From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@lst.de>
Subject: Re: Filesystem setattr/truncate notes and problems
Date: Thu, 3 Jun 2010 09:32:38 +0200
Message-ID: <20100603073238.GA3866@lst.de>
References: <20100601133923.GT9453@laptop> <20100601134801.GA11061@lst.de> <20100601135655.GU9453@laptop> <20100602195538.GG6152@laptop> <20100602200855.GH6152@laptop> <20100603072812.GA3346@lst.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Christoph Hellwig <hch@lst.de>, Al Viro <viro@ZenIV.linux.org.uk>,
	linux-fsdevel@vger.kernel.org, Miklos Szeredi <miklos@szeredi.hu>
To: Nick Piggin <npiggin@suse.de>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
Received: from verein.lst.de ([213.95.11.210]:38913 "EHLO verein.lst.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751783Ab0FCHcp (ORCPT <rfc822;linux-fsdevel@vger.kernel.org>);
	Thu, 3 Jun 2010 03:32:45 -0400
Content-Disposition: inline
In-Reply-To: <20100603072812.GA3346@lst.de>
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

On Thu, Jun 03, 2010 at 09:28:12AM +0200, Christoph Hellwig wrote:
> Which means XFS behaviour for truncate while not strictly against
> Posix is at least unexpected.  I'll fix it up.

Actually I'd prefer if you could throw this into your do_truncate
patch so that filesystems don't get the clear suid request if
the file size doesn't change.  That way I can just change XFS
to do everything requested but the actual size update for that case.
In fact just clearing out ATTR_SIZE in that case in do_truncate would
be nice.

Which brings up the question: are we guaranteed to have stable
and uptodate i_size in do_truncate?  I think normally we'd need
a ->getattr first to stabilize it.