1#include "../cache.h" 2#include "../refs.h" 3#include "refs-internal.h" 4#include "../lockfile.h" 5#include "../object.h" 6#include "../dir.h" 7 8struct ref_lock { 9 char *ref_name; 10 char *orig_ref_name; 11 struct lock_file *lk; 12 struct object_id old_oid; 13}; 14 15struct ref_entry; 16 17/* 18 * Information used (along with the information in ref_entry) to 19 * describe a single cached reference. This data structure only 20 * occurs embedded in a union in struct ref_entry, and only when 21 * (ref_entry->flag & REF_DIR) is zero. 22 */ 23struct ref_value { 24 /* 25 * The name of the object to which this reference resolves 26 * (which may be a tag object). If REF_ISBROKEN, this is 27 * null. If REF_ISSYMREF, then this is the name of the object 28 * referred to by the last reference in the symlink chain. 29 */ 30 struct object_id oid; 31 32 /* 33 * If REF_KNOWS_PEELED, then this field holds the peeled value 34 * of this reference, or null if the reference is known not to 35 * be peelable. See the documentation for peel_ref() for an 36 * exact definition of "peelable". 37 */ 38 struct object_id peeled; 39}; 40 41struct ref_cache; 42 43/* 44 * Information used (along with the information in ref_entry) to 45 * describe a level in the hierarchy of references. This data 46 * structure only occurs embedded in a union in struct ref_entry, and 47 * only when (ref_entry.flag & REF_DIR) is set. In that case, 48 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 49 * in the directory have already been read: 50 * 51 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 52 * or packed references, already read. 53 * 54 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 55 * references that hasn't been read yet (nor has any of its 56 * subdirectories). 57 * 58 * Entries within a directory are stored within a growable array of 59 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 60 * sorted are sorted by their component name in strcmp() order and the 61 * remaining entries are unsorted. 62 * 63 * Loose references are read lazily, one directory at a time. When a 64 * directory of loose references is read, then all of the references 65 * in that directory are stored, and REF_INCOMPLETE stubs are created 66 * for any subdirectories, but the subdirectories themselves are not 67 * read. The reading is triggered by get_ref_dir(). 68 */ 69struct ref_dir { 70 int nr, alloc; 71 72 /* 73 * Entries with index 0 <= i < sorted are sorted by name. New 74 * entries are appended to the list unsorted, and are sorted 75 * only when required; thus we avoid the need to sort the list 76 * after the addition of every reference. 77 */ 78 int sorted; 79 80 /* A pointer to the ref_cache that contains this ref_dir. */ 81 struct ref_cache *ref_cache; 82 83 struct ref_entry **entries; 84}; 85 86/* 87 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 88 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 89 * public values; see refs.h. 90 */ 91 92/* 93 * The field ref_entry->u.value.peeled of this value entry contains 94 * the correct peeled value for the reference, which might be 95 * null_sha1 if the reference is not a tag or if it is broken. 96 */ 97#define REF_KNOWS_PEELED 0x10 98 99/* ref_entry represents a directory of references */ 100#define REF_DIR 0x20 101 102/* 103 * Entry has not yet been read from disk (used only for REF_DIR 104 * entries representing loose references) 105 */ 106#define REF_INCOMPLETE 0x40 107 108/* 109 * A ref_entry represents either a reference or a "subdirectory" of 110 * references. 111 * 112 * Each directory in the reference namespace is represented by a 113 * ref_entry with (flags & REF_DIR) set and containing a subdir member 114 * that holds the entries in that directory that have been read so 115 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 116 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 117 * used for loose reference directories. 118 * 119 * References are represented by a ref_entry with (flags & REF_DIR) 120 * unset and a value member that describes the reference's value. The 121 * flag member is at the ref_entry level, but it is also needed to 122 * interpret the contents of the value field (in other words, a 123 * ref_value object is not very much use without the enclosing 124 * ref_entry). 125 * 126 * Reference names cannot end with slash and directories' names are 127 * always stored with a trailing slash (except for the top-level 128 * directory, which is always denoted by ""). This has two nice 129 * consequences: (1) when the entries in each subdir are sorted 130 * lexicographically by name (as they usually are), the references in 131 * a whole tree can be generated in lexicographic order by traversing 132 * the tree in left-to-right, depth-first order; (2) the names of 133 * references and subdirectories cannot conflict, and therefore the 134 * presence of an empty subdirectory does not block the creation of a 135 * similarly-named reference. (The fact that reference names with the 136 * same leading components can conflict *with each other* is a 137 * separate issue that is regulated by verify_refname_available().) 138 * 139 * Please note that the name field contains the fully-qualified 140 * reference (or subdirectory) name. Space could be saved by only 141 * storing the relative names. But that would require the full names 142 * to be generated on the fly when iterating in do_for_each_ref(), and 143 * would break callback functions, who have always been able to assume 144 * that the name strings that they are passed will not be freed during 145 * the iteration. 146 */ 147struct ref_entry { 148 unsigned char flag; /* ISSYMREF? ISPACKED? */ 149 union { 150 struct ref_value value; /* if not (flags&REF_DIR) */ 151 struct ref_dir subdir; /* if (flags&REF_DIR) */ 152 } u; 153 /* 154 * The full name of the reference (e.g., "refs/heads/master") 155 * or the full name of the directory with a trailing slash 156 * (e.g., "refs/heads/"): 157 */ 158 char name[FLEX_ARRAY]; 159}; 160 161static void read_loose_refs(const char *dirname, struct ref_dir *dir); 162static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len); 163static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 164 const char *dirname, size_t len, 165 int incomplete); 166static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry); 167 168static struct ref_dir *get_ref_dir(struct ref_entry *entry) 169{ 170 struct ref_dir *dir; 171 assert(entry->flag & REF_DIR); 172 dir = &entry->u.subdir; 173 if (entry->flag & REF_INCOMPLETE) { 174 read_loose_refs(entry->name, dir); 175 176 /* 177 * Manually add refs/bisect, which, being 178 * per-worktree, might not appear in the directory 179 * listing for refs/ in the main repo. 180 */ 181 if (!strcmp(entry->name, "refs/")) { 182 int pos = search_ref_dir(dir, "refs/bisect/", 12); 183 if (pos < 0) { 184 struct ref_entry *child_entry; 185 child_entry = create_dir_entry(dir->ref_cache, 186 "refs/bisect/", 187 12, 1); 188 add_entry_to_dir(dir, child_entry); 189 read_loose_refs("refs/bisect", 190 &child_entry->u.subdir); 191 } 192 } 193 entry->flag &= ~REF_INCOMPLETE; 194 } 195 return dir; 196} 197 198static struct ref_entry *create_ref_entry(const char *refname, 199 const unsigned char *sha1, int flag, 200 int check_name) 201{ 202 struct ref_entry *ref; 203 204 if (check_name && 205 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 206 die("Reference has invalid format: '%s'", refname); 207 FLEX_ALLOC_STR(ref, name, refname); 208 hashcpy(ref->u.value.oid.hash, sha1); 209 oidclr(&ref->u.value.peeled); 210 ref->flag = flag; 211 return ref; 212} 213 214static void clear_ref_dir(struct ref_dir *dir); 215 216static void free_ref_entry(struct ref_entry *entry) 217{ 218 if (entry->flag & REF_DIR) { 219 /* 220 * Do not use get_ref_dir() here, as that might 221 * trigger the reading of loose refs. 222 */ 223 clear_ref_dir(&entry->u.subdir); 224 } 225 free(entry); 226} 227 228/* 229 * Add a ref_entry to the end of dir (unsorted). Entry is always 230 * stored directly in dir; no recursion into subdirectories is 231 * done. 232 */ 233static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) 234{ 235 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 236 dir->entries[dir->nr++] = entry; 237 /* optimize for the case that entries are added in order */ 238 if (dir->nr == 1 || 239 (dir->nr == dir->sorted + 1 && 240 strcmp(dir->entries[dir->nr - 2]->name, 241 dir->entries[dir->nr - 1]->name) < 0)) 242 dir->sorted = dir->nr; 243} 244 245/* 246 * Clear and free all entries in dir, recursively. 247 */ 248static void clear_ref_dir(struct ref_dir *dir) 249{ 250 int i; 251 for (i = 0; i < dir->nr; i++) 252 free_ref_entry(dir->entries[i]); 253 free(dir->entries); 254 dir->sorted = dir->nr = dir->alloc = 0; 255 dir->entries = NULL; 256} 257 258/* 259 * Create a struct ref_entry object for the specified dirname. 260 * dirname is the name of the directory with a trailing slash (e.g., 261 * "refs/heads/") or "" for the top-level directory. 262 */ 263static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 264 const char *dirname, size_t len, 265 int incomplete) 266{ 267 struct ref_entry *direntry; 268 FLEX_ALLOC_MEM(direntry, name, dirname, len); 269 direntry->u.subdir.ref_cache = ref_cache; 270 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 271 return direntry; 272} 273 274static int ref_entry_cmp(const void *a, const void *b) 275{ 276 struct ref_entry *one = *(struct ref_entry **)a; 277 struct ref_entry *two = *(struct ref_entry **)b; 278 return strcmp(one->name, two->name); 279} 280 281static void sort_ref_dir(struct ref_dir *dir); 282 283struct string_slice { 284 size_t len; 285 const char *str; 286}; 287 288static int ref_entry_cmp_sslice(const void *key_, const void *ent_) 289{ 290 const struct string_slice *key = key_; 291 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; 292 int cmp = strncmp(key->str, ent->name, key->len); 293 if (cmp) 294 return cmp; 295 return '\0' - (unsigned char)ent->name[key->len]; 296} 297 298/* 299 * Return the index of the entry with the given refname from the 300 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 301 * no such entry is found. dir must already be complete. 302 */ 303static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 304{ 305 struct ref_entry **r; 306 struct string_slice key; 307 308 if (refname == NULL || !dir->nr) 309 return -1; 310 311 sort_ref_dir(dir); 312 key.len = len; 313 key.str = refname; 314 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 315 ref_entry_cmp_sslice); 316 317 if (r == NULL) 318 return -1; 319 320 return r - dir->entries; 321} 322 323/* 324 * Search for a directory entry directly within dir (without 325 * recursing). Sort dir if necessary. subdirname must be a directory 326 * name (i.e., end in '/'). If mkdir is set, then create the 327 * directory if it is missing; otherwise, return NULL if the desired 328 * directory cannot be found. dir must already be complete. 329 */ 330static struct ref_dir *search_for_subdir(struct ref_dir *dir, 331 const char *subdirname, size_t len, 332 int mkdir) 333{ 334 int entry_index = search_ref_dir(dir, subdirname, len); 335 struct ref_entry *entry; 336 if (entry_index == -1) { 337 if (!mkdir) 338 return NULL; 339 /* 340 * Since dir is complete, the absence of a subdir 341 * means that the subdir really doesn't exist; 342 * therefore, create an empty record for it but mark 343 * the record complete. 344 */ 345 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); 346 add_entry_to_dir(dir, entry); 347 } else { 348 entry = dir->entries[entry_index]; 349 } 350 return get_ref_dir(entry); 351} 352 353/* 354 * If refname is a reference name, find the ref_dir within the dir 355 * tree that should hold refname. If refname is a directory name 356 * (i.e., ends in '/'), then return that ref_dir itself. dir must 357 * represent the top-level directory and must already be complete. 358 * Sort ref_dirs and recurse into subdirectories as necessary. If 359 * mkdir is set, then create any missing directories; otherwise, 360 * return NULL if the desired directory cannot be found. 