Re: NFS locking bug -- limited mtime resolution means nfs_lock() does not provide coherency guarantee

[Theodore Y. Ts'o]

   Date:        Wed, 13 Sep 2000 12:54:49 +0200 (CEST)
   From: Trond Myklebust <[EMAIL PROTECTED]>

   Don't forget that 2^20 > 10^6, hence if you really want units of
   microseconds, you actually only need to save 3 bytes worth of data per
   timestamp.

   For the purposes of NFS, however the 'microseconds' field doesn't
   actually have to mean anything. It's just used as a cookie.
   Furthermore, only the mtime field, and to a limited extent the ctime
   field, are used for attribute consistency checking.

So this is a really stupid question, but I'll ask it anyway.  If you
just need a cookie, is there any way that you might be able to steal a
few bits from i_generation field for that purpose?  (This assumes that
we only worry about solving the problem for NFS.)

                                                        - Ted
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