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
  12 #define REACHABLE 0x0001
  13
  14 static int show_root = 0;
  15 static int show_tags = 0;
  16 static int show_unreachable = 0;
  17 static int standalone = 0;
  18 static int check_full = 0;
  19 static int check_strict = 0;
  20 static int keep_cache_objects = 0;
  21 static unsigned char head_sha1[20];
  22
  23
  24 static void objreport(struct object *obj, const char *severity,
  25                       const char *err, va_list params)
  26 {
  27         fprintf(stderr, "%s in %s %s: ",
  28                 severity, obj->type, sha1_to_hex(obj->sha1));
  29         vfprintf(stderr, err, params);
  30         fputs("\n", stderr);
  31 }
  32
  33 static int objerror(struct object *obj, const char *err, ...)
  34 {
  35         va_list params;
  36         va_start(params, err);
  37         objreport(obj, "error", err, params);
  38         va_end(params);
  39         return -1;
  40 }
  41
  42 static int objwarning(struct object *obj, const char *err, ...)
  43 {
  44         va_list params;
  45         va_start(params, err);
  46         objreport(obj, "warning", err, params);
  47         va_end(params);
  48         return -1;
  49 }
  50
  51
  52 static void check_connectivity(void)
  53 {
  54         int i;
  55
  56         /* Look up all the requirements, warn about missing objects.. */
  57         for (i = 0; i < nr_objs; i++) {
  58                 struct object *obj = objs[i];
  59                 struct object_list *refs;
  60
  61                 if (!obj->parsed) {
  62                         if (!standalone && has_sha1_file(obj->sha1))
  63                                 ; /* it is in pack */
  64                         else
  65                                 printf("missing %s %s\n",
  66                                        obj->type, sha1_to_hex(obj->sha1));
  67                         continue;
  68                 }
  69
  70                 for (refs = obj->refs; refs; refs = refs->next) {
  71                         if (refs->item->parsed ||
  72                             (!standalone && has_sha1_file(refs->item->sha1)))
  73                                 continue;
  74                         printf("broken link from %7s %s\n",
  75                                obj->type, sha1_to_hex(obj->sha1));
  76                         printf("              to %7s %s\n",
  77                                refs->item->type, sha1_to_hex(refs->item->sha1));
  78                 }
  79
  80                 if (show_unreachable && !(obj->flags & REACHABLE)) {
  81                         printf("unreachable %s %s\n",
  82                                obj->type, sha1_to_hex(obj->sha1));
  83                         continue;
  84                 }
  85
  86                 if (!obj->used) {
  87                         printf("dangling %s %s\n", obj->type,
  88                                sha1_to_hex(obj->sha1));
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * The entries in a tree are ordered in the _path_ order,
  95  * which means that a directory entry is ordered by adding
  96  * a slash to the end of it.
  97  *
  98  * So a directory called "a" is ordered _after_ a file
  99  * called "a.c", because "a/" sorts after "a.c".
 100  */
 101 #define TREE_UNORDERED (-1)
 102 #define TREE_HAS_DUPS  (-2)
 103
 104 static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
 105 {
 106         int len1 = strlen(a->name);
 107         int len2 = strlen(b->name);
 108         int len = len1 < len2 ? len1 : len2;
 109         unsigned char c1, c2;
 110         int cmp;
 111
 112         cmp = memcmp(a->name, b->name, len);
 113         if (cmp < 0)
 114                 return 0;
 115         if (cmp > 0)
 116                 return TREE_UNORDERED;
 117
 118         /*
 119          * Ok, the first <len> characters are the same.
 120          * Now we need to order the next one, but turn
 121          * a '\0' into a '/' for a directory entry.
 122          */
 123         c1 = a->name[len];
 124         c2 = b->name[len];
 125         if (!c1 && !c2)
 126                 /*
 127                  * git-write-tree used to write out a nonsense tree that has
 128                  * entries with the same name, one blob and one tree.  Make
 129                  * sure we do not have duplicate entries.
