SUNRPC: add a handful of per-xprt counters

Monitor generic transport events.  Add a transport switch callout to
format transport counters for export to user-land.

Test plan:
Compile kernel with CONFIG_NFS enabled.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 6ef99b14ff0..7eebbab7160 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -114,6 +114,7 @@ struct rpc_xprt_ops {
         void            (*release_request)(struct rpc_task *task);
         void            (*close)(struct rpc_xprt *xprt);
         void            (*destroy)(struct rpc_xprt *xprt);
+        void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 };
 
 struct rpc_xprt {
@@ -187,6 +188,18 @@ struct rpc_xprt {
 
         struct list_head        recv;
 
+        struct {
+                unsigned long           bind_count,     /* total number of binds */
+                                        connect_count,  /* total number of connects */
+                                        connect_start,  /* connect start timestamp */
+                                        connect_time,   /* jiffies waiting for connect */
+                                        sends,          /* how many complete requests */
+                                        recvs,          /* how many complete requests */
+                                        bad_xids;       /* lookup_rqst didn't find XID */
+
+                unsigned long long      req_u,          /* average requests on the wire */
+                                        bklog_u;        /* backlog queue utilization */
+        } stat;
 
         void                    (*old_data_ready)(struct sock *, int);
         void                    (*old_state_change)(struct sock *);