[PATCH 2/3] libtracefs: Add parameter to turn off warnings in str_read_file()

[Steven Rostedt <rostedt@xxxxxxxxxxx>]

From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

There may be cases when reading a file that warnings should not be
displayed. Add a parameter to str_read_file() that lets the caller tell it
not to warn on any errors.

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
 include/tracefs-local.h | 2 +-
 src/tracefs-events.c    | 6 +++---
 src/tracefs-instance.c  | 2 +-
 src/tracefs-utils.c     | 8 +++++---
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/tracefs-local.h b/include/tracefs-local.h
index 84e4b10..9e3aa18 100644
--- a/include/tracefs-local.h
+++ b/include/tracefs-local.h
@@ -42,7 +42,7 @@ static inline pthread_mutex_t *trace_get_lock(struct tracefs_instance *instance)
 /* Can be overridden */
 void tracefs_warning(const char *fmt, ...);
 
-int str_read_file(const char *file, char **buffer);
+int str_read_file(const char *file, char **buffer, bool warn);
 char *trace_append_file(const char *dir, const char *name);
 char *trace_find_tracing_dir(void);
 
diff --git a/src/tracefs-events.c b/src/tracefs-events.c
index 9a706ab..ab474e0 100644
--- a/src/tracefs-events.c
+++ b/src/tracefs-events.c
@@ -485,7 +485,7 @@ char **tracefs_tracers(const char *tracing_dir)
 	if (ret < 0)
 		goto out_free;
 
-	len = str_read_file(available_tracers, &buf);
+	len = str_read_file(available_tracers, &buf, true);
 	if (len <= 0)
 		goto out_free;
 
@@ -545,7 +545,7 @@ static int load_events(struct tep_handle *tep,
 		if (ret < 0)
 			goto next_event;
 
-		len = str_read_file(format, &buf);
+		len = str_read_file(format, &buf, true);
 		if (len <= 0)
 			goto next_event;
 
@@ -575,7 +575,7 @@ static int read_header(struct tep_handle *tep, const char *tracing_dir)
 	if (ret < 0)
 		goto out;
 
-	len = str_read_file(header, &buf);
+	len = str_read_file(header, &buf, true);
 	if (len <= 0)
 		goto out;
 
diff --git a/src/tracefs-instance.c b/src/tracefs-instance.c
index c6cfbda..b8ce36f 100644
--- a/src/tracefs-instance.c
+++ b/src/tracefs-instance.c
@@ -400,7 +400,7 @@ char *tracefs_instance_file_read(struct tracefs_instance *instance,
 	if (!path)
 		return NULL;
 
-	size = str_read_file(path, &buf);
+	size = str_read_file(path, &buf, true);
 
 	tracefs_put_tracing_file(path);
 	if (buf && psize)
diff --git a/src/tracefs-utils.c b/src/tracefs-utils.c
index 812a41a..e10b333 100644
--- a/src/tracefs-utils.c
+++ b/src/tracefs-utils.c
@@ -196,7 +196,7 @@ void tracefs_put_tracing_file(char *name)
 	free(name);
 }
 
-__hidden int str_read_file(const char *file, char **buffer)
+__hidden int str_read_file(const char *file, char **buffer, bool warn)
 {
 	char stbuf[BUFSIZ];
 	char *buf = NULL;
@@ -207,7 +207,8 @@ __hidden int str_read_file(const char *file, char **buffer)
 
 	fd = open(file, O_RDONLY);
 	if (fd < 0) {
-		tracefs_warning("File %s not found", file);
+		if (warn)
+			tracefs_warning("File %s not found", file);
 		return -1;
 	}
 
@@ -217,7 +218,8 @@ __hidden int str_read_file(const char *file, char **buffer)
 			continue;
 		nbuf = realloc(buf, size+r+1);
 		if (!nbuf) {
-			tracefs_warning("Failed to allocate file buffer");
+			if (warn)
+				tracefs_warning("Failed to allocate file buffer");
 			size = -1;
 			break;
 		}
-- 
2.29.2