nfs41: nfs4_setup_sequence

Perform the nfs4_setup_sequence in the rpc_call_prepare state.

If a session slot is not available, we will rpc_sleep_on the
slot wait queue leaving the tk_action as rpc_call_prepare.

Once we have a session slot, hang on to it even through rpc_restart_calls.
Ensure the nfs41_sequence_res sr_slot pointer is NULL before rpc_run_task is
called as nfs41_setup_sequence will only find a new slot if it is NULL.

A future patch will call free slot after any rpc_restart_calls, and handle the
rpc restart that result from a sequence operation error.

Signed-off-by: Rahul Iyer <iyer@netapp.com>
[nfs41: sequence res use slotid]
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: simplify nfs4_call_sync]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_call_sync]
[nfs41: check for session not minorversion]
[nfs41: remove rpc_message from nfs41_call_sync_args]
[moved NFS4_MAX_SLOT_TABLE logic into nfs41_setup_sequence]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: nfs41_call_sync_data use nfs_client not nfs_server]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: expose nfs4_call_sync_session for lease renewal]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: remove unnecessary return check]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 98 insertions, 2 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5878930b4c3b..90aed76e593b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -273,14 +273,110 @@ static void renew_lease(const struct nfs_server *server, unsigned long timestamp
 
 #if defined(CONFIG_NFS_V4_1)
 
+static int nfs41_setup_sequence(struct nfs4_session *session,
+                                struct nfs4_sequence_args *args,
+                                struct nfs4_sequence_res *res,
+                                int cache_reply,
+                                struct rpc_task *task)
+{
+        /* slot already allocated? */
+        if (res->sr_slotid != NFS4_MAX_SLOT_TABLE)
+                return 0;
+
+        memset(res, 0, sizeof(*res));
+        res->sr_slotid = NFS4_MAX_SLOT_TABLE;
+        return 0;
+}
+
+int nfs4_setup_sequence(struct nfs_client *clp,
+                        struct nfs4_sequence_args *args,
+                        struct nfs4_sequence_res *res,
+                        int cache_reply,
+                        struct rpc_task *task)
+{
+        int ret = 0;
+
+        dprintk("--> %s clp %p session %p sr_slotid %d\n",
+                __func__, clp, clp->cl_session, res->sr_slotid);
+
+        if (!nfs4_has_session(clp))
+                goto out;
+        ret = nfs41_setup_sequence(clp->cl_session, args, res, cache_reply,
+                                   task);
+        if (ret != -EAGAIN) {
+                /* terminate rpc task */
+                task->tk_status = ret;
+                task->tk_action = NULL;
+        }
+out:
+        dprintk("<-- %s status=%d\n", __func__, ret);
+        return ret;
+}
+
+struct nfs41_call_sync_data {
+        struct nfs_client *clp;
+        struct nfs4_sequence_args *seq_args;
+        struct nfs4_sequence_res *seq_res;
+        int cache_reply;
+};
+
+static void nfs41_call_sync_prepare(struct rpc_task *task, void *calldata)
+{
+        struct nfs41_call_sync_data *data = calldata;
+
+        dprintk("--> %s data->clp->cl_session %p\n", __func__,
+                data->clp->cl_session);
+        if (nfs4_setup_sequence(data->clp, data->seq_args,
+                                data->seq_res, data->cache_reply, task))
+                return;
+        rpc_call_start(task);
+}
+
+struct rpc_call_ops nfs41_call_sync_ops = {
+        .rpc_call_prepare = nfs41_call_sync_prepare,
+};
+
+static int nfs4_call_sync_sequence(struct nfs_client *clp,
+                                   struct rpc_clnt *clnt,
+                                   struct rpc_message *msg,
+                                   struct nfs4_sequence_args *args,
+                                   struct nfs4_sequence_res *res,
+                                   int cache_reply)
+{
+        int ret;
+        struct rpc_task *task;
+        struct nfs41_call_sync_data data = {
+                .clp = clp,
+                .seq_args = args,
+                .seq_res = res,
+                .cache_reply = cache_reply,
+        };
+        struct rpc_task_setup task_setup = {
+                .rpc_client = clnt,
+                .rpc_message = msg,
+                .callback_ops = &nfs41_call_sync_ops,
+                .callback_data = &data
+        };
+
+        res->sr_slotid = NFS4_MAX_SLOT_TABLE;
+        task = rpc_run_task(&task_setup);
+        if (IS_ERR(task))
+                ret = PTR_ERR(task);
+        else {
+                ret = task->tk_status;
+                rpc_put_task(task);
+        }
+        return ret;
+}
+
 int _nfs4_call_sync_session(struct nfs_server *server,
                             struct rpc_message *msg,
                             struct nfs4_sequence_args *args,
                             struct nfs4_sequence_res *res,
                             int cache_reply)
 {
-        /* in preparation for setting up the sequence op */
-        return rpc_call_sync(server->client, msg, 0);
+        return nfs4_call_sync_sequence(server->nfs_client, server->client,
+                                       msg, args, res, cache_reply);
 }
 
 #endif /* CONFIG_NFS_V4_1 */