[PATCH v3 02/12] worktree: skip reading HEAD when repairing worktrees
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Dec 29, 2023, 07:26 UTC
- Message-ID
- <77c7213c66d6b5caf2c24e17578d3e42f7b745a7.1703833819.git.ps@pks.im>
- In-Reply-To
- <cover.1703833818.git.ps@pks.im>
When calling `git init --separate-git-dir=<new-path>` on a preexisting repository, we move the Git directory of that repository to the new path specified by the user. If there are worktrees present in the repository, we need to repair the worktrees so that their gitlinks point to the new location of the repository.
This repair logic will load repositories via `get_worktrees()`, which will enumerate up and initialize all worktrees. Part of initialization is logic that we resolve their respective worktree HEADs, even though that information may not actually be needed in the end by all callers.
Although not a problem presently with the file-based reference backend, it will become a problem with the upcoming reftable backend. In the context of git-init(1) we do not have a fully-initialized repository set up via `setup_git_directory()` or friends. Consequently, we do not know about the repository format when `repair_worktrees()` is called, and properly setting up all parts of the repositroy in `init_db()` before we try to repair worktrees is not an easy task. With the introduction of the reftable backend, we would ultimately try to look up the worktree HEADs before we have figured out the reference format, which does not work.
We do not require the worktree HEADs at all to repair worktrees. So let's fix this issue by skipping over the step that reads them.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- worktree.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/worktree.c b/worktree.c index a56a6c2a3d..cc34a3419b 100644 --- a/worktree.c +++ b/worktree.c @@ -51,7 +51,7 @@ static void add_head_info(struct worktree *wt) /** * get the main worktree */ -static struct worktree *get_main_worktree(void) +static struct worktree *get_main_worktree(int skip_reading_head) { struct worktree *worktree = NULL; struct strbuf worktree_path = STRBUF_INIT; @@ -70,11 +70,13 @@ static struct worktree *get_main_worktree(void) */ worktree->is_bare = (is_bare_repository_cfg == 1) || is_bare_repository(); - add_head_info(worktree); + if (!skip_reading_head) + add_head_info(worktree); return worktree; } -static struct worktree *get_linked_worktree(const char *id) +static struct worktree *get_linked_worktree(const char *id, + int skip_reading_head) { struct worktree *worktree = NULL; struct strbuf path = STRBUF_INIT; @@ -93,7 +95,8 @@ static struct worktree *get_linked_worktree(const char *id) CALLOC_ARRAY(worktree, 1); worktree->path = strbuf_detach(&worktree_path, NULL); worktree->id = xstrdup(id); - add_head_info(worktree); + if (!skip_reading_head) + add_head_info(worktree); done: strbuf_release(&path); @@ -118,7 +121,14 @@ static void mark_current_worktree(struct worktree **worktrees) free(git_dir); } -struct worktree **get_worktrees(void) +/* + * NEEDSWORK: This function exists so that we can look up metadata of a + * worktree without trying to access any of its internals like the refdb. It + * would be preferable to instead have a corruption-tolerant function for + * retrieving worktree metadata that could be used when the worktree is known + * to not be in a healthy state, e.g. when creating or repairing it. + */ +static struct worktree **get_worktrees_internal(int skip_reading_head) { struct worktree **list = NULL; struct strbuf path = STRBUF_INIT; @@ -128,7 +138,7 @@ struct worktree **get_worktrees(void) ALLOC_ARRAY(list, alloc); - list[counter++] = get_main_worktree(); + list[counter++] = get_main_worktree(skip_reading_head); strbuf_addf(&path, "%s/worktrees", get_git_common_dir()); dir = opendir(path.buf); @@ -137,7 +147,7 @@ struct worktree **get_worktrees(void) while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) { struct worktree *linked = NULL; - if ((linked = get_linked_worktree(d->d_name))) { + if ((linked = get_linked_worktree(d->d_name, skip_reading_head))) { ALLOC_GROW(list, counter + 1, alloc); list[counter++] = linked; } @@ -151,6 +161,11 @@ struct worktree **get_worktrees(void) return list; } +struct worktree **get_worktrees(void) +{ + return get_worktrees_internal(0); +} + const char *get_worktree_git_dir(const struct worktree *wt) { if (!wt) @@ -591,7 +606,7 @@ static void repair_noop(int iserr UNUSED, void repair_worktrees(worktree_repair_fn fn, void *cb_data) { - struct worktree **worktrees = get_worktrees(); + struct worktree **worktrees = get_worktrees_internal(1); struct worktree **wt = worktrees + 1; /* +1 skips main worktree */ if (!fn)
-- 2.43.GIT