builtin-fsck.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tree.h"
   4 #include "blob.h"
   5 #include "tag.h"
   6 #include "refs.h"
   7 #include "pack.h"
   8 #include "cache-tree.h"
   9 #include "tree-walk.h"
  10
  11 #define REACHABLE 0x0001
  12 #define SEEN      0x0002
  13
  14 static int show_root;
  15 static int show_tags;
  16 static int show_unreachable;
  17 static int check_full;
  18 static int check_strict;
  19 static int keep_cache_objects;
  20 static unsigned char head_sha1[20];
  21 static int errors_found;
  22 #define ERROR_OBJECT 01
  23 #define ERROR_REACHABLE 02
  24
  25 #ifdef NO_D_INO_IN_DIRENT
  26 #define SORT_DIRENT 0
  27 #define DIRENT_SORT_HINT(de) 0
  28 #else
  29 #define SORT_DIRENT 1
  30 #define DIRENT_SORT_HINT(de) ((de)->d_ino)
  31 #endif
  32
  33 static void objreport(struct object *obj, const char *severity,
  34                       const char *err, va_list params)
  35 {
  36         fprintf(stderr, "%s in %s %s: ",
  37                 severity, typename(obj->type), sha1_to_hex(obj->sha1));
  38         vfprintf(stderr, err, params);
  39         fputs("\n", stderr);
  40 }
  41
  42 static int objerror(struct object *obj, const char *err, ...)
  43 {
  44         va_list params;
  45         va_start(params, err);
  46         errors_found |= ERROR_OBJECT;
  47         objreport(obj, "error", err, params);
  48         va_end(params);
  49         return -1;
  50 }
  51
  52 static int objwarning(struct object *obj, const char *err, ...)
  53 {
  54         va_list params;
  55         va_start(params, err);
  56         objreport(obj, "warning", err, params);
  57         va_end(params);
  58         return -1;
  59 }
  60
  61 /*
  62  * Check a single reachable object
  63  */
  64 static void check_reachable_object(struct object *obj)
  65 {
  66         const struct object_refs *refs;
  67
  68         /*
  69          * We obviously want the object to be parsed,
  70          * except if it was in a pack-file and we didn't
  71          * do a full fsck
  72          */
  73         if (!obj->parsed) {
  74                 if (has_sha1_pack(obj->sha1, NULL))
  75                         return; /* it is in pack - forget about it */
  76                 printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
  77                 errors_found |= ERROR_REACHABLE;
  78                 return;
  79         }
  80
  81         /*
  82          * Check that everything that we try to reference is also good.
  83          */
  84         refs = lookup_object_refs(obj);
  85         if (refs) {
  86                 unsigned j;
  87                 for (j = 0; j < refs->count; j++) {
  88                         struct object *ref = refs->ref[j];
  89                         if (ref->parsed ||
  90                             (has_sha1_file(ref->sha1)))
  91                                 continue;
  92                         printf("broken link from %7s %s\n",
  93                                typename(obj->type), sha1_to_hex(obj->sha1));
  94                         printf("              to %7s %s\n",
  95                                typename(ref->type), sha1_to_hex(ref->sha1));
  96                         errors_found |= ERROR_REACHABLE;
  97                 }
  98         }
  99 }
 100
 101 /*
 102  * Check a single unreachable object
 103  */
 104 static void check_unreachable_object(struct object *obj)
 105 {
 106         /*
 107          * Missing unreachable object? Ignore it. It's not like
 108          * we miss it (since it can't be reached), nor do we want
 109          * to complain about it being unreachable (since it does
 110          * not exist).
 111          */
 112         if (!obj->parsed)
 113                 return;
 114
 115         /*
 116          * Unreachable object that exists? Show it if asked to,
 117          * since this is something that is prunable.
