1#include "../cache.h" 2#include "../refs.h" 3#include "refs-internal.h" 4#include "../iterator.h" 5#include "../dir-iterator.h" 6#include "../lockfile.h" 7#include "../object.h" 8#include "../dir.h" 9 10struct ref_lock { 11 char *ref_name; 12 struct lock_file *lk; 13 struct object_id old_oid; 14}; 15 16struct ref_entry; 17 18/* 19 * Information used (along with the information in ref_entry) to 20 * describe a single cached reference. This data structure only 21 * occurs embedded in a union in struct ref_entry, and only when 22 * (ref_entry->flag & REF_DIR) is zero. 23 */ 24struct ref_value { 25 /* 26 * The name of the object to which this reference resolves 27 * (which may be a tag object). If REF_ISBROKEN, this is 28 * null. If REF_ISSYMREF, then this is the name of the object 29 * referred to by the last reference in the symlink chain. 30 */ 31 struct object_id oid; 32 33 /* 34 * If REF_KNOWS_PEELED, then this field holds the peeled value 35 * of this reference, or null if the reference is known not to 36 * be peelable. See the documentation for peel_ref() for an 37 * exact definition of "peelable". 38 */ 39 struct object_id peeled; 40}; 41 42struct files_ref_store; 43 44/* 45 * Information used (along with the information in ref_entry) to 46 * describe a level in the hierarchy of references. This data 47 * structure only occurs embedded in a union in struct ref_entry, and 48 * only when (ref_entry.flag & REF_DIR) is set. In that case, 49 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 50 * in the directory have already been read: 51 * 52 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 53 * or packed references, already read. 54 * 55 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 56 * references that hasn't been read yet (nor has any of its 57 * subdirectories). 58 * 59 * Entries within a directory are stored within a growable array of 60 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 61 * sorted are sorted by their component name in strcmp() order and the 62 * remaining entries are unsorted. 63 * 64 * Loose references are read lazily, one directory at a time. When a 65 * directory of loose references is read, then all of the references 66 * in that directory are stored, and REF_INCOMPLETE stubs are created 67 * for any subdirectories, but the subdirectories themselves are not 68 * read. The reading is triggered by get_ref_dir(). 69 */ 70struct ref_dir { 71 int nr, alloc; 72 73 /* 74 * Entries with index 0 <= i < sorted are sorted by name. New 75 * entries are appended to the list unsorted, and are sorted 76 * only when required; thus we avoid the need to sort the list 77 * after the addition of every reference. 78 */ 79 int sorted; 80 81 /* A pointer to the files_ref_store that contains this ref_dir. */ 82 struct files_ref_store *ref_store; 83 84 struct ref_entry **entries; 85}; 86 87/* 88 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 89 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 90 * public values; see refs.h. 91 */ 92 93/* 94 * The field ref_entry->u.value.peeled of this value entry contains 95 * the correct peeled value for the reference, which might be 96 * null_sha1 if the reference is not a tag or if it is broken. 97 */ 98#define REF_KNOWS_PEELED 0x10 99 100/* ref_entry represents a directory of references */ 101#define REF_DIR 0x20 102 103/* 104 * Entry has not yet been read from disk (used only for REF_DIR 105 * entries representing loose references) 106 */ 107#define REF_INCOMPLETE 0x40 108 109/* 110 * A ref_entry represents either a reference or a "subdirectory" of 111 * references. 112 * 113 * Each directory in the reference namespace is represented by a 114 * ref_entry with (flags & REF_DIR) set and containing a subdir member 115 * that holds the entries in that directory that have been read so 116 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 117 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 118 * used for loose reference directories. 119 * 120 * References are represented by a ref_entry with (flags & REF_DIR) 121 * unset and a value member that describes the reference's value. The 122 * flag member is at the ref_entry level, but it is also needed to 123 * interpret the contents of the value field (in other words, a 124 * ref_value object is not very much use without the enclosing 125 * ref_entry). 126 * 127 * Reference names cannot end with slash and directories' names are 128 * always stored with a trailing slash (except for the top-level 129 * directory, which is always denoted by ""). This has two nice 130 * consequences: (1) when the entries in each subdir are sorted 131 * lexicographically by name (as they usually are), the references in 132 * a whole tree can be generated in lexicographic order by traversing 133 * the tree in left-to-right, depth-first order; (2) the names of 134 * references and subdirectories cannot conflict, and therefore the 135 * presence of an empty subdirectory does not block the creation of a 136 * similarly-named reference. (The fact that reference names with the 137 * same leading components can conflict *with each other* is a 138 * separate issue that is regulated by verify_refname_available().) 139 * 140 * Please note that the name field contains the fully-qualified 141 * reference (or subdirectory) name. Space could be saved by only 142 * storing the relative names. But that would require the full names 143 * to be generated on the fly when iterating in do_for_each_ref(), and 144 * would break callback functions, who have always been able to assume 145 * that the name strings that they are passed will not be freed during 146 * the iteration. 147 */ 148struct ref_entry { 149 unsigned char flag; /* ISSYMREF? ISPACKED? */ 150 union { 151 struct ref_value value; /* if not (flags&REF_DIR) */ 152 struct ref_dir subdir; /* if (flags&REF_DIR) */ 153 } u; 154 /* 155 * The full name of the reference (e.g., "refs/heads/master") 156 * or the full name of the directory with a trailing slash 157 * (e.g., "refs/heads/"): 158 */ 159 char name[FLEX_ARRAY]; 160}; 161 162static void read_loose_refs(const char *dirname, struct ref_dir *dir); 163static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len); 164static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 165 const char *dirname, size_t len, 166 int incomplete); 167static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry); 168 169static struct ref_dir *get_ref_dir(struct ref_entry *entry) 170{ 171 struct ref_dir *dir; 172 assert(entry->flag & REF_DIR); 173 dir = &entry->u.subdir; 174 if (entry->flag & REF_INCOMPLETE) { 175 read_loose_refs(entry->name, dir); 176 177 /* 178 * Manually add refs/bisect, which, being 179 * per-worktree, might not appear in the directory 180 * listing for refs/ in the main repo. 181 */ 182 if (!strcmp(entry->name, "refs/")) { 183 int pos = search_ref_dir(dir, "refs/bisect/", 12); 184 if (pos < 0) { 185 struct ref_entry *child_entry; 186 child_entry = create_dir_entry(dir->ref_store, 187 "refs/bisect/", 188 12, 1); 189 add_entry_to_dir(dir, child_entry); 190 read_loose_refs("refs/bisect", 191 &child_entry->u.subdir); 192 } 193 } 194 entry->flag &= ~REF_INCOMPLETE; 195 } 196 return dir; 197} 198 199static struct ref_entry *create_ref_entry(const char *refname, 200 const unsigned char *sha1, int flag, 201 int check_name) 202{ 203 struct ref_entry *ref; 204 205 if (check_name && 206 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 207 die("Reference has invalid format: '%s'", refname); 208 FLEX_ALLOC_STR(ref, name, refname); 209 hashcpy(ref->u.value.oid.hash, sha1); 210 oidclr(&ref->u.value.peeled); 211 ref->flag = flag; 212 return ref; 213} 214 215static void clear_ref_dir(struct ref_dir *dir); 216 217static void free_ref_entry(struct ref_entry *entry) 218{ 219 if (entry->flag & REF_DIR) { 220 /* 221 * Do not use get_ref_dir() here, as that might 222 * trigger the reading of loose refs. 223 */ 224 clear_ref_dir(&entry->u.subdir); 225 } 226 free(entry); 227} 228 229/* 230 * Add a ref_entry to the end of dir (unsorted). Entry is always 231 * stored directly in dir; no recursion into subdirectories is 232 * done. 233 */ 234static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) 235{ 236 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 237 dir->entries[dir->nr++] = entry; 238 /* optimize for the case that entries are added in order */ 239 if (dir->nr == 1 || 240 (dir->nr == dir->sorted + 1 && 241 strcmp(dir->entries[dir->nr - 2]->name, 242 dir->entries[dir->nr - 1]->name) < 0)) 243 dir->sorted = dir->nr; 244} 245 246/* 247 * Clear and free all entries in dir, recursively. 248 */ 249static void clear_ref_dir(struct ref_dir *dir) 250{ 251 int i; 252 for (i = 0; i < dir->nr; i++) 253 free_ref_entry(dir->entries[i]); 254 free(dir->entries); 255 dir->sorted = dir->nr = dir->alloc = 0; 256 dir->entries = NULL; 257} 258 259/* 260 * Create a struct ref_entry object for the specified dirname. 261 * dirname is the name of the directory with a trailing slash (e.g., 262 * "refs/heads/") or "" for the top-level directory. 263 */ 264static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 265 const char *dirname, size_t len, 266 int incomplete) 267{ 268 struct ref_entry *direntry; 269 FLEX_ALLOC_MEM(direntry, name, dirname, len); 270 direntry->u.subdir.ref_store = ref_store; 271 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 272 return direntry; 273} 274 275static int ref_entry_cmp(const void *a, const void *b) 276{ 277 struct ref_entry *one = *(struct ref_entry **)a; 278 struct ref_entry *two = *(struct ref_entry **)b; 279 return strcmp(one->name, two->name); 280} 281 282static void sort_ref_dir(struct ref_dir *dir); 283 284struct string_slice { 285 size_t len; 286 const char *str; 287}; 288 289static int ref_entry_cmp_sslice(const void *key_, const void *ent_) 290{ 291 const struct string_slice *key = key_; 292 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; 293 int cmp = strncmp(key->str, ent->name, key->len); 294 if (cmp) 295 return cmp; 296 return '\0' - (unsigned char)ent->name[key->len]; 297} 298 299/* 300 * Return the index of the entry with the given refname from the 301 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 302 * no such entry is found. dir must already be complete. 303 */ 304static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 305{ 306 struct ref_entry **r; 307 struct string_slice key; 308 309 if (refname == NULL || !dir->nr) 310 return -1; 311 312 sort_ref_dir(dir); 313 key.len = len; 314 key.str = refname; 315 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 316 ref_entry_cmp_sslice); 317 318 if (r == NULL) 319 return -1; 320 321 return r - dir->entries; 322} 323 324/* 325 * Search for a directory entry directly within dir (without 326 * recursing). Sort dir if necessary. subdirname must be a directory 327 * name (i.e., end in '/'). If mkdir is set, then create the 328 * directory if it is missing; otherwise, return NULL if the desired 329 * directory cannot be found. dir must already be complete. 330 */ 331static struct ref_dir *search_for_subdir(struct ref_dir *dir, 332 const char *subdirname, size_t len, 333 int mkdir) 334{ 335 int entry_index = search_ref_dir(dir, subdirname, len); 336 struct ref_entry *entry; 337 if (entry_index == -1) { 338 if (!mkdir) 339 return NULL; 340 /* 341 * Since dir is complete, the absence of a subdir 342 * means that the subdir really doesn't exist; 343 * therefore, create an empty record for it but mark 344 * the record complete. 345 */ 346 entry = create_dir_entry(dir->ref_store, subdirname, len, 0); 347 add_entry_to_dir(dir, entry); 348 } else { 349 entry = dir->entries[entry_index]; 350 } 351 return get_ref_dir(entry); 352} 353 354/* 355 * If refname is a reference name, find the ref_dir within the dir 356 * tree that should hold refname. If refname is a directory name 357 * (i.e., ends in '/'), then return that ref_dir itself. dir must 358 * represent the top-level directory and must already be complete. 359 * Sort ref_dirs and recurse into subdirectories as necessary. If 360 * mkdir is set, then create any missing directories; otherwise, 361 * return NULL if the desired directory cannot be found. 362 */ 363static struct ref_dir *find_containing_dir(struct ref_dir *dir, 364 const char *refname, int mkdir) 365{ 366 const char *slash; 367 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 368 size_t dirnamelen = slash - refname + 1; 369 struct ref_dir *subdir; 370 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 371 if (!subdir) { 372 dir = NULL; 373 break; 374 } 375 dir = subdir; 376 } 377 378 return dir; 379} 380 381/* 382 * Find the value entry with the given name in dir, sorting ref_dirs 383 * and recursing into subdirectories as necessary. If the name is not 384 * found or it corresponds to a directory entry, return NULL. 385 */ 386static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) 387{ 388 int entry_index; 389 struct ref_entry *entry; 390 dir = find_containing_dir(dir, refname, 0); 391 if (!dir) 392 return NULL; 393 entry_index = search_ref_dir(dir, refname, strlen(refname)); 394 if (entry_index == -1) 395 return NULL; 396 entry = dir->entries[entry_index]; 397 return (entry->flag & REF_DIR) ? NULL : entry; 398} 399 400/* 401 * Remove the entry with the given name from dir, recursing into 402 * subdirectories as necessary. If refname is the name of a directory 403 * (i.e., ends with '/'), then remove the directory and its contents. 404 * If the removal was successful, return the number of entries 405 * remaining in the directory entry that contained the deleted entry. 406 * If the name was not found, return -1. Please note that this 407 * function only deletes the entry from the cache; it does not delete 408 * it from the filesystem or ensure that other cache entries (which 409 * might be symbolic references to the removed entry) are updated. 410 * Nor does it remove any containing dir entries that might be made 411 * empty by the removal. dir must represent the top-level directory 412 * and must already be complete. 413 */ 414static int remove_entry(struct ref_dir *dir, const char *refname) 415{ 416 int refname_len = strlen(refname); 417 int entry_index; 418 struct ref_entry *entry; 419 int is_dir = refname[refname_len - 1] == '/'; 420 if (is_dir) { 421 /* 422 * refname represents a reference directory. Remove 423 * the trailing slash; otherwise we will get the 424 * directory *representing* refname rather than the 425 * one *containing* it. 426 */ 427 char *dirname = xmemdupz(refname, refname_len - 1); 428 dir = find_containing_dir(dir, dirname, 0); 429 free(dirname); 430 } else { 431 dir = find_containing_dir(dir, refname, 0); 432 } 433 if (!dir) 434 return -1; 435 entry_index = search_ref_dir(dir, refname, refname_len); 436 if (entry_index == -1) 437 return -1; 438 entry = dir->entries[entry_index]; 439 440 memmove(&dir->entries[entry_index], 441 &dir->entries[entry_index + 1], 442 (dir->nr - entry_index - 1) * sizeof(*dir->entries) 443 ); 444 dir->nr--; 445 if (dir->sorted > entry_index) 446 dir->sorted--; 447 free_ref_entry(entry); 448 return dir->nr; 449} 450 451/* 452 * Add a ref_entry to the ref_dir (unsorted), recursing into 453 * subdirectories as necessary. dir must represent the top-level 454 * directory. Return 0 on success. 