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
0.82
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
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
PGLog: fix logging whitespace in trim

Signed-off-by: Samuel Just <sam.just@inktank.com>
rgw: allocate enough space for bucket instance id

Fixes: #8608
Backport: dumpling, firefly
Bucket instance id is a concatenation of zone name, rados instance id,
and a running counter. We need to allocate enough space to account zone
name length.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
Merge branch 'next'
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>
osd/: plumb rollback_trim_to through interfaces and messages

We simply trim the roll back info up to min_last_complete_ondisk
since we cannot correctly rollback past that point anyway!

ReplicatedPG
-> PGBackend::submit_transaction
-> Backend messages
-> PGBackend::Listener::log_operation
-> append_log

Signed-off-by: Samuel Just <sam.just@inktank.com>
osd/: in scrub, check for and remove obsolete rollback objs

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