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 from `packed_refs_file` into a newly-allocated 213 * `packed_ref_cache` and return it. The return value will already 214 * have its reference count incremented. 215 * 216 * A comment line of the form "# pack-refs with: " may contain zero or 217 * more traits. We interpret the traits as follows: 218 * 219 * No traits: 220 * 221 * Probably no references are peeled. But if the file contains a 222 * peeled value for a reference, we will use it. 223 * 224 * peeled: 225 * 226 * References under "refs/tags/", if they *can* be peeled, *are* 227 * peeled in this file. References outside of "refs/tags/" are 228 * probably not peeled even if they could have been, but if we find 229 * a peeled value for such a reference we will use it. 230 * 231 * fully-peeled: 232 * 233 * All references in the file that can be peeled are peeled. 234 * Inversely (and this is more important), any references in the 235 * file for which no peeled value is recorded is not peelable. This 236 * trait should typically be written alongside "peeled" for 237 * compatibility with older clients, but we do not require it 238 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 239 */ 240static struct packed_ref_cache *read_packed_refs(const char *packed_refs_file) 241{ 242 FILE *f; 243 struct packed_ref_cache *packed_refs = xcalloc(1, sizeof(*packed_refs)); 244 struct ref_entry *last = NULL; 245 struct strbuf line = STRBUF_INIT; 246 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 247 struct ref_dir *dir; 248 249 acquire_packed_ref_cache(packed_refs); 250 packed_refs->cache = create_ref_cache(NULL, NULL); 251 packed_refs->cache->root->flag &= ~REF_INCOMPLETE; 252 253 f = fopen(packed_refs_file, "r"); 254 if (!f) { 255 if (errno == ENOENT) { 256 /* 257 * This is OK; it just means that no 258 * "packed-refs" file has been written yet, 259 * which is equivalent to it being empty. 260 */ 261 return packed_refs; 262 } else { 263 die_errno("couldn't read %s", packed_refs_file); 264 } 265 } 266 267 stat_validity_update(&packed_refs->validity, fileno(f)); 268 269 dir = get_ref_dir(packed_refs->cache->root); 270 while (strbuf_getwholeline(&line, f, '\n') != EOF) { 271 struct object_id oid; 272 const char *refname; 273 const char *traits; 274 275 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { 276 if (strstr(traits, " fully-peeled ")) 277 peeled = PEELED_FULLY; 278 else if (strstr(traits, " peeled ")) 279 peeled = PEELED_TAGS; 280 /* perhaps other traits later as well */ 281 continue; 282 } 283 284 refname = parse_ref_line(&line, &oid); 285 if (refname) { 286 int flag = REF_ISPACKED; 287 288 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { 289 if (!refname_is_safe(refname)) 290 die("packed refname is dangerous: %s", refname); 291 oidclr(&oid); 292 flag |= REF_BAD_NAME | REF_ISBROKEN; 293 } 294 last = create_ref_entry(refname, &oid, flag, 0); 295 if (peeled == PEELED_FULLY || 296 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) 297 last->flag |= REF_KNOWS_PEELED; 298 add_ref_entry(dir, last); 299 continue; 300 } 301 if (last && 302 line.buf[0] == '^' && 303 line.len == PEELED_LINE_LENGTH && 304 line.buf[PEELED_LINE_LENGTH - 1] == '\n' && 305 !get_oid_hex(line.buf + 1, &oid)) { 306 oidcpy(&last->u.value.peeled, &oid); 307 /* 308 * Regardless of what the file header said, 309 * we definitely know the value of *this* 310 * reference: 311 */ 312 last->flag |= REF_KNOWS_PEELED; 313 } 314 } 315 316 fclose(f); 317 strbuf_release(&line); 318 319 return packed_refs; 320} 321 322static const char *files_packed_refs_path(struct files_ref_store *refs) 323{ 324 return refs->packed_refs_path; 325} 326 327static void files_reflog_path(struct files_ref_store *refs, 328 struct strbuf *sb, 329 const char *refname) 330{ 331 if (!refname) { 332 /* 333 * FIXME: of course this is wrong in multi worktree 334 * setting. To be fixed real soon. 335 */ 336 strbuf_addf(sb, "%s/logs", refs->gitcommondir); 337 return; 338 } 339 340 switch (ref_type(refname)) { 341 case REF_TYPE_PER_WORKTREE: 342 case REF_TYPE_PSEUDOREF: 343 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname); 344 break; 345 case REF_TYPE_NORMAL: 346 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname); 347 break; 348 default: 349 die("BUG: unknown ref type %d of ref %s", 350 ref_type(refname), refname); 351 } 352} 353 354static void files_ref_path(struct files_ref_store *refs, 355 struct strbuf *sb, 356 const char *refname) 357{ 358 switch (ref_type(refname)) { 359 case REF_TYPE_PER_WORKTREE: 360 case REF_TYPE_PSEUDOREF: 361 strbuf_addf(sb, "%s/%s", refs->gitdir, refname); 362 break; 363 case REF_TYPE_NORMAL: 364 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname); 365 break; 366 default: 367 die("BUG: unknown ref type %d of ref %s", 368 ref_type(refname), refname); 369 } 370} 371 372/* 373 * Get the packed_ref_cache for the specified files_ref_store, 374 * creating and populating it if it hasn't been read before or if the 375 * file has been changed (according to its `validity` field) since it 376 * was last read. On the other hand, if we hold the lock, then assume 377 * that the file hasn't been changed out from under us, so skip the 378 * extra `stat()` call in `stat_validity_check()`. 379 */ 380static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs) 381{ 382 const char *packed_refs_file = files_packed_refs_path(refs); 383 384 if (refs->packed && 385 !is_lock_file_locked(&refs->packed_refs_lock) && 386 !stat_validity_check(&refs->packed->validity, packed_refs_file)) 387 clear_packed_ref_cache(refs); 388 389 if (!refs->packed) 390 refs->packed = read_packed_refs(packed_refs_file); 391 392 return refs->packed; 393} 394 395static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) 396{ 397 return get_ref_dir(packed_ref_cache->cache->root); 398} 399 400static struct ref_dir *get_packed_refs(struct files_ref_store *refs) 401{ 402 return get_packed_ref_dir(get_packed_ref_cache(refs)); 403} 404 405/* 406 * Add a reference to the in-memory packed reference cache. This may 407 * only be called while the packed-refs file is locked (see 408 * lock_packed_refs()). To actually write the packed-refs file, call 409 * commit_packed_refs(). 410 */ 411static void add_packed_ref(struct files_ref_store *refs, 412 const char *refname, const struct object_id *oid) 413{ 414 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs); 415 416 if (!is_lock_file_locked(&refs->packed_refs_lock)) 417 die("BUG: packed refs not locked"); 418 add_ref_entry(get_packed_ref_dir(packed_ref_cache), 419 create_ref_entry(refname, oid, REF_ISPACKED, 1)); 420} 421 422/* 423 * Read the loose references from the namespace dirname into dir 424 * (without recursing). dirname must end with '/'. dir must be the 425 * directory entry corresponding to dirname. 426 */ 427static void loose_fill_ref_dir(struct ref_store *ref_store, 428 struct ref_dir *dir, const char *dirname) 429{ 430 struct files_ref_store *refs = 431 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir"); 432 DIR *d; 433 struct dirent *de; 434 int dirnamelen = strlen(dirname); 435 struct strbuf refname; 436 struct strbuf path = STRBUF_INIT; 437 size_t path_baselen; 438 439 files_ref_path(refs, &path, dirname); 440 path_baselen = path.len; 441 442 d = opendir(path.buf); 443 if (!d) { 444 strbuf_release(&path); 445 return; 446 } 447 448 strbuf_init(&refname, dirnamelen + 257); 449 strbuf_add(&refname, dirname, dirnamelen); 450 451 while ((de = readdir(d)) != NULL) { 452 struct object_id oid; 453 struct stat st; 454 int flag; 455 456 if (de->d_name[0] == '.') 457 continue; 458 if (ends_with(de->d_name, ".lock")) 459 continue; 460 strbuf_addstr(&refname, de->d_name); 461 strbuf_addstr(&path, de->d_name); 462 if (stat(path.buf, &st) < 0) { 463 ; /* silently ignore */ 464 } else if (S_ISDIR(st.st_mode)) { 465 strbuf_addch(&refname, '/'); 466 add_entry_to_dir(dir, 467 create_dir_entry(dir->cache, refname.buf, 468 refname.len, 1)); 469 } else { 470 if (!refs_resolve_ref_unsafe(&refs->base, 471 refname.buf, 472 RESOLVE_REF_READING, 473 oid.hash, &flag)) { 474 oidclr(&oid); 475 flag |= REF_ISBROKEN; 476 } else if (is_null_oid(&oid)) { 477 /* 478 * It is so astronomically unlikely 479 * that NULL_SHA1 is the SHA-1 of an 480 * actual object that we consider its 481 * appearance in a loose reference 482 * file to be repo corruption 483 * (probably due to a software bug). 484 */ 485 flag |= REF_ISBROKEN; 486 } 487 488 if (check_refname_format(refname.buf, 489 REFNAME_ALLOW_ONELEVEL)) { 490 if (!refname_is_safe(refname.buf)) 491 die("loose refname is dangerous: %s", refname.buf); 492 oidclr(&oid); 493 flag |= REF_BAD_NAME | REF_ISBROKEN; 494 } 495 add_entry_to_dir(dir, 496 create_ref_entry(refname.buf, &oid, flag, 0)); 497 } 498 strbuf_setlen(&refname, dirnamelen); 499 strbuf_setlen(&path, path_baselen); 500 } 501 strbuf_release(&refname); 502 strbuf_release(&path); 503 closedir(d); 504 505 /* 506 * Manually add refs/bisect, which, being per-worktree, might 507 * not appear in the directory listing for refs/ in the main 508 * repo. 509 */ 510 if (!strcmp(dirname, "refs/")) { 511 int pos = search_ref_dir(dir, "refs/bisect/", 12); 512 513 if (pos < 0) { 514 struct ref_entry *child_entry = create_dir_entry( 515 dir->cache, "refs/bisect/", 12, 1); 516 add_entry_to_dir(dir, child_entry); 517 } 518 } 519} 520 521static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) 522{ 523 if (!refs->loose) { 524 /* 525 * Mark the top-level directory complete because we 526 * are about to read the only subdirectory that can 527 * hold references: 528 */ 529 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir); 530 531 /* We're going to fill the top level ourselves: */ 532 refs->loose->root->flag &= ~REF_INCOMPLETE; 533 534 /* 535 * Add an incomplete entry for "refs/" (to be filled 536 * lazily): 537 */ 538 add_entry_to_dir(get_ref_dir(refs->loose->root), 539 create_dir_entry(refs->loose, "refs/", 5, 1)); 540 } 541 return refs->loose; 542} 543 544/* 545 * Return the ref_entry for the given refname from the packed 546 * references. If it does not exist, return NULL. 547 */ 548static struct ref_entry *get_packed_ref(struct files_ref_store *refs, 549 const char *refname) 550{ 551 return find_ref_entry(get_packed_refs(refs), refname); 552} 553 554/* 555 * A loose ref file doesn't exist; check for a packed ref. 556 */ 557static int resolve_packed_ref(struct files_ref_store *refs, 558 const char *refname, 559 unsigned char *sha1, unsigned int *flags) 560{ 561 struct ref_entry *entry; 562 563 /* 564 * The loose reference file does not exist; check for a packed 565 * reference. 566 */ 567 entry = get_packed_ref(refs, refname); 568 if (entry) { 569 hashcpy(sha1, entry->u.value.oid.hash); 570 *flags |= REF_ISPACKED; 571 return 0; 572 } 573 /* refname is not a packed reference. */ 574 return -1; 575} 576 577static int files_read_raw_ref(struct ref_store *ref_store, 578 const char *refname, unsigned char *sha1, 579 struct strbuf *referent, unsigned int *type) 580{ 581 struct files_ref_store *refs = 582 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); 583 struct strbuf sb_contents = STRBUF_INIT; 584 struct strbuf sb_path = STRBUF_INIT; 585 const char *path; 586 const char *buf; 587 struct stat st; 588 int fd; 589 int ret = -1; 590 int save_errno; 591 int remaining_retries = 3; 592 593 *type = 0; 594 strbuf_reset(&sb_path); 595 596 files_ref_path(refs, &sb_path, refname); 597 598 path = sb_path.buf; 599 600stat_ref: 601 /* 602 * We might have to loop back here to avoid a race 603 * condition: first we lstat() the file, then we try 604 * to read it as a link or as a file. But if somebody 605 * changes the type of the file (file <-> directory 606 * <-> symlink) between the lstat() and reading, then 607 * we don't want to report that as an error but rather 608 * try again starting with the lstat(). 