455 */ 456static int add_ref(struct ref_dir *dir, struct ref_entry *ref) 457{ 458 dir = find_containing_dir(dir, ref->name, 1); 459 if (!dir) 460 return -1; 461 add_entry_to_dir(dir, ref); 462 return 0; 463} 464 465/* 466 * Emit a warning and return true iff ref1 and ref2 have the same name 467 * and the same sha1. Die if they have the same name but different 468 * sha1s. 469 */ 470static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) 471{ 472 if (strcmp(ref1->name, ref2->name)) 473 return 0; 474 475 /* Duplicate name; make sure that they don't conflict: */ 476 477 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 478 /* This is impossible by construction */ 479 die("Reference directory conflict: %s", ref1->name); 480 481 if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 482 die("Duplicated ref, and SHA1s don't match: %s", ref1->name); 483 484 warning("Duplicated ref: %s", ref1->name); 485 return 1; 486} 487 488/* 489 * Sort the entries in dir non-recursively (if they are not already 490 * sorted) and remove any duplicate entries. 491 */ 492static void sort_ref_dir(struct ref_dir *dir) 493{ 494 int i, j; 495 struct ref_entry *last = NULL; 496 497 /* 498 * This check also prevents passing a zero-length array to qsort(), 499 * which is a problem on some platforms. 500 */ 501 if (dir->sorted == dir->nr) 502 return; 503 504 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 505 506 /* Remove any duplicates: */ 507 for (i = 0, j = 0; j < dir->nr; j++) { 508 struct ref_entry *entry = dir->entries[j]; 509 if (last && is_dup_ref(last, entry)) 510 free_ref_entry(entry); 511 else 512 last = dir->entries[i++] = entry; 513 } 514 dir->sorted = dir->nr = i; 515} 516 517/* 518 * Return true if refname, which has the specified oid and flags, can 519 * be resolved to an object in the database. If the referred-to object 520 * does not exist, emit a warning and return false. 521 */ 522static int ref_resolves_to_object(const char *refname, 523 const struct object_id *oid, 524 unsigned int flags) 525{ 526 if (flags & REF_ISBROKEN) 527 return 0; 528 if (!has_sha1_file(oid->hash)) { 529 error("%s does not point to a valid object!", refname); 530 return 0; 531 } 532 return 1; 533} 534 535/* 536 * Return true if the reference described by entry can be resolved to 537 * an object in the database; otherwise, emit a warning and return 538 * false. 539 */ 540static int entry_resolves_to_object(struct ref_entry *entry) 541{ 542 return ref_resolves_to_object(entry->name, 543 &entry->u.value.oid, entry->flag); 544} 545 546typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); 547 548/* 549 * Call fn for each reference in dir that has index in the range 550 * offset <= index < dir->nr. Recurse into subdirectories that are in 551 * that index range, sorting them before iterating. This function 552 * does not sort dir itself; it should be sorted beforehand. fn is 553 * called for all references, including broken ones. 554 */ 555static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 556 each_ref_entry_fn fn, void *cb_data) 557{ 558 int i; 559 assert(dir->sorted == dir->nr); 560 for (i = offset; i < dir->nr; i++) { 561 struct ref_entry *entry = dir->entries[i]; 562 int retval; 563 if (entry->flag & REF_DIR) { 564 struct ref_dir *subdir = get_ref_dir(entry); 565 sort_ref_dir(subdir); 566 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 567 } else { 568 retval = fn(entry, cb_data); 569 } 570 if (retval) 571 return retval; 572 } 573 return 0; 574} 575 576/* 577 * Load all of the refs from the dir into our in-memory cache. The hard work 578 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 579 * through all of the sub-directories. We do not even need to care about 580 * sorting, as traversal order does not matter to us. 581 */ 582static void prime_ref_dir(struct ref_dir *dir) 583{ 584 int i; 585 for (i = 0; i < dir->nr; i++) { 586 struct ref_entry *entry = dir->entries[i]; 587 if (entry->flag & REF_DIR) 588 prime_ref_dir(get_ref_dir(entry)); 589 } 590} 591 592/* 593 * A level in the reference hierarchy that is currently being iterated 594 * through. 595 */ 596struct cache_ref_iterator_level { 597 /* 598 * The ref_dir being iterated over at this level. The ref_dir 599 * is sorted before being stored here. 600 */ 601 struct ref_dir *dir; 602 603 /* 604 * The index of the current entry within dir (which might 605 * itself be a directory). If index == -1, then the iteration 606 * hasn't yet begun. If index == dir->nr, then the iteration 607 * through this level is over. 608 */ 609 int index; 610}; 611 612/* 613 * Represent an iteration through a ref_dir in the memory cache. The 614 * iteration recurses through subdirectories. 615 */ 616struct cache_ref_iterator { 617 struct ref_iterator base; 618 619 /* 620 * The number of levels currently on the stack. This is always 621 * at least 1, because when it becomes zero the iteration is 622 * ended and this struct is freed. 623 */ 624 size_t levels_nr; 625 626 /* The number of levels that have been allocated on the stack */ 627 size_t levels_alloc; 628 629 /* 630 * A stack of levels. levels[0] is the uppermost level that is 631 * being iterated over in this iteration. (This is not 632 * necessary the top level in the references hierarchy. If we 633 * are iterating through a subtree, then levels[0] will hold 634 * the ref_dir for that subtree, and subsequent levels will go 635 * on from there.) 636 */ 637 struct cache_ref_iterator_level *levels; 638}; 639 640static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator) 641{ 642 struct cache_ref_iterator *iter = 643 (struct cache_ref_iterator *)ref_iterator; 644 645 while (1) { 646 struct cache_ref_iterator_level *level = 647 &iter->levels[iter->levels_nr - 1]; 648 struct ref_dir *dir = level->dir; 649 struct ref_entry *entry; 650 651 if (level->index == -1) 652 sort_ref_dir(dir); 653 654 if (++level->index == level->dir->nr) { 655 /* This level is exhausted; pop up a level */ 656 if (--iter->levels_nr == 0) 657 return ref_iterator_abort(ref_iterator); 658 659 continue; 660 } 661 662 entry = dir->entries[level->index]; 663 664 if (entry->flag & REF_DIR) { 665 /* push down a level */ 666 ALLOC_GROW(iter->levels, iter->levels_nr + 1, 667 iter->levels_alloc); 668 669 level = &iter->levels[iter->levels_nr++]; 670 level->dir = get_ref_dir(entry); 671 level->index = -1; 672 } else { 673 iter->base.refname = entry->name; 674 iter->base.oid = &entry->u.value.oid; 675 iter->base.flags = entry->flag; 676 return ITER_OK; 677 } 678 } 679} 680 681static enum peel_status peel_entry(struct ref_entry *entry, int repeel); 682 683static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator, 684 struct object_id *peeled) 685{ 686 struct cache_ref_iterator *iter = 687 (struct cache_ref_iterator *)ref_iterator; 688 struct cache_ref_iterator_level *level; 689 struct ref_entry *entry; 690 691 level = &iter->levels[iter->levels_nr - 1]; 692 693 if (level->index == -1) 694 die("BUG: peel called before advance for cache iterator"); 695 696 entry = level->dir->entries[level->index]; 697 698 if (peel_entry(entry, 0)) 699 return -1; 700 hashcpy(peeled->hash, entry->u.value.peeled.hash); 701 return 0; 702} 703 704static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator) 705{ 706 struct cache_ref_iterator *iter = 707 (struct cache_ref_iterator *)ref_iterator; 708 709 free(iter->levels); 710 base_ref_iterator_free(ref_iterator); 711 return ITER_DONE; 712} 713 714static struct ref_iterator_vtable cache_ref_iterator_vtable = { 715 cache_ref_iterator_advance, 716 cache_ref_iterator_peel, 717 cache_ref_iterator_abort 718}; 719 720static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir) 721{ 722 struct cache_ref_iterator *iter; 723 struct ref_iterator *ref_iterator; 724 struct cache_ref_iterator_level *level; 725 726 iter = xcalloc(1, sizeof(*iter)); 727 ref_iterator = &iter->base; 728 base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable); 729 ALLOC_GROW(iter->levels, 10, iter->levels_alloc); 730 731 iter->levels_nr = 1; 732 level = &iter->levels[0]; 733 level->index = -1; 734 level->dir = dir; 735 736 return ref_iterator; 737} 738 739struct nonmatching_ref_data { 740 const struct string_list *skip; 741 const char *conflicting_refname; 742}; 743 744static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) 745{ 746 struct nonmatching_ref_data *data = vdata; 747 748 if (data->skip && string_list_has_string(data->skip, entry->name)) 749 return 0; 750 751 data->conflicting_refname = entry->name; 752 return 1; 753} 754 755/* 756 * Return 0 if a reference named refname could be created without 757 * conflicting with the name of an existing reference in dir. 758 * See verify_refname_available for more information. 759 */ 760static int verify_refname_available_dir(const char *refname, 761 const struct string_list *extras, 762 const struct string_list *skip, 763 struct ref_dir *dir, 764 struct strbuf *err) 765{ 766 const char *slash; 767 const char *extra_refname; 768 int pos; 769 struct strbuf dirname = STRBUF_INIT; 770 int ret = -1; 771 772 /* 773 * For the sake of comments in this function, suppose that 774 * refname is "refs/foo/bar". 775 */ 776 777 assert(err); 778 779 strbuf_grow(&dirname, strlen(refname) + 1); 780 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 781 /* Expand dirname to the new prefix, not including the trailing slash: */ 782 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 783 784 /* 785 * We are still at a leading dir of the refname (e.g., 786 * "refs/foo"; if there is a reference with that name, 787 * it is a conflict, *unless* it is in skip. 788 */ 789 if (dir) { 790 pos = search_ref_dir(dir, dirname.buf, dirname.len); 791 if (pos >= 0 && 792 (!skip || !string_list_has_string(skip, dirname.buf))) { 793 /* 794 * We found a reference whose name is 795 * a proper prefix of refname; e.g., 796 * "refs/foo", and is not in skip. 797 */ 798 strbuf_addf(err, "'%s' exists; cannot create '%s'", 799 dirname.buf, refname); 800 goto cleanup; 801 } 802 } 803 804 if (extras && string_list_has_string(extras, dirname.buf) && 805 (!skip || !string_list_has_string(skip, dirname.buf))) { 806 strbuf_addf(err, "cannot process '%s' and '%s' at the same time", 807 refname, dirname.buf); 808 goto cleanup; 809 } 810 811 /* 812 * Otherwise, we can try to continue our search with 813 * the next component. So try to look up the 814 * directory, e.g., "refs/foo/". If we come up empty, 815 * we know there is nothing under this whole prefix, 816 * but even in that case we still have to continue the 817 * search for conflicts with extras. 818 */ 819 strbuf_addch(&dirname, '/'); 820 if (dir) { 821 pos = search_ref_dir(dir, dirname.buf, dirname.len); 822 if (pos < 0) { 823 /* 824 * There was no directory "refs/foo/", 825 * so there is nothing under this 826 * whole prefix. So there is no need 827 * to continue looking for conflicting 828 * references. But we need to continue 829 * looking for conflicting extras. 830 */ 831 dir = NULL; 832 } else { 833 dir = get_ref_dir(dir->entries[pos]); 834 } 835 } 836 } 837 838 /* 839 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 840 * There is no point in searching for a reference with that 841 * name, because a refname isn't considered to conflict with 842 * itself. But we still need to check for references whose 843 * names are in the "refs/foo/bar/" namespace, because they 844 * *do* conflict. 845 */ 846 strbuf_addstr(&dirname, refname + dirname.len); 847 strbuf_addch(&dirname, '/'); 848 849 if (dir) { 850 pos = search_ref_dir(dir, dirname.buf, dirname.len); 851 852 if (pos >= 0) { 853 /* 854 * We found a directory named "$refname/" 855 * (e.g., "refs/foo/bar/"). It is a problem 856 * iff it contains any ref that is not in 857 * "skip". 858 */ 859 struct nonmatching_ref_data data; 860 861 data.skip = skip; 862 data.conflicting_refname = NULL; 863 dir = get_ref_dir(dir->entries[pos]); 864 sort_ref_dir(dir); 865 if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { 866 strbuf_addf(err, "'%s' exists; cannot create '%s'", 867 data.conflicting_refname, refname); 868 goto cleanup; 869 } 870 } 871 } 872 873 extra_refname = find_descendant_ref(dirname.buf, extras, skip); 874 if (extra_refname) 875 strbuf_addf(err, "cannot process '%s' and '%s' at the same time", 876 refname, extra_refname); 877 else 878 ret = 0; 879 880cleanup: 881 strbuf_release(&dirname); 882 return ret; 883} 884 885struct packed_ref_cache { 886 struct ref_entry *root; 887 888 /* 889 * Count of references to the data structure in this instance, 890 * including the pointer from files_ref_store::packed if any. 891 * The data will not be freed as long as the reference count 892 * is nonzero. 893 */ 894 unsigned int referrers; 895 896 /* 897 * Iff the packed-refs file associated with this instance is 898 * currently locked for writing, this points at the associated 899 * lock (which is owned by somebody else). The referrer count 900 * is also incremented when the file is locked and decremented 901 * when it is unlocked. 902 */ 903 struct lock_file *lock; 904 905 /* The metadata from when this packed-refs cache was read */ 906 struct stat_validity validity; 907}; 908 909/* 910 * Future: need to be in "struct repository" 911 * when doing a full libification. 912 */ 913struct files_ref_store { 914 struct ref_store base; 915 struct ref_entry *loose; 916 struct packed_ref_cache *packed; 917}; 918 919/* Lock used for the main packed-refs file: */ 920static struct lock_file packlock; 921 922/* 923 * Increment the reference count of *packed_refs. 924 */ 925static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 926{ 927 packed_refs->referrers++; 928} 929 930/* 931 * Decrease the reference count of *packed_refs. If it goes to zero, 932 * free *packed_refs and return true; otherwise return false. 933 */ 934static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 935{ 936 if (!--packed_refs->referrers) { 937 free_ref_entry(packed_refs->root); 938 stat_validity_clear(&packed_refs->validity); 939 free(packed_refs); 940 return 1; 941 } else { 942 return 0; 943 } 944} 945 946static void clear_packed_ref_cache(struct files_ref_store *refs) 947{ 948 if (refs->packed) { 949 struct packed_ref_cache *packed_refs = refs->packed; 950 951 if (packed_refs->lock) 952 die("internal error: packed-ref cache cleared while locked"); 953 refs->packed = NULL; 954 release_packed_ref_cache(packed_refs); 955 } 956} 957 958static void clear_loose_ref_cache(struct files_ref_store *refs) 959{ 960 if (refs->loose) { 961 free_ref_entry(refs->loose); 962 refs->loose = NULL; 963 } 964} 965 966/* 967 * Create a new submodule ref cache and add it to the internal 968 * set of caches. 