text-based mount.nfs: Implement falling back to NFSv2 and UDP
authorChuck Lever <chuck.lever@oracle.com>
Wed, 10 Oct 2007 19:06:35 +0000 (15:06 -0400)
committerNeil Brown <neilb@suse.de>
Thu, 11 Oct 2007 01:03:18 +0000 (11:03 +1000)
commit56cfa1320a00cec885fbdf51c54b72acb01a95c0
tree679acf5b65ea5b9a5204e2b104763efe7870bf12
parent5258d6c1aa4fd319976d1b13e27493adb57a4120
text-based mount.nfs: Implement falling back to NFSv2 and UDP

If the initial user-specified options fail (with EOPNOTSUPP or
EPROTONOSUPPORT) then the server has rejected the requested NFS version
or transport protocol.

In that case, probe the server, then construct a fresh set of mount
options that ask for the specific mountd and NFS version and transport
protocol that the server supports.  Rewrite the mount options based on
the results of the probe, then try the request again.

An additional kernel patch is required to cause the kernel to return
EOPNOTSUPP when an rpcbind fails during a NULL request.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Neil Brown <neilb@suse.de>
utils/mount/stropts.c