From: Christoph Hellwig <hch@lst.de>
Date: Wed, 23 Jan 2008 05:47:47 +0000
Subject: Re: 2.6.24-rc8-mm1: sparc64 warning at fs/file_table.c:49 __fput+0x1a8/0x1e0()
Message-Id: <20080123054747.GA14729@lst.de>
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References: <20080117023514.9df393cf.akpm@linux-foundation.org> <200801222130.24136.m.kozlowski@tuxland.pl> <20080122130228.e7596163.akpm@linux-foundation.org> <1201043638.7585.47.camel@nimitz.home.sr71.net>
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To: Dave Hansen <haveblue@us.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Mariusz Kozlowski <m.kozlowski@tuxland.pl>, linux-kernel@vger.kernel.org, davem@davemloft.net, sparclinux@vger.kernel.org, Christoph Hellwig <hch@lst.de>

On Tue, Jan 22, 2008 at 03:13:58PM -0800, Dave Hansen wrote:
> The emergency remount code forcibly removes FMODE_WRITE from
> filps.  The r/o bind mount code notices that this was done
> without a proper mnt_drop_write() and properly gives a
> warning.
> 
> This patch does a mnt_drop_write() and also notes in the
> filp that this was done to suppress any warning that would
> have otherwise been triggered.
> 
> I also wonder if inode->i_writecount is made inconsistent
> by the emergency remount code.  I guess it is, but the
> damage is limited to a single inode instead of being
> visible more globally like the mnt write count.  Probably
> not really worth fixing.

The right fix is to not simply remove FMODE_WRITE, but just remove
this whole function.  Until we have a proper revoke it will cause more
harm than good.