Description: Add options to tune the EXT FS produced in lb_binary_rootfs
 Adds --ext-block-size, --ext-resize-blocks and --ext-fudge-factor to
 enable building filesystem images with 4K blocks that can be
 online-resized to a configurable length.
Author: Daniel Watkins <daniel.watkins@canonical.com>

--- a/scripts/build/lb_binary_rootfs
+++ b/scripts/build/lb_binary_rootfs
@@ -129,7 +129,7 @@
 					FAKE_MTAB="true"
 				fi
 
-				Chroot chroot "mkfs.${LB_CHROOT_FILESYSTEM} -F -b 1024 -i 8192 -m 0 -L ${LB_HDD_LABEL} filesystem.${LB_CHROOT_FILESYSTEM}"
+				Chroot chroot "mkfs.${LB_CHROOT_FILESYSTEM} -F -b ${LB_EXT_BLOCKSIZE:-1024} -i 8192 -m 0 -L ${LB_HDD_LABEL} ${LB_EXT_RESIZEBLOCKS:+-E resize=${LB_EXT_RESIZEBLOCKS}} filesystem.${LB_CHROOT_FILESYSTEM}"
 
 				mkdir -p filesystem.tmp
 				${LB_ROOT_COMMAND} mount -o loop chroot/filesystem.${LB_CHROOT_FILESYSTEM} filesystem.tmp
@@ -199,7 +199,7 @@
 
 			false)
 				dd if=/dev/zero of=binary/${INITFS}/filesystem.${LB_CHROOT_FILESYSTEM} bs=1024k count=0 seek=${REAL_DIM}
-				mkfs.${LB_CHROOT_FILESYSTEM} -F -b 1024 -i 8192 -m 0 -L ${LB_HDD_LABEL} binary/${INITFS}/filesystem.${LB_CHROOT_FILESYSTEM}
+				mkfs.${LB_CHROOT_FILESYSTEM} -F -b ${LB_EXT_BLOCKSIZE:-1024} -i 8192 -m 0 -L ${LB_HDD_LABEL} ${LB_EXT_RESIZEBLOCKS:+-E resize=${LB_EXT_RESIZEBLOCKS}} binary/${INITFS}/filesystem.${LB_CHROOT_FILESYSTEM}
 
 				mkdir -p filesystem.tmp
 				${LB_ROOT_COMMAND} mount -o loop binary/${INITFS}/filesystem.${LB_CHROOT_FILESYSTEM} filesystem.tmp
--- a/scripts/build/lb_config
+++ b/scripts/build/lb_config
@@ -57,6 +57,9 @@
 \t    [--debian-installer-gui true|false]\n\
 \t    [--debug]\n\
 \t    [-d|--distribution CODENAME]\n\
+\t    [--ext-block-size 1024|2048|4096]\n\
+\t    [--ext-resize-blocks N]\n\
+\t    [--ext-fudge-factor PERCENTAGE]\n\
 \t    [--parent-distribution CODENAME]\n\
 \t    [--parent-debian-installer-distribution CODENAME]\n\
 \t    [--dump]\n\
@@ -157,7 +160,7 @@
 		apt-indices:,bootappend-install:,bootappend-live:,bootappend-failsafe:,bootloader:,checksums:,compression:,config:,zsync:,build-with-chroot:,
 		debian-installer:,debian-installer-distribution:,debian-installer-preseedfile:,debian-installer-gui:,
 		grub-splash:,isohybrid-options:,hdd-label:,hdd-size:,iso-application:,iso-preparer:,iso-publisher:,
-		iso-volume:,jffs2-eraseblock:,memtest:,net-root-filesystem:,net-root-mountoptions:,
+		iso-volume:,jffs2-eraseblock:,ext-block-size:,ext-resize-blocks:,ext-fudge-factor:,memtest:,net-root-filesystem:,net-root-mountoptions:,
 		net-root-path:,net-root-server:,net-cow-filesystem:,net-cow-mountoptions:,net-cow-path:,
 		net-cow-server:,net-tarball:,firmware-binary:,firmware-chroot:,swap-file-path:,swap-file-size:,syslinux-theme:,
 		win32-loader:,source:,source-images:,breakpoints,conffile:,debug,force,
@@ -683,6 +686,21 @@
 				shift 2
 				;;
 
+			--ext-block-size)
+				LB_EXT_BLOCKSIZE="${2}"
+				shift 2
+				;;
+
+			--ext-resize-blocks)
+				LB_EXT_RESIZEBLOCKS="${2}"
+				shift 2
+				;;
+
+			--ext-fudge-factor)
+				LB_EXT_FUDGEFACTOR="${2}"
+				shift 2
+				;;
+
 			--jffs2-eraseblock)
 				LB_JFFS2_ERASEBLOCK="${2}"
 				shift 2
@@ -1392,6 +1410,18 @@
 # (Default: ${LB_ISO_VOLUME})
 LB_ISO_VOLUME="${LB_ISO_VOLUME}"
 
+# \$LB_EXT_BLOCKSIZE: set EXT block size
+# (Default: unset)
+LB_EXT_BLOCKSIZE="${LB_EXT_BLOCKSIZE}"
+
+# \$LB_EXT_RESIZEBLOCKS: set EXT resize parameter
+# (Default: unset)
+LB_EXT_RESIZEBLOCKS="${LB_EXT_RESIZEBLOCKS}"
+
+# \$LB_EXT_FUDGEFACTOR: set extra size of EXT images (in %)
+# (Default: unset)
+LB_EXT_FUDGEFACTOR="${LB_EXT_FUDGEFACTOR}"
+
 # \$LB_JFFS2_ERASEBLOCK: set jffs2 eraseblock size
 # (Default: unset)
 LB_JFFS2_ERASEBLOCK=""
--- a/functions/losetup.sh
+++ b/functions/losetup.sh
@@ -68,7 +68,7 @@
 
 	case "${FILESYSTEM}" in
 		ext2|ext3|ext4)
-			PERCENT="5"
+			PERCENT="${LB_EXT_FUDGEFACTOR:-5}"
 			;;
 		*)
 			PERCENT="3"