1#include "../cache.h" 2#include "../refs.h" 3#include "refs-internal.h" 4#include "ref-cache.h" 5#include "../iterator.h" 6#include "../dir-iterator.h" 7#include "../lockfile.h" 8#include "../object.h" 9#include "../dir.h" 10 11struct ref_lock { 12 char *ref_name; 13 struct lock_file *lk; 14 struct object_id old_oid; 15}; 16 17/* 18 * Return true if refname, which has the specified oid and flags, can 19 * be resolved to an object in the database. If the referred-to object 20 * does not exist, emit a warning and return false. 21 */ 22static int ref_resolves_to_object(const char *refname, 23 const struct object_id *oid, 24 unsigned int flags) 25{ 26 if (flags & REF_ISBROKEN) 27 return 0; 28 if (!has_sha1_file(oid->hash)) { 29 error("%s does not point to a valid object!", refname); 30 return 0; 31 } 32 return 1; 33} 34 35struct packed_ref_cache { 36 struct ref_cache *cache; 37 38 /* 39 * Count of references to the data structure in this instance, 40 * including the pointer from files_ref_store::packed if any. 41 * The data will not be freed as long as the reference count 42 * is nonzero. 43 */ 44 unsigned int referrers; 45 46 /* The metadata from when this packed-refs cache was read */ 47 struct stat_validity validity; 48}; 49 50/* 51 * Future: need to be in "struct repository" 52 * when doing a full libification. 53 */ 54struct files_ref_store { 55 struct ref_store base; 56 unsigned int store_flags; 57 58 char *gitdir; 59 char *gitcommondir; 60 char *packed_refs_path; 61 62 struct ref_cache *loose; 63 struct packed_ref_cache *packed; 64 65 /* 66 * Iff the packed-refs file associated with this instance is 67 * currently locked for writing, this points at the associated 68 * lock (which is owned by somebody else). 69 */ 70 struct lock_file *packed_refs_lock; 71}; 72 73/* Lock used for the main packed-refs file: */ 74static struct lock_file packlock; 75 76/* 77 * Increment the reference count of *packed_refs. 78 */ 79static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 80{ 81 packed_refs->referrers++; 82} 83 84/* 85 * Decrease the reference count of *packed_refs. If it goes to zero, 86 * free *packed_refs and return true; otherwise return false. 87 */ 88static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 89{ 90 if (!--packed_refs->referrers) { 91 free_ref_cache(packed_refs->cache); 92 stat_validity_clear(&packed_refs->validity); 93 free(packed_refs); 94 return 1; 95 } else { 96 return 0; 97 } 98} 99 100static void clear_packed_ref_cache(struct files_ref_store *refs) 101{ 102 if (refs->packed) { 103 struct packed_ref_cache *packed_refs = refs->packed; 104 105 if (refs->packed_refs_lock) 106 die("BUG: packed-ref cache cleared while locked"); 107 refs->packed = NULL; 108 release_packed_ref_cache(packed_refs); 109 } 110} 111 112static void clear_loose_ref_cache(struct files_ref_store *refs) 113{ 114 if (refs->loose) { 115 free_ref_cache(refs->loose); 116 refs->loose = NULL; 117 } 118} 119 120/* 121 * Create a new submodule ref cache and add it to the internal 122 * set of caches. 123 */ 124static struct ref_store *files_ref_store_create(const char *gitdir, 125 unsigned int flags) 126{ 127 struct files_ref_store *refs = xcalloc(1, sizeof(*refs)); 128 struct ref_store *ref_store = (struct ref_store *)refs; 129 struct strbuf sb = STRBUF_INIT; 130 131 base_ref_store_init(ref_store, &refs_be_files); 132 refs->store_flags = flags; 133 134 refs->gitdir = xstrdup(gitdir); 135 get_common_dir_noenv(&sb, gitdir); 136 refs->gitcommondir = strbuf_detach(&sb, NULL); 137 strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir); 138 refs->packed_refs_path = strbuf_detach(&sb, NULL); 139 140 return ref_store; 141} 142 143/* 144 * Die if refs is not the main ref store. caller is used in any 145 * necessary error messages. 146 */ 147static void files_assert_main_repository(struct files_ref_store *refs, 148 const char *caller) 149{ 150 if (refs->store_flags & REF_STORE_MAIN) 151 return; 152 153 die("BUG: operation %s only allowed for main ref store", caller); 154} 155 156/* 157 * Downcast ref_store to files_ref_store. Die if ref_store is not a 158 * files_ref_store. required_flags is compared with ref_store's 159 * store_flags to ensure the ref_store has all required capabilities. 160 * "caller" is used in any necessary error messages. 161 */ 162static struct files_ref_store *files_downcast(struct ref_store *ref_store, 163 unsigned int required_flags, 164 const char *caller) 165{ 166 struct files_ref_store *refs; 167 168 if (ref_store->be != &refs_be_files) 169 die("BUG: ref_store is type \"%s\" not \"files\" in %s", 170 ref_store->be->name, caller); 171 172 refs = (struct files_ref_store *)ref_store; 173 174 if ((refs->store_flags & required_flags) != required_flags) 175 die("BUG: operation %s requires abilities 0x%x, but only have 0x%x", 176 caller, required_flags, refs->store_flags); 177 178 return refs; 179} 180 181/* The length of a peeled reference line in packed-refs, including EOL: */ 182#define PEELED_LINE_LENGTH 42 183 184/* 185 * The packed-refs header line that we write out. Perhaps other 186 * traits will be added later. The trailing space is required. 187 */ 188static const char PACKED_REFS_HEADER[] = 189 "# pack-refs with: peeled fully-peeled \n"; 190 191/* 192 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 193 * Return a pointer to the refname within the line (null-terminated), 194 * or NULL if there was a problem. 195 */ 196static const char *parse_ref_line(struct strbuf *line, struct object_id *oid) 197{ 198 const char *ref; 199 200 if (parse_oid_hex(line->buf, oid, &ref) < 0) 201 return NULL; 202 if (!isspace(*ref++)) 203 return NULL; 204 205 if (isspace(*ref)) 206 return NULL; 207 208 if (line->buf[line->len - 1] != '\n') 209 return NULL; 210 line->buf[--line->len] = 0; 211 212 return ref; 213} 214 215/* 216 * Read f, which is a packed-refs file, into dir. 217 * 218 * A comment line of the form "# pack-refs with: " may contain zero or 219 * more traits. We interpret the traits as follows: 220 * 221 * No traits: 222 * 223 * Probably no references are peeled. But if the file contains a 224 * peeled value for a reference, we will use it. 225 * 226 * peeled: 227 * 228 * References under "refs/tags/", if they *can* be peeled, *are* 229 * peeled in this file. References outside of "refs/tags/" are 230 * probably not peeled even if they could have been, but if we find 231 * a peeled value for such a reference we will use it. 232 * 233 * fully-peeled: 234 * 235 * All references in the file that can be peeled are peeled. 236 * Inversely (and this is more important), any references in the 237 * file for which no peeled value is recorded is not peelable. This 238 * trait should typically be written alongside "peeled" for 239 * compatibility with older clients, but we do not require it 240 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 241 */ 242static void read_packed_refs(FILE *f, struct ref_dir *dir) 243{ 244 struct ref_entry *last = NULL; 245 struct strbuf line = STRBUF_INIT; 246 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 247 248 while (strbuf_getwholeline(&line, f, '\n') != EOF) { 249 struct object_id oid; 250 const char *refname; 251 const char *traits; 252 253 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { 254 if (strstr(traits, " fully-peeled ")) 255 peeled = PEELED_FULLY; 256 else if (strstr(traits, " peeled ")) 257 peeled = PEELED_TAGS; 258 /* perhaps other traits later as well */ 259 continue; 260 } 261 262 refname = parse_ref_line(&line, &oid); 263 if (refname) { 264 int flag = REF_ISPACKED; 265 266 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { 267 if (!refname_is_safe(refname)) 268 die("packed refname is dangerous: %s", refname); 269 oidclr(&oid); 270 flag |= REF_BAD_NAME | REF_ISBROKEN; 271 } 272 last = create_ref_entry(refname, &oid, flag, 0); 273 if (peeled == PEELED_FULLY || 274 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) 275 last->flag |= REF_KNOWS_PEELED; 276 add_ref_entry(dir, last); 277 continue; 278 } 279 if (last && 280 line.buf[0] == '^' && 281 line.len == PEELED_LINE_LENGTH && 282 line.buf[PEELED_LINE_LENGTH - 1] == '\n' && 283 !get_oid_hex(line.buf + 1, &oid)) { 284 oidcpy(&last->u.value.peeled, &oid); 285 /* 286 * Regardless of what the file header said, 287 * we definitely know the value of *this* 288 * reference: 289 */ 290 last->flag |= REF_KNOWS_PEELED; 291 } 292 } 293 294 strbuf_release(&line); 295} 296 297static const char *files_packed_refs_path(struct files_ref_store *refs) 298{ 299 return refs->packed_refs_path; 300} 301 302static void files_reflog_path(struct files_ref_store *refs, 303 struct strbuf *sb, 304 const char *refname) 305{ 306 if (!refname) { 307 /* 308 * FIXME: of course this is wrong in multi worktree 309 * setting. To be fixed real soon. 310 */ 311 strbuf_addf(sb, "%s/logs", refs->gitcommondir); 312 return; 313 } 314 315 switch (ref_type(refname)) { 316 case REF_TYPE_PER_WORKTREE: 317 case REF_TYPE_PSEUDOREF: 318 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname); 319 break; 320 case REF_TYPE_NORMAL: 321 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname); 322 break; 323 default: 324 die("BUG: unknown ref type %d of ref %s", 325 ref_type(refname), refname); 326 } 327} 328 329static void files_ref_path(struct files_ref_store *refs, 330 struct strbuf *sb, 331 const char *refname) 332{ 333 switch (ref_type(refname)) { 334 case REF_TYPE_PER_WORKTREE: 335 case REF_TYPE_PSEUDOREF: 336 strbuf_addf(sb, "%s/%s", refs->gitdir, refname); 337 break; 338 case REF_TYPE_NORMAL: 339 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname); 340 break; 341 default: 342 die("BUG: unknown ref type %d of ref %s", 343 ref_type(refname), refname); 344 } 345} 346 347/* 348 * Get the packed_ref_cache for the specified files_ref_store, 349 * creating it if necessary. 350 */ 351static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs) 352{ 353 const char *packed_refs_file = files_packed_refs_path(refs); 354 355 if (refs->packed && 356 !stat_validity_check(&refs->packed->validity, packed_refs_file)) 357 clear_packed_ref_cache(refs); 358 359 if (!refs->packed) { 360 FILE *f; 361 362 refs->packed = xcalloc(1, sizeof(*refs->packed)); 363 acquire_packed_ref_cache(refs->packed); 364 refs->packed->cache = create_ref_cache(&refs->base, NULL); 365 refs->packed->cache->root->flag &= ~REF_INCOMPLETE; 366 f = fopen(packed_refs_file, "r"); 367 if (f) { 368 stat_validity_update(&refs->packed->validity, fileno(f)); 369 read_packed_refs(f, get_ref_dir(refs->packed->cache->root)); 370 fclose(f); 371 } 372 } 373 return refs->packed; 374} 375 376static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) 377{ 378 return get_ref_dir(packed_ref_cache->cache->root); 379} 380 381static struct ref_dir *get_packed_refs(struct files_ref_store *refs) 382{ 383 return get_packed_ref_dir(get_packed_ref_cache(refs)); 384} 385 386/* 387 * Add a reference to the in-memory packed reference cache. This may 388 * only be called while the packed-refs file is locked (see 389 * lock_packed_refs()). To actually write the packed-refs file, call 390 * commit_packed_refs(). 391 */ 392static void add_packed_ref(struct files_ref_store *refs, 393 const char *refname, const struct object_id *oid) 394{ 395 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs); 396 397 if (!refs->packed_refs_lock) 398 die("BUG: packed refs not locked"); 399 add_ref_entry(get_packed_ref_dir(packed_ref_cache), 400 create_ref_entry(refname, oid, REF_ISPACKED, 1)); 401} 402 403/* 404 * Read the loose references from the namespace dirname into dir 405 * (without recursing). dirname must end with '/'. dir must be the 406 * directory entry corresponding to dirname. 