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 41void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name) 42{ 43 struct cache_entry *old = istate->cache[nr], *new; 44 int namelen = strlen(new_name); 45 46 new = xmalloc(cache_entry_size(namelen)); 47 copy_cache_entry(new, old); 48 new->ce_flags &= ~(CE_STATE_MASK | CE_NAMEMASK); 49 new->ce_flags |= (namelen >= CE_NAMEMASK ? CE_NAMEMASK : namelen); 50 memcpy(new->name, new_name, namelen + 1); 51 52 cache_tree_invalidate_path(istate->cache_tree, old->name); 53 remove_index_entry_at(istate, nr); 54 add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); 55} 56 57/* 58 * This only updates the "non-critical" parts of the directory 59 * cache, ie the parts that aren't tracked by GIT, and only used 60 * to validate the cache. 61 */ 62void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) 63{ 64 ce->ce_ctime = st->st_ctime; 65 ce->ce_mtime = st->st_mtime; 66 ce->ce_dev = st->st_dev; 67 ce->ce_ino = st->st_ino; 68 ce->ce_uid = st->st_uid; 69 ce->ce_gid = st->st_gid; 70 ce->ce_size = st->st_size; 71 72 if (assume_unchanged) 73 ce->ce_flags |= CE_VALID; 74 75 if (S_ISREG(st->st_mode)) 76 ce_mark_uptodate(ce); 77} 78 79static int ce_compare_data(struct cache_entry *ce, struct stat *st) 80{ 81 int match = -1; 82 int fd = open(ce->name, O_RDONLY); 83 84 if (fd >= 0) { 85 unsigned char sha1[20]; 86 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name)) 87 match = hashcmp(sha1, ce->sha1); 88 /* index_fd() closed the file descriptor already */ 89 } 90 return match; 91} 92 93static int ce_compare_link(struct cache_entry *ce, size_t expected_size) 94{ 95 int match = -1; 96 char *target; 97 void *buffer; 98 unsigned long size; 99 enum object_type type; 100 int len; 101 102 target = xmalloc(expected_size); 103 len = readlink(ce->name, target, expected_size); 104 if (len != expected_size) { 105 free(target); 106 return -1; 107 } 108 buffer = read_sha1_file(ce->sha1, &type, &size); 109 if (!buffer) { 110 free(target); 111 return -1; 112 } 113 if (size == expected_size) 114 match = memcmp(buffer, target, size); 115 free(buffer); 116 free(target); 117 return match; 118} 119 120static int ce_compare_gitlink(struct cache_entry *ce) 121{ 122 unsigned char sha1[20]; 123 124 /* 125 * We don't actually require that the .git directory 126 * under GITLINK directory be a valid git directory. It 127 * might even be missing (in case nobody populated that 128 * sub-project). 129 * 130 * If so, we consider it always to match. 131 */ 132 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0) 133 return 0; 134 return hashcmp(sha1, ce->sha1); 135} 136 137static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st) 138{ 139 switch (st->st_mode & S_IFMT) { 140 case S_IFREG: 141 if (ce_compare_data(ce, st)) 142 return DATA_CHANGED; 143 break; 144 case S_IFLNK: 145 if (ce_compare_link(ce, xsize_t(st->st_size))) 146 return DATA_CHANGED; 147 break; 148 case S_IFDIR: 149 if (S_ISGITLINK(ce->ce_mode)) 150 return 0; 151 default: 152 return TYPE_CHANGED; 153 } 154 return 0; 155} 156 157static int is_empty_blob_sha1(const unsigned char *sha1) 158{ 159 static const unsigned char empty_blob_sha1[20] = { 160 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b, 161 0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91 162 }; 163 164 return !hashcmp(sha1, empty_blob_sha1); 165} 166 167static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) 168{ 169 unsigned int changed = 0; 170 171 if (ce->ce_flags & CE_REMOVE) 172 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; 173 174 switch (ce->ce_mode & S_IFMT) { 175 case S_IFREG: 176 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; 177 /* We consider only the owner x bit to be relevant for 178 * "mode changes" 179 */ 180 if (trust_executable_bit && 181 (0100 & (ce->ce_mode ^ st->st_mode))) 182 changed |= MODE_CHANGED; 183 break; 184 case S_IFLNK: 185 if (!S_ISLNK(st->st_mode) && 186 (has_symlinks || !S_ISREG(st->st_mode))) 187 changed |= TYPE_CHANGED; 188 break; 189 case S_IFGITLINK: 190 if (!S_ISDIR(st->st_mode)) 191 changed |= TYPE_CHANGED; 192 else if (ce_compare_gitlink(ce)) 193 changed |= DATA_CHANGED; 194 return changed; 195 default: 196 die("internal error: ce_mode is %o", ce->ce_mode); 197 } 198 if (ce->ce_mtime != (unsigned int) st->st_mtime) 199 changed |= MTIME_CHANGED; 200 if (ce->ce_ctime != (unsigned int) st->st_ctime) 201 changed |= CTIME_CHANGED; 202 203 if (ce->ce_uid != (unsigned int) st->st_uid || 204 ce->ce_gid != (unsigned int) st->st_gid) 205 changed |= OWNER_CHANGED; 206 if (ce->ce_ino != (unsigned int) st->st_ino) 207 changed |= INODE_CHANGED; 208 209#ifdef USE_STDEV 210 /* 211 * st_dev breaks on network filesystems where different 212 * clients will have different views of what "device" 213 * the filesystem is on 214 */ 215 if (ce->ce_dev != (unsigned int) st->st_dev) 216 changed |= INODE_CHANGED; 217#endif 218 219 if (ce->ce_size != (unsigned int) st->st_size) 220 changed |= DATA_CHANGED; 221 222 /* Racily smudged entry? */ 223 if (!ce->ce_size) { 224 if (!is_empty_blob_sha1(ce->sha1)) 225 changed |= DATA_CHANGED; 226 } 227 228 return changed; 229} 230 231static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce) 232{ 233 return (!S_ISGITLINK(ce->ce_mode) && 234 istate->timestamp && 235 ((unsigned int)istate->timestamp) <= ce->ce_mtime); 236} 237 238int ie_match_stat(const struct index_state *istate, 239 struct cache_entry *ce, struct stat *st, 240 unsigned int options) 241{ 242 unsigned int changed; 243 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 244 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; 245 246 /* 247 * If it's marked as always valid in the index, it's 248 * valid whatever the checked-out copy says. 249 */ 250 if (!ignore_valid && (ce->ce_flags & CE_VALID)) 251 return 0; 252 253 changed = ce_match_stat_basic(ce, st); 254 255 /* 256 * Within 1 second of this sequence: 257 * echo xyzzy >file && git-update-index --add file 258 * running this command: 259 * echo frotz >file 260 * would give a falsely clean cache entry. The mtime and 261 * length match the cache, and other stat fields do not change. 262 * 263 * We could detect this at update-index time (the cache entry 264 * being registered/updated records the same time as "now") 265 * and delay the return from git-update-index, but that would 266 * effectively mean we can make at most one commit per second, 267 * which is not acceptable. Instead, we check cache entries 268 * whose mtime are the same as the index file timestamp more 269 * carefully than others. 270 */ 271 if (!changed && is_racy_timestamp(istate, ce)) { 272 if (assume_racy_is_modified) 273 changed |= DATA_CHANGED; 274 else 275 changed |= ce_modified_check_fs(ce, st); 276 } 277 278 return changed; 279} 280 281int ie_modified(const struct index_state *istate, 282 struct cache_entry *ce, struct stat *st, unsigned int options) 283{ 284 int changed, changed_fs; 285 286 changed = ie_match_stat(istate, ce, st, options); 287 if (!changed) 288 return 0; 289 /* 290 * If the mode or type has changed, there's no point in trying 291 * to refresh the entry - it's not going to match 292 */ 293 if (changed & (MODE_CHANGED | TYPE_CHANGED)) 294 return changed; 295 296 /* Immediately after read-tree or update-index --cacheinfo, 297 * the length field is zero. For other cases the ce_size 298 * should match the SHA1 recorded in the index entry. 299 */ 300 if ((changed & DATA_CHANGED) && ce->ce_size != 0) 301 return changed; 302 303 changed_fs = ce_modified_check_fs(ce, st); 304 if (changed_fs) 305 return changed | changed_fs; 306 return 0; 307} 308 309int base_name_compare(const char *name1, int len1, int mode1, 310 const char *name2, int len2, int mode2) 311{ 312 unsigned char c1, c2; 313 int len = len1 < len2 ? len1 : len2; 314 int cmp; 315 316 cmp = memcmp(name1, name2, len); 317 if (cmp) 318 return cmp; 319 c1 = name1[len]; 320 c2 = name2[len]; 321 if (!c1 && S_ISDIR(mode1)) 322 c1 = '/'; 323 if (!c2 && S_ISDIR(mode2)) 324 c2 = '/'; 325 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; 326} 327 328/* 329 * df_name_compare() is identical to base_name_compare(), except it 330 * compares conflicting directory/file entries as equal. Note that 331 * while a directory name compares as equal to a regular file, they 332 * then individually compare _differently_ to a filename that has 333 * a dot after the basename (because '\0' < '.' < '/'). 334 * 335 * This is used by routines that want to traverse the git namespace 336 * but then handle conflicting entries together when possible. 337 */ 338int df_name_compare(const char *name1, int len1, int mode1, 339 const char *name2, int len2, int mode2) 340{ 341 int len = len1 < len2 ? len1 : len2, cmp; 342 unsigned char c1, c2; 343 344 cmp = memcmp(name1, name2, len); 345 if (cmp) 346 return cmp; 347 /* Directories and files compare equal (same length, same name) */ 348 if (len1 == len2) 349 return 0; 350 c1 = name1[len]; 351 if (!c1 && S_ISDIR(mode1)) 352 c1 = '/'; 353 c2 = name2[len]; 354 if (!c2 && S_ISDIR(mode2)) 355 c2 = '/'; 356 if (c1 == '/' && !c2) 357 return 0; 358 if (c2 == '/' && !c1) 359 return 0; 360 return c1 - c2; 361} 362 363int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) 364{ 365 int len1 = flags1 & CE_NAMEMASK; 366 int len2 = flags2 & CE_NAMEMASK; 367 int len = len1 < len2 ? len1 : len2; 368 int cmp; 369 370 cmp = memcmp(name1, name2, len); 371 if (cmp) 372 return cmp; 373 if (len1 < len2) 374 return -1; 375 if (len1 > len2) 376 return 1; 377 378 /* Compare stages */ 379 flags1 &= CE_STAGEMASK; 380 flags2 &= CE_STAGEMASK; 381 382 if (flags1 < flags2) 383 return -1; 384 if (flags1 > flags2) 385 return 1; 386 return 0; 387} 388 389int index_name_pos(const struct index_state *istate, const char *name, int namelen) 390{ 391 int first, last; 392 393 first = 0; 394 last = istate->cache_nr; 395 while (last > first) { 396 int next = (last + first) >> 1; 397 struct