From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 19/18] fs: split __inode_add_to_list
Date: Tue, 12 Oct 2010 07:31:30 -0400
Message-ID: <20101012113130.GA24650@infradead.org>
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 <20101009080854.GA15943@infradead.org>
 <20101012104727.GC32255@dastard>
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Cc: Christoph Hellwig <hch@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
To: Dave Chinner <david@fromorbit.com>
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On Tue, Oct 12, 2010 at 09:47:27PM +1100, Dave Chinner wrote:
> The only reason XFS hashed the inodes was to avoid problems in the
> generic code that checked for unhashed inodes during clear_inode(). The
> evict() changeover moved that unhashed check into
> generic_drop_inode(), which the filesystem can override. Hence if
> you add a ->drop_inode() method for XFS that just checks the link
> count, we can avoid ha??hing the inodes altogether for XFS.
> 
> I can add another patch on top of this one to do that if you want...

It's unfortunately not that simple.  Take a look at the unhashed check
in __mark_inode_dirty.  The drop_inode check could be avoided for
quite a long time now.  What we could do however is the same hack as
JFS does in diReadSpecial().