NFS V3 (and V4) support exclusive create by passing a 'cookie' which can get
stored with the file.  If the file exists but has exactly the right cookie
stored, then we assume this is a retransmit and the exclusive create was
successful.

The cookie is 64bits and is traditionally stored in the mtime and atime
fields.  This causes a problem with Solaris7 as negative mtime or atime
confuse it.  So we moved two bits into the mode word instead.

But inherited ACLs sometimes overwrite the mode word on create, so this is a
problem.

So we give up and just store 62 of the 64 bits and assume that is close
enough.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>