407 */ 408static void loose_fill_ref_dir(struct ref_store *ref_store, 409 struct ref_dir *dir, const char *dirname) 410{ 411 struct files_ref_store *refs = 412 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir"); 413 DIR *d; 414 struct dirent *de; 415 int dirnamelen = strlen(dirname); 416 struct strbuf refname; 417 struct strbuf path = STRBUF_INIT; 418 size_t path_baselen; 419 420 files_ref_path(refs, &path, dirname); 421 path_baselen = path.len; 422 423 d = opendir(path.buf); 424 if (!d) { 425 strbuf_release(&path); 426 return; 427 } 428 429 strbuf_init(&refname, dirnamelen + 257); 430 strbuf_add(&refname, dirname, dirnamelen); 431 432 while ((de = readdir(d)) != NULL) { 433 struct object_id oid; 434 struct stat st; 435 int flag; 436 437 if (de->d_name[0] == '.') 438 continue; 439 if (ends_with(de->d_name, ".lock")) 440 continue; 441 strbuf_addstr(&refname, de->d_name); 442 strbuf_addstr(&path, de->d_name); 443 if (stat(path.buf, &st) < 0) { 444 ; /* silently ignore */ 445 } else if (S_ISDIR(st.st_mode)) { 446 strbuf_addch(&refname, '/'); 447 add_entry_to_dir(dir, 448 create_dir_entry(dir->cache, refname.buf, 449 refname.len, 1)); 450 } else { 451 if (!refs_resolve_ref_unsafe(&refs->base, 452 refname.buf, 453 RESOLVE_REF_READING, 454 oid.hash, &flag)) { 455 oidclr(&oid); 456 flag |= REF_ISBROKEN; 457 } else if (is_null_oid(&oid)) { 458 /* 459 * It is so astronomically unlikely 460 * that NULL_SHA1 is the SHA-1 of an 461 * actual object that we consider its 462 * appearance in a loose reference 463 * file to be repo corruption 464 * (probably due to a software bug). 465 */ 466 flag |= REF_ISBROKEN; 467 } 468 469 if (check_refname_format(refname.buf, 470 REFNAME_ALLOW_ONELEVEL)) { 471 if (!refname_is_safe(refname.buf)) 472 die("loose refname is dangerous: %s", refname.buf); 473 oidclr(&oid); 474 flag |= REF_BAD_NAME | REF_ISBROKEN; 475 } 476 add_entry_to_dir(dir, 477 create_ref_entry(refname.buf, &oid, flag, 0)); 478 } 479 strbuf_setlen(&refname, dirnamelen); 480 strbuf_setlen(&path, path_baselen); 481 } 482 strbuf_release(&refname); 483 strbuf_release(&path); 484 closedir(d); 485 486 /* 487 * Manually add refs/bisect, which, being per-worktree, might 488 * not appear in the directory listing for refs/ in the main 489 * repo. 490 */ 491 if (!strcmp(dirname, "refs/")) { 492 int pos = search_ref_dir(dir, "refs/bisect/", 12); 493 494 if (pos < 0) { 495 struct ref_entry *child_entry = create_dir_entry( 496 dir->cache, "refs/bisect/", 12, 1); 497 add_entry_to_dir(dir, child_entry); 498 } 499 } 500} 501 502static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) 503{ 504 if (!refs->loose) { 505 /* 506 * Mark the top-level directory complete because we 507 * are about to read the only subdirectory that can 508 * hold references: 509 */ 510 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir); 511 512 /* We're going to fill the top level ourselves: */ 513 refs->loose->root->flag &= ~REF_INCOMPLETE; 514 515 /* 516 * Add an incomplete entry for "refs/" (to be filled 517 * lazily): 518 */ 519 add_entry_to_dir(get_ref_dir(refs->loose->root), 520 create_dir_entry(refs->loose, "refs/", 5, 1)); 521 } 522 return refs->loose; 523} 524 525/* 526 * Return the ref_entry for the given refname from the packed 527 * references. If it does not exist, return NULL. 528 */ 529static struct ref_entry *get_packed_ref(struct files_ref_store *refs, 530 const char *refname) 531{ 532 return find_ref_entry(get_packed_refs(refs), refname); 533} 534 535/* 536 * A loose ref file doesn't exist; check for a packed ref. 537 */ 538static int resolve_packed_ref(struct files_ref_store *refs, 539 const char *refname, 540 unsigned char *sha1, unsigned int *flags) 541{ 542 struct ref_entry *entry; 543 544 /* 545 * The loose reference file does not exist; check for a packed 546 * reference. 547 */ 548 entry = get_packed_ref(refs, refname); 549 if (entry) { 550 hashcpy(sha1, entry->u.value.oid.hash); 551 *flags |= REF_ISPACKED; 552 return 0; 553 } 554 /* refname is not a packed reference. */ 555 return -1; 556} 557 558static int files_read_raw_ref(struct ref_store *ref_store, 559 const char *refname, unsigned char *sha1, 560 struct strbuf *referent, unsigned int *type) 561{ 562 struct files_ref_store *refs = 563 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); 564 struct strbuf sb_contents = STRBUF_INIT; 565 struct strbuf sb_path = STRBUF_INIT; 566 const char *path; 567 const char *buf; 568 struct stat st; 569 int fd; 570 int ret = -1; 571 int save_errno; 572 int remaining_retries = 3; 573 574 *type = 0; 575 strbuf_reset(&sb_path); 576 577 files_ref_path(refs, &sb_path, refname); 578 579 path = sb_path.buf; 580 581stat_ref: 582 /* 583 * We might have to loop back here to avoid a race 584 * condition: first we lstat() the file, then we try 585 * to read it as a link or as a file. But if somebody 586 * changes the type of the file (file <-> directory 587 * <-> symlink) between the lstat() and reading, then 588 * we don't want to report that as an error but rather 589 * try again starting with the lstat(). 590 * 591 * We'll keep a count of the retries, though, just to avoid 592 * any confusing situation sending us into an infinite loop. 593 */ 594 595 if (remaining_retries-- <= 0) 596 goto out; 597 598 if (lstat(path, &st) < 0) { 599 if (errno != ENOENT) 600 goto out; 601 if (resolve_packed_ref(refs, refname, sha1, type)) { 602 errno = ENOENT; 603 goto out; 604 } 605 ret = 0; 606 goto out; 607 } 608 609 /* Follow "normalized" - ie "refs/.." symlinks by hand */ 610 if (S_ISLNK(st.st_mode)) { 611 strbuf_reset(&sb_contents); 612 if (strbuf_readlink(&sb_contents, path, 0) < 0) { 613 if (errno == ENOENT || errno == EINVAL) 614 /* inconsistent with lstat; retry */ 615 goto stat_ref; 616 else 617 goto out; 618 } 619 if (starts_with(sb_contents.buf, "refs/") && 620 !check_refname_format(sb_contents.buf, 0)) { 621 strbuf_swap(&sb_contents, referent); 622 *type |= REF_ISSYMREF; 623 ret = 0; 624 goto out; 625 } 626 /* 627 * It doesn't look like a refname; fall through to just 628 * treating it like a non-symlink, and reading whatever it 629 * points to. 630 */ 631 } 632 633 /* Is it a directory? */ 634 if (S_ISDIR(st.st_mode)) { 635 /* 636 * Even though there is a directory where the loose 637 * ref is supposed to be, there could still be a 638 * packed ref: 639 */ 640 if (resolve_packed_ref(refs, refname, sha1, type)) { 641 errno = EISDIR; 642 goto out; 643 } 644 ret = 0; 645 goto out; 646 } 647 648 /* 649 * Anything else, just open it and try to use it as 650 * a ref 651 */ 652 fd = open(path, O_RDONLY); 653 if (fd < 0) { 654 if (errno == ENOENT && !S_ISLNK(st.st_mode)) 655 /* inconsistent with lstat; retry */ 656 goto stat_ref; 657 else 658 goto out; 659 } 660 strbuf_reset(&sb_contents); 661 if (strbuf_read(&sb_contents, fd, 256) < 0) { 662 int save_errno = errno; 663 close(fd); 664 errno = save_errno; 665 goto out; 666 } 667 close(fd); 668 strbuf_rtrim(&sb_contents); 669 buf = sb_contents.buf; 670 if (starts_with(buf, "ref:")) { 671 buf += 4; 672 while (isspace(*buf)) 673 buf++; 674 675 strbuf_reset(referent); 676 strbuf_addstr(referent, buf); 677 *type |= REF_ISSYMREF; 678 ret = 0; 679 goto out; 680 } 681 682 /* 683 * Please note that FETCH_HEAD has additional 684 * data after the sha. 685 */ 686 if (get_sha1_hex(buf, sha1) || 687 (buf[40] != '\0' && !isspace(buf[40]))) { 688 *type |= REF_ISBROKEN; 689 errno = EINVAL; 690 goto out; 691 } 692 693 ret = 0; 694 695out: 696 save_errno = errno; 697 strbuf_release(&sb_path); 698 strbuf_release(&sb_contents); 699 errno = save_errno; 700 return ret; 701} 702 703static void unlock_ref(struct ref_lock *lock) 704{ 705 /* Do not free lock->lk -- atexit() still looks at them */ 706 if (lock->lk) 707 rollback_lock_file(lock->lk); 708 free(lock->ref_name); 709 free(lock); 710} 711 712/* 713 * Lock refname, without following symrefs, and set *lock_p to point 714 * at a newly-allocated lock object. Fill in lock->old_oid, referent, 715 * and type similarly to read_raw_ref(). 716 * 717 * The caller must verify that refname is a "safe" reference name (in 718 * the sense of refname_is_safe()) before calling this function. 719 * 720 * If the reference doesn't already exist, verify that refname doesn't 721 * have a D/F conflict with any existing references. extras and skip 722 * are passed to refs_verify_refname_available() for this check. 723 * 724 * If mustexist is not set and the reference is not found or is 725 * broken, lock the reference anyway but clear sha1. 726 * 727 * Return 0 on success. On failure, write an error message to err and 728 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR. 729 * 730 * Implementation note: This function is basically 731 * 732 * lock reference 733 * read_raw_ref() 734 * 735 * but it includes a lot more code to 736 * - Deal with possible races with other processes 737 * - Avoid calling refs_verify_refname_available() when it can be 738 * avoided, namely if we were successfully able to read the ref 739 * - Generate informative error messages in the case of failure 740 */ 741static int lock_raw_ref(struct files_ref_store *refs, 742 const char *refname, int mustexist, 743 const struct string_list *extras, 744 const struct string_list *skip, 745 struct ref_lock **lock_p, 746 struct strbuf *referent, 747 unsigned int *type, 748 struct strbuf *err) 749{ 750 struct ref_lock *lock; 751 struct strbuf ref_file = STRBUF_INIT; 752 int attempts_remaining = 3; 753 int ret = TRANSACTION_GENERIC_ERROR; 754 755 assert(err); 756 files_assert_main_repository(refs, "lock_raw_ref"); 757 758 *type = 0; 759 760 /* First lock the file so it can't change out from under us. */ 761 762 *lock_p = lock = xcalloc(1, sizeof(*lock)); 763 764 lock->ref_name = xstrdup(refname); 765 files_ref_path(refs, &ref_file, refname); 766 767retry: 768 switch (safe_create_leading_directories(ref_file.buf)) { 769 case SCLD_OK: 770 break; /* success */ 771 case SCLD_EXISTS: 772 /* 773 * Suppose refname is "refs/foo/bar". We just failed 774 * to create the containing directory, "refs/foo", 775 * because there was a non-directory in the way. This 776 * indicates a D/F conflict, probably because of 777 * another reference such as "refs/foo". There is no 778 * reason to expect this error to be transitory. 779 */ 780 if (refs_verify_refname_available(&refs->base, refname, 781 extras, skip, err)) { 782 if (mustexist) { 783 /* 784 * To the user the relevant error is 785 * that the "mustexist" reference is 786 * missing: 787 */ 788 strbuf_reset(err); 789 strbuf_addf(err, "unable to resolve reference '%s'", 790 refname); 791 } else { 792 /* 793 * The error message set by 794 * refs_verify_refname_available() is 795 * OK. 796 */ 797 ret = TRANSACTION_NAME_CONFLICT; 798 } 799 } else { 800 /* 801 * The file that is in the way isn't a loose 802 * reference. Report it as a low-level 803 * failure. 804 */ 805 strbuf_addf(err, "unable to create lock file %s.lock; " 806 "non-directory in the way", 807 ref_file.buf); 808 } 809 goto error_return; 810 case SCLD_VANISHED: 811 /* Maybe another process was tidying up. Try again. */ 812 if (--attempts_remaining > 0) 813 goto retry; 814 /* fall through */ 815 default: 816 strbuf_addf(err, "unable to create directory for %s", 817 ref_file.buf); 818 goto error_return; 819 } 820 821 if (!lock->lk) 822 lock->lk = xcalloc(1, sizeof(struct lock_file)); 823 824 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) { 825 if (errno == ENOENT && --attempts_remaining > 0) { 826 /* 827 * Maybe somebody just deleted one of the 828 * directories leading to ref_file. Try 829 * again: 830 */ 831 goto retry; 832 } else { 833 unable_to_lock_message(ref_file.buf, errno, err); 834 goto error_return; 835 } 836 } 837 838 /* 839 * Now we hold the lock and can read the reference without 840 * fear that its value will change. 841 */ 842 843 if (files_read_raw_ref(&refs->base, refname, 844 lock->old_oid.hash, referent, type)) { 845 if (errno == ENOENT) { 846 if (mustexist) { 847 /* Garden variety missing reference. */ 848 strbuf_addf(err, "unable to resolve reference '%s'", 849 refname); 850 goto error_return; 851 } else { 852 /* 853 * Reference is missing, but that's OK. We 854 * know that there is not a conflict with 855 * another loose reference because 856 * (supposing that we are trying to lock 857 * reference "refs/foo/bar"): 858 * 859 * - We were successfully able to create 860 * the lockfile refs/foo/bar.lock, so we 861 * know there cannot be a loose reference 862 * named "refs/foo". 