diff options
Diffstat (limited to 'third_party/git/refs/files-backend.c')
| -rw-r--r-- | third_party/git/refs/files-backend.c | 3201 |
1 files changed, 0 insertions, 3201 deletions
diff --git a/third_party/git/refs/files-backend.c b/third_party/git/refs/files-backend.c deleted file mode 100644 index d60767ab73..0000000000 --- a/third_party/git/refs/files-backend.c +++ /dev/null @@ -1,3201 +0,0 @@ -#include "../cache.h" -#include "../config.h" -#include "../refs.h" -#include "refs-internal.h" -#include "ref-cache.h" -#include "packed-backend.h" -#include "../iterator.h" -#include "../dir-iterator.h" -#include "../lockfile.h" -#include "../object.h" -#include "../dir.h" -#include "../chdir-notify.h" -#include "worktree.h" - -/* - * This backend uses the following flags in `ref_update::flags` for - * internal bookkeeping purposes. Their numerical values must not - * conflict with REF_NO_DEREF, REF_FORCE_CREATE_REFLOG, REF_HAVE_NEW, - * REF_HAVE_OLD, or REF_IS_PRUNING, which are also stored in - * `ref_update::flags`. - */ - -/* - * Used as a flag in ref_update::flags when a loose ref is being - * pruned. This flag must only be used when REF_NO_DEREF is set. - */ -#define REF_IS_PRUNING (1 << 4) - -/* - * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken - * refs (i.e., because the reference is about to be deleted anyway). - */ -#define REF_DELETING (1 << 5) - -/* - * Used as a flag in ref_update::flags when the lockfile needs to be - * committed. - */ -#define REF_NEEDS_COMMIT (1 << 6) - -/* - * Used as a flag in ref_update::flags when we want to log a ref - * update but not actually perform it. This is used when a symbolic - * ref update is split up. - */ -#define REF_LOG_ONLY (1 << 7) - -/* - * Used as a flag in ref_update::flags when the ref_update was via an - * update to HEAD. - */ -#define REF_UPDATE_VIA_HEAD (1 << 8) - -/* - * Used as a flag in ref_update::flags when the loose reference has - * been deleted. - */ -#define REF_DELETED_LOOSE (1 << 9) - -struct ref_lock { - char *ref_name; - struct lock_file lk; - struct object_id old_oid; -}; - -struct files_ref_store { - struct ref_store base; - unsigned int store_flags; - - char *gitdir; - char *gitcommondir; - - struct ref_cache *loose; - - struct ref_store *packed_ref_store; -}; - -static void clear_loose_ref_cache(struct files_ref_store *refs) -{ - if (refs->loose) { - free_ref_cache(refs->loose); - refs->loose = NULL; - } -} - -/* - * Create a new submodule ref cache and add it to the internal - * set of caches. - */ -static struct ref_store *files_ref_store_create(const char *gitdir, - unsigned int flags) -{ - struct files_ref_store *refs = xcalloc(1, sizeof(*refs)); - struct ref_store *ref_store = (struct ref_store *)refs; - struct strbuf sb = STRBUF_INIT; - - base_ref_store_init(ref_store, &refs_be_files); - refs->store_flags = flags; - - refs->gitdir = xstrdup(gitdir); - get_common_dir_noenv(&sb, gitdir); - refs->gitcommondir = strbuf_detach(&sb, NULL); - strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir); - refs->packed_ref_store = packed_ref_store_create(sb.buf, flags); - strbuf_release(&sb); - - chdir_notify_reparent("files-backend $GIT_DIR", - &refs->gitdir); - chdir_notify_reparent("files-backend $GIT_COMMONDIR", - &refs->gitcommondir); - - return ref_store; -} - -/* - * Die if refs is not the main ref store. caller is used in any - * necessary error messages. - */ -static void files_assert_main_repository(struct files_ref_store *refs, - const char *caller) -{ - if (refs->store_flags & REF_STORE_MAIN) - return; - - BUG("operation %s only allowed for main ref store", caller); -} - -/* - * Downcast ref_store to files_ref_store. Die if ref_store is not a - * files_ref_store. required_flags is compared with ref_store's - * store_flags to ensure the ref_store has all required capabilities. - * "caller" is used in any necessary error messages. - */ -static struct files_ref_store *files_downcast(struct ref_store *ref_store, - unsigned int required_flags, - const char *caller) -{ - struct files_ref_store *refs; - - if (ref_store->be != &refs_be_files) - BUG("ref_store is type \"%s\" not \"files\" in %s", - ref_store->be->name, caller); - - refs = (struct files_ref_store *)ref_store; - - if ((refs->store_flags & required_flags) != required_flags) - BUG("operation %s requires abilities 0x%x, but only have 0x%x", - caller, required_flags, refs->store_flags); - - return refs; -} - -static void files_reflog_path_other_worktrees(struct files_ref_store *refs, - struct strbuf *sb, - const char *refname) -{ - const char *real_ref; - const char *worktree_name; - int length; - - if (parse_worktree_ref(refname, &worktree_name, &length, &real_ref)) - BUG("refname %s is not a other-worktree ref", refname); - - if (worktree_name) - strbuf_addf(sb, "%s/worktrees/%.*s/logs/%s", refs->gitcommondir, - length, worktree_name, real_ref); - else - strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, - real_ref); -} - -static void files_reflog_path(struct files_ref_store *refs, - struct strbuf *sb, - const char *refname) -{ - switch (ref_type(refname)) { - case REF_TYPE_PER_WORKTREE: - case REF_TYPE_PSEUDOREF: - strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname); - break; - case REF_TYPE_OTHER_PSEUDOREF: - case REF_TYPE_MAIN_PSEUDOREF: - files_reflog_path_other_worktrees(refs, sb, refname); - break; - case REF_TYPE_NORMAL: - strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname); - break; - default: - BUG("unknown ref type %d of ref %s", - ref_type(refname), refname); - } -} - -static void files_ref_path(struct files_ref_store *refs, - struct strbuf *sb, - const char *refname) -{ - switch (ref_type(refname)) { - case REF_TYPE_PER_WORKTREE: - case REF_TYPE_PSEUDOREF: - strbuf_addf(sb, "%s/%s", refs->gitdir, refname); - break; - case REF_TYPE_MAIN_PSEUDOREF: - if (!skip_prefix(refname, "main-worktree/", &refname)) - BUG("ref %s is not a main pseudoref", refname); - /* fallthrough */ - case REF_TYPE_OTHER_PSEUDOREF: - case REF_TYPE_NORMAL: - strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname); - break; - default: - BUG("unknown ref type %d of ref %s", - ref_type(refname), refname); - } -} - -/* - * Manually add refs/bisect, refs/rewritten and refs/worktree, which, being - * per-worktree, might not appear in the directory listing for - * refs/ in the main repo. - */ -static void add_per_worktree_entries_to_dir(struct ref_dir *dir, const char *dirname) -{ - const char *prefixes[] = { "refs/bisect/", "refs/worktree/", "refs/rewritten/" }; - int ip; - - if (strcmp(dirname, "refs/")) - return; - - for (ip = 0; ip < ARRAY_SIZE(prefixes); ip++) { - const char *prefix = prefixes[ip]; - int prefix_len = strlen(prefix); - struct ref_entry *child_entry; - int pos; - - pos = search_ref_dir(dir, prefix, prefix_len); - if (pos >= 0) - continue; - child_entry = create_dir_entry(dir->cache, prefix, prefix_len, 1); - add_entry_to_dir(dir, child_entry); - } -} - -/* - * Read the loose references from the namespace dirname into dir - * (without recursing). dirname must end with '/'. dir must be the - * directory entry corresponding to dirname. - */ -static void loose_fill_ref_dir(struct ref_store *ref_store, - struct ref_dir *dir, const char *dirname) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir"); - DIR *d; - struct dirent *de; - int dirnamelen = strlen(dirname); - struct strbuf refname; - struct strbuf path = STRBUF_INIT; - size_t path_baselen; - - files_ref_path(refs, &path, dirname); - path_baselen = path.len; - - d = opendir(path.buf); - if (!d) { - strbuf_release(&path); - return; - } - - strbuf_init(&refname, dirnamelen + 257); - strbuf_add(&refname, dirname, dirnamelen); - - while ((de = readdir(d)) != NULL) { - struct object_id oid; - struct stat st; - int flag; - - if (de->d_name[0] == '.') - continue; - if (ends_with(de->d_name, ".lock")) - continue; - strbuf_addstr(&refname, de->d_name); - strbuf_addstr(&path, de->d_name); - if (stat(path.buf, &st) < 0) { - ; /* silently ignore */ - } else if (S_ISDIR(st.st_mode)) { - strbuf_addch(&refname, '/'); - add_entry_to_dir(dir, - create_dir_entry(dir->cache, refname.buf, - refname.len, 1)); - } else { - if (!refs_resolve_ref_unsafe(&refs->base, - refname.buf, - RESOLVE_REF_READING, - &oid, &flag)) { - oidclr(&oid); - flag |= REF_ISBROKEN; - } else if (is_null_oid(&oid)) { - /* - * It is so astronomically unlikely - * that null_oid is the OID of an - * actual object that we consider its - * appearance in a loose reference - * file to be repo corruption - * (probably due to a software bug). - */ - flag |= REF_ISBROKEN; - } - - if (check_refname_format(refname.buf, - REFNAME_ALLOW_ONELEVEL)) { - if (!refname_is_safe(refname.buf)) - die("loose refname is dangerous: %s", refname.buf); - oidclr(&oid); - flag |= REF_BAD_NAME | REF_ISBROKEN; - } - add_entry_to_dir(dir, - create_ref_entry(refname.buf, &oid, flag)); - } - strbuf_setlen(&refname, dirnamelen); - strbuf_setlen(&path, path_baselen); - } - strbuf_release(&refname); - strbuf_release(&path); - closedir(d); - - add_per_worktree_entries_to_dir(dir, dirname); -} - -static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) -{ - if (!refs->loose) { - /* - * Mark the top-level directory complete because we - * are about to read the only subdirectory that can - * hold references: - */ - refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir); - - /* We're going to fill the top level ourselves: */ - refs->loose->root->flag &= ~REF_INCOMPLETE; - - /* - * Add an incomplete entry for "refs/" (to be filled - * lazily): - */ - add_entry_to_dir(get_ref_dir(refs->loose->root), - create_dir_entry(refs->loose, "refs/", 5, 1)); - } - return refs->loose; -} - -static int files_read_raw_ref(struct ref_store *ref_store, - const char *refname, struct object_id *oid, - struct strbuf *referent, unsigned int *type) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); - struct strbuf sb_contents = STRBUF_INIT; - struct strbuf sb_path = STRBUF_INIT; - const char *path; - const char *buf; - const char *p; - struct stat st; - int fd; - int ret = -1; - int save_errno; - int remaining_retries = 3; - - *type = 0; - strbuf_reset(&sb_path); - - files_ref_path(refs, &sb_path, refname); - - path = sb_path.buf; - -stat_ref: - /* - * We might have to loop back here to avoid a race - * condition: first we lstat() the file, then we try - * to read it as a link or as a file. But if somebody - * changes the type of the file (file <-> directory - * <-> symlink) between the lstat() and reading, then - * we don't want to report that as an error but rather - * try again starting with the lstat(). - * - * We'll keep a count of the retries, though, just to avoid - * any confusing situation sending us into an infinite loop. - */ - - if (remaining_retries-- <= 0) - goto out; - - if (lstat(path, &st) < 0) { - if (errno != ENOENT) - goto out; - if (refs_read_raw_ref(refs->packed_ref_store, refname, - oid, referent, type)) { - errno = ENOENT; - goto out; - } - ret = 0; - goto out; - } - - /* Follow "normalized" - ie "refs/.." symlinks by hand */ - if (S_ISLNK(st.st_mode)) { - strbuf_reset(&sb_contents); - if (strbuf_readlink(&sb_contents, path, st.st_size) < 0) { - if (errno == ENOENT || errno == EINVAL) - /* inconsistent with lstat; retry */ - goto stat_ref; - else - goto out; - } - if (starts_with(sb_contents.buf, "refs/") && - !check_refname_format(sb_contents.buf, 0)) { - strbuf_swap(&sb_contents, referent); - *type |= REF_ISSYMREF; - ret = 0; - goto out; - } - /* - * It doesn't look like a refname; fall through to just - * treating it like a non-symlink, and reading whatever it - * points to. - */ - } - - /* Is it a directory? */ - if (S_ISDIR(st.st_mode)) { - /* - * Even though there is a directory where the loose - * ref is supposed to be, there could still be a - * packed ref: - */ - if (refs_read_raw_ref(refs->packed_ref_store, refname, - oid, referent, type)) { - errno = EISDIR; - goto out; - } - ret = 0; - goto out; - } - - /* - * Anything else, just open it and try to use it as - * a ref - */ - fd = open(path, O_RDONLY); - if (fd < 0) { - if (errno == ENOENT && !S_ISLNK(st.st_mode)) - /* inconsistent with lstat; retry */ - goto stat_ref; - else - goto out; - } - strbuf_reset(&sb_contents); - if (strbuf_read(&sb_contents, fd, 256) < 0) { - int save_errno = errno; - close(fd); - errno = save_errno; - goto out; - } - close(fd); - strbuf_rtrim(&sb_contents); - buf = sb_contents.buf; - if (starts_with(buf, "ref:")) { - buf += 4; - while (isspace(*buf)) - buf++; - - strbuf_reset(referent); - strbuf_addstr(referent, buf); - *type |= REF_ISSYMREF; - ret = 0; - goto out; - } - - /* - * Please note that FETCH_HEAD has additional - * data after the sha. - */ - if (parse_oid_hex(buf, oid, &p) || - (*p != '\0' && !isspace(*p))) { - *type |= REF_ISBROKEN; - errno = EINVAL; - goto out; - } - - ret = 0; - -out: - save_errno = errno; - strbuf_release(&sb_path); - strbuf_release(&sb_contents); - errno = save_errno; - return ret; -} - -static void unlock_ref(struct ref_lock *lock) -{ - rollback_lock_file(&lock->lk); - free(lock->ref_name); - free(lock); -} - -/* - * Lock refname, without following symrefs, and set *lock_p to point - * at a newly-allocated lock object. Fill in lock->old_oid, referent, - * and type similarly to read_raw_ref(). - * - * The caller must verify that refname is a "safe" reference name (in - * the sense of refname_is_safe()) before calling this function. - * - * If the reference doesn't already exist, verify that refname doesn't - * have a D/F conflict with any existing references. extras and skip - * are passed to refs_verify_refname_available() for this check. - * - * If mustexist is not set and the reference is not found or is - * broken, lock the reference anyway but clear old_oid. - * - * Return 0 on success. On failure, write an error message to err and - * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR. - * - * Implementation note: This function is basically - * - * lock reference - * read_raw_ref() - * - * but it includes a lot more code to - * - Deal with possible races with other processes - * - Avoid calling refs_verify_refname_available() when it can be - * avoided, namely if we were successfully able to read the ref - * - Generate informative error messages in the case of failure - */ -static int lock_raw_ref(struct files_ref_store *refs, - const char *refname, int mustexist, - const struct string_list *extras, - const struct string_list *skip, - struct ref_lock **lock_p, - struct strbuf *referent, - unsigned int *type, - struct strbuf *err) -{ - struct ref_lock *lock; - struct strbuf ref_file = STRBUF_INIT; - int attempts_remaining = 3; - int ret = TRANSACTION_GENERIC_ERROR; - - assert(err); - files_assert_main_repository(refs, "lock_raw_ref"); - - *type = 0; - - /* First lock the file so it can't change out from under us. */ - - *lock_p = lock = xcalloc(1, sizeof(*lock)); - - lock->ref_name = xstrdup(refname); - files_ref_path(refs, &ref_file, refname); - -retry: - switch (safe_create_leading_directories(ref_file.buf)) { - case SCLD_OK: - break; /* success */ - case SCLD_EXISTS: - /* - * Suppose refname is "refs/foo/bar". We just failed - * to create the containing directory, "refs/foo", - * because there was a non-directory in the way. This - * indicates a D/F conflict, probably because of - * another reference such as "refs/foo". There is no - * reason to expect this error to be transitory. - */ - if (refs_verify_refname_available(&refs->base, refname, - extras, skip, err)) { - if (mustexist) { - /* - * To the user the relevant error is - * that the "mustexist" reference is - * missing: - */ - strbuf_reset(err); - strbuf_addf(err, "unable to resolve reference '%s'", - refname); - } else { - /* - * The error message set by - * refs_verify_refname_available() is - * OK. - */ - ret = TRANSACTION_NAME_CONFLICT; - } - } else { - /* - * The file that is in the way isn't a loose - * reference. Report it as a low-level - * failure. - */ - strbuf_addf(err, "unable to create lock file %s.lock; " - "non-directory in the way", - ref_file.buf); - } - goto error_return; - case SCLD_VANISHED: - /* Maybe another process was tidying up. Try again. */ - if (--attempts_remaining > 0) - goto retry; - /* fall through */ - default: - strbuf_addf(err, "unable to create directory for %s", - ref_file.buf); - goto error_return; - } - - if (hold_lock_file_for_update_timeout( - &lock->lk, ref_file.buf, LOCK_NO_DEREF, - get_files_ref_lock_timeout_ms()) < 0) { - if (errno == ENOENT && --attempts_remaining > 0) { - /* - * Maybe somebody just deleted one of the - * directories leading to ref_file. Try - * again: - */ - goto retry; - } else { - unable_to_lock_message(ref_file.buf, errno, err); - goto error_return; - } - } - - /* - * Now we hold the lock and can read the reference without - * fear that its value will change. - */ - - if (files_read_raw_ref(&refs->base, refname, - &lock->old_oid, referent, type)) { - if (errno == ENOENT) { - if (mustexist) { - /* Garden variety missing reference. */ - strbuf_addf(err, "unable to resolve reference '%s'", - refname); - goto error_return; - } else { - /* - * Reference is missing, but that's OK. We - * know that there is not a conflict with - * another loose reference because - * (supposing that we are trying to lock - * reference "refs/foo/bar"): - * - * - We were successfully able to create - * the lockfile refs/foo/bar.lock, so we - * know there cannot be a loose reference - * named "refs/foo". - * - * - We got ENOENT and not EISDIR, so we - * know that there cannot be a loose - * reference named "refs/foo/bar/baz". - */ - } - } else if (errno == EISDIR) { - /* - * There is a directory in the way. It might have - * contained references that have been deleted. If - * we don't require that the reference already - * exists, try to remove the directory so that it - * doesn't cause trouble when we want to rename the - * lockfile into place later. - */ - if (mustexist) { - /* Garden variety missing reference. */ - strbuf_addf(err, "unable to resolve reference '%s'", - refname); - goto error_return; - } else if (remove_dir_recursively(&ref_file, - REMOVE_DIR_EMPTY_ONLY)) { - if (refs_verify_refname_available( - &refs->base, refname, - extras, skip, err)) { - /* - * The error message set by - * verify_refname_available() is OK. - */ - ret = TRANSACTION_NAME_CONFLICT; - goto error_return; - } else { - /* - * We can't delete the directory, - * but we also don't know of any - * references that it should - * contain. - */ - strbuf_addf(err, "there is a non-empty directory '%s' " - "blocking reference '%s'", - ref_file.buf, refname); - goto error_return; - } - } - } else if (errno == EINVAL && (*type & REF_ISBROKEN)) { - strbuf_addf(err, "unable to resolve reference '%s': " - "reference broken", refname); - goto error_return; - } else { - strbuf_addf(err, "unable to resolve reference '%s': %s", - refname, strerror(errno)); - goto error_return; - } - - /* - * If the ref did not exist and we are creating it, - * make sure there is no existing packed ref that - * conflicts with refname: - */ - if (refs_verify_refname_available( - refs->packed_ref_store, refname, - extras, skip, err)) - goto error_return; - } - - ret = 0; - goto out; - -error_return: - unlock_ref(lock); - *lock_p = NULL; - -out: - strbuf_release(&ref_file); - return ret; -} - -struct files_ref_iterator { - struct ref_iterator base; - - struct ref_iterator *iter0; - unsigned int flags; -}; - -static int files_ref_iterator_advance(struct ref_iterator *ref_iterator) -{ - struct files_ref_iterator *iter = - (struct files_ref_iterator *)ref_iterator; - int ok; - - while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) { - if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && - ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE) - continue; - - if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) && - !ref_resolves_to_object(iter->iter0->refname, - iter->iter0->oid, - iter->iter0->flags)) - continue; - - iter->base.refname = iter->iter0->refname; - iter->base.oid = iter->iter0->oid; - iter->base.flags = iter->iter0->flags; - return ITER_OK; - } - - iter->iter0 = NULL; - if (ref_iterator_abort(ref_iterator) != ITER_DONE) - ok = ITER_ERROR; - - return ok; -} - -static int files_ref_iterator_peel(struct ref_iterator *ref_iterator, - struct object_id *peeled) -{ - struct files_ref_iterator *iter = - (struct files_ref_iterator *)ref_iterator; - - return ref_iterator_peel(iter->iter0, peeled); -} - -static int files_ref_iterator_abort(struct ref_iterator *ref_iterator) -{ - struct files_ref_iterator *iter = - (struct files_ref_iterator *)ref_iterator; - int ok = ITER_DONE; - - if (iter->iter0) - ok = ref_iterator_abort(iter->iter0); - - base_ref_iterator_free(ref_iterator); - return ok; -} - -static struct ref_iterator_vtable files_ref_iterator_vtable = { - files_ref_iterator_advance, - files_ref_iterator_peel, - files_ref_iterator_abort -}; - -static struct ref_iterator *files_ref_iterator_begin( - struct ref_store *ref_store, - const char *prefix, unsigned int flags) -{ - struct files_ref_store *refs; - struct ref_iterator *loose_iter, *packed_iter, *overlay_iter; - struct files_ref_iterator *iter; - struct ref_iterator *ref_iterator; - unsigned int required_flags = REF_STORE_READ; - - if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) - required_flags |= REF_STORE_ODB; - - refs = files_downcast(ref_store, required_flags, "ref_iterator_begin"); - - /* - * We must make