Add DTrace probes to the NFS access and attribute caches. Access cache

events are:

  nfsclient:accesscache:flush:done
  nfsclient:accesscache:get:hit
  nfsclient:accesscache:get:miss
  nfsclient:accesscache:load:done

They pass the vnode, uid, and requested or loaded access mode (if any);
the load event may also report a load error if the RPC fails.

The attribute cache events are:

  nfsclient:attrcache:flush:done
  nfsclient:attrcache:get:hit
  nfsclient:attrcache:get:miss
  nfsclient:attrcache:load:done

They pass the vnode, optionally the vattr if one is present (hit or load),
and in the case of a load event, also a possible RPC error.

MFC after:	1 month
Sponsored by:	Google, Inc.

1 files changed, 121 insertions, 0 deletions

diff --git a/sys/nfsclient/nfs_kdtrace.h b/sys/nfsclient/nfs_kdtrace.h
new file mode 100644
index 0000000..4bd4557
--- /dev/null
+++ b/sys/nfsclient/nfs_kdtrace.h
@@ -0,0 +1,121 @@
+/*-
+ * Copyright (c) 2009 Robert N. M. Watson
+ * All rights reserved.
+ *
+ * This software was developed at the University of Cambridge Computer
+ * Laboratory with support from a grant from Google, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _NFSCLIENT_NFS_KDTRACE_H_
+#define	_NFSCLIENT_NFS_KDTRACE_H_
+
+#ifdef KDTRACE_HOOKS
+#include <sys/dtrace_bsd.h>
+
+/*
+ * Definitions for NFS access cache probes.
+ */
+extern uint32_t nfsclient_accesscache_flush_done_id;
+extern uint32_t nfsclient_accesscache_get_hit_id;
+extern uint32_t nfsclient_accesscache_get_miss_id;
+extern uint32_t nfsclient_accesscache_load_done_id;
+
+#define	KDTRACE_NFS_ACCESSCACHE_FLUSH_DONE(vp)	do {			\
+	if (dtrace_nfsclient_accesscache_flush_done_probe != NULL)	\
+		(dtrace_nfsclient_accesscache_flush_done_probe)(	\
+		    nfsclient_accesscache_flush_done_id, (vp));		\
+} while (0)
+
+#define	KDTRACE_NFS_ACCESSCACHE_GET_HIT(vp, uid, mode)	do {		\
+	if (dtrace_nfsclient_accesscache_get_hit_probe != NULL)		\
+		(dtrace_nfsclient_accesscache_get_hit_probe)(		\
+		    nfsclient_accesscache_get_hit_id, (vp), (uid),	\
+		    (mode));						\
+} while (0)
+	
+#define	KDTRACE_NFS_ACCESSCACHE_GET_MISS(vp, uid, mode)	do {		\
+	if (dtrace_nfsclient_accesscache_get_miss_probe != NULL)	\
+		(dtrace_nfsclient_accesscache_get_miss_probe)(		\
+		    nfsclient_accesscache_get_miss_id, (vp), (uid),	\
+		    (mode));						\
+} while (0)
+
+#define	KDTRACE_NFS_ACCESSCACHE_LOAD_DONE(vp, uid, rmode, error) do {	\
+	if (error && dtrace_nfsclient_accesscache_load_done_probe !=	\
+	    NULL)							\
+		(dtrace_nfsclient_accesscache_load_done_probe)(		\
+		    nfsclient_accesscache_load_done_id, (vp), (uid),	\
+		    (rmode), (error));					\
+} while (0)
+
+/*
+ * Definitions for NFS attribute cache probes.
+ */
+extern uint32_t nfsclient_attrcache_flush_done_id;
+extern uint32_t nfsclient_attrcache_get_hit_id;
+extern uint32_t nfsclient_attrcache_get_miss_id;
+extern uint32_t nfsclient_attrcache_load_done_id;
+
+#define	KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp)	do {			\
+	if (dtrace_nfsclient_attrcache_flush_done_probe != NULL)	\
+		(dtrace_nfsclient_attrcache_flush_done_probe)(		\
+		    nfsclient_attrcache_flush_done_id, (vp));		\
+} while (0)
+
+#define	KDTRACE_NFS_ATTRCACHE_GET_HIT(vp, vap)	do {			\
+	if (dtrace_nfsclient_attrcache_get_hit_probe != NULL)		\
+		(dtrace_nfsclient_attrcache_get_hit_probe)(		\
+		    nfsclient_attrcache_get_hit_id, (vp), (vap));	\
+} while (0)
+
+#define	KDTRACE_NFS_ATTRCACHE_GET_MISS(vp)	do {			\
+	if (dtrace_nfsclient_attrcache_get_miss_probe != NULL)		\
+		(dtrace_nfsclient_attrcache_get_miss_probe)(		\
+			    nfsclient_attrcache_get_miss_id, (vp));	\
+} while (0)
+
+#define	KDTRACE_NFS_ATTRCACHE_LOAD_DONE(vp, vap, error)	do {		\
+	if (dtrace_nfsclient_attrcache_load_done_probe != NULL)		\
+		(dtrace_nfsclient_attrcache_load_done_probe)(		\
+		    nfsclient_attrcache_load_done_id, (vp), (vap),	\
+		    (error));						\
+} while (0)
+
+#else /* !KDTRACE_HOOKS */
+
+#define	KDTRACE_NFS_ACCESSCACHE_FLUSH_DONE(vp)
+#define	KDTRACE_NFS_ACCESSCACHE_GET_HIT(vp, uid, mode)
+#define	KDTRACE_NFS_ACCESSCACHE_GET_MISS(vp, uid, mode)
+#define	KDTRACE_NFS_ACCESSCACHE_LOAD_DONE(vp, uid, rmode, error)
+
+#define	KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp)
+#define	KDTRACE_NFS_ATTRCACHE_GET_HIT(vp, vap)
+#define	KDTRACE_NFS_ATTRCACHE_GET_MISS(vp)
+#define	KDTRACE_NFS_ATTRCACHE_LOAD_DONE(vp, vap, error)
+
+#endif /* KDTRACE_HOOKS */
+
+#endif /* !_NFSCLIENT_NFS_KDTRACE_H_ */