361 */ 362static struct ref_dir *find_containing_dir(struct ref_dir *dir, 363 const char *refname, int mkdir) 364{ 365 const char *slash; 366 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 367 size_t dirnamelen = slash - refname + 1; 368 struct ref_dir *subdir; 369 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 370 if (!subdir) { 371 dir = NULL; 372 break; 373 } 374 dir = subdir; 375 } 376 377 return dir; 378} 379 380/* 381 * Find the value entry with the given name in dir, sorting ref_dirs 382 * and recursing into subdirectories as necessary. If the name is not 383 * found or it corresponds to a directory entry, return NULL. 384 */ 385static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) 386{ 387 int entry_index; 388 struct ref_entry *entry; 389 dir = find_containing_dir(dir, refname, 0); 390 if (!dir) 391 return NULL; 392 entry_index = search_ref_dir(dir, refname, strlen(refname)); 393 if (entry_index == -1) 394 return NULL; 395 entry = dir->entries[entry_index]; 396 return (entry->flag & REF_DIR) ? NULL : entry; 397} 398 399/* 400 * Remove the entry with the given name from dir, recursing into 401 * subdirectories as necessary. If refname is the name of a directory 402 * (i.e., ends with '/'), then remove the directory and its contents. 403 * If the removal was successful, return the number of entries 404 * remaining in the directory entry that contained the deleted entry. 405 * If the name was not found, return -1. Please note that this 406 * function only deletes the entry from the cache; it does not delete 407 * it from the filesystem or ensure that other cache entries (which 408 * might be symbolic references to the removed entry) are updated. 409 * Nor does it remove any containing dir entries that might be made 410 * empty by the removal. dir must represent the top-level directory 411 * and must already be complete. 412 */ 413static int remove_entry(struct ref_dir *dir, const char *refname) 414{ 415 int refname_len = strlen(refname); 416 int entry_index; 417 struct ref_entry *entry; 418 int is_dir = refname[refname_len - 1] == '/'; 419 if (is_dir) { 420 /* 421 * refname represents a reference directory. Remove 422 * the trailing slash; otherwise we will get the 423 * directory *representing* refname rather than the 424 * one *containing* it. 425 */ 426 char *dirname = xmemdupz(refname, refname_len - 1); 427 dir = find_containing_dir(dir, dirname, 0); 428 free(dirname); 429 } else { 430 dir = find_containing_dir(dir, refname, 0); 431 } 432 if (!dir) 433 return -1; 434 entry_index = search_ref_dir(dir, refname, refname_len); 435 if (entry_index == -1) 436 return -1; 437 entry = dir->entries[entry_index]; 438 439 memmove(&dir->entries[entry_index], 440 &dir->entries[entry_index + 1], 441 (dir->nr - entry_index - 1) * sizeof(*dir->entries) 442 ); 443 dir->nr--; 444 if (dir->sorted > entry_index) 445 dir->sorted--; 446 free_ref_entry(entry); 447 return dir->nr; 448} 449 450/* 451 * Add a ref_entry to the ref_dir (unsorted), recursing into 452 * subdirectories as necessary. dir must represent the top-level 453 * directory. Return 0 on success. 454 */ 455static int add_ref(struct ref_dir *dir, struct ref_entry *ref) 456{ 457 dir = find_containing_dir(dir, ref->name, 1); 458 if (!dir) 459 return -1; 460 add_entry_to_dir(dir, ref); 461 return 0; 462} 463 464/* 465 * Emit a warning and return true iff ref1 and ref2 have the same name 466 * and the same sha1. Die if they have the same name but different 467 * sha1s. 468 */ 469static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) 470{ 471 if (strcmp(ref1->name, ref2->name)) 472 return 0; 473 474 /* Duplicate name; make sure that they don't conflict: */ 475 476 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 477 /* This is impossible by construction */ 478 die("Reference directory conflict: %s", ref1->name); 479 480 if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 481 die("Duplicated ref, and SHA1s don't match: %s", ref1->name); 482 483 warning("Duplicated ref: %s", ref1->name); 484 return 1; 485} 486 487/* 488 * Sort the entries in dir non-recursively (if they are not already 489 * sorted) and remove any duplicate entries. 490 */ 491static void sort_ref_dir(struct ref_dir *dir) 492{ 493 int i, j; 494 struct ref_entry *last = NULL; 495 496 /* 497 * This check also prevents passing a zero-length array to qsort(), 498 * which is a problem on some platforms. 499 */ 500 if (dir->sorted == dir->nr) 501 return; 502 503 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 504 505 /* Remove any duplicates: */ 506 for (i = 0, j = 0; j < dir->nr; j++) { 507 struct ref_entry *entry = dir->entries[j]; 508 if (last && is_dup_ref(last, entry)) 509 free_ref_entry(entry); 510 else 511 last = dir->entries[i++] = entry; 512 } 513 dir->sorted = dir->nr = i; 514} 515 516/* 517 * Return true iff the reference described by entry can be resolved to 518 * an object in the database. Emit a warning if the referred-to 519 * object does not exist. 520 */ 521static int ref_resolves_to_object(struct ref_entry *entry) 522{ 523 if (entry->flag & REF_ISBROKEN) 524 return 0; 525 if (!has_sha1_file(entry->u.value.oid.hash)) { 526 error("%s does not point to a valid object!", entry->name); 527 return 0; 528 } 529 return 1; 530} 531 532/* 533 * current_ref is a performance hack: when iterating over references 534 * using the for_each_ref*() functions, current_ref is set to the 535 * current reference's entry before calling the callback function. If 536 * the callback function calls peel_ref(), then peel_ref() first 537 * checks whether the reference to be peeled is the current reference 538 * (it usually is) and if so, returns that reference's peeled version 539 * if it is available. This avoids a refname lookup in a common case. 540 */ 541static struct ref_entry *current_ref; 542 543typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); 544 545struct ref_entry_cb { 546 const char *base; 547 int trim; 548 int flags; 549 each_ref_fn *fn; 550 void *cb_data; 551}; 552 553/* 554 * Handle one reference in a do_for_each_ref*()-style iteration, 555 * calling an each_ref_fn for each entry. 556 */ 557static int do_one_ref(struct ref_entry *entry, void *cb_data) 558{ 559 struct ref_entry_cb *data = cb_data; 560 struct ref_entry *old_current_ref; 561 int retval; 562 563 if (!starts_with(entry->name, data->base)) 564 return 0; 565 566 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 567 !ref_resolves_to_object(entry)) 568 return 0; 569 570 /* Store the old value, in case this is a recursive call: */ 571 old_current_ref = current_ref; 572 current_ref = entry; 573 retval = data->fn(entry->name + data->trim, &entry->u.value.oid, 574 entry->flag, data->cb_data); 575 current_ref = old_current_ref; 576 return retval; 577} 578 579/* 580 * Call fn for each reference in dir that has index in the range 581 * offset <= index < dir->nr. Recurse into subdirectories that are in 582 * that index range, sorting them before iterating. This function 583 * does not sort dir itself; it should be sorted beforehand. fn is 584 * called for all references, including broken ones. 585 */ 586static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 587 each_ref_entry_fn fn, void *cb_data) 588{ 589 int i; 590 assert(dir->sorted == dir->nr); 591 for (i = offset; i < dir->nr; i++) { 592 struct ref_entry *entry = dir->entries[i]; 593 int retval; 594 if (entry->flag & REF_DIR) { 595 struct ref_dir *subdir = get_ref_dir(entry); 596 sort_ref_dir(subdir); 597 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 598 } else { 599 retval = fn(entry, cb_data); 600 } 601 if (retval) 602 return retval; 603 } 604 return 0; 605} 606 607/* 608 * Call fn for each reference in the union of dir1 and dir2, in order 609 * by refname. Recurse into subdirectories. If a value entry appears 610 * in both dir1 and dir2, then only process the version that is in 611 * dir2. The input dirs must already be sorted, but subdirs will be 612 * sorted as needed. fn is called for all references, including 613 * broken ones. 614 */ 615static int do_for_each_entry_in_dirs(struct ref_dir *dir1, 616 struct ref_dir *dir2, 617 each_ref_entry_fn fn, void *cb_data) 618{ 619 int retval; 620 int i1 = 0, i2 = 0; 621 622 assert(dir1->sorted == dir1->nr); 623 assert(dir2->sorted == dir2->nr); 624 while (1) { 625 struct ref_entry *e1, *e2; 626 int cmp; 627 if (i1 == dir1->nr) { 628 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); 629 } 630 if (i2 == dir2->nr) { 631 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); 632 } 633 e1 = dir1->entries[i1]; 634 e2 = dir2->entries[i2]; 635 cmp = strcmp(e1->name, e2->name); 636 if (cmp == 0) { 637 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 638 /* Both are directories; descend them in parallel. */ 639 struct ref_dir *subdir1 = get_ref_dir(e1); 640 struct ref_dir *subdir2 = get_ref_dir(e2); 641 sort_ref_dir(subdir1); 642 sort_ref_dir(subdir2); 643 retval = do_for_each_entry_in_dirs( 644 subdir1, subdir2, fn, cb_data); 645 i1++; 646 i2++; 647 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 648 /* Both are references; ignore the one from dir1. */ 649 retval = fn(e2, cb_data); 650 i1++; 651 i2++; 652 } else { 653 die("conflict between reference and directory: %s", 654 e1->name); 655 } 656 } else { 657 struct ref_entry *e; 658 if (cmp < 0) { 659 e = e1; 660 i1++; 661 } else { 662 e = e2; 663 i2++; 664 } 665 if (e->flag & REF_DIR) { 666 struct ref_dir *subdir = get_ref_dir(e); 667 sort_ref_dir(subdir); 668 retval = do_for_each_entry_in_dir( 669 subdir, 0, fn, cb_data); 670 } else { 671 retval = fn(e, cb_data); 672 } 673 } 674 if (retval) 675 return retval; 676 } 677} 678 679/* 680 * Load all of the refs from the dir into our in-memory cache. The hard work 681 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 682 * through all of the sub-directories. We do not even need to care about 683 * sorting, as traversal order does not matter to us. 684 */ 685static void prime_ref_dir(struct ref_dir *dir) 686{ 687 int i; 688 for (i = 0; i < dir->nr; i++) { 689 struct ref_entry *entry = dir->entries[i]; 690 if (entry->flag & REF_DIR) 691 prime_ref_dir(get_ref_dir(entry)); 692 } 693} 694 695struct nonmatching_ref_data { 696 const struct string_list *skip; 697 const char *conflicting_refname; 698}; 699 700static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) 701{ 702 struct nonmatching_ref_data *data = vdata; 703 704 if (data->skip && string_list_has_string(data->skip, entry->name)) 705 return 0; 706 707 data->conflicting_refname = entry->name; 708 return 1; 709} 710 711/* 712 * Return 0 if a reference named refname could be created without 713 * conflicting with the name of an existing reference in dir. 714 * See verify_refname_available for more information. 715 */ 716static int verify_refname_available_dir(const char *refname, 717 const struct string_list *extras, 718 const struct string_list *skip, 719 struct ref_dir *dir, 720 struct strbuf *err) 721{ 722 const char *slash; 723 const char *extra_refname; 724 int pos; 725 struct strbuf dirname = STRBUF_INIT; 726 int ret = -1; 727 728 /* 729 * For the sake of comments in this function, suppose that 730 * refname is "refs/foo/bar". 731 */ 732 733 assert(err); 734 735 strbuf_grow(&dirname, strlen(refname) + 1); 736 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 737 /* Expand dirname to the new prefix, not including the trailing slash: */ 738 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 739 740 /* 741 * We are still at a leading dir of the refname (e.g., 742 * "refs/foo"; if there is a reference with that name, 743 * it is a conflict, *unless* it is in skip. 744 */ 745 if (dir) { 746 pos = search_ref_dir(dir, dirname.buf, dirname.len); 747 if (pos >= 0 && 748 (!skip || !string_list_has_string(skip, dirname.buf))) { 749 /* 750 * We found a reference whose name is 751 * a proper prefix of refname; e.g., 752 * "refs/foo", and is not in skip. 753 */ 754 strbuf_addf(err, "'%s' exists; cannot create '%s'", 755 dirname.buf, refname); 756 goto cleanup; 757 } 758 } 759 760 if (extras && string_list_has_string(extras, dirname.buf) && 761 (!skip || !string_list_has_string(skip, dirname.buf))) { 762 strbuf_addf(err, "cannot process '%s' and '%s' at the same time", 763 refname, dirname.buf); 764 goto cleanup; 765 } 766 767 /* 768 * Otherwise, we can try to continue our search with 769 * the next component. So try to look up the 770 * directory, e.g., "refs/foo/". If we come up empty, 771 * we know there is nothing under this whole prefix, 772 * but even in that case we still have to continue the 773 * search for conflicts with extras. 774 */ 775 strbuf_addch(&dirname, '/'); 776 if (dir) { 777 pos = search_ref_dir(dir, dirname.buf, dirname.len); 778 if (pos < 0) { 779 /* 780 * There was no directory "refs/foo/", 781 * so there is nothing under this 782 * whole prefix. So there is no need 783 * to continue looking for conflicting 784 * references. But we need to continue 785 * looking for conflicting extras. 786 */ 787 dir = NULL; 788 } else { 789 dir = get_ref_dir(dir->entries[pos]); 790 } 791 } 792 } 793 794 /* 795 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 796 * There is no point in searching for a reference with that 797 * name, because a refname isn't considered to conflict with 798 * itself. But we still need to check for references whose 799 * names are in the "refs/foo/bar/" namespace, because they 800 * *do* conflict. 