From dc09142e7504cf106d5eaebea45a1384b61003ac Mon Sep 17 00:00:00 2001
From: ThomasKaiser <github@kaiser-edv.de>
Date: Mon, 28 Aug 2017 09:19:57 -0700
Subject: [PATCH] First take on resizable btrfs rootfs

---
 lib/configuration.sh                     |  2 +-
 lib/debootstrap-ng.sh                    | 18 ++++++--
 packages/bsp/common/etc/init.d/resize2fs | 57 +++++++++++++++---------
 3 files changed, 51 insertions(+), 26 deletions(-)

diff --git a/lib/configuration.sh b/lib/configuration.sh
index 096dfdee9f..74afc2fcf0 100644
--- a/lib/configuration.sh
+++ b/lib/configuration.sh
@@ -28,7 +28,7 @@ ROOTFS_CACHE_MAX=8 # max number of rootfs cache, older ones will be cleaned up
 # Fixed image size is in 1M dd blocks (MiB)
 # to get size of block device /dev/sdX execute as root:
 # echo $(( $(blockdev --getsize64 /dev/sdX) / 1024 / 1024 ))
-[[ "btrfs f2fs" == *$ROOTFS_TYPE* && -z $FIXED_IMAGE_SIZE ]] && exit_with_error "Please define FIXED_IMAGE_SIZE"
+[[ "f2fs" == *$ROOTFS_TYPE* && -z $FIXED_IMAGE_SIZE ]] && exit_with_error "Please define FIXED_IMAGE_SIZE"
 
 [[ $RELEASE == stretch && $CAN_BUILD_STRETCH != yes ]] && exit_with_error "Building Debian Stretch images with selected kernel is not supported"
 
diff --git a/lib/debootstrap-ng.sh b/lib/debootstrap-ng.sh
index b14af3db4d..19adc443ae 100644
--- a/lib/debootstrap-ng.sh
+++ b/lib/debootstrap-ng.sh
@@ -291,7 +291,7 @@ prepare_partitions()
 	# mountopts[ext2] is empty
 	# mountopts[fat] is empty
 	# mountopts[f2fs] is empty
-	# mountopts[btrfs] is empty
+	mountopts[btrfs]=',commit=600,compress=lzo'
 	# mountopts[nfs] is empty
 
 	# stage: determine partition configuration
@@ -330,9 +330,19 @@ prepare_partitions()
 		fi
 	else
 		local imagesize=$(( $rootfs_size + $OFFSET + $BOOTSIZE )) # MiB
-		# Hardcoded overhead +40% and +128MB for ext4 is needed for desktop images, for CLI it can be lower
-		# also add extra 128 MiB for the emergency swap file creation and align the size up to 4MiB
-		local sdsize=$(bc -l <<< "scale=0; ((($imagesize * 1.4) / 1 + 128) / 4 + 1) * 4")
+		case $ROOTFS_TYPE in
+			btrfs)
+				# Used for server images, currently no swap functionality, so disk space
+				# requirements are rather low since rootfs gets filled with compress-force=zlib
+				local sdsize=$(bc -l <<< "scale=0; (($imagesize * 0.9) / 4 + 1) * 4")
+				;;
+			*)
+				# Hardcoded overhead +40% and +128MB for ext4 is needed for desktop images,
+				# for CLI it could be lower. Also add extra 128 MiB for the emergency swap
+				# file creation and align the size up to 4MiB
+				local sdsize=$(bc -l <<< "scale=0; ((($imagesize * 1.4) / 1 + 128) / 4 + 1) * 4")
+				;;
+		esac
 	fi
 
 	# stage: create blank image
diff --git a/packages/bsp/common/etc/init.d/resize2fs b/packages/bsp/common/etc/init.d/resize2fs
index 18a7814c8a..e49c6cb587 100755
--- a/packages/bsp/common/etc/init.d/resize2fs
+++ b/packages/bsp/common/etc/init.d/resize2fs
@@ -119,35 +119,50 @@ do_expand_partition()
 	fi
 }
 
-do_expand_filesystem()
+do_expand_ext4()
 {
-	local rootpart=$(findmnt -n -o SOURCE /) # i.e. /dev/mmcblk0p1
+	echo -e "\n### [resize2fs] Start resizing ext4 partition $1 now\n" >> ${Log}
+	resize2fs ${rootpart} >> ${Log} 2>&1
+}
 
-	echo -e "\n### [resize2fs] Start resizing partition now\n" >> ${Log}
-	resize2fs $rootpart >> ${Log} 2>&1
+do_expand_btrfs()
+{
+	echo -e "\n### [btrfs resize] Start resizing btrfs partition $1 now\n" >> ${Log}
+	btrfs filesystem resize max / >> ${Log} 2>&1
 }
 
 case "$1" in
 	start)
-	# skip resizing if rootfs is not ext4 or if explicitly disabled
-	if [[ $(findmnt -n -o FSTYPE /) != ext4 || -f /root/.no_rootfs_resize ]]; then
-		systemctl disable resize2fs
+		# skip resizing if rootfs is neither ext4 not btrfs or if explicitly disabled
+		if [[ -f /root/.no_rootfs_resize ]]; then
+			systemctl disable resize2fs
+			exit 0
+		fi
+
+		rootfstype=$(findmnt -n -o FSTYPE /)
+		rootpart=$(findmnt -n -o SOURCE /) # i.e. /dev/mmcblk0p1
+		case ${rootfstype} in
+			ext4)
+				# first stage - resize the rootfs partition
+				[[ ! -f /var/lib/armbian/resize_second_stage ]] && do_expand_partition
+				# second stage - resize the filesystem
+				[[ ! -f /var/run/resize2fs-reboot ]] && do_expand_ext4 ${rootpart}
+				;;
+			btrfs)
+				# first stage - resize the rootfs partition
+				[[ ! -f /var/lib/armbian/resize_second_stage ]] && do_expand_partition
+				# second stage - resize the filesystem
+				do_expand_btrfs ${rootpart} && systemctl disable resize2fs
+				;;
+		esac
+
+		# disable itself
+		[[ ! -f /var/run/resize2fs-reboot ]] && systemctl disable resize2fs
 		exit 0
-	fi
-
-	# first stage - resize the partition
-	[[ ! -f /var/lib/armbian/resize_second_stage ]] && do_expand_partition
-
-	# second stage - resize the filesystem
-	[[ ! -f /var/run/resize2fs-reboot ]] && do_expand_filesystem
-
-	# disable itself
-	[[ ! -f /var/run/resize2fs-reboot ]] && systemctl disable resize2fs
-	exit 0
-	;;
+		;;
 
 	*)
-	echo "Usage: $0 start"
-	exit 0
+		echo "Usage: $0 start"
+		exit 0
 	;;
 esac