1/* 2 * GIT - The information manager from hell 3 * 4 * Copyright (C) Linus Torvalds, 2005 5 */ 6#define NO_THE_INDEX_COMPATIBILITY_MACROS 7#include "cache.h" 8#include "cache-tree.h" 9#include "refs.h" 10#include "dir.h" 11 12/* Index extensions. 13 * 14 * The first letter should be 'A'..'Z' for extensions that are not 15 * necessary for a correct operation (i.e. optimization data). 16 * When new extensions are added that _needs_ to be understood in 17 * order to correctly interpret the index file, pick character that 18 * is outside the range, to cause the reader to abort. 19 */ 20 21#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) ) 22#define CACHE_EXT_TREE 0x54524545 /* "TREE" */ 23 24struct index_state the_index; 25 26/* 27 * This only updates the "non-critical" parts of the directory 28 * cache, ie the parts that aren't tracked by GIT, and only used 29 * to validate the cache. 30 */ 31void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) 32{ 33 ce->ce_ctime.sec = htonl(st->st_ctime); 34 ce->ce_mtime.sec = htonl(st->st_mtime); 35#ifdef USE_NSEC 36 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec); 37 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec); 38#endif 39 ce->ce_dev = htonl(st->st_dev); 40 ce->ce_ino = htonl(st->st_ino); 41 ce->ce_uid = htonl(st->st_uid); 42 ce->ce_gid = htonl(st->st_gid); 43 ce->ce_size = htonl(st->st_size); 44 45 if (assume_unchanged) 46 ce->ce_flags |= htons(CE_VALID); 47} 48 49static int ce_compare_data(struct cache_entry *ce, struct stat *st) 50{ 51 int match = -1; 52 int fd = open(ce->name, O_RDONLY); 53 54 if (fd >= 0) { 55 unsigned char sha1[20]; 56 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name)) 57 match = hashcmp(sha1, ce->sha1); 58 /* index_fd() closed the file descriptor already */ 59 } 60 return match; 61} 62 63static int ce_compare_link(struct cache_entry *ce, size_t expected_size) 64{ 65 int match = -1; 66 char *target; 67 void *buffer; 68 unsigned long size; 69 enum object_type type; 70 int len; 71 72 target = xmalloc(expected_size); 73 len = readlink(ce->name, target, expected_size); 74 if (len != expected_size) { 75 free(target); 76 return -1; 77 } 78 buffer = read_sha1_file(ce->sha1, &type, &size); 79 if (!buffer) { 80 free(target); 81 return -1; 82 } 83 if (size == expected_size) 84 match = memcmp(buffer, target, size); 85 free(buffer); 86 free(target); 87 return match; 88} 89 90static int ce_compare_gitlink(struct cache_entry *ce) 91{ 92 unsigned char sha1[20]; 93 94 /* 95 * We don't actually require that the .git directory 96 * under GITLINK directory be a valid git directory. It 97 * might even be missing (in case nobody populated that 98 * sub-project). 99 * 100 * If so, we consider it always to match. 101 */ 102 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0) 103 return 0; 104 return hashcmp(sha1, ce->sha1); 105} 106 107static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st) 108{ 109 switch (st->st_mode & S_IFMT) { 110 case S_IFREG: 111 if (ce_compare_data(ce, st)) 112 return DATA_CHANGED; 113 break; 114 case S_IFLNK: 115 if (ce_compare_link(ce, xsize_t(st->st_size))) 116 return DATA_CHANGED; 117 break; 118 case S_IFDIR: 119 if (S_ISGITLINK(ntohl(ce->ce_mode))) 120 return 0; 121 default: 122 return TYPE_CHANGED; 123 } 124 return 0; 125} 126 127static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) 128{ 129 unsigned int changed = 0; 130 131 switch (ntohl(ce->ce_mode) & S_IFMT) { 132 case S_IFREG: 133 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; 134 /* We consider only the owner x bit to be relevant for 135 * "mode changes" 136 */ 137 if (trust_executable_bit && 138 (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))) 139 changed |= MODE_CHANGED; 140 break; 141 case S_IFLNK: 142 if (!S_ISLNK(st->st_mode) && 143 (has_symlinks || !S_ISREG(st->st_mode))) 144 changed |= TYPE_CHANGED; 145 break; 146 case S_IFGITLINK: 147 if (!S_ISDIR(st->st_mode)) 148 changed |= TYPE_CHANGED; 149 else if (ce_compare_gitlink(ce)) 150 changed |= DATA_CHANGED; 151 