801 */ 802 strbuf_addstr(&dirname, refname + dirname.len); 803 strbuf_addch(&dirname, '/'); 804 805 if (dir) { 806 pos = search_ref_dir(dir, dirname.buf, dirname.len); 807 808 if (pos >= 0) { 809 /* 810 * We found a directory named "$refname/" 811 * (e.g., "refs/foo/bar/"). It is a problem 812 * iff it contains any ref that is not in 813 * "skip". 814 */ 815 struct nonmatching_ref_data data; 816 817 data.skip = skip; 818 data.conflicting_refname = NULL; 819 dir = get_ref_dir(dir->entries[pos]); 820 sort_ref_dir(dir); 821 if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { 822 strbuf_addf(err, "'%s' exists; cannot create '%s'", 823 data.conflicting_refname, refname); 824 goto cleanup; 825 } 826 } 827 } 828 829 extra_refname = find_descendant_ref(dirname.buf, extras, skip); 830 if (extra_refname) 831 strbuf_addf(err, "cannot process '%s' and '%s' at the same time", 832 refname, extra_refname); 833 else 834 ret = 0; 835 836cleanup: 837 strbuf_release(&dirname); 838 return ret; 839} 840 841struct packed_ref_cache { 842 struct ref_entry *root; 843 844 /* 845 * Count of references to the data structure in this instance, 846 * including the pointer from ref_cache::packed if any. The 847 * data will not be freed as long as the reference count is 848 * nonzero. 849 */ 850 unsigned int referrers; 851 852 /* 853 * Iff the packed-refs file associated with this instance is 854 * currently locked for writing, this points at the associated 855 * lock (which is owned by somebody else). The referrer count 856 * is also incremented when the file is locked and decremented 857 * when it is unlocked. 858 */ 859 struct lock_file *lock; 860 861 /* The metadata from when this packed-refs cache was read */ 862 struct stat_validity validity; 863}; 864 865/* 866 * Future: need to be in "struct repository" 867 * when doing a full libification. 868 */ 869static struct ref_cache { 870 struct ref_cache *next; 871 struct ref_entry *loose; 872 struct packed_ref_cache *packed; 873 /* 874 * The submodule name, or "" for the main repo. We allocate 875 * length 1 rather than FLEX_ARRAY so that the main ref_cache 876 * is initialized correctly. 877 */ 878 char name[1]; 879} ref_cache, *submodule_ref_caches; 880 881/* Lock used for the main packed-refs file: */ 882static struct lock_file packlock; 883 884/* 885 * Increment the reference count of *packed_refs. 886 */ 887static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 888{ 889 packed_refs->referrers++; 890} 891 892/* 893 * Decrease the reference count of *packed_refs. If it goes to zero, 894 * free *packed_refs and return true; otherwise return false. 895 */ 896static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 897{ 898 if (!--packed_refs->referrers) { 899 free_ref_entry(packed_refs->root); 900 stat_validity_clear(&packed_refs->validity); 901 free(packed_refs); 902 return 1; 903 } else { 904 return 0; 905 } 906} 907 908static void clear_packed_ref_cache(struct ref_cache *refs) 909{ 910 if (refs->packed) { 911 struct packed_ref_cache *packed_refs = refs->packed; 912 913 if (packed_refs->lock) 914 die("internal error: packed-ref cache cleared while locked"); 915 refs->packed = NULL; 916 release_packed_ref_cache(packed_refs); 917 } 918} 919 920static void clear_loose_ref_cache(struct ref_cache *refs) 921{ 922 if (refs->loose) { 923 free_ref_entry(refs->loose); 924 refs->loose = NULL; 925 } 926} 927 928/* 929 * Create a new submodule ref cache and add it to the internal 930 * set of caches. 931 */ 932static struct ref_cache *create_ref_cache(const char *submodule) 933{ 934 struct ref_cache *refs; 935 if (!submodule) 936 submodule = ""; 937 FLEX_ALLOC_STR(refs, name, submodule); 938 refs->next = submodule_ref_caches; 939 submodule_ref_caches = refs; 940 return refs; 941} 942 943static struct ref_cache *lookup_ref_cache(const char *submodule) 944{ 945 struct ref_cache *refs; 946 947 if (!submodule || !*submodule) 948 return &ref_cache; 949 950 for (refs = submodule_ref_caches; refs; refs = refs->next) 951 if (!strcmp(submodule, refs->name)) 952 return refs; 953 return NULL; 954} 955 956/* 957 * Return a pointer to a ref_cache for the specified submodule. For 958 * the main repository, use submodule==NULL. The returned structure 959 * will be allocated and initialized but not necessarily populated; it 960 * should not be freed. 961 */ 962static struct ref_cache *get_ref_cache(const char *submodule) 963{ 964 struct ref_cache *refs = lookup_ref_cache(submodule); 965 if (!refs) 966 refs = create_ref_cache(submodule); 967 return refs; 968} 969 970/* The length of a peeled reference line in packed-refs, including EOL: */ 971#define PEELED_LINE_LENGTH 42 972 973/* 974 * The packed-refs header line that we write out. Perhaps other 975 * traits will be added later. The trailing space is required. 976 */ 977static const char PACKED_REFS_HEADER[] = 978 "# pack-refs with: peeled fully-peeled \n"; 979 980/* 981 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 982 * Return a pointer to the refname within the line (null-terminated), 983 * or NULL if there was a problem. 984 */ 985static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1) 986{ 987 const char *ref; 988 989 /* 990 * 42: the answer to everything. 991 * 992 * In this case, it happens to be the answer to 993 * 40 (length of sha1 hex representation) 994 * +1 (space in between hex and name) 995 * +1 (newline at the end of the line) 996 */ 997 if (line->len <= 42) 998 return NULL; 9991000 if (get_sha1_hex(line->buf, sha1) < 0)1001 return NULL;1002 if (!isspace(line->buf[40]))1003 return NULL;10041005 ref = line->buf + 41;1006 if (isspace(*ref))1007 return NULL;10081009 if (line->buf[line->len - 1] != '\n')1010 return NULL;1011 line->buf[--line->len] = 0;10121013 return ref;1014}10151016/*1017 * Read f, which is a packed-refs file, into dir.1018 *1019 * A comment line of the form "# pack-refs with: " may contain zero or1020 * more traits. We interpret the traits as follows:1021 *1022 * No traits:1023 *1024 * Probably no references are peeled. But if the file contains a1025 * peeled value for a reference, we will use it.1026 *1027 * peeled:1028 *1029 * References under "refs/tags/", if they *can* be peeled, *are*1030 * peeled in this file. References outside of "refs/tags/" are1031 * probably not peeled even if they could have been, but if we find1032 * a peeled value for such a reference we will use it.1033 *1034 * fully-peeled:1035 *1036 * All references in the file that can be peeled are peeled.1037 * Inversely (and this is more important), any references in the1038 * file for which no peeled value is recorded is not peelable. This1039 * trait should typically be written alongside "peeled" for1040 * compatibility with older clients, but we do not require it1041 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1042 */1043static void read_packed_refs(FILE *f, struct ref_dir *dir)1044{1045 struct ref_entry *last = NULL;1046 struct strbuf line = STRBUF_INIT;1047 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10481049 while (strbuf_getwholeline(&line, f, '\n') != EOF) {1050 unsigned char sha1[20];1051 const char *refname;1052 const char *traits;10531054 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {1055 if (strstr(traits, " fully-peeled "))1056 peeled = PEELED_FULLY;1057 else if (strstr(traits, " peeled "))1058 peeled = PEELED_TAGS;1059 /* perhaps other traits later as well */1060 continue;1061 }10621063 refname = parse_ref_line(&line, sha1);1064 if (refname) {1065 int flag = REF_ISPACKED;10661067 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1068 if (!refname_is_safe(refname))1069 die("packed refname is dangerous: %s", refname);1070 hashclr(sha1);1071 flag |= REF_BAD_NAME | REF_ISBROKEN;1072 }1073 last = create_ref_entry(refname, sha1, flag, 0);1074 if (peeled == PEELED_FULLY ||1075 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1076 last->flag |= REF_KNOWS_PEELED;1077 add_ref(dir, last);1078 continue;1079 }1080 if (last &&1081 line.buf[0] == '^' &&1082 line.len == PEELED_LINE_LENGTH &&1083 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&1084 !get_sha1_hex(line.buf + 1, sha1)) {1085 hashcpy(last->u.value.peeled.hash, sha1);1086 /*1087 * Regardless of what the file header said,1088 * we definitely know the value of *this*1089 * reference:1090 */1091 last->flag |= REF_KNOWS_PEELED;1092 }1093 }10941095 strbuf_release(&line);1096}10971098/*1099 * Get the packed_ref_cache for the specified ref_cache, creating it1100 * if necessary.1101 */1102static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1103{1104 char *packed_refs_file;11051106 if (*refs->name)1107 packed_refs_file = git_pathdup_submodule(refs->name, "packed-refs");1108 else1109 packed_refs_file = git_pathdup("packed-refs");11101111 if (refs->packed &&1112 !stat_validity_check(&refs->packed->validity, packed_refs_file))1113 clear_packed_ref_cache(refs);11141115 if (!refs->packed) {1116 FILE *f;11171118 refs->packed = xcalloc(1, sizeof(*refs->packed));1119 acquire_packed_ref_cache(refs->packed);1120 refs->packed->root = create_dir_entry(refs, "", 0, 0);1121 f = fopen(packed_refs_file, "r");1122 if (f) {1123 stat_validity_update(&refs->packed->validity, fileno(f));1124 read_packed_refs(f, get_ref_dir(refs->packed->root));1125 fclose(f);1126 }1127 }1128 free(packed_refs_file);1129 return refs->packed;1130}11311132static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1133{1134 return get_ref_dir(packed_ref_cache->root);1135}11361137static struct ref_dir *get_packed_refs(struct ref_cache *refs)1138{1139 return get_packed_ref_dir(get_packed_ref_cache(refs));1140}11411142/*1143 * Add a reference to the in-memory packed reference cache. This may1144 * only be called while the packed-refs file is locked (see1145 * lock_packed_refs()). To actually write the packed-refs file, call1146 * commit_packed_refs().1147 */1148static void add_packed_ref(const char *refname, const unsigned char *sha1)1149{1150 struct packed_ref_cache *packed_ref_cache =1151 get_packed_ref_cache(&ref_cache);11521153 if (!packed_ref_cache->lock)1154 die("internal error: packed refs not locked");1155 add_ref(get_packed_ref_dir(packed_ref_cache),1156 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1157}11581159/*1160 * Read the loose references from the namespace dirname into dir1161 * (without recursing). dirname must end with '/'. dir must be the1162 * directory entry corresponding to dirname.1163 */1164static void read_loose_refs(const char *dirname, struct ref_dir *dir)1165{1166 struct ref_cache *refs = dir->ref_cache;1167 DIR *d;1168 struct dirent *de;1169 int dirnamelen = strlen(dirname);1170 struct strbuf refname;1171 struct strbuf path = STRBUF_INIT;1172 size_t path_baselen;11731174 if (*refs->name)1175 strbuf_git_path_submodule(&path, refs->name, "%s", dirname);1176 else1177 strbuf_git_path(&path, "%s", dirname);1178 path_baselen = path.len;11791180 d = opendir(path.buf);1181 if (!d) {1182 strbuf_release(&path);1183 return;1184 }11851186 strbuf_init(&refname, dirnamelen + 257);1187 strbuf_add(&refname, dirname, dirnamelen);11881189 while ((de = readdir(d)) != NULL) {1190 unsigned char sha1[20];1191 struct stat st;1192 int flag;11931194 if (de->d_name[0] == '.')1195 continue;1196 if (ends_with(de->d_name, ".lock"))1197 continue;1198 strbuf_addstr(&refname, de->d_name);1199 strbuf_addstr(&path, de->d_name);1200 if (stat(path.buf, &st) < 0) {1201 ; /* silently ignore */1202 } else if (S_ISDIR(st.st_mode)) {1203 strbuf_addch(&refname, '/');1204 add_entry_to_dir(dir,1205 create_dir_entry(refs, refname.buf,1206 refname.len, 1));1207 } else {1208 int read_ok;12091210 if (*refs->name) {1211 hashclr(sha1);1212 flag = 0;1213 read_ok = !resolve_gitlink_ref(refs->name,1214 refname.buf, sha1);1215 } else {1216 read_ok = !read_ref_full(refname.buf,1217 RESOLVE_REF_READING,1218 sha1, &flag);1219 }12201221 if (!read_ok) {1222 hashclr(sha1);1223 flag |= REF_ISBROKEN;1224 } else if (is_null_sha1(sha1)) {1225 /*1226 * It is so astronomically unlikely1227 * that NULL_SHA1 is the SHA-1 of an1228 * actual object that we consider its1229 * appearance in a loose reference1230 * file to be repo corruption1231 * (probably due to a software bug).1232 */1233 flag |= REF_ISBROKEN;1234 }12351236 if (check_refname_format(refname.buf,1237 REFNAME_ALLOW_ONELEVEL)) {1238 if (!refname_is_safe(refname.buf))1239 die("loose refname is dangerous: %s", refname.buf);1240 hashclr(sha1);1241 flag |= REF_BAD_NAME | REF_ISBROKEN;1242 }1243 add_entry_to_dir(dir,1244 create_ref_entry(refname.buf, sha1, flag, 0));1245 }1246 strbuf_setlen(&refname, dirnamelen);1247 