sure that all loose refs are read before - * accessing the packed-refs file; this avoids a race - * condition if loose refs are migrated to the packed-refs - * file by a simultaneous process, but our in-memory view is - * from before the migration. We ensure this as follows: - * First, we call start the loose refs iteration with its - * `prime_ref` argument set to true. This causes the loose - * references in the subtree to be pre-read into the cache. - * (If they've already been read, that's OK; we only need to - * guarantee that they're read before the packed refs, not - * *how much* before.) After that, we call - * packed_ref_iterator_begin(), which internally checks - * whether the packed-ref cache is up to date with what is on - * disk, and re-reads it if not. - */ - - loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), - prefix, 1); - - /* - * The packed-refs file might contain broken references, for - * example an old version of a reference that points at an - * object that has since been garbage-collected. This is OK as - * long as there is a corresponding loose reference that - * overrides it, and we don't want to emit an error message in - * this case. So ask the packed_ref_store for all of its - * references, and (if needed) do our own check for broken - * ones in files_ref_iterator_advance(), after we have merged - * the packed and loose references. - */ - packed_iter = refs_ref_iterator_begin( - refs->packed_ref_store, prefix, 0, - DO_FOR_EACH_INCLUDE_BROKEN); - - overlay_iter = overlay_ref_iterator_begin(loose_iter, packed_iter); - - iter = xcalloc(1, sizeof(*iter)); - ref_iterator = &iter->base; - base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable, - overlay_iter->ordered); - iter->iter0 = overlay_iter; - iter->flags = flags; - - return ref_iterator; -} - -/* - * Verify that the reference locked by lock has the value old_oid - * (unless it is NULL). Fail if the reference doesn't exist and - * mustexist is set. Return 0 on success. On error, write an error - * message to err, set errno, and return a negative value. - */ -static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock, - const struct object_id *old_oid, int mustexist, - struct strbuf *err) -{ - assert(err); - - if (refs_read_ref_full(ref_store, lock->ref_name, - mustexist ? RESOLVE_REF_READING : 0, - &lock->old_oid, NULL)) { - if (old_oid) { - int save_errno = errno; - strbuf_addf(err, "can't verify ref '%s'", lock->ref_name); - errno = save_errno; - return -1; - } else { - oidclr(&lock->old_oid); - return 0; - } - } - if (old_oid && !oideq(&lock->old_oid, old_oid)) { - strbuf_addf(err, "ref '%s' is at %s but expected %s", - lock->ref_name, - oid_to_hex(&lock->old_oid), - oid_to_hex(old_oid)); - errno = EBUSY; - return -1; - } - return 0; -} - -static int remove_empty_directories(struct strbuf *path) -{ - /* - * we want to create a file but there is a directory there; - * if that is an empty directory (or a directory that contains - * only empty directories), remove them. - */ - return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY); -} - -static int create_reflock(const char *path, void *cb) -{ - struct lock_file *lk = cb; - - return hold_lock_file_for_update_timeout( - lk, path, LOCK_NO_DEREF, - get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0; -} - -/* - * Locks a ref returning the lock on success and NULL on failure. - * On failure errno is set to something meaningful. - */ -static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, - const char *refname, - const struct object_id *old_oid, - const struct string_list *extras, - const struct string_list *skip, - unsigned int flags, int *type, - struct strbuf *err) -{ - struct strbuf ref_file = STRBUF_INIT; - struct ref_lock *lock; - int last_errno = 0; - int mustexist = (old_oid && !is_null_oid(old_oid)); - int resolve_flags = RESOLVE_REF_NO_RECURSE; - int resolved; - - files_assert_main_repository(refs, "lock_ref_oid_basic"); - assert(err); - - lock = xcalloc(1, sizeof(struct ref_lock)); - - if (mustexist) - resolve_flags |= RESOLVE_REF_READING; - if (flags & REF_DELETING) - resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; - - files_ref_path(refs, &ref_file, refname); - resolved = !!refs_resolve_ref_unsafe(&refs->base, - refname, resolve_flags, - &lock->old_oid, type); - if (!resolved && errno == EISDIR) { - /* - * we are trying to lock foo but we used to - * have foo/bar which now does not exist; - * it is normal for the empty directory 'foo' - * to remain. - */ - if (remove_empty_directories(&ref_file)) { - last_errno = errno; - if (!refs_verify_refname_available( - &refs->base, - refname, extras, skip, err)) - strbuf_addf(err, "there are still refs under '%s'", - refname); - goto error_return; - } - resolved = !!refs_resolve_ref_unsafe(&refs->base, - refname, resolve_flags, - &lock->old_oid, type); - } - if (!resolved) { - last_errno = errno; - if (last_errno != ENOTDIR || - !refs_verify_refname_available(&refs->base, refname, - extras, skip, err)) - strbuf_addf(err, "unable to resolve reference '%s': %s", - refname, strerror(last_errno)); - - goto error_return; - } - - /* - * If the ref did not exist and we are creating it, make sure - * there is no existing packed ref whose name begins with our - * refname, nor a packed ref whose name is a proper prefix of - * our refname. - */ - if (is_null_oid(&lock->old_oid) && - refs_verify_refname_available(refs->packed_ref_store, refname, - extras, skip, err)) { - last_errno = ENOTDIR; - goto error_return; - } - - lock->ref_name = xstrdup(refname); - - if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) { - last_errno = errno; - unable_to_lock_message(ref_file.buf, errno, err); - goto error_return; - } - - if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) { - last_errno = errno; - goto error_return; - } - goto out; - - error_return: - unlock_ref(lock); - lock = NULL; - - out: - strbuf_release(&ref_file); - errno = last_errno; - return lock; -} - -struct ref_to_prune { - struct ref_to_prune *next; - struct object_id oid; - char name[FLEX_ARRAY]; -}; - -enum { - REMOVE_EMPTY_PARENTS_REF = 0x01, - REMOVE_EMPTY_PARENTS_REFLOG = 0x02 -}; - -/* - * Remove empty parent directories associated with the specified - * reference and/or its reflog, but spare [logs/]refs/ and immediate - * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or - * REMOVE_EMPTY_PARENTS_REFLOG. - */ -static void try_remove_empty_parents(struct files_ref_store *refs, - const char *refname, - unsigned int flags) -{ - struct strbuf buf = STRBUF_INIT; - struct strbuf sb = STRBUF_INIT; - char *p, *q; - int i; - - strbuf_addstr(&buf, refname); - p = buf.buf; - for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */ - while (*p && *p != '/') - p++; - /* tolerate duplicate slashes; see check_refname_format() */ - while (*p == '/') - p++; - } - q = buf.buf + buf.len; - while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) { - while (q > p && *q != '/') - q--; - while (q > p && *(q-1) == '/') - q--; - if (q == p) - break; - strbuf_setlen(&buf, q - buf.buf); - - strbuf_reset(&sb); - files_ref_path(refs, &sb, buf.buf); - if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf)) - flags &= ~REMOVE_EMPTY_PARENTS_REF; - - strbuf_reset(&sb); - files_reflog_path(refs, &sb, buf.buf); - if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf)) - flags &= ~REMOVE_EMPTY_PARENTS_REFLOG; - } - strbuf_release(&buf); - strbuf_release(&sb); -} - -/* make sure nobody touched the ref, and unlink */ -static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r) -{ - struct ref_transaction *transaction; - struct strbuf err = STRBUF_INIT; - int ret = -1; - - if (check_refname_format(r->name, 0)) - return; - - transaction = ref_store_transaction_begin(&refs->base, &err); - if (!transaction) - goto cleanup; - ref_transaction_add_update( - transaction, r->name, - REF_NO_DEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_IS_PRUNING, - &null_oid, &r->oid, NULL); - if (ref_transaction_commit(transaction, &err)) - goto cleanup; - - ret = 0; - -cleanup: - if (ret) - error("%s", err.buf); - strbuf_release(&err); - ref_transaction_free(transaction); - return; -} - -/* - * Prune the loose versions of the references in the linked list - * `*refs_to_prune`, freeing the entries in the list as we go. - */ -static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune) -{ - while (*refs_to_prune) { - struct ref_to_prune *r = *refs_to_prune; - *refs_to_prune = r->next; - prune_ref(refs, r); - free(r); - } -} - -/* - * Return true if the specified reference should be packed. - */ -static int should_pack_ref(const char *refname, - const struct object_id *oid, unsigned int ref_flags, - unsigned int pack_flags) -{ - /* Do not pack per-worktree refs: */ - if (ref_type(refname) != REF_TYPE_NORMAL) - return 0; - - /* Do not pack non-tags unless PACK_REFS_ALL is set: */ - if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/")) - return 0; - - /* Do not pack symbolic refs: */ - if (ref_flags & REF_ISSYMREF) - return 0; - - /* Do not pack broken refs: */ - if (!ref_resolves_to_object(refname, oid, ref_flags)) - return 0; - - return 1; -} - -static int files_pack_refs(struct ref_store *ref_store, unsigned int flags) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB, - "pack_refs"); - struct ref_iterator *iter; - int ok; - struct ref_to_prune *refs_to_prune = NULL; - struct strbuf err = STRBUF_INIT; - struct ref_transaction *transaction; - - transaction = ref_store_transaction_begin(refs->packed_ref_store, &err); - if (!transaction) - return -1; - - packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err); - - iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0); - while ((ok = ref_iterator_advance(iter)) == ITER_OK) { - /* - * If the loose reference can be packed, add an entry - * in the packed ref cache. If the reference should be - * pruned, also add it to refs_to_prune. - */ - if (!should_pack_ref(iter->refname, iter->oid, iter->flags, - flags)) - continue; - - /* - * Add a reference creation for this reference to the - * packed-refs transaction: - */ - if (ref_transaction_update(transaction, iter->refname, - iter->oid, NULL, - REF_NO_DEREF, NULL, &err)) - die("failure preparing to create packed reference %s: %s", - iter->refname, err.buf); - - /* Schedule the loose reference for pruning if requested. */ - if ((flags & PACK_REFS_PRUNE)) { - struct ref_to_prune *n; - FLEX_ALLOC_STR(n, name, iter->refname); - oidcpy(&n->oid, iter->oid); - n->next = refs_to_prune; - refs_to_prune = n; - } - } - if (ok != ITER_DONE) - die("error while iterating over references"); - - if (ref_transaction_commit(transaction, &err)) - die("unable to write new packed-refs: %s", err.buf); - - ref_transaction_free(transaction); - - packed_refs_unlock(refs->packed_ref_store); - - prune_refs(refs, &refs_to_prune); - strbuf_release(&err); - return 0; -} - -static int files_delete_refs(struct ref_store *ref_store, const char *msg, - struct string_list *refnames, unsigned int flags) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "delete_refs"); - struct strbuf err = STRBUF_INIT; - int i, result = 0; - - if (!refnames->nr) - return 0; - - if (packed_refs_lock(refs->packed_ref_store, 0, &err)) - goto error; - - if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) { - packed_refs_unlock(refs->packed_ref_store); - goto error; - } - - packed_refs_unlock(refs->packed_ref_store); - - for (i = 0; i < refnames->nr; i++) { - const char *refname = refnames->items[i].string; - - if (refs_delete_ref(&refs->base, msg, refname, NULL, flags)) - result |= error(_("could not remove reference %s"), refname); - } - - strbuf_release(&err); - return result; - -error: - /* - * If we failed to rewrite the packed-refs file, then it is - * unsafe to try to remove loose refs, because doing so might - * expose an obsolete packed value for a reference that might - * even point at an object that has been garbage collected. - */ - if (refnames->nr == 1) - error(_("could not delete reference %s: %s"), - refnames->items[0].string, err.buf); - else - error(_("could not delete references: %s"), err.buf); - - strbuf_release(&err); - return -1; -} - -/* - * People using contrib's git-new-workdir have .git/logs/refs -> - * /some/other/path/.git/logs/refs, and that may live on another device. - * - * IOW, to avoid cross device rename errors, the temporary renamed log must - * live into logs/refs. - */ -#define TMP_RENAMED_LOG "refs/.tmp-renamed-log" - -struct rename_cb { - const char *tmp_renamed_log; - int true_errno; -}; - -static int rename_tmp_log_callback(const char *path, void *cb_data) -{ - struct rename_cb *cb = cb_data; - - if (rename(cb->tmp_renamed_log, path)) { - /* - * rename(a, b) when b is an existing directory ought - * to result in ISDIR, but Solaris 5.8 gives ENOTDIR. - * Sheesh. Record the true errno for error reporting, - * but report EISDIR to raceproof_create_file() so - * that it knows to retry. - */ - cb->true_errno = errno; - if (errno == ENOTDIR) - errno = EISDIR; - return -1; - } else { - return 0; - } -} - -static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname) -{ - struct strbuf path = STRBUF_INIT; - struct strbuf tmp = STRBUF_INIT; - struct rename_cb cb; - int ret; - - files_reflog_path(refs, &path, newrefname); - files_reflog_path(refs, &tmp, TMP_RENAMED_LOG); - cb.tmp_renamed_log = tmp.buf; - ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb); - if (ret) { - if (errno == EISDIR) - error("directory not empty: %s", path.buf); - else - error("unable to move logfile %s to %s: %s", - tmp.buf, path.buf, - strerror(cb.true_errno)); - } - - strbuf_release(&path); - strbuf_release(&tmp); - return ret; -} - -static int write_ref_to_lockfile(struct ref_lock *lock, - const struct object_id *oid, struct strbuf *err); -static int commit_ref_update(struct files_ref_store *refs, - struct ref_lock *lock, - const struct object_id *oid, const char *logmsg, - struct strbuf *err); - -static int files_copy_or_rename_ref(struct ref_store *ref_store, - const char *oldrefname, const char *newrefname, - const char *logmsg, int copy) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "rename_ref"); - struct object_id oid, orig_oid; - int flag = 0, logmoved = 0; - struct ref_lock *lock; - struct stat loginfo; - struct strbuf sb_oldref = STRBUF_INIT; - struct strbuf sb_newref = STRBUF_INIT; - struct strbuf tmp_renamed_log = STRBUF_INIT; - int log, ret; - struct strbuf err = STRBUF_INIT; - - files_reflog_path(refs, &sb_oldref, oldrefname); - files_reflog_path(refs, &sb_newref, newrefname); - files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG); - - log = !lstat(sb_oldref.buf, &loginfo); - if (log && S_ISLNK(loginfo.st_mode)) { - ret = error("reflog for %s is a symlink", oldrefname); - goto out; - } - - if (!refs_resolve_ref_unsafe(&refs->base, oldrefname, - RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, - &orig_oid, &flag)) { - ret = error("refname %s not found", oldrefname); - goto out; - } - - if (flag & REF_ISSYMREF) { - if (copy) - ret = error("refname %s is a symbolic ref, copying it is not supported", - oldrefname); - else - ret = error("refname %s is a symbolic ref, renaming it is not supported", - oldrefname); - goto out; - } - if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) { - ret = 1; - goto out; - } - - if (!copy && log && rename(sb_oldref.buf, tmp_renamed_log.buf)) { - ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s", - oldrefname, strerror(errno)); - goto out; - } - - if (copy && log && copy_file(tmp_renamed_log.buf, sb_oldref.buf, 0644)) { - ret = error("unable to copy logfile logs/%s to logs/"TMP_RENAMED_LOG": %s", - oldrefname, strerror(errno)); - goto out; - } - - if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname, - &orig_oid, REF_NO_DEREF)) { - error("unable to delete old %s", oldrefname); - goto rollback; - } - - /* - * Since we are doing a shallow lookup, oid is not the - * correct value to pass to delete_ref as old_oid. But that - * doesn't matter, because an old_oid check wouldn't add to - * the safety anyway; we want to delete the reference whatever - * its current value. - */ - if (!copy && !refs_read_ref_full(&refs->base, newrefname, - RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, - &oid, NULL) && - refs_delete_ref(&refs->base, NULL, newrefname, - NULL, REF_NO_DEREF)) { - if (errno == EISDIR) { - struct strbuf path = STRBUF_INIT; - int result; - - files_ref_path(refs, &path, newrefname); - result = remove_empty_directories(&path); - strbuf_release(&path); - - if (result) { - error("Directory not empty: %s", newrefname); - goto rollback; - } - } else { - error("unable to delete existing %s", newrefname); - goto rollback; - } - } - - if (log && rename_tmp_log(refs, newrefname)) - goto rollback; - - logmoved = log; - - lock = lock_ref_oid_basic(refs, newrefname, NULL, NULL, NULL, - REF_NO_DEREF, NULL, &err); - if (!lock) { - if (copy) - error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf); - else - error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); - strbuf_release(&err); - goto rollback; - } - oidcpy(&lock->old_oid, &orig_oid); - - if (write_ref_to_lockfile(lock, &orig_oid, &err) || - commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) { - error("unable to write current sha1 into %s: %s", newrefname, err.buf); - strbuf_release(&err); - goto rollback; - } - - ret = 0; - goto out; - - rollback: - lock = lock_ref_oid_basic(refs, oldrefname, NULL, NULL, NULL, - REF_NO_DEREF, NULL, &err); - if (!lock) { - error("unable to lock %s for rollback: %s", oldrefname, err.buf); - strbuf_release(&err); - goto rollbacklog; - } - - flag = log_all_ref_updates; - log_all_ref_updates = LOG_REFS_NONE; - if (write_ref_to_lockfile(lock, &orig_oid, &err) || - commit_ref_update(refs, lock, &orig_oid, NULL, &err)) { - error("unable to write current sha1 into %s: %s", oldrefname, err.buf); - strbuf_release(&err); - } - log_all_ref_updates = flag; - - rollbacklog: - if (logmoved && rename(sb_newref.buf, sb_oldref.buf)) - error("unable to restore logfile %s from %s: %s", - oldrefname, newrefname, strerror(errno)); - if (!logmoved && log && - rename(tmp_renamed_log.buf, sb_oldref.buf)) - error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s", - oldrefname, strerror(errno)); - ret = 1; - out: - strbuf_release(&sb_newref); - strbuf_release(&sb_oldref); - strbuf_release(&tmp_renamed_log); - - return ret; -} - -static int files_rename_ref(struct ref_store *ref_store, - const char *oldrefname, const char *newrefname, - const char *logmsg) -{ - return files_copy_or_rename_ref(ref_store, oldrefname, - newrefname, logmsg, 0); -} - -static int files_copy_ref(struct ref_store *ref_store, - const char *oldrefname, const char *newrefname, - const char *logmsg) -{ - return files_copy_or_rename_ref(ref_store, oldrefname, - newrefname, logmsg, 1); -} - -static int close_ref_gently(struct ref_lock *lock) -{ - if (close_lock_file_gently(&lock->lk)) - return -1; - return 0; -} - -static int commit_ref(struct ref_lock *lock) -{ - char *path = get_locked_file_path(&lock->lk); - struct stat st; - - if (!lstat(path, &st) && S_ISDIR(st.st_mode)) { - /* - * There is a directory at the path we want to rename - * the lockfile to. Hopefully it is empty; try to - * delete it. - */ - size_t len = strlen(path); - struct strbuf sb_path = STRBUF_INIT; - - strbuf_attach(&sb_path, path, len, len); - - /* - * If this fails, commit_lock_file() will also fail - * and will report the problem. - */ - remove_empty_directories(&sb_path); - strbuf_release(&sb_path); - } else { - free(path); - } - - if (commit_lock_file(&lock->lk)) - return -1; - return 0; -} - -static int open_or_create_logfile(const char *path, void *cb) -{ - int *fd = cb; - - *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666); - return (*fd < 0) ? -1 : 0; -} - -/* - * Create a reflog for a ref. If force_create = 0, only create the - * reflog for certain refs (those for which should_autocreate_reflog - * returns non-zero). Otherwise, create it regardless of the reference - * name. If the logfile already existed or was created, return 0 and - * set *logfd to the file descriptor opened for appending to the file. - * If no logfile exists and we decided not to create one, return 0 and - * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and - * return -1. - */ -static int log_ref_setup(struct files_ref_store *refs, - const char *refname, int force_create, - int *logfd, struct strbuf *err) -{ - struct strbuf logfile_sb = STRBUF_INIT; - char *logfile; - - files_reflog_path(refs, &logfile_sb, refname); - logfile = strbuf_detach(&logfile_sb, NULL); - - if (force_create || should_autocreate_reflog(refname)) { - if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) { - if (errno == ENOENT) - strbuf_addf(err, "unable to create directory for '%s': " - "%s", logfile, strerror(errno)); - else if (errno == EISDIR) - strbuf_addf(err, "there are still logs under '%s'", - logfile); - else - strbuf_addf(err, "unable to append to '%s': %s", - logfile, strerror(errno)); - - goto error; - } - } else { - *logfd = open(logfile, O_APPEND | O_WRONLY, 0666); - if (*logfd < 0) { - if (errno == ENOENT || errno == EISDIR) { - /* - * The logfile doesn't already exist, - * but that is not an error; it only - * means that we won't write log - * entries to it. - */ - ; - } else { - strbuf_addf(err, "unable to append to '%s': %s", - logfile, strerror(errno)); - goto error; - } - } - } - - if (*logfd >= 0) - adjust_shared_perm(logfile); - - free(logfile); - return 0; - -error: - free(logfile); - return -1; -} - -static int files_create_reflog(struct ref_store *ref_store, - const char *refname, int force_create, - struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "create_reflog"); - int fd; - - if (log_ref_setup(refs, refname, force_create, &fd, err)) - return -1; - - if (fd >= 0) - close(fd); - - return 0; -} - -static int log_ref_write_fd(int fd, const struct object_id *old_oid, - const struct object_id *new_oid, - const char *committer, const char *msg) -{ - struct strbuf sb = STRBUF_INIT; - int ret = 0; - - strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer); - if (msg && *msg) - copy_reflog_msg(&sb, msg); - strbuf_addch(&sb, '\n'); - if (write_in_full(fd, sb.buf, sb.len) < 0) - ret = -1; - strbuf_release(&sb); - return ret; -} - -static int files_log_ref_write(struct files_ref_store *refs, - const char *refname, const struct object_id *old_oid, - const struct object_id *new_oid, const char *msg, - int flags, struct strbuf *err) -{ - int logfd, result; - - if (log_all_ref_updates == LOG_REFS_UNSET) - log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL; - - result = log_ref_setup(refs, refname, - flags & REF_FORCE_CREATE_REFLOG, - &logfd, err); - - if (result) - return result; - - if (logfd < 0) - return 0; - result = log_ref_write_fd(logfd, old_oid, new_oid, - git_committer_info(0), msg); - if (result) { - struct strbuf sb = STRBUF_INIT; - int save_errno = errno; - - files_reflog_path(refs, &sb, refname); - strbuf_addf(err, "unable to append to '%s': %s", - sb.buf, strerror(save_errno)); - strbuf_release(&sb); - close(logfd); - return -1; - } - if (close(logfd)) { - struct strbuf sb = STRBUF_INIT; - int save_errno = errno; - - files_reflog_path(refs, &sb, refname); - strbuf_addf(err, "unable to append to '%s': %s", - sb.buf, strerror(save_errno)); - strbuf_release(&sb); - return -1; - } - return 0; -} - -/* - * Write oid into the open lockfile, then close the lockfile. On - * errors, rollback the lockfile, fill in *err and return -1. - */ -static int write_ref_to_lockfile(struct ref_lock *lock, - const struct object_id *oid, struct strbuf *err) -{ - static char term = '\n'; - struct object *o; - int fd; - - o = parse_object(the_repository, oid); - if (!o) { - strbuf_addf(err, - "trying to write ref '%s' with nonexistent object %s", - lock->ref_name, oid_to_hex(oid)); - unlock_ref(lock); - return -1; - } - if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { - strbuf_addf(err, - "trying to write non-commit object %s to branch '%s'", - oid_to_hex(oid), lock->ref_name); - unlock_ref(lock); - return -1; - } - fd = get_lock_file_fd(&lock->lk); - if (write_in_full(fd, oid_to_hex(oid), the_hash_algo->hexsz) < 0 || - write_in_full(fd, &term, 1) < 0 || - close_ref_gently(lock) < 0) { - strbuf_addf(err, - "couldn't write '%s'", get_lock_file_path(&lock->lk)); - unlock_ref(lock); - return -1; - } - return 0; -} - -/* - * Commit a change to a loose reference that has already been written - * to the loose reference lockfile. Also update the reflogs if - * necessary, using the specified lockmsg (which can be NULL). - */ -static int commit_ref_update(struct files_ref_store *refs, - struct ref_lock *lock, - const struct object_id *oid, const char *logmsg, - struct strbuf *err) -{ - files_assert_main_repository(refs, "commit_ref_update"); - - clear_loose_ref_cache(refs); - if (files_log_ref_write(refs, lock->ref_name, - &lock->old_oid, oid, - logmsg, 0, err)) { - char *old_msg = strbuf_detach(err, NULL); - strbuf_addf(err, "cannot update the ref '%s': %s", - lock->ref_name, old_msg); - free(old_msg); - unlock_ref(lock); - return -1; - } - - if (strcmp(lock->ref_name, "HEAD") != 0) { - /* - * Special hack: If a branch is updated directly and HEAD - * points to it (may happen on the remote side of a push - * for example) then logically the HEAD reflog should be - * updated too. - * A generic solution implies reverse symref information, - * but finding all symrefs pointing to the given branch - * would be rather costly for this rare event (the direct - * update of a branch) to be worth it. So let's cheat and - * check with HEAD only which should cover 99% of all usage - * scenarios (even 100% of the default ones). - */ - int head_flag; - const char *head_ref; - - head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD", - RESOLVE_REF_READING, - NULL, &head_flag); - if (head_ref && (head_flag & REF_ISSYMREF) && - !strcmp(head_ref, lock->ref_name)) { - struct strbuf log_err = STRBUF_INIT; - if (files_log_ref_write(refs, "HEAD", - &lock->old_oid, oid, - logmsg, 0, &log_err)) { - error("%s", log_err.buf); - strbuf_release(&log_err); - } - } - } - - if (commit_ref(lock)) { - strbuf_addf(err, "couldn't set '%s'", lock->ref_name); - unlock_ref(lock); - return -1; - } - - unlock_ref(lock); - return 0; -} - -static int create_ref_symlink(struct ref_lock *lock, const char *target) -{ - int ret = -1; -#ifndef NO_SYMLINK_HEAD - char *ref_path = get_locked_file_path(&lock->lk); - unlink(ref_path); - ret = symlink(target, ref_path); - free(ref_path); - - if (ret) - fprintf(stderr, "no symlink - falling back to symbolic ref\n"); -#endif - return ret; -} - -static void update_symref_reflog(struct files_ref_store *refs, - struct ref_lock *lock, const char *refname, - const char *target, const char *logmsg) -{ - struct strbuf err = STRBUF_INIT; - struct object_id new_oid; - if (logmsg && - !refs_read_ref_full(&refs->base, target, - RESOLVE_REF_READING, &new_oid, NULL) && - files_log_ref_write(refs, refname, &lock->old_oid, - &new_oid, logmsg, 0, &err)) { - error("%s", err.buf); - strbuf_release(&err); - } -} - -static int create_symref_locked(struct files_ref_store *refs, - struct ref_lock *lock, const char *refname, - const char *target, const char *logmsg) -{ - if (prefer_symlink_refs && !create_ref_symlink(lock, target)) { - update_symref_reflog(refs, lock, refname, target, logmsg); - return 0; - } - - if (!fdopen_lock_file(&lock->lk, "w")) - return error("unable to fdopen %s: %s", - lock->lk.tempfile->filename.buf, strerror(errno)); - - update_symref_reflog(refs, lock, refname, target, logmsg); - - /* no error check; commit_ref will check ferror */ - fprintf(lock->lk.tempfile->fp, "ref: %s\n", target); - if (commit_ref(lock) < 0) - return error("unable to write symref for %s: %s", refname, - strerror(errno)); - return 0; -} - -static int files_create_symref(struct ref_store *ref_store, - const char *refname, const char *target, - const char *logmsg) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "create_symref"); - struct strbuf err = STRBUF_INIT; - struct ref_lock *lock; - int ret; - - lock = lock_ref_oid_basic(refs, refname, NULL, - NULL, NULL, REF_NO_DEREF, NULL, - &err); - if (!lock) { - error("%s", err.buf); - strbuf_release(&err); - return -1; - } - - ret = create_symref_locked(refs, lock, refname, target, logmsg); - unlock_ref(lock); - return ret; -} - -static int files_reflog_exists(struct ref_store *ref_store, - const char *refname) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, "reflog_exists"); - struct strbuf sb = STRBUF_INIT; - struct stat st; - int ret; - - files_reflog_path(refs, &sb, refname); - ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode); - strbuf_release(&sb); - return ret; -} - -static int files_delete_reflog(struct ref_store *ref_store, - const char *refname) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog"); - struct strbuf sb = STRBUF_INIT; - int ret; - - files_reflog_path(refs, &sb, refname); - ret = remove_path(sb.buf); - strbuf_release(&sb); - return ret; -} - -static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data) -{ - struct object_id ooid, noid; - char *email_end, *message; - timestamp_t timestamp; - int tz; - const char *p = sb->buf; - - /* old SP new SP name <email> SP time TAB msg LF */ - if (!sb->len || sb->buf[sb->len - 1] != '\n' || - parse_oid_hex(p, &ooid, &p) || *p++ != ' ' || - parse_oid_hex(p, &noid, &p) || *p++ != ' ' || - !(email_end = strchr(p, '>')) || - email_end[1] != ' ' || - !(timestamp = parse_timestamp(email_end + 2, &message, 10)) || - !message || message[0] != ' ' || - (message[1] != '+' && message[1] != '-') || - !isdigit(message[2]) || !isdigit(message[3]) || - !isdigit(message[4]) || !isdigit(message[5])) - return 0; /* corrupt? */ - email_end[1] = '\0'; - tz = strtol(message + 1, NULL, 10); - if (message[6] != '\t') - message += 6; - else - message += 7; - return fn(&ooid, &noid, p, timestamp, tz, message, cb_data); -} - -static char *find_beginning_of_line(char *bob, char *scan) -{ - while (bob < scan && *(--scan) != '\n') - ; /* keep scanning backwards */ - /* - * Return either beginning of the buffer, or LF at the end of - * the previous line. - */ - return scan; -} - -static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store, - const char *refname, - each_reflog_ent_fn fn, - void *cb_data) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, - "for_each_reflog_ent_reverse"); - struct strbuf sb = STRBUF_INIT; - FILE *logfp; - long pos; - int ret = 0, at_tail = 1; - - files_reflog_path(refs, &sb, refname); - logfp = fopen(sb.buf, "r"); - strbuf_release(&sb); - if (!logfp) - return -1; - - /* Jump to the end */ - if (fseek(logfp, 0, SEEK_END) < 0) - ret = error("cannot seek back reflog for %s: %s", - refname, strerror(errno)); - pos = ftell(logfp); - while (!ret && 0 < pos) { - int cnt; - size_t nread; - char buf[BUFSIZ]; - char *endp, *scanp; - - /* Fill next block from the end */ - cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos; - if (fseek(logfp, pos - cnt, SEEK_SET)) { - ret = error("cannot seek back reflog for %s: %s", - refname, strerror(errno)); - break; - } - nread = fread(buf, cnt, 1, logfp); - if (nread != 1) { - ret = error("cannot read %d bytes from reflog for %s: %s", - cnt, refname, strerror(errno)); - break; - } - pos -= cnt; - - scanp = endp = buf + cnt; - if (at_tail && scanp[-1] == '\n') - /* Looking at the final LF at the end of the file */ - scanp--; - at_tail = 0; - - while (buf < scanp) { - /* - * terminating LF of the previous line, or the beginning - * of the buffer. - */ - char *bp; - - bp = find_beginning_of_line(buf, scanp); - - if (*bp == '\n') { - /* - * The newline is the end of the previous line, - * so we know we have complete line starting - * at (bp + 1). Prefix it onto any prior data - * we collected for the line and process it. - */ - strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); - scanp = bp; - endp = bp + 1; - ret = show_one_reflog_ent(&sb, fn, cb_data); - strbuf_reset(&sb); - if (ret) - break; - } else if (!pos) { - /* - * We are at the start of the buffer, and the - * start of the file; there