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