strbuf_setlen(&path, path_baselen);1248 }1249 strbuf_release(&refname);1250 strbuf_release(&path);1251 closedir(d);1252}12531254static struct ref_dir *get_loose_refs(struct ref_cache *refs)1255{1256 if (!refs->loose) {1257 /*1258 * Mark the top-level directory complete because we1259 * are about to read the only subdirectory that can1260 * hold references:1261 */1262 refs->loose = create_dir_entry(refs, "", 0, 0);1263 /*1264 * Create an incomplete entry for "refs/":1265 */1266 add_entry_to_dir(get_ref_dir(refs->loose),1267 create_dir_entry(refs, "refs/", 5, 1));1268 }1269 return get_ref_dir(refs->loose);1270}12711272#define MAXREFLEN (1024)12731274/*1275 * Called by resolve_gitlink_ref_recursive() after it failed to read1276 * from the loose refs in ref_cache refs. Find <refname> in the1277 * packed-refs file for the submodule.1278 */1279static int resolve_gitlink_packed_ref(struct ref_cache *refs,1280 const char *refname, unsigned char *sha1)1281{1282 struct ref_entry *ref;1283 struct ref_dir *dir = get_packed_refs(refs);12841285 ref = find_ref(dir, refname);1286 if (ref == NULL)1287 return -1;12881289 hashcpy(sha1, ref->u.value.oid.hash);1290 return 0;1291}12921293static int resolve_gitlink_ref_recursive(struct ref_cache *refs,1294 const char *refname, unsigned char *sha1,1295 int recursion)1296{1297 int fd, len;1298 char buffer[128], *p;1299 char *path;13001301 if (recursion > SYMREF_MAXDEPTH || strlen(refname) > MAXREFLEN)1302 return -1;1303 path = *refs->name1304 ? git_pathdup_submodule(refs->name, "%s", refname)1305 : git_pathdup("%s", refname);1306 fd = open(path, O_RDONLY);1307 free(path);1308 if (fd < 0)1309 return resolve_gitlink_packed_ref(refs, refname, sha1);13101311 len = read(fd, buffer, sizeof(buffer)-1);1312 close(fd);1313 if (len < 0)1314 return -1;1315 while (len && isspace(buffer[len-1]))1316 len--;1317 buffer[len] = 0;13181319 /* Was it a detached head or an old-fashioned symlink? */1320 if (!get_sha1_hex(buffer, sha1))1321 return 0;13221323 /* Symref? */1324 if (strncmp(buffer, "ref:", 4))1325 return -1;1326 p = buffer + 4;1327 while (isspace(*p))1328 p++;13291330 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1331}13321333int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1334{1335 int len = strlen(path), retval;1336 struct strbuf submodule = STRBUF_INIT;1337 struct ref_cache *refs;13381339 while (len && path[len-1] == '/')1340 len--;1341 if (!len)1342 return -1;13431344 strbuf_add(&submodule, path, len);1345 refs = lookup_ref_cache(submodule.buf);1346 if (!refs) {1347 if (!is_nonbare_repository_dir(&submodule)) {1348 strbuf_release(&submodule);1349 return -1;1350 }1351 refs = create_ref_cache(submodule.buf);1352 }1353 strbuf_release(&submodule);13541355 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1356 return retval;1357}13581359/*1360 * Return the ref_entry for the given refname from the packed1361 * references. If it does not exist, return NULL.1362 */1363static struct ref_entry *get_packed_ref(const char *refname)1364{1365 return find_ref(get_packed_refs(&ref_cache), refname);1366}13671368/*1369 * A loose ref file doesn't exist; check for a packed ref.1370 */1371static int resolve_missing_loose_ref(const char *refname,1372 unsigned char *sha1,1373 unsigned int *flags)1374{1375 struct ref_entry *entry;13761377 /*1378 * The loose reference file does not exist; check for a packed1379 * reference.1380 */1381 entry = get_packed_ref(refname);1382 if (entry) {1383 hashcpy(sha1, entry->u.value.oid.hash);1384 *flags |= REF_ISPACKED;1385 return 0;1386 }1387 /* refname is not a packed reference. */1388 return -1;1389}13901391/*1392 * Read a raw ref from the filesystem or packed refs file.1393 *1394 * If the ref is a sha1, fill in sha1 and return 0.1395 *1396 * If the ref is symbolic, fill in *symref with the referrent1397 * (e.g. "refs/heads/master") and return 0. The caller is responsible1398 * for validating the referrent. Set REF_ISSYMREF in flags.1399 *1400 * If the ref doesn't exist, set errno to ENOENT and return -1.1401 *1402 * If the ref exists but is neither a symbolic ref nor a sha1, it is1403 * broken. Set REF_ISBROKEN in flags, set errno to EINVAL, and return1404 * -1.1405 *1406 * If there is another error reading the ref, set errno appropriately and1407 * return -1.1408 *1409 * Backend-specific flags might be set in flags as well, regardless of1410 * outcome.1411 *1412 * sb_path is workspace: the caller should allocate and free it.1413 *1414 * It is OK for refname to point into symref. In this case:1415 * - if the function succeeds with REF_ISSYMREF, symref will be1416 * overwritten and the memory pointed to by refname might be changed1417 * or even freed.1418 * - in all other cases, symref will be untouched, and therefore1419 * refname will still be valid and unchanged.1420 */1421int read_raw_ref(const char *refname, unsigned char *sha1,1422 struct strbuf *symref, unsigned int *flags)1423{1424 struct strbuf sb_contents = STRBUF_INIT;1425 struct strbuf sb_path = STRBUF_INIT;1426 const char *path;1427 const char *buf;1428 struct stat st;1429 int fd;1430 int ret = -1;1431 int save_errno;14321433 strbuf_reset(&sb_path);1434 strbuf_git_path(&sb_path, "%s", refname);1435 path = sb_path.buf;14361437stat_ref:1438 /*1439 * We might have to loop back here to avoid a race1440 * condition: first we lstat() the file, then we try1441 * to read it as a link or as a file. But if somebody1442 * changes the type of the file (file <-> directory1443 * <-> symlink) between the lstat() and reading, then1444 * we don't want to report that as an error but rather1445 * try again starting with the lstat().1446 */14471448 if (lstat(path, &st) < 0) {1449 if (errno != ENOENT)1450 goto out;1451 if (resolve_missing_loose_ref(refname, sha1, flags)) {1452 errno = ENOENT;1453 goto out;1454 }1455 ret = 0;1456 goto out;1457 }14581459 /* Follow "normalized" - ie "refs/.." symlinks by hand */1460 if (S_ISLNK(st.st_mode)) {1461 strbuf_reset(&sb_contents);1462 if (strbuf_readlink(&sb_contents, path, 0) < 0) {1463 if (errno == ENOENT || errno == EINVAL)1464 /* inconsistent with lstat; retry */1465 goto stat_ref;1466 else1467 goto out;1468 }1469 if (starts_with(sb_contents.buf, "refs/") &&1470 !check_refname_format(sb_contents.buf, 0)) {1471 strbuf_swap(&sb_contents, symref);1472 *flags |= REF_ISSYMREF;1473 ret = 0;1474 goto out;1475 }1476 }14771478 /* Is it a directory? */1479 if (S_ISDIR(st.st_mode)) {1480 /*1481 * Even though there is a directory where the loose1482 * ref is supposed to be, there could still be a1483 * packed ref:1484 */1485 if (resolve_missing_loose_ref(refname, sha1, flags)) {1486 errno = EISDIR;1487 goto out;1488 }1489 ret = 0;1490 goto out;1491 }14921493 /*1494 * Anything else, just open it and try to use it as1495 * a ref1496 */1497 fd = open(path, O_RDONLY);1498 if (fd < 0) {1499 if (errno == ENOENT)1500 /* inconsistent with lstat; retry */1501 goto stat_ref;1502 else1503 goto out;1504 }1505 strbuf_reset(&sb_contents);1506 if (strbuf_read(&sb_contents, fd, 256) < 0) {1507 int save_errno = errno;1508 close(fd);1509 errno = save_errno;1510 goto out;1511 }1512 close(fd);1513 strbuf_rtrim(&sb_contents);1514 buf = sb_contents.buf;1515 if (starts_with(buf, "ref:")) {1516 buf += 4;1517 while (isspace(*buf))1518 buf++;15191520 strbuf_reset(symref);1521 strbuf_addstr(symref, buf);1522 *flags |= REF_ISSYMREF;1523 ret = 0;1524 goto out;1525 }15261527 /*1528 * Please note that FETCH_HEAD has additional1529 * data after the sha.1530 */1531 if (get_sha1_hex(buf, sha1) ||1532 (buf[40] != '\0' && !isspace(buf[40]))) {1533 *flags |= REF_ISBROKEN;1534 errno = EINVAL;1535 goto out;1536 }15371538 ret = 0;15391540out:1541 save_errno = errno;1542 strbuf_release(&sb_path);1543 strbuf_release(&sb_contents);1544 errno = save_errno;1545 return ret;1546}15471548/*1549 * Peel the entry (if possible) and return its new peel_status. If1550 * repeel is true, re-peel the entry even if there is an old peeled1551 * value that is already stored in it.1552 *1553 * It is OK to call this function with a packed reference entry that1554 * might be stale and might even refer to an object that has since1555 * been garbage-collected. In such a case, if the entry has1556 * REF_KNOWS_PEELED then leave the status unchanged and return1557 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1558 */1559static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1560{1561 enum peel_status status;15621563 if (entry->flag & REF_KNOWS_PEELED) {1564 if (repeel) {1565 entry->flag &= ~REF_KNOWS_PEELED;1566 oidclr(&entry->u.value.peeled);1567 } else {1568 return is_null_oid(&entry->u.value.peeled) ?1569 PEEL_NON_TAG : PEEL_PEELED;1570 }1571 }1572 if (entry->flag & REF_ISBROKEN)1573 return PEEL_BROKEN;1574 if (entry->flag & REF_ISSYMREF)1575 return PEEL_IS_SYMREF;15761577 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1578 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1579 entry->flag |= REF_KNOWS_PEELED;1580 return status;1581}15821583int peel_ref(const char *refname, unsigned char *sha1)1584{1585 int flag;1586 unsigned char base[20];15871588 if (current_ref && (current_ref->name == refname1589 || !strcmp(current_ref->name, refname))) {1590 if (peel_entry(current_ref, 0))1591 return -1;1592 hashcpy(sha1, current_ref->u.value.peeled.hash);1593 return 0;1594 }15951596 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1597 return -1;15981599 /*1600 * If the reference is packed, read its ref_entry from the1601 * cache in the hope that we already know its peeled value.1602 * We only try this optimization on packed references because1603 * (a) forcing the filling of the loose reference cache could1604 * be expensive and (b) loose references anyway usually do not1605 * have REF_KNOWS_PEELED.1606 */1607 if (flag & REF_ISPACKED) {1608 struct ref_entry *r = get_packed_ref(refname);1609 if (r) {1610 if (peel_entry(r, 0))1611 return -1;1612 hashcpy(sha1, r->u.value.peeled.hash);1613 return 0;1614 }1615 }16161617 return peel_object(base, sha1);1618}16191620/*1621 * Call fn for each reference in the specified ref_cache, omitting1622 * references not in the containing_dir of base. fn is called for all1623 * references, including broken ones. If fn ever returns a non-zero1624 * value, stop the iteration and return that value; otherwise, return1625 * 0.1626 */1627static int do_for_each_entry(struct ref_cache *refs, const char *base,1628 each_ref_entry_fn fn, void *cb_data)1629{1630 struct packed_ref_cache *packed_ref_cache;1631 struct ref_dir *loose_dir;1632 struct ref_dir *packed_dir;1633 int retval = 0;16341635 /*1636 * We must make sure that all loose refs are read before accessing the1637 * packed-refs file; this avoids a race condition in which loose refs1638 * are migrated to the packed-refs file by a simultaneous process, but1639 * our in-memory view is from before the migration. get_packed_ref_cache()1640 * takes care of making sure our view is up to date with what is on1641 * disk.1642 */1643 loose_dir = get_loose_refs(refs);1644 if (base && *base) {1645 loose_dir = find_containing_dir(loose_dir, base, 0);1646 }1647 if (loose_dir)1648 prime_ref_dir(loose_dir);16491650 packed_ref_cache = get_packed_ref_cache(refs);1651 acquire_packed_ref_cache(packed_ref_cache);1652 packed_dir = get_packed_ref_dir(packed_ref_cache);1653 if (base && *base) {1654 packed_dir = find_containing_dir(packed_dir, base, 0);1655 }16561657 if (packed_dir && loose_dir) {1658 sort_ref_dir(packed_dir);1659 sort_ref_dir(loose_dir);1660 retval = do_for_each_entry_in_dirs(1661 packed_dir, loose_dir, fn, cb_data);1662 } else if (packed_dir) {1663 sort_ref_dir(packed_dir);1664 retval = do_for_each_entry_in_dir(1665 packed_dir, 0, fn, cb_data);1666 } else if (loose_dir) {1667 sort_ref_dir(loose_dir);1668 retval = do_for_each_entry_in_dir(1669 loose_dir, 0, fn, cb_data);1670 }16711672 release_packed_ref_cache(packed_ref_cache);1673 return retval;1674}16751676/*1677 * Call fn for each reference in the specified ref_cache for which the1678 * refname begins with base. If trim is non-zero, then trim that many1679 * characters off the beginning of each refname before passing the1680 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1681 * broken references in the iteration. If fn ever returns a non-zero1682 * value, stop the iteration and return that value; otherwise, return1683 * 0.1684 */1685int do_for_each_ref(const char *submodule, const char *base,1686 each_ref_fn fn, int trim, int flags, void *cb_data)1687{1688 struct ref_entry_cb data;1689 struct ref_cache *refs;16901691 refs = get_ref_cache(submodule);1692 data.base = base;1693 data.trim = trim;1694 data.flags = flags;1695 data.fn = fn;1696 data.cb_data = cb_data;16971698 if (ref_paranoia < 0)1699 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1700 if (ref_paranoia)1701 data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;17021703 return do_for_each_entry(refs, base, do_one_ref, &data);1704}17051706static void unlock_ref(struct ref_lock *lock)1707{1708 /* Do not free lock->lk -- atexit() still looks at them */1709 if (lock->lk)1710 rollback_lock_file(lock->lk);1711 free(lock->ref_name);1712 free(lock->orig_ref_name);1713 free(lock);1714}17151716/*1717 * Verify that the reference locked by lock has the value old_sha1.1718 * Fail if the reference doesn't exist and mustexist is set. Return 01719 * on success. On error, write an error message to err, set errno, and1720 * return a negative value.1721 */1722static int verify_lock(struct ref_lock *lock,1723 const unsigned char *old_sha1, int mustexist,1724 struct strbuf *err)1725{1726 assert(err);17271728 if (read_ref_full(lock->ref_name,1729 mustexist ? RESOLVE_REF_READING : 0,1730 lock->old_oid.hash, NULL)) {1731 if (old_sha1) {1732 int save_errno = errno;1733 strbuf_addf(err, "can't verify ref %s", lock->ref_name);1734 errno = save_errno;1735 return -1;1736 } else {1737 hashclr(lock->old_oid.hash);1738 return 0;1739 }1740 }1741 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1742 strbuf_addf(err, "ref %s is at %s but expected %s",1743 lock->ref_name,1744 sha1_to_hex(lock->old_oid.hash),1745 sha1_to_hex(old_sha1));1746 errno = EBUSY;1747 return -1;1748 }1749 return 0;1750}17511752static int remove_empty_directories(struct strbuf *path)1753{1754 /*1755 * we want to create a file but there is a directory there;1756 * if that is an empty directory (or a directory that contains1757 * only empty directories), remove them.1758 */1759 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1760}17611762/*1763 * Locks a ref returning the lock on success and NULL on failure.1764 * On failure errno is set to something meaningful.1765 */1766static struct ref_lock *lock_ref_sha1_basic(const char *refname,1767 const unsigned char *old_sha1,1768 const struct string_list *extras,1769 const struct string_list *skip,1770 unsigned int flags, int *type_p,1771 struct strbuf *err)1772{1773 struct strbuf ref_file = STRBUF_INIT;1774 struct strbuf orig_ref_file = STRBUF_INIT;1775 const char *orig_refname = refname;1776 struct ref_lock *lock;1777 int last_errno = 0;1778 int type;1779 int lflags = 0;1780 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1781 int resolve_flags = 0;1782 int attempts_remaining = 3;17831784 assert(err);17851786 lock = xcalloc(1, sizeof(struct ref_lock));17871788 if (mustexist)1789 resolve_flags |= RESOLVE_REF_READING;1790 if (flags & REF_DELETING)1791 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;1792 if (flags & REF_NODEREF) {1793 resolve_flags |= RESOLVE_REF_NO_RECURSE;1794 lflags |= LOCK_NO_DEREF;1795 }17961797 refname = resolve_ref_unsafe(refname, resolve_flags,1798 lock->old_oid.hash, &type);1799 if (!refname && errno == EISDIR) {1800 /*1801 * we are trying to lock foo but we used to1802 * have foo/bar which now does not exist;1803 * it is normal for the empty directory 'foo'1804 * to remain.1805 */1806 strbuf_git_path(&orig_ref_file, "%s", orig_refname);1807 if (remove_empty_directories(&orig_ref_file)) {1808 last_errno = errno;1809 if (!verify_refname_available_dir(orig_refname, extras, skip,1810 get_loose_refs(&ref_cache), err))1811 strbuf_addf(err, "there are still refs under '%s'",1812 orig_refname);1813 goto error_return;1814 }1815 refname = resolve_ref_unsafe(orig_refname, resolve_flags,1816 lock->old_oid.hash, &type);1817 }1818 if (type_p)1819 *type_p = type;1820 if (!refname) {1821 last_errno = errno;1822 if (last_errno != ENOTDIR ||1823 !verify_refname_available_dir(orig_refname, extras, skip,1824 get_loose_refs(&ref_cache), err))1825 strbuf_addf(err, "unable to resolve reference %s: %s",1826 orig_refname, strerror(last_errno));18271828 goto error_return;1829 }18301831 if (flags & REF_NODEREF)1832 refname = orig_refname;18331834 /*1835 * If the ref did not exist and we are creating it, make sure1836 * there is no existing packed ref whose name begins with our1837 * refname, nor a packed ref whose name is a proper prefix of1838 * our refname.1839 */1840 if (is_null_oid(&lock->old_oid) &&1841 verify_refname_available_dir(refname, extras, skip,1842 get_packed_refs(&ref_cache), err)) {1843 last_errno = ENOTDIR;1844 goto error_return;1845 }18461847 lock->lk = xcalloc(1, sizeof(struct lock_file));18481849 lock->ref_name = xstrdup(refname);1850 lock->orig_ref_name = xstrdup(orig_refname);1851 strbuf_git_path(&ref_file, "%s", refname);18521853 retry:1854 switch (safe_create_leading_directories_const(ref_file.buf)) {1855 case SCLD_OK:1856 break; /* success */1857 case SCLD_VANISHED:1858 if (--attempts_remaining > 0)1859 goto retry;1860 /* fall through */1861 default:1862 last_errno = errno;1863 strbuf_addf(err, "unable to create directory for %s",1864 ref_file.buf);1865 goto error_return;1866 }18671868 if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {1869 last_errno = errno;1870 if (errno == ENOENT && --attempts_remaining > 0)1871 /*1872 * Maybe somebody just deleted one of the1873 * directories leading to ref_file. Try1874 * again:1875 */1876 goto retry;1877 else {1878 unable_to_lock_message(ref_file.buf, errno, err);1879 goto error_return;1880 }1881 }1882 if (verify_lock(lock, old_sha1, mustexist, err)) {1883 last_errno = errno;1884 goto error_return;1885 }1886 goto out;18871888 error_return:1889 unlock_ref(lock);1890 lock = NULL;18911892 out:1893 strbuf_release(&ref_file);1894 strbuf_release(&orig_ref_file);1895 errno = last_errno;1896 return lock;1897}18981899/*1900 * Write an entry to the packed-refs file for the specified refname.1901 * If peeled is non-NULL, write it as the entry's peeled value.1902 */1903static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,1904 unsigned char *peeled)1905{1906 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);1907 if (peeled)1908 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));1909}19101911/*1912 * An each_ref_entry_fn that writes the entry to a packed-refs file.1913 */1914static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)1915{1916 enum peel_status peel_status = peel_entry(entry, 0);19171918 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)1919 error("internal error: %s is not a valid packed reference!",1920 entry->name);1921 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,1922 peel_status == PEEL_PEELED ?1923 entry->u.value.peeled.hash : NULL);1924 return 0;1925}19261927/*1928 * Lock the packed-refs file for writing. Flags is passed to1929 * hold_lock_file_for_update(). Return 0 on success. On errors, set1930 * errno appropriately and return a nonzero value.1931 */1932static int lock_packed_refs(int flags)1933{1934 static int timeout_configured = 0;1935 static int timeout_value = 1000;19361937 struct packed_ref_cache *packed_ref_cache;19381939 if (!timeout_configured) {1940 git_config_get_int("core.packedrefstimeout", &timeout_value);1941 timeout_configured = 1;1942 }19431944 if (hold_lock_file_for_update_timeout(1945 &packlock, git_path("packed-refs"),1946 flags, timeout_value) < 0)1947 return -1;1948 /*1949 * Get the current packed-refs while holding the lock. If the1950 * packed-refs file has been modified since we last read it,1951 * this will automatically invalidate the cache and re-read1952 * the packed-refs file.1953 */1954 packed_ref_cache = get_packed_ref_cache(&ref_cache);1955 packed_ref_cache->lock = &packlock;1956 /* Increment the reference count to prevent it from being freed: */1957 acquire_packed_ref_cache(packed_ref_cache);1958 return 0;1959}19601961/*1962 * Write the current version of the packed refs cache from memory to1963 * disk. The packed-refs file must already be locked for writing (see1964 * lock_packed_refs()). Return zero on success. On errors, set errno1965 * and return a nonzero value1966 */1967static int commit_packed_refs(void)1968{1969 struct packed_ref_cache *packed_ref_cache =1970 get_packed_ref_cache(&ref_cache);1971 int error = 0;1972 int save_errno = 0;1973 FILE *out;19741975 if (!packed_ref_cache->lock)1976 die("internal error: packed-refs not locked");19771978 out = fdopen_lock_file(packed_ref_cache->lock, "w");1979 if (!out)1980 die_errno("unable to fdopen packed-refs descriptor");19811982 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);1983 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),1984 0, write_packed_entry_fn, out);19851986 if (commit_lock_file(packed_ref_cache->lock)) {1987 save_errno = errno;1988 error = -1;1989 }1990 packed_ref_cache->lock = NULL;1991 release_packed_ref_cache(packed_ref_cache);1992 errno = save_errno;1993 return error;1994}19951996/*1997 * Rollback the lockfile for the packed-refs file, and discard the1998 * in-memory packed reference cache. (The packed-refs file will be1999 * read anew if it is needed again after this function is called.)2000 */2001static void rollback_packed_refs(void)2002{2003 struct packed_ref_cache *packed_ref_cache =2004 get_packed_ref_cache(&ref_cache);20052006 if (!packed_ref_cache->lock)2007 die("internal error: packed-refs not locked");2008 rollback_lock_file(packed_ref_cache->lock);2009 packed_ref_cache->lock = NULL;2010 release_packed_ref_cache(packed_ref_cache);2011 clear_packed_ref_cache(&ref_cache);2012}20132014struct ref_to_prune {2015 struct ref_to_prune *next;2016 unsigned char sha1[20];2017 char name[FLEX_ARRAY];2018};20192020struct pack_refs_cb_data {2021 unsigned int flags;2022 struct ref_dir *packed_refs;2023 struct ref_to_prune *ref_to_prune;2024};20252026/*2027 * An each_ref_entry_fn that is run over loose references only. If2028 * the loose reference can be packed, add an entry in the packed ref2029 * cache. If the reference should be pruned, also add it to2030 * ref_to_prune in the pack_refs_cb_data.2031 */2032static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2033{2034 struct pack_refs_cb_data *cb = cb_data;2035 enum peel_status peel_status;2036 struct ref_entry *packed_entry;2037 int is_tag_ref = starts_with(entry->name, "refs/tags/");20382039 /* Do not pack per-worktree refs: */2040 if (ref_type(entry->name) != REF_TYPE_NORMAL)2041 return 0;20422043 /* ALWAYS pack tags */2044 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2045 return 0;20462047 /* Do not pack symbolic or broken refs: */2048 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2049 return 0;20502051 /* Add a packed ref cache entry equivalent to the loose entry. */2052 peel_status = peel_entry(entry, 1);2053 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2054 die("internal error peeling reference %s (%s)",2055 entry->name, oid_to_hex(&entry->u.value.oid));2056 packed_entry = find_ref(cb->packed_refs, entry->name);2057 if (packed_entry) {2058 /* Overwrite existing packed entry with info from loose entry */2059 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2060 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2061 } else {2062 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,2063 REF_ISPACKED | REF_KNOWS_PEELED, 0);2064 add_ref(cb->packed_refs, packed_entry);2065 }2066 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);20672068 /* Schedule the loose reference for pruning if requested. */2069 if ((cb->flags & PACK_REFS_PRUNE)) {2070 struct ref_to_prune *n;2071 FLEX_ALLOC_STR(n, name, entry->name);2072 hashcpy(n->sha1, entry->u.value.oid.hash);2073 n->next = cb->ref_to_prune;2074 cb->ref_to_prune = n;2075 }2076 return 0;2077}20782079/*2080 * Remove empty parents, but spare refs/ and immediate subdirs.2081 * Note: munges *name.2082 */2083static void try_remove_empty_parents(char *name)2084{2085 char *p, *q;2086 int i;2087 p = name;2088 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2089 while (*p && *p != '/')2090 p++;2091 /* tolerate duplicate slashes; see check_refname_format() */2092 while (*p == '/')2093 p++;2094 }2095 for (q = p; *q; q++)2096 ;2097 while (1) {2098 while (q > p && *q != '/')2099 q--;2100 while (q > p && *(q-1) == '/')2101 q--;2102 if (q == p)2103 break;2104 *q = '\0';2105 if (rmdir(git_path("%s", name)))2106 break;2107 }2108}21092110/* make sure nobody touched the ref, and unlink */2111static void prune_ref(struct ref_to_prune *r)2112{2113 struct ref_transaction *transaction;2114 struct strbuf err = STRBUF_INIT;21152116 if (check_refname_format(r->name, 0))2117 return;21182119 transaction = ref_transaction_begin(&err);2120 if (!transaction ||2121 ref_transaction_delete(transaction, r->name, r->sha1,2122 REF_ISPRUNING, NULL, &err) ||2123 ref_transaction_commit(transaction, &err)) {2124 ref_transaction_free(transaction);2125 error("%s", err.buf);2126 