• Chuck Lever's avatar
    nfs: Referrals should use the same proto setting as their parent · 530ea421
    Chuck Lever authored
    Helen Chao <helen.chao@oracle.com> noticed that when a user
    traverses a referral on an NFS/RDMA mount, the resulting submount
    always uses TCP.
    This behavior does not match the vers= setting when traversing
    a referral (vers=4.1 is preserved). It also does not match the
    behavior of crossing from the pseudofs into a real filesystem
    (proto=rdma is preserved in that case).
    The Linux NFS client does not currently support the
    fs_locations_info attribute. The situation is similar for all
    NFSv4 servers I know of. Therefore until the community has broad
    support for fs_locations_info, when following a referral:
     - First try to connect with RPC-over-RDMA. This will fail quickly
       if the client has no RDMA-capable interfaces.
     - If connecting with RPC-over-RDMA fails, or the RPC-over-RDMA
       transport is not available, use TCP.
    Reported-by: default avatarHelen Chao <helen.chao@oracle.com>
    Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
    Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
nfs4namespace.c 12.7 KB