609 * 610 * We'll keep a count of the retries, though, just to avoid 611 * any confusing situation sending us into an infinite loop. 612 */ 613 614 if (remaining_retries-- <= 0) 615 goto out; 616 617 if (lstat(path, &st) < 0) { 618 if (errno != ENOENT) 619 goto out; 620 if (resolve_packed_ref(refs, refname, sha1, type)) { 621 errno = ENOENT; 622 goto out; 623 } 624 ret = 0; 625 goto out; 626 } 627 628 /* Follow "normalized" - ie "refs/.." symlinks by hand */ 629 if (S_ISLNK(st.st_mode)) { 630 strbuf_reset(&sb_contents); 631 if (strbuf_readlink(&sb_contents, path, 0) < 0) { 632 if (errno == ENOENT || errno == EINVAL) 633 /* inconsistent with lstat; retry */ 634 goto stat_ref; 635 else 636 goto out; 637 } 638 if (starts_with(sb_contents.buf, "refs/") && 639 !check_refname_format(sb_contents.buf, 0)) { 640 strbuf_swap(&sb_contents, referent); 641 *type |= REF_ISSYMREF; 642 ret = 0; 643 goto out; 644 } 645 /* 646 * It doesn't look like a refname; fall through to just 647 * treating it like a non-symlink, and reading whatever it 648 * points to. 649 */ 650 } 651 652 /* Is it a directory? */ 653 if (S_ISDIR(st.st_mode)) { 654 /* 655 * Even though there is a directory where the loose 656 * ref is supposed to be, there could still be a 657 * packed ref: 658 */ 659 if (resolve_packed_ref(refs, refname, sha1, type)) { 660 errno = EISDIR; 661 goto out; 662 } 663 ret = 0; 664 goto out; 665 } 666 667 /* 668 * Anything else, just open it and try to use it as 669 * a ref 670 */ 671 fd = open(path, O_RDONLY); 672 if (fd < 0) { 673 if (errno == ENOENT && !S_ISLNK(st.st_mode)) 674 /* inconsistent with lstat; retry */ 675 goto stat_ref; 676 else 677 goto out; 678 } 679 strbuf_reset(&sb_contents); 680 if (strbuf_read(&sb_contents, fd, 256) < 0) { 681 int save_errno = errno; 682 close(fd); 683 errno = save_errno; 684 goto out; 685 } 686 close(fd); 687 strbuf_rtrim(&sb_contents); 688 buf = sb_contents.buf; 689 if (starts_with(buf, "ref:")) { 690 buf += 4; 691 while (isspace(*buf)) 692 buf++; 693 694 strbuf_reset(referent); 695 strbuf_addstr(referent, buf); 696 *type |= REF_ISSYMREF; 697 ret = 0; 698 goto out; 699 } 700 701 /* 702 * Please note that FETCH_HEAD has additional 703 * data after the sha. 704 */ 705 if (get_sha1_hex(buf, sha1) || 706 (buf[40] != '\0' && !isspace(buf[40]))) { 707 *type |= REF_ISBROKEN; 708 errno = EINVAL; 709 goto out; 710 } 711 712 ret = 0; 713 714out: 715 save_errno = errno; 716 strbuf_release(&sb_path); 717 strbuf_release(&sb_contents); 718 errno = save_errno; 719 return ret; 720} 721 722static void unlock_ref(struct ref_lock *lock) 723{ 724 /* Do not free lock->lk -- atexit() still looks at them */ 725 if (lock->lk) 726 rollback_lock_file(lock->lk); 727 free(lock->ref_name); 728 free(lock); 729} 730 731/* 732 * Lock refname, without following symrefs, and set *lock_p to point 733 * at a newly-allocated lock object. Fill in lock->old_oid, referent, 734 * and type similarly to read_raw_ref(). 735 * 736 * The caller must verify that refname is a "safe" reference name (in 737 * the sense of refname_is_safe()) before calling this function. 738 * 739 * If the reference doesn't already exist, verify that refname doesn't 740 * have a D/F conflict with any existing references. extras and skip 741 * are passed to refs_verify_refname_available() for this check. 742 * 743 * If mustexist is not set and the reference is not found or is 744 * broken, lock the reference anyway but clear sha1. 745 * 746 * Return 0 on success. On failure, write an error message to err and 747 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR. 748 * 749 * Implementation note: This function is basically 750 * 751 * lock reference 752 * read_raw_ref() 753 * 754 * but it includes a lot more code to 755 * - Deal with possible races with other processes 756 * - Avoid calling refs_verify_refname_available() when it can be 757 * avoided, namely if we were successfully able to read the ref 758 * - Generate informative error messages in the case of failure 759 */ 760static int lock_raw_ref(struct files_ref_store *refs, 761 const char *refname, int mustexist, 762 const struct string_list *extras, 763 const struct string_list *skip, 764 struct ref_lock **lock_p, 765 struct strbuf *referent, 766 unsigned int *type, 767 struct strbuf *err) 768{ 769 struct ref_lock *lock; 770 struct strbuf ref_file = STRBUF_INIT; 771 int attempts_remaining = 3; 772 int ret = TRANSACTION_GENERIC_ERROR; 773 774 assert(err); 775 files_assert_main_repository(refs, "lock_raw_ref"); 776 777 *type = 0; 778 779 /* First lock the file so it can't change out from under us. */ 780 781 *lock_p = lock = xcalloc(1, sizeof(*lock)); 782 783 lock->ref_name = xstrdup(refname); 784 files_ref_path(refs, &ref_file, refname); 785 786retry: 787 switch (safe_create_leading_directories(ref_file.buf)) { 788 case SCLD_OK: 789 break; /* success */ 790 case SCLD_EXISTS: 791 /* 792 * Suppose refname is "refs/foo/bar". We just failed 793 * to create the containing directory, "refs/foo", 794 * because there was a non-directory in the way. This 795 * indicates a D/F conflict, probably because of 796 * another reference such as "refs/foo". There is no 797 * reason to expect this error to be transitory. 798 */ 799 if (refs_verify_refname_available(&refs->base, refname, 800 extras, skip, err)) { 801 if (mustexist) { 802 /* 803 * To the user the relevant error is 804 * that the "mustexist" reference is 805 * missing: 806 */ 807 strbuf_reset(err); 808 strbuf_addf(err, "unable to resolve reference '%s'", 809 refname); 810 } else { 811 /* 812 * The error message set by 813 * refs_verify_refname_available() is 814 * OK. 815 */ 816 ret = TRANSACTION_NAME_CONFLICT; 817 } 818 } else { 819 /* 820 * The file that is in the way isn't a loose 821 * reference. Report it as a low-level 822 * failure. 823 */ 824 strbuf_addf(err, "unable to create lock file %s.lock; " 825 "non-directory in the way", 826 ref_file.buf); 827 } 828 goto error_return; 829 case SCLD_VANISHED: 830 /* Maybe another process was tidying up. Try again. */ 831 if (--attempts_remaining > 0) 832 goto retry; 833 /* fall through */ 834 default: 835 strbuf_addf(err, "unable to create directory for %s", 836 ref_file.buf); 837 goto error_return; 838 } 839 840 if (!lock->lk) 841 lock->lk = xcalloc(1, sizeof(struct lock_file)); 842 843 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) { 844 if (errno == ENOENT && --attempts_remaining > 0) { 845 /* 846 * Maybe somebody just deleted one of the 847 * directories leading to ref_file. Try 848 * again: 849 */ 850 goto retry; 851 } else { 852 unable_to_lock_message(ref_file.buf, errno, err); 853 goto error_return; 854 } 855 } 856 857 /* 858 * Now we hold the lock and can read the reference without 859 * fear that its value will change. 860 */ 861 862 if (files_read_raw_ref(&refs->base, refname, 863 lock->old_oid.hash, referent, type)) { 864 if (errno == ENOENT) { 865 if (mustexist) { 866 /* Garden variety missing reference. */ 867 strbuf_addf(err, "unable to resolve reference '%s'", 868 refname); 869 goto error_return; 870 } else { 871 /* 872 * Reference is missing, but that's OK. We 873 * know that there is not a conflict with 874 * another loose reference because 875 * (supposing that we are trying to lock 876 * reference "refs/foo/bar"): 877 * 878 * - We were successfully able to create 879 * the lockfile refs/foo/bar.lock, so we 880 * know there cannot be a loose reference 881 * named "refs/foo". 882 * 883 * - We got ENOENT and not EISDIR, so we 884 * know that there cannot be a loose 885 * reference named "refs/foo/bar/baz". 886 */ 887 } 888 } else if (errno == EISDIR) { 889 /* 890 * There is a directory in the way. It might have 891 * contained references that have been deleted. If 892 * we don't require that the reference already 893 * exists, try to remove the directory so that it 894 * doesn't cause trouble when we want to rename the 895 * lockfile into place later. 896 */ 897 if (mustexist) { 898 /* Garden variety missing reference. */ 899 strbuf_addf(err, "unable to resolve reference '%s'", 900 refname); 901 goto error_return; 902 } else if (remove_dir_recursively(&ref_file, 903 REMOVE_DIR_EMPTY_ONLY)) { 904 if (refs_verify_refname_available( 905 &refs->base, refname, 906 extras, skip, err)) { 907 /* 908 * The error message set by 909 * verify_refname_available() is OK. 910 */ 911 ret = TRANSACTION_NAME_CONFLICT; 912 goto error_return; 913 } else { 914 /* 915 * We can't delete the directory, 916 * but we also don't know of any 917 * references that it should 918 * contain. 919 */ 920 strbuf_addf(err, "there is a non-empty directory '%s' " 921 "blocking reference '%s'", 922 ref_file.buf, refname); 923 goto error_return; 924 } 925 } 926 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) { 927 strbuf_addf(err, "unable to resolve reference '%s': " 928 "reference broken", refname); 929 goto error_return; 930 } else { 931 strbuf_addf(err, "unable to resolve reference '%s': %s", 932 refname, strerror(errno)); 933 goto error_return; 934 } 935 936 /* 937 * If the ref did not exist and we are creating it, 938 * make sure there is no existing ref that conflicts 939 * with refname: 940 */ 941 if (refs_verify_refname_available( 942 &refs->base, refname, 943 extras, skip, err)) 944 goto error_return; 945 } 946 947 ret = 0; 948 goto out; 949 950error_return: 951 unlock_ref(lock); 952 *lock_p = NULL; 953 954out: 955 strbuf_release(&ref_file); 956 return ret; 957} 958 959static int files_peel_ref(struct ref_store *ref_store, 960 const char *refname, unsigned char *sha1) 961{ 962 struct files_ref_store *refs = 963 files_downcast(ref_store, REF_STORE_READ | REF_STORE_ODB, 964 "peel_ref"); 965 int flag; 966 unsigned char base[20]; 967 968 if (current_ref_iter && current_ref_iter->refname == refname) { 969 struct object_id peeled; 970 971 if (ref_iterator_peel(current_ref_iter, &peeled)) 972 return -1; 973 hashcpy(sha1, peeled.hash); 974 return 0; 975 } 976 977 if (refs_read_ref_full(ref_store, refname, 978 RESOLVE_REF_READING, base, &flag)) 979 return -1; 980 981 /* 982 * If the reference is packed, read its ref_entry from the 983 * cache in the hope that we already know its peeled value. 984 * We only try this optimization on packed references because 985 * (a) forcing the filling of the loose reference cache could 986 * be expensive and (b) loose references anyway usually do not 987 * have REF_KNOWS_PEELED. 