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 * Lock used for the "packed-refs" file. Note that this (and 67 * thus the enclosing `files_ref_store`) must not be freed. 68 */ 69 struct lock_file packed_refs_lock; 70}; 71 72/* 73 * Increment the reference count of *packed_refs. 74 */ 75static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 76{ 77 packed_refs->referrers++; 78} 79 80/* 81 * Decrease the reference count of *packed_refs. If it goes to zero, 82 * free *packed_refs and return true; otherwise return false. 83 */ 84static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 85{ 86 if (!--packed_refs->referrers) { 87 free_ref_cache(packed_refs->cache); 88 stat_validity_clear(&packed_refs->validity); 89 free(packed_refs); 90 return 1; 91 } else { 92 return 0; 93 } 94} 95 96static void clear_packed_ref_cache(struct files_ref_store *refs) 97{ 98 if (refs->packed) { 99 struct packed_ref_cache *packed_refs = refs->packed; 100 101 if (is_lock_file_locked(&refs->packed_refs_lock)) 102 die("BUG: packed-ref cache cleared while locked"); 103 refs->packed = NULL; 104 release_packed_ref_cache(packed_refs); 105 } 106} 107 108static void clear_loose_ref_cache(struct files_ref_store *refs) 109{ 110 if (refs->loose) { 111 free_ref_cache(refs->loose); 112 refs->loose = NULL; 113 } 114} 115 116/* 117 * Create a new submodule ref cache and add it to the internal 118 * set of caches. 119 */ 120static struct ref_store *files_ref_store_create(const char *gitdir, 121 unsigned int flags) 122{ 123 struct files_ref_store *refs = xcalloc(1, sizeof(*refs)); 124 struct ref_store *ref_store = (struct ref_store *)refs; 125 struct strbuf sb = STRBUF_INIT; 126 127 base_ref_store_init(ref_store, &refs_be_files); 128 refs->store_flags = flags; 129 130 refs->gitdir = xstrdup(gitdir); 131 get_common_dir_noenv(&sb, gitdir); 132 refs->gitcommondir = strbuf_detach(&sb, NULL); 133 strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir); 134 refs->packed_refs_path = strbuf_detach(&sb, NULL); 135 136 return ref_store; 137} 138 139/* 140 * Die if refs is not the main ref store. caller is used in any 141 * necessary error messages. 142 */ 143static void files_assert_main_repository(struct files_ref_store *refs, 144 const char *caller) 145{ 146 if (refs->store_flags & REF_STORE_MAIN) 147 return; 148 149 die("BUG: operation %s only allowed for main ref store", caller); 150} 151 152/* 153 * Downcast ref_store to files_ref_store. Die if ref_store is not a 154 * files_ref_store. required_flags is compared with ref_store's 155 * store_flags to ensure the ref_store has all required capabilities. 156 * "caller" is used in any necessary error messages. 157 */ 158static struct files_ref_store *files_downcast(struct ref_store *ref_store, 159 unsigned int required_flags, 160 const char *caller) 161{ 162 struct files_ref_store *refs; 163 164 if (ref_store->be != &refs_be_files) 165 die("BUG: ref_store is type \"%s\" not \"files\" in %s", 166 ref_store->be->name, caller); 167 168 refs = (struct files_ref_store *)ref_store; 169 170 if ((refs->store_flags & required_flags) != required_flags) 171 die("BUG: operation %s requires abilities 0x%x, but only have 0x%x", 172 caller, required_flags, refs->store_flags); 173 174 return refs; 175} 176 177/* The length of a peeled reference line in packed-refs, including EOL: */ 178#define PEELED_LINE_LENGTH 42 179 180/* 181 * The packed-refs header line that we write out. Perhaps other 182 * traits will be added later. The trailing space is required. 183 */ 184static const char PACKED_REFS_HEADER[] = 185 "# pack-refs with: peeled fully-peeled \n"; 186 187/* 188 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 189 * Return a pointer to the refname within the line (null-terminated), 190 * or NULL if there was a problem. 191 */ 192static const char *parse_ref_line(struct strbuf *line, struct object_id *oid) 193{ 194 const char *ref; 195 196 if (parse_oid_hex(line->buf, oid, &ref) < 0) 197 return NULL; 198 if (!isspace(*ref++)) 199 return NULL; 200 201 if (isspace(*ref)) 202 return NULL; 203 204 if (line->buf[line->len - 1] != '\n') 205 return NULL; 206 line->buf[--line->len] = 0; 207 208 return ref; 209} 210 211/* 212 * Read f, which is a packed-refs file, into dir. 213 * 214 * A comment line of the form "# pack-refs with: " may contain zero or 215 * more traits. We interpret the traits as follows: 216 * 217 * No traits: 218 * 219 * Probably no references are peeled. But if the file contains a 220 * peeled value for a reference, we will use it. 221 * 222 * peeled: 223 * 224 * References under "refs/tags/", if they *can* be peeled, *are* 225 * peeled in this file. References outside of "refs/tags/" are 226 * probably not peeled even if they could have been, but if we find 227 * a peeled value for such a reference we will use it. 228 * 229 * fully-peeled: 230 * 231 * All references in the file that can be peeled are peeled. 232 * Inversely (and this is more important), any references in the 233 * file for which no peeled value is recorded is not peelable. This 234 * trait should typically be written alongside "peeled" for 235 * compatibility with older clients, but we do not require it 236 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 237 */ 238static void read_packed_refs(FILE *f, struct ref_dir *dir) 239{ 240 struct ref_entry *last = NULL; 241 struct strbuf line = STRBUF_INIT; 242 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 243 244 while (strbuf_getwholeline(&line, f, '\n') != EOF) { 245 struct object_id oid; 246 const char *refname; 247 const char *traits; 248 249 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { 250 if (strstr(traits, " fully-peeled ")) 251 peeled = PEELED_FULLY; 252 else if (strstr(traits, " peeled ")) 253 peeled = PEELED_TAGS; 254 /* perhaps other traits later as well */ 255 continue; 256 } 257 258 refname = parse_ref_line(&line, &oid); 259 if (refname) { 260 int flag = REF_ISPACKED; 261 262 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { 263 if (!refname_is_safe(refname)) 264 die("packed refname is dangerous: %s", refname); 265 oidclr(&oid); 266 flag |= REF_BAD_NAME | REF_ISBROKEN; 267 } 268 last = create_ref_entry(refname, &oid, flag, 0); 269 if (peeled == PEELED_FULLY || 270 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) 271 last->flag |= REF_KNOWS_PEELED; 272 add_ref_entry(dir, last); 273 continue; 274 } 275 if (last && 276 line.buf[0] == '^' && 277 line.len == PEELED_LINE_LENGTH && 278 line.buf[PEELED_LINE_LENGTH - 1] == '\n' && 279 !get_oid_hex(line.buf + 1, &oid)) { 280 oidcpy(&last->u.value.peeled, &oid); 281 /* 282 * Regardless of what the file header said, 283 * we definitely know the value of *this* 284 * reference: 285 */ 286 last->flag |= REF_KNOWS_PEELED; 287 } 288 } 289 290 strbuf_release(&line); 291} 292 293static const char *files_packed_refs_path(struct files_ref_store *refs) 294{ 295 return refs->packed_refs_path; 296} 297 298static void files_reflog_path(struct files_ref_store *refs, 299 struct strbuf *sb, 300 const char *refname) 301{ 302 if (!refname) { 303 /* 304 * FIXME: of course this is wrong in multi worktree 305 * setting. To be fixed real soon. 306 */ 307 strbuf_addf(sb, "%s/logs", refs->gitcommondir); 308 return; 309 } 310 311 switch (ref_type(refname)) { 312 case REF_TYPE_PER_WORKTREE: 313 case REF_TYPE_PSEUDOREF: 314 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname); 315 break; 316 case REF_TYPE_NORMAL: 317 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname); 318 break; 319 default: 320 die("BUG: unknown ref type %d of ref %s", 321 ref_type(refname), refname); 322 } 323} 324 325static void files_ref_path(struct files_ref_store *refs, 326 struct strbuf *sb, 327 const char *refname) 328{ 329 switch (ref_type(refname)) { 330 case REF_TYPE_PER_WORKTREE: 331 case REF_TYPE_PSEUDOREF: 332 strbuf_addf(sb, "%s/%s", refs->gitdir, refname); 333 break; 334 case REF_TYPE_NORMAL: 335 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname); 336 break; 337 default: 338 die("BUG: unknown ref type %d of ref %s", 339 ref_type(refname), refname); 340 } 341} 342 343/* 344 * Get the packed_ref_cache for the specified files_ref_store, 345 * creating it if necessary. 346 */ 347static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs) 348{ 349 const char *packed_refs_file = files_packed_refs_path(refs); 350 351 if (refs->packed && 352 !stat_validity_check(&refs->packed->validity, packed_refs_file)) 353 clear_packed_ref_cache(refs); 354 355 if (!refs->packed) { 356 FILE *f; 357 358 refs->packed = xcalloc(1, sizeof(*refs->packed)); 359 acquire_packed_ref_cache(refs->packed); 360 refs->packed->cache = create_ref_cache(&refs->base, NULL); 361 refs->packed->cache->root->flag &= ~REF_INCOMPLETE; 362 f = fopen(packed_refs_file, "r"); 363 if (f) { 364 stat_validity_update(&refs->packed->validity, fileno(f)); 365 read_packed_refs(f, get_ref_dir(refs->packed->cache->root)); 366 fclose(f); 367 } 368 } 369 return refs->packed; 370} 371 372static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) 373{ 374 return get_ref_dir(packed_ref_cache->cache->root); 375} 376 377static struct ref_dir *get_packed_refs(struct files_ref_store *refs) 378{ 379 return get_packed_ref_dir(get_packed_ref_cache(refs)); 380} 381 382/* 383 * Add a reference to the in-memory packed reference cache. This may 384 * only be called while the packed-refs file is locked (see 385 * lock_packed_refs()). To actually write the packed-refs file, call 386 * commit_packed_refs(). 387 */ 388static void add_packed_ref(struct files_ref_store *refs, 389 const char *refname, const struct object_id *oid) 390{ 391 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs); 392 393 if (!is_lock_file_locked(&refs->packed_refs_lock)) 394 die("BUG: packed refs not locked"); 395 add_ref_entry(get_packed_ref_dir(packed_ref_cache), 396 create_ref_entry(refname, oid, REF_ISPACKED, 1)); 397} 398 399/* 400 * Read the loose references from the namespace dirname into dir 401 * (without recursing). dirname must end with '/'. dir must be the 402 * directory entry corresponding to dirname. 403 */ 404static void loose_fill_ref_dir(struct ref_store *ref_store, 405 struct ref_dir *dir, const char *dirname) 406{ 407 struct files_ref_store *refs = 408 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir"); 409 DIR *d; 410 struct dirent *de; 411 int dirnamelen = strlen(dirname); 412 struct strbuf refname; 413 struct strbuf path = STRBUF_INIT; 414 size_t path_baselen; 415 416 files_ref_path(refs, &path, dirname); 417 path_baselen = path.len; 418 419 d = opendir(path.buf); 420 if (!d) { 421 strbuf_release(&path); 422 return; 423 } 424 425 strbuf_init(&refname, dirnamelen + 257); 426 strbuf_add(&refname, dirname, dirnamelen); 427 428 while ((de = readdir(d)) != NULL) { 429 struct object_id oid; 430 struct stat st; 431 int flag; 432 433 if (de->d_name[0] == '.') 434 continue; 435 if (ends_with(de->d_name, ".lock")) 436 continue; 437 strbuf_addstr(&refname, de->d_name); 438 strbuf_addstr(&path, de->d_name); 439 if (stat(path.buf, &st) < 0) { 440 ; /* silently ignore */ 441 } else if (S_ISDIR(st.st_mode)) { 442 strbuf_addch(&refname, '/'); 443 add_entry_to_dir(dir, 444 create_dir_entry(dir->cache, refname.buf, 445 refname.len, 1)); 446 } else { 447 if (!refs_resolve_ref_unsafe(&refs->base, 448 refname.buf, 449 RESOLVE_REF_READING, 450 oid.hash, &flag)) { 451 oidclr(&oid); 452 flag |= REF_ISBROKEN; 453 } else if (is_null_oid(&oid)) { 454 /* 455 * It is so astronomically unlikely 456 * that NULL_SHA1 is the SHA-1 of an 457 * actual object that we consider its 458 * appearance in a loose reference 459 * file to be repo corruption 460 * (probably due to a software bug). 