Build problems fixed:
- void* pointer arithmetic which is a GNU extension (works as byte*)
- "variable size object may not be initialized" which is OK under GCC
- nullptr_t related error in json11 (it lacks 'operator <' in clang)
Warnings fixed:
- empty nested struct initializer { 0 } replaced by {}
- removed several unused lambda captures
From now on, reads will return the server-side object version numbers
and writes and deletes will have an additional "version" parameter
which, if set to a non-zero value, will be atomically compared with
the current version of the object plus 1 and the modification will
fail if it doesn't match.
This feature opens the road to correct online flattening of snapshot
layers and other interesting things.
Basic naive implementation works, but it's highly non-optimal as
RNR retransmissions occur all the time. RDMA expects the receiver
to always have place for incoming WRs...
Rework client operation queue from a vector to a linked list.
This is required to rework continue_ops() as its current implementation
consumes ~25% of client process CPU.
Previous implementation didn't respect write ordering and could lead
to corrupted data when restarting writes after an OSD outage
Also rework cluster_client queueing logic and add tests for it to verify the correct behaviour