[PATCH v3 5/7] trace-cmd: Reafctored add_event_pid()to utilize write_instance_file()

[Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>]

This patch changes add_event_pid() to utilize write_instance_file() for
writing set_event_pid instance file, instead of directly opening it.

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
---
 tracecmd/trace-record.c | 89 +++++++++++++++++++----------------------
 1 file changed, 42 insertions(+), 47 deletions(-)

diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 6972b9f..a398723 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -1094,30 +1094,64 @@ static void update_sched_events(struct buffer_instance *instance, int pid)
 static int open_instance_fd(struct buffer_instance *instance,
 			    const char *file, int flags);
 
-static void add_event_pid(const char *buf, int len)
+static int write_file(const char *file, const char *str, const char *type)
 {
-	struct buffer_instance *instance;
+	char buf[BUFSIZ];
 	int fd;
+	int ret;
 
-	for_all_instances(instance) {
-		fd = open_instance_fd(instance, "set_event_pid", O_WRONLY);
-		write(fd, buf, len);
+	fd = open(file, O_WRONLY | O_TRUNC);
+	if (fd < 0)
+		die("opening to '%s'", file);
+	ret = write(fd, str, strlen(str));
+	close(fd);
+	if (ret < 0 && type) {
+		/* write failed */
+		fd = open(file, O_RDONLY);
+		if (fd < 0)
+			die("writing to '%s'", file);
+		/* the filter has the error */
+		while ((ret = read(fd, buf, BUFSIZ)) > 0)
+			fprintf(stderr, "%.*s", ret, buf);
+		die("Failed %s of %s\n", type, file);
 		close(fd);
 	}
+	return ret;
+}
+
+static int
+write_instance_file(struct buffer_instance *instance,
+		    const char *file, const char *str, const char *type)
+{
+	char *path;
+	int ret;
+
+	path = get_instance_file(instance, file);
+	ret = write_file(path, str, type);
+	tracecmd_put_tracing_file(path);
+
+	return ret;
+}
+
+static void add_event_pid(const char *buf)
+{
+	struct buffer_instance *instance;
+
+	for_all_instances(instance)
+		write_instance_file(instance, "set_event_pid", buf, "event_pid");
 }
 
 static void add_new_filter_pid(int pid)
 {
 	struct buffer_instance *instance;
 	char buf[100];
-	int len;
 
 	add_filter_pid(pid, 0);
-	len = sprintf(buf, "%d", pid);
+	sprintf(buf, "%d", pid);
 	update_ftrace_pid(buf, 0);
 
 	if (have_set_event_pid)
-		return add_event_pid(buf, len);
+		return add_event_pid(buf);
 
 	common_pid_filter = append_pid_filter(common_pid_filter, "common_pid", pid);
 
@@ -1596,45 +1630,6 @@ static void reset_events(void)
 		reset_events_instance(instance);
 }
 
-static int write_file(const char *file, const char *str, const char *type)
-{
-	char buf[BUFSIZ];
-	int fd;
-	int ret;
-
-	fd = open(file, O_WRONLY | O_TRUNC);
-	if (fd < 0)
-		die("opening to '%s'", file);
-	ret = write(fd, str, strlen(str));
-	close(fd);
-	if (ret < 0 && type) {
-		/* write failed */
-		fd = open(file, O_RDONLY);
-		if (fd < 0)
-			die("writing to '%s'", file);
-		/* the filter has the error */
-		while ((ret = read(fd, buf, BUFSIZ)) > 0)
-			fprintf(stderr, "%.*s", ret, buf);
-		die("Failed %s of %s\n", type, file);
-		close(fd);
-	}
-	return ret;
-}
-
-static int
-write_instance_file(struct buffer_instance *instance,
-		    const char *file, const char *str, const char *type)
-{
-	char *path;
-	int ret;
-
-	path = get_instance_file(instance, file);
-	ret = write_file(path, str, type);
-	tracecmd_put_tracing_file(path);
-
-	return ret;
-}
-
 enum {
 	STATE_NEWLINE,
 	STATE_SKIP,
-- 
2.20.1