return changed; 152 default: 153 die("internal error: ce_mode is %o", ntohl(ce->ce_mode)); 154 } 155 if (ce->ce_mtime.sec != htonl(st->st_mtime)) 156 changed |= MTIME_CHANGED; 157 if (ce->ce_ctime.sec != htonl(st->st_ctime)) 158 changed |= CTIME_CHANGED; 159 160#ifdef USE_NSEC 161 /* 162 * nsec seems unreliable - not all filesystems support it, so 163 * as long as it is in the inode cache you get right nsec 164 * but after it gets flushed, you get zero nsec. 165 */ 166 if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec)) 167 changed |= MTIME_CHANGED; 168 if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec)) 169 changed |= CTIME_CHANGED; 170#endif 171 172 if (ce->ce_uid != htonl(st->st_uid) || 173 ce->ce_gid != htonl(st->st_gid)) 174 changed |= OWNER_CHANGED; 175 if (ce->ce_ino != htonl(st->st_ino)) 176 changed |= INODE_CHANGED; 177 178#ifdef USE_STDEV 179 /* 180 * st_dev breaks on network filesystems where different 181 * clients will have different views of what "device" 182 * the filesystem is on 183 */ 184 if (ce->ce_dev != htonl(st->st_dev)) 185 changed |= INODE_CHANGED; 186#endif 187 188 if (ce->ce_size != htonl(st->st_size)) 189 changed |= DATA_CHANGED; 190 191 return changed; 192} 193 194int ie_match_stat(struct index_state *istate, 195 struct cache_entry *ce, struct stat *st, int options) 196{ 197 unsigned int changed; 198 int ignore_valid = options & 01; 199 int assume_racy_is_modified = options & 02; 200 201 /* 202 * If it's marked as always valid in the index, it's 203 * valid whatever the checked-out copy says. 204 */ 205 if (!ignore_valid && (ce->ce_flags & htons(CE_VALID))) 206 return 0; 207 208 changed = ce_match_stat_basic(ce, st); 209 210 /* 211 * Within 1 second of this sequence: 212 * echo xyzzy >file && git-update-index --add file 213 * running this command: 214 * echo frotz >file 215 * would give a falsely clean cache entry. The mtime and 216 * length match the cache, and other stat fields do not change. 217 * 218 * We could detect this at update-index time (the cache entry 219 * being registered/updated records the same time as "now") 220 * and delay the return from git-update-index, but that would 221 * effectively mean we can make at most one commit per second, 222 * which is not acceptable. Instead, we check cache entries 223 * whose mtime are the same as the index file timestamp more 224 * carefully than others. 225 */ 226 if (!changed && 227 istate->timestamp && 228 istate->timestamp <= ntohl(ce->ce_mtime.sec)) { 229 if (assume_racy_is_modified) 230 changed |= DATA_CHANGED; 231 else 232 changed |= ce_modified_check_fs(ce, st); 233 } 234 235 return changed; 236} 237 238int ie_modified(struct index_state *istate, 239 struct cache_entry *ce, struct stat *st, int really) 240{ 241 int changed, changed_fs; 242 changed = ie_match_stat(istate, ce, st, really); 243 if (!changed) 244 return 0; 245 /* 246 * If the mode or type has changed, there's no point in trying 247 * to refresh the entry - it's not going to match 248 */ 249 if (changed & (MODE_CHANGED | TYPE_CHANGED)) 250 return changed; 251 252 /* Immediately after read-tree or update-index --cacheinfo, 253 * the length field is zero. For other cases the ce_size 254 * should match the SHA1 recorded in the index entry. 255 */ 256 if ((changed & DATA_CHANGED) && ce->ce_size != htonl(0)) 257 return changed; 258 259 changed_fs = ce_modified_check_fs(ce, st); 260 if (changed_fs) 261 return changed | changed_fs; 262 return 0; 263} 264 265int base_name_compare(const char *name1, int len1, int mode1, 266 const char *name2, int len2, int mode2) 267{ 268 unsigned char c1, c2; 269 int len = len1 < len2 ? len1 : len2; 270 int cmp; 271 272 cmp = memcmp(name1, name2, len); 273 if (cmp) 274 return cmp; 275 c1 = name1[len]; 276 c2 = name2[len]; 277 if (!c1 && S_ISDIR(mode1)) 278 c1 = '/'; 279 if (!c2 && S_ISDIR(mode2)) 280 c2 = '/'; 281 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; 282} 283 284int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) 285{ 286 int len1 = flags1 & CE_NAMEMASK; 