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 * Read the loose references from the namespace dirname into dir
219 * (without recursing). dirname must end with '/'. dir must be the
220 * directory entry corresponding to dirname.
222 static void loose_fill_ref_dir(struct ref_store *ref_store,
223 struct ref_dir *dir, const char *dirname)
225 struct files_ref_store *refs =
226 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir");
229 int dirnamelen = strlen(dirname);
230 struct strbuf refname;
231 struct strbuf path = STRBUF_INIT;
234 files_ref_path(refs, &path, dirname);
235 path_baselen = path.len;
237 d = opendir(path.buf);
239 strbuf_release(&path);
243 strbuf_init(&refname, dirnamelen + 257);
244 strbuf_add(&refname, dirname, dirnamelen);
246 while ((de = readdir(d)) != NULL) {
247 struct object_id oid;
251 if (de->d_name[0] == '.')
253 if (ends_with(de->d_name, ".lock"))
255 strbuf_addstr(&refname, de->d_name);
256 strbuf_addstr(&path, de->d_name);
257 if (stat(path.buf, &st) < 0) {
258 ; /* silently ignore */
259 } else if (S_ISDIR(st.st_mode)) {
260 strbuf_addch(&refname, '/');
261 add_entry_to_dir(dir,
262 create_dir_entry(dir->cache, refname.buf,
265 if (!refs_resolve_ref_unsafe(&refs->base,
270 flag |= REF_ISBROKEN;
271 } else if (is_null_oid(&oid)) {
273 * It is so astronomically unlikely
274 * that null_oid is the OID of an
275 * actual object that we consider its
276 * appearance in a loose reference
277 * file to be repo corruption
278 * (probably due to a software bug).
280 flag |= REF_ISBROKEN;
283 if (check_refname_format(refname.buf,
284 REFNAME_ALLOW_ONELEVEL)) {
285 if (!refname_is_safe(refname.buf))
286 die("loose refname is dangerous: %s", refname.buf);
288 flag |= REF_BAD_NAME | REF_ISBROKEN;
290 add_entry_to_dir(dir,
291 create_ref_entry(refname.buf, &oid, flag));
293 strbuf_setlen(&refname, dirnamelen);
294 strbuf_setlen(&path, path_baselen);
296 strbuf_release(&refname);
297 strbuf_release(&path);
301 * Manually add refs/bisect and refs/worktree, which, being
302 * per-worktree, might not appear in the directory listing for
303 * refs/ in the main repo.
305 if (!strcmp(dirname, "refs/")) {
306 int pos = search_ref_dir(dir, "refs/bisect/", 12);
309 struct ref_entry *child_entry = create_dir_entry(
310 dir->cache, "refs/bisect/", 12, 1);
311 add_entry_to_dir(dir, child_entry);
314 pos = search_ref_dir(dir, "refs/worktree/", 11);
317 struct ref_entry *child_entry = create_dir_entry(
318 dir->cache, "refs/worktree/", 11, 1);
319 add_entry_to_dir(dir, child_entry);
324 static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)
328 * Mark the top-level directory complete because we
329 * are about to read the only subdirectory that can
332 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir);
334 /* We're going to fill the top level ourselves: */
335 refs->loose->root->flag &= ~REF_INCOMPLETE;
338 * Add an incomplete entry for "refs/" (to be filled
341 add_entry_to_dir(get_ref_dir(refs->loose->root),
342 create_dir_entry(refs->loose, "refs/", 5, 1));
347 static int files_read_raw_ref(struct ref_store *ref_store,
348 const char *refname, struct object_id *oid,
349 struct strbuf *referent, unsigned int *type)
351 struct files_ref_store *refs =
352 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
353 struct strbuf sb_contents = STRBUF_INIT;
354 struct strbuf sb_path = STRBUF_INIT;
362 int remaining_retries = 3;
365 strbuf_reset(&sb_path);
367 files_ref_path(refs, &sb_path, refname);
373 * We might have to loop back here to avoid a race
374 * condition: first we lstat() the file, then we try
375 * to read it as a link or as a file. But if somebody
376 * changes the type of the file (file <-> directory
377 * <-> symlink) between the lstat() and reading, then
378 * we don't want to report that as an error but rather
379 * try again starting with the lstat().
381 * We'll keep a count of the retries, though, just to avoid
382 * any confusing situation sending us into an infinite loop.
385 if (remaining_retries-- <= 0)
388 if (lstat(path, &st) < 0) {
391 if (refs_read_raw_ref(refs->packed_ref_store, refname,
392 oid, referent, type)) {
400 /* Follow "normalized" - ie "refs/.." symlinks by hand */
401 if (S_ISLNK(st.st_mode)) {
402 strbuf_reset(&sb_contents);
403 if (strbuf_readlink(&sb_contents, path, st.st_size) < 0) {
404 if (errno == ENOENT || errno == EINVAL)
405 /* inconsistent with lstat; retry */
410 if (starts_with(sb_contents.buf, "refs/") &&
411 !check_refname_format(sb_contents.buf, 0)) {
412 strbuf_swap(&sb_contents, referent);
413 *type |= REF_ISSYMREF;
418 * It doesn't look like a refname; fall through to just
419 * treating it like a non-symlink, and reading whatever it
424 /* Is it a directory? */
425 if (S_ISDIR(st.st_mode)) {
427 * Even though there is a directory where the loose
428 * ref is supposed to be, there could still be a
431 if (refs_read_raw_ref(refs->packed_ref_store, refname,
432 oid, referent, type)) {
441 * Anything else, just open it and try to use it as
444 fd = open(path, O_RDONLY);
446 if (errno == ENOENT && !S_ISLNK(st.st_mode))
447 /* inconsistent with lstat; retry */
452 strbuf_reset(&sb_contents);
453 if (strbuf_read(&sb_contents, fd, 256) < 0) {
454 int save_errno = errno;
460 strbuf_rtrim(&sb_contents);
461 buf = sb_contents.buf;
462 if (starts_with(buf, "ref:")) {
464 while (isspace(*buf))
467 strbuf_reset(referent);
468 strbuf_addstr(referent, buf);
469 *type |= REF_ISSYMREF;
475 * Please note that FETCH_HEAD has additional
476 * data after the sha.
478 if (parse_oid_hex(buf, oid, &p) ||
479 (*p != '\0' && !isspace(*p))) {
480 *type |= REF_ISBROKEN;
489 strbuf_release(&sb_path);
490 strbuf_release(&sb_contents);
495 static void unlock_ref(struct ref_lock *lock)
497 rollback_lock_file(&lock->lk);
498 free(lock->ref_name);
503 * Lock refname, without following symrefs, and set *lock_p to point
504 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
505 * and type similarly to read_raw_ref().
507 * The caller must verify that refname is a "safe" reference name (in
508 * the sense of refname_is_safe()) before calling this function.
510 * If the reference doesn't already exist, verify that refname doesn't
511 * have a D/F conflict with any existing references. extras and skip
512 * are passed to refs_verify_refname_available() for this check.
514 * If mustexist is not set and the reference is not found or is
515 * broken, lock the reference anyway but clear old_oid.
517 * Return 0 on success. On failure, write an error message to err and
518 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
520 * Implementation note: This function is basically
525 * but it includes a lot more code to
526 * - Deal with possible races with other processes
527 * - Avoid calling refs_verify_refname_available() when it can be
528 * avoided, namely if we were successfully able to read the ref
529 * - Generate informative error messages in the case of failure
531 static int lock_raw_ref(struct files_ref_store *refs,
532 const char *refname, int mustexist,
533 const struct string_list *extras,
534 const struct string_list *skip,
535 struct ref_lock **lock_p,
536 struct strbuf *referent,
540 struct ref_lock *lock;
541 struct strbuf ref_file = STRBUF_INIT;
542 int attempts_remaining = 3;
543 int ret = TRANSACTION_GENERIC_ERROR;
546 files_assert_main_repository(refs, "lock_raw_ref");
550 /* First lock the file so it can't change out from under us. */
552 *lock_p = lock = xcalloc(1, sizeof(*lock));
554 lock->ref_name = xstrdup(refname);
555 files_ref_path(refs, &ref_file, refname);
558 switch (safe_create_leading_directories(ref_file.buf)) {
563 * Suppose refname is "refs/foo/bar". We just failed
564 * to create the containing directory, "refs/foo",
565 * because there was a non-directory in the way. This
566 * indicates a D/F conflict, probably because of
567 * another reference such as "refs/foo". There is no
568 * reason to expect this error to be transitory.
570 if (refs_verify_refname_available(&refs->base, refname,
571 extras, skip, err)) {
574 * To the user the relevant error is
575 * that the "mustexist" reference is
579 strbuf_addf(err, "unable to resolve reference '%s'",
583 * The error message set by
584 * refs_verify_refname_available() is
587 ret = TRANSACTION_NAME_CONFLICT;
591 * The file that is in the way isn't a loose
592 * reference. Report it as a low-level
595 strbuf_addf(err, "unable to create lock file %s.lock; "
596 "non-directory in the way",
601 /* Maybe another process was tidying up. Try again. */
602 if (--attempts_remaining > 0)
606 strbuf_addf(err, "unable to create directory for %s",
611 if (hold_lock_file_for_update_timeout(
612 &lock->lk, ref_file.buf, LOCK_NO_DEREF,
613 get_files_ref_lock_timeout_ms()) < 0) {
614 if (errno == ENOENT && --attempts_remaining > 0) {
616 * Maybe somebody just deleted one of the
617 * directories leading to ref_file. Try
622 unable_to_lock_message(ref_file.buf, errno, err);
628 * Now we hold the lock and can read the reference without
629 * fear that its value will change.
