sunrpc: add some tracepoints in svc_rqst handling functions

...just around svc_send, svc_recv and svc_process for now.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

3 files changed, 88 insertions, 19 deletions

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 1fef3e6e9436..6260f5134212 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -6,6 +6,7 @@
 
 #include <linux/sunrpc/sched.h>
 #include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
 #include <net/tcp_states.h>
 #include <linux/net.h>
 #include <linux/tracepoint.h>
@@ -306,6 +307,60 @@ DEFINE_RPC_SOCKET_EVENT_DONE(rpc_socket_reset_connection);
 DEFINE_RPC_SOCKET_EVENT(rpc_socket_close);
 DEFINE_RPC_SOCKET_EVENT(rpc_socket_shutdown);
 
+TRACE_EVENT(svc_recv,
+        TP_PROTO(struct svc_rqst *rqst, int status),
+
+        TP_ARGS(rqst, status),
+
+        TP_STRUCT__entry(
+                __field(struct sockaddr *, addr)
+                __field(__be32, xid)
+                __field(int, status)
+        ),
+
+        TP_fast_assign(
+                __entry->addr = (struct sockaddr *)&rqst->rq_addr;
+                __entry->xid = status > 0 ? rqst->rq_xid : 0;
+                __entry->status = status;
+        ),
+
+        TP_printk("addr=%pIScp xid=0x%x status=%d", __entry->addr,
+                        be32_to_cpu(__entry->xid), __entry->status)
+);
+
+DECLARE_EVENT_CLASS(svc_rqst_status,
+
+        TP_PROTO(struct svc_rqst *rqst, int status),
+
+        TP_ARGS(rqst, status),
+
+        TP_STRUCT__entry(
+                __field(struct sockaddr *, addr)
+                __field(__be32, xid)
+                __field(int, dropme)
+                __field(int, status)
+        ),
+
+        TP_fast_assign(
+                __entry->addr = (struct sockaddr *)&rqst->rq_addr;
+                __entry->xid = rqst->rq_xid;
+                __entry->dropme = (int)rqst->rq_dropme;
+                __entry->status = status;
+        ),
+
+        TP_printk("addr=%pIScp rq_xid=0x%x dropme=%d status=%d",
+                __entry->addr, be32_to_cpu(__entry->xid), __entry->dropme,
+                __entry->status)
+);
+
+DEFINE_EVENT(svc_rqst_status, svc_process,
+        TP_PROTO(struct svc_rqst *rqst, int status),
+        TP_ARGS(rqst, status));
+
+DEFINE_EVENT(svc_rqst_status, svc_send,
+        TP_PROTO(struct svc_rqst *rqst, int status),
+        TP_ARGS(rqst, status));
+
 #endif /* _TRACE_SUNRPC_H */
 
 #include <trace/define_trace.h>
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index ca8a7958f4e6..371a8bbb43d6 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -28,6 +28,8 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/bc_xprt.h>
 
+#include <trace/events/sunrpc.h>
+
 #define RPCDBG_FACILITY RPCDBG_SVCDSP
 
 static void svc_unregister(const struct svc_serv *serv, struct net *net);
@@ -1314,24 +1316,25 @@ svc_process(struct svc_rqst *rqstp)
         rqstp->rq_res.tail[0].iov_base = NULL;
         rqstp->rq_res.tail[0].iov_len = 0;
 
-        rqstp->rq_xid = svc_getu32(argv);
-
         dir  = svc_getnl(argv);
         if (dir != 0) {
                 /* direction != CALL */
                 svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
                 serv->sv_stats->rpcbadfmt++;
-                svc_drop(rqstp);
-                return 0;
+                goto out_drop;
         }
 
         /* Returns 1 for send, 0 for drop */
-        if (svc_process_common(rqstp, argv, resv))
-                return svc_send(rqstp);
-        else {
-                svc_drop(rqstp);
-                return 0;
+        if (likely(svc_process_common(rqstp, argv, resv))) {
+                int ret = svc_send(rqstp);
+
+                trace_svc_process(rqstp, ret);
+                return ret;
         }
+out_drop:
+        trace_svc_process(rqstp, 0);
+        svc_drop(rqstp);
+        return 0;
 }
 
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index c179ca2a5aa4..bbb3b044b877 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -15,6 +15,7 @@
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/xprt.h>
 #include <linux/module.h>
+#include <trace/events/sunrpc.h>
 
 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
 
@@ -773,35 +774,43 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
 
         err = svc_alloc_arg(rqstp);
         if (err)
-                return err;
+                goto out;
 
         try_to_freeze();
         cond_resched();
+        err = -EINTR;
         if (signalled() || kthread_should_stop())
-                return -EINTR;
+                goto out;
 
         xprt = svc_get_next_xprt(rqstp, timeout);
-        if (IS_ERR(xprt))
-                return PTR_ERR(xprt);
+        if (IS_ERR(xprt)) {
+                err = PTR_ERR(xprt);
+                goto out;
+        }
 
         len = svc_handle_xprt(rqstp, xprt);
 
         /* No data, incomplete (TCP) read, or accept() */
+        err = -EAGAIN;
         if (len <= 0)
-                goto out;
+                goto out_release;
 
         clear_bit(XPT_OLD, &xprt->xpt_flags);
 
         rqstp->rq_secure = xprt->xpt_ops->xpo_secure_port(rqstp);
         rqstp->rq_chandle.defer = svc_defer;
+        rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]);
 
         if (serv->sv_stats)
                 serv->sv_stats->netcnt++;
+        trace_svc_recv(rqstp, len);
         return len;
-out:
+out_release:
         rqstp->rq_res.len = 0;
         svc_xprt_release(rqstp);
-        return -EAGAIN;
+out:
+        trace_svc_recv(rqstp, err);
+        return err;
 }
 EXPORT_SYMBOL_GPL(svc_recv);
 
@@ -821,12 +830,12 @@ EXPORT_SYMBOL_GPL(svc_drop);
 int svc_send(struct svc_rqst *rqstp)
 {
         struct svc_xprt *xprt;
-        int             len;
+        int             len = -EFAULT;
         struct xdr_buf  *xb;
 
         xprt = rqstp->rq_xprt;
         if (!xprt)
-                return -EFAULT;
+                goto out;
 
         /* release the receive skb before sending the reply */
         rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
@@ -849,7 +858,9 @@ int svc_send(struct svc_rqst *rqstp)
         svc_xprt_release(rqstp);
 
         if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
-                return 0;
+                len = 0;
+out:
+        trace_svc_send(rqstp, len);
         return len;
 }