From 2e573d61ffe3d1e7ea94673757fb69477c1499bc Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Mon, 8 Jan 2024 11:05:26 +0100 Subject: [PATCH 1/6] refs: prepare `refs_init_db()` for initializing worktree refs The purpose of `refs_init_db()` is to initialize the on-disk files of a new ref database. The function is quite inflexible right now though, as callers can neither specify the `struct ref_store` nor can they pass any flags. Refactor the interface to accept both of these. This will be required so that we can start initializing per-worktree ref databases via the ref backend instead of open-coding the initialization in "worktree.c". Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- refs.c | 6 ++---- refs.h | 2 +- refs/debug.c | 4 ++-- refs/files-backend.c | 4 +++- refs/packed-backend.c | 1 + refs/refs-internal.h | 4 +++- setup.c | 2 +- 7 files changed, 13 insertions(+), 10 deletions(-) diff --git a/refs.c b/refs.c index fdbf5f4cb1..254272ba6f 100644 --- a/refs.c +++ b/refs.c @@ -1944,11 +1944,9 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs, } /* backend functions */ -int refs_init_db(struct strbuf *err) +int refs_init_db(struct ref_store *refs, int flags, struct strbuf *err) { - struct ref_store *refs = get_main_ref_store(the_repository); - - return refs->be->init_db(refs, err); + return refs->be->init_db(refs, flags, err); } const char *resolve_ref_unsafe(const char *refname, int resolve_flags, diff --git a/refs.h b/refs.h index 916b874ae3..114caa272a 100644 --- a/refs.h +++ b/refs.h @@ -126,7 +126,7 @@ int should_autocreate_reflog(const char *refname); int is_branch(const char *refname); -int refs_init_db(struct strbuf *err); +int refs_init_db(struct ref_store *refs, int flags, struct strbuf *err); /* * Return the peeled value of the oid currently being iterated via diff --git a/refs/debug.c b/refs/debug.c index b9775f2c37..634681ca44 100644 --- a/refs/debug.c +++ b/refs/debug.c @@ -33,10 +33,10 @@ struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_stor return (struct ref_store *)res; } -static int debug_init_db(struct ref_store *refs, struct strbuf *err) +static int debug_init_db(struct ref_store *refs, int flags, struct strbuf *err) { struct debug_ref_store *drefs = (struct debug_ref_store *)refs; - int res = drefs->refs->be->init_db(drefs->refs, err); + int res = drefs->refs->be->init_db(drefs->refs, flags, err); trace_printf_key(&trace_refs, "init_db: %d\n", res); return res; } diff --git a/refs/files-backend.c b/refs/files-backend.c index 43fd0ac760..153efe6662 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -3220,7 +3220,9 @@ static int files_reflog_expire(struct ref_store *ref_store, return -1; } -static int files_init_db(struct ref_store *ref_store, struct strbuf *err UNUSED) +static int files_init_db(struct ref_store *ref_store, + int flags UNUSED, + struct strbuf *err UNUSED) { struct files_ref_store *refs = files_downcast(ref_store, REF_STORE_WRITE, "init_db"); diff --git a/refs/packed-backend.c b/refs/packed-backend.c index 8d1090e284..217f052d34 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -1246,6 +1246,7 @@ static const char PACKED_REFS_HEADER[] = "# pack-refs with: peeled fully-peeled sorted \n"; static int packed_init_db(struct ref_store *ref_store UNUSED, + int flags UNUSED, struct strbuf *err UNUSED) { /* Nothing to do. */ diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 8e9f04cc67..82219829b0 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -529,7 +529,9 @@ typedef struct ref_store *ref_store_init_fn(struct repository *repo, const char *gitdir, unsigned int flags); -typedef int ref_init_db_fn(struct ref_store *refs, struct strbuf *err); +typedef int ref_init_db_fn(struct ref_store *refs, + int flags, + struct strbuf *err); typedef int ref_transaction_prepare_fn(struct ref_store *refs, struct ref_transaction *transaction, diff --git a/setup.c b/setup.c index 1ab1a66bcb..6c8f656f7c 100644 --- a/setup.c +++ b/setup.c @@ -1943,7 +1943,7 @@ void create_reference_database(unsigned int ref_storage_format, adjust_shared_perm(git_path("refs")); repo_set_ref_storage_format(the_repository, ref_storage_format); - if (refs_init_db(&err)) + if (refs_init_db(get_main_ref_store(the_repository), 0, &err)) die("failed to set up refs db: %s", err.buf); /* From c358d165f2a4b3176b527e18c207105f6821335e Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Mon, 8 Jan 2024 11:05:30 +0100 Subject: [PATCH 2/6] setup: move creation of "refs/" into the files backend When creating the ref database we unconditionally create the "refs/" directory in "setup.c". This is a mandatory prerequisite for all Git repositories regardless of the ref backend in use, because Git will be unable to detect