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, 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/* The length of a peeled reference line in packed-refs, including EOL: */1001#define PEELED_LINE_LENGTH 4210021003/*1004 * The packed-refs header line that we write out. Perhaps other1005 * traits will be added later. The trailing space is required.1006 */1007static const char PACKED_REFS_HEADER[] =1008 "# pack-refs with: peeled fully-peeled \n";10091010/*1011 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1012 * Return a pointer to the refname within the line (null-terminated),1013 * or NULL if there was a problem.1014 */1015static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)1016{1017 const char *ref;10181019 /*1020 * 42: the answer to everything.1021 *1022 * In this case, it happens to be the answer to1023 * 40 (length of sha1 hex representation)1024 * +1 (space in between hex and name)1025 * +1 (newline at the end of the line)1026 */1027 if (line->len <= 42)1028 return NULL;10291030 if (get_sha1_hex(line->buf, sha1) < 0)1031 return NULL;1032 if (!isspace(line->buf[40]))1033 return NULL;10341035 ref = line->buf + 41;1036 if (isspace(*ref))1037 return NULL;10381039 if (line->buf[line->len - 1] != '\n')1040 return NULL;1041 line->buf[--line->len] = 0;10421043 return ref;1044}10451046/*1047 * Read f, which is a packed-refs file, into dir.1048 *1049 * A comment line of the form "# pack-refs with: " may contain zero or1050 * more traits. We interpret the traits as follows:1051 *1052 * No traits:1053 *1054 * Probably no references are peeled. But if the file contains a1055 * peeled value for a reference, we will use it.1056 *1057 * peeled:1058 *1059 * References under "refs/tags/", if they *can* be peeled, *are*1060 * peeled in this file. References outside of "refs/tags/" are1061 * probably not peeled even if they could have been, but if we find1062 * a peeled value for such a reference we will use it.1063 *1064 * fully-peeled:1065 *1066 * All references in the file that can be peeled are peeled.1067 * Inversely (and this is more important), any references in the1068 * file for which no peeled value is recorded is not peelable. This1069 * trait should typically be written alongside "peeled" for1070 * compatibility with older clients, but we do not require it1071 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1072 */1073static void read_packed_refs(FILE *f, struct ref_dir *dir)1074{1075 struct ref_entry *last = NULL;1076 struct strbuf line = STRBUF_INIT;1077 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10781079 while (strbuf_getwholeline(&line, f, '\n') != EOF) {1080 unsigned char sha1[20];1081 const char *refname;1082 const char *traits;10831084 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {1085 if (strstr(traits, " fully-peeled "))1086 peeled = PEELED_FULLY;1087 else if (strstr(traits, " peeled "))1088 peeled = PEELED_TAGS;1089 /* perhaps other traits later as well */1090 continue;1091 }10921093 refname = parse_ref_line(&line, sha1);1094 if (refname) {1095 int flag = REF_ISPACKED;10961097 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1098 if (!refname_is_safe(refname))1099 die("packed refname is dangerous: %s", refname);1100 hashclr(sha1);1101 flag |= REF_BAD_NAME | REF_ISBROKEN;1102 }1103 last = create_ref_entry(refname, sha1, flag, 0);1104 if (peeled == PEELED_FULLY ||1105 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1106 last->flag |= REF_KNOWS_PEELED;1107 add_ref(dir, last);1108 continue;1109 }1110 if (last &&1111 line.buf[0] == '^' &&1112 line.len == PEELED_LINE_LENGTH &&1113 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&1114 !get_sha1_hex(line.buf + 1, sha1)) {1115 hashcpy(last->u.value.peeled.hash, sha1);1116 /*1117 * Regardless of what the file header said,1118 * we definitely know the value of *this*1119 * reference:1120 */1121 last->flag |= REF_KNOWS_PEELED;1122 }1123 }11241125 strbuf_release(&line);1126}11271128/*1129 * Get the packed_ref_cache for the specified files_ref_store,1130 * creating it if necessary.1131 */1132static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1133{1134 char *packed_refs_file;11351136 if (*refs->base.submodule)1137 packed_refs_file = git_pathdup_submodule(refs->base.submodule,1138 "packed-refs");1139 else1140 packed_refs_file = git_pathdup("packed-refs");11411142 if (refs->packed &&1143 !stat_validity_check(&refs->packed->validity, packed_refs_file))1144 clear_packed_ref_cache(refs);11451146 if (!refs->packed) {1147 FILE *f;11481149 refs->packed = xcalloc(1, sizeof(*refs->packed));1150 acquire_packed_ref_cache(refs->packed);1151 refs->packed->root = create_dir_entry(refs, "", 0, 0);1152 f = fopen(packed_refs_file, "r");1153 if (f) {1154 stat_validity_update(&refs->packed->validity, fileno(f));1155 read_packed_refs(f, get_ref_dir(refs->packed->root));1156 fclose(f);1157 }1158 }1159 free(packed_refs_file);1160 return refs->packed;1161}11621163static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1164{1165 return get_ref_dir(packed_ref_cache->root);1166}11671168static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1169{1170 return get_packed_ref_dir(get_packed_ref_cache(refs));1171}11721173/*1174 * Add a reference to the in-memory packed reference cache. This may1175 * only be called while the packed-refs file is locked (see1176 * lock_packed_refs()). To actually write the packed-refs file, call1177 * commit_packed_refs().1178 */1179static void add_packed_ref(struct files_ref_store *refs,1180 const char *refname, const unsigned char *sha1)1181{1182 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);11831184 if (!packed_ref_cache->lock)1185 die("internal error: packed refs not locked");1186 add_ref(get_packed_ref_dir(packed_ref_cache),1187 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1188}11891190/*1191 * Read the loose references from the namespace dirname into dir1192 * (without recursing). dirname must end with '/'. dir must be the1193 * directory entry corresponding to dirname.1194 */1195static void read_loose_refs(const char *dirname, struct ref_dir *dir)1196{1197 struct files_ref_store *refs = dir->ref_store;1198 DIR *d;1199 struct dirent *de;1200 int dirnamelen = strlen(dirname);1201 struct strbuf refname;1202 struct strbuf path = STRBUF_INIT;1203 size_t path_baselen;1204 int err = 0;12051206 if (*refs->base.submodule)1207 err = strbuf_git_path_submodule(&path, refs->base.submodule, "%s", dirname);1208 else1209 strbuf_git_path(&path, "%s", dirname);1210 path_baselen = path.len;12111212 if (err) {1213 strbuf_release(&path);1214 return;1215 }12161217 d = opendir(path.buf);1218 if (!d) {1219 strbuf_release(&path);1220 return;1221 }12221223 strbuf_init(&refname, dirnamelen + 257);1224 strbuf_add(&refname, dirname, dirnamelen);12251226 while ((de = readdir(d)) != NULL) {1227 unsigned char sha1[20];1228 struct stat st;1229 int flag;12301231 if (de->d_name[0] == '.')1232 continue;1233 if (ends_with(de->d_name, ".lock"))1234 continue;1235 strbuf_addstr(&refname, de->d_name);1236 strbuf_addstr(&path, de->d_name);1237 if (stat(path.buf, &st) < 0) {1238 ; /* silently ignore */1239 } else if (S_ISDIR(st.st_mode)) {1240 strbuf_addch(&refname, '/');1241 add_entry_to_dir(dir,1242 create_dir_entry(refs, refname.buf,1243 refname.len, 1));1244 } else {1245 int read_ok;12461247 if (*refs->base.submodule) {1248 hashclr(sha1);1249 flag = 0;1250 read_ok = !resolve_gitlink_ref(refs->base.submodule,1251 refname.buf, sha1);1252 } else {1253 read_ok = !read_ref_full(refname.buf,1254 RESOLVE_REF_READING,1255 sha1, &flag);1256 }12571258 if (!read_ok) {1259 hashclr(sha1);1260 flag |= REF_ISBROKEN;1261 } else if (is_null_sha1(sha1)) {1262 /*1263 * It is so astronomically unlikely1264 * that NULL_SHA1 is the SHA-1 of an1265 * actual object that we consider its1266 * appearance in a loose reference1267 * file to be repo corruption1268 * (probably due to a software bug).1269 */1270 flag |= REF_ISBROKEN;1271 }12721273 if (check_refname_format(refname.buf,1274 REFNAME_ALLOW_ONELEVEL)) {1275 if (!refname_is_safe(refname.buf))1276 die("loose refname is dangerous: %s", refname.buf);1277 hashclr(sha1);1278 flag |= REF_BAD_NAME | REF_ISBROKEN;1279 }1280 add_entry_to_dir(dir,1281 create_ref_entry(refname.buf, sha1, flag, 0));1282 }1283 strbuf_setlen(&refname, dirnamelen);1284 strbuf_setlen(&path, path_baselen);1285 }1286 strbuf_release(&refname);1287 strbuf_release(&path);1288 closedir(d);1289}12901291static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1292{1293 if (!refs->loose) {1294 /*1295 * Mark the top-level directory complete because we1296 * are about to read the only subdirectory that can1297 * hold references:1298 */1299 refs->loose = create_dir_entry(refs, "", 0, 0);1300 /*1301 * Create an incomplete entry for "refs/":1302 */1303 add_entry_to_dir(get_ref_dir(refs->loose),1304 create_dir_entry(refs, "refs/", 5, 1));1305 }1306 return get_ref_dir(refs->loose);1307}13081309/*1310 * Return the ref_entry for the given refname from the packed1311 * references. If it does not exist, return NULL.1312 */1313static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1314 const char *refname)1315{1316 return find_ref(get_packed_refs(refs), refname);1317}13181319/*1320 * A loose ref file doesn't exist; check for a packed ref.1321 */1322static int resolve_packed_ref(struct files_ref_store *refs,1323 const char *refname,1324 unsigned char *sha1, unsigned int *flags)1325{1326 struct ref_entry *entry;13271328 /*1329 * The loose reference file does not exist; check for a packed1330 * reference.1331 */1332 entry = get_packed_ref(refs, refname);1333 if (entry) {1334 hashcpy(sha1, entry->u.value.oid.hash);1335 *flags |= REF_ISPACKED;1336 return 0;1337 }1338 /* refname is not a packed reference. */1339 return -1;1340}13411342static int files_read_raw_ref(struct ref_store *ref_store,1343 const char *refname, unsigned char *sha1,1344 struct strbuf *referent, unsigned int *type)1345{1346 struct files_ref_store *refs =1347 files_downcast(ref_store, 1, "read_raw_ref");1348 struct strbuf sb_contents = STRBUF_INIT;1349 struct strbuf sb_path = STRBUF_INIT;1350 const char *path;1351 const char *buf;1352 struct stat st;1353 int fd;1354 int ret = -1;1355 int save_errno;1356 int remaining_retries = 3;13571358 *type = 0;1359 strbuf_reset(&sb_path);13601361 if (*refs->base.submodule)1362 strbuf_git_path_submodule(&sb_path, refs->base.submodule, "%s", refname);1363 else1364 strbuf_git_path(&sb_path, "%s", refname);13651366 path = sb_path.buf;13671368stat_ref:1369 /*1370 * We might have to loop back here to avoid a race1371 * condition: first we lstat() the file, then we try1372 * to read it as a link or as a file. But if somebody1373 * changes the type of the file (file <-> directory1374 * <-> symlink) between the lstat() and reading, then1375 * we don't want to report that as an error but rather1376 * try again starting with the lstat().1377 *1378 * We'll keep a count of the retries, though, just to avoid1379 * any confusing situation sending us into an infinite loop.1380 */13811382 if (remaining_retries-- <= 0)1383 goto out;13841385 if (lstat(path, &st) < 0) {1386 if (errno != ENOENT)1387 goto out;1388 if (resolve_packed_ref(refs, refname, sha1, type)) {1389 errno = ENOENT;1390 goto out;1391 }1392 ret = 0;1393 goto out;1394 }13951396 /* Follow "normalized" - ie "refs/.." symlinks