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 26static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) 27{ 28 istate->cache[nr] = ce; 29 add_name_hash(istate, ce); 30} 31 32static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) 33{ 34 struct cache_entry *old = istate->cache[nr]; 35 36 remove_name_hash(old); 37 set_index_entry(istate, nr, ce); 38 istate->cache_changed = 1; 39} 40 41/* 42 * This only updates the "non-critical" parts of the directory 43 * cache, ie the parts that aren't tracked by GIT, and only used 44 * to validate the cache. 45 */ 46void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) 47{ 48 ce->ce_ctime = st->st_ctime; 49 ce->ce_mtime = st->st_mtime; 50 ce->ce_dev = st->st_dev; 51 ce->ce_ino = st->st_ino; 52 ce->ce_uid = st->st_uid; 53 ce->ce_gid = st->st_gid; 54 ce->ce_size = st->st_size; 55 56 if (assume_unchanged) 57 ce->ce_flags |= CE_VALID; 58 59 if (S_ISREG(st->st_mode)) 60 ce_mark_uptodate(ce); 61} 62 63static int ce_compare_data(struct cache_entry *ce, struct stat *st) 64{ 65 int match = -1; 66 int fd = open(ce->name, O_RDONLY); 67 68 if (fd >= 0) { 69 unsigned char sha1[20]; 70 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name)) 71 match = hashcmp(sha1, ce->sha1); 72 /* index_fd() closed the file descriptor already */ 73 } 74 return match; 75} 76 77static int ce_compare_link(struct cache_entry *ce, size_t expected_size) 78{ 79 int match = -1; 80 char *target; 81 void *buffer; 82 unsigned long size; 83 enum object_type type; 84 int len; 85 86 target = xmalloc(expected_size); 87 len = readlink(ce->name, target, expected_size); 88 if (len != expected_size) { 89 free(target); 90 return -1; 91 } 92 buffer = read_sha1_file(ce->sha1, &type, &size); 93 if (!buffer) { 94 free(target); 95 return -1; 96 } 97 if (size == expected_size) 98 match = memcmp(buffer, target, size); 99 free(buffer); 100 free(target); 101 return match; 102} 103 104static int ce_compare_gitlink(struct cache_entry *ce) 105{ 106 unsigned char sha1[20]; 107 108 /* 109 * We don't actually require that the .git directory 110 * under GITLINK directory be a valid git directory. It 111 * might even be missing (in case nobody populated that 112 * sub-project). 113 * 114 * If so, we consider it always to match. 115 */ 116 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0) 117 return 0; 118 return hashcmp(sha1, ce->sha1); 119} 120 121static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st) 122{ 123 switch (st->st_mode & S_IFMT) { 124 case S_IFREG: 125 if (ce_compare_data(ce, st)) 126 return DATA_CHANGED; 127 break; 128 case S_IFLNK: 129 if (ce_compare_link(ce, xsize_t(st->st_size))) 130 return DATA_CHANGED; 131 break; 132 case S_IFDIR: 133 if (S_ISGITLINK(ce->ce_mode)) 134 return 0; 135 default: 136 return TYPE_CHANGED; 137 } 138 return 0; 139} 140 141static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) 142{ 143 unsigned int changed = 0; 144 145 if (ce->ce_flags & CE_REMOVE) 146 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; 147 148 switch (ce->ce_mode & S_IFMT) { 149 case S_IFREG: 150 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; 151 /* We consider only the owner x bit to be relevant for 152 * "mode changes" 153 */ 154 if (trust_executable_bit && 155 (0100 & (ce->ce_mode ^ st->st_mode))) 156 changed |= MODE_CHANGED; 157 break; 158 case S_IFLNK: 159 if (!S_ISLNK(st->st_mode) && 160 (has_symlinks || !S_ISREG(st->st_mode))) 161 changed |= TYPE_CHANGED; 162 break; 163 case S_IFGITLINK: 164 if (!S_ISDIR(st->st_mode)) 165 changed |= TYPE_CHANGED; 166 else if (ce_compare_gitlink(ce)) 167 changed |= DATA_CHANGED; 168 return changed; 169 default: 170 die("internal error: ce_mode is %o", ce->ce_mode); 171 } 172 if (ce->ce_mtime != (unsigned int) st->st_mtime) 173 changed |= MTIME_CHANGED; 174 if (ce->ce_ctime != (unsigned int) st->st_ctime) 175 changed |= CTIME_CHANGED; 176 177 if (ce->ce_uid != (unsigned int) st->st_uid || 178 ce->ce_gid != (unsigned int) st->st_gid) 179 changed |= OWNER_CHANGED; 180 if (ce->ce_ino != (unsigned int) st->st_ino) 181 changed |= INODE_CHANGED; 182 183#ifdef USE_STDEV 184 /* 185 * st_dev breaks on network filesystems where different 186 * clients will have different views of what "device" 187 * the filesystem is on 188 */ 189 if (ce->ce_dev != (unsigned int) st->st_dev) 190 changed |= INODE_CHANGED; 191#endif 192 193 if (ce->ce_size != (unsigned int) st->st_size) 194 changed |= DATA_CHANGED; 195 196 return changed; 197} 198 