From 6d1b94af9745722847a3dfeef297015b84db0931 Mon Sep 17 00:00:00 2001
From: may <mzhboy@gmail.com>
Date: Fri, 10 May 2019 02:34:03 +0800
Subject: [PATCH] [general] new option to setup btrfs compression method

for support old and boring 3.x kernels
---
 lib/configuration.sh  | 12 ++++++++++++
 lib/debootstrap-ng.sh |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/lib/configuration.sh b/lib/configuration.sh
index 37a0ffbff5..722e7519f3 100644
--- a/lib/configuration.sh
+++ b/lib/configuration.sh
@@ -29,6 +29,18 @@ ROOT_MAPPER="armbian-root"
 [[ -z $ROOTFS_TYPE ]] && ROOTFS_TYPE=ext4 # default rootfs type is ext4
 [[ "ext4 f2fs btrfs nfs fel" != *$ROOTFS_TYPE* ]] && exit_with_error "Unknown rootfs type" "$ROOTFS_TYPE"
 
+# setup btrfs compression
+if [[ -z $BTRFS_COMPRESSION ]];then
+	BTRFS_COMPRESSION=lzo
+else
+	local btrfs_compression_ok=0
+	for c in 'lzo zlib zstd';do
+		[[ $c == $BTRFS_COMPRESSION ]] && btrfs_compression_ok=1
+	done
+	[[ $btrfs_compression_ok -eq 0 ]] && exit_with_error "wrong btrfs compression method" "$BTRFS_COMPRESSION"
+	unset btrfs_compression_ok
+fi
+
 # Fixed image size is in 1M dd blocks (MiB)
 # to get size of block device /dev/sdX execute as root:
 # echo $(( $(blockdev --getsize64 /dev/sdX) / 1024 / 1024 ))
diff --git a/lib/debootstrap-ng.sh b/lib/debootstrap-ng.sh
index 7efd3ceb7c..3fc5bd7047 100644
--- a/lib/debootstrap-ng.sh
+++ b/lib/debootstrap-ng.sh
@@ -310,7 +310,7 @@ prepare_partitions()
 	# mountopts[ext2] is empty
 	# mountopts[fat] is empty
 	# mountopts[f2fs] is empty
-	mountopts[btrfs]=',commit=600,compress=zstd'
+	mountopts[btrfs]=",commit=600,compress=${BTRFS_COMPRESSION}"
 	# mountopts[nfs] is empty
 
 	# stage: determine partition configuration
@@ -358,7 +358,7 @@ prepare_partitions()
 		case $ROOTFS_TYPE in
 			btrfs)
 				# Used for server images, currently no swap functionality, so disk space
-				# requirements are rather low since rootfs gets filled with compress=zstd
+				# requirements are rather low since rootfs gets filled with compress=$BTRFS_COMPRESSION
 				local sdsize=$(bc -l <<< "scale=0; (($imagesize * 0.8) / 4 + 1) * 4")
 				;;
 			*)
@@ -433,7 +433,7 @@ prepare_partitions()
 		display_alert "Creating rootfs" "$ROOTFS_TYPE on $rootdevice"
 		mkfs.${mkfs[$ROOTFS_TYPE]} ${mkopts[$ROOTFS_TYPE]} $rootdevice
 		[[ $ROOTFS_TYPE == ext4 ]] && tune2fs -o journal_data_writeback $rootdevice > /dev/null
-                [[ $ROOTFS_TYPE == btrfs ]] && local fscreateopt="-o compress=zstd,space_cache=v2"
+                [[ $ROOTFS_TYPE == btrfs ]] && local fscreateopt="-o compress=${BTRFS_COMPRESSION},space_cache=v2"
 		mount ${fscreateopt} $rootdevice $MOUNT/
                 if [[ $ROOTFS_TYPE == btrfs ]];then
                         btrfs subvolume create $MOUNT/@