strbuf_release(&err);2127 return;2128 }2129 ref_transaction_free(transaction);2130 strbuf_release(&err);2131 try_remove_empty_parents(r->name);2132}21332134static void prune_refs(struct ref_to_prune *r)2135{2136 while (r) {2137 prune_ref(r);2138 r = r->next;2139 }2140}21412142int pack_refs(unsigned int flags)2143{2144 struct pack_refs_cb_data cbdata;21452146 memset(&cbdata, 0, sizeof(cbdata));2147 cbdata.flags = flags;21482149 lock_packed_refs(LOCK_DIE_ON_ERROR);2150 cbdata.packed_refs = get_packed_refs(&ref_cache);21512152 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2153 pack_if_possible_fn, &cbdata);21542155 if (commit_packed_refs())2156 die_errno("unable to overwrite old ref-pack file");21572158 prune_refs(cbdata.ref_to_prune);2159 return 0;2160}21612162/*2163 * Rewrite the packed-refs file, omitting any refs listed in2164 * 'refnames'. On error, leave packed-refs unchanged, write an error2165 * message to 'err', and return a nonzero value.2166 *2167 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2168 */2169static int repack_without_refs(struct string_list *refnames, struct strbuf *err)2170{2171 struct ref_dir *packed;2172 struct string_list_item *refname;2173 int ret, needs_repacking = 0, removed = 0;21742175 assert(err);21762177 /* Look for a packed ref */2178 for_each_string_list_item(refname, refnames) {2179 if (get_packed_ref(refname->string)) {2180 needs_repacking = 1;2181 break;2182 }2183 }21842185 /* Avoid locking if we have nothing to do */2186 if (!needs_repacking)2187 return 0; /* no refname exists in packed refs */21882189 if (lock_packed_refs(0)) {2190 unable_to_lock_message(git_path("packed-refs"), errno, err);2191 return -1;2192 }2193 packed = get_packed_refs(&ref_cache);21942195 /* Remove refnames from the cache */2196 for_each_string_list_item(refname, refnames)2197 if (remove_entry(packed, refname->string) != -1)2198 removed = 1;2199 if (!removed) {2200 /*2201 * All packed entries disappeared while we were2202 * acquiring the lock.2203 */2204 rollback_packed_refs();2205 return 0;2206 }22072208 /* Write what remains */2209 ret = commit_packed_refs();2210 if (ret)2211 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2212 strerror(errno));2213 return ret;2214}22152216static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2217{2218 assert(err);22192220 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2221 /*2222 * loose. The loose file name is the same as the2223 * lockfile name, minus ".lock":2224 */2225 char *loose_filename = get_locked_file_path(lock->lk);2226 int res = unlink_or_msg(loose_filename, err);2227 free(loose_filename);2228 if (res)2229 return 1;2230 }2231 return 0;2232}22332234int delete_refs(struct string_list *refnames)2235{2236 struct strbuf err = STRBUF_INIT;2237 int i, result = 0;22382239 if (!refnames->nr)2240 return 0;22412242 result = repack_without_refs(refnames, &err);2243 if (result) {2244 /*2245 * If we failed to rewrite the packed-refs file, then2246 * it is unsafe to try to remove loose refs, because2247 * doing so might expose an obsolete packed value for2248 * a reference that might even point at an object that2249 * has been garbage collected.2250 */2251 if (refnames->nr == 1)2252 error(_("could not delete reference %s: %s"),2253 refnames->items[0].string, err.buf);2254 else2255 error(_("could not delete references: %s"), err.buf);22562257 goto out;2258 }22592260 for (i = 0; i < refnames->nr; i++) {2261 const char *refname = refnames->items[i].string;22622263 if (delete_ref(refname, NULL, 0))2264 result |= error(_("could not remove reference %s"), refname);2265 }22662267out:2268 strbuf_release(&err);2269 return result;2270}22712272/*2273 * People using contrib's git-new-workdir have .git/logs/refs ->2274 * /some/other/path/.git/logs/refs, and that may live on another device.2275 *2276 * IOW, to avoid cross device rename errors, the temporary renamed log must2277 * live into logs/refs.2278 */2279#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"22802281static int rename_tmp_log(const char *newrefname)2282{2283 int attempts_remaining = 4;2284 struct strbuf path = STRBUF_INIT;2285 int ret = -1;22862287 retry:2288 strbuf_reset(&path);2289 strbuf_git_path(&path, "logs/%s", newrefname);2290 switch (safe_create_leading_directories_const(path.buf)) {2291 case SCLD_OK:2292 break; /* success */2293 case SCLD_VANISHED:2294 if (--attempts_remaining > 0)2295 goto retry;2296 /* fall through */2297 default:2298 error("unable to create directory for %s", newrefname);2299 goto out;2300 }23012302 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {2303 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2304 /*2305 * rename(a, b) when b is an existing2306 * directory ought to result in ISDIR, but2307 * Solaris 5.8 gives ENOTDIR. Sheesh.2308 */2309 if (remove_empty_directories(&path)) {2310 error("Directory not empty: logs/%s", newrefname);2311 goto out;2312 }2313 goto retry;2314 } else if (errno == ENOENT && --attempts_remaining > 0) {2315 /*2316 * Maybe another process just deleted one of2317 * the directories in the path to newrefname.2318 * Try again from the beginning.2319 */2320 goto retry;2321 } else {2322 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2323 newrefname, strerror(errno));2324 goto out;2325 }2326 }2327 ret = 0;2328out:2329 strbuf_release(&path);2330 return ret;2331}23322333int verify_refname_available(const char *newname,2334 struct string_list *extras,2335 struct string_list *skip,2336 struct strbuf *err)2337{2338 struct ref_dir *packed_refs = get_packed_refs(&ref_cache);2339 struct ref_dir *loose_refs = get_loose_refs(&ref_cache);23402341 if (verify_refname_available_dir(newname, extras, skip,2342 packed_refs, err) ||2343 verify_refname_available_dir(newname, extras, skip,2344 loose_refs, err))2345 return -1;23462347 return 0;2348}23492350static int write_ref_to_lockfile(struct ref_lock *lock,2351 const unsigned char *sha1, struct strbuf *err);2352static int commit_ref_update(struct ref_lock *lock,2353 const unsigned char *sha1, const char *logmsg,2354 int flags, struct strbuf *err);23552356int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2357{2358 unsigned char sha1[20], orig_sha1[20];2359 int flag = 0, logmoved = 0;2360 struct ref_lock *lock;2361 struct stat loginfo;2362 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2363 const char *symref = NULL;2364 struct strbuf err = STRBUF_INIT;23652366 if (log && S_ISLNK(loginfo.st_mode))2367 return error("reflog for %s is a symlink", oldrefname);23682369 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2370 orig_sha1, &flag);2371 if (flag & REF_ISSYMREF)2372 return error("refname %s is a symbolic ref, renaming it is not supported",2373 oldrefname);2374 if (!symref)2375 return error("refname %s not found", oldrefname);23762377 if (!rename_ref_available(oldrefname, newrefname))2378 return 1;23792380 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2381 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2382 oldrefname, strerror(errno));23832384 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2385 error("unable to delete old %s", oldrefname);2386 goto rollback;2387 }23882389 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2390 delete_ref(newrefname, sha1, REF_NODEREF)) {2391 if (errno==EISDIR) {2392 struct strbuf path = STRBUF_INIT;2393 int result;23942395 strbuf_git_path(&path, "%s", newrefname);2396 result = remove_empty_directories(&path);2397 strbuf_release(&path);23982399 if (result) {2400 error("Directory not empty: %s", newrefname);2401 goto rollback;2402 }2403 } else {2404 error("unable to delete existing %s", newrefname);2405 goto rollback;2406 }2407 }24082409 if (log && rename_tmp_log(newrefname))2410 goto rollback;24112412 logmoved = log;24132414 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err);2415 if (!lock) {2416 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);2417 strbuf_release(&err);2418 goto rollback;2419 }2420 hashcpy(lock->old_oid.hash, orig_sha1);24212422 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2423 commit_ref_update(lock, orig_sha1, logmsg, 0, &err)) {2424 error("unable to write current sha1 into %s: %s", newrefname, err.buf);2425 strbuf_release(&err);2426 goto rollback;2427 }24282429 return 0;24302431 rollback:2432 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err);2433 if (!lock) {2434 error("unable to lock %s for rollback: %s", oldrefname, err.buf);2435 strbuf_release(&err);2436 goto rollbacklog;2437 }24382439 flag = log_all_ref_updates;2440 log_all_ref_updates = 0;2441 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2442 commit_ref_update(lock, orig_sha1, NULL, 0, &err)) {2443 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);2444 strbuf_release(&err);2445 }2446 log_all_ref_updates = flag;24472448 rollbacklog:2449 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2450 error("unable to restore logfile %s from %s: %s",2451 oldrefname, newrefname, strerror(errno));2452 if (!logmoved && log &&2453 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2454 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2455 oldrefname, strerror(errno));24562457 return 1;2458}24592460static int close_ref(struct ref_lock *lock)2461{2462 if (close_lock_file(lock->lk))2463 return -1;2464 return 0;2465}24662467static int commit_ref(struct ref_lock *lock)2468{2469 char *path = get_locked_file_path(lock->lk);2470 struct stat st;24712472 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {2473 /*2474 * There is a directory at the path we want to rename2475 * the lockfile to. Hopefully it is empty; try to2476 * delete it.2477 */2478 size_t len = strlen(path);2479 struct strbuf sb_path = STRBUF_INIT;24802481 strbuf_attach(&sb_path, path, len, len);24822483 /*2484 * If this fails, commit_lock_file() will also fail2485 * and will report the problem.2486 */2487 remove_empty_directories(&sb_path);2488 strbuf_release(&sb_path);2489 } else {2490 free(path);2491 }24922493 if (commit_lock_file(lock->lk))2494 return -1;2495 return 0;2496}24972498/*2499 * Create a reflog for a ref. If force_create = 0, the reflog will2500 * only be created for certain refs (those for which2501 * should_autocreate_reflog returns non-zero. Otherwise, create it2502 * regardless of the ref name. Fill in *err and return -1 on failure.2503 */2504static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)2505{2506 int logfd, oflags = O_APPEND | O_WRONLY;25072508 strbuf_git_path(logfile, "logs/%s", refname);2509 if (force_create || should_autocreate_reflog(refname)) {2510 if (safe_create_leading_directories(logfile->buf) < 0) {2511 strbuf_addf(err, "unable to create directory for %s: "2512 "%s", logfile->buf, strerror(errno));2513 return -1;2514 }2515 oflags |= O_CREAT;2516 }25172518 logfd = open(logfile->buf, oflags, 0666);2519 if (logfd < 0) {2520 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2521 return 0;25222523 if (errno == EISDIR) {2524 if (remove_empty_directories(logfile)) {2525 strbuf_addf(err, "There are still logs under "2526 "'%s'", logfile->buf);2527 return -1;2528 }2529 logfd = open(logfile->buf, oflags, 0666);2530 }25312532 if (logfd < 0) {2533 strbuf_addf(err, "unable to append to %s: %s",2534 logfile->buf, strerror(errno));2535 return -1;2536 }2537 }25382539 adjust_shared_perm(logfile->buf);2540 close(logfd);2541 return 0;2542}254325442545int safe_create_reflog(const char *refname, int force_create, struct strbuf *err)2546{2547 int ret;2548 struct strbuf sb = STRBUF_INIT;25492550 ret = log_ref_setup(refname, &sb, err, force_create);2551 strbuf_release(&sb);2552 return ret;2553}25542555static int log_ref_write_fd(int fd, const unsigned char *old_sha1,2556 const unsigned char *new_sha1,2557 const char *committer, const char *msg)2558{2559 int msglen, written;2560 unsigned maxlen, len;2561 char *logrec;25622563 msglen = msg ? strlen(msg) : 0;2564 maxlen = strlen(committer) + msglen + 100;2565 logrec = xmalloc(maxlen);2566 len = xsnprintf(logrec, maxlen, "%s %s %s\n",2567 sha1_to_hex(old_sha1),2568 sha1_to_hex(new_sha1),2569 committer);2570 if (msglen)2571 len += copy_reflog_msg(logrec + len - 1, msg) - 1;25722573 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2574 free(logrec);2575 if (written != len)2576 return -1;25772578 return 0;2579}25802581static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,2582 const unsigned char *new_sha1, const char *msg,2583 struct strbuf *logfile, int flags,2584 struct strbuf *err)2585{2586 int logfd, result, oflags = O_APPEND | O_WRONLY;25872588 if (log_all_ref_updates < 0)2589 log_all_ref_updates = !is_bare_repository();25902591 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);25922593 if (result)2594 return result;25952596 logfd = open(logfile->buf, oflags);2597 