287 int len2 = flags2 & CE_NAMEMASK; 288 int len = len1 < len2 ? len1 : len2; 289 int cmp; 290 291 cmp = memcmp(name1, name2, len); 292 if (cmp) 293 return cmp; 294 if (len1 < len2) 295 return -1; 296 if (len1 > len2) 297 return 1; 298 299 /* Compare stages */ 300 flags1 &= CE_STAGEMASK; 301 flags2 &= CE_STAGEMASK; 302 303 if (flags1 < flags2) 304 return -1; 305 if (flags1 > flags2) 306 return 1; 307 return 0; 308} 309 310int index_name_pos(struct index_state *istate, const char *name, int namelen) 311{ 312 int first, last; 313 314 first = 0; 315 last = istate->cache_nr; 316 while (last > first) { 317 int next = (last + first) >> 1; 318 struct cache_entry *ce = istate->cache[next]; 319 int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags)); 320 if (!cmp) 321 return next; 322 if (cmp < 0) { 323 last = next; 324 continue; 325 } 326 first = next+1; 327 } 328 return -first-1; 329} 330 331/* Remove entry, return true if there are more entries to go.. */ 332int remove_index_entry_at(struct index_state *istate, int pos) 333{ 334 istate->cache_changed = 1; 335 istate->cache_nr--; 336 if (pos >= istate->cache_nr) 337 return 0; 338 memmove(istate->cache + pos, 339 istate->cache + pos + 1, 340 (istate->cache_nr - pos) * sizeof(struct cache_entry *)); 341 return 1; 342} 343 344int remove_file_from_index(struct index_state *istate, const char *path) 345{ 346 int pos = index_name_pos(istate, path, strlen(path)); 347 if (pos < 0) 348 pos = -pos-1; 349 cache_tree_invalidate_path(istate->cache_tree, path); 350 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) 351 remove_index_entry_at(istate, pos); 352 return 0; 353} 354 355static int compare_name(struct cache_entry *ce, const char *path, int namelen) 356{ 357 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); 358} 359 360static int index_name_pos_also_unmerged(struct index_state *istate, 361 const char *path, int namelen) 362{ 363 int pos = index_name_pos(istate, path, namelen); 364 struct cache_entry *ce; 365 366 if (pos >= 0) 367 return pos; 368 369 /* maybe unmerged? */ 370 pos = -1 - pos; 371 if (pos >= istate->cache_nr || 372 compare_name((ce = istate->cache[pos]), path, namelen)) 373 return -1; 374 375 /* order of preference: stage 2, 1, 3 */ 376 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && 377 ce_stage((ce = istate->cache[pos + 1])) == 2 && 378 !compare_name(ce, path, namelen)) 379 pos++; 380 return pos; 381} 382 383int add_file_to_index(struct index_state *istate, const char *path, int verbose) 384{ 385 int size, namelen, pos; 386 struct stat st; 387 struct cache_entry *ce; 388 389 if (lstat(path, &st)) 390 die("%s: unable to stat (%s)", path, strerror(errno)); 391 392 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode)) 393 die("%s: can only add regular files, symbolic links or git-directories", path); 394 395 namelen = strlen(path); 396 if (S_ISDIR(st.st_mode)) { 397 while (namelen && path[namelen-1] == '/') 398 namelen--; 399 } 400 size = cache_entry_size(namelen); 401 ce = xcalloc(1, size); 402 memcpy(ce->name, path, namelen); 403 ce->ce_flags = htons(namelen); 404 fill_stat_cache_info(ce, &st); 405 406 if (trust_executable_bit && has_symlinks) 407 ce->ce_mode = create_ce_mode(st.st_mode); 408 else { 409 /* If there is an existing entry, pick the mode bits and type 410 * from it, otherwise assume unexecutable regular file. 411 */ 412 struct cache_entry *ent; 413 int pos = index_name_pos_also_unmerged(istate, path, namelen); 414 415 ent = (0 <= pos) ? istate->cache[pos] : NULL; 416 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode); 417 } 418 419 pos = index_name_pos(istate, ce->name, namelen); 420 if (0 <= pos && 421 !ce_stage(istate->cache[pos]) && 422 !ie_modified(istate, istate->cache[pos], &st, 1)) { 423 /* Nothing changed, really */ 424 free(ce); 425 return 0; 426 } 427 428 if (index_path(ce->sha1, path, &st, 1)) 429 die("unable to index file %s", path); 430 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE)) 431 die("unable to add %s to index",path); 432 if (verbose) 