969 */ 970static struct ref_store *files_ref_store_create(const char *submodule) 971{ 972 struct files_ref_store *refs = xcalloc(1, sizeof(*refs)); 973 struct ref_store *ref_store = (struct ref_store *)refs; 974 975 base_ref_store_init(ref_store, &refs_be_files, submodule); 976 977 return ref_store; 978} 979 980/* 981 * Downcast ref_store to files_ref_store. Die if ref_store is not a 982 * files_ref_store. If submodule_allowed is not true, then also die if 983 * files_ref_store is for a submodule (i.e., not for the main 984 * repository). caller is used in any necessary error messages. 985 */ 986static struct files_ref_store *files_downcast( 987 struct ref_store *ref_store, int submodule_allowed, 988 const char *caller) 989{ 990 if (ref_store->be != &refs_be_files) 991 die("BUG: ref_store is type \"%s\" not \"files\" in %s", 992 ref_store->be->name, caller); 993 994 if (!submodule_allowed) 995 assert_main_repository(ref_store, caller); 996 997 return (struct files_ref_store *)ref_store; 998} 9991000/*1001 * Return a pointer to the reference store for the specified1002 * submodule. For the main repository, use submodule==NULL; such a1003 * call cannot fail. For a submodule, the submodule must exist and be1004 * a nonbare repository, otherwise return NULL. Verify that the1005 * reference store is a files_ref_store, and cast it to that type1006 * before returning it.1007 */1008static struct files_ref_store *get_files_ref_store(const char *submodule,1009 const char *caller)1010{1011 struct ref_store *refs = get_ref_store(submodule);10121013 return refs ? files_downcast(refs, 1, caller) : NULL;1014}10151016/* The length of a peeled reference line in packed-refs, including EOL: */1017#define PEELED_LINE_LENGTH 4210181019/*1020 * The packed-refs header line that we write out. Perhaps other1021 * traits will be added later. The trailing space is required.1022 */1023static const char PACKED_REFS_HEADER[] =1024 "# pack-refs with: peeled fully-peeled \n";10251026/*1027 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1028 * Return a pointer to the refname within the line (null-terminated),1029 * or NULL if there was a problem.1030 */1031static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)1032{1033 const char *ref;10341035 /*1036 * 42: the answer to everything.1037 *1038 * In this case, it happens to be the answer to1039 * 40 (length of sha1 hex representation)1040 * +1 (space in between hex and name)1041 * +1 (newline at the end of the line)1042 */1043 if (line->len <= 42)1044 return NULL;10451046 if (get_sha1_hex(line->buf, sha1) < 0)1047 return NULL;1048 if (!isspace(line->buf[40]))1049 return NULL;10501051 ref = line->buf + 41;1052 if (isspace(*ref))1053 return NULL;10541055 if (line->buf[line->len - 1] != '\n')1056 return NULL;1057 line->buf[--line->len] = 0;10581059 return ref;1060}10611062/*1063 * Read f, which is a packed-refs file, into dir.1064 *1065 * A comment line of the form "# pack-refs with: " may contain zero or1066 * more traits. We interpret the traits as follows:1067 *1068 * No traits:1069 *1070 * Probably no references are peeled. But if the file contains a1071 * peeled value for a reference, we will use it.1072 *1073 * peeled:1074 *1075 * References under "refs/tags/", if they *can* be peeled, *are*1076 * peeled in this file. References outside of "refs/tags/" are1077 * probably not peeled even if they could have been, but if we find1078 * a peeled value for such a reference we will use it.1079 *1080 * fully-peeled:1081 *1082 * All references in the file that can be peeled are peeled.1083 * Inversely (and this is more important), any references in the1084 * file for which no peeled value is recorded is not peelable. This1085 * trait should typically be written alongside "peeled" for1086 * compatibility with older clients, but we do not require it1087 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1088 */1089static void read_packed_refs(FILE *f, struct ref_dir *dir)1090{1091 struct ref_entry *last = NULL;1092 struct strbuf line = STRBUF_INIT;1093 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10941095 while (strbuf_getwholeline(&line, f, '\n') != EOF) {1096 unsigned char sha1[20];1097 const char *refname;1098 const char *traits;10991100 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {1101 if (strstr(traits, " fully-peeled "))1102 peeled = PEELED_FULLY;1103 else if (strstr(traits, " peeled "))1104 peeled = PEELED_TAGS;1105 /* perhaps other traits later as well */1106 continue;1107 }11081109 refname = parse_ref_line(&line, sha1);1110 if (refname) {1111 int flag = REF_ISPACKED;11121113 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1114 if (!refname_is_safe(refname))1115 die("packed refname is dangerous: %s", refname);1116 hashclr(sha1);1117 flag |= REF_BAD_NAME | REF_ISBROKEN;1118 }1119 last = create_ref_entry(refname, sha1, flag, 0);1120 if (peeled == PEELED_FULLY ||1121 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1122 last->flag |= REF_KNOWS_PEELED;1123 add_ref(dir, last);1124 continue;1125 }1126 if (last &&1127 line.buf[0] == '^' &&1128 line.len == PEELED_LINE_LENGTH &&1129 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&1130 !get_sha1_hex(line.buf + 1, sha1)) {1131 hashcpy(last->u.value.peeled.hash, sha1);1132 /*1133 * Regardless of what the file header said,1134 * we definitely know the value of *this*1135 * reference:1136 */1137 last->flag |= REF_KNOWS_PEELED;1138 }1139 }11401141 strbuf_release(&line);1142}11431144/*1145 * Get the packed_ref_cache for the specified files_ref_store,1146 * creating it if necessary.1147 */1148static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1149{1150 char *packed_refs_file;11511152 if (*refs->base.submodule)1153 packed_refs_file = git_pathdup_submodule(refs->base.submodule,1154 "packed-refs");1155 else1156 packed_refs_file = git_pathdup("packed-refs");11571158 if (refs->packed &&1159 !stat_validity_check(&refs->packed->validity, packed_refs_file))1160 clear_packed_ref_cache(refs);11611162 if (!refs->packed) {1163 FILE *f;11641165 refs->packed = xcalloc(1, sizeof(*refs->packed));1166 acquire_packed_ref_cache(refs->packed);1167 refs->packed->root = create_dir_entry(refs, "", 0, 0);1168 f = fopen(packed_refs_file, "r");1169 if (f) {1170 stat_validity_update(&refs->packed->validity, fileno(f));1171 read_packed_refs(f, get_ref_dir(refs->packed->root));1172 fclose(f);1173 }1174 }1175 free(packed_refs_file);1176 return refs->packed;1177}11781179static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1180{1181 return get_ref_dir(packed_ref_cache->root);1182}11831184static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1185{1186 return get_packed_ref_dir(get_packed_ref_cache(refs));1187}11881189/*1190 * Add a reference to the in-memory packed reference cache. This may1191 * only be called while the packed-refs file is locked (see1192 * lock_packed_refs()). To actually write the packed-refs file, call1193 * commit_packed_refs().1194 */1195static void add_packed_ref(struct files_ref_store *refs,1196 const char *refname, const unsigned char *sha1)1197{1198 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);11991200 if (!packed_ref_cache->lock)1201 die("internal error: packed refs not locked");1202 add_ref(get_packed_ref_dir(packed_ref_cache),1203 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1204}12051206/*1207 * Read the loose references from the namespace dirname into dir1208 * (without recursing). dirname must end with '/'. dir must be the1209 * directory entry corresponding to dirname.1210 */1211static void read_loose_refs(const char *dirname, struct ref_dir *dir)1212{1213 struct files_ref_store *refs = dir->ref_store;1214 DIR *d;1215 struct dirent *de;1216 int dirnamelen = strlen(dirname);1217 struct strbuf refname;1218 struct strbuf path = STRBUF_INIT;1219 size_t path_baselen;12201221 if (*refs->base.submodule)1222 strbuf_git_path_submodule(&path, refs->base.submodule, "%s", dirname);1223 else1224 strbuf_git_path(&path, "%s", dirname);1225 path_baselen = path.len;12261227 d = opendir(path.buf);1228 if (!d) {1229 strbuf_release(&path);1230 return;1231 }12321233 strbuf_init(&refname, dirnamelen + 257);1234 strbuf_add(&refname, dirname, dirnamelen);12351236 while ((de = readdir(d)) != NULL) {1237 unsigned char sha1[20];1238 struct stat st;1239 int flag;12401241 if (de->d_name[0] == '.')1242 continue;1243 if (ends_with(de->d_name, ".lock"))1244 continue;1245 strbuf_addstr(&refname, de->d_name);1246 strbuf_addstr(&path, de->d_name);1247 if (stat(path.buf, &st) < 0) {1248 ; /* silently ignore */1249 } else if (S_ISDIR(st.st_mode)) {1250 strbuf_addch(&refname, '/');1251 add_entry_to_dir(dir,1252 create_dir_entry(refs, refname.buf,1253 refname.len, 1));1254 } else {1255 int read_ok;12561257 if (*refs->base.submodule) {1258 hashclr(sha1);1259 flag = 0;1260 read_ok = !resolve_gitlink_ref(refs->base.submodule,1261 refname.buf, sha1);1262 } else {1263 read_ok = !read_ref_full(refname.buf,1264 RESOLVE_REF_READING,1265 sha1, &flag);1266 }12671268 if (!read_ok) {1269 hashclr(sha1);1270 flag |= REF_ISBROKEN;1271 } else if (is_null_sha1(sha1)) {1272 /*1273 * It is so astronomically unlikely1274 * that NULL_SHA1 is the SHA-1 of an1275 * actual object that we consider its1276 * appearance in a loose reference1277 * file to be repo corruption1278 * (probably due to a software bug).1279 */1280 flag |= REF_ISBROKEN;1281 }12821283 if (check_refname_format(refname.buf,1284 REFNAME_ALLOW_ONELEVEL)) {1285 if (!refname_is_safe(refname.buf))1286 die("loose refname is dangerous: %s", refname.buf);1287 hashclr(sha1);1288 flag |= REF_BAD_NAME | REF_ISBROKEN;1289 }1290 add_entry_to_dir(dir,1291 create_ref_entry(refname.buf, sha1, flag, 0));1292 }1293 strbuf_setlen(&refname, dirnamelen);1294 strbuf_setlen(&path, path_baselen);1295 }1296 strbuf_release(&refname);1297 strbuf_release(&path);1298 closedir(d);1299}13001301static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1302{1303 if (!refs->loose) {1304 /*1305 * Mark the top-level directory complete because we1306 * are about to read the only subdirectory that can1307 * hold references:1308 */1309 refs->loose = create_dir_entry(refs, "", 0, 0);1310 /*1311 * Create an incomplete entry for "refs/":1312 */1313 add_entry_to_dir(get_ref_dir(refs->loose),1314 create_dir_entry(refs, "refs/", 5, 1));1315 }1316 return get_ref_dir(refs->loose);1317}13181319/*1320 * Return the ref_entry for the given refname from the packed1321 * references. If it does not exist, return NULL.1322 */1323static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1324 const char *refname)1325{1326 return find_ref(get_packed_refs(refs), refname);1327}13281329/*1330 * A loose ref file doesn't exist; check for a packed ref.1331 */1332static int resolve_packed_ref(struct files_ref_store *refs,1333 const char *refname,1334 unsigned char *sha1, unsigned int *flags)1335{1336 struct ref_entry *entry;13371338 /*1339 * The loose reference file does not exist; check for a packed1340 * reference.1341 */1342 entry = get_packed_ref(refs, refname);1343 if (entry) {1344 hashcpy(sha1, entry->u.value.oid.hash);1345 *flags |= REF_ISPACKED;1346 return 0;1347 }1348 /* refname is not a packed reference. */1349 return -1;1350}13511352int read_raw_ref(const char *refname, unsigned char *sha1,1353 struct strbuf *referent, unsigned int *type)1354{1355 struct files_ref_store *refs =1356 get_files_ref_store(NULL, "read_raw_ref");1357 struct strbuf sb_contents = STRBUF_INIT;1358 struct strbuf sb_path = STRBUF_INIT;1359 const char *path;1360 const char *buf;1361 struct stat st;1362 int fd;1363 int ret = -1;1364 int save_errno;13651366 *type = 0;1367 strbuf_reset(&sb_path);1368 strbuf_git_path(&sb_path, "%s", refname);1369 path = sb_path.buf;13701371stat_ref:1372 /*1373 * We might have to loop back here to avoid a race1374 * condition: first we lstat() the file, then we try1375 * to read it as a link or as a file. But if somebody1376 * changes the type of the file (file <-> directory1377 * <-> symlink) between the lstat() and reading, then1378 * we don't want to report that as an error but rather1379 * try again starting with the lstat().1380 */13811382 if (lstat(path, &st) < 0) {1383 if (errno != ENOENT)1384 goto out;1385 if (resolve_packed_ref(refs, refname, sha1, type)) {1386 errno = ENOENT;1387 goto out;1388 }1389 ret = 0;1390 goto out;1391 }13921393 /* Follow "normalized" - ie "refs/.." symlinks by hand */1394 if (S_ISLNK(st.st_mode)) {1395 strbuf_reset(&sb_contents);1396 if (strbuf_readlink(&sb_contents, path, 0) < 0) {1397 if (errno == ENOENT || errno == EINVAL)1398 /* inconsistent with lstat; retry */1399 goto stat_ref;1400 else1401 goto out;1402 }1403 if (starts_with(sb_contents.buf, "refs/") &&1404 !check_refname_format(sb_contents.buf, 0)) {1405 strbuf_swap(&sb_contents, referent);1406 *type |= REF_ISSYMREF;1407 ret = 0;1408 goto out;1409 }1410 }14111412 /* Is it a directory? */1413 if (S_ISDIR(st.st_mode)) {1414 /*1415 * Even though there is a directory where the loose1416 * ref is supposed to be, there could still be a1417 * packed ref:1418 */1419 if (resolve_packed_ref(refs, refname, sha1, type)) {1420 errno = EISDIR;1421 goto out;1422 }1423 ret = 0;1424 goto out;1425 }14261427 /*1428 * Anything else, just open it and try to use it as1429 * a ref1430 */1431 fd = open(path, O_RDONLY);1432 if (fd < 0) {1433 if (errno == ENOENT)1434 /* inconsistent with lstat; retry */1435 goto stat_ref;1436 else1437 goto out;1438 }1439 strbuf_reset(&sb_contents);1440 if (strbuf_read(&sb_contents, fd, 256) < 0) {1441 int save_errno = errno;1442 close(fd);1443 errno = save_errno;1444 goto out;1445 }1446 close(fd);1447 strbuf_rtrim(&sb_contents);1448 buf = sb_contents.buf;1449 if (starts_with(buf, "ref:")) {1450 buf += 4;1451 while (isspace(*buf))1452 buf++;14531454 strbuf_reset(referent);1455 strbuf_addstr(referent, buf);1456 *type |= REF_ISSYMREF;1457 ret = 0;1458 goto out;1459 }14601461 /*1462 * Please note that FETCH_HEAD has additional1463 * data after the sha.1464 */1465 if (get_sha1_hex(buf, sha1) ||1466 (buf[40] != '\0' && !isspace(buf[40]))) {1467 *type |= REF_ISBROKEN;1468 errno = EINVAL;1469 goto out;1470 }14711472 ret = 0;14731474out:1475 save_errno = errno;1476 strbuf_release(&sb_path);1477 strbuf_release(&sb_contents);1478 errno = save_errno;1479 return ret;1480}14811482static void unlock_ref(struct ref_lock *lock)1483{1484 /* Do not free lock->lk -- atexit() still looks at them */1485 if (lock->lk)1486 rollback_lock_file(lock->lk);1487 free(lock->ref_name);1488 free(lock);1489}14901491#define MAXREFLEN (1024)14921493static int resolve_gitlink_ref_recursive(struct files_ref_store *refs,1494 const char *refname, unsigned char *sha1,1495 int recursion)1496{1497 int fd, len;1498 char buffer[128], *p;1499 char *path;15001501 if (recursion > SYMREF_MAXDEPTH || strlen(refname) > MAXREFLEN)1502 return -1;1503 path = *refs->base.submodule1504 ? git_pathdup_submodule(refs->base.submodule, "%s", refname)1505 : git_pathdup("%s", refname);1506 fd = open(path, O_RDONLY);1507 free(path);1508 if (fd < 0) {1509 unsigned int flags;15101511 return