From: Andrew Morton <akpm@osdl.org>
To: Valdis.Kletnieks@vt.edu
Cc: jcwren@jcwren.com, linux-kernel@vger.kernel.org
Subject: Re: Bug in open() function (?)
Date: Fri, 11 Jul 2003 22:23:00 -0700 [thread overview]
Message-ID: <20030711222300.7627a811.akpm@osdl.org> (raw)
In-Reply-To: <200307120511.h6C5BCSe017963@turing-police.cc.vt.edu>
Valdis.Kletnieks@vt.edu wrote:
>
> On Fri, 11 Jul 2003 20:38:09 PDT, Andrew Morton said:
> > "J.C. Wren" <jcwren@jcwren.com> wrote:
> > >
> > > I was playing around today and found that if an existing file is opened wit
> h
> > > O_TRUNC | O_RDONLY, the existing file is truncated.
> >
> > Well that's fairly idiotic, isn't it?
>
> Not idiotic at all
Sigh. I meant the kernel behaviour is idiotic. Returning -EINVAL would
have been much better behaviour.
>
> > The Open Group go on to say "The result of using O_TRUNC with O_RDONLY is
> > undefined" which is also rather silly.
> >
> > I'd be inclined to leave it as-is, really.
>
> I hate to think how many programmers are relying on the *documented* behavior to
> prevent data loss during debugging/test runs....
We've lived with it for this long.
The behaviour is "undefined". Any application which uses O_RDONLY|O_TRUNC
is buggy.
If we were to alter the behaviour now, any buggy-but-happens-to-work app
which is accidentally using O_RDONLY|O_TRUNC may break. And now is not the
time to break things.
Given that the behaviour is undefined, the behaviour which we should
implement is clearly "whatever 2.4 is doing". So let's leave it alone.
next prev parent reply other threads:[~2003-07-12 5:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-12 1:17 [PATCH] [2.5] adding ppp xon/xoff support Samuel Thibault
2003-07-12 1:30 ` Paul Mackerras
2003-07-12 2:42 ` Samuel Thibault
2003-07-12 3:09 ` Bug in open() function (?) J.C. Wren
2003-07-12 3:38 ` Andrew Morton
2003-07-12 5:11 ` Valdis.Kletnieks
2003-07-12 5:23 ` Andrew Morton [this message]
2003-07-12 6:14 ` Valdis.Kletnieks
2003-07-12 9:37 ` Andries Brouwer
2003-07-12 12:04 ` jw schultz
2003-07-12 5:39 ` J.C. Wren
2003-07-26 21:35 ` [PATCH] [2.6] adding xon/xoff support to ppp Samuel Thibault
2003-07-17 7:54 Bug in open() function (?) Michael Kerrisk
2003-07-17 10:54 ` Andries Brouwer
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