1 files changed, 55 insertions, 0 deletions

diff --git a/src/btrfs-receive-root.sh b/src/btrfs-receive-root.sh
new file mode 100644
index 0000000..f553c2c
--- /dev/null
+++ b/src/btrfs-receive-root.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+. sami/btrfs-functions.sh
+. sami/var.sh
+
+disable_stdout() { exec 3>&1; exec >&2; }
+enable_stdout() { exec >&3; }
+
+with_stdout() { enable_stdout; "$@"; disable_stdout; }
+
+create_layer_filesystem()
+{
+    [ ! -e "$layer_file" ] || return
+    ! mountpoint "$mountpoint" || return
+    mkdir -p "$mountpoint"                                         &&
+    sex dd if=/dev/zero of="$layer_file" bs=1M count="$layer_size" &&
+    sex mount -o subvol=/,compress "$seed_file" "$mountpoint"      &&
+    layer_dev=$(losetup -f --show "$layer_file")                   &&
+    sex btrfs device add "$layer_dev" "$mountpoint"                &&
+    mount -o rw,remount "$mountpoint"
+}
+
+finish()
+{
+    local subv_id
+    sex mv "$mountpoint"/ROOT "$mountpoint"/ROOT.old                              || return
+    sex btrfs subvolume snapshot "$mountpoint"/"$receive_subv" "$mountpoint"/ROOT || return
+    subv_id=$(btrfs_show_subvolume_id "$mountpoint"/ROOT)                         || return
+    sex btrfs subvolume set-default "$subv_id" "$mountpoint"                      || return
+    sex btrfs subvolume delete "$mountpoint"/ROOT.old                             || return
+    umount "$mountpoint"                                                          || return
+    sex btrfstune -S1 "$layer_file"                                               || return
+    losetup -d "$layer_dev"
+}
+
+set -e
+disable_stdout
+
+receive_dest=$1
+receive_subv=$2
+
+[ "$receive_subv" ]
+[ "$receive_dest" ]
+
+mountpoint=$(realpath -m --relative-base=. "$receive_dest")
+
+seed_file=sami/debian-live-8.4.0-amd64-standard.btrfs
+layer_file_FINAL=sami/debian-live-8.4.0-amd64-standard.layer.$receive_subv.btrfs
+layer_file=$layer_file_FINAL.part
+layer_size=1000
+
+create_layer_filesystem
+with_stdout sex btrfs receive "$mountpoint"
+finish
+mv "$layer_file" "$layer_file_FINAL"