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 = st->st_ctime; 34 ce->ce_mtime = st->st_mtime; 35 ce->ce_dev = st->st_dev; 36 ce->ce_ino = st->st_ino; 37 ce->ce_uid = st->st_uid; 38 ce->ce_gid = st->st_gid; 39 ce->ce_size = st->st_size; 40 41 if (assume_unchanged) 42 ce->ce_flags |= CE_VALID; 43 44 if (S_ISREG(st->st_mode)) 45 ce_mark_uptodate(ce); 46} 47 48static int ce_compare_data(struct cache_entry *ce, struct stat *st) 49{ 50 int match = -1; 51 int fd = open(ce->name, O_RDONLY); 52 53 if (fd >= 0) { 54 unsigned char sha1[20]; 55 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name)) 56 match = hashcmp(sha1, ce->sha1); 57 /* index_fd() closed the file descriptor already */ 58 } 59 return match; 60} 61 62static int ce_compare_link(struct cache_entry *ce, size_t expected_size) 63{ 64 int match = -1; 65 char *target; 66 void *buffer; 67 unsigned long size; 68 enum object_type type; 69 int len; 70 71 target = xmalloc(expected_size); 72 len = readlink(ce->name, target, expected_size); 73 if (len != expected_size) { 74 free(target); 75 return -1; 76 } 77 buffer = read_sha1_file(ce->sha1, &type, &size); 78 if (!buffer) { 79 free(target); 80 return -1; 81 } 82 if (size == expected_size) 83 match = memcmp(buffer, target, size); 84 free(buffer); 85 free(target); 86 return match; 87} 88 89static int ce_compare_gitlink(struct cache_entry *ce) 90{ 91 unsigned char sha1[20]; 92 93 /* 94 * We don't actually require that the .git directory 95 * under GITLINK directory be a valid git directory. It 96 * might even be missing (in case nobody populated that 97 * sub-project). 98 * 99 * If so, we consider it always to match. 100 */ 101 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0) 102 return 0; 103 return hashcmp(sha1, ce->sha1); 104} 105 106static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st) 107{ 108 switch (st->st_mode & S_IFMT) { 109 case S_IFREG: 110 if (ce_compare_data(ce, st)) 111 return DATA_CHANGED; 112 break; 113 case S_IFLNK: 114 if (ce_compare_link(ce, xsize_t(st->st_size))) 115 return DATA_CHANGED; 116 break; 117 case S_IFDIR: 118 if (S_ISGITLINK(ce->ce_mode)) 119 return 0; 120 default: 121 return TYPE_CHANGED; 122 } 123 return 0; 124} 125 126static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) 127{ 128 unsigned int changed = 0; 129 130 if (ce->ce_flags & CE_REMOVE) 131 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; 132 133 switch (ce->ce_mode & S_IFMT) { 134 case S_IFREG: 135 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; 136 /* We consider only the owner x bit to be relevant for 137 * "mode changes" 138 */ 139 if (trust_executable_bit && 140 (0100 & (ce->ce_mode ^ st->st_mode))) 141 changed |= MODE_CHANGED; 142 break; 143 case S_IFLNK: 144 if (!S_ISLNK(st->st_mode) && 145 (has_symlinks || !S_ISREG(st->st_mode))) 146 changed |= TYPE_CHANGED; 147 break; 148 case S_IFGITLINK: 149 if (!S_ISDIR(st->st_mode)) 150 changed |= TYPE_CHANGED; 151 else if (ce_compare_gitlink(ce)) 152 changed |= DATA_CHANGED; 153 return changed; 154 default: 155 die("internal error: ce_mode is %o", ce->ce_mode); 156 } 157 if (ce->ce_mtime != (unsigned int) st->st_mtime) 158 changed |= MTIME_CHANGED; 159 if (ce->ce_ctime != (unsigned int) st->st_ctime) 160 changed |= CTIME_CHANGED; 161 162 if (ce->ce_uid != (unsigned int) st->st_uid || 163 ce->ce_gid != (unsigned int) st->st_gid) 164 changed |= OWNER_CHANGED; 165 if (ce->ce_ino != (unsigned int) st->st_ino) 166 changed |= INODE_CHANGED; 167 168#ifdef USE_STDEV 169 /* 170 * st_dev breaks on network filesystems where different 171 * clients will have different views of what "device" 172 * the filesystem is on 173 */ 174 if (ce->ce_dev != (unsigned int) st->st_dev) 175 changed |= INODE_CHANGED; 176#endif 177 178 if (ce->ce_size != (unsigned int) st->st_size) 179 changed |= DATA_CHANGED; 180 181 return changed; 182} 183 184static int is_racy_timestamp(struct index_state *istate, struct cache_entry *ce) 185{ 186 return (istate->timestamp && 187 ((unsigned int)istate->timestamp) <= ce->ce_mtime); 188} 189 190int ie_match_stat(struct index_state *istate, 191 struct cache_entry *ce, struct stat *st, 192 unsigned int options) 193{ 194 unsigned int changed; 195 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 196 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; 197 198 /* 199 * If it's marked as always valid in the index, it's 200 * valid whatever the checked-out copy says. 201 */ 202 if (!ignore_valid && (ce->ce_flags & CE_VALID)) 203 return 0; 204 205 changed = ce_match_stat_basic(ce, st); 206 207 /* 208 * Within 1 second of this sequence: 209 * echo xyzzy >file && git-update-index --add file 210 * running this command: 211 * echo frotz >file 212 * would give a falsely clean cache entry. The mtime and 213 * length match the cache, and other stat fields do not change. 