is no previous - * line, and we have everything for this one. - * Process it, and we can end the loop. - */ - strbuf_splice(&sb, 0, 0, buf, endp - buf); - ret = show_one_reflog_ent(&sb, fn, cb_data); - strbuf_reset(&sb); - break; - } - - if (bp == buf) { - /* - * We are at the start of the buffer, and there - * is more file to read backwards. Which means - * we are in the middle of a line. Note that we - * may get here even if *bp was a newline; that - * just means we are at the exact end of the - * previous line, rather than some spot in the - * middle. - * - * Save away what we have to be combined with - * the data from the next read. - */ - strbuf_splice(&sb, 0, 0, buf, endp - buf); - break; - } - } - - } - if (!ret && sb.len) - BUG("reverse reflog parser had leftover data"); - - fclose(logfp); - strbuf_release(&sb); - return ret; -} - -static int files_for_each_reflog_ent(struct ref_store *ref_store, - const char *refname, - each_reflog_ent_fn fn, void *cb_data) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, - "for_each_reflog_ent"); - FILE *logfp; - struct strbuf sb = STRBUF_INIT; - int ret = 0; - - files_reflog_path(refs, &sb, refname); - logfp = fopen(sb.buf, "r"); - strbuf_release(&sb); - if (!logfp) - return -1; - - while (!ret && !strbuf_getwholeline(&sb, logfp, '\n')) - ret = show_one_reflog_ent(&sb, fn, cb_data); - fclose(logfp); - strbuf_release(&sb); - return ret; -} - -struct files_reflog_iterator { - struct ref_iterator base; - - struct ref_store *ref_store; - struct dir_iterator *dir_iterator; - struct object_id oid; -}; - -static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator) -{ - struct files_reflog_iterator *iter = - (struct files_reflog_iterator *)ref_iterator; - struct dir_iterator *diter = iter->dir_iterator; - int ok; - - while ((ok = dir_iterator_advance(diter)) == ITER_OK) { - int flags; - - if (!S_ISREG(diter->st.st_mode)) - continue; - if (diter->basename[0] == '.') - continue; - if (ends_with(diter->basename, ".lock")) - continue; - - if (refs_read_ref_full(iter->ref_store, - diter->relative_path, 0, - &iter->oid, &flags)) { - error("bad ref for %s", diter->path.buf); - continue; - } - - iter->base.refname = diter->relative_path; - iter->base.oid = &iter->oid; - iter->base.flags = flags; - return ITER_OK; - } - - iter->dir_iterator = NULL; - if (ref_iterator_abort(ref_iterator) == ITER_ERROR) - ok = ITER_ERROR; - return ok; -} - -static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator, - struct object_id *peeled) -{ - BUG("ref_iterator_peel() called for reflog_iterator"); -} - -static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator) -{ - struct files_reflog_iterator *iter = - (struct files_reflog_iterator *)ref_iterator; - int ok = ITER_DONE; - - if (iter->dir_iterator) - ok = dir_iterator_abort(iter->dir_iterator); - - base_ref_iterator_free(ref_iterator); - return ok; -} - -static struct ref_iterator_vtable files_reflog_iterator_vtable = { - files_reflog_iterator_advance, - files_reflog_iterator_peel, - files_reflog_iterator_abort -}; - -static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store, - const char *gitdir) -{ - struct dir_iterator *diter; - struct files_reflog_iterator *iter; - struct ref_iterator *ref_iterator; - struct strbuf sb = STRBUF_INIT; - - strbuf_addf(&sb, "%s/logs", gitdir); - - diter = dir_iterator_begin(sb.buf, 0); - if (!diter) { - strbuf_release(&sb); - return empty_ref_iterator_begin(); - } - - iter = xcalloc(1, sizeof(*iter)); - ref_iterator = &iter->base; - - base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0); - iter->dir_iterator = diter; - iter->ref_store = ref_store; - strbuf_release(&sb); - - return ref_iterator; -} - -static enum iterator_selection reflog_iterator_select( - struct ref_iterator *iter_worktree, - struct ref_iterator *iter_common, - void *cb_data) -{ - if (iter_worktree) { - /* - * We're a bit loose here. We probably should ignore - * common refs if they are accidentally added as - * per-worktree refs. - */ - return ITER_SELECT_0; - } else if (iter_common) { - if (ref_type(iter_common->refname) == REF_TYPE_NORMAL) - return ITER_SELECT_1; - - /* - * The main ref store may contain main worktree's - * per-worktree refs, which should be ignored - */ - return ITER_SKIP_1; - } else - return ITER_DONE; -} - -static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, - "reflog_iterator_begin"); - - if (!strcmp(refs->gitdir, refs->gitcommondir)) { - return reflog_iterator_begin(ref_store, refs->gitcommondir); - } else { - return merge_ref_iterator_begin( - 0, - reflog_iterator_begin(ref_store, refs->gitdir), - reflog_iterator_begin(ref_store, refs->gitcommondir), - reflog_iterator_select, refs); - } -} - -/* - * If update is a direct update of head_ref (the reference pointed to - * by HEAD), then add an extra REF_LOG_ONLY update for HEAD. - */ -static int split_head_update(struct ref_update *update, - struct ref_transaction *transaction, - const char *head_ref, - struct string_list *affected_refnames, - struct strbuf *err) -{ - struct string_list_item *item; - struct ref_update *new_update; - - if ((update->flags & REF_LOG_ONLY) || - (update->flags & REF_IS_PRUNING) || - (update->flags & REF_UPDATE_VIA_HEAD)) - return 0; - - if (strcmp(update->refname, head_ref)) - return 0; - - /* - * First make sure that HEAD is not already in the - * transaction. This check is O(lg N) in the transaction - * size, but it happens at most once per transaction. - */ - if (string_list_has_string(affected_refnames, "HEAD")) { - /* An entry already existed */ - strbuf_addf(err, - "multiple updates for 'HEAD' (including one " - "via its referent '%s') are not allowed", - update->refname); - return TRANSACTION_NAME_CONFLICT; - } - - new_update = ref_transaction_add_update( - transaction, "HEAD", - update->flags | REF_LOG_ONLY | REF_NO_DEREF, - &update->new_oid, &update->old_oid, - update->msg); - - /* - * Add "HEAD". This insertion is O(N) in the transaction - * size, but it happens at most once per transaction. - * Add new_update->refname instead of a literal "HEAD". - */ - if (strcmp(new_update->refname, "HEAD")) - BUG("%s unexpectedly not 'HEAD'", new_update->refname); - item = string_list_insert(affected_refnames, new_update->refname); - item->util = new_update; - - return 0; -} - -/* - * update is for a symref that points at referent and doesn't have - * REF_NO_DEREF set. Split it into two updates: - * - The original update, but with REF_LOG_ONLY and REF_NO_DEREF set - * - A new, separate update for the referent reference - * Note that the new update will itself be subject to splitting when - * the iteration gets to it. - */ -static int split_symref_update(struct ref_update *update, - const char *referent, - struct ref_transaction *transaction, - struct string_list *affected_refnames, - struct strbuf *err) -{ - struct string_list_item *item; - struct ref_update *new_update; - unsigned int new_flags; - - /* - * First make sure that referent is not already in the - * transaction. This check is O(lg N) in the transaction - * size, but it happens at most once per symref in a - * transaction. - */ - if (string_list_has_string(affected_refnames, referent)) { - /* An entry already exists */ - strbuf_addf(err, - "multiple updates for '%s' (including one " - "via symref '%s') are not allowed", - referent, update->refname); - return TRANSACTION_NAME_CONFLICT; - } - - new_flags = update->flags; - if (!strcmp(update->refname, "HEAD")) { - /* - * Record that the new update came via HEAD, so that - * when we process it, split_head_update() doesn't try - * to add another reflog update for HEAD. Note that - * this bit will be propagated if the new_update - * itself needs to be split. - */ - new_flags |= REF_UPDATE_VIA_HEAD; - } - - new_update = ref_transaction_add_update( - transaction, referent, new_flags, - &update->new_oid, &update->old_oid, - update->msg); - - new_update->parent_update = update; - - /* - * Change the symbolic ref update to log only. Also, it - * doesn't need to check its old OID value, as that will be - * done when new_update is processed. - */ - update->flags |= REF_LOG_ONLY | REF_NO_DEREF; - update->flags &= ~REF_HAVE_OLD; - - /* - * Add the referent. This insertion is O(N) in the transaction - * size, but it happens at most once per symref in a - * transaction. Make sure to add new_update->refname, which will - * be valid as long as affected_refnames is in use, and NOT - * referent, which might soon be freed by our caller. - */ - item = string_list_insert(affected_refnames, new_update->refname); - if (item->util) - BUG("%s unexpectedly found in affected_refnames", - new_update->refname); - item->util = new_update; - - return 0; -} - -/* - * Return the refname under which update was originally requested. - */ -static const char *original_update_refname(struct ref_update *update) -{ - while (update->parent_update) - update = update->parent_update; - - return update->refname; -} - -/* - * Check whether the REF_HAVE_OLD and old_oid values stored in update - * are consistent with oid, which is the reference's current value. If - * everything is OK, return 0; otherwise, write an error message to - * err and return -1. - */ -static int check_old_oid(struct ref_update *update, struct object_id *oid, - struct strbuf *err) -{ - if (!