1 files changed, 15 insertions, 0 deletions

diff --git a/src/initrd/loop-layer.sh b/src/initrd/loop-layer.sh
new file mode 100644
index 0000000..7e08e12
--- /dev/null
+++ b/src/initrd/loop-layer.sh
@@ -0,0 +1,15 @@
+losetup_snapshot()
+{
+    local ro_dev rw_dev new_dev_name size persist chunksize
+    ro_file=$1
+    rw_file=$2
+
+    ro_dev=$(LoSetup -r -f --show "$ro_file") || return
+    rw_dev=$(LoSetup -f --show "$rw_file") || return
+    new_dev_name=${ro_dev##*/}
+    size=$(blockdev --getsz "$ro_dev") || return
+    persist=p
+    chunksize=16
+    dmsetup create "$new_dev_name" --table "0 $size snapshot $ro_dev $rw_dev $persist $chunksize" || return
+    echo /dev/mapper/"$new_dev_name"
+}