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}13901391int read_raw_ref(const char *refname, unsigned char *sha1,1392 struct strbuf *referent, unsigned int *type)1393{1394 struct strbuf sb_contents = STRBUF_INIT;1395 struct strbuf sb_path = STRBUF_INIT;1396 const char *path;1397 const char *buf;1398 struct stat st;1399 int fd;1400 int ret = -1;1401 int save_errno;14021403 *type = 0;1404 strbuf_reset(&sb_path);1405 strbuf_git_path(&sb_path, "%s", refname);1406 path = sb_path.buf;14071408stat_ref:1409 /*1410 * We might have to loop back here to avoid a race1411 * condition: first we lstat() the file, then we try1412 * to read it as a link or as a file. But if somebody1413 * changes the type of the file (file <-> directory1414 * <-> symlink) between the lstat() and reading, then1415 * we don't want to report that as an error but rather1416 * try again starting with the lstat().1417 */14181419 if (lstat(path, &st) < 0) {1420 if (errno != ENOENT)1421 goto out;1422 if (resolve_missing_loose_ref(refname, sha1, type)) {1423 errno = ENOENT;1424 goto out;1425 }1426 ret = 0;1427 goto out;1428 }14291430 /* Follow "normalized" - ie "refs/.." symlinks by hand */1431 if (S_ISLNK(st.st_mode)) {1432 strbuf_reset(&sb_contents);1433 if (strbuf_readlink(&sb_contents, path, 0) < 0) {1434 if (errno == ENOENT || errno == EINVAL)1435 /* inconsistent with lstat; retry */1436 goto stat_ref;1437 else1438 goto out;1439 }1440 if (starts_with(sb_contents.buf, "refs/") &&1441 !check_refname_format(sb_contents.buf, 0)) {1442 strbuf_swap(&sb_contents, referent);1443 *type |= REF_ISSYMREF;1444 ret = 0;1445 goto out;1446 }1447 }14481449 /* Is it a directory? */1450 if (S_ISDIR(st.st_mode)) {1451 /*1452 * Even though there is a directory where the loose1453 * ref is supposed to be, there could still be a1454 * packed ref:1455 */1456 if (resolve_missing_loose_ref(refname, sha1, type)) {1457 errno = EISDIR;1458 goto out;1459 }1460 ret = 0;1461 goto out;1462 }14631464 /*1465 * Anything else, just open it and try to use it as1466 * a ref1467 */1468 fd = open(path, O_RDONLY);1469 if (fd < 0) {1470 if (errno == ENOENT)1471 /* inconsistent with lstat; retry */1472 goto stat_ref;1473 else1474 goto out;1475 }1476 strbuf_reset(&sb_contents);1477 if (strbuf_read(&sb_contents, fd, 256) < 0) {1478 int save_errno = errno;1479 close(fd);1480 errno = save_errno;1481 goto out;1482 }1483 close(fd);1484 strbuf_rtrim(&sb_contents);1485 buf = sb_contents.buf;1486 if (starts_with(buf, "ref:")) {1487 buf += 4;1488 while (isspace(*buf))1489 buf++;14901491 strbuf_reset(referent);1492 strbuf_addstr(referent, buf);1493 *type |= REF_ISSYMREF;1494 ret = 0;1495 goto out;1496 }14971498 /*1499 * Please note that FETCH_HEAD has additional1500 * data after the sha.1501 */1502 if (get_sha1_hex(buf, sha1) ||1503 (buf[40] != '\0' && !isspace(buf[40]))) {1504 *type |= REF_ISBROKEN;1505 errno = EINVAL;1506 goto out;1507 }15081509 ret = 0;15101511out:1512 save_errno = errno;1513 strbuf_release(&sb_path);1514 strbuf_release(&sb_contents);1515 errno = save_errno;1516 return ret;1517}15181519static void unlock_ref(struct ref_lock *lock)1520{1521 /* Do not free lock->lk -- atexit() still looks at them */1522 if (lock->lk)1523 rollback_lock_file(lock->lk);1524 free(lock->ref_name);1525 free(lock->orig_ref_name);1526 free(lock);1527}15281529/*1530 * Peel the entry (if possible) and return its new peel_status. If1531 * repeel is true, re-peel the entry even if there is an old peeled1532 * value that is already stored in it.1533 *1534 * It is OK to call this function with a packed reference entry that1535 * might be stale and might even refer to an object that has since1536 * been garbage-collected. In such a case, if the entry has1537 * REF_KNOWS_PEELED then leave the status unchanged and return1538 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1539 */1540static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1541{1542 enum peel_status status;15431544 if (entry->flag & REF_KNOWS_PEELED) {1545 if (repeel) {1546 entry->flag &= ~REF_KNOWS_PEELED;1547 oidclr(&entry->u.value.peeled);1548 } else {1549 return is_null_oid(&entry->u.value.peeled) ?1550 PEEL_NON_TAG : PEEL_PEELED;1551 }1552 }1553 if (entry->flag & REF_ISBROKEN)1554 return PEEL_BROKEN;1555 if (entry->flag & REF_ISSYMREF)1556 return PEEL_IS_SYMREF;15571558 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1559 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1560 entry->flag |= REF_KNOWS_PEELED;1561 return status;1562}15631564int peel_ref(const char *refname, unsigned char *sha1)1565{1566 int flag;1567 unsigned char base[20];15681569 if (current_ref && (current_ref->name == refname1570 || !strcmp(current_ref->name, refname))) {1571 if (peel_entry(current_ref, 0))1572 return -1;1573 hashcpy(sha1, current_ref->u.value.peeled.hash);1574 return 0;1575 }15761577 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1578 return -1;15791580 /*1581 * If the reference is packed, read its ref_entry from the1582 * cache in the hope that we already know its peeled value.1583 * We only try this optimization on packed references because1584 * (a) forcing the filling of the loose reference cache could1585 * be expensive and (b) loose references anyway usually do not1586 * have REF_KNOWS_PEELED.1587 */1588 if (flag & REF_ISPACKED) {1589 struct ref_entry *r = get_packed_ref(refname);1590 if (r) {1591 if (peel_entry(r, 0))1592 return -1;1593 hashcpy(sha1, r->u.value.peeled.hash);1594 return 0;1595 }1596 }15971598 return peel_object(base, sha1);1599}16001601/*1602 * Call fn for each reference in the specified ref_cache, omitting1603 * references not in the containing_dir of base. fn is called for all1604 * references, including broken ones. If fn ever returns a non-zero1605 * value, stop the iteration and return that value; otherwise, return1606 * 0.1607 */1608static int do_for_each_entry(struct ref_cache *refs, const char *base,1609 each_ref_entry_fn fn, void *cb_data)1610{1611 struct packed_ref_cache *packed_ref_cache;1612 struct ref_dir *loose_dir;1613 struct ref_dir *packed_dir;1614 int retval = 0;16151616 /*1617 * We must make sure that all loose refs are read before accessing the1618 * packed-refs file; this avoids a race condition in which loose refs1619 * are migrated to the packed-refs file by a simultaneous process, but1620 * our in-memory view is from before the migration. get_packed_ref_cache()1621 * takes care of making sure our view is up to date with what is on1622 * disk.1623 */1624 loose_dir = get_loose_refs(refs);1625 if (base && *base) {1626 loose_dir = find_containing_dir(loose_dir, base, 0);1627 }1628 if (loose_dir)1629 prime_ref_dir(loose_dir);16301631 packed_ref_cache = get_packed_ref_cache(refs);1632 acquire_packed_ref_cache(packed_ref_cache);1633 packed_dir = get_packed_ref_dir(packed_ref_cache);1634 if (base && *base) {1635 packed_dir = find_containing_dir(packed_dir, base, 0);1636 }16371638 if (packed_dir && loose_dir) {1639 sort_ref_dir(packed_dir);1640 sort_ref_dir(loose_dir);1641 retval = do_for_each_entry_in_dirs(1642 packed_dir, loose_dir, fn, cb_data);1643 } else if (packed_dir) {1644 sort_ref_dir(packed_dir);1645 retval = do_for_each_entry_in_dir(1646 packed_dir, 0, fn, cb_data);1647 } else if (loose_dir) {1648 sort_ref_dir(loose_dir);1649 retval = do_for_each_entry_in_dir(1650 loose_dir, 0, fn, cb_data);1651 }16521653 release_packed_ref_cache(packed_ref_cache);1654 return retval;1655}16561657/*1658 * Call fn for each reference in the specified ref_cache