by hand */1397 if (S_ISLNK(st.st_mode)) {1398 strbuf_reset(&sb_contents);1399 if (strbuf_readlink(&sb_contents, path, 0) < 0) {1400 if (errno == ENOENT || errno == EINVAL)1401 /* inconsistent with lstat; retry */1402 goto stat_ref;1403 else1404 goto out;1405 }1406 if (starts_with(sb_contents.buf, "refs/") &&1407 !check_refname_format(sb_contents.buf, 0)) {1408 strbuf_swap(&sb_contents, referent);1409 *type |= REF_ISSYMREF;1410 ret = 0;1411 goto out;1412 }1413 /*1414 * It doesn't look like a refname; fall through to just1415 * treating it like a non-symlink, and reading whatever it1416 * points to.1417 */1418 }14191420 /* Is it a directory? */1421 if (S_ISDIR(st.st_mode)) {1422 /*1423 * Even though there is a directory where the loose1424 * ref is supposed to be, there could still be a1425 * packed ref:1426 */1427 if (resolve_packed_ref(refs, refname, sha1, type)) {1428 errno = EISDIR;1429 goto out;1430 }1431 ret = 0;1432 goto out;1433 }14341435 /*1436 * Anything else, just open it and try to use it as1437 * a ref1438 */1439 fd = open(path, O_RDONLY);1440 if (fd < 0) {1441 if (errno == ENOENT && !S_ISLNK(st.st_mode))1442 /* inconsistent with lstat; retry */1443 goto stat_ref;1444 else1445 goto out;1446 }1447 strbuf_reset(&sb_contents);1448 if (strbuf_read(&sb_contents, fd, 256) < 0) {1449 int save_errno = errno;1450 close(fd);1451 errno = save_errno;1452 goto out;1453 }1454 close(fd);1455 strbuf_rtrim(&sb_contents);1456 buf = sb_contents.buf;1457 if (starts_with(buf, "ref:")) {1458 buf += 4;1459 while (isspace(*buf))1460 buf++;14611462 strbuf_reset(referent);1463 strbuf_addstr(referent, buf);1464 *type |= REF_ISSYMREF;1465 ret = 0;1466 goto out;1467 }14681469 /*1470 * Please note that FETCH_HEAD has additional1471 * data after the sha.1472 */1473 if (get_sha1_hex(buf, sha1) ||1474 (buf[40] != '\0' && !isspace(buf[40]))) {1475 *type |= REF_ISBROKEN;1476 errno = EINVAL;1477 goto out;1478 }14791480 ret = 0;14811482out:1483 save_errno = errno;1484 strbuf_release(&sb_path);1485 strbuf_release(&sb_contents);1486 errno = save_errno;1487 return ret;1488}14891490static void unlock_ref(struct ref_lock *lock)1491{1492 /* Do not free lock->lk -- atexit() still looks at them */1493 if (lock->lk)1494 rollback_lock_file(lock->lk);1495 free(lock->ref_name);1496 free(lock);1497}14981499/*1500 * Lock refname, without following symrefs, and set *lock_p to point1501 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1502 * and type similarly to read_raw_ref().1503 *1504 * The caller must verify that refname is a "safe" reference name (in1505 * the sense of refname_is_safe()) before calling this function.1506 *1507 * If the reference doesn't already exist, verify that refname doesn't1508 * have a D/F conflict with any existing references. extras and skip1509 * are passed to verify_refname_available_dir() for this check.1510 *1511 * If mustexist is not set and the reference is not found or is1512 * broken, lock the reference anyway but clear sha1.1513 *1514 * Return 0 on success. On failure, write an error message to err and1515 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1516 *1517 * Implementation note: This function is basically1518 *1519 * lock reference1520 * read_raw_ref()1521 *1522 * but it includes a lot more code to1523 * - Deal with possible races with other processes1524 * - Avoid calling verify_refname_available_dir() when it can be1525 * avoided, namely if we were successfully able to read the ref1526 * - Generate informative error messages in the case of failure1527 */1528static int lock_raw_ref(struct files_ref_store *refs,1529 const char *refname, int mustexist,1530 const struct string_list *extras,1531 const struct string_list *skip,1532 struct ref_lock **lock_p,1533 struct strbuf *referent,1534 unsigned int *type,1535 struct strbuf *err)1536{1537 struct ref_lock *lock;1538 struct strbuf ref_file = STRBUF_INIT;1539 int attempts_remaining = 3;1540 int ret = TRANSACTION_GENERIC_ERROR;15411542 assert(err);1543 assert_main_repository(&refs->base, "lock_raw_ref");15441545 *type = 0;15461547 /* First lock the file so it can't change out from under us. */15481549 *lock_p = lock = xcalloc(1, sizeof(*lock));15501551 lock->ref_name = xstrdup(refname);1552 strbuf_git_path(&ref_file, "%s", refname);15531554retry:1555 switch (safe_create_leading_directories(ref_file.buf)) {1556 case SCLD_OK:1557 break; /* success */1558 case SCLD_EXISTS:1559 /*1560 * Suppose refname is "refs/foo/bar". We just failed1561 * to create the containing directory, "refs/foo",1562 * because there was a non-directory in the way. This1563 * indicates a D/F conflict, probably because of1564 * another reference such as "refs/foo". There is no1565 * reason to expect this error to be transitory.1566 */1567 if (verify_refname_available(refname, extras, skip, err)) {1568 if (mustexist) {1569 /*1570 * To the user the relevant error is1571 * that the "mustexist" reference is1572 * missing:1573 */1574 strbuf_reset(err);1575 strbuf_addf(err, "unable to resolve reference '%s'",1576 refname);1577 } else {1578 /*1579 * The error message set by1580 * verify_refname_available_dir() is OK.1581 */1582 ret = TRANSACTION_NAME_CONFLICT;1583 }1584 } else {1585 /*1586 * The file that is in the way isn't a loose1587 * reference. Report it as a low-level1588 * failure.1589 */1590 strbuf_addf(err, "unable to create lock file %s.lock; "1591 "non-directory in the way",1592 ref_file.buf);1593 }1594 goto error_return;1595 case SCLD_VANISHED:1596 /* Maybe another process was tidying up. Try again. */1597 if (--attempts_remaining > 0)1598 goto retry;1599 /* fall through */1600 default:1601 strbuf_addf(err, "unable to create directory for %s",1602 ref_file.buf);1603 goto error_return;1604 }16051606 if (!lock->lk)1607 lock->lk = xcalloc(1, sizeof(struct lock_file));16081609 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {1610 if (errno == ENOENT && --attempts_remaining > 0) {1611 /*1612 * Maybe somebody just deleted one of the1613 * directories leading to ref_file. Try1614 * again:1615 */1616 goto retry;1617 } else {1618 unable_to_lock_message(ref_file.buf, errno, err);1619 goto error_return;1620 }1621 }16221623 /*1624 * Now we hold the lock and can read the reference without1625 * fear that its value will change.1626 */16271628 if (files_read_raw_ref(&refs->base, refname,1629 lock->old_oid.hash, referent, type)) {1630 if (errno == ENOENT) {1631 if (mustexist) {1632 /* Garden variety missing reference. */1633 strbuf_addf(err, "unable to resolve reference '%s'",1634 refname);1635 goto error_return;1636 } else {1637 /*1638 * Reference is missing, but that's OK. We1639 * know that there is not a conflict with1640 * another loose reference because1641 * (supposing that we are trying to lock1642 * reference "refs/foo/bar"):1643 *1644 * - We were successfully able to create1645 * the lockfile refs/foo/bar.lock, so we1646 * know there cannot be a loose reference1647 * named "refs/foo".1648 *1649 * - We got ENOENT and not EISDIR, so we1650 * know that there cannot be a loose1651 * reference named "refs/foo/bar/baz".1652 */1653 }1654 } else if (errno == EISDIR) {1655 /*1656 * There is a directory in the way. It might have1657 * contained references that have been deleted. If1658 * we don't require that the reference already1659 * exists, try to remove the directory so that it1660 * doesn't cause trouble when we want to rename the1661 * lockfile into place later.1662 */1663 if (mustexist) {1664 /* Garden variety missing reference. */1665 strbuf_addf(err, "unable to resolve reference '%s'",1666 refname);1667 goto error_return;1668 } else if (remove_dir_recursively(&ref_file,1669 REMOVE_DIR_EMPTY_ONLY)) {1670 if (verify_refname_available_dir(1671 refname, extras, skip,1672 get_loose_refs(refs),1673 err)) {1674 /*1675 * The error message set by1676 * verify_refname_available() is OK.1677 */1678 ret = TRANSACTION_NAME_CONFLICT;1679 goto error_return;1680 } else {1681 /*1682 * We can't delete the directory,1683 * but we also don't know of any1684 * references that it should1685 * contain.1686 */1687 strbuf_addf(err, "there is a non-empty directory '%s' "1688 "blocking reference '%s'",1689 ref_file.buf, refname);1690 goto error_return;1691 }1692 }1693 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {1694 strbuf_addf(err, "unable to resolve reference '%s': "1695 "reference broken", refname);1696 goto error_return;1697 } else {1698 strbuf_addf(err, "unable to resolve reference '%s': %s",1699 refname, strerror(errno));1700 goto error_return;1701 }17021703 /*1704 * If the ref did not exist and we are creating it,1705 * make sure there is no existing packed ref whose1706 * name begins with our refname, nor a packed ref1707 * whose name is a proper prefix of our refname.1708 */1709 if (verify_refname_available_dir(1710 refname, extras, skip,1711 get_packed_refs(refs),1712 err)) {1713 goto error_return;1714 }1715 }17161717 ret = 0;1718 goto out;17191720error_return:1721 unlock_ref(lock);1722 *lock_p = NULL;17231724out:1725 strbuf_release(&ref_file);1726 return ret;1727}17281729/*1730 * Peel the entry (if possible) and return its new peel_status. If1731 * repeel is true, re-peel the entry even if there is an old peeled1732 * value that is already stored in it.1733 *1734 * It is OK to call this function with a packed reference entry that1735 * might be stale and might even refer to an object that has since1736 * been garbage-collected. In such a case, if the entry has1737 * REF_KNOWS_PEELED then leave the status unchanged and return1738 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1739 */1740static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1741{1742 enum peel_status status;17431744 if (entry->flag & REF_KNOWS_PEELED) {1745 if (repeel) {1746 entry->flag &= ~REF_KNOWS_PEELED;1747 oidclr(&entry->u.value.peeled);1748 } else {1749 return is_null_oid(&entry->u.value.peeled) ?1750 PEEL_NON_TAG : PEEL_PEELED;1751 }1752 }1753 if (entry->flag & REF_ISBROKEN)1754 return PEEL_BROKEN;1755 if (entry->flag & REF_ISSYMREF)1756 return PEEL_IS_SYMREF;17571758 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1759 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1760 entry->flag |= REF_KNOWS_PEELED;1761 return status;1762}17631764static int files_peel_ref(struct ref_store *ref_store,1765 const char *refname, unsigned char *sha1)1766{1767 struct files_ref_store *refs = files_downcast(ref_store, 0, "peel_ref");1768 int flag;1769 unsigned char base[20];17701771 if (current_ref_iter && current_ref_iter->refname == refname) {1772 struct object_id peeled;17731774 if (ref_iterator_peel(current_ref_iter, &peeled))1775 return -1;1776 hashcpy(sha1, peeled.hash);1777 return 0;1778 }17791780 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1781 return -1;17821783 /*1784 * If the reference is packed, read its ref_entry from the1785 * cache in the hope that we already know its peeled value.1786 * We only try this optimization on packed references because1787 * (a) forcing the filling of the loose reference cache could1788 * be expensive and (b) loose references anyway usually do not1789 * have REF_KNOWS_PEELED.1790 */1791 if (flag & REF_ISPACKED) {1792 struct ref_entry *r = get_packed_ref(refs, refname);1793 if (r) {1794 if (peel_entry(r, 0))1795 return -1;1796 hashcpy(sha1, r->u.value.peeled.hash);1797 return 0;1798 }1799 }18001801 return peel_object(base, sha1);1802}18031804struct files_ref_iterator {1805 struct ref_iterator base;18061807 struct packed_ref_cache *packed_ref_cache;1808 struct ref_iterator *iter0;1809 unsigned int flags;1810};18111812static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)1813{1814 struct files_ref_iterator *iter =1815 (struct files_ref_iterator *)ref_iterator;1816 int ok;18171818 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {1819 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1820 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1821 continue;18221823 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1824 !ref_resolves_to_object(iter->iter0->refname,1825 iter->iter0->oid,1826 iter->iter0->flags))1827 continue;18281829 iter->base.refname = iter->iter0->refname;1830 iter->base.oid = iter->iter0->oid;1831 iter->base.flags = iter->iter0->flags;1832 return ITER_OK;1833 }18341835 iter->iter0 = NULL;1836 if (ref_iterator_abort(ref_iterator) != ITER_DONE)1837 ok = ITER_ERROR;18381839 return ok;1840}18411842static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,1843 struct object_id *peeled)1844{1845 struct files_ref_iterator *iter =1846 (struct files_ref_iterator *)ref_iterator;18471848 return ref_iterator_peel(iter->iter0, peeled);1849}18501851static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)1852{1853 struct files_ref_iterator *iter =1854 (struct files_ref_iterator *)ref_iterator;1855 int ok = ITER_DONE;18561857 if (iter->iter0)1858 ok = ref_iterator_abort(iter->iter0);18591860 release_packed_ref_cache(iter->packed_ref_cache);1861 base_ref_iterator_free(ref_iterator);1862 return ok;1863}18641865static struct ref_iterator_vtable files_ref_iterator_vtable = {1866 files_ref_iterator_advance,1867 files_ref_iterator_peel,1868 files_ref_iterator_abort1869};18701871static struct ref_iterator *files_ref_iterator_begin(1872 struct ref_store *ref_store,1873 const char *prefix, unsigned int flags)1874{1875 struct files_ref_store *refs =1876 files_downcast(ref_store, 1, "ref_iterator_begin");1877 struct ref_dir *loose_dir, *packed_dir;1878 struct ref_iterator *loose_iter, *packed_iter;1879 struct files_ref_iterator *iter;1880 struct ref_iterator *ref_iterator;18811882 if (!refs)1883 return empty_ref_iterator_begin();18841885 if (ref_paranoia < 0)1886 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1887 if (ref_paranoia)1888 flags |= DO_FOR_EACH_INCLUDE_BROKEN;18891890 iter = xcalloc(1, sizeof(*iter));1891 ref_iterator = &iter->base;1892 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);18931894 /*1895 * We must make sure that all loose refs are read before1896 * accessing the packed-refs file; this avoids a race1897 * condition if loose refs are migrated to the packed-refs1898 * file by a simultaneous process, but our in-memory view is1899 * from before the migration. We ensure this as follows:1900 * First, we call prime_ref_dir(), which pre-reads the loose1901 * references for the subtree into the cache. (If they've1902 * already been read, that's OK; we only need to guarantee1903 * that they're read before the packed refs, not *how much*1904 * before.) After that, we call get_packed_ref_cache(), which1905 * internally checks whether the packed-ref cache is up to1906 * date with what is on disk, and re-reads it if not.1907 */19081909 loose_dir = get_loose_refs(refs);19101911 if (prefix && *prefix)1912 loose_dir = find_containing_dir(loose_dir, prefix, 0);19131914 if (loose_dir) {1915 prime_ref_dir(loose_dir);1916 loose_iter = cache_ref_iterator_begin(loose_dir);1917 } else {1918 /* There's nothing to iterate over. */1919 loose_iter = empty_ref_iterator_begin();1920 }19211922 iter->packed_ref_cache = get_packed_ref_cache(refs);1923 acquire_packed_ref_cache(iter->packed_ref_cache);1924 packed_dir = get_packed_ref_dir(iter->packed_ref_cache);19251926 if (prefix && *prefix)1927 packed_dir = find_containing_dir(packed_dir, prefix, 0);19281929 if (packed_dir) {1930 packed_iter = cache_ref_iterator_begin(packed_dir);1931 } else {1932 /* There's nothing to iterate over. */1933 packed_iter = empty_ref_iterator_begin();1934 }19351936 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);1937 iter->flags = flags;19381939 return ref_iterator;1940}19411942/*1943 * Verify that the reference locked by lock has the value old_sha1.1944 * Fail if the reference doesn't exist and mustexist is set. Return 01945 * on success. On error, write an error message to err, set errno, and1946 * return a negative value.1947 */1948static int verify_lock(struct ref_lock *lock,1949 const unsigned char *old_sha1, int mustexist,1950 struct strbuf *err)1951{1952 assert(err);19531954 if (read_ref_full(lock->ref_name,1955 mustexist ? RESOLVE_REF_READING : 0,1956 lock->old_oid.hash, NULL)) {1957 if (old_sha1) {1958 int save_errno = errno;1959 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);1960 errno = save_errno;1961 return -1;1962 } else {1963 oidclr(&lock->old_oid);1964 return 0;1965 }1966 }1967 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1968 strbuf_addf(err, "ref '%s' is at %s but expected %s",1969 lock->ref_name,1970 oid_to_hex(&lock->old_oid),1971 sha1_to_hex(old_sha1));1972 errno = EBUSY;1973 return -1;1974 }1975 return 0;1976}19771978static int remove_empty_directories(struct strbuf *path)1979{1980 /*1981 * we want to create a file but there is a directory there;1982 * if that is an empty directory (or a directory that contains1983 * only empty directories), remove them.1984 */1985 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1986}19871988static int create_reflock(const char *path, void *cb)1989{1990 struct lock_file *lk = cb;19911992 return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;1993}19941995/*1996 * Locks a ref returning the lock on success and NULL on failure.1997 * On failure errno is set to something meaningful.1998 */1999static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,2000 const char *refname,2001 const unsigned char *old_sha1,2002 const struct string_list *extras,2003 const struct string_list *skip,2004 unsigned int flags, int *type,2005 struct strbuf *err)2006{2007 struct strbuf ref_file = STRBUF_INIT;2008 struct ref_lock *lock;2009 int last_errno = 0;2010 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2011 int resolve_flags = RESOLVE_REF_NO_RECURSE;2012 int resolved;20132014 assert_main_repository(&refs->base, "lock_ref_sha1_basic");2015 assert(err);20162017 lock = xcalloc(1, sizeof(struct ref_lock));20182019 if (mustexist)2020 resolve_flags |= RESOLVE_REF_READING;2021 if (flags & REF_DELETING)2022 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20232024 strbuf_git_path(&ref_file, "%s", refname);2025 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2026 lock->old_oid.hash, type);2027 if (!resolved && errno == EISDIR) {2028 /*2029 * we are trying to lock foo but we used to2030 * have foo/bar which now does not exist;2031 * it is normal for the empty directory 'foo'2032 * to remain.2033 */2034 if (remove_empty_directories(&ref_file)) {2035 last_errno = errno;2036 if (!verify_refname_available_dir(2037 refname, extras, skip,2038 get_loose_refs(refs), err))2039 strbuf_addf(err, "there are still refs under '%s'",2040 refname);2041 goto error_return;2042 }2043 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2044 lock->old_oid.hash, type);2045 }2046 if (!resolved) {2047 last_errno = errno;2048 if (last_errno != ENOTDIR ||2049 !verify_refname_available_dir(2050 refname, extras, skip,2051 get_loose_refs(refs), err))2052 strbuf_addf(err, "unable to resolve reference '%s': %s",2053 refname, strerror(last_errno));20542055 goto error_return;2056 }20572058 /*2059 * If the ref did not exist and we are creating it, make sure2060 * there is no existing packed ref whose name begins with our2061 * refname, nor a packed ref whose name is a proper prefix of2062 * our refname.2063 */2064 if (is_null_oid(&lock->old_oid) &&2065 verify_refname_available_dir(refname, extras, skip,2066 get_packed_refs(refs),2067 err)) {2068 last_errno = ENOTDIR;2069 goto error_return;2070 }20712072 lock->lk = xcalloc(1, sizeof(struct lock_file));20732074 lock->ref_name = xstrdup(refname);20752076 if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {2077 last_errno = errno;2078 unable_to_lock_message(ref_file.buf, errno, err);2079 goto error_return;2080 }20812082 if (verify_lock(lock, old_sha1, mustexist, err)) {2083 last_errno = errno;2084 goto error_return;2085 }2086 goto out;20872088 error_return:2089 unlock_ref(lock);2090 lock = NULL;20912092 out:2093 strbuf_release(&ref_file);2094 errno = last_errno;2095 return lock;2096}20972098/*2099 * Write an entry to the packed-refs file for the specified refname.2100 * If peeled is non-NULL, write it as the entry's peeled value.2101 */2102static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,2103 unsigned char *peeled)2104{2105 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);2106 if (peeled)2107 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));2108}21092110/*2111 * An each_ref_entry_fn that writes the entry to a packed-refs file.2112 */2113static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2114{2115 enum peel_status peel_status = peel_entry(entry, 0);21162117 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2118 error("internal error: %s is not a valid packed reference!",2119 entry->name);2120 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2121 peel_status == PEEL_PEELED ?2122 entry->u.value.peeled.hash : NULL);2123 return 0;2124}21252126/*2127 * Lock the packed-refs file for writing. Flags is passed to2128 * hold_lock_file_for_update(). Return 0 on success. On errors, set2129 * errno appropriately and return a nonzero value.2130 */2131static int lock_packed_refs(struct files_ref_store *refs, int flags)2132{2133 static int timeout_configured = 0;2134 static int timeout_value = 1000;2135 struct packed_ref_cache *packed_ref_cache;21362137 assert_main_repository(&refs->base, "lock_packed_refs");21382139 if (!timeout_configured) {2140 git_config_get_int("core.packedrefstimeout", &timeout_value);2141 timeout_configured = 1;2142 }21432144 if (hold_lock_file_for_update_timeout(2145 &packlock, git_path("packed-refs"),2146 flags, timeout_value) < 0)2147 return -1;2148 /*2149 * Get the current packed-refs while holding the lock. If the2150 * packed-refs file has been modified since we last read it,2151 * this will automatically invalidate the cache and re-read2152 * the packed-refs file.2153 */2154 packed_ref_cache = get_packed_ref_cache(refs);2155 packed_ref_cache->lock = &packlock;2156 /* Increment the reference count to prevent it from being freed: */2157 acquire_packed_ref_cache(packed_ref_cache);2158 return 0;2159}21602161/*2162 * Write the current version of the packed refs cache from memory to2163 * disk. The packed-refs file must already be locked for writing (see2164 * lock_packed_refs()). Return zero on success. On errors, set errno2165 * and return a nonzero value2166 */2167static int commit_packed_refs(struct files_ref_store *refs)2168{2169 struct packed_ref_cache *packed_ref_cache =2170 get_packed_ref_cache(refs);2171 int error = 0;2172 int save_errno = 0;2173 FILE *out;21742175 assert_main_repository(&refs->base, "commit_packed_refs");21762177 if (!packed_ref_cache->lock)2178 die("internal error: packed-refs