fsck-objects.c

   1 #include <sys/types.h>
   2 #include <dirent.h>
   3
   4 #include "cache.h"
   5 #include "commit.h"
   6 #include "tree.h"
   7 #include "blob.h"
   8 #include "tag.h"
   9 #include "refs.h"
  10 #include "pack.h"
  11 #include "cache-tree.h"
  12 #include "tree-walk.h"
  13
  14 #define REACHABLE 0x0001
  15 #define SEEN      0x0002
  16
  17 static int show_root = 0;
  18 static int show_tags = 0;
  19 static int show_unreachable = 0;
  20 static int check_full = 0;
  21 static int check_strict = 0;
  22 static int keep_cache_objects = 0;
  23 static unsigned char head_sha1[20];
  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         objreport(obj, "error", err, params);
  47         va_end(params);
  48         return -1;
  49 }
  50
  51 static int objwarning(struct object *obj, const char *err, ...)
  52 {
  53         va_list params;
  54         va_start(params, err);
  55         objreport(obj, "warning", err, params);
  56         va_end(params);
  57         return -1;
  58 }
  59
  60
  61 static void check_connectivity(void)
  62 {
  63         int i;
  64
  65         /* Look up all the requirements, warn about missing objects.. */
  66         for (i = 0; i < obj_allocs; i++) {
  67                 const struct object_refs *refs;
  68                 struct object *obj = objs[i];
  69
  70                 if (!obj)
  71                         continue;
  72
  73                 if (!obj->parsed) {
  74                         if (has_sha1_file(obj->sha1))
  75                                 ; /* it is in pack */
  76                         else
  77                                 printf("missing %s %s\n",
  78                                        typename(obj->type), sha1_to_hex(obj->sha1));
  79                         continue;
  80                 }
  81
  82                 refs = lookup_object_refs(obj);
  83                 if (refs) {
  84                         unsigned j;
  85                         for (j = 0; j < refs->count; j++) {
  86                                 struct object *ref = refs->ref[j];
  87                                 if (ref->parsed ||
  88                                     (has_sha1_file(ref->sha1)))
  89                                         continue;
  90                                 printf("broken link from %7s %s\n",
  91                                        typename(obj->type), sha1_to_hex(obj->sha1));
  92                                 printf("              to %7s %s\n",
  93                                        typename(ref->type), sha1_to_hex(ref->sha1));
  94                         }
  95                 }
  96
  97                 if (show_unreachable && !(obj->flags & REACHABLE)) {
  98                         printf("unreachable %s %s\n",
  99                                typename(obj->type), sha1_to_hex(obj->sha1));
 100                         continue;
 101                 }
 102
 103                 if (!obj->used) {
 104                         printf("dangling %s %s\n", typename(obj->type),
 105                                sha1_to_hex(obj->sha1));
 106                 }
 107         }
 108 }
 109
 110 /*
 111  * The entries in a tree are ordered in the _path_ order,
 112  * which means that a directory entry is ordered by adding
 113  * a slash to the end of it.
 114  *
 115  * So a directory called "a" is ordered _after_ a file
 116  * called "a.c", because "a/" sorts after "a.c".
 117  */
 118 #define TREE_UNORDERED (-1)
 119 #define TREE_HAS_DUPS  (-2)
 120
 121 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 122 {
 123         int len1 = strlen(name1);
 124         int len2 = strlen(name2);
 125         int len = len1 < len2 ? len1 : len2;
 126         unsigned char c1, c2;
 127         int cmp;
 128
 129         cmp = memcmp(name1, name2, len);
 130         if (cmp < 0)
 131                 return 0;
 132         if (cmp > 0)
 133                 return TREE_UNORDERED;
 134
 135         /*
 136          * Ok, the first <len> characters are the same.
 137          * Now we need to order the next one, but turn
 138          * a '\0' into a '/' for a directory entry.
 139          */
 140         c1 = name1[len];
 141         c2 = name2[len];
 142         if (!c1 && !c2)
 143                 /*
 144                  * git-write-tree used to write out a nonsense tree that has
 145                  * entries with the same name, one blob and one tree.  Make
 146                  * sure we do not have duplicate entries.
