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 is_empty_blob_sha1(const unsigned char *sha1) 142{ 143 static const unsigned char empty_blob_sha1[20] = { 144 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b, 145 0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91 146 }; 147 148 return !hashcmp(sha1, empty_blob_sha1); 149} 150 151static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) 152{ 153 unsigned int changed = 0; 154 155 if (ce->ce_flags & CE_REMOVE) 156 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; 157 158 switch (ce->ce_mode & S_IFMT) { 159 case S_IFREG: 160 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; 161 /* We consider only the owner x bit to be relevant for 162 * "mode changes" 163 */ 164 if (trust_executable_bit && 165 (0100 & (ce->ce_mode ^ st->st_mode))) 166 changed |= MODE_CHANGED; 167 break; 168 case S_IFLNK: 169 if (!S_ISLNK(st->st_mode) && 170 (has_symlinks || !S_ISREG(st->st_mode))) 171 changed |= TYPE_CHANGED; 172 break; 173 case S_IFGITLINK: 174 if (!S_ISDIR(st->st_mode)) 175 changed |= TYPE_CHANGED; 176 else if (ce_compare_gitlink(ce)) 177 changed |= DATA_CHANGED; 178 return changed; 179 default: 180 die("internal error: ce_mode is %o", ce->ce_mode); 181 } 182 if (ce->ce_mtime != (unsigned int) st->st_mtime) 183 changed |= MTIME_CHANGED; 184 if (ce->ce_ctime != (unsigned int) st->st_ctime) 185 changed |= CTIME_CHANGED; 186 187 if (ce->ce_uid != (unsigned int) st->st_uid || 188 ce->ce_gid != (unsigned int) st->st_gid) 189 changed |= OWNER_CHANGED; 190 if (ce->ce_ino != (unsigned int) st->st_ino) 191 changed |= INODE_CHANGED; 192 193#ifdef USE_STDEV 194 /* 195 * st_dev breaks on network filesystems where different 196 * clients will have different views of what "device" 197 * the filesystem is on 198 */ 199 if (ce->ce_dev != (unsigned int) st->st_dev) 200 changed |= INODE_CHANGED; 201#endif 202 203 if (ce->ce_size != (unsigned int) st->st_size) 204 changed |= DATA_CHANGED; 205 206 /* Racily smudged entry? */ 207 if (!ce->ce_size) { 208 if (!is_empty_blob_sha1(ce->sha1)) 209 changed |= DATA_CHANGED; 210 } 211 212 return changed; 213} 214 215static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce) 216{ 217 return (!S_ISGITLINK(ce->ce_mode) && 218 istate->timestamp && 219 ((unsigned int)istate->timestamp) <= ce->ce_mtime); 220} 221 222int ie_match_stat(const struct index_state *istate, 223 struct cache_entry *ce, struct stat *st, 224 unsigned int options) 225{ 226 unsigned int changed; 227 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 228 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; 229 230 /* 231 * If it's marked as always valid in the index, it's 232 * valid whatever the checked-out copy says. 233 */ 234 if (!ignore_valid && (ce->ce_flags & CE_VALID)) 235 return 0; 236 237 changed = ce_match_stat_basic(ce, st); 238 239 /* 240 * Within 1 second of this sequence: 241 * echo xyzzy >file && git-update-index --add file 242 * running this command: 243 * echo frotz >file 244 * would give a falsely clean cache entry. The mtime and 245 * length match the cache, and other stat fields do not change. 246 * 247 * We could detect this at update-index time (the cache entry 248 * being registered/updated records the same time as "now") 249 * and delay the return from git-update-index, but that would 250 * effectively mean we can make at most one commit per second, 251 * which is not acceptable. Instead, we check cache entries 252 * whose mtime are the same as the index file timestamp more 253 * carefully than others. 254 */ 255 if (!changed && is_racy_timestamp(istate, ce)) { 256 if (assume_racy_is_modified) 257 changed |= DATA_CHANGED; 258 else 259 changed |= ce_modified_check_fs(ce, st); 260 } 261 262 return changed; 263} 264 265int ie_modified(const struct index_state *istate, 266 struct cache_entry *ce, struct stat *st, unsigned int options) 267{ 268 int changed, changed_fs; 269 270 changed = ie_match_stat(istate, ce, st, options); 271 if (!changed) 272 return 0; 273 /* 274 * If the mode or type has changed, there's no point in trying 275 * to refresh the entry - it's not going to match 276 */ 277 if (changed & (MODE_CHANGED | TYPE_CHANGED)) 278 return changed; 279 280 /* Immediately after read-tree or update-index --cacheinfo, 281 * the length field is zero. For other cases the ce_size 282 * should match the SHA1 recorded in the index entry. 