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Date: Sun, 29 Jan 2012 00:37:12 +0100
From: Jilles Tjoelker <jilles@stack.nl>
To: Giovanni Trematerra <gianni@freebsd.org>
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Cc: Attilio Rao <attilio@freebsd.org>, flo@freebsd.org,
	Konstantin Belousov <kib@freebsd.org>, freebsd-arch@freebsd.org
Subject: Re: pipe/fifo code merged.
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On Tue, Jan 17, 2012 at 12:43:19PM +0100, Giovanni Trematerra wrote:
> Did you agree that this patch
> http://www.trematerra.net/patches/pipefifo_merge2.4.diff

> doesn't introduce any further regressions while it fixes

> - style bugs you pointed out.
> - pipe_stat now use underlying filesystem information for pipes.
> - comment about pipeinfo was intended for.
> - race into pipe_poll (look at fifo_iseof line).

I tested this version of the patch and found that it breaks opening a
fifo with O_TRUNC: it fails with [EINVAL]. This appears to be
pipe_truncate()'s doing. Previously, truncate requests went to the
vnode.

In particular, this happens when opening a fifo for writing using
sh(1)'s > (unless 'set -C' is in effect) or >| redirection operators.
The open properly blocks until a reader arrives but then fails with
[EINVAL]. Several tests in tools/regression/bin/sh do this.

-- 
Jilles Tjoelker