214 * 215 * We could detect this at update-index time (the cache entry 216 * being registered/updated records the same time as "now") 217 * and delay the return from git-update-index, but that would 218 * effectively mean we can make at most one commit per second, 219 * which is not acceptable. Instead, we check cache entries 220 * whose mtime are the same as the index file timestamp more 221 * carefully than others. 222 */ 223 if (!changed && is_racy_timestamp(istate, ce)) { 224 if (assume_racy_is_modified) 225 changed |= DATA_CHANGED; 226 else 227 changed |= ce_modified_check_fs(ce, st); 228 } 229 230 return changed; 231} 232 233int ie_modified(struct index_state *istate, 234 struct cache_entry *ce, struct stat *st, unsigned int options) 235{ 236 int changed, changed_fs; 237 238 changed = ie_match_stat(istate, ce, st, options); 239 if (!changed) 240 return 0; 241 /* 242 * If the mode or type has changed, there's no point in trying 243 * to refresh the entry - it's not going to match 244 */ 245 if (changed & (MODE_CHANGED | TYPE_CHANGED)) 246 return changed; 247 248 /* Immediately after read-tree or update-index --cacheinfo, 249 * the length field is zero. For other cases the ce_size 250 * should match the SHA1 recorded in the index entry. 251 */ 252 if ((changed & DATA_CHANGED) && ce->ce_size != 0) 253 return changed; 254 255 changed_fs = ce_modified_check_fs(ce, st); 256 if (changed_fs) 257 return changed | changed_fs; 258 return 0; 259} 260 261int base_name_compare(const char *name1, int len1, int mode1, 262 const char *name2, int len2, int mode2) 263{ 264 unsigned char c1, c2; 265 int len = len1 < len2 ? len1 : len2; 266 int cmp; 267 268 cmp = memcmp(name1, name2, len); 269 if (cmp) 270 return cmp; 271 c1 = name1[len]; 272 c2 = name2[len]; 273 if (!c1 && S_ISDIR(mode1)) 274 c1 = '/'; 275 if (!c2 && S_ISDIR(mode2)) 276 c2 = '/'; 277 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; 278} 279 280int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) 281{ 282 int len1 = flags1 & CE_NAMEMASK; 283 int len2 = flags2 & CE_NAMEMASK; 284 int len = len1 < len2 ? len1 : len2; 285 int cmp; 286 287 cmp = memcmp(name1, name2, len); 288 if (cmp) 289 return cmp; 290 if (len1 < len2) 291 return -1; 292 if (len1 > len2) 293 return 1; 294 295 /* Compare stages */ 296 flags1 &= CE_STAGEMASK; 297 flags2 &= CE_STAGEMASK; 298 299 if (flags1 < flags2) 300 return -1; 301 if (flags1 > flags2) 302 return 1; 303 return 0; 304} 305 306int index_name_pos(struct index_state *istate, const char *name, int namelen) 307{ 308 int first, last; 309 310 first = 0; 311 last = istate->cache_nr; 312 while (last > first) { 313 int next = (last + first) >> 1; 314 struct cache_entry *ce = istate->cache[next]; 315 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags); 316 if (!cmp) 317 return next; 318 if (cmp < 0) { 319 last = next; 320 continue; 321 } 322 first = next+1; 323 } 324 return -first-1; 325} 326 327/* Remove entry, return true if there are more entries to go.. */ 328int remove_index_entry_at(struct index_state *istate, int pos) 329{ 330 istate->cache_changed = 1; 331 istate->cache_nr--; 332 if (pos >= istate->cache_nr) 333 return 0; 334 memmove(istate->cache + pos, 335 istate->cache + pos + 1, 336 (istate->cache_nr - pos) * sizeof(struct cache_entry *)); 337 return 1; 338} 339 340int remove_file_from_index(struct index_state *istate, const char *path) 341{ 342 int pos = index_name_pos(istate, path, strlen(path)); 343 if (pos < 0) 344 pos = -pos-1; 345 cache_tree_invalidate_path(istate->cache_tree, path); 346 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) 