From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 1/4] vfs: vfs-level fiemap interface
Date: Tue, 7 Oct 2008 09:28:54 -0400
Message-ID: <20081007132854.GA15953@infradead.org>
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Cc: Christoph Hellwig <hch@infradead.org>,
	Theodore Tso <tytso@mit.edu>, jim owens <jowens@hp.com>,
	linux-fsdevel@vger.kernel.org, Mark Fasheh <mfasheh@suse.com>,
	Michael Kerrisk <mtk.manpages@googlemail.com>,
	linux-abi@vger.kernel.org
To: Jamie Lokier <jamie@shareable.org>
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On Tue, Oct 07, 2008 at 02:24:36PM +0100, Jamie Lokier wrote:
> Ok, without getting in the way any more :-) it would be good to
> clarify in the description whether !(flags & FIEMAP_EXTENT_ENCODED)
> means only reading is allowed, or if it means writing over the data
> blocks is safe too.
> 
> Just so that filesystems will know whether to set the flag for blocks
> which can be read but not written.  This may include tail-merged
> blocks.

I think writing to a filesystem without fs assistance is always a bad
idea.  And yes, we should add this to the description.