199static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce) 200{ 201 return (istate->timestamp && 202 ((unsigned int)istate->timestamp) <= ce->ce_mtime); 203} 204 205int ie_match_stat(const struct index_state *istate, 206 struct cache_entry *ce, struct stat *st, 207 unsigned int options) 208{ 209 unsigned int changed; 210 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 211 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; 212 213 /* 214 * If it's marked as always valid in the index, it's 215 * valid whatever the checked-out copy says. 216 */ 217 if (!ignore_valid && (ce->ce_flags & CE_VALID)) 218 return 0; 219 220 changed = ce_match_stat_basic(ce, st); 221 222 /* 223 * Within 1 second of this sequence: 224 * echo xyzzy >file && git-update-index --add file 225 * running this command: 226 * echo frotz >file 227 * would give a falsely clean cache entry. The mtime and 228 * length match the cache, and other stat fields do not change. 229 * 230 * We could detect this at update-index time (the cache entry 231 * being registered/updated records the same time as "now") 232 * and delay the return from git-update-index, but that would 233 * effectively mean we can make at most one commit per second, 234 * which is not acceptable. Instead, we check cache entries 235 * whose mtime are the same as the index file timestamp more 236 * carefully than others. 237 */ 238 if (!changed && is_racy_timestamp(istate, ce)) { 239 if (assume_racy_is_modified) 240 changed |= DATA_CHANGED; 241 else 242 changed |= ce_modified_check_fs(ce, st); 243 } 244 245 return changed; 246} 247 248int ie_modified(const struct index_state *istate, 249 struct cache_entry *ce, struct stat *st, unsigned int options) 250{ 251 int changed, changed_fs; 252 253 changed = ie_match_stat(istate, ce, st, options); 254 if (!changed) 255 return 0; 256 /* 257 * If the mode or type has changed, there's no point in trying 258 * to refresh the entry - it's not going to match 259 */ 260 if (changed & (MODE_CHANGED | TYPE_CHANGED)) 261 return changed; 262 263 /* Immediately after read-tree or update-index --cacheinfo, 264 * the length field is zero. For other cases the ce_size 265 * should match the SHA1 recorded in the index entry. 266 */ 267 if ((changed & DATA_CHANGED) && ce->ce_size != 0) 268 return changed; 269 270 changed_fs = ce_modified_check_fs(ce, st); 271 if (changed_fs) 272 return changed | changed_fs; 273 return 0; 274} 275 276int base_name_compare(const char *name1, int len1, int mode1, 277 const char *name2, int len2, int mode2) 278{ 279 unsigned char c1, c2; 280 int len = len1 < len2 ? len1 : len2; 281 int cmp; 282 283 cmp = memcmp(name1, name2, len); 284 if (cmp) 285 return cmp; 286 c1 = name1[len]; 287 c2 = name2[len]; 288 if (!c1 && S_ISDIR(mode1)) 289 c1 = '/'; 290 if (!c2 && S_ISDIR(mode2)) 291 c2 = '/'; 292 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; 293} 294 295/* 296 * df_name_compare() is identical to base_name_compare(), except it 297 * compares conflicting directory/file entries as equal. Note that 298 * while a directory name compares as equal to a regular file, they 299 * then individually compare _differently_ to a filename that has 300 * a dot after the basename (because '\0' < '.' < '/'). 301 * 302 * This is used by routines that want to traverse the git namespace 303 * but then handle conflicting entries together when possible. 304 */ 305int df_name_compare(const char *name1, int len1, int mode1, 306 const char *name2, int len2, int mode2) 307{ 308 int len = len1 < len2 ? len1 : len2, cmp; 309 unsigned char c1, c2; 310 311 cmp = memcmp(name1, name2, len); 312 if (cmp) 313 return cmp; 314 /* Directories and files compare equal (same length, same name) */ 315 if (len1 == len2) 316 return 0; 317 c1 = name1[len]; 318 if (!c1 && S_ISDIR(mode1)) 319 c1 = '/'; 320 c2 = name2[len]; 321 if (!c2 && S_ISDIR(mode2)) 322 c2 = '/'; 323 if (c1 == '/' && !c2) 324 return 0; 325 if (c2 == '/' && !c1) 326 return 0; 327 return c1 - c2; 328} 329 330int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) 331{ 332 int len1 = flags1 & CE_NAMEMASK; 333 int len2 = flags2 & CE_NAMEMASK; 334 int len = len1 < len2 ? len1 : len2; 335 int cmp; 336 337 cmp = memcmp(name1, name2, len); 338 if (cmp) 339 return cmp; 340 if (len1 < len2) 341 return -1; 342 if (len1 > len2) 343 return 1; 344 345 /* Compare stages */ 346 flags1 &= CE_STAGEMASK; 347 flags2 &= CE_STAGEMASK; 348 349 if (flags1 < flags2) 350 return -1; 351 if (flags1 > flags2) 352 return 1; 353 return 0; 354} 