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}13511352static int files_read_raw_ref(struct ref_store *ref_store,1353 const char *refname, unsigned char *sha1,1354 struct strbuf *referent, unsigned int *type)1355{1356 struct files_ref_store *refs =1357 files_downcast(ref_store, 1, "read_raw_ref");1358 struct strbuf sb_contents = STRBUF_INIT;1359 struct strbuf sb_path = STRBUF_INIT;1360 const char *path;1361 const char *buf;1362 struct stat st;1363 int fd;1364 int ret = -1;1365 int save_errno;13661367 *type = 0;1368 strbuf_reset(&sb_path);13691370 if (*refs->base.submodule)1371 strbuf_git_path_submodule(&sb_path, refs->base.submodule, "%s", refname);1372 else1373 strbuf_git_path(&sb_path, "%s", refname);13741375 path = sb_path.buf;13761377stat_ref:1378 /*1379 * We might have to loop back here to avoid a race1380 * condition: first we lstat() the file, then we try1381 * to read it as a link or as a file. But if somebody1382 * changes the type of the file (file <-> directory1383 * <-> symlink) between the lstat() and reading, then1384 * we don't want to report that as an error but rather1385 * try again starting with the lstat().1386 */13871388 if (lstat(path, &st) < 0) {1389 if (errno != ENOENT)1390 goto out;1391 if (resolve_packed_ref(refs, refname, sha1, type)) {1392 errno = ENOENT;1393 goto out;1394 }1395 ret = 0;1396 goto out;1397 }13981399 /* Follow "normalized" - ie "refs/.." symlinks by hand */1400 if (S_ISLNK(st.st_mode)) {1401 strbuf_reset(&sb_contents);1402 if (strbuf_readlink(&sb_contents, path, 0) < 0) {1403 if (errno == ENOENT || errno == EINVAL)1404 /* inconsistent with lstat; retry */1405 goto stat_ref;1406 else1407 goto out;1408 }1409 if (starts_with(sb_contents.buf, "refs/") &&1410 !check_refname_format(sb_contents.buf, 0)) {1411 strbuf_swap(&sb_contents, referent);1412 *type |= REF_ISSYMREF;1413 ret = 0;1414 goto out;1415 }1416 }14171418 /* Is it a directory? */1419 if (S_ISDIR(st.st_mode)) {1420 /*1421 * Even though there is a directory where the loose1422 * ref is supposed to be, there could still be a1423 * packed ref:1424 */1425 if (resolve_packed_ref(refs, refname, sha1, type)) {1426 errno = EISDIR;1427 goto out;1428 }1429 ret = 0;1430 goto out;1431 }14321433 /*1434 * Anything else, just open it and try to use it as1435 * a ref1436 */1437 fd = open(path, O_RDONLY);1438 if (fd < 0) {1439 if (errno == ENOENT)1440 /* inconsistent with lstat; retry */1441 goto stat_ref;1442 else1443 goto out;1444 }1445 strbuf_reset(&sb_contents);1446 if (strbuf_read(&sb_contents, fd, 256) < 0) {1447 int save_errno = errno;1448 close(fd);1449 errno = save_errno;1450 goto out;1451 }1452 close(fd);1453 strbuf_rtrim(&sb_contents);1454 buf = sb_contents.buf;1455 if (starts_with(buf, "ref:")) {1456 buf += 4;1457 while (isspace(*buf))1458 buf++;14591460 strbuf_reset(referent);1461 strbuf_addstr(referent, buf);1462 *type |= REF_ISSYMREF;1463 ret = 0;1464 goto out;1465 }14661467 /*1468 * Please note that FETCH_HEAD has additional1469 * data after the sha.1470 */1471 if (get_sha1_hex(buf, sha1) ||1472 (buf[40] != '\0' && !isspace(buf[40]))) {1473 *type |= REF_ISBROKEN;1474 errno = EINVAL;1475 goto out;1476 }14771478 ret = 0;14791480out:1481 save_errno = errno;1482 strbuf_release(&sb_path);1483 strbuf_release(&sb_contents);1484 errno = save_errno;1485 return ret;1486}14871488static void unlock_ref(struct ref_lock *lock)1489{1490 /* Do not free lock->lk -- atexit() still looks at them */1491 if (lock->lk)1492 rollback_lock_file(lock->lk);1493 free(lock->ref_name);1494 free(lock);1495}14961497/*1498 * Lock refname, without following symrefs, and set *lock_p to point1499 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1500 * and type similarly to read_raw_ref().1501 *1502 * The caller must verify that refname is a "safe" reference name (in1503 * the sense of refname_is_safe()) before calling this function.1504 *1505 * If the reference doesn't already exist, verify that refname doesn't1506 * have a D/F conflict with any existing references. extras and skip1507 * are passed to verify_refname_available_dir() for this check.1508 *1509 * If mustexist is not set and the reference is not found or is1510 * broken, lock the reference anyway but clear sha1.1511 *1512 * Return 0 on success. On failure, write an error message to err and1513 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1514 *1515 * Implementation note: This function is basically1516 *1517 * lock reference1518 * read_raw_ref()1519 *1520 * but it includes a lot more code to1521 * - Deal with possible races with other processes1522 * - Avoid calling verify_refname_available_dir() when it can be1523 * avoided, namely if we were successfully able to read the ref1524 * - Generate informative error messages in the case of failure1525 */1526static int lock_raw_ref(struct files_ref_store *refs,1527 const char *refname, int mustexist,1528 const struct string_list *extras,1529 const struct string_list *skip,1530 struct ref_lock **lock_p,1531 struct strbuf *referent,1532 unsigned int *type,1533 struct strbuf *err)1534{1535 struct ref_lock *lock;1536 struct strbuf ref_file = STRBUF_INIT;1537 int attempts_remaining = 3;1538 int ret = TRANSACTION_GENERIC_ERROR;15391540 assert(err);1541 assert_main_repository(&refs->base, "lock_raw_ref");15421543 *type = 0;15441545 /* First lock the file so it can't change out from under us. */15461547 *lock_p = lock = xcalloc(1, sizeof(*lock));15481549 lock->ref_name = xstrdup(refname);1550 strbuf_git_path(&ref_file, "%s", refname);15511552retry:1553 switch (safe_create_leading_directories(ref_file.buf)) {1554 case SCLD_OK:1555 break; /* success */1556 case SCLD_EXISTS:1557 /*1558 * Suppose refname is "refs/foo/bar". We just failed1559 * to create the containing directory, "refs/foo",1560 * because there was a non-directory in the way. This1561 * indicates a D/F conflict, probably because of1562 * another reference such as "refs/foo". There is no1563 * reason to expect this error to be transitory.1564 */1565 if (verify_refname_available(refname, extras, skip, err)) {1566 if (mustexist) {1567 /*1568 * To the user the relevant error is1569 * that the "mustexist" reference is1570 * missing:1571 */1572 strbuf_reset(err);1573 strbuf_addf(err, "unable to resolve reference '%s'",1574 refname);1575 } else {1576 /*1577 * The error message set by1578 * verify_refname_available_dir() is OK.1579 */1580 ret = TRANSACTION_NAME_CONFLICT;1581 }1582 } else {1583 /*1584 * The file that is in the way isn't a loose1585 * reference. Report it as a low-level1586 * failure.1587 */1588 strbuf_addf(err, "unable to create lock file %s.lock; "1589 "non-directory in the way",1590 ref_file.buf);1591 }1592 goto error_return;1593 case SCLD_VANISHED:1594 /* Maybe another process was tidying up. Try again. */1595 if (--attempts_remaining > 0)1596 goto retry;1597 /* fall through */1598 default:1599 strbuf_addf(err, "unable to create directory for %s",1600 ref_file.buf);1601 goto error_return;1602 }16031604 if (!lock->lk)1605 lock->lk = xcalloc(1, sizeof(struct lock_file));16061607 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {1608 if (errno == ENOENT && --attempts_remaining > 0) {1609 /*1610 * Maybe somebody just deleted one of the1611 * directories leading to ref_file. Try1612 * again:1613 */1614 goto retry;1615 } else {1616 unable_to_lock_message(ref_file.buf, errno, err);1617 goto error_return;1618 }1619 }16201621 /*1622 * Now we hold the lock and can read the reference without1623 * fear that its value will change.1624 */16251626 if (files_read_raw_ref(&refs->base, refname,1627 lock->old_oid.hash, referent, type)) {1628 if (errno == ENOENT) {1629 if (mustexist) {1630 /* Garden variety missing reference. */1631 strbuf_addf(err, "unable to resolve reference '%s'",1632 refname);1633 goto error_return;1634 } else {1635 /*1636 * Reference is missing, but that's OK. We1637 * know that there is not a conflict with1638 * another loose reference because1639 * (supposing that we are trying to lock1640 * reference "refs/foo/bar"):1641 *1642 * - We were successfully able to create1643 * the lockfile refs/foo/bar.lock, so we1644 * know there cannot be a loose reference1645 * named "refs/foo".1646 *1647 * - We got ENOENT and not EISDIR, so we1648 * know that there cannot be a loose1649 * reference named "refs/foo/bar/baz".1650 */1651 }1652 } else if (errno == EISDIR) {1653 /*1654 * There is a directory in the way. It might have1655 * contained references that have been deleted. If1656 * we don't require that the reference already1657 * exists, try to remove the directory so that it1658 * doesn't cause trouble when we want to rename the1659 * lockfile into place later.1660 */1661 if (mustexist) {1662 /* Garden variety missing reference. */1663 strbuf_addf(err, "unable to resolve reference '%s'",1664 refname);1665 goto error_return;1666 } else if (remove_dir_recursively(&ref_file,1667 REMOVE_DIR_EMPTY_ONLY)) {1668 if (verify_refname_available_dir(1669 refname, extras, skip,1670 get_loose_refs(refs),1671 err)) {1672 /*1673 * The error message set by1674 * verify_refname_available() is OK.1675 */1676 ret = TRANSACTION_NAME_CONFLICT;1677 goto error_return;1678 } else {1679 /*1680 * We can't delete the directory,1681 * but we also don't know of any1682 * references that it should1683 * contain.1684 */1685 strbuf_addf(err, "there is a non-empty directory '%s' "1686 "blocking reference '%s'",1687 ref_file.buf, refname);1688 goto error_return;1689 }1690 }1691 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {1692 strbuf_addf(err, "unable to resolve reference '%s': "1693 "reference broken", refname);1694 goto error_return;1695 } else {1696 strbuf_addf(err, "unable to resolve reference '%s': %s",1697 refname, strerror(errno));1698 goto error_return;1699 }17001701 /*1702 * If the ref did not