for which the1659 * refname begins with base. If trim is non-zero, then trim that many1660 * characters off the beginning of each refname before passing the1661 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1662 * broken references in the iteration. If fn ever returns a non-zero1663 * value, stop the iteration and return that value; otherwise, return1664 * 0.1665 */1666int do_for_each_ref(const char *submodule, const char *base,1667 each_ref_fn fn, int trim, int flags, void *cb_data)1668{1669 struct ref_entry_cb data;1670 struct ref_cache *refs;16711672 refs = get_ref_cache(submodule);1673 data.base = base;1674 data.trim = trim;1675 data.flags = flags;1676 data.fn = fn;1677 data.cb_data = cb_data;16781679 if (ref_paranoia < 0)1680 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1681 if (ref_paranoia)1682 data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;16831684 return do_for_each_entry(refs, base, do_one_ref, &data);1685}16861687/*1688 * Verify that the reference locked by lock has the value old_sha1.1689 * Fail if the reference doesn't exist and mustexist is set. Return 01690 * on success. On error, write an error message to err, set errno, and1691 * return a negative value.1692 */1693static int verify_lock(struct ref_lock *lock,1694 const unsigned char *old_sha1, int mustexist,1695 struct strbuf *err)1696{1697 assert(err);16981699 if (read_ref_full(lock->ref_name,1700 mustexist ? RESOLVE_REF_READING : 0,1701 lock->old_oid.hash, NULL)) {1702 if (old_sha1) {1703 int save_errno = errno;1704 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);1705 errno = save_errno;1706 return -1;1707 } else {1708 hashclr(lock->old_oid.hash);1709 return 0;1710 }1711 }1712 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {1713 strbuf_addf(err, "ref '%s' is at %s but expected %s",1714 lock->ref_name,1715 sha1_to_hex(lock->old_oid.hash),1716 sha1_to_hex(old_sha1));1717 errno = EBUSY;1718 return -1;1719 }1720 return 0;1721}17221723static int remove_empty_directories(struct strbuf *path)1724{1725 /*1726 * we want to create a file but there is a directory there;1727 * if that is an empty directory (or a directory that contains1728 * only empty directories), remove them.1729 */1730 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1731}17321733/*1734 * Locks a ref returning the lock on success and NULL on failure.1735 * On failure errno is set to something meaningful.1736 */1737static struct ref_lock *lock_ref_sha1_basic(const char *refname,1738 const unsigned char *old_sha1,1739 const struct string_list *extras,1740 const struct string_list *skip,1741 unsigned int flags, int *type,1742 struct strbuf *err)1743{1744 struct strbuf ref_file = STRBUF_INIT;1745 struct strbuf orig_ref_file = STRBUF_INIT;1746 const char *orig_refname = refname;1747 struct ref_lock *lock;1748 int last_errno = 0;1749 int lflags = 0;1750 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1751 int resolve_flags = 0;1752 int attempts_remaining = 3;17531754 assert(err);17551756 lock = xcalloc(1, sizeof(struct ref_lock));17571758 if (mustexist)1759 resolve_flags |= RESOLVE_REF_READING;1760 if (flags & REF_DELETING)1761 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;1762 if (flags & REF_NODEREF) {1763 resolve_flags |= RESOLVE_REF_NO_RECURSE;1764 lflags |= LOCK_NO_DEREF;1765 }17661767 refname = resolve_ref_unsafe(refname, resolve_flags,1768 lock->old_oid.hash, type);1769 if (!refname && errno == EISDIR) {1770 /*1771 * we are trying to lock foo but we used to1772 * have foo/bar which now does not exist;1773 * it is normal for the empty directory 'foo'1774 * to remain.1775 */1776 strbuf_git_path(&orig_ref_file, "%s", orig_refname);1777 if (remove_empty_directories(&orig_ref_file)) {1778 last_errno = errno;1779 if (!verify_refname_available_dir(orig_refname, extras, skip,1780 get_loose_refs(&ref_cache), err))1781 strbuf_addf(err, "there are still refs under '%s'",1782 orig_refname);1783 goto error_return;1784 }1785 refname = resolve_ref_unsafe(orig_refname, resolve_flags,1786 lock->old_oid.hash, type);1787 }1788 if (!refname) {1789 last_errno = errno;1790 if (last_errno != ENOTDIR ||1791 !verify_refname_available_dir(orig_refname, extras, skip,1792 get_loose_refs(&ref_cache), err))1793 strbuf_addf(err, "unable to resolve reference '%s': %s",1794 orig_refname, strerror(last_errno));17951796 goto error_return;1797 }17981799 if (flags & REF_NODEREF)1800 refname = orig_refname;18011802 /*1803 * If the ref did not exist and we are creating it, make sure1804 * there is no existing packed ref whose name begins with our1805 * refname, nor a packed ref whose name is a proper prefix of1806 * our refname.1807 */1808 if (is_null_oid(&lock->old_oid) &&1809 verify_refname_available_dir(refname, extras, skip,1810 get_packed_refs(&ref_cache), err)) {1811 last_errno = ENOTDIR;1812 goto error_return;1813 }18141815 lock->lk = xcalloc(1, sizeof(struct lock_file));18161817 lock->ref_name = xstrdup(refname);1818 lock->orig_ref_name = xstrdup(orig_refname);1819 strbuf_git_path(&ref_file, "%s", refname);18201821 retry:1822 switch (safe_create_leading_directories_const(ref_file.buf)) {1823 case SCLD_OK:1824 break; /* success */1825 case SCLD_VANISHED:1826 if (--attempts_remaining > 0)1827 goto retry;1828 /* fall through */1829 default:1830 last_errno = errno;1831 strbuf_addf(err, "unable to create directory for '%s'",1832 ref_file.buf);1833 goto error_return;1834 }18351836 if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {1837 last_errno = errno;1838 if (errno == ENOENT && --attempts_remaining > 0)1839 /*1840 * Maybe somebody just deleted one of the1841 * directories leading to ref_file. Try1842 * again:1843 */1844 goto retry;1845 else {1846 unable_to_lock_message(ref_file.buf, errno, err);1847 goto error_return;1848 }1849 }1850 if (verify_lock(lock, old_sha1, mustexist, err)) {1851 last_errno = errno;1852 goto error_return;1853 }1854 goto out;18551856 error_return:1857 unlock_ref(lock);1858 lock = NULL;18591860 out:1861 strbuf_release(&ref_file);1862 strbuf_release(&orig_ref_file);1863 errno = last_errno;1864 return lock;1865}18661867/*1868 * Write an entry to the packed-refs file for the specified refname.1869 * If peeled is non-NULL, write it as the entry's peeled value.1870 */1871static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,1872 unsigned char *peeled)1873{1874 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);1875 if (peeled)1876 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));1877}18781879/*1880 * An each_ref_entry_fn that writes the entry to a packed-refs file.1881 */1882static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)1883{1884 enum peel_status peel_status = peel_entry(entry, 0);18851886 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)1887 error("internal error: %s is not a valid packed reference!",1888 entry->name);1889 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,1890 peel_status == PEEL_PEELED ?1891 entry->u.value.peeled.hash : NULL);1892 return 0;1893}18941895/*1896 * Lock the packed-refs file for writing. Flags is passed to1897 * hold_lock_file_for_update(). Return 0 on success. On errors, set1898 * errno appropriately and return a nonzero value.1899 */1900static int lock_packed_refs(int flags)1901{1902 static int timeout_configured = 0;1903 static int timeout_value = 1000;19041905 struct packed_ref_cache *packed_ref_cache;19061907 if (!timeout_configured) {1908 git_config_get_int("core.packedrefstimeout", &timeout_value);1909 timeout_configured = 1;1910 }19111912 if (hold_lock_file_for_update_timeout(1913 &packlock, git_path("packed-refs"),1914 flags, timeout_value) < 0)1915 return -1;1916 /*1917 * Get the current packed-refs while holding the lock. If the1918 * packed-refs file has been modified since we last read it,1919 * this will automatically invalidate the cache and re-read1920 * the packed-refs file.1921 */1922 packed_ref_cache = get_packed_ref_cache(&ref_cache);1923 packed_ref_cache->lock = &packlock;1924 /* Increment the reference count to prevent it from being freed: */1925 acquire_packed_ref_cache(packed_ref_cache);1926 return 0;1927}19281929/*1930 * Write the current version of the packed refs cache from memory to1931 * disk. The packed-refs file must already be locked for writing (see1932 * lock_packed_refs()). Return zero on success. On errors, set errno1933 * and return a nonzero value1934 */1935static int commit_packed_refs(void)1936{1937 struct packed_ref_cache *packed_ref_cache =1938 get_packed_ref_cache(&ref_cache);1939 int error = 0;1940 int save_errno = 0;1941 FILE *out;19421943 if (!packed_ref_cache->lock)1944 die("internal error: packed-refs not locked");19451946 out = fdopen_lock_file(packed_ref_cache->lock, "w");1947 if (!out)1948 die_errno("unable to fdopen packed-refs descriptor");19491950 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);1951 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),1952 0, write_packed_entry_fn, out);19531954 if (commit_lock_file(packed_ref_cache->lock)) {1955 save_errno = errno;1956 error = -1;1957 }1958 packed_ref_cache->lock = NULL;1959 release_packed_ref_cache(packed_ref_cache);1960 errno = save_errno;1961 return error;1962}19631964/*1965 * Rollback the lockfile for the packed-refs file, and discard the1966 * in-memory packed reference cache. (The packed-refs file will be1967 * read anew if it is needed again after this function is called.)1968 */1969static void rollback_packed_refs(void)1970{1971 struct packed_ref_cache *packed_ref_cache =1972 get_packed_ref_cache(&ref_cache);19731974 if (!packed_ref_cache->lock)1975 die("internal error: packed-refs not locked");1976 rollback_lock_file(packed_ref_cache->lock);1977 packed_ref_cache->lock = NULL;1978 release_packed_ref_cache(packed_ref_cache);1979 clear_packed_ref_cache(&ref_cache);1980}19811982struct ref_to_prune {1983 struct ref_to_prune *next;1984 unsigned char sha1[20];1985 char name[FLEX_ARRAY];1986};19871988struct pack_refs_cb_data {1989 unsigned int flags;1990 struct ref_dir *packed_refs;1991 struct ref_to_prune *ref_to_prune;1992};19931994/*1995 * An each_ref_entry_fn that is run over loose references only. If1996 * the loose reference can be packed, add an entry in the packed ref1997 * cache. If the reference should be pruned, also add it to1998 * ref_to_prune in the pack_refs_cb_data.1999 */2000static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2001{2002 struct pack_refs_cb_data *cb = cb_data;2003 enum peel_status peel_status;2004 struct ref_entry *packed_entry;2005 int is_tag_ref = starts_with(entry->name, "refs/tags/");20062007 /* Do not pack per-worktree refs: */2008 if (ref_type(entry->name) != REF_TYPE_NORMAL)2009 return 0;20102011 /* ALWAYS pack tags */2012 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2013 return 0;20142015 /* Do not pack symbolic or broken refs: */2016 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2017 return 0;20182019 /* Add a packed ref cache entry equivalent to the loose entry. */2020 peel_status = peel_entry(entry, 1);2021 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2022 die("internal error peeling reference %s (%s)",2023 entry->name, oid_to_hex(&entry->u.value.oid));2024 packed_entry = find_ref(cb->packed_refs, entry->name);2025 if (packed_entry) {2026 /* Overwrite existing packed entry with info from loose entry */2027 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2028 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2029 } else {2030 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,2031 REF_ISPACKED | REF_KNOWS_PEELED, 0);2032 add_ref(cb->packed_refs, packed_entry);2033 }2034 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);20352036 /* Schedule the loose reference for pruning if requested. */2037 if ((cb->flags & PACK_REFS_PRUNE)) {2038 struct ref_to_prune *n;2039 FLEX_ALLOC_STR(n, name, entry->name);2040 hashcpy(n->sha1, entry->u.value.oid.hash);2041 n->next = cb->ref_to_prune;2042 cb->ref_to_prune = n;2043 }2044 return 0;2045}20462047/*2048 * Remove empty parents, but spare refs/ and immediate subdirs.2049 * Note: munges *name.2050 */2051static void try_remove_empty_parents(char *name)2052{2053 char *p, *q;2054 int i;2055 p = name;2056 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2057 while (*p && *p != '/')2058 p++;2059 /* tolerate duplicate slashes; see check_refname_format() */2060 while (*p == '/')2061 p++;2062 }2063 for (q = p; *q; q++)2064 ;2065 while (1) {2066 while (q > p && *q != '/')2067 q--;2068 while (q > p && *(q-1) == '/')2069 q--;2070 if (q == p)2071 break;2072 *q = '\0';2073 if (rmdir(git_path("%s", name)))2074 break;2075 }2076}20772078/* make sure nobody touched the ref, and unlink */2079static void prune_ref(struct ref_to_prune *r)2080{2081 struct ref_transaction *transaction;2082 struct strbuf err = STRBUF_INIT;20832084 if (check_refname_format(r->name, 0))2085 return;20862087 transaction = ref_transaction_begin(&err);2088 if (!transaction ||2089 ref_transaction_delete(transaction, r->name, r->sha1,2090 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2091 ref_transaction_commit(transaction, &err)) {2092 ref_transaction_free(transaction);2093 error("%s", err.buf);2094 strbuf_release(&err);2095 return;2096 }2097 ref_transaction_free(transaction);2098 strbuf_release(&err);2099 try_remove_empty_parents(r->name);2100}21012102static void prune_refs(struct ref_to_prune *r)2103{2104 while (r) {2105 prune_ref(r);2106 r = r->next;2107 }2108}21092110int pack_refs(unsigned int flags)2111{2112 struct pack_refs_cb_data cbdata;21132114 memset(&cbdata, 0, sizeof(cbdata));2115 cbdata.flags = flags;21162117 lock_packed_refs(LOCK_DIE_ON_ERROR);2118 cbdata.packed_refs = get_packed_refs(&ref_cache);21192120 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2121 pack_if_possible_fn, &cbdata);21222123 if (commit_packed_refs())2124 die_errno("unable to overwrite old ref-pack file");21252126 prune_refs(cbdata.ref_to_prune);2127 return 0;2128}21292130/*2131 * Rewrite the packed-refs file, omitting any refs listed in2132 * 'refnames'. On error, leave packed-refs unchanged, write an error2133 * message to 'err', and return a nonzero value.2134 *2135 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2136 */2137static int repack_without_refs(struct string_list *refnames, struct strbuf *err)2138{2139 struct ref_dir *packed;2140 struct string_list_item *refname;2141 int ret, needs_repacking = 0, removed = 0;21422143 assert(err);21442145 /* Look for a packed ref */2146 for_each_string_list_item(refname, refnames) {2147 if (get_packed_ref(refname->string)) {2148 needs_repacking = 1;2149 break;2150 }2151 }21522153 /* Avoid locking if we have nothing to do */2154 if (!needs_repacking)2155 return 0; /* no refname exists in packed refs */21562157 if (lock_packed_refs(0)) {2158 unable_to_lock_message(git_path("packed-refs"), errno, err);2159 return -1;2160 }2161 packed = get_packed_refs(&ref_cache);21622163 /* Remove refnames from the cache */2164 for_each_string_list_item(refname, refnames)2165 