433 printf("add '%s'\n", path); 434 return 0; 435} 436 437struct cache_entry *make_cache_entry(unsigned int mode, 438 const unsigned char *sha1, const char *path, int stage, 439 int refresh) 440{ 441 int size, len; 442 struct cache_entry *ce; 443 444 if (!verify_path(path)) 445 return NULL; 446 447 len = strlen(path); 448 size = cache_entry_size(len); 449 ce = xcalloc(1, size); 450 451 hashcpy(ce->sha1, sha1); 452 memcpy(ce->name, path, len); 453 ce->ce_flags = create_ce_flags(len, stage); 454 ce->ce_mode = create_ce_mode(mode); 455 456 if (refresh) 457 return refresh_cache_entry(ce, 0); 458 459 return ce; 460} 461 462int ce_same_name(struct cache_entry *a, struct cache_entry *b) 463{ 464 int len = ce_namelen(a); 465 return ce_namelen(b) == len && !memcmp(a->name, b->name, len); 466} 467 468int ce_path_match(const struct cache_entry *ce, const char **pathspec) 469{ 470 const char *match, *name; 471 int len; 472 473 if (!pathspec) 474 return 1; 475 476 len = ce_namelen(ce); 477 name = ce->name; 478 while ((match = *pathspec++) != NULL) { 479 int matchlen = strlen(match); 480 if (matchlen > len) 481 continue; 482 if (memcmp(name, match, matchlen)) 483 continue; 484 if (matchlen && name[matchlen-1] == '/') 485 return 1; 486 if (name[matchlen] == '/' || !name[matchlen]) 487 return 1; 488 if (!matchlen) 489 return 1; 490 } 491 return 0; 492} 493 494/* 495 * We fundamentally don't like some paths: we don't want 496 * dot or dot-dot anywhere, and for obvious reasons don't 497 * want to recurse into ".git" either. 498 * 499 * Also, we don't want double slashes or slashes at the 500 * end that can make pathnames ambiguous. 501 */ 502static int verify_dotfile(const char *rest) 503{ 504 /* 505 * The first character was '.', but that 506 * has already been discarded, we now test 507 * the rest. 508 */ 509 switch (*rest) { 510 /* "." is not allowed */ 511 case '\0': case '/': 512 return 0; 513 514 /* 515 * ".git" followed by NUL or slash is bad. This 516 * shares the path end test with the ".." case. 517 */ 518 case 'g': 519 if (rest[1] != 'i') 520 break; 521 if (rest[2] != 't') 522 break; 523 rest += 2; 524 /* fallthrough */ 525 case '.': 526 if (rest[1] == '\0' || rest[1] == '/') 527 return 0; 528 } 529 return 1; 530} 531 532int verify_path(const char *path) 533{ 534 char c; 535 536 goto inside; 537 for (;;) { 538 if (!c) 539 return 1; 540 if (c == '/') { 541inside: 542 c = *path++; 543 switch (c) { 544 default: 545 continue; 546 case '/': case '\0': 547 break; 548 case '.': 549 if (verify_dotfile(path)) 550 continue; 551 } 552 return 0; 553 } 554 c = *path++; 555 } 556} 557 558/* 559 * Do we have another file that has the beginning components being a 560 * proper superset of the name we're trying to add? 561 */ 562static int has_file_name(struct index_state *istate, 563 const struct cache_entry *ce, int pos, int ok_to_replace) 564{ 565 int retval = 0; 566 int len = ce_namelen(ce); 567 int stage = ce_stage(ce); 568 const char *name = ce->name; 569 570 while (pos < istate->cache_nr) { 571 struct cache_entry *p = istate->cache[pos++]; 572 573 if (len >= ce_namelen(p)) 574 break; 575 if (memcmp(name, p->name, len)) 576 break; 577 if (ce_stage(p) != stage) 578 continue; 579 if (p->name[len] != '/') 580 continue; 581 if (!ce_stage(p) && !p->ce_mode) 582 continue; 583 retval = -1; 584 if (!ok_to_replace) 585 break; 586 remove_index_entry_at(istate, --pos); 587 } 588 return retval; 589} 590 591/* 592 * Do we have another file with a pathname that is a proper 593 * subset of the name we're trying to add? 594 */ 595static int has_dir_name(struct index_state *istate, 596 const struct cache_entry *ce, int pos, int ok_to_replace) 597{ 598 int retval = 0; 599 int stage = ce_stage(ce); 600 const char *name = ce->name; 601 const char *slash = name + ce_namelen(ce); 602 603 for (;;) { 604 int len; 605 606 for (;;) { 607 if (*--slash == '/') 608 break; 609 if (slash <= ce->name) 610 return retval; 611 } 612 len = slash - name; 613 614 pos = index_name_pos(istate, name, ntohs(create_ce_flags(len, stage))); 