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Date: Tue, 3 Jan 2017 22:29:06 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Fabian Frederick <fabf@skynet.be>
Cc: Andrew Morton <akpm@linux-foundation.org>, Jan Kara <jack@suse.cz>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 3/6 linux-next] fs/affs: make affs exportable
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On Tue, Jan 03, 2017 at 10:30:39PM +0100, Fabian Frederick wrote:
> Add standard functions making AFFS work with NFS.
> 
> Functions based on ext4 implementation.
> Tested on loop device.

How the hell is that supposed to work with cold dcache?  You don't have
->get_parent() there at all...

There *IS* a reference to parent directory in those suckers - not the same
kind as in normal unix filesystems (".." is not a directory entry there -
it's all fake), but it's doable.  be32_to_cpu(AFFS_TAIL(sb, bh)->parent) 
would be the inumber you need, where bh is the inode block of directory.

So it can be done, but not in this form.  NAK for the time being...