From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.7 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 363D41F9E5 for ; Fri, 23 Apr 2021 15:31:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242689AbhDWPc2 (ORCPT ); Fri, 23 Apr 2021 11:32:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231748AbhDWPc1 (ORCPT ); Fri, 23 Apr 2021 11:32:27 -0400 Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 303BBC061574 for ; Fri, 23 Apr 2021 08:31:51 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id y5-20020a05600c3645b0290132b13aaa3bso1452415wmq.1 for ; Fri, 23 Apr 2021 08:31:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=53/5RIkW7qI9pjwI746C+8SQCpV4VoLRFI66jslH+E0=; b=ikd/LxAGZbQ+HnSsHqfkLFUAbr29KIy6GbX/VX3v3Ncst7yhujehyvloBfDJIVtWB4 9ZXw+4ig8P8cr2nGzu2um9uoWX4Fc6u1n2rYd8ruO/ewDJXQgL4PPxdWucRVuzJYZmx/ C/LDIgqHlnhreawgBjWNjCvr+NxHLaZ5c0hYA41HVBZzU4lZv8W+aWCtC0ufZLAA2n6S iuR06bHbPgp2rjWoPB1BbSd0CVZqh9LzYYrqg0ACbpj1A5wG6tGQpym9WutWsqMp0Jep ai6Wp89BDykJ9i40MChuqOZaf5fR3eKIvjUq+MkLrOa6GpuAe/xGq8ht9WI3FMqR3Jhr XLFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=53/5RIkW7qI9pjwI746C+8SQCpV4VoLRFI66jslH+E0=; b=ToOx2wB7GrjHaOwPM5tgRCzv6kEsPMxqFFImuMZ0cQKjyywmolrgpYjdJRPcCZwLUL b2H0m6ogT54O9JDj4MRIVMAVVCDi+LlShf5e8dfpZzQP5Duvq3x+v99tgc1UbIHdp5eP A8cM7TA4wRh0ZD5rmY/DcKa8BCFCWA4+P3UdR6jWvA+EWhFjM2ZfOtbwIZHxLK2si96I wyCaDXmsJM0M3RUf6V+dgeMaBoNuIiQz4Rfyp4lkkzKbd92eYyz5P50IHYcMJhJEhcQa e1Zs5UXH7lMifMe3WoaXN0384PdphwnvuPVusuDHa+7wOTKg1F6r0teLICuOSFiBanDK 6Hrw== X-Gm-Message-State: AOAM532dre31MAzRMkHv7svesGA94QPI2pi+ucRlV5bLJTa33wn6o15N kM0PALiUSFxbwfcQjVPVL8Y+RJO97Q0= X-Google-Smtp-Source: ABdhPJyge7FVLy8ExniKaIZgLZQSdwHcLl2kXD6eH93ZnpEkQ4neUO4tl9dKvdlkmGpnHlst8H9pag== X-Received: by 2002:a05:600c:3545:: with SMTP id i5mr4714886wmq.121.1619191909819; Fri, 23 Apr 2021 08:31:49 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id t17sm7903054wmq.12.2021.04.23.08.31.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Apr 2021 08:31:49 -0700 (PDT) Message-Id: In-Reply-To: References: From: "Han-Wen Nienhuys via GitGitGadget" Date: Fri, 23 Apr 2021 15:31:46 +0000 Subject: [PATCH v2 2/3] refs/files-backend: stop setting errno from lock_ref_oid_basic Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Han-Wen Nienhuys , Han-Wen Nienhuys , Han-Wen Nienhuys Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Han-Wen Nienhuys 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 --- 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