4 #include "refs-internal.h"
6 #include "packed-backend.h"
7 #include "../iterator.h"
8 #include "../dir-iterator.h"
9 #include "../lockfile.h"
10 #include "../object.h"
12 #include "../chdir-notify.h"
16 * This backend uses the following flags in `ref_update::flags` for
17 * internal bookkeeping purposes. Their numerical values must not
18 * conflict with REF_NO_DEREF, REF_FORCE_CREATE_REFLOG, REF_HAVE_NEW,
19 * REF_HAVE_OLD, or REF_IS_PRUNING, which are also stored in
20 * `ref_update::flags`.
24 * Used as a flag in ref_update::flags when a loose ref is being
25 * pruned. This flag must only be used when REF_NO_DEREF is set.
27 #define REF_IS_PRUNING (1 << 4)
30 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
31 * refs (i.e., because the reference is about to be deleted anyway).
33 #define REF_DELETING (1 << 5)
36 * Used as a flag in ref_update::flags when the lockfile needs to be
39 #define REF_NEEDS_COMMIT (1 << 6)
42 * Used as a flag in ref_update::flags when we want to log a ref
43 * update but not actually perform it. This is used when a symbolic
44 * ref update is split up.
46 #define REF_LOG_ONLY (1 << 7)
49 * Used as a flag in ref_update::flags when the ref_update was via an
52 #define REF_UPDATE_VIA_HEAD (1 << 8)
55 * Used as a flag in ref_update::flags when the loose reference has
58 #define REF_DELETED_LOOSE (1 << 9)
63 struct object_id old_oid;
66 struct files_ref_store {
67 struct ref_store base;
68 unsigned int store_flags;
73 struct ref_cache *loose;
75 struct ref_store *packed_ref_store;
78 static void clear_loose_ref_cache(struct files_ref_store *refs)
81 free_ref_cache(refs->loose);
87 * Create a new submodule ref cache and add it to the internal
90 static struct ref_store *files_ref_store_create(const char *gitdir,
93 struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
94 struct ref_store *ref_store = (struct ref_store *)refs;
95 struct strbuf sb = STRBUF_INIT;
97 base_ref_store_init(ref_store, &refs_be_files);
98 refs->store_flags = flags;
100 refs->gitdir = xstrdup(gitdir);
101 get_common_dir_noenv(&sb, gitdir);
102 refs->gitcommondir = strbuf_detach(&sb, NULL);
103 strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir);
104 refs->packed_ref_store = packed_ref_store_create(sb.buf, flags);
107 chdir_notify_reparent("files-backend $GIT_DIR",
109 chdir_notify_reparent("files-backend $GIT_COMMONDIR",
110 &refs->gitcommondir);
116 * Die if refs is not the main ref store. caller is used in any
117 * necessary error messages.
119 static void files_assert_main_repository(struct files_ref_store *refs,
122 if (refs->store_flags & REF_STORE_MAIN)
125 BUG("operation %s only allowed for main ref store", caller);
129 * Downcast ref_store to files_ref_store. Die if ref_store is not a
130 * files_ref_store. required_flags is compared with ref_store's
131 * store_flags to ensure the ref_store has all required capabilities.
132 * "caller" is used in any necessary error messages.
134 static struct files_ref_store *files_downcast(struct ref_store *ref_store,
135 unsigned int required_flags,
138 struct files_ref_store *refs;
140 if (ref_store->be != &refs_be_files)
141 BUG("ref_store is type \"%s\" not \"files\" in %s",
142 ref_store->be->name, caller);
144 refs = (struct files_ref_store *)ref_store;
146 if ((refs->store_flags & required_flags) != required_flags)
147 BUG("operation %s requires abilities 0x%x, but only have 0x%x",
148 caller, required_flags, refs->store_flags);
153 static void files_reflog_path_other_worktrees(struct files_ref_store *refs,
157 const char *real_ref;
158 const char *worktree_name;
161 if (parse_worktree_ref(refname, &worktree_name, &length, &real_ref))
162 BUG("refname %s is not a other-worktree ref", refname);
165 strbuf_addf(sb, "%s/worktrees/%.*s/logs/%s", refs->gitcommondir,
166 length, worktree_name, real_ref);
168 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir,
172 static void files_reflog_path(struct files_ref_store *refs,
176 switch (ref_type(refname)) {
177 case REF_TYPE_PER_WORKTREE:
178 case REF_TYPE_PSEUDOREF:
179 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname);
181 case REF_TYPE_OTHER_PSEUDOREF:
182 case REF_TYPE_MAIN_PSEUDOREF:
183 files_reflog_path_other_worktrees(refs, sb, refname);
185 case REF_TYPE_NORMAL:
186 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname);
189 BUG("unknown ref type %d of ref %s",
190 ref_type(refname), refname);
194 static void files_ref_path(struct files_ref_store *refs,
198 switch (ref_type(refname)) {
199 case REF_TYPE_PER_WORKTREE:
200 case REF_TYPE_PSEUDOREF:
201 strbuf_addf(sb, "%s/%s", refs->gitdir, refname);
203 case REF_TYPE_MAIN_PSEUDOREF:
204 if (!skip_prefix(refname, "main-worktree/", &refname))
205 BUG("ref %s is not a main pseudoref", refname);
207 case REF_TYPE_OTHER_PSEUDOREF:
208 case REF_TYPE_NORMAL:
209 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname);
212 BUG("unknown ref type %d of ref %s",
213 ref_type(refname), refname);
218 * Manually add refs/bisect, refs/rewritten and refs/worktree, which, being
219 * per-worktree, might not appear in the directory listing for
220 * refs/ in the main repo.
222 static void add_per_worktree_entries_to_dir(struct ref_dir *dir, const char *dirname)
224 const char *prefixes[] = { "refs/bisect/", "refs/worktree/", "refs/rewritten/" };
227 if (strcmp(dirname, "refs/"))
230 for (ip = 0; ip < ARRAY_SIZE(prefixes); ip++) {
231 const char *prefix = prefixes[ip];
232 int prefix_len = strlen(prefix);
233 struct ref_entry *child_entry;
236 pos = search_ref_dir(dir, prefix, prefix_len);
239 child_entry = create_dir_entry(dir->cache, prefix, prefix_len, 1);
240 add_entry_to_dir(dir, child_entry);
245 * Read the loose references from the namespace dirname into dir
246 * (without recursing). dirname must end with '/'. dir must be the
247 * directory entry corresponding to dirname.
249 static void loose_fill_ref_dir(struct ref_store *ref_store,
250 struct ref_dir *dir, const char *dirname)
252 struct files_ref_store *refs =
253 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir");
256 int dirnamelen = strlen(dirname);
257 struct strbuf refname;
258 struct strbuf path = STRBUF_INIT;
261 files_ref_path(refs, &path, dirname);
262 path_baselen = path.len;
264 d = opendir(path.buf);
266 strbuf_release(&path);
270 strbuf_init(&refname, dirnamelen + 257);
271 strbuf_add(&refname, dirname, dirnamelen);
273 while ((de = readdir(d)) != NULL) {
274 struct object_id oid;
278 if (de->d_name[0] == '.')
280 if (ends_with(de->d_name, ".lock"))
282 strbuf_addstr(&refname, de->d_name);
283 strbuf_addstr(&path, de->d_name);
284 if (stat(path.buf, &st) < 0) {
285 ; /* silently ignore */
286 } else if (S_ISDIR(st.st_mode)) {
287 strbuf_addch(&refname, '/');
288 add_entry_to_dir(dir,
289 create_dir_entry(dir->cache, refname.buf,
292 if (!refs_resolve_ref_unsafe(&refs->base,
297 flag |= REF_ISBROKEN;
298 } else if (is_null_oid(&oid)) {
300 * It is so astronomically unlikely
301 * that null_oid is the OID of an
302 * actual object that we consider its
303 * appearance in a loose reference
304 * file to be repo corruption
305 * (probably due to a software bug).
307 flag |= REF_ISBROKEN;
310 if (check_refname_format(refname.buf,
311 REFNAME_ALLOW_ONELEVEL)) {
312 if (!refname_is_safe(refname.buf))
313 die("loose refname is dangerous: %s", refname.buf);
315 flag |= REF_BAD_NAME | REF_ISBROKEN;
317 add_entry_to_dir(dir,
318 create_ref_entry(refname.buf, &oid, flag));
320 strbuf_setlen(&refname, dirnamelen);
321 strbuf_setlen(&path, path_baselen);
323 strbuf_release(&refname);
324 strbuf_release(&path);
327 add_per_worktree_entries_to_dir(dir, dirname);
330 static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)
334 * Mark the top-level directory complete because we
335 * are about to read the only subdirectory that can
338 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir);
340 /* We're going to fill the top level ourselves: */
341 refs->loose->root->flag &= ~REF_INCOMPLETE;
344 * Add an incomplete entry for "refs/" (to be filled
347 add_entry_to_dir(get_ref_dir(refs->loose->root),
348 create_dir_entry(refs->loose, "refs/", 5, 1));
353 static int files_read_raw_ref(struct ref_store *ref_store,
354 const char *refname, struct object_id *oid,
355 struct strbuf *referent, unsigned int *type)
357 struct files_ref_store *refs =
358 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
359 struct strbuf sb_contents = STRBUF_INIT;
360 struct strbuf sb_path = STRBUF_INIT;
368 int remaining_retries = 3;
371 strbuf_reset(&sb_path);
373 files_ref_path(refs, &sb_path, refname);
379 * We might have to loop back here to avoid a race
380 * condition: first we lstat() the file, then we try
381 * to read it as a link or as a file. But if somebody
382 * changes the type of the file (file <-> directory
383 * <-> symlink) between the lstat() and reading, then
384 * we don't want to report that as an error but rather
385 * try again starting with the lstat().
387 * We'll keep a count of the retries, though, just to avoid
388 * any confusing situation sending us into an infinite loop.