not locked");21792180 out = fdopen_lock_file(packed_ref_cache->lock, "w");2181 if (!out)2182 die_errno("unable to fdopen packed-refs descriptor");21832184 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);2185 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2186 0, write_packed_entry_fn, out);21872188 if (commit_lock_file(packed_ref_cache->lock)) {2189 save_errno = errno;2190 error = -1;2191 }2192 packed_ref_cache->lock = NULL;2193 release_packed_ref_cache(packed_ref_cache);2194 errno = save_errno;2195 return error;2196}21972198/*2199 * Rollback the lockfile for the packed-refs file, and discard the2200 * in-memory packed reference cache. (The packed-refs file will be2201 * read anew if it is needed again after this function is called.)2202 */2203static void rollback_packed_refs(struct files_ref_store *refs)2204{2205 struct packed_ref_cache *packed_ref_cache =2206 get_packed_ref_cache(refs);22072208 assert_main_repository(&refs->base, "rollback_packed_refs");22092210 if (!packed_ref_cache->lock)2211 die("internal error: packed-refs not locked");2212 rollback_lock_file(packed_ref_cache->lock);2213 packed_ref_cache->lock = NULL;2214 release_packed_ref_cache(packed_ref_cache);2215 clear_packed_ref_cache(refs);2216}22172218struct ref_to_prune {2219 struct ref_to_prune *next;2220 unsigned char sha1[20];2221 char name[FLEX_ARRAY];2222};22232224struct pack_refs_cb_data {2225 unsigned int flags;2226 struct ref_dir *packed_refs;2227 struct ref_to_prune *ref_to_prune;2228};22292230/*2231 * An each_ref_entry_fn that is run over loose references only. If2232 * the loose reference can be packed, add an entry in the packed ref2233 * cache. If the reference should be pruned, also add it to2234 * ref_to_prune in the pack_refs_cb_data.2235 */2236static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2237{2238 struct pack_refs_cb_data *cb = cb_data;2239 enum peel_status peel_status;2240 struct ref_entry *packed_entry;2241 int is_tag_ref = starts_with(entry->name, "refs/tags/");22422243 /* Do not pack per-worktree refs: */2244 if (ref_type(entry->name) != REF_TYPE_NORMAL)2245 return 0;22462247 /* ALWAYS pack tags */2248 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2249 return 0;22502251 /* Do not pack symbolic or broken refs: */2252 if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2253 return 0;22542255 /* Add a packed ref cache entry equivalent to the loose entry. */2256 peel_status = peel_entry(entry, 1);2257 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2258 die("internal error peeling reference %s (%s)",2259 entry->name, oid_to_hex(&entry->u.value.oid));2260 packed_entry = find_ref(cb->packed_refs, entry->name);2261 if (packed_entry) {2262 /* Overwrite existing packed entry with info from loose entry */2263 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2264 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2265 } else {2266 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,2267 REF_ISPACKED | REF_KNOWS_PEELED, 0);2268 add_ref(cb->packed_refs, packed_entry);2269 }2270 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);22712272 /* Schedule the loose reference for pruning if requested. */2273 if ((cb->flags & PACK_REFS_PRUNE)) {2274 struct ref_to_prune *n;2275 FLEX_ALLOC_STR(n, name, entry->name);2276 hashcpy(n->sha1, entry->u.value.oid.hash);2277 n->next = cb->ref_to_prune;2278 cb->ref_to_prune = n;2279 }2280 return 0;2281}22822283/*2284 * Remove empty parents, but spare refs/ and immediate subdirs.2285 * Note: munges *name.2286 */2287static void try_remove_empty_parents(char *name)2288{2289 char *p, *q;2290 int i;2291 p = name;2292 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2293 while (*p && *p != '/')2294 p++;2295 /* tolerate duplicate slashes; see check_refname_format() */2296 while (*p == '/')2297 p++;2298 }2299 for (q = p; *q; q++)2300 ;2301 while (1) {2302 while (q > p && *q != '/')2303 q--;2304 while (q > p && *(q-1) == '/')2305 q--;2306 if (q == p)2307 break;2308 *q = '\0';2309 if (rmdir(git_path("%s", name)))2310 break;2311 }2312}23132314/* make sure nobody touched the ref, and unlink */2315static void prune_ref(struct ref_to_prune *r)2316{2317 struct ref_transaction *transaction;2318 struct strbuf err = STRBUF_INIT;23192320 if (check_refname_format(r->name, 0))2321 return;23222323 transaction = ref_transaction_begin(&err);2324 if (!transaction ||2325 ref_transaction_delete(transaction, r->name, r->sha1,2326 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2327 ref_transaction_commit(transaction, &err)) {2328 ref_transaction_free(transaction);2329 error("%s", err.buf);2330 strbuf_release(&err);2331 return;2332 }2333 ref_transaction_free(transaction);2334 strbuf_release(&err);2335 try_remove_empty_parents(r->name);2336}23372338static void prune_refs(struct ref_to_prune *r)2339{2340 while (r) {2341 prune_ref(r);2342 r = r->next;2343 }2344}23452346static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)2347{2348 struct files_ref_store *refs =2349 files_downcast(ref_store, 0, "pack_refs");2350 struct pack_refs_cb_data cbdata;23512352 memset(&cbdata, 0, sizeof(cbdata));2353 cbdata.flags = flags;23542355 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2356 cbdata.packed_refs = get_packed_refs(refs);23572358 do_for_each_entry_in_dir(get_loose_refs(refs), 0,2359 pack_if_possible_fn, &cbdata);23602361 if (commit_packed_refs(refs))2362 die_errno("unable to overwrite old ref-pack file");23632364 prune_refs(cbdata.ref_to_prune);2365 return 0;2366}23672368/*2369 * Rewrite the packed-refs file, omitting any refs listed in2370 * 'refnames'. On error, leave packed-refs unchanged, write an error2371 * message to 'err', and return a nonzero value.2372 *2373 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2374 */2375static int repack_without_refs(struct files_ref_store *refs,2376 struct string_list *refnames, struct strbuf *err)2377{2378 struct ref_dir *packed;2379 struct string_list_item *refname;2380 int ret, needs_repacking = 0, removed = 0;23812382 assert_main_repository(&refs->base, "repack_without_refs");2383 assert(err);23842385 /* Look for a packed ref */2386 for_each_string_list_item(refname, refnames) {2387 if (get_packed_ref(refs, refname->string)) {2388 needs_repacking = 1;2389 break;2390 }2391 }23922393 /* Avoid locking if we have nothing to do */2394 if (!needs_repacking)2395 return 0; /* no refname exists in packed refs */23962397 if (lock_packed_refs(refs, 0)) {2398 unable_to_lock_message(git_path("packed-refs"), errno, err);2399 return -1;2400 }2401 packed = get_packed_refs(refs);24022403 /* Remove refnames from the cache */2404 for_each_string_list_item(refname, refnames)2405 if (remove_entry(packed, refname->string) != -1)2406 removed = 1;2407 if (!removed) {2408 /*2409 * All packed entries disappeared while we were2410 * acquiring the lock.2411 */2412 rollback_packed_refs(refs);2413 return 0;2414 }24152416 /* Write what remains */2417 ret = commit_packed_refs(refs);2418 if (ret)2419 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2420 strerror(errno));2421 return ret;2422}24232424static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2425{2426 assert(err);24272428 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2429 /*2430 * loose. The loose file name is the same as the2431 * lockfile name, minus ".lock":2432 */2433 char *loose_filename = get_locked_file_path(lock->lk);2434 int res = unlink_or_msg(loose_filename, err);2435 free(loose_filename);2436 if (res)2437 return 1;2438 }2439 return 0;2440}24412442static int files_delete_refs(struct ref_store *ref_store,2443 struct string_list *refnames, unsigned int flags)2444{2445 struct files_ref_store *refs =2446 files_downcast(ref_store, 0, "delete_refs");2447 struct strbuf err = STRBUF_INIT;2448 int i, result = 0;24492450 if (!refnames->nr)2451 return 0;24522453 result = repack_without_refs(refs, refnames, &err);2454 if (result) {2455 /*2456 * If we failed to rewrite the packed-refs file, then2457 * it is unsafe to try to remove loose refs, because2458 * doing so might expose an obsolete packed value for2459 * a reference that might even point at an object that2460 * has been garbage collected.2461 */2462 if (refnames->nr == 1)2463 error(_("could not delete reference %s: %s"),2464 refnames->items[0].string, err.buf);2465 else2466 error(_("could not delete references: %s"), err.buf);24672468 goto out;2469 }24702471 for (i = 0; i < refnames->nr; i++) {2472 const char *refname = refnames->items[i].string;24732474 if (delete_ref(refname, NULL, flags))2475 result |= error(_("could not remove reference %s"), refname);2476 }24772478out:2479 strbuf_release(&err);2480 return result;2481}24822483/*2484 * People using contrib's git-new-workdir have .git/logs/refs ->2485 * /some/other/path/.git/logs/refs, and that may live on another device.2486 *2487 * IOW, to avoid cross device rename errors, the temporary renamed log must2488 * live into logs/refs.2489 */2490#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"24912492static int rename_tmp_log(const char *newrefname)2493{2494 int attempts_remaining = 4;2495 struct strbuf path = STRBUF_INIT;2496 int ret = -1;24972498 retry:2499 strbuf_reset(&path);2500 strbuf_git_path(&path, "logs/%s", newrefname);2501 switch (safe_create_leading_directories_const(path.buf)) {2502 case SCLD_OK:2503 break; /* success */2504 case SCLD_VANISHED:2505 if (--attempts_remaining > 0)2506 goto retry;2507 /* fall through */2508 default:2509 error("unable to create directory for %s", newrefname);2510 goto out;2511 }25122513 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {2514 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2515 /*2516 * rename(a, b) when b is an existing2517 * directory ought to result in ISDIR, but2518 * Solaris 5.8 gives ENOTDIR. Sheesh.2519 */2520 if (remove_empty_directories(&path)) {2521 error("Directory not empty: logs/%s", newrefname);2522 goto out;2523 }2524 goto retry;2525 } else if (errno == ENOENT && --attempts_remaining > 0) {2526 /*2527 * Maybe another process just deleted one of2528 * the directories in the path to newrefname.2529 * Try again from the beginning.2530 */2531 goto retry;2532 } else {2533 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2534 newrefname, strerror(errno));2535 goto out;2536 }2537 }2538 ret = 0;2539out:2540 strbuf_release(&path);2541 return ret;2542}25432544static int files_verify_refname_available(struct ref_store *ref_store,2545 const char *newname,2546 const struct string_list *extras,2547 const struct string_list *skip,2548 struct strbuf *err)2549{2550 struct files_ref_store *refs =2551 files_downcast(ref_store, 1, "verify_refname_available");2552 struct ref_dir *packed_refs = get_packed_refs(refs);2553 struct ref_dir *loose_refs = get_loose_refs(refs);25542555 if (verify_refname_available_dir(newname, extras, skip,2556 packed_refs, err) ||2557 verify_refname_available_dir(newname, extras, skip,2558 loose_refs, err))2559 return -1;25602561 return 0;2562}25632564static int write_ref_to_lockfile(struct ref_lock *lock,2565 const unsigned char *sha1, struct strbuf *err);2566static int commit_ref_update(struct files_ref_store *refs,2567 struct ref_lock *lock,2568 const unsigned char *sha1, const char *logmsg,2569 struct strbuf *err);25702571static int files_rename_ref(struct ref_store *ref_store,2572 const char *oldrefname, const