making btrfs subvolumes should be idempotent

1 files changed, 25 insertions, 10 deletions

diff --git a/src/initrd/btrfs-create.sh b/src/initrd/btrfs-create.sh
index ff09bf7..567ad97 100644
--- a/src/initrd/btrfs-create.sh
+++ b/src/initrd/btrfs-create.sh
@@ -109,19 +109,34 @@ copy_execs()
     done
 }
 
-initialize_root_filesystem()
+is_subvolume()
 {
-    rm -r /root/root
-    btrfs subvolume create /root/root                   || return
-    mv /gpg/gnupghome /root/root/.gnupg                 || return
+    btrfs subvolume show "$1" >/dev/null 2>&1
+}
+
+make_subvolume_idem()
+{
+    is_subvolume "$1" && return
+    if [ -d "$1" ]; then
+        rmdir "$1" || mv "$1" "$1"~
+        btrfs subvolume create "$1"
+        mv "$1"~/* "$1"~/.* "$1"/ 2>&1
+    else
+        if [ -e "$1" ]; then
+            rm -f "$1"
+        fi
+        btrfs subvolume create "$1"
+    fi
+}
 
-    rmdir /root/srv
-    btrfs subvolume create /root/srv
-    rm -r /root/var/cache/apt/archives
-    btrfs subvolume create /root/var/cache/apt/archives || return
+initialize_root_filesystem()
+{
+    for d in /root/root /root/srv /root/var/cache/apt/archives /root/home; do
+        make_subvolume_idem "$d"
+    done
 
-    rmdir /root/home
-    btrfs subvolume create /root/home                   || return
+    mv /root/root/.gnupg /root/root/.gnupg~
+    mv /gpg/gnupghome /root/root/.gnupg                 || return
 
     copy_execs sbin  mdadm dmsetup cryptsetup fsck.hfsplus
     copy_execs bin   btrfs rsync gpg gpg2 gpg-agent