RFC: Solaris style extended attributes for FreeBSD

First off, I cross posted because I don't think many read freebsd-arch@.
There seems to be a nice market for Solaris style extended attributes.
Since ZFS is already wired for them, adding the basics is pretty
straightforward. I am not suggesting that they should replace the
current FreeBSD extended attributes.

For those not familiar with them (I am not very familiar myself;-),
a Solaris style extended attribute is in a directory that hangs off
the file object and the entries in the directory (the attributes) can
be manipulated with open/read/write/lseek just like a regular file.
(They can be as large as a regular file, but there is no atomicity
guarantees.)

At this point I have a couple of rough patches:
https://people.freebsd.org/~rmacklem/xattr.patch - the VFS/ZFS part
https://people.freebsd.org/~rmacklem/nfs-xattr.patch - the NFSv4 part

I have a simple test program to test the above:
https://people.freebsd.org/~rmacklem/xattrtest.c

The VFS/ZFS patch defines:
O_NAMEDATTR - similar to O_XATTR, but uses the NFSv4 named
   attribute terminology to avoid confusion with the other style of
   FreeBSD extended attributes.
   (The semantics probably are not exactly the same either. I do not
     have a Solaris system to test on, so I am going from the NFSv4
     and Solaris doc. I have handy.)
--> You can look at xattrtest.c to see how this is used.

I have not done any userland patches and am not sure what might be
needed? (I suspect a variant of pax/tar that knows about these is the
minimum?)

I defined a couple of new v_irflag bits to indicate that a vnode is
a named attribute directory or a named attribute. That way, they
are still of v_type VDIR or VREG and can be handled by most
of the code without change.

So, now for the questions...
1 - Do you think this should be put in FreeBSD?
     (If the consensus is no, I will try and maintain out of tree patches.)
2 - If the answer for #1 is yes, what do you think is needed beyond
     what I already have (which is a way to open the named attribute
     directory and named attributes within that directory).

Thanks in advance for any comments, rick