 118          */
 119         if (show_unreachable) {
 120                 printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
 121                 return;
 122         }
 123
 124         /*
 125          * "!used" means that nothing at all points to it, including
 126          * other unreachable objects. In other words, it's the "tip"
 127          * of some set of unreachable objects, usually a commit that
 128          * got dropped.
 129          *
 130          * Such starting points are more interesting than some random
 131          * set of unreachable objects, so we show them even if the user
 132          * hasn't asked for _all_ unreachable objects. If you have
 133          * deleted a branch by mistake, this is a prime candidate to
 134          * start looking at, for example.
 135          */
 136         if (!obj->used) {
 137                 printf("dangling %s %s\n", typename(obj->type),
 138                        sha1_to_hex(obj->sha1));
 139                 return;
 140         }
 141
 142         /*
 143          * Otherwise? It's there, it's unreachable, and some other unreachable
 144          * object points to it. Ignore it - it's not interesting, and we showed
 145          * all the interesting cases above.
 146          */
 147 }
 148
 149 static void check_object(struct object *obj)
 150 {
 151         if (obj->flags & REACHABLE)
 152                 check_reachable_object(obj);
 153         else
 154                 check_unreachable_object(obj);
 155 }
 156
 157 static void check_connectivity(void)
 158 {
 159         int i, max;
 160
 161         /* Look up all the requirements, warn about missing objects.. */
 162         max = get_max_object_index();
 163         for (i = 0; i < max; i++) {
 164                 struct object *obj = get_indexed_object(i);
 165
 166                 if (obj)
 167                         check_object(obj);
 168         }
 169 }
 170
 171 /*
 172  * The entries in a tree are ordered in the _path_ order,
 173  * which means that a directory entry is ordered by adding
 174  * a slash to the end of it.
 175  *
 176  * So a directory called "a" is ordered _after_ a file
 177  * called "a.c", because "a/" sorts after "a.c".
 178  */
 179 #define TREE_UNORDERED (-1)
 180 #define TREE_HAS_DUPS  (-2)
 181
 182 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 183 {
 184         int len1 = strlen(name1);
 185         int len2 = strlen(name2);
 186         int len = len1 < len2 ? len1 : len2;
 187         unsigned char c1, c2;
 188         int cmp;
 189
 190         cmp = memcmp(name1, name2, len);
 191         if (cmp < 0)
 192                 return 0;
 193         if (cmp > 0)
 194                 return TREE_UNORDERED;
 195
 196         /*
 197          * Ok, the first <len> characters are the same.
 198          * Now we need to order the next one, but turn
 199          * a '\0' into a '/' for a directory entry.
 200          */
 201         c1 = name1[len];
 202         c2 = name2[len];
 203         if (!c1 && !c2)
 204                 /*
 205                  * git-write-tree used to write out a nonsense tree that has
 206                  * entries with the same name, one blob and one tree.  Make
 207                  * sure we do not have duplicate entries.
 208                  */
 209                 return TREE_HAS_DUPS;
 210         if (!c1 && S_ISDIR(mode1))
 211                 c1 = '/';
 212         if (!c2 && S_ISDIR(mode2))
 213                 c2 = '/';
 214         return c1 < c2 ? 0 : TREE_UNORDERED;
 215 }
 216
 217 static int fsck_tree(struct tree *item)
 218 {
 219         int retval;
 220         int has_full_path = 0;
 221         int has_empty_name = 0;
 222         int has_zero_pad = 0;
 223         int has_bad_modes = 0;
 224         int has_dup_entries = 0;
 225         int not_properly_sorted = 0;
 226         struct tree_desc desc;
 227         unsigned o_mode;
 228         const char *o_name;
 229         const unsigned char *o_sha1;
 230
 231         init_tree_desc(&desc, item->buffer, item->size);
 232
 233         o_mode = 0;
 234         o_name = NULL;
 235         o_sha1 = NULL;
 236         while (desc.size) {
 237                 unsigned mode;
 238                 const char *name;
 239                 const unsigned char *sha1;
 240
 241                 sha1 = tree_entry_extract(&desc, &name, &mode);
 242
 243                 if (strchr(name, '/'))
 244                         has_full_path = 1;
 245                 if (!*name)
 246                         has_empty_name = 1;
 247                 has_zero_pad |= *(char *)desc.buffer == '0';
 248                 update_tree_entry(&desc);
 249
 250                 switch (mode) {
 251                 /*
 252                  * Standard modes..