if (remove_entry(packed, refname->string) != -1)2166 removed = 1;2167 if (!removed) {2168 /*2169 * All packed entries disappeared while we were2170 * acquiring the lock.2171 */2172 rollback_packed_refs();2173 return 0;2174 }21752176 /* Write what remains */2177 ret = commit_packed_refs();2178 if (ret)2179 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2180 strerror(errno));2181 return ret;2182}21832184static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2185{2186 assert(err);21872188 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2189 /*2190 * loose. The loose file name is the same as the2191 * lockfile name, minus ".lock":2192 */2193 char *loose_filename = get_locked_file_path(lock->lk);2194 int res = unlink_or_msg(loose_filename, err);2195 free(loose_filename);2196 if (res)2197 return 1;2198 }2199 return 0;2200}22012202int delete_refs(struct string_list *refnames)2203{2204 struct strbuf err = STRBUF_INIT;2205 int i, result = 0;22062207 if (!refnames->nr)2208 return 0;22092210 result = repack_without_refs(refnames, &err);2211 if (result) {2212 /*2213 * If we failed to rewrite the packed-refs file, then2214 * it is unsafe to try to remove loose refs, because2215 * doing so might expose an obsolete packed value for2216 * a reference that might even point at an object that2217 * has been garbage collected.2218 */2219 if (refnames->nr == 1)2220 error(_("could not delete reference %s: %s"),2221 refnames->items[0].string, err.buf);2222 else2223 error(_("could not delete references: %s"), err.buf);22242225 goto out;2226 }22272228 for (i = 0; i < refnames->nr; i++) {2229 const char *refname = refnames->items[i].string;22302231 if (delete_ref(refname, NULL, 0))2232 result |= error(_("could not remove reference %s"), refname);2233 }22342235out:2236 strbuf_release(&err);2237 return result;2238}22392240/*2241 * People using contrib's git-new-workdir have .git/logs/refs ->2242 * /some/other/path/.git/logs/refs, and that may live on another device.2243 *2244 * IOW, to avoid cross device rename errors, the temporary renamed log must2245 * live into logs/refs.2246 */2247#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"22482249static int rename_tmp_log(const char *newrefname)2250{2251 int attempts_remaining = 4;2252 struct strbuf path = STRBUF_INIT;2253 int ret = -1;22542255 retry:2256 strbuf_reset(&path);2257 strbuf_git_path(&path, "logs/%s", newrefname);2258 switch (safe_create_leading_directories_const(path.buf)) {2259 case SCLD_OK:2260 break; /* success */2261 case SCLD_VANISHED:2262 if (--attempts_remaining > 0)2263 goto retry;2264 /* fall through */2265 default:2266 error("unable to create directory for %s", newrefname);2267 goto out;2268 }22692270 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {2271 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2272 /*2273 * rename(a, b) when b is an existing2274 * directory ought to result in ISDIR, but2275 * Solaris 5.8 gives ENOTDIR. Sheesh.2276 */2277 if (remove_empty_directories(&path)) {2278 error("Directory not empty: logs/%s", newrefname);2279 goto out;2280 }2281 goto retry;2282 } else if (errno == ENOENT && --attempts_remaining > 0) {2283 /*2284 * Maybe another process just deleted one of2285 * the directories in the path to newrefname.2286 * Try again from the beginning.2287 */2288 goto retry;2289 } else {2290 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2291 newrefname, strerror(errno));2292 goto out;2293 }2294 }2295 ret = 0;2296out:2297 strbuf_release(&path);2298 return ret;2299}23002301int verify_refname_available(const char *newname,2302 const struct string_list *extras,2303 const struct string_list *skip,2304 struct strbuf *err)2305{2306 struct ref_dir *packed_refs = get_packed_refs(&ref_cache);2307 struct ref_dir *loose_refs = get_loose_refs(&ref_cache);23082309 if (verify_refname_available_dir(newname, extras, skip,2310 packed_refs, err) ||2311 verify_refname_available_dir(newname, extras, skip,2312 loose_refs, err))2313 return -1;23142315 return 0;2316}23172318static int write_ref_to_lockfile(struct ref_lock *lock,2319 const unsigned char *sha1, struct strbuf *err);2320static int commit_ref_update(struct ref_lock *lock,2321 const unsigned char *sha1, const char *logmsg,2322 int flags, struct strbuf *err);23232324int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2325{2326 unsigned char sha1[20], orig_sha1[20];2327 int flag = 0, logmoved = 0;2328 struct ref_lock *lock;2329 struct stat loginfo;2330 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2331 struct strbuf err = STRBUF_INIT;23322333 if (log && S_ISLNK(loginfo.st_mode))2334 return error("reflog for %s is a symlink", oldrefname);23352336 if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2337 orig_sha1, &flag))2338 return error("refname %s not found", oldrefname);23392340 if (flag & REF_ISSYMREF)2341 return error("refname %s is a symbolic ref, renaming it is not supported",2342 oldrefname);2343 if (!rename_ref_available(oldrefname, newrefname))2344 return 1;23452346 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2347 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2348 oldrefname, strerror(errno));23492350 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2351 error("unable to delete old %s", oldrefname);2352 goto rollback;2353 }23542355 /*2356 * Since we are doing a shallow lookup, sha1 is not the2357 * correct value to pass to delete_ref as old_sha1. But that2358 * doesn't matter, because an old_sha1 check wouldn't add to2359 * the safety anyway; we want to delete the reference whatever2360 * its current value.2361 */2362 if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2363 sha1, NULL) &&2364 delete_ref(newrefname, NULL, REF_NODEREF)) {2365 if (errno==EISDIR) {2366 struct strbuf path = STRBUF_INIT;2367 int result;23682369 strbuf_git_path(&path, "%s", newrefname);2370 result = remove_empty_directories(&path);2371 strbuf_release(&path);23722373 if (result) {2374 error("Directory not empty: %s", newrefname);2375 goto rollback;2376 }2377 } else {2378 error("unable to delete existing %s", newrefname);2379 goto rollback;2380 }2381 }23822383 if (log && rename_tmp_log(newrefname))2384 goto rollback;23852386 logmoved = log;23872388 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,2389 NULL, &err);2390 if (!lock) {2391 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);2392 strbuf_release(&err);2393 goto rollback;2394 }2395 hashcpy(lock->old_oid.hash, orig_sha1);23962397 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2398 commit_ref_update(lock, orig_sha1, logmsg, 0, &err)) {2399 error("unable to write current sha1 into %s: %s", newrefname, err.buf);2400 strbuf_release(&err);2401 goto rollback;2402 }24032404 return 0;24052406 rollback:2407 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,2408 NULL, &err);2409 if (!lock) {2410 error("unable to lock %s for rollback: %s", oldrefname, err.buf);2411 strbuf_release(&err);2412 goto rollbacklog;2413 }24142415 flag = log_all_ref_updates;2416 log_all_ref_updates = 0;2417 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||2418 commit_ref_update(lock, orig_sha1, NULL, 0, &err)) {2419 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);2420 strbuf_release(&err);2421 }2422 log_all_ref_updates = flag;24232424 rollbacklog:2425 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2426 error("unable to restore logfile %s from %s: %s",2427 oldrefname, newrefname, strerror(errno));2428 if (!logmoved && log &&2429 