The one other minor thing we could do is skip adding the UDP listener entirely in the v4-only case. I think that's a job for rpc.nfsd? --b. On Fri, Feb 24, 2017 at 01:25:21PM -0500, Jeff Layton wrote: > v2: comment clarifications, and commit log cleanup. No functional changes. > > RFC5661 says: > > NFSv4.1 works over Remote Direct Memory Access (RDMA) and non-RDMA- > based transports with the following attributes: > > > o The transport supports reliable delivery of data, which NFSv4.1 > requires but neither NFSv4.1 nor RPC has facilities for ensuring > [34]. > > o The transport delivers data in the order it was sent. Ordered > delivery simplifies detection of transmit errors, and simplifies > the sending of arbitrary sized requests and responses via the > record marking protocol [3]. > > ...and then some hand-wavy stuff about congestion control. RFC7530 > doesn't mention needing reliable and ordered delivery, but it does need > congestion control. > > In practical terms, that means we should be excluding NFSv4 from UDP > transports. The NFS server has never enforced this requirement, > however, so a user could issue NFSv4 calls against the server via UDP. > > This patchset adds a small bit of infrastructure to the sunrpc layer to > enforce this requirement, and has the nfs and nfsd layers set the > appropriate flags for it on their server-side transports. It also has > the rpcbind client skip registering the protocol version on a UDP port > when that flag is set. > > Lightly tested by hand, but it's fairly straightforward. > > Jeff Layton (4): > sunrpc: turn bitfield flags in svc_version into bools > sunrpc: flag transports as having both reliable and ordered delivery, > and congestion control > nfs/nfsd/sunrpc: enforce transport requirements for NFSv4 > sunrpc: don't register UDP port with rpcbind when version needs > congestion control > > fs/nfs/callback_xdr.c | 6 ++++-- > fs/nfsd/nfs2acl.c | 1 - > fs/nfsd/nfs3acl.c | 1 - > fs/nfsd/nfs4proc.c | 13 +++++++------ > include/linux/sunrpc/svc.h | 12 ++++++++---- > include/linux/sunrpc/svc_xprt.h | 1 + > net/sunrpc/svc.c | 23 ++++++++++++++++++++++- > net/sunrpc/svcsock.c | 1 + > net/sunrpc/xprtrdma/svc_rdma_transport.c | 8 ++++++++ > 9 files changed, 51 insertions(+), 15 deletions(-) > > -- > 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
