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Date: Mon, 14 Oct 2002 17:16:39 +0100
From: Christoph Hellwig <hch@infradead.org>
To: Michael Clark <michael@metaparadigm.com>,
       Christoph Hellwig <hch@infradead.org>,
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Subject: Re: [Evms-devel] Re: Linux v2.5.42
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In-Reply-To: <20021014044355.GQ3045@clusterfs.com>; from adilger@clusterfs.com on Sun, Oct 13, 2002 at 10:43:55PM -0600
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On Sun, Oct 13, 2002 at 10:43:55PM -0600, Andreas Dilger wrote:
> I never did get a clear understanding why Christoph wants access to
> "intermediate" block devices from EVMS, except for the ioctl issue.

It's not really the userspace access that matters (it comes for free
when doing it properly) but more that I want to avoid duplicating
kernel-internal data structures and code.  Just look at ldev_mgr.c
in the evms source code and see how much simpler it would get if we
merged struct evms_logical_node (and it's members) into struct gendisk and
struct block_device - sure that's not a trivial task, but it'll pay
out in the long term.

> It's like "ls -l" showing you each and every block that makes up a file,
> or "ps aux"

It's more like ps aux showing you all threads of a multithreaded
process.  Yes, people have turned it off now, but you really want
to be able to see it without doing hacks.