347 remove_index_entry_at(istate, pos); 348 return 0; 349} 350 351static int compare_name(struct cache_entry *ce, const char *path, int namelen) 352{ 353 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); 354} 355 356static int index_name_pos_also_unmerged(struct index_state *istate, 357 const char *path, int namelen) 358{ 359 int pos = index_name_pos(istate, path, namelen); 360 struct cache_entry *ce; 361 362 if (pos >= 0) 363 return pos; 364 365 /* maybe unmerged? */ 366 pos = -1 - pos; 367 if (pos >= istate->cache_nr || 368 compare_name((ce = istate->cache[pos]), path, namelen)) 369 return -1; 370 371 /* order of preference: stage 2, 1, 3 */ 372 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && 373 ce_stage((ce = istate->cache[pos + 1])) == 2 && 374 !compare_name(ce, path, namelen)) 375 pos++; 376 return pos; 377} 378 379int add_file_to_index(struct index_state *istate, const char *path, int verbose) 380{ 381 int size, namelen, pos; 382 struct stat st; 383 struct cache_entry *ce; 384 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY; 385 386 if (lstat(path, &st)) 387 die("%s: unable to stat (%s)", path, strerror(errno)); 388 389 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode)) 390 die("%s: can only add regular files, symbolic links or git-directories", path); 391 392 namelen = strlen(path); 393 if (S_ISDIR(st.st_mode)) { 394 while (namelen && path[namelen-1] == '/') 395 namelen--; 396 } 397 size = cache_entry_size(namelen); 398 ce = xcalloc(1, size); 399 memcpy(ce->name, path, namelen); 400 ce->ce_flags = namelen; 401 fill_stat_cache_info(ce, &st); 402 403 if (trust_executable_bit && has_symlinks) 404 ce->ce_mode = create_ce_mode(st.st_mode); 405 else { 406 /* If there is an existing entry, pick the mode bits and type 407 * from it, otherwise assume unexecutable regular file. 408 */ 409 struct cache_entry *ent; 410 int pos = index_name_pos_also_unmerged(istate, path, namelen); 411 412 ent = (0 <= pos) ? istate->cache[pos] : NULL; 413 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode); 414 } 415 416 pos = index_name_pos(istate, ce->name, namelen); 417 if (0 <= pos && 418 !ce_stage(istate->cache[pos]) && 419 !ie_match_stat(istate, istate->cache[pos], &st, ce_option)) { 420 /* Nothing changed, really */ 421 free(ce); 422 ce_mark_uptodate(istate->cache[pos]); 423 return 0; 424 } 425 426 if (index_path(ce->sha1, path, &st, 1)) 427 die("unable to index file %s", path); 428 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE)) 429 die("unable to add %s to index",path); 430 if (verbose) 431 printf("add '%s'\n", path); 432 return 0; 433} 434 435struct cache_entry *make_cache_entry(unsigned int mode, 436 const unsigned char *sha1, const char *path, int stage, 437 int refresh) 438{ 439 int size, len; 440 struct cache_entry *ce; 441 442 if (!verify_path(path)) 443 return NULL; 444 445 len = strlen(path); 446 size = cache_entry_size(len); 447 ce = xcalloc(1, size); 448 449 hashcpy(ce->sha1, sha1); 450 memcpy(ce->name, path, len); 451 ce->ce_flags = create_ce_flags(len, stage); 452 ce->ce_mode = create_ce_mode(mode); 453 454 if (refresh) 455 return refresh_cache_entry(ce, 0); 456 457 return ce; 458} 459 460int ce_same_name(struct cache_entry *a, struct cache_entry *b) 461{ 462 int len = ce_namelen(a); 463 return ce_namelen(b) == len && !memcmp(a->name, b->name, len); 464} 465 466int ce_path_match(const struct cache_entry *ce, const char **pathspec) 467{ 468 const char *match, *name; 469 int len; 470 471 if (!pathspec) 472 return 1; 473 474 len = ce_namelen(ce); 475 name = ce->name; 476 while ((match = *pathspec++) != NULL) { 477 int matchlen = strlen(match); 478 if (matchlen > len) 479 continue; 480 if (memcmp(name, match, matchlen)) 481 continue; 482 if (matchlen && name[matchlen-1] == '/') 483 return 1; 484 if (name[matchlen] == '/' || !name[matchlen]) 485 return 1; 486 if (!matchlen) 487 return 1; 488 } 489 return 0; 490} 491 492/* 493 * We fundamentally don't like some paths: we don't want 494 * dot or dot-dot anywhere, and for obvious reasons don't 495 * want to recurse into ".git" either. 496 * 497 * Also, we don't want double slashes or slashes at the 498 * end that can make pathnames ambiguous. 