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