[PATCH v2 1/3] libtracefs: Add API to set the log level

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

Library log level is added and new API to set the desired level.
Log levels defined in libtraceevent are used. By default, the log level
of tracefs library is TEP_LOG_CRITICAL. When a new level is set, it is
also propagated to the libtraceevent.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 include/tracefs.h   |  4 ++++
 src/tracefs-utils.c | 18 +++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/include/tracefs.h b/include/tracefs.h
index 73ee42b..08dda13 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -180,4 +180,8 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char *filte
 int tracefs_function_notrace(struct tracefs_instance *instance, const char *filter,
 			     const char *module, unsigned int flags);
 
+
+/* Control library logs */
+void tracefs_set_loglevel(enum tep_loglevel level);
+
 #endif /* _TRACE_FS_H */
diff --git a/src/tracefs-utils.c b/src/tracefs-utils.c
index e10b333..9e37e75 100644
--- a/src/tracefs-utils.c
+++ b/src/tracefs-utils.c
@@ -15,6 +15,7 @@
 #include <unistd.h>
 #include <errno.h>
 
+#include <traceevent/event-parse.h>
 #include <traceevent/event-utils.h>
 #include "tracefs.h"
 #include "tracefs-local.h"
@@ -25,12 +26,27 @@
 #define _STR(x) #x
 #define STR(x) _STR(x)
 
+static int log_level = TEP_LOG_CRITICAL;
+
+/**
+ * tracefs_set_loglevel - set log level of the library
+ * @level: desired level of the library messages
+ */
+void tracefs_set_loglevel(enum tep_loglevel level)
+{
+	log_level = level;
+	tep_set_loglevel(level);
+}
+
 void __weak tracefs_warning(const char *fmt, ...)
 {
 	va_list ap;
 
+	if (log_level < TEP_LOG_WARNING)
+		return;
+
 	va_start(ap, fmt);
-	tep_vwarning("libtracefs", fmt, ap);
+	tep_vprint("libtracefs", TEP_LOG_WARNING, true, fmt, ap);
 	va_end(ap);
 }
 
-- 
2.31.1