499 */ 500static int verify_dotfile(const char *rest) 501{ 502 /* 503 * The first character was '.', but that 504 * has already been discarded, we now test 505 * the rest. 506 */ 507 switch (*rest) { 508 /* "." is not allowed */ 509 case '\0': case '/': 510 return 0; 511 512 /* 513 * ".git" followed by NUL or slash is bad. This 514 * shares the path end test with the ".." case. 515 */ 516 case 'g': 517 if (rest[1] != 'i') 518 break; 519 if (rest[2] != 't') 520 break; 521 rest += 2; 522 /* fallthrough */ 523 case '.': 524 if (rest[1] == '\0' || rest[1] == '/') 525 return 0; 526 } 527 return 1; 528} 529 530int verify_path(const char *path) 531{ 532 char c; 533 534 goto inside; 535 for (;;) { 536 if (!c) 537 return 1; 538 if (c == '/') { 539inside: 540 c = *path++; 541 switch (c) { 542 default: 543 continue; 544 case '/': case '\0': 545 break; 546 case '.': 547 if (verify_dotfile(path)) 548 continue; 549 } 550 return 0; 551 } 552 c = *path++; 553 } 554} 555 556/* 557 * Do we have another file that has the beginning components being a 558 * proper superset of the name we're trying to add? 559 */ 560static int has_file_name(struct index_state *istate, 561 const struct cache_entry *ce, int pos, int ok_to_replace) 562{ 563 int retval = 0; 564 int len = ce_namelen(ce); 565 int stage = ce_stage(ce); 566 const char *name = ce->name; 567 568 while (pos < istate->cache_nr) { 569 struct cache_entry *p = istate->cache[pos++]; 570 571 if (len >= ce_namelen(p)) 572 break; 573 if (memcmp(name, p->name, len)) 574 break; 575 if (ce_stage(p) != stage) 576 continue; 577 if (p->name[len] != '/') 578 continue; 579 if (p->ce_flags & CE_REMOVE) 580 continue; 581 retval = -1; 582 if (!ok_to_replace) 583 break; 584 remove_index_entry_at(istate, --pos); 585 } 586 return retval; 587} 588 589/* 590 * Do we have another file with a pathname that is a proper 591 * subset of the name we're trying to add? 592 */ 593static int has_dir_name(struct index_state *istate, 594 const struct cache_entry *ce, int pos, int ok_to_replace) 595{ 596 int retval = 0; 597 int stage = ce_stage(ce); 598 const char *name = ce->name; 599 const char *slash = name + ce_namelen(ce); 600 601 for (;;) { 602 int len; 603 604 for (;;) { 605 if (*--slash == '/') 606 break; 607 if (slash <= ce->name) 608 return retval; 609 } 610 len = slash - name; 611 612 pos = index_name_pos(istate, name, create_ce_flags(len, stage)); 613 if (pos >= 0) { 614 /* 615 * Found one, but not so fast. This could 616 * be a marker that says "I was here, but 617 * I am being removed". Such an entry is 618 * not a part of the resulting tree, and 619 * it is Ok to have a directory at the same 620 * path. 621 */ 622 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) { 623 retval = -1; 624 if (!ok_to_replace) 625 break; 626 remove_index_entry_at(istate, pos); 627 continue; 628 } 629 } 630 else 631 pos = -pos-1; 632 633 /* 634 * Trivial optimization: if we find an entry that 635 * already matches the sub-directory, then we know 636 * we're ok, and we can exit. 637 */ 638 while (pos < istate->cache_nr) { 639 struct cache_entry *p = istate->cache[pos]; 640 if ((ce_namelen(p) <= len) || 641 (p->name[len] != '/') || 642 memcmp(p->name, name, len)) 643 break; /* not our subdirectory */ 644 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) 645 /* 646 * p is at the same stage as our entry, and 647 * is a subdirectory of what we are looking 648 * at, so we cannot have conflicts at our 649 * level or anything shorter. 650 */ 651 return retval; 652 pos++; 653 } 654 } 655 return retval; 656} 657 658/* We may be in a situation where we already have path/file and path 659 * is being added, or we already have path and path/file is being 660 * added. Either one would result in a nonsense tree that has path 661 * twice when git-write-tree tries to write it out. Prevent it. 662 * 663 * If ok-to-replace is specified, we remove the conflicting entries 664 * from the cache so the caller should recompute the insert position. 