632 if (files_read_raw_ref(&refs->base, refname,
633 &lock->old_oid, referent, type)) {
634 if (errno == ENOENT) {
636 /* Garden variety missing reference. */
637 strbuf_addf(err, "unable to resolve reference '%s'",
642 * Reference is missing, but that's OK. We
643 * know that there is not a conflict with
644 * another loose reference because
645 * (supposing that we are trying to lock
646 * reference "refs/foo/bar"):
648 * - We were successfully able to create
649 * the lockfile refs/foo/bar.lock, so we
650 * know there cannot be a loose reference
653 * - We got ENOENT and not EISDIR, so we
654 * know that there cannot be a loose
655 * reference named "refs/foo/bar/baz".
658 } else if (errno == EISDIR) {
660 * There is a directory in the way. It might have
661 * contained references that have been deleted. If
662 * we don't require that the reference already
663 * exists, try to remove the directory so that it
664 * doesn't cause trouble when we want to rename the
665 * lockfile into place later.
668 /* Garden variety missing reference. */
669 strbuf_addf(err, "unable to resolve reference '%s'",
672 } else if (remove_dir_recursively(&ref_file,
673 REMOVE_DIR_EMPTY_ONLY)) {
674 if (refs_verify_refname_available(
675 &refs->base, refname,
676 extras, skip, err)) {
678 * The error message set by
679 * verify_refname_available() is OK.
681 ret = TRANSACTION_NAME_CONFLICT;
685 * We can't delete the directory,
686 * but we also don't know of any
687 * references that it should
690 strbuf_addf(err, "there is a non-empty directory '%s' "
691 "blocking reference '%s'",
692 ref_file.buf, refname);
696 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
697 strbuf_addf(err, "unable to resolve reference '%s': "
698 "reference broken", refname);
701 strbuf_addf(err, "unable to resolve reference '%s': %s",
702 refname, strerror(errno));
707 * If the ref did not exist and we are creating it,
708 * make sure there is no existing packed ref that
709 * conflicts with refname:
711 if (refs_verify_refname_available(
712 refs->packed_ref_store, refname,
725 strbuf_release(&ref_file);
729 struct files_ref_iterator {
730 struct ref_iterator base;
732 struct ref_iterator *iter0;
736 static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
738 struct files_ref_iterator *iter =
739 (struct files_ref_iterator *)ref_iterator;
742 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
743 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
744 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
747 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
748 !ref_resolves_to_object(iter->iter0->refname,
753 iter->base.refname = iter->iter0->refname;
754 iter->base.oid = iter->iter0->oid;
755 iter->base.flags = iter->iter0->flags;
760 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
766 static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
767 struct object_id *peeled)
769 struct files_ref_iterator *iter =
770 (struct files_ref_iterator *)ref_iterator;
772 return ref_iterator_peel(iter->iter0, peeled);
775 static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
777 struct files_ref_iterator *iter =
778 (struct files_ref_iterator *)ref_iterator;
782 ok = ref_iterator_abort(iter->iter0);
784 base_ref_iterator_free(ref_iterator);
788 static struct ref_iterator_vtable files_ref_iterator_vtable = {
789 files_ref_iterator_advance,
790 files_ref_iterator_peel,
791 files_ref_iterator_abort
794 static struct ref_iterator *files_ref_iterator_begin(
795 struct ref_store *ref_store,
796 const char *prefix, unsigned int flags)
798 struct files_ref_store *refs;
799 struct ref_iterator *loose_iter, *packed_iter, *overlay_iter;
800 struct files_ref_iterator *iter;
801 struct ref_iterator *ref_iterator;
802 unsigned int required_flags = REF_STORE_READ;
804 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN))
805 required_flags |= REF_STORE_ODB;
807 refs = files_downcast(ref_store, required_flags, "ref_iterator_begin");
810 * We must make sure that all loose refs are read before
811 * accessing the packed-refs file; this avoids a race
812 * condition if loose refs are migrated to the packed-refs
813 * file by a simultaneous process, but our in-memory view is
814 * from before the migration. We ensure this as follows:
815 * First, we call start the loose refs iteration with its
816 * `prime_ref` argument set to true. This causes the loose
817 * references in the subtree to be pre-read into the cache.
818 * (If they've already been read, that's OK; we only need to
819 * guarantee that they're read before the packed refs, not
820 * *how much* before.) After that, we call
821 * packed_ref_iterator_begin(), which internally checks
822 * whether the packed-ref cache is up to date with what is on
823 * disk, and re-reads it if not.
826 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),
830 * The packed-refs file might contain broken references, for
831 * example an old version of a reference that points at an
832 * object that has since been garbage-collected. This is OK as
833 * long as there is a corresponding loose reference that
834 * overrides it, and we don't want to emit an error message in
835 * this case. So ask the packed_ref_store for all of its
836 * references, and (if needed) do our own check for broken
837 * ones in files_ref_iterator_advance(), after we have merged
838 * the packed and loose references.
840 packed_iter = refs_ref_iterator_begin(
841 refs->packed_ref_store, prefix, 0,
842 DO_FOR_EACH_INCLUDE_BROKEN);
844 overlay_iter = overlay_ref_iterator_begin(loose_iter, packed_iter);
846 iter = xcalloc(1, sizeof(*iter));
847 ref_iterator = &iter->base;
848 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable,
849 overlay_iter->ordered);
850 iter->iter0 = overlay_iter;
857 * Verify that the reference locked by lock has the value old_oid
858 * (unless it is NULL). Fail if the reference doesn't exist and
859 * mustexist is set. Return 0 on success. On error, write an error
860 * message to err, set errno, and return a negative value.
862 static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
863 const struct object_id *old_oid, int mustexist,
868 if (refs_read_ref_full(ref_store, lock->ref_name,
869 mustexist ? RESOLVE_REF_READING : 0,
870 &lock->old_oid, NULL)) {
872 int save_errno = errno;
873 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
877 oidclr(&lock->old_oid);
881 if (old_oid && !oideq(&lock->old_oid, old_oid)) {
882 strbuf_addf(err, "ref '%s' is at %s but expected %s",
884 oid_to_hex(&lock->old_oid),
885 oid_to_hex(old_oid));
892 static int remove_empty_directories(struct strbuf *path)
895 * we want to create a file but there is a directory there;
896 * if that is an empty directory (or a directory that contains
897 * only empty directories), remove them.
899 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
902 static int create_reflock(const char *path, void *cb)
904 struct lock_file *lk = cb;
906 return hold_lock_file_for_update_timeout(
907 lk, path, LOCK_NO_DEREF,
908 get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0;
912 * Locks a ref returning the lock on success and NULL on failure.
913 * On failure errno is set to something meaningful.
915 static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
917 const struct object_id *old_oid,
918 const struct string_list *extras,
919 const struct string_list *skip,
920 unsigned int flags, int *type,
923 struct strbuf ref_file = STRBUF_INIT;
924 struct ref_lock *lock;
926 int mustexist = (old_oid && !is_null_oid(old_oid));
927 int resolve_flags = RESOLVE_REF_NO_RECURSE;
930 files_assert_main_repository(refs, "lock_ref_oid_basic");
933 lock = xcalloc(1, sizeof(struct ref_lock));
936 resolve_flags |= RESOLVE_REF_READING;
937 if (flags & REF_DELETING)
938 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
940 files_ref_path(refs, &ref_file, refname);
941 resolved = !!refs_resolve_ref_unsafe(&refs->base,
942 refname, resolve_flags,
943 &lock->old_oid, type);
944 if (!resolved && errno == EISDIR) {
946 * we are trying to lock foo but we used to
947 * have foo/bar which now does not exist;
948 * it is normal for the empty directory 'foo'
951 if (remove_empty_directories(&ref_file)) {
953 if (!refs_verify_refname_available(
955 refname, extras, skip, err))
956 strbuf_addf(err, "there are still refs under '%s'",
960 resolved = !!refs_resolve_ref_unsafe(&refs->base,
961 refname, resolve_flags,
962 &lock->old_oid, type);
966 if (last_errno != ENOTDIR ||
967 !refs_verify_refname_available(&refs->base, refname,
969 strbuf_addf(err, "unable to resolve reference '%s': %s",
970 refname, strerror(last_errno));
976 * If the ref did not exist and we are creating it, make sure
977 * there is no existing packed ref whose name begins with our
978 * refname, nor a packed ref whose name is a proper prefix of
981 if (is_null_oid(&lock->old_oid) &&
982 refs_verify_refname_available(refs->packed_ref_store, refname,
983 extras, skip, err)) {
984 last_errno = ENOTDIR;
988 lock->ref_name = xstrdup(refname);
990 if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) {
992 unable_to_lock_message(ref_file.buf, errno, err);
996 if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) {
1007 strbuf_release(&ref_file);
1012 struct ref_to_prune {
1013 struct ref_to_prune *next;
1014 struct object_id oid;
1015 char name[FLEX_ARRAY];
1019 REMOVE_EMPTY_PARENTS_REF = 0x01,
1020 REMOVE_EMPTY_PARENTS_REFLOG = 0x02
1024 * Remove empty parent directories associated with the specified
1025 * reference and/or its reflog, but spare [logs/]refs/ and immediate
1026 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
1027 * REMOVE_EMPTY_PARENTS_REFLOG.