 130                  */
 131                 return TREE_HAS_DUPS;
 132         if (!c1 && a->directory)
 133                 c1 = '/';
 134         if (!c2 && b->directory)
 135                 c2 = '/';
 136         return c1 < c2 ? 0 : TREE_UNORDERED;
 137 }
 138
 139 static int fsck_tree(struct tree *item)
 140 {
 141         int retval;
 142         int has_full_path = 0;
 143         int has_zero_pad = 0;
 144         int has_bad_modes = 0;
 145         int has_dup_entries = 0;
 146         int not_properly_sorted = 0;
 147         struct tree_entry_list *entry, *last;
 148
 149         last = NULL;
 150         for (entry = item->entries; entry; entry = entry->next) {
 151                 if (strchr(entry->name, '/'))
 152                         has_full_path = 1;
 153                 has_zero_pad |= entry->zeropad;
 154
 155                 switch (entry->mode) {
 156                 /*
 157                  * Standard modes..
 158                  */
 159                 case S_IFREG | 0755:
 160                 case S_IFREG | 0644:
 161                 case S_IFLNK:
 162                 case S_IFDIR:
 163                         break;
 164                 /*
 165                  * This is nonstandard, but we had a few of these
 166                  * early on when we honored the full set of mode
 167                  * bits..
 168                  */
 169                 case S_IFREG | 0664:
 170                         if (!check_strict)
 171                                 break;
 172                 default:
 173                         has_bad_modes = 1;
 174                 }
 175
 176                 if (last) {
 177                         switch (verify_ordered(last, entry)) {
 178                         case TREE_UNORDERED:
 179                                 not_properly_sorted = 1;
 180                                 break;
 181                         case TREE_HAS_DUPS:
 182                                 has_dup_entries = 1;
 183                                 break;
 184                         default:
 185                                 break;
 186                         }
 187                 }
 188
 189                 last = entry;
 190         }
 191
 192         retval = 0;
 193         if (has_full_path) {
 194                 objwarning(&item->object, "contains full pathnames");
 195         }
 196         if (has_zero_pad) {
 197                 objwarning(&item->object, "contains zero-padded file modes");
 198         }
 199         if (has_bad_modes) {
 200                 objwarning(&item->object, "contains bad file modes");
 201         }
 202         if (has_dup_entries) {
 203                 retval = objerror(&item->object, "contains duplicate file entries");
 204         }
 205         if (not_properly_sorted) {
 206                 retval = objerror(&item->object, "not properly sorted");
 207         }
 208         return retval;
 209 }
 210
 211 static int fsck_commit(struct commit *commit)
 212 {
 213         char *buffer = commit->buffer;
 214         unsigned char tree_sha1[20], sha1[20];
 215
 216         if (memcmp(buffer, "tree ", 5))
 217                 return objerror(&commit->object, "invalid format - expected 'tree' line");
 218         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
 219                 return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
 220         buffer += 46;
 221         while (!memcmp(buffer, "parent ", 7)) {
 222                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
 223                         return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
 224                 buffer += 48;
 225         }
 226         if (memcmp(buffer, "author ", 7))
 227                 return objerror(&commit->object, "invalid format - expected 'author' line");
 228         free(commit->buffer);
 229         commit->buffer = NULL;
 230         if (!commit->tree)
 231                 return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
 232         if (!commit->parents && show_root)
 233                 printf("root %s\n", sha1_to_hex(commit->object.sha1));
 234         if (!commit->date)
 235                 printf("bad commit date in %s\n",
 236                        sha1_to_hex(commit->object.sha1));
 237         return 0;
 238 }
 239
 240 static int fsck_tag(struct tag *tag)
 241 {
 242         struct object *tagged = tag->tagged;
 243
 244         if (!tagged) {
 245                 return objerror(&tag->object, "could not load tagged object");
 246         }
 247         if (!show_tags)
 248                 return 0;
 249
 250         printf("tagged %s %s", tagged->type, sha1_to_hex(tagged->sha1));
 251         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 252         return 0;
 253 }
 254
 255 static int fsck_sha1(unsigned char *sha1)
 256 {
 257         struct object *obj = parse_object(sha1);
 258         if (!obj)
 259                 return error("%s: object not found", sha1_to_hex(sha1));
 260         if (obj->type == blob_type)
 261                 return 0;
 262         if (obj->type == tree_type)
 263                 return fsck_tree((struct tree *) obj);
 264         if (obj->type == commit_type)
 265                 return fsck_commit((struct commit *) obj);
 266         if (obj->type == tag_type)
 267                 return fsck_tag((struct tag *) obj);
 268         /* By now, parse_object() would've returned NULL instead. */
 269         return objerror(obj, "unknown type '%s' (internal fsck error)", obj->type);
 270 }
 271
 272 /*
 273  * This is the sorting chunk size: make it reasonably
 274  * big so that we can sort well..