resolve_packed_ref(refs, refname, sha1, &flags);1512 }15131514 len = read(fd, buffer, sizeof(buffer)-1);1515 close(fd);1516 if (len < 0)1517 return -1;1518 while (len && isspace(buffer[len-1]))1519 len--;1520 buffer[len] = 0;15211522 /* Was it a detached head or an old-fashioned symlink? */1523 if (!get_sha1_hex(buffer, sha1))1524 return 0;15251526 /* Symref? */1527 if (strncmp(buffer, "ref:", 4))1528 return -1;1529 p = buffer + 4;1530 while (isspace(*p))1531 p++;15321533 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1534}15351536int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1537{1538 int len = strlen(path);1539 struct strbuf submodule = STRBUF_INIT;1540 struct files_ref_store *refs;15411542 while (len && path[len-1] == '/')1543 len--;1544 if (!len)1545 return -1;15461547 strbuf_add(&submodule, path, len);1548 refs = get_files_ref_store(submodule.buf, "resolve_gitlink_ref");1549 if (!refs) {1550 strbuf_release(&submodule);1551 return -1;1552 }1553 strbuf_release(&submodule);15541555 return resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1556}15571558/*1559 * Lock refname, without following symrefs, and set *lock_p to point1560 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1561 * and type similarly to read_raw_ref().1562 *1563 * The caller must verify that refname is a "safe" reference name (in1564 * the sense of refname_is_safe()) before calling this function.1565 *1566 * If the reference doesn't already exist, verify that refname doesn't1567 * have a D/F conflict with any existing references. extras and skip1568 * are passed to verify_refname_available_dir() for this check.1569 *1570 * If mustexist is not set and the reference is not found or is1571 * broken, lock the reference anyway but clear sha1.1572 *1573 * Return 0 on success. On failure, write an error message to err and1574 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1575 *1576 * Implementation note: This function is basically1577 *1578 * lock reference1579 * read_raw_ref()1580 *1581 * but it includes a lot more code to1582 * - Deal with possible races with other processes1583 * - Avoid calling verify_refname_available_dir() when it can be1584 * avoided, namely if we were successfully able to read the ref1585 * - Generate informative error messages in the case of failure1586 */1587static int lock_raw_ref(const char *refname, int mustexist,1588 const struct string_list *extras,1589 const struct string_list *skip,1590 struct ref_lock **lock_p,1591 struct strbuf *referent,1592 unsigned int *type,1593 struct strbuf *err)1594{1595 struct files_ref_store *refs =1596 get_files_ref_store(NULL, "lock_raw_ref");1597 struct ref_lock *lock;1598 struct strbuf ref_file = STRBUF_INIT;1599 int attempts_remaining = 3;1600 int ret = TRANSACTION_GENERIC_ERROR;16011602 assert(err);1603 *type = 0;16041605 /* First lock the file so it can't change out from under us. */16061607 *lock_p = lock = xcalloc(1, sizeof(*lock));16081609 lock->ref_name = xstrdup(refname);1610 strbuf_git_path(&ref_file, "%s", refname);16111612retry:1613 switch (safe_create_leading_directories(ref_file.buf)) {1614 case SCLD_OK:1615 break; /* success */1616 case SCLD_EXISTS:1617 /*1618 * Suppose refname is "refs/foo/bar". We just failed1619 * to create the containing directory, "refs/foo",1620 * because there was a non-directory in the way. This1621 * indicates a D/F conflict, probably because of1622 * another reference such as "refs/foo". There is no1623 * reason to expect this error to be transitory.1624 */1625 if (verify_refname_available(refname, extras, skip, err)) {1626 if (mustexist) {1627 /*1628 * To the user the relevant error is1629 * that the "mustexist" reference is1630 * missing:1631 */1632 strbuf_reset(err);1633 strbuf_addf(err, "unable to resolve reference '%s'",1634 refname);1635 } else {1636 /*1637 * The error message set by1638 * verify_refname_available_dir() is OK.1639 */1640 ret = TRANSACTION_NAME_CONFLICT;1641 }1642 } else {1643 /*1644 * The file that is in the way isn't a loose1645 * reference. Report it as a low-level1646 * failure.1647 */1648 strbuf_addf(err, "unable to create lock file %s.lock; "1649 "non-directory in the way",1650 ref_file.buf);1651 }1652 goto error_return;1653 case SCLD_VANISHED:1654 /* Maybe another process was tidying up. Try again. */1655 if (--attempts_remaining > 0)1656 goto retry;1657 /* fall through */1658 default:1659 strbuf_addf(err, "unable to create directory for %s",1660 ref_file.buf);1661 goto error_return;1662 }16631664 if (!lock->lk)1665 lock->lk = xcalloc(1, sizeof(struct lock_file));16661667 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {1668 if (errno == ENOENT && --attempts_remaining > 0) {1669 /*1670 * Maybe somebody just deleted one of the1671 * directories leading to ref_file. Try1672 * again:1673 */1674 goto retry;1675 } else {1676 unable_to_lock_message(ref_file.buf, errno, err);1677 goto error_return;1678 }1679 }16801681 /*1682 * Now we hold the lock and can read the reference without1683 * fear that its value will change.1684 */16851686 if (read_raw_ref(refname, lock->old_oid.hash, referent, type)) {1687 if (errno == ENOENT) {1688 if (mustexist) {1689 /* Garden variety missing reference. */1690 strbuf_addf(err, "unable to resolve reference '%s'",1691 refname);1692 goto error_return;1693 } else {1694 /*1695 * Reference is missing, but that's OK. We1696 * know that there is not a conflict with1697 * another loose reference because1698 * (supposing that we are trying to lock1699 * reference "refs/foo/bar"):1700 *1701 * - We were successfully able to create1702 * the lockfile refs/foo/bar.lock, so we1703 * know there cannot be a loose reference1704 * named "refs/foo".1705 *1706 * - We got ENOENT and not EISDIR, so we1707 * know that there cannot be a loose1708 * reference named "refs/foo/bar/baz".1709 */1710 }1711 } else if (errno == EISDIR) {1712 /*1713 * There is a directory in the way. It might have1714 * contained references that have been deleted. If1715 * we don't require that the reference already1716 * exists, try to remove the directory so that it1717 * doesn't cause trouble when we want to rename the1718 * lockfile into place later.1719 */1720 if (mustexist) {1721 /* Garden variety missing reference. */1722 strbuf_addf(err, "unable to resolve reference '%s'",1723 refname);1724 goto error_return;1725 } else if (remove_dir_recursively(&ref_file,1726 REMOVE_DIR_EMPTY_ONLY)) {1727 if (verify_refname_available_dir(1728 refname, extras, skip,1729 get_loose_refs(refs),1730 err)) {1731 /*1732 * The error message set by1733 * verify_refname_available() is OK.1734 */1735 ret = TRANSACTION_NAME_CONFLICT;1736 goto error_return;1737 } else {1738 /*1739 * We can't delete the directory,1740 * but we also don't know of any1741 * references that it should1742 * contain.1743 */1744 strbuf_addf(err, "there is a non-empty directory '%s' "1745 "blocking reference '%s'",1746 ref_file.buf, refname);1747 goto error_return;1748 }1749 }1750 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {1751 strbuf_addf(err, "unable to resolve reference '%s': "1752 "reference broken", refname);1753 goto error_return;1754 } else {1755 strbuf_addf(err, "unable to resolve reference '%s': %s",1756 refname, strerror(errno));1757 goto error_return;1758 }17591760 /*1761 * If the ref did not exist and we are creating it,1762 * make sure there is no existing packed ref whose1763 * name begins with our refname, nor a packed ref1764 * whose name is a proper prefix of our refname.1765 */1766 if (verify_refname_available_dir(1767 refname, extras, skip,1768 get_packed_refs(refs),1769 err)) {1770 goto error_return;1771 }1772 }17731774 ret = 0;1775 goto out;17761777error_return:1778 unlock_ref(lock);1779 *lock_p = NULL;17801781out:1782 strbuf_release(&ref_file);1783 return ret;1784}17851786/*1787 * Peel the entry (if possible) and return its new peel_status. If1788 * repeel is true, re-peel the entry even if there is an old peeled1789 * value that is already stored in it.1790 *1791 * It is OK to call this function with a packed reference entry that1792 * might be stale and might even refer to an object that has since1793 * been garbage-collected. In such a case, if the entry has1794 * REF_KNOWS_PEELED then leave the status unchanged and return1795 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1796 */1797static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1798{1799 enum peel_status status;18001801 if (entry->flag & REF_KNOWS_PEELED) {1802 if (repeel) {1803 entry->flag &= ~REF_KNOWS_PEELED;1804 oidclr(&entry->u.value.peeled);1805 } else {1806 return is_null_oid(&entry->u.value.peeled) ?1807 PEEL_NON_TAG : PEEL_PEELED;1808 }1809 }1810 if (entry->flag & REF_ISBROKEN)1811 return PEEL_BROKEN;1812 if (entry->flag & REF_ISSYMREF)1813 return PEEL_IS_SYMREF;18141815 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1816 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1817 entry->flag |= REF_KNOWS_PEELED;1818 return status;1819}18201821int peel_ref(const char *refname, unsigned char *sha1)1822{1823 struct files_ref_store *refs = get_files_ref_store(NULL, "peel_ref");1824 int flag;1825 unsigned char base[20];18261827 if (current_ref_iter && current_ref_iter->refname == refname) {1828 struct object_id peeled;18291830 if (ref_iterator_peel(current_ref_iter, &peeled))1831 return -1;1832 hashcpy(sha1, peeled.hash);1833 return 0;1834 }18351836 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1837 return -1;18381839 /*1840 * If the reference is packed, read its ref_entry from the1841 * cache in the hope that we already know its peeled value.1842 * We only try this optimization on packed references because1843 * (a) forcing the filling of the loose reference cache could1844 * be expensive and (b) loose references anyway usually do not1845 * have REF_KNOWS_PEELED.1846 */1847 if (flag & REF_ISPACKED) {1848 struct ref_entry *r = get_packed_ref(refs, refname);1849 if (r) {1850 if (peel_entry(r, 0))1851 return -1;1852 hashcpy(sha1, r->u.value.peeled.hash);1853 return 0;1854 }1855 }18561857 return peel_object(base, sha1);1858}18591860struct files_ref_iterator {1861 struct ref_iterator base;18621863 struct packed_ref_cache *packed_ref_cache;1864 struct ref_iterator *iter0;1865 unsigned int flags;1866};18671868static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)1869{1870 struct files_ref_iterator *iter =1871 (struct files_ref_iterator *)ref_iterator;1872 int ok;18731874 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {1875 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1876 !ref_resolves_to_object(iter->iter0->refname,1877 iter->iter0->oid,1878 iter->iter0->flags))1879 continue;18801881 iter->base.refname = iter->iter0->refname;1882 iter->base.oid = iter->iter0->oid;1883 iter->base.flags = iter->iter0->flags;1884 return ITER_OK;1885 }18861887 iter->iter0 = NULL;1888 if (ref_iterator_abort(ref_iterator) != ITER_DONE)1889 ok = ITER_ERROR;18901891 return ok;1892}18931894static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,1895 struct object_id *peeled)1896{1897 struct files_ref_iterator *iter =1898 (struct files_ref_iterator *)ref_iterator;18991900 return ref_iterator_peel(iter->iter0, peeled);1901}19021903static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)1904{1905 struct files_ref_iterator *iter =1906 (struct files_ref_iterator *)ref_iterator;1907 int ok = ITER_DONE;19081909 if (iter->iter0)1910 ok = ref_iterator_abort(iter->iter0);19111912 release_packed_ref_cache(iter->packed_ref_cache);1913 base_ref_iterator_free(ref_iterator);1914 return ok;1915}19161917static struct ref_iterator_vtable files_ref_iterator_vtable = {1918 files_ref_iterator_advance,1919 files_ref_iterator_peel,1920 files_ref_iterator_abort1921};19221923struct ref_iterator *files_ref_iterator_begin(1924 const char *submodule,1925 const char *prefix, unsigned int flags)1926{1927 struct files_ref_store *refs =1928 get_files_ref_store(submodule, "ref_iterator_begin");1929 struct ref_dir *loose_dir, *packed_dir;1930 struct ref_iterator *loose_iter, *packed_iter;1931 struct files_ref_iterator *iter;1932 struct ref_iterator *ref_iterator;19331934 if (!refs)1935 return empty_ref_iterator_begin();19361937 if (ref_paranoia < 0)1938 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1939 if (ref_paranoia)1940 flags |= DO_FOR_EACH_INCLUDE_BROKEN;19411942 iter = xcalloc(1, sizeof(*iter));1943 ref_iterator = &iter->base;1944 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);19451946 /*1947 * We must make sure that all loose refs are read before1948 * accessing the packed-refs file; this avoids a race1949 * condition if loose refs are migrated to the packed-refs1950 * file by a simultaneous process, but our in-memory view is1951 * from before the migration. We ensure this as follows:1952 * First, we call prime_ref_dir(), which pre-reads the loose1953 * references for the subtree into the cache. (If they've1954 * already been read, that's OK; we only need to guarantee1955 * that they're read before the packed refs, not *how much*1956 * before.) After that, we call get_packed_ref_cache(), which1957 * internally checks whether the packed-ref cache is up to1958 * date with what is on disk, and re-reads it if not.1959 */19601961 loose_dir = get_loose_refs(refs);19621963 if (prefix && *prefix)1964 loose_dir = find_containing_dir(loose_dir, prefix, 0);19651966 if (loose_dir) {1967 prime_ref_dir(loose_dir);1968 loose_iter = cache_ref_iterator_begin(loose_dir);1969 } else {1970 /* There's nothing to iterate over. */1971 loose_iter = empty_ref_iterator_begin();1972 }19731974 iter->packed_ref_cache = get_packed_ref_cache(refs);1975 acquire_packed_ref_cache(iter->packed_ref_cache);1976 packed_dir = get_packed_ref_dir(iter->packed_ref_cache);19771978 if (prefix && *prefix)1979 packed_dir = find_containing_dir(packed_dir, prefix, 0);19801981 if (packed_dir) {1982 packed_iter = cache_ref_iterator_begin(packed_dir);1983 } else {1984 /* There's nothing to iterate over. */1985 packed_iter = empty_ref_iterator_begin();1986 }19871988 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);1989 iter->flags = flags;19901991 return ref_iterator;1992}19931994/*1995 * Verify that the reference locked by lock has the value old_sha1.1996 * Fail if the reference doesn't exist and mustexist is set. Return 01997 * on success. On error, write an error message to err, set errno, and1998 * return a negative value.1999 */2000static int verify_lock(struct ref_lock *lock,2001 const unsigned char *old_sha1, int mustexist,2002 struct strbuf *err)2003{2004 assert(err);20052006 if (read_ref_full(lock->ref_name,2007 mustexist ? RESOLVE_REF_READING : 0,2008 lock->old_oid.hash, NULL)) {2009 if (old_sha1) {2010 int save_errno = errno;2011 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);2012 errno = save_errno;2013 return -1;2014 } else {2015 hashclr(lock->old_oid.hash);2016 return 0;2017 }2018 }2019 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {2020 strbuf_addf(err, "ref '%s' is at %s but expected %s",2021 lock->ref_name,2022 sha1_to_hex(lock->old_oid.hash),2023 