988 */ 989 if (flag & REF_ISPACKED) { 990 struct ref_entry *r = get_packed_ref(refs, refname); 991 if (r) { 992 if (peel_entry(r, 0)) 993 return -1; 994 hashcpy(sha1, r->u.value.peeled.hash); 995 return 0; 996 } 997 } 998 999 return peel_object(base, sha1);1000}10011002struct files_ref_iterator {1003 struct ref_iterator base;10041005 struct packed_ref_cache *packed_ref_cache;1006 struct ref_iterator *iter0;1007 unsigned int flags;1008};10091010static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)1011{1012 struct files_ref_iterator *iter =1013 (struct files_ref_iterator *)ref_iterator;1014 int ok;10151016 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {1017 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1018 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1019 continue;10201021 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1022 !ref_resolves_to_object(iter->iter0->refname,1023 iter->iter0->oid,1024 iter->iter0->flags))1025 continue;10261027 iter->base.refname = iter->iter0->refname;1028 iter->base.oid = iter->iter0->oid;1029 iter->base.flags = iter->iter0->flags;1030 return ITER_OK;1031 }10321033 iter->iter0 = NULL;1034 if (ref_iterator_abort(ref_iterator) != ITER_DONE)1035 ok = ITER_ERROR;10361037 return ok;1038}10391040static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,1041 struct object_id *peeled)1042{1043 struct files_ref_iterator *iter =1044 (struct files_ref_iterator *)ref_iterator;10451046 return ref_iterator_peel(iter->iter0, peeled);1047}10481049static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)1050{1051 struct files_ref_iterator *iter =1052 (struct files_ref_iterator *)ref_iterator;1053 int ok = ITER_DONE;10541055 if (iter->iter0)1056 ok = ref_iterator_abort(iter->iter0);10571058 release_packed_ref_cache(iter->packed_ref_cache);1059 base_ref_iterator_free(ref_iterator);1060 return ok;1061}10621063static struct ref_iterator_vtable files_ref_iterator_vtable = {1064 files_ref_iterator_advance,1065 files_ref_iterator_peel,1066 files_ref_iterator_abort1067};10681069static struct ref_iterator *files_ref_iterator_begin(1070 struct ref_store *ref_store,1071 const char *prefix, unsigned int flags)1072{1073 struct files_ref_store *refs;1074 struct ref_iterator *loose_iter, *packed_iter;1075 struct files_ref_iterator *iter;1076 struct ref_iterator *ref_iterator;1077 unsigned int required_flags = REF_STORE_READ;10781079 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN))1080 required_flags |= REF_STORE_ODB;10811082 refs = files_downcast(ref_store, required_flags, "ref_iterator_begin");10831084 iter = xcalloc(1, sizeof(*iter));1085 ref_iterator = &iter->base;1086 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);10871088 /*1089 * We must make sure that all loose refs are read before1090 * accessing the packed-refs file; this avoids a race1091 * condition if loose refs are migrated to the packed-refs1092 * file by a simultaneous process, but our in-memory view is1093 * from before the migration. We ensure this as follows:1094 * First, we call start the loose refs iteration with its1095 * `prime_ref` argument set to true. This causes the loose1096 * references in the subtree to be pre-read into the cache.1097 * (If they've already been read, that's OK; we only need to1098 * guarantee that they're read before the packed refs, not1099 * *how much* before.) After that, we call1100 * get_packed_ref_cache(), which internally checks whether the1101 * packed-ref cache is up to date with what is on disk, and1102 * re-reads it if not.1103 */11041105 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),1106 prefix, 1);11071108 iter->packed_ref_cache = get_packed_ref_cache(refs);1109 acquire_packed_ref_cache(iter->packed_ref_cache);1110 packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache,1111 prefix, 0);11121113 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);1114 iter->flags = flags;11151116 return ref_iterator;1117}11181119/*1120 * Verify that the reference locked by lock has the value old_sha1.1121 * Fail if the reference doesn't exist and mustexist is set. Return 01122 * on success. On error, write an error message to err, set errno, and1123 * return a negative value.1124 */1125static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,1126 const unsigned char *old_sha1, int mustexist,1127 struct strbuf *err)1128{1129 assert(err);11301131 if (refs_read_ref_full(ref_store, lock->ref_name,1132 mustexist ? RESOLVE_REF_READING : 0,1133 lock->old_oid.hash, NULL)) {1134 if (old_sha1) {1135 int save_errno = errno;1136 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);1137 errno = save_errno;1138 return -1;1139 } else {1140 oidclr(&lock->old_oid);1141 return 0;1142 }1143 }1144 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1145 strbuf_addf(err, "ref '%s' is at %s but expected %s",1146 lock->ref_name,1147 oid_to_hex(&lock->old_oid),1148 sha1_to_hex(old_sha1));1149 errno = EBUSY;1150 return -1;1151 }1152 return 0;1153}11541155static int remove_empty_directories(struct strbuf *path)1156{1157 /*1158 * we want to create a file but there is a directory there;1159 * if that is an empty directory (or a directory that contains1160 * only empty directories), remove them.1161 */1162 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1163}11641165static int create_reflock(const char *path, void *cb)1166{1167 struct lock_file *lk = cb;11681169 return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;1170}11711172/*1173 * Locks a ref returning the lock on success and NULL on failure.1174 * On failure errno is set to something meaningful.1175 */1176static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,1177 const char *refname,1178 const unsigned char *old_sha1,1179 const struct string_list *extras,1180 const struct string_list *skip,1181 unsigned int flags, int *type,1182 struct strbuf *err)1183{1184 struct strbuf ref_file = STRBUF_INIT;1185 struct ref_lock *lock;1186 int last_errno = 0;1187 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1188 int resolve_flags = RESOLVE_REF_NO_RECURSE;1189 int resolved;11901191 files_assert_main_repository(refs, "lock_ref_sha1_basic");1192 assert(err);11931194 lock = xcalloc(1, sizeof(struct ref_lock));11951196 if (mustexist)1197 resolve_flags |= RESOLVE_REF_READING;1198 if (flags & REF_DELETING)1199 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;12001201 files_ref_path(refs, &ref_file, refname);1202 resolved = !!refs_resolve_ref_unsafe(&refs->base,1203 refname, resolve_flags,1204 lock->old_oid.hash, type);1205 if (!resolved && errno == EISDIR) {1206 /*1207 * we are trying to lock foo but we used to1208 * have foo/bar which now does not exist;1209 * it is normal for the empty directory 'foo'1210 * to remain.1211 */1212 if (remove_empty_directories(&ref_file)) {1213 last_errno = errno;1214 if (!refs_verify_refname_available(1215 &refs->base,1216 refname, extras, skip, err))1217 strbuf_addf(err, "there are still refs under '%s'",1218 refname);1219 goto error_return;1220 }1221 resolved = !!refs_resolve_ref_unsafe(&refs->base,1222 refname, resolve_flags,1223 lock->old_oid.hash, type);1224 }1225 if (!resolved) {1226 last_errno = errno;1227 if (last_errno != ENOTDIR ||1228 !refs_verify_refname_available(&refs->base, refname,1229 extras, skip, err))1230 strbuf_addf(err, "unable to resolve reference '%s': %s",1231 refname, strerror(last_errno));12321233 goto error_return;1234 }12351236 /*1237 * If the ref did not exist and we are creating it, make sure1238 * there is no existing packed ref whose name begins with our1239 * refname, nor a packed ref whose name is a proper prefix of1240 * our refname.1241 */1242 if (is_null_oid(&lock->old_oid) &&1243 refs_verify_refname_available(&refs->base, refname,1244 extras, skip, err)) {1245 last_errno = ENOTDIR;1246 goto error_return;1247 }12481249 lock->lk = xcalloc(1, sizeof(struct lock_file));12501251 lock->ref_name = xstrdup(refname);12521253 if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {1254 last_errno = errno;1255 unable_to_lock_message(ref_file.buf, errno, err);1256 goto error_return;1257 }12581259 if (verify_lock(&refs->base, lock, old_sha1, mustexist, err)) {1260 last_errno = errno;1261 goto error_return;1262 }1263 goto out;12641265 error_return:1266 unlock_ref(lock);1267 lock = NULL;12681269 out:1270 strbuf_release(&ref_file);1271 errno = last_errno;1272 return lock;1273}12741275/*1276 * Write an entry to the packed-refs file for the specified refname.1277 * If peeled is non-NULL, write it as the entry's peeled value.1278 */1279static void write_packed_entry(FILE *fh, const char *refname,1280 const unsigned char *sha1,1281 const unsigned char *peeled)1282{1283 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);1284 if (peeled)1285 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));1286}12871288/*1289 * Lock the packed-refs file for writing. Flags is passed to1290 * hold_lock_file_for_update(). Return 0 on success. On errors, set1291 * errno appropriately and return a nonzero value.1292 */1293static int lock_packed_refs(struct files_ref_store *refs, int flags)1294{1295 static int timeout_configured = 0;1296 static int timeout_value = 1000;1297 struct packed_ref_cache *packed_ref_cache;12981299 files_assert_main_repository(refs, "lock_packed_refs");13001301 if (!timeout_configured) {1302 git_config_get_int("core.packedrefstimeout", &timeout_value);1303 timeout_configured = 1;1304 }13051306 if (hold_lock_file_for_update_timeout(1307 &refs->packed_refs_lock, files_packed_refs_path(refs),1308 flags, timeout_value) < 0)1309 return -1;1310 /*1311 * Get the current packed-refs while holding the lock. It is1312 * important that we call `get_packed_ref_cache()` before1313 * setting `packed_ref_cache->lock`, because otherwise the1314 * former will see that the file is locked and assume that the1315 * cache can't be stale.1316 */1317 packed_ref_cache = get_packed_ref_cache(refs);1318 /* Increment the reference count to prevent it from being freed: */1319 acquire_packed_ref_cache(packed_ref_cache);1320 return 0;1321}13221323/*1324 * Write the current version of the packed refs cache from memory to1325 * disk. The packed-refs file must already be locked for writing (see1326 * lock_packed_refs()). Return zero on success. On errors, set errno1327 * and return a nonzero value1328 */1329static int commit_packed_refs(struct files_ref_store *refs)1330{1331 struct packed_ref_cache *packed_ref_cache =1332 get_packed_ref_cache(refs);1333 int ok, error = 0;1334 int save_errno = 0;1335 FILE *out;1336 struct ref_iterator *iter;13371338 files_assert_main_repository(refs, "commit_packed_refs");13391340 if (!is_lock_file_locked(&refs->packed_refs_lock))1341 die("BUG: packed-refs not locked");13421343 out = fdopen_lock_file(&refs->packed_refs_lock, "w");1344 if (!out)1345 die_errno("unable to fdopen packed-refs descriptor");13461347 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);13481349 iter = cache_ref_iterator_begin(packed_ref_cache->cache, NULL, 0);1350 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {1351 struct object_id peeled;1352 int peel_error = ref_iterator_peel(iter, &peeled);13531354 write_packed_entry(out, iter->refname, iter->oid->hash,1355 peel_error ? NULL : peeled.hash);1356 }13571358 if (ok != ITER_DONE)1359 die("error while iterating over references");13601361 if (commit_lock_file(&refs->packed_refs_lock)) {1362 save_errno = errno;1363 error = -1;1364 }1365 release_packed_ref_cache(packed_ref_cache);1366 errno = save_errno;1367 return error;1368}13691370/*1371 * Rollback the lockfile for the packed-refs file, and discard the1372 * in-memory packed reference cache. (The packed-refs file will be1373 * read anew if it is needed again after this function is called.)1374 */1375static void rollback_packed_refs(struct files_ref_store *refs)1376{1377 struct packed_ref_cache *packed_ref_cache =1378 get_packed_ref_cache(refs);13791380 files_assert_main_repository(refs, "rollback_packed_refs");13811382 if (!is_lock_file_locked(&refs->packed_refs_lock))1383 die("BUG: packed-refs not locked");1384 rollback_lock_file(&refs->packed_refs_lock);1385 release_packed_ref_cache(packed_ref_cache);1386 clear_packed_ref_cache(refs);1387}13881389struct ref_to_prune {1390 struct ref_to_prune *next;1391 unsigned char sha1[20];1392 char name[FLEX_ARRAY];1393};13941395enum {1396 REMOVE_EMPTY_PARENTS_REF = 0x01,1397 REMOVE_EMPTY_PARENTS_REFLOG = 0x021398};13991400/*1401 * Remove empty parent directories associated with