s_default_mount_opts.flags

	
0001	Print debugging info upon (re)mount.
0002	New files take the gid of the containing directory.
0004	Support userspace-provided extended attributes.
0008	Support POSIX access control lists (ACLs).
0010	Do not support 32-bit UIDs.
0020	All data and metadata are commited to the journal.
0040	All data are flushed to the disk before metadata are committed to the journal.
# should probably check this value...
0060	Data ordering is not preserved; data may be written after the metadata has been written.
0100	Disable write flushes.
0200	Track which blocks in a filesystem are metadata and therefore should not be used as data blocks.
0400	Enable DISCARD support, where the storage device is told about blocks becoming unused.
0800	Disable delayed allocation.