sha1_to_hex(old_sha1));2024 errno = EBUSY;2025 return -1;2026 }2027 return 0;2028}20292030static int remove_empty_directories(struct strbuf *path)2031{2032 /*2033 * we want to create a file but there is a directory there;2034 * if that is an empty directory (or a directory that contains2035 * only empty directories), remove them.2036 */2037 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);2038}20392040/*2041 * Locks a ref returning the lock on success and NULL on failure.2042 * On failure errno is set to something meaningful.2043 */2044static struct ref_lock *lock_ref_sha1_basic(const char *refname,2045 const unsigned char *old_sha1,2046 const struct string_list *extras,2047 const struct string_list *skip,2048 unsigned int flags, int *type,2049 struct strbuf *err)2050{2051 struct files_ref_store *refs =2052 get_files_ref_store(NULL, "lock_ref_sha1_basic");2053 struct strbuf ref_file = STRBUF_INIT;2054 struct ref_lock *lock;2055 int last_errno = 0;2056 int lflags = LOCK_NO_DEREF;2057 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2058 int resolve_flags = RESOLVE_REF_NO_RECURSE;2059 int attempts_remaining = 3;2060 int resolved;20612062 assert(err);20632064 lock = xcalloc(1, sizeof(struct ref_lock));20652066 if (mustexist)2067 resolve_flags |= RESOLVE_REF_READING;2068 if (flags & REF_DELETING)2069 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20702071 strbuf_git_path(&ref_file, "%s", refname);2072 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2073 lock->old_oid.hash, type);2074 if (!resolved && errno == EISDIR) {2075 /*2076 * we are trying to lock foo but we used to2077 * have foo/bar which now does not exist;2078 * it is normal for the empty directory 'foo'2079 * to remain.2080 */2081 if (remove_empty_directories(&ref_file)) {2082 last_errno = errno;2083 if (!verify_refname_available_dir(2084 refname, extras, skip,2085 get_loose_refs(refs), err))2086 strbuf_addf(err, "there are still refs under '%s'",2087 refname);2088 goto error_return;2089 }2090 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2091 lock->old_oid.hash, type);2092 }2093 if (!resolved) {2094 last_errno = errno;2095 if (last_errno != ENOTDIR ||2096 !verify_refname_available_dir(2097 refname, extras, skip,2098 get_loose_refs(refs), err))2099 strbuf_addf(err, "unable to resolve reference '%s': %s",2100 refname, strerror(last_errno));21012102 goto error_return;2103 }21042105 /*2106 * If the ref did not exist and we are creating it, make sure2107 * there is no existing packed ref whose name begins with our2108 * refname, nor a packed ref whose name is a proper prefix of2109 * our refname.2110 */2111 if (is_null_oid(&lock->old_oid) &&2112 verify_refname_available_dir(refname, extras, skip,2113 get_packed_refs(refs),2114 err)) {2115 last_errno = ENOTDIR;2116 goto error_return;2117 }21182119 lock->lk = xcalloc(1, sizeof(struct lock_file));21202121 lock->ref_name = xstrdup(refname);21222123 retry:2124 switch (safe_create_leading_directories_const(ref_file.buf)) {2125 case SCLD_OK:2126 break; /* success */2127 case SCLD_VANISHED:2128 if (--attempts_remaining > 0)2129 goto retry;2130 /* fall through */2131 default:2132 last_errno = errno;2133 strbuf_addf(err, "unable to create directory for '%s'",2134 ref_file.buf);2135 goto error_return;2136 }21372138 if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {2139 last_errno = errno;2140 if (errno == ENOENT && --attempts_remaining > 0)2141 /*2142 * Maybe somebody just deleted one of the2143 * directories leading to ref_file. Try2144 * again:2145 */2146 goto retry;2147 else {2148 unable_to_lock_message(ref_file.buf, errno, err);2149 goto error_return;2150 }2151 }2152 if (verify_lock(lock, old_sha1, mustexist, err)) {2153 last_errno = errno;2154 goto error_return;2155 }2156 goto out;21572158 error_return:2159 unlock_ref(lock);2160 lock = NULL;21612162 out:2163 strbuf_release(&ref_file);2164 errno = last_errno;2165 return lock;2166}21672168/*2169 * Write an entry to the packed-refs file for the specified refname.2170 * If peeled is non-NULL, write it as the entry's peeled value.2171 */2172static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,2173 unsigned char *peeled)2174{2175 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);2176 if (peeled)2177 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));2178}21792180/*2181 * An each_ref_entry_fn that writes the entry to a packed-refs file.2182 */2183static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2184{2185 enum peel_status peel_status = peel_entry(entry, 0);21862187 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2188 error("internal error: %s is not a valid packed reference!",2189 entry->name);2190 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2191 peel_status == PEEL_PEELED ?2192 entry->u.value.peeled.hash : NULL);2193 return 0;2194}21952196/*2197 * Lock the packed-refs file for writing. Flags is passed to2198 * hold_lock_file_for_update(). Return 0 on success. On errors, set2199 * errno appropriately and return a nonzero value.2200 */2201static int lock_packed_refs(struct files_ref_store *refs, int flags)2202{2203 static int timeout_configured = 0;2204 static int timeout_value = 1000;2205 struct packed_ref_cache *packed_ref_cache;22062207 assert_main_repository(&refs->base, "lock_packed_refs");22082209 if (!timeout_configured) {2210 git_config_get_int("core.packedrefstimeout", &timeout_value);2211 timeout_configured = 1;2212 }22132214 if (hold_lock_file_for_update_timeout(2215 &packlock, git_path("packed-refs"),2216 flags, timeout_value) < 0)2217 return -1;2218 /*2219 * Get the current packed-refs while holding the lock. If the2220 * packed-refs file has been modified since we last read it,2221 * this will automatically invalidate the cache and re-read2222 * the packed-refs file.2223 */2224 packed_ref_cache = get_packed_ref_cache(refs);2225 packed_ref_cache->lock = &packlock;2226 /* Increment the reference count to prevent it from being freed: */2227 acquire_packed_ref_cache(packed_ref_cache);2228 return 0;2229}22302231/*2232 * Write the current version of the packed refs cache from memory to2233 * disk. The packed-refs file must already be locked for writing (see2234 * lock_packed_refs()). Return zero on success. On errors, set errno2235 * and return a nonzero value2236 */2237static int commit_packed_refs(struct files_ref_store *refs)2238{2239 struct packed_ref_cache *packed_ref_cache =2240 get_packed_ref_cache(refs);2241 int error = 0;2242 int save_errno = 0;2243 FILE *out;22442245 assert_main_repository(&refs->base, "commit_packed_refs");22462247 if (!packed_ref_cache->lock)2248 die("internal error: packed-refs not locked");22492250 out = fdopen_lock_file(packed_ref_cache->lock, "w");2251 if (!out)2252 die_errno("unable to fdopen packed-refs descriptor");22532254 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);2255 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2256 0, write_packed_entry_fn, out);22572258 if (commit_lock_file(packed_ref_cache->lock)) {2259 save_errno = errno;2260 error = -1;2261 }2262 packed_ref_cache->lock = NULL;2263 release_packed_ref_cache(packed_ref_cache);2264 errno = save_errno;2265 return error;2266}22672268/*2269 * Rollback the lockfile for the packed-refs file, and discard the2270 * in-memory packed reference cache. (The packed-refs file will be2271 * read anew if it is needed again after this function is called.)2272 */2273static void rollback_packed_refs(struct files_ref_store *refs)2274{2275 struct packed_ref_cache *packed_ref_cache =2276 get_packed_ref_cache(refs);22772278 assert_main_repository(&refs->base, "rollback_packed_refs");22792280 if (!packed_ref_cache->lock)2281 die("internal error: packed-refs not locked");2282 rollback_lock_file(packed_ref_cache->lock);2283 packed_ref_cache->lock = NULL;2284 release_packed_ref_cache(packed_ref_cache);2285 clear_packed_ref_cache(refs);2286}22872288struct ref_to_prune {2289 struct ref_to_prune *next;2290 unsigned char sha1[20];2291 char name[FLEX_ARRAY];2292};22932294struct pack_refs_cb_data {2295 unsigned int flags;2296 struct ref_dir *packed_refs;2297 struct ref_to_prune *ref_to_prune;2298};22992300/*2301 * An each_ref_entry_fn that is run over loose references only. If2302 * the loose reference can be packed, add an entry in the packed ref2303 * cache. If the reference should be pruned, also add it to2304 * ref_to_prune in the pack_refs_cb_data.2305 */2306static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2307{2308 struct pack_refs_cb_data *cb = cb_data;2309 enum peel_status peel_status;2310 struct ref_entry *packed_entry;2311 int is_tag_ref = starts_with(entry->name, "refs/tags/");23122313 /* Do not pack per-worktree refs: */2314 if (ref_type(entry->name) != REF_TYPE_NORMAL)2315 return 0;23162317 /* ALWAYS pack tags */2318 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2319 return 0;23202321 /* Do not pack symbolic or broken refs: */2322 if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2323 return 0;23242325 /* Add a packed ref cache entry equivalent to the loose entry. */2326 peel_status = peel_entry(entry, 1);2327 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2328 die("internal error peeling reference %s (%s)",2329 entry->name, oid_to_hex(&entry->u.value.oid));2330 packed_entry = find_ref(cb->packed_refs, entry->name);2331 if (packed_entry) {2332 /* Overwrite existing packed entry with info from loose entry */2333 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2334 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2335 } else {2336 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,2337 REF_ISPACKED | REF_KNOWS_PEELED, 0);2338 add_ref(cb->packed_refs, packed_entry);2339 }2340 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);23412342 /* Schedule the loose reference for pruning if requested. */2343 if ((cb->flags & PACK_REFS_PRUNE)) {2344 struct ref_to_prune *n;2345 FLEX_ALLOC_STR(n, name, entry->name);2346 hashcpy(n->sha1, entry->u.value.oid.hash);2347 n->next = cb->ref_to_prune;2348 cb->ref_to_prune = n;2349 }2350 return 0;2351}23522353/*2354 * Remove empty parents, but spare refs/ and immediate subdirs.2355 * Note: munges *name.2356 */2357static void try_remove_empty_parents(char *name)2358{2359 char *p, *q;2360 int i;2361 p = name;2362 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2363 while (*p && *p != '/')2364 p++;2365 /* tolerate duplicate slashes; see check_refname_format() */2366 while (*p == '/')2367 p++;2368 }2369 for (q = p; *q; q++)2370 ;2371 while (1) {2372 while (q > p && *q != '/')2373 q--;2374 while (q > p && *(q-1) == '/')2375 q--;2376 if (q == p)2377 break;2378 *q = '\0';2379 if (rmdir(git_path("%s", name)))2380 break;2381 }2382}23832384/* make sure nobody touched the ref, and unlink */2385static void prune_ref(struct ref_to_prune *r)2386{2387 struct ref_transaction *transaction;2388 struct strbuf err = STRBUF_INIT;23892390 if (check_refname_format(r->name, 0))2391 return;23922393 transaction = ref_transaction_begin(&err);2394 if (!transaction ||2395 ref_transaction_delete(transaction, r->name, r->sha1,2396 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2397 ref_transaction_commit(transaction, &err)) {2398 ref_transaction_free(transaction);2399 error("%s", err.buf);2400 strbuf_release(&err);2401 return;2402 }2403 ref_transaction_free(transaction);2404 strbuf_release(&err);2405 try_remove_empty_parents(r->name);2406}24072408static void prune_refs(struct ref_to_prune *r)2409{2410 while (r) {2411 prune_ref(r);2412 r = r->next;2413 }2414}24152416int pack_refs(unsigned int flags)2417{2418 struct files_ref_store *refs =2419 get_files_ref_store(NULL, "pack_refs");2420 struct pack_refs_cb_data cbdata;24212422 memset(&cbdata, 0, sizeof(cbdata));2423 cbdata.flags = flags;24242425 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2426 cbdata.packed_refs = get_packed_refs(refs);24272428 do_for_each_entry_in_dir(get_loose_refs(refs), 0,2429 pack_if_possible_fn, &cbdata);24302431 if (commit_packed_refs(refs))2432 die_errno("unable to overwrite old ref-pack file");24332434 prune_refs(cbdata.ref_to_prune);2435 return 0;2436}24372438/*2439 * Rewrite the packed-refs file, omitting any refs listed in2440 * 'refnames'. On error, leave packed-refs unchanged, write an error2441 * message to 'err', and return a nonzero value.2442 *2443 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2444 */2445static int repack_without_refs(struct string_list *refnames, struct strbuf *err)2446{2447 struct files_ref_store *refs =2448 get_files_ref_store(NULL, "repack_without_refs");2449 struct ref_dir *packed;2450 struct string_list_item *refname;2451 int ret, needs_repacking = 0, removed = 0;24522453 assert(err);24542455 /* Look for a packed ref */2456 for_each_string_list_item(refname, refnames) {2457 if (get_packed_ref(refs, refname->string)) {2458 needs_repacking = 1;2459 break;2460 }2461 }24622463 /* Avoid locking if we have nothing to do */2464 if (!needs_repacking)2465 return 0; /* no refname exists in packed refs */24662467 if (lock_packed_refs(refs, 0)) {2468 unable_to_lock_message(git_path("packed-refs"), errno, err);2469 return -1;2470 }2471 packed = get_packed_refs(refs);24722473 /* Remove refnames from the cache */2474 for_each_string_list_item(refname, refnames)2475 if (remove_entry(packed, refname->string) != -1)2476 removed = 1;2477 if (!removed) {2478 /*2479 * All packed entries disappeared while we were2480 * acquiring the lock.2481 */2482 rollback_packed_refs(refs);2483 return 0;2484 }24852486 /* Write what remains */2487 ret = commit_packed_refs(refs);2488 if (ret)2489 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2490 strerror(errno));2491 return ret;2492}24932494static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2495{2496 assert(err);24972498 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2499 /*2500 * loose. The loose file name is the same as the2501 * lockfile name, minus ".lock":2502 */2503 char *loose_filename = get_locked_file_path(lock->lk);2504 int res = unlink_or_msg(loose_filename, err);2505 free(loose_filename);2506 if (res)2507 return 1;2508 }2509 return 0;2510}25112512int delete_refs(struct string_list *refnames, unsigned int flags)2513{2514 struct strbuf err = STRBUF_INIT;2515 int i, result = 0;25162517 if (!refnames->nr)2518 return 0;25192520 result = repack_without_refs(refnames, &err);2521 if (result) {2522 /*2523 * If we failed to rewrite the packed-refs file, then2524 * it is unsafe to try to remove loose refs, because2525 * doing so might expose an obsolete packed value for2526 * a reference that might even point at an object that2527 * has been garbage collected.2528 */2529 if (refnames->nr == 1)2530 error(_("could not delete reference %s: %s"),2531 refnames->items[0].string, err.buf);2532 else2533 error(_("could not delete references: %s"), err.buf);25342535 goto out;2536 }25372538 for (i = 0; i < refnames->nr; i++) {2539 const char *refname = refnames->items[i].string;25402541 if (delete_ref(refname, NULL, flags))2542 result |= error(_("could