391 if (remaining_retries-- <= 0)
394 if (lstat(path, &st) < 0) {
397 if (refs_read_raw_ref(refs->packed_ref_store, refname,
398 oid, referent, type)) {
406 /* Follow "normalized" - ie "refs/.." symlinks by hand */
407 if (S_ISLNK(st.st_mode)) {
408 strbuf_reset(&sb_contents);
409 if (strbuf_readlink(&sb_contents, path, st.st_size) < 0) {
410 if (errno == ENOENT || errno == EINVAL)
411 /* inconsistent with lstat; retry */
416 if (starts_with(sb_contents.buf, "refs/") &&
417 !check_refname_format(sb_contents.buf, 0)) {
418 strbuf_swap(&sb_contents, referent);
419 *type |= REF_ISSYMREF;
424 * It doesn't look like a refname; fall through to just
425 * treating it like a non-symlink, and reading whatever it
430 /* Is it a directory? */
431 if (S_ISDIR(st.st_mode)) {
433 * Even though there is a directory where the loose
434 * ref is supposed to be, there could still be a
437 if (refs_read_raw_ref(refs->packed_ref_store, refname,
438 oid, referent, type)) {
447 * Anything else, just open it and try to use it as
450 fd = open(path, O_RDONLY);
452 if (errno == ENOENT && !S_ISLNK(st.st_mode))
453 /* inconsistent with lstat; retry */
458 strbuf_reset(&sb_contents);
459 if (strbuf_read(&sb_contents, fd, 256) < 0) {
460 int save_errno = errno;
466 strbuf_rtrim(&sb_contents);
467 buf = sb_contents.buf;
468 if (starts_with(buf, "ref:")) {
470 while (isspace(*buf))
473 strbuf_reset(referent);
474 strbuf_addstr(referent, buf);
475 *type |= REF_ISSYMREF;
481 * Please note that FETCH_HEAD has additional
482 * data after the sha.
484 if (parse_oid_hex(buf, oid, &p) ||
485 (*p != '\0' && !isspace(*p))) {
486 *type |= REF_ISBROKEN;
495 strbuf_release(&sb_path);
496 strbuf_release(&sb_contents);
501 static void unlock_ref(struct ref_lock *lock)
503 rollback_lock_file(&lock->lk);
504 free(lock->ref_name);
509 * Lock refname, without following symrefs, and set *lock_p to point
510 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
511 * and type similarly to read_raw_ref().
513 * The caller must verify that refname is a "safe" reference name (in
514 * the sense of refname_is_safe()) before calling this function.
516 * If the reference doesn't already exist, verify that refname doesn't
517 * have a D/F conflict with any existing references. extras and skip
518 * are passed to refs_verify_refname_available() for this check.
520 * If mustexist is not set and the reference is not found or is
521 * broken, lock the reference anyway but clear old_oid.
523 * Return 0 on success. On failure, write an error message to err and
524 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
526 * Implementation note: This function is basically
531 * but it includes a lot more code to
532 * - Deal with possible races with other processes
533 * - Avoid calling refs_verify_refname_available() when it can be
534 * avoided, namely if we were successfully able to read the ref
535 * - Generate informative error messages in the case of failure
537 static int lock_raw_ref(struct files_ref_store *refs,
538 const char *refname, int mustexist,
539 const struct string_list *extras,
540 const struct string_list *skip,
541 struct ref_lock **lock_p,
542 struct strbuf *referent,
546 struct ref_lock *lock;
547 struct strbuf ref_file = STRBUF_INIT;
548 int attempts_remaining = 3;
549 int ret = TRANSACTION_GENERIC_ERROR;
552 files_assert_main_repository(refs, "lock_raw_ref");
556 /* First lock the file so it can't change out from under us. */
558 *lock_p = lock = xcalloc(1, sizeof(*lock));
560 lock->ref_name = xstrdup(refname);
561 files_ref_path(refs, &ref_file, refname);
564 switch (safe_create_leading_directories(ref_file.buf)) {
569 * Suppose refname is "refs/foo/bar". We just failed
570 * to create the containing directory, "refs/foo",
571 * because there was a non-directory in the way. This
572 * indicates a D/F conflict, probably because of
573 * another reference such as "refs/foo". There is no
574 * reason to expect this error to be transitory.
576 if (refs_verify_refname_available(&refs->base, refname,
577 extras, skip, err)) {
580 * To the user the relevant error is
581 * that the "mustexist" reference is
585 strbuf_addf(err, "unable to resolve reference '%s'",
589 * The error message set by
590 * refs_verify_refname_available() is
593 ret = TRANSACTION_NAME_CONFLICT;
597 * The file that is in the way isn't a loose
598 * reference. Report it as a low-level
601 strbuf_addf(err, "unable to create lock file %s.lock; "
602 "non-directory in the way",
607 /* Maybe another process was tidying up. Try again. */
608 if (--attempts_remaining > 0)
612 strbuf_addf(err, "unable to create directory for %s",
617 if (hold_lock_file_for_update_timeout(
618 &lock->lk, ref_file.buf, LOCK_NO_DEREF,
619 get_files_ref_lock_timeout_ms()) < 0) {
620 if (errno == ENOENT && --attempts_remaining > 0) {
622 * Maybe somebody just deleted one of the
623 * directories leading to ref_file. Try
628 unable_to_lock_message(ref_file.buf, errno, err);
634 * Now we hold the lock and can read the reference without
635 * fear that its value will change.
638 if (files_read_raw_ref(&refs->base, refname,
639 &lock->old_oid, referent, type)) {
640 if (errno == ENOENT) {
642 /* Garden variety missing reference. */
643 strbuf_addf(err, "unable to resolve reference '%s'",
648 * Reference is missing, but that's OK. We
649 * know that there is not a conflict with
650 * another loose reference because
651 * (supposing that we are trying to lock
652 * reference "refs/foo/bar"):
654 * - We were successfully able to create
655 * the lockfile refs/foo/bar.lock, so we
656 * know there cannot be a loose reference
659 * - We got ENOENT and not EISDIR, so we
660 * know that there cannot be a loose
661 * reference named "refs/foo/bar/baz".
664 } else if (errno == EISDIR) {
666 * There is a directory in the way. It might have
667 * contained references that have been deleted. If
668 * we don't require that the reference already
669 * exists, try to remove the directory so that it
670 * doesn't cause trouble when we want to rename the
671 * lockfile into place later.
674 /* Garden variety missing reference. */
675 strbuf_addf(err, "unable to resolve reference '%s'",
678 } else if (remove_dir_recursively(&ref_file,
679 REMOVE_DIR_EMPTY_ONLY)) {
680 if (refs_verify_refname_available(
681 &refs->base, refname,
682 extras, skip, err)) {
684 * The error message set by
685 * verify_refname_available() is OK.
687 ret = TRANSACTION_NAME_CONFLICT;
691 * We can't delete the directory,
692 * but we also don't know of any
693 * references that it should
696 strbuf_addf(err, "there is a non-empty directory '%s' "
697 "blocking reference '%s'",
698 ref_file.buf, refname);
702 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
703 strbuf_addf(err, "unable to resolve reference '%s': "
704 "reference broken", refname);
707 strbuf_addf(err, "unable to resolve reference '%s': %s",
708 refname, strerror(errno));
713 * If the ref did not exist and we are creating it,
714 * make sure there is no existing packed ref that
715 * conflicts with refname:
717 if (refs_verify_refname_available(
718 refs->packed_ref_store, refname,
731 strbuf_release(&ref_file);
735 struct files_ref_iterator {
736 struct ref_iterator base;
738 struct ref_iterator *iter0;
742 static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
744 struct files_ref_iterator *iter =
745 (struct files_ref_iterator *)ref_iterator;
748 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
749 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
750 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
753 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
754 !ref_resolves_to_object(iter->iter0->refname,
759 iter->base.refname = iter->iter0->refname;
760 iter->base.oid = iter->iter0->oid;
761 iter->base.flags = iter->iter0->flags;
766 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
772 static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
773 struct object_id *peeled)
775 struct files_ref_iterator *iter =
776 (struct files_ref_iterator *)ref_iterator;
778 return ref_iterator_peel(iter->iter0, peeled);
781 static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
783 struct files_ref_iterator *iter =
784 (struct files_ref_iterator *)ref_iterator;
788 ok = ref_iterator_abort(iter->iter0);
790 base_ref_iterator_free(ref_iterator);
794 static struct ref_iterator_vtable files_ref_iterator_vtable = {
795 files_ref_iterator_advance,
796 files_ref_iterator_peel,
797 files_ref_iterator_abort
800 static struct ref_iterator *files_ref_iterator_begin(
801 struct ref_store *ref_store,
802 const char *prefix, unsigned int flags)
804 struct files_ref_store *refs;
805 struct ref_iterator *loose_iter, *packed_iter, *overlay_iter;
806 struct files_ref_iterator *iter;
807 struct ref_iterator *ref_iterator;
808 unsigned int required_flags = REF_STORE_READ;
810 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN))
811 required_flags |= REF_STORE_ODB;
813 refs = files_downcast(ref_store, required_flags, "ref_iterator_begin");
816 * We must make sure that all loose refs are read before
817 * accessing the packed-refs file; this avoids a race
818 * condition if loose refs are migrated to the packed-refs
819 * file by a simultaneous process, but our in-memory view is
820 * from before the migration. We ensure this as follows:
821 * First, we call start the loose refs iteration with its
822 * `prime_ref` argument set to true. This causes the loose
823 * references in the subtree to be pre-read into the cache.
824 * (If they've already been read, that's OK; we only need to
825 * guarantee that they're read before the packed refs, not
826 * *how much* before.) After that, we call
827 * packed_ref_iterator_begin(), which internally checks
828 * whether the packed-ref cache is up to date with what is on
829 * disk, and re-reads it if not.
832 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),
836 * The packed-refs file might contain broken references, for
837 * example an old version of a reference that points at an
838 * object that has since been garbage-collected. This is OK as
839 * long as there is a corresponding loose reference that
840 * overrides it, and we don't want to emit an error message in
841 * this case. So ask the packed_ref_store for all of its
842 * references, and (if needed) do our own check for broken
843 * ones in files_ref_iterator_advance(), after we have merged
844 * the packed and loose references.