461 */ 462 flag |= REF_ISBROKEN; 463 } 464 465 if (check_refname_format(refname.buf, 466 REFNAME_ALLOW_ONELEVEL)) { 467 if (!refname_is_safe(refname.buf)) 468 die("loose refname is dangerous: %s", refname.buf); 469 oidclr(&oid); 470 flag |= REF_BAD_NAME | REF_ISBROKEN; 471 } 472 add_entry_to_dir(dir, 473 create_ref_entry(refname.buf, &oid, flag, 0)); 474 } 475 strbuf_setlen(&refname, dirnamelen); 476 strbuf_setlen(&path, path_baselen); 477 } 478 strbuf_release(&refname); 479 strbuf_release(&path); 480 closedir(d); 481 482 /* 483 * Manually add refs/bisect, which, being per-worktree, might 484 * not appear in the directory listing for refs/ in the main 485 * repo. 486 */ 487 if (!strcmp(dirname, "refs/")) { 488 int pos = search_ref_dir(dir, "refs/bisect/", 12); 489 490 if (pos < 0) { 491 struct ref_entry *child_entry = create_dir_entry( 492 dir->cache, "refs/bisect/", 12, 1); 493 add_entry_to_dir(dir, child_entry); 494 } 495 } 496} 497 498static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) 499{ 500 if (!refs->loose) { 501 /* 502 * Mark the top-level directory complete because we 503 * are about to read the only subdirectory that can 504 * hold references: 505 */ 506 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir); 507 508 /* We're going to fill the top level ourselves: */ 509 refs->loose->root->flag &= ~REF_INCOMPLETE; 510 511 /* 512 * Add an incomplete entry for "refs/" (to be filled 513 * lazily): 514 */ 515 add_entry_to_dir(get_ref_dir(refs->loose->root), 516 create_dir_entry(refs->loose, "refs/", 5, 1)); 517 } 518 return refs->loose; 519} 520 521/* 522 * Return the ref_entry for the given refname from the packed 523 * references. If it does not exist, return NULL. 524 */ 525static struct ref_entry *get_packed_ref(struct files_ref_store *refs, 526 const char *refname) 527{ 528 return find_ref_entry(get_packed_refs(refs), refname); 529} 530 531/* 532 * A loose ref file doesn't exist; check for a packed ref. 533 */ 534static int resolve_packed_ref(struct files_ref_store *refs, 535 const char *refname, 536 unsigned char *sha1, unsigned int *flags) 537{ 538 struct ref_entry *entry; 539 540 /* 541 * The loose reference file does not exist; check for a packed 542 * reference. 543 */ 544 entry = get_packed_ref(refs, refname); 545 if (entry) { 546 hashcpy(sha1, entry->u.value.oid.hash); 547 *flags |= REF_ISPACKED; 548 return 0; 549 } 550 /* refname is not a packed reference. */ 551 return -1; 552} 553 554static int files_read_raw_ref(struct ref_store *ref_store, 555 const char *refname, unsigned char *sha1, 556 struct strbuf *referent, unsigned int *type) 557{ 558 struct files_ref_store *refs = 559 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); 560 struct strbuf sb_contents = STRBUF_INIT; 561 struct strbuf sb_path = STRBUF_INIT; 562 const char *path; 563 const char *buf; 564 struct stat st; 565 int fd; 566 int ret = -1; 567 int save_errno; 568 int remaining_retries = 3; 569 570 *type = 0; 571 strbuf_reset(&sb_path); 572 573 files_ref_path(refs, &sb_path, refname); 574 575 path = sb_path.buf; 576 577stat_ref: 578 /* 579 * We might have to loop back here to avoid a race 580 * condition: first we lstat() the file, then we try 581 * to read it as a link or as a file. But if somebody 582 * changes the type of the file (file <-> directory 583 * <-> symlink) between the lstat() and reading, then 584 * we don't want to report that as an error but rather 585 * try again starting with the lstat(). 586 * 587 * We'll keep a count of the retries, though, just to avoid 588 * any confusing situation sending us into an infinite loop. 589 */ 590 591 if (remaining_retries-- <= 0) 592 goto out; 593 594 if (lstat(path, &st) < 0) { 595 if (errno != ENOENT) 596 goto out; 597 if (resolve_packed_ref(refs, refname, sha1, type)) { 598 errno = ENOENT; 599 goto out; 600 } 601 ret = 0; 602 goto out; 603 } 604 605 /* Follow "normalized" - ie "refs/.." symlinks by hand */ 606 if (S_ISLNK(st.st_mode)) { 607 strbuf_reset(&sb_contents); 608 if (strbuf_readlink(&sb_contents, path, 0) < 0) { 609 if (errno == ENOENT || errno == EINVAL) 610 /* inconsistent with lstat; retry */ 611 goto stat_ref; 612 else 613 goto out; 614 } 615 if (starts_with(sb_contents.buf, "refs/") && 616 !check_refname_format(sb_contents.buf, 0)) { 617 strbuf_swap(&sb_contents, referent); 618 *type |= REF_ISSYMREF; 619 ret = 0; 620 goto out; 621 } 622 /* 623 * It doesn't look like a refname; fall through to just 624 * treating it like a non-symlink, and reading whatever it 625 * points to. 626 */ 627 } 628 629 /* Is it a directory? */ 630 if (S_ISDIR(st.st_mode)) { 631 /* 632 * Even though there is a directory where the loose 633 * ref is supposed to be, there could still be a 634 * packed ref: 635 */ 636 if (resolve_packed_ref(refs, refname, sha1, type)) { 637 errno = EISDIR; 638 goto out; 639 } 640 ret = 0; 641 goto out; 642 } 643 644 /* 645 * Anything else, just open it and try to use it as 646 * a ref 647 */ 648 fd = open(path, O_RDONLY); 649 if (fd < 0) { 650 if (errno == ENOENT && !S_ISLNK(st.st_mode)) 651 /* inconsistent with lstat; retry */ 652 goto stat_ref; 653 else 654 goto out; 655 } 656 strbuf_reset(&sb_contents); 657 if (strbuf_read(&sb_contents, fd, 256) < 0) { 658 int save_errno = errno; 659 close(fd); 660 errno = save_errno; 661 goto out; 662 } 663 close(fd); 664 strbuf_rtrim(&sb_contents); 665 buf = sb_contents.buf; 666 if (starts_with(buf, "ref:")) { 667 buf += 4; 668 while (isspace(*buf)) 669 buf++; 670 671 strbuf_reset(referent); 672 strbuf_addstr(referent, buf); 673 *type |= REF_ISSYMREF; 674 ret = 0; 675 goto out; 676 } 677 678 /* 679 * Please note that FETCH_HEAD has additional 680 * data after the sha. 681 */ 682 if (get_sha1_hex(buf, sha1) || 683 (buf[40] != '\0' && !isspace(buf[40]))) { 684 *type |= REF_ISBROKEN; 685 errno = EINVAL; 686 goto out; 687 } 688 689 ret = 0; 690 691out: 692 save_errno = errno; 693 strbuf_release(&sb_path); 694 strbuf_release(&sb_contents); 695 errno = save_errno; 696 return ret; 697} 698 699static void unlock_ref(struct ref_lock *lock) 700{ 701 /* Do not free lock->lk -- atexit() still looks at them */ 702 if (lock->lk) 703 rollback_lock_file(lock->lk); 704 free(lock->ref_name); 705 free(lock); 706} 707 708/* 709 * Lock refname, without following symrefs, and set *lock_p to point 710 * at a newly-allocated lock object. Fill in lock->old_oid, referent, 711 * and type similarly to read_raw_ref(). 712 * 713 * The caller must verify that refname is a "safe" reference name (in 714 * the sense of refname_is_safe()) before calling this function. 715 * 716 * If the reference doesn't already exist, verify that refname doesn't 717 * have a D/F conflict with any existing references. extras and skip 718 * are passed to refs_verify_refname_available() for this check. 719 * 720 * If mustexist is not set and the reference is not found or is 721 * broken, lock the reference anyway but clear sha1. 722 * 723 * Return 0 on success. On failure, write an error message to err and 724 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR. 725 * 726 * Implementation note: This function is basically 727 * 728 * lock reference 729 * read_raw_ref() 730 * 731 * but it includes a lot more code to 732 * - Deal with possible races with other processes 733 * - Avoid calling refs_verify_refname_available() when it can be 734 * avoided, namely if we were successfully able to read the ref 735 * - Generate informative error messages in the case of failure 736 */ 737static int lock_raw_ref(struct files_ref_store *refs, 738 const char *refname, int mustexist, 739 const struct string_list *extras, 740 const struct string_list *skip, 741 struct ref_lock **lock_p, 742 struct strbuf *referent, 743 unsigned int *type, 744 struct strbuf *err) 745{ 746 struct ref_lock *lock; 747 struct strbuf ref_file = STRBUF_INIT; 748 int attempts_remaining = 3; 749 int ret = TRANSACTION_GENERIC_ERROR; 750 751 assert(err); 752 files_assert_main_repository(refs, "lock_raw_ref"); 753 754 *type = 0; 755 756 /* First lock the file so it can't change out from under us. */ 757 758 *lock_p = lock = xcalloc(1, sizeof(*lock)); 759 760 lock->ref_name = xstrdup(refname); 761 files_ref_path(refs, &ref_file, refname); 762 763retry: 764 switch (safe_create_leading_directories(ref_file.buf)) { 765 case SCLD_OK: 766 break; /* success */ 767 case SCLD_EXISTS: 768 /* 769 * Suppose refname is "refs/foo/bar". We just failed 770 * to create the containing directory, "refs/foo", 771 * because there was a non-directory in the way. This 772 * indicates a D/F conflict, probably because of 773 * another reference such as "refs/foo". There is no 774 * reason to expect this error to be transitory. 775 */ 776 if (refs_verify_refname_available(&refs->base, refname, 777 extras, skip, err)) { 778 if (mustexist) { 779 /* 780 * To the user the relevant error is 781 * that the "mustexist" reference is 782 * missing: 783 */ 784 strbuf_reset(err); 785 strbuf_addf(err, "unable to resolve reference '%s'", 786 refname); 787 } else { 788 /* 789 * The error message set by 790 * refs_verify_refname_available() is 791 * OK. 792 */ 793 ret = TRANSACTION_NAME_CONFLICT; 794 } 795 } else { 796 /* 797 * The file that is in the way isn't a loose 798 * reference. Report it as a low-level 799 * failure. 800 */ 801 strbuf_addf(err, "unable to create lock file %s.lock; " 802 "non-directory in the way", 803 ref_file.buf); 804 } 805 goto error_return; 806 case SCLD_VANISHED: 807 /* Maybe another process was tidying up. Try again. */ 808 if (--attempts_remaining > 0) 809 goto retry; 810 /* fall through */ 811 default: 812 strbuf_addf(err, "unable to create directory for %s", 813 ref_file.buf); 814 goto error_return; 815 } 816 817 if (!lock->lk) 818 lock->lk = xcalloc(1, sizeof(struct lock_file)); 819 820 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) { 821 if (errno == ENOENT && --attempts_remaining > 0) { 822 /* 823 * Maybe somebody just deleted one of the 824 * directories leading to ref_file. Try 825 * again: 826 */ 827 goto retry; 828 } else { 829 unable_to_lock_message(ref_file.buf, errno, err); 830 goto error_return; 831 } 832 } 833 834 /* 835 * Now we hold the lock and can read the reference without 836 * fear that its value will change. 837 */ 838 839 if (files_read_raw_ref(&refs->base, refname, 840 lock->old_oid.hash, referent, type)) { 841 if (errno == ENOENT) { 842 if (mustexist) { 843 /* Garden variety missing reference. */ 844 strbuf_addf(err, "unable to resolve reference '%s'", 845 refname); 846 goto error_return; 847 } else { 848 /* 849 * Reference is missing, but that's OK. We 850 * know that there is not a conflict with 851 * another loose reference because 852 * (supposing that we are trying to lock 853 * reference "refs/foo/bar"): 854 * 855 * - We were successfully able to create 856 * the lockfile refs/foo/bar.lock, so we 857 * know there cannot be a loose reference 858 * named "refs/foo". 859 * 860 * - We got ENOENT and not EISDIR, so we 861 * know that there cannot be a loose 862 * reference named "refs/foo/bar/baz". 863 */ 864 } 865 } else if (errno == EISDIR) { 866 /* 867 * There is a directory in the way. It might have 868 * contained references that have been deleted. If 869 * we don't require that the reference already 870 * exists, try to remove the directory so that it 871 * doesn't cause trouble when we want to rename the 872 * lockfile into place later. 873 */ 874 if (mustexist) { 875 /* Garden variety missing reference. */ 876 strbuf_addf(err, "unable to resolve reference '%s'", 877 refname); 878 goto error_return; 879 } else if (remove_dir_recursively(&ref_file, 880 REMOVE_DIR_EMPTY_ONLY)) { 881 if (refs_verify_refname_available( 882 &refs->base, refname, 883 extras, skip, err)) { 884 /* 885 * The error message set by 886 * verify_refname_available() is OK. 887 */ 888 ret = TRANSACTION_NAME_CONFLICT; 889 goto error_return; 890 } else { 891 /* 892 * We can't delete the directory, 893 * but we also don't know of any 894 * references that it should 895 * contain. 