615 if (pos >= 0) { 616 /* 617 * Found one, but not so fast. This could 618 * be a marker that says "I was here, but 619 * I am being removed". Such an entry is 620 * not a part of the resulting tree, and 621 * it is Ok to have a directory at the same 622 * path. 623 */ 624 if (stage || istate->cache[pos]->ce_mode) { 625 retval = -1; 626 if (!ok_to_replace) 627 break; 628 remove_index_entry_at(istate, pos); 629 continue; 630 } 631 } 632 else 633 pos = -pos-1; 634 635 /* 636 * Trivial optimization: if we find an entry that 637 * already matches the sub-directory, then we know 638 * we're ok, and we can exit. 639 */ 640 while (pos < istate->cache_nr) { 641 struct cache_entry *p = istate->cache[pos]; 642 if ((ce_namelen(p) <= len) || 643 (p->name[len] != '/') || 644 memcmp(p->name, name, len)) 645 break; /* not our subdirectory */ 646 if (ce_stage(p) == stage && (stage || p->ce_mode)) 647 /* p is at the same stage as our entry, and 648 * is a subdirectory of what we are looking 649 * at, so we cannot have conflicts at our 650 * level or anything shorter. 651 */ 652 return retval; 653 pos++; 654 } 655 } 656 return retval; 657} 658 659/* We may be in a situation where we already have path/file and path 660 * is being added, or we already have path and path/file is being 661 * added. Either one would result in a nonsense tree that has path 662 * twice when git-write-tree tries to write it out. Prevent it. 663 * 664 * If ok-to-replace is specified, we remove the conflicting entries 665 * from the cache so the caller should recompute the insert position. 666 * When this happens, we return non-zero. 667 */ 668static int check_file_directory_conflict(struct index_state *istate, 669 const struct cache_entry *ce, 670 int pos, int ok_to_replace) 671{ 672 int retval; 673 674 /* 675 * When ce is an "I am going away" entry, we allow it to be added 676 */ 677 if (!ce_stage(ce) && !ce->ce_mode) 678 return 0; 679 680 /* 681 * We check if the path is a sub-path of a subsequent pathname 682 * first, since removing those will not change the position 683 * in the array. 684 */ 685 retval = has_file_name(istate, ce, pos, ok_to_replace); 686 687 /* 688 * Then check if the path might have a clashing sub-directory 689 * before it. 690 */ 691 return retval + has_dir_name(istate, ce, pos, ok_to_replace); 692} 693 694static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) 695{ 696 int pos; 697 int ok_to_add = option & ADD_CACHE_OK_TO_ADD; 698 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; 699 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; 700 701 cache_tree_invalidate_path(istate->cache_tree, ce->name); 702 pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags)); 703 704 /* existing match? Just replace it. */ 705 if (pos >= 0) { 706 istate->cache_changed = 1; 707 istate->cache[pos] = ce; 708 return 0; 709 } 710 pos = -pos-1; 711 712 /* 713 * Inserting a merged entry ("stage 0") into the index 714 * will always replace all non-merged entries.. 715 */ 716 if (pos < istate->cache_nr && ce_stage(ce) == 0) { 717 while (ce_same_name(istate->cache[pos], ce)) { 718 ok_to_add = 1; 719 if (!remove_index_entry_at(istate, pos)) 720 break; 721 } 722 } 723 724 if (!ok_to_add) 725 return -1; 726 if (!verify_path(ce->name)) 727 return -1; 728 729 if (!skip_df_check && 730 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { 731 if (!ok_to_replace) 732 return error("'%s' appears as both a file and as a directory", 733 ce->name); 734 pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags)); 735 pos = -pos-1; 736 } 737 return pos + 1; 738} 739 740int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) 741{ 742 int pos; 743 744 if (option & ADD_CACHE_JUST_APPEND) 745 pos = istate->cache_nr; 746 else { 747 int ret; 748 ret = add_index_entry_with_check(istate, ce, option); 749 if (ret <= 0) 750 return ret; 751 pos = ret - 1; 752 } 753 754 /* Make sure the array is big enough .. */ 755 if (istate->cache_nr == istate->cache_alloc) { 756 istate->cache_alloc = alloc_nr(istate->cache_alloc); 757 istate->cache = xrealloc(istate->cache, 758 istate->cache_alloc * sizeof(struct cache_entry *)); 759 } 760 761 /* Add it in.. */ 762 istate->cache_nr++; 763 if (istate->cache_nr > pos + 1) 764 memmove(istate->cache + pos + 1, 765 istate->cache + pos, 766 (istate->cache_nr - pos - 1) * sizeof(ce)); 767 istate->cache[pos] = ce; 768 istate->cache_changed = 1; 769 return 0; 770} 771 772/* 773 * "refresh" does not calculate a new sha1 file or bring the 774 * cache up-to-date for mode/content changes. But what it 775 * _does_ do is to "re-match" the stat information of a file 776 * with the cache, so that you can refresh the cache for a 777 * file that hasn't been changed but where the stat entry is 778 * out of date. 779 * 780 * For example, you'd want to do this after doing a "git-read-tree", 781 * to link up the stat cache details with the proper files. 782 */ 783static struct cache_entry *refresh_cache_ent(struct index_state *istate, 784 struct cache_entry *ce, int really, int *err) 785{ 786 struct stat st; 787 struct cache_entry *updated; 788 int changed, size; 789 790 if (lstat(ce->name, &st) < 0) { 791 if (err) 792 *err = errno; 793 return NULL; 794 } 795 796 changed = ie_match_stat(istate, ce, &st, really); 797 if (!changed) { 798 if (really && assume_unchanged && 799 !(ce->ce_flags & htons(CE_VALID))) 800 ; /* mark this one VALID again */ 801 else 802 return ce; 803 } 804 805 if (ie_modified(istate, ce, &st, really)) { 806 if (err) 807 *err = EINVAL; 808 return NULL; 809 } 810 811 size = ce_size(ce); 812 updated = xmalloc(size); 813 memcpy(updated, ce, size); 814 fill_stat_cache_info(updated, &st); 815 816 /* In this case, if really is not set, we should leave 817 * CE_VALID bit alone. Otherwise, paths marked with 818 * --no-assume-unchanged (i.e. things to be edited) will 819 * reacquire CE_VALID bit automatically, which is not 820 * really what we want. 821 */ 822 if (!really && assume_unchanged && !(ce->ce_flags & htons(CE_VALID))) 823 updated->ce_flags &= ~htons(CE_VALID); 824 825 return updated; 826} 827 828int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen) 829{ 830 int i; 831 int has_errors = 0; 832 int really = (flags & REFRESH_REALLY) != 0; 833 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; 834 int quiet = (flags & REFRESH_QUIET) != 0; 835 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; 836 837 for (i = 0; i < istate->cache_nr; i++) { 838 struct cache_entry *ce, *new; 839 int cache_errno = 0; 840 841 ce = istate->cache[i]; 842 if (ce_stage(ce)) { 843 while ((i < istate->cache_nr) && 844 ! strcmp(istate->cache[i]->name, ce->name)) 845 i++; 846 i--; 847 if (allow_unmerged) 848 continue; 849 printf("%s: needs merge\n", ce->name); 850 has_errors = 1; 851 continue; 852 } 853 854 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen)) 855 continue; 856 857 new = refresh_cache_ent(istate, ce, really, &cache_errno); 858 if (new == ce) 859 continue; 860 if (!new) { 861 if (not_new && cache_errno == ENOENT) 862 continue; 863 if (really && cache_errno == EINVAL) { 864 /* If we are doing --really-refresh that 865 * means the index is not valid anymore. 866 */ 867 ce->ce_flags &= ~htons(CE_VALID); 868 istate->cache_changed = 1; 869 } 870 if (quiet) 871 continue; 872 printf("%s: needs update\n", ce->name); 873 has_errors = 1; 874 continue; 875 } 876 istate->cache_changed = 1; 877 /* You can NOT just free istate->cache[i] here, since it 878 * might not be necessarily malloc()ed but can also come 879 * from mmap(). */ 880 istate->cache[i] = new; 881 } 882 return has_errors; 883} 884 885struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really) 886{ 887 return refresh_cache_ent(&the_index, ce, really, NULL); 888} 889 890static int verify_hdr(struct cache_header *hdr, unsigned long size) 891{ 892 SHA_CTX c; 893 unsigned char sha1[20]; 894 895 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) 896 return error("bad signature"); 897 if (hdr->hdr_version != htonl(2)) 898 return error("bad index version"); 899 