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2430 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2431 oldrefname, strerror(errno));24322433 return 1;2434}24352436static int close_ref(struct ref_lock *lock)2437{2438 if (close_lock_file(lock->lk))2439 return -1;2440 return 0;2441}24422443static int commit_ref(struct ref_lock *lock)2444{2445 char *path = get_locked_file_path(lock->lk);2446 struct stat st;24472448 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {2449 /*2450 * There is a directory at the path we want to rename2451 * the lockfile to. Hopefully it is empty; try to2452 * delete it.2453 */2454 size_t len = strlen(path);2455 struct strbuf sb_path = STRBUF_INIT;24562457 strbuf_attach(&sb_path, path, len, len);24582459 /*2460 * If this fails, commit_lock_file() will also fail2461 * and will report the problem.2462 */2463 remove_empty_directories(&sb_path);2464 strbuf_release(&sb_path);2465 } else {2466 free(path);2467 }24682469 if (commit_lock_file(lock->lk))2470 return -1;2471 return 0;2472}24732474/*2475 * Create a reflog for a ref. If force_create = 0, the reflog will2476 * only be created for certain refs (those for which2477 * should_autocreate_reflog returns non-zero. Otherwise, create it2478 * regardless of the ref name. Fill in *err and return -1 on failure.2479 */2480static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)2481{2482 int logfd, oflags = O_APPEND | O_WRONLY;24832484 strbuf_git_path(logfile, "logs/%s", refname);2485 if (force_create || should_autocreate_reflog(refname)) {2486 if (safe_create_leading_directories(logfile->buf) < 0) {2487 strbuf_addf(err, "unable to create directory for '%s': "2488 "%s", logfile->buf, strerror(errno));2489 return -1;2490 }2491 oflags |= O_CREAT;2492 }24932494 logfd = open(logfile->buf, oflags, 0666);2495 if (logfd < 0) {2496 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2497 return 0;24982499 if (errno == EISDIR) {2500 if (remove_empty_directories(logfile)) {2501 strbuf_addf(err, "there are still logs under "2502 "'%s'", logfile->buf);2503 return -1;2504 }2505 logfd = open(logfile->buf, oflags, 0666);2506 }25072508 if (logfd < 0) {2509 strbuf_addf(err, "unable to append to '%s': %s",2510 logfile->buf, strerror(errno));2511 return -1;2512 }2513 }25142515 adjust_shared_perm(logfile->buf);2516 close(logfd);2517 return 0;2518}251925202521int safe_create_reflog(const char *refname, int force_create, struct strbuf *err)2522{2523 int ret;2524 struct strbuf sb = STRBUF_INIT;25252526 ret = log_ref_setup(refname, &sb, err, force_create);2527 strbuf_release(&sb);2528 return ret;2529}25302531static int log_ref_write_fd(int fd, const unsigned char *old_sha1,2532 const unsigned char *new_sha1,2533 const char *committer, const char *msg)2534{2535 int msglen, written;2536 unsigned maxlen, len;2537 char *logrec;25382539 msglen = msg ? strlen(msg) : 0;2540 maxlen = strlen(committer) + msglen + 100;2541 logrec = xmalloc(maxlen);2542 len = xsnprintf(logrec, maxlen, "%s %s %s\n",2543 sha1_to_hex(old_sha1),2544 sha1_to_hex(new_sha1),2545 committer);2546 if (msglen)2547 len += copy_reflog_msg(logrec + len - 1, msg) - 1;25482549 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;2550 free(logrec);2551 if (written != len)2552 return -1;25532554 return 0;2555}25562557static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,2558 const unsigned char *new_sha1, const char *msg,2559 struct strbuf *logfile, int flags,2560 struct strbuf *err)2561{2562 int logfd, result, oflags = O_APPEND | O_WRONLY;25632564 if (log_all_ref_updates < 0)2565 log_all_ref_updates = !is_bare_repository();25662567 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);25682569 if (result)2570 return result;25712572 logfd = open(logfile->buf, oflags);2573 if (logfd < 0)2574 return 0;2575 result = log_ref_write_fd(logfd, old_sha1, new_sha1,2576 git_committer_info(0), msg);2577 if (result) {2578 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2579 strerror(errno));2580 close(logfd);2581 return -1;2582 }2583 if (close(logfd)) {2584 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,2585 strerror(errno));2586 return -1;2587 }2588 return 0;2589}25902591static int log_ref_write(const char *refname, const unsigned char *old_sha1,2592 const unsigned char *new_sha1, const char *msg,2593 int flags, struct strbuf *err)2594{2595 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2596 err);2597}25982599int files_log_ref_write(const char *refname, const unsigned char *old_sha1,2600 const unsigned char *new_sha1, const char *msg,2601 int flags, struct strbuf *err)2602{2603 struct strbuf sb = STRBUF_INIT;2604 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2605 err);2606 strbuf_release(&sb);2607 return ret;2608}26092610/*2611 * Write sha1 into the open lockfile, then close the lockfile. On2612 * errors, rollback the lockfile, fill in *err and2613 * return -1.2614 */2615static int write_ref_to_lockfile(struct ref_lock *lock,2616 const unsigned char *sha1, struct strbuf *err)2617{2618 static char term = '\n';2619 struct object *o;2620 int fd;26212622 o = parse_object(sha1);2623 if (!o) {2624 strbuf_addf(err,2625 "trying to write ref '%s' with nonexistent object %s",2626 lock->ref_name, sha1_to_hex(sha1));2627 unlock_ref(lock);2628 return -1;2629 }2630 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2631 strbuf_addf(err,2632 "trying to write non-commit object %s to branch '%s'",2633 sha1_to_hex(sha1), lock->ref_name);2634 unlock_ref(lock);2635 return -1;2636 }2637 fd = get_lock_file_fd(lock->lk);2638 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||2639 write_in_full(fd, &term, 1) != 1 ||2640 close_ref(lock) < 0) {2641 strbuf_addf(err,2642 "couldn't write '%s'", get_lock_file_path(lock->lk));2643 unlock_ref(lock);2644 return -1;2645 }2646 return 0;2647}26482649/*2650 * Commit a change to a loose reference that has already been written2651 * to the loose reference lockfile. Also update the reflogs if2652 * necessary, using the specified lockmsg (which can be NULL).2653 */2654static int commit_ref_update(struct ref_lock *lock,2655 const unsigned char *sha1, const char *logmsg,2656 int flags, struct strbuf *err)2657{2658 clear_loose_ref_cache(&ref_cache);2659 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0 ||2660 (strcmp(lock->ref_name, lock->orig_ref_name) &&2661 log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0)) {2662 char *old_msg = strbuf_detach(err, NULL);2663 strbuf_addf(err, "cannot update the ref '%s': %s",2664 lock->ref_name, old_msg);2665 free(old_msg);2666 unlock_ref(lock);2667 return -1;2668 }2669 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {2670 /*2671 * Special hack: If a branch is updated directly and HEAD2672 * points to it (may happen on the remote side of a push2673 * for example) then logically the HEAD reflog should be2674 * updated too.2675 * A generic solution implies reverse symref information,2676 * but finding all symrefs pointing to the given branch2677 * would be rather costly for this rare event (the direct2678 * update of a branch) to be worth it. So let's cheat and2679 * check with HEAD only which should cover 99% of all usage2680 * scenarios (even 100% of the default ones).2681 */2682 unsigned char head_sha1[20];2683 int head_flag;2684 const char *head_ref;2685 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2686 head_sha1, &head_flag);2687 if (head_ref && (head_flag & REF_ISSYMREF) &&2688 !strcmp(head_ref, lock->ref_name)) {2689 struct strbuf log_err = STRBUF_INIT;2690 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,2691 logmsg, 0, &log_err)) {2692 error("%s", log_err.buf);2693 strbuf_release(&log_err);2694 }2695 }2696 }2697 if (!