
 340static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 341{
 342        struct sha1_entry *entry = xmalloc(sizeof(*entry));
 343        int nr;
 344
 345        entry->ino = ino;
 346        hashcpy(entry->sha1, sha1);
 347        nr = sha1_list.nr;
 348        if (nr == MAX_SHA1_ENTRIES) {
 349                fsck_sha1_list();
 350                nr = 0;
 351        }
 352        sha1_list.entry[nr] = entry;
 353        sha1_list.nr = ++nr;
 354}
 355
 356static void fsck_dir(int i, char *path)
 357{
 358        DIR *dir = opendir(path);
 359        struct dirent *de;
 360
 361        if (!dir)
 362                return;
 363
 364        if (verbose)
 365                fprintf(stderr, "Checking directory %s\n", path);
 366
 367        while ((de = readdir(dir)) != NULL) {
 368                char name[100];
 369                unsigned char sha1[20];
 370                int len = strlen(de->d_name);
 371
 372                switch (len) {
 373                case 2:
 374                        if (de->d_name[1] != '.')
 375                                break;
 376                case 1:
 377                        if (de->d_name[0] != '.')
 378                                break;
 379                        continue;
 380                case 38:
 381                        sprintf(name, "%02x", i);
 382                        memcpy(name+2, de->d_name, len+1);
 383                        if (get_sha1_hex(name, sha1) < 0)
 384                                break;
 385                        add_sha1_list(sha1, DIRENT_SORT_HINT(de));
 386                        continue;
 387                }
 388                if (!prefixcmp(de->d_name, "tmp_obj_"))
 389                        continue;
 390                fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 391        }
 392        closedir(dir);
 393}
 394
 395static int default_refs;
 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        struct object *obj;
 402
 403        if (verbose)
 404                fprintf(stderr, "Checking reflog %s->%s\n",
 405                        sha1_to_hex(osha1), sha1_to_hex(nsha1));
 406
 407        if (!is_null_sha1(osha1)) {
 408                obj = lookup_object(osha1);
 409                if (obj) {
 410                        obj->used = 1;
 411                        mark_object_reachable(obj);
 412                }
 413        }
 414        obj = lookup_object(nsha1);
 415        if (obj) {
 416                obj->used = 1;
 417                mark_object_reachable(obj);
 418        }
 419        return 0;
 420}
 421
 422static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
 423{
 424        for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
 425        return 0;
 426}
 427
 428static int is_branch(const char *refname)
 429{
 430        return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
 431}
 432
 433static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 434{
 435        struct object *obj;
 436
 437        obj = parse_object(sha1);
 438        if (!obj) {
 439                error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
 440                /* We'll continue with the rest despite the error.. */
 441                return 0;
 442        }
 443        if (obj->type != OBJ_COMMIT && is_branch(refname))
 444                error("%s: not a commit", refname);
 445        default_refs++;
 446        obj->used = 1;
 447        mark_object_reachable(obj);
 448
 449        return 0;
 450}
 451
 452static void get_default_heads(void)
 453{
 454        for_each_ref(fsck_handle_ref, NULL);
 455        if (include_reflogs)
 456                for_each_reflog(fsck_handle_reflog, NULL);
 457
 458        /*
 459         * Not having any default heads isn't really fatal, but
 460         * it does mean that "--unreachable" no longer makes any
 461         * sense (since in this case everything will obviously
 462         * be unreachable by definition.
 463         *
 464         * Showing dangling objects is valid, though (as those
 465         * dangling objects are likely lost heads).
 466         *
 467         * So we just print a warning about it, and clear the
 468         * "show_unreachable" flag.
