Add write_file function

write_file() will write a buffer to a file. The file is created
if necessary.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs/fs.c

@@ -67,6 +67,25 @@ err_out:
 
 EXPORT_SYMBOL(read_file);
 
+int write_file(const char *filename, void *buf, size_t size)
+{
+	int fd, ret;
+
+	fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT);
+	if (fd < 0)
+		return fd;
+
+	ret = write_full(fd, buf, size);
+
+	close(fd);
+
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL(write_file);
+
 char *mkmodestr(unsigned long mode, char *str)
 {
 	static const char *l = "xwr";

include/fs.h

@@ -166,6 +166,11 @@ char *mkmodestr(unsigned long mode, char *str);
  */
 void *read_file(const char *filename, size_t *size);
 
+/*
+ * Write a buffer to a file. This file is newly created.
+ */
+int write_file(const char *filename, void *buf, size_t size);
+
 /*
  * This function turns 'path' into an absolute path and removes all occurrences
  * of "..", "." and double slashes. The returned string must be freed wit free().