the specified1402 * reference and/or its reflog, but spare [logs/]refs/ and immediate1403 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or1404 * REMOVE_EMPTY_PARENTS_REFLOG.1405 */1406static void try_remove_empty_parents(struct files_ref_store *refs,1407 const char *refname,1408 unsigned int flags)1409{1410 struct strbuf buf = STRBUF_INIT;1411 struct strbuf sb = STRBUF_INIT;1412 char *p, *q;1413 int i;14141415 strbuf_addstr(&buf, refname);1416 p = buf.buf;1417 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */1418 while (*p && *p != '/')1419 p++;1420 /* tolerate duplicate slashes; see check_refname_format() */1421 while (*p == '/')1422 p++;1423 }1424 q = buf.buf + buf.len;1425 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {1426 while (q > p && *q != '/')1427 q--;1428 while (q > p && *(q-1) == '/')1429 q--;1430 if (q == p)1431 break;1432 strbuf_setlen(&buf, q - buf.buf);14331434 strbuf_reset(&sb);1435 files_ref_path(refs, &sb, buf.buf);1436 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))1437 flags &= ~REMOVE_EMPTY_PARENTS_REF;14381439 strbuf_reset(&sb);1440 files_reflog_path(refs, &sb, buf.buf);1441 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))1442 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;1443 }1444 strbuf_release(&buf);1445 strbuf_release(&sb);1446}14471448/* make sure nobody touched the ref, and unlink */1449static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)1450{1451 struct ref_transaction *transaction;1452 struct strbuf err = STRBUF_INIT;14531454 if (check_refname_format(r->name, 0))1455 return;14561457 transaction = ref_store_transaction_begin(&refs->base, &err);1458 if (!transaction ||1459 ref_transaction_delete(transaction, r->name, r->sha1,1460 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||1461 ref_transaction_commit(transaction, &err)) {1462 ref_transaction_free(transaction);1463 error("%s", err.buf);1464 strbuf_release(&err);1465 return;1466 }1467 ref_transaction_free(transaction);1468 strbuf_release(&err);1469}14701471static void prune_refs(struct files_ref_store *refs, struct ref_to_prune *r)1472{1473 while (r) {1474 prune_ref(refs, r);1475 r = r->next;1476 }1477}14781479/*1480 * Return true if the specified reference should be packed.1481 */1482static int should_pack_ref(const char *refname,1483 const struct object_id *oid, unsigned int ref_flags,1484 unsigned int pack_flags)1485{1486 /* Do not pack per-worktree refs: */1487 if (ref_type(refname) != REF_TYPE_NORMAL)1488 return 0;14891490 /* Do not pack non-tags unless PACK_REFS_ALL is set: */1491 if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/"))1492 return 0;14931494 /* Do not pack symbolic refs: */1495 if (ref_flags & REF_ISSYMREF)1496 return 0;14971498 /* Do not pack broken refs: */1499 if (!ref_resolves_to_object(refname, oid, ref_flags))1500 return 0;15011502 return 1;1503}15041505static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)1506{1507 struct files_ref_store *refs =1508 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,1509 "pack_refs");1510 struct ref_iterator *iter;1511 struct ref_dir *packed_refs;1512 int ok;1513 struct ref_to_prune *refs_to_prune = NULL;15141515 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);1516 packed_refs = get_packed_refs(refs);15171518 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);1519 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {1520 /*1521 * If the loose reference can be packed, add an entry1522 * in the packed ref cache. If the reference should be1523 * pruned, also add it to refs_to_prune.1524 */1525 struct ref_entry *packed_entry;15261527 if (!should_pack_ref(iter->refname, iter->oid, iter->flags,1528 flags))1529 continue;15301531 /*1532 * Create an entry in the packed-refs cache equivalent1533 * to the one from the loose ref cache, except that1534 * we don't copy the peeled status, because we want it1535 * to be re-peeled.1536 */1537 packed_entry = find_ref_entry(packed_refs, iter->refname);1538 if (packed_entry) {1539 /* Overwrite existing packed entry with info from loose entry */1540 packed_entry->flag = REF_ISPACKED;1541 oidcpy(&packed_entry->u.value.oid, iter->oid);1542 } else {1543 packed_entry = create_ref_entry(iter->refname, iter->oid,1544 REF_ISPACKED, 0);1545 add_ref_entry(packed_refs, packed_entry);1546 }1547 oidclr(&packed_entry->u.value.peeled);15481549 /* Schedule the loose reference for pruning if requested. */1550 if ((flags & PACK_REFS_PRUNE)) {1551 struct ref_to_prune *n;1552 FLEX_ALLOC_STR(n, name, iter->refname);1553 hashcpy(n->sha1, iter->oid->hash);1554 n->next = refs_to_prune;1555 refs_to_prune = n;1556 }1557 }1558 if (ok != ITER_DONE)1559 die("error while iterating over references");15601561 if (commit_packed_refs(refs))1562 die_errno("unable to overwrite old ref-pack file");15631564 prune_refs(refs, refs_to_prune);1565 return 0;1566}15671568/*1569 * Rewrite the packed-refs file, omitting any refs listed in1570 * 'refnames'. On error, leave packed-refs unchanged, write an error1571 * message to 'err', and return a nonzero value.1572 *1573 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.1574 */1575static int repack_without_refs(struct files_ref_store *refs,1576 struct string_list *refnames, struct strbuf *err)1577{1578 struct ref_dir *packed;1579 struct string_list_item *refname;1580 int ret, needs_repacking = 0, removed = 0;15811582 files_assert_main_repository(refs, "repack_without_refs");1583 assert(err);15841585 /* Look for a packed ref */1586 for_each_string_list_item(refname, refnames) {1587 if (get_packed_ref(refs, refname->string)) {1588 needs_repacking = 1;1589 break;1590 }1591 }15921593 /* Avoid locking if we have nothing to do */1594 if (!needs_repacking)1595 return 0; /* no refname exists in packed refs */15961597 if (lock_packed_refs(refs, 0)) {1598 unable_to_lock_message(files_packed_refs_path(refs), errno, err);1599 return -1;1600 }1601 packed = get_packed_refs(refs);16021603 /* Remove refnames from the cache */1604 for_each_string_list_item(refname, refnames)1605 if (remove_entry_from_dir(packed, refname->string) != -1)1606 removed = 1;1607 if (!removed) {1608 /*1609 * All packed entries disappeared while we were1610 * acquiring the lock.1611 */1612 rollback_packed_refs(refs);1613 return 0;1614 }16151616 /* Write what remains */1617 ret = commit_packed_refs(refs);1618 if (ret)1619 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",1620 strerror(errno));1621 return ret;1622}16231624static int files_delete_refs(struct ref_store *ref_store, const char *msg,1625 struct string_list *refnames, unsigned int flags)1626{1627 struct files_ref_store *refs =1628 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");1629 struct strbuf err = STRBUF_INIT;1630 int i, result = 0;16311632 if (!refnames->nr)1633 return 0;16341635 result = repack_without_refs(refs, refnames, &err);1636 if (result) {1637 /*1638 * If we failed to rewrite the packed-refs file, then1639 * it is unsafe to try to remove loose refs, because1640 * doing so might expose an obsolete packed value for1641 * a reference that might even point at an object that1642 * has been garbage collected.1643 */1644 if (refnames->nr == 1)1645 error(_("could not delete reference %s: %s"),1646 refnames->items[0].string, err.buf);1647 else1648 error(_("could not delete references: %s"), err.buf);16491650 goto out;1651 }16521653 for (i = 0; i < refnames->nr; i++) {1654 const char *refname = refnames->items[i].string;16551656 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))1657 result |= error(_("could not remove reference %s"), refname);1658 }16591660out:1661 strbuf_release(&err);1662 return result;1663}16641665/*1666 * People using contrib's git-new-workdir have .git/logs/refs ->1667 * /some/other/path/.git/logs/refs, and that may live on another device.1668 *1669 * IOW, to avoid cross device rename errors, the temporary renamed log must1670 * live into logs/refs.1671 */1672#define TMP_RENAMED_LOG "refs/.tmp-renamed-log"16731674struct rename_cb {1675 const char *tmp_renamed_log;1676 int true_errno;1677};16781679static int rename_tmp_log_callback(const char *path, void *cb_data)1680{1681 struct rename_cb *cb = cb_data;16821683 if (rename(cb->tmp_renamed_log, path)) {1684 /*1685 * rename(a, b) when b is an existing directory ought1686 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.1687 * Sheesh. Record the true errno for error reporting,1688 * but report EISDIR to raceproof_create_file() so1689 * that it knows to retry.1690 */1691 cb->true_errno = errno;1692 if (errno == ENOTDIR)1693 errno = EISDIR;1694 return -1;1695 } else {1696 return 0;1697 }1698}16991700static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)1701{1702 struct strbuf path = STRBUF_INIT;1703 struct strbuf tmp = STRBUF_INIT;1704 struct rename_cb cb;1705 int ret;17061707 files_reflog_path(refs, &path, newrefname);1708 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);1709 cb.tmp_renamed_log = tmp.buf;1710 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);1711 if (ret) {1712 if (errno == EISDIR)1713 error("directory not empty: %s", path.buf);1714 else1715 error("unable to move logfile %s to %s: %s",1716 tmp.buf, path.buf,1717 strerror(cb.true_errno));1718 }17191720 strbuf_release(&path);1721 strbuf_release(&tmp);1722 return ret;1723}17241725static int write_ref_to_lockfile(struct ref_lock *lock,1726 const struct object_id *oid, struct strbuf *err);1727static int commit_ref_update(struct files_ref_store *refs,1728 struct ref_lock *lock,1729 const struct object_id *oid, const char *logmsg,1730 struct strbuf *err);17311732static int files_rename_ref(struct ref_store *ref_store,1733 const char *oldrefname, const char *newrefname,1734 const char *logmsg)1735{1736 struct files_ref_store *refs =1737 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");1738 struct object_id oid, orig_oid;1739 int flag = 0, logmoved = 0;1740 struct ref_lock *lock;1741 struct stat loginfo;1742 struct strbuf sb_oldref = STRBUF_INIT;1743 struct strbuf sb_newref = STRBUF_INIT;1744 struct strbuf tmp_renamed_log = STRBUF_INIT;1745 int log, ret;1746 struct strbuf err = STRBUF_INIT;17471748 files_reflog_path(refs, &sb_oldref, oldrefname);1749 files_reflog_path(refs, &sb_newref, newrefname);1750 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);17511752 log = !lstat(sb_oldref.buf, &loginfo);1753 if (log && S_ISLNK(loginfo.st_mode)) {1754 ret = error("reflog for %s is a symlink", oldrefname);1755 goto out;1756 }17571758 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,1759 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,1760 orig_oid.hash, &flag)) {1761 ret = error("refname %s not found", oldrefname);1762 goto out;1763 }17641765 if (flag & REF_ISSYMREF) {1766 ret = error("refname %s is a symbolic ref, renaming it is not supported",1767 oldrefname);1768 goto out;1769 }1770 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {1771 ret = 1;1772 goto out;1773 }17741775 if (log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {1776 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",1777 oldrefname, strerror(errno));1778 goto out;1779 }17801781 if (refs_delete_ref(&refs->base, logmsg, oldrefname,1782 orig_oid.hash, REF_NODEREF)) {1783 error("unable to delete old %s", oldrefname);1784 goto rollback;1785 }17861787 /*1788 * Since we are doing a shallow lookup, oid is not the1789 * correct value to pass to delete_ref as old_oid. But that1790 * doesn't matter, because an old_oid check wouldn't add to1791 * the safety anyway; we want to delete the reference whatever1792 * its current value.1793 */1794 if (!refs_read_ref_full(&refs->base, newrefname,1795 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,1796 oid.hash, NULL) &&1797 refs_delete_ref(&refs->base, NULL, newrefname,1798 NULL, REF_NODEREF)) {1799 if (errno == EISDIR) {1800 struct strbuf path = STRBUF_INIT;1801 int result;18021803 files_ref_path(refs, &path, newrefname);1804 result = remove_empty_directories(&path);1805 strbuf_release(&path);18061807 if (result) {1808 error("Directory not empty: %s", newrefname);1809 goto rollback;1810 }1811 } else {1812 error("unable to delete existing %s", newrefname);1813 goto rollback;1814 }1815 }18161817 if (log && rename_tmp_log(refs, newrefname))1818 goto rollback;18191820 logmoved = log;18211822 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,1823 REF_NODEREF, NULL, &err);1824 if (!lock) {1825 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);1826 strbuf_release(&err);1827 goto rollback;1828 }1829 oidcpy(&lock->old_oid, &orig_oid);18301831 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||1832 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {1833 error("unable to write current sha1 into %s: %s", newrefname, err.buf);1834 strbuf_release(&err);1835 goto rollback;1836 }18371838 ret = 0;1839 goto out;18401841 rollback:1842 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,1843 REF_NODEREF, NULL, &err);1844 if (!lock) {1845 error("unable to lock %s for rollback: %s", oldrefname, err.buf);1846 strbuf_release(&err);1847 goto rollbacklog;1848 }18491850 flag = log_all_ref_updates;1851 log_all_ref_updates = LOG_REFS_NONE;1852 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||1853 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {1854 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);1855 strbuf_release(&err);1856 }1857 log_all_ref_updates = flag;18581859 rollbacklog:1860 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))1861 error("unable to restore logfile %s from %s: %s",1862 oldrefname, newrefname, strerror(errno));1863 if (!logmoved && log &&1864 rename(tmp_renamed_log.buf, sb_oldref.buf))1865 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",1866 oldrefname, strerror(errno));1867 ret = 1;1868 out:1869 strbuf_release(&sb_newref);1870 strbuf_release(&sb_oldref);1871 strbuf_release(&tmp_renamed_log);18721873 return ret;1874}18751876static int close_ref(struct ref_lock *lock)1877{1878 if (close_lock_file(lock->lk))1879 return -1;1880 return 0;1881}18821883static int commit_ref(struct ref_lock *lock)1884{1885 char *path = get_locked_file_path(lock->lk);1886 struct stat st;18871888 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {1889 /*1890 * There is a directory at the path we want to rename1891 * the lockfile to. Hopefully it is empty; try to1892 * delete it.1893 */1894 size_t len = strlen(path);1895 struct strbuf sb_path = STRBUF_INIT;18961897 strbuf_attach(&sb_path, path, len, len);18981899 /*1900 * If this fails, commit_lock_file() will also fail1901 * and will report the problem.1902 */1903 remove_empty_directories(&sb_path);1904 strbuf_release(&sb_path);1905 } else {1906 free(path);1907 }19081909 if (commit_lock_file(lock->lk))1910 return -1;1911 return 0;1912}19131914static int open_or_create_logfile(const char *path, void *cb)1915{1916 int *fd = cb;19171918 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);1919 return (*fd < 0) ? -1 : 0;1920}19211922/*1923 * Create a reflog for a ref. If force_create = 0, only create the1924 * reflog for certain refs (those for which should_autocreate_reflog1925 * returns non-zero). Otherwise, create it regardless of the reference1926 * name. If the logfile already existed or was created, return 0 and1927 * set *logfd to the file descriptor opened for appending to the file.1928 * If no logfile exists and we decided not to create one, return 0 and1929 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and1930 * return -1.1931 */1932static int log_ref_setup(struct files_ref_store *refs,1933 const char *refname, int force_create,1934 int *logfd, struct strbuf *err)1935{1936 struct strbuf logfile_sb = STRBUF_INIT;1937 char *logfile;19381939 files_reflog_path(refs, &logfile_sb, refname);1940 logfile = strbuf_detach(&logfile_sb, NULL);19411942 if (force_create || should_autocreate_reflog(refname)) {1943 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {1944 if (errno == ENOENT)1945 strbuf_addf(err, "unable to create directory for '%s': "1946 "%s", logfile, strerror(errno));1947 else if (errno == EISDIR)1948 strbuf_addf(err, "there are still logs under '%s'",1949 logfile);1950 else1951 strbuf_addf(err, "unable to append to '%s': %s",1952 logfile, strerror(errno));19531954 goto error;1955 }1956 } else {1957 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);1958 if (*logfd < 0) {1959 if (errno == ENOENT || errno == EISDIR) {1960 /*1961 * The logfile doesn't already exist,1962 * but that is not an error; it only1963 * means that we won't write log1964 * entries to it.1965 */1966 ;1967 } else {1968 strbuf_addf(err, "unable to append to '%s': %s",1969 logfile, strerror(errno));1970 goto error;1971 }1972 }1973 }19741975 if (*logfd >= 0)1976 adjust_shared_perm(logfile);19771978 free(logfile);1979 return 0;19801981error:1982 free(logfile);1983 return -1;1984}19851986static int files_create_reflog(struct ref_store *ref_store,1987 const char *refname, int force_create,1988 struct strbuf *err)1989{1990 struct files_ref_store *refs =1991 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");1992 int fd;19931994 if (log_ref_setup(refs, refname, force_create, &fd, err))1995 return -1;19961997 if (fd >= 0)1998 close(fd);19992000 return 0;2001}20022003static int log_ref_write_fd(int fd, const struct object_id *old_oid,2004 const struct object_id *new_oid,2005 const char *committer, const char *msg)2006{2007 int msglen, written;2008 unsigned maxlen, len;2009 char *logrec;20102011 msglen = msg ? strlen(msg) : 0;2012 maxlen = strlen(committer) + msglen + 100;2013 logrec = xmalloc(maxlen);2014 len = xsnprintf(logrec, maxlen, "%s %s %s\n",2015 oid_to_hex(old_oid),2016 oid_to_hex(new_oid),2017 committer);2018 if (msglen)2019 len += copy_reflog_msg(logrec + len - 1, msg) - 1;20202021 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2022 free(logrec);2023 if (written != len)2024 return -1;20252026 return 0;2027}20282029static int files_log_ref_write(struct files_ref_store *refs,2030 const char *refname, const struct object_id *old_oid,2031 const struct object_id *new_oid, const char *msg,2032 int flags, struct strbuf *err)2033{2034 int logfd, result;20352036 if (log_all_ref_updates == LOG_REFS_UNSET)2037 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;20382039 result = log_ref_setup(refs, refname,2040 flags & REF_FORCE_CREATE_REFLOG,2041 &logfd, err);20422043 if (result)2044 return result;20452046 if (logfd < 0)2047 return 0;2048 result = log_ref_write_fd(logfd, old_oid, new_oid,2049 git_committer_info(0), msg);2050 if (result) {2051 struct strbuf sb = STRBUF_INIT;2052 int save_errno = errno;20532054 files_reflog_path(refs, &sb, refname);2055 strbuf_addf(err, "unable to append to '%s': %s",2056 sb.buf, strerror(save_errno));2057 strbuf_release(&sb);2058 close(logfd);2059 return -1;2060 }2061 if (close(logfd)) {2062 struct strbuf sb = STRBUF_INIT;2063 int save_errno = errno;20642065 files_reflog_path(refs, &sb, refname);2066 strbuf_addf(err, "unable to append to '%s': %s",2067 sb.buf, strerror(save_errno));2068 strbuf_release(&sb);2069 return -1;2070 }2071 return 0;2072}20732074/*2075 * Write sha1 into the open lockfile, then close the lockfile. On2076 * errors, rollback the lockfile, fill in *err and2077 * return -1.2078 */2079static int write_ref_to_lockfile(struct ref_lock *lock,2080 const struct object_id *oid, struct strbuf *err)2081{2082 static char term = '\n';2083 struct object *o;2084 int fd;20852086 o = parse_object(oid);2087 if (!o) {2088 strbuf_addf(err,2089 "trying to write ref '%s' with nonexistent object %s",2090 lock->ref_name, oid_to_hex(oid));2091 unlock_ref(lock);2092 return -1;2093 }2094 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2095 strbuf_addf(err,2096 "trying to write non-commit object %s to branch '%s'",2097 oid_to_hex(oid), lock->ref_name);2098 unlock_ref(lock);2099 return -1;2100 }2101 fd = get_lock_file_fd(lock->lk);2102 if (write_in_full(fd, oid_to_hex(oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||2103 write_in_full(fd, &term, 1) != 1 ||2104 close_ref(lock) < 0) {2105 strbuf_addf(err,2106 "couldn't write '%s'", get_lock_file_path(lock->lk));2107 unlock_ref(lock);2108 return -1;2109 }2110 return 0;2111}21122113/*2114 * Commit a change to a loose reference that has already been written2115 * to the loose reference lockfile. Also update the reflogs if2116 * necessary, using the specified lockmsg (which can be NULL).2117 */2118static int commit_ref_update(struct files_ref_store *refs,2119 struct ref_lock *lock,2120 const struct object_id *oid, const char *logmsg,2121 struct strbuf *err)2122{2123 files_assert_main_repository(refs, "commit_ref_update");21242125 clear_loose_ref_cache(refs);2126 if (files_log_ref_write(refs, lock->ref_name,2127 &lock->old_oid, oid,2128 logmsg, 0, err)) {2129 char *old_msg = strbuf_detach(err, NULL);2130 strbuf_addf(err, "cannot update the ref '%s': %s",2131 lock->ref_name, old_msg);2132 free(old_msg);2133 unlock_ref(lock);2134 return -1;2135 }21362137 if (strcmp(lock->ref_name, "HEAD") != 0) {2138 /*2139 * Special hack: If a branch is updated directly and HEAD2140 * points to it (may happen on the remote side of a push2141 * for example) then logically the HEAD reflog should be2142 * updated too.2143 * A generic solution implies reverse symref information,2144 * but finding all symrefs pointing to the given branch2145 * would be rather costly for this rare event (the direct2146 * update of a branch) to be worth it. So let's cheat and2147 * check with HEAD only which should cover 99% of all usage2148 * scenarios (even 100% of the default ones).2149 */2150 struct object_id head_oid;2151 int head_flag;2152 const char *head_ref;21532154 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",2155 RESOLVE_REF_READING,2156 head_oid.hash, &head_flag);2157 if (head_ref && (head_flag & REF_ISSYMREF) &&2158 !strcmp(head_ref, lock->ref_name)) {2159 struct strbuf log_err = STRBUF_INIT;2160 if (files_log_ref_write(refs, "HEAD",2161 &lock->old_oid, oid,2162 logmsg, 0, &log_err)) {2163 error("%s", log_err.buf);2164 strbuf_release(&log_err);2165 }2166 }2167 }21682169 if (commit_ref(lock)) {2170 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2171 unlock_ref(lock);2172 return -1;2173 }21742175 unlock_ref(lock);2176 return 0;2177}21782179static int create_ref_symlink(struct ref_lock *lock, const char *target)2180{2181 int ret = -1;2182#ifndef NO_SYMLINK_HEAD2183 char *ref_path = get_locked_file_path(lock->lk);2184 unlink(ref_path);2185 ret = symlink(target, ref_path);2186 free(ref_path);21872188 if (ret)2189 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2190#endif2191 return ret;2192}21932194static void update_symref_reflog(struct files_ref_store *refs,2195 struct ref_lock *lock, const char *refname,2196 const char *target, const char *logmsg)2197{2198 struct strbuf err = STRBUF_INIT;2199 struct object_id new_oid;2200 if (logmsg &&2201 !refs_read_ref_full(&refs->base, target,2202 RESOLVE_REF_READING, new_oid.hash, NULL) &&2203 files_log_ref_write(refs, refname, &lock->old_oid,2204 &new_oid, logmsg, 0, &err)) {2205 error("%s", err.buf);2206 strbuf_release(&err);2207 }2208}22092210static int create_symref_locked(struct files_ref_store *refs,2211 struct ref_lock *lock, const char *refname,2212 const char *target, const char *logmsg)2213{2214 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {2215 update_symref_reflog(refs, lock, refname, target, logmsg);2216 return 0;2217 }22182219 if (!fdopen_lock_file(lock->lk, "w"))2220 return error("unable to fdopen %s: %s",2221 lock->lk->tempfile.filename.buf, strerror(errno));22222223 update_symref_reflog(refs, lock, refname, target, logmsg);22242225 /* no error check; commit_ref will check ferror */2226 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);2227 if (commit_ref(lock) < 0)2228 return error("unable to write symref for %s: %s", refname,2229 strerror(errno));2230 return 0;2231}22322233static int files_create_symref(struct ref_store *ref_store,2234 const char *refname, const char *target,2235 const char *logmsg)2236{2237 struct files_ref_store *refs =2238 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");2239 struct strbuf err = STRBUF_INIT;2240 struct ref_lock *lock;2241 int ret;22422243 lock = lock_ref_sha1_basic(refs, refname, NULL,2244 NULL, NULL, REF_NODEREF, NULL,2245 &err);2246 if (!lock) {2247 error("%s", err.buf);2248 strbuf_release(&err);2249 return -1;2250 }22512252 ret = create_symref_locked(refs, lock, refname, target, logmsg);2253 unlock_ref(lock);2254 return ret;2255}22562257static int files_reflog_exists(struct ref_store *ref_store,2258 const char *refname)2259{2260 struct files_ref_store *refs =2261 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");2262 struct strbuf sb = STRBUF_INIT;2263 struct stat st;2264 int ret;22652266 files_reflog_path(refs, &sb, refname);2267 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);2268 strbuf_release(&sb);2269 return ret;2270}22712272static int files_delete_reflog(struct ref_store *ref_store,2273 const char *refname)2274{2275 struct files_ref_store *refs =2276 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");2277 struct strbuf sb = STRBUF_INIT;2278 int ret;22792280 files_reflog_path(refs, &sb, refname);2281 ret = remove_path(sb.buf);2282 strbuf_release(&sb);2283 return ret;2284}22852286static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)2287{2288 struct object_id ooid, noid;2289 char *email_end, *message;2290 timestamp_t timestamp;2291 int tz;2292 const char *p = sb->buf;22932294 /* old SP new SP name <email> SP time TAB msg LF */2295 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||2296 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||2297 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||2298 !(email_end = strchr(p, '>')) ||2299 email_end[1] != ' ' ||2300 !(timestamp = parse_timestamp(email_end + 2, &message, 10)) ||2301 !message || message[0] != ' ' ||2302 (message[1] != '+' && message[1] != '-') ||2303 !isdigit(message[2]) || !isdigit(message[3]) ||2304 !isdigit(message[4]) || !isdigit(message[5]))2305 return 0; /* corrupt? */2306 email_end[1] = '\0';2307 tz = strtol(message + 1, NULL, 10);2308 if (message[6] != '\t')2309 message += 6;2310 else2311 message += 7;2312 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);2313}23142315static char *find_beginning_of_line(char *bob, char *scan)2316{2317 while (bob < scan && *(--scan) != '\n')2318 ; /* keep scanning backwards */2319 /*2320 * Return either beginning of the buffer, or LF at the end of2321 * the previous line.2322 */2323 return scan;2324}23252326static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,2327 const char *refname,2328 each_reflog_ent_fn fn,2329 void *cb_data)2330{2331 struct files_ref_store *refs =2332 files_downcast(ref_store, REF_STORE_READ,2333 "for_each_reflog_ent_reverse");2334 struct strbuf sb = STRBUF_INIT;2335 FILE *logfp;2336 long pos;2337 int ret = 0, at_tail = 1;23382339 files_reflog_path(refs, &sb, refname);2340 logfp = fopen(sb.buf, "r");2341 strbuf_release(&sb);2342 if (!logfp)2343 return -1;23442345 /* Jump to the end */2346 if (fseek(logfp, 0, SEEK_END) < 0)2347 ret = error("cannot seek back reflog for %s: %s",2348 refname, strerror(errno));2349 pos = ftell(logfp);2350 while (!ret && 0 < pos) {2351 int cnt;2352 size_t nread;2353 char buf[BUFSIZ];2354 char *endp, *scanp;23552356 /* Fill next block from the end */2357 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;2358 if (fseek(logfp, pos - cnt, SEEK_SET)) {2359 ret = error("cannot seek back reflog for %s: %s",2360 refname, strerror(errno));2361 break;2362 }2363 nread = fread(buf, cnt, 1, logfp);2364 if (nread != 1) {2365 ret = error("cannot read %d bytes from reflog for %s: %s",2366 cnt, refname, strerror(errno));2367 break;2368 }2369 pos -= cnt;23702371 scanp = endp = buf + cnt;2372 if (at_tail && scanp[-1] == '\n')2373 /* Looking at the final LF at the end of the file */2374 scanp--;2375 at_tail = 0;23762377 while (buf < scanp) {2378 /*2379 * terminating LF of the previous line, or the beginning2380 * of the buffer.2381 */2382 char *bp;23832384 bp = find_beginning_of_line(buf, scanp);23852386 if (*bp == '\n') {2387 /*2388 * The newline is the end of the previous line,2389 * so we know we have complete line starting2390 * at (bp + 1). Prefix it onto any prior data2391 * we collected for the line and process it.2392 */2393 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));2394 scanp = bp;2395 endp = bp + 1;2396 ret = show_one_reflog_ent(&sb, fn, cb_data);2397 strbuf_reset(&sb);2398 if (ret)2399 break;2400 } else if (!pos) {2401 /*2402 * We are at the start of the buffer, and the2403 * start of the file; there is no previous2404 * line, and we have everything for this one.2405 * Process it, and we can end the loop.2406 */2407 strbuf_splice(&sb, 0, 0, buf, endp - buf);2408 ret = show_one_reflog_ent(&sb, fn, cb_data);2409 strbuf_reset(&sb);2410 break;2411 }24122413 if (bp == buf) {2414 /*2415 * We are at the start of the buffer, and there2416 * is more file to read backwards. Which means2417 * we are in the middle of a line. Note that we2418 * may get here even if *bp was a newline; that2419 * just means we are at the exact end of the2420 * previous line, rather than some spot in the2421 * middle.2422 *2423 * Save away what we have to be combined with2424 * the data from the next read.2425 */2426 strbuf_splice(&sb, 0, 0, buf, endp - buf);2427 break;2428 }2429 }24302431 }2432 if (!ret && sb.len)2433 die("BUG: reverse reflog parser had leftover data");24342435 fclose(logfp);2436 strbuf_release(&sb);2437 return ret;2438}24392440static int files_for_each_reflog_ent(struct ref_store *ref_store,2441 const char *refname,2442 each_reflog_ent_fn fn, void *cb_data)2443{2444 struct files_ref_store *refs =2445 files_downcast(ref_store, REF_STORE_READ,2446 "for_each_reflog_ent");2447 FILE *logfp;2448 struct strbuf sb = STRBUF_INIT;2449 int ret = 0;24502451 files_reflog_path(refs, &sb, refname);2452 logfp = fopen(sb.buf, "r");2453 strbuf_release(&sb);2454 if (!logfp)2455 return -1;24562457 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))2458 ret = show_one_reflog_ent(&sb, fn, cb_data);2459 fclose(logfp);2460 strbuf_release(&sb);2461 return ret;2462}24632464struct files_reflog_iterator {2465 struct ref_iterator base;24662467 struct ref_store *ref_store;2468 struct dir_iterator *dir_iterator;2469 struct object_id oid;2470};24712472static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)2473{2474 struct files_reflog_iterator *iter =2475 (struct files_reflog_iterator *)ref_iterator;2476 struct dir_iterator *diter = iter->dir_iterator;2477 int ok;24782479 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {2480 int flags;24812482 if (!S_ISREG(diter->st.st_mode))2483 continue;2484 if (diter->basename[0] == '.')2485 continue;2486 if (ends_with(diter->basename, ".lock"))2487 continue;24882489 if (refs_read_ref_full(iter->ref_store,2490 diter->relative_path, 0,2491 iter->oid.hash, &flags)) {2492 error("bad ref for %s", diter->path.buf);2493 continue;2494 }24952496 iter->base.refname = diter->relative_path;2497 iter->base.oid = &iter->oid;2498 iter->base.flags = flags;2499 return ITER_OK;2500 }25012502 iter->dir_iterator = NULL;2503 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)2504 ok = ITER_ERROR;2505 return ok;2506}25072508static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,2509 struct object_id *peeled)2510{2511 die("BUG: ref_iterator_peel() called for reflog_iterator");2512}25132514static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)2515{2516 struct files_reflog_iterator *iter =2517 (struct files_reflog_iterator *)ref_iterator;2518 int ok = ITER_DONE;25192520 if (iter->dir_iterator)2521 ok = dir_iterator_abort(iter->dir_iterator);25222523 base_ref_iterator_free(ref_iterator);2524 return ok;2525}25262527static struct ref_iterator_vtable files_reflog_iterator_vtable = {2528 files_reflog_iterator_advance,2529 files_reflog_iterator_peel,2530 files_reflog_iterator_abort2531};25322533static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)2534{2535 struct files_ref_store *refs =2536 files_downcast(ref_store, REF_STORE_READ,2537 "reflog_iterator_begin");2538 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));2539 struct ref_iterator *ref_iterator = &iter->base;2540 struct strbuf sb = STRBUF_INIT;25412542 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);2543 files_reflog_path(refs, &sb, NULL);2544 iter->dir_iterator = dir_iterator_begin(sb.buf);2545 iter->ref_store = ref_store;2546 strbuf_release(&sb);2547 return ref_iterator;2548}25492550/*2551 * If update is a direct update of head_ref (the reference pointed to2552 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.2553 */2554static int split_head_update(struct ref_update *update,2555 struct ref_transaction *transaction,2556 const char *head_ref,2557 struct string_list *affected_refnames,2558 struct strbuf *err)2559{2560 struct string_list_item *item;2561 struct ref_update *new_update;25622563 if ((update->flags & REF_LOG_ONLY) ||2564 (update->flags & REF_ISPRUNING) ||2565 (update->flags & REF_UPDATE_VIA_HEAD))2566 return 0;25672568 if (strcmp(update->refname, head_ref))2569 return 0;25702571 /*2572 * First make sure that HEAD is not already in the2573 * transaction. This insertion is O(N) in the transaction2574 * size, but it happens at most once per transaction.2575 */2576 item = string_list_insert(affected_refnames, "HEAD");2577 if (item->util) {2578 /* An entry already existed */2579 strbuf_addf(err,2580 "multiple updates for 'HEAD' (including one "2581 "via its referent '%s') are not allowed",2582 update->refname);2583 return TRANSACTION_NAME_CONFLICT;2584 }25852586 new_update = ref_transaction_add_update(2587 transaction, "HEAD",2588 update->flags | REF_LOG_ONLY | REF_NODEREF,2589 update->new_oid.hash, update->old_oid.hash,2590 update->msg);25912592 item->util = new_update;25932594 return 0;2595}25962597/*2598 * update is for a symref that points at referent and doesn't have2599 * REF_NODEREF set. Split it into two updates:2600 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set2601 * - A new, separate update for the referent reference2602 * Note that the new update will itself be subject to splitting when2603 * the iteration gets to it.2604 */2605static int split_symref_update(struct files_ref_store *refs,2606 struct ref_update *update,2607 const char *referent,2608 struct ref_transaction *transaction,2609 struct string_list *affected_refnames,2610 struct strbuf *err)2611{2612 struct string_list_item *item;2613 struct ref_update *new_update;2614 unsigned int new_flags;26152616 /*2617 * First make sure that referent is not already in the2618 * transaction. This insertion is O(N) in the transaction2619 * size, but it