2.4.0	GFS_PROTOCOL_VERSION == GFS_PROTOCOL_VERSION_V2_4 == 2
	(replica generation)
	GFM_PROTO_SWITCH_ASYNC_BACK_CHANNEL
	GFM_PROTO_CLOSE_WRITE_V2_4
	GFM_PROTO_GENERATION_UPDATE
	(gfmd initiated replication)
	GFM_PROTO_REPLICA_INFO_GET
	GFM_PROTO_REPLICATE_FILE_FROM_TO
	GFM_PROTO_REPLICATE_FILE_TO (not used)
	GFM_PROTO_REPLICATION_RESULT
	GFS_PROTO_REPLICATION_REQUEST
	GFS_PROTO_REPLICATION_CANCEL (not used)
2.4.1	(#128 xattr cache)
	GFM_PROTO_FGETATTRPLUS
	GFM_PROTO_GETDIRENTSPLUSXATTR
	(#170 replica lost)
	GFM_PROTO_REPLICA_REMOVE is renamed to GFM_PROTO_REPLICA_LOST
2.5.0	(metadata replication)
	GFM_PROTOCOL_VERSION == GFM_PROTOCOL_VERSION_V2_5_0 == 1
	GFM_INTER_GFMD_PROTOCOL_VERSION == GFM_PROTOCOL_VERSION_V2_5_0
	GFM_PROTO_SWITCH_GFMD_CHANNEL
	GFM_PROTO_JOURNAL_READY_TO_RECV
	GFM_PROTO_JOURNAL_SEND
	GFM_PROTO_METADB_SERVER_GET
	GFM_PROTO_METADB_SERVER_GET_ALL
	GFM_PROTO_METADB_SERVER_SET
	GFM_PROTO_METADB_SERVER_MODIFY
	GFM_PROTO_METADB_SERVER_REMOVE
	(gfmd failover)
	GFM_PROTO_REVOKE_GFSD_ACCESS
2.5.1	GFARM_METADB_SERVER_FLAG_SEQNUM_IS_UNKNOWN
	GFARM_METADB_SERVER_FLAG_SEQNUM_IS_OK
	GFARM_METADB_SERVER_FLAG_SEQNUM_IS_OUT_OF_SYNC
	GFARM_METADB_SERVER_FLAG_SEQNUM_IS_ERROR
2.5.2	GFM_PROTO_FHCLOSE_READ
	GFM_PROTO_FHCLOSE_WRITE
	GFM_PROTO_GENERATION_UPDATED_BY_COOKIE
2.5.3	GFS_PROTO_PROCESS_RESET
2.5.5	GFARM_METADB_SERVER_FLAG_IS_MEMORY_OWNED_BY_FS
	GFARM_METADB_SERVER_FLAG_IS_REMOVED
2.5.6	GFM_PROTO_REPLICA_GET_MY_ENTRIES
	GFM_PROTO_REPLICA_CREATE_FILE_IN_LOST_FOUND
2.5.8	GFM_PROTO_REPLICA_GET_MY_ENTRIES2
	GFS_PROTO_WRITE
2.5.8.5	(md5 cksum)
	GFM_PROTO_FHOPEN
	GFM_PROTO_REPLICA_CHECK_CTRL
	GFS_PROTO_CKSUM
2.5.8.7	GFM_PROTO_FHCLOSE_WRITE_CKSUM
2.6.0	(#494/#711 fsngroup)
	GFM_PROTO_FSNGROUP_GET_ALL
	GFM_PROTO_FSNGROUP_GET_BY_HOSTNAME
	GFM_PROTO_FSNGROUP_MODIFY
	(#769/#771/#774/#757 cksum enhancement)
	GFM_PROTO_REPLICATION_CKSUM_RESULT
	GFM_PROTO_REPLICA_ADDING_CKSUM
	GFM_PROTO_REPLICA_ADDED_CKSUM
	GFARM_METADB_SERVER_FLAG_SEQNUM_IS_BEHIND
	GFS_PROTOCOL_VERSION == GFS_PROTOCOL_VERSION_V2_6 == 3
	(gfs_pio_sendfile(3)/gfs_pio_recvfile(3))
