From b36e87600d858f34b8cb90932e87dc61ef0aa28a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Tue, 1 Apr 2025 16:22:34 +0200
Subject: [PATCH] zfs: properly disable zfs-based swap

---
 disk-deactivate/disk-deactivate        |  2 ++
 disk-deactivate/zfs-swap-deactivate.jq | 10 ++++++++++
 flake.nix                              |  1 +
 3 files changed, 13 insertions(+)
 create mode 100644 disk-deactivate/zfs-swap-deactivate.jq

diff --git a/disk-deactivate/disk-deactivate b/disk-deactivate/disk-deactivate
index 9ddb2de..f7c678d 100755
--- a/disk-deactivate/disk-deactivate
+++ b/disk-deactivate/disk-deactivate
@@ -4,5 +4,7 @@ set -efux -o pipefail
 disk=$(realpath "$1")
 
 lsblk -a -f >&2
+# since we currently cannot recursively deactivate swaps on zfs volumes, we need to deactivate all of them.
+lsblk --output-all --json | jq -r -f "$(dirname "$0")/zfs-swap-deactivate.jq" | bash -x
 lsblk --output-all --json | jq -r --arg disk_to_clear "$disk" -f "$(dirname "$0")/disk-deactivate.jq" | bash -x
 lsblk -a -f >&2
diff --git a/disk-deactivate/zfs-swap-deactivate.jq b/disk-deactivate/zfs-swap-deactivate.jq
new file mode 100644
index 0000000..0a8ec87
--- /dev/null
+++ b/disk-deactivate/zfs-swap-deactivate.jq
@@ -0,0 +1,10 @@
+def turnOffSwaps:
+    if (.name | test("^zd[0-9]+$")) and .type == "disk" then
+        "swapoff /dev/" + .name
+    else
+        []
+    end
+;
+
+.blockdevices | map(turnOffSwaps) | flatten | join("\n")
+
diff --git a/flake.nix b/flake.nix
index dc18b01..cc2ee86 100644
--- a/flake.nix
+++ b/flake.nix
@@ -71,6 +71,7 @@
 
           checkJqSyntax = pkgs.runCommand "check-jq-syntax" { nativeBuildInputs = [ pkgs.jq ]; } ''
             echo '{ "blockdevices" : [] }' | jq -r -f ${./disk-deactivate/disk-deactivate.jq} --arg disk_to_clear foo
+            echo '{ "blockdevices" : [] }' | jq -r -f ${./disk-deactivate/zfs-swap-deactivate.jq}
             touch $out
           '';