not remove reference %s"), refname);2543 }25442545out:2546 strbuf_release(&err);2547 return result;2548}25492550/*2551 * People using contrib's git-new-workdir have .git/logs/refs ->2552 * /some/other/path/.git/logs/refs, and that may live on another device.2553 *2554 * IOW, to avoid cross device rename errors, the temporary renamed log must2555 * live into logs/refs.2556 */2557#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"25582559static int rename_tmp_log(const char *newrefname)2560{2561 int attempts_remaining = 4;2562 struct strbuf path = STRBUF_INIT;2563 int ret = -1;25642565 retry:2566 strbuf_reset(&path);2567 strbuf_git_path(&path, "logs/%s", newrefname);2568 switch (safe_create_leading_directories_const(path.buf)) {2569 case SCLD_OK:2570 break; /* success */2571 case SCLD_VANISHED:2572 if (--attempts_remaining > 0)2573 goto retry;2574 /* fall through */2575 default:2576 error("unable to create directory for %s", newrefname);2577 goto out;2578 }25792580 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {2581 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2582 /*2583 * rename(a, b) when b is an existing2584 * directory ought to result in ISDIR, but2585 * Solaris 5.8 gives ENOTDIR. Sheesh.2586 */2587 if (remove_empty_directories(&path)) {2588 error("Directory not empty: logs/%s", newrefname);2589 goto out;2590 }2591 goto retry;2592 } else if (errno == ENOENT && --attempts_remaining > 0) {2593 /*2594 * Maybe another process just deleted one of2595 * the directories in the path to newrefname.2596 * Try again from the beginning.2597 */2598 goto retry;2599 } else {2600 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2601 newrefname, strerror(errno));2602 goto out;2603 }2604 }2605 ret = 0;2606out:2607 strbuf_release(&path);2608 return ret;2609}26102611int verify_refname_available(const char *newname,2612 const struct string_list *extras,2613 const struct string_list *skip,2614 struct strbuf *err)2615{2616 struct files_ref_store *refs =2617 get_files_ref_store(NULL, "verify_refname_available");2618 struct ref_dir *packed_refs = get_packed_refs(refs);2619 struct ref_dir *loose_refs = get_loose_refs(refs);26202621 if (verify_refname_available_dir(newname, extras, skip,2622 packed_refs, err) ||2623 verify_refname_available_dir(newname, extras, skip,2624 loose_refs, err))2625 return -1;26262627 return 0;2628}26292630static int write_ref_to_lockfile(struct ref_lock *lock,2631 const unsigned char *sha1, struct strbuf *err);2632static int commit_ref_update(struct ref_lock *lock,2633 const unsigned char *sha1, const char *logmsg,2634 struct strbuf *err);26352636int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2637{2638 unsigned char sha1[20], orig_sha1[20];2639 int flag = 0, logmoved = 0;2640 struct ref_lock *lock;2641 struct stat loginfo;2642 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2643 struct strbuf err = STRBUF_INIT;26442645 if (log && S_ISLNK(loginfo.st_mode))2646 return error("reflog for %s is a symlink", oldrefname);26472648 if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2649 orig_sha1, &flag))2650 return error("refname %s not found", oldrefname);26512652 if (flag & REF_ISSYMREF)2653 return error("refname %s is a symbolic ref, renaming it is not supported",2654 oldrefname);2655 if (!rename_ref_available(oldrefname, newrefname))2656 return 1;26572658 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2659 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2660 oldrefname, strerror(errno));26612662 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2663 error("unable to delete old %s", oldrefname);2664 goto rollback;2665 }26662667 /*2668 * Since we are doing a shallow lookup, sha1 is not the2669 * correct value to pass to delete_ref as old_sha1. But that2670 * doesn't matter, because an old_sha1 check wouldn't add to2671 * the safety anyway; we want to delete the reference whatever2672 * its current value.2673 */2674 if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2675 sha1, NULL) &&2676 delete_ref(newrefname, NULL, REF_NODEREF)) {2677 if (errno==EISDIR) {2678 struct strbuf path = STRBUF_INIT;2679 int result;26802681 strbuf_git_path(&path, "%s", newrefname);2682 result = remove_empty_directories(&path);2683 strbuf_release(&path);26842685 if (result) {2686 error("Directory not empty: %s", newrefname);2687 goto rollback;2688 }2689 } else {2690 error("unable to delete existing %s", newrefname);2691 goto rollback;2692 }2693 }26942695 if (log && rename_tmp_log(newrefname))2696 goto rollback;26972698 logmoved = log;26992700 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,2701 NULL, &err);2702 if (!lock) {2703 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);2704 strbuf_release(&err);2705 goto rollback;2706 }2707 hashcpy(lock->old_oid.hash, orig_sha1);27082709 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2710 commit_ref_update(lock, orig_sha1, logmsg, &err)) {2711 error("unable to write current sha1 into %s: %s", newrefname, err.buf);2712 strbuf_release(&err);2713 goto rollback;2714 }27152716 return 0;27172718 rollback:2719 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,2720 NULL, &err);2721 if (!lock) {2722 error("unable to lock %s for rollback: %s", oldrefname, err.buf);2723 strbuf_release(&err);2724 goto rollbacklog;2725 }27262727 flag = log_all_ref_updates;2728 log_all_ref_updates = 0;2729 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2730 commit_ref_update(lock, orig_sha1, NULL, &err)) {2731 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);2732 strbuf_release(&err);2733 }2734 log_all_ref_updates = flag;27352736 rollbacklog:2737 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2738 error("unable to restore logfile %s from %s: %s",2739 oldrefname, newrefname, strerror(errno));2740 if (!logmoved && log &&2741 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2742 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2743 oldrefname, strerror(errno));27442745 return 1;2746}27472748static int close_ref(struct ref_lock *lock)2749{2750 if (close_lock_file(lock->lk))2751 return -1;2752 return 0;2753}27542755static int commit_ref(struct ref_lock *lock)2756{2757 char *path = get_locked_file_path(lock->lk);2758 struct stat st;27592760 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {2761 /*2762 * There is a directory at the path we want to rename2763 * the lockfile to. Hopefully it is empty; try to2764 * delete it.2765 */2766 size_t len = strlen(path);2767 struct strbuf sb_path = STRBUF_INIT;27682769 strbuf_attach(&sb_path, path, len, len);27702771 /*2772 * If this fails, commit_lock_file() will also fail2773 * and will report the problem.2774 */2775 remove_empty_directories(&sb_path);2776 strbuf_release(&sb_path);2777 } else {2778 free(path);2779 }27802781 if (commit_lock_file(lock->lk))2782 return -1;2783 return 0;2784}27852786/*2787 * Create a reflog for a ref. If force_create = 0, the reflog will2788 * only be created for certain refs (those for which2789 * should_autocreate_reflog returns non-zero. Otherwise, create it2790 * regardless of the ref name. Fill in *err and return -1 on failure.2791 */2792static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)2793{2794 int logfd, oflags = O_APPEND | O_WRONLY;27952796 strbuf_git_path(logfile, "logs/%s", refname);2797 if (force_create || should_autocreate_reflog(refname)) {2798 if (safe_create_leading_directories(logfile->buf) < 0) {2799 strbuf_addf(err, "unable to create directory for '%s': "2800 "%s", logfile->buf, strerror(errno));2801 return -1;2802 }2803 oflags |= O_CREAT;2804 }28052806 logfd = open(logfile->buf, oflags, 0666);2807 if (logfd < 0) {2808 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2809 return 0;28102811 if (errno == EISDIR) {2812 if (remove_empty_directories(logfile)) {2813 strbuf_addf(err, "there are still logs under "2814 "'%s'", logfile->buf);2815 return -1;2816 }2817 logfd = open(logfile->buf, oflags, 0666);2818 }28192820 if (logfd < 0) {2821 strbuf_addf(err, "unable to append to '%s': %s",2822 logfile->buf, strerror(errno));2823 return -1;2824 }2825 }28262827 adjust_shared_perm(logfile->buf);2828 close(logfd);2829 return 0;2830}283128322833int safe_create_reflog(const char *refname, int force_create, struct strbuf *err)2834{2835 int ret;2836 struct strbuf sb = STRBUF_INIT;28372838 ret = log_ref_setup(refname, &sb, err, force_create);2839 strbuf_release(&sb);2840 return ret;2841}28422843static int log_ref_write_fd(int fd, const unsigned char *old_sha1,2844 const unsigned char *new_sha1,2845 const char *committer, const char *msg)2846{2847 int msglen, written;2848 unsigned maxlen, len;2849 char *logrec;28502851 msglen = msg ? strlen(msg) : 0;2852 maxlen = strlen(committer) + msglen + 100;2853 logrec = xmalloc(maxlen);2854 len = xsnprintf(logrec, maxlen, "%s %s %s\n",2855 sha1_to_hex(old_sha1),2856 sha1_to_hex(new_sha1),2857 committer);2858 if (msglen)2859 len += copy_reflog_msg(logrec + len - 1, msg) - 1;28602861 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2862 free(logrec);2863 if (written != len)2864 return -1;28652866 return 0;2867}28682869static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,2870 const unsigned char *new_sha1, const char *msg,2871 struct strbuf *logfile, int flags,2872 struct strbuf *err)2873{2874 int logfd, result, oflags = O_APPEND | O_WRONLY;28752876 if (log_all_ref_updates < 0)2877 log_all_ref_updates = !is_bare_repository();28782879 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28802881 if (result)2882 return result;28832884 logfd = open(logfile->buf, oflags);2885 if (logfd < 0)2886 return 0;2887 result = log_ref_write_fd(logfd, old_sha1, new_sha1,2888 git_committer_info(0), msg);2889 if (result) {2890 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2891 strerror(errno));2892 close(logfd);2893 return -1;2894 }2895 if (close(logfd)) {2896 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2897 strerror(errno));2898 return -1;2899 }2900 return 0;2901}29022903static int log_ref_write(const char *refname, const unsigned char *old_sha1,2904 const unsigned char *new_sha1, const char *msg,2905 int flags, struct strbuf *err)2906{2907 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2908 err);2909}29102911int files_log_ref_write(const char *refname, const unsigned char *old_sha1,2912 const unsigned char *new_sha1, const char *msg,2913 int flags, struct strbuf *err)2914{2915 struct strbuf sb = STRBUF_INIT;2916 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2917 err);2918 strbuf_release(&sb);2919 return ret;2920}29212922/*2923 * Write sha1 into the open lockfile, then close the lockfile. On2924 * errors, rollback the lockfile, fill in *err and2925 * return -1.2926 */2927static int write_ref_to_lockfile(struct ref_lock *lock,2928 const unsigned char *sha1, struct strbuf *err)2929{2930 static char term = '\n';2931 struct object *o;2932 int fd;29332934 o = parse_object(sha1);2935 if (!o) {2936 strbuf_addf(err,2937 "trying to write ref '%s' with nonexistent object %s",2938 lock->ref_name, sha1_to_hex(sha1));2939 unlock_ref(lock);2940 return -1;2941 }2942 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2943 strbuf_addf(err,2944 "trying to write non-commit object %s to branch '%s'",2945 sha1_to_hex(sha1), lock->ref_name);2946 unlock_ref(lock);2947 return -1;2948 }2949 fd = get_lock_file_fd(lock->lk);2950 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||2951 write_in_full(fd, &term, 1) != 1 ||2952 close_ref(lock) < 0) {2953 strbuf_addf(err,2954 "couldn't write '%s'", get_lock_file_path(lock->lk));2955 unlock_ref(lock);2956 return -1;2957 }2958 return 0;2959}29602961/*2962 * Commit a change to a loose reference that has already been written2963 * to the loose reference lockfile. Also update the reflogs if2964 * necessary, using the specified lockmsg (which can be NULL).2965 */2966static int commit_ref_update(struct ref_lock *lock,2967 const unsigned char *sha1, const char *logmsg,2968 struct strbuf *err)2969{2970 struct files_ref_store *refs =2971 get_files_ref_store(NULL, "commit_ref_update");29722973 clear_loose_ref_cache(refs);2974 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {2975 char *old_msg = strbuf_detach(err, NULL);2976 strbuf_addf(err, "cannot update the ref '%s': %s",2977 lock->ref_name, old_msg);2978 free(old_msg);2979 unlock_ref(lock);2980 return -1;2981 }29822983 if (strcmp(lock->ref_name, "HEAD") != 0) {2984 /*2985 * Special hack: If a branch is updated directly and HEAD2986 * points to it (may happen on the remote side of a push2987 * for example) then logically the HEAD reflog should be2988 * updated too.2989 * A generic solution implies reverse symref information,2990 * but finding all symrefs pointing to the given branch2991 * would be rather costly for this rare event (the direct2992 * update of a branch) to be worth it. So let's cheat and2993 * check with HEAD only which should cover 99% of all usage2994 * scenarios (even 100% of the default ones).2995 */2996 unsigned char head_sha1[20];2997 int head_flag;2998 const char *head_ref;29993000 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3001 head_sha1, &head_flag);3002 if (head_ref && (head_flag & REF_ISSYMREF) &&3003 !strcmp(head_ref, lock->ref_name)) {3004 struct strbuf log_err = STRBUF_INIT;3005 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,3006 logmsg, 0, &log_err)) {3007 error("%s", log_err.buf);3008 strbuf_release(&log_err);3009 }3010 }3011 }30123013 if (commit_ref(lock)) {3014 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);3015 unlock_ref(lock);3016 return -1;3017 }30183019 unlock_ref(lock);3020 return 0;3021}30223023static int create_ref_symlink(struct ref_lock *lock, const char *target)3024{3025 int ret = -1;3026#ifndef NO_SYMLINK_HEAD3027 char *ref_path = get_locked_file_path(lock->lk);3028 unlink(ref_path);3029 ret = symlink(target, ref_path);3030 free(ref_path);30313032 if (ret)3033 fprintf(stderr, "no symlink - falling back to symbolic ref\n");3034#endif3035 return ret;3036}30373038static void update_symref_reflog(struct ref_lock *lock, const char *refname,3039 const char *target, const char *logmsg)3040{3041 struct strbuf err = STRBUF_INIT;3042 unsigned char new_sha1[20];3043 if (logmsg && !read_ref(target, new_sha1) &&3044 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {3045 error("%s", err.buf);3046 strbuf_release(&err);3047 }3048}30493050static int create_symref_locked(struct ref_lock *lock, const char *refname,3051 const char *target, const char *logmsg)3052{3053 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {3054 update_symref_reflog(lock, refname, target, logmsg);3055 return 0;3056 }30573058 if (!fdopen_lock_file(lock->lk, "w"))3059 return error("unable to fdopen %s: %s",3060 lock->lk->tempfile.filename.buf, strerror(errno));30613062 update_symref_reflog(lock, refname, target, logmsg);30633064 /* no error check; commit_ref will check ferror */3065 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);3066 if (commit_ref(lock) < 0)3067 return error("unable to write symref for %s: %s", refname,3068 