283 */ 284 if ((changed & DATA_CHANGED) && ce->ce_size != 0) 285 return changed; 286 287 changed_fs = ce_modified_check_fs(ce, st); 288 if (changed_fs) 289 return changed | changed_fs; 290 return 0; 291} 292 293int base_name_compare(const char *name1, int len1, int mode1, 294 const char *name2, int len2, int mode2) 295{ 296 unsigned char c1, c2; 297 int len = len1 < len2 ? len1 : len2; 298 int cmp; 299 300 cmp = memcmp(name1, name2, len); 301 if (cmp) 302 return cmp; 303 c1 = name1[len]; 304 c2 = name2[len]; 305 if (!c1 && S_ISDIR(mode1)) 306 c1 = '/'; 307 if (!c2 && S_ISDIR(mode2)) 308 c2 = '/'; 309 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; 310} 311 312/* 313 * df_name_compare() is identical to base_name_compare(), except it 314 * compares conflicting directory/file entries as equal. Note that 315 * while a directory name compares as equal to a regular file, they 316 * then individually compare _differently_ to a filename that has 317 * a dot after the basename (because '\0' < '.' < '/'). 318 * 319 * This is used by routines that want to traverse the git namespace 320 * but then handle conflicting entries together when possible. 321 */ 322int df_name_compare(const char *name1, int len1, int mode1, 323 const char *name2, int len2, int mode2) 324{ 325 int len = len1 < len2 ? len1 : len2, cmp; 326 unsigned char c1, c2; 327 328 cmp = memcmp(name1, name2, len); 329 if (cmp) 330 return cmp; 331 /* Directories and files compare equal (same length, same name) */ 332 if (len1 == len2) 333 return 0; 334 c1 = name1[len]; 335 if (!c1 && S_ISDIR(mode1)) 336 c1 = '/'; 337 c2 = name2[len]; 338 if (!c2 && S_ISDIR(mode2)) 339 c2 = '/'; 340 if (c1 == '/' && !c2) 341 return 0; 342 if (c2 == '/' && !c1) 343 return 0; 344 return c1 - c2; 345} 346 347int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) 348{ 349 int len1 = flags1 & CE_NAMEMASK; 350 int len2 = flags2 & CE_NAMEMASK; 351 int len = len1 < len2 ? len1 : len2; 352 int cmp; 353 354 cmp = memcmp(name1, name2, len); 355 if (cmp) 356 return cmp; 357 if (len1 < len2) 358 return -1; 359 if (len1 > len2) 360 return 1; 361 362 /* Compare stages */ 363 flags1 &= CE_STAGEMASK; 364 flags2 &= CE_STAGEMASK; 365 366 if (flags1 < flags2) 367 return -1; 368 if (flags1 > flags2) 369 return 1; 370 return 0; 371} 372 373int index_name_pos(const struct index_state *istate, const char *name, int namelen) 374{ 375 int first, last; 376 377 first = 0; 378 last = istate->cache_nr; 379 while (last > first) { 380 int next = (last + first) >> 1; 381 struct cache_entry *ce = istate->cache[next]; 382 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags); 383 if (!cmp) 384 return next; 385 if (cmp < 0) { 386 last = next; 387 continue; 388 } 389 first = next+1; 390 } 391 return -first-1; 392} 393 394/* Remove entry, return true if there are more entries to go.. */ 395int remove_index_entry_at(struct index_state *istate, int pos) 396{ 397 struct cache_entry *ce = istate->cache[pos]; 398 399 remove_name_hash(ce); 400 istate->cache_changed = 1; 401 istate->cache_nr--; 402 if (pos >= istate->cache_nr) 403 return 0; 404 memmove(istate->cache + pos, 405 istate->cache + pos + 1, 406 (istate->cache_nr - pos) * sizeof(struct cache_entry *)); 407 return 1; 408} 409 410int remove_file_from_index(struct index_state *istate, const char *path) 411{ 412 int pos = index_name_pos(istate, path, strlen(path)); 413 if (pos < 0) 414 pos = -pos-1; 415 cache_tree_invalidate_path(istate->cache_tree, path); 416 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) 417 remove_index_entry_at(istate, pos); 418 return 0; 419} 420 421static int compare_name(struct cache_entry *ce, const char *path, int namelen) 422{ 423 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); 424} 425 426static int index_name_pos_also_unmerged(struct index_state *istate, 427 const char *path, int namelen) 428{ 429 int pos = index_name_pos(istate, path, namelen); 430 struct cache_entry *ce; 431 432 if (pos >= 0) 433 return pos; 434 435 /* maybe unmerged? */ 436 pos = -1 - pos; 437 if (pos >= istate->cache_nr || 438 compare_name((ce = istate->cache[pos]), path, namelen)) 439 return -1; 440 441 /* order of preference: stage 2, 1, 3 */ 442 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && 443 ce_stage((ce = istate->cache[pos + 1])) == 2 && 444 !compare_name(ce, path, namelen)) 445 pos++; 446 return pos; 447} 448 449static int different_name(struct cache_entry *ce, struct cache_entry *alias) 450{ 451 int len = ce_namelen(ce); 452 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len); 453} 454 455/* 456 * If we add a filename that aliases in the cache, we will use the 457 * name that we already have - but we don't want to update the same 458 * alias twice, because that implies that there were actually two 459 * different files with aliasing names! 