1029 static void try_remove_empty_parents(struct files_ref_store *refs,
1030 const char *refname,
1033 struct strbuf buf = STRBUF_INIT;
1034 struct strbuf sb = STRBUF_INIT;
1038 strbuf_addstr(&buf, refname);
1040 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
1041 while (*p && *p != '/')
1043 /* tolerate duplicate slashes; see check_refname_format() */
1047 q = buf.buf + buf.len;
1048 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
1049 while (q > p && *q != '/')
1051 while (q > p && *(q-1) == '/')
1055 strbuf_setlen(&buf, q - buf.buf);
1058 files_ref_path(refs, &sb, buf.buf);
1059 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
1060 flags &= ~REMOVE_EMPTY_PARENTS_REF;
1063 files_reflog_path(refs, &sb, buf.buf);
1064 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))
1065 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
1067 strbuf_release(&buf);
1068 strbuf_release(&sb);
1071 /* make sure nobody touched the ref, and unlink */
1072 static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
1074 struct ref_transaction *transaction;
1075 struct strbuf err = STRBUF_INIT;
1078 if (check_refname_format(r->name, 0))
1081 transaction = ref_store_transaction_begin(&refs->base, &err);
1084 ref_transaction_add_update(
1085 transaction, r->name,
1086 REF_NO_DEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_IS_PRUNING,
1087 &null_oid, &r->oid, NULL);
1088 if (ref_transaction_commit(transaction, &err))
1095 error("%s", err.buf);
1096 strbuf_release(&err);
1097 ref_transaction_free(transaction);
1102 * Prune the loose versions of the references in the linked list
1103 * `*refs_to_prune`, freeing the entries in the list as we go.
1105 static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune)
1107 while (*refs_to_prune) {
1108 struct ref_to_prune *r = *refs_to_prune;
1109 *refs_to_prune = r->next;
1116 * Return true if the specified reference should be packed.
1118 static int should_pack_ref(const char *refname,
1119 const struct object_id *oid, unsigned int ref_flags,
1120 unsigned int pack_flags)
1122 /* Do not pack per-worktree refs: */
1123 if (ref_type(refname) != REF_TYPE_NORMAL)
1126 /* Do not pack non-tags unless PACK_REFS_ALL is set: */
1127 if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/"))
1130 /* Do not pack symbolic refs: */
1131 if (ref_flags & REF_ISSYMREF)
1134 /* Do not pack broken refs: */
1135 if (!ref_resolves_to_object(refname, oid, ref_flags))
1141 static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
1143 struct files_ref_store *refs =
1144 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,
1146 struct ref_iterator *iter;
1148 struct ref_to_prune *refs_to_prune = NULL;
1149 struct strbuf err = STRBUF_INIT;
1150 struct ref_transaction *transaction;
1152 transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
1156 packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err);
1158 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);
1159 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1161 * If the loose reference can be packed, add an entry
1162 * in the packed ref cache. If the reference should be
1163 * pruned, also add it to refs_to_prune.
1165 if (!should_pack_ref(iter->refname, iter->oid, iter->flags,
1170 * Add a reference creation for this reference to the
1171 * packed-refs transaction:
1173 if (ref_transaction_update(transaction, iter->refname,
1175 REF_NO_DEREF, NULL, &err))
1176 die("failure preparing to create packed reference %s: %s",
1177 iter->refname, err.buf);
1179 /* Schedule the loose reference for pruning if requested. */
1180 if ((flags & PACK_REFS_PRUNE)) {
1181 struct ref_to_prune *n;
1182 FLEX_ALLOC_STR(n, name, iter->refname);
1183 oidcpy(&n->oid, iter->oid);
1184 n->next = refs_to_prune;
1188 if (ok != ITER_DONE)
1189 die("error while iterating over references");
1191 if (ref_transaction_commit(transaction, &err))
1192 die("unable to write new packed-refs: %s", err.buf);
1194 ref_transaction_free(transaction);
1196 packed_refs_unlock(refs->packed_ref_store);
1198 prune_refs(refs, &refs_to_prune);
1199 strbuf_release(&err);
1203 static int files_delete_refs(struct ref_store *ref_store, const char *msg,
1204 struct string_list *refnames, unsigned int flags)
1206 struct files_ref_store *refs =
1207 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
1208 struct strbuf err = STRBUF_INIT;
1214 if (packed_refs_lock(refs->packed_ref_store, 0, &err))
1217 if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) {
1218 packed_refs_unlock(refs->packed_ref_store);
1222 packed_refs_unlock(refs->packed_ref_store);
1224 for (i = 0; i < refnames->nr; i++) {
1225 const char *refname = refnames->items[i].string;
1227 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))
1228 result |= error(_("could not remove reference %s"), refname);
1231 strbuf_release(&err);
1236 * If we failed to rewrite the packed-refs file, then it is
1237 * unsafe to try to remove loose refs, because doing so might
1238 * expose an obsolete packed value for a reference that might
1239 * even point at an object that has been garbage collected.
1241 if (refnames->nr == 1)
1242 error(_("could not delete reference %s: %s"),
1243 refnames->items[0].string, err.buf);
1245 error(_("could not delete references: %s"), err.buf);
1247 strbuf_release(&err);
1252 * People using contrib's git-new-workdir have .git/logs/refs ->
1253 * /some/other/path/.git/logs/refs, and that may live on another device.
1255 * IOW, to avoid cross device rename errors, the temporary renamed log must
1256 * live into logs/refs.
1258 #define TMP_RENAMED_LOG "refs/.tmp-renamed-log"
1261 const char *tmp_renamed_log;
1265 static int rename_tmp_log_callback(const char *path, void *cb_data)
1267 struct rename_cb *cb = cb_data;
1269 if (rename(cb->tmp_renamed_log, path)) {
1271 * rename(a, b) when b is an existing directory ought
1272 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
1273 * Sheesh. Record the true errno for error reporting,
1274 * but report EISDIR to raceproof_create_file() so
1275 * that it knows to retry.
1277 cb->true_errno = errno;
1278 if (errno == ENOTDIR)
1286 static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)
1288 struct strbuf path = STRBUF_INIT;
1289 struct strbuf tmp = STRBUF_INIT;
1290 struct rename_cb cb;
1293 files_reflog_path(refs, &path, newrefname);
1294 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);
1295 cb.tmp_renamed_log = tmp.buf;
1296 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
1298 if (errno == EISDIR)
1299 error("directory not empty: %s", path.buf);
1301 error("unable to move logfile %s to %s: %s",
1303 strerror(cb.true_errno));
1306 strbuf_release(&path);
1307 strbuf_release(&tmp);
1311 static int write_ref_to_lockfile(struct ref_lock *lock,
1312 const struct object_id *oid, struct strbuf *err);
1313 static int commit_ref_update(struct files_ref_store *refs,
1314 struct ref_lock *lock,
1315 const struct object_id *oid, const char *logmsg,
1316 struct strbuf *err);
1318 static int files_copy_or_rename_ref(struct ref_store *ref_store,
1319 const char *oldrefname, const char *newrefname,
1320 const char *logmsg, int copy)
1322 struct files_ref_store *refs =
1323 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
1324 struct object_id oid, orig_oid;
1325 int flag = 0, logmoved = 0;
1326 struct ref_lock *lock;
1327 struct stat loginfo;
1328 struct strbuf sb_oldref = STRBUF_INIT;
1329 struct strbuf sb_newref = STRBUF_INIT;
1330 struct strbuf tmp_renamed_log = STRBUF_INIT;
1332 struct strbuf err = STRBUF_INIT;
1334 files_reflog_path(refs, &sb_oldref, oldrefname);
1335 files_reflog_path(refs, &sb_newref, newrefname);
1336 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);
1338 log = !lstat(sb_oldref.buf, &loginfo);
1339 if (log && S_ISLNK(loginfo.st_mode)) {
1340 ret = error("reflog for %s is a symlink", oldrefname);
1344 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,
1345 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
1346 &orig_oid, &flag)) {
1347 ret = error("refname %s not found", oldrefname);
1351 if (flag & REF_ISSYMREF) {
1353 ret = error("refname %s is a symbolic ref, copying it is not supported",
1356 ret = error("refname %s is a symbolic ref, renaming it is not supported",
1360 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {
1365 if (!copy && log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
1366 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1367 oldrefname, strerror(errno));
1371 if (copy && log && copy_file(tmp_renamed_log.buf, sb_oldref.buf, 0644)) {
1372 ret = error("unable to copy logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1373 oldrefname, strerror(errno));
1377 if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname,
1378 &orig_oid, REF_NO_DEREF)) {
1379 error("unable to delete old %s", oldrefname);
1384 * Since we are doing a shallow lookup, oid is not the
1385 * correct value to pass to delete_ref as old_oid. But that
1386 * doesn't matter, because an old_oid check wouldn't add to
1387 * the safety anyway; we want to delete the reference whatever
1388 * its current value.