896 */ 897 strbuf_addf(err, "there is a non-empty directory '%s' " 898 "blocking reference '%s'", 899 ref_file.buf, refname); 900 goto error_return; 901 } 902 } 903 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) { 904 strbuf_addf(err, "unable to resolve reference '%s': " 905 "reference broken", refname); 906 goto error_return; 907 } else { 908 strbuf_addf(err, "unable to resolve reference '%s': %s", 909 refname, strerror(errno)); 910 goto error_return; 911 } 912 913 /* 914 * If the ref did not exist and we are creating it, 915 * make sure there is no existing ref that conflicts 916 * with refname: 917 */ 918 if (refs_verify_refname_available( 919 &refs->base, refname, 920 extras, skip, err)) 921 goto error_return; 922 } 923 924 ret = 0; 925 goto out; 926 927error_return: 928 unlock_ref(lock); 929 *lock_p = NULL; 930 931out: 932 strbuf_release(&ref_file); 933 return ret; 934} 935 936static int files_peel_ref(struct ref_store *ref_store, 937 const char *refname, unsigned char *sha1) 938{ 939 struct files_ref_store *refs = 940 files_downcast(ref_store, REF_STORE_READ | REF_STORE_ODB, 941 "peel_ref"); 942 int flag; 943 unsigned char base[20]; 944 945 if (current_ref_iter && current_ref_iter->refname == refname) { 946 struct object_id peeled; 947 948 if (ref_iterator_peel(current_ref_iter, &peeled)) 949 return -1; 950 hashcpy(sha1, peeled.hash); 951 return 0; 952 } 953 954 if (refs_read_ref_full(ref_store, refname, 955 RESOLVE_REF_READING, base, &flag)) 956 return -1; 957 958 /* 959 * If the reference is packed, read its ref_entry from the 960 * cache in the hope that we already know its peeled value. 961 * We only try this optimization on packed references because 962 * (a) forcing the filling of the loose reference cache could 963 * be expensive and (b) loose references anyway usually do not 964 * have REF_KNOWS_PEELED. 965 */ 966 if (flag & REF_ISPACKED) { 967 struct ref_entry *r = get_packed_ref(refs, refname); 968 if (r) { 969 if (peel_entry(r, 0)) 970 return -1; 971 hashcpy(sha1, r->u.value.peeled.hash); 972 return 0; 973 } 974 } 975 976 return peel_object(base, sha1); 977} 978 979struct files_ref_iterator { 980 struct ref_iterator base; 981 982 struct packed_ref_cache *packed_ref_cache; 983 struct ref_iterator *iter0; 984 unsigned int flags; 985}; 986 987static int files_ref_iterator_advance(struct ref_iterator *ref_iterator) 988{ 989 struct files_ref_iterator *iter = 990 (struct files_ref_iterator *)ref_iterator; 991 int ok; 992 993 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) { 994 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && 995 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE) 996 continue; 997 998 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 999 !ref_resolves_to_object(iter->iter0->refname,1000 iter->iter0->oid,1001 iter->iter0->flags))1002 continue;10031004 iter->base.refname = iter->iter0->refname;1005 iter->base.oid = iter->iter0->oid;1006 iter->base.flags = iter->iter0->flags;1007 return ITER_OK;1008 }10091010 iter->iter0 = NULL;1011 if (ref_iterator_abort(ref_iterator) != ITER_DONE)1012 ok = ITER_ERROR;10131014 return ok;1015}10161017static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,1018 struct object_id *peeled)1019{1020 struct files_ref_iterator *iter =1021 (struct files_ref_iterator *)ref_iterator;10221023 return ref_iterator_peel(iter->iter0, peeled);1024}10251026static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)1027{1028 struct files_ref_iterator *iter =1029 (struct files_ref_iterator *)ref_iterator;1030 int ok = ITER_DONE;10311032 if (iter->iter0)1033 ok = ref_iterator_abort(iter->iter0);10341035 release_packed_ref_cache(iter->packed_ref_cache);1036 base_ref_iterator_free(ref_iterator);1037 return ok;1038}10391040static struct ref_iterator_vtable files_ref_iterator_vtable = {1041 files_ref_iterator_advance,1042 files_ref_iterator_peel,1043 files_ref_iterator_abort1044};10451046static struct ref_iterator *files_ref_iterator_begin(1047 struct ref_store *ref_store,1048 const char *prefix, unsigned int flags)1049{1050 struct files_ref_store *refs;1051 struct ref_iterator *loose_iter, *packed_iter;1052 struct files_ref_iterator *iter;1053 struct ref_iterator *ref_iterator;10541055 if (ref_paranoia < 0)1056 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1057 if (ref_paranoia)1058 flags |= DO_FOR_EACH_INCLUDE_BROKEN;10591060 refs = files_downcast(ref_store,1061 REF_STORE_READ | (ref_paranoia ? 0 : REF_STORE_ODB),1062 "ref_iterator_begin");10631064 iter = xcalloc(1, sizeof(*iter));1065 ref_iterator = &iter->base;1066 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);10671068 /*1069 * We must make sure that all loose refs are read before1070 * accessing the packed-refs file; this avoids a race1071 * condition if loose refs are migrated to the packed-refs1072 * file by a simultaneous process, but our in-memory view is1073 * from before the migration. We ensure this as follows:1074 * First, we call start the loose refs iteration with its1075 * `prime_ref` argument set to true. This causes the loose1076 * references in the subtree to be pre-read into the cache.1077 * (If they've already been read, that's OK; we only need to1078 * guarantee that they're read before the packed refs, not1079 * *how much* before.) After that, we call1080 * get_packed_ref_cache(), which internally checks whether the1081 * packed-ref cache is up to date with what is on disk, and1082 * re-reads it if not.1083 */10841085 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),1086 prefix, 1);10871088 iter->packed_ref_cache = get_packed_ref_cache(refs);1089 acquire_packed_ref_cache(iter->packed_ref_cache);1090 packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache,1091 prefix, 0);10921093 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);1094 iter->flags = flags;10951096 return ref_iterator;1097}10981099/*1100 * Verify that the reference locked by lock has the value old_sha1.1101 * Fail if the reference doesn't exist and mustexist is set. Return 01102 * on success. On error, write an error message to err, set errno, and1103 * return a negative value.1104 */1105static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,1106 const unsigned char *old_sha1, int mustexist,1107 struct strbuf *err)1108{1109 assert(err);11101111 if (refs_read_ref_full(ref_store, lock->ref_name,1112 mustexist ? RESOLVE_REF_READING : 0,1113 lock->old_oid.hash, NULL)) {1114 if (old_sha1) {1115 int save_errno = errno;1116 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);1117 errno = save_errno;1118 return -1;1119 } else {1120 oidclr(&lock->old_oid);1121 return 0;1122 }1123 }1124 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1125 strbuf_addf(err, "ref '%s' is at %s but expected %s",1126 lock->ref_name,1127 oid_to_hex(&lock->old_oid),1128 sha1_to_hex(old_sha1));1129 errno = EBUSY;1130 return -1;1131 }1132 return 0;1133}11341135static int remove_empty_directories(struct strbuf *path)1136{1137 /*1138 * we want to create a file but there is a directory there;1139 * if that is an empty directory (or a directory that contains1140 * only empty directories), remove them.1141 */1142 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1143}11441145static int create_reflock(const char *path, void *cb)1146{1147 struct lock_file *lk = cb;11481149 return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;1150}11511152/*1153 * Locks a ref returning the lock on success and NULL on failure.1154 * On failure errno is set to something meaningful.1155 */1156static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,1157 const char *refname,1158 const unsigned char *old_sha1,1159 const struct string_list *extras,1160 const struct string_list *skip,1161 unsigned int flags, int *type,1162 struct strbuf *err)1163{1164 struct strbuf ref_file = STRBUF_INIT;1165 struct ref_lock *lock;1166 int last_errno = 0;1167 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1168 int resolve_flags = RESOLVE_REF_NO_RECURSE;1169 int resolved;11701171 files_assert_main_repository(refs, "lock_ref_sha1_basic");1172 assert(err);11731174 lock = xcalloc(1, sizeof(struct ref_lock));11751176 if (mustexist)1177 resolve_flags |= RESOLVE_REF_READING;1178 if (flags & REF_DELETING)1179 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;11801181 files_ref_path(refs, &ref_file, refname);1182 resolved = !!refs_resolve_ref_unsafe(&refs->base,1183 refname, resolve_flags,1184 lock->old_oid.hash, type);1185 if (!resolved && errno == EISDIR) {1186 /*1187 * we are trying to lock foo but we used to1188 * have foo/bar which now does not exist;1189 * it is normal for the empty directory 'foo'1190 * to remain.1191 */1192 if (remove_empty_directories(&ref_file)) {1193 last_errno = errno;1194 if (!refs_verify_refname_available(1195 &refs->base,1196 refname, extras, skip, err))1197 strbuf_addf(err, "there are still refs under '%s'",1198 refname);1199 goto error_return;1200 }1201 resolved = !!refs_resolve_ref_unsafe(&refs->base,1202 refname, resolve_flags,1203 lock->old_oid.hash, type);1204 }1205 if (!resolved) {1206 last_errno = errno;1207 if (last_errno != ENOTDIR ||1208 !refs_verify_refname_available(&refs->base, refname,1209 extras, skip, err))1210 strbuf_addf(err, "unable to resolve reference '%s': %s",1211 refname, strerror(last_errno));12121213 goto error_return;1214 }12151216 /*1217 * If the ref did not exist and we are creating it, make sure1218 * there is no existing packed ref whose name begins with our1219 * refname, nor a packed ref whose name is a proper prefix of1220 * our refname.1221 */1222 if (is_null_oid(&lock->old_oid) &&1223 refs_verify_refname_available(&refs->base, refname,1224 extras, skip, err)) {1225 last_errno = ENOTDIR;1226 goto error_return;1227 }12281229 lock->lk = xcalloc(1, sizeof(struct lock_file));12301231 lock->ref_name = xstrdup(refname);12321233 if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {1234 last_errno = errno;1235 unable_to_lock_message(ref_file.buf, errno, err);1236 goto error_return;1237 }12381239 if (verify_lock(&refs->base, lock, old_sha1, mustexist, err)) {1240 last_errno = errno;1241 goto error_return;1242 }1243 goto out;12441245 error_return:1246 unlock_ref(lock);1247 lock = NULL;12481249 out:1250 strbuf_release(&ref_file);1251 errno = last_errno;1252 return lock;1253}12541255/*1256 * Write an entry to the packed-refs file for the specified refname.1257 * If peeled is non-NULL, write it as the entry's peeled value.1258 */1259static void write_packed_entry(FILE *fh, const char *refname,1260 const unsigned char *sha1,1261 const unsigned char *peeled)1262{1263 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);1264 if (peeled)1265 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));1266}12671268/*1269 * Lock the packed-refs file for writing. Flags is passed to1270 * hold_lock_file_for_update(). Return 0 on success. On errors, set1271 * errno appropriately and return a nonzero value.1272 */1273static int lock_packed_refs(struct files_ref_store *refs, int flags)1274{1275 static int timeout_configured = 0;1276 static int timeout_value = 1000;1277 struct packed_ref_cache *packed_ref_cache;12781279 files_assert_main_repository(refs, "lock_packed_refs");12801281 if (!timeout_configured) {1282 git_config_get_int("core.packedrefstimeout", &timeout_value);1283 timeout_configured = 1;1284 }12851286 if (hold_lock_file_for_update_timeout(1287 &refs->packed_refs_lock, files_packed_refs_path(refs),1288 flags, timeout_value) < 0)1289 return -1;1290 /*1291 * Get the current packed-refs while holding the lock. If the1292 * packed-refs file has been modified since we last read it,1293 * this will automatically invalidate the cache and re-read1294 * the packed-refs file.1295 */1296 packed_ref_cache = get_packed_ref_cache(refs);1297 /* Increment the reference count to prevent it from being freed: */1298 acquire_packed_ref_cache(packed_ref_cache);1299 return 0;1300}13011302/*1303 * Write the current version of the packed refs cache from memory to1304 * disk. The packed-refs file must already be locked for writing (see1305 * lock_packed_refs()). Return zero on success. On errors, set errno1306 * and return a nonzero value1307 */1308static int commit_packed_refs(struct files_ref_store *refs)1309{1310 struct packed_ref_cache *packed_ref_cache =1311 