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, 15 insertions, 6 deletions

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 8ff2c8acb223..93a0a3ca0d5f 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -548,6 +548,7 @@ void xprt_connect(struct rpc_task *task)
 
                 task->tk_timeout = xprt->connect_timeout;
                 rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL);
+                xprt->stat.connect_start = jiffies;
                 xprt->ops->connect(task);
         }
         return;
@@ -558,6 +559,8 @@ static void xprt_connect_status(struct rpc_task *task)
         struct rpc_xprt *xprt = task->tk_xprt;
 
         if (task->tk_status >= 0) {
+                xprt->stat.connect_count++;
+                xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
                 dprintk("RPC: %4d xprt_connect_status: connection established\n",
                                 task->tk_pid);
                 return;
@@ -601,16 +604,14 @@ static void xprt_connect_status(struct rpc_task *task)
 struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid)
 {
         struct list_head *pos;
-        struct rpc_rqst *req = NULL;
 
         list_for_each(pos, &xprt->recv) {
                 struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list);
-                if (entry->rq_xid == xid) {
-                        req = entry;
-                        break;
-                }
+                if (entry->rq_xid == xid)
+                        return entry;
         }
-        return req;
+        xprt->stat.bad_xids++;
+        return NULL;
 }
 
 /**
@@ -646,6 +647,7 @@ void xprt_complete_rqst(struct rpc_task *task, int copied)
         dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
                         task->tk_pid, ntohl(req->rq_xid), copied);
 
+        task->tk_xprt->stat.recvs++;
         list_del_init(&req->rq_list);
         req->rq_received = req->rq_private_buf.len = copied;
         rpc_wake_up_task(task);
@@ -744,12 +746,19 @@ void xprt_transmit(struct rpc_task *task)
         if (status == 0) {
                 dprintk("RPC: %4d xmit complete\n", task->tk_pid);
                 spin_lock_bh(&xprt->transport_lock);
+
                 xprt->ops->set_retrans_timeout(task);
+
+                xprt->stat.sends++;
+                xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
+                xprt->stat.bklog_u += xprt->backlog.qlen;
+
                 /* Don't race with disconnect */
                 if (!xprt_connected(xprt))
                         task->tk_status = -ENOTCONN;
                 else if (!req->rq_received)
                         rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer);
+
                 xprt->ops->release_xprt(xprt, task);
                 spin_unlock_bh(&xprt->transport_lock);
                 return;