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From: Jeff King <peff@peff•net>
To: Taylor Blau <me@ttaylorr•com>
Cc: Paulo Casaretto via GitGitGadget <gitgitgadget@gmail•com>,
	git@vger•kernel.org, Paulo Casaretto <pcasaretto@gmail•com>
Subject: Re: [PATCH] lockfile: add PID file for debugging stale locks
Date: Fri, 5 Dec 2025 13:46:48 -0500	[thread overview]
Message-ID: <20251205184648.GC33447@coredump.intra.peff.net> (raw)
In-Reply-To: <aTDFks3RW57Ytwvq@nand.local>

On Wed, Dec 03, 2025 at 06:19:46PM -0500, Taylor Blau wrote:

> Changing the naming scheme as above would cause us to hold
> "foo.pid.lock" in addition to "foo.lock". That would allow process B
> here to write branch "foo.lock.pid" (as is the case today). But if the
> scenario were instead "process B wants to write branch foo.pid.lock", it
> would fail immediately since the ".lock" suffix is reserved.

I agree that this gets rid of any corruption or race issues, since all
versions understand how to handle ".lock" specially (and assuming we
create foo.pid.lock with O_EXCL). But there is still a namespace
collision; I cannot write refs "foo" and "foo.pid" at the same time.

> > So I dunno what that means for your patch. I notice that the user has to
> > enable the feature manually. But it feels more like it should be
> > selective based on which subsystem is using the lockfile (so refs would
> > never want it, but other lockfiles/tempfiles might).
> 
> Yeah, I think that something similar to the "which files do we fsync()
> and how?" configuration we have today would be a nice complement here.

I'm not sure it makes sense for the user to configure this. I more meant
that the ref files-backend code would set a flag for "no, do not create
a pid file for me ever" (or inversely, other bits of the code would
add a flag for "yes, it's OK to do so").

-Peff

  parent reply	other threads:[~2025-12-05 18:46 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-02 15:07 [PATCH] lockfile: add PID file for debugging stale locks Paulo Casaretto via GitGitGadget
2025-12-02 22:29 ` D. Ben Knoble
2025-12-03 19:48 ` Torsten Bögershausen
2025-12-03 21:16 ` Jeff King
2025-12-03 22:21   ` Junio C Hamano
2025-12-03 22:32     ` Jeff King
2025-12-03 23:19   ` Taylor Blau
2025-12-05 11:03     ` Patrick Steinhardt
2025-12-05 18:46     ` Jeff King [this message]
2025-12-03 23:39 ` Taylor Blau
2025-12-17 18:59 ` [PATCH v2] " Paulo Casaretto via GitGitGadget
2025-12-18  0:32   ` Junio C Hamano
2025-12-18  0:47   ` Junio C Hamano
2025-12-18  1:33     ` Junio C Hamano
2025-12-18  3:38   ` Ben Knoble
2025-12-18  8:07   ` Patrick Steinhardt
2025-12-24 12:24   ` [PATCH v3] " Paulo Casaretto via GitGitGadget
2025-12-25  0:01     ` Junio C Hamano
2025-12-27  7:50     ` Jeff King
2026-01-05 12:23       ` Patrick Steinhardt
2026-01-07 16:45     ` [PATCH v4] " Paulo Casaretto via GitGitGadget
2026-01-08  1:59       ` Junio C Hamano
2026-01-08 14:19         ` D. Ben Knoble
2026-01-20 18:32       ` [PATCH v5] " Paulo Casaretto via GitGitGadget
2026-01-20 20:02         ` Junio C Hamano
2026-01-21  7:13         ` Jeff King
2026-01-21  8:13           ` Eric Sunshine
2026-01-21 10:14             ` Johannes Sixt
2026-01-21 16:39             ` Jeff King
2026-01-21 18:55               ` Junio C Hamano
2026-01-21 19:53                 ` Jeff King
2026-01-21 16:23           ` Junio C Hamano
2026-01-22 19:23         ` [PATCH v6] " Paulo Casaretto via GitGitGadget
2026-01-22 20:17           ` Junio C Hamano
2026-02-06 16:27           ` Patrick Steinhardt
2026-02-06 19:31             ` Junio C Hamano

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