355 356int index_name_pos(const struct index_state *istate, const char *name, int namelen) 357{ 358 int first, last; 359 360 first = 0; 361 last = istate->cache_nr; 362 while (last > first) { 363 int next = (last + first) >> 1; 364 struct cache_entry *ce = istate->cache[next]; 365 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags); 366 if (!cmp) 367 return next; 368 if (cmp < 0) { 369 last = next; 370 continue; 371 } 372 first = next+1; 373 } 374 return -first-1; 375} 376 377/* Remove entry, return true if there are more entries to go.. */ 378int remove_index_entry_at(struct index_state *istate, int pos) 379{ 380 struct cache_entry *ce = istate->cache[pos]; 381 382 remove_name_hash(ce); 383 istate->cache_changed = 1; 384 istate->cache_nr--; 385 if (pos >= istate->cache_nr) 386 return 0; 387 memmove(istate->cache + pos, 388 istate->cache + pos + 1, 389 (istate->cache_nr - pos) * sizeof(struct cache_entry *)); 390 return 1; 391} 392 393int remove_file_from_index(struct index_state *istate, const char *path) 394{ 395 int pos = index_name_pos(istate, path, strlen(path)); 396 if (pos < 0) 397 pos = -pos-1; 398 cache_tree_invalidate_path(istate->cache_tree, path); 399 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) 400 remove_index_entry_at(istate, pos); 401 return 0; 402} 403 404static int compare_name(struct cache_entry *ce, const char *path, int namelen) 405{ 406 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); 407} 408 409static int index_name_pos_also_unmerged(struct index_state *istate, 410 const char *path, int namelen) 411{ 412 int pos = index_name_pos(istate, path, namelen); 413 struct cache_entry *ce; 414 415 if (pos >= 0) 416 return pos; 417 418 /* maybe unmerged? */ 419 pos = -1 - pos; 420 if (pos >= istate->cache_nr || 421 compare_name((ce = istate->cache[pos]), path, namelen)) 422 return -1; 423 424 /* order of preference: stage 2, 1, 3 */ 425 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && 426 ce_stage((ce = istate->cache[pos + 1])) == 2 && 427 !compare_name(ce, path, namelen)) 428 pos++; 429 return pos; 430} 431 432int add_file_to_index(struct index_state *istate, const char *path, int verbose) 433{ 434 int size, namelen, pos; 435 struct stat st; 436 struct cache_entry *ce; 437 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY; 438 439 if (lstat(path, &st)) 440 die("%s: unable to stat (%s)", path, strerror(errno)); 441 442 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode)) 443 die("%s: can only add regular files, symbolic links or git-directories", path); 444 445 namelen = strlen(path); 446 if (S_ISDIR(st.st_mode)) { 447 while (namelen && path[namelen-1] == '/') 448 namelen--; 449 } 450 size = cache_entry_size(namelen); 451 ce = xcalloc(1, size); 452 memcpy(ce->name, path, namelen); 453 ce->ce_flags = namelen; 454 fill_stat_cache_info(ce, &st); 455 456 if (trust_executable_bit && has_symlinks) 457 ce->ce_mode = create_ce_mode(st.st_mode); 458 else { 459 /* If there is an existing entry, pick the mode bits and type 460 * from it, otherwise assume unexecutable regular file. 461 */ 462 struct cache_entry *ent; 463 int pos = index_name_pos_also_unmerged(istate, path, namelen); 464 465 ent = (0 <= pos) ? istate->cache[pos] : NULL; 466 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode); 467 } 468 469 pos = index_name_pos(istate, ce->name, namelen); 470 if (0 <= pos && 471 !ce_stage(istate->cache[pos]) && 472 !ie_match_stat(istate, istate->cache[pos], &st, ce_option)) { 473 /* Nothing changed, really */ 474 free(ce); 475 ce_mark_uptodate(istate->cache[pos]); 476 return 0; 477 } 478 479 if (index_path(ce->sha1, path, &st, 1)) 480 die("unable to index file %s", path); 481 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE)) 482 die("unable to add %s to index",path); 483 if (verbose) 484 printf("add '%s'\n", path); 485 return 0; 486} 487 488struct cache_entry *make_cache_entry(unsigned int mode, 489 const unsigned char *sha1, const char *path, int stage, 490 int refresh) 491{ 492 int size, len; 493 struct cache_entry *ce; 494 495 if (!verify_path(path)) 496 return NULL; 497 498 len = strlen(path); 499 size = cache_entry_size(len); 500 ce = xcalloc(1, size); 501 502 hashcpy(ce->sha1, sha1); 503 memcpy(ce->name, path, len); 504 ce->ce_flags = create_ce_flags(len, stage); 505 ce->ce_mode = create_ce_mode(mode); 506 507 if (refresh) 508 return refresh_cache_entry(ce, 0); 509 510 return ce; 511} 512 513int ce_same_name(struct cache_entry *a, struct cache_entry *b) 514{ 