SHA1_Init(&c); 900 SHA1_Update(&c, hdr, size - 20); 901 SHA1_Final(sha1, &c); 902 if (hashcmp(sha1, (unsigned char *)hdr + size - 20)) 903 return error("bad index file sha1 signature"); 904 return 0; 905} 906 907static int read_index_extension(struct index_state *istate, 908 const char *ext, void *data, unsigned long sz) 909{ 910 switch (CACHE_EXT(ext)) { 911 case CACHE_EXT_TREE: 912 istate->cache_tree = cache_tree_read(data, sz); 913 break; 914 default: 915 if (*ext < 'A' || 'Z' < *ext) 916 return error("index uses %.4s extension, which we do not understand", 917 ext); 918 fprintf(stderr, "ignoring %.4s extension\n", ext); 919 break; 920 } 921 return 0; 922} 923 924int read_index(struct index_state *istate) 925{ 926 return read_index_from(istate, get_index_file()); 927} 928 929/* remember to discard_cache() before reading a different cache! */ 930int read_index_from(struct index_state *istate, const char *path) 931{ 932 int fd, i; 933 struct stat st; 934 unsigned long offset; 935 struct cache_header *hdr; 936 937 errno = EBUSY; 938 if (istate->mmap) 939 return istate->cache_nr; 940 941 errno = ENOENT; 942 istate->timestamp = 0; 943 fd = open(path, O_RDONLY); 944 if (fd < 0) { 945 if (errno == ENOENT) 946 return 0; 947 die("index file open failed (%s)", strerror(errno)); 948 } 949 950 if (fstat(fd, &st)) 951 die("cannot stat the open index (%s)", strerror(errno)); 952 953 errno = EINVAL; 954 istate->mmap_size = xsize_t(st.st_size); 955 if (istate->mmap_size < sizeof(struct cache_header) + 20) 956 die("index file smaller than expected"); 957 958 istate->mmap = xmmap(NULL, istate->mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); 959 close(fd); 960 961 hdr = istate->mmap; 962 if (verify_hdr(hdr, istate->mmap_size) < 0) 963 goto unmap; 964 965 istate->cache_nr = ntohl(hdr->hdr_entries); 966 istate->cache_alloc = alloc_nr(istate->cache_nr); 967 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *)); 968 969 offset = sizeof(*hdr); 970 for (i = 0; i < istate->cache_nr; i++) { 971 struct cache_entry *ce; 972 973 ce = (struct cache_entry *)((char *)(istate->mmap) + offset); 974 offset = offset + ce_size(ce); 975 istate->cache[i] = ce; 976 } 977 istate->timestamp = st.st_mtime; 978 while (offset <= istate->mmap_size - 20 - 8) { 979 /* After an array of active_nr index entries, 980 * there can be arbitrary number of extended 981 * sections, each of which is prefixed with 982 * extension name (4-byte) and section length 983 * in 4-byte network byte order. 984 */ 985 unsigned long extsize; 986 memcpy(&extsize, (char *)(istate->mmap) + offset + 4, 4); 987 extsize = ntohl(extsize); 988 if (read_index_extension(istate, 989 ((const char *) (istate->mmap)) + offset, 990 (char *) (istate->mmap) + offset + 8, 991 extsize) < 0) 992 goto unmap; 993 offset += 8; 994 offset += extsize; 995 } 996 return istate->cache_nr; 997 998unmap: 999 munmap(istate->mmap, istate->mmap_size);1000 errno = EINVAL;1001 die("index file corrupt");1002}10031004int discard_index(struct index_state *istate)1005{1006 int ret;10071008 istate->cache_nr = 0;1009 istate->cache_changed = 0;1010 istate->timestamp = 0;1011 cache_tree_free(&(istate->cache_tree));1012 if (istate->mmap == NULL)1013 return 0;1014 ret = munmap(istate->mmap, istate->mmap_size);1015 istate->mmap = NULL;1016 istate->mmap_size = 0;10171018 /* no need to throw away allocated active_cache */1019 return ret;1020}10211022#define WRITE_BUFFER_SIZE 81921023static unsigned char write_buffer[WRITE_BUFFER_SIZE];1024static unsigned long write_buffer_len;10251026static int ce_write_flush(SHA_CTX *context, int fd)1027{1028 unsigned int buffered = write_buffer_len;1029 if (buffered) {1030 SHA1_Update(context, write_buffer, buffered);1031 if (write_in_full(fd, write_buffer, buffered) != buffered)1032 return -1;1033 write_buffer_len = 0;1034 }1035 return 0;1036}10371038static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)1039{1040 while (len) {1041 unsigned int buffered = write_buffer_len;1042 unsigned int partial = WRITE_BUFFER_SIZE - buffered;1043 