is opened. An open file can always be read from and/or written to,
depending on how it was opened.
Therefore, the read/write/commit RPCs should never return EACCESS,
as they are only performed on files that have been successfully opened
already.
This change improves the current situation and works in most cases.
It simply always uses the most recently known owner/group of the file,
iff the authentication mechanism is AUTH_UNIX (in other cases, the
creds for a succesful open are used, but note that no other cases
are currently implemented).
A retry mechanism can be used to catch a few more cases, but this is
a good improvement for now.
b916f59963