(flags & REF_LOG_ONLY) && commit_ref(lock)) {2698 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);2699 unlock_ref(lock);2700 return -1;2701 }27022703 unlock_ref(lock);2704 return 0;2705}27062707static int create_ref_symlink(struct ref_lock *lock, const char *target)2708{2709 int ret = -1;2710#ifndef NO_SYMLINK_HEAD2711 char *ref_path = get_locked_file_path(lock->lk);2712 unlink(ref_path);2713 ret = symlink(target, ref_path);2714 free(ref_path);27152716 if (ret)2717 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2718#endif2719 return ret;2720}27212722static void update_symref_reflog(struct ref_lock *lock, const char *refname,2723 const char *target, const char *logmsg)2724{2725 struct strbuf err = STRBUF_INIT;2726 unsigned char new_sha1[20];2727 if (logmsg && !read_ref(target, new_sha1) &&2728 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {2729 error("%s", err.buf);2730 strbuf_release(&err);2731 }2732}27332734static int create_symref_locked(struct ref_lock *lock, const char *refname,2735 const char *target, const char *logmsg)2736{2737 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {2738 update_symref_reflog(lock, refname, target, logmsg);2739 return 0;2740 }27412742 if (!fdopen_lock_file(lock->lk, "w"))2743 return error("unable to fdopen %s: %s",2744 lock->lk->tempfile.filename.buf, strerror(errno));27452746 update_symref_reflog(lock, refname, target, logmsg);27472748 /* no error check; commit_ref will check ferror */2749 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);2750 if (commit_ref(lock) < 0)2751 return error("unable to write symref for %s: %s", refname,2752 strerror(errno));2753 return 0;2754}27552756int create_symref(const char *refname, const char *target, const char *logmsg)2757{2758 struct strbuf err = STRBUF_INIT;2759 struct ref_lock *lock;2760 int ret;27612762 lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,2763 &err);2764 if (!lock) {2765 error("%s", err.buf);2766 strbuf_release(&err);2767 return -1;2768 }27692770 ret = create_symref_locked(lock, refname, target, logmsg);2771 unlock_ref(lock);2772 return ret;2773}27742775int set_worktree_head_symref(const char *gitdir, const char *target)2776{2777 static struct lock_file head_lock;2778 struct ref_lock *lock;2779 struct strbuf head_path = STRBUF_INIT;2780 const char *head_rel;2781 int ret;27822783 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));2784 if (hold_lock_file_for_update(&head_lock, head_path.buf,2785 LOCK_NO_DEREF) < 0) {2786 struct strbuf err = STRBUF_INIT;2787 unable_to_lock_message(head_path.buf, errno, &err);2788 error("%s", err.buf);2789 strbuf_release(&err);2790 strbuf_release(&head_path);2791 return -1;2792 }27932794 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for2795 linked trees */2796 head_rel = remove_leading_path(head_path.buf,2797 absolute_path(get_git_common_dir()));2798 /* to make use of create_symref_locked(), initialize ref_lock */2799 lock = xcalloc(1, sizeof(struct ref_lock));2800 lock->lk = &head_lock;2801 lock->ref_name = xstrdup(head_rel);2802 lock->orig_ref_name = xstrdup(head_rel);28032804 ret = create_symref_locked(lock, head_rel, target, NULL);28052806 unlock_ref(lock); /* will free lock */2807 strbuf_release(&head_path);2808 return ret;2809}28102811int reflog_exists(const char *refname)2812{2813 struct stat st;28142815 return !lstat(git_path("logs/%s", refname), &st) &&2816 S_ISREG(st.st_mode);2817}28182819int delete_reflog(const char *refname)2820{2821 return remove_path(git_path("logs/%s", refname));2822}28232824static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)2825{2826 unsigned char osha1[20], nsha1[20];2827 char *email_end, *message;2828 unsigned long timestamp;2829 int tz;28302831 /* old SP new SP name <email> SP time TAB msg LF */2832 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||2833 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||2834 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||2835 !(email_end = strchr(sb->buf + 82, '>')) ||2836 email_end[1] != ' ' ||2837 !(timestamp = strtoul(email_end + 2, &message, 10)) ||2838 !message || message[0] != ' ' ||2839 (message[1] != '+' && message[1] != '-') ||2840 !isdigit(message[2]) || !isdigit(message[3]) ||2841 !isdigit(message[4]) || !isdigit(message[5]))2842 return 0; /* corrupt? */2843 email_end[1] = '\0';2844 tz = strtol(message + 1, NULL, 10);2845 if (message[6] != '\t')2846 message += 6;2847 else2848 message += 7;2849 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);2850}28512852static char *find_beginning_of_line(char *bob, char *scan)2853{2854 while (bob < scan && *(--scan) != '\n')2855 ; /* keep scanning backwards */2856 /*2857 * Return either beginning of the buffer, or LF at the end of2858 * the previous line.2859 */2860 return scan;2861}28622863int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)2864{2865 struct strbuf sb = STRBUF_INIT;2866 FILE *logfp;2867 long pos;2868 int ret = 0, at_tail = 1;28692870 logfp = fopen(git_path("logs/%s", refname), "r");2871 if (!logfp)2872 return -1;28732874 /* Jump to the end */2875 if (fseek(logfp, 0, SEEK_END) < 0)2876 return error("cannot seek back reflog for %s: %s",2877 refname, strerror(errno));2878 pos = ftell(logfp);2879 while (!ret && 0 < pos) {2880 int cnt;2881 size_t nread;2882 char buf[BUFSIZ];2883 char *endp, *scanp;28842885 /* Fill next block from the end */2886 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;2887 if (fseek(logfp, pos - cnt, SEEK_SET))2888 return error("cannot seek back reflog for %s: %s",2889 refname, strerror(errno));2890 nread = fread(buf, cnt, 1, logfp);2891 if (nread != 1)2892 return error("cannot read %d bytes from reflog for %s: %s",2893 cnt, refname, strerror(errno));2894 pos -= cnt;28952896 scanp = endp = buf + cnt;2897 if (at_tail && scanp[-1] == '\n')2898 /* Looking at the final LF at the end of the file */2899 scanp--;2900 at_tail = 0;29012902 while (buf < scanp) {2903 /*2904 * terminating LF of the previous line, or the beginning2905 * of the buffer.2906 */2907 char *bp;29082909 bp = find_beginning_of_line(buf, scanp);29102911 if (*bp == '\n') {2912 /*2913 * The newline is the end of the previous line,2914 * so we know we have complete line starting2915 * at (bp + 1). Prefix it onto any prior data2916 * we collected for the line and process it.2917 */2918 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));2919 scanp = bp;2920 endp = bp + 1;2921 ret = show_one_reflog_ent(&sb, fn, cb_data);2922 strbuf_reset(&sb);2923 if (ret)2924 break;2925 } else if (!pos) {2926 /*2927 * We are at the start of the buffer, and the2928 * start of the file; there is no previous2929 * line, and we have everything for this one.2930 * Process it, and we can end the loop.2931 */2932 strbuf_splice(&sb, 0, 0, buf, endp - buf);2933 ret = show_one_reflog_ent(&sb, fn, cb_data);2934 strbuf_reset(&sb);2935 break;2936 }29372938 if (bp == buf) {2939 /*2940 * We are at the start of the buffer, and there2941 * is more file to read backwards. Which means2942 * we are in the middle of a line. Note that we2943 * may get here even if *bp was a newline; that2944 * just means we are at the exact end of the2945 * previous line, rather than some spot in the2946 * middle.2947 *2948 * Save away what we have to be combined with2949 * the data from the next read.2950 */2951 strbuf_splice(&sb, 0, 0, buf, endp - buf);2952 