 147                  */
 148                 return TREE_HAS_DUPS;
 149         if (!c1 && S_ISDIR(mode1))
 150                 c1 = '/';
 151         if (!c2 && S_ISDIR(mode2))
 152                 c2 = '/';
 153         return c1 < c2 ? 0 : TREE_UNORDERED;
 154 }
 155
 156 static int fsck_tree(struct tree *item)
 157 {
 158         int retval;
 159         int has_full_path = 0;
 160         int has_zero_pad = 0;
 161         int has_bad_modes = 0;
 162         int has_dup_entries = 0;
 163         int not_properly_sorted = 0;
 164         struct tree_desc desc;
 165         unsigned o_mode;
 166         const char *o_name;
 167         const unsigned char *o_sha1;
 168
 169         desc.buf = item->buffer;
 170         desc.size = item->size;
 171
 172         o_mode = 0;
 173         o_name = NULL;
 174         o_sha1 = NULL;
 175         while (desc.size) {
 176                 unsigned mode;
 177                 const char *name;
 178                 const unsigned char *sha1;
 179
 180                 sha1 = tree_entry_extract(&desc, &name, &mode);
 181
 182                 if (strchr(name, '/'))
 183                         has_full_path = 1;
 184                 has_zero_pad |= *(char *)desc.buf == '0';
 185                 update_tree_entry(&desc);
 186
 187                 switch (mode) {
 188                 /*
 189                  * Standard modes..
 190                  */
 191                 case S_IFREG | 0755:
 192                 case S_IFREG | 0644:
 193                 case S_IFLNK:
 194                 case S_IFDIR:
 195                         break;
 196                 /*
 197                  * This is nonstandard, but we had a few of these
 198                  * early on when we honored the full set of mode
 199                  * bits..
 200                  */
 201                 case S_IFREG | 0664:
 202                         if (!check_strict)
 203                                 break;
 204                 default:
 205                         has_bad_modes = 1;
 206                 }
 207
 208                 if (o_name) {
 209                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 210                         case TREE_UNORDERED:
 211                                 not_properly_sorted = 1;
 212                                 break;
 213                         case TREE_HAS_DUPS:
 214                                 has_dup_entries = 1;
 215                                 break;
 216                         default:
 217                                 break;
 218                         }
 219                 }
 220
 221                 o_mode = mode;
 222                 o_name = name;
 223                 o_sha1 = sha1;
 224         }
 225         free(item->buffer);
 226         item->buffer = NULL;
 227
 228         retval = 0;
 229         if (has_full_path) {
 230                 objwarning(&item->object, "contains full pathnames");
 231         }
 232         if (has_zero_pad) {
 233                 objwarning(&item->object, "contains zero-padded file modes");
 234         }
 235         if (has_bad_modes) {
 236                 objwarning(&item->object, "contains bad file modes");
 237         }
 238         if (has_dup_entries) {
 239                 retval = objerror(&item->object, "contains duplicate file entries");
 240         }
 241         if (not_properly_sorted) {
 242                 retval = objerror(&item->object, "not properly sorted");
 243         }
 244         return retval;
 245 }
 246
 247 static int fsck_commit(struct commit *commit)
 248 {
 249         char *buffer = commit->buffer;
 250         unsigned char tree_sha1[20], sha1[20];
 251
 252         if (memcmp(buffer, "tree ", 5))
 253                 return objerror(&commit->object, "invalid format - expected 'tree' line");
 254         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
 255                 return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
 256         buffer += 46;
 257         while (!memcmp(buffer, "parent ", 7)) {
 258                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
 259                         return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
 260                 buffer += 48;
 261         }
 262         if (memcmp(buffer, "author ", 7))
 263                 return objerror(&commit->object, "invalid format - expected 'author' line");
 264         free(commit->buffer);
 265         commit->buffer = NULL;
 266         if (!commit->tree)
 267                 return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
 268         if (!commit->parents && show_root)
 269                 printf("root %s\n", sha1_to_hex(commit->object.sha1));
 270         if (!commit->date)
 271                 printf("bad commit date in %s\n",
 272                        sha1_to_hex(commit->object.sha1));
 273         return 0;
 274 }
 275
 276 static int fsck_tag(struct tag *tag)
 277 {
 278         struct object *tagged = tag->tagged;
 279
 280         if (!tagged) {
 281                 return objerror(&tag->object, "could not load tagged object");
 282         }
 283         if (!show_tags)
 284                 return 0;
 285
 286         printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
 287         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 288         return 0;
 289 }
 290
 291 static int fsck_sha1(unsigned char *sha1)
 292 {
 293         struct object *obj = parse_object(sha1);
 294         if (!obj)
 295                 return error("%s: object not found", sha1_to_hex(sha1));
 296         if (obj->flags & SEEN)
 297                 return 0;
 298         obj->flags |= SEEN;
 299         if (obj->type == TYPE_BLOB)
 300                 return 0;
 301         if (obj->type == TYPE_TREE)
 302                 return fsck_tree((struct tree *) obj);
 303         if (obj->type == TYPE_COMMIT)
 304                 return fsck_commit((struct commit *) obj);
 305         if (obj->type == TYPE_TAG)
 306                 return fsck_tag((struct tag *) obj);
 307         /* By now, parse_object() would've returned NULL instead. */
 308         return objerror(obj, "unknown type '%d' (internal fsck error)", obj->type);
 309 }
 310
 311 /*
 312  * This is the sorting chunk size: make it reasonably
 313  * big so that we can sort well..