 253                  */
 254                 case S_IFREG | 0755:
 255                 case S_IFREG | 0644:
 256                 case S_IFLNK:
 257                 case S_IFDIR:
 258                         break;
 259                 /*
 260                  * This is nonstandard, but we had a few of these
 261                  * early on when we honored the full set of mode
 262                  * bits..
 263                  */
 264                 case S_IFREG | 0664:
 265                         if (!check_strict)
 266                                 break;
 267                 default:
 268                         has_bad_modes = 1;
 269                 }
 270
 271                 if (o_name) {
 272                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 273                         case TREE_UNORDERED:
 274                                 not_properly_sorted = 1;
 275                                 break;
 276                         case TREE_HAS_DUPS:
 277                                 has_dup_entries = 1;
 278                                 break;
 279                         default:
 280                                 break;
 281                         }
 282                 }
 283
 284                 o_mode = mode;
 285                 o_name = name;
 286                 o_sha1 = sha1;
 287         }
 288         free(item->buffer);
 289         item->buffer = NULL;
 290
 291         retval = 0;
 292         if (has_full_path) {
 293                 objwarning(&item->object, "contains full pathnames");
 294         }
 295         if (has_empty_name) {
 296                 objwarning(&item->object, "contains empty pathname");
 297         }
 298         if (has_zero_pad) {
 299                 objwarning(&item->object, "contains zero-padded file modes");
 300         }
 301         if (has_bad_modes) {
 302                 objwarning(&item->object, "contains bad file modes");
 303         }
 304         if (has_dup_entries) {
 305                 retval = objerror(&item->object, "contains duplicate file entries");
 306         }
 307         if (not_properly_sorted) {
 308                 retval = objerror(&item->object, "not properly sorted");
 309         }
 310         return retval;
 311 }
 312
 313 static int fsck_commit(struct commit *commit)
 314 {
 315         char *buffer = commit->buffer;
 316         unsigned char tree_sha1[20], sha1[20];
 317
 318         if (memcmp(buffer, "tree ", 5))
 319                 return objerror(&commit->object, "invalid format - expected 'tree' line");
 320         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
 321                 return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
 322         buffer += 46;
 323         while (!memcmp(buffer, "parent ", 7)) {
 324                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
 325                         return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
 326                 buffer += 48;
 327         }
 328         if (memcmp(buffer, "author ", 7))
 329                 return objerror(&commit->object, "invalid format - expected 'author' line");
 330         free(commit->buffer);
 331         commit->buffer = NULL;
 332         if (!commit->tree)
 333                 return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
 334         if (!commit->parents && show_root)
 335                 printf("root %s\n", sha1_to_hex(commit->object.sha1));
 336         if (!commit->date)
 337                 printf("bad commit date in %s\n",
 338                        sha1_to_hex(commit->object.sha1));
 339         return 0;
 340 }
 341
 342 static int fsck_tag(struct tag *tag)
 343 {
 344         struct object *tagged = tag->tagged;
 345
 346         if (!tagged) {
 347                 return objerror(&tag->object, "could not load tagged object");
 348         }
 349         if (!show_tags)
 350                 return 0;
 351
 352         printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
 353         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 354         return 0;
 355 }
 356
 357 static int fsck_sha1(unsigned char *sha1)
 358 {
 359         struct object *obj = parse_object(sha1);
 360         if (!obj) {
 361                 errors_found |= ERROR_OBJECT;
 362                 return error("%s: object corrupt or missing",
 363                              sha1_to_hex(sha1));
 364         }
 365         if (obj->flags & SEEN)
 366                 return 0;
 367         obj->flags |= SEEN;
 368         if (obj->type == OBJ_BLOB)
 369                 return 0;
 370         if (obj->type == OBJ_TREE)
 371                 return fsck_tree((struct tree *) obj);
 372         if (obj->type == OBJ_COMMIT)
 373                 return fsck_commit((struct commit *) obj);
 374         if (obj->type == OBJ_TAG)
 375                 return fsck_tag((struct tag *) obj);
 376
 377         /* By now, parse_object() would've returned NULL instead. */
 378         return objerror(obj, "unknown type '%d' (internal fsck error)",
 379                         obj->type);
 380 }
 381
 382 /*
 383  * This is the sorting chunk size: make it reasonably
 384  * big so that we can sort well..
