[PACTH v1] trace: Add trace events for open(), exec() and uselib()

[robert . foss]

From: Scott James Remnant <scott@xxxxxxxxxx>

This patch uses TRACE_EVENT to add tracepoints for the open(),
exec() and uselib() syscalls so that ureadahead can cheaply trace
the boot sequence to determine what to read to speed up the next.

Signed-off-by: Scott James Remnant <scott@xxxxxxxxxx>
Tested-by: Robert Foss <robert.foss@xxxxxxxxxxxxx>
Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxxxxx>
---
 fs/exec.c                 |  7 ++++++-
 fs/open.c                 |  4 ++++
 include/trace/events/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 include/trace/events/fs.h

diff --git a/fs/exec.c b/fs/exec.c
index 887c1c9..123b257 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -58,6 +58,8 @@
 #include <linux/compat.h>
 #include <linux/vmalloc.h>
 
+#include <trace/events/fs.h>
+
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
 #include <asm/tlb.h>
@@ -797,9 +799,12 @@ static struct file *do_open_execat(int fd, struct filename *name, int flags)
 	if (err)
 		goto exit;
 
-	if (name->name[0] != '\0')
+	if (name->name[0] != '\0') {
 		fsnotify_open(file);
 
+		trace_open_exec(name->name);
+	}
+
 out:
 	return file;
 
diff --git a/fs/open.c b/fs/open.c
index 93ae3cd..2ec0680 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -34,6 +34,9 @@
 
 #include "internal.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/fs.h>
+
 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
 	struct file *filp)
 {
@@ -1020,6 +1023,7 @@ long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
 		} else {
 			fsnotify_open(f);
 			fd_install(fd, f);
+			trace_do_sys_open(tmp->name, flags, mode);
 		}
 	}
 	putname(tmp);
diff --git a/include/trace/events/fs.h b/include/trace/events/fs.h
new file mode 100644
index 0000000..fb634b7
--- /dev/null
+++ b/include/trace/events/fs.h
@@ -0,0 +1,53 @@
+#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(const 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)
+);
+
+TRACE_EVENT(open_exec,
+
+	TP_PROTO(const char *filename),
+
+	TP_ARGS(filename),
+
+	TP_STRUCT__entry(
+		__string(	filename, filename		)
+	),
+
+	TP_fast_assign(
+		__assign_str(filename, filename);
+	),
+
+	TP_printk("\"%s\"",
+		  __get_str(filename))
+);
+
+#endif /* _TRACE_FS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.7.4