cache_entry *ce = istate->cache[next]; 398 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags); 399 if (!cmp) 400 return next; 401 if (cmp < 0) { 402 last = next; 403 continue; 404 } 405 first = next+1; 406 } 407 return -first-1; 408} 409 410/* Remove entry, return true if there are more entries to go.. */ 411int remove_index_entry_at(struct index_state *istate, int pos) 412{ 413 struct cache_entry *ce = istate->cache[pos]; 414 415 remove_name_hash(ce); 416 istate->cache_changed = 1; 417 istate->cache_nr--; 418 if (pos >= istate->cache_nr) 419 return 0; 420 memmove(istate->cache + pos, 421 istate->cache + pos + 1, 422 (istate->cache_nr - pos) * sizeof(struct cache_entry *)); 423 return 1; 424} 425 426int remove_file_from_index(struct index_state *istate, const char *path) 427{ 428 int pos = index_name_pos(istate, path, strlen(path)); 429 if (pos < 0) 430 pos = -pos-1; 431 cache_tree_invalidate_path(istate->cache_tree, path); 432 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) 433 remove_index_entry_at(istate, pos); 434 return 0; 435} 436 437static int compare_name(struct cache_entry *ce, const char *path, int namelen) 438{ 439 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); 440} 441 442static int index_name_pos_also_unmerged(struct index_state *istate, 443 const char *path, int namelen) 444{ 445 int pos = index_name_pos(istate, path, namelen); 446 struct cache_entry *ce; 447 448 if (pos >= 0) 449 return pos; 450 451 /* maybe unmerged? */ 452 pos = -1 - pos; 453 if (pos >= istate->cache_nr || 454 compare_name((ce = istate->cache[pos]), path, namelen)) 455 return -1; 456 457 /* order of preference: stage 2, 1, 3 */ 458 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && 459 ce_stage((ce = istate->cache[pos + 1])) == 2 && 460 !compare_name(ce, path, namelen)) 461 pos++; 462 return pos; 463} 464 465static int different_name(struct cache_entry *ce, struct cache_entry *alias) 466{ 467 int len = ce_namelen(ce); 468 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len); 469} 470 471/* 472 * If we add a filename that aliases in the cache, we will use the 473 * name that we already have - but we don't want to update the same 474 * alias twice, because that implies that there were actually two 475 * different files with aliasing names! 476 * 477 * So we use the CE_ADDED flag to verify that the alias was an old 478 * one before we accept it as 479 */ 480static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias) 481{ 482 int len; 483 struct cache_entry *new; 484 485 if (alias->ce_flags & CE_ADDED) 486 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name); 487 488 /* Ok, create the new entry using the name of the existing alias */ 489 len = ce_namelen(alias); 490 new = xcalloc(1, cache_entry_size(len)); 491 memcpy(new->name, alias->name, len); 492 copy_cache_entry(new, ce); 493 free(ce); 494 return new; 495} 496 497int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags) 498{ 499 int size, namelen, was_same; 500 mode_t st_mode = st->st_mode; 501 struct cache_entry *ce, *alias; 502 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY; 503 int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND); 504 int pretend = flags & ADD_CACHE_PRETEND; 505 506 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode)) 507 return error("%s: can only add regular files, symbolic links or git-directories", path); 508 509 namelen = strlen(path); 510 if (S_ISDIR(st_mode)) { 511 while (namelen && path[namelen-1] == '/') 512 namelen--; 513 } 514 size = cache_entry_size(namelen); 515 ce = xcalloc(1, size); 516 memcpy(ce->name, path, namelen); 517 ce->ce_flags = namelen; 518 fill_stat_cache_info(ce, st); 519 520 if (trust_executable_bit && has_symlinks) 521 ce->ce_mode = create_ce_mode(st_mode); 522 else { 523 /* If there is an existing entry, pick the mode bits and type 524 * from it, otherwise assume unexecutable regular file. 525 */ 526 struct cache_entry *ent; 527 int pos = index_name_pos_also_unmerged(istate, path, namelen); 528 529 ent = (0 <= pos) ? istate->cache[pos] : NULL; 530 ce->ce_mode = ce_mode_from_stat(ent, st_mode); 531 } 532 533 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case); 534 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) { 535 /* Nothing changed, really */ 536 free(ce); 537 ce_mark_uptodate(alias); 538 alias->ce_flags |= CE_ADDED; 539 return 0; 540 } 541 if (index_path(ce->sha1, path, st, 1)) 542 return error("unable to index file %s", path); 543 if (ignore_case && alias && different_name(ce, alias)) 544 ce = create_alias_ce(ce, alias); 545 ce->ce_flags |= CE_ADDED; 546 547 /* It was suspected to be racily clean, but it turns out to be Ok */ 548 was_same = (alias && 549 !ce_stage(alias) && 550 !hashcmp(alias->sha1, ce->sha1) && 551 ce->ce_mode == alias->ce_mode); 552 553 if (pretend) 554 ; 555 else if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE)) 556 return error("unable to add %s to index",path); 557 if (verbose && !was_same) 