863 * 864 * - We got ENOENT and not EISDIR, so we 865 * know that there cannot be a loose 866 * reference named "refs/foo/bar/baz". 867 */ 868 } 869 } else if (errno == EISDIR) { 870 /* 871 * There is a directory in the way. It might have 872 * contained references that have been deleted. If 873 * we don't require that the reference already 874 * exists, try to remove the directory so that it 875 * doesn't cause trouble when we want to rename the 876 * lockfile into place later. 877 */ 878 if (mustexist) { 879 /* Garden variety missing reference. */ 880 strbuf_addf(err, "unable to resolve reference '%s'", 881 refname); 882 goto error_return; 883 } else if (remove_dir_recursively(&ref_file, 884 REMOVE_DIR_EMPTY_ONLY)) { 885 if (refs_verify_refname_available( 886 &refs->base, refname, 887 extras, skip, err)) { 888 /* 889 * The error message set by 890 * verify_refname_available() is OK. 891 */ 892 ret = TRANSACTION_NAME_CONFLICT; 893 goto error_return; 894 } else { 895 /* 896 * We can't delete the directory, 897 * but we also don't know of any 898 * references that it should 899 * contain. 900 */ 901 strbuf_addf(err, "there is a non-empty directory '%s' " 902 "blocking reference '%s'", 903 ref_file.buf, refname); 904 goto error_return; 905 } 906 } 907 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) { 908 strbuf_addf(err, "unable to resolve reference '%s': " 909 "reference broken", refname); 910 goto error_return; 911 } else { 912 strbuf_addf(err, "unable to resolve reference '%s': %s", 913 refname, strerror(errno)); 914 goto error_return; 915 } 916 917 /* 918 * If the ref did not exist and we are creating it, 919 * make sure there is no existing ref that conflicts 920 * with refname: 921 */ 922 if (refs_verify_refname_available( 923 &refs->base, refname, 924 extras, skip, err)) 925 goto error_return; 926 } 927 928 ret = 0; 929 goto out; 930 931error_return: 932 unlock_ref(lock); 933 *lock_p = NULL; 934 935out: 936 strbuf_release(&ref_file); 937 return ret; 938} 939 940static int files_peel_ref(struct ref_store *ref_store, 941 const char *refname, unsigned char *sha1) 942{ 943 struct files_ref_store *refs = 944 files_downcast(ref_store, REF_STORE_READ | REF_STORE_ODB, 945 "peel_ref"); 946 int flag; 947 unsigned char base[20]; 948 949 if (current_ref_iter && current_ref_iter->refname == refname) { 950 struct object_id peeled; 951 952 if (ref_iterator_peel(current_ref_iter, &peeled)) 953 return -1; 954 hashcpy(sha1, peeled.hash); 955 return 0; 956 } 957 958 if (refs_read_ref_full(ref_store, refname, 959 RESOLVE_REF_READING, base, &flag)) 960 return -1; 961 962 /* 963 * If the reference is packed, read its ref_entry from the 964 * cache in the hope that we already know its peeled value. 965 * We only try this optimization on packed references because 966 * (a) forcing the filling of the loose reference cache could 967 * be expensive and (b) loose references anyway usually do not 968 * have REF_KNOWS_PEELED. 969 */ 970 if (flag & REF_ISPACKED) { 971 struct ref_entry *r = get_packed_ref(refs, refname); 972 if (r) { 973 if (peel_entry(r, 0)) 974 return -1; 975 hashcpy(sha1, r->u.value.peeled.hash); 976 return 0; 977 } 978 } 979 980 return peel_object(base, sha1); 981} 982 983struct files_ref_iterator { 984 struct ref_iterator base; 985 986 struct packed_ref_cache *packed_ref_cache; 987 struct ref_iterator *iter0; 988 unsigned int flags; 989}; 990 991static int files_ref_iterator_advance(struct ref_iterator *ref_iterator) 992{ 993 struct files_ref_iterator *iter = 994 (struct files_ref_iterator *)ref_iterator; 995 int ok; 996 997 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) { 998 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && 999 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1000 continue;10011002 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1003 !ref_resolves_to_object(iter->iter0->refname,1004 iter->iter0->oid,1005 iter->iter0->flags))1006 continue;10071008 iter->base.refname = iter->iter0->refname;1009 iter->base.oid = iter->iter0->oid;1010 iter->base.flags = iter->iter0->flags;1011 return ITER_OK;1012 }10131014 iter->iter0 = NULL;1015 if (ref_iterator_abort(ref_iterator) != ITER_DONE)1016 ok = ITER_ERROR;10171018 return ok;1019}10201021static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,1022 struct object_id *peeled)1023{1024 struct files_ref_iterator *iter =1025 (struct files_ref_iterator *)ref_iterator;10261027 return ref_iterator_peel(iter->iter0, peeled);1028}10291030static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)1031{1032 struct files_ref_iterator *iter =1033 (struct files_ref_iterator *)ref_iterator;1034 int ok = ITER_DONE;10351036 if (iter->iter0)1037 ok = ref_iterator_abort(iter->iter0);10381039 release_packed_ref_cache(iter->packed_ref_cache);1040 base_ref_iterator_free(ref_iterator);1041 return ok;1042}10431044static struct ref_iterator_vtable files_ref_iterator_vtable = {1045 files_ref_iterator_advance,1046 files_ref_iterator_peel,1047 files_ref_iterator_abort1048};10491050static struct ref_iterator *files_ref_iterator_begin(1051 struct ref_store *ref_store,1052 const char *prefix, unsigned int flags)1053{1054 struct files_ref_store *refs;1055 struct ref_iterator *loose_iter, *packed_iter;1056 struct files_ref_iterator *iter;1057 struct ref_iterator *ref_iterator;10581059 if (ref_paranoia < 0)1060 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1061 if (ref_paranoia)1062 flags |= DO_FOR_EACH_INCLUDE_BROKEN;10631064 refs = files_downcast(ref_store,1065 REF_STORE_READ | (ref_paranoia ? 0 : REF_STORE_ODB),1066 "ref_iterator_begin");10671068 iter = xcalloc(1, sizeof(*iter));1069 ref_iterator = &iter->base;1070 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);10711072 /*1073 * We must make sure that all loose refs are read before1074 * accessing the packed-refs file; this avoids a race1075 * condition if loose refs are migrated to the packed-refs1076 * file by a simultaneous process, but our in-memory view is1077 * from before the migration. We ensure this as follows:1078 * First, we call start the loose refs iteration with its1079 * `prime_ref` argument set to true. This causes the loose1080 * references in the subtree to be pre-read into the cache.1081 * (If they've already been read, that's OK; we only need to1082 * guarantee that they're read before the packed refs, not1083 * *how much* before.) After that, we call1084 * get_packed_ref_cache(), which internally checks whether the1085 * packed-ref cache is up to date with what is on disk, and1086 * re-reads it if not.1087 */10881089 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),1090 prefix, 1);10911092 iter->packed_ref_cache = get_packed_ref_cache(refs);1093 acquire_packed_ref_cache(iter->packed_ref_cache);1094 packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache,1095 prefix, 0);10961097 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);1098 iter->flags = flags;10991100 return ref_iterator;1101}11021103/*1104 * Verify that the reference locked by lock has the value old_sha1.1105 * Fail if the reference doesn't exist and mustexist is set. Return 01106 * on success. On error, write an error message to err, set errno, and1107 * return a negative value.1108 */1109static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,1110 const unsigned char *old_sha1, int mustexist,1111 struct strbuf *err)1112{1113 assert(err);11141115 if (refs_read_ref_full(ref_store, lock->ref_name,1116 mustexist ? RESOLVE_REF_READING : 0,1117 lock->old_oid.hash, NULL)) {1118 if (old_sha1) {1119 int save_errno = errno;1120 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);1121 errno = save_errno;1122 return -1;1123 } else {1124 oidclr(&lock->old_oid);1125 return 0;1126 }1127 }1128 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1129 strbuf_addf(err, "ref '%s' is at %s but expected %s",1130 lock->ref_name,1131 oid_to_hex(&lock->old_oid),1132 sha1_to_hex(old_sha1));1133 errno = EBUSY;1134 return -1;1135 }1136 return 0;1137}11381139static int remove_empty_directories(struct strbuf *path)1140{1141 /*1142 * we want to create a file but there is a directory there;1143 * if that is an empty directory (or a directory that contains1144 * only empty directories), remove them.1145 */1146 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1147}11481149static int create_reflock(const char *path, void *cb)1150{1151 struct lock_file *lk = cb;11521153 return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;1154}11551156/*1157 * Locks a ref returning the lock on success and NULL on failure.1158 * On failure errno is set to something meaningful.1159 */1160static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,1161 const char *refname,1162 const unsigned char *old_sha1,1163 const struct string_list *extras,1164 const struct string_list *skip,1165 unsigned int flags, int *type,1166 struct strbuf *err)1167{1168 struct strbuf ref_file = STRBUF_INIT;1169 struct ref_lock *lock;1170 int last_errno = 0;1171 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1172 int resolve_flags = RESOLVE_REF_NO_RECURSE;1173 int resolved;11741175 files_assert_main_repository(refs, "lock_ref_sha1_basic");1176 assert(err);11771178 lock = xcalloc(1, sizeof(struct ref_lock));11791180 if (mustexist)1181 resolve_flags |= RESOLVE_REF_READING;1182 if (flags & REF_DELETING)1183 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;11841185 files_ref_path(refs, &ref_file, refname);1186 resolved = !!refs_resolve_ref_unsafe(&refs->base,1187 refname, resolve_flags,1188 lock->old_oid.hash, type);1189 if (!resolved && errno == EISDIR) {1190 /*1191 * we are trying to lock foo but we used to1192 * have foo/bar which now does not exist;1193 * it is normal for the empty directory 'foo'1194 * to remain.1195 */1196 if (remove_empty_directories(&ref_file)) {1197 last_errno = errno;1198 if (!refs_verify_refname_available(1199 &refs->base,1200 refname, extras, skip, err))1201 strbuf_addf(err, "there are still refs under '%s'",1202 refname);1203 goto error_return;1204 }1205 resolved = !!refs_resolve_ref_unsafe(&refs->base,1206 refname, resolve_flags,1207 lock->old_oid.hash, type);1208 }1209 if (!resolved) {1210 last_errno = errno;1211 if (last_errno != ENOTDIR ||1212 !refs_verify_refname_available(&refs->base, refname,1213 extras, skip, err))1214 strbuf_addf(err, "unable to resolve reference '%s': %s",1215 refname, strerror(last_errno));12161217 goto error_return;1218 }12191220 /*1221 * If the ref did not exist and we are creating it, make sure1222 * there is no existing packed ref whose name begins with our1223 * refname, nor a packed ref whose name is a proper prefix of1224 * our refname.1225 */1226 if (is_null_oid(&lock->old_oid) &&1227 refs_verify_refname_available(&refs->base, refname,1228 extras, skip, err)) {1229 last_errno = ENOTDIR;1230 goto error_return;1231 }12321233 lock->lk = xcalloc(1, sizeof(struct lock_file));12341235 lock->ref_name = xstrdup(refname);12361237 if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {1238 last_errno = errno;1239 unable_to_lock_message(ref_file.buf, errno, err);1240 goto error_return;1241 }12421243 if (verify_lock(&refs->base, lock, old_sha1, mustexist, err)) {1244 last_errno = errno;1245 goto error_return;1246 }1247 goto out;12481249 error_return:1250 unlock_ref(lock);1251 lock = NULL;12521253 out:1254 strbuf_release(&ref_file);1255 errno = last_errno;1256 return lock;1257}12581259/*1260 * Write an entry to the packed-refs file for the specified refname.1261 * If peeled is non-NULL, write it as the entry's peeled value.1262 */1263static void write_packed_entry(FILE *fh, const char *refname,1264 const unsigned char *sha1,1265 const unsigned char *peeled)1266{1267 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);1268 if (peeled)1269 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));1270}12711272/*1273 * Lock the packed-refs file for writing. Flags is passed to1274 * hold_lock_file_for_update(). Return 0 on success. On errors, set1275 * errno appropriately and