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