665 * When this happens, we return non-zero. 666 */ 667static int check_file_directory_conflict(struct index_state *istate, 668 const struct cache_entry *ce, 669 int pos, int ok_to_replace) 670{ 671 int retval; 672 673 /* 674 * When ce is an "I am going away" entry, we allow it to be added 675 */ 676 if (ce->ce_flags & CE_REMOVE) 677 return 0; 678 679 /* 680 * We check if the path is a sub-path of a subsequent pathname 681 * first, since removing those will not change the position 682 * in the array. 683 */ 684 retval = has_file_name(istate, ce, pos, ok_to_replace); 685 686 /* 687 * Then check if the path might have a clashing sub-directory 688 * before it. 689 */ 690 return retval + has_dir_name(istate, ce, pos, ok_to_replace); 691} 692 693static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) 694{ 695 int pos; 696 int ok_to_add = option & ADD_CACHE_OK_TO_ADD; 697 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; 698 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; 699 700 cache_tree_invalidate_path(istate->cache_tree, ce->name); 701 pos = index_name_pos(istate, ce->name, ce->ce_flags); 702 703 /* existing match? Just replace it. */ 704 if (pos >= 0) { 705 istate->cache_changed = 1; 706 istate->cache[pos] = ce; 707 return 0; 708 } 709 pos = -pos-1; 710 711 /* 712 * Inserting a merged entry ("stage 0") into the index 713 * will always replace all non-merged entries.. 714 */ 715 if (pos < istate->cache_nr && ce_stage(ce) == 0) { 716 while (ce_same_name(istate->cache[pos], ce)) { 717 ok_to_add = 1; 718 if (!remove_index_entry_at(istate, pos)) 719 break; 720 } 721 } 722 723 if (!ok_to_add) 724 return -1; 725 if (!verify_path(ce->name)) 726 return -1; 727 728 if (!skip_df_check && 729 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { 730 if (!ok_to_replace) 731 return error("'%s' appears as both a file and as a directory", 732 ce->name); 733 pos = index_name_pos(istate, ce->name, ce->ce_flags); 734 pos = -pos-1; 735 } 736 return pos + 1; 737} 738 739int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) 740{ 741 int pos; 742 743 if (option & ADD_CACHE_JUST_APPEND) 744 pos = istate->cache_nr; 745 else { 746 int ret; 747 ret = add_index_entry_with_check(istate, ce, option); 748 if (ret <= 0) 749 return ret; 750 pos = ret - 1; 751 } 752 753 /* Make sure the array is big enough .. */ 754 if (istate->cache_nr == istate->cache_alloc) { 755 istate->cache_alloc = alloc_nr(istate->cache_alloc); 756 istate->cache = xrealloc(istate->cache, 757 istate->cache_alloc * sizeof(struct cache_entry *)); 758 } 759 760 /* Add it in.. */ 761 istate->cache_nr++; 762 if (istate->cache_nr > pos + 1) 763 memmove(istate->cache + pos + 1, 764 istate->cache + pos, 765 (istate->cache_nr - pos - 1) * sizeof(ce)); 766 istate->cache[pos] = ce; 767 istate->cache_changed = 1; 768 return 0; 769} 770 771/* 772 * "refresh" does not calculate a new sha1 file or bring the 773 * cache up-to-date for mode/content changes. But what it 774 * _does_ do is to "re-match" the stat information of a file 775 * with the cache, so that you can refresh the cache for a 776 * file that hasn't been changed but where the stat entry is 777 * out of date. 778 * 779 * For example, you'd want to do this after doing a "git-read-tree", 780 * to link up the stat cache details with the proper files. 781 */ 782static struct cache_entry *refresh_cache_ent(struct index_state *istate, 783 struct cache_entry *ce, 784 unsigned int options, int *err) 785{ 786 struct stat st; 787 struct cache_entry *updated; 788 int changed, size; 789 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 790 791 if (ce_uptodate(ce)) 792 return ce; 793 794 if (lstat(ce->name, &st) < 0) { 795 if (err) 796 *err = errno; 797 return NULL; 798 } 799 800 changed = ie_match_stat(istate, ce, &st, options); 801 if (!changed) { 802 /* 803 * The path is unchanged. If we were told to ignore 804 * valid bit, then we did the actual stat check and 805 * found that the entry is unmodified. If the entry 806 * is not marked VALID, this is the place to mark it 807 * valid again, under "assume unchanged" mode. 808 */ 809 if (ignore_valid && assume_unchanged && 810 !