return a nonzero value.1276 */1277static int lock_packed_refs(struct files_ref_store *refs, int flags)1278{1279 static int timeout_configured = 0;1280 static int timeout_value = 1000;1281 struct packed_ref_cache *packed_ref_cache;12821283 files_assert_main_repository(refs, "lock_packed_refs");12841285 if (!timeout_configured) {1286 git_config_get_int("core.packedrefstimeout", &timeout_value);1287 timeout_configured = 1;1288 }12891290 if (hold_lock_file_for_update_timeout(1291 &packlock, files_packed_refs_path(refs),1292 flags, timeout_value) < 0)1293 return -1;1294 /*1295 * Get the current packed-refs while holding the lock. If the1296 * packed-refs file has been modified since we last read it,1297 * this will automatically invalidate the cache and re-read1298 * the packed-refs file.1299 */1300 packed_ref_cache = get_packed_ref_cache(refs);1301 refs->packed_refs_lock = &packlock;1302 /* Increment the reference count to prevent it from being freed: */1303 acquire_packed_ref_cache(packed_ref_cache);1304 return 0;1305}13061307/*1308 * Write the current version of the packed refs cache from memory to1309 * disk. The packed-refs file must already be locked for writing (see1310 * lock_packed_refs()). Return zero on success. On errors, set errno1311 * and return a nonzero value1312 */1313static int commit_packed_refs(struct files_ref_store *refs)1314{1315 struct packed_ref_cache *packed_ref_cache =1316 get_packed_ref_cache(refs);1317 int ok, error = 0;1318 int save_errno = 0;1319 FILE *out;1320 struct ref_iterator *iter;13211322 files_assert_main_repository(refs, "commit_packed_refs");13231324 if (!refs->packed_refs_lock)1325 die("BUG: packed-refs not locked");13261327 out = fdopen_lock_file(refs->packed_refs_lock, "w");1328 if (!out)1329 die_errno("unable to fdopen packed-refs descriptor");13301331 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);13321333 iter = cache_ref_iterator_begin(packed_ref_cache->cache, NULL, 0);1334 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {1335 struct object_id peeled;1336 int peel_error = ref_iterator_peel(iter, &peeled);13371338 write_packed_entry(out, iter->refname, iter->oid->hash,1339 peel_error ? NULL : peeled.hash);1340 }13411342 if (ok != ITER_DONE)1343 die("error while iterating over references");13441345 if (commit_lock_file(refs->packed_refs_lock)) {1346 save_errno = errno;1347 error = -1;1348 }1349 refs->packed_refs_lock = NULL;1350 release_packed_ref_cache(packed_ref_cache);1351 errno = save_errno;1352 return error;1353}13541355/*1356 * Rollback the lockfile for the packed-refs file, and discard the1357 * in-memory packed reference cache. (The packed-refs file will be1358 * read anew if it is needed again after this function is called.)1359 */1360static void rollback_packed_refs(struct files_ref_store *refs)1361{1362 struct packed_ref_cache *packed_ref_cache =1363 get_packed_ref_cache(refs);13641365 files_assert_main_repository(refs, "rollback_packed_refs");13661367 if (!refs->packed_refs_lock)1368 die("BUG: packed-refs not locked");1369 rollback_lock_file(refs->packed_refs_lock);1370 refs->packed_refs_lock = NULL;1371 release_packed_ref_cache(packed_ref_cache);1372 clear_packed_ref_cache(refs);1373}13741375struct ref_to_prune {1376 struct ref_to_prune *next;1377 unsigned char sha1[20];1378 char name[FLEX_ARRAY];1379};13801381enum {1382 REMOVE_EMPTY_PARENTS_REF = 0x01,1383 REMOVE_EMPTY_PARENTS_REFLOG = 0x021384};13851386/*1387 * Remove empty parent directories associated with the specified1388 * reference and/or its reflog, but spare [logs/]refs/ and immediate1389 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or1390 * REMOVE_EMPTY_PARENTS_REFLOG.1391 */1392static void try_remove_empty_parents(struct files_ref_store *refs,1393 const char *refname,1394 unsigned int flags)1395{1396 struct strbuf buf = STRBUF_INIT;1397 struct strbuf sb = STRBUF_INIT;1398 char *p, *q;1399 int i;14001401 strbuf_addstr(&buf, refname);1402 p = buf.buf;1403 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */1404 while (*p && *p != '/')1405 p++;1406 /* tolerate duplicate slashes; see check_refname_format() */1407 while (*p == '/')1408 p++;1409 }1410 q = buf.buf + buf.len;1411 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {1412 while (q > p && *q != '/')1413 q--;1414 while (q > p && *(q-1) == '/')1415 q--;1416 if (q == p)1417 break;1418 strbuf_setlen(&buf, q - buf.buf);14191420 strbuf_reset(&sb);1421 files_ref_path(refs, &sb, buf.buf);1422 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))1423 flags &= ~REMOVE_EMPTY_PARENTS_REF;14241425 strbuf_reset(&sb);1426 files_reflog_path(refs, &sb, buf.buf);1427 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))1428 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;1429 }1430 strbuf_release(&buf);1431 strbuf_release(&sb);1432}14331434/* make sure nobody touched the ref, and unlink */1435static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)1436{1437 struct ref_transaction *transaction;1438 struct strbuf err = STRBUF_INIT;14391440 if (check_refname_format(r->name, 0))1441 return;14421443 transaction = ref_store_transaction_begin(&refs->base, &err);1444 if (!transaction ||1445 ref_transaction_delete(transaction, r->name, r->sha1,1446 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||1447 ref_transaction_commit(transaction, &err)) {1448 ref_transaction_free(transaction);1449 error("%s", err.buf);1450 strbuf_release(&err);1451 return;1452 }1453 ref_transaction_free(transaction);1454 strbuf_release(&err);1455}14561457static void prune_refs(struct files_ref_store *refs, struct ref_to_prune *r)1458{1459 while (r) {1460 prune_ref(refs, r);1461 r = r->next;1462 }1463}14641465static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)1466{1467 struct files_ref_store *refs =1468 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,1469 "pack_refs");1470 struct ref_iterator *iter;1471 struct ref_dir *packed_refs;1472 int ok;1473 struct ref_to_prune *refs_to_prune = NULL;14741475 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);1476 packed_refs = get_packed_refs(refs);14771478 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);1479 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {1480 /*1481 * If the loose reference can be packed, add an entry1482 * in the packed ref cache. If the reference should be1483 * pruned, also add it to refs_to_prune.1484 */1485 struct ref_entry *packed_entry;1486 int is_tag_ref = starts_with(iter->refname, "refs/tags/");14871488 /* Do not pack per-worktree refs: */1489 if (ref_type(iter->refname) != REF_TYPE_NORMAL)1490 continue;14911492 /* ALWAYS pack tags */1493 if (!(flags & PACK_REFS_ALL) && !is_tag_ref)1494 continue;14951496 /* Do not pack symbolic or broken refs: */1497 if (iter->flags & REF_ISSYMREF)1498 continue;14991500 if (!ref_resolves_to_object(iter->refname, iter->oid, iter->flags))1501 continue;15021503 /*1504 * Create an entry in the packed-refs cache equivalent1505 * to the one from the loose ref cache, except that1506 * we don't copy the peeled status, because we want it1507 * to be re-peeled.1508 */1509 packed_entry = find_ref_entry(packed_refs, iter->refname);1510 if (packed_entry) {1511 /* Overwrite existing packed entry with info from loose entry */1512 packed_entry->flag = REF_ISPACKED;1513 oidcpy(&packed_entry->u.value.oid, iter->oid);1514 } else {1515 packed_entry = create_ref_entry(iter->refname, iter->oid,1516 REF_ISPACKED, 0);1517 add_ref_entry(packed_refs, packed_entry);1518 }1519 oidclr(&packed_entry->u.value.peeled);15201521 /* Schedule the loose reference for pruning if requested. */1522 if ((flags & PACK_REFS_PRUNE)) {1523 struct ref_to_prune *n;1524 FLEX_ALLOC_STR(n, name, iter->refname);1525 hashcpy(n->sha1, iter->oid->hash);1526 n->next = refs_to_prune;1527 refs_to_prune = n;1528 }1529 }1530 if (ok != ITER_DONE)1531 die("error while iterating over references");15321533 if (commit_packed_refs(refs))1534 die_errno("unable to overwrite old ref-pack file");15351536 prune_refs(refs, refs_to_prune);1537 return 0;1538}15391540/*1541 * Rewrite the packed-refs file, omitting any refs listed in1542 * 'refnames'. On error, leave packed-refs unchanged, write an error1543 * message to 'err', and return a nonzero value.1544 *1545 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.1546 */1547static int repack_without_refs(struct files_ref_store *refs,1548 struct string_list *refnames, struct strbuf *err)1549{1550 struct ref_dir *packed;1551 struct string_list_item *refname;1552 int ret, needs_repacking = 0, removed = 0;15531554 files_assert_main_repository(refs, "repack_without_refs");1555 assert(err);15561557 /* Look for a packed ref */1558 for_each_string_list_item(refname, refnames) {1559 if (get_packed_ref(refs, refname->string)) {1560 needs_repacking = 1;1561 break;1562 }1563 }15641565 /* Avoid locking if we have nothing to do */1566 if (!needs_repacking)1567 return 0; /* no refname exists in packed refs */15681569 if (lock_packed_refs(refs, 0)) {1570 unable_to_lock_message(files_packed_refs_path(refs), errno, err);1571 return -1;1572 }1573 packed = get_packed_refs(refs);15741575 /* Remove refnames from the cache */1576 for_each_string_list_item(refname, refnames)1577 if (remove_entry_from_dir(packed, refname->string) != -1)1578 removed = 1;1579 if (!removed) {1580 /*1581 * All packed entries disappeared while we were1582 * acquiring the lock.1583 */1584 rollback_packed_refs(refs);1585 return 0;1586 }15871588 /* Write what remains */1589 ret = commit_packed_refs(refs);1590 if (ret)1591 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",1592 strerror(errno));1593 return ret;1594}15951596static int files_delete_refs(struct ref_store *ref_store, const char *msg,1597 struct string_list *refnames, unsigned int flags)1598{1599 struct files_ref_store *refs =1600 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");1601 struct strbuf err = STRBUF_INIT;1602 int i, result = 0;16031604 if (!refnames->nr)1605 return 0;16061607 result = repack_without_refs(refs, refnames, &err);1608 if (result) {1609 /*1610 * If we failed to rewrite the packed-refs file, then1611 * it is unsafe to try to remove loose refs, because1612 * doing so might expose an obsolete packed value for1613 * a reference that might even point at an object that1614 * has been garbage collected.1615 */1616 if (refnames->nr == 1)1617 error(_("could not delete reference %s: %s"),1618 refnames->items[0].string, err.buf);1619 else1620 error(_("could not delete references: %s"), err.buf);16211622 goto out;1623 }16241625 for (i = 0; i < refnames->nr; i++) {1626 const char *refname = refnames->items[i].string;16271628 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))1629 result |= error(_("could not remove reference %s"), refname);1630 }16311632out:1633 strbuf_release(&err);1634 return result;1635}16361637/*1638 * People using contrib's git-new-workdir have .git/logs/refs ->1639 * /some/other/path/.git/logs/refs, and that may live on another device.1640 *1641 * IOW, to avoid cross device rename errors, the temporary renamed log must1642 * live into logs/refs.1643 */1644#define TMP_RENAMED_LOG "refs/.tmp-renamed-log"16451646struct rename_cb {1647 const char *tmp_renamed_log;1648 int true_errno;1649};16501651static int rename_tmp_log_callback(const char *path, void *cb_data)1652{1653 struct rename_cb *cb = cb_data;16541655 if (rename(cb->tmp_renamed_log, path)) {1656 /*1657 * rename(a, b) when b is an existing directory ought1658 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.1659 * Sheesh. Record the true errno for error reporting,1660 * but report EISDIR to raceproof_create_file() so1661 * that it knows to retry.1662 */1663 cb->true_errno = errno;1664 if (errno == ENOTDIR)1665 errno = EISDIR;1666 return -1;1667 } else {1668 return 0;1669 }1670}16711672static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)1673{1674 struct strbuf path = STRBUF_INIT;1675 struct strbuf tmp = STRBUF_INIT;1676 struct rename_cb cb;1677 int ret;16781679 files_reflog_path(refs, &path, newrefname);1680 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);1681 