From: David Woodhouse <dwmw2@infradead.org>
Subject: Re: [RFC] Reinstate NFS exportability for JFFS2.
Date: Fri, 01 Aug 2008 09:13:38 +0100
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Cc: Neil Brown <neilb@suse.de>, Christoph Hellwig <hch@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
	linux-mtd@lists.infradead.org
To: chucklever@gmail.com
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On Thu, 2008-07-31 at 21:31 -0400, Chuck Lever wrote:
> It looks like it needs a directory entry's dentry for a couple of
> reasons:
> 
> 1.  To determine whether a directory entry is a mount point
> 
> 2.  If the client has asked for file handles (via a bitmask) for the
> directory entries

Theoretically, neither of those actually need the _inode_. If it's a
mountpoint, won't it be in the dcache already? So a purely dcache-based
lookup would find it, without having to call through to the file
system's ->lookup() method on a dcache miss?

And to generate the file handle, all you need in the common case is
i_generation? You don't need to pull every inode into core.

-- 
dwmw2