 275  */
 276 #define MAX_SHA1_ENTRIES (1024)
 277
 278 struct sha1_entry {
 279         unsigned long ino;
 280         unsigned char sha1[20];
 281 };
 282
 283 static struct {
 284         unsigned long nr;
 285         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 286 } sha1_list;
 287
 288 static int ino_compare(const void *_a, const void *_b)
 289 {
 290         const struct sha1_entry *a = _a, *b = _b;
 291         unsigned long ino1 = a->ino, ino2 = b->ino;
 292         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 293 }
 294
 295 static void fsck_sha1_list(void)
 296 {
 297         int i, nr = sha1_list.nr;
 298
 299         qsort(sha1_list.entry, nr, sizeof(struct sha1_entry *), ino_compare);
 300         for (i = 0; i < nr; i++) {
 301                 struct sha1_entry *entry = sha1_list.entry[i];
 302                 unsigned char *sha1 = entry->sha1;
 303
 304                 sha1_list.entry[i] = NULL;
 305                 fsck_sha1(sha1);
 306                 free(entry);
 307         }
 308         sha1_list.nr = 0;
 309 }
 310
 311 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 312 {
 313         struct sha1_entry *entry = xmalloc(sizeof(*entry));
 314         int nr;
 315
 316         entry->ino = ino;
 317         memcpy(entry->sha1, sha1, 20);
 318         nr = sha1_list.nr;
 319         if (nr == MAX_SHA1_ENTRIES) {
 320                 fsck_sha1_list();
 321                 nr = 0;
 322         }
 323         sha1_list.entry[nr] = entry;
 324         sha1_list.nr = ++nr;
 325 }
 326
 327 static int fsck_dir(int i, char *path)
 328 {
 329         DIR *dir = opendir(path);
 330         struct dirent *de;
 331
 332         if (!dir) {
 333                 return error("missing sha1 directory '%s'", path);
 334         }
 335
 336         while ((de = readdir(dir)) != NULL) {
 337                 char name[100];
 338                 unsigned char sha1[20];
 339                 int len = strlen(de->d_name);
 340
 341                 switch (len) {
 342                 case 2:
 343                         if (de->d_name[1] != '.')
 344                                 break;
 345                 case 1:
 346                         if (de->d_name[0] != '.')
 347                                 break;
 348                         continue;
 349                 case 38:
 350                         sprintf(name, "%02x", i);
 351                         memcpy(name+2, de->d_name, len+1);
 352                         if (get_sha1_hex(name, sha1) < 0)
 353                                 break;
 354                         add_sha1_list(sha1, de->d_ino);
 355                         continue;
 356                 }
 357                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 358         }
 359         closedir(dir);
 360         return 0;
 361 }
 362
 363 static int default_refs = 0;
 364
 365 static int fsck_handle_ref(const char *refname, const unsigned char *sha1)
 366 {
 367         struct object *obj;
 368
 369         obj = lookup_object(sha1);
 370         if (!obj) {
 371                 if (!standalone && has_sha1_file(sha1)) {
 372                         default_refs++;
 373                         return 0; /* it is in a pack */
 374                 }
 375                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
 376                 /* We'll continue with the rest despite the error.. */
 377                 return 0;
 378         }
 379         default_refs++;
 380         obj->used = 1;
 381         mark_reachable(obj, REACHABLE);
 382         return 0;
 383 }
 384
 385 static void get_default_heads(void)
 386 {
 387         for_each_ref(fsck_handle_ref);
 388         if (!default_refs)
 389                 die("No default references");
 390 }
 391
 392 static void fsck_object_dir(const char *path)
 393 {
 394         int i;
 395         for (i = 0; i < 256; i++) {
 396                 static char dir[4096];
 397                 sprintf(dir, "%s/%02x", path, i);
 398                 fsck_dir(i, dir);
 399         }
 400         fsck_sha1_list();
 401 }
 402
 403 static int fsck_head_link(void)
 404 {
 405         unsigned char sha1[20];
 406         const char *git_HEAD = strdup(git_path("HEAD"));
 407         const char *git_refs_heads_master = resolve_ref(git_HEAD, sha1, 1);
 408         int pfxlen = strlen(git_HEAD) - 4; /* strip .../.git/ part */
 409
 410         if (!git_refs_heads_master)
 411                 return error("HEAD is not a symbolic ref");
 412         if (strncmp(git_refs_heads_master + pfxlen, "refs/heads/", 11))
 413                 return error("HEAD points to something strange (%s)",
 414                              git_refs_heads_master + pfxlen);
 415         if (!memcmp(null_sha1, sha1, 20))
 416                 return error("HEAD: not a valid git pointer");
 417         return 0;
 418 }
