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 "delta.h"
  10
  11 #define REACHABLE 0x0001
  12
  13 static int show_root = 0;
  14 static int show_tags = 0;
  15 static int show_unreachable = 0;
  16 static int show_max_delta_depth = 0;
  17 static int keep_cache_objects = 0;
  18 static unsigned char head_sha1[20];
  19
  20 static void expand_deltas(void)
  21 {
  22         int i, max_depth = 0;
  23
  24         /*
  25          * To be as efficient as possible we look for delta heads and
  26          * recursively process them going backward, and parsing
  27          * resulting objects along the way.  This allows for processing
  28          * each delta objects only once regardless of the delta depth.
  29          */
  30         for (i = 0; i < nr_objs; i++) {
  31                 struct object *obj = objs[i];
  32                 if (obj->parsed && !obj->delta && obj->attached_deltas) {
  33                         int depth = 0;
  34                         char type[10];
  35                         unsigned long size;
  36                         void *buf = read_sha1_file(obj->sha1, type, &size);
  37                         if (!buf)
  38                                 continue;
  39                         depth = process_deltas(buf, size, obj->type,
  40                                                obj->attached_deltas);
  41                         if (max_depth < depth)
  42                                 max_depth = depth;
  43                 }
  44         }
  45         if (show_max_delta_depth)
  46                 printf("maximum delta depth = %d\n", max_depth);
  47 }
  48
  49 static void check_connectivity(void)
  50 {
  51         int i;
  52
  53         /* Look up all the requirements, warn about missing objects.. */
  54         for (i = 0; i < nr_objs; i++) {
  55                 struct object *obj = objs[i];
  56                 struct object_list *refs;
  57
  58                 if (!obj->parsed) {
  59                         if (obj->delta)
  60                                 printf("unresolved delta %s\n",
  61                                        sha1_to_hex(obj->sha1));
  62                         else
  63                                 printf("missing %s %s\n",
  64                                        obj->type, sha1_to_hex(obj->sha1));
  65                         continue;
  66                 }
  67
  68                 for (refs = obj->refs; refs; refs = refs->next) {
  69                         if (refs->item->parsed)
  70                                 continue;
  71                         printf("broken link from %7s %s\n",
  72                                obj->type, sha1_to_hex(obj->sha1));
  73                         printf("              to %7s %s\n",
  74                                refs->item->type, sha1_to_hex(refs->item->sha1));
  75                 }
  76
  77                 if (show_unreachable && !(obj->flags & REACHABLE)) {
  78                         if (obj->attached_deltas)
  79                                 printf("foreign delta reference %s\n",
  80                                        sha1_to_hex(obj->sha1));
  81                         else
  82                                 printf("unreachable %s %s\n",
  83                                        obj->type, sha1_to_hex(obj->sha1));
  84                         continue;
  85                 }
  86
  87                 if (!obj->used) {
  88                         printf("dangling %s %s\n", obj->type,
  89                                sha1_to_hex(obj->sha1));
  90                 }
  91         }
  92 }
  93
  94 /*
  95  * The entries in a tree are ordered in the _path_ order,
  96  * which means that a directory entry is ordered by adding
  97  * a slash to the end of it.
  98  *
  99  * So a directory called "a" is ordered _after_ a file
 100  * called "a.c", because "a/" sorts after "a.c".
 101  */
 102 #define TREE_UNORDERED (-1)
 103 #define TREE_HAS_DUPS  (-2)
 104
 105 static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
 106 {
 107         int len1 = strlen(a->name);
 108         int len2 = strlen(b->name);
 109         int len = len1 < len2 ? len1 : len2;
 110         unsigned char c1, c2;
 111         int cmp;
 112
 113         cmp = memcmp(a->name, b->name, len);
 114         if (cmp < 0)
 115                 return 0;
 116         if (cmp > 0)
 117                 return TREE_UNORDERED;
 118
 119         /*
 120          * Ok, the first <len> characters are the same.
 121          * Now we need to order the next one, but turn
 122          * a '\0' into a '/' for a directory entry.