get_packed_ref_cache(refs);1312 int ok, error = 0;1313 int save_errno = 0;1314 FILE *out;1315 struct ref_iterator *iter;13161317 files_assert_main_repository(refs, "commit_packed_refs");13181319 if (!is_lock_file_locked(&refs->packed_refs_lock))1320 die("BUG: packed-refs not locked");13211322 out = fdopen_lock_file(&refs->packed_refs_lock, "w");1323 if (!out)1324 die_errno("unable to fdopen packed-refs descriptor");13251326 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);13271328 iter = cache_ref_iterator_begin(packed_ref_cache->cache, NULL, 0);1329 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {1330 struct object_id peeled;1331 int peel_error = ref_iterator_peel(iter, &peeled);13321333 write_packed_entry(out, iter->refname, iter->oid->hash,1334 peel_error ? NULL : peeled.hash);1335 }13361337 if (ok != ITER_DONE)1338 die("error while iterating over references");13391340 if (commit_lock_file(&refs->packed_refs_lock)) {1341 save_errno = errno;1342 error = -1;1343 }1344 release_packed_ref_cache(packed_ref_cache);1345 errno = save_errno;1346 return error;1347}13481349/*1350 * Rollback the lockfile for the packed-refs file, and discard the1351 * in-memory packed reference cache. (The packed-refs file will be1352 * read anew if it is needed again after this function is called.)1353 */1354static void rollback_packed_refs(struct files_ref_store *refs)1355{1356 struct packed_ref_cache *packed_ref_cache =1357 get_packed_ref_cache(refs);13581359 files_assert_main_repository(refs, "rollback_packed_refs");13601361 if (!is_lock_file_locked(&refs->packed_refs_lock))1362 die("BUG: packed-refs not locked");1363 rollback_lock_file(&refs->packed_refs_lock);1364 release_packed_ref_cache(packed_ref_cache);1365 clear_packed_ref_cache(refs);1366}13671368struct ref_to_prune {1369 struct ref_to_prune *next;1370 unsigned char sha1[20];1371 char name[FLEX_ARRAY];1372};13731374enum {1375 REMOVE_EMPTY_PARENTS_REF = 0x01,1376 REMOVE_EMPTY_PARENTS_REFLOG = 0x021377};13781379/*1380 * Remove empty parent directories associated with the specified1381 * reference and/or its reflog, but spare [logs/]refs/ and immediate1382 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or1383 * REMOVE_EMPTY_PARENTS_REFLOG.1384 */1385static void try_remove_empty_parents(struct files_ref_store *refs,1386 const char *refname,1387 unsigned int flags)1388{1389 struct strbuf buf = STRBUF_INIT;1390 struct strbuf sb = STRBUF_INIT;1391 char *p, *q;1392 int i;13931394 strbuf_addstr(&buf, refname);1395 p = buf.buf;1396 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */1397 while (*p && *p != '/')1398 p++;1399 /* tolerate duplicate slashes; see check_refname_format() */1400 while (*p == '/')1401 p++;1402 }1403 q = buf.buf + buf.len;1404 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {1405 while (q > p && *q != '/')1406 q--;1407 while (q > p && *(q-1) == '/')1408 q--;1409 if (q == p)1410 break;1411 strbuf_setlen(&buf, q - buf.buf);14121413 strbuf_reset(&sb);1414 files_ref_path(refs, &sb, buf.buf);1415 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))1416 flags &= ~REMOVE_EMPTY_PARENTS_REF;14171418 strbuf_reset(&sb);1419 files_reflog_path(refs, &sb, buf.buf);1420 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))1421 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;1422 }1423 strbuf_release(&buf);1424 strbuf_release(&sb);1425}14261427/* make sure nobody touched the ref, and unlink */1428static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)1429{1430 struct ref_transaction *transaction;1431 struct strbuf err = STRBUF_INIT;14321433 if (check_refname_format(r->name, 0))1434 return;14351436 transaction = ref_store_transaction_begin(&refs->base, &err);1437 if (!transaction ||1438 ref_transaction_delete(transaction, r->name, r->sha1,1439 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||1440 ref_transaction_commit(transaction, &err)) {1441 ref_transaction_free(transaction);1442 error("%s", err.buf);1443 strbuf_release(&err);1444 return;1445 }1446 ref_transaction_free(transaction);1447 strbuf_release(&err);1448}14491450static void prune_refs(struct files_ref_store *refs, struct ref_to_prune *r)1451{1452 while (r) {1453 prune_ref(refs, r);1454 r = r->next;1455 }1456}14571458/*1459 * Return true if the specified reference should be packed.1460 */1461static int should_pack_ref(const char *refname,1462 const struct object_id *oid, unsigned int ref_flags,1463 unsigned int pack_flags)1464{1465 /* Do not pack per-worktree refs: */1466 if (ref_type(refname) != REF_TYPE_NORMAL)1467 return 0;14681469 /* Do not pack non-tags unless PACK_REFS_ALL is set: */1470 if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/"))1471 return 0;14721473 /* Do not pack symbolic refs: */1474 if (ref_flags & REF_ISSYMREF)1475 return 0;14761477 /* Do not pack broken refs: */1478 if (!ref_resolves_to_object(refname, oid, ref_flags))1479 return 0;14801481 return 1;1482}14831484static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)1485{1486 struct files_ref_store *refs =1487 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,1488 "pack_refs");1489 struct ref_iterator *iter;1490 struct ref_dir *packed_refs;1491 int ok;1492 struct ref_to_prune *refs_to_prune = NULL;14931494 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);1495 packed_refs = get_packed_refs(refs);14961497 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);1498 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {1499 /*1500 * If the loose reference can be packed, add an entry1501 * in the packed ref cache. If the reference should be1502 * pruned, also add it to refs_to_prune.1503 */1504 struct ref_entry *packed_entry;15051506 if (!should_pack_ref(iter->refname, iter->oid, iter->flags,1507 flags))1508 continue;15091510 /*1511 * Create an entry in the packed-refs cache equivalent1512 * to the one from the loose ref cache, except that1513 * we don't copy the peeled status, because we want it1514 * to be re-peeled.1515 */1516 packed_entry = find_ref_entry(packed_refs, iter->refname);1517 if (packed_entry) {1518 /* Overwrite existing packed entry with info from loose entry */1519 packed_entry->flag = REF_ISPACKED;1520 oidcpy(&packed_entry->u.value.oid, iter->oid);1521 } else {1522 packed_entry = create_ref_entry(iter->refname, iter->oid,1523 REF_ISPACKED, 0);1524 add_ref_entry(packed_refs, packed_entry);1525 }1526 oidclr(&packed_entry->u.value.peeled);15271528 /* Schedule the loose reference for pruning if requested. */1529 if ((flags & PACK_REFS_PRUNE)) {1530 struct ref_to_prune *n;1531 FLEX_ALLOC_STR(n, name, iter->refname);1532 hashcpy(n->sha1, iter->oid->hash);1533 n->next = refs_to_prune;1534 refs_to_prune = n;1535 }1536 }1537 if (ok != ITER_DONE)1538 die("error while iterating over references");15391540 if (commit_packed_refs(refs))1541 die_errno("unable to overwrite old ref-pack file");15421543 prune_refs(refs, refs_to_prune);1544 return 0;1545}15461547/*1548 * Rewrite the packed-refs file, omitting any refs listed in1549 * 'refnames'. On error, leave packed-refs unchanged, write an error1550 * message to 'err', and return a nonzero value.1551 *1552 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.1553 */1554static int repack_without_refs(struct files_ref_store *refs,1555 struct string_list *refnames, struct strbuf *err)1556{1557 struct ref_dir *packed;1558 struct string_list_item *refname;1559 int ret, needs_repacking = 0, removed = 0;15601561 files_assert_main_repository(refs, "repack_without_refs");1562 assert(err);15631564 /* Look for a packed ref */1565 for_each_string_list_item(refname, refnames) {1566 if (get_packed_ref(refs, refname->string)) {1567 needs_repacking = 1;1568 break;1569 }1570 }15711572 /* Avoid locking if we have nothing to do */1573 if (!needs_repacking)1574 return 0; /* no refname exists in packed refs */15751576 if (lock_packed_refs(refs, 0)) {1577 unable_to_lock_message(files_packed_refs_path(refs), errno, err);1578 return -1;1579 }1580 packed = get_packed_refs(refs);15811582 /* Remove refnames from the cache */1583 for_each_string_list_item(refname, refnames)1584 if (remove_entry_from_dir(packed, refname->string) != -1)1585 removed = 1;1586 if (!removed) {1587 /*1588 * All packed entries disappeared while we were1589 * acquiring the lock.1590 */1591 rollback_packed_refs(refs);1592 return 0;1593 }15941595 /* Write what remains */1596 ret = commit_packed_refs(refs);1597 if (ret)1598 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",1599 strerror(errno));1600 return ret;1601}16021603static int files_delete_refs(struct ref_store *ref_store, const char *msg,1604 struct string_list *refnames, unsigned int flags)1605{1606 struct files_ref_store *refs =1607 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");1608 struct strbuf err = STRBUF_INIT;1609 int i, result = 0;16101611 if (!refnames->nr)1612 return 0;16131614 result = repack_without_refs(refs, refnames, &err);1615 if (result) {1616 /*1617 * If we failed to rewrite the packed-refs file, then1618 * it is unsafe to try to remove loose refs, because1619 * doing so might expose an obsolete packed value for1620 * a reference that might even point at an object that1621 * has been garbage collected.1622 */1623 if (refnames->nr == 1)1624 error(_("could not delete reference %s: %s"),1625 refnames->items[0].string, err.buf);1626 else1627 error(_("could not delete references: %s"), err.buf);16281629 goto out;1630 }16311632 for (i = 0; i < refnames->nr; i++) {1633 const char *refname = refnames->items[i].string;16341635 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))1636 result |= error(_("could not remove reference %s"), refname);1637 }16381639out:1640 strbuf_release(&err);1641 return result;1642}16431644/*1645 * People using contrib's git-new-workdir have .git/logs/refs ->1646 * /some/other/path/.git/logs/refs, and that may live on another device.1647 *1648 * IOW, to avoid cross device rename errors, the temporary renamed log must1649 * live into logs/refs.1650 */1651#define TMP_RENAMED_LOG "refs/.tmp-renamed-log"16521653struct rename_cb {1654 const char *tmp_renamed_log;1655 int true_errno;1656};16571658static int rename_tmp_log_callback(const char *path, void *cb_data)1659{1660 struct rename_cb *cb = cb_data;16611662 if (rename(cb->tmp_renamed_log, path)) {1663 /*1664 * rename(a, b) when b is an existing directory ought1665 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.1666 * Sheesh. Record the true errno for error reporting,1667 * but report EISDIR to raceproof_create_file() so1668 * that it knows to retry.1669 */1670 cb->true_errno = errno;1671 if (errno == ENOTDIR)1672 errno = EISDIR;1673 return -1;1674 } else {1675 return 0;1676 }1677}16781679static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)1680{1681 struct strbuf path = STRBUF_INIT;1682 struct strbuf tmp = STRBUF_INIT;1683 struct rename_cb cb;1684 int ret;16851686 files_reflog_path(refs, &path, newrefname);1687 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);1688 cb.tmp_renamed_log = tmp.buf;1689 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);1690 if (ret) {1691 if (errno == EISDIR)1692 error("directory not empty: %s", path.buf);1693 else1694 error("unable to move logfile %s to %s: %s",1695 tmp.buf, path.buf,1696 strerror(cb.true_errno));1697 }16981699 strbuf_release(&path);1700 strbuf_release(&tmp);1701 return ret;1702}17031704static int write_ref_to_lockfile(struct ref_lock *lock,1705 const struct object_id *oid, struct strbuf *err);1706static int commit_ref_update(struct files_ref_store *refs,1707 struct ref_lock *lock,1708 const struct object_id *oid, const char *logmsg,1709 struct strbuf *err);17101711static int files_rename_ref(struct ref_store *ref_store,1712 const char *oldrefname, const char *newrefname,1713 const char *logmsg)1714{1715 struct files_ref_store *refs =1716 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");1717 struct object_id oid, orig_oid;1718 int flag = 0, logmoved = 0;1719 struct ref_lock *lock;1720 struct stat loginfo;1721 struct strbuf