common/Finisher: add queue(list<Context*>&)

Signed-off-by: Samuel Just <sam.just@inktank.com>
osd_types: add pg_log_t::rollback_info_trimmed_to

Signed-off-by: Samuel Just <sam.just@inktank.com>
PGLog: initialize complete_to

Signed-off-by: Samuel Just <sam.just@inktank.com>
Update RBD doc for OpenStack

Some updates from Icehouse, best practice configurations and
explanations.

Signed-off-by: Sébastien Han <sebastien.han@enovance.com>

Conflicts:
	doc/rbd/rbd-openstack.rst
MOSDOp: The functions are returned by const ref and parameters passed by ref

get_snapid(),get_snap_seq,get_pg,get_object_locator,get_version are returning
by reference and the corresponding setter is accepting the param by reference.
MOSDOp constructor is is accepting pg_t  by reference now.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
MOSDOpreply: The functions are returned by const ref and parameters passed by ref

get_oid,get_pg,get_replay_version,get_user_version are returning by reference and
corresponding setter is accepting param by reference.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
MOSDOpReply: Constructor initialization list is used to instantiate members

constructor initialization list is modified to initialize ops,oid,pgid with
copy constructor instead of assignment operator in the constructor body.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
mds: pass finish context to MDlog::submit_entry()

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: add get_metablob() to log events

later commits will use it to get EMetaBlob and update EMetaBlob's
event sequence number.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: introduce sequence number for log events

Use the sequence number to index log segments. Later commit will defer
encoding/submitting log events to separate thread, log events' offsets
are unknown before they are encoded.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: print sequence number of log segment
OSD: pass param by ref to avoid copying overrhead

passing OpRequestRef, OSDMapRef by ref to avoid refcounting overhead
and in some cases passing structures by const ref.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
os/: add async flush_commit() method to Sequencer and implementations

Signed-off-by: Samuel Just <sam.just@inktank.com>
PG: add machinery to temporarily buffer outgoing recovery messages

Signed-off-by: Samuel Just <sam.just@inktank.com>
PG: block outgoing peering messages until the last interval is durable

Signed-off-by: Samuel Just <sam.just@inktank.com>
Merge remote-tracking branch 'upstream/master' into wip-7999-master

Conflicts:
	src/os/KeyValueStore.h
OSDMap: avoid passing pg_t by value

Passing pg_t param by cons ref for avoiding copies.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
PGLog: fix logging whitespace in trim

Signed-off-by: Samuel Just <sam.just@inktank.com>
doc/release-notes: v0.82

Signed-off-by: Sage Weil <sage@inktank.com>
PGLog: add rollback_info_trimmed_to_riter to IndexedLog and use in PG

Signed-off-by: Samuel Just <sam.just@inktank.com>