846 packed_iter = refs_ref_iterator_begin(
847 refs->packed_ref_store, prefix, 0,
848 DO_FOR_EACH_INCLUDE_BROKEN);
850 overlay_iter = overlay_ref_iterator_begin(loose_iter, packed_iter);
852 iter = xcalloc(1, sizeof(*iter));
853 ref_iterator = &iter->base;
854 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable,
855 overlay_iter->ordered);
856 iter->iter0 = overlay_iter;
863 * Verify that the reference locked by lock has the value old_oid
864 * (unless it is NULL). Fail if the reference doesn't exist and
865 * mustexist is set. Return 0 on success. On error, write an error
866 * message to err, set errno, and return a negative value.
868 static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
869 const struct object_id *old_oid, int mustexist,
874 if (refs_read_ref_full(ref_store, lock->ref_name,
875 mustexist ? RESOLVE_REF_READING : 0,
876 &lock->old_oid, NULL)) {
878 int save_errno = errno;
879 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
883 oidclr(&lock->old_oid);
887 if (old_oid && !oideq(&lock->old_oid, old_oid)) {
888 strbuf_addf(err, "ref '%s' is at %s but expected %s",
890 oid_to_hex(&lock->old_oid),
891 oid_to_hex(old_oid));
898 static int remove_empty_directories(struct strbuf *path)
901 * we want to create a file but there is a directory there;
902 * if that is an empty directory (or a directory that contains
903 * only empty directories), remove them.
905 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
908 static int create_reflock(const char *path, void *cb)
910 struct lock_file *lk = cb;
912 return hold_lock_file_for_update_timeout(
913 lk, path, LOCK_NO_DEREF,
914 get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0;
918 * Locks a ref returning the lock on success and NULL on failure.
919 * On failure errno is set to something meaningful.
921 static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
923 const struct object_id *old_oid,
924 const struct string_list *extras,
925 const struct string_list *skip,
926 unsigned int flags, int *type,
929 struct strbuf ref_file = STRBUF_INIT;
930 struct ref_lock *lock;
932 int mustexist = (old_oid && !is_null_oid(old_oid));
933 int resolve_flags = RESOLVE_REF_NO_RECURSE;
936 files_assert_main_repository(refs, "lock_ref_oid_basic");
939 lock = xcalloc(1, sizeof(struct ref_lock));
942 resolve_flags |= RESOLVE_REF_READING;
943 if (flags & REF_DELETING)
944 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
946 files_ref_path(refs, &ref_file, refname);
947 resolved = !!refs_resolve_ref_unsafe(&refs->base,
948 refname, resolve_flags,
949 &lock->old_oid, type);
950 if (!resolved && errno == EISDIR) {
952 * we are trying to lock foo but we used to
953 * have foo/bar which now does not exist;
954 * it is normal for the empty directory 'foo'
957 if (remove_empty_directories(&ref_file)) {
959 if (!refs_verify_refname_available(
961 refname, extras, skip, err))
962 strbuf_addf(err, "there are still refs under '%s'",
966 resolved = !!refs_resolve_ref_unsafe(&refs->base,
967 refname, resolve_flags,
968 &lock->old_oid, type);
972 if (last_errno != ENOTDIR ||
973 !refs_verify_refname_available(&refs->base, refname,
975 strbuf_addf(err, "unable to resolve reference '%s': %s",
976 refname, strerror(last_errno));
982 * If the ref did not exist and we are creating it, make sure
983 * there is no existing packed ref whose name begins with our
984 * refname, nor a packed ref whose name is a proper prefix of
987 if (is_null_oid(&lock->old_oid) &&
988 refs_verify_refname_available(refs->packed_ref_store, refname,
989 extras, skip, err)) {
990 last_errno = ENOTDIR;
994 lock->ref_name = xstrdup(refname);
996 if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) {
998 unable_to_lock_message(ref_file.buf, errno, err);
1002 if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) {
1013 strbuf_release(&ref_file);
1018 struct ref_to_prune {
1019 struct ref_to_prune *next;
1020 struct object_id oid;
1021 char name[FLEX_ARRAY];
1025 REMOVE_EMPTY_PARENTS_REF = 0x01,
1026 REMOVE_EMPTY_PARENTS_REFLOG = 0x02
1030 * Remove empty parent directories associated with the specified
1031 * reference and/or its reflog, but spare [logs/]refs/ and immediate
1032 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
1033 * REMOVE_EMPTY_PARENTS_REFLOG.
1035 static void try_remove_empty_parents(struct files_ref_store *refs,
1036 const char *refname,
1039 struct strbuf buf = STRBUF_INIT;
1040 struct strbuf sb = STRBUF_INIT;
1044 strbuf_addstr(&buf, refname);
1046 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
1047 while (*p && *p != '/')
1049 /* tolerate duplicate slashes; see check_refname_format() */
1053 q = buf.buf + buf.len;
1054 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
1055 while (q > p && *q != '/')
1057 while (q > p && *(q-1) == '/')
1061 strbuf_setlen(&buf, q - buf.buf);
1064 files_ref_path(refs, &sb, buf.buf);
1065 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
1066 flags &= ~REMOVE_EMPTY_PARENTS_REF;
1069 files_reflog_path(refs, &sb, buf.buf);
1070 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))
1071 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
1073 strbuf_release(&buf);
1074 strbuf_release(&sb);
1077 /* make sure nobody touched the ref, and unlink */
1078 static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
1080 struct ref_transaction *transaction;
1081 struct strbuf err = STRBUF_INIT;
1084 if (check_refname_format(r->name, 0))
1087 transaction = ref_store_transaction_begin(&refs->base, &err);
1090 ref_transaction_add_update(
1091 transaction, r->name,
1092 REF_NO_DEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_IS_PRUNING,
1093 &null_oid, &r->oid, NULL);
1094 if (ref_transaction_commit(transaction, &err))
1101 error("%s", err.buf);
1102 strbuf_release(&err);
1103 ref_transaction_free(transaction);
1108 * Prune the loose versions of the references in the linked list
1109 * `*refs_to_prune`, freeing the entries in the list as we go.
1111 static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune)
1113 while (*refs_to_prune) {
1114 struct ref_to_prune *r = *refs_to_prune;
1115 *refs_to_prune = r->next;
1122 * Return true if the specified reference should be packed.
1124 static int should_pack_ref(const char *refname,
1125 const struct object_id *oid, unsigned int ref_flags,
1126 unsigned int pack_flags)
1128 /* Do not pack per-worktree refs: */
1129 if (ref_type(refname) != REF_TYPE_NORMAL)
1132 /* Do not pack non-tags unless PACK_REFS_ALL is set: */
1133 if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/"))
1136 /* Do not pack symbolic refs: */
1137 if (ref_flags & REF_ISSYMREF)
1140 /* Do not pack broken refs: */
1141 if (!ref_resolves_to_object(refname, oid, ref_flags))
1147 static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
1149 struct files_ref_store *refs =
1150 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,
1152 struct ref_iterator *iter;
1154 struct ref_to_prune *refs_to_prune = NULL;
1155 struct strbuf err = STRBUF_INIT;
1156 struct ref_transaction *transaction;
1158 transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
1162 packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err);
1164 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);
1165 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1167 * If the loose reference can be packed, add an entry
1168 * in the packed ref cache. If the reference should be
1169 * pruned, also add it to refs_to_prune.
1171 if (!should_pack_ref(iter->refname, iter->oid, iter->flags,
1176 * Add a reference creation for this reference to the
1177 * packed-refs transaction:
1179 if (ref_transaction_update(transaction, iter->refname,
1181 REF_NO_DEREF, NULL, &err))
1182 die("failure preparing to create packed reference %s: %s",
1183 iter->refname, err.buf);
1185 /* Schedule the loose reference for pruning if requested. */
1186 if ((flags & PACK_REFS_PRUNE)) {
1187 struct ref_to_prune *n;
1188 FLEX_ALLOC_STR(n, name, iter->refname);
1189 oidcpy(&n->oid, iter->oid);
1190 n->next = refs_to_prune;
1194 if (ok != ITER_DONE)
1195 die("error while iterating over references");
1197 if (ref_transaction_commit(transaction, &err))
1198 die("unable to write new packed-refs: %s", err.buf);
1200 ref_transaction_free(transaction);
1202 packed_refs_unlock(refs->packed_ref_store);
1204 prune_refs(refs, &refs_to_prune);
1205 strbuf_release(&err);
1209 static int files_delete_refs(struct ref_store *ref_store, const char *msg,
1210 struct string_list *refnames, unsigned int flags)
1212 struct files_ref_store *refs =
1213 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
1214 struct strbuf err = STRBUF_INIT;
1220 if (packed_refs_lock(refs->packed_ref_store, 0, &err))
1223 if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) {
1224 packed_refs_unlock(refs->packed_ref_store);
1228 packed_refs_unlock(refs->packed_ref_store);
1230 for (i = 0; i < refnames->nr; i++) {
1231 const char *refname = refnames->items[i].string;
1233 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))
1234 result |= error(_("could not remove reference %s"), refname);
1237 strbuf_release(&err);
1242 * If we failed to rewrite the packed-refs file, then it is
1243 * unsafe to try to remove loose refs, because doing so might
1244 * expose an obsolete packed value for a reference that might
1245 * even point at an object that has been garbage collected.
1247 if (refnames->nr == 1)
1248 error(_("could not delete reference %s: %s"),
1249 refnames->items[0].string, err.buf);
1251 error(_("could not delete references: %s"), err.buf);
1253 strbuf_release(&err);
1258 * People using contrib's git-new-workdir have .git/logs/refs ->
1259 * /some/other/path/.git/logs/refs, and that may live on another device.
1261 * IOW, to avoid cross device rename errors, the temporary renamed log must
1262 * live into logs/refs.
1264 #define TMP_RENAMED_LOG "refs/.tmp-renamed-log"
1267 const char *tmp_renamed_log;
1271 static int rename_tmp_log_callback(const char *path, void *cb_data)
1273 struct rename_cb *cb = cb_data;
1275 if (rename(cb->tmp_renamed_log, path)) {
1277 * rename(a, b) when b is an existing directory ought
1278 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
1279 * Sheesh. Record the true errno for error reporting,
1280 * but report EISDIR to raceproof_create_file() so
1281 * that it knows to retry.