(update->flags & REF_HAVE_OLD) || - oideq(oid, &update->old_oid)) - return 0; - - if (is_null_oid(&update->old_oid)) - strbuf_addf(err, "cannot lock ref '%s': " - "reference already exists", - original_update_refname(update)); - else if (is_null_oid(oid)) - strbuf_addf(err, "cannot lock ref '%s': " - "reference is missing but expected %s", - original_update_refname(update), - oid_to_hex(&update->old_oid)); - else - strbuf_addf(err, "cannot lock ref '%s': " - "is at %s but expected %s", - original_update_refname(update), - oid_to_hex(oid), - oid_to_hex(&update->old_oid)); - - return -1; -} - -/* - * Prepare for carrying out update: - * - Lock the reference referred to by update. - * - Read the reference under lock. - * - Check that its old OID value (if specified) is correct, and in - * any case record it in update->lock->old_oid for later use when - * writing the reflog. - * - If it is a symref update without REF_NO_DEREF, split it up into a - * REF_LOG_ONLY update of the symref and add a separate update for - * the referent to transaction. - * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY - * update of HEAD. - */ -static int lock_ref_for_update(struct files_ref_store *refs, - struct ref_update *update, - struct ref_transaction *transaction, - const char *head_ref, - struct string_list *affected_refnames, - struct strbuf *err) -{ - struct strbuf referent = STRBUF_INIT; - int mustexist = (update->flags & REF_HAVE_OLD) && - !is_null_oid(&update->old_oid); - int ret = 0; - struct ref_lock *lock; - - files_assert_main_repository(refs, "lock_ref_for_update"); - - if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid)) - update->flags |= REF_DELETING; - - if (head_ref) { - ret = split_head_update(update, transaction, head_ref, - affected_refnames, err); - if (ret) - goto out; - } - - ret = lock_raw_ref(refs, update->refname, mustexist, - affected_refnames, NULL, - &lock, &referent, - &update->type, err); - if (ret) { - char *reason; - - reason = strbuf_detach(err, NULL); - strbuf_addf(err, "cannot lock ref '%s': %s", - original_update_refname(update), reason); - free(reason); - goto out; - } - - update->backend_data = lock; - - if (update->type & REF_ISSYMREF) { - if (update->flags & REF_NO_DEREF) { - /* - * We won't be reading the referent as part of - * the transaction, so we have to read it here - * to record and possibly check old_oid: - */ - if (refs_read_ref_full(&refs->base, - referent.buf, 0, - &lock->old_oid, NULL)) { - if (update->flags & REF_HAVE_OLD) { - strbuf_addf(err, "cannot lock ref '%s': " - "error reading reference", - original_update_refname(update)); - ret = TRANSACTION_GENERIC_ERROR; - goto out; - } - } else if (check_old_oid(update, &lock->old_oid, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto out; - } - } else { - /* - * Create a new update for the reference this - * symref is pointing at. Also, we will record - * and verify old_oid for this update as part - * of processing the split-off update, so we - * don't have to do it here. - */ - ret = split_symref_update(update, - referent.buf, transaction, - affected_refnames, err); - if (ret) - goto out; - } - } else { - struct ref_update *parent_update; - - if (check_old_oid(update, &lock->old_oid, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto out; - } - - /* - * If this update is happening indirectly because of a - * symref update, record the old OID in the parent - * update: - */ - for (parent_update = update->parent_update; - parent_update; - parent_update = parent_update->parent_update) { - struct ref_lock *parent_lock = parent_update->backend_data; - oidcpy(&parent_lock->old_oid, &lock->old_oid); - } - } - - if ((update->flags & REF_HAVE_NEW) && - !(update->flags & REF_DELETING) && - !(update->flags & REF_LOG_ONLY)) { - if (!(update->type & REF_ISSYMREF) && - oideq(&lock->old_oid, &update->new_oid)) { - /* - * The reference already has the desired - * value, so we don't need to write it. - */ - } else if (write_ref_to_lockfile(lock, &update->new_oid, - err)) { - char *write_err = strbuf_detach(err, NULL); - - /* - * The lock was freed upon failure of - * write_ref_to_lockfile(): - */ - update->backend_data = NULL; - strbuf_addf(err, - "cannot update ref '%s': %s", - update->refname, write_err); - free(write_err); - ret = TRANSACTION_GENERIC_ERROR; - goto out; - } else { - update->flags |= REF_NEEDS_COMMIT; - } - } - if (!(update->flags & REF_NEEDS_COMMIT)) { - /* - * We didn't call write_ref_to_lockfile(), so - * the lockfile is still open. Close it to - * free up the file descriptor: - */ - if (close_ref_gently(lock)) { - strbuf_addf(err, "couldn't close '%s.lock'", - update->refname); - ret = TRANSACTION_GENERIC_ERROR; - goto out; - } - } - -out: - strbuf_release(&referent); - return ret; -} - -struct files_transaction_backend_data { - struct ref_transaction *packed_transaction; - int packed_refs_locked; -}; - -/* - * Unlock any references in `transaction` that are still locked, and - * mark the transaction closed. - */ -static void files_transaction_cleanup(struct files_ref_store *refs, - struct ref_transaction *transaction) -{ - size_t i; - struct files_transaction_backend_data *backend_data = - transaction->backend_data; - struct strbuf err = STRBUF_INIT; - - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - struct ref_lock *lock = update->backend_data; - - if (lock) { - unlock_ref(lock); - update->backend_data = NULL; - } - } - - if (backend_data->packed_transaction && - ref_transaction_abort(backend_data->packed_transaction, &err)) { - error("error aborting transaction: %s", err.buf); - strbuf_release(&err); - } - - if (backend_data->packed_refs_locked) - packed_refs_unlock(refs->packed_ref_store); - - free(backend_data); - - transaction->state = REF_TRANSACTION_CLOSED; -} - -static int files_transaction_prepare(struct ref_store *ref_store, - struct ref_transaction *transaction, - struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, - "ref_transaction_prepare"); - size_t i; - int ret = 0; - struct string_list affected_refnames = STRING_LIST_INIT_NODUP; - char *head_ref = NULL; - int head_type; - struct files_transaction_backend_data *backend_data; - struct ref_transaction *packed_transaction = NULL; - - assert(err); - - if (!transaction->nr) - goto cleanup; - - backend_data = xcalloc(1, sizeof(*backend_data)); - transaction->backend_data = backend_data; - - /* - * Fail if a refname appears more than once in the - * transaction. (If we end up splitting up any updates using - * split_symref_update() or split_head_update(), those - * functions will check that the new updates don't have the - * same refname as any existing ones.) Also fail if any of the - * updates use REF_IS_PRUNING without REF_NO_DEREF. - */ - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - struct string_list_item *item = - string_list_append(&affected_refnames, update->refname); - - if ((update->flags & REF_IS_PRUNING) && - !(update->flags & REF_NO_DEREF)) - BUG("REF_IS_PRUNING set without REF_NO_DEREF"); - - /* - * We store a pointer to update in item->util, but at - * the moment we never use the value of this field - * except to check whether it is non-NULL. - */ - item->util = update; - } - string_list_sort(&affected_refnames); - if (ref_update_reject_duplicates(&affected_refnames, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - /* - * Special hack: If a branch is updated directly and HEAD - * points to it (may happen on the remote side of a push - * for example) then logically the HEAD reflog should be - * updated too. - * - * A generic solution would require reverse symref lookups, - * but finding all symrefs pointing to a given branch would be - * rather costly for this rare event (the direct update of a - * branch) to be worth it. So let's cheat and check with HEAD - * only, which should cover 99% of all usage scenarios (even - * 100% of the default ones). - * - * So if HEAD is a symbolic reference, then record the name of - * the reference that it points to. If we see an update of - * head_ref within the transaction, then split_head_update() - * arranges for the reflog of HEAD to be updated, too. - */ - head_ref = refs_resolve_refdup(ref_store, "HEAD", - RESOLVE_REF_NO_RECURSE, - NULL, &head_type); - - if (head_ref && !(head_type & REF_ISSYMREF)) { - FREE_AND_NULL(head_ref); - } - - /* - * Acquire all locks, verify old values if provided, check - * that new values are valid, and write new values to the - * lockfiles, ready to be activated. Only keep one lockfile - * open at a time to avoid running out of file descriptors. - * Note that lock_ref_for_update() might append more updates - * to the transaction. - */ - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - - ret = lock_ref_for_update(refs, update, transaction, - head_ref, &affected_refnames, err); - if (ret) - goto cleanup; - - if (update->flags & REF_DELETING && - !(update->flags & REF_LOG_ONLY) && - !(update->flags & REF_IS_PRUNING)) { - /* - * This reference has to be deleted from - * packed-refs if it exists there. - */ - if (!packed_transaction) { - packed_transaction = ref_store_transaction_begin( - refs->packed_ref_store, err); - if (!packed_transaction) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - backend_data->packed_transaction = - packed_transaction; - } - - ref_transaction_add_update( - packed_transaction, update->refname, - REF_HAVE_NEW | REF_NO_DEREF, - &update->new_oid, NULL, - NULL); - } - } - - if (packed_transaction) { - if (packed_refs_lock(refs->packed_ref_store, 0, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - backend_data->packed_refs_locked = 1; - - if (is_packed_transaction_needed(refs->packed_ref_store, - packed_transaction)) { - ret = ref_transaction_prepare(packed_transaction, err); - /* - * A failure during the prepare step will abort - * itself, but not free. Do that now, and disconnect - * from the files_transaction so it does not try to - * abort us when we hit the cleanup code below. - */ - if (ret) { - ref_transaction_free(packed_transaction); - backend_data->packed_transaction = NULL; - } - } else { - /* - * We can skip rewriting the `packed-refs` - * file. But we do need to leave it locked, so - * that somebody else doesn't pack a reference - * that we are trying to delete. - * - * We need to disconnect our transaction from - * backend_data, since the abort (whether successful or - * not) will free it. - */ - backend_data->packed_transaction = NULL; - if (ref_transaction_abort(packed_transaction, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - } - } - -cleanup: - free(head_ref); - string_list_clear(&affected_refnames, 0); - - if (ret) - files_transaction_cleanup(refs, transaction); - else - transaction->state = REF_TRANSACTION_PREPARED; - - return ret; -} - -static int files_transaction_finish(struct ref_store *ref_store, - struct ref_transaction *transaction, - struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, 0, "ref_transaction_finish"); - size_t i; - int ret = 0; - struct strbuf sb = STRBUF_INIT; - struct files_transaction_backend_data *backend_data; - struct ref_transaction *packed_transaction; - - - assert(err); - - if (!transaction->nr) { - transaction->state = REF_TRANSACTION_CLOSED; - return 0; - } - - backend_data = transaction->backend_data; - packed_transaction = backend_data->packed_transaction; - - /* Perform updates first so live commits remain referenced */ - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - struct ref_lock *lock = update->backend_data; - - if (update->flags & REF_NEEDS_COMMIT || - update->flags & REF_LOG_ONLY) { - if (files_log_ref_write(refs, - lock->ref_name, - &lock->old_oid, - &update->new_oid, - update->msg, update->flags, - err)) { - char *old_msg = strbuf_detach(err, NULL); - - strbuf_addf(err, "cannot update the ref '%s': %s", - lock->ref_name, old_msg); - free(old_msg); - unlock_ref(lock); - update->backend_data = NULL; - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - } - if (update->flags & REF_NEEDS_COMMIT) { - clear_loose_ref_cache(refs); - if (commit_ref(lock)) { - strbuf_addf(err, "couldn't set '%s'", lock->ref_name); - unlock_ref(lock); - update->backend_data = NULL; - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - } - } - - /* - * Now that updates are safely completed, we can perform - * deletes. First delete the reflogs of any references that - * will be deleted, since (in the unexpected event of an - * error) leaving a reference without a reflog is less bad - * than leaving a reflog without a reference (the latter is a - * mildly invalid repository state): - */ - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - if (update->flags & REF_DELETING && - !