exist and we are creating it,1703 * make sure there is no existing packed ref whose1704 * name begins with our refname, nor a packed ref1705 * whose name is a proper prefix of our refname.1706 */1707 if (verify_refname_available_dir(1708 refname, extras, skip,1709 get_packed_refs(refs),1710 err)) {1711 goto error_return;1712 }1713 }17141715 ret = 0;1716 goto out;17171718error_return:1719 unlock_ref(lock);1720 *lock_p = NULL;17211722out:1723 strbuf_release(&ref_file);1724 return ret;1725}17261727/*1728 * Peel the entry (if possible) and return its new peel_status. If1729 * repeel is true, re-peel the entry even if there is an old peeled1730 * value that is already stored in it.1731 *1732 * It is OK to call this function with a packed reference entry that1733 * might be stale and might even refer to an object that has since1734 * been garbage-collected. In such a case, if the entry has1735 * REF_KNOWS_PEELED then leave the status unchanged and return1736 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1737 */1738static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1739{1740 enum peel_status status;17411742 if (entry->flag & REF_KNOWS_PEELED) {1743 if (repeel) {1744 entry->flag &= ~REF_KNOWS_PEELED;1745 oidclr(&entry->u.value.peeled);1746 } else {1747 return is_null_oid(&entry->u.value.peeled) ?1748 PEEL_NON_TAG : PEEL_PEELED;1749 }1750 }1751 if (entry->flag & REF_ISBROKEN)1752 return PEEL_BROKEN;1753 if (entry->flag & REF_ISSYMREF)1754 return PEEL_IS_SYMREF;17551756 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1757 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1758 entry->flag |= REF_KNOWS_PEELED;1759 return status;1760}17611762static int files_peel_ref(struct ref_store *ref_store,1763 const char *refname, unsigned char *sha1)1764{1765 struct files_ref_store *refs = files_downcast(ref_store, 0, "peel_ref");1766 int flag;1767 unsigned char base[20];17681769 if (current_ref_iter && current_ref_iter->refname == refname) {1770 struct object_id peeled;17711772 if (ref_iterator_peel(current_ref_iter, &peeled))1773 return -1;1774 hashcpy(sha1, peeled.hash);1775 return 0;1776 }17771778 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1779 return -1;17801781 /*1782 * If the reference is packed, read its ref_entry from the1783 * cache in the hope that we already know its peeled value.1784 * We only try this optimization on packed references because1785 * (a) forcing the filling of the loose reference cache could1786 * be expensive and (b) loose references anyway usually do not1787 * have REF_KNOWS_PEELED.1788 */1789 if (flag & REF_ISPACKED) {1790 struct ref_entry *r = get_packed_ref(refs, refname);1791 if (r) {1792 if (peel_entry(r, 0))1793 return -1;1794 hashcpy(sha1, r->u.value.peeled.hash);1795 return 0;1796 }1797 }17981799 return peel_object(base, sha1);1800}18011802struct files_ref_iterator {1803 struct ref_iterator base;18041805 struct packed_ref_cache *packed_ref_cache;1806 struct ref_iterator *iter0;1807 unsigned int flags;1808};18091810static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)1811{1812 struct files_ref_iterator *iter =1813 (struct files_ref_iterator *)ref_iterator;1814 int ok;18151816 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {1817 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1818 !ref_resolves_to_object(iter->iter0->refname,1819 iter->iter0->oid,1820 iter->iter0->flags))1821 continue;18221823 iter->base.refname = iter->iter0->refname;1824 iter->base.oid = iter->iter0->oid;1825 iter->base.flags = iter->iter0->flags;1826 return ITER_OK;1827 }18281829 iter->iter0 = NULL;1830 if (ref_iterator_abort(ref_iterator) != ITER_DONE)1831 ok = ITER_ERROR;18321833 return ok;1834}18351836static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,1837 struct object_id *peeled)1838{1839 struct files_ref_iterator *iter =1840 (struct files_ref_iterator *)ref_iterator;18411842 return ref_iterator_peel(iter->iter0, peeled);1843}18441845static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)1846{1847 struct files_ref_iterator *iter =1848 (struct files_ref_iterator *)ref_iterator;1849 int ok = ITER_DONE;18501851 if (iter->iter0)1852 ok = ref_iterator_abort(iter->iter0);18531854 release_packed_ref_cache(iter->packed_ref_cache);1855 base_ref_iterator_free(ref_iterator);1856 return ok;1857}18581859static struct ref_iterator_vtable files_ref_iterator_vtable = {1860 files_ref_iterator_advance,1861 files_ref_iterator_peel,1862 files_ref_iterator_abort1863};18641865struct ref_iterator *files_ref_iterator_begin(1866 const char *submodule,1867 const char *prefix, unsigned int flags)1868{1869 struct files_ref_store *refs =1870 get_files_ref_store(submodule, "ref_iterator_begin");1871 struct ref_dir *loose_dir, *packed_dir;1872 struct ref_iterator *loose_iter, *packed_iter;1873 struct files_ref_iterator *iter;1874 struct ref_iterator *ref_iterator;18751876 if (!refs)1877 return empty_ref_iterator_begin();18781879 if (ref_paranoia < 0)1880 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1881 if (ref_paranoia)1882 flags |= DO_FOR_EACH_INCLUDE_BROKEN;18831884 iter = xcalloc(1, sizeof(*iter));1885 ref_iterator = &iter->base;1886 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);18871888 /*1889 * We must make sure that all loose refs are read before1890 * accessing the packed-refs file; this avoids a race1891 * condition if loose refs are migrated to the packed-refs1892 * file by a simultaneous process, but our in-memory view is1893 * from before the migration. We ensure this as follows:1894 * First, we call prime_ref_dir(), which pre-reads the loose1895 * references for the subtree into the cache. (If they've1896 * already been read, that's OK; we only need to guarantee1897 * that they're read before the packed refs, not *how much*1898 * before.) After that, we call get_packed_ref_cache(), which1899 * internally checks whether the packed-ref cache is up to1900 * date with what is on disk, and re-reads it if not.1901 */19021903 loose_dir = get_loose_refs(refs);19041905 if (prefix && *prefix)1906 loose_dir = find_containing_dir(loose_dir, prefix, 0);19071908 if (loose_dir) {1909 prime_ref_dir(loose_dir);1910 loose_iter = cache_ref_iterator_begin(loose_dir);1911 } else {1912 /* There's nothing to iterate over. */1913 loose_iter = empty_ref_iterator_begin();1914 }19151916 iter->packed_ref_cache = get_packed_ref_cache(refs);1917 acquire_packed_ref_cache(iter->packed_ref_cache);1918 packed_dir = get_packed_ref_dir(iter->packed_ref_cache);19191920 if (prefix && *prefix)1921 packed_dir = find_containing_dir(packed_dir, prefix, 0);19221923 if (packed_dir) {1924 packed_iter = cache_ref_iterator_begin(packed_dir);1925 } else {1926 /* There's nothing to iterate over. */1927 packed_iter = empty_ref_iterator_begin();1928 }19291930 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);1931 iter->flags = flags;19321933 return ref_iterator;1934}19351936/*1937 * Verify that the reference locked by lock has the value old_sha1.1938 * Fail if the reference doesn't exist and mustexist is set. Return 01939 * on success. On error, write an error message to err, set errno, and1940 * return a negative value.1941 */1942static int verify_lock(struct ref_lock *lock,1943 const unsigned char *old_sha1, int mustexist,1944 struct strbuf *err)1945{1946 assert(err);19471948 if (read_ref_full(lock->ref_name,1949 mustexist ? RESOLVE_REF_READING : 0,1950 lock->old_oid.hash, NULL)) {1951 if (old_sha1) {1952 int save_errno = errno;1953 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);1954 errno = save_errno;1955 return -1;1956 } else {1957 hashclr(lock->old_oid.hash);1958 return 0;1959 }1960 }1961 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1962 strbuf_addf(err, "ref '%s' is at %s but expected %s",1963 lock->ref_name,1964 sha1_to_hex(lock->old_oid.hash),1965 sha1_to_hex(old_sha1));1966 errno = EBUSY;1967 return -1;1968 }1969 return 0;1970}19711972static int remove_empty_directories(struct strbuf *path)1973{1974 /*1975 * we want to create a file but there is a directory there;1976 * if that is an empty directory (or a directory that contains1977 * only empty directories), remove them.1978 */1979 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1980}19811982/*1983 * Locks a ref returning the lock on success and NULL on failure.1984 * On failure errno is set to something meaningful.1985 */1986static struct ref_lock *lock_ref_sha1_basic(const char *refname,1987 const unsigned char *old_sha1,1988 const struct string_list *extras,1989 const struct string_list *skip,1990 unsigned int flags, int *type,1991 struct strbuf *err)1992{1993 struct files_ref_store *refs =1994 get_files_ref_store(NULL, "lock_ref_sha1_basic");1995 struct strbuf ref_file = STRBUF_INIT;1996 struct ref_lock *lock;1997 int last_errno = 0;1998 int lflags = LOCK_NO_DEREF;1999 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2000 int resolve_flags = RESOLVE_REF_NO_RECURSE;2001 int attempts_remaining = 3;2002 int resolved;20032004 assert(err);20052006 lock = xcalloc(1, sizeof(struct ref_lock));20072008 if (mustexist)2009 resolve_flags |= RESOLVE_REF_READING;2010 if (flags & REF_DELETING)2011 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20122013 strbuf_git_path(&ref_file, "%s", refname);2014 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2015 lock->old_oid.hash, type);2016 if (!resolved && errno == EISDIR) {2017 /*2018 * we are trying to lock foo but we used to2019 * have foo/bar which now does not exist;2020 * it is normal for the empty directory 'foo'2021 * to remain.2022 */2023 if (remove_empty_directories(&ref_file)) {2024 last_errno = errno;2025 if (!verify_refname_available_dir(2026 refname, extras, skip,2027 get_loose_refs(refs), err))2028 strbuf_addf(err, "there are still refs under '%s'",2029 refname);2030 goto