From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4A0DC07E96 for ; Sun, 11 Jul 2021 11:48:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93954611F2 for ; Sun, 11 Jul 2021 11:48:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232679AbhGKLvX (ORCPT ); Sun, 11 Jul 2021 07:51:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229688AbhGKLvX (ORCPT ); Sun, 11 Jul 2021 07:51:23 -0400 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D941C0613DD for ; Sun, 11 Jul 2021 04:48:35 -0700 (PDT) Received: by mail-ej1-x62b.google.com with SMTP id i20so27376517ejw.4 for ; Sun, 11 Jul 2021 04:48:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:references:user-agent:in-reply-to :message-id:mime-version; bh=qFGDQkNV7xYlkZEzwRtEW7tTZiI7wEQqjlmi10cJmqE=; b=W0ZY6djttKc2FwZ1qjL9zeumBIj0TLvDHtw/gJaB5WRcUtruLQ+qg1Grl4Muo5R/5t L1H7q/LjMEtQjlOGLtfZiv3NCV0L2Mob8O4dsbgM0X7AsiZ5KHwdfB8bk+7lGazOeitk JLTOZ5NW+dP2hKpUEZunuNVOuGRzK8iCB4NqGV16tZVT9CCogfVt70+V/qa1DRnoJj6g YawmtuV+vkS82fO7rkh+TomOI53NPCaZFd7p8kfJ4dFkI3kC+XtUL/Inj0g/WZ7mqQCk 3V4iSgb4OUMKGTFYYO2QTN23Aa9U05KoXLo1RRv+q31J5aYIhpoQfYScKPrh9+TjI9md s7tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:references:user-agent :in-reply-to:message-id:mime-version; bh=qFGDQkNV7xYlkZEzwRtEW7tTZiI7wEQqjlmi10cJmqE=; b=U9xJ0gmbnf7QmFDYwbZyP/RetO+M8Fd2C4tc6UUqzTkyRSwOOhfR0GPWGby0gSu0aP ABM/ReoCZg06971Osu++DOgfbSGH5uDxbwRHJWUZ7UM5p78Rwwq6A81JjkUSCfsKeYM9 brl+MgCEIJmBPMcHuAvhKFboQkoLuxvymsPBownQmGA1bPJjxyOvq7sJSMWS/by8tiv1 2857MnE8KAM4Stgsb2Qn9aDm4RoQVAv3/4iDk1T5qaujJG2pReTmagtt2/gdWd5tJ9S4 HDfg4TBIMHeTCtcD72YE1lgmloTagNPpBnx19OldT2esIM1CrCBsPeuhRe3Lo1P8/l/z 7+Yg== X-Gm-Message-State: AOAM532CSyJYtg316MTKEAsVWzrcx+OeEQUxO+GyNu47CiM2NlnkQ6De iwkhic5HrbUs3jmazY0vyHgjqAqrYPiB9g== X-Google-Smtp-Source: ABdhPJxtQjZ5Y+DOenkJlvcOxDwNNZx9kQD04KYNxqkEXkk8sVOTJwKKS3UY3MaMrb7dMEZg5+TBLw== X-Received: by 2002:a17:906:c34b:: with SMTP id ci11mr22067200ejb.223.1626004113828; Sun, 11 Jul 2021 04:48:33 -0700 (PDT) Received: from evledraar (j57224.upc-j.chello.nl. [24.132.57.224]) by smtp.gmail.com with ESMTPSA id u26sm4878826ejx.8.2021.07.11.04.48.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Jul 2021 04:48:33 -0700 (PDT) From: =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason To: Han-Wen Nienhuys via GitGitGadget Cc: git@vger.kernel.org, Jonathan Tan , Han-Wen Nienhuys , Han-Wen Nienhuys Subject: Re: [PATCH v5 2/6] refs/files-backend: stop setting errno from lock_ref_oid_basic Date: Sun, 11 Jul 2021 13:38:48 +0200 References: <95025080c16f535599826ed4f013845d712b0e8d.1625684869.git.gitgitgadget@gmail.com> User-agent: Debian GNU/Linux 11 (bullseye); Emacs 27.1; mu4e 1.5.13 In-reply-to: <95025080c16f535599826ed4f013845d712b0e8d.1625684869.git.gitgitgadget@gmail.com> Message-ID: <87lf6d3wbz.fsf@evledraar.gmail.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Jul 07 2021, Han-Wen Nienhuys via GitGitGadget wrote: > /* > * 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)) > @@ -962,10 +959,13 @@ 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)) > + /* in case of D/F conflict, try to generate a better error > + * message. If that fails, fall back to strerror(ENOTDIR). > + */ > + !refs_verify_refname_available(&refs->base, refname, extras, > + skip, err)) > strbuf_addf(err, "unable to resolve reference '%s': %s", > refname, strerror(last_errno)); I don't think it's some dealbreaker and we can move on, but just FWIW I think what I mentioned ending in your https://lore.kernel.org/git/CAFQ2z_NpyJQLuM70MhJ8K1h2v3QXFuAZRjN=SvSsjnukNRJ8pw@mail.gmail.com/ is still outstanding. I.e. you added the comment, which is just says what the error emitting looks like, that's all well & good. But what I was pointing out that it didn't make sense to do any "last_errno" here at all anymore. You pointed to 5b2d8d6f218 (lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts, 2015-05-11), we started setting "last_errno" there, but that was *not* to avoid clobbering between the !resolved and the strbuf_add(strerror(last_errno)) here, but rather to carry the "last_errno" forward to the end of this lock_ref_oid_basic(), because other things (after this hunk) might reset/clear errno. Anyway, as noted there it doesn't actually matter, just reviewing & looking if there's any loose ends, and for future source spelunking for anyone reading this thread. I.e. something like what I mentioned in https://lore.kernel.org/git/87k0mae0ga.fsf@evledraar.gmail.com/ could be squashed in, or better yet (probably) this: diff --git a/refs/files-backend.c b/refs/files-backend.c index 83ddfb3b627..f0ce0aac857 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -958,17 +958,15 @@ static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, refname, resolve_flags, &lock->old_oid, type); } - if (!resolved) { - int last_errno = errno; - if (last_errno != ENOTDIR || - /* in case of D/F conflict, try to generate a better error - * message. If that fails, fall back to strerror(ENOTDIR). - */ - !refs_verify_refname_available(&refs->base, refname, extras, - skip, err)) - strbuf_addf(err, "unable to resolve reference '%s': %s", - refname, strerror(last_errno)); - + if (!resolved && + (errno != ENOTDIR || + /* in case of D/F conflict, try to generate a better error + * message. If that fails, fall back to strerror(ENOTDIR). + */ + !refs_verify_refname_available(&refs->base, refname, extras, + skip, err))) { + strbuf_addf(err, "unable to resolve reference '%s': %s", + refname, strerror(errno)); goto error_return; }