(ce->ce_flags & CE_VALID)) 811 ; /* mark this one VALID again */ 812 else { 813 /* 814 * We do not mark the index itself "modified" 815 * because CE_UPTODATE flag is in-core only; 816 * we are not going to write this change out. 817 */ 818 ce_mark_uptodate(ce); 819 return ce; 820 } 821 } 822 823 if (ie_modified(istate, ce, &st, options)) { 824 if (err) 825 *err = EINVAL; 826 return NULL; 827 } 828 829 size = ce_size(ce); 830 updated = xmalloc(size); 831 memcpy(updated, ce, size); 832 fill_stat_cache_info(updated, &st); 833 /* 834 * If ignore_valid is not set, we should leave CE_VALID bit 835 * alone. Otherwise, paths marked with --no-assume-unchanged 836 * (i.e. things to be edited) will reacquire CE_VALID bit 837 * automatically, which is not really what we want. 838 */ 839 if (!ignore_valid && assume_unchanged && 840 !(ce->ce_flags & CE_VALID)) 841 updated->ce_flags &= ~CE_VALID; 842 843 return updated; 844} 845 846int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen) 847{ 848 int i; 849 int has_errors = 0; 850 int really = (flags & REFRESH_REALLY) != 0; 851 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; 852 int quiet = (flags & REFRESH_QUIET) != 0; 853 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; 854 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0; 855 856 for (i = 0; i < istate->cache_nr; i++) { 857 struct cache_entry *ce, *new; 858 int cache_errno = 0; 859 860 ce = istate->cache[i]; 861 if (ce_stage(ce)) { 862 while ((i < istate->cache_nr) && 863 ! strcmp(istate->cache[i]->name, ce->name)) 864 i++; 865 i--; 866 if (allow_unmerged) 867 continue; 868 printf("%s: needs merge\n", ce->name); 869 has_errors = 1; 870 continue; 871 } 872 873 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen)) 874 continue; 875 876 new = refresh_cache_ent(istate, ce, options, &cache_errno); 877 if (new == ce) 878 continue; 879 if (!new) { 880 if (not_new && cache_errno == ENOENT) 881 continue; 882 if (really && cache_errno == EINVAL) { 883 /* If we are doing --really-refresh that 884 * means the index is not valid anymore. 885 */ 886 ce->ce_flags &= ~CE_VALID; 887 istate->cache_changed = 1; 888 } 889 if (quiet) 890 continue; 891 printf("%s: needs update\n", ce->name); 892 has_errors = 1; 893 continue; 894 } 895 istate->cache_changed = 1; 896 /* You can NOT just free istate->cache[i] here, since it 897 * might not be necessarily malloc()ed but can also come 898 * from mmap(). */ 899 istate->cache[i] = new; 900 } 901 return has_errors; 902} 903 904struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really) 905{ 906 return refresh_cache_ent(&the_index, ce, really, NULL); 907} 908 909static int verify_hdr(struct cache_header *hdr, unsigned long size) 910{ 911 SHA_CTX c; 912 unsigned char sha1[20]; 913 914 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) 915 return error("bad signature"); 916 if (hdr->hdr_version != htonl(2)) 917 return error("bad index version"); 918 SHA1_Init(&c); 919 SHA1_Update(&c, hdr, size - 20); 920 SHA1_Final(sha1, &c); 921 if (hashcmp(sha1, (unsigned char *)hdr + size - 20)) 922 return error("bad index file sha1 signature"); 923 return 0; 924} 925 926static int read_index_extension(struct index_state *istate, 927 const char *ext, void *data, unsigned long sz) 928{ 929 switch (CACHE_EXT(ext)) { 930 case CACHE_EXT_TREE: 931 istate->cache_tree = cache_tree_read(data, sz); 932 break; 933 default: 934 if (*ext < 'A' || 'Z' < *ext) 935 return error("index uses %.4s extension, which we do not understand", 936 ext); 937 fprintf(stderr, "ignoring %.4s extension\n", ext); 938 break; 939 } 940 return 0; 941} 942 943int read_index(struct index_state *istate) 944{ 945 return read_index_from(istate, get_index_file()); 946} 947 948static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce) 949{ 950 size_t len; 951 952 ce->ce_ctime = ntohl(ondisk->ctime.sec); 953 ce->ce_mtime = ntohl(ondisk->mtime.sec); 954 ce->ce_dev = ntohl(ondisk->dev); 955 ce->ce_ino = ntohl(ondisk->ino); 956 ce->ce_mode = ntohl(ondisk->mode); 957 ce->ce_uid = ntohl(ondisk->uid); 958 ce->ce_gid = ntohl(ondisk->gid); 959 ce->ce_size = ntohl(ondisk->size); 960 /* On-disk flags are just 16 bits */ 961 ce->ce_flags = ntohs(ondisk->flags); 962 hashcpy(ce->sha1, ondisk->sha1); 963 964 len = ce->ce_flags & CE_NAMEMASK; 965 if (len == CE_NAMEMASK) 966 len = strlen(ondisk->name); 967 /* 968 * NEEDSWORK: If the original index is crafted, this copy could 969 * go unchecked. 