 385  */
 386 #define MAX_SHA1_ENTRIES (1024)
 387
 388 struct sha1_entry {
 389         unsigned long ino;
 390         unsigned char sha1[20];
 391 };
 392
 393 static struct {
 394         unsigned long nr;
 395         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 396 } sha1_list;
 397
 398 static int ino_compare(const void *_a, const void *_b)
 399 {
 400         const struct sha1_entry *a = _a, *b = _b;
 401         unsigned long ino1 = a->ino, ino2 = b->ino;
 402         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 403 }
 404
 405 static void fsck_sha1_list(void)
 406 {
 407         int i, nr = sha1_list.nr;
 408
 409         if (SORT_DIRENT)
 410                 qsort(sha1_list.entry, nr,
 411                       sizeof(struct sha1_entry *), ino_compare);
 412         for (i = 0; i < nr; i++) {
 413                 struct sha1_entry *entry = sha1_list.entry[i];
 414                 unsigned char *sha1 = entry->sha1;
 415
 416                 sha1_list.entry[i] = NULL;
 417                 fsck_sha1(sha1);
 418                 free(entry);
 419         }
 420         sha1_list.nr = 0;
 421 }
 422
 423 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 424 {
 425         struct sha1_entry *entry = xmalloc(sizeof(*entry));
 426         int nr;
 427
 428         entry->ino = ino;
 429         hashcpy(entry->sha1, sha1);
 430         nr = sha1_list.nr;
 431         if (nr == MAX_SHA1_ENTRIES) {
 432                 fsck_sha1_list();
 433                 nr = 0;
 434         }
 435         sha1_list.entry[nr] = entry;
 436         sha1_list.nr = ++nr;
 437 }
 438
 439 static void fsck_dir(int i, char *path)
 440 {
 441         DIR *dir = opendir(path);
 442         struct dirent *de;
 443
 444         if (!dir)
 445                 return;
 446
 447         while ((de = readdir(dir)) != NULL) {
 448                 char name[100];
 449                 unsigned char sha1[20];
 450                 int len = strlen(de->d_name);
 451
 452                 switch (len) {
 453                 case 2:
 454                         if (de->d_name[1] != '.')
 455                                 break;
 456                 case 1:
 457                         if (de->d_name[0] != '.')
