: Blktap kernel compat layer

diff -r db4f08203b8a drivers/xen/blktap/blktap.c
@@ -89,8 +89,13 @@
 /*Data struct handed back to userspace for tapdisk device to VBD mapping*/
 typedef struct domid_translate {
 	unsigned short domid;
+	unsigned short busid;
+} domid_translate_t ;
+
+typedef struct domid_translate_ext {
+	unsigned short domid;
 	u32 busid;
-} domid_translate_t ;
+} domid_translate_ext_t ;
 
 /*Data struct associated with each of the tapdisk devices*/
 typedef struct tap_blkif {

@@ -110,7 +115,7 @@
 	unsigned long *idx_map;       /*Record the user ring id to kern 
 					[req id, idx] tuple                  */
 	blkif_t *blkif;               /*Associate blkif with tapdev          */
-	struct domid_translate trans; /*Translation from domid to bus.       */
+	struct domid_translate_ext trans; /*Translation from domid to bus.   */
 } tap_blkif_t;
 
 static struct tap_blkif *tapfds[MAX_TAP_DEV];

@@ -213,6 +218,7 @@
 #define BLKTAP_IOCTL_MAJOR	     7
 #define BLKTAP_QUERY_ALLOC_REQS      8
 #define BLKTAP_IOCTL_FREEINTF        9
+#define BLKTAP_IOCTL_NEWINTF_EXT     50
 #define BLKTAP_IOCTL_PRINT_IDXS      100  
 
 /* blktap switching modes: (Set with BLKTAP_IOCTL_SETMODE)             */

@@ -782,6 +788,26 @@
 		}
 		info->trans.domid = tr->domid;
 		info->trans.busid = tr->busid;
+		return info->minor;
+	}
+	case BLKTAP_IOCTL_NEWINTF_EXT:
+	{
+		void __user *udata = (void __user *) arg;
+		domid_translate_ext_t tr;
+
+		if (copy_from_user(&tr, udata, sizeof(domid_translate_ext_t)))
+			return -EFAULT;
+
+		DPRINTK("NEWINTF_EXT Req for domid %d and bus id %d\n", 
+		       tr.domid, tr.busid);
+		info = get_next_free_dev();
+		if (!info) {
+			WPRINTK("Error initialising /dev/xen/blktap - "
+				"No more devices\n");
+			return -1;
+		}
+		info->trans.domid = tr.domid;
+		info->trans.busid = tr.busid;
 		return info->minor;
 	}
 	case BLKTAP_IOCTL_FREEINTF: