Theodore Ts'o [off-list ref] wrote:

As a result, I would suggest that we not try to use the
FS_IOC_[GS]ETFLAGS number scheme for any new interface, so we're at
least not making a bad situation worse.

The only reason why some other file systems have chosen to use
FS_IOC_[GS]ETFLAGS, instead of defining their own ioctl, is so they
can use lsattr/chattr from e2fsprogs instead of creating their own
utility.  But for statx, there isn't a good reason use the same flags
number space.  At the very least, can we use a new flags field for the
Windows file attributes?  It's not like lsattr/chattr has the ability
to set those flags today anyway.  So we might as well use a new flags
field and a new flags numberspace for them.

Hmmm...  I was trying to make it so that these bits would be saved to disk as
part of the IOC flags so that Samba could make use of them.  I guess they'll
have to be stored in an xattr instead.

David