[PATCH] trace: add trace_event for the open() syscall

[Scott James Remnant]

This patch uses TRACE_EVENT to add a tracepoint for the open()
syscall, in the spirit of the previous patch for sreadahead
that added the trace with ftrace.

It's not upstream because a much better system for adding tracepoints
for all syscalls is being worked on upstream, this is a stop-gap until
we have that.

Signed-off-by: Scott James Remnant <scott at ubuntu.com>
---
 fs/open.c                 |    4 ++++
 include/trace/events/fs.h |   35 +++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 0 deletions(-)
 create mode 100644 include/trace/events/fs.h

diff --git a/fs/open.c b/fs/open.c
index dd98e80..bc70440 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -31,6 +31,9 @@
 #include <linux/falloc.h>
 #include <linux/fs_struct.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/fs.h>
+
 int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	int retval = -ENODEV;
@@ -1040,6 +1043,7 @@ long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
 			} else {
 				fsnotify_open(f->f_path.dentry);
 				fd_install(fd, f);
+				trace_do_sys_open(tmp, flags, mode);
 			}
 		}
 		putname(tmp);
diff --git a/include/trace/events/fs.h b/include/trace/events/fs.h
new file mode 100644
index 0000000..ae330c8
--- /dev/null
+++ b/include/trace/events/fs.h
@@ -0,0 +1,35 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fs
+
+#if !defined(_TRACE_FS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FS_H
+
+#include <linux/fs.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(do_sys_open,
+
+	TP_PROTO(char *filename, int flags, int mode),
+
+	TP_ARGS(filename, flags, mode),
+
+	TP_STRUCT__entry(
+		__string(	filename, filename		)
+		__field(	int, flags			)
+		__field(	int, mode			)
+	),
+
+	TP_fast_assign(
+		__assign_str(filename, filename);
+		__entry->flags = flags;
+		__entry->mode = mode;
+	),
+
+	TP_printk("\"%s\" %x %o",
+		  __get_str(filename), __entry->flags, __entry->mode)
+);
+
+#endif /* _TRACE_FS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
1.6.0.5