if (logfd < 0)2598 return 0;2599 result = log_ref_write_fd(logfd, old_sha1, new_sha1,2600 git_committer_info(0), msg);2601 if (result) {2602 strbuf_addf(err, "unable to append to %s: %s", logfile->buf,2603 strerror(errno));2604 close(logfd);2605 return -1;2606 }2607 if (close(logfd)) {2608 strbuf_addf(err, "unable to append to %s: %s", logfile->buf,2609 strerror(errno));2610 return -1;2611 }2612 return 0;2613}26142615static int log_ref_write(const char *refname, const unsigned char *old_sha1,2616 const unsigned char *new_sha1, const char *msg,2617 int flags, struct strbuf *err)2618{2619 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2620 err);2621}26222623int files_log_ref_write(const char *refname, const unsigned char *old_sha1,2624 const unsigned char *new_sha1, const char *msg,2625 int flags, struct strbuf *err)2626{2627 struct strbuf sb = STRBUF_INIT;2628 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2629 err);2630 strbuf_release(&sb);2631 return ret;2632}26332634/*2635 * Write sha1 into the open lockfile, then close the lockfile. On2636 * errors, rollback the lockfile, fill in *err and2637 * return -1.2638 */2639static int write_ref_to_lockfile(struct ref_lock *lock,2640 const unsigned char *sha1, struct strbuf *err)2641{2642 static char term = '\n';2643 struct object *o;2644 int fd;26452646 o = parse_object(sha1);2647 if (!o) {2648 strbuf_addf(err,2649 "Trying to write ref %s with nonexistent object %s",2650 lock->ref_name, sha1_to_hex(sha1));2651 unlock_ref(lock);2652 return -1;2653 }2654 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2655 strbuf_addf(err,2656 "Trying to write non-commit object %s to branch %s",2657 sha1_to_hex(sha1), lock->ref_name);2658 unlock_ref(lock);2659 return -1;2660 }2661 fd = get_lock_file_fd(lock->lk);2662 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||2663 write_in_full(fd, &term, 1) != 1 ||2664 close_ref(lock) < 0) {2665 strbuf_addf(err,2666 "Couldn't write %s", get_lock_file_path(lock->lk));2667 unlock_ref(lock);2668 return -1;2669 }2670 return 0;2671}26722673/*2674 * Commit a change to a loose reference that has already been written2675 * to the loose reference lockfile. Also update the reflogs if2676 * necessary, using the specified lockmsg (which can be NULL).2677 */2678static int commit_ref_update(struct ref_lock *lock,2679 const unsigned char *sha1, const char *logmsg,2680 int flags, struct strbuf *err)2681{2682 clear_loose_ref_cache(&ref_cache);2683 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0 ||2684 (strcmp(lock->ref_name, lock->orig_ref_name) &&2685 log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0)) {2686 char *old_msg = strbuf_detach(err, NULL);2687 strbuf_addf(err, "Cannot update the ref '%s': %s",2688 lock->ref_name, old_msg);2689 free(old_msg);2690 unlock_ref(lock);2691 return -1;2692 }2693 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {2694 /*2695 * Special hack: If a branch is updated directly and HEAD2696 * points to it (may happen on the remote side of a push2697 * for example) then logically the HEAD reflog should be2698 * updated too.2699 * A generic solution implies reverse symref information,2700 * but finding all symrefs pointing to the given branch2701 * would be rather costly for this rare event (the direct2702 * update of a branch) to be worth it. So let's cheat and2703 * check with HEAD only which should cover 99% of all usage2704 * scenarios (even 100% of the default ones).2705 */2706 unsigned char head_sha1[20];2707 int head_flag;2708 const char *head_ref;2709 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2710 head_sha1, &head_flag);2711 if (head_ref && (head_flag & REF_ISSYMREF) &&2712 !strcmp(head_ref, lock->ref_name)) {2713 struct strbuf log_err = STRBUF_INIT;2714 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,2715 logmsg, 0, &log_err)) {2716 error("%s", log_err.buf);2717 strbuf_release(&log_err);2718 }2719 }2720 }2721 if (commit_ref(lock)) {2722 strbuf_addf(err, "Couldn't set %s", lock->ref_name);2723 unlock_ref(lock);2724 return -1;2725 }27262727 unlock_ref(lock);2728 return 0;2729}27302731static int create_ref_symlink(struct ref_lock *lock, const char *target)2732{2733 int ret = -1;2734#ifndef NO_SYMLINK_HEAD2735 char *ref_path = get_locked_file_path(lock->lk);2736 unlink(ref_path);2737 ret = symlink(target, ref_path);2738 free(ref_path);27392740 if (ret)2741 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2742#endif2743 return ret;2744}27452746static void update_symref_reflog(struct ref_lock *lock, const char *refname,2747 const char *target, const char *logmsg)2748{2749 struct strbuf err = STRBUF_INIT;2750 unsigned char new_sha1[20];2751 if (logmsg && !read_ref(target, new_sha1) &&2752 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {2753 error("%s", err.buf);2754 strbuf_release(&err);2755 }2756}27572758static int create_symref_locked(struct ref_lock *lock, const char *refname,2759 const char *target, const char *logmsg)2760{2761 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {2762 update_symref_reflog(lock, refname, target, logmsg);2763 return 0;2764 }27652766 if (!fdopen_lock_file(lock->lk, "w"))2767 return error("unable to fdopen %s: %s",2768 lock->lk->tempfile.filename.buf, strerror(errno));27692770 update_symref_reflog(lock, refname, target, logmsg);27712772 /* no error check; commit_ref will check ferror */2773 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);2774 if (commit_ref(lock) < 0)2775 return error("unable to write symref for %s: %s", refname,2776 strerror(errno));2777 return 0;2778}27792780int create_symref(const char *refname, const char *target, const char *logmsg)2781{2782 struct strbuf err = STRBUF_INIT;2783 struct ref_lock *lock;2784 int ret;27852786 lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,2787 &err);2788 if (!lock) {2789 error("%s", err.buf);2790 strbuf_release(&err);2791 return -1;2792 }27932794 ret = create_symref_locked(lock, refname, target, logmsg);2795 unlock_ref(lock);2796 return ret;2797}27982799int set_worktree_head_symref(const char *gitdir, const char *target)2800{2801 static struct lock_file head_lock;2802 struct ref_lock *lock;2803 struct strbuf head_path = STRBUF_INIT;2804 const char *head_rel;2805 int ret;28062807 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));2808 if (hold_lock_file_for_update(&head_lock, head_path.buf,2809 LOCK_NO_DEREF) < 0) {2810 struct strbuf err = STRBUF_INIT;2811 unable_to_lock_message(head_path.buf, errno, &err);2812 error("%s", err.buf);2813 strbuf_release(&err);2814 strbuf_release(&head_path);2815 return -1;2816 }28172818 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for2819 linked trees */2820 head_rel = remove_leading_path(head_path.buf,2821 absolute_path(get_git_common_dir()));2822 /* to make use of create_symref_locked(), initialize ref_lock */2823 lock = xcalloc(1, sizeof(struct ref_lock));2824 lock->lk = &head_lock;2825 lock->ref_name = xstrdup(head_rel);2826 lock->orig_ref_name = xstrdup(head_rel);28272828 ret = create_symref_locked(lock, head_rel, target, NULL);28292830 unlock_ref(lock); /* will free lock */2831 strbuf_release(&head_path);2832 return ret;2833}28342835int reflog_exists(const char *refname)2836{2837 struct stat st;28382839 return !lstat(git_path("logs/%s", refname), &st) &&2840 S_ISREG(st.st_mode);2841}28422843int delete_reflog(const char *refname)2844{2845 return remove_path(git_path("logs/%s", refname));2846}28472848static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)2849{2850 unsigned char osha1[20], nsha1[20];2851 char *email_end, *message;2852 unsigned long timestamp;2853 int tz;28542855 /* old SP new SP name <email> SP time TAB msg LF */2856 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||2857 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||2858 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||2859 !(email_end = strchr(sb->buf + 82, '>')) ||2860 email_end[1] != ' ' ||2861 !(timestamp = strtoul(email_end + 2, &message, 10)) ||2862 !message || message[0] != ' ' ||2863 (message[1] != '+' && message[1] != '-') ||2864 !isdigit(message[2]) || !isdigit(message[3]) ||2865 !isdigit(message[4]) || !isdigit(message[5]))2866 return 0; /* corrupt? */2867 email_end[1] = '\0';2868 tz = strtol(message + 1, NULL, 10);2869 if (message[6] != '\t')2870 message += 6;2871 else2872 message += 7;2873 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);2874}28752876static char *find_beginning_of_line(char *bob, char *scan)2877{2878 while (bob < scan && *(--scan) != '\n')2879 ; /* keep scanning backwards */2880 /*2881 * Return either beginning of the buffer, or LF at the end of2882 * the previous line.2883 */2884 return scan;2885}28862887int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)2888{2889 struct strbuf sb = STRBUF_INIT;2890 FILE *logfp;2891 long pos;2892 int ret = 0, at_tail = 1;28932894 logfp = fopen(git_path("logs/%s", refname), "r");2895 if (!logfp)2896 return -1;28972898 /* Jump to the end */2899 if (fseek(logfp, 0, SEEK_END) < 0)2900 return error("cannot seek back reflog for %s: %s",2901 refname, strerror(errno));2902 pos = ftell(logfp);2903 while (!ret && 0 < pos) {2904 int cnt;2905 size_t nread;2906 char buf[BUFSIZ];2907 char *endp, *scanp;29082909 /* Fill next block from the end */2910 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;2911 if (fseek(logfp, pos - cnt, SEEK_SET))2912 return error("cannot seek back reflog for %s: %s",2913 refname, strerror(errno));2914 nread = fread(buf, cnt, 1, logfp);2915 if (nread != 1)2916 return error("cannot read %d bytes from reflog for %s: %s",2917 cnt, refname, strerror(errno));2918 pos -= cnt;29192920 scanp = endp = buf + cnt;2921 if (at_tail && scanp[-1] == '\n')2922 /* Looking at the final LF at the end of the file */2923 scanp--;2924 at_tail = 0;29252926 while (buf < scanp) {2927 /*2928 * terminating LF of the previous line, or the beginning2929 * of the buffer.2930 */2931 char *bp;29322933 bp = find_beginning_of_line(buf, scanp);29342935 if (*bp == '\n') {2936 /*2937 * The newline is the end of the previous line,2938 * so we know we have complete line starting2939 * at (bp + 1). Prefix it onto any prior data2940 * we collected for the line and process it.2941 */2942 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));2943 scanp = bp;2944 endp = bp + 1;2945 ret = show_one_reflog_ent(&sb, fn, cb_data);2946 strbuf_reset(&sb);2947 if (ret)2948 break;2949 } else if (!pos) {2950 /*2951 * We are at the start of the buffer, and the2952 * start of the file; there is no previous2953 * line, and we have everything for this one.2954 * Process it, and we can end the loop.2955 */2956 strbuf_splice(&sb, 0, 0, buf, endp - buf);2957 ret = show_one_reflog_ent(&sb, fn, cb_data);2958 strbuf_reset(&sb);2959 break;2960 }29612962 if (bp == buf) {2963 /*2964 * We are at the start of the buffer, and there2965 * is more file to read backwards. Which means2966 * we are in the middle of a line. Note that we2967 * may get here even if *bp was a newline; that2968 * just means we are at the exact end of the2969 * previous line, rather than some spot in the2970 * middle.2971 *2972 * Save away what we have to be combined with2973 * the data from the next read.2974 */2975 strbuf_splice(&sb, 0, 0, buf, endp - buf);2976 break;2977 }2978 }29792980 }2981 if (!ret && sb.len)2982 die("BUG: reverse reflog parser had leftover data");29832984 fclose(logfp);2985 strbuf_release(&sb);2986 return ret;2987}29882989int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)2990{2991 FILE *logfp;2992 struct strbuf sb = STRBUF_INIT;2993 int ret = 0;29942995 logfp = fopen(git_path("logs/%s", refname), "r");2996 if (!logfp)2997 return -1;29982999 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3000 ret = show_one_reflog_ent(&sb, fn, cb_data);3001 fclose(logfp);3002 strbuf_release(&sb);3003 return ret;3004}3005/*3006 * Call fn for each reflog in the namespace indicated by name. name3007 * must be empty or end with '/'. Name will be used as a scratch3008 * space, but its contents will be restored before return.3009 */3010static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)3011{3012 DIR *d = opendir(git_path("logs/%s", name->buf));3013 int retval = 0;3014 struct dirent *de;3015 int oldlen = name->len;30163017 if (!d)3018 return name->len ? errno : 0;30193020 while ((de = readdir(d)) != NULL) {3021 struct stat st;30223023 if (de->d_name[0] == '.')3024 continue;3025 if (ends_with(de->d_name, ".lock"))3026 continue;3027 strbuf_addstr(name, de->d_name);3028 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3029 ; /* silently ignore */3030 } else {3031 if (S_ISDIR(st.st_mode)) {3032 strbuf_addch(name, '/');3033 retval = do_for_each_reflog(name, fn, cb_data);3034 } else {3035 