 419
 420 int main(int argc, char **argv)
 421 {
 422         int i, heads;
 423
 424         for (i = 1; i < argc; i++) {
 425                 const char *arg = argv[i];
 426
 427                 if (!strcmp(arg, "--unreachable")) {
 428                         show_unreachable = 1;
 429                         continue;
 430                 }
 431                 if (!strcmp(arg, "--tags")) {
 432                         show_tags = 1;
 433                         continue;
 434                 }
 435                 if (!strcmp(arg, "--root")) {
 436                         show_root = 1;
 437                         continue;
 438                 }
 439                 if (!strcmp(arg, "--cache")) {
 440                         keep_cache_objects = 1;
 441                         continue;
 442                 }
 443                 if (!strcmp(arg, "--standalone")) {
 444                         standalone = 1;
 445                         continue;
 446                 }
 447                 if (!strcmp(arg, "--full")) {
 448                         check_full = 1;
 449                         continue;
 450                 }
 451                 if (!strcmp(arg, "--strict")) {
 452                         check_strict = 1;
 453                         continue;
 454                 }
 455                 if (*arg == '-')
 456                         usage("git-fsck-objects [--tags] [--root] [[--unreachable] [--cache] [--standalone | --full] [--strict] <head-sha1>*]");
 457         }
 458
 459         if (standalone && check_full)
 460                 die("Only one of --standalone or --full can be used.");
 461         if (standalone)
 462                 putenv("GIT_ALTERNATE_OBJECT_DIRECTORIES=");
 463
 464         fsck_head_link();
 465         fsck_object_dir(get_object_directory());
 466         if (check_full) {
 467                 struct alternate_object_database *alt;
 468                 struct packed_git *p;
 469                 prepare_alt_odb();
 470                 for (alt = alt_odb_list; alt; alt = alt->next) {
 471                         char namebuf[PATH_MAX];
 472                         int namelen = alt->name - alt->base;
 473                         memcpy(namebuf, alt->base, namelen);
 474                         namebuf[namelen - 1] = 0;
 475                         fsck_object_dir(namebuf);
 476                 }
 477                 prepare_packed_git();
 478                 for (p = packed_git; p; p = p->next)
 479                         /* verify gives error messages itself */
 480                         verify_pack(p, 0);
 481
 482                 for (p = packed_git; p; p = p->next) {
 483                         int num = num_packed_objects(p);
 484                         for (i = 0; i < num; i++) {
 485                                 unsigned char sha1[20];
 486                                 nth_packed_object_sha1(p, i, sha1);
 487                                 fsck_sha1(sha1);
 488                         }
 489                 }
 490         }
 491
 492         heads = 0;
 493         for (i = 1; i < argc; i++) {
 494                 const char *arg = argv[i];
 495
 496                 if (*arg == '-')
 497                         continue;
 498
 499                 if (!get_sha1(arg, head_sha1)) {
 500                         struct object *obj = lookup_object(head_sha1);
 501
 502                         /* Error is printed by lookup_object(). */
 503                         if (!obj)
 504                                 continue;
 505
 506                         obj->used = 1;
 507                         mark_reachable(obj, REACHABLE);
 508                         heads++;
 509                         continue;
 510                 }
 511                 error("invalid parameter: expected sha1, got '%s'", arg);
 512         }
 513
 514         /*
 515          * If we've not been given any explicit head information, do the
 516          * default ones from .git/refs. We also consider the index file
 517          * in this case (ie this implies --cache).
 518          */
 519         if (!heads) {
 520                 get_default_heads();
 521                 keep_cache_objects = 1;
 522         }
 523
 524         if (keep_cache_objects) {
 525                 int i;
 526                 read_cache();
 527                 for (i = 0; i < active_nr; i++) {
 528                         struct blob *blob = lookup_blob(active_cache[i]->sha1);
 529                         struct object *obj;
 530                         if (!blob)
 531                                 continue;
 532                         obj = &blob->object;
 533                         obj->used = 1;
 534                         mark_reachable(obj, REACHABLE);
 535                 }
 536         }
 537
 538         check_connectivity();
 539         return 0;
 540 }