error_return;2031 }2032 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2033 lock->old_oid.hash, type);2034 }2035 if (!resolved) {2036 last_errno = errno;2037 if (last_errno != ENOTDIR ||2038 !verify_refname_available_dir(2039 refname, extras, skip,2040 get_loose_refs(refs), err))2041 strbuf_addf(err, "unable to resolve reference '%s': %s",2042 refname, strerror(last_errno));20432044 goto error_return;2045 }20462047 /*2048 * If the ref did not exist and we are creating it, make sure2049 * there is no existing packed ref whose name begins with our2050 * refname, nor a packed ref whose name is a proper prefix of2051 * our refname.2052 */2053 if (is_null_oid(&lock->old_oid) &&2054 verify_refname_available_dir(refname, extras, skip,2055 get_packed_refs(refs),2056 err)) {2057 last_errno = ENOTDIR;2058 goto error_return;2059 }20602061 lock->lk = xcalloc(1, sizeof(struct lock_file));20622063 lock->ref_name = xstrdup(refname);20642065 retry:2066 switch (safe_create_leading_directories_const(ref_file.buf)) {2067 case SCLD_OK:2068 break; /* success */2069 case SCLD_VANISHED:2070 if (--attempts_remaining > 0)2071 goto retry;2072 /* fall through */2073 default:2074 last_errno = errno;2075 strbuf_addf(err, "unable to create directory for '%s'",2076 ref_file.buf);2077 goto error_return;2078 }20792080 if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {2081 last_errno = errno;2082 if (errno == ENOENT && --attempts_remaining > 0)2083 /*2084 * Maybe somebody just deleted one of the2085 * directories leading to ref_file. Try2086 * again:2087 */2088 goto retry;2089 else {2090 unable_to_lock_message(ref_file.buf, errno, err);2091 goto error_return;2092 }2093 }2094 if (verify_lock(lock, old_sha1, mustexist, err)) {2095 last_errno = errno;2096 goto error_return;2097 }2098 goto out;20992100 error_return:2101 unlock_ref(lock);2102 lock = NULL;21032104 out:2105 strbuf_release(&ref_file);2106 errno = last_errno;2107 return lock;2108}21092110/*2111 * Write an entry to the packed-refs file for the specified refname.2112 * If peeled is non-NULL, write it as the entry's peeled value.2113 */2114static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,2115 unsigned char *peeled)2116{2117 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);2118 if (peeled)2119 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));2120}21212122/*2123 * An each_ref_entry_fn that writes the entry to a packed-refs file.2124 */2125static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2126{2127 enum peel_status peel_status = peel_entry(entry, 0);21282129 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2130 error("internal error: %s is not a valid packed reference!",2131 entry->name);2132 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2133 peel_status == PEEL_PEELED ?2134 entry->u.value.peeled.hash : NULL);2135 return 0;2136}21372138/*2139 * Lock the packed-refs file for writing. Flags is passed to2140 * hold_lock_file_for_update(). Return 0 on success. On errors, set2141 * errno appropriately and return a nonzero value.2142 */2143static int lock_packed_refs(struct files_ref_store *refs, int flags)2144{2145 static int timeout_configured = 0;2146 static int timeout_value = 1000;2147 struct packed_ref_cache *packed_ref_cache;21482149 assert_main_repository(&refs->base, "lock_packed_refs");21502151 if (!timeout_configured) {2152 git_config_get_int("core.packedrefstimeout", &timeout_value);2153 timeout_configured = 1;2154 }21552156 if (hold_lock_file_for_update_timeout(2157 &packlock, git_path("packed-refs"),2158 flags, timeout_value) < 0)2159 return -1;2160 /*2161 * Get the current packed-refs while holding the lock. If the2162 * packed-refs file has been modified since we last read it,2163 * this will automatically invalidate the cache and re-read2164 * the packed-refs file.2165 */2166 packed_ref_cache = get_packed_ref_cache(refs);2167 packed_ref_cache->lock = &packlock;2168 /* Increment the reference count to prevent it from being freed: */2169 acquire_packed_ref_cache(packed_ref_cache);2170 return 0;2171}21722173/*2174 * Write the current version of the packed refs cache from memory to2175 * disk. The packed-refs file must already be locked for writing (see2176 * lock_packed_refs()). Return zero on success. On errors, set errno2177 * and return a nonzero value2178 */2179static int commit_packed_refs(struct files_ref_store *refs)2180{2181 struct packed_ref_cache *packed_ref_cache =2182 get_packed_ref_cache(refs);2183 int error = 0;2184 int save_errno = 0;2185 FILE *out;21862187 assert_main_repository(&refs->base, "commit_packed_refs");21882189 if (!packed_ref_cache->lock)2190 die("internal error: packed-refs not locked");21912192 out = fdopen_lock_file(packed_ref_cache->lock, "w");2193 if (!out)2194 die_errno("unable to fdopen packed-refs descriptor");21952196 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);2197 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2198 0, write_packed_entry_fn, out);21992200 if (commit_lock_file(packed_ref_cache->lock)) {2201 save_errno = errno;2202 error = -1;2203 }2204 packed_ref_cache->lock = NULL;2205 release_packed_ref_cache(packed_ref_cache);2206 errno = save_errno;2207 return error;2208}22092210/*2211 * Rollback the lockfile for the packed-refs file, and discard the2212 * in-memory packed reference cache. (The packed-refs file will be2213 * read anew if it is needed again after this function is called.)2214 */2215static void rollback_packed_refs(struct files_ref_store *refs)2216{2217 struct packed_ref_cache *packed_ref_cache =2218 get_packed_ref_cache(refs);22192220 assert_main_repository(&refs->base, "rollback_packed_refs");22212222 if (!packed_ref_cache->lock)2223 die("internal error: packed-refs not locked");2224 rollback_lock_file(packed_ref_cache->lock);2225 packed_ref_cache->lock = NULL;2226 release_packed_ref_cache(packed_ref_cache);2227 clear_packed_ref_cache(refs);2228}22292230struct ref_to_prune {2231 struct ref_to_prune *next;2232 unsigned char sha1[20];2233 char name[FLEX_ARRAY];2234};22352236struct pack_refs_cb_data {2237 unsigned int flags;2238 struct ref_dir *packed_refs;2239 struct ref_to_prune *ref_to_prune;2240};22412242/*2243 * An each_ref_entry_fn that is run over loose references only. If2244 * the loose reference can be packed, add an entry in the packed ref2245 * cache. If the reference should be pruned, also add it to2246 * ref_to_prune in the pack_refs_cb_data.2247 */2248static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2249{2250 struct pack_refs_cb_data *cb = cb_data;2251 enum peel_status peel_status;2252 struct ref_entry *packed_entry;2253 int is_tag_ref = starts_with(entry->name, "refs/tags/");22542255 /* Do not pack per-worktree refs: */2256 if (ref_type(entry->name) != REF_TYPE_NORMAL)2257 return 0;22582259 /* ALWAYS pack tags */2260 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2261 return 0;22622263 /* Do not pack symbolic or broken refs: */2264 if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2265 return 0;22662267 /* Add a packed ref cache entry equivalent to the loose entry. */2268 peel_status = peel_entry(entry, 1);2269 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2270 die("internal error peeling reference %s (%s)",2271 entry->name, oid_to_hex(&entry->u.value.oid));2272 packed_entry = find_ref(cb->packed_refs, entry->name);2273 if (packed_entry) {2274 /* Overwrite existing packed entry with info from loose entry */2275 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2276 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2277 } else {2278 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,2279 REF_ISPACKED | REF_KNOWS_PEELED, 0);2280 add_ref(cb->packed_refs, packed_entry);2281 }2282 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);22832284 /* Schedule the loose reference for pruning if requested. */2285 if ((cb->flags & PACK_REFS_PRUNE)) {2286 struct ref_to_prune *n;2287 FLEX_ALLOC_STR(n, name, entry->name);2288 hashcpy(n->sha1, entry->u.value.oid.hash);2289 n->next = cb->ref_to_prune;2290 cb->ref_to_prune = n;2291 }2292 return 0;2293}22942295/*2296 * Remove empty parents, but spare refs/ and immediate subdirs.2297 * Note: munges *name.2298 */2299static void try_remove_empty_parents(char *name)2300{2301 char *p, *q;2302 int i;2303 p = name;2304 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2305 while (*p && *p != '/')2306 p++;2307 /* tolerate duplicate slashes; see check_refname_format() */2308 while (*p == '/')2309 p++;2310 }2311 for (q = p; *q; q++)2312 ;2313 while (1) {2314 while (q > p && *q != '/')2315 q--;2316 while (q > p && *(q-1) == '/')2317 q--;2318 if (q == p)2319 break;2320 *q = '\0';2321 if (rmdir(git_path("%s", name)))2322 break;2323 }2324}23252326/* make sure nobody touched the ref, and unlink */2327static void prune_ref(struct ref_to_prune *r)2328{2329 struct ref_transaction *transaction;2330 struct strbuf err = STRBUF_INIT;23312332 if (check_refname_format(r->name, 0))2333 return;23342335 transaction = ref_transaction_begin(&err);2336 if (!transaction ||2337 ref_transaction_delete(transaction, r->name, r->sha1,2338 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2339 ref_transaction_commit(transaction, &err)) {2340 ref_transaction_free(transaction);2341 error("%s", err.buf);2342 strbuf_release(&err);2343 return;2344 }2345 ref_transaction_free(transaction);2346 strbuf_release(&err);2347 try_remove_empty_parents(r->name);2348}23492350static void prune_refs(struct ref_to_prune *r)2351{2352 while (r) {2353 prune_ref(r);2354 r = r->next;2355 }2356}23572358static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)2359{2360 struct files_ref_store *refs =2361 files_downcast(ref_store, 0, "pack_refs");2362 struct pack_refs_cb_data cbdata;23632364 memset(&cbdata, 0, sizeof(cbdata));2365 cbdata.flags = flags;23662367 