From: Han-Wen Nienhuys <hanwen@google.com>
Date: Wed, 28 Apr 2021 10:55:07 GMT
Subject: Re: [PATCH v2 2/3] refs/files-backend: stop setting errno from lock_ref_oid_basic
Message-ID: <CAFQ2z_O=4sUjh1wk6nRijp9Gz2eeqX4=EY+Q-OTi9ppb9ikg3g@mail.gmail.com>
In-Reply-To: <xmqqzgxjavks.fsf@gitster.g>

On Wed, Apr 28, 2021 at 6:20 AM Junio C Hamano <gitster@pobox.com> wrote:
> > These calls do I/O and therefore clobber errno. They are not inspecting the
> > incoming errno.
>
> Hmph, are you saying that these calls do I/O and always the I/O
> would fail?  A system call that is successfull don't touch errno;
> only the calls that resulted in failure do.

I'm saying that callers cannot reliably observe the errno result of
lock_ref_oid_basic, because it might be clobbered by a failing
follow-up call.

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Han-Wen Nienhuys - Google Munich
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