sb_oldref = STRBUF_INIT;1722 struct strbuf sb_newref = STRBUF_INIT;1723 struct strbuf tmp_renamed_log = STRBUF_INIT;1724 int log, ret;1725 struct strbuf err = STRBUF_INIT;17261727 files_reflog_path(refs, &sb_oldref, oldrefname);1728 files_reflog_path(refs, &sb_newref, newrefname);1729 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);17301731 log = !lstat(sb_oldref.buf, &loginfo);1732 if (log && S_ISLNK(loginfo.st_mode)) {1733 ret = error("reflog for %s is a symlink", oldrefname);1734 goto out;1735 }17361737 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,1738 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,1739 orig_oid.hash, &flag)) {1740 ret = error("refname %s not found", oldrefname);1741 goto out;1742 }17431744 if (flag & REF_ISSYMREF) {1745 ret = error("refname %s is a symbolic ref, renaming it is not supported",1746 oldrefname);1747 goto out;1748 }1749 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {1750 ret = 1;1751 goto out;1752 }17531754 if (log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {1755 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",1756 oldrefname, strerror(errno));1757 goto out;1758 }17591760 if (refs_delete_ref(&refs->base, logmsg, oldrefname,1761 orig_oid.hash, REF_NODEREF)) {1762 error("unable to delete old %s", oldrefname);1763 goto rollback;1764 }17651766 /*1767 * Since we are doing a shallow lookup, oid is not the1768 * correct value to pass to delete_ref as old_oid. But that1769 * doesn't matter, because an old_oid check wouldn't add to1770 * the safety anyway; we want to delete the reference whatever1771 * its current value.1772 */1773 if (!refs_read_ref_full(&refs->base, newrefname,1774 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,1775 oid.hash, NULL) &&1776 refs_delete_ref(&refs->base, NULL, newrefname,1777 NULL, REF_NODEREF)) {1778 if (errno == EISDIR) {1779 struct strbuf path = STRBUF_INIT;1780 int result;17811782 files_ref_path(refs, &path, newrefname);1783 result = remove_empty_directories(&path);1784 strbuf_release(&path);17851786 if (result) {1787 error("Directory not empty: %s", newrefname);1788 goto rollback;1789 }1790 } else {1791 error("unable to delete existing %s", newrefname);1792 goto rollback;1793 }1794 }17951796 if (log && rename_tmp_log(refs, newrefname))1797 goto rollback;17981799 logmoved = log;18001801 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,1802 REF_NODEREF, NULL, &err);1803 if (!lock) {1804 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);1805 strbuf_release(&err);1806 goto rollback;1807 }1808 oidcpy(&lock->old_oid, &orig_oid);18091810 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||1811 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {1812 error("unable to write current sha1 into %s: %s", newrefname, err.buf);1813 strbuf_release(&err);1814 goto rollback;1815 }18161817 ret = 0;1818 goto out;18191820 rollback:1821 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,1822 REF_NODEREF, NULL, &err);1823 if (!lock) {1824 error("unable to lock %s for rollback: %s", oldrefname, err.buf);1825 strbuf_release(&err);1826 goto rollbacklog;1827 }18281829 flag = log_all_ref_updates;1830 log_all_ref_updates = LOG_REFS_NONE;1831 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||1832 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {1833 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);1834 strbuf_release(&err);1835 }1836 log_all_ref_updates = flag;18371838 rollbacklog:1839 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))1840 error("unable to restore logfile %s from %s: %s",1841 oldrefname, newrefname, strerror(errno));1842 if (!logmoved && log &&1843 rename(tmp_renamed_log.buf, sb_oldref.buf))1844 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",1845 oldrefname, strerror(errno));1846 ret = 1;1847 out:1848 strbuf_release(&sb_newref);1849 strbuf_release(&sb_oldref);1850 strbuf_release(&tmp_renamed_log);18511852 return ret;1853}18541855static int close_ref(struct ref_lock *lock)1856{1857 if (close_lock_file(lock->lk))1858 return -1;1859 return 0;1860}18611862static int commit_ref(struct ref_lock *lock)1863{1864 char *path = get_locked_file_path(lock->lk);1865 struct stat st;18661867 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {1868 /*1869 * There is a directory at the path we want to rename1870 * the lockfile to. Hopefully it is empty; try to1871 * delete it.1872 */1873 size_t len = strlen(path);1874 struct strbuf sb_path = STRBUF_INIT;18751876 strbuf_attach(&sb_path, path, len, len);18771878 /*1879 * If this fails, commit_lock_file() will also fail1880 * and will report the problem.1881 */1882 remove_empty_directories(&sb_path);1883 strbuf_release(&sb_path);1884 } else {1885 free(path);1886 }18871888 if (commit_lock_file(lock->lk))1889 return -1;1890 return 0;1891}18921893static int open_or_create_logfile(const char *path, void *cb)1894{1895 int *fd = cb;18961897 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);1898 return (*fd < 0) ? -1 : 0;1899}19001901/*1902 * Create a reflog for a ref. If force_create = 0, only create the1903 * reflog for certain refs (those for which should_autocreate_reflog1904 * returns non-zero). Otherwise, create it regardless of the reference1905 * name. If the logfile already existed or was created, return 0 and1906 * set *logfd to the file descriptor opened for appending to the file.1907 * If no logfile exists and we decided not to create one, return 0 and1908 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and1909 * return -1.1910 */1911static int log_ref_setup(struct files_ref_store *refs,1912 const char *refname, int force_create,1913 int *logfd, struct strbuf *err)1914{1915 struct strbuf logfile_sb = STRBUF_INIT;1916 char *logfile;19171918 files_reflog_path(refs, &logfile_sb, refname);1919 logfile = strbuf_detach(&logfile_sb, NULL);19201921 if (force_create || should_autocreate_reflog(refname)) {1922 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {1923 if (errno == ENOENT)1924 strbuf_addf(err, "unable to create directory for '%s': "1925 "%s", logfile, strerror(errno));1926 else if (errno == EISDIR)1927 strbuf_addf(err, "there are still logs under '%s'",1928 logfile);1929 else1930 strbuf_addf(err, "unable to append to '%s': %s",1931 logfile, strerror(errno));19321933 goto error;1934 }1935 } else {1936 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);1937 if (*logfd < 0) {1938 if (errno == ENOENT || errno == EISDIR) {1939 /*1940 * The logfile doesn't already exist,1941 * but that is not an error; it only1942 * means that we won't write log1943 * entries to it.1944 */1945 ;1946 } else {1947 strbuf_addf(err, "unable to append to '%s': %s",1948 logfile, strerror(errno));1949 goto error;1950 }1951 }1952 }19531954 if (*logfd >= 0)1955 adjust_shared_perm(logfile);19561957 free(logfile);1958 return 0;19591960error:1961 free(logfile);1962 return -1;1963}19641965static int files_create_reflog(struct ref_store *ref_store,1966 const char *refname, int force_create,1967 struct strbuf *err)1968{1969 struct files_ref_store *refs =1970 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");1971 int fd;19721973 if (log_ref_setup(refs, refname, force_create, &fd, err))1974 return -1;19751976 if (fd >= 0)1977 close(fd);19781979 return 0;1980}19811982static int log_ref_write_fd(int fd, const struct object_id *old_oid,1983 const struct object_id *new_oid,1984 const char *committer, const char *msg)1985{1986 int msglen, written;1987 unsigned maxlen, len;1988 char *logrec;19891990 msglen = msg ? strlen(msg) : 0;1991 maxlen = strlen(committer) + msglen + 100;1992 logrec = xmalloc(maxlen);1993 len = xsnprintf(logrec, maxlen, "%s %s %s\n",1994 oid_to_hex(old_oid),1995 oid_to_hex(new_oid),1996 committer);1997 if (msglen)1998 len += copy_reflog_msg(logrec + len - 1, msg) - 1;19992000 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2001 free(logrec);2002 if (written != len)2003 return -1;20042005 return 0;2006}20072008static int files_log_ref_write(struct files_ref_store *refs,2009 const char *refname, const struct object_id *old_oid,2010 const struct object_id *new_oid, const char *msg,2011 int flags, struct strbuf *err)2012{2013 int logfd, result;20142015 if (log_all_ref_updates == LOG_REFS_UNSET)2016 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;20172018 result = log_ref_setup(refs, refname,2019 flags & REF_FORCE_CREATE_REFLOG,2020 &logfd, err);20212022 if (result)2023 return result;20242025 if (logfd < 0)2026 return 0;2027 result = log_ref_write_fd(logfd, old_oid, new_oid,2028 git_committer_info(0), msg);2029 if (result) {2030 struct strbuf sb = STRBUF_INIT;2031 int save_errno = errno;20322033 files_reflog_path(refs, &sb, refname);2034 strbuf_addf(err, "unable to append to '%s': %s",2035 sb.buf, strerror(save_errno));2036 strbuf_release(&sb);2037 close(logfd);2038 return -1;2039 }2040 if (close(logfd)) {2041 struct strbuf sb = STRBUF_INIT;2042 int save_errno = errno;20432044 files_reflog_path(refs, &sb, refname);2045 strbuf_addf(err, "unable to append to '%s': %s",2046 sb.buf, strerror(save_errno));2047 strbuf_release(&sb);2048 return -1;2049 }2050 return 0;2051}20522053/*2054 * Write sha1 into the open lockfile, then close the lockfile. On2055 * errors, rollback the lockfile, fill in *err and2056 * return -1.2057 */2058static int write_ref_to_lockfile(struct ref_lock *lock,2059 const struct object_id *oid, struct strbuf *err)2060{2061 static char term = '\n';2062 struct object *o;2063 int fd;20642065 o = parse_object(oid);2066 if (!o) {2067 strbuf_addf(err,2068 "trying to write ref '%s' with nonexistent object %s",2069 lock->ref_name, oid_to_hex(oid));2070 unlock_ref(lock);2071 return -1;2072 }2073 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2074 strbuf_addf(err,2075 "trying to write non-commit object %s to branch '%s'",2076 oid_to_hex(oid), lock->ref_name);2077 unlock_ref(lock);2078 return -1;2079 }2080 fd = get_lock_file_fd(lock->lk);2081 if (write_in_full(fd, oid_to_hex(oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||2082 write_in_full(fd, &term, 1) != 1 ||2083 close_ref(lock) < 0) {2084 strbuf_addf(err,2085 "couldn't write '%s'", get_lock_file_path(lock->lk));2086 unlock_ref(lock);2087 return -1;2088 }2089 return 0;2090}20912092/*2093 * Commit a change to a loose reference that has already been written2094 * to the loose reference lockfile. Also update the reflogs if2095 * necessary, using the specified lockmsg (which can be NULL).2096 */2097static int commit_ref_update(struct files_ref_store *refs,2098 struct ref_lock *lock,2099 const struct object_id *oid, const char *logmsg,2100 struct strbuf *err)2101{2102 files_assert_main_repository(refs, "commit_ref_update");21032104 clear_loose_ref_cache(refs);2105 if (files_log_ref_write(refs, lock->ref_name,2106 &lock->old_oid, oid,2107 logmsg, 0, err)) {2108 char *old_msg = strbuf_detach(err, NULL);2109 strbuf_addf(err, "cannot update the ref '%s': %s",2110 lock->ref_name, old_msg);2111 free(old_msg);2112 unlock_ref(lock);2113 return -1;2114 }21152116 if (strcmp(lock->ref_name, "HEAD") != 0) {2117 /*2118 * Special hack: If a branch is updated directly and HEAD2119 * points to it (may happen on the remote side of a push2120 * for example) then logically the HEAD reflog should be2121 * updated too.2122 * A generic solution implies reverse symref information,2123 * but finding all symrefs pointing to the given branch2124 * would be rather costly for this rare event (the direct2125 * update of a branch) to be worth it. So let's cheat and2126 * check with HEAD only which should cover 99% of all usage2127 * scenarios (even 100% of the default ones).2128 */2129 struct object_id head_oid;2130 int head_flag;2131 const char *head_ref;21322133 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",2134 RESOLVE_REF_READING,2135 head_oid.hash, &head_flag);2136 if (head_ref && (head_flag & REF_ISSYMREF) &&2137 !strcmp(head_ref, lock->ref_name)) {2138 struct strbuf log_err = STRBUF_INIT;2139 if (files_log_ref_write(refs, "HEAD",2140 &lock->old_oid, oid,2141 logmsg, 0, &log_err)) {2142 error("%s", log_err.buf);2143 strbuf_release(&log_err);2144 }2145 }2146 }21472148 if (commit_ref(lock)) {2149 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2150 unlock_ref(lock);2151 return -1;2152 }21532154 unlock_ref(lock);2155 return 0;2156}21572158static int create_ref_symlink(struct ref_lock *lock, const char *target)2159{2160 int ret = -1;2161#ifndef NO_SYMLINK_HEAD2162 char *ref_path = get_locked_file_path(lock->lk);2163 unlink(ref_path);2164 ret = symlink(target, ref_path);2165 free(ref_path);21662167 if (ret)2168 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2169#endif2170 return ret;2171}21722173static void update_symref_reflog(struct files_ref_store *refs,2174 struct ref_lock *lock, const char *refname,2175 const char *target, const char *logmsg)2176{2177 struct strbuf err = STRBUF_INIT;2178 struct object_id new_oid;2179 if (logmsg &&2180 !refs_read_ref_full(&refs->base, target,2181 RESOLVE_REF_READING, new_oid.hash, NULL) &&2182 files_log_ref_write(refs, refname, &lock->old_oid,2183 &new_oid, logmsg, 0, &err)) {2184 error("%s", err.buf);2185 strbuf_release(&err);2186 }2187}21882189static int create_symref_locked(struct files_ref_store *refs,2190 struct ref_lock *lock, const char *refname,2191 const char *target, const char *logmsg)2192{2193 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {2194 update_symref_reflog(refs, lock, refname, target, logmsg);2195 return 0;2196 }21972198 if (!fdopen_lock_file(lock->lk, "w"))2199 return error("unable to fdopen %s: %s",2200 lock->lk->tempfile.filename.buf, strerror(errno));22012202 update_symref_reflog(refs, lock, refname, target, logmsg);22032204 /* no error check; commit_ref will check ferror */2205 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);2206 if (commit_ref(lock) < 0)2207 return error("unable to write symref for %s: %s", refname,2208 strerror(errno));2209 return 0;2210}22112212static int files_create_symref(struct ref_store *ref_store,2213 const char *refname, const char *target,2214 const char *logmsg)2215{2216 struct files_ref_store *refs =2217 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");2218 struct strbuf err = STRBUF_INIT;2219 struct ref_lock *lock;2220 int ret;22212222 lock = lock_ref_sha1_basic(refs, refname, NULL,2223 NULL, NULL, REF_NODEREF, NULL,2224 &err);2225 if (!lock) {2226 error("%s", err.buf);2227 strbuf_release(&err);2228 return -1;2229 }22302231 ret = create_symref_locked(refs, lock, refname, target, logmsg);2232 unlock_ref(lock);2233 return ret;2234}22352236static int files_reflog_exists(struct ref_store *ref_store,2237 const char *refname)2238{2239 struct files_ref_store *refs =2240 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");2241 struct strbuf sb = STRBUF_INIT;2242 struct stat st;2243 int ret;22442245 files_reflog_path(refs, &sb, refname);2246 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);2247 strbuf_release(&sb);2248 return ret;2249}22502251static int files_delete_reflog(struct ref_store *ref_store,2252 const char *refname)2253{2254 struct files_ref_store *refs =2255 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");2256 struct strbuf sb = STRBUF_INIT;2257 int ret;22582259 files_reflog_path(refs, &sb, refname);2260 ret = remove_path(sb.buf);2261 strbuf_release(&sb);2262 return ret;2263}22642265static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)2266{2267 struct object_id ooid, noid;2268 char *email_end, *message;2269 timestamp_t timestamp;2270 int tz;2271 const char *p = sb->buf;22722273 /* old SP new SP name <email> SP time TAB msg LF */2274 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||2275 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||2276 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||2277 !(email_end = strchr(p, '>')) ||2278 email_end[1] != ' ' ||2279 !(timestamp = parse_timestamp(email_end + 2, &message, 10)) ||2280 !message || message[0] != ' ' ||2281 (message[1] != '+' && message[1] != '-') ||2282 !isdigit(message[2]) || !isdigit(message[3]) ||2283 !isdigit(message[4]) || !isdigit(message[5]))2284 return 0; /* corrupt? */2285 email_end[1] = '\0';2286 tz = strtol(message + 1, NULL, 10);2287 if (message[6] != '\t')2288 message += 6;2289 else2290 message += 7;2291 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);2292}22932294static char *find_beginning_of_line(char *bob, char *scan)2295{2296 while (bob < scan && *(--scan) != '\n')2297 ; /* keep scanning backwards */2298 /*2299 * Return either beginning of the buffer, or LF at the end of2300 * the previous line.2301 */2302 return scan;2303}23042305static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,2306 const char *refname,2307 each_reflog_ent_fn fn,2308 void *cb_data)2309{2310 struct files_ref_store *refs =2311 files_downcast(ref_store, REF_STORE_READ,2312 "for_each_reflog_ent_reverse");2313 struct strbuf sb = STRBUF_INIT;2314 FILE *logfp;2315 long pos;2316 int ret = 0, at_tail = 1;23172318 files_reflog_path(refs, &sb, refname);2319 logfp = fopen(sb.buf, "r");2320 strbuf_release(&sb);2321 if (!logfp)2322 return -1;23232324 /* Jump to the end */2325 if (fseek(logfp, 0, SEEK_END) < 0)2326 ret = error("cannot seek back reflog for %s: %s",2327 refname, strerror(errno));2328 pos = ftell(logfp);2329 while (!ret && 0 < pos) {2330 int cnt;2331 size_t nread;2332 char buf[BUFSIZ];2333 char *endp, *scanp;23342335 /* Fill next block from the end */2336 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;2337 if (fseek(logfp, pos - cnt, SEEK_SET)) {2338 ret = error("cannot seek back reflog for %s: %s",2339 refname, strerror(errno));2340 break;2341 }2342 nread = fread(buf, cnt, 1, logfp);2343 if (nread != 1) {2344 ret = error("cannot read %d bytes from reflog for %s: %s",2345 cnt, refname, strerror(errno));2346 break;2347 }2348 pos -= cnt;23492350 scanp = endp = buf + cnt;2351 if (at_tail && scanp[-1] == '\n')2352 /* Looking at the final LF at the end of the file */2353 scanp--;2354 at_tail = 0;23552356 while (buf < scanp) {2357 /*2358 * terminating LF of the previous line, or the beginning2359 * of the buffer.2360 */2361 char *bp;23622363 bp = find_beginning_of_line(buf, scanp);23642365 if (*bp == '\n') {2366 /*2367 * The newline is the end of the previous line,2368 * so we know we have complete line starting2369 * at (bp + 1). Prefix it onto any prior data2370 * we collected for the line and process it.2371 */2372 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));2373 scanp = bp;2374 endp = bp + 1;2375 ret = show_one_reflog_ent(&sb, fn, cb_data);2376 strbuf_reset(&sb);2377 if (ret)2378 break;2379 } else if (!pos) {2380 /*2381 * We are at the start of the buffer, and the2382 * start of the file; there is no previous2383 * line, and we have everything for this one.2384 * Process it, and we can end the loop.2385 */2386 strbuf_splice(&sb, 0, 0, buf, endp - buf);2387 ret = show_one_reflog_ent(&sb, fn, cb_data);2388 strbuf_reset(&sb);2389 break;2390 }23912392 if (bp == buf) {2393 /*2394 * We are at the start of the buffer, and there2395 * is more file to read backwards. Which means2396 * we are in the middle of a line. Note that we2397 * may get here even if *bp was a newline; that2398 * just means we are at the exact end of the2399 * previous line, rather than some spot in the2400 * middle.2401 *2402 * Save away what we have to be combined with2403 * the data from the next read.2404 */2405 strbuf_splice(&sb, 0, 0, buf, endp - buf);2406 break;2407 }2408 }24092410 }2411 if (!ret && sb.len)2412 die("BUG: reverse reflog parser had leftover data");24132414 fclose(logfp);2415 strbuf_release(&sb);2416 return ret;2417}24182419static int files_for_each_reflog_ent(struct ref_store *ref_store,2420 const char *refname,2421 each_reflog_ent_fn fn, void *cb_data)2422{2423 struct files_ref_store *refs =2424 files_downcast(ref_store, REF_STORE_READ,2425 "for_each_reflog_ent");2426 FILE *logfp;2427 struct strbuf sb = STRBUF_INIT;2428 int ret = 0;24292430 files_reflog_path(refs, &sb, refname);2431 logfp = fopen(sb.buf, "r");2432 strbuf_release(&sb);2433 if (!logfp)2434 return -1;24352436 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))2437 ret = show_one_reflog_ent(&sb, fn, cb_data);2438 fclose(logfp);2439 strbuf_release(&sb);2440 return ret;2441}24422443struct files_reflog_iterator {2444 struct ref_iterator base;24452446 struct ref_store *ref_store;2447 struct dir_iterator *dir_iterator;2448 struct object_id oid;2449};24502451static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)2452{2453 struct files_reflog_iterator *iter =2454 (struct files_reflog_iterator *)ref_iterator;2455 struct dir_iterator *diter = iter->dir_iterator;2456 int ok;24572458 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {2459 int flags;24602461 if (!S_ISREG(diter->st.st_mode))2462 continue;2463 if (diter->basename[0] == '.')2464 continue;2465 if (ends_with(diter->basename, ".lock"))2466 continue;24672468 if (refs_read_ref_full(iter->ref_store,2469 diter->relative_path, 0,2470 iter->oid.hash, &flags)) {2471 error("bad ref for %s", diter->path.buf);2472 continue;2473 }24742475 iter->base.refname = diter->relative_path;2476 iter->base.oid = &iter->oid;2477 iter->base.flags = flags;2478 return ITER_OK;2479 }24802481 iter->dir_iterator = NULL;2482 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)2483 ok = ITER_ERROR;2484 return ok;2485}24862487static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,2488 struct object_id *peeled)2489{2490 die("BUG: ref_iterator_peel() called for reflog_iterator");2491}24922493static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)2494{2495 struct files_reflog_iterator *iter =2496 (struct files_reflog_iterator *)ref_iterator;2497 int ok = ITER_DONE;24982499 if (iter->dir_iterator)2500 ok = dir_iterator_abort(iter->dir_iterator);25012502 base_ref_iterator_free(ref_iterator);2503 return ok;2504}25052506static struct ref_iterator_vtable files_reflog_iterator_vtable = {2507 files_reflog_iterator_advance,2508 files_reflog_iterator_peel,2509 files_reflog_iterator_abort2510};25112512static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)2513{2514 struct files_ref_store *refs =2515 files_downcast(ref_store, REF_STORE_READ,2516 "reflog_iterator_begin");2517 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));2518 struct ref_iterator *ref_iterator = &iter->base;2519 struct strbuf sb = STRBUF_INIT;25202521 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);2522 files_reflog_path(refs, &sb, NULL);2523 iter->dir_iterator = dir_iterator_begin(sb.buf);2524 iter->ref_store = ref_store;2525 strbuf_release(&sb);2526 return ref_iterator;2527}25282529/*2530 * If update is a direct update of head_ref (the reference pointed to2531 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.2532 */2533static int split_head_update(struct ref_update *update,2534 struct ref_transaction *transaction,2535 const char *head_ref,2536 struct string_list *affected_refnames,2537 struct strbuf *err)2538{2539 struct string_list_item *item;2540 struct ref_update *new_update;25412542 if ((update->flags & REF_LOG_ONLY) ||2543 (update->flags & REF_ISPRUNING) ||2544 (update->flags & REF_UPDATE_VIA_HEAD))2545 return 0;25462547 if (strcmp(update->refname, head_ref))2548 return 0;25492550 /*2551 * First make sure that HEAD is not already in the2552 * transaction. This insertion is O(N) in the transaction2553 * size, but it happens at most once per transaction.2554 */2555 item = string_list_insert(affected_refnames, "HEAD");2556 if (item->util) {2557 /* An entry already existed */2558 strbuf_addf(err,2559 "multiple updates for 'HEAD' (including one "2560 "via its referent '%s') are not allowed",2561 update->refname);2562 return TRANSACTION_NAME_CONFLICT;2563 }25642565 new_update = ref_transaction_add_update(2566 transaction, "HEAD",2567 update->flags | REF_LOG_ONLY | REF_NODEREF,2568 update->new_oid.hash, update->old_oid.hash,2569 update->msg);25702571 item->util = new_update;25722573 return 0;2574}25752576/*2577 * update is