Enable nconnect mount option and multipathing behavior for NFSv3 and NFSv4. Signed-off-by: Jui-Yu Chang <juchang@xxxxxxxxxxxxxxx> --- fs/nfs/client.c | 3 +++ fs/nfs/nfs4client.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 08baa66..8d11a11 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -653,6 +653,9 @@ static int nfs_init_server(struct nfs_server *server, struct nfs_client *clp; int error; + if (data->nfs_server.protocol == XPRT_TRANSPORT_TCP) + cl_init.nconnect = data->nfs_server.nconnect; + nfs_init_timeout_values(&timeparms, data->nfs_server.protocol, data->timeo, data->retrans); if (data->flags & NFS_MOUNT_NORESVPORT) diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index f11dec1..6ef1baa 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -849,7 +849,7 @@ static int nfs4_set_client(struct nfs_server *server, }; struct nfs_client *clp; - if (minorversion > 0 && proto == XPRT_TRANSPORT_TCP) + if (proto == XPRT_TRANSPORT_TCP) cl_init.nconnect = nconnect; if (server->flags & NFS_MOUNT_NORESVPORT) set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags); -- 1.9.1 On Tue, Aug 15, 2017 at 5:46 PM, Bennett Amodio <bamodio@xxxxxxxxxxxxxxx> wrote: > After seeing Trond’s patches for NFS multipathing on NFSv4.1, we > decided to try using the same concept for NFSv3/4. The primary issue > we identified was XID collision in the duplicate request cache (replay > cache) for NFSv3/4. In NFSv3/4, entries are hashed based on XID > instead of the slot ID and sequence ID that NFSv4.1 uses. Since the > XIDs are generated by the RPC transports, and Trond’s patches create > multiple transports for multipathing, different transports can end up > using an overlapping set of XIDs. > > > To fix this, we apply a mask to XIDs. Each transport is constrained to > its own segment of the total XID range, and they can never overlap. > In terms of loss of entropy, by masking out just enough bits from the > XID, we are convinced that the probability of XID wraparound or > collision on NFS client restart has not increased to a problematic > level (so long as the RPCs are distributed round-robin, as in Trond’s > patches). > > > We tested multipathing out and discovered that it enables NFS to get > more bandwidth on a bonded interface (instead of using only one > physical link, it can use multiple). Specifically, we tested on a > setup where the client was connected to the server via 4 bonded 10Gb/s > links. Without multipathing, the client could only achieve 10Gb/s > (using one physical link). With multipathing, the client was able to > achieve a maximum of close to 40Gb/s. > > > However, although the maximum performance was close to 40Gb/s, > achieving an average throughput of even 30Gb/s required many > connections. The performance of individual trials had a high > variance. We traced this uneven performance to colliding network > paths. With round-robin distribution of RPCs, no single TCP > connection can exceed the performance of the slowest one. If the > connections are distributed unevenly across network paths, some > connections can bottleneck others. To solve this problem, we are > currently working on patches to provide load-balancing as an > alternative to round-robin for distributing RPCs. > > > To use these patches, you first have to apply Trond's 5 patches > (Available at https://www.spinics.net/lists/linux-nfs/msg63368.html). > Let us know what you think or if you have any ideas for improving > this. > > > Jui-Yu Chang (1): > NFS: Allow multiple connections to NFSv3 and NFSv4.0 servers > > Bennett Amodio (1): > SUNRPC: Mask XIDs to prevent replay cache collision > > fs/nfs/client.c | 3 +++ > fs/nfs/nfs4client.c | 2 +- > include/linux/sunrpc/xprt.h | 5 +++++ > net/sunrpc/clnt.c | 8 ++++++++ > net/sunrpc/xprt.c | 14 ++++++-------- > 5 files changed, 23 insertions(+), 9 deletions(-) > > -- > 1.9.1 -- 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