 458                                 break;
 459                         continue;
 460                 case 38:
 461                         sprintf(name, "%02x", i);
 462                         memcpy(name+2, de->d_name, len+1);
 463                         if (get_sha1_hex(name, sha1) < 0)
 464                                 break;
 465                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
 466                         continue;
 467                 }
 468                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 469         }
 470         closedir(dir);
 471 }
 472
 473 static int default_refs;
 474
 475 static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 476                 const char *email, unsigned long timestamp, int tz,
 477                 const char *message, void *cb_data)
 478 {
 479         struct object *obj;
 480
 481         if (!is_null_sha1(osha1)) {
 482                 obj = lookup_object(osha1);
 483                 if (obj) {
 484                         obj->used = 1;
 485                         mark_reachable(obj, REACHABLE);
 486                 }
 487         }
 488         obj = lookup_object(nsha1);
 489         if (obj) {
 490                 obj->used = 1;
 491                 mark_reachable(obj, REACHABLE);
 492         }
 493         return 0;
 494 }
 495
 496 static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
 497 {
 498         for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
 499         return 0;
 500 }
 501
 502 static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 503 {
 504         struct object *obj;
 505
 506         obj = lookup_object(sha1);
 507         if (!obj) {
 508                 if (has_sha1_file(sha1)) {
 509                         default_refs++;
 510                         return 0; /* it is in a pack */
 511                 }
 512                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
 513                 /* We'll continue with the rest despite the error.. */
 514                 return 0;
 515         }
 516         default_refs++;
 517         obj->used = 1;
 518         mark_reachable(obj, REACHABLE);
 519
 520         return 0;
 521 }
 522
 523 static void get_default_heads(void)
 524 {
 525         for_each_ref(fsck_handle_ref, NULL);
 526         for_each_reflog(fsck_handle_reflog, NULL);
 527
 528         /*
 529          * Not having any default heads isn't really fatal, but
 530          * it does mean that "--unreachable" no longer makes any
 531          * sense (since in this case everything will obviously
 532          * be unreachable by definition.
 533          *
 534          * Showing dangling objects is valid, though (as those
 535          * dangling objects are likely lost heads).
 536          *
 537          * So we just print a warning about it, and clear the
 538          * "show_unreachable" flag.
 539          */
 540         if (!default_refs) {
 541                 fprintf(stderr, "notice: No default references\n");
 542                 show_unreachable = 0;
 543         }
 544 }
 545
 546 static void fsck_object_dir(const char *path)
 547 {
 548         int i;
 549         for (i = 0; i < 256; i++) {
 550                 static char dir[4096];
 551                 sprintf(dir, "%s/%02x", path, i);
 552                 fsck_dir(i, dir);
 553         }
 554         fsck_sha1_list();
 555 }
 556
 557 static int fsck_head_link(void)
 558 {
 559         unsigned char sha1[20];
 560         int flag;
 561         int null_is_error = 0;
 562         const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag);
 563
 564         if (!head_points_at)
 565                 return error("Invalid HEAD");
 566         if (!strcmp(head_points_at, "HEAD"))
 567                 /* detached HEAD */
 568                 null_is_error = 1;
 569         else if (prefixcmp(head_points_at, "refs/heads/"))
 570                 return error("HEAD points to something strange (%s)",
 571                              head_points_at);
 572         if (is_null_sha1(sha1)) {
 573                 if (null_is_error)
 574                         return error("HEAD: detached HEAD points at nothing");
 575                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
 576                         head_points_at + 11);
 577         }
 578         return 0;
 579 }
 580
 581 static int fsck_cache_tree(struct cache_tree *it)
 582 {
 583         int i;
 584         int err = 0;
 585
 586         if (0 <= it->entry_count) {
 587                 struct object *obj = parse_object(it->sha1);
 588                 if (!obj) {
 589                         error("%s: invalid sha1 pointer in cache-tree",
 590                               sha1_to_hex(it->sha1));
 591                         return 1;
 592                 }
 593                 mark_reachable(obj, REACHABLE);
 594                 obj->used = 1;
 595                 if (obj->type != OBJ_TREE)
