libceph, rbd: ceph_osd_linger_request, watch/notify v2
This adds support and switches rbd to a new, more reliable version of
watch/notify protocol. As with the OSD client update, this is mostly
about getting the right structures linked into the right places so that
reconnects are properly sent when needed. watch/notify v2 also
requires sending regular pings to the OSDs - send_linger_ping().
A major change from the old watch/notify implementation is the
introduction of ceph_osd_linger_request - linger requests no longer
piggy back on ceph_osd_request. ceph_osd_event has been merged into
ceph_osd_linger_request.
All the details are now hidden within libceph, the interface consists
of a simple pair of watch/unwatch functions and ceph_osdc_notify_ack().
ceph_osdc_watch() does return ceph_osd_linger_request, but only to keep
the lifetime management simple.
ceph_osdc_notify_ack() accepts an optional data payload, which is
relayed back to the notifier.
Portions of this patch are loosely based on work by Douglas Fuller
<dfuller@redhat.com> and Mike Christie <michaelc@cs.wisc.edu>.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
7 files changed