558 printf("add '%s'\n", path); 559 return 0; 560} 561 562int add_file_to_index(struct index_state *istate, const char *path, int flags) 563{ 564 struct stat st; 565 if (lstat(path, &st)) 566 die("%s: unable to stat (%s)", path, strerror(errno)); 567 return add_to_index(istate, path, &st, flags); 568} 569 570struct cache_entry *make_cache_entry(unsigned int mode, 571 const unsigned char *sha1, const char *path, int stage, 572 int refresh) 573{ 574 int size, len; 575 struct cache_entry *ce; 576 577 if (!verify_path(path)) 578 return NULL; 579 580 len = strlen(path); 581 size = cache_entry_size(len); 582 ce = xcalloc(1, size); 583 584 hashcpy(ce->sha1, sha1); 585 memcpy(ce->name, path, len); 586 ce->ce_flags = create_ce_flags(len, stage); 587 ce->ce_mode = create_ce_mode(mode); 588 589 if (refresh) 590 return refresh_cache_entry(ce, 0); 591 592 return ce; 593} 594 595int ce_same_name(struct cache_entry *a, struct cache_entry *b) 596{ 597 int len = ce_namelen(a); 598 return ce_namelen(b) == len && !memcmp(a->name, b->name, len); 599} 600 601int ce_path_match(const struct cache_entry *ce, const char **pathspec) 602{ 603 const char *match, *name; 604 int len; 605 606 if (!pathspec) 607 return 1; 608 609 len = ce_namelen(ce); 610 name = ce->name; 611 while ((match = *pathspec++) != NULL) { 612 int matchlen = strlen(match); 613 if (matchlen > len) 614 continue; 615 if (memcmp(name, match, matchlen)) 616 continue; 617 if (matchlen && name[matchlen-1] == '/') 618 return 1; 619 if (name[matchlen] == '/' || !name[matchlen]) 620 return 1; 621 if (!matchlen) 622 return 1; 623 } 624 return 0; 625} 626 627/* 628 * We fundamentally don't like some paths: we don't want 629 * dot or dot-dot anywhere, and for obvious reasons don't 630 * want to recurse into ".git" either. 631 * 632 * Also, we don't want double slashes or slashes at the 633 * end that can make pathnames ambiguous. 634 */ 635static int verify_dotfile(const char *rest) 636{ 637 /* 638 * The first character was '.', but that 639 * has already been discarded, we now test 640 * the rest. 641 */ 642 switch (*rest) { 643 /* "." is not allowed */ 644 case '\0': case '/': 645 return 0; 646 647 /* 648 * ".git" followed by NUL or slash is bad. This 649 * shares the path end test with the ".." case. 650 */ 651 case 'g': 652 if (rest[1] != 'i') 653 break; 654 if (rest[2] != 't') 655 break; 656 rest += 2; 657 /* fallthrough */ 658 case '.': 659 if (rest[1] == '\0' || rest[1] == '/') 660 return 0; 661 } 662 return 1; 663} 664 665int verify_path(const char *path) 666{ 667 char c; 668 669 goto inside; 670 for (;;) { 671 if (!c) 672 return 1; 673 if (c == '/') { 674inside: 675 c = *path++; 676 switch (c) { 677 default: 678 continue; 679 case '/': case '\0': 680 break; 681 case '.': 682 if (verify_dotfile(path)) 683 continue; 684 } 685 return 0; 686 } 687 c = *path++; 688 } 689} 690 691/* 692 * Do we have another file that has the beginning components being a 693 * proper superset of the name we're trying to add? 694 */ 695static int has_file_name(struct index_state *istate, 696 const struct cache_entry *ce, int pos, int ok_to_replace) 697{ 698 int retval = 0; 699 int len = ce_namelen(ce); 700 int stage = ce_stage(ce); 701 const char *name = ce->name; 702 703 while (pos < istate->cache_nr) { 704 struct cache_entry *p = istate->cache[pos++]; 705 706 if (len >= ce_namelen(p)) 707 break; 708 if (memcmp(name, p->name, len)) 709 break; 710 if (ce_stage(p) != stage) 711 continue; 712 if (p->name[len] != '/') 713 continue; 714 if (p->ce_flags & CE_REMOVE) 715 continue; 716 retval = -1; 717 if (!ok_to_replace) 718 break; 719 remove_index_entry_at(istate, --pos); 720 } 721 return retval; 722} 723 724/* 725 * Do we have another file with a pathname that is a proper 726 * subset of the name we're trying to add? 727 */ 728static int has_dir_name(struct index_state *istate, 729 const struct cache_entry *ce, int pos, int ok_to_replace) 730{ 731 int retval = 0; 732 int stage = ce_stage(ce); 733 const char *name = ce->name; 734 const char *slash = name + ce_namelen(ce); 735 736 for (;;) { 737 int len; 738 739 for (;;) { 740 if (*--slash == '/') 741 break; 742 if (slash <= ce->name) 743 return retval; 744 } 745 len = slash - name; 746 747 pos = index_name_pos(istate, name, create_ce_flags(len, stage)); 748 if (pos >= 0) { 749 /* 750 * Found one, but not so fast. This could 751 * be a marker that says "I was here, but 752 * I am being removed". Such an entry is 753 * not a part of the resulting tree, and 754 * it is Ok to have a directory at the same 755 * path. 756 */ 757 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) { 758 retval = -1; 759 if (!ok_to_replace) 760 break; 761 remove_index_entry_at(istate, pos); 762 continue; 763 } 764 } 765 else 766 pos = -pos-1; 767 768 /* 769 * Trivial optimization: if we find an entry that 770 * already matches the sub-directory, then we know 771 * we're ok, and we can exit. 772 */ 773 while (pos < istate->cache_nr) { 774 struct cache_entry *p = istate->cache[pos]; 775 if ((ce_namelen(p) <= len) || 776 (p->name[len] != '/') || 777 memcmp(p->name, name, len)) 778 break; /* not our subdirectory */ 779 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) 780 /* 781 * p is at the same stage as our entry, and 782 * is a subdirectory of what we are looking 783 * at, so we cannot have conflicts at our 784 * level or anything shorter. 