	GFS_PROTO_BULKREAD
	GFS_PROTO_BULKWRITE
	GFS_PROTO_REPLICA_RECV_CKSUM
	GFS_PROTO_REPLICATION_CKSUM_REQUEST
	(#461 ext3fs-specific race condition)
	GFS_PROTO_CLOSE_WRITE
	(infiniband RDMA protocols, released as 2.7.0)
	GFS_PROTO_RDMA_EXCH_INFO
	GFS_PROTO_RDMA_HELLO
	GFS_PROTO_RDMA_PREAD
	GFS_PROTO_RDMA_PWRITE
2.6.1	GFM_PROTO_CKSUM_SET_REPORT_ONLY
2.6.2	removed (never used): GFM_PROTO_CKSUM_SET_FILE_MODIFIED
2.6.5	GFM_PROTO_REPLICA_CHECK_CTRL_REMOVE_ENABLE
	GFM_PROTO_REPLICA_CHECK_CTRL_REMOVE_DISABLE
	GFM_PROTO_REPLICA_CHECK_CTRL_REDUCED_LOG_ENABLE
	GFM_PROTO_REPLICA_CHECK_CTRL_REDUCED_LOG_DISABLE
2.6.6	GFM_PROTO_REPLICA_OPEN_STATUS
2.6.8	GFM_PROTO_REPLICA_GET_CKSUM
	GFM_PROTO_FHSET_CKSUM
	GFM_PROTO_CONFIG_GET
2.6.9	GFM_PROTO_CONFIG_SET
2.6.14	GFM_PROTO_PROCESS_FD_INFO
2.6.22	GFM_PROTO_REPLICA_CHECK_STATUS
	GFM_PROTO_REPLICA_GET_MY_ENTRIES_RANGE
2.7.0	(#967 directory quota)
	GFM_PROTO_DIRSET_INFO_SET
	GFM_PROTO_DIRSET_INFO_REMOVE
	GFM_PROTO_DIRSET_INFO_LIST
	GFM_PROTO_QUOTA_DIRSET_GET
	GFM_PROTO_QUOTA_DIRSET_SET
	GFM_PROTO_QUOTA_DIR_GET
	GFM_PROTO_QUOTA_DIR_SET
	GFM_PROTO_DIRSET_DIR_LIST
	(infiniband RDMA)
	GFM_PROTO_CLOSE_GETGEN
	removed: GFM_PROTO_REPLICA_CHECK_STATUS
	removed: GFM_PROTO_REPLICA_GET_MY_ENTRIES_RANGE
2.7.6	GFM_PROTO_REPLICA_GET_MY_ENTRIES_RANGE (revive)
2.7.7	GFM_PROTO_REPLICA_CHECK_STATUS (revive)
2.7.13	GFM_PROTO_SCHEDULE_HOST_DOMAIN_USE_REAL_DISK_SPACE
	GFM_PROTO_SCHED_FLAG_READONLY
	GFS_PROTOCOL_VERSION == GFS_PROTOCOL_VERSION_V2_7_13 == 4
	GFS_PROTO_STATUS2 (from gfmd back channel)
2.8.0	(tls_sharedsecret/tls_client_certificate)
	(kerberos_auth/kerberos)
	(sasl_auth/sasl)
	(multitenancy)
	GFM_PROTO_USER_INFO_GET_MY_OWN
	GFM_PROTO_USER_INFO_GET_BY_AUTH_ID
	GFM_PROTO_USER_AUTH_GET
	GFM_PROTO_USER_AUTH_MODIFY
	(#1126 mdhost race fix)
	GFM_PROTO_CLOSE_WRITE_V2_8 (from gfsd)
	GFM_PROTO_GENERATION_UPDATED_V2_8 (from gfsd)
	GFM_PROTO_FHCLOSE_WRITE_V2_8  (from gfsd)
	GFM_PROTO_GENERATION_UPDATED_BY_COOKIE_V2_8  (from gfsd)
2.8.1	GFM_PROTOCOL_VERSION == GFM_PROTOCOL_VERSION_V2_8_0 == 21

