[RFC] Reinstate NFS exportability for JFFS2.

[David Woodhouse]

On Thu, 2008-05-01 at 16:48 -0400, Christoph Hellwig wrote:
> Yes, and get_fsid would be extremly useful, especially for those
> filesystems that already have an uuid in the superblock
> (*cough*, XFS, *cough*), but it'll need some co-operations with
> nfs-utils on when to use it.

Why do you need to co-operate with userspace? Userspace shouldn't need
to do anything -- we'll just generate a suitable fsid/uuid for
ourselves, unless userspace deliberately overrides it for the export in
question.

> Patch looks good for me except for the few introduced overlong lines.

Bah, don't you start. A less onanistic problem with it is the deadlock
with NFS readdirplus (->readdir->encode_entry->compose_entry_fh->lookup)

I wonder if we should postpone the calls to compose_entry_fh() until
_after_ readdir() has completed. Leave space in the response for the
filehandles, but only walk through it again calling compose_entry_fh()
once we're done in readdir. That would allow us to get rid of the
various icky hacks that file systems have to avoid that deadlock.

-- 
dwmw2