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2368 cbdata.packed_refs = get_packed_refs(refs);23692370 do_for_each_entry_in_dir(get_loose_refs(refs), 0,2371 pack_if_possible_fn, &cbdata);23722373 if (commit_packed_refs(refs))2374 die_errno("unable to overwrite old ref-pack file");23752376 prune_refs(cbdata.ref_to_prune);2377 return 0;2378}23792380/*2381 * Rewrite the packed-refs file, omitting any refs listed in2382 * 'refnames'. On error, leave packed-refs unchanged, write an error2383 * message to 'err', and return a nonzero value.2384 *2385 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2386 */2387static int repack_without_refs(struct files_ref_store *refs,2388 struct string_list *refnames, struct strbuf *err)2389{2390 struct ref_dir *packed;2391 struct string_list_item *refname;2392 int ret, needs_repacking = 0, removed = 0;23932394 assert_main_repository(&refs->base, "repack_without_refs");2395 assert(err);23962397 /* Look for a packed ref */2398 for_each_string_list_item(refname, refnames) {2399 if (get_packed_ref(refs, refname->string)) {2400 needs_repacking = 1;2401 break;2402 }2403 }24042405 /* Avoid locking if we have nothing to do */2406 if (!needs_repacking)2407 return 0; /* no refname exists in packed refs */24082409 if (lock_packed_refs(refs, 0)) {2410 unable_to_lock_message(git_path("packed-refs"), errno, err);2411 return -1;2412 }2413 packed = get_packed_refs(refs);24142415 /* Remove refnames from the cache */2416 for_each_string_list_item(refname, refnames)2417 if (remove_entry(packed, refname->string) != -1)2418 removed = 1;2419 if (!removed) {2420 /*2421 * All packed entries disappeared while we were2422 * acquiring the lock.2423 */2424 rollback_packed_refs(refs);2425 return 0;2426 }24272428 /* Write what remains */2429 ret = commit_packed_refs(refs);2430 if (ret)2431 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2432 strerror(errno));2433 return ret;2434}24352436static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2437{2438 assert(err);24392440 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2441 /*2442 * loose. The loose file name is the same as the2443 * lockfile name, minus ".lock":2444 */2445 char *loose_filename = get_locked_file_path(lock->lk);2446 int res = unlink_or_msg(loose_filename, err);2447 free(loose_filename);2448 if (res)2449 return 1;2450 }2451 return 0;2452}24532454int delete_refs(struct string_list *refnames, unsigned int flags)2455{2456 struct files_ref_store *refs =2457 get_files_ref_store(NULL, "delete_refs");2458 struct strbuf err = STRBUF_INIT;2459 int i, result = 0;24602461 if (!refnames->nr)2462 return 0;24632464 result = repack_without_refs(refs, refnames, &err);2465 if (result) {2466 /*2467 * If we failed to rewrite the packed-refs file, then2468 * it is unsafe to try to remove loose refs, because2469 * doing so might expose an obsolete packed value for2470 * a reference that might even point at an object that2471 * has been garbage collected.2472 */2473 if (refnames->nr == 1)2474 error(_("could not delete reference %s: %s"),2475 refnames->items[0].string, err.buf);2476 else2477 error(_("could not delete references: %s"), err.buf);24782479 goto out;2480 }24812482 for (i = 0; i < refnames->nr; i++) {2483 const char *refname = refnames->items[i].string;24842485 if (delete_ref(refname, NULL, flags))2486 result |= error(_("could not remove reference %s"), refname);2487 }24882489out:2490 strbuf_release(&err);2491 return result;2492}24932494/*2495 * People using contrib's git-new-workdir have .git/logs/refs ->2496 * /some/other/path/.git/logs/refs, and that may live on another device.2497 *2498 * IOW, to avoid cross device rename errors, the temporary renamed log must2499 * live into logs/refs.2500 */2501#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"25022503static int rename_tmp_log(const char *newrefname)2504{2505 int attempts_remaining = 4;2506 struct strbuf path = STRBUF_INIT;2507 int ret = -1;25082509 retry:2510 strbuf_reset(&path);2511 strbuf_git_path(&path, "logs/%s", newrefname);2512 switch (safe_create_leading_directories_const(path.buf)) {2513 case SCLD_OK:2514 break; /* success */2515 case SCLD_VANISHED:2516 if (--attempts_remaining > 0)2517 goto retry;2518 /* fall through */2519 default:2520 error("unable to create directory for %s", newrefname);2521 goto out;2522 }25232524 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {2525 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2526 /*2527 * rename(a, b) when b is an existing2528 * directory ought to result in ISDIR, but2529 * Solaris 5.8 gives ENOTDIR. Sheesh.2530 */2531 if (remove_empty_directories(&path)) {2532 error("Directory not empty: logs/%s", newrefname);2533 goto out;2534 }2535 goto retry;2536 } else if (errno == ENOENT && --attempts_remaining > 0) {2537 /*2538 * Maybe another process just deleted one of2539 * the directories in the path to newrefname.2540 * Try again from the beginning.2541 */2542 goto retry;2543 } else {2544 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2545 newrefname, strerror(errno));2546 goto out;2547 }2548 }2549 ret = 0;2550out:2551 strbuf_release(&path);2552 return ret;2553}25542555static int files_verify_refname_available(struct ref_store *ref_store,2556 const char *newname,2557 const struct string_list *extras,2558 const struct string_list *skip,2559 struct strbuf *err)2560{2561 struct files_ref_store *refs =2562 files_downcast(ref_store, 1, "verify_refname_available");2563 struct ref_dir *packed_refs = get_packed_refs(refs);2564 struct ref_dir *loose_refs = get_loose_refs(refs);25652566 if (verify_refname_available_dir(newname, extras, skip,2567 packed_refs, err) ||2568 verify_refname_available_dir(newname, extras, skip,2569 loose_refs, err))2570 return -1;25712572 return 0;2573}25742575static int write_ref_to_lockfile(struct ref_lock *lock,2576 const unsigned char *sha1, struct strbuf *err);2577static int commit_ref_update(struct files_ref_store *refs,2578 struct ref_lock *lock,2579 const unsigned char *sha1, const char *logmsg,2580 struct strbuf *err);25812582int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2583{2584 struct files_ref_store *refs = get_files_ref_store(NULL, "rename_ref");2585 unsigned char sha1[20], orig_sha1[20];2586 int flag = 0, logmoved = 0;2587 struct ref_lock *lock;2588 struct stat loginfo;2589 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2590 struct strbuf err = STRBUF_INIT;25912592 if (log && S_ISLNK(loginfo.st_mode))2593 return error("reflog for %s is a symlink", oldrefname);25942595 if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2596 orig_sha1, &flag))2597 return error("refname %s not found", oldrefname);25982599 if (flag & REF_ISSYMREF)2600 return error("refname %s is a symbolic ref, renaming it is not supported",2601 oldrefname);2602 if (!rename_ref_available(oldrefname, newrefname))2603 return 1;26042605 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2606 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2607 oldrefname, strerror(errno));26082609 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2610 error("unable to delete old %s", oldrefname);2611 goto rollback;2612 }26132614 /*2615 * Since we are doing a shallow lookup, sha1 is not the2616 * correct value to pass to delete_ref as old_sha1. But that2617 * doesn't matter, because an old_sha1 check wouldn't add to2618 * the safety anyway; we want to delete the reference whatever2619 * its current value.2620 */2621 if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2622 sha1, NULL) &&2623 delete_ref(newrefname, NULL, REF_NODEREF)) {2624 if (errno==EISDIR) {2625 struct strbuf path = STRBUF_INIT;2626 int result;26272628 strbuf_git_path(&path, "%s", newrefname);2629 result = remove_empty_directories(&path);2630 strbuf_release(&path);26312632 if (result) {2633 error("Directory not empty: %s", newrefname);2634 goto rollback;2635 }2636 } else {2637 error("unable to delete existing %s", newrefname);2638 goto rollback;2639 }2640 }26412642 if (log && rename_tmp_log(newrefname))2643 goto rollback;26442645 logmoved = log;26462647 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,2648 NULL, &err);2649 if (!lock) {2650 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);2651 strbuf_release(&err);2652 goto rollback;2653 }2654 hashcpy(lock->old_oid.hash, orig_sha1);26552656 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2657 commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2658 error("unable to write current sha1 into %s: %s", newrefname, err.buf);2659 strbuf_release(&err);2660 goto rollback;2661 }26622663 return 0;26642665 rollback:2666 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,2667 NULL, &err);2668 if (!lock) {2669 error("unable to lock %s for rollback: %s", oldrefname, err.buf);2670 strbuf_release(&err);2671 goto rollbacklog;2672 }26732674 flag = log_all_ref_updates;2675 log_all_ref_updates = 0;2676 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2677 commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2678 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);2679 strbuf_release(&err);2680 }2681 log_all_ref_updates = flag;26822683 rollbacklog:2684 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2685 error("unable to restore logfile %s from %s: %s",2686 oldrefname, newrefname, strerror(errno));2687 if (!logmoved && log &&2688 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2689 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2690 oldrefname, strerror(errno));26912692 return 1;2693}26942695static int close_ref(struct ref_lock *lock)2696{2697 if (close_lock_file(lock->lk))2698 return -1;2699 return 0;2700}27012702static int commit_ref(struct ref_lock *lock)2703{2704 char *path = get_locked_file_path(lock->lk);2705 struct stat st;27062707 