[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>

drivers/block/Kconfig

@@ -401,7 +401,6 @@ config BLK_DEV_RAM_SIZE
 
 config BLK_DEV_INITRD
 	bool "Initial RAM disk (initrd) support"
-	depends on BLK_DEV_RAM=y
 	help
 	  The initial RAM disk is a RAM disk that is loaded by the boot loader
 	  (loadlin or lilo) and that is mounted as root before the normal boot

init/initramfs.c

@@ -506,6 +506,7 @@ void __init populate_rootfs(void)
 		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 @@ void __init populate_rootfs(void)
 			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
 }