515 int len = ce_namelen(a); 516 return ce_namelen(b) == len && !memcmp(a->name, b->name, len); 517} 518 519int ce_path_match(const struct cache_entry *ce, const char **pathspec) 520{ 521 const char *match, *name; 522 int len; 523 524 if (!pathspec) 525 return 1; 526 527 len = ce_namelen(ce); 528 name = ce->name; 529 while ((match = *pathspec++) != NULL) { 530 int matchlen = strlen(match); 531 if (matchlen > len) 532 continue; 533 if (memcmp(name, match, matchlen)) 534 continue; 535 if (matchlen && name[matchlen-1] == '/') 536 return 1; 537 if (name[matchlen] == '/' || !name[matchlen]) 538 return 1; 539 if (!matchlen) 540 return 1; 541 } 542 return 0; 543} 544 545/* 546 * We fundamentally don't like some paths: we don't want 547 * dot or dot-dot anywhere, and for obvious reasons don't 548 * want to recurse into ".git" either. 549 * 550 * Also, we don't want double slashes or slashes at the 551 * end that can make pathnames ambiguous. 552 */ 553static int verify_dotfile(const char *rest) 554{ 555 /* 556 * The first character was '.', but that 557 * has already been discarded, we now test 558 * the rest. 559 */ 560 switch (*rest) { 561 /* "." is not allowed */ 562 case '\0': case '/': 563 return 0; 564 565 /* 566 * ".git" followed by NUL or slash is bad. This 567 * shares the path end test with the ".." case. 568 */ 569 case 'g': 570 if (rest[1] != 'i') 571 break; 572 if (rest[2] != 't') 573 break; 574 rest += 2; 575 /* fallthrough */ 576 case '.': 577 if (rest[1] == '\0' || rest[1] == '/') 578 return 0; 579 } 580 return 1; 581} 582 583int verify_path(const char *path) 584{ 585 char c; 586 587 goto inside; 588 for (;;) { 589 if (!c) 590 return 1; 591 if (c == '/') { 592inside: 593 c = *path++; 594 switch (c) { 595 default: 596 continue; 597 case '/': case '\0': 598 break; 599 case '.': 600 if (verify_dotfile(path)) 601 continue; 602 } 603 return 0; 604 } 605 c = *path++; 606 } 607} 608 609/* 610 * Do we have another file that has the beginning components being a 611 * proper superset of the name we're trying to add? 612 */ 613static int has_file_name(struct index_state *istate, 614 const struct cache_entry *ce, int pos, int ok_to_replace) 615{ 616 int retval = 0; 617 int len = ce_namelen(ce); 618 int stage = ce_stage(ce); 619 const char *name = ce->name; 620 621 while (pos < istate->cache_nr) { 622 struct cache_entry *p = istate->cache[pos++]; 623 624 if (len >= ce_namelen(p)) 625 break; 626 if (memcmp(name, p->name, len)) 627 break; 628 if (ce_stage(p) != stage) 629 continue; 630 if (p->name[len] != '/') 631 continue; 632 if (p->ce_flags & CE_REMOVE) 633 continue; 634 retval = -1; 635 if (!ok_to_replace) 636 break; 637 remove_index_entry_at(istate, --pos); 638 } 639 return retval; 640} 641 642/* 643 * Do we have another file with a pathname that is a proper 644 * subset of the name we're trying to add? 645 */ 646static int has_dir_name(struct index_state *istate, 647 const struct cache_entry *ce, int pos, int ok_to_replace) 648{ 649 int retval = 0; 650 int stage = ce_stage(ce); 651 const char *name = ce->name; 652 const char *slash = name + ce_namelen(ce); 653 654 for (;;) { 655 int len; 656 657 for (;;) { 658 if (*--slash == '/') 659 break; 660 if (slash <= ce->name) 661 return retval; 662 } 663 len = slash - name; 664 665 pos = index_name_pos(istate, name, create_ce_flags(len, stage)); 666 if (pos >= 0) { 667 /* 668 * Found one, but not so fast. This could 669 * be a marker that says "I was here, but 670 * I am being removed". Such an entry is 671 * not a part of the resulting tree, and 672 * it is Ok to have a directory at the same 673 * path. 674 */ 675 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) { 676 retval = -1; 677 if (!ok_to_replace) 678 break; 679 remove_index_entry_at(istate, pos); 680 continue; 681 } 682 } 683 else 684 pos = -pos-1; 685 686 /* 687 * Trivial optimization: if we find an entry that 688 * already matches the sub-directory, then we know 689 * we're ok, and we can exit. 690 */ 691 while (pos < istate->cache_nr) { 692 struct cache_entry *p = istate->cache[pos]; 693 if ((ce_namelen(p) <= len) || 694 (p->name[len] != '/') || 695 memcmp(p->name, name, len)) 696 break; /* not our subdirectory */ 697 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) 698 /* 699 * p is at the same stage as our entry, and 700 * is a subdirectory of what we are looking 701 * at, so we cannot have conflicts at our 702 * level or anything shorter. 