Re: [ANNOUNCE] Git v2.32.0-rc3 - t5300 Still Broken on NonStop ia64/x86

From: Taylor Blau <me@ttaylorr.com>
Date: Jun 4, 2021, 02:17 UTC
Message-ID: <YLmNHpf+dXdK7OeH@nand.local>
In-Reply-To: <xmqqk0na2yyc.fsf@gitster.g>

On Fri, Jun 04, 2021 at 10:36:11AM +0900, Junio C Hamano wrote:

Show 21 quoted lines

> Jeff King <peff@peff.net> writes:
>
> > This looks as I'd expect. But after seeing Eric's response, we perhaps
> > want to do away with the knob entirely.
>
> Thanks.  I was hoping somebody in the thread would tie the loose
> ends, but upon inspection of the output from
>
>     $ git grep -e fsync\( maint seen -- \*.[ch]
>
> it turns out that fsync_or_die() is the only place that calls
> fsync(), so perhaps doing it in a way that is quite different from
> what has been discussed may be even a better alternative.
>
> If any new callers care about the return value of fsync(), I'd
> expect that they would be calling this wrapper, and the "best
> effort" callers that do not check the returned value by definition
> do not care if fsync() does not complete due to an interrupt, so I
> am hoping that the current "we only call it from this wrapper" is
> not just "the code currently happens to be this way", but it is
> sensible that the code will stay that way in the future.

That makes total sense to me; I can't imagine a scenario where you would want to call fsync() over fsync_or_die(). But if you did, then you probably don't care about whether or not fsync() was interrupted, or can check the return value yourself.

If it became more common, then I wouldn't mind #undef-ing fsync() and replacing it with our own hacked up version.

> Obviously I appreciate reviews and possibly tests, but sanity
> checking my observation that fsync() is called only from here is a
> good thing to have.

Your patch looks good to me (and Randall already tested my version with the additional knob on NonStop and reported it working as expected[1]), so this has my:

  Reviewed-by: Taylor Blau <me@ttaylorr.com>

Thanks, Taylor

[1]: https://lore.kernel.org/git/009901d758b4$12016d80$36044880$@nexbridge.com/