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {2708 /*2709 * There is a directory at the path we want to rename2710 * the lockfile to. Hopefully it is empty; try to2711 * delete it.2712 */2713 size_t len = strlen(path);2714 struct strbuf sb_path = STRBUF_INIT;27152716 strbuf_attach(&sb_path, path, len, len);27172718 /*2719 * If this fails, commit_lock_file() will also fail2720 * and will report the problem.2721 */2722 remove_empty_directories(&sb_path);2723 strbuf_release(&sb_path);2724 } else {2725 free(path);2726 }27272728 if (commit_lock_file(lock->lk))2729 return -1;2730 return 0;2731}27322733/*2734 * Create a reflog for a ref. If force_create = 0, the reflog will2735 * only be created for certain refs (those for which2736 * should_autocreate_reflog returns non-zero. Otherwise, create it2737 * regardless of the ref name. Fill in *err and return -1 on failure.2738 */2739static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)2740{2741 int logfd, oflags = O_APPEND | O_WRONLY;27422743 strbuf_git_path(logfile, "logs/%s", refname);2744 if (force_create || should_autocreate_reflog(refname)) {2745 if (safe_create_leading_directories(logfile->buf) < 0) {2746 strbuf_addf(err, "unable to create directory for '%s': "2747 "%s", logfile->buf, strerror(errno));2748 return -1;2749 }2750 oflags |= O_CREAT;2751 }27522753 logfd = open(logfile->buf, oflags, 0666);2754 if (logfd < 0) {2755 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2756 return 0;27572758 if (errno == EISDIR) {2759 if (remove_empty_directories(logfile)) {2760 strbuf_addf(err, "there are still logs under "2761 "'%s'", logfile->buf);2762 return -1;2763 }2764 logfd = open(logfile->buf, oflags, 0666);2765 }27662767 if (logfd < 0) {2768 strbuf_addf(err, "unable to append to '%s': %s",2769 logfile->buf, strerror(errno));2770 return -1;2771 }2772 }27732774 adjust_shared_perm(logfile->buf);2775 close(logfd);2776 return 0;2777}277827792780int safe_create_reflog(const char *refname, int force_create, struct strbuf *err)2781{2782 int ret;2783 struct strbuf sb = STRBUF_INIT;27842785 ret = log_ref_setup(refname, &sb, err, force_create);2786 strbuf_release(&sb);2787 return ret;2788}27892790static int log_ref_write_fd(int fd, const unsigned char *old_sha1,2791 const unsigned char *new_sha1,2792 const char *committer, const char *msg)2793{2794 int msglen, written;2795 unsigned maxlen, len;2796 char *logrec;27972798 msglen = msg ? strlen(msg) : 0;2799 maxlen = strlen(committer) + msglen + 100;2800 logrec = xmalloc(maxlen);2801 len = xsnprintf(logrec, maxlen, "%s %s %s\n",2802 sha1_to_hex(old_sha1),2803 sha1_to_hex(new_sha1),2804 committer);2805 if (msglen)2806 len += copy_reflog_msg(logrec + len - 1, msg) - 1;28072808 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2809 free(logrec);2810 if (written != len)2811 return -1;28122813 return 0;2814}28152816static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,2817 const unsigned char *new_sha1, const char *msg,2818 struct strbuf *logfile, int flags,2819 struct strbuf *err)2820{2821 int logfd, result, oflags = O_APPEND | O_WRONLY;28222823 if (log_all_ref_updates < 0)2824 log_all_ref_updates = !is_bare_repository();28252826 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28272828 if (result)2829 return result;28302831 logfd = open(logfile->buf, oflags);2832 if (logfd < 0)2833 return 0;2834 result = log_ref_write_fd(logfd, old_sha1, new_sha1,2835 git_committer_info(0), msg);2836 if (result) {2837 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2838 strerror(errno));2839 close(logfd);2840 return -1;2841 }2842 if (close(logfd)) {2843 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2844 strerror(errno));2845 return -1;2846 }2847 return 0;2848}28492850static int log_ref_write(const char *refname, const unsigned char *old_sha1,2851 const unsigned char *new_sha1, const char *msg,2852 int flags, struct strbuf *err)2853{2854 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2855 err);2856}28572858int files_log_ref_write(const char *refname, const unsigned char *old_sha1,2859 const unsigned char *new_sha1, const char *msg,2860 int flags, struct strbuf *err)2861{2862 struct strbuf sb = STRBUF_INIT;2863 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2864 err);2865 strbuf_release(&sb);2866 return ret;2867}28682869/*2870 * Write sha1 into the open lockfile, then close the lockfile. On2871 * errors, rollback the lockfile, fill in *err and2872 * return -1.2873 */2874static int write_ref_to_lockfile(struct ref_lock *lock,2875 const unsigned char *sha1, struct strbuf *err)2876{2877 static char term = '\n';2878 struct object *o;2879 int fd;28802881 o = parse_object(sha1);2882 if (!o) {2883 strbuf_addf(err,2884 "trying to write ref '%s' with nonexistent object %s",2885 lock->ref_name, sha1_to_hex(sha1));2886 unlock_ref(lock);2887 return -1;2888 }2889 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2890 strbuf_addf(err,2891 "trying to write non-commit object %s to branch '%s'",2892 sha1_to_hex(sha1), lock->ref_name);2893 unlock_ref(lock);2894 return -1;2895 }2896 fd = get_lock_file_fd(lock->lk);2897 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||2898 write_in_full(fd, &term, 1) != 1 ||2899 close_ref(lock) < 0) {2900 strbuf_addf(err,2901 "couldn't write '%s'", get_lock_file_path(lock->lk));2902 unlock_ref(lock);2903 return -1;2904 }2905 return 0;2906}29072908/*2909 * Commit a change to a loose reference that has already been written2910 * to the loose reference lockfile. Also update the reflogs if2911 * necessary, using the specified lockmsg (which can be NULL).2912 */2913static int commit_ref_update(struct files_ref_store *refs,2914 struct ref_lock *lock,2915 const unsigned char *sha1, const char *logmsg,2916 struct strbuf *err)2917{2918 assert_main_repository(&refs->base, "commit_ref_update");29192920 clear_loose_ref_cache(refs);2921 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {2922 char *old_msg = strbuf_detach(err, NULL);2923 strbuf_addf(err, "cannot update the ref '%s': %s",2924 lock->ref_name, old_msg);2925 free(old_msg);2926 unlock_ref(lock);2927 return -1;2928 }29292930 if (strcmp(lock->ref_name, "HEAD") != 0) {2931 /*2932 * Special hack: If a branch is updated directly and HEAD2933 * points to it (may happen on the remote side of a push2934 * for example) then logically the HEAD reflog should be2935 * updated too.2936 * A generic solution implies reverse symref information,2937 * but finding all symrefs pointing to the given branch2938 * would be rather costly for this rare event (the direct2939 * update of a branch) to be worth it. So let's cheat and2940 * check with HEAD only which should cover 99% of all usage2941 * scenarios (even 100% of the default ones).2942 */2943 unsigned char head_sha1[20];2944 int head_flag;2945 const char *head_ref;29462947 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2948 head_sha1, &head_flag);2949 if (head_ref && (head_flag & REF_ISSYMREF) &&2950 !strcmp(head_ref, lock->ref_name)) {2951 struct strbuf log_err = STRBUF_INIT;2952 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,2953 logmsg, 0, &log_err)) {2954 error("%s", log_err.buf);2955 strbuf_release(&log_err);2956 }2957 }2958 }29592960 if (commit_ref(lock)) {2961 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2962 unlock_ref(lock);2963 return -1;2964 }29652966 unlock_ref(lock);2967 return 0;2968}29692970static int create_ref_symlink(struct ref_lock *lock, const char *target)2971{2972 int ret = -1;2973#ifndef NO_SYMLINK_HEAD2974 char *ref_path = get_locked_file_path(lock->lk);2975 unlink(ref_path);2976 ret = symlink(target, ref_path);2977 free(ref_path);29782979 if (ret)2980 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2981#endif2982 return ret;2983}29842985static void update_symref_reflog(struct ref_lock *lock, const char *refname,2986 const char *target, const char *logmsg)2987{2988 struct strbuf err = STRBUF_INIT;2989 unsigned char new_sha1[20];2990 if (logmsg && !read_ref(target, new_sha1) &&2991 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {2992 error("%s", err.buf);2993 strbuf_release(&err);2994 }2995}29962997static int create_symref_locked(struct ref_lock *lock, const char *refname,2998 const char *target, const char *logmsg)2999{3000 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {3001 update_symref_reflog(lock, refname, target, logmsg);3002 return 0;3003 }30043005 if (!fdopen_lock_file(lock->lk, "w"))3006 return error("unable to fdopen %s: %s",3007 lock->lk->tempfile.filename.buf, strerror(errno));30083009 update_symref_reflog(lock, refname, target, logmsg);30103011 /* no error check; commit_ref will check ferror */3012 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);3013 if (commit_ref(lock) < 0)3014 return error("unable to write symref for %s: %s", refname,3015 strerror(errno));3016 return 0;3017}30183019static int files_create_symref(struct ref_store *ref_store,3020 const char *refname, const char *target,3021 const char *logmsg)3022{3023 struct strbuf err = STRBUF_INIT;3024 struct ref_lock *lock;3025 int ret;30263027 files_downcast(ref_store, 0, "create_symref");30283029 lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,3030 &err);3031 if (!lock) {3032 error("%s", err.buf);3033 strbuf_release(&err);3034 return -1;3035 }30363037 ret = create_symref_locked(lock, refname, target, logmsg);3038 unlock_ref(lock);3039 return ret;3040}30413042int set_worktree_head_symref(const char *gitdir, const char *target)3043{3044 static struct lock_file head_lock;3045 struct ref_lock *lock;3046 struct strbuf head_path = STRBUF_INIT;3047 const char *head_rel;3048 int ret;30493050 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));3051 if (hold_lock_file_for_update(&head_lock, head_path.buf,3052 LOCK_NO_DEREF) < 0) {3053 struct strbuf err = STRBUF_INIT;3054 unable_to_lock_message(head_path.buf, errno, &err);3055 error("%s", err.buf);3056 strbuf_release(&err);3057 strbuf_release(&head_path);3058 return -1;3059 }30603061 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3062 linked trees */3063 head_rel = remove_leading_path(head_path.buf,3064 absolute_path(get_git_common_dir()));3065 /* to make use of create_symref_locked(), initialize ref_lock */3066 lock = xcalloc(1, sizeof(struct ref_lock));3067 lock->lk = &head_lock;3068 lock->ref_name = xstrdup(head_rel);30693070 ret = create_symref_locked(lock, head_rel, target, NULL);30713072 unlock_ref(lock); /* will free lock */3073 strbuf_release(&head_path);3074 return ret;3075}30763077int reflog_exists(const char *refname)3078{3079 struct stat st;30803081 return !lstat(git_path("logs/%s", refname), &st) &&3082 S_ISREG(st.st_mode);3083}30843085int delete_reflog(const char *refname)3086{3087 return remove_path(git_path("logs/%s", refname));3088}30893090static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3091{3092 unsigned char osha1[20], nsha1[20];3093 char *email_end, *message;3094 unsigned long timestamp;3095 int tz;30963097 /* old SP new SP name <email> SP time TAB msg LF */3098 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3099 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3100 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3101 !