703 */ 704 return retval; 705 pos++; 706 } 707 } 708 return retval; 709} 710 711/* We may be in a situation where we already have path/file and path 712 * is being added, or we already have path and path/file is being 713 * added. Either one would result in a nonsense tree that has path 714 * twice when git-write-tree tries to write it out. Prevent it. 715 * 716 * If ok-to-replace is specified, we remove the conflicting entries 717 * from the cache so the caller should recompute the insert position. 718 * When this happens, we return non-zero. 719 */ 720static int check_file_directory_conflict(struct index_state *istate, 721 const struct cache_entry *ce, 722 int pos, int ok_to_replace) 723{ 724 int retval; 725 726 /* 727 * When ce is an "I am going away" entry, we allow it to be added 728 */ 729 if (ce->ce_flags & CE_REMOVE) 730 return 0; 731 732 /* 733 * We check if the path is a sub-path of a subsequent pathname 734 * first, since removing those will not change the position 735 * in the array. 736 */ 737 retval = has_file_name(istate, ce, pos, ok_to_replace); 738 739 /* 740 * Then check if the path might have a clashing sub-directory 741 * before it. 742 */ 743 return retval + has_dir_name(istate, ce, pos, ok_to_replace); 744} 745 746static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) 747{ 748 int pos; 749 int ok_to_add = option & ADD_CACHE_OK_TO_ADD; 750 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; 751 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; 752 753 cache_tree_invalidate_path(istate->cache_tree, ce->name); 754 pos = index_name_pos(istate, ce->name, ce->ce_flags); 755 756 /* existing match? Just replace it. */ 757 if (pos >= 0) { 758 replace_index_entry(istate, pos, ce); 759 return 0; 760 } 761 pos = -pos-1; 762 763 /* 764 * Inserting a merged entry ("stage 0") into the index 765 * will always replace all non-merged entries.. 766 */ 767 if (pos < istate->cache_nr && ce_stage(ce) == 0) { 768 while (ce_same_name(istate->cache[pos], ce)) { 769 ok_to_add = 1; 770 if (!remove_index_entry_at(istate, pos)) 771 break; 772 } 773 } 774 775 if (!ok_to_add) 776 return -1; 777 if (!verify_path(ce->name)) 778 return -1; 779 780 if (!skip_df_check && 781 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { 782 if (!ok_to_replace) 783 return error("'%s' appears as both a file and as a directory", 784 ce->name); 785 pos = index_name_pos(istate, ce->name, ce->ce_flags); 786 pos = -pos-1; 787 } 788 return pos + 1; 789} 790 791int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) 792{ 793 int pos; 794 795 if (option & ADD_CACHE_JUST_APPEND) 796 pos = istate->cache_nr; 797 else { 798 int ret; 799 ret = add_index_entry_with_check(istate, ce, option); 800 if (ret <= 0) 801 return ret; 802 pos = ret - 1; 803 } 804 805 /* Make sure the array is big enough .. */ 806 if (istate->cache_nr == istate->cache_alloc) { 807 istate->cache_alloc = alloc_nr(istate->cache_alloc); 808 istate->cache = xrealloc(istate->cache, 809 istate->cache_alloc * sizeof(struct cache_entry *)); 810 } 811 812 /* Add it in.. */ 813 istate->cache_nr++; 814 if (istate->cache_nr > pos + 1) 815 memmove(istate->cache + pos + 1, 816 istate->cache + pos, 817 (istate->cache_nr - pos - 1) * sizeof(ce)); 818 set_index_entry(istate, pos, ce); 819 istate->cache_changed = 1; 820 return 0; 821} 822 823/* 824 * "refresh" does not calculate a new sha1 file or bring the 825 * cache up-to-date for mode/content changes. But what it 826 * _does_ do is to "re-match" the stat information of a file 827 * with the cache, so that you can refresh the cache for a 828 * file that hasn't been changed but where the stat entry is 829 * out of date. 830 * 831 * For example, you'd want to do this after doing a "git-read-tree", 832 * to link up the stat cache details with the proper files. 833 */ 834static struct cache_entry *refresh_cache_ent(struct index_state *istate, 835 struct cache_entry *ce, 836 unsigned int options, int *err) 837{ 838 struct stat st; 839 struct cache_entry *updated; 840 int changed, size; 841 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 842 843 if (ce_uptodate(ce)) 844 return ce; 845 846 if (lstat(ce->name, &st) < 0) { 847 if (err) 848 *err = errno; 849 return NULL; 850 } 851 852 changed = ie_match_stat(istate, ce, &st, options); 853 if (!changed) { 854 /* 855 * The path is unchanged. If we were told to ignore 856 * valid bit, then we did the actual stat check and 857 * found that the entry is unmodified. If the entry 858 * is not marked VALID, this is the place to mark it 859 * valid again, under "assume unchanged" mode. 860 */ 861 if (ignore_valid && assume_unchanged && 862 !