460 * 461 * So we use the CE_ADDED flag to verify that the alias was an old 462 * one before we accept it as 463 */ 464static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias) 465{ 466 int len; 467 struct cache_entry *new; 468 469 if (alias->ce_flags & CE_ADDED) 470 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name); 471 472 /* Ok, create the new entry using the name of the existing alias */ 473 len = ce_namelen(alias); 474 new = xcalloc(1, cache_entry_size(len)); 475 memcpy(new->name, alias->name, len); 476 copy_cache_entry(new, ce); 477 free(ce); 478 return new; 479} 480 481int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags) 482{ 483 int size, namelen, was_same; 484 mode_t st_mode = st->st_mode; 485 struct cache_entry *ce, *alias; 486 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY; 487 int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND); 488 int pretend = flags & ADD_CACHE_PRETEND; 489 490 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode)) 491 return error("%s: can only add regular files, symbolic links or git-directories", path); 492 493 namelen = strlen(path); 494 if (S_ISDIR(st_mode)) { 495 while (namelen && path[namelen-1] == '/') 496 namelen--; 497 } 498 size = cache_entry_size(namelen); 499 ce = xcalloc(1, size); 500 memcpy(ce->name, path, namelen); 501 ce->ce_flags = namelen; 502 fill_stat_cache_info(ce, st); 503 504 if (trust_executable_bit && has_symlinks) 505 ce->ce_mode = create_ce_mode(st_mode); 506 else { 507 /* If there is an existing entry, pick the mode bits and type 508 * from it, otherwise assume unexecutable regular file. 509 */ 510 struct cache_entry *ent; 511 int pos = index_name_pos_also_unmerged(istate, path, namelen); 512 513 ent = (0 <= pos) ? istate->cache[pos] : NULL; 514 ce->ce_mode = ce_mode_from_stat(ent, st_mode); 515 } 516 517 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case); 518 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) { 519 /* Nothing changed, really */ 520 free(ce); 521 ce_mark_uptodate(alias); 522 alias->ce_flags |= CE_ADDED; 523 return 0; 524 } 525 if (index_path(ce->sha1, path, st, 1)) 526 return error("unable to index file %s", path); 527 if (ignore_case && alias && different_name(ce, alias)) 528 ce = create_alias_ce(ce, alias); 529 ce->ce_flags |= CE_ADDED; 530 531 /* It was suspected to be recily clean, but it turns out to be Ok */ 532 was_same = (alias && 533 !ce_stage(alias) && 534 !hashcmp(alias->sha1, ce->sha1) && 535 ce->ce_mode == alias->ce_mode); 536 537 if (pretend) 538 ; 539 else if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE)) 540 return error("unable to add %s to index",path); 541 if (verbose && !was_same) 542 printf("add '%s'\n", path); 543 return 0; 544} 545 546int add_file_to_index(struct index_state *istate, const char *path, int flags) 547{ 548 struct stat st; 549 if (lstat(path, &st)) 550 die("%s: unable to stat (%s)", path, strerror(errno)); 551 return add_to_index(istate, path, &st, flags); 552} 553 554struct cache_entry *make_cache_entry(unsigned int mode, 555 const unsigned char *sha1, const char *path, int stage, 556 int refresh) 557{ 558 int size, len; 559 struct cache_entry *ce; 560 561 if (!verify_path(path)) 562 return NULL; 563 564 len = strlen(path); 565 size = cache_entry_size(len); 566 ce = xcalloc(1, size); 567 568 hashcpy(ce->sha1, sha1); 569 memcpy(ce->name, path, len); 570 ce->ce_flags = create_ce_flags(len, stage); 571 ce->ce_mode = create_ce_mode(mode); 572 573 if (refresh) 574 return refresh_cache_entry(ce, 0); 575 576 return ce; 577} 578 579int ce_same_name(struct cache_entry *a, struct cache_entry *b) 580{ 581 int len = ce_namelen(a); 582 return ce_namelen(b) == len && !memcmp(a->name, b->name, len); 583} 584 585int ce_path_match(const struct cache_entry *ce, const char **pathspec) 586{ 587 const char *match, *name; 588 int len; 589 590 if (!pathspec) 591 return 1; 592 593 len = ce_namelen(ce); 594 name = ce->name; 595 while ((match = *pathspec++) != NULL) { 596 int matchlen = strlen(match); 597 if (matchlen > len) 598 continue; 599 if (memcmp(name, match, matchlen)) 600 continue; 601 if (matchlen && name[matchlen-1] == '/') 602 return 1; 603 if (name[matchlen] == '/' || !name[matchlen]) 604 return 1; 605 if (!matchlen) 606 return 1; 607 } 608 return 0; 609} 610 611/* 612 * We fundamentally don't like some paths: we don't want 613 * dot or dot-dot anywhere, and for obvious reasons don't 614 * want to recurse into ".git" either. 