1283 cb->true_errno = errno;
1284 if (errno == ENOTDIR)
1292 static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)
1294 struct strbuf path = STRBUF_INIT;
1295 struct strbuf tmp = STRBUF_INIT;
1296 struct rename_cb cb;
1299 files_reflog_path(refs, &path, newrefname);
1300 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);
1301 cb.tmp_renamed_log = tmp.buf;
1302 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
1304 if (errno == EISDIR)
1305 error("directory not empty: %s", path.buf);
1307 error("unable to move logfile %s to %s: %s",
1309 strerror(cb.true_errno));
1312 strbuf_release(&path);
1313 strbuf_release(&tmp);
1317 static int write_ref_to_lockfile(struct ref_lock *lock,
1318 const struct object_id *oid, struct strbuf *err);
1319 static int commit_ref_update(struct files_ref_store *refs,
1320 struct ref_lock *lock,
1321 const struct object_id *oid, const char *logmsg,
1322 struct strbuf *err);
1324 static int files_copy_or_rename_ref(struct ref_store *ref_store,
1325 const char *oldrefname, const char *newrefname,
1326 const char *logmsg, int copy)
1328 struct files_ref_store *refs =
1329 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
1330 struct object_id oid, orig_oid;
1331 int flag = 0, logmoved = 0;
1332 struct ref_lock *lock;
1333 struct stat loginfo;
1334 struct strbuf sb_oldref = STRBUF_INIT;
1335 struct strbuf sb_newref = STRBUF_INIT;
1336 struct strbuf tmp_renamed_log = STRBUF_INIT;
1338 struct strbuf err = STRBUF_INIT;
1340 files_reflog_path(refs, &sb_oldref, oldrefname);
1341 files_reflog_path(refs, &sb_newref, newrefname);
1342 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);
1344 log = !lstat(sb_oldref.buf, &loginfo);
1345 if (log && S_ISLNK(loginfo.st_mode)) {
1346 ret = error("reflog for %s is a symlink", oldrefname);
1350 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,
1351 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
1352 &orig_oid, &flag)) {
1353 ret = error("refname %s not found", oldrefname);
1357 if (flag & REF_ISSYMREF) {
1359 ret = error("refname %s is a symbolic ref, copying it is not supported",
1362 ret = error("refname %s is a symbolic ref, renaming it is not supported",
1366 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {
1371 if (!copy && log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
1372 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1373 oldrefname, strerror(errno));
1377 if (copy && log && copy_file(tmp_renamed_log.buf, sb_oldref.buf, 0644)) {
1378 ret = error("unable to copy logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1379 oldrefname, strerror(errno));
1383 if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname,
1384 &orig_oid, REF_NO_DEREF)) {
1385 error("unable to delete old %s", oldrefname);
1390 * Since we are doing a shallow lookup, oid is not the
1391 * correct value to pass to delete_ref as old_oid. But that
1392 * doesn't matter, because an old_oid check wouldn't add to
1393 * the safety anyway; we want to delete the reference whatever
1394 * its current value.
1396 if (!copy && !refs_read_ref_full(&refs->base, newrefname,
1397 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
1399 refs_delete_ref(&refs->base, NULL, newrefname,
1400 NULL, REF_NO_DEREF)) {
1401 if (errno == EISDIR) {
1402 struct strbuf path = STRBUF_INIT;
1405 files_ref_path(refs, &path, newrefname);
1406 result = remove_empty_directories(&path);
1407 strbuf_release(&path);
1410 error("Directory not empty: %s", newrefname);
1414 error("unable to delete existing %s", newrefname);
1419 if (log && rename_tmp_log(refs, newrefname))
1424 lock = lock_ref_oid_basic(refs, newrefname, NULL, NULL, NULL,
1425 REF_NO_DEREF, NULL, &err);
1428 error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1430 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1431 strbuf_release(&err);
1434 oidcpy(&lock->old_oid, &orig_oid);
1436 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1437 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {
1438 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
1439 strbuf_release(&err);
1447 lock = lock_ref_oid_basic(refs, oldrefname, NULL, NULL, NULL,
1448 REF_NO_DEREF, NULL, &err);
1450 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
1451 strbuf_release(&err);
1455 flag = log_all_ref_updates;
1456 log_all_ref_updates = LOG_REFS_NONE;
1457 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1458 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {
1459 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
1460 strbuf_release(&err);
1462 log_all_ref_updates = flag;
1465 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
1466 error("unable to restore logfile %s from %s: %s",
1467 oldrefname, newrefname, strerror(errno));
1468 if (!logmoved && log &&
1469 rename(tmp_renamed_log.buf, sb_oldref.buf))
1470 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",
1471 oldrefname, strerror(errno));
1474 strbuf_release(&sb_newref);
1475 strbuf_release(&sb_oldref);
1476 strbuf_release(&tmp_renamed_log);
1481 static int files_rename_ref(struct ref_store *ref_store,
1482 const char *oldrefname, const char *newrefname,
1485 return files_copy_or_rename_ref(ref_store, oldrefname,
1486 newrefname, logmsg, 0);
1489 static int files_copy_ref(struct ref_store *ref_store,
1490 const char *oldrefname, const char *newrefname,
1493 return files_copy_or_rename_ref(ref_store, oldrefname,
1494 newrefname, logmsg, 1);
1497 static int close_ref_gently(struct ref_lock *lock)
1499 if (close_lock_file_gently(&lock->lk))
1504 static int commit_ref(struct ref_lock *lock)
1506 char *path = get_locked_file_path(&lock->lk);
1509 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
1511 * There is a directory at the path we want to rename
1512 * the lockfile to. Hopefully it is empty; try to
1515 size_t len = strlen(path);
1516 struct strbuf sb_path = STRBUF_INIT;
1518 strbuf_attach(&sb_path, path, len, len);
1521 * If this fails, commit_lock_file() will also fail
1522 * and will report the problem.
1524 remove_empty_directories(&sb_path);
1525 strbuf_release(&sb_path);
1530 if (commit_lock_file(&lock->lk))
1535 static int open_or_create_logfile(const char *path, void *cb)
1539 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
1540 return (*fd < 0) ? -1 : 0;
1544 * Create a reflog for a ref. If force_create = 0, only create the
1545 * reflog for certain refs (those for which should_autocreate_reflog
1546 * returns non-zero). Otherwise, create it regardless of the reference
1547 * name. If the logfile already existed or was created, return 0 and
1548 * set *logfd to the file descriptor opened for appending to the file.
1549 * If no logfile exists and we decided not to create one, return 0 and
1550 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
1553 static int log_ref_setup(struct files_ref_store *refs,
1554 const char *refname, int force_create,
1555 int *logfd, struct strbuf *err)
1557 struct strbuf logfile_sb = STRBUF_INIT;
1560 files_reflog_path(refs, &logfile_sb, refname);
1561 logfile = strbuf_detach(&logfile_sb, NULL);
1563 if (force_create || should_autocreate_reflog(refname)) {
1564 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
1565 if (errno == ENOENT)
1566 strbuf_addf(err, "unable to create directory for '%s': "
1567 "%s", logfile, strerror(errno));
1568 else if (errno == EISDIR)
1569 strbuf_addf(err, "there are still logs under '%s'",
1572 strbuf_addf(err, "unable to append to '%s': %s",
1573 logfile, strerror(errno));
1578 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
1580 if (errno == ENOENT || errno == EISDIR) {
1582 * The logfile doesn't already exist,
1583 * but that is not an error; it only
1584 * means that we won't write log
1589 strbuf_addf(err, "unable to append to '%s': %s",
1590 logfile, strerror(errno));
1597 adjust_shared_perm(logfile);
1607 static int files_create_reflog(struct ref_store *ref_store,
1608 const char *refname, int force_create,
1611 struct files_ref_store *refs =
1612 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");
1615 if (log_ref_setup(refs, refname, force_create, &fd, err))
1624 static int log_ref_write_fd(int fd, const struct object_id *old_oid,
1625 const struct object_id *new_oid,
1626 const char *committer, const char *msg)
1628 struct strbuf sb = STRBUF_INIT;
1631 strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer);
1633 copy_reflog_msg(&sb, msg);
1634 strbuf_addch(&sb, '\n');
1635 if (write_in_full(fd, sb.buf, sb.len) < 0)
1637 strbuf_release(&sb);
1641 static int files_log_ref_write(struct files_ref_store *refs,
1642 const char *refname, const struct object_id *old_oid,
1643 const struct object_id *new_oid, const char *msg,
1644 int flags, struct strbuf *err)
1648 if (log_all_ref_updates == LOG_REFS_UNSET)
1649 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
1651 result = log_ref_setup(refs, refname,
1652 flags & REF_FORCE_CREATE_REFLOG,
1660 result = log_ref_write_fd(logfd, old_oid, new_oid,
1661 git_committer_info(0), msg);
1663 struct strbuf sb = STRBUF_INIT;
1664 int save_errno = errno;
1666 files_reflog_path(refs, &sb, refname);
1667 strbuf_addf(err, "unable to append to '%s': %s",
1668 sb.buf, strerror(save_errno));
1669 strbuf_release(&sb);
1674 struct strbuf sb = STRBUF_INIT;
1675 int save_errno = errno;
1677 files_reflog_path(refs, &sb, refname);
1678 strbuf_addf(err, "unable to append to '%s': %s",
1679 sb.buf, strerror(save_errno));
1680 strbuf_release(&sb);
1687 * Write oid into the open lockfile, then close the lockfile. On
1688 * errors, rollback the lockfile, fill in *err and return -1.