(ce->ce_flags & CE_VALID)) 863 ; /* mark this one VALID again */ 864 else { 865 /* 866 * We do not mark the index itself "modified" 867 * because CE_UPTODATE flag is in-core only; 868 * we are not going to write this change out. 869 */ 870 ce_mark_uptodate(ce); 871 return ce; 872 } 873 } 874 875 if (ie_modified(istate, ce, &st, options)) { 876 if (err) 877 *err = EINVAL; 878 return NULL; 879 } 880 881 size = ce_size(ce); 882 updated = xmalloc(size); 883 memcpy(updated, ce, size); 884 fill_stat_cache_info(updated, &st); 885 /* 886 * If ignore_valid is not set, we should leave CE_VALID bit 887 * alone. Otherwise, paths marked with --no-assume-unchanged 888 * (i.e. things to be edited) will reacquire CE_VALID bit 889 * automatically, which is not really what we want. 890 */ 891 if (!ignore_valid && assume_unchanged && 892 !(ce->ce_flags & CE_VALID)) 893 updated->ce_flags &= ~CE_VALID; 894 895 return updated; 896} 897 898int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen) 899{ 900 int i; 901 int has_errors = 0; 902 int really = (flags & REFRESH_REALLY) != 0; 903 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; 904 int quiet = (flags & REFRESH_QUIET) != 0; 905 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; 906 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0; 907 908 for (i = 0; i < istate->cache_nr; i++) { 909 struct cache_entry *ce, *new; 910 int cache_errno = 0; 911 912 ce = istate->cache[i]; 913 if (ce_stage(ce)) { 914 while ((i < istate->cache_nr) && 915 ! strcmp(istate->cache[i]->name, ce->name)) 916 i++; 917 i--; 918 if (allow_unmerged) 919 continue; 920 printf("%s: needs merge\n", ce->name); 921 has_errors = 1; 922 continue; 923 } 924 925 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen)) 926 continue; 927 928 new = refresh_cache_ent(istate, ce, options, &cache_errno); 929 if (new == ce) 930 continue; 931 if (!new) { 932 if (not_new && cache_errno == ENOENT) 933 continue; 934 if (really && cache_errno == EINVAL) { 935 /* If we are doing --really-refresh that 936 * means the index is not valid anymore. 937 */ 938 ce->ce_flags &= ~CE_VALID; 939 istate->cache_changed = 1; 940 } 941 if (quiet) 942 continue; 943 printf("%s: needs update\n", ce->name); 944 has_errors = 1; 945 continue; 946 } 947 948 replace_index_entry(istate, i, new); 949 } 950 return has_errors; 951} 952 953struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really) 954{ 955 return refresh_cache_ent(&the_index, ce, really, NULL); 956} 957 958static int verify_hdr(struct cache_header *hdr, unsigned long size) 959{ 960 SHA_CTX c; 961 unsigned char sha1[20]; 962 963 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) 964 return error("bad signature"); 965 if (hdr->hdr_version != htonl(2)) 966 return error("bad index version"); 967 SHA1_Init(&c); 968 SHA1_Update(&c, hdr, size - 20); 969 SHA1_Final(sha1, &c); 970 if (hashcmp(sha1, (unsigned char *)hdr + size - 20)) 971 return error("bad index file sha1 signature"); 972 return 0; 973} 974 975static int read_index_extension(struct index_state *istate, 976 const char *ext, void *data, unsigned long sz) 977{ 978 switch (CACHE_EXT(ext)) { 979 case CACHE_EXT_TREE: 980 istate->cache_tree = cache_tree_read(data, sz); 981 break; 982 default: 983 if (*ext < 'A' || 'Z' < *ext) 984 return error("index uses %.4s extension, which we do not understand", 985 ext); 986 fprintf(stderr, "ignoring %.4s extension\n", ext); 987 break; 988 } 989 return 0; 990} 991 992int read_index(struct index_state *istate) 993{ 994 return read_index_from(istate, get_index_file()); 995} 996 997static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce) 998{ 999 size_t len;10001001 ce->ce_ctime = ntohl(ondisk->ctime.sec);1002 ce->ce_mtime = ntohl(ondisk->mtime.sec);1003 ce->ce_dev = ntohl(ondisk->dev);1004 ce->ce_ino = ntohl(ondisk->ino);1005 ce->ce_mode = ntohl(ondisk->mode);1006 ce->ce_uid = ntohl(ondisk->uid);1007 ce->ce_gid = ntohl(ondisk->gid);1008 ce->ce_size = ntohl(ondisk->size);1009 /* On-disk flags are just 16 bits */1010 ce->ce_flags = ntohs(ondisk->flags);1011 hashcpy(ce->sha1, ondisk->sha1);10121013 len = ce->ce_flags & CE_NAMEMASK;1014 if (len == CE_NAMEMASK)1015 len = strlen(ondisk->name);1016 /*1017 * NEEDSWORK: If the original index is crafted, this copy could1018 * go unchecked.1019 */1020 memcpy(ce->name, ondisk->name, len + 1);1021}10221023static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)1024{1025 