1390 if (!copy && !refs_read_ref_full(&refs->base, newrefname,
1391 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
1393 refs_delete_ref(&refs->base, NULL, newrefname,
1394 NULL, REF_NO_DEREF)) {
1395 if (errno == EISDIR) {
1396 struct strbuf path = STRBUF_INIT;
1399 files_ref_path(refs, &path, newrefname);
1400 result = remove_empty_directories(&path);
1401 strbuf_release(&path);
1404 error("Directory not empty: %s", newrefname);
1408 error("unable to delete existing %s", newrefname);
1413 if (log && rename_tmp_log(refs, newrefname))
1418 lock = lock_ref_oid_basic(refs, newrefname, NULL, NULL, NULL,
1419 REF_NO_DEREF, NULL, &err);
1422 error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1424 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1425 strbuf_release(&err);
1428 oidcpy(&lock->old_oid, &orig_oid);
1430 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1431 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {
1432 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
1433 strbuf_release(&err);
1441 lock = lock_ref_oid_basic(refs, oldrefname, NULL, NULL, NULL,
1442 REF_NO_DEREF, NULL, &err);
1444 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
1445 strbuf_release(&err);
1449 flag = log_all_ref_updates;
1450 log_all_ref_updates = LOG_REFS_NONE;
1451 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1452 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {
1453 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
1454 strbuf_release(&err);
1456 log_all_ref_updates = flag;
1459 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
1460 error("unable to restore logfile %s from %s: %s",
1461 oldrefname, newrefname, strerror(errno));
1462 if (!logmoved && log &&
1463 rename(tmp_renamed_log.buf, sb_oldref.buf))
1464 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",
1465 oldrefname, strerror(errno));
1468 strbuf_release(&sb_newref);
1469 strbuf_release(&sb_oldref);
1470 strbuf_release(&tmp_renamed_log);
1475 static int files_rename_ref(struct ref_store *ref_store,
1476 const char *oldrefname, const char *newrefname,
1479 return files_copy_or_rename_ref(ref_store, oldrefname,
1480 newrefname, logmsg, 0);
1483 static int files_copy_ref(struct ref_store *ref_store,
1484 const char *oldrefname, const char *newrefname,
1487 return files_copy_or_rename_ref(ref_store, oldrefname,
1488 newrefname, logmsg, 1);
1491 static int close_ref_gently(struct ref_lock *lock)
1493 if (close_lock_file_gently(&lock->lk))
1498 static int commit_ref(struct ref_lock *lock)
1500 char *path = get_locked_file_path(&lock->lk);
1503 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
1505 * There is a directory at the path we want to rename
1506 * the lockfile to. Hopefully it is empty; try to
1509 size_t len = strlen(path);
1510 struct strbuf sb_path = STRBUF_INIT;
1512 strbuf_attach(&sb_path, path, len, len);
1515 * If this fails, commit_lock_file() will also fail
1516 * and will report the problem.
1518 remove_empty_directories(&sb_path);
1519 strbuf_release(&sb_path);
1524 if (commit_lock_file(&lock->lk))
1529 static int open_or_create_logfile(const char *path, void *cb)
1533 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
1534 return (*fd < 0) ? -1 : 0;
1538 * Create a reflog for a ref. If force_create = 0, only create the
1539 * reflog for certain refs (those for which should_autocreate_reflog
1540 * returns non-zero). Otherwise, create it regardless of the reference
1541 * name. If the logfile already existed or was created, return 0 and
1542 * set *logfd to the file descriptor opened for appending to the file.
1543 * If no logfile exists and we decided not to create one, return 0 and
1544 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
1547 static int log_ref_setup(struct files_ref_store *refs,
1548 const char *refname, int force_create,
1549 int *logfd, struct strbuf *err)
1551 struct strbuf logfile_sb = STRBUF_INIT;
1554 files_reflog_path(refs, &logfile_sb, refname);
1555 logfile = strbuf_detach(&logfile_sb, NULL);
1557 if (force_create || should_autocreate_reflog(refname)) {
1558 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
1559 if (errno == ENOENT)
1560 strbuf_addf(err, "unable to create directory for '%s': "
1561 "%s", logfile, strerror(errno));
1562 else if (errno == EISDIR)
1563 strbuf_addf(err, "there are still logs under '%s'",
1566 strbuf_addf(err, "unable to append to '%s': %s",
1567 logfile, strerror(errno));
1572 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
1574 if (errno == ENOENT || errno == EISDIR) {
1576 * The logfile doesn't already exist,
1577 * but that is not an error; it only
1578 * means that we won't write log
1583 strbuf_addf(err, "unable to append to '%s': %s",
1584 logfile, strerror(errno));
1591 adjust_shared_perm(logfile);
1601 static int files_create_reflog(struct ref_store *ref_store,
1602 const char *refname, int force_create,
1605 struct files_ref_store *refs =
1606 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");
1609 if (log_ref_setup(refs, refname, force_create, &fd, err))
1618 static int log_ref_write_fd(int fd, const struct object_id *old_oid,
1619 const struct object_id *new_oid,
1620 const char *committer, const char *msg)
1622 struct strbuf sb = STRBUF_INIT;
1625 strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer);
1627 copy_reflog_msg(&sb, msg);
1628 strbuf_addch(&sb, '\n');
1629 if (write_in_full(fd, sb.buf, sb.len) < 0)
1631 strbuf_release(&sb);
1635 static int files_log_ref_write(struct files_ref_store *refs,
1636 const char *refname, const struct object_id *old_oid,
1637 const struct object_id *new_oid, const char *msg,
1638 int flags, struct strbuf *err)
1642 if (log_all_ref_updates == LOG_REFS_UNSET)
1643 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
1645 result = log_ref_setup(refs, refname,
1646 flags & REF_FORCE_CREATE_REFLOG,
1654 result = log_ref_write_fd(logfd, old_oid, new_oid,
1655 git_committer_info(0), msg);
1657 struct strbuf sb = STRBUF_INIT;
1658 int save_errno = errno;
1660 files_reflog_path(refs, &sb, refname);
1661 strbuf_addf(err, "unable to append to '%s': %s",
1662 sb.buf, strerror(save_errno));
1663 strbuf_release(&sb);
1668 struct strbuf sb = STRBUF_INIT;
1669 int save_errno = errno;
1671 files_reflog_path(refs, &sb, refname);
1672 strbuf_addf(err, "unable to append to '%s': %s",
1673 sb.buf, strerror(save_errno));
1674 strbuf_release(&sb);
1681 * Write oid into the open lockfile, then close the lockfile. On
1682 * errors, rollback the lockfile, fill in *err and return -1.
1684 static int write_ref_to_lockfile(struct ref_lock *lock,
1685 const struct object_id *oid, struct strbuf *err)
1687 static char term = '\n';
1691 o = parse_object(the_repository, oid);
1694 "trying to write ref '%s' with nonexistent object %s",
1695 lock->ref_name, oid_to_hex(oid));
1699 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1701 "trying to write non-commit object %s to branch '%s'",
1702 oid_to_hex(oid), lock->ref_name);
1706 fd = get_lock_file_fd(&lock->lk);
1707 if (write_in_full(fd, oid_to_hex(oid), the_hash_algo->hexsz) < 0 ||
1708 write_in_full(fd, &term, 1) < 0 ||
1709 close_ref_gently(lock) < 0) {
1711 "couldn't write '%s'", get_lock_file_path(&lock->lk));
1719 * Commit a change to a loose reference that has already been written
1720 * to the loose reference lockfile. Also update the reflogs if
1721 * necessary, using the specified lockmsg (which can be NULL).
1723 static int commit_ref_update(struct files_ref_store *refs,
1724 struct ref_lock *lock,
1725 const struct object_id *oid, const char *logmsg,
1728 files_assert_main_repository(refs, "commit_ref_update");
1730 clear_loose_ref_cache(refs);
1731 if (files_log_ref_write(refs, lock->ref_name,
1732 &lock->old_oid, oid,
1734 char *old_msg = strbuf_detach(err, NULL);
1735 strbuf_addf(err, "cannot update the ref '%s': %s",
1736 lock->ref_name, old_msg);
1742 if (strcmp(lock->ref_name, "HEAD") != 0) {
1744 * Special hack: If a branch is updated directly and HEAD
1745 * points to it (may happen on the remote side of a push
1746 * for example) then logically the HEAD reflog should be
1748 * A generic solution implies reverse symref information,
1749 * but finding all symrefs pointing to the given branch
1750 * would be rather costly for this rare event (the direct
1751 * update of a branch) to be worth it. So let's cheat and
1752 * check with HEAD only which should cover 99% of all usage
1753 * scenarios (even 100% of the default ones).
