SUNRPC: Don't allocate a full sockaddr_storage for tracing

We're always tracing IPv4 or IPv6 addresses, so we can save a lot
of space on the ringbuffer by allocating the correct sockaddr size.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Fixes: 83a712e0afef "sunrpc: add some tracepoints around ..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 34 insertions, 13 deletions

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 003dca933803..5664ca07c9c7 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -529,20 +529,27 @@ TRACE_EVENT(svc_xprt_do_enqueue,
 
         TP_STRUCT__entry(
                 __field(struct svc_xprt *, xprt)
-                __field_struct(struct sockaddr_storage, ss)
                 __field(int, pid)
                 __field(unsigned long, flags)
+                __dynamic_array(unsigned char, addr, xprt != NULL ?
+                        xprt->xpt_remotelen : 0)
         ),
 
         TP_fast_assign(
                 __entry->xprt = xprt;
-                xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss));
                 __entry->pid = rqst? rqst->rq_task->pid : 0;
-                __entry->flags = xprt ? xprt->xpt_flags : 0;
+                if (xprt) {
+                        memcpy(__get_dynamic_array(addr),
+                                &xprt->xpt_remote,
+                                xprt->xpt_remotelen);
+                        __entry->flags = xprt->xpt_flags;
+                } else
+                        __entry->flags = 0;
         ),
 
         TP_printk("xprt=0x%p addr=%pIScp pid=%d flags=%s", __entry->xprt,
-                (struct sockaddr *)&__entry->ss,
+                __get_dynamic_array_len(addr) != 0 ?
+                        (struct sockaddr *)__get_dynamic_array(addr) : NULL,
                 __entry->pid, show_svc_xprt_flags(__entry->flags))
 );
 
@@ -553,18 +560,25 @@ TRACE_EVENT(svc_xprt_dequeue,
 
         TP_STRUCT__entry(
                 __field(struct svc_xprt *, xprt)
-                __field_struct(struct sockaddr_storage, ss)
                 __field(unsigned long, flags)
+                __dynamic_array(unsigned char, addr, xprt != NULL ?
+                        xprt->xpt_remotelen : 0)
         ),
 
         TP_fast_assign(
-                __entry->xprt = xprt,
-                xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss));
-                __entry->flags = xprt ? xprt->xpt_flags : 0;
+                __entry->xprt = xprt;
+                if (xprt) {
+                        memcpy(__get_dynamic_array(addr),
+                                        &xprt->xpt_remote,
+                                        xprt->xpt_remotelen);
+                        __entry->flags = xprt->xpt_flags;
+                } else
+                        __entry->flags = 0;
         ),
 
         TP_printk("xprt=0x%p addr=%pIScp flags=%s", __entry->xprt,
-                (struct sockaddr *)&__entry->ss,
+                __get_dynamic_array_len(addr) != 0 ?
+                        (struct sockaddr *)__get_dynamic_array(addr) : NULL,
                 show_svc_xprt_flags(__entry->flags))
 );
 
@@ -592,19 +606,26 @@ TRACE_EVENT(svc_handle_xprt,
         TP_STRUCT__entry(
                 __field(struct svc_xprt *, xprt)
                 __field(int, len)
-                __field_struct(struct sockaddr_storage, ss)
                 __field(unsigned long, flags)
+                __dynamic_array(unsigned char, addr, xprt != NULL ?
+                        xprt->xpt_remotelen : 0)
         ),
 
         TP_fast_assign(
                 __entry->xprt = xprt;
-                xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss));
                 __entry->len = len;
-                __entry->flags = xprt ? xprt->xpt_flags : 0;
+                if (xprt) {
+                        memcpy(__get_dynamic_array(addr),
+                                        &xprt->xpt_remote,
+                                        xprt->xpt_remotelen);
+                        __entry->flags = xprt->xpt_flags;
+                } else
+                        __entry->flags = 0;
         ),
 
         TP_printk("xprt=0x%p addr=%pIScp len=%d flags=%s", __entry->xprt,
-                (struct sockaddr *)&__entry->ss,
+                __get_dynamic_array_len(addr) != 0 ?
+                        (struct sockaddr *)__get_dynamic_array(addr) : NULL,
                 __entry->len, show_svc_xprt_flags(__entry->flags))
 );
 #endif /* _TRACE_SUNRPC_H */