for a symref that points at referent and doesn't have2578 * REF_NODEREF set. Split it into two updates:2579 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set2580 * - A new, separate update for the referent reference2581 * Note that the new update will itself be subject to splitting when2582 * the iteration gets to it.2583 */2584static int split_symref_update(struct files_ref_store *refs,2585 struct ref_update *update,2586 const char *referent,2587 struct ref_transaction *transaction,2588 struct string_list *affected_refnames,2589 struct strbuf *err)2590{2591 struct string_list_item *item;2592 struct ref_update *new_update;2593 unsigned int new_flags;25942595 /*2596 * First make sure that referent is not already in the2597 * transaction. This insertion is O(N) in the transaction2598 * size, but it happens at most once per symref in a2599 * transaction.2600 */2601 item = string_list_insert(affected_refnames, referent);2602 if (item->util) {2603 /* An entry already existed */2604 strbuf_addf(err,2605 "multiple updates for '%s' (including one "2606 "via symref '%s') are not allowed",2607 referent, update->refname);2608 return TRANSACTION_NAME_CONFLICT;2609 }26102611 new_flags = update->flags;2612 if (!strcmp(update->refname, "HEAD")) {2613 /*2614 * Record that the new update came via HEAD, so that2615 * when we process it, split_head_update() doesn't try2616 * to add another reflog update for HEAD. Note that2617 * this bit will be propagated if the new_update2618 * itself needs to be split.2619 */2620 new_flags |= REF_UPDATE_VIA_HEAD;2621 }26222623 new_update = ref_transaction_add_update(2624 transaction, referent, new_flags,2625 update->new_oid.hash, update->old_oid.hash,2626 update->msg);26272628 new_update->parent_update = update;26292630 /*2631 * Change the symbolic ref update to log only. Also, it2632 * doesn't need to check its old SHA-1 value, as that will be2633 * done when new_update is processed.2634 */2635 update->flags |= REF_LOG_ONLY | REF_NODEREF;2636 update->flags &= ~REF_HAVE_OLD;26372638 item->util = new_update;26392640 return 0;2641}26422643/*2644 * Return the refname under which update was originally requested.2645 */2646static const char *original_update_refname(struct ref_update *update)2647{2648 while (update->parent_update)2649 update = update->parent_update;26502651 return update->refname;2652}26532654/*2655 * Check whether the REF_HAVE_OLD and old_oid values stored in update2656 * are consistent with oid, which is the reference's current value. If2657 * everything is OK, return 0; otherwise, write an error message to2658 * err and return -1.2659 */2660static int check_old_oid(struct ref_update *update, struct object_id *oid,2661 struct strbuf *err)2662{2663 if (!(update->flags & REF_HAVE_OLD) ||2664 !oidcmp(oid, &update->old_oid))2665 return 0;26662667 if (is_null_oid(&update->old_oid))2668 strbuf_addf(err, "cannot lock ref '%s': "2669 "reference already exists",2670 original_update_refname(update));2671 else if (is_null_oid(oid))2672 strbuf_addf(err, "cannot lock ref '%s': "2673 "reference is missing but expected %s",2674 original_update_refname(update),2675 oid_to_hex(&update->old_oid));2676 else2677 strbuf_addf(err, "cannot lock ref '%s': "2678 "is at %s but expected %s",2679 original_update_refname(update),2680 oid_to_hex(oid),2681 oid_to_hex(&update->old_oid));26822683 return -1;2684}26852686/*2687 * Prepare for carrying out update:2688 * - Lock the reference referred to by update.2689 * - Read the reference under lock.2690 * - Check that its old SHA-1 value (if specified) is correct, and in2691 * any case record it in update->lock->old_oid for later use when2692 * writing the reflog.2693 * - If it is a symref update without REF_NODEREF, split it up into a2694 * REF_LOG_ONLY update of the symref and add a separate update for2695 * the referent to transaction.2696 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY2697 * update of HEAD.2698 */2699static int lock_ref_for_update(struct files_ref_store *refs,2700 struct ref_update *update,2701 struct ref_transaction *transaction,2702 const char *head_ref,2703 struct string_list *affected_refnames,2704 struct strbuf *err)2705{2706 struct strbuf referent = STRBUF_INIT;2707 int mustexist = (update->flags & REF_HAVE_OLD) &&2708 !is_null_oid(&update->old_oid);2709 int ret;2710 struct ref_lock *lock;27112712 files_assert_main_repository(refs, "lock_ref_for_update");27132714 if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid))2715 update->flags |= REF_DELETING;27162717 if (head_ref) {2718 ret = split_head_update(update, transaction, head_ref,2719 affected_refnames, err);2720 if (ret)2721 return ret;2722 }27232724 ret = lock_raw_ref(refs, update->refname, mustexist,2725 affected_refnames, NULL,2726 &lock, &referent,2727 &update->type, err);2728 if (ret) {2729 char *reason;27302731 reason = strbuf_detach(err, NULL);2732 strbuf_addf(err, "cannot lock ref '%s': %s",2733 original_update_refname(update), reason);2734 free(reason);2735 return ret;2736 }27372738 update->backend_data = lock;27392740 if (update->type & REF_ISSYMREF) {2741 if (update->flags & REF_NODEREF) {2742 /*2743 * We won't be reading the referent as part of2744 * the transaction, so we have to read it here2745 * to record and possibly check old_sha1:2746 */2747 if (refs_read_ref_full(&refs->base,2748 referent.buf, 0,2749 lock->old_oid.hash, NULL)) {2750 if (update->flags & REF_HAVE_OLD) {2751 strbuf_addf(err, "cannot lock ref '%s': "2752 "error reading reference",2753 original_update_refname(update));2754 return -1;2755 }2756 } else if (check_old_oid(update, &lock->old_oid, err)) {2757 return TRANSACTION_GENERIC_ERROR;2758 }2759 } else {2760 /*2761 * Create a new update for the reference this2762 * symref is pointing at. Also, we will record2763 * and verify old_sha1 for this update as part2764 * of processing the split-off update, so we2765 * don't have to do it here.2766 */2767 ret = split_symref_update(refs, update,2768 referent.buf, transaction,2769 affected_refnames, err);2770 if (ret)2771 return ret;2772 }2773 } else {2774 struct ref_update *parent_update;27752776 if (check_old_oid(update, &lock->old_oid, err))2777 return TRANSACTION_GENERIC_ERROR;27782779 /*2780 * If this update is happening indirectly because of a2781 * symref update, record the old SHA-1 in the parent2782 * update:2783 */2784 for (parent_update = update->parent_update;2785 parent_update;2786 parent_update = parent_update->parent_update) {2787 struct ref_lock *parent_lock = parent_update->backend_data;2788 oidcpy(&parent_lock->old_oid, &lock->old_oid);2789 }2790 }27912792 if ((update->flags & REF_HAVE_NEW) &&2793 !(update->flags & REF_DELETING) &&2794 !(update->flags & REF_LOG_ONLY)) {2795 if (!(update->type & REF_ISSYMREF) &&2796 !oidcmp(&lock->old_oid, &update->new_oid)) {2797 /*2798 * The reference already has the desired2799 * value, so we don't need to write it.2800 */2801 } else if (write_ref_to_lockfile(lock, &update->new_oid,2802 err)) {2803 char *write_err = strbuf_detach(err, NULL);28042805 /*2806 * The lock was freed upon failure of2807 * write_ref_to_lockfile():2808 */2809 update->backend_data = NULL;2810 strbuf_addf(err,2811 "cannot update ref '%s': %s",2812 update->refname, write_err);2813 free(write_err);2814 return TRANSACTION_GENERIC_ERROR;2815 } else {2816 update->flags |= REF_NEEDS_COMMIT;2817 }2818 }2819 if (!(update->flags & REF_NEEDS_COMMIT)) {2820 /*2821 * We didn't call write_ref_to_lockfile(), so2822 * the lockfile is still open. Close it to2823 * free up the file descriptor:2824 */2825 if (close_ref(lock)) {2826 strbuf_addf(err, "couldn't close '%s.lock'",2827 update->refname);2828 return TRANSACTION_GENERIC_ERROR;2829 }2830 }2831 return 0;2832}28332834/*2835 * Unlock any references in `transaction` that are still locked, and2836 * mark the transaction closed.2837 */2838static void files_transaction_cleanup(struct ref_transaction *transaction)2839{2840 size_t i;28412842 for (i = 0; i < transaction->nr; i++) {2843 struct ref_update *update = transaction->updates[i];2844 struct ref_lock *lock = update->backend_data;28452846 if (lock) {2847 unlock_ref(lock);2848 update->backend_data = NULL;2849 }2850 }28512852 transaction->state = REF_TRANSACTION_CLOSED;2853}28542855static int files_transaction_prepare(struct ref_store *ref_store,2856 struct ref_transaction *transaction,2857 struct strbuf *err)2858{2859 struct files_ref_store *refs =2860 files_downcast(ref_store, REF_STORE_WRITE,2861 "ref_transaction_prepare");2862 size_t i;2863 int ret = 0;2864 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;2865 char *head_ref = NULL;2866 int head_type;2867 struct object_id head_oid;28682869 assert(err);28702871 if (!transaction->nr)2872 goto cleanup;28732874 /*2875 * Fail if a refname appears more than once in the2876 * transaction. (If we end up splitting up any updates using2877 * split_symref_update() or split_head_update(), those2878 * functions will check that the new updates don't have the2879 * same refname as any existing ones.)2880 */2881 for (i = 0; i < transaction->nr; i++) {2882 struct ref_update *update = transaction->updates[i];2883 struct string_list_item *item =2884 string_list_append(&affected_refnames, update->refname);28852886 /*2887 * We store a pointer to update in item->util, but at2888 * the moment we never use the value of this field2889 * except to check whether it is non-NULL.2890 */2891 item->util = update;2892 }2893 string_list_sort(&affected_refnames);2894 if (ref_update_reject_duplicates(&affected_refnames, err)) {2895 ret = TRANSACTION_GENERIC_ERROR;2896 goto cleanup;2897 }28982899 /*2900 * Special hack: If a branch is updated directly and HEAD2901 * points to it (may happen on the remote side of a push2902 * for example) then logically the HEAD reflog should be2903 * updated too.2904 *2905 * A generic solution would require reverse symref lookups,2906 * but finding all symrefs pointing to a given branch would be2907 * rather costly for this rare event (the direct update of a2908 * branch) to be worth it. So let's cheat and check with HEAD2909 * only, which should cover 99% of all usage scenarios (even2910 * 100% of the default ones).2911 *2912 * So if HEAD is a symbolic reference, then record the name of2913 * the reference that it points to. If we see an update of2914 * head_ref within the transaction, then split_head_update()2915 * arranges for the reflog of HEAD to be updated, too.2916 */2917 head_ref = refs_resolve_refdup(ref_store, "HEAD",2918 RESOLVE_REF_NO_RECURSE,2919 head_oid.hash, &head_type);29202921 if (head_ref && !(head_type & REF_ISSYMREF)) {2922 free(head_ref);2923 head_ref = NULL;2924 }29252926 /*2927 * Acquire all locks, verify old values if provided, check2928 * that new values are valid, and write new values to the2929 * lockfiles, ready to be activated. Only keep one lockfile2930 * open at a time to avoid running out of file descriptors.2931 * Note that lock_ref_for_update() might append more updates2932 * to the transaction.2933 */2934 for (i = 0; i < transaction->nr; i++) {2935 struct ref_update *update = transaction->updates[i];29362937 ret = lock_ref_for_update(refs, update, transaction,2938 head_ref, &affected_refnames, err);2939 if (ret)2940 break;2941 }29422943cleanup:2944 free(head_ref);2945 string_list_clear(&affected_refnames, 0);29462947 if (ret)2948 files_transaction_cleanup(transaction);2949 else2950 transaction->state = REF_TRANSACTION_PREPARED;29512952 return ret;2953}29542955static int files_transaction_finish(struct ref_store *ref_store,2956 struct ref_transaction *transaction,2957 struct strbuf *err)2958{2959 struct files_ref_store *refs =2960 files_downcast(ref_store, 0, "ref_transaction_finish");2961 size_t i;2962 int ret = 0;2963 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;2964 struct string_list_item *ref_to_delete;2965 struct strbuf sb = STRBUF_INIT;29662967 assert(err);29682969 if (!transaction->nr) {2970 transaction->state = REF_TRANSACTION_CLOSED;2971 return 0;2972 }29732974 /* Perform updates first so live commits remain referenced */2975 for (i = 0; i < transaction->nr; i++) {2976 struct ref_update *update = transaction->updates[i];2977 struct ref_lock *lock = update->backend_data;29782979 if (update->flags & REF_NEEDS_COMMIT ||2980 update->flags & REF_LOG_ONLY) {2981 if (files_log_ref_write(refs,2982 lock->ref_name,2983 &lock->old_oid,2984 &update->new_oid,2985 update->msg, update->flags,2986 err)) {2987 char *old_msg = strbuf_detach(err, NULL);29882989 strbuf_addf(err, "cannot update the ref '%s': %s",2990 lock->ref_name, old_msg);2991 free(old_msg);2992 unlock_ref(lock);2993 update->backend_data = NULL;2994 ret = TRANSACTION_GENERIC_ERROR;2995 goto cleanup;2996 }2997 }2998 if (update->flags & REF_NEEDS_COMMIT) {2999 clear_loose_ref_cache(refs);3000 if (commit_ref(lock)) {3001 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);3002 unlock_ref(lock);3003 update->backend_data = NULL;3004 ret = TRANSACTION_GENERIC_ERROR;3005 goto cleanup;3006 }3007 }3008 }3009 /* Perform deletes now that updates are safely completed */3010 for (i = 0; i < transaction->nr; i++) {3011 struct ref_update *update = transaction->updates[i];3012 struct ref_lock *lock = update->backend_data;30133014 if (update->flags & REF_DELETING &&3015 !