 314  */
 315 #define MAX_SHA1_ENTRIES (1024)
 316
 317 struct sha1_entry {
 318         unsigned long ino;
 319         unsigned char sha1[20];
 320 };
 321
 322 static struct {
 323         unsigned long nr;
 324         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 325 } sha1_list;
 326
 327 static int ino_compare(const void *_a, const void *_b)
 328 {
 329         const struct sha1_entry *a = _a, *b = _b;
 330         unsigned long ino1 = a->ino, ino2 = b->ino;
 331         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 332 }
 333
 334 static void fsck_sha1_list(void)
 335 {
 336         int i, nr = sha1_list.nr;
 337
 338         if (SORT_DIRENT)
 339                 qsort(sha1_list.entry, nr,
 340                       sizeof(struct sha1_entry *), ino_compare);
 341         for (i = 0; i < nr; i++) {
 342                 struct sha1_entry *entry = sha1_list.entry[i];
 343                 unsigned char *sha1 = entry->sha1;
 344
 345                 sha1_list.entry[i] = NULL;
 346                 fsck_sha1(sha1);
 347                 free(entry);
 348         }
 349         sha1_list.nr = 0;
 350 }
 351
 352 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 353 {
 354         struct sha1_entry *entry = xmalloc(sizeof(*entry));
 355         int nr;
 356
 357         entry->ino = ino;
 358         memcpy(entry->sha1, sha1, 20);
 359         nr = sha1_list.nr;
 360         if (nr == MAX_SHA1_ENTRIES) {
 361                 fsck_sha1_list();
 362                 nr = 0;
 363         }
 364         sha1_list.entry[nr] = entry;
 365         sha1_list.nr = ++nr;
 366 }
 367
 368 static int fsck_dir(int i, char *path)
 369 {
 370         DIR *dir = opendir(path);
 371         struct dirent *de;
 372
 373         if (!dir)
 374                 return 0;
 375
 376         while ((de = readdir(dir)) != NULL) {
 377                 char name[100];
 378                 unsigned char sha1[20];
 379                 int len = strlen(de->d_name);
 380
 381                 switch (len) {
 382                 case 2:
 383                         if (de->d_name[1] != '.')
 384                                 break;
 385                 case 1:
 386                         if (de->d_name[0] != '.')
 387                                 break;
 388                         continue;
 389                 case 38:
 390                         sprintf(name, "%02x", i);
 391                         memcpy(name+2, de->d_name, len+1);
 392                         if (get_sha1_hex(name, sha1) < 0)
 393                                 break;
 394                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
 395                         continue;
 396                 }
 397                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 398         }
 399         closedir(dir);
 400         return 0;
 401 }
 402
 403 static int default_refs = 0;
 404
 405 static int fsck_handle_ref(const char *refname, const unsigned char *sha1)
 406 {
 407         struct object *obj;
 408
 409         obj = lookup_object(sha1);
 410         if (!obj) {
 411                 if (has_sha1_file(sha1)) {
 412                         default_refs++;
 413                         return 0; /* it is in a pack */
 414                 }
 415                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
 416                 /* We'll continue with the rest despite the error.. */
 417                 return 0;
 418         }
 419         default_refs++;
 420         obj->used = 1;
 421         mark_reachable(obj, REACHABLE);
 422         return 0;
 423 }
 424
 425 static void get_default_heads(void)
 426 {
 427         for_each_ref(fsck_handle_ref);
 428         if (!default_refs)
 429                 die("No default references");
 430 }
 431
 432 static void fsck_object_dir(const char *path)
 433 {
 434         int i;
 435         for (i = 0; i < 256; i++) {
 436                 static char dir[4096];
 437                 sprintf(dir, "%s/%02x", path, i);
 438                 fsck_dir(i, dir);
 439         }
 440         fsck_sha1_list();
 441 }
 442
 443 static int fsck_head_link(void)
 444 {
 445         unsigned char sha1[20];
 446         const char *git_HEAD = strdup(git_path("HEAD"));
 447         const char *git_refs_heads_master = resolve_ref(git_HEAD, sha1, 1);
 448         int pfxlen = strlen(git_HEAD) - 4; /* strip .../.git/ part */
 449
 450         if (!git_refs_heads_master)
 451                 return error("HEAD is not a symbolic ref");
 452         if (strncmp(git_refs_heads_master + pfxlen, "refs/heads/", 11))
 453                 return error("HEAD points to something strange (%s)",
 454                              git_refs_heads_master + pfxlen);
 455         if (!memcmp(null_sha1, sha1, 20))
 456                 return error("HEAD: not a valid git pointer");
 457         return 0;
 458 }
 459
 460 static int fsck_cache_tree(struct cache_tree *it)
 461 {
 462         int i;
 463         int err = 0;
 464
 465         if (0 <= it->entry_count) {
 466                 struct object *obj = parse_object(it->sha1);
 467                 if (!obj) {
 468                         error("%s: invalid sha1 pointer in cache-tree",
