syscalls. (strictly speaking, it breaks abi. i don't think it's a problem
because this feature is short-lived and there are no affected in-tree
filesystems.)
While touching all vptofh/fhtovp functions, get rid of VFS_MAXFIDSIZ,
version the getfh(2) syscall and explicitly pass the size available in
the filehandle from userland.
Discussed on tech-kern, with lots of help from yamt (thanks!).
EPROTONOSUPPORT instead of EAFNOSUPPORT.
from pavel@ with a little bit of clean up from myself.
XXX: netbsd32 (and perhaps other emulations) should be able
XXX: to call the standard socket calls for this i think, but
XXX: revisit this at another time.
