[PATCH] BLK_DEV_INITRD: do not require BLK_DEV_RAM=y

Initramfs initrd images do not need a ramdisk device, so remove this
restriction in Kconfig.  BLK_DEV_RAM=n saves about 13k on i386.  Also
without ramdisk device there's no need for "dry run", so initramfs unpacks
much faster.

People using cramfs, squashfs, or gzipped ext2/minix initrd images are
probably smart enough not to turn off ramdisk support by accident.

Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/init/initramfs.c b/init/initramfs.c
index 637344b..77b934c 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -506,6 +506,7 @@
 		panic(err);
 #ifdef CONFIG_BLK_DEV_INITRD
 	if (initrd_start) {
+#ifdef CONFIG_BLK_DEV_RAM
 		int fd;
 		printk(KERN_INFO "checking if image is initramfs...");
 		err = unpack_to_rootfs((char *)initrd_start,
@@ -525,6 +526,15 @@
 			sys_close(fd);
 			free_initrd();
 		}
+#else
+		printk(KERN_INFO "Unpacking initramfs...");
+		err = unpack_to_rootfs((char *)initrd_start,
+			initrd_end - initrd_start, 0);
+		if (err)
+			panic(err);
+		printk(" done\n");
+		free_initrd();
+#endif
 	}
 #endif
 }