615 * 616 * Also, we don't want double slashes or slashes at the 617 * end that can make pathnames ambiguous. 618 */ 619static int verify_dotfile(const char *rest) 620{ 621 /* 622 * The first character was '.', but that 623 * has already been discarded, we now test 624 * the rest. 625 */ 626 switch (*rest) { 627 /* "." is not allowed */ 628 case '\0': case '/': 629 return 0; 630 631 /* 632 * ".git" followed by NUL or slash is bad. This 633 * shares the path end test with the ".." case. 634 */ 635 case 'g': 636 if (rest[1] != 'i') 637 break; 638 if (rest[2] != 't') 639 break; 640 rest += 2; 641 /* fallthrough */ 642 case '.': 643 if (rest[1] == '\0' || rest[1] == '/') 644 return 0; 645 } 646 return 1; 647} 648 649int verify_path(const char *path) 650{ 651 char c; 652 653 goto inside; 654 for (;;) { 655 if (!c) 656 return 1; 657 if (c == '/') { 658inside: 659 c = *path++; 660 switch (c) { 661 default: 662 continue; 663 case '/': case '\0': 664 break; 665 case '.': 666 if (verify_dotfile(path)) 667 continue; 668 } 669 return 0; 670 } 671 c = *path++; 672 } 673} 674 675/* 676 * Do we have another file that has the beginning components being a 677 * proper superset of the name we're trying to add? 678 */ 679static int has_file_name(struct index_state *istate, 680 const struct cache_entry *ce, int pos, int ok_to_replace) 681{ 682 int retval = 0; 683 int len = ce_namelen(ce); 684 int stage = ce_stage(ce); 685 const char *name = ce->name; 686 687 while (pos < istate->cache_nr) { 688 struct cache_entry *p = istate->cache[pos++]; 689 690 if (len >= ce_namelen(p)) 691 break; 692 if (memcmp(name, p->name, len)) 693 break; 694 if (ce_stage(p) != stage) 695 continue; 696 if (p->name[len] != '/') 697 continue; 698 if (p->ce_flags & CE_REMOVE) 699 continue; 700 retval = -1; 701 if (!ok_to_replace) 702 break; 703 remove_index_entry_at(istate, --pos); 704 } 705 return retval; 706} 707 708/* 709 * Do we have another file with a pathname that is a proper 710 * subset of the name we're trying to add? 711 */ 712static int has_dir_name(struct index_state *istate, 713 const struct cache_entry *ce, int pos, int ok_to_replace) 714{ 715 int retval = 0; 716 int stage = ce_stage(ce); 717 const char *name = ce->name; 718 const char *slash = name + ce_namelen(ce); 719 720 for (;;) { 721 int len; 722 723 for (;;) { 724 if (*--slash == '/') 725 break; 726 if (slash <= ce->name) 727 return retval; 728 } 729 len = slash - name; 730 731 pos = index_name_pos(istate, name, create_ce_flags(len, stage)); 732 if (pos >= 0) { 733 /* 734 * Found one, but not so fast. This could 735 * be a marker that says "I was here, but 736 * I am being removed". Such an entry is 737 * not a part of the resulting tree, and 738 * it is Ok to have a directory at the same 739 * path. 740 */ 741 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) { 742 retval = -1; 743 if (!ok_to_replace) 744 break; 745 remove_index_entry_at(istate, pos); 746 continue; 747 } 748 } 749 else 750 pos = -pos-1; 751 752 /* 753 * Trivial optimization: if we find an entry that 754 * already matches the sub-directory, then we know 755 * we're ok, and we can exit. 756 */ 757 while (pos < istate->cache_nr) { 758 struct cache_entry *p = istate->cache[pos]; 759 if ((ce_namelen(p) <= len) || 760 (p->name[len] != '/') || 761 memcmp(p->name, name, len)) 762 break; /* not our subdirectory */ 763 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) 764 /* 765 * p is at the same stage as our entry, and 766 * is a subdirectory of what we are looking 767 * at, so we cannot have conflicts at our 768 * level or anything shorter. 769 */ 770 return retval; 771 pos++; 772 } 773 } 774 return retval; 775} 776 777/* We may be in a situation where we already have path/file and path 778 * is being added, or we already have path and path/file is being 779 * added. Either one would result in a nonsense tree that has path 780 * twice when git-write-tree tries to write it out. Prevent it. 781 * 782 * If ok-to-replace is specified, we remove the conflicting entries 783 * from the cache so the caller should recompute the insert position. 