1690 static int write_ref_to_lockfile(struct ref_lock *lock,
1691 const struct object_id *oid, struct strbuf *err)
1693 static char term = '\n';
1697 o = parse_object(the_repository, oid);
1700 "trying to write ref '%s' with nonexistent object %s",
1701 lock->ref_name, oid_to_hex(oid));
1705 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1707 "trying to write non-commit object %s to branch '%s'",
1708 oid_to_hex(oid), lock->ref_name);
1712 fd = get_lock_file_fd(&lock->lk);
1713 if (write_in_full(fd, oid_to_hex(oid), the_hash_algo->hexsz) < 0 ||
1714 write_in_full(fd, &term, 1) < 0 ||
1715 close_ref_gently(lock) < 0) {
1717 "couldn't write '%s'", get_lock_file_path(&lock->lk));
1725 * Commit a change to a loose reference that has already been written
1726 * to the loose reference lockfile. Also update the reflogs if
1727 * necessary, using the specified lockmsg (which can be NULL).
1729 static int commit_ref_update(struct files_ref_store *refs,
1730 struct ref_lock *lock,
1731 const struct object_id *oid, const char *logmsg,
1734 files_assert_main_repository(refs, "commit_ref_update");
1736 clear_loose_ref_cache(refs);
1737 if (files_log_ref_write(refs, lock->ref_name,
1738 &lock->old_oid, oid,
1740 char *old_msg = strbuf_detach(err, NULL);
1741 strbuf_addf(err, "cannot update the ref '%s': %s",
1742 lock->ref_name, old_msg);
1748 if (strcmp(lock->ref_name, "HEAD") != 0) {
1750 * Special hack: If a branch is updated directly and HEAD
1751 * points to it (may happen on the remote side of a push
1752 * for example) then logically the HEAD reflog should be
1754 * A generic solution implies reverse symref information,
1755 * but finding all symrefs pointing to the given branch
1756 * would be rather costly for this rare event (the direct
1757 * update of a branch) to be worth it. So let's cheat and
1758 * check with HEAD only which should cover 99% of all usage
1759 * scenarios (even 100% of the default ones).
1762 const char *head_ref;
1764 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",
1765 RESOLVE_REF_READING,
1767 if (head_ref && (head_flag & REF_ISSYMREF) &&
1768 !strcmp(head_ref, lock->ref_name)) {
1769 struct strbuf log_err = STRBUF_INIT;
1770 if (files_log_ref_write(refs, "HEAD",
1771 &lock->old_oid, oid,
1772 logmsg, 0, &log_err)) {
1773 error("%s", log_err.buf);
1774 strbuf_release(&log_err);
1779 if (commit_ref(lock)) {
1780 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
1789 static int create_ref_symlink(struct ref_lock *lock, const char *target)
1792 #ifndef NO_SYMLINK_HEAD
1793 char *ref_path = get_locked_file_path(&lock->lk);
1795 ret = symlink(target, ref_path);
1799 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1804 static void update_symref_reflog(struct files_ref_store *refs,
1805 struct ref_lock *lock, const char *refname,
1806 const char *target, const char *logmsg)
1808 struct strbuf err = STRBUF_INIT;
1809 struct object_id new_oid;
1811 !refs_read_ref_full(&refs->base, target,
1812 RESOLVE_REF_READING, &new_oid, NULL) &&
1813 files_log_ref_write(refs, refname, &lock->old_oid,
1814 &new_oid, logmsg, 0, &err)) {
1815 error("%s", err.buf);
1816 strbuf_release(&err);
1820 static int create_symref_locked(struct files_ref_store *refs,
1821 struct ref_lock *lock, const char *refname,
1822 const char *target, const char *logmsg)
1824 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
1825 update_symref_reflog(refs, lock, refname, target, logmsg);
1829 if (!fdopen_lock_file(&lock->lk, "w"))
1830 return error("unable to fdopen %s: %s",
1831 lock->lk.tempfile->filename.buf, strerror(errno));
1833 update_symref_reflog(refs, lock, refname, target, logmsg);
1835 /* no error check; commit_ref will check ferror */
1836 fprintf(lock->lk.tempfile->fp, "ref: %s\n", target);
1837 if (commit_ref(lock) < 0)
1838 return error("unable to write symref for %s: %s", refname,
1843 static int files_create_symref(struct ref_store *ref_store,
1844 const char *refname, const char *target,
1847 struct files_ref_store *refs =
1848 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");
1849 struct strbuf err = STRBUF_INIT;
1850 struct ref_lock *lock;
1853 lock = lock_ref_oid_basic(refs, refname, NULL,
1854 NULL, NULL, REF_NO_DEREF, NULL,
1857 error("%s", err.buf);
1858 strbuf_release(&err);
1862 ret = create_symref_locked(refs, lock, refname, target, logmsg);
1867 static int files_reflog_exists(struct ref_store *ref_store,
1868 const char *refname)
1870 struct files_ref_store *refs =
1871 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");
1872 struct strbuf sb = STRBUF_INIT;
1876 files_reflog_path(refs, &sb, refname);
1877 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);
1878 strbuf_release(&sb);
1882 static int files_delete_reflog(struct ref_store *ref_store,
1883 const char *refname)
1885 struct files_ref_store *refs =
1886 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");
1887 struct strbuf sb = STRBUF_INIT;
1890 files_reflog_path(refs, &sb, refname);
1891 ret = remove_path(sb.buf);
1892 strbuf_release(&sb);
1896 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
1898 struct object_id ooid, noid;
1899 char *email_end, *message;
1900 timestamp_t timestamp;
1902 const char *p = sb->buf;
1904 /* old SP new SP name <email> SP time TAB msg LF */
1905 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
1906 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
1907 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
1908 !(email_end = strchr(p, '>')) ||
1909 email_end[1] != ' ' ||
1910 !(timestamp = parse_timestamp(email_end + 2, &message, 10)) ||
1911 !message || message[0] != ' ' ||
1912 (message[1] != '+' && message[1] != '-') ||
1913 !isdigit(message[2]) || !isdigit(message[3]) ||
1914 !isdigit(message[4]) || !isdigit(message[5]))
1915 return 0; /* corrupt? */
1916 email_end[1] = '\0';
1917 tz = strtol(message + 1, NULL, 10);
1918 if (message[6] != '\t')
1922 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
1925 static char *find_beginning_of_line(char *bob, char *scan)
1927 while (bob < scan && *(--scan) != '\n')
1928 ; /* keep scanning backwards */
1930 * Return either beginning of the buffer, or LF at the end of
1931 * the previous line.
1936 static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,
1937 const char *refname,
1938 each_reflog_ent_fn fn,
1941 struct files_ref_store *refs =
1942 files_downcast(ref_store, REF_STORE_READ,
1943 "for_each_reflog_ent_reverse");
1944 struct strbuf sb = STRBUF_INIT;
1947 int ret = 0, at_tail = 1;
1949 files_reflog_path(refs, &sb, refname);
1950 logfp = fopen(sb.buf, "r");
1951 strbuf_release(&sb);
1955 /* Jump to the end */
1956 if (fseek(logfp, 0, SEEK_END) < 0)
1957 ret = error("cannot seek back reflog for %s: %s",
1958 refname, strerror(errno));
1960 while (!ret && 0 < pos) {
1966 /* Fill next block from the end */
1967 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
1968 if (fseek(logfp, pos - cnt, SEEK_SET)) {
1969 ret = error("cannot seek back reflog for %s: %s",
1970 refname, strerror(errno));
1973 nread = fread(buf, cnt, 1, logfp);
1975 ret = error("cannot read %d bytes from reflog for %s: %s",
1976 cnt, refname, strerror(errno));
1981 scanp = endp = buf + cnt;
1982 if (at_tail && scanp[-1] == '\n')
1983 /* Looking at the final LF at the end of the file */
1987 while (buf < scanp) {
1989 * terminating LF of the previous line, or the beginning
1994 bp = find_beginning_of_line(buf, scanp);
1998 * The newline is the end of the previous line,
1999 * so we know we have complete line starting
2000 * at (bp + 1). Prefix it onto any prior data
2001 * we collected for the line and process it.
2003 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
2006 ret = show_one_reflog_ent(&sb, fn, cb_data);
2012 * We are at the start of the buffer, and the
2013 * start of the file; there is no previous
2014 * line, and we have everything for this one.
2015 * Process it, and we can end the loop.
2017 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2018 ret = show_one_reflog_ent(&sb, fn, cb_data);
2025 * We are at the start of the buffer, and there
2026 * is more file to read backwards. Which means
2027 * we are in the middle of a line. Note that we
2028 * may get here even if *bp was a newline; that
2029 * just means we are at the exact end of the
2030 * previous line, rather than some spot in the
2033 * Save away what we have to be combined with
2034 * the data from the next read.
2036 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2043 BUG("reverse reflog parser had leftover data");
2046 strbuf_release(&sb);
2050 static int files_for_each_reflog_ent(struct ref_store *ref_store,
2051 const char *refname,
2052 each_reflog_ent_fn fn, void *cb_data)
2054 struct files_ref_store *refs =
2055 files_downcast(ref_store, REF_STORE_READ,
2056 "for_each_reflog_ent");
2058 struct strbuf sb = STRBUF_INIT;
2061 files_reflog_path(refs, &sb, refname);
2062 logfp = fopen(sb.buf, "r");
2063 strbuf_release(&sb);
2067 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
2068 ret = show_one_reflog_ent(&sb, fn, cb_data);
2070 strbuf_release(&sb);
2074 struct files_reflog_iterator {
2075 struct ref_iterator base;
2077 struct ref_store *ref_store;
2078 struct dir_iterator *dir_iterator;
2079 struct object_id oid;
2082 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
2084 struct files_reflog_iterator *iter =
2085 (struct files_reflog_iterator *)ref_iterator;
2086 struct dir_iterator *diter = iter->dir_iterator;
2089 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
2092 if (!S_ISREG(diter->st.st_mode))
2094 if (diter->basename[0] == '.')