char *newrefname,2573 const char *logmsg)2574{2575 struct files_ref_store *refs =2576 files_downcast(ref_store, 0, "rename_ref");2577 unsigned char sha1[20], orig_sha1[20];2578 int flag = 0, logmoved = 0;2579 struct ref_lock *lock;2580 struct stat loginfo;2581 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2582 struct strbuf err = STRBUF_INIT;25832584 if (log && S_ISLNK(loginfo.st_mode))2585 return error("reflog for %s is a symlink", oldrefname);25862587 if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2588 orig_sha1, &flag))2589 return error("refname %s not found", oldrefname);25902591 if (flag & REF_ISSYMREF)2592 return error("refname %s is a symbolic ref, renaming it is not supported",2593 oldrefname);2594 if (!rename_ref_available(oldrefname, newrefname))2595 return 1;25962597 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2598 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2599 oldrefname, strerror(errno));26002601 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2602 error("unable to delete old %s", oldrefname);2603 goto rollback;2604 }26052606 /*2607 * Since we are doing a shallow lookup, sha1 is not the2608 * correct value to pass to delete_ref as old_sha1. But that2609 * doesn't matter, because an old_sha1 check wouldn't add to2610 * the safety anyway; we want to delete the reference whatever2611 * its current value.2612 */2613 if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2614 sha1, NULL) &&2615 delete_ref(newrefname, NULL, REF_NODEREF)) {2616 if (errno == EISDIR) {2617 struct strbuf path = STRBUF_INIT;2618 int result;26192620 strbuf_git_path(&path, "%s", newrefname);2621 result = remove_empty_directories(&path);2622 strbuf_release(&path);26232624 if (result) {2625 error("Directory not empty: %s", newrefname);2626 goto rollback;2627 }2628 } else {2629 error("unable to delete existing %s", newrefname);2630 goto rollback;2631 }2632 }26332634 if (log && rename_tmp_log(newrefname))2635 goto rollback;26362637 logmoved = log;26382639 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,2640 REF_NODEREF, NULL, &err);2641 if (!lock) {2642 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);2643 strbuf_release(&err);2644 goto rollback;2645 }2646 hashcpy(lock->old_oid.hash, orig_sha1);26472648 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2649 commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2650 error("unable to write current sha1 into %s: %s", newrefname, err.buf);2651 strbuf_release(&err);2652 goto rollback;2653 }26542655 return 0;26562657 rollback:2658 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,2659 REF_NODEREF, NULL, &err);2660 if (!lock) {2661 error("unable to lock %s for rollback: %s", oldrefname, err.buf);2662 strbuf_release(&err);2663 goto rollbacklog;2664 }26652666 flag = log_all_ref_updates;2667 log_all_ref_updates = 0;2668 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2669 commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2670 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);2671 strbuf_release(&err);2672 }2673 log_all_ref_updates = flag;26742675 rollbacklog:2676 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2677 error("unable to restore logfile %s from %s: %s",2678 oldrefname, newrefname, strerror(errno));2679 if (!logmoved && log &&2680 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2681 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2682 oldrefname, strerror(errno));26832684 return 1;2685}26862687static int close_ref(struct ref_lock *lock)2688{2689 if (close_lock_file(lock->lk))2690 return -1;2691 return 0;2692}26932694static int commit_ref(struct ref_lock *lock)2695{2696 char *path = get_locked_file_path(lock->lk);2697 struct stat st;26982699 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {2700 /*2701 * There is a directory at the path we want to rename2702 * the lockfile to. Hopefully it is empty; try to2703 * delete it.2704 */2705 size_t len = strlen(path);2706 struct strbuf sb_path = STRBUF_INIT;27072708 strbuf_attach(&sb_path, path, len, len);27092710 /*2711 * If this fails, commit_lock_file() will also fail2712 * and will report the problem.2713 */2714 remove_empty_directories(&sb_path);2715 strbuf_release(&sb_path);2716 } else {2717 free(path);2718 }27192720 if (commit_lock_file(lock->lk))2721 return -1;2722 return 0;2723}27242725/*2726 * Create a reflog for a ref. If force_create = 0, the reflog will2727 * only be created for certain refs (those for which2728 * should_autocreate_reflog returns non-zero. Otherwise, create it2729 * regardless of the ref name. Fill in *err and return -1 on failure.2730 */2731static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)2732{2733 int logfd, oflags = O_APPEND | O_WRONLY;27342735 strbuf_git_path(logfile, "logs/%s", refname);2736 if (force_create || should_autocreate_reflog(refname)) {2737 if (safe_create_leading_directories(logfile->buf) < 0) {2738 strbuf_addf(err, "unable to create directory for '%s': "2739 "%s", logfile->buf, strerror(errno));2740 return -1;2741 }2742 oflags |= O_CREAT;2743 }27442745 logfd = open(logfile->buf, oflags, 0666);2746 if (logfd < 0) {2747 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2748 return 0;27492750 if (errno == EISDIR) {2751 if (remove_empty_directories(logfile)) {2752 strbuf_addf(err, "there are still logs under "2753 "'%s'", logfile->buf);2754 return -1;2755 }2756 logfd = open(logfile->buf, oflags, 0666);2757 }27582759 if (logfd < 0) {2760 strbuf_addf(err, "unable to append to '%s': %s",2761 logfile->buf, strerror(errno));2762 return -1;2763 }2764 }27652766 adjust_shared_perm(logfile->buf);2767 close(logfd);2768 return 0;2769}277027712772static int files_create_reflog(struct ref_store *ref_store,2773 const char *refname, int force_create,2774 struct strbuf *err)2775{2776 int ret;2777 struct strbuf sb = STRBUF_INIT;27782779 /* Check validity (but we don't need the result): */2780 files_downcast(ref_store, 0, "create_reflog");27812782 ret = log_ref_setup(refname, &sb, err, force_create);2783 strbuf_release(&sb);2784 return ret;2785}27862787static int log_ref_write_fd(int fd, const unsigned char *old_sha1,2788 const unsigned char *new_sha1,2789 const char *committer, const char *msg)2790{2791 int msglen, written;2792 unsigned maxlen, len;2793 char *logrec;27942795 msglen = msg ? strlen(msg) : 0;2796 maxlen = strlen(committer) + msglen + 100;2797 logrec = xmalloc(maxlen);2798 len = xsnprintf(logrec, maxlen, "%s %s %s\n",2799 sha1_to_hex(old_sha1),2800 sha1_to_hex(new_sha1),2801 committer);2802 if (msglen)2803 len += copy_reflog_msg(logrec + len - 1, msg) - 1;28042805 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2806 free(logrec);2807 if (written != len)2808 return -1;28092810 return 0;2811}28122813static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,2814 const unsigned char *new_sha1, const char *msg,2815 struct strbuf *logfile, int flags,2816 struct strbuf *err)2817{2818 int logfd, result, oflags = O_APPEND | O_WRONLY;28192820 if (log_all_ref_updates < 0)2821 log_all_ref_updates = !is_bare_repository();28222823 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28242825 if (result)2826 return result;28272828 logfd = open(logfile->buf, oflags);2829 if (logfd < 0)2830 return 0;2831 result = log_ref_write_fd(logfd, old_sha1, new_sha1,2832 git_committer_info(0), msg);2833 if (result) {2834 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2835 strerror(errno));2836 close(logfd);2837 return -1;2838 }2839 if (close(logfd)) {2840 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2841 strerror(errno));2842 return -1;2843 }2844 return 0;2845}28462847static int log_ref_write(const char *refname, const unsigned char *old_sha1,2848 const unsigned char *new_sha1, const char *msg,2849 int flags, struct strbuf *err)2850{2851 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2852 err);2853}28542855int files_log_ref_write(const char *refname, const unsigned char *old_sha1,2856 const unsigned char *new_sha1, const char *msg,2857 int flags, struct strbuf *err)2858{2859 struct strbuf sb = STRBUF_INIT;2860 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2861 err);2862 strbuf_release(&sb);2863 return ret;2864}28652866/*2867 * Write sha1 into the open lockfile, then close the lockfile. On2868 * errors, rollback the lockfile, fill in *err and2869 * return -1.2870 */2871static int write_ref_to_lockfile(struct ref_lock *lock,2872 const unsigned char *sha1, struct strbuf *err)2873{2874 static char term = '\n';2875 struct object *o;2876 int fd;28772878 o = parse_object(sha1);2879 if (!o) {2880 strbuf_addf(err,2881 "trying to write ref '%s' with nonexistent object %s",2882 lock->ref_name, sha1_to_hex(sha1));2883 unlock_ref(lock);2884 return -1;2885 }2886 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2887 strbuf_addf(err,2888 "trying to write non-commit object %s to branch '%s'",2889 sha1_to_hex(sha1), lock->ref_name);2890 unlock_ref(lock);2891 return -1;2892 }2893 fd = get_lock_file_fd(lock->lk);2894 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||2895 write_in_full(fd, &term, 1) != 1 ||2896 close_ref(lock) < 0) {2897 strbuf_addf(err,2898 "couldn't write '%s'", get_lock_file_path(lock->lk));2899 unlock_ref(lock);2900 return -1;2901 }2902 return 0;2903}29042905/*2906 * Commit a change to a loose reference that has already been written2907 * to the loose reference lockfile. Also update the reflogs if2908 * necessary, using the specified lockmsg (which can be NULL).2909 */2910static int commit_ref_update(struct files_ref_store *refs,2911 struct ref_lock *lock,2912 const unsigned char *sha1, const char *logmsg,2913 struct strbuf *err)2914{2915 assert_main_repository(&refs->base, "commit_ref_update");29162917 clear_loose_ref_cache(refs);2918 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {2919 char *old_msg = strbuf_detach(err, NULL);2920 strbuf_addf(err, "cannot update the ref '%s': %s",2921 lock->ref_name, old_msg);2922 free(old_msg);2923 unlock_ref(lock);2924 return -1;2925 }29262927 if (strcmp(lock->ref_name, "HEAD") != 0) {2928 /*2929 * Special hack: If a branch is updated directly and HEAD2930 * points to it (may happen on the remote side of a push2931 * for example) then logically the HEAD reflog should be2932 * updated too.2933 * A generic solution implies reverse symref information,2934 * but finding all symrefs pointing to the given branch2935 * would be rather costly for this rare event (the direct2936 * update of a branch) to be worth it. So let's cheat and2937 * check with HEAD only which should cover 99% of all usage2938 * scenarios (even 100% of the default ones).2939 */2940 unsigned char head_sha1[20];2941 int head_flag;2942 const char *head_ref;29432944 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2945 head_sha1, &head_flag);2946 if (head_ref && (head_flag & REF_ISSYMREF) &&2947 !strcmp(head_ref, lock->ref_name)) {2948 struct strbuf log_err = STRBUF_INIT;2949 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,2950 logmsg, 0, &log_err)) {2951 error("%s", log_err.buf);2952 strbuf_release(&log_err);2953 }2954 }2955 }29562957 if (commit_ref(lock)) {2958 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2959 unlock_ref(lock);2960 return -1;2961 }29622963 unlock_ref(lock);2964 return 0;2965}29662967static int create_ref_symlink(struct ref_lock *lock, const char *target)2968{2969 int ret = -1;2970#ifndef NO_SYMLINK_HEAD2971 char *ref_path = get_locked_file_path(lock->lk);2972 unlink(ref_path);2973 ret = symlink(target, ref_path);2974 free(ref_path);29752976 if (ret)2977 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2978#endif2979 return ret;2980}29812982static void update_symref_reflog(struct ref_lock *lock, const char *refname,2983 const char *target, const char *logmsg)2984{2985 struct strbuf err = STRBUF_INIT;2986 unsigned char new_sha1[20];2987 if (logmsg && !read_ref(target, new_sha1) &&2988 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {2989 error("%s", err.buf);2990 strbuf_release(&err);2991 }2992}29932994static int create_symref_locked(struct ref_lock *lock, const char *refname,2995 const char *target, const char *logmsg)2996{2997 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {2998 update_symref_reflog(lock, refname, target, logmsg);2999 return 0;3000 }30013002 if (!fdopen_lock_file(lock->lk, "w"))3003 return error("unable to fdopen %s: %s",3004 lock->lk->tempfile.filename.buf, strerror(errno));30053006 update_symref_reflog(lock, refname, target, logmsg);30073008 /* no error check; commit_ref will check ferror */3009 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);3010 if (commit_ref(lock) < 0)3011 return error("unable to write symref for %s: %s", refname,3012 strerror(errno));3013 return 0;3014}30153016static int files_create_symref(struct ref_store *ref_store,3017 const char *refname, const char *target,3018 const char *logmsg)3019{3020 struct files_ref_store *refs =3021 files_downcast(ref_store, 0, "create_symref");3022 struct strbuf err = STRBUF_INIT;3023 struct ref_lock *lock;3024 int ret;30253026 lock = lock_ref_sha1_basic(refs, refname, NULL,3027 NULL, NULL, REF_NODEREF, NULL,3028 &err);3029 if (!lock) {3030 error("%s", err.buf);3031 strbuf_release(&err);3032 return -1;3033 }30343035 ret = create_symref_locked(lock, refname, target, logmsg);3036 unlock_ref(lock);3037 return ret;3038}30393040int set_worktree_head_symref(const char *gitdir, const char *target)3041{3042 static struct lock_file head_lock;3043 struct ref_lock *lock;3044 struct strbuf head_path = STRBUF_INIT;3045 const char *head_rel;3046 int ret;30473048 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));3049 if (hold_lock_file_for_update(&head_lock, head_path.buf,3050 LOCK_NO_DEREF) < 0) {3051 struct strbuf err = STRBUF_INIT;3052 unable_to_lock_message(head_path.buf, errno, &err);3053 error("%s", err.buf);3054 strbuf_release(&err);3055 strbuf_release(&head_path);3056 return -1;3057 }30583059 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3060 linked trees */3061 head_rel = remove_leading_path(head_path.buf,3062 absolute_path(get_git_common_dir()));3063 /* to make use of create_symref_locked(), initialize ref_lock */3064 lock = xcalloc(1, sizeof(struct ref_lock));3065 lock->lk = &head_lock;3066 lock->ref_name = xstrdup(head_rel);30673068 ret = create_symref_locked(lock, head_rel, target, NULL);30693070 unlock_ref(lock); /* will free lock */3071 strbuf_release(&head_path);3072 return ret;3073}30743075static int files_reflog_exists(struct ref_store *ref_store,3076 const char *refname)3077{3078 struct stat st;30793080 /* Check validity (but we don't need the result): */3081 files_downcast(ref_store, 0, "reflog_exists");30823083 return !lstat(git_path("logs/%s", refname), &st) &&3084 S_ISREG(st.st_mode);3085}30863087static int files_delete_reflog(struct ref_store *ref_store,3088 const char *refname)3089{3090 /* Check validity (but we don't need the result): */3091 files_downcast(ref_store, 0, "delete_reflog");30923093 return remove_path(git_path("logs/%s", refname));3094}30953096static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3097{3098 unsigned char osha1[20], nsha1[20];3099 char *email_end, *message;3100 unsigned long timestamp;3101 int tz;31023103 /* old SP new SP name <email> SP time TAB msg LF */3104 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3105 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3106 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3107 !(email_end = strchr(sb->buf + 82, '>')) ||3108 email_end[1] != ' ' ||3109 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3110 !message || message[0] != ' ' ||3111 (message[1] != '+' && message[1] != '-') ||3112 !isdigit(message[2]) || !isdigit(message[3]) ||3113 !isdigit(message[4]) || !isdigit(message[5]))3114 return 0; /* corrupt? */3115 email_end[1] = '\0';3116 tz = strtol(message + 1, NULL, 10);3117 if (message[6] != '\t')3118 message += 6;3119 else3120 message += 7;3121 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3122}31233124static char *find_beginning_of_line(char *bob, char *scan)3125{3126 while (bob < scan && *(--scan) != '\n')3127 ; /* keep scanning backwards */3128 /*3129 * Return either beginning of the buffer, or LF at the end of3130 * the previous line.3131 */3132 return scan;3133}31343135static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,3136 const char *refname,3137 each_reflog_ent_fn fn,3138 void *cb_data)3139{3140 struct strbuf sb = STRBUF_INIT;3141 FILE *logfp;3142 long pos;3143 int ret = 0, at_tail = 1;31443145 /* Check validity (but we don't need the result): */3146 files_downcast(ref_store, 0, "for_each_reflog_ent_reverse");31473148 logfp = fopen(git_path("logs/%s", refname), "r");3149 if (!logfp)3150 return -1;31513152 /* Jump to the end */3153 if (fseek(logfp, 0, SEEK_END) < 0)3154 return error("cannot seek back reflog for %s: %s",3155 refname, strerror(errno));3156 pos = ftell(logfp);3157 while (!ret && 0 < pos) {3158 int cnt;3159 size_t nread;3160 char buf[BUFSIZ];3161 char *endp, *scanp;31623163 /* Fill next block from the end */3164 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3165 if (fseek(logfp, pos - cnt, SEEK_SET))3166 return error("cannot seek back reflog for %s: %s",3167 refname, strerror(errno));3168 nread = fread(buf, cnt, 1, logfp);3169 if (nread != 1)3170 return error("cannot read %d bytes from reflog for %s: %s",3171 cnt, refname, strerror(errno));3172 pos -= cnt;31733174 scanp = endp = buf + cnt;3175 if (at_tail && scanp[-1] == '\n')3176 /* Looking at the final LF at the end of the file */3177 scanp--;3178 at_tail = 0;31793180 while (buf < scanp) {3181 /*3182 * terminating LF of the previous line, or the beginning3183 * of the buffer.3184 */3185 char *bp;31863187 bp = find_beginning_of_line(buf, scanp);31883189 if (*bp == '\n') {3190 /*3191 * The newline is the end of the previous line,3192 * so we know we have complete line starting3193 * at (bp + 1). Prefix it onto any prior data3194 * we collected for the line and process it.3195 */3196 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3197 scanp = bp;3198 endp = bp + 1;3199 ret = show_one_reflog_ent(&sb, fn, cb_data);3200 strbuf_reset(&sb);3201 if (ret)3202 break;3203 } else if (!pos) {3204 /*3205 * We are at the start of the buffer, and the3206 * start of the file; there is no previous3207 * line, and we have everything for this one.3208 * Process it, and we can end the loop.3209 */3210 strbuf_splice(&sb, 0, 0, buf, endp - buf);3211 ret = show_one_reflog_ent(&sb, fn, cb_data);3212 strbuf_reset(&sb);3213 break;3214 }32153216 if (bp == buf) {3217 /*3218 * We are at the start of the buffer, and there3219 * is more file to read backwards. Which means3220 * we are in the middle of a line. Note that we3221 * may get here even if *bp was a newline; that3222 * just means we are at the exact end of the3223 * previous line, rather than some spot in the3224 * middle.3225 *3226 * Save away what we have to be combined with3227 * the data from the next read.3228 */3229 strbuf_splice(&sb, 0, 0, buf, endp - buf);3230 break;3231 }3232 }32333234 }3235 if (!ret && sb.len)3236 die("BUG: reverse reflog parser had leftover data");32373238 fclose(logfp);3239 strbuf_release(&sb);3240 return ret;3241}32423243static int files_for_each_reflog_ent(struct ref_store *ref_store,3244 const char *refname,3245 each_reflog_ent_fn fn, void *cb_data)3246{3247 FILE *logfp;3248 struct strbuf sb = STRBUF_INIT;3249 int ret = 0;32503251 /* Check validity (but we don't need the result): */3252 files_downcast(ref_store, 0, "for_each_reflog_ent");32533254 logfp = fopen(git_path("logs/%s", refname), "r");3255 if (!logfp)3256 return -1;32573258 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3259 ret = show_one_reflog_ent(&sb, fn, cb_data);3260 fclose(logfp);3261 strbuf_release(&sb);3262 return ret;3263}32643265struct files_reflog_iterator {3266 struct ref_iterator base;32673268 struct dir_iterator *dir_iterator;3269 struct object_id oid;3270};32713272static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)3273{3274 struct files_reflog_iterator *iter =3275 (struct files_reflog_iterator *)ref_iterator;3276 struct dir_iterator *diter = iter->dir_iterator;3277 int ok;32783279 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {3280 int flags;32813282 if (!S_ISREG(diter->st.st_mode))3283 continue;3284 if (diter->basename[0] == '.')3285 continue;3286 if (ends_with(diter->basename, ".lock"))3287 continue;32883289 if (read_ref_full(diter->relative_path, 0,3290 iter->oid.hash, &flags)) {3291 error("bad ref for %s", diter->path.buf);3292 continue;3293 }32943295 iter->base.refname = diter->relative_path;3296 iter->base.oid = &iter->oid;3297 iter->base.flags = flags;3298 return ITER_OK;3299 }33003301 iter->dir_iterator = NULL;3302 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)3303 ok = ITER_ERROR;3304 return ok;3305}33063307static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,3308 struct object_id *peeled)3309{3310 die("BUG: ref_iterator_peel() called for reflog_iterator");3311}33123313static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)3314{3315 struct files_reflog_iterator *iter =3316 (struct files_reflog_iterator *)ref_iterator;3317 int ok = ITER_DONE;33183319 if (iter->dir_iterator)3320 ok = dir_iterator_abort(iter->dir_iterator);33213322 base_ref_iterator_free(ref_iterator);3323 return ok;3324}33253326static struct ref_iterator_vtable files_reflog_iterator_vtable = {3327 files_reflog_iterator_advance,3328 files_reflog_iterator_peel,3329 files_reflog_iterator_abort3330};33313332static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)3333{3334 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));3335 struct ref_iterator *ref_iterator = &iter->base;33363337 /* Check validity (but we don't need the result): */3338 files_downcast(ref_store, 0, "reflog_iterator_begin");33393340 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3341 iter->dir_iterator = dir_iterator_begin(git_path("logs"));3342 return ref_iterator;3343}33443345static int ref_update_reject_duplicates(struct string_list *refnames,3346 struct strbuf *err)3347{3348 int i, n = refnames->nr;33493350 assert(err);33513352 for (i = 1; i < n; i++)3353 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {3354 strbuf_addf(err,3355 "multiple updates for ref '%s' not allowed.",3356 refnames->items[i].string);3357 return 1;3358 }3359 return 0;3360}33613362/*3363 * If update is a direct update of head_ref (the reference pointed to3364 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3365 */3366static int split_head_update(struct ref_update *update,3367 struct ref_transaction *transaction,3368 const char *head_ref,3369 struct string_list *affected_refnames,3370 struct