break;2953 }2954 }29552956 }2957 if (!ret && sb.len)2958 die("BUG: reverse reflog parser had leftover data");29592960 fclose(logfp);2961 strbuf_release(&sb);2962 return ret;2963}29642965int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)2966{2967 FILE *logfp;2968 struct strbuf sb = STRBUF_INIT;2969 int ret = 0;29702971 logfp = fopen(git_path("logs/%s", refname), "r");2972 if (!logfp)2973 return -1;29742975 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))2976 ret = show_one_reflog_ent(&sb, fn, cb_data);2977 fclose(logfp);2978 strbuf_release(&sb);2979 return ret;2980}2981/*2982 * Call fn for each reflog in the namespace indicated by name. name2983 * must be empty or end with '/'. Name will be used as a scratch2984 * space, but its contents will be restored before return.2985 */2986static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)2987{2988 DIR *d = opendir(git_path("logs/%s", name->buf));2989 int retval = 0;2990 struct dirent *de;2991 int oldlen = name->len;29922993 if (!d)2994 return name->len ? errno : 0;29952996 while ((de = readdir(d)) != NULL) {2997 struct stat st;29982999 if (de->d_name[0] == '.')3000 continue;3001 if (ends_with(de->d_name, ".lock"))3002 continue;3003 strbuf_addstr(name, de->d_name);3004 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3005 ; /* silently ignore */3006 } else {3007 if (S_ISDIR(st.st_mode)) {3008 strbuf_addch(name, '/');3009 retval = do_for_each_reflog(name, fn, cb_data);3010 } else {3011 struct object_id oid;30123013 if (read_ref_full(name->buf, 0, oid.hash, NULL))3014 retval = error("bad ref for %s", name->buf);3015 else3016 retval = fn(name->buf, &oid, 0, cb_data);3017 }3018 if (retval)3019 break;3020 }3021 strbuf_setlen(name, oldlen);3022 }3023 closedir(d);3024 return retval;3025}30263027int for_each_reflog(each_ref_fn fn, void *cb_data)3028{3029 int retval;3030 struct strbuf name;3031 strbuf_init(&name, PATH_MAX);3032 retval = do_for_each_reflog(&name, fn, cb_data);3033 strbuf_release(&name);3034 return retval;3035}30363037static int ref_update_reject_duplicates(struct string_list *refnames,3038 struct strbuf *err)3039{3040 int i, n = refnames->nr;30413042 assert(err);30433044 for (i = 1; i < n; i++)3045 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {3046 strbuf_addf(err,3047 "multiple updates for ref '%s' not allowed.",3048 refnames->items[i].string);3049 return 1;3050 }3051 return 0;3052}30533054/*3055 * Acquire all locks, verify old values if provided, check3056 * that new values are valid, and write new values to the3057 * lockfiles, ready to be activated. Only keep one lockfile3058 * open at a time to avoid running out of file descriptors.3059 */3060static int lock_ref_for_update(struct ref_update *update,3061 struct ref_transaction *transaction,3062 struct string_list *affected_refnames,3063 struct strbuf *err)3064{3065 int ret;30663067 if ((update->flags & REF_HAVE_NEW) &&3068 is_null_sha1(update->new_sha1))3069 update->flags |= REF_DELETING;3070 update->lock = lock_ref_sha1_basic(3071 update->refname,3072 ((update->flags & REF_HAVE_OLD) ?3073 update->old_sha1 : NULL),3074 affected_refnames, NULL,3075 update->flags,3076 &update->type,3077 err);3078 if (!update->lock) {3079 char *reason;30803081 ret = (errno == ENOTDIR)3082 ? TRANSACTION_NAME_CONFLICT3083 : TRANSACTION_GENERIC_ERROR;3084 reason = strbuf_detach(err, NULL);3085 strbuf_addf(err, "cannot lock ref '%s': %s",3086 update->refname, reason);3087 free(reason);3088 return ret;3089 }3090 if ((update->flags & REF_HAVE_NEW) &&3091 !(update->flags & REF_DELETING) &&3092 !(update->flags & REF_LOG_ONLY)) {3093 int overwriting_symref = ((update->type & REF_ISSYMREF) &&3094 (update->flags & REF_NODEREF));30953096 if (!overwriting_symref &&3097 !hashcmp(update->lock->old_oid.hash, update->new_sha1)) {3098 /*3099 * The reference already has the desired3100 * value, so we don't need to write it.3101 */3102 } else if (write_ref_to_lockfile(update->lock,3103 update->new_sha1,3104 err)) {3105 char *write_err = strbuf_detach(err, NULL);31063107 /*3108 * The lock was freed upon failure of3109 * write_ref_to_lockfile():3110 */3111 update->lock = NULL;3112 strbuf_addf(err,3113 "cannot update the ref '%s': %s",3114 update->refname, write_err);3115 free(write_err);3116 return TRANSACTION_GENERIC_ERROR;3117 } else {3118 update->flags |= REF_NEEDS_COMMIT;3119 }3120 }3121 if (!(update->flags & REF_NEEDS_COMMIT)) {3122 /*3123 * We didn't call write_ref_to_lockfile(), so3124 * the lockfile is still open. Close it to3125 * free up the file descriptor:3126 */3127 if (close_ref(update->lock)) {3128 strbuf_addf(err, "couldn't close '%s.lock'",3129 update->refname);3130 return TRANSACTION_GENERIC_ERROR;3131 }3132 }3133 return 0;3134}31353136int ref_transaction_commit(struct ref_transaction *transaction,3137 struct strbuf *err)3138{3139 int ret = 0, i;3140 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3141 struct string_list_item *ref_to_delete;3142 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;31433144 assert(err);31453146 if (transaction->state != REF_TRANSACTION_OPEN)3147 die("BUG: commit called for transaction that is not open");31483149 if (!transaction->nr) {3150 transaction->state = REF_TRANSACTION_CLOSED;3151 return 0;3152 }31533154 /* Fail if a refname appears more than once in the transaction: */3155 for (i = 0; i < transaction->nr; i++)3156 string_list_append(&affected_refnames,3157 transaction->updates[i]->refname);3158 string_list_sort(&affected_refnames);3159 if (ref_update_reject_duplicates(&affected_refnames, err)) {3160 ret = TRANSACTION_GENERIC_ERROR;3161 goto cleanup;3162 }31633164 /*3165 * Acquire all locks, verify old values if provided, check3166 * that new values are valid, and write new values to the3167 * lockfiles, ready to be activated. Only keep one lockfile3168 * open at a time to avoid running out of file descriptors.3169 */3170 for (i = 0; i < transaction->nr; i++) {3171 struct ref_update *update = transaction->updates[i];31723173 ret = lock_ref_for_update(update, transaction,3174 &affected_refnames, err);3175 if (ret)3176 goto cleanup;3177 }31783179 /* Perform updates first so live commits remain referenced */3180 for (i = 0; i < transaction->nr; i++) {3181 struct ref_update *update = transaction->updates[i];31823183 if (update->flags & REF_NEEDS_COMMIT ||3184 update->flags & REF_LOG_ONLY) {3185 if (commit_ref_update(update->lock,3186 update->new_sha1, update->msg,3187 update->flags, err)) {3188 /* freed by commit_ref_update(): */3189 update->lock = NULL;3190 ret = TRANSACTION_GENERIC_ERROR;3191 goto cleanup;3192 } else {3193 /* freed by commit_ref_update(): */3194 update->lock = NULL;3195 }3196 }3197 }31983199 /* Perform deletes now that updates are safely completed */3200 for (i = 0; i < transaction->nr; i++) {3201 struct ref_update *update = transaction->updates[i];32023203 if (update->flags & REF_DELETING &&3204 !(update->flags & REF_LOG_ONLY)) {3205 if (delete_ref_loose(update->lock, update->type, err)) {3206 ret = TRANSACTION_GENERIC_ERROR;3207 goto cleanup;3208 }32093210 if (!