(update->flags & REF_LOG_ONLY)) {3016 if (!(update->type & REF_ISPACKED) ||3017 update->type & REF_ISSYMREF) {3018 /* It is a loose reference. */3019 strbuf_reset(&sb);3020 files_ref_path(refs, &sb, lock->ref_name);3021 if (unlink_or_msg(sb.buf, err)) {3022 ret = TRANSACTION_GENERIC_ERROR;3023 goto cleanup;3024 }3025 update->flags |= REF_DELETED_LOOSE;3026 }30273028 if (!(update->flags & REF_ISPRUNING))3029 string_list_append(&refs_to_delete,3030 lock->ref_name);3031 }3032 }30333034 if (repack_without_refs(refs, &refs_to_delete, err)) {3035 ret = TRANSACTION_GENERIC_ERROR;3036 goto cleanup;3037 }30383039 /* Delete the reflogs of any references that were deleted: */3040 for_each_string_list_item(ref_to_delete, &refs_to_delete) {3041 strbuf_reset(&sb);3042 files_reflog_path(refs, &sb, ref_to_delete->string);3043 if (!unlink_or_warn(sb.buf))3044 try_remove_empty_parents(refs, ref_to_delete->string,3045 REMOVE_EMPTY_PARENTS_REFLOG);3046 }30473048 clear_loose_ref_cache(refs);30493050cleanup:3051 files_transaction_cleanup(transaction);30523053 for (i = 0; i < transaction->nr; i++) {3054 struct ref_update *update = transaction->updates[i];30553056 if (update->flags & REF_DELETED_LOOSE) {3057 /*3058 * The loose reference was deleted. Delete any3059 * empty parent directories. (Note that this3060 * can only work because we have already3061 * removed the lockfile.)3062 */3063 try_remove_empty_parents(refs, update->refname,3064 REMOVE_EMPTY_PARENTS_REF);3065 }3066 }30673068 strbuf_release(&sb);3069 string_list_clear(&refs_to_delete, 0);3070 return ret;3071}30723073static int files_transaction_abort(struct ref_store *ref_store,3074 struct ref_transaction *transaction,3075 struct strbuf *err)3076{3077 files_transaction_cleanup(transaction);3078 return 0;3079}30803081static int ref_present(const char *refname,3082 const struct object_id *oid, int flags, void *cb_data)3083{3084 struct string_list *affected_refnames = cb_data;30853086 return string_list_has_string(affected_refnames, refname);3087}30883089static int files_initial_transaction_commit(struct ref_store *ref_store,3090 struct ref_transaction *transaction,3091 struct strbuf *err)3092{3093 struct files_ref_store *refs =3094 files_downcast(ref_store, REF_STORE_WRITE,3095 "initial_ref_transaction_commit");3096 size_t i;3097 int ret = 0;3098 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;30993100 assert(err);31013102 if (transaction->state != REF_TRANSACTION_OPEN)3103 die("BUG: commit called for transaction that is not open");31043105 /* Fail if a refname appears more than once in the transaction: */3106 for (i = 0; i < transaction->nr; i++)3107 string_list_append(&affected_refnames,3108 transaction->updates[i]->refname);3109 string_list_sort(&affected_refnames);3110 if (ref_update_reject_duplicates(&affected_refnames, err)) {3111 ret = TRANSACTION_GENERIC_ERROR;3112 goto cleanup;3113 }31143115 /*3116 * It's really undefined to call this function in an active3117 * repository or when there are existing references: we are3118 * only locking and changing packed-refs, so (1) any3119 * simultaneous processes might try to change a reference at3120 * the same time we do, and (2) any existing loose versions of3121 * the references that we are setting would have precedence3122 * over our values. But some remote helpers create the remote3123 * "HEAD" and "master" branches before calling this function,3124 * so here we really only check that none of the references3125 * that we are creating already exists.3126 */3127 if (refs_for_each_rawref(&refs->base, ref_present,3128 &affected_refnames))3129 die("BUG: initial ref transaction called with existing refs");31303131 for (i = 0; i < transaction->nr; i++) {3132 struct ref_update *update = transaction->updates[i];31333134 if ((update->flags & REF_HAVE_OLD) &&3135 !is_null_oid(&update->old_oid))3136 die("BUG: initial ref transaction with old_sha1 set");3137 if (refs_verify_refname_available(&refs->base, update->refname,3138 &affected_refnames, NULL,3139 err)) {3140 ret = TRANSACTION_NAME_CONFLICT;3141 goto cleanup;3142 }3143 }31443145 if (lock_packed_refs(refs, 0)) {3146 strbuf_addf(err, "unable to lock packed-refs file: %s",3147 strerror(errno));3148 ret = TRANSACTION_GENERIC_ERROR;3149 goto cleanup;3150 }31513152 for (i = 0; i < transaction->nr; i++) {3153 struct ref_update *update = transaction->updates[i];31543155 if ((update->flags & REF_HAVE_NEW) &&3156 !is_null_oid(&update->new_oid))3157 add_packed_ref(refs, update->refname,3158 &update->new_oid);3159 }31603161 if (commit_packed_refs(refs)) {3162 strbuf_addf(err, "unable to commit packed-refs file: %s",3163 strerror(errno));3164 ret = TRANSACTION_GENERIC_ERROR;3165 goto cleanup;3166 }31673168cleanup:3169 transaction->state = REF_TRANSACTION_CLOSED;3170 string_list_clear(&affected_refnames, 0);3171 return ret;3172}31733174struct expire_reflog_cb {3175 unsigned int flags;3176 reflog_expiry_should_prune_fn *should_prune_fn;3177 void *policy_cb;3178 FILE *newlog;3179 struct object_id last_kept_oid;3180};31813182static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,3183 const char *email, timestamp_t timestamp, int tz,3184 const char *message, void *cb_data)3185{3186 struct expire_reflog_cb *cb = cb_data;3187 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;31883189 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3190 ooid = &cb->last_kept_oid;31913192 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,3193 message, policy_cb)) {3194 if (!cb->newlog)3195 printf("would prune %s", message);3196 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3197 printf("prune %s", message);3198 } else {3199 if (cb->newlog) {3200 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",3201 oid_to_hex(ooid), oid_to_hex(noid),3202 email, timestamp, tz, message);3203 oidcpy(&cb->last_kept_oid, noid);3204 }3205 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3206 printf("keep %s", message);3207 }3208 return 0;3209}32103211static int files_reflog_expire(struct ref_store *ref_store,3212 const char *refname, const unsigned char *sha1,3213 unsigned int flags,3214 reflog_expiry_prepare_fn prepare_fn,3215 reflog_expiry_should_prune_fn should_prune_fn,3216 reflog_expiry_cleanup_fn cleanup_fn,3217 void *policy_cb_data)3218{3219 struct files_ref_store *refs =3220 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");3221 static struct lock_file reflog_lock;3222 struct expire_reflog_cb cb;3223 struct ref_lock *lock;3224 struct strbuf log_file_sb = STRBUF_INIT;3225 char *log_file;3226 int status = 0;3227 int type;3228 struct strbuf err = STRBUF_INIT;3229 struct object_id oid;32303231 memset(&cb, 0, sizeof(cb));3232 cb.flags = flags;3233 cb.policy_cb = policy_cb_data;3234 cb.should_prune_fn = should_prune_fn;32353236 /*3237 * The reflog file is locked by holding the lock on the3238 * reference itself, plus we might need to update the3239 * reference if --updateref was specified:3240 */3241 lock = lock_ref_sha1_basic(refs, refname, sha1,3242 NULL, NULL, REF_NODEREF,3243 &type, &err);3244 if (!lock) {3245 error("cannot lock ref '%s': %s", refname, err.buf);3246 strbuf_release(&err);3247 return -1;3248 }3249 if (!refs_reflog_exists(ref_store, refname)) {3250 unlock_ref(lock);3251 return 0;3252 }32533254 files_reflog_path(refs, &log_file_sb, refname);3255 log_file = strbuf_detach(&log_file_sb, NULL);3256 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3257 /*3258 * Even though holding $GIT_DIR/logs/$reflog.lock has3259 * no locking implications, we use the lock_file3260 * machinery here anyway because it does a lot of the3261 * work we need, including cleaning up if the program3262 * exits unexpectedly.3263 */3264 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {3265 struct strbuf err = STRBUF_INIT;3266 unable_to_lock_message(log_file, errno, &err);3267 error("%s", err.buf);3268 strbuf_release(&err);3269 goto failure;3270 }3271 cb.newlog = fdopen_lock_file(&reflog_lock, "w");3272 if (!cb.newlog) {3273 error("cannot fdopen %s (%s)",3274 get_lock_file_path(&reflog_lock), strerror(errno));3275 goto failure;3276 }3277 }32783279 hashcpy(oid.hash, sha1);32803281 (*prepare_fn)(refname, &oid, cb.policy_cb);3282 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);3283 (*cleanup_fn)(cb.policy_cb);32843285 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3286 /*3287 * It doesn't make sense to adjust a reference pointed3288 * to by a symbolic ref based on expiring entries in3289 * the symbolic reference's reflog. Nor can we update3290 * a reference if there are no remaining reflog3291 * entries.3292 */3293 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3294 !(type & REF_ISSYMREF) &&3295 !is_null_oid(&cb.last_kept_oid);32963297 if (close_lock_file(&reflog_lock)) {3298 status |= error("couldn't write %s: %s", log_file,3299 strerror(errno));3300 } else if (update &&3301 (write_in_full(get_lock_file_fd(lock->lk),3302 oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||3303 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||3304 close_ref(lock) < 0)) {3305 status |= error("couldn't write %s",3306 get_lock_file_path(lock->lk));3307 rollback_lock_file(&reflog_lock);3308 } else if (commit_lock_file(&reflog_lock)) {3309 status |= error("unable to write reflog '%s' (%s)",3310 log_file, strerror(errno));3311 } else if (update && commit_ref(lock)) {3312 status |= error("couldn't set %s", lock->ref_name);3313 }3314 }3315 free(log_file);3316 unlock_ref(lock);3317 return status;33183319 failure:3320 rollback_lock_file(&reflog_lock);3321 free(log_file);3322 unlock_ref(lock);3323 return -1;3324}33253326static int files_init_db(struct ref_store *ref_store, struct strbuf *err)3327{3328 struct files_ref_store *refs =3329 files_downcast(ref_store, REF_STORE_WRITE, "init_db");3330 struct strbuf sb = STRBUF_INIT;33313332 /*3333 * Create .git/refs/{heads,tags}3334 */3335 files_ref_path(refs, &sb, "refs/heads");3336 safe_create_dir(sb.buf, 1);33373338 strbuf_reset(&sb);3339 files_ref_path(refs, &sb, "refs/tags");3340 safe_create_dir(sb.buf, 1);33413342 strbuf_release(&sb);3343 return 0;3344}33453346struct ref_storage_be refs_be_files = {3347 NULL,3348 "files",3349 files_ref_store_create,3350 files_init_db,3351 files_transaction_prepare,3352 files_transaction_finish,3353 files_transaction_abort,3354 files_initial_transaction_commit,33553356 files_pack_refs,3357 files_peel_ref,3358 files_create_symref,3359 files_delete_refs,3360 files_rename_ref,33613362 files_ref_iterator_begin,3363 files_read_raw_ref,33643365 files_reflog_iterator_begin,3366 files_for_each_reflog_ent,3367 files_for_each_reflog_ent_reverse,3368 files_reflog_exists,3369 files_create_reflog,3370 files_delete_reflog,3371 files_reflog_expire3372};