From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cyrill Gorcunov <gorcunov@openvz.org>
Subject: Re: [patch 4/8] fs, exportfs: Add export_encode_inode_fh helper
Date: Thu, 16 Aug 2012 19:09:32 +0400
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Cc: "J. Bruce Fields" <bfields@fieldses.org>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Pavel Emelyanov <xemul@parallels.com>,
	James Bottomley <jbottomley@parallels.com>,
	Matthew Helsley <matt.helsley@gmail.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
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On Thu, Aug 16, 2012 at 04:05:42PM +0100, Al Viro wrote:
> On Thu, Aug 16, 2012 at 06:57:00PM +0400, Cyrill Gorcunov wrote:
> 
> > Guys, would the patch below be more-less acceptible?
> > In inotify I think we could pass "parent" as NULL and use general
> > encode engine then (ie it will look like someone called for
> > name_to_handle_at on inotify target).
> 
> Wait.  What the hell are you going to do with those afterwards?
> Again, there's a shitload of filesystems that cannot be exported
> over NFS, exactly because there's no way to implement sanely
> working fhandles.  And idiotify is allowed for all of them.

Yes, just recognized that, Al. There will be no way to restore them
from fhandle provided via fdinfo. /me scratching the head...

> You *can't* decode anything fhandle-like on e.g. sysfs.  Or procfs.
> Or configfs.  Or any network filesystem (I'd argue that we should simply
> ban idiotify on those, but good luck doing that).  You *can* do that
> for FAT derivatives, but only if you have parent directory when creating
> that sucker.

	Cyrill