long per_entry;10261027 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);10281029 /*1030 * Alignment can cause differences. This should be "alignof", but1031 * since that's a gcc'ism, just use the size of a pointer.1032 */1033 per_entry += sizeof(void *);1034 return ondisk_size + entries*per_entry;1035}10361037/* remember to discard_cache() before reading a different cache! */1038int read_index_from(struct index_state *istate, const char *path)1039{1040 int fd, i;1041 struct stat st;1042 unsigned long src_offset, dst_offset;1043 struct cache_header *hdr;1044 void *mmap;1045 size_t mmap_size;10461047 errno = EBUSY;1048 if (istate->alloc)1049 return istate->cache_nr;10501051 errno = ENOENT;1052 istate->timestamp = 0;1053 fd = open(path, O_RDONLY);1054 if (fd < 0) {1055 if (errno == ENOENT)1056 return 0;1057 die("index file open failed (%s)", strerror(errno));1058 }10591060 if (fstat(fd, &st))1061 die("cannot stat the open index (%s)", strerror(errno));10621063 errno = EINVAL;1064 mmap_size = xsize_t(st.st_size);1065 if (mmap_size < sizeof(struct cache_header) + 20)1066 die("index file smaller than expected");10671068 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);1069 close(fd);1070 if (mmap == MAP_FAILED)1071 die("unable to map index file");10721073 hdr = mmap;1074 if (verify_hdr(hdr, mmap_size) < 0)1075 goto unmap;10761077 istate->cache_nr = ntohl(hdr->hdr_entries);1078 istate->cache_alloc = alloc_nr(istate->cache_nr);1079 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));10801081 /*1082 * The disk format is actually larger than the in-memory format,1083 * due to space for nsec etc, so even though the in-memory one1084 * has room for a few more flags, we can allocate using the same1085 * index size1086 */1087 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));10881089 src_offset = sizeof(*hdr);1090 dst_offset = 0;1091 for (i = 0; i < istate->cache_nr; i++) {1092 struct ondisk_cache_entry *disk_ce;1093 struct cache_entry *ce;10941095 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);1096 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);1097 convert_from_disk(disk_ce, ce);1098 set_index_entry(istate, i, ce);10991100 src_offset += ondisk_ce_size(ce);1101 dst_offset += ce_size(ce);1102 }1103 istate->timestamp = st.st_mtime;1104 while (src_offset <= mmap_size - 20 - 8) {1105 /* After an array of active_nr index entries,1106 * there can be arbitrary number of extended1107 * sections, each of which is prefixed with1108 * extension name (4-byte) and section length1109 * in 4-byte network byte order.1110 */1111 unsigned long extsize;1112 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);1113 extsize = ntohl(extsize);1114 if (read_index_extension(istate,1115 (const char *) mmap + src_offset,1116 (char *) mmap + src_offset + 8,1117 extsize) < 0)1118 goto unmap;1119 src_offset += 8;1120 src_offset += extsize;1121 }1122 munmap(mmap, mmap_size);1123 return istate->cache_nr;11241125unmap:1126 munmap(mmap, mmap_size);1127 errno = EINVAL;1128 die("index file corrupt");1129}11301131int discard_index(struct index_state *istate)1132{1133 istate->cache_nr = 0;1134 istate->cache_changed = 0;1135 istate->timestamp = 0;1136 free_hash(&istate->name_hash);1137 cache_tree_free(&(istate->cache_tree));1138 free(istate->alloc);1139 istate->alloc = NULL;11401141 /* no need to throw away allocated active_cache */1142 return 0;1143}11441145int unmerged_index(const struct index_state *istate)1146{1147 int i;1148 for (i = 0; i < istate->cache_nr; i++) {1149 if (ce_stage(istate->cache[i]))1150 return 1;1151 }1152 return 0;1153}11541155#define WRITE_BUFFER_SIZE 81921156static unsigned char write_buffer[WRITE_BUFFER_SIZE];1157static unsigned long write_buffer_len;11581159static int ce_write_flush(SHA_CTX *context, int fd)1160{1161 unsigned int buffered = write_buffer_len;1162 if (buffered) {1163 SHA1_Update(context, write_buffer, buffered);1164 if (write_in_full(fd, write_buffer, buffered) != buffered)1165 return -1;1166 write_buffer_len = 0;1167 }1168 return 0;1169}11701171static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)1172{1173 while (len) {1174 unsigned int buffered = write_buffer_len;1175 unsigned int partial = WRITE_BUFFER_SIZE - buffered;1176 if (partial > len)1177 partial = len;1178 memcpy(write_buffer + buffered, data, partial);1179 buffered += partial;1180 if (buffered == WRITE_BUFFER_SIZE) {1181 write_buffer_len = buffered;1182 if (ce_write_flush(context, fd))1183 