(email_end = strchr(sb->buf + 82, '>')) ||3102 email_end[1] != ' ' ||3103 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3104 !message || message[0] != ' ' ||3105 (message[1] != '+' && message[1] != '-') ||3106 !isdigit(message[2]) || !isdigit(message[3]) ||3107 !isdigit(message[4]) || !isdigit(message[5]))3108 return 0; /* corrupt? */3109 email_end[1] = '\0';3110 tz = strtol(message + 1, NULL, 10);3111 if (message[6] != '\t')3112 message += 6;3113 else3114 message += 7;3115 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3116}31173118static char *find_beginning_of_line(char *bob, char *scan)3119{3120 while (bob < scan && *(--scan) != '\n')3121 ; /* keep scanning backwards */3122 /*3123 * Return either beginning of the buffer, or LF at the end of3124 * the previous line.3125 */3126 return scan;3127}31283129int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3130{3131 struct strbuf sb = STRBUF_INIT;3132 FILE *logfp;3133 long pos;3134 int ret = 0, at_tail = 1;31353136 logfp = fopen(git_path("logs/%s", refname), "r");3137 if (!logfp)3138 return -1;31393140 /* Jump to the end */3141 if (fseek(logfp, 0, SEEK_END) < 0)3142 return error("cannot seek back reflog for %s: %s",3143 refname, strerror(errno));3144 pos = ftell(logfp);3145 while (!ret && 0 < pos) {3146 int cnt;3147 size_t nread;3148 char buf[BUFSIZ];3149 char *endp, *scanp;31503151 /* Fill next block from the end */3152 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3153 if (fseek(logfp, pos - cnt, SEEK_SET))3154 return error("cannot seek back reflog for %s: %s",3155 refname, strerror(errno));3156 nread = fread(buf, cnt, 1, logfp);3157 if (nread != 1)3158 return error("cannot read %d bytes from reflog for %s: %s",3159 cnt, refname, strerror(errno));3160 pos -= cnt;31613162 scanp = endp = buf + cnt;3163 if (at_tail && scanp[-1] == '\n')3164 /* Looking at the final LF at the end of the file */3165 scanp--;3166 at_tail = 0;31673168 while (buf < scanp) {3169 /*3170 * terminating LF of the previous line, or the beginning3171 * of the buffer.3172 */3173 char *bp;31743175 bp = find_beginning_of_line(buf, scanp);31763177 if (*bp == '\n') {3178 /*3179 * The newline is the end of the previous line,3180 * so we know we have complete line starting3181 * at (bp + 1). Prefix it onto any prior data3182 * we collected for the line and process it.3183 */3184 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3185 scanp = bp;3186 endp = bp + 1;3187 ret = show_one_reflog_ent(&sb, fn, cb_data);3188 strbuf_reset(&sb);3189 if (ret)3190 break;3191 } else if (!pos) {3192 /*3193 * We are at the start of the buffer, and the3194 * start of the file; there is no previous3195 * line, and we have everything for this one.3196 * Process it, and we can end the loop.3197 */3198 strbuf_splice(&sb, 0, 0, buf, endp - buf);3199 ret = show_one_reflog_ent(&sb, fn, cb_data);3200 strbuf_reset(&sb);3201 break;3202 }32033204 if (bp == buf) {3205 /*3206 * We are at the start of the buffer, and there3207 * is more file to read backwards. Which means3208 * we are in the middle of a line. Note that we3209 * may get here even if *bp was a newline; that3210 * just means we are at the exact end of the3211 * previous line, rather than some spot in the3212 * middle.3213 *3214 * Save away what we have to be combined with3215 * the data from the next read.3216 */3217 strbuf_splice(&sb, 0, 0, buf, endp - buf);3218 break;3219 }3220 }32213222 }3223 if (!ret && sb.len)3224 die("BUG: reverse reflog parser had leftover data");32253226 fclose(logfp);3227 strbuf_release(&sb);3228 return ret;3229}32303231int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3232{3233 FILE *logfp;3234 struct strbuf sb = STRBUF_INIT;3235 int ret = 0;32363237 logfp = fopen(git_path("logs/%s", refname), "r");3238 if (!logfp)3239 return -1;32403241 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3242 ret = show_one_reflog_ent(&sb, fn, cb_data);3243 fclose(logfp);3244 strbuf_release(&sb);3245 return ret;3246}32473248struct files_reflog_iterator {3249 struct ref_iterator base;32503251 struct dir_iterator *dir_iterator;3252 struct object_id oid;3253};32543255static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)3256{3257 struct files_reflog_iterator *iter =3258 (struct files_reflog_iterator *)ref_iterator;3259 struct dir_iterator *diter = iter->dir_iterator;3260 int ok;32613262 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {3263 int flags;32643265 if (!S_ISREG(diter->st.st_mode))3266 continue;3267 if (diter->basename[0] == '.')3268 continue;3269 if (ends_with(diter->basename, ".lock"))3270 continue;32713272 if (read_ref_full(diter->relative_path, 0,3273 iter->oid.hash, &flags)) {3274 error("bad ref for %s", diter->path.buf);3275 continue;3276 }32773278 iter->base.refname = diter->relative_path;3279 iter->base.oid = &iter->oid;3280 iter->base.flags = flags;3281 return ITER_OK;3282 }32833284 iter->dir_iterator = NULL;3285 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)3286 ok = ITER_ERROR;3287 return ok;3288}32893290static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,3291 struct object_id *peeled)3292{3293 die("BUG: ref_iterator_peel() called for reflog_iterator");3294}32953296static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)3297{3298 struct files_reflog_iterator *iter =3299 (struct files_reflog_iterator *)ref_iterator;3300 int ok = ITER_DONE;33013302 if (iter->dir_iterator)3303 ok = dir_iterator_abort(iter->dir_iterator);33043305 base_ref_iterator_free(ref_iterator);3306 return ok;3307}33083309static struct ref_iterator_vtable files_reflog_iterator_vtable = {3310 files_reflog_iterator_advance,3311 files_reflog_iterator_peel,3312 files_reflog_iterator_abort3313};33143315struct ref_iterator *files_reflog_iterator_begin(void)3316{3317 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));3318 struct ref_iterator *ref_iterator = &iter->base;33193320 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3321 iter->dir_iterator = dir_iterator_begin(git_path("logs"));3322 return ref_iterator;3323}33243325int for_each_reflog(each_ref_fn fn, void *cb_data)3326{3327 return do_for_each_ref_iterator(files_reflog_iterator_begin(),3328 fn, cb_data);3329}33303331static int ref_update_reject_duplicates(struct string_list *refnames,3332 struct strbuf *err)3333{3334 int i, n = refnames->nr;33353336 assert(err);33373338 for (i = 1; i < n; i++)3339 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {3340 strbuf_addf(err,3341 "multiple updates for ref '%s' not allowed.",3342 refnames->items[i].string);3343 return 1;3344 }3345 return 0;3346}33473348/*3349 * If update is a direct update of head_ref (the reference pointed to3350 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3351 */3352static int split_head_update(struct ref_update *update,3353 struct ref_transaction *transaction,3354 const char *head_ref,3355 struct string_list *affected_refnames,3356 struct strbuf *err)3357{3358 struct string_list_item *item;3359 struct ref_update *new_update;33603361 if ((update->flags & REF_LOG_ONLY) ||3362 (update->flags & REF_ISPRUNING) ||3363 (update->flags & REF_UPDATE_VIA_HEAD))3364 return 0;33653366 if (strcmp(update->refname, head_ref))3367 return 0;33683369 /*3370 * First make sure that HEAD is not already in the3371 * transaction. This insertion is O(N) in the transaction3372 * size, but it happens at most once per transaction.3373 */3374 item = string_list_insert(affected_refnames, "HEAD");3375 if (item->util) {3376 /* An entry already existed */3377 strbuf_addf(err,3378 "multiple updates for 'HEAD' (including one "3379 "via its referent '%s') are not allowed",3380 update->refname);3381 return TRANSACTION_NAME_CONFLICT;3382 }33833384 new_update = ref_transaction_add_update(3385 transaction, "HEAD",3386 update->flags | REF_LOG_ONLY | REF_NODEREF,3387 update->new_sha1, update->old_sha1,3388 update->msg);33893390 item->util = new_update;33913392 return 0;3393}33943395/*3396 * update is for a symref that points at referent and doesn't have3397 * REF_NODEREF set. Split it into two updates:3398 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3399 * - A new, separate update for the referent reference3400 * Note that the new update will itself be subject to splitting when3401 * the iteration gets to it.3402 */3403static int split_symref_update(struct ref_update *update,3404 const char *referent,3405 struct ref_transaction *transaction,3406 struct string_list *affected_refnames,3407 struct strbuf *err)3408{3409 struct string_list_item *item;3410 struct ref_update *new_update;3411 unsigned int new_flags;34123413 /*3414 * First make sure that referent is not already in the3415 * transaction. This insertion is O(N) in the transaction3416 * size, but it happens at most once per symref in a3417 * transaction.3418 */3419 item = string_list_insert(affected_refnames, referent);3420 if (item->util) {3421 /* An entry already existed */3422 strbuf_addf(err,3423 "multiple updates for '%s' (including one "3424 "via symref '%s') are not allowed",3425 referent, update->refname);3426 return TRANSACTION_NAME_CONFLICT;3427 }34283429 new_flags = update->flags;3430 if (!strcmp(update->refname, "HEAD")) {3431 /*3432 * Record that the new update came via HEAD, so that3433 * when we process it, split_head_update() doesn't try3434 * to add another reflog update for HEAD. Note that3435 * this bit will be propagated if the new_update3436 * itself needs to be split.3437 */3438 new_flags |= REF_UPDATE_VIA_HEAD;3439 }34403441 new_update = ref_transaction_add_update(3442 transaction, referent, new_flags,3443 update->new_sha1, update->old_sha1,3444 update->msg);34453446 new_update->parent_update = update;34473448 /*3449 * Change the symbolic ref update to log only. Also, it3450 * doesn't need to check its old SHA-1 value, as that will be3451 * done when new_update is processed.3452 */3453 update->flags |= REF_LOG_ONLY | REF_NODEREF;3454 update->flags &= ~REF_HAVE_OLD;34553456 item->util = new_update;34573458 return 0;3459}34603461/*3462 * Return the refname under which update was originally requested.3463 */3464static const char *original_update_refname(struct ref_update *update)3465{3466 while (update->parent_update)3467 update = update->parent_update;34683469 return update->refname;3470}34713472/*3473 * Prepare for carrying out update:3474 * - Lock the reference referred to by update.3475 * - Read the reference under lock.3476 * - Check that its old SHA-1 value (if specified) is correct, and in3477 * any case record it in update->lock->old_oid for later use when3478 * writing the reflog.3479 * - If it is a symref update without REF_NODEREF, split it up into a3480 * REF_LOG_ONLY update of the symref and add a separate update for3481 * the referent to transaction.3482 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3483 * update of HEAD.3484 */3485static int lock_ref_for_update(struct files_ref_store *refs,3486 struct ref_update *update,3487 struct ref_transaction *transaction,3488 const char *head_ref,3489 struct string_list *affected_refnames,3490 struct strbuf *err)3491{3492 struct strbuf referent = STRBUF_INIT;3493 int mustexist = (update->flags & REF_HAVE_OLD) &&3494 !is_null_sha1(update->old_sha1);3495 int ret;3496 struct ref_lock *lock;34973498 assert_main_repository(&refs->base, "lock_ref_for_update");34993500 if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))3501 update->flags |= REF_DELETING;35023503 if (head_ref) {3504 ret = split_head_update(update, transaction, head_ref,3505 affected_refnames, err);3506 if (ret)3507 return ret;3508 }35093510 ret = lock_raw_ref(refs, update->refname, mustexist,3511 affected_refnames, NULL,3512 &update->lock, &referent,3513 &update->type, err);35143515 if (ret) {3516 char *reason;35173518 reason = strbuf_detach(err, NULL);3519 strbuf_addf(err, "cannot lock ref '%s': %s",3520 update->refname, reason);3521 free(reason);3522 return ret;3523 }35243525 lock = update->lock;35263527 if (update->type & REF_ISSYMREF) {3528 if (update->flags & REF_NODEREF) {3529 /*3530 * We won't be reading the referent as part of3531 * the transaction, so we have to read it here3532 * to record and possibly check old_sha1:3533 */3534 if (read_ref_full(update->refname,3535 mustexist ? RESOLVE_REF_READING : 0,3536 lock->old_oid.hash, NULL)) {3537 if (update->flags & REF_HAVE_OLD) {3538 strbuf_addf(err, "cannot lock ref '%s': "3539 "can't resolve old value",3540 update->refname);3541 return TRANSACTION_GENERIC_ERROR;3542 } else {3543 hashclr(lock->old_oid.hash);3544 }3545 }3546 if ((update->flags & REF_HAVE_OLD) &&3547 hashcmp(lock->old_oid.hash, update->old_sha1)) {3548 strbuf_addf(err, "cannot lock ref '%s': "3549 "is at %s but expected %s",3550 update->refname,3551 sha1_to_hex(lock->old_oid.hash),3552 sha1_to_hex(update->old_sha1));3553 return TRANSACTION_GENERIC_ERROR;3554 }35553556 } else {3557 /*3558 * Create a new update for the reference this3559 * symref is pointing at. Also, we will record3560 * and verify old_sha1 for this update as part3561 * of processing the split-off update, so we3562 * don't have to do it here.3563 */3564 ret = split_symref_update(update, referent.buf, transaction,3565 affected_refnames, err);3566 if (ret)3567 return ret;3568 }3569 } else {3570 struct ref_update *parent_update;35713572 /*3573 * If this update is happening indirectly because of a3574 * symref update, record the old SHA-1 in the parent3575 * update:3576 */3577 for (parent_update = update->parent_update;3578 parent_update;3579 parent_update = parent_update->parent_update) {3580 oidcpy(&parent_update->lock->old_oid, &lock->old_oid);3581 }35823583 if ((update->flags & REF_HAVE_OLD) &&3584 hashcmp(lock->old_oid.hash, update->old_sha1)) {3585 if (is_null_sha1(update->old_sha1))3586 strbuf_addf(err, "cannot lock ref '%s': reference already exists",3587 original_update_refname(update));3588 else3589 strbuf_addf(err, "cannot lock ref '%s': is at %s but expected %s",3590 original_update_refname(update),3591 sha1_to_hex(lock->old_oid.hash),3592 sha1_to_hex(update->old_sha1));35933594 return TRANSACTION_GENERIC_ERROR;3595 }3596 }35973598 if ((update->flags & REF_HAVE_NEW) &&3599 !(update->flags & REF_DELETING) &&3600 !(update->flags & REF_LOG_ONLY)) {3601 if (!(update->type & REF_ISSYMREF) &&3602 !hashcmp(lock->old_oid.hash, update->new_sha1)) {3603 /*3604 * The reference already has the desired3605 * value, so we don't need to write it.3606 */3607 } else if (write_ref_to_lockfile(lock, update->new_sha1,3608 err)) {3609 char *write_err = strbuf_detach(err, NULL);36103611 /*3612 * The lock was freed upon failure of3613 * write_ref_to_lockfile():3614 */3615 update->lock = NULL;3616 strbuf_addf(err,3617 "cannot update the ref '%s': %s",3618 update->refname, write_err);3619 free(write_err);3620 return TRANSACTION_GENERIC_ERROR;3621 } else {3622 update->flags |= REF_NEEDS_COMMIT;3623 }3624 }3625 if (!(update->flags & REF_NEEDS_COMMIT)) {3626 /*3627 * We didn't call write_ref_to_lockfile(), so3628 * the lockfile is still open. Close it to3629 * free up the file descriptor:3630 */3631 if (close_ref(lock)) {3632 strbuf_addf(err, "couldn't close '%s.lock'",3633 update->refname);3634 return TRANSACTION_GENERIC_ERROR;3635 }3636 }3637 return 0;3638}36393640static int files_transaction_commit(struct ref_store *ref_store,3641 struct ref_transaction *transaction,3642 struct strbuf *err)3643{3644 struct files_ref_store *refs =3645 files_downcast(ref_store, 0, "ref_transaction_commit");3646 int ret = 0, i;3647 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3648 struct string_list_item *ref_to_delete;3649 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3650 char *head_ref = NULL;3651 int head_type;3652 struct object_id head_oid;36533654 assert(err);36553656 if (transaction->state != REF_TRANSACTION_OPEN)3657 die("BUG: commit called for transaction that is not open");36583659 if (!transaction->nr) {3660 transaction->state = REF_TRANSACTION_CLOSED;3661 return 0;3662 }36633664 /*3665 * Fail if a refname appears more than once in the3666 * transaction. (If we end up splitting up any updates using3667 * split_symref_update() or split_head_update(), those3668 * functions will check that the new updates don't have the3669 * same refname as any existing ones.)3670 */3671 for (i = 0; i < transaction->nr; i++) {3672 struct ref_update *update = transaction->updates[i];3673 struct string_list_item *item =3674 string_list_append(&affected_refnames, update->refname);36753676 /*3677 * We store a pointer to update in item->util, but at3678 * the moment we never use the value of this field3679 * except to check whether it is non-NULL.3680 */3681 item->util = update;3682 }3683 string_list_sort(&affected_refnames);3684 if (ref_update_reject_duplicates(&affected_refnames, err)) {3685 ret = TRANSACTION_GENERIC_ERROR;3686 goto cleanup;3687 }36883689 /*3690 * Special hack: If a branch is updated directly and HEAD3691 * points to it (may happen on the remote side of a push3692 * for example) then logically the HEAD reflog should be3693 * updated too.3694 *3695 * A generic solution would require reverse symref lookups,3696 * but finding all symrefs pointing to a given branch would be3697 * rather costly for this rare event (the direct update of a3698 * branch) to be worth it. So let's cheat and check with HEAD3699 * only, which should cover 99% of all usage scenarios (even3700 * 100% of the default ones).3701 *3702 * So if HEAD is a symbolic reference, then record the name of3703 * the reference that it points to. If we see an update of3704 * head_ref within the transaction, then split_head_update()3705 * arranges for the reflog of HEAD to be updated, too.3706 */3707 head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3708 head_oid.hash, &head_type);37093710 if (head_ref && !