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