2096 if (ends_with(diter->basename, ".lock"))
2099 if (refs_read_ref_full(iter->ref_store,
2100 diter->relative_path, 0,
2101 &iter->oid, &flags)) {
2102 error("bad ref for %s", diter->path.buf);
2106 iter->base.refname = diter->relative_path;
2107 iter->base.oid = &iter->oid;
2108 iter->base.flags = flags;
2112 iter->dir_iterator = NULL;
2113 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
2118 static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
2119 struct object_id *peeled)
2121 BUG("ref_iterator_peel() called for reflog_iterator");
2124 static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
2126 struct files_reflog_iterator *iter =
2127 (struct files_reflog_iterator *)ref_iterator;
2130 if (iter->dir_iterator)
2131 ok = dir_iterator_abort(iter->dir_iterator);
2133 base_ref_iterator_free(ref_iterator);
2137 static struct ref_iterator_vtable files_reflog_iterator_vtable = {
2138 files_reflog_iterator_advance,
2139 files_reflog_iterator_peel,
2140 files_reflog_iterator_abort
2143 static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
2146 struct dir_iterator *diter;
2147 struct files_reflog_iterator *iter;
2148 struct ref_iterator *ref_iterator;
2149 struct strbuf sb = STRBUF_INIT;
2151 strbuf_addf(&sb, "%s/logs", gitdir);
2153 diter = dir_iterator_begin(sb.buf, 0);
2155 strbuf_release(&sb);
2156 return empty_ref_iterator_begin();
2159 iter = xcalloc(1, sizeof(*iter));
2160 ref_iterator = &iter->base;
2162 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0);
2163 iter->dir_iterator = diter;
2164 iter->ref_store = ref_store;
2165 strbuf_release(&sb);
2167 return ref_iterator;
2170 static enum iterator_selection reflog_iterator_select(
2171 struct ref_iterator *iter_worktree,
2172 struct ref_iterator *iter_common,
2175 if (iter_worktree) {
2177 * We're a bit loose here. We probably should ignore
2178 * common refs if they are accidentally added as
2179 * per-worktree refs.
2181 return ITER_SELECT_0;
2182 } else if (iter_common) {
2183 if (ref_type(iter_common->refname) == REF_TYPE_NORMAL)
2184 return ITER_SELECT_1;
2187 * The main ref store may contain main worktree's
2188 * per-worktree refs, which should be ignored
2195 static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
2197 struct files_ref_store *refs =
2198 files_downcast(ref_store, REF_STORE_READ,
2199 "reflog_iterator_begin");
2201 if (!strcmp(refs->gitdir, refs->gitcommondir)) {
2202 return reflog_iterator_begin(ref_store, refs->gitcommondir);
2204 return merge_ref_iterator_begin(
2206 reflog_iterator_begin(ref_store, refs->gitdir),
2207 reflog_iterator_begin(ref_store, refs->gitcommondir),
2208 reflog_iterator_select, refs);
2213 * If update is a direct update of head_ref (the reference pointed to
2214 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
2216 static int split_head_update(struct ref_update *update,
2217 struct ref_transaction *transaction,
2218 const char *head_ref,
2219 struct string_list *affected_refnames,
2222 struct string_list_item *item;
2223 struct ref_update *new_update;
2225 if ((update->flags & REF_LOG_ONLY) ||
2226 (update->flags & REF_IS_PRUNING) ||
2227 (update->flags & REF_UPDATE_VIA_HEAD))
2230 if (strcmp(update->refname, head_ref))
2234 * First make sure that HEAD is not already in the
2235 * transaction. This check is O(lg N) in the transaction
2236 * size, but it happens at most once per transaction.
2238 if (string_list_has_string(affected_refnames, "HEAD")) {
2239 /* An entry already existed */
2241 "multiple updates for 'HEAD' (including one "
2242 "via its referent '%s') are not allowed",
2244 return TRANSACTION_NAME_CONFLICT;
2247 new_update = ref_transaction_add_update(
2248 transaction, "HEAD",
2249 update->flags | REF_LOG_ONLY | REF_NO_DEREF,
2250 &update->new_oid, &update->old_oid,
2254 * Add "HEAD". This insertion is O(N) in the transaction
2255 * size, but it happens at most once per transaction.
2256 * Add new_update->refname instead of a literal "HEAD".
2258 if (strcmp(new_update->refname, "HEAD"))
2259 BUG("%s unexpectedly not 'HEAD'", new_update->refname);
2260 item = string_list_insert(affected_refnames, new_update->refname);
2261 item->util = new_update;
2267 * update is for a symref that points at referent and doesn't have
2268 * REF_NO_DEREF set. Split it into two updates:
2269 * - The original update, but with REF_LOG_ONLY and REF_NO_DEREF set
2270 * - A new, separate update for the referent reference
2271 * Note that the new update will itself be subject to splitting when
2272 * the iteration gets to it.
2274 static int split_symref_update(struct ref_update *update,
2275 const char *referent,
2276 struct ref_transaction *transaction,
2277 struct string_list *affected_refnames,
2280 struct string_list_item *item;
2281 struct ref_update *new_update;
2282 unsigned int new_flags;
2285 * First make sure that referent is not already in the
2286 * transaction. This check is O(lg N) in the transaction
2287 * size, but it happens at most once per symref in a
2290 if (string_list_has_string(affected_refnames, referent)) {
2291 /* An entry already exists */
2293 "multiple updates for '%s' (including one "
2294 "via symref '%s') are not allowed",
2295 referent, update->refname);
2296 return TRANSACTION_NAME_CONFLICT;
2299 new_flags = update->flags;
2300 if (!strcmp(update->refname, "HEAD")) {
2302 * Record that the new update came via HEAD, so that
2303 * when we process it, split_head_update() doesn't try
2304 * to add another reflog update for HEAD. Note that
2305 * this bit will be propagated if the new_update
2306 * itself needs to be split.
2308 new_flags |= REF_UPDATE_VIA_HEAD;
2311 new_update = ref_transaction_add_update(
2312 transaction, referent, new_flags,
2313 &update->new_oid, &update->old_oid,
2316 new_update->parent_update = update;
2319 * Change the symbolic ref update to log only. Also, it
2320 * doesn't need to check its old OID value, as that will be
2321 * done when new_update is processed.
2323 update->flags |= REF_LOG_ONLY | REF_NO_DEREF;
2324 update->flags &= ~REF_HAVE_OLD;
2327 * Add the referent. This insertion is O(N) in the transaction
2328 * size, but it happens at most once per symref in a
2329 * transaction. Make sure to add new_update->refname, which will
2330 * be valid as long as affected_refnames is in use, and NOT
2331 * referent, which might soon be freed by our caller.
2333 item = string_list_insert(affected_refnames, new_update->refname);
2335 BUG("%s unexpectedly found in affected_refnames",
2336 new_update->refname);
2337 item->util = new_update;
2343 * Return the refname under which update was originally requested.
2345 static const char *original_update_refname(struct ref_update *update)
2347 while (update->parent_update)
2348 update = update->parent_update;
2350 return update->refname;
2354 * Check whether the REF_HAVE_OLD and old_oid values stored in update
2355 * are consistent with oid, which is the reference's current value. If
2356 * everything is OK, return 0; otherwise, write an error message to
2357 * err and return -1.
2359 static int check_old_oid(struct ref_update *update, struct object_id *oid,
2362 if (!(update->flags & REF_HAVE_OLD) ||
2363 oideq(oid, &update->old_oid))
2366 if (is_null_oid(&update->old_oid))
2367 strbuf_addf(err, "cannot lock ref '%s': "
2368 "reference already exists",
2369 original_update_refname(update));
2370 else if (is_null_oid(oid))
2371 strbuf_addf(err, "cannot lock ref '%s': "
2372 "reference is missing but expected %s",
2373 original_update_refname(update),
2374 oid_to_hex(&update->old_oid));
2376 strbuf_addf(err, "cannot lock ref '%s': "
2377 "is at %s but expected %s",
2378 original_update_refname(update),
2380 oid_to_hex(&update->old_oid));
2386 * Prepare for carrying out update:
2387 * - Lock the reference referred to by update.
2388 * - Read the reference under lock.
2389 * - Check that its old OID value (if specified) is correct, and in
2390 * any case record it in update->lock->old_oid for later use when
2391 * writing the reflog.
2392 * - If it is a symref update without REF_NO_DEREF, split it up into a
2393 * REF_LOG_ONLY update of the symref and add a separate update for
2394 * the referent to transaction.
2395 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
2398 static int lock_ref_for_update(struct files_ref_store *refs,
2399 struct ref_update *update,
2400 struct ref_transaction *transaction,
2401 const char *head_ref,
2402 struct string_list *affected_refnames,
2405 struct strbuf referent = STRBUF_INIT;
2406 int mustexist = (update->flags & REF_HAVE_OLD) &&
2407 !is_null_oid(&update->old_oid);
2409 struct ref_lock *lock;
2411 files_assert_main_repository(refs, "lock_ref_for_update");
2413 if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid))
2414 update->flags |= REF_DELETING;
2417 ret = split_head_update(update, transaction, head_ref,
2418 affected_refnames, err);
2423 ret = lock_raw_ref(refs, update->refname, mustexist,
2424 affected_refnames, NULL,
2426 &update->type, err);
2430 reason = strbuf_detach(err, NULL);
2431 strbuf_addf(err, "cannot lock ref '%s': %s",
2432 original_update_refname(update), reason);
2437 update->backend_data = lock;
2439 if (update->type & REF_ISSYMREF) {
2440 if (update->flags & REF_NO_DEREF) {
2442 * We won't be reading the referent as part of
2443 * the transaction, so we have to read it here
2444 * to record and possibly check old_oid:
2446 if (refs_read_ref_full(&refs->base,
2448 &lock->old_oid, NULL)) {
2449 if (update->flags & REF_HAVE_OLD) {
2450 strbuf_addf(err, "cannot lock ref '%s': "
2451 "error reading reference",
2452 original_update_refname(update));
2453 ret = TRANSACTION_GENERIC_ERROR;
2456 } else if (check_old_oid(update, &lock->old_oid, err)) {
2457 ret = TRANSACTION_GENERIC_ERROR;
2462 * Create a new update for the reference this
2463 * symref is pointing at. Also, we will record
2464 * and verify old_oid for this update as part
2465 * of processing the split-off update, so we
2466 * don't have to do it here.
