SUNRPC: Add a tracepoint for server socket out-of-space conditions

Add a tracepoint to track when the processing of incoming RPC data gets
deferred due to out-of-space issues on the outgoing transport.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 4f01f63102ee..4d2189a562af 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -333,8 +333,12 @@ static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt)
 {
         if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE)))
                 return true;
-        if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED)))
-                return xprt->xpt_ops->xpo_has_wspace(xprt);
+        if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED))) {
+                if (xprt->xpt_ops->xpo_has_wspace(xprt))
+                        return true;
+                trace_svc_xprt_no_write_space(xprt);
+                return false;
+        }
         return false;
 }