fs: binding of pipes to vnodes

kernel-src/include/kernel/pipefs.h

@@ -18,5 +18,6 @@ typedef struct pipenode_t {
 
 void pipefs_init();
 int pipefs_newpipe(vnode_t **nodep);
+int pipefs_getbinding(vnode_t *node, vnode_t **pipep);
 
 #endif

kernel-src/include/kernel/vfs.h

@@ -78,7 +78,11 @@ typedef struct vnode_t {
 	int type;
 	vfs_t *vfs;
 	vfs_t *vfsmounted;
-	void *socketbinding;
+	union {
+		void *socketbinding;
+		void *fifobinding;
+	};
+
 	struct page_t *pages;
 } vnode_t;