2468 ret = split_symref_update(update,
2469 referent.buf, transaction,
2470 affected_refnames, err);
2475 struct ref_update *parent_update;
2477 if (check_old_oid(update, &lock->old_oid, err)) {
2478 ret = TRANSACTION_GENERIC_ERROR;
2483 * If this update is happening indirectly because of a
2484 * symref update, record the old OID in the parent
2487 for (parent_update = update->parent_update;
2489 parent_update = parent_update->parent_update) {
2490 struct ref_lock *parent_lock = parent_update->backend_data;
2491 oidcpy(&parent_lock->old_oid, &lock->old_oid);
2495 if ((update->flags & REF_HAVE_NEW) &&
2496 !(update->flags & REF_DELETING) &&
2497 !(update->flags & REF_LOG_ONLY)) {
2498 if (!(update->type & REF_ISSYMREF) &&
2499 oideq(&lock->old_oid, &update->new_oid)) {
2501 * The reference already has the desired
2502 * value, so we don't need to write it.
2504 } else if (write_ref_to_lockfile(lock, &update->new_oid,
2506 char *write_err = strbuf_detach(err, NULL);
2509 * The lock was freed upon failure of
2510 * write_ref_to_lockfile():
2512 update->backend_data = NULL;
2514 "cannot update ref '%s': %s",
2515 update->refname, write_err);
2517 ret = TRANSACTION_GENERIC_ERROR;
2520 update->flags |= REF_NEEDS_COMMIT;
2523 if (!(update->flags & REF_NEEDS_COMMIT)) {
2525 * We didn't call write_ref_to_lockfile(), so
2526 * the lockfile is still open. Close it to
2527 * free up the file descriptor:
2529 if (close_ref_gently(lock)) {
2530 strbuf_addf(err, "couldn't close '%s.lock'",
2532 ret = TRANSACTION_GENERIC_ERROR;
2538 strbuf_release(&referent);
2542 struct files_transaction_backend_data {
2543 struct ref_transaction *packed_transaction;
2544 int packed_refs_locked;
2548 * Unlock any references in `transaction` that are still locked, and
2549 * mark the transaction closed.
2551 static void files_transaction_cleanup(struct files_ref_store *refs,
2552 struct ref_transaction *transaction)
2555 struct files_transaction_backend_data *backend_data =
2556 transaction->backend_data;
2557 struct strbuf err = STRBUF_INIT;
2559 for (i = 0; i < transaction->nr; i++) {
2560 struct ref_update *update = transaction->updates[i];
2561 struct ref_lock *lock = update->backend_data;
2565 update->backend_data = NULL;
2569 if (backend_data->packed_transaction &&
2570 ref_transaction_abort(backend_data->packed_transaction, &err)) {
2571 error("error aborting transaction: %s", err.buf);
2572 strbuf_release(&err);
2575 if (backend_data->packed_refs_locked)
2576 packed_refs_unlock(refs->packed_ref_store);
2580 transaction->state = REF_TRANSACTION_CLOSED;
2583 static int files_transaction_prepare(struct ref_store *ref_store,
2584 struct ref_transaction *transaction,
2587 struct files_ref_store *refs =
2588 files_downcast(ref_store, REF_STORE_WRITE,
2589 "ref_transaction_prepare");
2592 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
2593 char *head_ref = NULL;
2595 struct files_transaction_backend_data *backend_data;
2596 struct ref_transaction *packed_transaction = NULL;
2600 if (!transaction->nr)
2603 backend_data = xcalloc(1, sizeof(*backend_data));
2604 transaction->backend_data = backend_data;
2607 * Fail if a refname appears more than once in the
2608 * transaction. (If we end up splitting up any updates using
2609 * split_symref_update() or split_head_update(), those
2610 * functions will check that the new updates don't have the
2611 * same refname as any existing ones.) Also fail if any of the
2612 * updates use REF_IS_PRUNING without REF_NO_DEREF.
2614 for (i = 0; i < transaction->nr; i++) {
2615 struct ref_update *update = transaction->updates[i];
2616 struct string_list_item *item =
2617 string_list_append(&affected_refnames, update->refname);
2619 if ((update->flags & REF_IS_PRUNING) &&
2620 !(update->flags & REF_NO_DEREF))
2621 BUG("REF_IS_PRUNING set without REF_NO_DEREF");
2624 * We store a pointer to update in item->util, but at
2625 * the moment we never use the value of this field
2626 * except to check whether it is non-NULL.
2628 item->util = update;
2630 string_list_sort(&affected_refnames);
2631 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2632 ret = TRANSACTION_GENERIC_ERROR;
2637 * Special hack: If a branch is updated directly and HEAD
2638 * points to it (may happen on the remote side of a push
2639 * for example) then logically the HEAD reflog should be
2642 * A generic solution would require reverse symref lookups,
2643 * but finding all symrefs pointing to a given branch would be
2644 * rather costly for this rare event (the direct update of a
2645 * branch) to be worth it. So let's cheat and check with HEAD
2646 * only, which should cover 99% of all usage scenarios (even
2647 * 100% of the default ones).
2649 * So if HEAD is a symbolic reference, then record the name of
2650 * the reference that it points to. If we see an update of
2651 * head_ref within the transaction, then split_head_update()
2652 * arranges for the reflog of HEAD to be updated, too.
2654 head_ref = refs_resolve_refdup(ref_store, "HEAD",
2655 RESOLVE_REF_NO_RECURSE,
2658 if (head_ref && !(head_type & REF_ISSYMREF)) {
2659 FREE_AND_NULL(head_ref);
2663 * Acquire all locks, verify old values if provided, check
2664 * that new values are valid, and write new values to the
2665 * lockfiles, ready to be activated. Only keep one lockfile
2666 * open at a time to avoid running out of file descriptors.
2667 * Note that lock_ref_for_update() might append more updates
2668 * to the transaction.
2670 for (i = 0; i < transaction->nr; i++) {
2671 struct ref_update *update = transaction->updates[i];
2673 ret = lock_ref_for_update(refs, update, transaction,
2674 head_ref, &affected_refnames, err);
2678 if (update->flags & REF_DELETING &&
2679 !(update->flags & REF_LOG_ONLY) &&
2680 !(update->flags & REF_IS_PRUNING)) {
2682 * This reference has to be deleted from
2683 * packed-refs if it exists there.
2685 if (!packed_transaction) {
2686 packed_transaction = ref_store_transaction_begin(
2687 refs->packed_ref_store, err);
2688 if (!packed_transaction) {
2689 ret = TRANSACTION_GENERIC_ERROR;
2693 backend_data->packed_transaction =
2697 ref_transaction_add_update(
2698 packed_transaction, update->refname,
2699 REF_HAVE_NEW | REF_NO_DEREF,
2700 &update->new_oid, NULL,
2705 if (packed_transaction) {
2706 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
2707 ret = TRANSACTION_GENERIC_ERROR;
2710 backend_data->packed_refs_locked = 1;
2712 if (is_packed_transaction_needed(refs->packed_ref_store,
2713 packed_transaction)) {
2714 ret = ref_transaction_prepare(packed_transaction, err);
2716 * A failure during the prepare step will abort
2717 * itself, but not free. Do that now, and disconnect
2718 * from the files_transaction so it does not try to
2719 * abort us when we hit the cleanup code below.
2722 ref_transaction_free(packed_transaction);
2723 backend_data->packed_transaction = NULL;
2727 * We can skip rewriting the `packed-refs`
2728 * file. But we do need to leave it locked, so
2729 * that somebody else doesn't pack a reference
2730 * that we are trying to delete.
2732 * We need to disconnect our transaction from
2733 * backend_data, since the abort (whether successful or
2734 * not) will free it.
2736 backend_data->packed_transaction = NULL;
2737 if (ref_transaction_abort(packed_transaction, err)) {
2738 ret = TRANSACTION_GENERIC_ERROR;
2746 string_list_clear(&affected_refnames, 0);
2749 files_transaction_cleanup(refs, transaction);
2751 transaction->state = REF_TRANSACTION_PREPARED;
2756 static int files_transaction_finish(struct ref_store *ref_store,
2757 struct ref_transaction *transaction,
2760 struct files_ref_store *refs =
2761 files_downcast(ref_store, 0, "ref_transaction_finish");
2764 struct strbuf sb = STRBUF_INIT;
2765 struct files_transaction_backend_data *backend_data;
2766 struct ref_transaction *packed_transaction;
2771 if (!transaction->nr) {
2772 transaction->state = REF_TRANSACTION_CLOSED;
2776 backend_data = transaction->backend_data;
2777 packed_transaction = backend_data->packed_transaction;
2779 /* Perform updates first so live commits remain referenced */
2780 for (i = 0; i < transaction->nr; i++) {
2781 struct ref_update *update = transaction->updates[i];
2782 struct ref_lock *lock = update->backend_data;
2784 if (update->flags & REF_NEEDS_COMMIT ||
2785 update->flags & REF_LOG_ONLY) {
2786 if (files_log_ref_write(refs,
2790 update->msg, update->flags,
2792 char *old_msg = strbuf_detach(err, NULL);
2794 strbuf_addf(err, "cannot update the ref '%s': %s",
2795 lock->ref_name, old_msg);
2798 update->backend_data = NULL;
2799 ret = TRANSACTION_GENERIC_ERROR;
2803 if (update->flags & REF_NEEDS_COMMIT) {
2804 clear_loose_ref_cache(refs);
2805 if (commit_ref(lock)) {
2806 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
2808 update->backend_data = NULL;
2809 ret = TRANSACTION_GENERIC_ERROR;
2816 * Now that updates are safely completed, we can perform
2817 * deletes. First delete the reflogs of any references that
2818 * will be deleted, since (in the unexpected event of an
2819 * error) leaving a reference without a reflog is less bad
2820 * than leaving a reflog without a reference (the latter is a
2821 * mildly invalid repository state):
2823 for (i = 0; i < transaction->nr; i++) {
2824 struct ref_update *update = transaction->updates[i];
2825 if (update->flags & REF_DELETING &&
2826 !(update->flags & REF_LOG_ONLY) &&
2827 !(update->flags & REF_IS_PRUNING)) {
2829 files_reflog_path(refs, &sb, update->refname);
2830 if (!unlink_or_warn(sb.buf))
2831 try_remove_empty_parents(refs, update->refname,
2832 REMOVE_EMPTY_PARENTS_REFLOG);
2837 * Perform deletes now that updates are safely completed.
