From: Karthik Nayak Date: Mon, 09 Feb 2026 12:52:03 GMT Subject: Re: [PATCH v4 3/4] refs: parse and use the reference storage payload Message-ID: In-Reply-To: Patrick Steinhardt writes: > On Mon, Feb 02, 2026 at 01:26:32PM +0100, Karthik Nayak wrote: >> The previous commit extended the 'extensions.refStorage' config to add >> support for a reference storage payload. The payload provides backend >> specific information on where to store references for a given directory. >> >> Propagate this information to individual backends when initializing them >> via the 'init()' function. Both the files and reftable backends will >> parse the information to be filesystem paths to store references. >> >> To enable this, provide a 'refs_compute_filesystem_location()' function >> which will parse the current 'gitdir' and the 'payload' to provide the >> final reference directory and common reference directory (if working in >> a linked worktree). >> >> Finally, for linked worktrees, traditionally references were stored in >> the '$GIT_DIR/worktrees/' path. But when using an alternate >> reference storage path, it doesn't make sense to store main worktree >> references in the new path, and linked worktree references in the >> $GIT_DIR path. So, let's store linked worktree references in >> '$ALTERNATE_REFERENCE_DIR/worktrees/ > s/wt_id/&>/ > Thanks! >> diff --git a/Documentation/config/extensions.adoc b/Documentation/config/extensions.adoc >> index 532456644b..df86da6aa7 100644 >> --- a/Documentation/config/extensions.adoc >> +++ b/Documentation/config/extensions.adoc >> @@ -57,10 +57,24 @@ For historical reasons, this extension is respected regardless of the >> `core.repositoryFormatVersion` setting. >> >> refStorage::: >> - Specify the ref storage format to use. The acceptable values are: >> + Specify the ref storage format and location to use. The value can be >> + either a format name or a URI: >> + >> -- >> +* A format name alone (e.g., `reftable` or `files`) uses the default >> + location (the repository's common directory). >> + >> +* A URI format `://` explicitly specifies both the > > I think I mentioned this before, but shouldn't we say payload instead of > location here? It may not be a location for all backends. > Yeah, you did. I missed this entirely somehow. Will re-do this. >> diff --git a/builtin/worktree.c b/builtin/worktree.c >> index fbdaf2eb2e..800a376ac5 100644 >> --- a/builtin/worktree.c >> +++ b/builtin/worktree.c >> @@ -425,6 +425,40 @@ static int make_worktree_orphan(const char * ref, const struct add_opts *opts, >> return run_command(&cp); >> } >> >> +/* >> + * References for worktress are generally stored in '$GIT_DIR/worktrees/'. >> + * But when using alternate reference directories, we want to store the worktree >> + * references in '$ALTERNATE_REFERENCE_DIR/worktrees/'. >> + * >> + * Create the necessary folder structure to facilitate the same. But to ensure >> + * that the former path is still considered a Git directory, add stubs (similar >> + * to how we do in the reftable backend). >> + */ > > I think the last part in the braces isn't necessary to say anymore given > that we simply shell out to a function now. > Yeah, will remove. >> diff --git a/refs.c b/refs.c >> index 32b4edaf2d..c1d69082a9 100644 >> --- a/refs.c >> +++ b/refs.c >> @@ -2224,7 +2225,11 @@ static struct ref_store *ref_store_init(struct repository *repo, >> if (!be) >> BUG("reference backend is unknown"); >> >> - refs = be->init(repo, gitdir, flags); >> + /* >> + * TODO Send in a 'struct worktree' instead of a 'gitdir', and >> + * allow the backend to handle how it wants to deal with worktrees. >> + */ > > It would be nice if the commit message mentioned why this isn't done now > already. Will do! >> diff --git a/refs/files-backend.c b/refs/files-backend.c >> index 240d3c3b26..160ecb53b7 100644 >> --- a/refs/files-backend.c >> +++ b/refs/files-backend.c >> @@ -106,19 +106,24 @@ static void clear_loose_ref_cache(struct files_ref_store *refs) >> * set of caches. >> */ >> static struct ref_store *files_ref_store_init(struct repository *repo, >> + const char *payload, >> 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; >> + struct strbuf ref_common_dir = STRBUF_INIT; >> + struct strbuf refdir = STRBUF_INIT; >> + bool is_worktree; >> + >> + refs_compute_filesystem_location(gitdir, payload, &is_worktree, &refdir, >> + &ref_common_dir); >> >> - base_ref_store_init(ref_store, repo, gitdir, &refs_be_files); >> + base_ref_store_init(ref_store, repo, refdir.buf, &refs_be_files); >> refs->store_flags = flags; >> - get_common_dir_noenv(&sb, gitdir); >> - refs->gitcommondir = strbuf_detach(&sb, NULL); >> + refs->gitcommondir = xstrdup(ref_common_dir.buf); > > We can use `strbuf_detach()` instead to save an allocation and then use > `refs->gitcommondir` below. > That's a good suggestion. >> refs->packed_ref_store = >> - packed_ref_store_init(repo, refs->gitcommondir, flags); >> + packed_ref_store_init(repo, payload, ref_common_dir.buf, flags); >> refs->log_all_ref_updates = repo_settings_get_log_all_ref_updates(repo); >> repo_config_get_bool(repo, "core.prefersymlinkrefs", &refs->prefer_symlink_refs); > > Patrick Thanks!