 596                         err |= objerror(obj, "non-tree in cache-tree");
 597         }
 598         for (i = 0; i < it->subtree_nr; i++)
 599                 err |= fsck_cache_tree(it->down[i]->cache_tree);
 600         return err;
 601 }
 602
 603 static const char fsck_usage[] =
 604 "git-fsck [--tags] [--root] [[--unreachable] [--cache] [--full] "
 605 "[--strict] <head-sha1>*]";
 606
 607 int cmd_fsck(int argc, char **argv, const char *prefix)
 608 {
 609         int i, heads;
 610
 611         track_object_refs = 1;
 612         errors_found = 0;
 613
 614         for (i = 1; i < argc; i++) {
 615                 const char *arg = argv[i];
 616
 617                 if (!strcmp(arg, "--unreachable")) {
 618                         show_unreachable = 1;
 619                         continue;
 620                 }
 621                 if (!strcmp(arg, "--tags")) {
 622                         show_tags = 1;
 623                         continue;
 624                 }
 625                 if (!strcmp(arg, "--root")) {
 626                         show_root = 1;
 627                         continue;
 628                 }
 629                 if (!strcmp(arg, "--cache")) {
 630                         keep_cache_objects = 1;
 631                         continue;
 632                 }
 633                 if (!strcmp(arg, "--full")) {
 634                         check_full = 1;
 635                         continue;
 636                 }
 637                 if (!strcmp(arg, "--strict")) {
 638                         check_strict = 1;
 639                         continue;
 640                 }
 641                 if (*arg == '-')
 642                         usage(fsck_usage);
 643         }
 644
 645         fsck_head_link();
 646         fsck_object_dir(get_object_directory());
 647         if (check_full) {
 648                 struct alternate_object_database *alt;
 649                 struct packed_git *p;
 650                 prepare_alt_odb();
 651                 for (alt = alt_odb_list; alt; alt = alt->next) {
 652                         char namebuf[PATH_MAX];
 653                         int namelen = alt->name - alt->base;
 654                         memcpy(namebuf, alt->base, namelen);
 655                         namebuf[namelen - 1] = 0;
 656                         fsck_object_dir(namebuf);
 657                 }
 658                 prepare_packed_git();
 659                 for (p = packed_git; p; p = p->next)
 660                         /* verify gives error messages itself */
 661                         verify_pack(p, 0);
 662
 663                 for (p = packed_git; p; p = p->next) {
 664                         uint32_t i, num = num_packed_objects(p);
 665                         for (i = 0; i < num; i++) {
 666                                 unsigned char sha1[20];
 667                                 nth_packed_object_sha1(p, i, sha1);
 668                                 fsck_sha1(sha1);
 669                         }
 670                 }
 671         }
 672
 673         heads = 0;
 674         for (i = 1; i < argc; i++) {
 675                 const char *arg = argv[i];
 676
 677                 if (*arg == '-')
 678                         continue;
 679
 680                 if (!get_sha1(arg, head_sha1)) {
 681                         struct object *obj = lookup_object(head_sha1);
 682
 683                         /* Error is printed by lookup_object(). */
 684                         if (!obj)
 685                                 continue;
 686
 687                         obj->used = 1;
 688                         mark_reachable(obj, REACHABLE);
 689                         heads++;
 690                         continue;
 691                 }
 692                 error("invalid parameter: expected sha1, got '%s'", arg);
 693         }
 694
 695         /*
 696          * If we've not been given any explicit head information, do the
 697          * default ones from .git/refs. We also consider the index file
 698          * in this case (ie this implies --cache).
 699          */
 700         if (!heads) {
 701                 get_default_heads();
 702                 keep_cache_objects = 1;
 703         }
 704
 705         if (keep_cache_objects) {
 706                 int i;
 707                 read_cache();
 708                 for (i = 0; i < active_nr; i++) {
 709                         struct blob *blob = lookup_blob(active_cache[i]->sha1);
 710                         struct object *obj;
 711                         if (!blob)
 712                                 continue;
 713                         obj = &blob->object;
 714                         obj->used = 1;
 715                         mark_reachable(obj, REACHABLE);
 716                 }
 717                 if (active_cache_tree)
 718                         fsck_cache_tree(active_cache_tree);
 719         }
 720
 721         check_connectivity();
 722         return errors_found;
 723 }