strerror(errno));3069 return 0;3070}30713072int create_symref(const char *refname, const char *target, const char *logmsg)3073{3074 struct strbuf err = STRBUF_INIT;3075 struct ref_lock *lock;3076 int ret;30773078 lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,3079 &err);3080 if (!lock) {3081 error("%s", err.buf);3082 strbuf_release(&err);3083 return -1;3084 }30853086 ret = create_symref_locked(lock, refname, target, logmsg);3087 unlock_ref(lock);3088 return ret;3089}30903091int set_worktree_head_symref(const char *gitdir, const char *target)3092{3093 static struct lock_file head_lock;3094 struct ref_lock *lock;3095 struct strbuf head_path = STRBUF_INIT;3096 const char *head_rel;3097 int ret;30983099 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));3100 if (hold_lock_file_for_update(&head_lock, head_path.buf,3101 LOCK_NO_DEREF) < 0) {3102 struct strbuf err = STRBUF_INIT;3103 unable_to_lock_message(head_path.buf, errno, &err);3104 error("%s", err.buf);3105 strbuf_release(&err);3106 strbuf_release(&head_path);3107 return -1;3108 }31093110 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3111 linked trees */3112 head_rel = remove_leading_path(head_path.buf,3113 absolute_path(get_git_common_dir()));3114 /* to make use of create_symref_locked(), initialize ref_lock */3115 lock = xcalloc(1, sizeof(struct ref_lock));3116 lock->lk = &head_lock;3117 lock->ref_name = xstrdup(head_rel);31183119 ret = create_symref_locked(lock, head_rel, target, NULL);31203121 unlock_ref(lock); /* will free lock */3122 strbuf_release(&head_path);3123 return ret;3124}31253126int reflog_exists(const char *refname)3127{3128 struct stat st;31293130 return !lstat(git_path("logs/%s", refname), &st) &&3131 S_ISREG(st.st_mode);3132}31333134int delete_reflog(const char *refname)3135{3136 return remove_path(git_path("logs/%s", refname));3137}31383139static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3140{3141 unsigned char osha1[20], nsha1[20];3142 char *email_end, *message;3143 unsigned long timestamp;3144 int tz;31453146 /* old SP new SP name <email> SP time TAB msg LF */3147 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3148 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3149 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3150 !(email_end = strchr(sb->buf + 82, '>')) ||3151 email_end[1] != ' ' ||3152 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3153 !message || message[0] != ' ' ||3154 (message[1] != '+' && message[1] != '-') ||3155 !isdigit(message[2]) || !isdigit(message[3]) ||3156 !isdigit(message[4]) || !isdigit(message[5]))3157 return 0; /* corrupt? */3158 email_end[1] = '\0';3159 tz = strtol(message + 1, NULL, 10);3160 if (message[6] != '\t')3161 message += 6;3162 else3163 message += 7;3164 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3165}31663167static char *find_beginning_of_line(char *bob, char *scan)3168{3169 while (bob < scan && *(--scan) != '\n')3170 ; /* keep scanning backwards */3171 /*3172 * Return either beginning of the buffer, or LF at the end of3173 * the previous line.3174 */3175 return scan;3176}31773178int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3179{3180 struct strbuf sb = STRBUF_INIT;3181 FILE *logfp;3182 long pos;3183 int ret = 0, at_tail = 1;31843185 logfp = fopen(git_path("logs/%s", refname), "r");3186 if (!logfp)3187 return -1;31883189 /* Jump to the end */3190 if (fseek(logfp, 0, SEEK_END) < 0)3191 return error("cannot seek back reflog for %s: %s",3192 refname, strerror(errno));3193 pos = ftell(logfp);3194 while (!ret && 0 < pos) {3195 int cnt;3196 size_t nread;3197 char buf[BUFSIZ];3198 char *endp, *scanp;31993200 /* Fill next block from the end */3201 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3202 if (fseek(logfp, pos - cnt, SEEK_SET))3203 return error("cannot seek back reflog for %s: %s",3204 refname, strerror(errno));3205 nread = fread(buf, cnt, 1, logfp);3206 if (nread != 1)3207 return error("cannot read %d bytes from reflog for %s: %s",3208 cnt, refname, strerror(errno));3209 pos -= cnt;32103211 scanp = endp = buf + cnt;3212 if (at_tail && scanp[-1] == '\n')3213 /* Looking at the final LF at the end of the file */3214 scanp--;3215 at_tail = 0;32163217 while (buf < scanp) {3218 /*3219 * terminating LF of the previous line, or the beginning3220 * of the buffer.3221 */3222 char *bp;32233224 bp = find_beginning_of_line(buf, scanp);32253226 if (*bp == '\n') {3227 /*3228 * The newline is the end of the previous line,3229 * so we know we have complete line starting3230 * at (bp + 1). Prefix it onto any prior data3231 * we collected for the line and process it.3232 */3233 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3234 scanp = bp;3235 endp = bp + 1;3236 ret = show_one_reflog_ent(&sb, fn, cb_data);3237 strbuf_reset(&sb);3238 if (ret)3239 break;3240 } else if (!pos) {3241 /*3242 * We are at the start of the buffer, and the3243 * start of the file; there is no previous3244 * line, and we have everything for this one.3245 * Process it, and we can end the loop.3246 */3247 strbuf_splice(&sb, 0, 0, buf, endp - buf);3248 ret = show_one_reflog_ent(&sb, fn, cb_data);3249 strbuf_reset(&sb);3250 break;3251 }32523253 if (bp == buf) {3254 /*3255 * We are at the start of the buffer, and there3256 * is more file to read backwards. Which means3257 * we are in the middle of a line. Note that we3258 * may get here even if *bp was a newline; that3259 * just means we are at the exact end of the3260 * previous line, rather than some spot in the3261 * middle.3262 *3263 * Save away what we have to be combined with3264 * the data from the next read.3265 */3266 strbuf_splice(&sb, 0, 0, buf, endp - buf);3267 break;3268 }3269 }32703271 }3272 if (!ret && sb.len)3273 die("BUG: reverse reflog parser had leftover data");32743275 fclose(logfp);3276 strbuf_release(&sb);3277 return ret;3278}32793280int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3281{3282 FILE *logfp;3283 struct strbuf sb = STRBUF_INIT;3284 int ret = 0;32853286 logfp = fopen(git_path("logs/%s", refname), "r");3287 if (!logfp)3288 return -1;32893290 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3291 ret = show_one_reflog_ent(&sb, fn, cb_data);3292 fclose(logfp);3293 strbuf_release(&sb);3294 return ret;3295}32963297struct files_reflog_iterator {3298 struct ref_iterator base;32993300 struct dir_iterator *dir_iterator;3301 struct object_id oid;3302};33033304static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)3305{3306 struct files_reflog_iterator *iter =3307 (struct files_reflog_iterator *)ref_iterator;3308 struct dir_iterator *diter = iter->dir_iterator;3309 int ok;33103311 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {3312 int flags;33133314 if (!S_ISREG(diter->st.st_mode))3315 continue;3316 if (diter->basename[0] == '.')3317 continue;3318 if (ends_with(diter->basename, ".lock"))3319 continue;33203321 if (read_ref_full(diter->relative_path, 0,3322 iter->oid.hash, &flags)) {3323 error("bad ref for %s", diter->path.buf);3324 continue;3325 }33263327 iter->base.refname = diter->relative_path;3328 iter->base.oid = &iter->oid;3329 iter->base.flags = flags;3330 return ITER_OK;3331 }33323333 iter->dir_iterator = NULL;3334 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)3335 ok = ITER_ERROR;3336 return ok;3337}33383339static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,3340 struct object_id *peeled)3341{3342 die("BUG: ref_iterator_peel() called for reflog_iterator");3343}33443345static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)3346{3347 struct files_reflog_iterator *iter =3348 (struct files_reflog_iterator *)ref_iterator;3349 int ok = ITER_DONE;33503351 if (iter->dir_iterator)3352 ok = dir_iterator_abort(iter->dir_iterator);33533354 base_ref_iterator_free(ref_iterator);3355 return ok;3356}33573358static struct ref_iterator_vtable files_reflog_iterator_vtable = {3359 files_reflog_iterator_advance,3360 files_reflog_iterator_peel,3361 files_reflog_iterator_abort3362};33633364struct ref_iterator *files_reflog_iterator_begin(void)3365{3366 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));3367 struct ref_iterator *ref_iterator = &iter->base;33683369 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3370 iter->dir_iterator = dir_iterator_begin(git_path("logs"));3371 return ref_iterator;3372}33733374int for_each_reflog(each_ref_fn fn, void *cb_data)3375{3376 return do_for_each_ref_iterator(files_reflog_iterator_begin(),3377 fn, cb_data);3378}33793380static int ref_update_reject_duplicates(struct string_list *refnames,3381 struct strbuf *err)3382{3383 int i, n = refnames->nr;33843385 assert(err);33863387 for (i = 1; i < n; i++)3388 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {3389 strbuf_addf(err,3390 "multiple updates for ref '%s' not allowed.",3391 refnames->items[i].string);3392 return 1;3393 }3394 return 0;3395}33963397/*3398 * If update is a direct update of head_ref (the reference pointed to3399 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3400 */3401static int split_head_update(struct ref_update *update,3402 struct ref_transaction *transaction,3403 const char *head_ref,3404 struct string_list *affected_refnames,3405 struct strbuf *err)3406{3407 struct string_list_item *item;3408 struct ref_update *new_update;34093410 if ((update->flags & REF_LOG_ONLY) ||3411 (update->flags & REF_ISPRUNING) ||3412 (update->flags & REF_UPDATE_VIA_HEAD))3413 return 0;34143415 if (strcmp(update->refname, head_ref))3416 return 0;34173418 /*3419 * First make sure that HEAD is not already in the3420 * transaction. This insertion is O(N) in the transaction3421 * size, but it happens at most once per transaction.3422 */3423 item = string_list_insert(affected_refnames, "HEAD");3424 if (item->util) {3425 /* An entry already existed */3426 strbuf_addf(err,3427 "multiple updates for 'HEAD' (including one "3428 "via its referent '%s') are not allowed",3429 update->refname);3430 return TRANSACTION_NAME_CONFLICT;3431 }34323433 new_update = ref_transaction_add_update(3434 transaction, "HEAD",3435 update->flags | REF_LOG_ONLY | REF_NODEREF,3436 update->new_sha1, update->old_sha1,3437 update->msg);34383439 item->util = new_update;34403441 return 0;3442}34433444/*3445 * update is for a symref that points at referent and doesn't have3446 * REF_NODEREF set. Split it into two updates:3447 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3448 * - A new, separate update for the referent reference3449 * Note that the new update will itself be subject to splitting when3450 * the iteration gets to it.3451 */3452static int split_symref_update(struct ref_update *update,3453 const char *referent,3454 struct ref_transaction *transaction,3455 struct string_list *affected_refnames,3456 struct strbuf *err)3457{3458 struct string_list_item *item;3459 struct ref_update *new_update;3460 unsigned int new_flags;34613462 /*3463 * First make sure that referent is not already in the3464 * transaction. This insertion is O(N) in the transaction3465 * size, but it happens at most once per symref in a3466 * transaction.3467 */3468 item = string_list_insert(affected_refnames, referent);3469 if (item->util) {3470 /* An entry already existed */3471 strbuf_addf(err,3472 "multiple updates for '%s' (including one "3473 "via symref '%s') are not allowed",3474 referent, update->refname);3475 return TRANSACTION_NAME_CONFLICT;3476 }34773478 new_flags = update->flags;3479 if (!strcmp(update->refname, "HEAD")) {3480 /*3481 * Record that the new update came via HEAD, so that3482 * when we process it, split_head_update() doesn't try3483 * to add another reflog update for HEAD. Note that3484 * this bit will be propagated if the new_update3485 * itself needs to be split.3486 */3487 new_flags |= REF_UPDATE_VIA_HEAD;3488 }34893490 new_update = ref_transaction_add_update(3491 transaction, referent, new_flags,3492 update->new_sha1, update->old_sha1,3493 update->msg);34943495 new_update->parent_update = update;34963497 /*3498 * Change the symbolic ref update to log only. Also, it3499 * doesn't need to check its old SHA-1 value, as that will be3500 * done when new_update is processed.3501 */3502 update->flags |= REF_LOG_ONLY | REF_NODEREF;3503 update->flags &= ~REF_HAVE_OLD;35043505 item->util = new_update;35063507 return 0;3508}35093510/*3511 * Return the refname under which update was originally requested.3512 */3513static const char *original_update_refname(struct ref_update *update)3514{3515 while (update->parent_update)3516 update = update->parent_update;35173518 return update->refname;3519}35203521/*3522 * Prepare for carrying out update:3523 * - Lock the reference referred to by update.3524 * - Read the reference under lock.3525 * - Check that its old SHA-1 value (if specified) is correct, and in3526 * any case record it in update->lock->old_oid for later use when3527 * writing the reflog.3528 * - If it is a symref update without REF_NODEREF, split it up into a3529 * REF_LOG_ONLY update of the symref and add a separate update for3530 * the referent to transaction.3531 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3532 * update of HEAD.3533 */3534static int lock_ref_for_update(struct ref_update *update,3535 struct ref_transaction *transaction,3536 const char *head_ref,3537 struct string_list *affected_refnames,3538 struct strbuf *err)3539{3540 struct strbuf referent = STRBUF_INIT;3541 int mustexist = (update->flags & REF_HAVE_OLD) &&3542 !is_null_sha1(update->old_sha1);3543 int ret;3544 struct ref_lock *lock;35453546 if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))3547 update->flags |= REF_DELETING;35483549 if (head_ref) {3550 ret = split_head_update(update, transaction, head_ref,3551 affected_refnames, err);3552 if (ret)3553 return ret;3554 }35553556 ret = lock_raw_ref(update->refname, mustexist,3557 affected_refnames, NULL,3558 &update->lock, &referent,3559 &update->type, err);35603561 if (ret) {3562 char *reason;35633564 reason = strbuf_detach(err, NULL);3565 strbuf_addf(err, "cannot lock ref '%s': %s",3566 update->refname, reason);3567 free(reason);3568 return ret;3569 }35703571 lock = update->lock;35723573 if (update->type & REF_ISSYMREF) {3574 if (update->flags & REF_NODEREF) {3575 /*3576 * We won't be reading the referent as part of3577 * the transaction, so we have to read it here3578 * to record and possibly check old_sha1:3579 */3580 if (read_ref_full(update->refname,3581 mustexist ? RESOLVE_REF_READING : 0,3582 lock->old_oid.hash, NULL)) {3583 if (update->flags & REF_HAVE_OLD) {3584 strbuf_addf(err, "cannot lock ref '%s': "3585 "can't resolve old value",3586 update->refname);3587 return TRANSACTION_GENERIC_ERROR;3588 } else {3589 hashclr(lock->old_oid.hash);3590 }3591 }3592 if ((update->flags & REF_HAVE_OLD) &&3593 hashcmp(lock->old_oid.hash, update->old_sha1)) {3594 strbuf_addf(err, "cannot lock ref '%s': "3595 "is at %s but expected %s",3596 update->refname,3597 sha1_to_hex(lock->old_oid.hash),3598 sha1_to_hex(update->old_sha1));3599 return TRANSACTION_GENERIC_ERROR;3600 }36013602 } else {3603 /*3604 * Create a new update for the reference this3605 * symref is pointing at. Also, we will record3606 * and verify old_sha1 for this update as part3607 * of processing the split-off update, so we3608 * don't have to do it here.3609 */3610 ret = split_symref_update(update, referent.buf, transaction,3611 affected_refnames, err);3612 if (ret)3613 return ret;3614 }3615 } else {3616 struct ref_update *parent_update;36173618 /*3619 * If this update is happening indirectly because of a3620 * symref update, record the old SHA-1 in the parent3621 * update:3622 */3623 for (parent_update = update->parent_update;3624 parent_update;3625 parent_update = parent_update->parent_update) {3626 oidcpy(&parent_update->lock->old_oid, &lock->old_oid);3627 }36283629 if ((update->flags & REF_HAVE_OLD) &&3630 hashcmp(lock->old_oid.hash, update->old_sha1)) {3631 if (is_null_sha1(update->old_sha1))3632 strbuf_addf(err, "cannot lock ref '%s': reference already exists",3633 original_update_refname(update));3634 else3635 strbuf_addf(err, "cannot lock ref '%s': is at %s but expected %s",3636 original_update_refname(update),3637 sha1_to_hex(lock->old_oid.hash),3638 sha1_to_hex(update->old_sha1));36393640 return TRANSACTION_GENERIC_ERROR;3641 }3642 }36433644 if ((update->flags & REF_HAVE_NEW) &&3645 !