1756 const char *head_ref;
1758 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",
1759 RESOLVE_REF_READING,
1761 if (head_ref && (head_flag & REF_ISSYMREF) &&
1762 !strcmp(head_ref, lock->ref_name)) {
1763 struct strbuf log_err = STRBUF_INIT;
1764 if (files_log_ref_write(refs, "HEAD",
1765 &lock->old_oid, oid,
1766 logmsg, 0, &log_err)) {
1767 error("%s", log_err.buf);
1768 strbuf_release(&log_err);
1773 if (commit_ref(lock)) {
1774 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
1783 static int create_ref_symlink(struct ref_lock *lock, const char *target)
1786 #ifndef NO_SYMLINK_HEAD
1787 char *ref_path = get_locked_file_path(&lock->lk);
1789 ret = symlink(target, ref_path);
1793 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1798 static void update_symref_reflog(struct files_ref_store *refs,
1799 struct ref_lock *lock, const char *refname,
1800 const char *target, const char *logmsg)
1802 struct strbuf err = STRBUF_INIT;
1803 struct object_id new_oid;
1805 !refs_read_ref_full(&refs->base, target,
1806 RESOLVE_REF_READING, &new_oid, NULL) &&
1807 files_log_ref_write(refs, refname, &lock->old_oid,
1808 &new_oid, logmsg, 0, &err)) {
1809 error("%s", err.buf);
1810 strbuf_release(&err);
1814 static int create_symref_locked(struct files_ref_store *refs,
1815 struct ref_lock *lock, const char *refname,
1816 const char *target, const char *logmsg)
1818 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
1819 update_symref_reflog(refs, lock, refname, target, logmsg);
1823 if (!fdopen_lock_file(&lock->lk, "w"))
1824 return error("unable to fdopen %s: %s",
1825 lock->lk.tempfile->filename.buf, strerror(errno));
1827 update_symref_reflog(refs, lock, refname, target, logmsg);
1829 /* no error check; commit_ref will check ferror */
1830 fprintf(lock->lk.tempfile->fp, "ref: %s\n", target);
1831 if (commit_ref(lock) < 0)
1832 return error("unable to write symref for %s: %s", refname,
1837 static int files_create_symref(struct ref_store *ref_store,
1838 const char *refname, const char *target,
1841 struct files_ref_store *refs =
1842 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");
1843 struct strbuf err = STRBUF_INIT;
1844 struct ref_lock *lock;
1847 lock = lock_ref_oid_basic(refs, refname, NULL,
1848 NULL, NULL, REF_NO_DEREF, NULL,
1851 error("%s", err.buf);
1852 strbuf_release(&err);
1856 ret = create_symref_locked(refs, lock, refname, target, logmsg);
1861 static int files_reflog_exists(struct ref_store *ref_store,
1862 const char *refname)
1864 struct files_ref_store *refs =
1865 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");
1866 struct strbuf sb = STRBUF_INIT;
1870 files_reflog_path(refs, &sb, refname);
1871 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);
1872 strbuf_release(&sb);
1876 static int files_delete_reflog(struct ref_store *ref_store,
1877 const char *refname)
1879 struct files_ref_store *refs =
1880 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");
1881 struct strbuf sb = STRBUF_INIT;
1884 files_reflog_path(refs, &sb, refname);
1885 ret = remove_path(sb.buf);
1886 strbuf_release(&sb);
1890 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
1892 struct object_id ooid, noid;
1893 char *email_end, *message;
1894 timestamp_t timestamp;
1896 const char *p = sb->buf;
1898 /* old SP new SP name <email> SP time TAB msg LF */
1899 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
1900 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
1901 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
1902 !(email_end = strchr(p, '>')) ||
1903 email_end[1] != ' ' ||
1904 !(timestamp = parse_timestamp(email_end + 2, &message, 10)) ||
1905 !message || message[0] != ' ' ||
1906 (message[1] != '+' && message[1] != '-') ||
1907 !isdigit(message[2]) || !isdigit(message[3]) ||
1908 !isdigit(message[4]) || !isdigit(message[5]))
1909 return 0; /* corrupt? */
1910 email_end[1] = '\0';
1911 tz = strtol(message + 1, NULL, 10);
1912 if (message[6] != '\t')
1916 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
1919 static char *find_beginning_of_line(char *bob, char *scan)
1921 while (bob < scan && *(--scan) != '\n')
1922 ; /* keep scanning backwards */
1924 * Return either beginning of the buffer, or LF at the end of
1925 * the previous line.
1930 static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,
1931 const char *refname,
1932 each_reflog_ent_fn fn,
1935 struct files_ref_store *refs =
1936 files_downcast(ref_store, REF_STORE_READ,
1937 "for_each_reflog_ent_reverse");
1938 struct strbuf sb = STRBUF_INIT;
1941 int ret = 0, at_tail = 1;
1943 files_reflog_path(refs, &sb, refname);
1944 logfp = fopen(sb.buf, "r");
1945 strbuf_release(&sb);
1949 /* Jump to the end */
1950 if (fseek(logfp, 0, SEEK_END) < 0)
1951 ret = error("cannot seek back reflog for %s: %s",
1952 refname, strerror(errno));
1954 while (!ret && 0 < pos) {
1960 /* Fill next block from the end */
1961 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
1962 if (fseek(logfp, pos - cnt, SEEK_SET)) {
1963 ret = error("cannot seek back reflog for %s: %s",
1964 refname, strerror(errno));
1967 nread = fread(buf, cnt, 1, logfp);
1969 ret = error("cannot read %d bytes from reflog for %s: %s",
1970 cnt, refname, strerror(errno));
1975 scanp = endp = buf + cnt;
1976 if (at_tail && scanp[-1] == '\n')
1977 /* Looking at the final LF at the end of the file */
1981 while (buf < scanp) {
1983 * terminating LF of the previous line, or the beginning
1988 bp = find_beginning_of_line(buf, scanp);
1992 * The newline is the end of the previous line,
1993 * so we know we have complete line starting
1994 * at (bp + 1). Prefix it onto any prior data
1995 * we collected for the line and process it.
1997 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
2000 ret = show_one_reflog_ent(&sb, fn, cb_data);
2006 * We are at the start of the buffer, and the
2007 * start of the file; there is no previous
2008 * line, and we have everything for this one.
2009 * Process it, and we can end the loop.
2011 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2012 ret = show_one_reflog_ent(&sb, fn, cb_data);
2019 * We are at the start of the buffer, and there
2020 * is more file to read backwards. Which means
2021 * we are in the middle of a line. Note that we
2022 * may get here even if *bp was a newline; that
2023 * just means we are at the exact end of the
2024 * previous line, rather than some spot in the
2027 * Save away what we have to be combined with
2028 * the data from the next read.
2030 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2037 BUG("reverse reflog parser had leftover data");
2040 strbuf_release(&sb);
2044 static int files_for_each_reflog_ent(struct ref_store *ref_store,
2045 const char *refname,
2046 each_reflog_ent_fn fn, void *cb_data)
2048 struct files_ref_store *refs =
2049 files_downcast(ref_store, REF_STORE_READ,
2050 "for_each_reflog_ent");
2052 struct strbuf sb = STRBUF_INIT;
2055 files_reflog_path(refs, &sb, refname);
2056 logfp = fopen(sb.buf, "r");
2057 strbuf_release(&sb);
2061 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
2062 ret = show_one_reflog_ent(&sb, fn, cb_data);
2064 strbuf_release(&sb);
2068 struct files_reflog_iterator {
2069 struct ref_iterator base;
2071 struct ref_store *ref_store;
2072 struct dir_iterator *dir_iterator;
2073 struct object_id oid;
2076 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
2078 struct files_reflog_iterator *iter =
2079 (struct files_reflog_iterator *)ref_iterator;
2080 struct dir_iterator *diter = iter->dir_iterator;
2083 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
2086 if (!S_ISREG(diter->st.st_mode))
2088 if (diter->basename[0] == '.')
2090 if (ends_with(diter->basename, ".lock"))
2093 if (refs_read_ref_full(iter->ref_store,
2094 diter->relative_path, 0,
2095 &iter->oid, &flags)) {
2096 error("bad ref for %s", diter->path.buf);
2100 iter->base.refname = diter->relative_path;
2101 iter->base.oid = &iter->oid;
2102 iter->base.flags = flags;
2106 iter->dir_iterator = NULL;
2107 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
2112 static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
2113 struct object_id *peeled)
2115 BUG("ref_iterator_peel() called for reflog_iterator");
2118 static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
2120 struct files_reflog_iterator *iter =
2121 (struct files_reflog_iterator *)ref_iterator;
2124 if (iter->dir_iterator)
2125 ok = dir_iterator_abort(iter->dir_iterator);
2127 base_ref_iterator_free(ref_iterator);
2131 static struct ref_iterator_vtable files_reflog_iterator_vtable = {
2132 files_reflog_iterator_advance,
2133 files_reflog_iterator_peel,
2134 files_reflog_iterator_abort
2137 static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
2140 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
2141 struct ref_iterator *ref_iterator = &iter->base;
2142 struct strbuf sb = STRBUF_INIT;
2144 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0);
2145 strbuf_addf(&sb, "%s/logs", gitdir);
2146 iter->dir_iterator = dir_iterator_begin(sb.buf);
2147 iter->ref_store = ref_store;
2148 strbuf_release(&sb);
2150 return ref_iterator;
2153 static enum iterator_selection reflog_iterator_select(
2154 struct ref_iterator *iter_worktree,
2155 struct ref_iterator *iter_common,
2158 if (iter_worktree) {
2160 * We're a bit loose here. We probably should ignore
2161 * common refs if they are accidentally added as
2162 * per-worktree refs.
