From: Han-Wen Nienhuys <hanwen@google.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Han-Wen Nienhuys via GitGitGadget <gitgitgadget@gmail.com>,
git <git@vger.kernel.org>, Han-Wen Nienhuys <hanwenn@gmail.com>
Subject: Re: [PATCH v2 2/3] refs/files-backend: stop setting errno from lock_ref_oid_basic
Date: Wed, 28 Apr 2021 12:55:07 +0200 [thread overview]
Message-ID: <CAFQ2z_O=4sUjh1wk6nRijp9Gz2eeqX4=EY+Q-OTi9ppb9ikg3g@mail.gmail.com> (raw)
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.
--
Han-Wen Nienhuys - Google Munich
I work 80%. Don't expect answers from me on Fridays.
--
Google Germany GmbH, Erika-Mann-Strasse 33, 80636 Munich
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
next prev parent reply other threads:[~2021-04-28 10:55 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 ` [PATCH v2 2/3] refs/files-backend: stop setting errno from lock_ref_oid_basic Han-Wen Nienhuys via GitGitGadget
2021-04-28 4:20 ` Junio C Hamano
2021-04-28 10:55 ` Han-Wen Nienhuys [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAFQ2z_O=4sUjh1wk6nRijp9Gz2eeqX4=EY+Q-OTi9ppb9ikg3g@mail.gmail.com' \
--to=hanwen@google.com \
--cc=git@vger.kernel.org \
--cc=gitgitgadget@gmail.com \
--cc=gitster@pobox.com \
--cc=hanwenn@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).