2839 * First delete any packed versions of the references, while
2840 * retaining the packed-refs lock:
2842 if (packed_transaction) {
2843 ret = ref_transaction_commit(packed_transaction, err);
2844 ref_transaction_free(packed_transaction);
2845 packed_transaction = NULL;
2846 backend_data->packed_transaction = NULL;
2851 /* Now delete the loose versions of the references: */
2852 for (i = 0; i < transaction->nr; i++) {
2853 struct ref_update *update = transaction->updates[i];
2854 struct ref_lock *lock = update->backend_data;
2856 if (update->flags & REF_DELETING &&
2857 !(update->flags & REF_LOG_ONLY)) {
2858 if (!(update->type & REF_ISPACKED) ||
2859 update->type & REF_ISSYMREF) {
2860 /* It is a loose reference. */
2862 files_ref_path(refs, &sb, lock->ref_name);
2863 if (unlink_or_msg(sb.buf, err)) {
2864 ret = TRANSACTION_GENERIC_ERROR;
2867 update->flags |= REF_DELETED_LOOSE;
2872 clear_loose_ref_cache(refs);
2875 files_transaction_cleanup(refs, transaction);
2877 for (i = 0; i < transaction->nr; i++) {
2878 struct ref_update *update = transaction->updates[i];
2880 if (update->flags & REF_DELETED_LOOSE) {
2882 * The loose reference was deleted. Delete any
2883 * empty parent directories. (Note that this
2884 * can only work because we have already
2885 * removed the lockfile.)
2887 try_remove_empty_parents(refs, update->refname,
2888 REMOVE_EMPTY_PARENTS_REF);
2892 strbuf_release(&sb);
2896 static int files_transaction_abort(struct ref_store *ref_store,
2897 struct ref_transaction *transaction,
2900 struct files_ref_store *refs =
2901 files_downcast(ref_store, 0, "ref_transaction_abort");
2903 files_transaction_cleanup(refs, transaction);
2907 static int ref_present(const char *refname,
2908 const struct object_id *oid, int flags, void *cb_data)
2910 struct string_list *affected_refnames = cb_data;
2912 return string_list_has_string(affected_refnames, refname);
2915 static int files_initial_transaction_commit(struct ref_store *ref_store,
2916 struct ref_transaction *transaction,
2919 struct files_ref_store *refs =
2920 files_downcast(ref_store, REF_STORE_WRITE,
2921 "initial_ref_transaction_commit");
2924 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
2925 struct ref_transaction *packed_transaction = NULL;
2929 if (transaction->state != REF_TRANSACTION_OPEN)
2930 BUG("commit called for transaction that is not open");
2932 /* Fail if a refname appears more than once in the transaction: */
2933 for (i = 0; i < transaction->nr; i++)
2934 string_list_append(&affected_refnames,
2935 transaction->updates[i]->refname);
2936 string_list_sort(&affected_refnames);
2937 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2938 ret = TRANSACTION_GENERIC_ERROR;
2943 * It's really undefined to call this function in an active
2944 * repository or when there are existing references: we are
2945 * only locking and changing packed-refs, so (1) any
2946 * simultaneous processes might try to change a reference at
2947 * the same time we do, and (2) any existing loose versions of
2948 * the references that we are setting would have precedence
2949 * over our values. But some remote helpers create the remote
2950 * "HEAD" and "master" branches before calling this function,
2951 * so here we really only check that none of the references
2952 * that we are creating already exists.
2954 if (refs_for_each_rawref(&refs->base, ref_present,
2955 &affected_refnames))
2956 BUG("initial ref transaction called with existing refs");
2958 packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err);
2959 if (!packed_transaction) {
2960 ret = TRANSACTION_GENERIC_ERROR;
2964 for (i = 0; i < transaction->nr; i++) {
2965 struct ref_update *update = transaction->updates[i];
2967 if ((update->flags & REF_HAVE_OLD) &&
2968 !is_null_oid(&update->old_oid))
2969 BUG("initial ref transaction with old_sha1 set");
2970 if (refs_verify_refname_available(&refs->base, update->refname,
2971 &affected_refnames, NULL,
2973 ret = TRANSACTION_NAME_CONFLICT;
2978 * Add a reference creation for this reference to the
2979 * packed-refs transaction:
2981 ref_transaction_add_update(packed_transaction, update->refname,
2982 update->flags & ~REF_HAVE_OLD,
2983 &update->new_oid, &update->old_oid,
2987 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
2988 ret = TRANSACTION_GENERIC_ERROR;
2992 if (initial_ref_transaction_commit(packed_transaction, err)) {
2993 ret = TRANSACTION_GENERIC_ERROR;
2996 packed_refs_unlock(refs->packed_ref_store);
2998 if (packed_transaction)
2999 ref_transaction_free(packed_transaction);
3000 transaction->state = REF_TRANSACTION_CLOSED;
3001 string_list_clear(&affected_refnames, 0);
3005 struct expire_reflog_cb {
3007 reflog_expiry_should_prune_fn *should_prune_fn;
3010 struct object_id last_kept_oid;
3013 static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
3014 const char *email, timestamp_t timestamp, int tz,
3015 const char *message, void *cb_data)
3017 struct expire_reflog_cb *cb = cb_data;
3018 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
3020 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
3021 ooid = &cb->last_kept_oid;
3023 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,
3024 message, policy_cb)) {
3026 printf("would prune %s", message);
3027 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3028 printf("prune %s", message);
3031 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",
3032 oid_to_hex(ooid), oid_to_hex(noid),
3033 email, timestamp, tz, message);
3034 oidcpy(&cb->last_kept_oid, noid);
3036 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3037 printf("keep %s", message);
3042 static int files_reflog_expire(struct ref_store *ref_store,
3043 const char *refname, const struct object_id *oid,
3045 reflog_expiry_prepare_fn prepare_fn,
3046 reflog_expiry_should_prune_fn should_prune_fn,
3047 reflog_expiry_cleanup_fn cleanup_fn,
3048 void *policy_cb_data)
3050 struct files_ref_store *refs =
3051 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");
3052 struct lock_file reflog_lock = LOCK_INIT;
3053 struct expire_reflog_cb cb;
3054 struct ref_lock *lock;
3055 struct strbuf log_file_sb = STRBUF_INIT;
3059 struct strbuf err = STRBUF_INIT;
3061 memset(&cb, 0, sizeof(cb));
3063 cb.policy_cb = policy_cb_data;
3064 cb.should_prune_fn = should_prune_fn;
3067 * The reflog file is locked by holding the lock on the
3068 * reference itself, plus we might need to update the
3069 * reference if --updateref was specified:
3071 lock = lock_ref_oid_basic(refs, refname, oid,
3072 NULL, NULL, REF_NO_DEREF,
3075 error("cannot lock ref '%s': %s", refname, err.buf);
3076 strbuf_release(&err);
3079 if (!refs_reflog_exists(ref_store, refname)) {
3084 files_reflog_path(refs, &log_file_sb, refname);
3085 log_file = strbuf_detach(&log_file_sb, NULL);
3086 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3088 * Even though holding $GIT_DIR/logs/$reflog.lock has
3089 * no locking implications, we use the lock_file
3090 * machinery here anyway because it does a lot of the
3091 * work we need, including cleaning up if the program
3092 * exits unexpectedly.
3094 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
3095 struct strbuf err = STRBUF_INIT;
3096 unable_to_lock_message(log_file, errno, &err);
3097 error("%s", err.buf);
3098 strbuf_release(&err);
3101 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
3103 error("cannot fdopen %s (%s)",
3104 get_lock_file_path(&reflog_lock), strerror(errno));
3109 (*prepare_fn)(refname, oid, cb.policy_cb);
3110 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);
3111 (*cleanup_fn)(cb.policy_cb);
3113 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3115 * It doesn't make sense to adjust a reference pointed
3116 * to by a symbolic ref based on expiring entries in
3117 * the symbolic reference's reflog. Nor can we update
3118 * a reference if there are no remaining reflog
3121 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
3122 !(type & REF_ISSYMREF) &&
3123 !is_null_oid(&cb.last_kept_oid);
3125 if (close_lock_file_gently(&reflog_lock)) {
3126 status |= error("couldn't write %s: %s", log_file,
3128 rollback_lock_file(&reflog_lock);
3129 } else if (update &&
3130 (write_in_full(get_lock_file_fd(&lock->lk),
3131 oid_to_hex(&cb.last_kept_oid), the_hash_algo->hexsz) < 0 ||
3132 write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 0 ||
3133 close_ref_gently(lock) < 0)) {
3134 status |= error("couldn't write %s",
3135 get_lock_file_path(&lock->lk));
3136 rollback_lock_file(&reflog_lock);
3137 } else if (commit_lock_file(&reflog_lock)) {
3138 status |= error("unable to write reflog '%s' (%s)",
3139 log_file, strerror(errno));
3140 } else if (update && commit_ref(lock)) {
3141 status |= error("couldn't set %s", lock->ref_name);
3149 rollback_lock_file(&reflog_lock);
3155 static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
3157 struct files_ref_store *refs =
3158 files_downcast(ref_store, REF_STORE_WRITE, "init_db");
3159 struct strbuf sb = STRBUF_INIT;
3162 * Create .git/refs/{heads,tags}
3164 files_ref_path(refs, &sb, "refs/heads");
3165 safe_create_dir(sb.buf, 1);
3168 files_ref_path(refs, &sb, "refs/tags");
3169 safe_create_dir(sb.buf, 1);
3171 strbuf_release(&sb);
3175 struct ref_storage_be refs_be_files = {
3178 files_ref_store_create,
3180 files_transaction_prepare,
3181 files_transaction_finish,
3182 files_transaction_abort,
3183 files_initial_transaction_commit,
3186 files_create_symref,
3191 files_ref_iterator_begin,
3194 files_reflog_iterator_begin,
3195 files_for_each_reflog_ent,
3196 files_for_each_reflog_ent_reverse,
3197 files_reflog_exists,
3198 files_create_reflog,
3199 files_delete_reflog,