 123          */
 124         c1 = a->name[len];
 125         c2 = b->name[len];
 126         if (!c1 && !c2)
 127                 /*
 128                  * git-write-tree used to write out a nonsense tree that has
 129                  * entries with the same name, one blob and one tree.  Make
 130                  * sure we do not have duplicate entries.
 131                  */
 132                 return TREE_HAS_DUPS;
 133         if (!c1 && a->directory)
 134                 c1 = '/';
 135         if (!c2 && b->directory)
 136                 c2 = '/';
 137         return c1 < c2 ? 0 : TREE_UNORDERED;
 138 }
 139
 140 static int fsck_tree(struct tree *item)
 141 {
 142         int has_full_path = 0;
 143         struct tree_entry_list *entry, *last;
 144
 145         last = NULL;
 146         for (entry = item->entries; entry; entry = entry->next) {
 147                 if (strchr(entry->name, '/'))
 148                         has_full_path = 1;
 149
 150                 switch (entry->mode) {
 151                 /*
 152                  * Standard modes..
 153                  */
 154                 case S_IFREG | 0755:
 155                 case S_IFREG | 0644:
 156                 case S_IFLNK:
 157                 case S_IFDIR:
 158                         break;
 159                 /*
 160                  * This is nonstandard, but we had a few of these
 161                  * early on when we honored the full set of mode
 162                  * bits..
 163                  */
 164                 case S_IFREG | 0664:
 165                         break;
 166                 default:
 167                         printf("tree %s has entry %o %s\n",
 168                                 sha1_to_hex(item->object.sha1),
 169                                 entry->mode, entry->name);
 170                 }
 171
 172                 if (last) {
 173                         switch (verify_ordered(last, entry)) {
 174                         case TREE_UNORDERED:
 175                                 fprintf(stderr, "tree %s not ordered\n",
 176                                         sha1_to_hex(item->object.sha1));
 177                                 return -1;
 178                         case TREE_HAS_DUPS:
 179                                 fprintf(stderr, "tree %s has duplicate entries for '%s'\n",
 180                                         sha1_to_hex(item->object.sha1),
 181                                         entry->name);
 182                                 return -1;
 183                         default:
 184                                 break;
 185                         }
 186                 }
 187
 188                 last = entry;
 189         }
 190
 191         if (has_full_path) {
 192                 fprintf(stderr, "warning: git-fsck-cache: tree %s "
 193                         "has full pathnames in it\n",
 194                         sha1_to_hex(item->object.sha1));
 195         }
 196
 197         return 0;
 198 }
 199
 200 static int fsck_commit(struct commit *commit)
 201 {
 202         free(commit->buffer);
 203         commit->buffer = NULL;
 204         if (!commit->tree)
 205                 return -1;
 206         if (!commit->parents && show_root)
 207                 printf("root %s\n", sha1_to_hex(commit->object.sha1));
 208         if (!commit->date)
 209                 printf("bad commit date in %s\n",
 210                        sha1_to_hex(commit->object.sha1));
 211         return 0;
 212 }
 213
 214 static int fsck_tag(struct tag *tag)
 215 {
 216         struct object *tagged = tag->tagged;
 217
 218         if (!tagged) {
 219                 printf("bad object in tag %s\n", sha1_to_hex(tag->object.sha1));
 220                 return -1;
 221         }
 222         if (!show_tags)
 223                 return 0;
 224
 225         printf("tagged %s %s", tagged->type, sha1_to_hex(tagged->sha1));
 226         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 227         return 0;
 228 }
 229
 230 static int fsck_sha1(unsigned char *sha1)
 231 {
 232         struct object *obj = parse_object(sha1);
 233         if (!obj)
 234                 return -1;
 235         if (obj->type == blob_type)
 236                 return 0;
 237         if (obj->type == tree_type)
 238                 return fsck_tree((struct tree *) obj);
 239         if (obj->type == commit_type)
 240                 return fsck_commit((struct commit *) obj);
 241         if (obj->type == tag_type)
 242                 return fsck_tag((struct tag *) obj);
 243         if (!obj->type && obj->delta)
 244                 return 0;
 245         return -1;
 246 }
 247
 248 /*
 249  * This is the sorting chunk size: make it reasonably
 250  * big so that we can sort well..