2164 return ITER_SELECT_0;
2165 } else if (iter_common) {
2166 if (ref_type(iter_common->refname) == REF_TYPE_NORMAL)
2167 return ITER_SELECT_1;
2170 * The main ref store may contain main worktree's
2171 * per-worktree refs, which should be ignored
2178 static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
2180 struct files_ref_store *refs =
2181 files_downcast(ref_store, REF_STORE_READ,
2182 "reflog_iterator_begin");
2184 if (!strcmp(refs->gitdir, refs->gitcommondir)) {
2185 return reflog_iterator_begin(ref_store, refs->gitcommondir);
2187 return merge_ref_iterator_begin(
2189 reflog_iterator_begin(ref_store, refs->gitdir),
2190 reflog_iterator_begin(ref_store, refs->gitcommondir),
2191 reflog_iterator_select, refs);
2196 * If update is a direct update of head_ref (the reference pointed to
2197 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
2199 static int split_head_update(struct ref_update *update,
2200 struct ref_transaction *transaction,
2201 const char *head_ref,
2202 struct string_list *affected_refnames,
2205 struct string_list_item *item;
2206 struct ref_update *new_update;
2208 if ((update->flags & REF_LOG_ONLY) ||
2209 (update->flags & REF_IS_PRUNING) ||
2210 (update->flags & REF_UPDATE_VIA_HEAD))
2213 if (strcmp(update->refname, head_ref))
2217 * First make sure that HEAD is not already in the
2218 * transaction. This check is O(lg N) in the transaction
2219 * size, but it happens at most once per transaction.
2221 if (string_list_has_string(affected_refnames, "HEAD")) {
2222 /* An entry already existed */
2224 "multiple updates for 'HEAD' (including one "
2225 "via its referent '%s') are not allowed",
2227 return TRANSACTION_NAME_CONFLICT;
2230 new_update = ref_transaction_add_update(
2231 transaction, "HEAD",
2232 update->flags | REF_LOG_ONLY | REF_NO_DEREF,
2233 &update->new_oid, &update->old_oid,
2237 * Add "HEAD". This insertion is O(N) in the transaction
2238 * size, but it happens at most once per transaction.
2239 * Add new_update->refname instead of a literal "HEAD".
2241 if (strcmp(new_update->refname, "HEAD"))
2242 BUG("%s unexpectedly not 'HEAD'", new_update->refname);
2243 item = string_list_insert(affected_refnames, new_update->refname);
2244 item->util = new_update;
2250 * update is for a symref that points at referent and doesn't have
2251 * REF_NO_DEREF set. Split it into two updates:
2252 * - The original update, but with REF_LOG_ONLY and REF_NO_DEREF set
2253 * - A new, separate update for the referent reference
2254 * Note that the new update will itself be subject to splitting when
2255 * the iteration gets to it.
2257 static int split_symref_update(struct files_ref_store *refs,
2258 struct ref_update *update,
2259 const char *referent,
2260 struct ref_transaction *transaction,
2261 struct string_list *affected_refnames,
2264 struct string_list_item *item;
2265 struct ref_update *new_update;
2266 unsigned int new_flags;
2269 * First make sure that referent is not already in the
2270 * transaction. This check is O(lg N) in the transaction
2271 * size, but it happens at most once per symref in a
2274 if (string_list_has_string(affected_refnames, referent)) {
2275 /* An entry already exists */
2277 "multiple updates for '%s' (including one "
2278 "via symref '%s') are not allowed",
2279 referent, update->refname);
2280 return TRANSACTION_NAME_CONFLICT;
2283 new_flags = update->flags;
2284 if (!strcmp(update->refname, "HEAD")) {
2286 * Record that the new update came via HEAD, so that
2287 * when we process it, split_head_update() doesn't try
2288 * to add another reflog update for HEAD. Note that
2289 * this bit will be propagated if the new_update
2290 * itself needs to be split.
2292 new_flags |= REF_UPDATE_VIA_HEAD;
2295 new_update = ref_transaction_add_update(
2296 transaction, referent, new_flags,
2297 &update->new_oid, &update->old_oid,
2300 new_update->parent_update = update;
2303 * Change the symbolic ref update to log only. Also, it
2304 * doesn't need to check its old OID value, as that will be
2305 * done when new_update is processed.
2307 update->flags |= REF_LOG_ONLY | REF_NO_DEREF;
2308 update->flags &= ~REF_HAVE_OLD;
2311 * Add the referent. This insertion is O(N) in the transaction
2312 * size, but it happens at most once per symref in a
2313 * transaction. Make sure to add new_update->refname, which will
2314 * be valid as long as affected_refnames is in use, and NOT
2315 * referent, which might soon be freed by our caller.
2317 item = string_list_insert(affected_refnames, new_update->refname);
2319 BUG("%s unexpectedly found in affected_refnames",
2320 new_update->refname);
2321 item->util = new_update;
2327 * Return the refname under which update was originally requested.
2329 static const char *original_update_refname(struct ref_update *update)
2331 while (update->parent_update)
2332 update = update->parent_update;
2334 return update->refname;
2338 * Check whether the REF_HAVE_OLD and old_oid values stored in update
2339 * are consistent with oid, which is the reference's current value. If
2340 * everything is OK, return 0; otherwise, write an error message to
2341 * err and return -1.
2343 static int check_old_oid(struct ref_update *update, struct object_id *oid,
2346 if (!(update->flags & REF_HAVE_OLD) ||
2347 oideq(oid, &update->old_oid))
2350 if (is_null_oid(&update->old_oid))
2351 strbuf_addf(err, "cannot lock ref '%s': "
2352 "reference already exists",
2353 original_update_refname(update));
2354 else if (is_null_oid(oid))
2355 strbuf_addf(err, "cannot lock ref '%s': "
2356 "reference is missing but expected %s",
2357 original_update_refname(update),
2358 oid_to_hex(&update->old_oid));
2360 strbuf_addf(err, "cannot lock ref '%s': "
2361 "is at %s but expected %s",
2362 original_update_refname(update),
2364 oid_to_hex(&update->old_oid));
2370 * Prepare for carrying out update:
2371 * - Lock the reference referred to by update.
2372 * - Read the reference under lock.
2373 * - Check that its old OID value (if specified) is correct, and in
2374 * any case record it in update->lock->old_oid for later use when
2375 * writing the reflog.
2376 * - If it is a symref update without REF_NO_DEREF, split it up into a
2377 * REF_LOG_ONLY update of the symref and add a separate update for
2378 * the referent to transaction.
2379 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
2382 static int lock_ref_for_update(struct files_ref_store *refs,
2383 struct ref_update *update,
2384 struct ref_transaction *transaction,
2385 const char *head_ref,
2386 struct string_list *affected_refnames,
2389 struct strbuf referent = STRBUF_INIT;
2390 int mustexist = (update->flags & REF_HAVE_OLD) &&
2391 !is_null_oid(&update->old_oid);
2393 struct ref_lock *lock;
2395 files_assert_main_repository(refs, "lock_ref_for_update");
2397 if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid))
2398 update->flags |= REF_DELETING;
2401 ret = split_head_update(update, transaction, head_ref,
2402 affected_refnames, err);
2407 ret = lock_raw_ref(refs, update->refname, mustexist,
2408 affected_refnames, NULL,
2410 &update->type, err);
2414 reason = strbuf_detach(err, NULL);
2415 strbuf_addf(err, "cannot lock ref '%s': %s",
2416 original_update_refname(update), reason);
2421 update->backend_data = lock;
2423 if (update->type & REF_ISSYMREF) {
2424 if (update->flags & REF_NO_DEREF) {
2426 * We won't be reading the referent as part of
2427 * the transaction, so we have to read it here
2428 * to record and possibly check old_oid:
2430 if (refs_read_ref_full(&refs->base,
2432 &lock->old_oid, NULL)) {
2433 if (update->flags & REF_HAVE_OLD) {
2434 strbuf_addf(err, "cannot lock ref '%s': "
2435 "error reading reference",
2436 original_update_refname(update));
2437 ret = TRANSACTION_GENERIC_ERROR;
2440 } else if (check_old_oid(update, &lock->old_oid, err)) {
2441 ret = TRANSACTION_GENERIC_ERROR;
2446 * Create a new update for the reference this
2447 * symref is pointing at. Also, we will record
2448 * and verify old_oid for this update as part
2449 * of processing the split-off update, so we
2450 * don't have to do it here.
2452 ret = split_symref_update(refs, update,
2453 referent.buf, transaction,
2454 affected_refnames, err);
2459 struct ref_update *parent_update;
2461 if (check_old_oid(update, &lock->old_oid, err)) {
2462 ret = TRANSACTION_GENERIC_ERROR;
2467 * If this update is happening indirectly because of a
2468 * symref update, record the old OID in the parent
2471 for (parent_update = update->parent_update;
2473 parent_update = parent_update->parent_update) {
2474 struct ref_lock *parent_lock = parent_update->backend_data;
2475 oidcpy(&parent_lock->old_oid, &lock->old_oid);
2479 if ((update->flags & REF_HAVE_NEW) &&
2480 !(update->flags & REF_DELETING) &&
2481 !(update->flags & REF_LOG_ONLY)) {
2482 if (!(update->type & REF_ISSYMREF) &&
2483 oideq(&lock->old_oid, &update->new_oid)) {
2485 * The reference already has the desired
2486 * value, so we don't need to write it.
2488 } else if (write_ref_to_lockfile(lock, &update->new_oid,
2490 char *write_err = strbuf_detach(err, NULL);
2493 * The lock was freed upon failure of
2494 * write_ref_to_lockfile():
2496 update->backend_data = NULL;
2498 "cannot update ref '%s': %s",
2499 update->refname, write_err);
2501 ret = TRANSACTION_GENERIC_ERROR;
2504 update->flags |= REF_NEEDS_COMMIT;
2507 if (!(update->flags & REF_NEEDS_COMMIT)) {
2509 * We didn't call write_ref_to_lockfile(), so
2510 * the lockfile is still open. Close it to
2511 * free up the file descriptor:
2513 if (close_ref_gently(lock)) {
2514 strbuf_addf(err, "couldn't close '%s.lock'",
2516 ret = TRANSACTION_GENERIC_ERROR;
2522 strbuf_release(&referent);
2526 struct files_transaction_backend_data {
2527 struct ref_transaction *packed_transaction;
2528 int packed_refs_locked;
2532 * Unlock any references in `transaction` that are still locked, and
2533 * mark the transaction closed.