if (partial > len)1044 partial = len;1045 memcpy(write_buffer + buffered, data, partial);1046 buffered += partial;1047 if (buffered == WRITE_BUFFER_SIZE) {1048 write_buffer_len = buffered;1049 if (ce_write_flush(context, fd))1050 return -1;1051 buffered = 0;1052 }1053 write_buffer_len = buffered;1054 len -= partial;1055 data = (char *) data + partial;1056 }1057 return 0;1058}10591060static int write_index_ext_header(SHA_CTX *context, int fd,1061 unsigned int ext, unsigned int sz)1062{1063 ext = htonl(ext);1064 sz = htonl(sz);1065 return ((ce_write(context, fd, &ext, 4) < 0) ||1066 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;1067}10681069static int ce_flush(SHA_CTX *context, int fd)1070{1071 unsigned int left = write_buffer_len;10721073 if (left) {1074 write_buffer_len = 0;1075 SHA1_Update(context, write_buffer, left);1076 }10771078 /* Flush first if not enough space for SHA1 signature */1079 if (left + 20 > WRITE_BUFFER_SIZE) {1080 if (write_in_full(fd, write_buffer, left) != left)1081 return -1;1082 left = 0;1083 }10841085 /* Append the SHA1 signature at the end */1086 SHA1_Final(write_buffer + left, context);1087 left += 20;1088 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;1089}10901091static void ce_smudge_racily_clean_entry(struct cache_entry *ce)1092{1093 /*1094 * The only thing we care about in this function is to smudge the1095 * falsely clean entry due to touch-update-touch race, so we leave1096 * everything else as they are. We are called for entries whose1097 * ce_mtime match the index file mtime.1098 */1099 struct stat st;11001101 if (lstat(ce->name, &st) < 0)1102 return;1103 if (ce_match_stat_basic(ce, &st))1104 return;1105 if (ce_modified_check_fs(ce, &st)) {1106 /* This is "racily clean"; smudge it. Note that this1107 * is a tricky code. At first glance, it may appear1108 * that it can break with this sequence:1109 *1110 * $ echo xyzzy >frotz1111 * $ git-update-index --add frotz1112 * $ : >frotz1113 * $ sleep 31114 * $ echo filfre >nitfol1115 * $ git-update-index --add nitfol1116 *1117 * but it does not. When the second update-index runs,1118 * it notices that the entry "frotz" has the same timestamp1119 * as index, and if we were to smudge it by resetting its1120 * size to zero here, then the object name recorded1121 * in index is the 6-byte file but the cached stat information1122 * becomes zero --- which would then match what we would1123 * obtain from the filesystem next time we stat("frotz").1124 *1125 * However, the second update-index, before calling1126 * this function, notices that the cached size is 61127 * bytes and what is on the filesystem is an empty1128 * file, and never calls us, so the cached size information1129 * for "frotz" stays 6 which does not match the filesystem.1130 */1131 ce->ce_size = htonl(0);1132 }1133}11341135int write_index(struct index_state *istate, int newfd)1136{1137 SHA_CTX c;1138 struct cache_header hdr;1139 int i, removed;1140 struct cache_entry **cache = istate->cache;1141 int entries = istate->cache_nr;11421143 for (i = removed = 0; i < entries; i++)1144 if (!cache[i]->ce_mode)1145 removed++;11461147 hdr.hdr_signature = htonl(CACHE_SIGNATURE);1148 hdr.hdr_version = htonl(2);1149 hdr.hdr_entries = htonl(entries - removed);11501151 SHA1_Init(&c);1152 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)1153 return -1;11541155 for (i = 0; i < entries; i++) {1156 struct cache_entry *ce = cache[i];1157 if (!ce->ce_mode)1158 continue;1159 if (istate->timestamp &&1160 istate->timestamp <= ntohl(ce->ce_mtime.sec))1161 ce_smudge_racily_clean_entry(ce);1162 if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)1163 return -1;1164 }11651166 /* Write extension data here */1167 if (istate->cache_tree) {1168 unsigned long sz;1169 void *data = cache_tree_write(istate->cache_tree, &sz);1170 if (data &&1171 !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) &&1172 !ce_write(&c, newfd, data, sz))1173 free(data);1174 else {1175 free(data);1176 return -1;1177 }1178 }1179 return ce_flush(&c, newfd);1180}