happens at most once per symref in a2620 * transaction.2621 */2622 item = string_list_insert(affected_refnames, referent);2623 if (item->util) {2624 /* An entry already existed */2625 strbuf_addf(err,2626 "multiple updates for '%s' (including one "2627 "via symref '%s') are not allowed",2628 referent, update->refname);2629 return TRANSACTION_NAME_CONFLICT;2630 }26312632 new_flags = update->flags;2633 if (!strcmp(update->refname, "HEAD")) {2634 /*2635 * Record that the new update came via HEAD, so that2636 * when we process it, split_head_update() doesn't try2637 * to add another reflog update for HEAD. Note that2638 * this bit will be propagated if the new_update2639 * itself needs to be split.2640 */2641 new_flags |= REF_UPDATE_VIA_HEAD;2642 }26432644 new_update = ref_transaction_add_update(2645 transaction, referent, new_flags,2646 update->new_oid.hash, update->old_oid.hash,2647 update->msg);26482649 new_update->parent_update = update;26502651 /*2652 * Change the symbolic ref update to log only. Also, it2653 * doesn't need to check its old SHA-1 value, as that will be2654 * done when new_update is processed.2655 */2656 update->flags |= REF_LOG_ONLY | REF_NODEREF;2657 update->flags &= ~REF_HAVE_OLD;26582659 item->util = new_update;26602661 return 0;2662}26632664/*2665 * Return the refname under which update was originally requested.2666 */2667static const char *original_update_refname(struct ref_update *update)2668{2669 while (update->parent_update)2670 update = update->parent_update;26712672 return update->refname;2673}26742675/*2676 * Check whether the REF_HAVE_OLD and old_oid values stored in update2677 * are consistent with oid, which is the reference's current value. If2678 * everything is OK, return 0; otherwise, write an error message to2679 * err and return -1.2680 */2681static int check_old_oid(struct ref_update *update, struct object_id *oid,2682 struct strbuf *err)2683{2684 if (!(update->flags & REF_HAVE_OLD) ||2685 !oidcmp(oid, &update->old_oid))2686 return 0;26872688 if (is_null_oid(&update->old_oid))2689 strbuf_addf(err, "cannot lock ref '%s': "2690 "reference already exists",2691 original_update_refname(update));2692 else if (is_null_oid(oid))2693 strbuf_addf(err, "cannot lock ref '%s': "2694 "reference is missing but expected %s",2695 original_update_refname(update),2696 oid_to_hex(&update->old_oid));2697 else2698 strbuf_addf(err, "cannot lock ref '%s': "2699 "is at %s but expected %s",2700 original_update_refname(update),2701 oid_to_hex(oid),2702 oid_to_hex(&update->old_oid));27032704 return -1;2705}27062707/*2708 * Prepare for carrying out update:2709 * - Lock the reference referred to by update.2710 * - Read the reference under lock.2711 * - Check that its old SHA-1 value (if specified) is correct, and in2712 * any case record it in update->lock->old_oid for later use when2713 * writing the reflog.2714 * - If it is a symref update without REF_NODEREF, split it up into a2715 * REF_LOG_ONLY update of the symref and add a separate update for2716 * the referent to transaction.2717 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY2718 * update of HEAD.2719 */2720static int lock_ref_for_update(struct files_ref_store *refs,2721 struct ref_update *update,2722 struct ref_transaction *transaction,2723 const char *head_ref,2724 struct string_list *affected_refnames,2725 struct strbuf *err)2726{2727 struct strbuf referent = STRBUF_INIT;2728 int mustexist = (update->flags & REF_HAVE_OLD) &&2729 !is_null_oid(&update->old_oid);2730 int ret;2731 struct ref_lock *lock;27322733 files_assert_main_repository(refs, "lock_ref_for_update");27342735 if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid))2736 update->flags |= REF_DELETING;27372738 if (head_ref) {2739 ret = split_head_update(update, transaction, head_ref,2740 affected_refnames, err);2741 if (ret)2742 return ret;2743 }27442745 ret = lock_raw_ref(refs, update->refname, mustexist,2746 affected_refnames, NULL,2747 &lock, &referent,2748 &update->type, err);2749 if (ret) {2750 char *reason;27512752 reason = strbuf_detach(err, NULL);2753 strbuf_addf(err, "cannot lock ref '%s': %s",2754 original_update_refname(update), reason);2755 free(reason);2756 return ret;2757 }27582759 update->backend_data = lock;27602761 if (update->type & REF_ISSYMREF) {2762 if (update->flags & REF_NODEREF) {2763 /*2764 * We won't be reading the referent as part of2765 * the transaction, so we have to read it here2766 * to record and possibly check old_sha1:2767 */2768 if (refs_read_ref_full(&refs->base,2769 referent.buf, 0,2770 lock->old_oid.hash, NULL)) {2771 if (update->flags & REF_HAVE_OLD) {2772 strbuf_addf(err, "cannot lock ref '%s': "2773 "error reading reference",2774 original_update_refname(update));2775 return -1;2776 }2777 } else if (check_old_oid(update, &lock->old_oid, err)) {2778 return TRANSACTION_GENERIC_ERROR;2779 }2780 } else {2781 /*2782 * Create a new update for the reference this2783 * symref is pointing at. Also, we will record2784 * and verify old_sha1 for this update as part2785 * of processing the split-off update, so we2786 * don't have to do it here.2787 */2788 ret = split_symref_update(refs, update,2789 referent.buf, transaction,2790 affected_refnames, err);2791 if (ret)2792 return ret;2793 }2794 } else {2795 struct ref_update *parent_update;27962797 if (check_old_oid(update, &lock->old_oid, err))2798 return TRANSACTION_GENERIC_ERROR;27992800 /*2801 * If this update is happening indirectly because of a2802 * symref update, record the old SHA-1 in the parent2803 * update:2804 */2805 for (parent_update = update->parent_update;2806 parent_update;2807 parent_update = parent_update->parent_update) {2808 struct ref_lock *parent_lock = parent_update->backend_data;2809 oidcpy(&parent_lock->old_oid, &lock->old_oid);2810 }2811 }28122813 if ((update->flags & REF_HAVE_NEW) &&2814 !(update->flags & REF_DELETING) &&2815 !(update->flags & REF_LOG_ONLY)) {2816 if (!(update->type & REF_ISSYMREF) &&2817 !oidcmp(&lock->old_oid, &update->new_oid)) {2818 /*2819 * The reference already has the desired2820 * value, so we don't need to write it.2821 */2822 } else if (write_ref_to_lockfile(lock, &update->new_oid,2823 err)) {2824 char *write_err = strbuf_detach(err, NULL);28252826 /*2827 * The lock was freed upon failure of2828 * write_ref_to_lockfile():2829 */2830 update->backend_data = NULL;2831 strbuf_addf(err,2832 "cannot update ref '%s': %s",2833 update->refname, write_err);2834 free(write_err);2835 return TRANSACTION_GENERIC_ERROR;2836 } else {2837 update->flags |= REF_NEEDS_COMMIT;2838 }2839 }2840 if (!(update->flags & REF_NEEDS_COMMIT)) {2841 /*2842 * We didn't call write_ref_to_lockfile(), so2843 * the lockfile is still open. Close it to2844 * free up the file descriptor:2845 */2846 if (close_ref(lock)) {2847 strbuf_addf(err, "couldn't close '%s.lock'",2848 update->refname);2849 return TRANSACTION_GENERIC_ERROR;2850 }2851 }2852 return 0;2853}28542855/*2856 * Unlock any references in `transaction` that are still locked, and2857 * mark the transaction closed.2858 */2859static void files_transaction_cleanup(struct ref_transaction *transaction)2860{2861 size_t i;28622863 for (i = 0; i < transaction->nr; i++) {2864 struct ref_update *update = transaction->updates[i];2865 struct ref_lock *lock = update->backend_data;28662867 if (lock) {2868 unlock_ref(lock);2869 update->backend_data = NULL;2870 }2871 }28722873 transaction->state = REF_TRANSACTION_CLOSED;2874}28752876static int files_transaction_prepare(struct ref_store *ref_store,2877 struct ref_transaction *transaction,2878 struct strbuf *err)2879{2880 struct files_ref_store *refs =2881 files_downcast(ref_store, REF_STORE_WRITE,2882 "ref_transaction_prepare");2883 size_t i;2884 int ret = 0;2885 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;2886 char *head_ref = NULL;2887 int head_type;2888 struct object_id head_oid;28892890 assert(err);28912892 if (!transaction->nr)2893 goto cleanup;28942895 /*2896 * Fail if a refname appears more than once in the2897 * transaction. (If we end up splitting up any updates using2898 * split_symref_update() or split_head_update(), those2899 * functions will check that the new updates don't have the2900 * same refname as any existing ones.)2901 */2902 for (i = 0; i < transaction->nr; i++) {2903 struct ref_update *update = transaction->updates[i];2904 struct string_list_item *item =2905 string_list_append(&affected_refnames, update->refname);29062907 /*2908 * We store a pointer to update in item->util, but at2909 * the moment we never use the value of this field2910 * except to check whether it is non-NULL.2911 */2912 item->util = update;2913 }2914 string_list_sort(&affected_refnames);2915 if (ref_update_reject_duplicates(&affected_refnames, err)) {2916 ret = TRANSACTION_GENERIC_ERROR;2917 goto cleanup;2918 }29192920 /*2921 * Special hack: If a branch is updated directly and HEAD2922 * points to it (may happen on the remote side of a push2923 * for example) then logically the HEAD reflog should be2924 * updated too.2925 *2926 * A generic solution would require reverse symref lookups,2927 * but finding all symrefs pointing to a given branch would be2928 * rather costly for this rare event (the direct update of a2929 * branch) to be worth it. So let's cheat and check with HEAD2930 * only, which should cover 99% of all usage scenarios (even2931 * 100% of the default ones).2932 *2933 * So if HEAD is a symbolic reference, then record the name of2934 * the reference that it points to. If we see an update of2935 * head_ref within the transaction, then split_head_update()2936 * arranges for the reflog of HEAD to be updated, too.2937 */2938 head_ref = refs_resolve_refdup(ref_store, "HEAD",2939 RESOLVE_REF_NO_RECURSE,2940 head_oid.hash, &head_type);29412942 if (head_ref && !(head_type & REF_ISSYMREF)) {2943 free(head_ref);2944 head_ref = NULL;2945 }29462947 /*2948 * Acquire all locks, verify old values if provided, check2949 * that new values are valid, and write new values to the2950 * lockfiles, ready to be activated. Only keep one lockfile2951 * open at a time to avoid running out of file descriptors.2952 * Note that lock_ref_for_update() might append more updates2953 * to the transaction.2954 */2955 for (i = 0; i < transaction->nr; i++) {2956 struct ref_update *update = transaction->updates[i];29572958 ret = lock_ref_for_update(refs, update, transaction,2959 head_ref, &affected_refnames, err);2960 if (ret)2961 break;2962 }29632964cleanup:2965 free(head_ref);2966 string_list_clear(&affected_refnames, 0);29672968 if (ret)2969 files_transaction_cleanup(transaction);2970 else2971 transaction->state = REF_TRANSACTION_PREPARED;29722973 return ret;2974}29752976static int files_transaction_finish(struct ref_store *ref_store,2977 struct ref_transaction *transaction,2978 struct strbuf *err)2979{2980 struct files_ref_store *refs =2981 files_downcast(ref_store, 0, "ref_transaction_finish");2982 size_t i;2983 int ret = 0;2984 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;2985 struct string_list_item *ref_to_delete;2986 struct strbuf sb = STRBUF_INIT;29872988 assert(err);29892990 if (!transaction->nr) {2991 transaction->state = REF_TRANSACTION_CLOSED;2992 return 0;2993 }29942995 /* Perform updates first so live commits remain referenced */2996 for (i = 0; i < transaction->nr; i++) {2997 struct ref_update *update = transaction->updates[i];2998 struct ref_lock *lock = update->backend_data;29993000 if (update->flags & REF_NEEDS_COMMIT ||3001 update->flags & REF_LOG_ONLY) {3002 if (files_log_ref_write(refs,3003 lock->ref_name,3004 &lock->old_oid,3005 &update->new_oid,3006 update->msg, update->flags,3007 err)) {3008 char *old_msg = strbuf_detach(err, NULL);30093010 strbuf_addf(err, "cannot update the ref '%s': %s",3011 lock->ref_name, old_msg);3012 free(old_msg);3013 unlock_ref(lock);3014 update->backend_data = NULL;3015 ret = TRANSACTION_GENERIC_ERROR;3016 goto cleanup;3017 }3018 }3019 if (update->flags & REF_NEEDS_COMMIT) {3020 clear_loose_ref_cache(refs);3021 if (commit_ref(lock)) {3022 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);3023 unlock_ref(lock);3024 update->backend_data = NULL;3025 ret = TRANSACTION_GENERIC_ERROR;3026 goto cleanup;3027 }3028 }3029 }3030 /* Perform deletes now that updates are safely completed */3031 for (i = 0; i < transaction->nr; i++) {3032 struct ref_update *update = transaction->updates[i];3033 struct ref_lock *lock = update->backend_data;30343035 if (update->flags & REF_DELETING &&3036 !