gfs2_edit behaves weird when changing flag values. It is inconsistent with respect to 0x prefixes:

# gfs2_edit -x -p 18 field di_flags ./foo
{{200

1. gfs2_edit -p 18 field di_flags 200 ./foo
   GFS2_DIF_EA_INDIRECT/GFS2_DIF_APPENDONLY/GFS2_DIF_NOATIME}}

Here, the value reported as 200 is actually 0x200 and when trying to set the field to 200, the number is interpreted as 200 decimal, which corresponds to 0xc8. Specifying the base explicitly works:

{{# gfs2_edit -x -p 18 field di_flags 0x200 ./foo
200}}

Symbolic values don't really work, either:

{{# gfs2_edit -p 18 field di_flags ./foo
GFS2_DIF_SYSTEM

1. gfs2_edit -p 18 field di_flags GFS2_DIF_SYSTEM ./foo
   Could not set 'di_flags' to 'GFS2_DIF_SYSTEM': Inappropriate ioctl for device}}