strbuf *err)3371{3372 struct string_list_item *item;3373 struct ref_update *new_update;33743375 if ((update->flags & REF_LOG_ONLY) ||3376 (update->flags & REF_ISPRUNING) ||3377 (update->flags & REF_UPDATE_VIA_HEAD))3378 return 0;33793380 if (strcmp(update->refname, head_ref))3381 return 0;33823383 /*3384 * First make sure that HEAD is not already in the3385 * transaction. This insertion is O(N) in the transaction3386 * size, but it happens at most once per transaction.3387 */3388 item = string_list_insert(affected_refnames, "HEAD");3389 if (item->util) {3390 /* An entry already existed */3391 strbuf_addf(err,3392 "multiple updates for 'HEAD' (including one "3393 "via its referent '%s') are not allowed",3394 update->refname);3395 return TRANSACTION_NAME_CONFLICT;3396 }33973398 new_update = ref_transaction_add_update(3399 transaction, "HEAD",3400 update->flags | REF_LOG_ONLY | REF_NODEREF,3401 update->new_sha1, update->old_sha1,3402 update->msg);34033404 item->util = new_update;34053406 return 0;3407}34083409/*3410 * update is for a symref that points at referent and doesn't have3411 * REF_NODEREF set. Split it into two updates:3412 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3413 * - A new, separate update for the referent reference3414 * Note that the new update will itself be subject to splitting when3415 * the iteration gets to it.3416 */3417static int split_symref_update(struct files_ref_store *refs,3418 struct ref_update *update,3419 const char *referent,3420 struct ref_transaction *transaction,3421 struct string_list *affected_refnames,3422 struct strbuf *err)3423{3424 struct string_list_item *item;3425 struct ref_update *new_update;3426 unsigned int new_flags;34273428 /*3429 * First make sure that referent is not already in the3430 * transaction. This insertion is O(N) in the transaction3431 * size, but it happens at most once per symref in a3432 * transaction.3433 */3434 item = string_list_insert(affected_refnames, referent);3435 if (item->util) {3436 /* An entry already existed */3437 strbuf_addf(err,3438 "multiple updates for '%s' (including one "3439 "via symref '%s') are not allowed",3440 referent, update->refname);3441 return TRANSACTION_NAME_CONFLICT;3442 }34433444 new_flags = update->flags;3445 if (!strcmp(update->refname, "HEAD")) {3446 /*3447 * Record that the new update came via HEAD, so that3448 * when we process it, split_head_update() doesn't try3449 * to add another reflog update for HEAD. Note that3450 * this bit will be propagated if the new_update3451 * itself needs to be split.3452 */3453 new_flags |= REF_UPDATE_VIA_HEAD;3454 }34553456 new_update = ref_transaction_add_update(3457 transaction, referent, new_flags,3458 update->new_sha1, update->old_sha1,3459 update->msg);34603461 new_update->parent_update = update;34623463 /*3464 * Change the symbolic ref update to log only. Also, it3465 * doesn't need to check its old SHA-1 value, as that will be3466 * done when new_update is processed.3467 */3468 update->flags |= REF_LOG_ONLY | REF_NODEREF;3469 update->flags &= ~REF_HAVE_OLD;34703471 item->util = new_update;34723473 return 0;3474}34753476/*3477 * Return the refname under which update was originally requested.3478 */3479static const char *original_update_refname(struct ref_update *update)3480{3481 while (update->parent_update)3482 update = update->parent_update;34833484 return update->refname;3485}34863487/*3488 * Check whether the REF_HAVE_OLD and old_oid values stored in update3489 * are consistent with oid, which is the reference's current value. If3490 * everything is OK, return 0; otherwise, write an error message to3491 * err and return -1.3492 */3493static int check_old_oid(struct ref_update *update, struct object_id *oid,3494 struct strbuf *err)3495{3496 if (!(update->flags & REF_HAVE_OLD) ||3497 !hashcmp(oid->hash, update->old_sha1))3498 return 0;34993500 if (is_null_sha1(update->old_sha1))3501 strbuf_addf(err, "cannot lock ref '%s': "3502 "reference already exists",3503 original_update_refname(update));3504 else if (is_null_oid(oid))3505 strbuf_addf(err, "cannot lock ref '%s': "3506 "reference is missing but expected %s",3507 original_update_refname(update),3508 sha1_to_hex(update->old_sha1));3509 else3510 strbuf_addf(err, "cannot lock ref '%s': "3511 "is at %s but expected %s",3512 original_update_refname(update),3513 oid_to_hex(oid),3514 sha1_to_hex(update->old_sha1));35153516 return -1;3517}35183519/*3520 * Prepare for carrying out update:3521 * - Lock the reference referred to by update.3522 * - Read the reference under lock.3523 * - Check that its old SHA-1 value (if specified) is correct, and in3524 * any case record it in update->lock->old_oid for later use when3525 * writing the reflog.3526 * - If it is a symref update without REF_NODEREF, split it up into a3527 * REF_LOG_ONLY update of the symref and add a separate update for3528 * the referent to transaction.3529 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3530 * update of HEAD.3531 */3532static int lock_ref_for_update(struct files_ref_store *refs,3533 struct ref_update *update,3534 struct ref_transaction *transaction,3535 const char *head_ref,3536 struct string_list *affected_refnames,3537 struct strbuf *err)3538{3539 struct strbuf referent = STRBUF_INIT;3540 int mustexist = (update->flags & REF_HAVE_OLD) &&3541 !is_null_sha1(update->old_sha1);3542 int ret;3543 struct ref_lock *lock;35443545 assert_main_repository(&refs->base, "lock_ref_for_update");35463547 if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))3548 update->flags |= REF_DELETING;35493550 if (head_ref) {3551 ret = split_head_update(update, transaction, head_ref,3552 affected_refnames, err);3553 if (ret)3554 return ret;3555 }35563557 ret = lock_raw_ref(refs, update->refname, mustexist,3558 affected_refnames, NULL,3559 &lock, &referent,3560 &update->type, err);3561 if (ret) {3562 char *reason;35633564 reason = strbuf_detach(err, NULL);3565 strbuf_addf(err, "cannot lock ref '%s': %s",3566 original_update_refname(update), reason);3567 free(reason);3568 return ret;3569 }35703571 update->backend_data = lock;35723573 if (update->type & REF_ISSYMREF) {3574 if (update->flags & REF_NODEREF) {3575 /*3576 * We won't be reading the referent as part of3577 * the transaction, so we have to read it here3578 * to record and possibly check old_sha1:3579 */3580 if (read_ref_full(referent.buf, 0,3581 lock->old_oid.hash, NULL)) {3582 if (update->flags & REF_HAVE_OLD) {3583 strbuf_addf(err, "cannot lock ref '%s': "3584 "error reading reference",3585 original_update_refname(update));3586 return -1;3587 }3588 } else if (check_old_oid(update, &lock->old_oid, err)) {3589 return TRANSACTION_GENERIC_ERROR;3590 }3591 } else {3592 /*3593 * Create a new update for the reference this3594 * symref is pointing at. Also, we will record3595 * and verify old_sha1 for this update as part3596 * of processing the split-off update, so we3597 * don't have to do it here.3598 */3599 ret = split_symref_update(refs, update,3600 referent.buf, transaction,3601 affected_refnames, err);3602 if (ret)3603 return ret;3604 }3605 } else {3606 struct ref_update *parent_update;36073608 if (check_old_oid(update, &lock->old_oid, err))3609 return TRANSACTION_GENERIC_ERROR;36103611 /*3612 * If this update is happening indirectly because of a3613 * symref update, record the old SHA-1 in the parent3614 * update:3615 */3616 for (parent_update = update->parent_update;3617 parent_update;3618 parent_update = parent_update->parent_update) {3619 struct ref_lock *parent_lock = parent_update->backend_data;3620 oidcpy(&parent_lock->old_oid, &lock->old_oid);3621 }3622 }36233624 if ((update->flags & REF_HAVE_NEW) &&3625 !(update->flags & REF_DELETING) &&3626 !(update->flags & REF_LOG_ONLY)) {3627 if (!(update->type & REF_ISSYMREF) &&3628 !hashcmp(lock->old_oid.hash, update->new_sha1)) {3629 /*3630 * The reference already has the desired3631 * value, so we don't need to write it.3632 */3633 } else if (write_ref_to_lockfile(lock, update->new_sha1,3634 err)) {3635 char *write_err = strbuf_detach(err, NULL);36363637 /*3638 * The lock was freed upon failure of3639 * write_ref_to_lockfile():3640 */3641 update->backend_data = NULL;3642 strbuf_addf(err,3643 "cannot update ref '%s': %s",3644 update->refname, write_err);3645 free(write_err);3646 return TRANSACTION_GENERIC_ERROR;3647 } else {3648 update->flags |= REF_NEEDS_COMMIT;3649 }3650 }3651 if (!(update->flags & REF_NEEDS_COMMIT)) {3652 /*3653 * We didn't call write_ref_to_lockfile(), so3654 * the lockfile is still open. Close it to3655 * free up the file descriptor:3656 */3657 if (close_ref(lock)) {3658 strbuf_addf(err, "couldn't close '%s.lock'",3659 update->refname);3660 return TRANSACTION_GENERIC_ERROR;3661 }3662 }3663 return 0;3664}36653666static int files_transaction_commit(struct ref_store *ref_store,3667 struct ref_transaction *transaction,3668 struct strbuf *err)3669{3670 struct files_ref_store *refs =3671 files_downcast(ref_store, 0, "ref_transaction_commit");3672 int ret = 0, i;3673 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3674 struct string_list_item *ref_to_delete;3675 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3676 char *head_ref = NULL;3677 int head_type;3678 struct object_id head_oid;36793680 assert(err);36813682 if (transaction->state != REF_TRANSACTION_OPEN)3683 die("BUG: commit called for transaction that is not open");36843685 if (!transaction->nr) {3686 transaction->state = REF_TRANSACTION_CLOSED;3687 return 0;3688 }36893690 /*3691 * Fail if a refname appears more than once in the3692 * transaction. (If we end up splitting up any updates using3693 * split_symref_update() or split_head_update(), those3694 * functions will check that the new updates don't have the3695 * same refname as any existing ones.)3696 */3697 for (i = 0; i < transaction->nr; i++) {3698 struct ref_update *update = transaction->updates[i];3699 struct string_list_item *item =3700 string_list_append(&affected_refnames, update->refname);37013702 /*3703 * We store a pointer to update in item->util, but at3704 * the moment we never use the value of this field3705 * except to check whether it is non-NULL.3706 */3707 item->util = update;3708 }3709 string_list_sort(&affected_refnames);3710 if (ref_update_reject_duplicates(&affected_refnames, err)) {3711 ret = TRANSACTION_GENERIC_ERROR;3712 goto cleanup;3713 }37143715 /*3716 * Special hack: If a branch is updated directly and HEAD3717 * points to it (may happen on the remote side of a push3718 * for example) then logically the HEAD reflog should be3719 * updated too.3720 *3721 * A generic solution would require reverse symref lookups,3722 * but finding all symrefs pointing to a given branch would be3723 * rather costly for this rare event (the direct update of a3724 * branch) to be worth it. So let's cheat and check with HEAD3725 * only, which should cover 99% of all usage scenarios (even3726 * 100% of the default ones).3727 *3728 * So if HEAD is a symbolic reference, then record the name of3729 * the reference that it points to. If we see an update of3730 * head_ref within the transaction, then split_head_update()3731 * arranges for the reflog of HEAD to be updated, too.3732 */3733 head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3734 head_oid.hash, &head_type);37353736 if (head_ref && !