785 */ 786 return retval; 787 pos++; 788 } 789 } 790 return retval; 791} 792 793/* We may be in a situation where we already have path/file and path 794 * is being added, or we already have path and path/file is being 795 * added. Either one would result in a nonsense tree that has path 796 * twice when git-write-tree tries to write it out. Prevent it. 797 * 798 * If ok-to-replace is specified, we remove the conflicting entries 799 * from the cache so the caller should recompute the insert position. 800 * When this happens, we return non-zero. 801 */ 802static int check_file_directory_conflict(struct index_state *istate, 803 const struct cache_entry *ce, 804 int pos, int ok_to_replace) 805{ 806 int retval; 807 808 /* 809 * When ce is an "I am going away" entry, we allow it to be added 810 */ 811 if (ce->ce_flags & CE_REMOVE) 812 return 0; 813 814 /* 815 * We check if the path is a sub-path of a subsequent pathname 816 * first, since removing those will not change the position 817 * in the array. 818 */ 819 retval = has_file_name(istate, ce, pos, ok_to_replace); 820 821 /* 822 * Then check if the path might have a clashing sub-directory 823 * before it. 824 */ 825 return retval + has_dir_name(istate, ce, pos, ok_to_replace); 826} 827 828static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) 829{ 830 int pos; 831 int ok_to_add = option & ADD_CACHE_OK_TO_ADD; 832 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; 833 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; 834 835 cache_tree_invalidate_path(istate->cache_tree, ce->name); 836 pos = index_name_pos(istate, ce->name, ce->ce_flags); 837 838 /* existing match? Just replace it. */ 839 if (pos >= 0) { 840 replace_index_entry(istate, pos, ce); 841 return 0; 842 } 843 pos = -pos-1; 844 845 /* 846 * Inserting a merged entry ("stage 0") into the index 847 * will always replace all non-merged entries.. 848 */ 849 if (pos < istate->cache_nr && ce_stage(ce) == 0) { 850 while (ce_same_name(istate->cache[pos], ce)) { 851 ok_to_add = 1; 852 if (!remove_index_entry_at(istate, pos)) 853 break; 854 } 855 } 856 857 if (!ok_to_add) 858 return -1; 859 if (!verify_path(ce->name)) 860 return -1; 861 862 if (!skip_df_check && 863 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { 864 if (!ok_to_replace) 865 return error("'%s' appears as both a file and as a directory", 866 ce->name); 867 pos = index_name_pos(istate, ce->name, ce->ce_flags); 868 pos = -pos-1; 869 } 870 return pos + 1; 871} 872 873int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) 874{ 875 int pos; 876 877 if (option & ADD_CACHE_JUST_APPEND) 878 pos = istate->cache_nr; 879 else { 880 int ret; 881 ret = add_index_entry_with_check(istate, ce, option); 882 if (ret <= 0) 883 return ret; 884 pos = ret - 1; 885 } 886 887 /* Make sure the array is big enough .. */ 888 if (istate->cache_nr == istate->cache_alloc) { 889 istate->cache_alloc = alloc_nr(istate->cache_alloc); 890 istate->cache = xrealloc(istate->cache, 891 istate->cache_alloc * sizeof(struct cache_entry *)); 892 } 893 894 /* Add it in.. */ 895 istate->cache_nr++; 896 if (istate->cache_nr > pos + 1) 897 memmove(istate->cache + pos + 1, 898 istate->cache + pos, 899 (istate->cache_nr - pos - 1) * sizeof(ce)); 900 set_index_entry(istate, pos, ce); 901 istate->cache_changed = 1; 902 return 0; 903} 904 905/* 906 * "refresh" does not calculate a new sha1 file or bring the 907 * cache up-to-date for mode/content changes. But what it 908 * _does_ do is to "re-match" the stat information of a file 909 * with the cache, so that you can refresh the cache for a 910 * file that hasn't been changed but where the stat entry is 911 * out of date. 912 * 913 * For example, you'd want to do this after doing a "git-read-tree", 914 * to link up the stat cache details with the proper files. 915 */ 916static struct cache_entry *refresh_cache_ent(struct index_state *istate, 917 struct cache_entry *ce, 918 unsigned int options, int *err) 919{ 920 struct stat st; 921 struct cache_entry *updated; 922 int changed, size; 923 int ignore_valid = options & CE_MATCH_IGNORE_VALID; 924 925 if (ce_uptodate(ce)) 926 return ce; 927 928 /* 929 * CE_VALID means the user promised us that the change to 930 * the work tree does not matter and told us not to worry. 