Hi Chuck, On 12/04/2017 02:13 PM, Chuck Lever wrote: > Helen Chao <helen.chao@xxxxxxxxxx> 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. Won't this have the opposite problem if the client and server have RDMA interfaces, but are currently mounted over TCP instead? Anna > > Reported-by: Helen Chao <helen.chao@xxxxxxxxxx> > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > --- > fs/nfs/nfs4client.c | 23 ++++++++++++++++++++--- > fs/nfs/nfs4namespace.c | 2 -- > 2 files changed, 20 insertions(+), 5 deletions(-) > > diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c > index 12bbab0..a3d5592 100644 > --- a/fs/nfs/nfs4client.c > +++ b/fs/nfs/nfs4client.c > @@ -1114,19 +1114,36 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data, > /* Initialise the client representation from the parent server */ > nfs_server_copy_userdata(server, parent_server); > > - /* Get a client representation. > - * Note: NFSv4 always uses TCP, */ > + /* Get a client representation */ > +#ifdef CONFIG_SUNRPC_XPRT_RDMA > + rpc_set_port(data->addr, NFS_RDMA_PORT); > error = nfs4_set_client(server, data->hostname, > data->addr, > data->addrlen, > parent_client->cl_ipaddr, > - rpc_protocol(parent_server->client), > + XPRT_TRANSPORT_RDMA, > + parent_server->client->cl_timeout, > + parent_client->cl_mvops->minor_version, > + parent_client->cl_net); > + if (!error) > + goto init_server; > +#endif /* CONFIG_SUNRPC_XPRT_RDMA */ > + > + rpc_set_port(data->addr, NFS_PORT); > + error = nfs4_set_client(server, data->hostname, > + data->addr, > + data->addrlen, > + parent_client->cl_ipaddr, > + XPRT_TRANSPORT_TCP, > parent_server->client->cl_timeout, > parent_client->cl_mvops->minor_version, > parent_client->cl_net); > if (error < 0) > goto error; > > +#ifdef CONFIG_SUNRPC_XPRT_RDMA > +init_server: > +#endif > error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor); > if (error < 0) > goto error; > diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c > index 8c3f327..24f06dc 100644 > --- a/fs/nfs/nfs4namespace.c > +++ b/fs/nfs/nfs4namespace.c > @@ -270,8 +270,6 @@ static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, > if (mountdata->addrlen == 0) > continue; > > - rpc_set_port(mountdata->addr, NFS_PORT); > - > memcpy(page2, buf->data, buf->len); > page2[buf->len] = '\0'; > mountdata->hostname = page2; > -- 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