(head_type & REF_ISSYMREF)) {3737 free(head_ref);3738 head_ref = NULL;3739 }37403741 /*3742 * Acquire all locks, verify old values if provided, check3743 * that new values are valid, and write new values to the3744 * lockfiles, ready to be activated. Only keep one lockfile3745 * open at a time to avoid running out of file descriptors.3746 */3747 for (i = 0; i < transaction->nr; i++) {3748 struct ref_update *update = transaction->updates[i];37493750 ret = lock_ref_for_update(refs, update, transaction,3751 head_ref, &affected_refnames, err);3752 if (ret)3753 goto cleanup;3754 }37553756 /* Perform updates first so live commits remain referenced */3757 for (i = 0; i < transaction->nr; i++) {3758 struct ref_update *update = transaction->updates[i];3759 struct ref_lock *lock = update->backend_data;37603761 if (update->flags & REF_NEEDS_COMMIT ||3762 update->flags & REF_LOG_ONLY) {3763 if (log_ref_write(lock->ref_name, lock->old_oid.hash,3764 update->new_sha1,3765 update->msg, update->flags, err)) {3766 char *old_msg = strbuf_detach(err, NULL);37673768 strbuf_addf(err, "cannot update the ref '%s': %s",3769 lock->ref_name, old_msg);3770 free(old_msg);3771 unlock_ref(lock);3772 update->backend_data = NULL;3773 ret = TRANSACTION_GENERIC_ERROR;3774 goto cleanup;3775 }3776 }3777 if (update->flags & REF_NEEDS_COMMIT) {3778 clear_loose_ref_cache(refs);3779 if (commit_ref(lock)) {3780 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);3781 unlock_ref(lock);3782 update->backend_data = NULL;3783 ret = TRANSACTION_GENERIC_ERROR;3784 goto cleanup;3785 }3786 }3787 }3788 /* Perform deletes now that updates are safely completed */3789 for (i = 0; i < transaction->nr; i++) {3790 struct ref_update *update = transaction->updates[i];3791 struct ref_lock *lock = update->backend_data;37923793 if (update->flags & REF_DELETING &&3794 !(update->flags & REF_LOG_ONLY)) {3795 if (delete_ref_loose(lock, update->type, err)) {3796 ret = TRANSACTION_GENERIC_ERROR;3797 goto cleanup;3798 }37993800 if (!(update->flags & REF_ISPRUNING))3801 string_list_append(&refs_to_delete,3802 lock->ref_name);3803 }3804 }38053806 if (repack_without_refs(refs, &refs_to_delete, err)) {3807 ret = TRANSACTION_GENERIC_ERROR;3808 goto cleanup;3809 }3810 for_each_string_list_item(ref_to_delete, &refs_to_delete)3811 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3812 clear_loose_ref_cache(refs);38133814cleanup:3815 transaction->state = REF_TRANSACTION_CLOSED;38163817 for (i = 0; i < transaction->nr; i++)3818 if (transaction->updates[i]->backend_data)3819 unlock_ref(transaction->updates[i]->backend_data);3820 string_list_clear(&refs_to_delete, 0);3821 free(head_ref);3822 string_list_clear(&affected_refnames, 0);38233824 return ret;3825}38263827static int ref_present(const char *refname,3828 const struct object_id *oid, int flags, void *cb_data)3829{3830 struct string_list *affected_refnames = cb_data;38313832 return string_list_has_string(affected_refnames, refname);3833}38343835static int files_initial_transaction_commit(struct ref_store *ref_store,3836 struct ref_transaction *transaction,3837 struct strbuf *err)3838{3839 struct files_ref_store *refs =3840 files_downcast(ref_store, 0, "initial_ref_transaction_commit");3841 int ret = 0, i;3842 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38433844 assert(err);38453846 if (transaction->state != REF_TRANSACTION_OPEN)3847 die("BUG: commit called for transaction that is not open");38483849 /* Fail if a refname appears more than once in the transaction: */3850 for (i = 0; i < transaction->nr; i++)3851 string_list_append(&affected_refnames,3852 transaction->updates[i]->refname);3853 string_list_sort(&affected_refnames);3854 if (ref_update_reject_duplicates(&affected_refnames, err)) {3855 ret = TRANSACTION_GENERIC_ERROR;3856 goto cleanup;3857 }38583859 /*3860 * It's really undefined to call this function in an active3861 * repository or when there are existing references: we are3862 * only locking and changing packed-refs, so (1) any3863 * simultaneous processes might try to change a reference at3864 * the same time we do, and (2) any existing loose versions of3865 * the references that we are setting would have precedence3866 * over our values. But some remote helpers create the remote3867 * "HEAD" and "master" branches before calling this function,3868 * so here we really only check that none of the references3869 * that we are creating already exists.3870 */3871 if (for_each_rawref(ref_present, &affected_refnames))3872 die("BUG: initial ref transaction called with existing refs");38733874 for (i = 0; i < transaction->nr; i++) {3875 struct ref_update *update = transaction->updates[i];38763877 if ((update->flags & REF_HAVE_OLD) &&3878 !is_null_sha1(update->old_sha1))3879 die("BUG: initial ref transaction with old_sha1 set");3880 if (verify_refname_available(update->refname,3881 &affected_refnames, NULL,3882 err)) {3883 ret = TRANSACTION_NAME_CONFLICT;3884 goto cleanup;3885 }3886 }38873888 if (lock_packed_refs(refs, 0)) {3889 strbuf_addf(err, "unable to lock packed-refs file: %s",3890 strerror(errno));3891 ret = TRANSACTION_GENERIC_ERROR;3892 goto cleanup;3893 }38943895 for (i = 0; i < transaction->nr; i++) {3896 struct ref_update *update = transaction->updates[i];38973898 if ((update->flags & REF_HAVE_NEW) &&3899 !is_null_sha1(update->new_sha1))3900 add_packed_ref(refs, update->refname, update->new_sha1);3901 }39023903 if (commit_packed_refs(refs)) {3904 strbuf_addf(err, "unable to commit packed-refs file: %s",3905 strerror(errno));3906 ret = TRANSACTION_GENERIC_ERROR;3907 goto cleanup;3908 }39093910cleanup:3911 transaction->state = REF_TRANSACTION_CLOSED;3912 string_list_clear(&affected_refnames, 0);3913 return ret;3914}39153916struct expire_reflog_cb {3917 unsigned int flags;3918 reflog_expiry_should_prune_fn *should_prune_fn;3919 void *policy_cb;3920 FILE *newlog;3921 unsigned char last_kept_sha1[20];3922};39233924static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,3925 const char *email, unsigned long timestamp, int tz,3926 const char *message, void *cb_data)3927{3928 struct expire_reflog_cb *cb = cb_data;3929 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39303931 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3932 osha1 = cb->last_kept_sha1;39333934 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3935 message, policy_cb)) {3936 if (!cb->newlog)3937 printf("would prune %s", message);3938 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3939 printf("prune %s", message);3940 } else {3941 if (cb->newlog) {3942 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",3943 sha1_to_hex(osha1), sha1_to_hex(nsha1),3944 email, timestamp, tz, message);3945 hashcpy(cb->last_kept_sha1, nsha1);3946 }3947 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3948 printf("keep %s", message);3949 }3950 return 0;3951}39523953static int files_reflog_expire(struct ref_store *ref_store,3954 const char *refname, const unsigned char *sha1,3955 unsigned int flags,3956 reflog_expiry_prepare_fn prepare_fn,3957 reflog_expiry_should_prune_fn should_prune_fn,3958 reflog_expiry_cleanup_fn cleanup_fn,3959 void *policy_cb_data)3960{3961 struct files_ref_store *refs =3962 files_downcast(ref_store, 0, "reflog_expire");3963 static struct lock_file reflog_lock;3964 struct expire_reflog_cb cb;3965 struct ref_lock *lock;3966 char *log_file;3967 int status = 0;3968 int type;3969 struct strbuf err = STRBUF_INIT;39703971 memset(&cb, 0, sizeof(cb));3972 cb.flags = flags;3973 cb.policy_cb = policy_cb_data;3974 cb.should_prune_fn = should_prune_fn;39753976 /*3977 * The reflog file is locked by holding the lock on the3978 * reference itself, plus we might need to update the3979 * reference if --updateref was specified:3980 */3981 lock = lock_ref_sha1_basic(refs, refname, sha1,3982 NULL, NULL, REF_NODEREF,3983 &type, &err);3984 if (!lock) {3985 error("cannot lock ref '%s': %s", refname, err.buf);3986 strbuf_release(&err);3987 return -1;3988 }3989 if (!reflog_exists(refname)) {3990 unlock_ref(lock);3991 return 0;3992 }39933994 log_file = git_pathdup("logs/%s", refname);3995 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3996 /*3997 * Even though holding $GIT_DIR/logs/$reflog.lock has3998 * no locking implications, we use the lock_file3999 * machinery here anyway because it does a lot of the4000 * work we need, including cleaning up if the program4001 * exits unexpectedly.4002 */4003 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {4004 struct strbuf err = STRBUF_INIT;4005 unable_to_lock_message(log_file, errno, &err);4006 error("%s", err.buf);4007 strbuf_release(&err);4008 goto failure;4009 }4010 cb.newlog = fdopen_lock_file(&reflog_lock, "w");4011 if (!cb.newlog) {4012 error("cannot fdopen %s (%s)",4013 get_lock_file_path(&reflog_lock), strerror(errno));4014 goto failure;4015 }4016 }40174018 (*prepare_fn)(refname, sha1, cb.policy_cb);4019 for_each_reflog_ent(refname, expire_reflog_ent, &cb);4020 (*cleanup_fn)(cb.policy_cb);40214022 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4023 /*4024 * It doesn't make sense to adjust a reference pointed4025 * to by a symbolic ref based on expiring entries in4026 * the symbolic reference's reflog. Nor can we update4027 * a reference if there are no remaining reflog4028 * entries.4029 */4030 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4031 !(type & REF_ISSYMREF) &&4032 !is_null_sha1(cb.last_kept_sha1);40334034 if (close_lock_file(&reflog_lock)) {4035 status |= error("couldn't write %s: %s", log_file,4036 strerror(errno));4037 } else if (update &&4038 (write_in_full(get_lock_file_fd(lock->lk),4039 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||4040 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||4041 close_ref(lock) < 0)) {4042 status |= error("couldn't write %s",4043 get_lock_file_path(lock->lk));4044 rollback_lock_file(&reflog_lock);4045 } else if (commit_lock_file(&reflog_lock)) {4046 status |= error("unable to write reflog '%s' (%s)",4047 log_file, strerror(errno));4048 } else if (update && commit_ref(lock)) {4049 status |= error("couldn't set %s", lock->ref_name);4050 }4051 }4052 free(log_file);4053 unlock_ref(lock);4054 return status;40554056 failure:4057 rollback_lock_file(&reflog_lock);4058 free(log_file);4059 unlock_ref(lock);4060 return -1;4061}40624063static int files_init_db(struct ref_store *ref_store, struct strbuf *err)4064{4065 /* Check validity (but we don't need the result): */4066 files_downcast(ref_store, 0, "init_db");40674068 /*4069 * Create .git/refs/{heads,tags}4070 */4071 safe_create_dir(git_path("refs/heads"), 1);4072 safe_create_dir(git_path("refs/tags"), 1);4073 if (get_shared_repository()) {4074 adjust_shared_perm(git_path("refs/heads"));4075 adjust_shared_perm(git_path("refs/tags"));4076 }4077 return 0;4078}40794080struct ref_storage_be refs_be_files = {4081 NULL,4082 "files",4083 files_ref_store_create,4084 files_init_db,4085 files_transaction_commit,4086 files_initial_transaction_commit,40874088 files_pack_refs,4089 files_peel_ref,4090 files_create_symref,4091 files_delete_refs,4092 files_rename_ref,40934094 files_ref_iterator_begin,4095 files_read_raw_ref,4096 files_verify_refname_available,40974098 files_reflog_iterator_begin,4099 files_for_each_reflog_ent,4100 files_for_each_reflog_ent_reverse,4101 files_reflog_exists,4102 files_create_reflog,4103 files_delete_reflog,4104 files_reflog_expire4105};