From: Eric Wong <e@80x24.org>
To: Lars Schneider <larsxschneider@gmail.com>
Cc: Git Mailing List <git@vger.kernel.org>,
gitster@pobox.com, tboegi@web.de, Johannes.Schindelin@gmx.de
Subject: Re: [PATCH v1 2/2] read-cache: make sure file handles are not inherited by child processes
Date: Wed, 7 Sep 2016 18:10:36 +0000 [thread overview]
Message-ID: <20160907181036.GA14931@starla> (raw)
In-Reply-To: <7B903664-0324-4375-A81C-1317020CBE9B@gmail.com>
Lars Schneider <larsxschneider@gmail.com> wrote:
> > On 06 Sep 2016, at 23:06, Eric Wong <e@80x24.org> wrote:
> > larsxschneider@gmail.com wrote:
> >> static int ce_compare_data(const struct cache_entry *ce, struct stat *st)
> >> {
> >> int match = -1;
> >> - int fd = open(ce->name, O_RDONLY);
> >> + int fd = open(ce->name, O_RDONLY | O_CLOEXEC);
> >>
> >> if (fd >= 0) {
> >> unsigned char sha1[20];
> >
> > Also, this needs to check EINVAL when O_CLOEXEC != 0 the same
> > way create_tempfile currently does. Somebody could be building
> > with modern headers but running an old kernel that doesn't
> > understand O_CLOEXEC.
> >
> > There should probably be a open() wrapper for handling this case
> > since we're now up to 3 places where open(... O_CLOEXEC) is
> > used.
>
> Right! Actually "sha1_file.c:git_open_noatime()" is already a wrapper, no?
> Can't we use this here? The O_NOATIME flag shouldn't hurt, right?
For ce_compare_data (and other O_RDONLY users), I guess
git_open_noatime is fine; and probably preferable because of
O_NOATIME.
We probably should be using O_NOATIME for all O_RDONLY cases
to get the last bit of performance out (especially since
non-modern-Linux systems probably still lack relatime).
However, create_tempfile needs O_RDWR|O_CREAT|O_EXCL
but I guess we can clean that up in another series.
next prev parent reply other threads:[~2016-09-07 18:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-05 21:11 [PATCH v1 0/2] Use CLOEXEC to avoid fd leaks larsxschneider
2016-09-05 21:11 ` [PATCH v1 1/2] sha1_file: open window into packfiles with CLOEXEC larsxschneider
2016-09-05 22:27 ` Eric Wong
2016-09-06 9:36 ` Jakub Narębski
2016-09-06 11:38 ` Johannes Schindelin
2016-09-07 13:20 ` Lars Schneider
2016-09-07 18:17 ` Eric Wong
2016-09-05 21:11 ` [PATCH v1 2/2] read-cache: make sure file handles are not inherited by child processes larsxschneider
2016-09-06 11:41 ` Johannes Schindelin
2016-09-06 21:06 ` Eric Wong
2016-09-07 13:39 ` Lars Schneider
2016-09-07 18:10 ` Eric Wong [this message]
2016-09-07 18:23 ` Junio C Hamano
2016-09-08 5:57 ` Lars Schneider
2016-09-08 17:37 ` Junio C Hamano
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