784 * When this happens, we return non-zero. 785 */ 786static int check_file_directory_conflict(struct index_state *istate, 787 const struct cache_entry *ce, 788 int pos, int ok_to_replace) 789{ 790 int retval; 791 792 /* 793 * When ce is an "I am going away" entry, we allow it to be added 794 */ 795 if (ce->ce_flags & CE_REMOVE) 796 return 0; 797 798 /* 799 * We check if the path is a sub-path of a subsequent pathname 800 * first, since removing those will not change the position 801 * in the array. 802 */ 803 retval = has_file_name(istate, ce, pos, ok_to_replace); 804 805 /* 806 * Then check if the path might have a clashing sub-directory 807 * before it. 808 */ 809 return retval + has_dir_name(istate, ce, pos, ok_to_replace); 810} 811 812static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) 813{ 814 int pos; 815 int ok_to_add = option & ADD_CACHE_OK_TO_ADD; 816 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; 817 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; 818 819 cache_tree_invalidate_path(istate->cache_tree, ce->name); 820 pos = index_name_pos(istate, ce->name, ce->ce_flags); 821 822 /* existing match? Just replace it. */ 823 if (pos >= 0) { 824 replace_index_entry(istate, pos, ce); 825 return 0; 826 } 827 pos = -pos-1; 828 829 /* 830 * Inserting a merged entry ("stage 0") into the index 831 * will always replace all non-merged entries.. 832 */ 833 if (pos < istate->cache_nr && ce_stage(ce) == 0) { 834 while (ce_same_name(istate->cache[pos], ce)) { 835 ok_to_add = 1; 836 if (!remove_index_entry_at(istate, pos)) 837 break; 838 } 839 } 840 841 if (!ok_to_add) 842 return -1; 843 if (!verify_path(ce->name)) 844 return -1; 845 846 if (!skip_df_check && 847 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { 848 if (!ok_to_replace) 849 return error("'%s' appears as both a file and as a directory", 850 ce->name); 851 pos = index_name_pos(istate, ce->name, ce->ce_flags); 852 pos = -pos-1; 853 } 854 return pos + 1; 855} 856 857int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) 858{ 859 int pos; 860 861 if (option & ADD_CACHE_JUST_APPEND) 862 pos = istate->cache_nr; 863 else { 864 int ret; 865 ret = add_index_entry_with_check(istate, ce, option); 866 if (ret <= 0) 867 return ret; 868 pos = ret - 1; 869 } 870 871 /* Make sure the array is big enough .. */ 872 if (istate->cache_nr == istate->cache_alloc) { 873 istate->cache_alloc = alloc_nr(istate->cache_alloc); 874 istate->cache = xrealloc(istate->cache, 875 istate->cache_alloc * sizeof(struct cache_entry *)); 876 } 877 878 /* Add it in.. */ 879 istate->cache_nr++; 880 if (istate->cache_nr > pos + 1) 881 memmove(istate->cache + pos + 1, 882 istate->cache + pos, 883 (istate->cache_nr - pos - 1) * sizeof(ce)); 884 set_index_entry(istate, pos, ce); 885 istate->cache_changed = 1; 886 return 0; 887} 888 889/* 890 * "refresh" does not calculate a new sha1 file or bring the 891 * cache up-to-date for mode/content changes. But what it 892 * _does_ do is to "re-match" the stat information of a file 893 * with the cache, so that you can refresh the cache for a 894 * file that hasn't been changed but where the stat entry is 895 * out of date. 896 * 897 * For example, you'd want to do this after doing a "git-read-tree", 898 * to link up the stat cache details with the proper files. 899 */ 900static struct cache_entry *refresh_cache_ent(struct index_state *istate, 901 struct cache_entry *ce, 902 unsigned int options, int *err) 903{ 904 struct stat st; 905 struct cache_entry *updated; 906 int changed, size; 907 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 908 909 if (ce_uptodate(ce)) 910 return ce; 911 912 /* 913 * CE_VALID means the user promised us that the change to 914 * the work tree does not matter and told us not to worry. 915 */ 916 if (!ignore_valid && (ce->ce_flags & CE_VALID)) { 917 ce_mark_uptodate(ce); 918 return ce; 919 } 920 921 if (lstat(ce->name, &st) < 0) { 922 if (err) 923 *err = errno; 924 return NULL; 925 } 926 927 changed = ie_match_stat(istate, ce, &st, options); 928 if (!changed) { 929 /* 930 * The path is unchanged. If we were told to ignore 931 * valid bit, then we did the actual stat check and 932 * found that the entry is unmodified. If the entry 933 * is not marked VALID, this is the place to mark it 934 * valid again, under "assume unchanged" mode. 935 */ 936 if (ignore_valid && assume_unchanged && 937 !(ce->ce_flags & CE_VALID)) 938 ; /* mark this one VALID again */ 939 else { 940 /* 941 * We do not mark the index itself "modified" 942 * because CE_UPTODATE flag is in-core only; 943 * we are not going to write this change out. 944 */ 945 ce_mark_uptodate(ce); 946 return ce; 947 } 948 } 949 950 if (ie_modified(istate, ce, &st, options)) { 951 if (err) 952 *err = EINVAL; 953 return NULL; 954 } 955 956 size = ce_size(ce); 957 updated = xmalloc(size); 958 memcpy(updated, ce, size); 959 fill_stat_cache_info(updated, &st); 960 /* 961 * If ignore_valid is not set, we should leave CE_VALID bit 962 * alone. Otherwise, paths marked with --no-assume-unchanged 963 * (i.e. things to be edited) will reacquire CE_VALID bit 964 * automatically, which is not really what we want. 965 */ 966 if (!ignore_valid && assume_unchanged && 967 !(ce->ce_flags & CE_VALID)) 968 updated->ce_flags &= ~CE_VALID; 969 970 return updated; 971} 972 973int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen) 974{ 975 int i; 976 int has_errors = 0; 977 int really = (flags & REFRESH_REALLY) != 0; 978 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; 979 int quiet = (flags & REFRESH_QUIET) != 0; 980 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; 981 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0; 982 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0; 983 984 for (i = 0; i < istate->cache_nr; i++) { 985 struct cache_entry *ce, *new; 986 int cache_errno = 0; 987 988 ce = istate->cache[i]; 989 if (ignore_submodules && S_ISGITLINK(ce->ce_mode)) 990 continue; 991 992 if (ce_stage(ce)) { 993 while ((i < istate->cache_nr) && 994 ! strcmp(istate->cache[i]->name, ce->name)) 995 i++; 996 i--; 997 if (allow_unmerged) 998 continue; 999 printf("%s: needs merge\n", ce->name);1000 has_errors = 1;1001 continue;1002 }10031004 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))1005 continue;10061007 new = refresh_cache_ent(istate, ce, options, &cache_errno);1008 if (new == ce)1009 continue;1010 if (!new) {1011 if (not_new && cache_errno == ENOENT)1012 continue;1013 if (really && cache_errno == EINVAL) {1014 /* If we are doing --really-refresh that1015 * means the index is not valid anymore.1016 */1017 ce->ce_flags &= ~CE_VALID;1018 istate->cache_changed = 1;1019 }1020 if (quiet)1021 continue;1022 printf("%s: needs update\n", ce->name);1023 has_errors = 1;1024 continue;1025 }10261027 replace_index_entry(istate, i, new);1028 }1029 return has_errors;1030}10311032struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)1033{1034 return refresh_cache_ent(&the_index, ce, really, NULL);1035}10361037static int verify_hdr(struct cache_header *hdr, unsigned long size)1038{1039 SHA_CTX c;1040 unsigned char sha1[20];10411042 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))1043 return error("bad signature");1044 if (hdr->hdr_version != htonl(2))1045 return error("bad index version");1046 SHA1_Init(&c);1047 SHA1_Update(&c, hdr, size - 20);1048 SHA1_Final(sha1, &c);1049 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))1050 return error("bad index file sha1 signature");1051 return 0;1052}10531054static int read_index_extension(struct index_state *istate,1055 const char *ext, void *data, unsigned long sz)1056{1057 switch (CACHE_EXT(ext)) {1058 case CACHE_EXT_TREE:1059 istate->cache_tree = cache_tree_read(data, sz);1060 break;1061 default:1062 if (*ext < 'A' || 'Z' < *ext)1063 return error("index uses %.4s extension, which we do not understand",1064 ext);1065 fprintf(stderr, "ignoring %.4s extension\n", ext);1066 break;1067 }1068 return 0;1069}10701071int read_index(struct index_state *istate)1072{1073 return read_index_from(istate, get_index_file());1074}10751076static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)1077{1078 size_t len;10791080 ce->ce_ctime = ntohl(ondisk->ctime.sec);1081 ce->ce_mtime = ntohl(ondisk->mtime.sec);1082 ce->ce_dev = ntohl(ondisk->dev);1083 ce->ce_ino = ntohl(ondisk->ino);1084 ce->ce_mode = ntohl(ondisk->mode);1085 ce->ce_uid = ntohl(ondisk->uid);1086 ce->ce_gid = ntohl(ondisk->gid);1087 ce->ce_size = ntohl(ondisk->size);1088 /* On-disk flags are just 16 bits */1089 ce->ce_flags = ntohs(ondisk->flags);1090 hashcpy(ce->sha1, ondisk->sha1);10911092 len = ce->ce_flags & CE_NAMEMASK;1093 if (len == CE_NAMEMASK)1094 len = strlen(ondisk->name);1095 /*1096 * NEEDSWORK: If the original index is crafted, this copy could1097 * go unchecked.1098 */1099 memcpy(ce->name, ondisk->name, len + 1);1100}11011102static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)1103{1104 long per_entry;11051106 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);11071108 /*1109 * Alignment can cause differences. This should be "alignof", but1110 * since that's a gcc'ism, just use the size of a pointer.1111 */1112 per_entry += sizeof(void *);1113 return ondisk_size + entries*per_entry;1114}11151116/* remember to discard_cache() before reading a different cache! */1117int read_index_from(struct index_state *istate, const char *path)1118{1119 int fd, i;1120 struct stat st;1121 unsigned long src_offset, dst_offset;1122 struct cache_header *hdr;1123 void *mmap;1124 size_t mmap_size;11251126 errno = EBUSY;1127 if (istate->alloc)1128 return istate->cache_nr;11291130 errno = ENOENT;1131 istate->timestamp = 0;1132 fd = open(path, O_RDONLY);1133 if (fd < 0) {1134 if (errno == ENOENT)1135 return 0;1136 die("index file open failed (%s)", strerror(errno));1137 }11381139 if (fstat(fd, &st))1140 die("cannot stat the open index (%s)", strerror(errno));11411142 errno = EINVAL;1143 mmap_size = xsize_t(st.st_size);1144 if (mmap_size < sizeof(struct cache_header) + 20)1145 die("index file smaller than expected");11461147 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);1148 close(fd);1149 if (mmap == MAP_FAILED)1150 die("unable to map index file");11511152 hdr = mmap;1153 if (verify_hdr(hdr, mmap_size) < 0)1154 goto unmap;11551156 istate->cache_nr = ntohl(hdr->hdr_entries);1157 istate->cache_alloc = alloc_nr(istate->cache_nr);1158 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));11591160 /*1161 * The disk format is actually larger than the in-memory format,1162 * due to space for nsec etc, so even though the in-memory one1163 * has room for a few more flags, we can allocate using the same1164 * index size1165 */1166 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));11671168 src_offset = sizeof(*hdr);1169 dst_offset = 0;1170 for (i = 0; i < istate->cache_nr; i++) {1171 struct ondisk_cache_entry *disk_ce;1172 struct cache_entry *ce;11731174 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);1175 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);1176 convert_from_disk(disk_ce, ce);1177 set_index_entry(istate, i, ce);11781179 src_offset += ondisk_ce_size(ce);1180 dst_offset += ce_size(ce);1181 }1182 istate->timestamp = st.st_mtime;1183 while (src_offset <= mmap_size - 20 - 8) {1184 /* After an array of active_nr index entries,1185 * there can be arbitrary number of extended1186 * sections, each of which is prefixed with1187 * extension name (4-byte) and section length1188 * in 4-byte network byte order.1189 */1190 unsigned long extsize;1191 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);1192 extsize = ntohl(extsize);1193 if (read_index_extension(istate,1194 (const char *) mmap + src_offset,1195 (char *) mmap + src_offset + 8,1196 extsize) < 0)1197 goto unmap;1198 src_offset += 8;1199 src_offset += extsize;1200 }1201 munmap(mmap, mmap_size);1202 return istate->cache_nr;12031204unmap:1205 munmap(mmap, mmap_size);1206 errno = EINVAL;1207 die("index file corrupt");1208}12091210int discard_index(struct index_state *istate)1211{1212 istate->cache_nr = 0;1213 istate->cache_changed = 0;1214 istate->timestamp = 0;1215 free_hash(&istate->name_hash);1216 cache_tree_free(&(istate->cache_tree));1217 free(istate->alloc);1218 istate->alloc = NULL;12191220 /* no need to throw away allocated active_cache */1221 return 0;1222}12231224int unmerged_index(const struct index_state *istate)1225{1226 int i;1227 for (i = 0; i < istate->cache_nr; i++) {1228 if (ce_stage(istate->cache[i]))1229 return 1;1230 }1231 return 0;1232}12331234#define WRITE_BUFFER_SIZE 81921235static unsigned char write_buffer[WRITE_BUFFER_SIZE];1236static unsigned long write_buffer_len;12371238static int ce_write_flush(SHA_CTX *context, int fd)1239{1240 unsigned int buffered = write_buffer_len;1241 if (buffered) {1242 SHA1_Update(context, write_buffer, buffered);1243 if (write_in_full(fd, write_buffer, buffered) != buffered)1244 return -1;1245 write_buffer_len = 0;1246 }1247 return 0;1248}12491250static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)1251{1252 while (len) {1253 unsigned int buffered = write_buffer_len;1254 unsigned int partial = WRITE_BUFFER_SIZE - buffered;1255 if (partial > len)1256 partial = len;1257 memcpy(write_buffer + buffered, data, partial);1258 buffered += partial;1259 if (buffered == WRITE_BUFFER_SIZE) {1260 write_buffer_len = buffered;1261 if (ce_write_flush(context, fd))1262 return -1;1263 buffered = 0;1264 }1265 write_buffer_len = buffered;1266 len -= partial;1267 data = (char *) data + partial;1268 }1269 return 0;1270}12711272static int write_index_ext_header(SHA_CTX *context, int fd,1273 unsigned int ext, unsigned int sz)1274{1275 ext = htonl(ext);1276 sz = htonl(sz);1277 return ((ce_write(context, fd, &ext, 4) < 0) ||1278 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;1279}12801281static int ce_flush(SHA_CTX *context, int fd)1282{1283 unsigned int left = write_buffer_len;12841285 if (left) {1286 write_buffer_len = 0;1287 SHA1_Update(context, write_buffer, left);1288 }12891290 /* Flush first if not enough space for SHA1 signature */1291 if (left + 20 > WRITE_BUFFER_SIZE) {1292 if (write_in_full(fd, write_buffer, left) != left)1293 return -1;1294 left = 0;1295 }12961297 /* Append the SHA1 signature at the end */1298 SHA1_Final(write_buffer + left, context);1299 left += 20;1300 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;1301}13021303static void ce_smudge_racily_clean_entry(struct cache_entry *ce)1304{1305 /*1306 * The only thing we care about in this function is to smudge the1307 * falsely clean entry due to touch-update-touch race, so we leave1308 * everything else as they are. We are called for entries whose1309 * ce_mtime match the index file mtime.1310 */1311 struct stat st;13121313 if (lstat(ce->name, &st) < 0)1314 return;1315 if (ce_match_stat_basic(ce, &st))1316 return;1317 if (ce_modified_check_fs(ce, &st)) {1318 /* This is "racily clean"; smudge it. Note that this1319 * is a tricky code. At first glance, it may appear1320 * that it can break with this sequence:1321 *1322 * $ echo xyzzy >frotz1323 * $ git-update-index --add frotz1324 * $ : >frotz1325 * $ sleep 31326 * $ echo filfre >nitfol1327 * $ git-update-index --add nitfol1328 *1329 * but it does not. When the second update-index runs,1330 * it notices that the entry "frotz" has the same timestamp1331 * as index, and if we were to smudge it by resetting its1332 * size to zero here, then the object name recorded1333 * in index is the 6-byte file but the cached stat information1334 * becomes zero --- which would then match what we would1335 * obtain from the filesystem next time we stat("frotz").1336 *1337 * However, the second update-index, before calling1338 * this function, notices that the cached size is 61339 * bytes and what is on the filesystem is an empty1340 * file, and never calls us, so the cached size information1341 * for "frotz" stays 6 which does not match the filesystem.1342 */1343 ce->ce_size = 0;1344 }1345}13461347static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)1348{1349 int size = ondisk_ce_size(ce);1350 struct ondisk_cache_entry *ondisk = xcalloc(1, size);13511352 ondisk->ctime.sec = htonl(ce->ce_ctime);1353 ondisk->ctime.nsec = 0;1354 ondisk->mtime.sec = htonl(ce->ce_mtime);1355 ondisk->mtime.nsec = 0;1356 ondisk->dev = htonl(ce->ce_dev);1357 ondisk->ino = htonl(ce->ce_ino);1358 ondisk->mode = htonl(ce->ce_mode);1359 ondisk->uid = htonl(ce->ce_uid);1360 ondisk->gid = htonl(ce->ce_gid);1361 ondisk->size = htonl(ce->ce_size);1362 hashcpy(ondisk->sha1, ce->sha1);1363 ondisk->flags = htons(ce->ce_flags);1364 memcpy(ondisk->name, ce->name, ce_namelen(ce));13651366 return ce_write(c, fd, ondisk, size);1367}13681369int write_index(const struct index_state *istate, int newfd)1370{1371 SHA_CTX c;1372 struct cache_header hdr;1373 int i, err, removed;1374 struct cache_entry **cache = istate->cache;1375 int entries = istate->cache_nr;13761377 for (i = removed = 0; i < entries; i++)1378 if (cache[i]->ce_flags & CE_REMOVE)1379 removed++;13801381 hdr.hdr_signature = htonl(CACHE_SIGNATURE);1382 hdr.hdr_version = htonl(2);1383 hdr.hdr_entries = htonl(entries - removed);13841385 SHA1_Init(&c);1386 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)1387 return -1;13881389 for (i = 0; i < entries; i++) {1390 struct cache_entry *ce = cache[i];1391 if (ce->ce_flags & CE_REMOVE)1392 continue;1393 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))1394 ce_smudge_racily_clean_entry(ce);1395 if (ce_write_entry(&c, newfd, ce) < 0)1396 return -1;1397 }13981399 /* Write extension data here */1400 if (istate->cache_tree) {1401 struct strbuf sb;14021403 strbuf_init(&sb, 0);1404 cache_tree_write(&sb, istate->cache_tree);1405 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 01406 || ce_write(&c, newfd, sb.buf, sb.len) < 0;1407 strbuf_release(&sb);1408 if (err)1409 return -1;1410 }1411 return ce_flush(&c, newfd);1412}