[PATCH v9 3/7] refs/files-backend: stop setting errno from lock_ref_oid_basic
From: Ævar Arnfjörð Bjarmason <hidden>
Date: 2021-07-20 10:35:12
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Han-Wen Nienhuys <redacted> refs/files-backend.c::lock_ref_oid_basic() tries to signal how it failed to its callers using errno. It is safe to stop setting errno here, because the callers of this file-scope static function are * files_copy_or_rename_ref() * files_create_symref() * files_reflog_expire() None of them looks at errno after seeing a negative return from lock_ref_oid_basic() to make any decision, and no caller of these three functions looks at errno after they signal a failure by returning a negative value. In particular, * files_copy_or_rename_ref() - here, calls are followed by error() (which performs I/O) or write_ref_to_lockfile() (which calls parse_object() which may perform I/O) * files_create_symref() - here, calls are followed by error() or create_symref_locked() (which performs I/O and does not inspect errno) * files_reflog_expire() - here, calls are followed by error() or refs_reflog_exists() (which calls a function in a vtable that is not documented to use and/or preserve errno) Signed-off-by: Han-Wen Nienhuys <redacted> Signed-off-by: Ævar Arnfjörð Bjarmason <redacted> --- refs/files-backend.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 9fc596fc75a..9e00da76121 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c@@ -982,7 +982,6 @@ static int create_reflock(const char *path, void *cb) /* * 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,
@@ -991,7 +990,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, { struct strbuf ref_file = STRBUF_INIT; struct ref_lock *lock; - int last_errno = 0; files_assert_main_repository(refs, "lock_ref_oid_basic"); assert(err);
@@ -1002,11 +1000,10 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, if (!refs_resolve_ref_unsafe(&refs->base, refname, RESOLVE_REF_NO_RECURSE, &lock->old_oid, type)) { - last_errno = errno; if (!refs_verify_refname_available(&refs->base, refname, NULL, NULL, err)) strbuf_addf(err, "unable to resolve reference '%s': %s", - refname, strerror(last_errno)); + refname, strerror(errno)); goto error_return; }
@@ -1019,15 +1016,12 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, */ if (is_null_oid(&lock->old_oid) && refs_verify_refname_available(refs->packed_ref_store, refname, - NULL, NULL, err)) { - last_errno = ENOTDIR; + NULL, NULL, err)) 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; }
@@ -1044,7 +1038,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, out: strbuf_release(&ref_file); - errno = last_errno; return lock; }
--
2.32.0.874.ge7a9d58bfcf