(update->flags & REF_LOG_ONLY) && - !(update->flags & REF_IS_PRUNING)) { - strbuf_reset(&sb); - files_reflog_path(refs, &sb, update->refname); - if (!unlink_or_warn(sb.buf)) - try_remove_empty_parents(refs, update->refname, - REMOVE_EMPTY_PARENTS_REFLOG); - } - } - - /* - * Perform deletes now that updates are safely completed. - * - * First delete any packed versions of the references, while - * retaining the packed-refs lock: - */ - if (packed_transaction) { - ret = ref_transaction_commit(packed_transaction, err); - ref_transaction_free(packed_transaction); - packed_transaction = NULL; - backend_data->packed_transaction = NULL; - if (ret) - goto cleanup; - } - - /* Now delete the loose versions of the references: */ - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - struct ref_lock *lock = update->backend_data; - - if (update->flags & REF_DELETING && - !(update->flags & REF_LOG_ONLY)) { - if (!(update->type & REF_ISPACKED) || - update->type & REF_ISSYMREF) { - /* It is a loose reference. */ - strbuf_reset(&sb); - files_ref_path(refs, &sb, lock->ref_name); - if (unlink_or_msg(sb.buf, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - update->flags |= REF_DELETED_LOOSE; - } - } - } - - clear_loose_ref_cache(refs); - -cleanup: - files_transaction_cleanup(refs, transaction); - - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - - if (update->flags & REF_DELETED_LOOSE) { - /* - * The loose reference was deleted. Delete any - * empty parent directories. (Note that this - * can only work because we have already - * removed the lockfile.) - */ - try_remove_empty_parents(refs, update->refname, - REMOVE_EMPTY_PARENTS_REF); - } - } - - strbuf_release(&sb); - return ret; -} - -static int files_transaction_abort(struct ref_store *ref_store, - struct ref_transaction *transaction, - struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, 0, "ref_transaction_abort"); - - files_transaction_cleanup(refs, transaction); - return 0; -} - -static int ref_present(const char *refname, - const struct object_id *oid, int flags, void *cb_data) -{ - struct string_list *affected_refnames = cb_data; - - return string_list_has_string(affected_refnames, refname); -} - -static int files_initial_transaction_commit(struct ref_store *ref_store, - struct ref_transaction *transaction, - struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, - "initial_ref_transaction_commit"); - size_t i; - int ret = 0; - struct string_list affected_refnames = STRING_LIST_INIT_NODUP; - struct ref_transaction *packed_transaction = NULL; - - assert(err); - - if (transaction->state != REF_TRANSACTION_OPEN) - BUG("commit called for transaction that is not open"); - - /* Fail if a refname appears more than once in the transaction: */ - for (i = 0; i < transaction->nr; i++) - string_list_append(&affected_refnames, - transaction->updates[i]->refname); - string_list_sort(&affected_refnames); - if (ref_update_reject_duplicates(&affected_refnames, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - /* - * It's really undefined to call this function in an active - * repository or when there are existing references: we are - * only locking and changing packed-refs, so (1) any - * simultaneous processes might try to change a reference at - * the same time we do, and (2) any existing loose versions of - * the references that we are setting would have precedence - * over our values. But some remote helpers create the remote - * "HEAD" and "master" branches before calling this function, - * so here we really only check that none of the references - * that we are creating already exists. - */ - if (refs_for_each_rawref(&refs->base, ref_present, - &affected_refnames)) - BUG("initial ref transaction called with existing refs"); - - packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err); - if (!packed_transaction) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - - if ((update->flags & REF_HAVE_OLD) && - !is_null_oid(&update->old_oid)) - BUG("initial ref transaction with old_sha1 set"); - if (refs_verify_refname_available(&refs->base, update->refname, - &affected_refnames, NULL, - err)) { - ret = TRANSACTION_NAME_CONFLICT; - goto cleanup; - } - - /* - * Add a reference creation for this reference to the - * packed-refs transaction: - */ - ref_transaction_add_update(packed_transaction, update->refname, - update->flags & ~REF_HAVE_OLD, - &update->new_oid, &update->old_oid, - NULL); - } - - if (packed_refs_lock(refs->packed_ref_store, 0, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - if (initial_ref_transaction_commit(packed_transaction, err)) { - ret = TRANSACTION_GENERIC_ERROR; - } - - packed_refs_unlock(refs->packed_ref_store); -cleanup: - if (packed_transaction) - ref_transaction_free(packed_transaction); - transaction->state = REF_TRANSACTION_CLOSED; - string_list_clear(&affected_refnames, 0); - return ret; -} - -struct expire_reflog_cb { - unsigned int flags; - reflog_expiry_should_prune_fn *should_prune_fn; - void *policy_cb; - FILE *newlog; - struct object_id last_kept_oid; -}; - -static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid, - const char *email, timestamp_t timestamp, int tz, - const char *message, void *cb_data) -{ - struct expire_reflog_cb *cb = cb_data; - struct expire_reflog_policy_cb *policy_cb = cb->policy_cb; - - if (cb->flags & EXPIRE_REFLOGS_REWRITE) - ooid = &cb->last_kept_oid; - - if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz, - message, policy_cb)) { - if (!cb->newlog) - printf("would prune %s", message); - else if (cb->flags & EXPIRE_REFLOGS_VERBOSE) - printf("prune %s", message); - } else { - if (cb->newlog) { - fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s", - oid_to_hex(ooid), oid_to_hex(noid), - email, timestamp, tz, message); - oidcpy(&cb->last_kept_oid, noid); - } - if (cb->flags & EXPIRE_REFLOGS_VERBOSE) - printf("keep %s", message); - } - return 0; -} - -static int files_reflog_expire(struct ref_store *ref_store, - const char *refname, const struct object_id *oid, - unsigned int flags, - reflog_expiry_prepare_fn prepare_fn, - reflog_expiry_should_prune_fn should_prune_fn, - reflog_expiry_cleanup_fn cleanup_fn, - void *policy_cb_data) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire"); - struct lock_file reflog_lock = LOCK_INIT; - struct expire_reflog_cb cb; - struct ref_lock *lock; - struct strbuf log_file_sb = STRBUF_INIT; - char *log_file; - int status = 0; - int type; - struct strbuf err = STRBUF_INIT; - - memset(&cb, 0, sizeof(cb)); - cb.flags = flags; - cb.policy_cb = policy_cb_data; - cb.should_prune_fn = should_prune_fn; - - /* - * The reflog file is locked by holding the lock on the - * reference itself, plus we might need to update the - * reference if --updateref was specified: - */ - lock = lock_ref_oid_basic(refs, refname, oid, - NULL, NULL, REF_NO_DEREF, - &type, &err); - if (!lock) { - error("cannot lock ref '%s': %s", refname, err.buf); - strbuf_release(&err); - return -1; - } - if (!refs_reflog_exists(ref_store, refname)) { - unlock_ref(lock); - return 0; - } - - files_reflog_path(refs, &log_file_sb, refname); - log_file = strbuf_detach(&log_file_sb, NULL); - if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { - /* - * Even though holding $GIT_DIR/logs/$reflog.lock has - * no locking implications, we use the lock_file - * machinery here anyway because it does a lot of the - * work we need, including cleaning up if the program - * exits unexpectedly. - */ - if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { - struct strbuf err = STRBUF_INIT; - unable_to_lock_message(log_file, errno, &err); - error("%s", err.buf); - strbuf_release(&err); - goto failure; - } - cb.newlog = fdopen_lock_file(&reflog_lock, "w"); - if (!cb.newlog) { - error("cannot fdopen %s (%s)", - get_lock_file_path(&reflog_lock), strerror(errno)); - goto failure; - } - } - - (*prepare_fn)(refname, oid, cb.policy_cb); - refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb); - (*cleanup_fn)(cb.policy_cb); - - if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { - /* - * It doesn't make sense to adjust a reference pointed - * to by a symbolic ref based on expiring entries in - * the symbolic reference's reflog. Nor can we update - * a reference if there are no remaining reflog - * entries. - */ - int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) && - !(type & REF_ISSYMREF) && - !is_null_oid(&cb.last_kept_oid); - - if (close_lock_file_gently(&reflog_lock)) { - status |= error("couldn't write %s: %s", log_file, - strerror(errno)); - rollback_lock_file(&reflog_lock); - } else if (update && - (write_in_full(get_lock_file_fd(&lock->lk), - oid_to_hex(&cb.last_kept_oid), the_hash_algo->hexsz) < 0 || - write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 0 || - close_ref_gently(lock) < 0)) { - status |= error("couldn't write %s", - get_lock_file_path(&lock->lk)); - rollback_lock_file(&reflog_lock); - } else if (commit_lock_file(&reflog_lock)) { - status |= error("unable to write reflog '%s' (%s)", - log_file, strerror(errno)); - } else if (update && commit_ref(lock)) { - status |= error("couldn't set %s", lock->ref_name); - } - } - free(log_file); - unlock_ref(lock); - return status; - - failure: - rollback_lock_file(&reflog_lock); - free(log_file); - unlock_ref(lock); - return -1; -} - -static int files_init_db(struct ref_store *ref_store, struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_WRITE, "init_db"); - struct strbuf sb = STRBUF_INIT; - - /* - * Create .git/refs/{heads,tags} - */ - files_ref_path(refs, &sb, "refs/heads"); - safe_create_dir(sb.buf, 1); - - strbuf_reset(&sb); - files_ref_path(refs, &sb, "refs/tags"); - safe_create_dir(sb.buf, 1); - - strbuf_release(&sb); - return 0; -} - -struct ref_storage_be refs_be_files = { - NULL, - "files", - files_ref_store_create, - files_init_db, - files_transaction_prepare, - files_transaction_finish, - files_transaction_abort, - files_initial_transaction_commit, - - files_pack_refs, - files_create_symref, - files_delete_refs, - files_rename_ref, - files_copy_ref, - - files_ref_iterator_begin, - files_read_raw_ref, - - files_reflog_iterator_begin, - files_for_each_reflog_ent, - files_for_each_reflog_ent_reverse, - files_reflog_exists, - files_create_reflog, - files_delete_reflog, - files_reflog_expire -}; |