struct object_id oid;30363037 if (read_ref_full(name->buf, 0, oid.hash, NULL))3038 retval = error("bad ref for %s", name->buf);3039 else3040 retval = fn(name->buf, &oid, 0, cb_data);3041 }3042 if (retval)3043 break;3044 }3045 strbuf_setlen(name, oldlen);3046 }3047 closedir(d);3048 return retval;3049}30503051int for_each_reflog(each_ref_fn fn, void *cb_data)3052{3053 int retval;3054 struct strbuf name;3055 strbuf_init(&name, PATH_MAX);3056 retval = do_for_each_reflog(&name, fn, cb_data);3057 strbuf_release(&name);3058 return retval;3059}30603061static int ref_update_reject_duplicates(struct string_list *refnames,3062 struct strbuf *err)3063{3064 int i, n = refnames->nr;30653066 assert(err);30673068 for (i = 1; i < n; i++)3069 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {3070 strbuf_addf(err,3071 "Multiple updates for ref '%s' not allowed.",3072 refnames->items[i].string);3073 return 1;3074 }3075 return 0;3076}30773078int ref_transaction_commit(struct ref_transaction *transaction,3079 struct strbuf *err)3080{3081 int ret = 0, i;3082 int n = transaction->nr;3083 struct ref_update **updates = transaction->updates;3084 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3085 struct string_list_item *ref_to_delete;3086 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;30873088 assert(err);30893090 if (transaction->state != REF_TRANSACTION_OPEN)3091 die("BUG: commit called for transaction that is not open");30923093 if (!n) {3094 transaction->state = REF_TRANSACTION_CLOSED;3095 return 0;3096 }30973098 /* Fail if a refname appears more than once in the transaction: */3099 for (i = 0; i < n; i++)3100 string_list_append(&affected_refnames, updates[i]->refname);3101 string_list_sort(&affected_refnames);3102 if (ref_update_reject_duplicates(&affected_refnames, err)) {3103 ret = TRANSACTION_GENERIC_ERROR;3104 goto cleanup;3105 }31063107 /*3108 * Acquire all locks, verify old values if provided, check3109 * that new values are valid, and write new values to the3110 * lockfiles, ready to be activated. Only keep one lockfile3111 * open at a time to avoid running out of file descriptors.3112 */3113 for (i = 0; i < n; i++) {3114 struct ref_update *update = updates[i];31153116 if ((update->flags & REF_HAVE_NEW) &&3117 is_null_sha1(update->new_sha1))3118 update->flags |= REF_DELETING;3119 update->lock = lock_ref_sha1_basic(3120 update->refname,3121 ((update->flags & REF_HAVE_OLD) ?3122 update->old_sha1 : NULL),3123 &affected_refnames, NULL,3124 update->flags,3125 &update->type,3126 err);3127 if (!update->lock) {3128 char *reason;31293130 ret = (errno == ENOTDIR)3131 ? TRANSACTION_NAME_CONFLICT3132 : TRANSACTION_GENERIC_ERROR;3133 reason = strbuf_detach(err, NULL);3134 strbuf_addf(err, "cannot lock ref '%s': %s",3135 update->refname, reason);3136 free(reason);3137 goto cleanup;3138 }3139 if ((update->flags & REF_HAVE_NEW) &&3140 !(update->flags & REF_DELETING)) {3141 int overwriting_symref = ((update->type & REF_ISSYMREF) &&3142 (update->flags & REF_NODEREF));31433144 if (!overwriting_symref &&3145 !hashcmp(update->lock->old_oid.hash, update->new_sha1)) {3146 /*3147 * The reference already has the desired3148 * value, so we don't need to write it.3149 */3150 } else if (write_ref_to_lockfile(update->lock,3151 update->new_sha1,3152 err)) {3153 char *write_err = strbuf_detach(err, NULL);31543155 /*3156 * The lock was freed upon failure of3157 * write_ref_to_lockfile():3158 */3159 update->lock = NULL;3160 strbuf_addf(err,3161 "cannot update the ref '%s': %s",3162 update->refname, write_err);3163 free(write_err);3164 ret = TRANSACTION_GENERIC_ERROR;3165 goto cleanup;3166 } else {3167 update->flags |= REF_NEEDS_COMMIT;3168 }3169 }3170 if (!(update->flags & REF_NEEDS_COMMIT)) {3171 /*3172 * We didn't have to write anything to the lockfile.3173 * Close it to free up the file descriptor:3174 */3175 if (close_ref(update->lock)) {3176 strbuf_addf(err, "Couldn't close %s.lock",3177 update->refname);3178 goto cleanup;3179 }3180 }3181 }31823183 /* Perform updates first so live commits remain referenced */3184 for (i = 0; i < n; i++) {3185 struct ref_update *update = updates[i];31863187 if (update->flags & REF_NEEDS_COMMIT) {3188 if (commit_ref_update(update->lock,3189 update->new_sha1, update->msg,3190 update->flags, err)) {3191 /* freed by commit_ref_update(): */3192 update->lock = NULL;3193 ret = TRANSACTION_GENERIC_ERROR;3194 goto cleanup;3195 } else {3196 /* freed by commit_ref_update(): */3197 update->lock = NULL;3198 }3199 }3200 }32013202 /* Perform deletes now that updates are safely completed */3203 for (i = 0; i < n; i++) {3204 struct ref_update *update = updates[i];32053206 if (update->flags & REF_DELETING) {3207 if (delete_ref_loose(update->lock, update->type, err)) {3208 ret = TRANSACTION_GENERIC_ERROR;3209 goto cleanup;3210 }32113212 if (!(update->flags & REF_ISPRUNING))3213 string_list_append(&refs_to_delete,3214 update->lock->ref_name);3215 }3216 }32173218 if (repack_without_refs(&refs_to_delete, err)) {3219 ret = TRANSACTION_GENERIC_ERROR;3220 goto cleanup;3221 }3222 for_each_string_list_item(ref_to_delete, &refs_to_delete)3223 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3224 clear_loose_ref_cache(&ref_cache);32253226cleanup:3227 transaction->state = REF_TRANSACTION_CLOSED;32283229 for (i = 0; i < n; i++)3230 if (updates[i]->lock)3231 unlock_ref(updates[i]->lock);3232 string_list_clear(&refs_to_delete, 0);3233 string_list_clear(&affected_refnames, 0);3234 return ret;3235}32363237static int ref_present(const char *refname,3238 const struct object_id *oid, int flags, void *cb_data)3239{3240 struct string_list *affected_refnames = cb_data;32413242 return string_list_has_string(affected_refnames, refname);3243}32443245int initial_ref_transaction_commit(struct ref_transaction *transaction,3246 struct strbuf *err)3247{3248 int ret = 0, i;3249 int n = transaction->nr;3250 struct ref_update **updates = transaction->updates;3251 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;32523253 assert(err);32543255 if (transaction->state != REF_TRANSACTION_OPEN)3256 die("BUG: commit called for transaction that is not open");32573258 /* Fail if a refname appears more than once in the transaction: */3259 for (i = 0; i < n; i++)3260 string_list_append(&affected_refnames, updates[i]->refname);3261 string_list_sort(&affected_refnames);3262 if (ref_update_reject_duplicates(&affected_refnames, err)) {3263 ret = TRANSACTION_GENERIC_ERROR;3264 goto cleanup;3265 }32663267 /*3268 * It's really undefined to call this function in an active3269 * repository or when there are existing references: we are3270 * only locking and changing packed-refs, so (1) any3271 * simultaneous processes might try to change a reference at3272 * the same time we do, and (2) any existing loose versions of3273 * the references that we are setting would have precedence3274 * over our values. But some remote helpers create the remote3275 * "HEAD" and "master" branches before calling this function,3276 * so here we really only check that none of the references3277 * that we are creating already exists.3278 */3279 if (for_each_rawref(ref_present, &affected_refnames))3280 die("BUG: initial ref transaction called with existing refs");32813282 for (i = 0; i < n; i++) {3283 struct ref_update *update = updates[i];32843285 if ((update->flags & REF_HAVE_OLD) &&3286 !is_null_sha1(update->old_sha1))3287 die("BUG: initial ref transaction with old_sha1 set");3288 if (verify_refname_available(update->refname,3289 &affected_refnames, NULL,3290 err)) {3291 ret = TRANSACTION_NAME_CONFLICT;3292 goto cleanup;3293 }3294 }32953296 if (lock_packed_refs(0)) {3297 strbuf_addf(err, "unable to lock packed-refs file: %s",3298 strerror(errno));3299 ret = TRANSACTION_GENERIC_ERROR;3300 goto cleanup;3301 }33023303 for (i = 0; i < n; i++) {3304 struct ref_update *update = updates[i];33053306 if ((update->flags & REF_HAVE_NEW) &&3307 !is_null_sha1(update->new_sha1))3308 add_packed_ref(update->refname, update->new_sha1);3309 }33103311 if (commit_packed_refs()) {3312 strbuf_addf(err, "unable to commit packed-refs file: %s",3313 strerror(errno));3314 ret = TRANSACTION_GENERIC_ERROR;3315 goto cleanup;3316 }33173318cleanup:3319 transaction->state = REF_TRANSACTION_CLOSED;3320 string_list_clear(&affected_refnames, 0);3321 return ret;3322}33233324struct expire_reflog_cb {3325 unsigned int flags;3326 reflog_expiry_should_prune_fn *should_prune_fn;3327 void *policy_cb;3328 FILE *newlog;3329 unsigned char last_kept_sha1[20];3330};33313332static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,3333 const char *email, unsigned long timestamp, int tz,3334 const char *message, void *cb_data)3335{3336 struct expire_reflog_cb *cb = cb_data;3337 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;33383339 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3340 osha1 = cb->last_kept_sha1;33413342 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3343 message, policy_cb)) {3344 if (!cb->newlog)3345 printf("would prune %s", message);3346 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3347 printf("prune %s", message);3348 } else {3349 if (cb->newlog) {3350 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",3351 sha1_to_hex(osha1), sha1_to_hex(nsha1),3352 email, timestamp, tz, message);3353 hashcpy(cb->last_kept_sha1, nsha1);3354 }3355 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3356 printf("keep %s", message);3357 }3358 return 0;3359}33603361int reflog_expire(const char *refname, const unsigned char *sha1,3362 unsigned int flags,3363 reflog_expiry_prepare_fn prepare_fn,3364 reflog_expiry_should_prune_fn should_prune_fn,3365 reflog_expiry_cleanup_fn cleanup_fn,3366 void *policy_cb_data)3367{3368 static struct lock_file reflog_lock;3369 struct expire_reflog_cb cb;3370 struct ref_lock *lock;3371 char *log_file;3372 int status = 0;3373 int type;3374 struct strbuf err = STRBUF_INIT;33753376 memset(&cb, 0, sizeof(cb));3377 cb.flags = flags;3378 cb.policy_cb = policy_cb_data;3379 cb.should_prune_fn = should_prune_fn;33803381 /*3382 * The reflog file is locked by holding the lock on the3383 * reference itself, plus we might need to update the3384 * reference if --updateref was specified:3385 */3386 lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,3387 &type, &err);3388 if (!lock) {3389 error("cannot lock ref '%s': %s", refname, err.buf);3390 strbuf_release(&err);3391 return -1;3392 }3393 if (!reflog_exists(refname)) {3394 unlock_ref(lock);3395 return 0;3396 }33973398 log_file = git_pathdup("logs/%s", refname);3399 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3400 /*3401 * Even though holding $GIT_DIR/logs/$reflog.lock has3402 * no locking implications, we use the lock_file3403 * machinery here anyway because it does a lot of the3404 * work we need, including cleaning up if the program3405 * exits unexpectedly.3406 */3407 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {3408 struct strbuf err = STRBUF_INIT;3409 unable_to_lock_message(log_file, errno, &err);3410 error("%s", err.buf);3411 strbuf_release(&err);3412 goto failure;3413 }3414 cb.newlog = fdopen_lock_file(&reflog_lock, "w");3415 if (!cb.newlog) {3416 error("cannot fdopen %s (%s)",3417 get_lock_file_path(&reflog_lock), strerror(errno));3418 goto failure;3419 }3420 }34213422 (*prepare_fn)(refname, sha1, cb.policy_cb);3423 for_each_reflog_ent(refname, expire_reflog_ent, &cb);3424 (*cleanup_fn)(cb.policy_cb);34253426 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3427 /*3428 * It doesn't make sense to adjust a reference pointed3429 * to by a symbolic ref based on expiring entries in3430 * the symbolic reference's reflog. Nor can we update3431 * a reference if there are no remaining reflog3432 * entries.3433 */3434 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3435 !(type & REF_ISSYMREF) &&3436 !is_null_sha1(cb.last_kept_sha1);34373438 if (close_lock_file(&reflog_lock)) {3439 status |= error("couldn't write %s: %s", log_file,3440 strerror(errno));3441 } else if (update &&3442 (write_in_full(get_lock_file_fd(lock->lk),3443 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||3444 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||3445 close_ref(lock) < 0)) {3446 status |= error("couldn't write %s",3447 get_lock_file_path(lock->lk));3448 rollback_lock_file(&reflog_lock);3449 } else if (commit_lock_file(&reflog_lock)) {3450 status |= error("unable to write reflog '%s' (%s)",3451 log_file, strerror(errno));3452 } else if (update && commit_ref(lock)) {3453 status |= error("couldn't set %s", lock->ref_name);3454 }3455 }3456 free(log_file);3457 unlock_ref(lock);3458 return status;34593460 failure:3461 rollback_lock_file(&reflog_lock);3462 free(log_file);3463 unlock_ref(lock);3464 return -1;3465}