return -1;1184 buffered = 0;1185 }1186 write_buffer_len = buffered;1187 len -= partial;1188 data = (char *) data + partial;1189 }1190 return 0;1191}11921193static int write_index_ext_header(SHA_CTX *context, int fd,1194 unsigned int ext, unsigned int sz)1195{1196 ext = htonl(ext);1197 sz = htonl(sz);1198 return ((ce_write(context, fd, &ext, 4) < 0) ||1199 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;1200}12011202static int ce_flush(SHA_CTX *context, int fd)1203{1204 unsigned int left = write_buffer_len;12051206 if (left) {1207 write_buffer_len = 0;1208 SHA1_Update(context, write_buffer, left);1209 }12101211 /* Flush first if not enough space for SHA1 signature */1212 if (left + 20 > WRITE_BUFFER_SIZE) {1213 if (write_in_full(fd, write_buffer, left) != left)1214 return -1;1215 left = 0;1216 }12171218 /* Append the SHA1 signature at the end */1219 SHA1_Final(write_buffer + left, context);1220 left += 20;1221 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;1222}12231224static void ce_smudge_racily_clean_entry(struct cache_entry *ce)1225{1226 /*1227 * The only thing we care about in this function is to smudge the1228 * falsely clean entry due to touch-update-touch race, so we leave1229 * everything else as they are. We are called for entries whose1230 * ce_mtime match the index file mtime.1231 */1232 struct stat st;12331234 if (lstat(ce->name, &st) < 0)1235 return;1236 if (ce_match_stat_basic(ce, &st))1237 return;1238 if (ce_modified_check_fs(ce, &st)) {1239 /* This is "racily clean"; smudge it. Note that this1240 * is a tricky code. At first glance, it may appear1241 * that it can break with this sequence:1242 *1243 * $ echo xyzzy >frotz1244 * $ git-update-index --add frotz1245 * $ : >frotz1246 * $ sleep 31247 * $ echo filfre >nitfol1248 * $ git-update-index --add nitfol1249 *1250 * but it does not. When the second update-index runs,1251 * it notices that the entry "frotz" has the same timestamp1252 * as index, and if we were to smudge it by resetting its1253 * size to zero here, then the object name recorded1254 * in index is the 6-byte file but the cached stat information1255 * becomes zero --- which would then match what we would1256 * obtain from the filesystem next time we stat("frotz").1257 *1258 * However, the second update-index, before calling1259 * this function, notices that the cached size is 61260 * bytes and what is on the filesystem is an empty1261 * file, and never calls us, so the cached size information1262 * for "frotz" stays 6 which does not match the filesystem.1263 */1264 ce->ce_size = 0;1265 }1266}12671268static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)1269{1270 int size = ondisk_ce_size(ce);1271 struct ondisk_cache_entry *ondisk = xcalloc(1, size);12721273 ondisk->ctime.sec = htonl(ce->ce_ctime);1274 ondisk->ctime.nsec = 0;1275 ondisk->mtime.sec = htonl(ce->ce_mtime);1276 ondisk->mtime.nsec = 0;1277 ondisk->dev = htonl(ce->ce_dev);1278 ondisk->ino = htonl(ce->ce_ino);1279 ondisk->mode = htonl(ce->ce_mode);1280 ondisk->uid = htonl(ce->ce_uid);1281 ondisk->gid = htonl(ce->ce_gid);1282 ondisk->size = htonl(ce->ce_size);1283 hashcpy(ondisk->sha1, ce->sha1);1284 ondisk->flags = htons(ce->ce_flags);1285 memcpy(ondisk->name, ce->name, ce_namelen(ce));12861287 return ce_write(c, fd, ondisk, size);1288}12891290int write_index(const struct index_state *istate, int newfd)1291{1292 SHA_CTX c;1293 struct cache_header hdr;1294 int i, err, removed;1295 struct cache_entry **cache = istate->cache;1296 int entries = istate->cache_nr;12971298 for (i = removed = 0; i < entries; i++)1299 if (cache[i]->ce_flags & CE_REMOVE)1300 removed++;13011302 hdr.hdr_signature = htonl(CACHE_SIGNATURE);1303 hdr.hdr_version = htonl(2);1304 hdr.hdr_entries = htonl(entries - removed);13051306 SHA1_Init(&c);1307 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)1308 return -1;13091310 for (i = 0; i < entries; i++) {1311 struct cache_entry *ce = cache[i];1312 if (ce->ce_flags & CE_REMOVE)1313 continue;1314 if (is_racy_timestamp(istate, ce))1315 ce_smudge_racily_clean_entry(ce);1316 if (ce_write_entry(&c, newfd, ce) < 0)1317 return -1;1318 }13191320 /* Write extension data here */1321 if (istate->cache_tree) {1322 struct strbuf sb;13231324 strbuf_init(&sb, 0);1325 cache_tree_write(&sb, istate->cache_tree);1326 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 01327 || ce_write(&c, newfd, sb.buf, sb.len) < 0;1328 strbuf_release(&sb);1329 if (err)1330 return -1;1331 }1332 return ce_flush(&c, newfd);1333}