cb.tmp_renamed_log = tmp.buf;1682 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);1683 if (ret) {1684 if (errno == EISDIR)1685 error("directory not empty: %s", path.buf);1686 else1687 error("unable to move logfile %s to %s: %s",1688 tmp.buf, path.buf,1689 strerror(cb.true_errno));1690 }16911692 strbuf_release(&path);1693 strbuf_release(&tmp);1694 return ret;1695}16961697static int write_ref_to_lockfile(struct ref_lock *lock,1698 const struct object_id *oid, struct strbuf *err);1699static int commit_ref_update(struct files_ref_store *refs,1700 struct ref_lock *lock,1701 const struct object_id *oid, const char *logmsg,1702 struct strbuf *err);17031704static int files_rename_ref(struct ref_store *ref_store,1705 const char *oldrefname, const char *newrefname,1706 const char *logmsg)1707{1708 struct files_ref_store *refs =1709 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");1710 struct object_id oid, orig_oid;1711 int flag = 0, logmoved = 0;1712 struct ref_lock *lock;1713 struct stat loginfo;1714 struct strbuf sb_oldref = STRBUF_INIT;1715 struct strbuf sb_newref = STRBUF_INIT;1716 struct strbuf tmp_renamed_log = STRBUF_INIT;1717 int log, ret;1718 struct strbuf err = STRBUF_INIT;17191720 files_reflog_path(refs, &sb_oldref, oldrefname);1721 files_reflog_path(refs, &sb_newref, newrefname);1722 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);17231724 log = !lstat(sb_oldref.buf, &loginfo);1725 if (log && S_ISLNK(loginfo.st_mode)) {1726 ret = error("reflog for %s is a symlink", oldrefname);1727 goto out;1728 }17291730 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,1731 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,1732 orig_oid.hash, &flag)) {1733 ret = error("refname %s not found", oldrefname);1734 goto out;1735 }17361737 if (flag & REF_ISSYMREF) {1738 ret = error("refname %s is a symbolic ref, renaming it is not supported",1739 oldrefname);1740 goto out;1741 }1742 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {1743 ret = 1;1744 goto out;1745 }17461747 if (log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {1748 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",1749 oldrefname, strerror(errno));1750 goto out;1751 }17521753 if (refs_delete_ref(&refs->base, logmsg, oldrefname,1754 orig_oid.hash, REF_NODEREF)) {1755 error("unable to delete old %s", oldrefname);1756 goto rollback;1757 }17581759 /*1760 * Since we are doing a shallow lookup, oid is not the1761 * correct value to pass to delete_ref as old_oid. But that1762 * doesn't matter, because an old_oid check wouldn't add to1763 * the safety anyway; we want to delete the reference whatever1764 * its current value.1765 */1766 if (!refs_read_ref_full(&refs->base, newrefname,1767 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,1768 oid.hash, NULL) &&1769 refs_delete_ref(&refs->base, NULL, newrefname,1770 NULL, REF_NODEREF)) {1771 if (errno == EISDIR) {1772 struct strbuf path = STRBUF_INIT;1773 int result;17741775 files_ref_path(refs, &path, newrefname);1776 result = remove_empty_directories(&path);1777 strbuf_release(&path);17781779 if (result) {1780 error("Directory not empty: %s", newrefname);1781 goto rollback;1782 }1783 } else {1784 error("unable to delete existing %s", newrefname);1785 goto rollback;1786 }1787 }17881789 if (log && rename_tmp_log(refs, newrefname))1790 goto rollback;17911792 logmoved = log;17931794 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,1795 REF_NODEREF, NULL, &err);1796 if (!lock) {1797 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);1798 strbuf_release(&err);1799 goto rollback;1800 }1801 oidcpy(&lock->old_oid, &orig_oid);18021803 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||1804 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {1805 error("unable to write current sha1 into %s: %s", newrefname, err.buf);1806 strbuf_release(&err);1807 goto rollback;1808 }18091810 ret = 0;1811 goto out;18121813 rollback:1814 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,1815 REF_NODEREF, NULL, &err);1816 if (!lock) {1817 error("unable to lock %s for rollback: %s", oldrefname, err.buf);1818 strbuf_release(&err);1819 goto rollbacklog;1820 }18211822 flag = log_all_ref_updates;1823 log_all_ref_updates = LOG_REFS_NONE;1824 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||1825 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {1826 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);1827 strbuf_release(&err);1828 }1829 log_all_ref_updates = flag;18301831 rollbacklog:1832 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))1833 error("unable to restore logfile %s from %s: %s",1834 oldrefname, newrefname, strerror(errno));1835 if (!logmoved && log &&1836 rename(tmp_renamed_log.buf, sb_oldref.buf))1837 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",1838 oldrefname, strerror(errno));1839 ret = 1;1840 out:1841 strbuf_release(&sb_newref);1842 strbuf_release(&sb_oldref);1843 strbuf_release(&tmp_renamed_log);18441845 return ret;1846}18471848static int close_ref(struct ref_lock *lock)1849{1850 if (close_lock_file(lock->lk))1851 return -1;1852 return 0;1853}18541855static int commit_ref(struct ref_lock *lock)1856{1857 char *path = get_locked_file_path(lock->lk);1858 struct stat st;18591860 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {1861 /*1862 * There is a directory at the path we want to rename1863 * the lockfile to. Hopefully it is empty; try to1864 * delete it.1865 */1866 size_t len = strlen(path);1867 struct strbuf sb_path = STRBUF_INIT;18681869 strbuf_attach(&sb_path, path, len, len);18701871 /*1872 * If this fails, commit_lock_file() will also fail1873 * and will report the problem.1874 */1875 remove_empty_directories(&sb_path);1876 strbuf_release(&sb_path);1877 } else {1878 free(path);1879 }18801881 if (commit_lock_file(lock->lk))1882 return -1;1883 return 0;1884}18851886static int open_or_create_logfile(const char *path, void *cb)1887{1888 int *fd = cb;18891890 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);1891 return (*fd < 0) ? -1 : 0;1892}18931894/*1895 * Create a reflog for a ref. If force_create = 0, only create the1896 * reflog for certain refs (those for which should_autocreate_reflog1897 * returns non-zero). Otherwise, create it regardless of the reference1898 * name. If the logfile already existed or was created, return 0 and1899 * set *logfd to the file descriptor opened for appending to the file.1900 * If no logfile exists and we decided not to create one, return 0 and1901 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and1902 * return -1.1903 */1904static int log_ref_setup(struct files_ref_store *refs,1905 const char *refname, int force_create,1906 int *logfd, struct strbuf *err)1907{1908 struct strbuf logfile_sb = STRBUF_INIT;1909 char *logfile;19101911 files_reflog_path(refs, &logfile_sb, refname);1912 logfile = strbuf_detach(&logfile_sb, NULL);19131914 if (force_create || should_autocreate_reflog(refname)) {1915 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {1916 if (errno == ENOENT)1917 strbuf_addf(err, "unable to create directory for '%s': "1918 "%s", logfile, strerror(errno));1919 else if (errno == EISDIR)1920 strbuf_addf(err, "there are still logs under '%s'",1921 logfile);1922 else1923 strbuf_addf(err, "unable to append to '%s': %s",1924 logfile, strerror(errno));19251926 goto error;1927 }1928 } else {1929 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);1930 if (*logfd < 0) {1931 if (errno == ENOENT || errno == EISDIR) {1932 /*1933 * The logfile doesn't already exist,1934 * but that is not an error; it only1935 * means that we won't write log1936 * entries to it.1937 */1938 ;1939 } else {1940 strbuf_addf(err, "unable to append to '%s': %s",1941 logfile, strerror(errno));1942 goto error;1943 }1944 }1945 }19461947 if (*logfd >= 0)1948 adjust_shared_perm(logfile);19491950 free(logfile);1951 return 0;19521953error:1954 free(logfile);1955 return -1;1956}19571958static int files_create_reflog(struct ref_store *ref_store,1959 const char *refname, int force_create,1960 struct strbuf *err)1961{1962 struct files_ref_store *refs =1963 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");1964 int fd;19651966 if (log_ref_setup(refs, refname, force_create, &fd, err))1967 return -1;19681969 if (fd >= 0)1970 close(fd);19711972 return 0;1973}19741975static int log_ref_write_fd(int fd, const struct object_id *old_oid,1976 const struct object_id *new_oid,1977 const char *committer, const char *msg)1978{1979 int msglen, written;1980 unsigned maxlen, len;1981 char *logrec;19821983 msglen = msg ? strlen(msg) : 0;1984 maxlen = strlen(committer) + msglen + 100;1985 logrec = xmalloc(maxlen);1986 len = xsnprintf(logrec, maxlen, "%s %s %s\n",1987 oid_to_hex(old_oid),1988 oid_to_hex(new_oid),1989 committer);1990 if (msglen)1991 len += copy_reflog_msg(logrec + len - 1, msg) - 1;19921993 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;1994 free(logrec);1995 if (written != len)1996 return -1;19971998 return 0;1999}20002001static int files_log_ref_write(struct files_ref_store *refs,2002 const char *refname, const struct object_id *old_oid,2003 const struct object_id *new_oid, const char *msg,2004 int flags, struct strbuf *err)2005{2006 int logfd, result;20072008 if (log_all_ref_updates == LOG_REFS_UNSET)2009 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;20102011 result = log_ref_setup(refs, refname,2012 flags & REF_FORCE_CREATE_REFLOG,2013 &logfd, err);20142015 if (result)2016 return result;20172018 if (logfd < 0)2019 return 0;2020 result = log_ref_write_fd(logfd, old_oid, new_oid,2021 git_committer_info(0), msg);2022 if (result) {2023 struct strbuf sb = STRBUF_INIT;2024 int save_errno = errno;20252026 files_reflog_path(refs, &sb, refname);2027 strbuf_addf(err, "unable to append to '%s': %s",2028 sb.buf, strerror(save_errno));2029 strbuf_release(&sb);2030 close(logfd);2031 return -1;2032 }2033 if (close(logfd)) {2034 struct strbuf sb = STRBUF_INIT;2035 int save_errno = errno;20362037 files_reflog_path(refs, &sb, refname);2038 strbuf_addf(err, "unable to append to '%s': %s",2039 sb.buf, strerror(save_errno));2040 strbuf_release(&sb);2041 return -1;2042 }2043 return 0;2044}20452046/*2047 * Write sha1 into the open lockfile, then close the lockfile. On2048 * errors, rollback the lockfile, fill in *err and2049 * return -1.2050 */2051static int write_ref_to_lockfile(struct ref_lock *lock,2052 const struct object_id *oid, struct strbuf *err)2053{2054 static char term = '\n';2055 struct object *o;2056 int fd;20572058 o = parse_object(oid);2059 if (!o) {2060 strbuf_addf(err,2061 "trying to write ref '%s' with nonexistent object %s",2062 lock->ref_name, oid_to_hex(oid));2063 unlock_ref(lock);2064 return -1;2065 }2066 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2067 strbuf_addf(err,2068 "trying to write non-commit object %s to branch '%s'",2069 oid_to_hex(oid), lock->ref_name);2070 unlock_ref(lock);2071 return -1;2072 }2073 fd = get_lock_file_fd(lock->lk);2074 if (write_in_full(fd, oid_to_hex(oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||2075 write_in_full(fd, &term, 1) != 1 ||2076 close_ref(lock) < 0) {2077 strbuf_addf(err,2078 "couldn't write '%s'", get_lock_file_path(lock->lk));2079 unlock_ref(lock);2080 return -1;2081 }2082 return 0;2083}20842085/*2086 * Commit a change to a loose reference that has already been written2087 * to the loose reference lockfile. Also update the reflogs if2088 * necessary, using the specified lockmsg (which can be NULL).2089 */2090static int commit_ref_update(struct files_ref_store *refs,2091 struct ref_lock *lock,2092 const struct object_id *oid, const char *logmsg,2093 struct strbuf *err)2094{2095 files_assert_main_repository(refs, "commit_ref_update");20962097 clear_loose_ref_cache(refs);2098 if (files_log_ref_write(refs, lock->ref_name,2099 &lock->old_oid, oid,2100 logmsg, 0, err)) {2101 char *old_msg = strbuf_detach(err, NULL);2102 strbuf_addf(err, "cannot update the ref '%s': %s",2103 lock->ref_name, old_msg);2104 free(old_msg);2105 unlock_ref(lock);2106 return -1;2107 }21082109 if (strcmp(lock->ref_name, "HEAD") != 0) {2110 /*2111 * Special hack: If a branch is updated directly and HEAD2112 * points to it (may happen on the remote side of a push2113 * for example) then logically the HEAD reflog should be2114 * updated too.2115 * A generic solution implies reverse symref information,2116 * but finding all symrefs pointing to the given branch2117 * would be rather costly for this rare event (the direct2118 * update of a branch) to be worth it. So let's cheat and2119 * check with HEAD only which should cover 99% of all usage2120 * scenarios (even 100% of the default ones).2121 */2122 struct object_id head_oid;2123 int head_flag;2124 const char *head_ref;21252126 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",2127 RESOLVE_REF_READING,2128 head_oid.hash, &head_flag);2129 if (head_ref && (head_flag & REF_ISSYMREF) &&2130 !strcmp(head_ref, lock->ref_name)) {2131 struct strbuf log_err = STRBUF_INIT;2132 if (files_log_ref_write(refs, "HEAD",2133 &lock->old_oid, oid,2134 logmsg, 0, &log_err)) {2135 error("%s", log_err.buf);2136 strbuf_release(&log_err);2137 }2138 }2139 }21402141 if (commit_ref(lock)) {2142 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2143 unlock_ref(lock);2144 return -1;2145 }21462147 unlock_ref(lock);2148 return 0;2149}21502151static int create_ref_symlink(struct ref_lock *lock, const char *target)2152{2153 int ret = -1;2154#ifndef NO_SYMLINK_HEAD2155 char *ref_path = get_locked_file_path(lock->lk);2156 unlink(ref_path);2157 ret = symlink(target, ref_path);2158 free(ref_path);21592160 if (ret)2161 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2162#endif2163 return ret;2164}21652166static void update_symref_reflog(struct files_ref_store *refs,2167 struct ref_lock *lock, const char *refname,2168 const char *target, const char *logmsg)2169{2170 struct strbuf err = STRBUF_INIT;2171 struct object_id new_oid;2172 if (logmsg &&2173 !refs_read_ref_full(&refs->base, target,2174 RESOLVE_REF_READING, new_oid.hash, NULL) &&2175 files_log_ref_write(refs, refname, &lock->old_oid,2176 &new_oid, logmsg, 0, &err)) {2177 error("%s", err.buf);2178 strbuf_release(&err);2179 }2180}21812182static int create_symref_locked(struct files_ref_store *refs,2183 struct ref_lock *lock, const char *refname,2184 const char *target, const char *logmsg)2185{2186 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {2187 update_symref_reflog(refs, lock, refname, target, logmsg);2188 return 0;2189 }21902191 if (!fdopen_lock_file(lock->lk, "w"))2192 return error("unable to fdopen %s: %s",2193 lock->lk->tempfile.filename.buf, strerror(errno));21942195 update_symref_reflog(refs, lock, refname, target, logmsg);21962197 /* no error check; commit_ref will check ferror */2198 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);2199 if (commit_ref(lock) < 0)2200 return error("unable to write symref for %s: %s", refname,2201 strerror(errno));2202 return 0;2203}22042205static int files_create_symref(struct ref_store *ref_store,2206 const char *refname, const char *target,2207 const char *logmsg)2208{2209 struct files_ref_store *refs =2210 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");2211 struct strbuf err = STRBUF_INIT;2212 struct ref_lock *lock;2213 int ret;22142215 lock = lock_ref_sha1_basic(refs, refname, NULL,2216 NULL, NULL, REF_NODEREF, NULL,2217 &err);2218 if (!lock) {2219 error("%s", err.buf);2220 strbuf_release(&err);2221 return -1;2222 }22232224 ret = create_symref_locked(refs, lock, refname, target, logmsg);2225 unlock_ref(lock);2226 return ret;2227}22282229static int files_reflog_exists(struct ref_store *ref_store,2230 const char *refname)2231{2232 struct files_ref_store *refs =2233 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");2234 struct strbuf sb = STRBUF_INIT;2235 struct stat st;2236 int ret;22372238 files_reflog_path(refs, &sb, refname);2239 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);2240 strbuf_release(&sb);2241 return ret;2242}22432244static int files_delete_reflog(struct ref_store *ref_store,2245 const char *refname)2246{2247 struct files_ref_store *refs =2248 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");2249 struct strbuf sb = STRBUF_INIT;2250 int ret;22512252 files_reflog_path(refs, &sb, refname);2253 ret = remove_path(sb.buf);2254 strbuf_release(&sb);2255 return ret;2256}22572258static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)2259{2260 struct object_id ooid, noid;2261 char *email_end, *message;2262 timestamp_t timestamp;2263 int tz;2264 const char *p = sb->buf;22652266 /* old SP new SP name <email> SP time TAB msg LF */2267 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||2268 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||2269 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||2270 !(email_end = strchr(p, '>')) ||2271 email_end[1] != ' ' ||2272 !(timestamp = parse_timestamp(email_end + 2, &message, 10)) ||2273 !message || message[0] != ' ' ||2274 (message[1] != '+' && message[1] != '-') ||2275 !isdigit(message[2]) || !isdigit(message[3]) ||2276 !isdigit(message[4]) || !isdigit(message[5]))2277 return 0; /* corrupt? */2278 email_end[1] = '\0';2279 tz = strtol(message + 1, NULL, 10);2280 if (message[6] != '\t')2281 message += 6;2282 else2283 message += 7;2284 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);2285}22862287static char *find_beginning_of_line(char *bob, char *scan)2288{2289 while (bob < scan && *(--scan) != '\n')2290 ; /* keep scanning backwards */2291 /*2292 * Return either beginning of the buffer, or LF at the end of2293 * the previous line.2294 */2295 return scan;2296}22972298static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,2299 const char *refname,2300 each_reflog_ent_fn fn,2301 void *cb_data)2302{2303 struct files_ref_store *refs =2304 files_downcast(ref_store, REF_STORE_READ,2305 "for_each_reflog_ent_reverse");2306 struct strbuf sb = STRBUF_INIT;2307 FILE *logfp;2308 long pos;2309 int ret = 0, at_tail = 1;23102311 files_reflog_path(refs, &sb, refname);2312 logfp = fopen(sb.buf, "r");2313 strbuf_release(&sb);2314 if (!logfp)2315 return -1;23162317 /* Jump to the end */2318 if (fseek(logfp, 0, SEEK_END) < 0)2319 ret = error("cannot seek back reflog for %s: %s",2320 refname, strerror(errno));2321 pos = ftell(logfp);2322 while (!ret && 0 < pos) {2323 int cnt;2324 size_t nread;2325 char buf[BUFSIZ];2326 char *endp, *scanp;23272328 /* Fill next block from the end */2329 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;2330 if (fseek(logfp, pos - cnt, SEEK_SET)) {2331 ret = error("cannot seek back reflog for %s: %s",2332 refname, strerror(errno));2333 break;2334 }2335 nread = fread(buf, cnt, 1, logfp);2336 if (nread != 1) {2337 ret = error("cannot read %d bytes from reflog for %s: %s",2338 cnt, refname, strerror(errno));2339 break;2340 }2341 pos -= cnt;23422343 scanp = endp = buf + cnt;2344 if (at_tail && scanp[-1] == '\n')2345 /* Looking at the final LF at the end of the file */2346 scanp--;2347 at_tail = 0;23482349 while (buf < scanp) {2350 /*2351 * terminating LF of the previous line, or the beginning2352 * of the buffer.2353 */2354 char *bp;23552356 bp = find_beginning_of_line(buf, scanp);23572358 if (*bp == '\n') {2359 /*2360 * The newline is the end of the previous line,2361 * so we know we have complete line starting2362 * at (bp + 1). Prefix it onto any prior data2363 * we collected for the line and process it.2364 */2365 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));2366 scanp = bp;2367 endp = bp + 1;2368 ret = show_one_reflog_ent(&sb, fn, cb_data);2369 strbuf_reset(&sb);2370 if (ret)2371 break;2372 } else if (!pos) {2373 /*2374 * We are at the start of the buffer, and the2375 * start of the file; there is no previous2376 * line, and we have everything for this one.2377 * Process it, and we can end the loop.2378 */2379 strbuf_splice(&sb, 0, 0, buf, endp - buf);2380 ret = show_one_reflog_ent(&sb, fn, cb_data);2381 strbuf_reset(&sb);2382 break;2383 }23842385 if (bp == buf) {2386 /*2387 * We are at the start of the buffer, and there2388 * is more file to read backwards. Which means2389 * we are in the middle of a line. Note that we2390 * may get here even if *bp was a newline; that2391 * just means we are at the exact end of the2392 * previous line, rather than some spot in the2393 * middle.2394 *2395 * Save away what we have to be combined with2396 * the data from the next read.2397 */2398 strbuf_splice(&sb, 0, 0, buf, endp - buf);2399 break;2400 }2401 }24022403 }2404 if (!ret && sb.len)2405 die("BUG: reverse reflog parser had leftover data");24062407 fclose(logfp);2408 strbuf_release(&sb);2409 return ret;2410}24112412static int files_for_each_reflog_ent(struct ref_store *ref_store,2413 const char *refname,2414 each_reflog_ent_fn fn, void *cb_data)2415{2416 struct files_ref_store *refs =2417 files_downcast(ref_store, REF_STORE_READ,2418 "for_each_reflog_ent");2419 FILE *logfp;2420 struct strbuf sb = STRBUF_INIT;2421 int ret = 0;24222423 files_reflog_path(refs, &sb, refname);2424 logfp = fopen(sb.buf, "r");2425 strbuf_release(&sb);2426 if (!logfp)2427 return -1;24282429 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))2430 ret = show_one_reflog_ent(&sb, fn, cb_data);2431 fclose(logfp);2432 strbuf_release(&sb);2433 return ret;2434}24352436struct files_reflog_iterator {2437 struct ref_iterator base;24382439 struct ref_store *ref_store;2440 struct dir_iterator *dir_iterator;2441 struct object_id oid;2442};24432444static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)2445{2446 struct files_reflog_iterator *iter =2447 (struct files_reflog_iterator *)ref_iterator;2448 struct dir_iterator *diter = iter->dir_iterator;2449 int ok;24502451 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {2452 int flags;24532454 if (!S_ISREG(diter->st.st_mode))2455 continue;2456 if (diter->basename[0] == '.')2457 continue;2458 if (ends_with(diter->basename, ".lock"))2459 continue;24602461 if (refs_read_ref_full(iter->ref_store,2462 diter->relative_path, 0,2463 iter->oid.hash, &flags)) {2464 error("bad ref for %s", diter->path.buf);2465 continue;2466 }24672468 iter->base.refname = diter->relative_path;2469 iter->base.oid = &iter->oid;2470 iter->base.flags = flags;2471 return ITER_OK;2472 }24732474 iter->dir_iterator = NULL;2475 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)2476 ok = ITER_ERROR;2477 return ok;2478}24792480static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,2481 struct object_id *peeled)2482{2483 die("BUG: ref_iterator_peel() called for reflog_iterator");2484}24852486static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)2487{2488 struct files_reflog_iterator *iter =2489 (struct files_reflog_iterator *)ref_iterator;2490 int ok = ITER_DONE;24912492 if (iter->dir_iterator)2493 ok = dir_iterator_abort(iter->dir_iterator);24942495 base_ref_iterator_free(ref_iterator);2496 return ok;2497}24982499static struct ref_iterator_vtable files_reflog_iterator_vtable = {2500 files_reflog_iterator_advance,2501 files_reflog_iterator_peel,2502 files_reflog_iterator_abort2503};25042505static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)2506{2507 struct files_ref_store *refs =2508 files_downcast(ref_store, REF_STORE_READ,2509 "reflog_iterator_begin");2510 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));2511 struct ref_iterator *ref_iterator = &iter->base;2512 struct strbuf sb = STRBUF_INIT;25132514 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);2515 files_reflog_path(refs, &sb, NULL);2516 iter->dir_iterator = dir_iterator_begin(sb.buf);2517 iter->ref_store = ref_store;2518 strbuf_release(&sb);2519 return ref_iterator;2520}25212522static int ref_update_reject_duplicates(struct string_list *refnames,2523 struct strbuf *err)2524{2525 int i, n = refnames->nr;25262527 assert(err);25282529 for (i = 1; i < n; i++)2530 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {2531 strbuf_addf(err,2532 "multiple updates for ref '%s' not allowed.",2533 refnames->items[i].string);2534 return 1;2535 }2536 return 0;2537}25382539/*2540 * If update is a direct update of head_ref (the reference pointed