got these params: fstype=reiserfs, logdir=/cruc/runs/2226/test_output, mountdev=, mountpoint=
  mountoptions=data=writeback, fsblocksize=2048, iosched=
usage: run_fsx -t fstype+ -l logdir -d mountdev+ -p mountpoint+ -o mountoption* -b fsblocksize -s iosched
+ parameters are required,
although mount info can be from ENV variables or from mountinfo.rc file
-o mountoption: can be entered multiple times; the options will be separated with commas.
Must be run as root