 469                               sha1_to_hex(it->sha1));
 470                         return 1;
 471                 }
 472                 mark_reachable(obj, REACHABLE);
 473                 obj->used = 1;
 474                 if (obj->type != TYPE_TREE)
 475                         err |= objerror(obj, "non-tree in cache-tree");
 476         }
 477         for (i = 0; i < it->subtree_nr; i++)
 478                 err |= fsck_cache_tree(it->down[i]->cache_tree);
 479         return err;
 480 }
 481
 482 int main(int argc, char **argv)
 483 {
 484         int i, heads;
 485
 486         track_object_refs = 1;
 487         setup_git_directory();
 488
 489         for (i = 1; i < argc; i++) {
 490                 const char *arg = argv[i];
 491
 492                 if (!strcmp(arg, "--unreachable")) {
 493                         show_unreachable = 1;
 494                         continue;
 495                 }
 496                 if (!strcmp(arg, "--tags")) {
 497                         show_tags = 1;
 498                         continue;
 499                 }
 500                 if (!strcmp(arg, "--root")) {
 501                         show_root = 1;
 502                         continue;
 503                 }
 504                 if (!strcmp(arg, "--cache")) {
 505                         keep_cache_objects = 1;
 506                         continue;
 507                 }
 508                 if (!strcmp(arg, "--full")) {
 509                         check_full = 1;
 510                         continue;
 511                 }
 512                 if (!strcmp(arg, "--strict")) {
 513                         check_strict = 1;
 514                         continue;
 515                 }
 516                 if (*arg == '-')
 517                         usage("git-fsck-objects [--tags] [--root] [[--unreachable] [--cache] [--full] [--strict] <head-sha1>*]");
 518         }
 519
 520         fsck_head_link();
 521         fsck_object_dir(get_object_directory());
 522         if (check_full) {
 523                 struct alternate_object_database *alt;
 524                 struct packed_git *p;
 525                 prepare_alt_odb();
 526                 for (alt = alt_odb_list; alt; alt = alt->next) {
 527                         char namebuf[PATH_MAX];
 528                         int namelen = alt->name - alt->base;
 529                         memcpy(namebuf, alt->base, namelen);
 530                         namebuf[namelen - 1] = 0;
 531                         fsck_object_dir(namebuf);
 532                 }
 533                 prepare_packed_git();
 534                 for (p = packed_git; p; p = p->next)
 535                         /* verify gives error messages itself */
 536                         verify_pack(p, 0);
 537
 538                 for (p = packed_git; p; p = p->next) {
 539                         int num = num_packed_objects(p);
 540                         for (i = 0; i < num; i++) {
 541                                 unsigned char sha1[20];
 542                                 nth_packed_object_sha1(p, i, sha1);
 543                                 fsck_sha1(sha1);
 544                         }
 545                 }
 546         }
 547
 548         heads = 0;
 549         for (i = 1; i < argc; i++) {
 550                 const char *arg = argv[i];
 551
 552                 if (*arg == '-')
 553                         continue;
 554
 555                 if (!get_sha1(arg, head_sha1)) {
 556                         struct object *obj = lookup_object(head_sha1);
 557
 558                         /* Error is printed by lookup_object(). */
 559                         if (!obj)
 560                                 continue;
 561
 562                         obj->used = 1;
 563                         mark_reachable(obj, REACHABLE);
 564                         heads++;
 565                         continue;
 566                 }
 567                 error("invalid parameter: expected sha1, got '%s'", arg);
 568         }
 569
 570         /*
 571          * If we've not been given any explicit head information, do the
 572          * default ones from .git/refs. We also consider the index file
 573          * in this case (ie this implies --cache).
 574          */
 575         if (!heads) {
 576                 get_default_heads();
 577                 keep_cache_objects = 1;
 578         }
 579
 580         if (keep_cache_objects) {
 581                 int i;
 582                 read_cache();
 583                 for (i = 0; i < active_nr; i++) {
 584                         struct blob *blob = lookup_blob(active_cache[i]->sha1);
 585                         struct object *obj;
 586                         if (!blob)
 587                                 continue;
 588                         obj = &blob->object;
 589                         obj->used = 1;
 590                         mark_reachable(obj, REACHABLE);
 591                 }
 592                 if (active_cache_tree)
 593                         fsck_cache_tree(active_cache_tree);
 594         }
 595
 596         check_connectivity();
 597         return 0;
 598 }