(head_type & REF_ISSYMREF)) {3711 free(head_ref);3712 head_ref = NULL;3713 }37143715 /*3716 * Acquire all locks, verify old values if provided, check3717 * that new values are valid, and write new values to the3718 * lockfiles, ready to be activated. Only keep one lockfile3719 * open at a time to avoid running out of file descriptors.3720 */3721 for (i = 0; i < transaction->nr; i++) {3722 struct ref_update *update = transaction->updates[i];37233724 ret = lock_ref_for_update(refs, update, transaction,3725 head_ref, &affected_refnames, err);3726 if (ret)3727 goto cleanup;3728 }37293730 /* Perform updates first so live commits remain referenced */3731 for (i = 0; i < transaction->nr; i++) {3732 struct ref_update *update = transaction->updates[i];3733 struct ref_lock *lock = update->lock;37343735 if (update->flags & REF_NEEDS_COMMIT ||3736 update->flags & REF_LOG_ONLY) {3737 if (log_ref_write(lock->ref_name, lock->old_oid.hash,3738 update->new_sha1,3739 update->msg, update->flags, err)) {3740 char *old_msg = strbuf_detach(err, NULL);37413742 strbuf_addf(err, "cannot update the ref '%s': %s",3743 lock->ref_name, old_msg);3744 free(old_msg);3745 unlock_ref(lock);3746 update->lock = NULL;3747 ret = TRANSACTION_GENERIC_ERROR;3748 goto cleanup;3749 }3750 }3751 if (update->flags & REF_NEEDS_COMMIT) {3752 clear_loose_ref_cache(refs);3753 if (commit_ref(lock)) {3754 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);3755 unlock_ref(lock);3756 update->lock = NULL;3757 ret = TRANSACTION_GENERIC_ERROR;3758 goto cleanup;3759 }3760 }3761 }3762 /* Perform deletes now that updates are safely completed */3763 for (i = 0; i < transaction->nr; i++) {3764 struct ref_update *update = transaction->updates[i];37653766 if (update->flags & REF_DELETING &&3767 !(update->flags & REF_LOG_ONLY)) {3768 if (delete_ref_loose(update->lock, update->type, err)) {3769 ret = TRANSACTION_GENERIC_ERROR;3770 goto cleanup;3771 }37723773 if (!(update->flags & REF_ISPRUNING))3774 string_list_append(&refs_to_delete,3775 update->lock->ref_name);3776 }3777 }37783779 if (repack_without_refs(refs, &refs_to_delete, err)) {3780 ret = TRANSACTION_GENERIC_ERROR;3781 goto cleanup;3782 }3783 for_each_string_list_item(ref_to_delete, &refs_to_delete)3784 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3785 clear_loose_ref_cache(refs);37863787cleanup:3788 transaction->state = REF_TRANSACTION_CLOSED;37893790 for (i = 0; i < transaction->nr; i++)3791 if (transaction->updates[i]->lock)3792 unlock_ref(transaction->updates[i]->lock);3793 string_list_clear(&refs_to_delete, 0);3794 free(head_ref);3795 string_list_clear(&affected_refnames, 0);37963797 return ret;3798}37993800static int ref_present(const char *refname,3801 const struct object_id *oid, int flags, void *cb_data)3802{3803 struct string_list *affected_refnames = cb_data;38043805 return string_list_has_string(affected_refnames, refname);3806}38073808int initial_ref_transaction_commit(struct ref_transaction *transaction,3809 struct strbuf *err)3810{3811 struct files_ref_store *refs =3812 get_files_ref_store(NULL, "initial_ref_transaction_commit");3813 int ret = 0, i;3814 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38153816 assert(err);38173818 if (transaction->state != REF_TRANSACTION_OPEN)3819 die("BUG: commit called for transaction that is not open");38203821 /* Fail if a refname appears more than once in the transaction: */3822 for (i = 0; i < transaction->nr; i++)3823 string_list_append(&affected_refnames,3824 transaction->updates[i]->refname);3825 string_list_sort(&affected_refnames);3826 if (ref_update_reject_duplicates(&affected_refnames, err)) {3827 ret = TRANSACTION_GENERIC_ERROR;3828 goto cleanup;3829 }38303831 /*3832 * It's really undefined to call this function in an active3833 * repository or when there are existing references: we are3834 * only locking and changing packed-refs, so (1) any3835 * simultaneous processes might try to change a reference at3836 * the same time we do, and (2) any existing loose versions of3837 * the references that we are setting would have precedence3838 * over our values. But some remote helpers create the remote3839 * "HEAD" and "master" branches before calling this function,3840 * so here we really only check that none of the references3841 * that we are creating already exists.3842 */3843 if (for_each_rawref(ref_present, &affected_refnames))3844 die("BUG: initial ref transaction called with existing refs");38453846 for (i = 0; i < transaction->nr; i++) {3847 struct ref_update *update = transaction->updates[i];38483849 if ((update->flags & REF_HAVE_OLD) &&3850 !is_null_sha1(update->old_sha1))3851 die("BUG: initial ref transaction with old_sha1 set");3852 if (verify_refname_available(update->refname,3853 &affected_refnames, NULL,3854 err)) {3855 ret = TRANSACTION_NAME_CONFLICT;3856 goto cleanup;3857 }3858 }38593860 if (lock_packed_refs(refs, 0)) {3861 strbuf_addf(err, "unable to lock packed-refs file: %s",3862 strerror(errno));3863 ret = TRANSACTION_GENERIC_ERROR;3864 goto cleanup;3865 }38663867 for (i = 0; i < transaction->nr; i++) {3868 struct ref_update *update = transaction->updates[i];38693870 if ((update->flags & REF_HAVE_NEW) &&3871 !is_null_sha1(update->new_sha1))3872 add_packed_ref(refs, update->refname, update->new_sha1);3873 }38743875 if (commit_packed_refs(refs)) {3876 strbuf_addf(err, "unable to commit packed-refs file: %s",3877 strerror(errno));3878 ret = TRANSACTION_GENERIC_ERROR;3879 goto cleanup;3880 }38813882cleanup:3883 transaction->state = REF_TRANSACTION_CLOSED;3884 string_list_clear(&affected_refnames, 0);3885 return ret;3886}38873888struct expire_reflog_cb {3889 unsigned int flags;3890 reflog_expiry_should_prune_fn *should_prune_fn;3891 void *policy_cb;3892 FILE *newlog;3893 unsigned char last_kept_sha1[20];3894};38953896static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,3897 const char *email, unsigned long timestamp, int tz,3898 const char *message, void *cb_data)3899{3900 struct expire_reflog_cb *cb = cb_data;3901 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39023903 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3904 osha1 = cb->last_kept_sha1;39053906 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3907 message, policy_cb)) {3908 if (!cb->newlog)3909 printf("would prune %s", message);3910 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3911 printf("prune %s", message);3912 } else {3913 if (cb->newlog) {3914 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",3915 sha1_to_hex(osha1), sha1_to_hex(nsha1),3916 email, timestamp, tz, message);3917 hashcpy(cb->last_kept_sha1, nsha1);3918 }3919 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3920 printf("keep %s", message);3921 }3922 return 0;3923}39243925int reflog_expire(const char *refname, const unsigned char *sha1,3926 unsigned int flags,3927 reflog_expiry_prepare_fn prepare_fn,3928 reflog_expiry_should_prune_fn should_prune_fn,3929 reflog_expiry_cleanup_fn cleanup_fn,3930 void *policy_cb_data)3931{3932 static struct lock_file reflog_lock;3933 struct expire_reflog_cb cb;3934 struct ref_lock *lock;3935 char *log_file;3936 int status = 0;3937 int type;3938 struct strbuf err = STRBUF_INIT;39393940 memset(&cb, 0, sizeof(cb));3941 cb.flags = flags;3942 cb.policy_cb = policy_cb_data;3943 cb.should_prune_fn = should_prune_fn;39443945 /*3946 * The reflog file is locked by holding the lock on the3947 * reference itself, plus we might need to update the3948 * reference if --updateref was specified:3949 */3950 lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,3951 &type, &err);3952 if (!lock) {3953 error("cannot lock ref '%s': %s", refname, err.buf);3954 strbuf_release(&err);3955 return -1;3956 }3957 if (!reflog_exists(refname)) {3958 unlock_ref(lock);3959 return 0;3960 }39613962 log_file = git_pathdup("logs/%s", refname);3963 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3964 /*3965 * Even though holding $GIT_DIR/logs/$reflog.lock has3966 * no locking implications, we use the lock_file3967 * machinery here anyway because it does a lot of the3968 * work we need, including cleaning up if the program3969 * exits unexpectedly.3970 */3971 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {3972 struct strbuf err = STRBUF_INIT;3973 unable_to_lock_message(log_file, errno, &err);3974 error("%s", err.buf);3975 strbuf_release(&err);3976 goto failure;3977 }3978 cb.newlog = fdopen_lock_file(&reflog_lock, "w");3979 if (!cb.newlog) {3980 error("cannot fdopen %s (%s)",3981 get_lock_file_path(&reflog_lock), strerror(errno));3982 goto failure;3983 }3984 }39853986 (*prepare_fn)(refname, sha1, cb.policy_cb);3987 for_each_reflog_ent(refname, expire_reflog_ent, &cb);3988 (*cleanup_fn)(cb.policy_cb);39893990 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3991 /*3992 * It doesn't make sense to adjust a reference pointed3993 * to by a symbolic ref based on expiring entries in3994 * the symbolic reference's reflog. Nor can we update3995 * a reference if there are no remaining reflog3996 * entries.3997 */3998 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3999 !(type & REF_ISSYMREF) &&4000 !is_null_sha1(cb.last_kept_sha1);40014002 if (close_lock_file(&reflog_lock)) {4003 status |= error("couldn't write %s: %s", log_file,4004 strerror(errno));4005 } else if (update &&4006 (write_in_full(get_lock_file_fd(lock->lk),4007 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||4008 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||4009 close_ref(lock) < 0)) {4010 status |= error("couldn't write %s",4011 get_lock_file_path(lock->lk));4012 rollback_lock_file(&reflog_lock);4013 } else if (commit_lock_file(&reflog_lock)) {4014 status |= error("unable to write reflog '%s' (%s)",4015 log_file, strerror(errno));4016 } else if (update && commit_ref(lock)) {4017 status |= error("couldn't set %s", lock->ref_name);4018 }4019 }4020 free(log_file);4021 unlock_ref(lock);4022 return status;40234024 failure:4025 rollback_lock_file(&reflog_lock);4026 free(log_file);4027 unlock_ref(lock);4028 return -1;4029}40304031struct ref_storage_be refs_be_files = {4032 NULL,4033 "files",4034 files_ref_store_create,4035 files_transaction_commit,40364037 files_pack_refs,4038 files_peel_ref,4039 files_create_symref,40404041 files_read_raw_ref,4042 files_verify_refname_available4043};