2535 static void files_transaction_cleanup(struct files_ref_store *refs,
2536 struct ref_transaction *transaction)
2539 struct files_transaction_backend_data *backend_data =
2540 transaction->backend_data;
2541 struct strbuf err = STRBUF_INIT;
2543 for (i = 0; i < transaction->nr; i++) {
2544 struct ref_update *update = transaction->updates[i];
2545 struct ref_lock *lock = update->backend_data;
2549 update->backend_data = NULL;
2553 if (backend_data->packed_transaction &&
2554 ref_transaction_abort(backend_data->packed_transaction, &err)) {
2555 error("error aborting transaction: %s", err.buf);
2556 strbuf_release(&err);
2559 if (backend_data->packed_refs_locked)
2560 packed_refs_unlock(refs->packed_ref_store);
2564 transaction->state = REF_TRANSACTION_CLOSED;
2567 static int files_transaction_prepare(struct ref_store *ref_store,
2568 struct ref_transaction *transaction,
2571 struct files_ref_store *refs =
2572 files_downcast(ref_store, REF_STORE_WRITE,
2573 "ref_transaction_prepare");
2576 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
2577 char *head_ref = NULL;
2579 struct files_transaction_backend_data *backend_data;
2580 struct ref_transaction *packed_transaction = NULL;
2584 if (!transaction->nr)
2587 backend_data = xcalloc(1, sizeof(*backend_data));
2588 transaction->backend_data = backend_data;
2591 * Fail if a refname appears more than once in the
2592 * transaction. (If we end up splitting up any updates using
2593 * split_symref_update() or split_head_update(), those
2594 * functions will check that the new updates don't have the
2595 * same refname as any existing ones.) Also fail if any of the
2596 * updates use REF_IS_PRUNING without REF_NO_DEREF.
2598 for (i = 0; i < transaction->nr; i++) {
2599 struct ref_update *update = transaction->updates[i];
2600 struct string_list_item *item =
2601 string_list_append(&affected_refnames, update->refname);
2603 if ((update->flags & REF_IS_PRUNING) &&
2604 !(update->flags & REF_NO_DEREF))
2605 BUG("REF_IS_PRUNING set without REF_NO_DEREF");
2608 * We store a pointer to update in item->util, but at
2609 * the moment we never use the value of this field
2610 * except to check whether it is non-NULL.
2612 item->util = update;
2614 string_list_sort(&affected_refnames);
2615 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2616 ret = TRANSACTION_GENERIC_ERROR;
2621 * Special hack: If a branch is updated directly and HEAD
2622 * points to it (may happen on the remote side of a push
2623 * for example) then logically the HEAD reflog should be
2626 * A generic solution would require reverse symref lookups,
2627 * but finding all symrefs pointing to a given branch would be
2628 * rather costly for this rare event (the direct update of a
2629 * branch) to be worth it. So let's cheat and check with HEAD
2630 * only, which should cover 99% of all usage scenarios (even
2631 * 100% of the default ones).
2633 * So if HEAD is a symbolic reference, then record the name of
2634 * the reference that it points to. If we see an update of
2635 * head_ref within the transaction, then split_head_update()
2636 * arranges for the reflog of HEAD to be updated, too.
2638 head_ref = refs_resolve_refdup(ref_store, "HEAD",
2639 RESOLVE_REF_NO_RECURSE,
2642 if (head_ref && !(head_type & REF_ISSYMREF)) {
2643 FREE_AND_NULL(head_ref);
2647 * Acquire all locks, verify old values if provided, check
2648 * that new values are valid, and write new values to the
2649 * lockfiles, ready to be activated. Only keep one lockfile
2650 * open at a time to avoid running out of file descriptors.
2651 * Note that lock_ref_for_update() might append more updates
2652 * to the transaction.
2654 for (i = 0; i < transaction->nr; i++) {
2655 struct ref_update *update = transaction->updates[i];
2657 ret = lock_ref_for_update(refs, update, transaction,
2658 head_ref, &affected_refnames, err);
2662 if (update->flags & REF_DELETING &&
2663 !(update->flags & REF_LOG_ONLY) &&
2664 !(update->flags & REF_IS_PRUNING)) {
2666 * This reference has to be deleted from
2667 * packed-refs if it exists there.
2669 if (!packed_transaction) {
2670 packed_transaction = ref_store_transaction_begin(
2671 refs->packed_ref_store, err);
2672 if (!packed_transaction) {
2673 ret = TRANSACTION_GENERIC_ERROR;
2677 backend_data->packed_transaction =
2681 ref_transaction_add_update(
2682 packed_transaction, update->refname,
2683 REF_HAVE_NEW | REF_NO_DEREF,
2684 &update->new_oid, NULL,
2689 if (packed_transaction) {
2690 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
2691 ret = TRANSACTION_GENERIC_ERROR;
2694 backend_data->packed_refs_locked = 1;
2696 if (is_packed_transaction_needed(refs->packed_ref_store,
2697 packed_transaction)) {
2698 ret = ref_transaction_prepare(packed_transaction, err);
2700 * A failure during the prepare step will abort
2701 * itself, but not free. Do that now, and disconnect
2702 * from the files_transaction so it does not try to
2703 * abort us when we hit the cleanup code below.
2706 ref_transaction_free(packed_transaction);
2707 backend_data->packed_transaction = NULL;
2711 * We can skip rewriting the `packed-refs`
2712 * file. But we do need to leave it locked, so
2713 * that somebody else doesn't pack a reference
2714 * that we are trying to delete.
2716 * We need to disconnect our transaction from
2717 * backend_data, since the abort (whether successful or
2718 * not) will free it.
2720 backend_data->packed_transaction = NULL;
2721 if (ref_transaction_abort(packed_transaction, err)) {
2722 ret = TRANSACTION_GENERIC_ERROR;
2730 string_list_clear(&affected_refnames, 0);
2733 files_transaction_cleanup(refs, transaction);
2735 transaction->state = REF_TRANSACTION_PREPARED;
2740 static int files_transaction_finish(struct ref_store *ref_store,
2741 struct ref_transaction *transaction,
2744 struct files_ref_store *refs =
2745 files_downcast(ref_store, 0, "ref_transaction_finish");
2748 struct strbuf sb = STRBUF_INIT;
2749 struct files_transaction_backend_data *backend_data;
2750 struct ref_transaction *packed_transaction;
2755 if (!transaction->nr) {
2756 transaction->state = REF_TRANSACTION_CLOSED;
2760 backend_data = transaction->backend_data;
2761 packed_transaction = backend_data->packed_transaction;
2763 /* Perform updates first so live commits remain referenced */
2764 for (i = 0; i < transaction->nr; i++) {
2765 struct ref_update *update = transaction->updates[i];
2766 struct ref_lock *lock = update->backend_data;
2768 if (update->flags & REF_NEEDS_COMMIT ||
2769 update->flags & REF_LOG_ONLY) {
2770 if (files_log_ref_write(refs,
2774 update->msg, update->flags,
2776 char *old_msg = strbuf_detach(err, NULL);
2778 strbuf_addf(err, "cannot update the ref '%s': %s",
2779 lock->ref_name, old_msg);
2782 update->backend_data = NULL;
2783 ret = TRANSACTION_GENERIC_ERROR;
2787 if (update->flags & REF_NEEDS_COMMIT) {
2788 clear_loose_ref_cache(refs);
2789 if (commit_ref(lock)) {
2790 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
2792 update->backend_data = NULL;
2793 ret = TRANSACTION_GENERIC_ERROR;
2800 * Now that updates are safely completed, we can perform
2801 * deletes. First delete the reflogs of any references that
2802 * will be deleted, since (in the unexpected event of an
2803 * error) leaving a reference without a reflog is less bad
2804 * than leaving a reflog without a reference (the latter is a
2805 * mildly invalid repository state):
2807 for (i = 0; i < transaction->nr; i++) {
2808 struct ref_update *update = transaction->updates[i];
2809 if (update->flags & REF_DELETING &&
2810 !(update->flags & REF_LOG_ONLY) &&
2811 !(update->flags & REF_IS_PRUNING)) {
2813 files_reflog_path(refs, &sb, update->refname);
2814 if (!unlink_or_warn(sb.buf))
2815 try_remove_empty_parents(refs, update->refname,
2816 REMOVE_EMPTY_PARENTS_REFLOG);
2821 * Perform deletes now that updates are safely completed.