 251  */
 252 #define MAX_SHA1_ENTRIES (1024)
 253
 254 struct sha1_entry {
 255         unsigned long ino;
 256         unsigned char sha1[20];
 257 };
 258
 259 static struct {
 260         unsigned long nr;
 261         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
 262 } sha1_list;
 263
 264 static int ino_compare(const void *_a, const void *_b)
 265 {
 266         const struct sha1_entry *a = _a, *b = _b;
 267         unsigned long ino1 = a->ino, ino2 = b->ino;
 268         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
 269 }
 270
 271 static void fsck_sha1_list(void)
 272 {
 273         int i, nr = sha1_list.nr;
 274
 275         qsort(sha1_list.entry, nr, sizeof(struct sha1_entry *), ino_compare);
 276         for (i = 0; i < nr; i++) {
 277                 struct sha1_entry *entry = sha1_list.entry[i];
 278                 unsigned char *sha1 = entry->sha1;
 279
 280                 sha1_list.entry[i] = NULL;
 281                 if (fsck_sha1(sha1) < 0)
 282                         fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(sha1));
 283                 free(entry);
 284         }
 285         sha1_list.nr = 0;
 286 }
 287
 288 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
 289 {
 290         struct sha1_entry *entry = xmalloc(sizeof(*entry));
 291         int nr;
 292
 293         entry->ino = ino;
 294         memcpy(entry->sha1, sha1, 20);
 295         nr = sha1_list.nr;
 296         if (nr == MAX_SHA1_ENTRIES) {
 297                 fsck_sha1_list();
 298                 nr = 0;
 299         }
 300         sha1_list.entry[nr] = entry;
 301         sha1_list.nr = ++nr;
 302 }
 303
 304 static int fsck_dir(int i, char *path)
 305 {
 306         DIR *dir = opendir(path);
 307         struct dirent *de;
 308
 309         if (!dir) {
 310                 return error("missing sha1 directory '%s'", path);
 311         }
 312
 313         while ((de = readdir(dir)) != NULL) {
 314                 char name[100];
 315                 unsigned char sha1[20];
 316                 int len = strlen(de->d_name);
 317
 318                 switch (len) {
 319                 case 2:
 320                         if (de->d_name[1] != '.')
 321                                 break;
 322                 case 1:
 323                         if (de->d_name[0] != '.')
 324                                 break;
 325                         continue;
 326                 case 38:
 327                         sprintf(name, "%02x", i);
 328                         memcpy(name+2, de->d_name, len+1);
 329                         if (get_sha1_hex(name, sha1) < 0)
 330                                 break;
 331                         add_sha1_list(sha1, de->d_ino);
 332                         continue;
 333                 }
 334                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 335         }
 336         closedir(dir);
 337         return 0;
 338 }
 339
 340 static int read_sha1_reference(const char *path)
 341 {
 342         char hexname[60];
 343         unsigned char sha1[20];
 344         int fd = open(path, O_RDONLY), len;
 345         struct object *obj;
 346
 347         if (fd < 0)
 348                 return -1;
 349
 350         len = read(fd, hexname, sizeof(hexname));
 351         close(fd);
 352         if (len < 40)
 353                 return -1;
 354
 355         if (get_sha1_hex(hexname, sha1) < 0)
 356                 return -1;
 357
 358         obj = lookup_object(sha1);
 359         if (!obj)
 360                 return error("%s: invalid sha1 pointer %.40s", path, hexname);
 361
 362         obj->used = 1;
 363         mark_reachable(obj, REACHABLE);
 364         return 0;
 365 }
 366
 367 static int find_file_objects(const char *base, const char *name)
 368 {
 369         int baselen = strlen(base);
 370         int namelen = strlen(name);
 371         char *path = xmalloc(baselen + namelen + 2);
 372         struct stat st;
 373
 374         memcpy(path, base, baselen);
 375         path[baselen] = '/';
 376         memcpy(path + baselen + 1, name, namelen+1);
 377         if (stat(path, &st) < 0)
 378                 return 0;
 379
 380         /*
 381          * Recurse into directories
 382          */
 383         if (S_ISDIR(st.st_mode)) {
 384                 int count = 0;
 385                 DIR *dir = opendir(path);
 386                 if (dir) {
 387                         struct dirent *de;
 388                         while ((de = readdir(dir)) != NULL) {
 389                                 if (de->d_name[0] == '.')