the directory as a repository if "refs/" doesn't exist. We are about to add another new caller that will want to create a ref database when creating worktrees. We would require the same logic to create the "refs/" directory even though the caller really should not care about such low-level details. Ideally, the ref database should be fully initialized after calling `refs_init_db()`. Move the code to create the directory into the files backend itself to make it so. This means that future ref backends will also need to have equivalent logic around to ensure that the directory exists, but it seems a lot more sensible to have it this way round than to require callers to create the directory themselves. An alternative to this would be to create "refs/" in `refs_init_db()` directly. This feels conceptually unclean though as the creation of the refdb is now cluttered across different callsites. Furthermore, both the "files" and the upcoming "reftable" backend write backend-specific data into the "refs/" directory anyway, so splitting up this logic would only make it harder to reason about. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- refs/files-backend.c | 17 +++++++++++++++++ setup.c | 15 --------------- 2 files changed, 17 insertions(+), 15 deletions(-) diff --git a/refs/files-backend.c b/refs/files-backend.c index 153efe6662..054ecdbca3 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -3228,9 +3228,26 @@ static int files_init_db(struct ref_store *ref_store, files_downcast(ref_store, REF_STORE_WRITE, "init_db"); struct strbuf sb = STRBUF_INIT; + /* + * We need to create a "refs" dir in any case so that older versions of + * Git can tell that this is a repository. This serves two main purposes: + * + * - Clients will know to stop walking the parent-directory chain when + * detecting the Git repository. Otherwise they may end up detecting + * a Git repository in a parent directory instead. + * + * - Instead of failing to detect a repository with unknown reference + * format altogether, old clients will print an error saying that + * they do not understand the reference format extension. + */ + strbuf_addf(&sb, "%s/refs", ref_store->gitdir); + safe_create_dir(sb.buf, 1); + adjust_shared_perm(sb.buf); + /* * Create .git/refs/{heads,tags} */ + strbuf_reset(&sb); files_ref_path(refs, &sb, "refs/heads"); safe_create_dir(sb.buf, 1); diff --git a/setup.c b/setup.c index 6c8f656f7c..abb271e017 100644 --- a/setup.c +++ b/setup.c @@ -1927,21 +1927,6 @@ void create_reference_database(unsigned int ref_storage_format, struct strbuf err = STRBUF_INIT; int reinit = is_reinit(); - /* - * We need to create a "refs" dir in any case so that older versions of - * Git can tell that this is a repository. This serves two main purposes: - * - * - Clients will know to stop walking the parent-directory chain when - * detecting the Git repository. Otherwise they may end up detecting - * a Git repository in a parent directory instead. - * - * - Instead of failing to detect a repository with unknown reference - * format altogether, old clients will print an error saying that - * they do not understand the reference format extension. - */ - safe_create_dir(git_path("refs"), 1); - adjust_shared_perm(git_path("refs")); - repo_set_ref_storage_format(the_repository, ref_storage_format); if (refs_init_db(get_main_ref_store(the_repository), 0, &err)) die("failed to set up refs db: %s", err.buf); From 2eb1d0c45271faf149a13b61bb74af52abd7b3aa Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Mon, 8 Jan 2024 11:05:35 +0100 Subject: [PATCH 3/6] refs/files: skip creation of "refs/{heads,tags}" for worktrees The files ref backend will create both "refs/heads" and "refs/tags" in the Git directory. While this logic makes sense for normal repositories, it does not for worktrees because those refs are "common" refs that would always be contained in the main repository's ref database. Introduce a new flag telling the backend that it is expected to create a per-worktree ref database and skip creation of these dirs in the files backend when the flag is set. No other backends (currently) need worktree-specific logic, so this is the only required change to start creating per-worktree ref databases via `refs_init_db()`. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- refs.h | 2 ++ refs/files-backend.c | 22 ++++++++++++++-------- 2 files changed, 16 insertions(+), 8 deletions(-) diff --git a/refs.h b/refs.h index 114caa272a..c2dfe451a1 100644 --- a/refs.h +++ b/refs.h @@ -126,6 +126,8 @@ int should_autocreate_reflog(const char *refname); int is_branch(const char *refname); +#define REFS_INIT_DB_IS_WORKTREE (1 << 0) + int refs_init_db(struct ref_store *refs, int flags, struct strbuf *err); /* diff --git a/refs/files-backend.c b/refs/files-backend.c index 054ecdbca3..6dae37e351 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -3221,7 +3221,7 @@ static int files_reflog_expire(struct ref_store *ref_store, } static int files_init_db(struct ref_store *ref_store, - int flags UNUSED, + int flags, struct strbuf *err UNUSED) { struct files_ref_store *refs = @@ -3245,15 +3245,21 @@ static int files_init_db(struct ref_store *ref_store, adjust_shared_perm(sb.buf); /* - * Create .git/refs/{heads,tags} + * There is no need to create directories for common refs when creating + * a worktree ref store. */ - strbuf_reset(&sb); - files_ref_path(refs, &sb, "refs/heads"); - safe_create_dir(sb.buf, 1); + if (!(flags & REFS_INIT_DB_IS_WORKTREE)) { + /* + * Create .git/refs/{heads,tags} + */ + strbuf_reset(&sb); + 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_reset(&sb); + files_ref_path(refs, &sb, "refs/tags"); + safe_create_dir(sb.buf, 1); + } strbuf_release(&sb); return 0; From 84f0ea956fbd3a3c9989a2d44da27881c0a5f546 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Mon, 8 Jan 2024 11:05:39 +0100 Subject: [PATCH 4/6] builtin/worktree: move setup of commondir file earlier Shuffle around how we create supporting worktree files so that we first ensure that the worktree has all link files ("gitdir", "commondir") before we try to initialize the ref database by writing "HEAD". This will be required by a subsequent commit where we start to initialize the ref database via `refs_init_db()`, which will require an initialized `struct worktree *`. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/worktree.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/builtin/worktree.c b/builtin/worktree.c index 4ac1621541..58937a2a68 100644 --- a/builtin/worktree.c +++ b/builtin/worktree.c @@ -495,6 +495,10 @@ static int add_worktree(const char *path, const char *refname, strbuf_realpath(&realpath, get_git_common_dir(), 1); write_file(sb_git.buf, "gitdir: %s/worktrees/%s", realpath.buf, name); + strbuf_reset(&sb); + strbuf_addf(&sb, "%s/commondir", sb_repo.buf); + write_file(sb.buf, "../.."); + /* * This is to keep resolve_ref() happy. We need a valid HEAD * or is_git_directory() will reject the directory. Any value which @@ -505,9 +509,6 @@ static int add_worktree(const char *path, const char *refname, strbuf_reset(&sb); strbuf_addf(&sb, "%s/HEAD", sb_repo.buf); write_file(sb.buf, "%s", oid_to_hex(null_oid())); - strbuf_reset(&sb); - strbuf_addf(&sb, "%s/commondir", sb_repo.buf); - write_file(sb.buf, "../.."); /* * If the current worktree has sparse-checkout enabled, then copy From b8a846b2e03610e6f550d364c75e514532ef7adf Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Mon, 8 Jan 2024 11:05:43 +0100 Subject: [PATCH 5/6] worktree: expose interface to look up worktree by name Our worktree interfaces do not provide a way to look up a worktree by its name. Expose `get_linked_worktree()` to allow for this usecase. As callers are responsible for freeing this worktree, introduce a new function `free_worktree()` that does so. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- worktree.c | 27 ++++++++++++++++----------- worktree.h | 12 ++++++++++++ 2 files changed, 28 insertions(+), 11 deletions(-) diff --git a/worktree.c b/worktree.c index cc34a3419b..5d5dd46609 100644 --- a/worktree.c +++ b/worktree.c @@ -12,18 +12,23 @@ #include "wt-status.h" #include "config.h" +void free_worktree(struct worktree *worktree) +{ + if (!worktree) + return; + free(worktree->path); + free(worktree->id); + free(worktree->head_ref); + free(worktree->lock_reason); + free(worktree->prune_reason); + free(worktree); +} + void free_worktrees(struct worktree **worktrees) { int i = 0; - - for (i = 0; worktrees[i]; i++) { - free(worktrees[i]->path); - free(worktrees[i]->id); - free(worktrees[i]->head_ref); - free(worktrees[i]->lock_reason); - free(worktrees[i]->prune_reason); - free(worktrees[i]); - } + for (i = 0; worktrees[i]; i++) + free_worktree(worktrees[i]); free (worktrees); } @@ -75,8 +80,8 @@ static struct worktree *get_main_worktree(int skip_reading_head) return worktree; } -static struct worktree *get_linked_worktree(const char *id, - int skip_reading_head) +struct worktree *get_linked_worktree(const char *id, + int skip_reading_head) { struct worktree *worktree = NULL; struct strbuf path = STRBUF_INIT; diff --git a/worktree.h b/worktree.h index ce45b66de9..f14784a2ff 100644 --- a/worktree.h +++ b/worktree.h @@ -57,6 +57,13 @@ struct worktree *find_worktree(struct worktree **list, const char *prefix, const char *arg); +/* + * Look up the worktree corresponding to `id`, or NULL of no such worktree + * exists. + */ +struct worktree *get_linked_worktree(const char *id, + int skip_reading_head); + /* * Return the worktree corresponding to `path`, or NULL if no such worktree * exists. @@ -134,6 +141,11 @@ void repair_worktrees(worktree_repair_fn, void *cb_data); */ void repair_worktree_at_path(const char *, worktree_repair_fn, void *cb_data); +/* + * Free up the memory for a worktree. + */ +void free_worktree(struct worktree *); + /* * Free up the memory for worktree(s) */ From 8f4c00de954f809e83daf8b1425de82561f3721e Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Mon, 8 Jan 2024 11:05:47 +0100 Subject: [PATCH 6/6] builtin/worktree: create refdb via ref backend When creating a worktree we create the worktree's ref database manually by first writing a "HEAD" file so that the directory is recognized as a Git repository by other commands, and then running git-update-ref(1) or git-symbolic-ref(1) to write the actual value. But while this is fine for the files backend, this logic simply assumes too much about how the ref backend works and will leave behind an invalid ref database once any other ref backend lands. Refactor the code to instead use `refs_init_db()` to initialize the ref database so that git-worktree(1) itself does not need to know about how to initialize it. This will allow future ref backends to customize how the per-worktree ref database is set up. Furthermore, as we now already have a worktree ref store around, we can also avoid spawning external commands to write the HEAD reference and instead use the refs API to do so. Note that we do not have an equivalent to passing the `--quiet` flag to git-symbolic-ref(1) as we did before. This flag does not have an effect anyway though, as git-symbolic-ref(1) only honors it when reading a symref, but never when writing one. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/worktree.c | 48 +++++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 26 deletions(-) diff --git a/builtin/worktree.c b/builtin/worktree.c index 58937a2a68..dd10446d81 100644 --- a/builtin/worktree.c +++ b/builtin/worktree.c @@ -416,7 +416,6 @@ static int add_worktree(const char *path, const char *refname, struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT; struct strbuf sb = STRBUF_INIT, realpath = STRBUF_INIT; const char *name; - struct child_process cp = CHILD_PROCESS_INIT; struct strvec child_env = STRVEC_INIT; unsigned int counter = 0; int len, ret; @@ -424,7 +423,8 @@ static int add_worktree(const char *path, const char *refname, struct commit *commit = NULL; int is_branch = 0; struct strbuf sb_name = STRBUF_INIT; - struct worktree **worktrees; + struct worktree **worktrees, *wt = NULL; + struct ref_store *wt_refs; worktrees = get_worktrees(); check_candidate_path(path, opts->force, worktrees, "add"); @@ -500,15 +500,26 @@ static int add_worktree(const char *path, const char *refname, write_file(sb.buf, "../.."); /* - * This is to keep resolve_ref() happy. We need a valid HEAD - * or is_git_directory() will reject the directory. Any value which - * looks like an object ID will do since it will be immediately - * replaced by the symbolic-ref or update-ref invocation in the new - * worktree. + * Set up the ref store of the worktree and create the HEAD reference. */ - strbuf_reset(&sb); - strbuf_addf(&sb, "%s/HEAD", sb_repo.buf); - write_file(sb.buf, "%s", oid_to_hex(null_oid())); + wt = get_linked_worktree(name, 1); + if (!wt) { + ret = error(_("could not find created worktree '%s'"), name); + goto done; + } + wt_refs = get_worktree_ref_store(wt); + + ret = refs_init_db(wt_refs, REFS_INIT_DB_IS_WORKTREE, &sb); + if (ret) + goto done; + + if (!is_branch && commit) + ret = refs_update_ref(wt_refs, NULL, "HEAD", &commit->object.oid, + NULL, 0, UPDATE_REFS_MSG_ON_ERR); + else + ret = refs_create_symref(wt_refs, "HEAD", symref.buf, NULL); + if (ret) + goto done; /* * If the current worktree has sparse-checkout enabled, then copy @@ -527,22 +538,6 @@ static int add_worktree(const char *path, const char *refname, strvec_pushf(&child_env, "%s=%s", GIT_DIR_ENVIRONMENT, sb_git.buf); strvec_pushf(&child_env, "%s=%s", GIT_WORK_TREE_ENVIRONMENT, path); - cp.git_cmd = 1; - - if (!is_branch && commit) { - strvec_pushl(&cp.args, "update-ref", "HEAD", - oid_to_hex(&commit->object.oid), NULL); - } else { - strvec_pushl(&cp.args, "symbolic-ref", "HEAD", - symref.buf, NULL); - if (opts->quiet) - strvec_push(&cp.args, "--quiet"); - } - - strvec_pushv(&cp.env, child_env.v); - ret = run_command(&cp); - if (ret) - goto done; if (opts->orphan && (ret = make_worktree_orphan(refname, opts, &child_env))) @@ -588,6 +583,7 @@ done: strbuf_release(&sb_git); strbuf_release(&sb_name); strbuf_release(&realpath); + free_worktree(wt); return ret; }