(update->flags & REF_DELETING) &&3646 !(update->flags & REF_LOG_ONLY)) {3647 if (!(update->type & REF_ISSYMREF) &&3648 !hashcmp(lock->old_oid.hash, update->new_sha1)) {3649 /*3650 * The reference already has the desired3651 * value, so we don't need to write it.3652 */3653 } else if (write_ref_to_lockfile(lock, update->new_sha1,3654 err)) {3655 char *write_err = strbuf_detach(err, NULL);36563657 /*3658 * The lock was freed upon failure of3659 * write_ref_to_lockfile():3660 */3661 update->lock = NULL;3662 strbuf_addf(err,3663 "cannot update the ref '%s': %s",3664 update->refname, write_err);3665 free(write_err);3666 return TRANSACTION_GENERIC_ERROR;3667 } else {3668 update->flags |= REF_NEEDS_COMMIT;3669 }3670 }3671 if (!(update->flags & REF_NEEDS_COMMIT)) {3672 /*3673 * We didn't call write_ref_to_lockfile(), so3674 * the lockfile is still open. Close it to3675 * free up the file descriptor:3676 */3677 if (close_ref(lock)) {3678 strbuf_addf(err, "couldn't close '%s.lock'",3679 update->refname);3680 return TRANSACTION_GENERIC_ERROR;3681 }3682 }3683 return 0;3684}36853686static int files_transaction_commit(struct ref_store *ref_store,3687 struct ref_transaction *transaction,3688 struct strbuf *err)3689{3690 struct files_ref_store *refs =3691 files_downcast(ref_store, 0, "ref_transaction_commit");3692 int ret = 0, i;3693 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3694 struct string_list_item *ref_to_delete;3695 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3696 char *head_ref = NULL;3697 int head_type;3698 struct object_id head_oid;36993700 assert(err);37013702 if (transaction->state != REF_TRANSACTION_OPEN)3703 die("BUG: commit called for transaction that is not open");37043705 if (!transaction->nr) {3706 transaction->state = REF_TRANSACTION_CLOSED;3707 return 0;3708 }37093710 /*3711 * Fail if a refname appears more than once in the3712 * transaction. (If we end up splitting up any updates using3713 * split_symref_update() or split_head_update(), those3714 * functions will check that the new updates don't have the3715 * same refname as any existing ones.)3716 */3717 for (i = 0; i < transaction->nr; i++) {3718 struct ref_update *update = transaction->updates[i];3719 struct string_list_item *item =3720 string_list_append(&affected_refnames, update->refname);37213722 /*3723 * We store a pointer to update in item->util, but at3724 * the moment we never use the value of this field3725 * except to check whether it is non-NULL.3726 */3727 item->util = update;3728 }3729 string_list_sort(&affected_refnames);3730 if (ref_update_reject_duplicates(&affected_refnames, err)) {3731 ret = TRANSACTION_GENERIC_ERROR;3732 goto cleanup;3733 }37343735 /*3736 * Special hack: If a branch is updated directly and HEAD3737 * points to it (may happen on the remote side of a push3738 * for example) then logically the HEAD reflog should be3739 * updated too.3740 *3741 * A generic solution would require reverse symref lookups,3742 * but finding all symrefs pointing to a given branch would be3743 * rather costly for this rare event (the direct update of a3744 * branch) to be worth it. So let's cheat and check with HEAD3745 * only, which should cover 99% of all usage scenarios (even3746 * 100% of the default ones).3747 *3748 * So if HEAD is a symbolic reference, then record the name of3749 * the reference that it points to. If we see an update of3750 * head_ref within the transaction, then split_head_update()3751 * arranges for the reflog of HEAD to be updated, too.3752 */3753 head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3754 head_oid.hash, &head_type);37553756 if (head_ref && !(head_type & REF_ISSYMREF)) {3757 free(head_ref);3758 head_ref = NULL;3759 }37603761 /*3762 * Acquire all locks, verify old values if provided, check3763 * that new values are valid, and write new values to the3764 * lockfiles, ready to be activated. Only keep one lockfile3765 * open at a time to avoid running out of file descriptors.3766 */3767 for (i = 0; i < transaction->nr; i++) {3768 struct ref_update *update = transaction->updates[i];37693770 ret = lock_ref_for_update(update, transaction, head_ref,3771 &affected_refnames, err);3772 if (ret)3773 goto cleanup;3774 }37753776 /* Perform updates first so live commits remain referenced */3777 for (i = 0; i < transaction->nr; i++) {3778 struct ref_update *update = transaction->updates[i];3779 struct ref_lock *lock = update->lock;37803781 if (update->flags & REF_NEEDS_COMMIT ||3782 update->flags & REF_LOG_ONLY) {3783 if (log_ref_write(lock->ref_name, lock->old_oid.hash,3784 update->new_sha1,3785 update->msg, update->flags, err)) {3786 char *old_msg = strbuf_detach(err, NULL);37873788 strbuf_addf(err, "cannot update the ref '%s': %s",3789 lock->ref_name, old_msg);3790 free(old_msg);3791 unlock_ref(lock);3792 update->lock = NULL;3793 ret = TRANSACTION_GENERIC_ERROR;3794 goto cleanup;3795 }3796 }3797 if (update->flags & REF_NEEDS_COMMIT) {3798 clear_loose_ref_cache(refs);3799 if (commit_ref(lock)) {3800 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);3801 unlock_ref(lock);3802 update->lock = NULL;3803 ret = TRANSACTION_GENERIC_ERROR;3804 goto cleanup;3805 }3806 }3807 }3808 /* Perform deletes now that updates are safely completed */3809 for (i = 0; i < transaction->nr; i++) {3810 struct ref_update *update = transaction->updates[i];38113812 if (update->flags & REF_DELETING &&3813 !(update->flags & REF_LOG_ONLY)) {3814 if (delete_ref_loose(update->lock, update->type, err)) {3815 ret = TRANSACTION_GENERIC_ERROR;3816 goto cleanup;3817 }38183819 if (!(update->flags & REF_ISPRUNING))3820 string_list_append(&refs_to_delete,3821 update->lock->ref_name);3822 }3823 }38243825 if (repack_without_refs(&refs_to_delete, err)) {3826 ret = TRANSACTION_GENERIC_ERROR;3827 goto cleanup;3828 }3829 for_each_string_list_item(ref_to_delete, &refs_to_delete)3830 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3831 clear_loose_ref_cache(refs);38323833cleanup:3834 transaction->state = REF_TRANSACTION_CLOSED;38353836 for (i = 0; i < transaction->nr; i++)3837 if (transaction->updates[i]->lock)3838 unlock_ref(transaction->updates[i]->lock);3839 string_list_clear(&refs_to_delete, 0);3840 free(head_ref);3841 string_list_clear(&affected_refnames, 0);38423843 return ret;3844}38453846static int ref_present(const char *refname,3847 const struct object_id *oid, int flags, void *cb_data)3848{3849 struct string_list *affected_refnames = cb_data;38503851 return string_list_has_string(affected_refnames, refname);3852}38533854int initial_ref_transaction_commit(struct ref_transaction *transaction,3855 struct strbuf *err)3856{3857 struct files_ref_store *refs =3858 get_files_ref_store(NULL, "initial_ref_transaction_commit");3859 int ret = 0, i;3860 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38613862 assert(err);38633864 if (transaction->state != REF_TRANSACTION_OPEN)3865 die("BUG: commit called for transaction that is not open");38663867 /* Fail if a refname appears more than once in the transaction: */3868 for (i = 0; i < transaction->nr; i++)3869 string_list_append(&affected_refnames,3870 transaction->updates[i]->refname);3871 string_list_sort(&affected_refnames);3872 if (ref_update_reject_duplicates(&affected_refnames, err)) {3873 ret = TRANSACTION_GENERIC_ERROR;3874 goto cleanup;3875 }38763877 /*3878 * It's really undefined to call this function in an active3879 * repository or when there are existing references: we are3880 * only locking and changing packed-refs, so (1) any3881 * simultaneous processes might try to change a reference at3882 * the same time we do, and (2) any existing loose versions of3883 * the references that we are setting would have precedence3884 * over our values. But some remote helpers create the remote3885 * "HEAD" and "master" branches before calling this function,3886 * so here we really only check that none of the references3887 * that we are creating already exists.3888 */3889 if (for_each_rawref(ref_present, &affected_refnames))3890 die("BUG: initial ref transaction called with existing refs");38913892 for (i = 0; i < transaction->nr; i++) {3893 struct ref_update *update = transaction->updates[i];38943895 if ((update->flags & REF_HAVE_OLD) &&3896 !is_null_sha1(update->old_sha1))3897 die("BUG: initial ref transaction with old_sha1 set");3898 if (verify_refname_available(update->refname,3899 &affected_refnames, NULL,3900 err)) {3901 ret = TRANSACTION_NAME_CONFLICT;3902 goto cleanup;3903 }3904 }39053906 if (lock_packed_refs(refs, 0)) {3907 strbuf_addf(err, "unable to lock packed-refs file: %s",3908 strerror(errno));3909 ret = TRANSACTION_GENERIC_ERROR;3910 goto cleanup;3911 }39123913 for (i = 0; i < transaction->nr; i++) {3914 struct ref_update *update = transaction->updates[i];39153916 if ((update->flags & REF_HAVE_NEW) &&3917 !is_null_sha1(update->new_sha1))3918 add_packed_ref(refs, update->refname, update->new_sha1);3919 }39203921 if (commit_packed_refs(refs)) {3922 strbuf_addf(err, "unable to commit packed-refs file: %s",3923 strerror(errno));3924 ret = TRANSACTION_GENERIC_ERROR;3925 goto cleanup;3926 }39273928cleanup:3929 transaction->state = REF_TRANSACTION_CLOSED;3930 string_list_clear(&affected_refnames, 0);3931 return ret;3932}39333934struct expire_reflog_cb {3935 unsigned int flags;3936 reflog_expiry_should_prune_fn *should_prune_fn;3937 void *policy_cb;3938 FILE *newlog;3939 unsigned char last_kept_sha1[20];3940};39413942static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,3943 const char *email, unsigned long timestamp, int tz,3944 const char *message, void *cb_data)3945{3946 struct expire_reflog_cb *cb = cb_data;3947 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39483949 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3950 osha1 = cb->last_kept_sha1;39513952 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3953 message, policy_cb)) {3954 if (!cb->newlog)3955 printf("would prune %s", message);3956 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3957 printf("prune %s", message);3958 } else {3959 if (cb->newlog) {3960 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",3961 sha1_to_hex(osha1), sha1_to_hex(nsha1),3962 email, timestamp, tz, message);3963 hashcpy(cb->last_kept_sha1, nsha1);3964 }3965 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3966 printf("keep %s", message);3967 }3968 return 0;3969}39703971int reflog_expire(const char *refname, const unsigned char *sha1,3972 unsigned int flags,3973 reflog_expiry_prepare_fn prepare_fn,3974 reflog_expiry_should_prune_fn should_prune_fn,3975 reflog_expiry_cleanup_fn cleanup_fn,3976 void *policy_cb_data)3977{3978 static struct lock_file reflog_lock;3979 struct expire_reflog_cb cb;3980 struct ref_lock *lock;3981 char *log_file;3982 int status = 0;3983 int type;3984 struct strbuf err = STRBUF_INIT;39853986 memset(&cb, 0, sizeof(cb));3987 cb.flags = flags;3988 cb.policy_cb = policy_cb_data;3989 cb.should_prune_fn = should_prune_fn;39903991 /*3992 * The reflog file is locked by holding the lock on the3993 * reference itself, plus we might need to update the3994 * reference if --updateref was specified:3995 */3996 lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,3997 &type, &err);3998 if (!lock) {3999 error("cannot lock ref '%s': %s", refname, err.buf);4000 strbuf_release(&err);4001 return -1;4002 }4003 if (!reflog_exists(refname)) {4004 unlock_ref(lock);4005 return 0;4006 }40074008 log_file = git_pathdup("logs/%s", refname);4009 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4010 /*4011 * Even though holding $GIT_DIR/logs/$reflog.lock has4012 * no locking implications, we use the lock_file4013 * machinery here anyway because it does a lot of the4014 * work we need, including cleaning up if the program4015 * exits unexpectedly.4016 */4017 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {4018 struct strbuf err = STRBUF_INIT;4019 unable_to_lock_message(log_file, errno, &err);4020 error("%s", err.buf);4021 strbuf_release(&err);4022 goto failure;4023 }4024 cb.newlog = fdopen_lock_file(&reflog_lock, "w");4025 if (!cb.newlog) {4026 error("cannot fdopen %s (%s)",4027 get_lock_file_path(&reflog_lock), strerror(errno));4028 goto failure;4029 }4030 }40314032 (*prepare_fn)(refname, sha1, cb.policy_cb);4033 for_each_reflog_ent(refname, expire_reflog_ent, &cb);4034 (*cleanup_fn)(cb.policy_cb);40354036 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4037 /*4038 * It doesn't make sense to adjust a reference pointed4039 * to by a symbolic ref based on expiring entries in4040 * the symbolic reference's reflog. Nor can we update4041 * a reference if there are no remaining reflog4042 * entries.4043 */4044 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4045 !(type & REF_ISSYMREF) &&4046 !is_null_sha1(cb.last_kept_sha1);40474048 if (close_lock_file(&reflog_lock)) {4049 status |= error("couldn't write %s: %s", log_file,4050 strerror(errno));4051 } else if (update &&4052 (write_in_full(get_lock_file_fd(lock->lk),4053 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||4054 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||4055 close_ref(lock) < 0)) {4056 status |= error("couldn't write %s",4057 get_lock_file_path(lock->lk));4058 rollback_lock_file(&reflog_lock);4059 } else if (commit_lock_file(&reflog_lock)) {4060 status |= error("unable to write reflog '%s' (%s)",4061 log_file, strerror(errno));4062 } else if (update && commit_ref(lock)) {4063 status |= error("couldn't set %s", lock->ref_name);4064 }4065 }4066 free(log_file);4067 unlock_ref(lock);4068 return status;40694070 failure:4071 rollback_lock_file(&reflog_lock);4072 free(log_file);4073 unlock_ref(lock);4074 return -1;4075}40764077struct ref_storage_be refs_be_files = {4078 NULL,4079 "files",4080 files_ref_store_create,4081 files_transaction_commit4082};