970 */ 971 memcpy(ce->name, ondisk->name, len + 1); 972} 973 974/* remember to discard_cache() before reading a different cache! */ 975int read_index_from(struct index_state *istate, const char *path) 976{ 977 int fd, i; 978 struct stat st; 979 unsigned long src_offset, dst_offset; 980 struct cache_header *hdr; 981 void *mmap; 982 size_t mmap_size; 983 984 errno = EBUSY; 985 if (istate->alloc) 986 return istate->cache_nr; 987 988 errno = ENOENT; 989 istate->timestamp = 0; 990 fd = open(path, O_RDONLY); 991 if (fd < 0) { 992 if (errno == ENOENT) 993 return 0; 994 die("index file open failed (%s)", strerror(errno)); 995 } 996 997 if (fstat(fd, &st)) 998 die("cannot stat the open index (%s)", strerror(errno)); 9991000 errno = EINVAL;1001 mmap_size = xsize_t(st.st_size);1002 if (mmap_size < sizeof(struct cache_header) + 20)1003 die("index file smaller than expected");10041005 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);1006 close(fd);1007 if (mmap == MAP_FAILED)1008 die("unable to map index file");10091010 hdr = mmap;1011 if (verify_hdr(hdr, mmap_size) < 0)1012 goto unmap;10131014 istate->cache_nr = ntohl(hdr->hdr_entries);1015 istate->cache_alloc = alloc_nr(istate->cache_nr);1016 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));10171018 /*1019 * The disk format is actually larger than the in-memory format,1020 * due to space for nsec etc, so even though the in-memory one1021 * has room for a few more flags, we can allocate using the same1022 * index size1023 */1024 istate->alloc = xmalloc(mmap_size);10251026 src_offset = sizeof(*hdr);1027 dst_offset = 0;1028 for (i = 0; i < istate->cache_nr; i++) {1029 struct ondisk_cache_entry *disk_ce;1030 struct cache_entry *ce;10311032 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);1033 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);1034 convert_from_disk(disk_ce, ce);1035 istate->cache[i] = ce;10361037 src_offset += ondisk_ce_size(ce);1038 dst_offset += ce_size(ce);1039 }1040 istate->timestamp = st.st_mtime;1041 while (src_offset <= mmap_size - 20 - 8) {1042 /* After an array of active_nr index entries,1043 * there can be arbitrary number of extended1044 * sections, each of which is prefixed with1045 * extension name (4-byte) and section length1046 * in 4-byte network byte order.1047 */1048 unsigned long extsize;1049 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);1050 extsize = ntohl(extsize);1051 if (read_index_extension(istate,1052 (const char *) mmap + src_offset,1053 (char *) mmap + src_offset + 8,1054 extsize) < 0)1055 goto unmap;1056 src_offset += 8;1057 src_offset += extsize;1058 }1059 munmap(mmap, mmap_size);1060 return istate->cache_nr;10611062unmap:1063 munmap(mmap, mmap_size);1064 errno = EINVAL;1065 die("index file corrupt");1066}10671068int discard_index(struct index_state *istate)1069{1070 istate->cache_nr = 0;1071 istate->cache_changed = 0;1072 istate->timestamp = 0;1073 cache_tree_free(&(istate->cache_tree));1074 free(istate->alloc);1075 istate->alloc = NULL;10761077 /* no need to throw away allocated active_cache */1078 return 0;1079}10801081#define WRITE_BUFFER_SIZE 81921082static unsigned char write_buffer[WRITE_BUFFER_SIZE];1083static unsigned long write_buffer_len;10841085static int ce_write_flush(SHA_CTX *context, int fd)1086{1087 unsigned int buffered = write_buffer_len;1088 if (buffered) {1089 SHA1_Update(context, write_buffer, buffered);1090 if (write_in_full(fd, write_buffer, buffered) != buffered)1091 return -1;1092 write_buffer_len = 0;1093 }1094 return 0;1095}10961097static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)1098{1099 while (len) {1100 unsigned int buffered = write_buffer_len;1101 unsigned int partial = WRITE_BUFFER_SIZE - buffered;1102 if (partial > len)1103 partial = len;1104 memcpy(write_buffer + buffered, data, partial);1105 buffered += partial;1106 if (buffered == WRITE_BUFFER_SIZE) {1107 write_buffer_len = buffered;1108 if (ce_write_flush(context, fd))1109 return -1;1110 buffered = 0;1111 }1112 write_buffer_len = buffered;1113 len -= partial;1114 data = (char *) data + partial;1115 }1116 return 0;1117}11181119static int write_index_ext_header(SHA_CTX *context, int fd,1120 unsigned int ext, unsigned int sz)1121{1122 ext = htonl(ext);1123 