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Date: Thu, 16 Aug 2012 15:55:27 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: James Bottomley <jbottomley@parallels.com>,
        Pavel Emelianov <xemul@parallels.com>,
        "J. Bruce Fields" <bfields@fieldses.org>,
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        Alexey Dobriyan <adobriyan@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Matthew Helsley <matt.helsley@gmail.com>
Subject: Re: [patch 4/8] fs, exportfs: Add export_encode_inode_fh helper
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On Thu, Aug 16, 2012 at 06:48:35PM +0400, Cyrill Gorcunov wrote:

> > Good luck doing that with e.g. VFAT...  And then there's such thing
> > as filesystems that don't have ->encode_fh() for a lot of very good
> 
> Wait, Al, it seems I messed up. If some fs has no encode_fh() implemented
> the default encoding with FILEID_INO32_GEN_PARENT will be used for that.

... which doesn't work for a lot of filesystems.  Not if you want to be
able to decode the result afterwards and get something useful out of
that.  Trying to implement ->fh_to_dentry(), especially with fhandle
generated by inode alone is going to be really interesting for a bunch
of stuff...