2823 * First delete any packed versions of the references, while
2824 * retaining the packed-refs lock:
2826 if (packed_transaction) {
2827 ret = ref_transaction_commit(packed_transaction, err);
2828 ref_transaction_free(packed_transaction);
2829 packed_transaction = NULL;
2830 backend_data->packed_transaction = NULL;
2835 /* Now delete the loose versions of the references: */
2836 for (i = 0; i < transaction->nr; i++) {
2837 struct ref_update *update = transaction->updates[i];
2838 struct ref_lock *lock = update->backend_data;
2840 if (update->flags & REF_DELETING &&
2841 !(update->flags & REF_LOG_ONLY)) {
2842 if (!(update->type & REF_ISPACKED) ||
2843 update->type & REF_ISSYMREF) {
2844 /* It is a loose reference. */
2846 files_ref_path(refs, &sb, lock->ref_name);
2847 if (unlink_or_msg(sb.buf, err)) {
2848 ret = TRANSACTION_GENERIC_ERROR;
2851 update->flags |= REF_DELETED_LOOSE;
2856 clear_loose_ref_cache(refs);
2859 files_transaction_cleanup(refs, transaction);
2861 for (i = 0; i < transaction->nr; i++) {
2862 struct ref_update *update = transaction->updates[i];
2864 if (update->flags & REF_DELETED_LOOSE) {
2866 * The loose reference was deleted. Delete any
2867 * empty parent directories. (Note that this
2868 * can only work because we have already
2869 * removed the lockfile.)
2871 try_remove_empty_parents(refs, update->refname,
2872 REMOVE_EMPTY_PARENTS_REF);
2876 strbuf_release(&sb);
2880 static int files_transaction_abort(struct ref_store *ref_store,
2881 struct ref_transaction *transaction,
2884 struct files_ref_store *refs =
2885 files_downcast(ref_store, 0, "ref_transaction_abort");
2887 files_transaction_cleanup(refs, transaction);
2891 static int ref_present(const char *refname,
2892 const struct object_id *oid, int flags, void *cb_data)
2894 struct string_list *affected_refnames = cb_data;
2896 return string_list_has_string(affected_refnames, refname);
2899 static int files_initial_transaction_commit(struct ref_store *ref_store,
2900 struct ref_transaction *transaction,
2903 struct files_ref_store *refs =
2904 files_downcast(ref_store, REF_STORE_WRITE,
2905 "initial_ref_transaction_commit");
2908 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
2909 struct ref_transaction *packed_transaction = NULL;
2913 if (transaction->state != REF_TRANSACTION_OPEN)
2914 BUG("commit called for transaction that is not open");
2916 /* Fail if a refname appears more than once in the transaction: */
2917 for (i = 0; i < transaction->nr; i++)
2918 string_list_append(&affected_refnames,
2919 transaction->updates[i]->refname);
2920 string_list_sort(&affected_refnames);
2921 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2922 ret = TRANSACTION_GENERIC_ERROR;
2927 * It's really undefined to call this function in an active
2928 * repository or when there are existing references: we are
2929 * only locking and changing packed-refs, so (1) any
2930 * simultaneous processes might try to change a reference at
2931 * the same time we do, and (2) any existing loose versions of
2932 * the references that we are setting would have precedence
2933 * over our values. But some remote helpers create the remote
2934 * "HEAD" and "master" branches before calling this function,
2935 * so here we really only check that none of the references
2936 * that we are creating already exists.
2938 if (refs_for_each_rawref(&refs->base, ref_present,
2939 &affected_refnames))
2940 BUG("initial ref transaction called with existing refs");
2942 packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err);
2943 if (!packed_transaction) {
2944 ret = TRANSACTION_GENERIC_ERROR;
2948 for (i = 0; i < transaction->nr; i++) {
2949 struct ref_update *update = transaction->updates[i];
2951 if ((update->flags & REF_HAVE_OLD) &&
2952 !is_null_oid(&update->old_oid))
2953 BUG("initial ref transaction with old_sha1 set");
2954 if (refs_verify_refname_available(&refs->base, update->refname,
2955 &affected_refnames, NULL,
2957 ret = TRANSACTION_NAME_CONFLICT;
2962 * Add a reference creation for this reference to the
2963 * packed-refs transaction:
2965 ref_transaction_add_update(packed_transaction, update->refname,
2966 update->flags & ~REF_HAVE_OLD,
2967 &update->new_oid, &update->old_oid,
2971 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
2972 ret = TRANSACTION_GENERIC_ERROR;
2976 if (initial_ref_transaction_commit(packed_transaction, err)) {
2977 ret = TRANSACTION_GENERIC_ERROR;
2980 packed_refs_unlock(refs->packed_ref_store);
2982 if (packed_transaction)
2983 ref_transaction_free(packed_transaction);
2984 transaction->state = REF_TRANSACTION_CLOSED;
2985 string_list_clear(&affected_refnames, 0);
2989 struct expire_reflog_cb {
2991 reflog_expiry_should_prune_fn *should_prune_fn;
2994 struct object_id last_kept_oid;
2997 static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
2998 const char *email, timestamp_t timestamp, int tz,
2999 const char *message, void *cb_data)
3001 struct expire_reflog_cb *cb = cb_data;
3002 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
3004 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
3005 ooid = &cb->last_kept_oid;
3007 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,
3008 message, policy_cb)) {
3010 printf("would prune %s", message);
3011 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3012 printf("prune %s", message);
3015 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",
3016 oid_to_hex(ooid), oid_to_hex(noid),
3017 email, timestamp, tz, message);
3018 oidcpy(&cb->last_kept_oid, noid);
3020 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3021 printf("keep %s", message);
3026 static int files_reflog_expire(struct ref_store *ref_store,
3027 const char *refname, const struct object_id *oid,
3029 reflog_expiry_prepare_fn prepare_fn,
3030 reflog_expiry_should_prune_fn should_prune_fn,
3031 reflog_expiry_cleanup_fn cleanup_fn,
3032 void *policy_cb_data)
3034 struct files_ref_store *refs =
3035 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");
3036 struct lock_file reflog_lock = LOCK_INIT;
3037 struct expire_reflog_cb cb;
3038 struct ref_lock *lock;
3039 struct strbuf log_file_sb = STRBUF_INIT;
3043 struct strbuf err = STRBUF_INIT;
3045 memset(&cb, 0, sizeof(cb));
3047 cb.policy_cb = policy_cb_data;
3048 cb.should_prune_fn = should_prune_fn;
3051 * The reflog file is locked by holding the lock on the
3052 * reference itself, plus we might need to update the
3053 * reference if --updateref was specified:
3055 lock = lock_ref_oid_basic(refs, refname, oid,
3056 NULL, NULL, REF_NO_DEREF,
3059 error("cannot lock ref '%s': %s", refname, err.buf);
3060 strbuf_release(&err);
3063 if (!refs_reflog_exists(ref_store, refname)) {
3068 files_reflog_path(refs, &log_file_sb, refname);
3069 log_file = strbuf_detach(&log_file_sb, NULL);
3070 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3072 * Even though holding $GIT_DIR/logs/$reflog.lock has
3073 * no locking implications, we use the lock_file
3074 * machinery here anyway because it does a lot of the
3075 * work we need, including cleaning up if the program
3076 * exits unexpectedly.
3078 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
3079 struct strbuf err = STRBUF_INIT;
3080 unable_to_lock_message(log_file, errno, &err);
3081 error("%s", err.buf);
3082 strbuf_release(&err);
3085 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
3087 error("cannot fdopen %s (%s)",
3088 get_lock_file_path(&reflog_lock), strerror(errno));
3093 (*prepare_fn)(refname, oid, cb.policy_cb);
3094 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);
3095 (*cleanup_fn)(cb.policy_cb);
3097 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3099 * It doesn't make sense to adjust a reference pointed
3100 * to by a symbolic ref based on expiring entries in
3101 * the symbolic reference's reflog. Nor can we update
3102 * a reference if there are no remaining reflog
3105 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
3106 !(type & REF_ISSYMREF) &&
3107 !is_null_oid(&cb.last_kept_oid);
3109 if (close_lock_file_gently(&reflog_lock)) {
3110 status |= error("couldn't write %s: %s", log_file,
3112 rollback_lock_file(&reflog_lock);
3113 } else if (update &&
3114 (write_in_full(get_lock_file_fd(&lock->lk),
3115 oid_to_hex(&cb.last_kept_oid), the_hash_algo->hexsz) < 0 ||
3116 write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 0 ||
3117 close_ref_gently(lock) < 0)) {
3118 status |= error("couldn't write %s",
3119 get_lock_file_path(&lock->lk));
3120 rollback_lock_file(&reflog_lock);
3121 } else if (commit_lock_file(&reflog_lock)) {
3122 status |= error("unable to write reflog '%s' (%s)",
3123 log_file, strerror(errno));
3124 } else if (update && commit_ref(lock)) {
3125 status |= error("couldn't set %s", lock->ref_name);
3133 rollback_lock_file(&reflog_lock);
3139 static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
3141 struct files_ref_store *refs =
3142 files_downcast(ref_store, REF_STORE_WRITE, "init_db");
3143 struct strbuf sb = STRBUF_INIT;
3146 * Create .git/refs/{heads,tags}
3148 files_ref_path(refs, &sb, "refs/heads");
3149 safe_create_dir(sb.buf, 1);
3152 files_ref_path(refs, &sb, "refs/tags");
3153 safe_create_dir(sb.buf, 1);
3155 strbuf_release(&sb);
3159 struct ref_storage_be refs_be_files = {
3162 files_ref_store_create,
3164 files_transaction_prepare,
3165 files_transaction_finish,
3166 files_transaction_abort,
3167 files_initial_transaction_commit,
3170 files_create_symref,
3175 files_ref_iterator_begin,
3178 files_reflog_iterator_begin,
3179 files_for_each_reflog_ent,
3180 files_for_each_reflog_ent_reverse,
3181 files_reflog_exists,
3182 files_create_reflog,
3183 files_delete_reflog,