 469         */
 470        if (!default_refs) {
 471                fprintf(stderr, "notice: No default references\n");
 472                show_unreachable = 0;
 473        }
 474}
 475
 476static void fsck_object_dir(const char *path)
 477{
 478        int i;
 479
 480        if (verbose)
 481                fprintf(stderr, "Checking object directory\n");
 482
 483        for (i = 0; i < 256; i++) {
 484                static char dir[4096];
 485                sprintf(dir, "%s/%02x", path, i);
 486                fsck_dir(i, dir);
 487        }
 488        fsck_sha1_list();
 489}
 490
 491static int fsck_head_link(void)
 492{
 493        unsigned char sha1[20];
 494        int flag;
 495        int null_is_error = 0;
 496        const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag);
 497
 498        if (verbose)
 499                fprintf(stderr, "Checking HEAD link\n");
 500
 501        if (!head_points_at)
 502                return error("Invalid HEAD");
 503        if (!strcmp(head_points_at, "HEAD"))
 504                /* detached HEAD */
 505                null_is_error = 1;
 506        else if (prefixcmp(head_points_at, "refs/heads/"))
 507                return error("HEAD points to something strange (%s)",
 508                             head_points_at);
 509        if (is_null_sha1(sha1)) {
 510                if (null_is_error)
 511                        return error("HEAD: detached HEAD points at nothing");
 512                fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
 513                        head_points_at + 11);
 514        }
 515        return 0;
 516}
 517
 518static int fsck_cache_tree(struct cache_tree *it)
 519{
 520        int i;
 521        int err = 0;
 522
 523        if (verbose)
 524                fprintf(stderr, "Checking cache tree\n");
 525
 526        if (0 <= it->entry_count) {
 527                struct object *obj = parse_object(it->sha1);
 528                if (!obj) {
 529                        error("%s: invalid sha1 pointer in cache-tree",
 530                              sha1_to_hex(it->sha1));
 531                        return 1;
 532                }
 533                mark_object_reachable(obj);
 534                obj->used = 1;
 535                if (obj->type != OBJ_TREE)
 536                        err |= objerror(obj, "non-tree in cache-tree");
 537        }
 538        for (i = 0; i < it->subtree_nr; i++)
 539                err |= fsck_cache_tree(it->down[i]->cache_tree);
 540        return err;
 541}
 542
 543static char const * const fsck_usage[] = {
 544        "git fsck [options] [<object>...]",
 545        NULL
 546};
 547
 548static struct option fsck_opts[] = {
 549        OPT__VERBOSE(&verbose),
 550        OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
 551        OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
 552        OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
 553        OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
 554        OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
 555        OPT_BOOLEAN(0, "full", &check_full, "also consider alternate objects"),
 556        OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
 557        OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
 558                                "write dangling objects in .git/lost-found"),
 559        OPT_END(),
 560};
 561
 562int cmd_fsck(int argc, const char **argv, const char *prefix)
 563{
 564        int i, heads;
 565
 566        errors_found = 0;
 567
 568        argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0);
 569        if (write_lost_and_found) {
 570                check_full = 1;
 571                include_reflogs = 0;
 572        }
 573
 574        fsck_head_link();
 575        fsck_object_dir(get_object_directory());
 576        if (check_full) {
 577                struct alternate_object_database *alt;
 578                struct packed_git *p;
 579                prepare_alt_odb();
 580                for (alt = alt_odb_list; alt; alt = alt->next) {
 581                        char namebuf[PATH_MAX];
 582                        int namelen = alt->name - alt->base;
 583                        memcpy(namebuf, alt->base, namelen);
 584                        namebuf[namelen - 1] = 0;
 585                        fsck_object_dir(namebuf);
 586                }
 587                prepare_packed_git();
 588                for (p = packed_git; p; p = p->next)
 589                        /* verify gives error messages itself */
 590                        verify_pack(p);
 591
 592                for (p = packed_git; p; p = p->next) {
 593                        uint32_t j, num;
 594                        if (open_pack_index(p))
 595                                continue;
 596                        num = p->num_objects;
 597                        for (j = 0; j < num; j++)
 598                                fsck_sha1(nth_packed_object_sha1(p, j));
 599                }
 600        }
 601
 602        heads = 0;
 603        for (i = 1; i < argc; i++) {
 604                const char *arg = argv[i];
 605                if (!get_sha1(arg, head_sha1)) {
 606                        struct object *obj = lookup_object(head_sha1);
 607
 608                        /* Error is printed by lookup_object(). */
 609                        if (!obj)
 610                                continue;
 611
 612                        obj->used = 1;
 613                        mark_object_reachable(obj);
 614                        heads++;
 615                        continue;
 616                }
 617                error("invalid parameter: expected sha1, got '%s'", arg);
 618        }
 619
 620        /*
 621         * If we've not been given any explicit head information, do the
 622         * default ones from .git/refs. We also consider the index file
 623         * in this case (ie this implies --cache).
 624         */
 625        if (!heads) {
 626                get_default_heads();
 627                keep_cache_objects = 1;
 628        }
 629
 630        if (keep_cache_objects) {
 631                read_cache();
 632                for (i = 0; i < active_nr; i++) {
 633                        unsigned int mode;
 634                        struct blob *blob;
 635                        struct object *obj;
 636
 637                        mode = active_cache[i]->ce_mode;
 638                        if (S_ISGITLINK(mode))
 639                                continue;
 640                        blob = lookup_blob(active_cache[i]->sha1);
 641                        if (!blob)
 642                                continue;
 643                        obj = &blob->object;
 644                        obj->used = 1;
 645                        mark_object_reachable(obj);
 646                }
 647                if (active_cache_tree)
 648                        fsck_cache_tree(active_cache_tree);
 649        }
 650
 651        check_connectivity();
 652        return errors_found;
 653}