infra: start dual compatibility with/out prepatch

Automatic detection whether the prepatch is applied or not.

kernel/brick_mem.h

@@ -24,6 +24,12 @@
 #ifndef BRICK_MEM_H
 #define BRICK_MEM_H
 
+/* TRANSITIONAL compatibility to BOTH the old prepatch
+ * and the new wrapper around vfs_*(). Both will be replaced
+ * for kernel upstream.
+ */
+#include "compat.h"
+
 #include <linux/mm_types.h>
 
 #ifndef CONFIG_MARS_MODULE

kernel/brick_say.c

@@ -47,6 +47,8 @@
 
 #include <asm/uaccess.h>
 
+#include "compat.h"
+
 #ifndef GFP_BRICK
 #define GFP_BRICK GFP_NOIO
 #endif

kernel/mars.h

@@ -24,8 +24,15 @@
 #ifndef MARS_H
 #define MARS_H
 
+/* TRANSITIONAL compatibility to BOTH the old prepatch
+ * and the new wrapper around vfs_*(). Both will be replaced
+ * for kernel upstream.
+ */
+#include "compat.h"
+
 #include <linux/semaphore.h>
 #include <linux/rwsem.h>
+#include <linux/major.h>
 
 //#define MARS_TRACING // write runtime trace data to /mars/trace.csv
 
@@ -58,7 +65,6 @@
 #error Fixme: CONFIG_DEBUG_SG does not work (fix the bio offset calculation)
 #endif
 
-
 /////////////////////////////////////////////////////////////////////////
 
 // include the generic brick infrastructure