931 */ 932 if (!ignore_valid && (ce->ce_flags & CE_VALID)) { 933 ce_mark_uptodate(ce); 934 return ce; 935 } 936 937 if (lstat(ce->name, &st) < 0) { 938 if (err) 939 *err = errno; 940 return NULL; 941 } 942 943 changed = ie_match_stat(istate, ce, &st, options); 944 if (!changed) { 945 /* 946 * The path is unchanged. If we were told to ignore 947 * valid bit, then we did the actual stat check and 948 * found that the entry is unmodified. If the entry 949 * is not marked VALID, this is the place to mark it 950 * valid again, under "assume unchanged" mode. 951 */ 952 if (ignore_valid && assume_unchanged && 953 !(ce->ce_flags & CE_VALID)) 954 ; /* mark this one VALID again */ 955 else { 956 /* 957 * We do not mark the index itself "modified" 958 * because CE_UPTODATE flag is in-core only; 959 * we are not going to write this change out. 960 */ 961 ce_mark_uptodate(ce); 962 return ce; 963 } 964 } 965 966 if (ie_modified(istate, ce, &st, options)) { 967 if (err) 968 *err = EINVAL; 969 return NULL; 970 } 971 972 size = ce_size(ce); 973 updated = xmalloc(size); 974 memcpy(updated, ce, size); 975 fill_stat_cache_info(updated, &st); 976 /* 977 * If ignore_valid is not set, we should leave CE_VALID bit 978 * alone. Otherwise, paths marked with --no-assume-unchanged 979 * (i.e. things to be edited) will reacquire CE_VALID bit 980 * automatically, which is not really what we want. 981 */ 982 if (!ignore_valid && assume_unchanged && 983 !(ce->ce_flags & CE_VALID)) 984 updated->ce_flags &= ~CE_VALID; 985 986 return updated; 987} 988 989int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen) 990{ 991 int i; 992 int has_errors = 0; 993 int really = (flags & REFRESH_REALLY) != 0; 994 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; 995 int quiet = (flags & REFRESH_QUIET) != 0; 996 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; 997 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0; 998 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0; 999 const char *needs_update_message;10001001 needs_update_message = ((flags & REFRESH_SAY_CHANGED)1002 ? "locally modified" : "needs update");1003 for (i = 0; i < istate->cache_nr; i++) {1004 struct cache_entry *ce, *new;1005 int cache_errno = 0;10061007 ce = istate->cache[i];1008 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))1009 continue;10101011 if (ce_stage(ce)) {1012 while ((i < istate->cache_nr) &&1013 ! strcmp(istate->cache[i]->name, ce->name))1014 i++;1015 i--;1016 if (allow_unmerged)1017 continue;1018 printf("%s: needs merge\n", ce->name);1019 has_errors = 1;1020 continue;1021 }10221023 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))1024 continue;10251026 new = refresh_cache_ent(istate, ce, options, &cache_errno);1027 if (new == ce)1028 continue;1029 if (!new) {1030 if (not_new && cache_errno == ENOENT)1031 continue;1032 if (really && cache_errno == EINVAL) {1033 /* If we are doing --really-refresh that1034 * means the index is not valid anymore.1035 */1036 ce->ce_flags &= ~CE_VALID;1037 istate->cache_changed = 1;1038 }1039 if (quiet)1040 continue;1041 printf("%s: %s\n", ce->name, needs_update_message);1042 has_errors = 1;1043 continue;1044 }10451046 replace_index_entry(istate, i, new);1047 }1048 return has_errors;1049}10501051struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)1052{1053 return refresh_cache_ent(&the_index, ce, really, NULL);1054}10551056static int verify_hdr(struct cache_header *hdr, unsigned long size)1057{1058 SHA_CTX c;1059 unsigned char sha1[20];10601061 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))1062 return error("bad signature");1063 if (hdr->hdr_version != htonl(2))1064 return error("bad index version");1065 SHA1_Init(&c);1066 SHA1_Update(&c, hdr, size - 20);1067 SHA1_Final(sha1, &c);1068 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))1069 return error("bad index file sha1 signature");1070 return 0;1071}10721073static int read_index_extension(struct index_state *istate,1074 const char *ext, void *data, unsigned long sz)1075{1076 switch (CACHE_EXT(ext)) {1077 case CACHE_EXT_TREE:1078 istate->cache_tree = cache_tree_read(data, sz);1079 break;1080 default:1081 if (*ext < 'A' || 'Z' < *ext)1082 return error("index uses %.4s extension, which we do not understand",1083 ext);1084 fprintf(stderr, "ignoring %.4s extension\n", ext);1085 break;1086 }1087 return 0;1088}10891090int read_index(struct index_state *istate)1091{1092 return read_index_from(istate, get_index_file());1093}10941095static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)1096{1097 size_t len;10981099 ce->ce_ctime = ntohl(ondisk->ctime.sec);1100 ce->ce_mtime = ntohl(ondisk->mtime.sec);1101 ce->ce_dev = ntohl(ondisk->dev);1102 ce->ce_ino = ntohl(ondisk->ino);1103 ce->ce_mode = ntohl(ondisk->mode);1104 ce->ce_uid = ntohl(ondisk->uid);1105 ce->ce_gid = ntohl(ondisk->gid);1106 ce->ce_size = ntohl(ondisk->size);1107 /* On-disk flags are just 16 bits */1108 ce->ce_flags = ntohs(ondisk->flags);1109 hashcpy(ce->sha1, ondisk->sha1);11101111 len = ce->ce_flags & CE_NAMEMASK;1112 if (len == CE_NAMEMASK)1113 len = strlen(ondisk->name);1114 /*1115 * NEEDSWORK: If the original index is crafted, this copy could1116 * go unchecked.1117 */1118 memcpy(ce->name, ondisk->name, len + 