Here's a proposal for adding support in mount.nfs for mounting NFSv4
servers over IPv6. It provides mount.nfs4 with the ability to resolve a
hostname to an IPv6 address and pass it to the kernel. It can also pass an
IPv6 local address via clientaddr=.
Kernel level sunrpc support rpcbind protocol versions 3 and 4 must be
enabled via Kconfig. Support for user-space rpcbind operations for IPv6
addresses is not needed with NFSv4, since the kernel handles rpcbind
operations for NFS version 4.
To support NFS version 2 and 3 mounts over IPv6, user level support for
rpcbind versions 3 and 4 will be required. That is currently under
Unmount support in umount.nfs4 for IPv6 is not needed for NFSv4 since
unmounting an nfs4 file system is a local client operation only.
This code is untested; it is posted for review only.
corporate: <chuck dot lever at oracle dot com>