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