- explain what magic numbers we're using here.
diff --git a/util-linux/freeramdisk.c b/util-linux/freeramdisk.c
index 923a151..1f010c7 100644
--- a/util-linux/freeramdisk.c
+++ b/util-linux/freeramdisk.c
@@ -18,6 +18,11 @@
#include <unistd.h>
#include "busybox.h"
+/* From linux/fs.h */
+#define BLKFLSBUF _IO(0x12,97)
+/* From <linux/fd.h> */
+#define FDFLUSH _IO(2,0x4b)
+
int freeramdisk_main(int argc, char **argv)
{
int result;
@@ -29,7 +34,7 @@
// Act like freeramdisk, fdflush, or both depending on configuration.
result = ioctl(fd, (ENABLE_FREERAMDISK && bb_applet_name[1]=='r')
- || !ENABLE_FDFLUSH ? _IO(0x12,97) : _IO(2,0x4b));
+ || !ENABLE_FDFLUSH ? BLKFLSBUF : FDFLUSH);
if (ENABLE_FEATURE_CLEAN_UP) close(fd);