(update->flags & REF_LOG_ONLY)) {3037 if (!(update->type & REF_ISPACKED) ||3038 update->type & REF_ISSYMREF) {3039 /* It is a loose reference. */3040 strbuf_reset(&sb);3041 files_ref_path(refs, &sb, lock->ref_name);3042 if (unlink_or_msg(sb.buf, err)) {3043 ret = TRANSACTION_GENERIC_ERROR;3044 goto cleanup;3045 }3046 update->flags |= REF_DELETED_LOOSE;3047 }30483049 if (!(update->flags & REF_ISPRUNING))3050 string_list_append(&refs_to_delete,3051 lock->ref_name);3052 }3053 }30543055 if (repack_without_refs(refs, &refs_to_delete, err)) {3056 ret = TRANSACTION_GENERIC_ERROR;3057 goto cleanup;3058 }30593060 /* Delete the reflogs of any references that were deleted: */3061 for_each_string_list_item(ref_to_delete, &refs_to_delete) {3062 strbuf_reset(&sb);3063 files_reflog_path(refs, &sb, ref_to_delete->string);3064 if (!unlink_or_warn(sb.buf))3065 try_remove_empty_parents(refs, ref_to_delete->string,3066 REMOVE_EMPTY_PARENTS_REFLOG);3067 }30683069 clear_loose_ref_cache(refs);30703071cleanup:3072 files_transaction_cleanup(transaction);30733074 for (i = 0; i < transaction->nr; i++) {3075 struct ref_update *update = transaction->updates[i];30763077 if (update->flags & REF_DELETED_LOOSE) {3078 /*3079 * The loose reference was deleted. Delete any3080 * empty parent directories. (Note that this3081 * can only work because we have already3082 * removed the lockfile.)3083 */3084 try_remove_empty_parents(refs, update->refname,3085 REMOVE_EMPTY_PARENTS_REF);3086 }3087 }30883089 strbuf_release(&sb);3090 string_list_clear(&refs_to_delete, 0);3091 return ret;3092}30933094static int files_transaction_abort(struct ref_store *ref_store,3095 struct ref_transaction *transaction,3096 struct strbuf *err)3097{3098 files_transaction_cleanup(transaction);3099 return 0;3100}31013102static int ref_present(const char *refname,3103 const struct object_id *oid, int flags, void *cb_data)3104{3105 struct string_list *affected_refnames = cb_data;31063107 return string_list_has_string(affected_refnames, refname);3108}31093110static int files_initial_transaction_commit(struct ref_store *ref_store,3111 struct ref_transaction *transaction,3112 struct strbuf *err)3113{3114 struct files_ref_store *refs =3115 files_downcast(ref_store, REF_STORE_WRITE,3116 "initial_ref_transaction_commit");3117 size_t i;3118 int ret = 0;3119 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;31203121 assert(err);31223123 if (transaction->state != REF_TRANSACTION_OPEN)3124 die("BUG: commit called for transaction that is not open");31253126 /* Fail if a refname appears more than once in the transaction: */3127 for (i = 0; i < transaction->nr; i++)3128 string_list_append(&affected_refnames,3129 transaction->updates[i]->refname);3130 string_list_sort(&affected_refnames);3131 if (ref_update_reject_duplicates(&affected_refnames, err)) {3132 ret = TRANSACTION_GENERIC_ERROR;3133 goto cleanup;3134 }31353136 /*3137 * It's really undefined to call this function in an active3138 * repository or when there are existing references: we are3139 * only locking and changing packed-refs, so (1) any3140 * simultaneous processes might try to change a reference at3141 * the same time we do, and (2) any existing loose versions of3142 * the references that we are setting would have precedence3143 * over our values. But some remote helpers create the remote3144 * "HEAD" and "master" branches before calling this function,3145 * so here we really only check that none of the references3146 * that we are creating already exists.3147 */3148 if (refs_for_each_rawref(&refs->base, ref_present,3149 &affected_refnames))3150 die("BUG: initial ref transaction called with existing refs");31513152 for (i = 0; i < transaction->nr; i++) {3153 struct ref_update *update = transaction->updates[i];31543155 if ((update->flags & REF_HAVE_OLD) &&3156 !is_null_oid(&update->old_oid))3157 die("BUG: initial ref transaction with old_sha1 set");3158 if (refs_verify_refname_available(&refs->base, update->refname,3159 &affected_refnames, NULL,3160 err)) {3161 ret = TRANSACTION_NAME_CONFLICT;3162 goto cleanup;3163 }3164 }31653166 if (lock_packed_refs(refs, 0)) {3167 strbuf_addf(err, "unable to lock packed-refs file: %s",3168 strerror(errno));3169 ret = TRANSACTION_GENERIC_ERROR;3170 goto cleanup;3171 }31723173 for (i = 0; i < transaction->nr; i++) {3174 struct ref_update *update = transaction->updates[i];31753176 if ((update->flags & REF_HAVE_NEW) &&3177 !is_null_oid(&update->new_oid))3178 add_packed_ref(refs, update->refname,3179 &update->new_oid);3180 }31813182 if (commit_packed_refs(refs)) {3183 strbuf_addf(err, "unable to commit packed-refs file: %s",3184 strerror(errno));3185 ret = TRANSACTION_GENERIC_ERROR;3186 goto cleanup;3187 }31883189cleanup:3190 transaction->state = REF_TRANSACTION_CLOSED;3191 string_list_clear(&affected_refnames, 0);3192 return ret;3193}31943195struct expire_reflog_cb {3196 unsigned int flags;3197 reflog_expiry_should_prune_fn *should_prune_fn;3198 void *policy_cb;3199 FILE *newlog;3200 struct object_id last_kept_oid;3201};32023203static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,3204 const char *email, timestamp_t timestamp, int tz,3205 const char *message, void *cb_data)3206{3207 struct expire_reflog_cb *cb = cb_data;3208 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;32093210 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3211 ooid = &cb->last_kept_oid;32123213 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,3214 message, policy_cb)) {3215 if (!cb->newlog)3216 printf("would prune %s", message);3217 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3218 printf("prune %s", message);3219 } else {3220 if (cb->newlog) {3221 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",3222 oid_to_hex(ooid), oid_to_hex(noid),3223 email, timestamp, tz, message);3224 oidcpy(&cb->last_kept_oid, noid);3225 }3226 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3227 printf("keep %s", message);3228 }3229 return 0;3230}32313232static int files_reflog_expire(struct ref_store *ref_store,3233 const char *refname, const unsigned char *sha1,3234 unsigned int flags,3235 reflog_expiry_prepare_fn prepare_fn,3236 reflog_expiry_should_prune_fn should_prune_fn,3237 reflog_expiry_cleanup_fn cleanup_fn,3238 void *policy_cb_data)3239{3240 struct files_ref_store *refs =3241 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");3242 static struct lock_file reflog_lock;3243 struct expire_reflog_cb cb;3244 struct ref_lock *lock;3245 struct strbuf log_file_sb = STRBUF_INIT;3246 char *log_file;3247 int status = 0;3248 int type;3249 struct strbuf err = STRBUF_INIT;3250 struct object_id oid;32513252 memset(&cb, 0, sizeof(cb));3253 cb.flags = flags;3254 cb.policy_cb = policy_cb_data;3255 cb.should_prune_fn = should_prune_fn;32563257 /*3258 * The reflog file is locked by holding the lock on the3259 * reference itself, plus we might need to update the3260 * reference if --updateref was specified:3261 */3262 lock = lock_ref_sha1_basic(refs, refname, sha1,3263 NULL, NULL, REF_NODEREF,3264 &type, &err);3265 if (!lock) {3266 error("cannot lock ref '%s': %s", refname, err.buf);3267 strbuf_release(&err);3268 return -1;3269 }3270 if (!refs_reflog_exists(ref_store, refname)) {3271 unlock_ref(lock);3272 return 0;3273 }32743275 files_reflog_path(refs, &log_file_sb, refname);3276 log_file = strbuf_detach(&log_file_sb, NULL);3277 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3278 /*3279 * Even though holding $GIT_DIR/logs/$reflog.lock has3280 * no locking implications, we use the lock_file3281 * machinery here anyway because it does a lot of the3282 * work we need, including cleaning up if the program3283 * exits unexpectedly.3284 */3285 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {3286 struct strbuf err = STRBUF_INIT;3287 unable_to_lock_message(log_file, errno, &err);3288 error("%s", err.buf);3289 strbuf_release(&err);3290 goto failure;3291 }3292 cb.newlog = fdopen_lock_file(&reflog_lock, "w");3293 if (!cb.newlog) {3294 error("cannot fdopen %s (%s)",3295 get_lock_file_path(&reflog_lock), strerror(errno));3296 goto failure;3297 }3298 }32993300 hashcpy(oid.hash, sha1);33013302 (*prepare_fn)(refname, &oid, cb.policy_cb);3303 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);3304 (*cleanup_fn)(cb.policy_cb);33053306 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3307 /*3308 * It doesn't make sense to adjust a reference pointed3309 * to by a symbolic ref based on expiring entries in3310 * the symbolic reference's reflog. Nor can we update3311 * a reference if there are no remaining reflog3312 * entries.3313 */3314 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3315 !(type & REF_ISSYMREF) &&3316 !is_null_oid(&cb.last_kept_oid);33173318 if (close_lock_file(&reflog_lock)) {3319 status |= error("couldn't write %s: %s", log_file,3320 strerror(errno));3321 } else if (update &&3322 (write_in_full(get_lock_file_fd(lock->lk),3323 oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||3324 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||3325 close_ref(lock) < 0)) {3326 status |= error("couldn't write %s",3327 get_lock_file_path(lock->lk));3328 rollback_lock_file(&reflog_lock);3329 } else if (commit_lock_file(&reflog_lock)) {3330 status |= error("unable to write reflog '%s' (%s)",3331 log_file, strerror(errno));3332 } else if (update && commit_ref(lock)) {3333 status |= error("couldn't set %s", lock->ref_name);3334 }3335 }3336 free(log_file);3337 unlock_ref(lock);3338 return status;33393340 failure:3341 rollback_lock_file(&reflog_lock);3342 free(log_file);3343 unlock_ref(lock);3344 return -1;3345}33463347static int files_init_db(struct ref_store *ref_store, struct strbuf *err)3348{3349 struct files_ref_store *refs =3350 files_downcast(ref_store, REF_STORE_WRITE, "init_db");3351 struct strbuf sb = STRBUF_INIT;33523353 /*3354 * Create .git/refs/{heads,tags}3355 */3356 files_ref_path(refs, &sb, "refs/heads");3357 safe_create_dir(sb.buf, 1);33583359 strbuf_reset(&sb);3360 files_ref_path(refs, &sb, "refs/tags");3361 safe_create_dir(sb.buf, 1);33623363 strbuf_release(&sb);3364 return 0;3365}33663367struct ref_storage_be refs_be_files = {3368 NULL,3369 "files",3370 files_ref_store_create,3371 files_init_db,3372 files_transaction_prepare,3373 files_transaction_finish,3374 files_transaction_abort,3375 files_initial_transaction_commit,33763377 files_pack_refs,3378 files_peel_ref,3379 files_create_symref,3380 files_delete_refs,3381 files_rename_ref,33823383 files_ref_iterator_begin,3384 files_read_raw_ref,33853386 files_reflog_iterator_begin,3387 files_for_each_reflog_ent,3388 files_for_each_reflog_ent_reverse,3389 files_reflog_exists,3390 files_create_reflog,3391 files_delete_reflog,3392 files_reflog_expire3393};