(update->flags & REF_ISPRUNING))3211 string_list_append(&refs_to_delete,3212 update->lock->ref_name);3213 }3214 }32153216 if (repack_without_refs(&refs_to_delete, err)) {3217 ret = TRANSACTION_GENERIC_ERROR;3218 goto cleanup;3219 }3220 for_each_string_list_item(ref_to_delete, &refs_to_delete)3221 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3222 clear_loose_ref_cache(&ref_cache);32233224cleanup:3225 transaction->state = REF_TRANSACTION_CLOSED;32263227 for (i = 0; i < transaction->nr; i++)3228 if (transaction->updates[i]->lock)3229 unlock_ref(transaction->updates[i]->lock);3230 string_list_clear(&refs_to_delete, 0);3231 string_list_clear(&affected_refnames, 0);3232 return ret;3233}32343235static int ref_present(const char *refname,3236 const struct object_id *oid, int flags, void *cb_data)3237{3238 struct string_list *affected_refnames = cb_data;32393240 return string_list_has_string(affected_refnames, refname);3241}32423243int initial_ref_transaction_commit(struct ref_transaction *transaction,3244 struct strbuf *err)3245{3246 int ret = 0, i;3247 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;32483249 assert(err);32503251 if (transaction->state != REF_TRANSACTION_OPEN)3252 die("BUG: commit called for transaction that is not open");32533254 /* Fail if a refname appears more than once in the transaction: */3255 for (i = 0; i < transaction->nr; i++)3256 string_list_append(&affected_refnames,3257 transaction->updates[i]->refname);3258 string_list_sort(&affected_refnames);3259 if (ref_update_reject_duplicates(&affected_refnames, err)) {3260 ret = TRANSACTION_GENERIC_ERROR;3261 goto cleanup;3262 }32633264 /*3265 * It's really undefined to call this function in an active3266 * repository or when there are existing references: we are3267 * only locking and changing packed-refs, so (1) any3268 * simultaneous processes might try to change a reference at3269 * the same time we do, and (2) any existing loose versions of3270 * the references that we are setting would have precedence3271 * over our values. But some remote helpers create the remote3272 * "HEAD" and "master" branches before calling this function,3273 * so here we really only check that none of the references3274 * that we are creating already exists.3275 */3276 if (for_each_rawref(ref_present, &affected_refnames))3277 die("BUG: initial ref transaction called with existing refs");32783279 for (i = 0; i < transaction->nr; i++) {3280 struct ref_update *update = transaction->updates[i];32813282 if ((update->flags & REF_HAVE_OLD) &&3283 !is_null_sha1(update->old_sha1))3284 die("BUG: initial ref transaction with old_sha1 set");3285 if (verify_refname_available(update->refname,3286 &affected_refnames, NULL,3287 err)) {3288 ret = TRANSACTION_NAME_CONFLICT;3289 goto cleanup;3290 }3291 }32923293 if (lock_packed_refs(0)) {3294 strbuf_addf(err, "unable to lock packed-refs file: %s",3295 strerror(errno));3296 ret = TRANSACTION_GENERIC_ERROR;3297 goto cleanup;3298 }32993300 for (i = 0; i < transaction->nr; i++) {3301 struct ref_update *update = transaction->updates[i];33023303 if ((update->flags & REF_HAVE_NEW) &&3304 !is_null_sha1(update->new_sha1))3305 add_packed_ref(update->refname, update->new_sha1);3306 }33073308 if (commit_packed_refs()) {3309 strbuf_addf(err, "unable to commit packed-refs file: %s",3310 strerror(errno));3311 ret = TRANSACTION_GENERIC_ERROR;3312 goto cleanup;3313 }33143315cleanup:3316 transaction->state = REF_TRANSACTION_CLOSED;3317 string_list_clear(&affected_refnames, 0);3318 return ret;3319}33203321struct expire_reflog_cb {3322 unsigned int flags;3323 reflog_expiry_should_prune_fn *should_prune_fn;3324 void *policy_cb;3325 FILE *newlog;3326 unsigned char last_kept_sha1[20];3327};33283329static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,3330 const char *email, unsigned long timestamp, int tz,3331 const char *message, void *cb_data)3332{3333 struct expire_reflog_cb *cb = cb_data;3334 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;33353336 if (cb->flags & EXPIRE_REFLOGS_REWRITE)3337 osha1 = cb->last_kept_sha1;33383339 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3340 message, policy_cb)) {3341 if (!cb->newlog)3342 printf("would prune %s", message);3343 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3344 printf("prune %s", message);3345 } else {3346 if (cb->newlog) {3347 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",3348 sha1_to_hex(osha1), sha1_to_hex(nsha1),3349 email, timestamp, tz, message);3350 hashcpy(cb->last_kept_sha1, nsha1);3351 }3352 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)3353 printf("keep %s", message);3354 }3355 return 0;3356}33573358int reflog_expire(const char *refname, const unsigned char *sha1,3359 unsigned int flags,3360 reflog_expiry_prepare_fn prepare_fn,3361 reflog_expiry_should_prune_fn should_prune_fn,3362 reflog_expiry_cleanup_fn cleanup_fn,3363 void *policy_cb_data)3364{3365 static struct lock_file reflog_lock;3366 struct expire_reflog_cb cb;3367 struct ref_lock *lock;3368 char *log_file;3369 int status = 0;3370 int type;3371 struct strbuf err = STRBUF_INIT;33723373 memset(&cb, 0, sizeof(cb));3374 cb.flags = flags;3375 cb.policy_cb = policy_cb_data;3376 cb.should_prune_fn = should_prune_fn;33773378 /*3379 * The reflog file is locked by holding the lock on the3380 * reference itself, plus we might need to update the3381 * reference if --updateref was specified:3382 */3383 lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,3384 &type, &err);3385 if (!lock) {3386 error("cannot lock ref '%s': %s", refname, err.buf);3387 strbuf_release(&err);3388 return -1;3389 }3390 if (!reflog_exists(refname)) {3391 unlock_ref(lock);3392 return 0;3393 }33943395 log_file = git_pathdup("logs/%s", refname);3396 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3397 /*3398 * Even though holding $GIT_DIR/logs/$reflog.lock has3399 * no locking implications, we use the lock_file3400 * machinery here anyway because it does a lot of the3401 * work we need, including cleaning up if the program3402 * exits unexpectedly.3403 */3404 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {3405 struct strbuf err = STRBUF_INIT;3406 unable_to_lock_message(log_file, errno, &err);3407 error("%s", err.buf);3408 strbuf_release(&err);3409 goto failure;3410 }3411 cb.newlog = fdopen_lock_file(&reflog_lock, "w");3412 if (!cb.newlog) {3413 error("cannot fdopen %s (%s)",3414 get_lock_file_path(&reflog_lock), strerror(errno));3415 goto failure;3416 }3417 }34183419 (*prepare_fn)(refname, sha1, cb.policy_cb);3420 for_each_reflog_ent(refname, expire_reflog_ent, &cb);3421 (*cleanup_fn)(cb.policy_cb);34223423 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3424 /*3425 * It doesn't make sense to adjust a reference pointed3426 * to by a symbolic ref based on expiring entries in3427 * the symbolic reference's reflog. Nor can we update3428 * a reference if there are no remaining reflog3429 * entries.3430 */3431 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3432 !(type & REF_ISSYMREF) &&3433 !is_null_sha1(cb.last_kept_sha1);34343435 if (close_lock_file(&reflog_lock)) {3436 status |= error("couldn't write %s: %s", log_file,3437 strerror(errno));3438 } else if (update &&3439 (write_in_full(get_lock_file_fd(lock->lk),3440 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||3441 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||3442 close_ref(lock) < 0)) {3443 status |= error("couldn't write %s",3444 get_lock_file_path(lock->lk));3445 rollback_lock_file(&reflog_lock);3446 } else if (commit_lock_file(&reflog_lock)) {3447 status |= error("unable to write reflog '%s' (%s)",3448 log_file, strerror(errno));3449 } else if (update && commit_ref(lock)) {3450 status |= error("couldn't set %s", lock->ref_name);3451 }3452 }3453 free(log_file);3454 unlock_ref(lock);3455 return status;34563457 failure:3458 rollback_lock_file(&reflog_lock);3459 free(log_file);3460 unlock_ref(lock);3461 return -1;3462}