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