Hello,

I made a patch to port "Extended Attributes for UFS1" from FreeBSD and
OpenBSD. You can find the diff at

http://Qwosh.tripod.co.jp/extattr.diff

Although this is mostly working, I have sevaral questions before send-pr.

1. For filesystems which don't support VFS_EXTATTRCTL, FreeBSD made
   vfs_stdextattrctl() function in kern/vfs_default.c. But genfs_extattrctl()
   is better?

2. Two extended attributes functions
     - extattr_namespace_to_string()
     - extattr_string_to_namespace()
   are declared in util.h, and belong to libc. Is this OK? I feel that when
   functions are declared in util.h, they need to belong to libutil.

3. When FreeBSD use fdrop, I replaced it with FILE_UNUSE. Is this correct?

4. FreeBSD calls ufs_extattr_autostart() at end of ffs_mountfs(), but I moved
   to inside of ufs_start(). Is this ok?

----
// Hiramatsu, Yoshifumi
// hiramatu@boreas.dti.ne.jp