to2541 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.2542 */2543static int split_head_update(struct ref_update *update,2544 struct ref_transaction *transaction,2545 const char *head_ref,2546 struct string_list *affected_refnames,2547 struct strbuf *err)2548{2549 struct string_list_item *item;2550 struct ref_update *new_update;25512552 if ((update->flags & REF_LOG_ONLY) ||2553 (update->flags & REF_ISPRUNING) ||2554 (update->flags & REF_UPDATE_VIA_HEAD))2555 return 0;25562557 if (strcmp(update->refname, head_ref))2558 return 0;25592560 /*2561 * First make sure that HEAD is not already in the2562 * transaction. This insertion is O(N) in the transaction2563 * size, but it happens at most once per transaction.2564 */2565 item = string_list_insert(affected_refnames, "HEAD");2566 if (item->util) {2567 /* An entry already existed */2568 strbuf_addf(err,2569 "multiple updates for 'HEAD' (including one "2570 "via its referent '%s') are not allowed",2571 update->refname);2572 return TRANSACTION_NAME_CONFLICT;2573 }25742575 new_update = ref_transaction_add_update(2576 transaction, "HEAD",2577 update->flags | REF_LOG_ONLY | REF_NODEREF,2578 update->new_oid.hash, update->old_oid.hash,2579 update->msg);25802581 item->util = new_update;25822583 return 0;2584}25852586/*2587 * update is for a symref that points at referent and doesn't have2588 * REF_NODEREF set. Split it into two updates:2589 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set2590 * - A new, separate update for the referent reference2591 * Note that the new update will itself be subject to splitting when2592 * the iteration gets to it.2593 */2594static int split_symref_update(struct files_ref_store *refs,2595 struct ref_update *update,2596 const char *referent,2597 struct ref_transaction *transaction,2598 struct string_list *affected_refnames,2599 struct strbuf *err)2600{2601 struct string_list_item *item;2602 struct ref_update *new_update;2603 unsigned int new_flags;26042605 /*2606 * First make sure that referent is not already in the2607 * transaction. This insertion is O(N) in the transaction2608 * size, but it happens at most once per symref in a2609 * transaction.2610 */2611 item = string_list_insert(affected_refnames, referent);2612 if (item->util) {2613 /* An entry already existed */2614 strbuf_addf(err,2615 "multiple updates for '%s' (including one "2616 "via symref '%s') are not allowed",2617 referent, update->refname);2618 return TRANSACTION_NAME_CONFLICT;2619 }26202621 new_flags = update->flags;2622 if (!strcmp(update->refname, "HEAD")) {2623 /*2624 * Record that the new update came via HEAD, so that2625 * when we process it, split_head_update() doesn't try2626 * to add another reflog update for HEAD. Note that2627 * this bit will be propagated if the new_update2628 * itself needs to be split.2629 */2630 new_flags |= REF_UPDATE_VIA_HEAD;2631 }26322633 new_update = ref_transaction_add_update(2634 transaction, referent, new_flags,2635 update->new_oid.hash, update->old_oid.hash,2636 update->msg);26372638 new_update->parent_update = update;26392640 /*2641 * Change the symbolic ref update to log only. Also, it2642 * doesn't need to check its old SHA-1 value, as that will be2643 * done when new_update is processed.2644 */2645 update->flags |= REF_LOG_ONLY | REF_NODEREF;2646 update->flags &= ~REF_HAVE_OLD;26472648 item->util = new_update;26492650 return 0;2651}26522653/*2654 * Return the refname under which update was originally requested.2655 */2656static const char *original_update_refname(struct ref_update *update)2657{2658 while (update->parent_update)2659 update = update->parent_update;26602661 return update->refname;2662}26632664/*2665 * Check whether the REF_HAVE_OLD and old_oid values stored in update2666 * are consistent with oid, which is the reference's current value. If2667 * everything is OK, return 0; otherwise, write an error message to2668 * err and return -1.2669 */2670static int check_old_oid(struct ref_update *update, struct object_id *oid,2671 struct strbuf *err)2672{2673 if (!(update->flags & REF_HAVE_OLD) ||2674 !oidcmp(oid, &update->old_oid))2675 return 0;26762677 if (is_null_oid(&update->old_oid))2678 strbuf_addf(err, "cannot lock ref '%s': "2679 "reference already exists",2680 original_update_refname(update));2681 else if (is_null_oid(oid))2682 strbuf_addf(err, "cannot lock ref '%s': "2683 "reference is missing but expected %s",2684 original_update_refname(update),2685 oid_to_hex(&update->old_oid));2686 else2687 strbuf_addf(err, "cannot lock ref '%s': "2688 "is at %s but expected %s",2689 original_update_refname(update),2690 oid_to_hex(oid),2691 oid_to_hex(&update->old_oid));26922693 return -1;2694}26952696/*2697 * Prepare for carrying out update:2698 * - Lock the reference referred to by update.2699 * - Read the reference under lock.2700 * - Check that its old SHA-1 value (if specified) is correct, and in2701 * any case record it in update->lock->old_oid for later use when2702 * writing the reflog.2703 * - If it is a symref update without REF_NODEREF, split it up into a2704 * REF_LOG_ONLY update of the symref and add a separate update for2705 * the referent to transaction.2706 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY2707 * update of HEAD.2708 */2709static int lock_ref_for_update(struct files_ref_store *refs,2710 struct ref_update *update,2711 struct ref_transaction *transaction,2712 const char *head_ref,2713 struct string_list *affected_refnames,2714 struct strbuf *err)2715{2716 struct strbuf referent = STRBUF_INIT;2717 int mustexist = (update->flags & REF_HAVE_OLD) &&2718 !is_null_oid(&update->old_oid);2719 int ret;2720 struct ref_lock *lock;27212722 files_assert_main_repository(refs, "lock_ref_for_update");27232724 if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid))2725 update->flags |= REF_DELETING;27262727 if (head_ref) {2728 ret = split_head_update(update, transaction, head_ref,2729 affected_refnames, err);2730 if (ret)2731 return ret;2732 }27332734 ret = lock_raw_ref(refs, update->refname, mustexist,2735 affected_refnames, NULL,2736 &lock, &referent,2737 &update->type, err);2738 if (ret) {2739 char *reason;27402741 reason = strbuf_detach(err, NULL);2742 strbuf_addf(err, "cannot lock ref '%s': %s",2743 original_update_refname(update), reason);2744 free(reason);2745 return ret;2746 }27472748 update->backend_data = lock;27492750 if (update->type & REF_ISSYMREF) {2751 if (update->flags & REF_NODEREF) {2752 /*2753 * We won't be reading the referent as part of2754 * the transaction, so we have to read it here2755 * to record and possibly check old_sha1:2756 */2757 if (refs_read_ref_full(&refs->base,2758 referent.buf, 0,2759 lock->old_oid.hash, NULL)) {2760 if (update->flags & REF_HAVE_OLD) {2761 strbuf_addf(err, "cannot lock ref '%s': "2762 "error reading reference",2763 original_update_refname(update));2764 return -1;2765 }2766 } else if (check_old_oid(update, &lock->old_oid, err)) {2767 return TRANSACTION_GENERIC_ERROR;2768 }2769 } else {2770 /*2771 * Create a new update for the reference this2772 * symref is pointing at. Also, we will record2773 * and verify old_sha1 for this update as part2774 * of processing the split-off update, so we2775 * don't have to do it here.2776 */2777 ret = split_symref_update(refs, update,2778 referent.buf, transaction,2779 affected_refnames, err);2780 if (ret)2781 return ret;2782 }2783 } else {2784 struct ref_update *parent_update;27852786 if (check_old_oid(update, &lock->old_oid, err))2787 return TRANSACTION_GENERIC_ERROR;27882789 /*2790 * If this update is happening indirectly because of a2791 * symref update, record the old SHA-1 in the parent2792 * update:2793 */2794 for (parent_update = update->parent_update;2795 parent_update;2796 parent_update = parent_update->parent_update) {2797 struct ref_lock *parent_lock = parent_update->backend_data;2798 oidcpy(&parent_lock->old_oid, &lock->old_oid);2799 }2800 }28012802 if ((update->flags & REF_HAVE_NEW) &&2803 !(update->flags & REF_DELETING) &&2804 !(update->flags & REF_LOG_ONLY)) {2805 if (!(update->type & REF_ISSYMREF) &&2806 !oidcmp(&lock->old_oid, &update->new_oid)) {2807 /*2808 * The reference already has the desired2809 * value, so we don't need to write it.2810 */2811 } else if (write_ref_to_lockfile(lock, &update->new_oid,2812 err)) {2813 char *write_err = strbuf_detach(err, NULL);28142815 /*2816 * The lock was freed upon failure of2817 * write_ref_to_lockfile():2818 */2819 update->backend_data = NULL;2820 strbuf_addf(err,2821 "cannot update ref '%s': %s",2822 update->refname, write_err);2823 free(write_err);2824 return TRANSACTION_GENERIC_ERROR;2825 } else {2826 update->flags |= REF_NEEDS_COMMIT;2827 }2828 }2829 if (!(update->flags & REF_NEEDS_COMMIT)) {2830 /*2831 * We didn't call write_ref_to_lockfile(), so2832 * the lockfile is still open. Close it to2833 * free up the file descriptor:2834 */2835 if (close_ref(lock)) {2836 strbuf_addf(err, "couldn't close '%s.lock'",2837 update->refname);2838 return TRANSACTION_GENERIC_ERROR;2839 }2840 }2841 return 0;2842}28432844static int files_transaction_commit(struct ref_store *ref_store,2845 struct ref_transaction *transaction,2846 struct strbuf *err)2847{2848 struct files_ref_store *refs =2849 files_downcast(ref_store, REF_STORE_WRITE,2850 "ref_transaction_commit");2851 size_t i;2852 int ret = 0;2853 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;2854 struct string_list_item *ref_to_delete;2855 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;2856 char *head_ref = NULL;2857 int head_type;2858 struct object_id head_oid;2859 struct strbuf sb = STRBUF_INIT;28602861 assert(err);28622863 if (transaction->state != REF_TRANSACTION_OPEN)2864 die("BUG: commit called for transaction that is not open");28652866 if (!transaction->nr) {2867 transaction->state = REF_TRANSACTION_CLOSED;2868 return 0;2869 }28702871 /*2872 * Fail if a refname appears more than once in the2873 * transaction. (If we end up splitting up any updates using2874 * split_symref_update() or split_head_update(), those2875 * functions will check that the new updates don't have the2876 * same refname as any existing ones.)2877 */2878 for (i = 0; i < transaction->nr; i++) {2879 struct ref_update *update = transaction->updates[i];2880 struct string_list_item *item =2881 string_list_append(&affected_refnames, update->refname);28822883 /*2884 * We store a pointer to update in item->util, but at2885 * the moment we never use the value of this field2886 * except to check whether it is non-NULL.2887 */2888 item->util = update;2889 }2890 string_list_sort(&affected_refnames);2891 if (ref_update_reject_duplicates(&affected_refnames, err)) {2892 ret = TRANSACTION_GENERIC_ERROR;2893 goto cleanup;2894 }28952896 /*2897 * Special hack: If a branch is updated directly and HEAD2898 * points to it (may happen on the remote side of a push2899 * for example) then logically the HEAD reflog should be2900 * updated too.2901 *2902 * A generic solution would require reverse symref lookups,2903 * but finding all symrefs pointing to a given branch would be2904 * rather costly for this rare event (the direct update of a2905 * branch) to be worth it. So let's cheat and check with HEAD2906 * only, which should cover 99% of all usage scenarios (even2907 * 100% of the default ones).2908 *2909 * So if HEAD is a symbolic reference, then record the name of2910 * the reference that it points to. If we see an update of2911 * head_ref within the transaction, then split_head_update()2912 * arranges for the reflog of HEAD to be updated, too.2913 */2914 head_ref = refs_resolve_refdup(ref_store, "HEAD",2915 RESOLVE_REF_NO_RECURSE,2916 head_oid.hash, &head_type);29172918 if (head_ref && !