1);1119}11201121static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)1122{1123 long per_entry;11241125 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);11261127 /*1128 * Alignment can cause differences. This should be "alignof", but1129 * since that's a gcc'ism, just use the size of a pointer.1130 */1131 per_entry += sizeof(void *);1132 return ondisk_size + entries*per_entry;1133}11341135/* remember to discard_cache() before reading a different cache! */1136int read_index_from(struct index_state *istate, const char *path)1137{1138 int fd, i;1139 struct stat st;1140 unsigned long src_offset, dst_offset;1141 struct cache_header *hdr;1142 void *mmap;1143 size_t mmap_size;11441145 errno = EBUSY;1146 if (istate->alloc)1147 return istate->cache_nr;11481149 errno = ENOENT;1150 istate->timestamp = 0;1151 fd = open(path, O_RDONLY);1152 if (fd < 0) {1153 if (errno == ENOENT)1154 return 0;1155 die("index file open failed (%s)", strerror(errno));1156 }11571158 if (fstat(fd, &st))1159 die("cannot stat the open index (%s)", strerror(errno));11601161 errno = EINVAL;1162 mmap_size = xsize_t(st.st_size);1163 if (mmap_size < sizeof(struct cache_header) + 20)1164 die("index file smaller than expected");11651166 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);1167 close(fd);1168 if (mmap == MAP_FAILED)1169 die("unable to map index file");11701171 hdr = mmap;1172 if (verify_hdr(hdr, mmap_size) < 0)1173 goto unmap;11741175 istate->cache_nr = ntohl(hdr->hdr_entries);1176 istate->cache_alloc = alloc_nr(istate->cache_nr);1177 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));11781179 /*1180 * The disk format is actually larger than the in-memory format,1181 * due to space for nsec etc, so even though the in-memory one1182 * has room for a few more flags, we can allocate using the same1183 * index size1184 */1185 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));11861187 src_offset = sizeof(*hdr);1188 dst_offset = 0;1189 for (i = 0; i < istate->cache_nr; i++) {1190 struct ondisk_cache_entry *disk_ce;1191 struct cache_entry *ce;11921193 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);1194 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);1195 convert_from_disk(disk_ce, ce);1196 set_index_entry(istate, i, ce);11971198 src_offset += ondisk_ce_size(ce);1199 dst_offset += ce_size(ce);1200 }1201 istate->timestamp = st.st_mtime;1202 while (src_offset <= mmap_size - 20 - 8) {1203 /* After an array of active_nr index entries,1204 * there can be arbitrary number of extended1205 * sections, each of which is prefixed with1206 * extension name (4-byte) and section length1207 * in 4-byte network byte order.1208 */1209 unsigned long extsize;1210 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);1211 extsize = ntohl(extsize);1212 if (read_index_extension(istate,1213 (const char *) mmap + src_offset,1214 (char *) mmap + src_offset + 8,1215 extsize) < 0)1216 goto unmap;1217 src_offset += 8;1218 src_offset += extsize;1219 }1220 munmap(mmap, mmap_size);1221 return istate->cache_nr;12221223unmap:1224 munmap(mmap, mmap_size);1225 errno = EINVAL;1226 die("index file corrupt");1227}12281229int discard_index(struct index_state *istate)1230{1231 istate->cache_nr = 0;1232 istate->cache_changed = 0;1233 istate->timestamp = 0;1234 free_hash(&istate->name_hash);1235 cache_tree_free(&(istate->cache_tree));1236 free(istate->alloc);1237 istate->alloc = NULL;12381239 /* no need to throw away allocated active_cache */1240 return 0;1241}12421243int unmerged_index(const struct index_state *istate)1244{1245 int i;1246 for (i = 0; i < istate->cache_nr; i++) {1247 if (ce_stage(istate->cache[i]))1248 return 1;1249 }1250 return 0;1251}12521253#define WRITE_BUFFER_SIZE 81921254static unsigned char write_buffer[WRITE_BUFFER_SIZE];1255static unsigned long write_buffer_len;12561257static int ce_write_flush(SHA_CTX *context, int fd)1258{1259 unsigned int buffered = write_buffer_len;1260 if (buffered) {1261 SHA1_Update(context, write_buffer, buffered);1262 if (write_in_full(fd, write_buffer, buffered) != buffered)1263 return -1;1264 write_buffer_len = 0;1265 }1266 return 0;1267}12681269static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)1270{1271 while (len) {1272 unsigned int buffered = write_buffer_len;1273 unsigned int partial = WRITE_BUFFER_SIZE - buffered;1274 if (partial > len)1275 partial = len;1276 memcpy(write_buffer + buffered, data, partial);1277 buffered += partial;1278 if (buffered == WRITE_BUFFER_SIZE) {1279 write_buffer_len = buffered;1280 if (ce_write_flush(context, fd))1281 return -1;1282 buffered = 0;1283 }1284 write_buffer_len = buffered;1285 len -= partial;1286 data = (char *) data + partial;1287 }1288 return 0;1289}12901291static int write_index_ext_header(SHA_CTX *context, int fd,1292 unsigned int ext, unsigned int sz)1293{1294 ext = htonl(ext);1295 sz = htonl(sz);1296 return ((ce_write(context, fd, &ext, 4) < 0) ||1297 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;1298}12991300static int ce_flush(SHA_CTX *context, int fd)1301{1302 unsigned int left = write_buffer_len;13031304 if (left) {1305 write_buffer_len = 0;1306 SHA1_Update(context, write_buffer, left);1307 }13081309 /* Flush first if not enough space for SHA1 signature */1310 if (left + 20 > WRITE_BUFFER_SIZE) {1311 if (write_in_full(fd, write_buffer, left) != left)1312 return -1;1313 left = 0;1314 }13151316 /* Append the SHA1 signature at the end */1317 SHA1_Final(write_buffer + left, context);1318 left += 20;1319 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;1320}13211322static void ce_smudge_racily_clean_entry(struct cache_entry *ce)1323{1324 /*1325 * The only thing we care about in this function is to smudge the1326 * falsely clean entry due to touch-update-touch race, so we leave1327 * everything else as they are. We are called for entries whose1328 * ce_mtime match the index file mtime.1329 */1330 struct stat st;13311332 if (lstat(ce->name, &st) < 0)1333 return;1334 if (ce_match_stat_basic(ce, &st))1335 return;1336 if (ce_modified_check_fs(ce, &st)) {1337 /* This is "racily clean"; smudge it. Note that this1338 * is a tricky code. At first glance, it may appear1339 * that it can break with this sequence:1340 *1341 * $ echo xyzzy >frotz1342 * $ git-update-index --add frotz1343 * $ : >frotz1344 * $ sleep 31345 * $ echo filfre >nitfol1346 * $ git-update-index --add nitfol1347 *1348 * but it does not. When the second update-index runs,1349 * it notices that the entry "frotz" has the same timestamp1350 * as index, and if we were to smudge it by resetting its1351 * size to zero here, then the object name recorded1352 * in index is the 6-byte file but the cached stat information1353 * becomes zero --- which would then match what we would1354 * obtain from the filesystem next time we stat("frotz").1355 *1356 * However, the second update-index, before calling1357 * this function, notices that the cached size is 61358 * bytes and what is on the filesystem is an empty1359 * file, and never calls us, so the cached size information1360 * for "frotz" stays 6 which does not match the filesystem.1361 */1362 ce->ce_size = 0;1363 }1364}13651366static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)1367{1368 int size = ondisk_ce_size(ce);1369 struct ondisk_cache_entry *ondisk = xcalloc(1, size);13701371 ondisk->ctime.sec = htonl(ce->ce_ctime);1372 ondisk->ctime.nsec = 0;1373 ondisk->mtime.sec = htonl(ce->ce_mtime);1374 ondisk->mtime.nsec = 0;1375 ondisk->dev = htonl(ce->ce_dev);1376 ondisk->ino = htonl(ce->ce_ino);1377 ondisk->mode = htonl(ce->ce_mode);1378 ondisk->uid = htonl(ce->ce_uid);1379 ondisk->gid = htonl(ce->ce_gid);1380 ondisk->size = htonl(ce->ce_size);1381 hashcpy(ondisk->sha1, ce->sha1);1382 ondisk->flags = htons(ce->ce_flags);1383 memcpy(ondisk->name, ce->name, ce_namelen(ce));13841385 return ce_write(c, fd, ondisk, size);1386}13871388int write_index(const struct index_state *istate, int newfd)1389{1390 SHA_CTX c;1391 struct cache_header hdr;1392 int i, err, removed;1393 struct cache_entry **cache = istate->cache;1394 int entries = istate->cache_nr;13951396 for (i = removed = 0; i < entries; i++)1397 if (cache[i]->ce_flags & CE_REMOVE)1398 removed++;13991400 hdr.hdr_signature = htonl(CACHE_SIGNATURE);1401 hdr.hdr_version = htonl(2);1402 hdr.hdr_entries = htonl(entries - removed);14031404 SHA1_Init(&c);1405 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)1406 return -1;14071408 for (i = 0; i < entries; i++) {1409 struct cache_entry *ce = cache[i];1410 if (ce->ce_flags & CE_REMOVE)1411 continue;1412 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))1413 ce_smudge_racily_clean_entry(ce);1414 if (ce_write_entry(&c, newfd, ce) < 0)1415 return -1;1416 }14171418 /* Write extension data here */1419 if (istate->cache_tree) {1420 struct strbuf sb;14211422 strbuf_init(&sb, 0);1423 cache_tree_write(&sb, istate->cache_tree);1424 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 01425 || ce_write(&c, newfd, sb.buf, sb.len) < 0;1426 strbuf_release(&sb);1427 if (err)1428 return -1;1429 }1430 return ce_flush(&c, newfd);1431}14321433/*1434 * Read the index file that is potentially unmerged into given1435 * index_state, dropping any unmerged entries. Returns true is1436 * the index is unmerged. Callers who want to refuse to work1437 * from an unmerged state can call this and check its return value,1438 * instead of calling read_cache().1439 */1440int read_index_unmerged(struct index_state *istate)1441{1442 int i;1443 struct cache_entry **dst;1444 struct cache_entry *last = NULL;14451446 read_index(istate);1447 dst = istate->cache;1448 for (i = 0; i < istate->cache_nr; i++) {1449 struct cache_entry *ce = istate->cache[i];1450 if (ce_stage(ce)) {1451 remove_name_hash(ce);1452 if (last && !strcmp(ce->name, last->name))1453 continue;1454 cache_tree_invalidate_path(istate->cache_tree, ce->name);1455 last = ce;1456 continue;1457 }1458 *dst++ = ce;1459 }1460 istate->cache_nr = dst - istate->cache;1461 return !!last;1462}