From: "Han-Wen Nienhuys via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: Han-Wen Nienhuys <hanwen@google.com>,
Han-Wen Nienhuys <hanwenn@gmail.com>,
Han-Wen Nienhuys <hanwen@google.com>
Subject: [PATCH v2 2/3] refs/files-backend: stop setting errno from lock_ref_oid_basic
Date: Fri, 23 Apr 2021 15:31:46 +0000 [thread overview]
Message-ID: <db5da7d7fb5178c14c1f5733d35bb69813c9c644.1619191907.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.1011.v2.git.git.1619191907.gitgitgadget@gmail.com>
From: Han-Wen Nienhuys <hanwen@google.com>
Errno is a global variable written by almost all system calls, and therefore it
is hard to reason about its state.
This is a functional noop, because calls to lock_ref_oid_basic() in this file
are followed by:
* lock_ref_oid_basic (copy/rename rollback error path)
* write_ref_to_lockfile (both in the rollback path and the success path of
copy/rename)
* create_symref_locked (files_create_symref)
* refs_reflog_exists (reflog expiry)
These calls do I/O and therefore clobber errno. They are not inspecting the
incoming errno.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
---
refs/files-backend.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 119972ee16f8..c9511da1d387 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -910,7 +910,6 @@ 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,
@@ -922,7 +921,6 @@ 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;
int mustexist = (old_oid && !is_null_oid(old_oid));
int resolve_flags = RESOLVE_REF_NO_RECURSE;
int resolved;
@@ -949,7 +947,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
* to remain.
*/
if (remove_empty_directories(&ref_file)) {
- last_errno = errno;
if (!refs_verify_refname_available(
&refs->base,
refname, extras, skip, err))
@@ -962,7 +959,7 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
&lock->old_oid, type);
}
if (!resolved) {
- last_errno = errno;
+ int last_errno = errno;
if (last_errno != ENOTDIR ||
!refs_verify_refname_available(&refs->base, refname,
extras, skip, err))
@@ -981,20 +978,17 @@ 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,
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;
@@ -1005,7 +999,6 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
out:
strbuf_release(&ref_file);
- errno = last_errno;
return lock;
}
--
gitgitgadget
next prev parent reply other threads:[~2021-04-23 15:31 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 10:24 [PATCH] refs: remove EINVAL specification from the errno sideband in read_raw_ref_fn Han-Wen Nienhuys via GitGitGadget
2021-04-23 12:57 ` Jeff King
2021-04-23 15:25 ` Han-Wen Nienhuys
2021-04-23 15:31 ` [PATCH v2 0/3] refs: cleanup errno sideband ref related functions Han-Wen Nienhuys via GitGitGadget
2021-04-23 15:31 ` [PATCH v2 1/3] refs: remove EINVAL specification from the errno sideband in read_raw_ref_fn Han-Wen Nienhuys via GitGitGadget
2021-04-23 15:31 ` Han-Wen Nienhuys via GitGitGadget [this message]
2021-04-28 4:20 ` [PATCH v2 2/3] refs/files-backend: stop setting errno from lock_ref_oid_basic Junio C Hamano
2021-04-28 10:55 ` Han-Wen Nienhuys
2021-04-29 1:55 ` Junio C Hamano
2021-04-29 8:52 ` Han-Wen Nienhuys
2021-04-23 15:31 ` [PATCH v2 3/3] refs: make errno output explicit for read_raw_ref_fn Han-Wen Nienhuys via GitGitGadget
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