Add 'opendir' option

This option adds all files from a directory and downward in the
filesystem hierarchy.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.h b/fio.h
index 7db3090..5173464 100644
--- a/fio.h
+++ b/fio.h
@@ -393,6 +393,7 @@
 	unsigned int file_service_type;
 	unsigned int group_reporting;
 	unsigned int open_files;
+	char *opendir;
 
 	char *read_iolog_file;
 	char *write_iolog_file;
@@ -660,6 +661,7 @@
 extern void add_file(struct thread_data *, const char *);
 extern void get_file(struct fio_file *);
 extern void put_file(struct thread_data *, struct fio_file *);
+extern int add_dir_files(struct thread_data *, const char *);
 
 /*
  * ETA/status stuff