ipconfig: Handle CONFIG_CIFS_ROOT option

The experimental root file system support in cifs.ko relies on
ipconfig to set up the network stack and then accessing the SMB share
that contains the rootfs files.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ipconfig.c

@@ -1483,10 +1483,10 @@ static int __init ip_auto_config(void)
 	 * missing values.
 	 */
 	if (ic_myaddr == NONE ||
-#ifdef CONFIG_ROOT_NFS
+#if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
 	    (root_server_addr == NONE &&
 	     ic_servaddr == NONE &&
-	     ROOT_DEV == Root_NFS) ||
+	     (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
 #endif
 	    ic_first_dev->next) {
 #ifdef IPCONFIG_DYNAMIC
@@ -1513,6 +1513,12 @@ static int __init ip_auto_config(void)
 				goto try_try_again;
 			}
 #endif
+#ifdef CONFIG_CIFS_ROOT
+			if (ROOT_DEV == Root_CIFS) {
+				pr_err("IP-Config: Retrying forever (CIFS root)...\n");
+				goto try_try_again;
+			}
+#endif
 
 			if (--retries) {
 				pr_err("IP-Config: Reopening network devices...\n");