 390                                         continue;
 391                                 count += find_file_objects(path, de->d_name);
 392                         }
 393                         closedir(dir);
 394                 }
 395                 return count;
 396         }
 397         if (S_ISREG(st.st_mode))
 398                 return read_sha1_reference(path) == 0;
 399         return 0;
 400 }
 401
 402 static void get_default_heads(void)
 403 {
 404         char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
 405         int count = find_file_objects(git_dir, "refs");
 406         if (!count)
 407                 die("No default references");
 408 }
 409
 410 int main(int argc, char **argv)
 411 {
 412         int i, heads;
 413         char *sha1_dir;
 414
 415         for (i = 1; i < argc; i++) {
 416                 const char *arg = argv[i];
 417
 418                 if (!strcmp(arg, "--unreachable")) {
 419                         show_unreachable = 1;
 420                         continue;
 421                 }
 422                 if (!strcmp(arg, "--tags")) {
 423                         show_tags = 1;
 424                         continue;
 425                 }
 426                 if (!strcmp(arg, "--root")) {
 427                         show_root = 1;
 428                         continue;
 429                 }
 430                 if (!strcmp(arg, "--delta-depth")) {
 431                         show_max_delta_depth = 1;
 432                         continue;
 433                 }
 434                 if (!strcmp(arg, "--cache")) {
 435                         keep_cache_objects = 1;
 436                         continue;
 437                 }
 438                 if (*arg == '-')
 439                         usage("git-fsck-cache [--tags] [[--unreachable] [--cache] <head-sha1>*]");
 440         }
 441
 442         sha1_dir = get_object_directory();
 443         for (i = 0; i < 256; i++) {
 444                 static char dir[4096];
 445                 sprintf(dir, "%s/%02x", sha1_dir, i);
 446                 fsck_dir(i, dir);
 447         }
 448         fsck_sha1_list();
 449
 450         expand_deltas();
 451
 452         heads = 0;
 453         for (i = 1; i < argc; i++) {
 454                 const char *arg = argv[i];
 455
 456                 if (*arg == '-')
 457                         continue;
 458
 459                 if (!get_sha1(arg, head_sha1)) {
 460                         struct object *obj = lookup_object(head_sha1);
 461
 462                         /* Error is printed by lookup_object(). */
 463                         if (!obj)
 464                                 continue;
 465
 466                         obj->used = 1;
 467                         mark_reachable(obj, REACHABLE);
 468                         heads++;
 469                         continue;
 470                 }
 471                 error("expected sha1, got %s", arg);
 472         }
 473
 474         /*
 475          * If we've not been given any explicit head information, do the
 476          * default ones from .git/refs. We also consider the index file
 477          * in this case (ie this implies --cache).
 478          */
 479         if (!heads) {
 480                 get_default_heads();
 481                 keep_cache_objects = 1;
 482         }
 483
 484         if (keep_cache_objects) {
 485                 int i;
 486                 read_cache();
 487                 for (i = 0; i < active_nr; i++) {
 488                         struct blob *blob = lookup_blob(active_cache[i]->sha1);
 489                         struct object *obj;
 490                         if (!blob)
 491                                 continue;
 492                         obj = &blob->object;
 493                         obj->used = 1;
 494                         mark_reachable(obj, REACHABLE);
 495                 }
 496         }
 497
 498         check_connectivity();
 499         return 0;
 500 }