Hi Neil, On Thu, 2019-05-30 at 10:41 +1000, NeilBrown wrote: > With NFSv4.1, different network connections need to be explicitly > bound to a session. During session startup, this is not possible > so only a single connection must be used for session startup. > > So add a task flag to disable the default round-robin choice of > connections (when nconnect > 1) and force the use of a single > connection. > Then use that flag on all requests for session management - for > consistence, include NFSv4.0 management (SETCLIENTID) and session > destruction > > Reported-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > Signed-off-by: NeilBrown <neilb@xxxxxxxx> > --- > fs/nfs/nfs4proc.c | 22 +++++++++++++--------- > include/linux/sunrpc/sched.h | 1 + > net/sunrpc/clnt.c | 24 +++++++++++++++++++++++- > 3 files changed, 37 insertions(+), 10 deletions(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index c29cbef6b53f..22b3dbfc4fa1 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -5978,7 +5978,7 @@ int nfs4_proc_setclientid(struct nfs_client > *clp, u32 program, > .rpc_message = &msg, > .callback_ops = &nfs4_setclientid_ops, > .callback_data = &setclientid, > - .flags = RPC_TASK_TIMEOUT, > + .flags = RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN, > }; > int status; > > @@ -6044,7 +6044,8 @@ int nfs4_proc_setclientid_confirm(struct > nfs_client *clp, > dprintk("NFS call setclientid_confirm auth=%s, (client ID > %llx)\n", > clp->cl_rpcclient->cl_auth->au_ops->au_name, > clp->cl_clientid); > - status = rpc_call_sync(clp->cl_rpcclient, &msg, > RPC_TASK_TIMEOUT); > + status = rpc_call_sync(clp->cl_rpcclient, &msg, > + RPC_TASK_TIMEOUT | > RPC_TASK_NO_ROUND_ROBIN); > trace_nfs4_setclientid_confirm(clp, status); > dprintk("NFS reply setclientid_confirm: %d\n", status); > return status; > @@ -7633,7 +7634,7 @@ static int _nfs4_proc_secinfo(struct inode > *dir, const struct qstr *name, struct > NFS_SP4_MACH_CRED_SECINFO, &clnt, &msg); > > status = nfs4_call_sync(clnt, NFS_SERVER(dir), &msg, > &args.seq_args, > - &res.seq_res, 0); > + &res.seq_res, RPC_TASK_NO_ROUND_ROBIN); I'm confused about what setting RPC_TASK_NO_ROUND_ROBIN as the "cache_reply" argument to nfs4_call_sync() actually does. As far as I can tell, it's passed to nfs4_init_sequence() which sets it to the nfs4_sequence_args "sa_cache_this" field, which is a one bit boolean (defined in include/linux/nfs_xdr.h). So why pass the flag? > dprintk("NFS reply secinfo: %d\n", status); > > put_cred(cred); > @@ -7971,7 +7972,7 @@ nfs4_run_exchange_id(struct nfs_client *clp, > const struct cred *cred, > .rpc_client = clp->cl_rpcclient, > .callback_ops = &nfs4_exchange_id_call_ops, > .rpc_message = &msg, > - .flags = RPC_TASK_TIMEOUT, > + .flags = RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN, > }; > struct nfs41_exchange_id_data *calldata; > int status; > @@ -8196,7 +8197,8 @@ static int _nfs4_proc_destroy_clientid(struct > nfs_client *clp, > }; > int status; > > - status = rpc_call_sync(clp->cl_rpcclient, &msg, > RPC_TASK_TIMEOUT); > + status = rpc_call_sync(clp->cl_rpcclient, &msg, > + RPC_TASK_TIMEOUT | > RPC_TASK_NO_ROUND_ROBIN); > trace_nfs4_destroy_clientid(clp, status); > if (status) > dprintk("NFS: Got error %d from the server %s on " > @@ -8475,7 +8477,8 @@ static int _nfs4_proc_create_session(struct > nfs_client *clp, > nfs4_init_channel_attrs(&args, clp->cl_rpcclient); > args.flags = (SESSION4_PERSIST | SESSION4_BACK_CHAN); > > - status = rpc_call_sync(session->clp->cl_rpcclient, &msg, > RPC_TASK_TIMEOUT); > + status = rpc_call_sync(session->clp->cl_rpcclient, &msg, > + RPC_TASK_TIMEOUT | > RPC_TASK_NO_ROUND_ROBIN); > trace_nfs4_create_session(clp, status); > > switch (status) { > @@ -8551,7 +8554,8 @@ int nfs4_proc_destroy_session(struct > nfs4_session *session, > if (!test_and_clear_bit(NFS4_SESSION_ESTABLISHED, &session- > >session_state)) > return 0; > > - status = rpc_call_sync(session->clp->cl_rpcclient, &msg, > RPC_TASK_TIMEOUT); > + status = rpc_call_sync(session->clp->cl_rpcclient, &msg, > + RPC_TASK_TIMEOUT | > RPC_TASK_NO_ROUND_ROBIN); > trace_nfs4_destroy_session(session->clp, status); > > if (status) > @@ -8805,7 +8809,7 @@ static int nfs41_proc_reclaim_complete(struct > nfs_client *clp, > .rpc_client = clp->cl_rpcclient, > .rpc_message = &msg, > .callback_ops = &nfs4_reclaim_complete_call_ops, > - .flags = RPC_TASK_ASYNC, > + .flags = RPC_TASK_ASYNC | RPC_TASK_NO_ROUND_ROBIN, > }; > int status = -ENOMEM; > > @@ -9324,7 +9328,7 @@ _nfs41_proc_secinfo_no_name(struct nfs_server > *server, struct nfs_fh *fhandle, > > dprintk("--> %s\n", __func__); > status = nfs4_call_sync(clnt, server, &msg, &args.seq_args, > - &res.seq_res, 0); > + &res.seq_res, RPC_TASK_NO_ROUND_ROBIN); Same question here. Thanks, Anna > dprintk("<-- %s status=%d\n", __func__, status); > > put_cred(cred); > diff --git a/include/linux/sunrpc/sched.h > b/include/linux/sunrpc/sched.h > index d0e451868f02..11424bdf09e6 100644 > --- a/include/linux/sunrpc/sched.h > +++ b/include/linux/sunrpc/sched.h > @@ -126,6 +126,7 @@ struct rpc_task_setup { > #define RPC_CALL_MAJORSEEN 0x0020 /* major timeout seen > */ > #define RPC_TASK_ROOTCREDS 0x0040 /* force root creds > */ > #define RPC_TASK_DYNAMIC 0x0080 /* task was > kmalloc'ed */ > +#define RPC_TASK_NO_ROUND_ROBIN 0x0100 /* send > requests on "main" xprt */ > #define RPC_TASK_SOFT 0x0200 /* Use soft > timeouts */ > #define RPC_TASK_SOFTCONN 0x0400 /* Fail if can't > connect */ > #define RPC_TASK_SENT 0x0800 /* message > was sent */ > diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c > index 3619dd5e9e0e..45802dd3fc86 100644 > --- a/net/sunrpc/clnt.c > +++ b/net/sunrpc/clnt.c > @@ -1013,6 +1013,24 @@ xprt_get_client(struct rpc_xprt *xprt, struct > rpc_clnt *clnt) > return xprt; > } > > +static struct rpc_xprt * > +rpc_task_get_first_xprt(struct rpc_clnt *clnt) > +{ > + struct rpc_xprt_switch *xps; > + struct rpc_xprt *xprt; > + > + rcu_read_lock(); > + xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); > + if (xprt) { > + atomic_long_inc(&xprt->queuelen); > + xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch); > + atomic_long_inc(&xps->xps_queuelen); > + } > + rcu_read_unlock(); > + > + return xprt; > +} > + > static void > rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt) > { > @@ -1060,7 +1078,11 @@ void rpc_task_release_client(struct rpc_task > *task) > static > void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt > *clnt) > { > - if (!task->tk_xprt) > + if (task->tk_xprt) > + return; > + if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) > + task->tk_xprt = rpc_task_get_first_xprt(clnt); > + else > task->tk_xprt = rpc_task_get_xprt(clnt); > } > > >