The delegation code mostly pretends to support either read or write
delegations. However, correct support for write delegations would
require, for example, breaking of delegations (and/or implementation of
cb_getattr) on stat. Currently all that stops us from handing out
delegations is a subtle reference-counting issue.
Avoid confusion by adding an earlier check that explicitly refuses write
delegations.
For now, though, I'm not going so far as to rip out existing
half-support for write delegations, in case we get around to using that
soon.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
c3e4808086