+* readahead: use BTRFS_IOC_DEFRAG_RANGE instead of BTRFS_IOC_DEFRAG ioctl, with START_IO
+
+* readahead: check whether a btrfs volume includes ssd by checking mount flag "ssd"
+
+* hostnamed: make file updates atomic
+
+* support sd_notify() style notificatio when reload is finished (RELOADED=1)
+