sz = htonl(sz);1124 return ((ce_write(context, fd, &ext, 4) < 0) ||1125 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;1126}11271128static int ce_flush(SHA_CTX *context, int fd)1129{1130 unsigned int left = write_buffer_len;11311132 if (left) {1133 write_buffer_len = 0;1134 SHA1_Update(context, write_buffer, left);1135 }11361137 /* Flush first if not enough space for SHA1 signature */1138 if (left + 20 > WRITE_BUFFER_SIZE) {1139 if (write_in_full(fd, write_buffer, left) != left)1140 return -1;1141 left = 0;1142 }11431144 /* Append the SHA1 signature at the end */1145 SHA1_Final(write_buffer + left, context);1146 left += 20;1147 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;1148}11491150static void ce_smudge_racily_clean_entry(struct cache_entry *ce)1151{1152 /*1153 * The only thing we care about in this function is to smudge the1154 * falsely clean entry due to touch-update-touch race, so we leave1155 * everything else as they are. We are called for entries whose1156 * ce_mtime match the index file mtime.1157 */1158 struct stat st;11591160 if (lstat(ce->name, &st) < 0)1161 return;1162 if (ce_match_stat_basic(ce, &st))1163 return;1164 if (ce_modified_check_fs(ce, &st)) {1165 /* This is "racily clean"; smudge it. Note that this1166 * is a tricky code. At first glance, it may appear1167 * that it can break with this sequence:1168 *1169 * $ echo xyzzy >frotz1170 * $ git-update-index --add frotz1171 * $ : >frotz1172 * $ sleep 31173 * $ echo filfre >nitfol1174 * $ git-update-index --add nitfol1175 *1176 * but it does not. When the second update-index runs,1177 * it notices that the entry "frotz" has the same timestamp1178 * as index, and if we were to smudge it by resetting its1179 * size to zero here, then the object name recorded1180 * in index is the 6-byte file but the cached stat information1181 * becomes zero --- which would then match what we would1182 * obtain from the filesystem next time we stat("frotz").1183 *1184 * However, the second update-index, before calling1185 * this function, notices that the cached size is 61186 * bytes and what is on the filesystem is an empty1187 * file, and never calls us, so the cached size information1188 * for "frotz" stays 6 which does not match the filesystem.1189 */1190 ce->ce_size = 0;1191 }1192}11931194static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)1195{1196 int size = ondisk_ce_size(ce);1197 struct ondisk_cache_entry *ondisk = xcalloc(1, size);11981199 ondisk->ctime.sec = htonl(ce->ce_ctime);1200 ondisk->ctime.nsec = 0;1201 ondisk->mtime.sec = htonl(ce->ce_mtime);1202 ondisk->mtime.nsec = 0;1203 ondisk->dev = htonl(ce->ce_dev);1204 ondisk->ino = htonl(ce->ce_ino);1205 ondisk->mode = htonl(ce->ce_mode);1206 ondisk->uid = htonl(ce->ce_uid);1207 ondisk->gid = htonl(ce->ce_gid);1208 ondisk->size = htonl(ce->ce_size);1209 hashcpy(ondisk->sha1, ce->sha1);1210 ondisk->flags = htons(ce->ce_flags);1211 memcpy(ondisk->name, ce->name, ce_namelen(ce));12121213 return ce_write(c, fd, ondisk, size);1214}12151216int write_index(struct index_state *istate, int newfd)1217{1218 SHA_CTX c;1219 struct cache_header hdr;1220 int i, err, removed;1221 struct cache_entry **cache = istate->cache;1222 int entries = istate->cache_nr;12231224 for (i = removed = 0; i < entries; i++)1225 if (cache[i]->ce_flags & CE_REMOVE)1226 removed++;12271228 hdr.hdr_signature = htonl(CACHE_SIGNATURE);1229 hdr.hdr_version = htonl(2);1230 hdr.hdr_entries = htonl(entries - removed);12311232 SHA1_Init(&c);1233 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)1234 return -1;12351236 for (i = 0; i < entries; i++) {1237 struct cache_entry *ce = cache[i];1238 if (ce->ce_flags & CE_REMOVE)1239 continue;1240 if (is_racy_timestamp(istate, ce))1241 ce_smudge_racily_clean_entry(ce);1242 if (ce_write_entry(&c, newfd, ce) < 0)1243 return -1;1244 }12451246 /* Write extension data here */1247 if (istate->cache_tree) {1248 struct strbuf sb;12491250 strbuf_init(&sb, 0);1251 cache_tree_write(&sb, istate->cache_tree);1252 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 01253 || ce_write(&c, newfd, sb.buf, sb.len) < 0;1254 strbuf_release(&sb);1255 if (err)1256 return -1;1257 }1258 return ce_flush(&c, newfd);1259}