(head_type & REF_ISSYMREF)) {2919 free(head_ref);2920 head_ref = NULL;2921 }29222923 /*2924 * Acquire all locks, verify old values if provided, check2925 * that new values are valid, and write new values to the2926 * lockfiles, ready to be activated. Only keep one lockfile2927 * open at a time to avoid running out of file descriptors.2928 */2929 for (i = 0; i < transaction->nr; i++) {2930 struct ref_update *update = transaction->updates[i];29312932 ret = lock_ref_for_update(refs, update, transaction,2933 head_ref, &affected_refnames, err);2934 if (ret)2935 goto cleanup;2936 }29372938 /* Perform updates first so live commits remain referenced */2939 for (i = 0; i < transaction->nr; i++) {2940 struct ref_update *update = transaction->updates[i];2941 struct ref_lock *lock = update->backend_data;29422943 if (update->flags & REF_NEEDS_COMMIT ||2944 update->flags & REF_LOG_ONLY) {2945 if (files_log_ref_write(refs,2946 lock->ref_name,2947 &lock->old_oid,2948 &update->new_oid,2949 update->msg, update->flags,2950 err)) {2951 char *old_msg = strbuf_detach(err, NULL);29522953 strbuf_addf(err, "cannot update the ref '%s': %s",2954 lock->ref_name, old_msg);2955 free(old_msg);2956 unlock_ref(lock);2957 update->backend_data = NULL;2958 ret = TRANSACTION_GENERIC_ERROR;2959 goto cleanup;2960 }2961 }2962 if (update->flags & REF_NEEDS_COMMIT) {2963 clear_loose_ref_cache(refs);2964 if (commit_ref(lock)) {2965 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2966 unlock_ref(lock);2967 update->backend_data = NULL;2968 ret = TRANSACTION_GENERIC_ERROR;2969 goto cleanup;2970 }2971 }2972 }2973 /* Perform deletes now that updates are safely completed */2974 for (i = 0; i < transaction->nr; i++) {2975 struct ref_update *update = transaction->updates[i];2976 struct ref_lock *lock = update->backend_data;29772978 if (update->flags & REF_DELETING &&2979 !(update->flags & REF_LOG_ONLY)) {2980 if (!(update->type & REF_ISPACKED) ||2981 update->type & REF_ISSYMREF) {2982 /* It is a loose reference. */2983 strbuf_reset(&sb);2984 files_ref_path(refs, &sb, lock->ref_name);2985 if (unlink_or_msg(sb.buf, err)) {2986 ret = TRANSACTION_GENERIC_ERROR;2987 goto cleanup;2988 }2989 update->flags |= REF_DELETED_LOOSE;2990 }29912992 if (!(update->flags & REF_ISPRUNING))2993 string_list_append(&refs_to_delete,2994 lock->ref_name);2995 }2996 }29972998 if (repack_without_refs(refs, &refs_to_delete, err)) {2999 ret = TRANSACTION_GENERIC_ERROR;3000 goto cleanup;3001 }30023003 /* Delete the reflogs of any references that were deleted: */3004 for_each_string_list_item(ref_to_delete, &refs_to_delete) {3005 strbuf_reset(&sb);3006 files_reflog_path(refs, &sb, ref_to_delete->string);3007 if (!unlink_or_warn(sb.buf))3008 try_remove_empty_parents(refs, ref_to_delete->string,3009 REMOVE_EMPTY_PARENTS_REFLOG);3010 }30113012 clear_loose_ref_cache(refs);30133014cleanup:3015 strbuf_release(&sb);3016 transaction->state = REF_TRANSACTION_CLOSED;30173018 for (i = 0; i < transaction->nr; i++) {3019 struct ref_update *update = transaction->updates[i];3020 struct ref_lock *lock = update->backend_data;30213022 if (lock)3023 unlock_ref(lock);30243025 if (update->flags & REF_DELETED_LOOSE) {3026 /*3027 * The loose reference was deleted. Delete any3028 * empty parent directories. (Note that this3029 * can only work because we have already3030 * removed the lockfile.)3031 */3032 try_remove_empty_parents(refs, update->refname,3033 REMOVE_EMPTY_PARENTS_REF);3034 }3035 }30363037 string_list_clear(&refs_to_delete, 0);3038 free(head_ref);3039 string_list_clear(&affected_refnames, 0);30403041 return ret;3042}30433044static int ref_present(const char *refname,3045 const struct object_id *oid, int flags, void *cb_data)3046{3047 struct string_list *affected_refnames = cb_data;30483049 return string_list_has_string(affected_refnames, refname);3050}30513052static int files_initial_transaction_commit(struct ref_store *ref_store,3053 struct ref_transaction *transaction,3054 struct strbuf *err)3055{3056 struct files_ref_store *refs =3057 files_downcast(ref_store, REF_STORE_WRITE,3058 "initial_ref_transaction_commit");3059 size_t i;3060 int ret = 0;3061 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;30623063 assert(err);30643065 if (transaction->state != REF_TRANSACTION_OPEN)3066 die("BUG: commit called for transaction that is not open");30673068 /* Fail if a refname appears more than once in the transaction: */3069 for (i = 0; i < transaction->nr; i++)3070 string_list_append(&affected_refnames,3071 transaction->updates[i]->refname);3072 string_list_sort(&affected_refnames);3073 if (ref_update_reject_duplicates(&affected_refnames, err)) {3074 ret = TRANSACTION_GENERIC_ERROR;3075 goto cleanup;3076 }30773078 /*3079 * It's really undefined to call this function in an active3080 * repository or when there are existing references: we are3081 * only locking and changing packed-refs, so (1) any3082 * simultaneous processes might try to change a reference at3083 * the same time we do, and (2) any existing loose versions of3084 * the references that we are setting would have precedence3085 * over our values. But some remote helpers create the remote3086 * "HEAD" and "master" branches before calling this function,3087 * so here we really only check that none of the references3088 * that we are creating already exists.3089 */3090 if (refs_for_each_rawref(&refs->base, ref_present,3091 &affected_refnames))3092 die("BUG: initial ref transaction called with existing refs");30933094 for (i = 0; i < transaction->nr; i++) {3095 struct ref_update *update = transaction->updates[i];30963097 if ((update->flags & REF_HAVE_OLD) &&3098 !is_null_oid(&update->old_oid))3099 die("BUG: initial ref transaction with old_sha1 set");3100 if (refs_verify_refname_available(&refs->base, update->refname,3101 &affected_refnames, NULL,3102 err)) {3103 ret = TRANSACTION_NAME_CONFLICT;3104 goto cleanup;3105 }3106 }31073108 if (lock_packed_refs(refs, 0)) {3109 strbuf_addf(err, "unable to lock packed-refs file: %s",3110 strerror(errno));3111 ret = TRANSACTION_GENERIC_ERROR;3112 goto cleanup;3113 }31143115 for (i = 0; i < transaction->nr; i++) {3116 struct ref_update *update = transaction->updates[i];31173118 if ((update->flags & REF_HAVE_NEW) &&3119 !is_null_oid(&update->new_oid))3120 add_packed_ref(refs, update->refname,3121 &update->new_oid);3122 }31233124 if (commit_packed_refs(refs)) {3125 strbuf_addf(err, "unable to commit packed-refs file: %s",3126 strerror(errno));3127 ret = TRANSACTION_GENERIC_ERROR;3128 goto cleanup;3129 }31303131cleanup:3132 transaction->state = REF_TRANSACTION_CLOSED;3133 string_list_clear(&affected_refnames, 0);3134 return ret;3135}31363137struct expire_reflog_cb {3138 unsigned int flags;3139 reflog_expiry_should_prune_fn *should_prune_fn;3140 void *policy_cb;3141 FILE *newlog;3142 struct object_id last_kept_oid;3143};31443145static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,3146 const char *email, timestamp_t timestamp, int tz,3147 const char *message, void *cb_data)3148{3149 struct expire_reflog_cb *cb = cb_data;3150 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;31513152 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3153 ooid = &cb->last_kept_oid;31543155 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,3156 message, policy_cb)) {3157 if (!cb->newlog)3158 printf("would prune %s", message);3159 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3160 printf("prune %s", message);3161 } else {3162 if (cb->newlog) {3163 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",3164 oid_to_hex(ooid), oid_to_hex(noid),3165 email, timestamp, tz, message);3166 oidcpy(&cb->last_kept_oid, noid);3167 }3168 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3169 printf("keep %s", message);3170 }3171 return 0;3172}31733174static int files_reflog_expire(struct ref_store *ref_store,3175 const char *refname, const unsigned char *sha1,3176 unsigned int flags,3177 reflog_expiry_prepare_fn prepare_fn,3178 reflog_expiry_should_prune_fn should_prune_fn,3179 reflog_expiry_cleanup_fn cleanup_fn,3180 void *policy_cb_data)3181{3182 struct files_ref_store *refs =3183 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");3184 static struct lock_file reflog_lock;3185 struct expire_reflog_cb cb;3186 struct ref_lock *lock;3187 struct strbuf log_file_sb = STRBUF_INIT;3188 char *log_file;3189 int status = 0;3190 int type;3191 struct strbuf err = STRBUF_INIT;3192 struct object_id oid;31933194 memset(&cb, 0, sizeof(cb));3195 cb.flags = flags;3196 cb.policy_cb = policy_cb_data;3197 cb.should_prune_fn = should_prune_fn;31983199 /*3200 * The reflog file is locked by holding the lock on the3201 * reference itself, plus we might need to update the3202 * reference if --updateref was specified:3203 */3204 lock = lock_ref_sha1_basic(refs, refname, sha1,3205 NULL, NULL, REF_NODEREF,3206 &type, &err);3207 if (!lock) {3208 error("cannot lock ref '%s': %s", refname, err.buf);3209 strbuf_release(&err);3210 return -1;3211 }3212 if (!refs_reflog_exists(ref_store, refname)) {3213 unlock_ref(lock);3214 return 0;3215 }32163217 files_reflog_path(refs, &log_file_sb, refname);3218 log_file = strbuf_detach(&log_file_sb, NULL);3219 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3220 /*3221 * Even though holding $GIT_DIR/logs/$reflog.lock has3222 * no locking implications, we use the lock_file3223 * machinery here anyway because it does a lot of the3224 * work we need, including cleaning up if the program3225 * exits unexpectedly.3226 */3227 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {3228 struct strbuf err = STRBUF_INIT;3229 unable_to_lock_message(log_file, errno, &err);3230 error("%s", err.buf);3231 strbuf_release(&err);3232 goto failure;3233 }3234 cb.newlog = fdopen_lock_file(&reflog_lock, "w");3235 if (!cb.newlog) {3236 error("cannot fdopen %s (%s)",3237 get_lock_file_path(&reflog_lock), strerror(errno));3238 goto failure;3239 }3240 }32413242 hashcpy(oid.hash, sha1);32433244 (*prepare_fn)(refname, &oid, cb.policy_cb);3245 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);3246 (*cleanup_fn)(cb.policy_cb);32473248 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3249 /*3250 * It doesn't make sense to adjust a reference pointed3251 * to by a symbolic ref based on expiring entries in3252 * the symbolic reference's reflog. Nor can we update3253 * a reference if there are no remaining reflog3254 * entries.3255 */3256 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3257 !(type & REF_ISSYMREF) &&3258 !is_null_oid(&cb.last_kept_oid);32593260 if (close_lock_file(&reflog_lock)) {3261 status |= error("couldn't write %s: %s", log_file,3262 strerror(errno));3263 } else if (update &&3264 (write_in_full(get_lock_file_fd(lock->lk),3265 oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||3266 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||3267 close_ref(lock) < 0)) {3268 status |= error("couldn't write %s",3269 get_lock_file_path(lock->lk));3270 rollback_lock_file(&reflog_lock);3271 } else if (commit_lock_file(&reflog_lock)) {3272 status |= error("unable to write reflog '%s' (%s)",3273 log_file, strerror(errno));3274 } else if (update && commit_ref(lock)) {3275 status |= error("couldn't set %s", lock->ref_name);3276 }3277 }3278 free(log_file);3279 unlock_ref(lock);3280 return status;32813282 failure:3283 rollback_lock_file(&reflog_lock);3284 free(log_file);3285 unlock_ref(lock);3286 return -1;3287}32883289static int files_init_db(struct ref_store *ref_store, struct strbuf *err)3290{3291 struct files_ref_store *refs =3292 files_downcast(ref_store, REF_STORE_WRITE, "init_db");3293 struct strbuf sb = STRBUF_INIT;32943295 /*3296 * Create .git/refs/{heads,tags}3297 */3298 files_ref_path(refs, &sb, "refs/heads");3299 safe_create_dir(sb.buf, 1);33003301 strbuf_reset(&sb);3302 files_ref_path(refs, &sb, "refs/tags");3303 safe_create_dir(sb.buf, 1);33043305 strbuf_release(&sb);3306 return 0;3307}33083309struct ref_storage_be refs_be_files = {3310 NULL,3311 "files",3312 files_ref_store_create,3313 files_init_db,3314 files_transaction_commit,3315 files_initial_transaction_commit,33163317 files_pack_refs,3318 files_peel_ref,3319 files_create_symref,3320 files_delete_refs,3321 files_rename_ref,33223323 files_ref_iterator_begin,3324 files_read_raw_ref,33253326 files_reflog_iterator_begin,3327 files_for_each_reflog_ent,3328 files_for_each_reflog_ent_reverse,3329 files_reflog_exists,3330 files_create_reflog,3331 files_delete_reflog,3332 files_reflog_expire3333};