From 3a6565903b8a2c88d0fba389bf628431dca38ff1 Mon Sep 17 00:00:00 2001
From: Mart Frauenlob <AllKind@fastest.cc>
Date: Wed, 18 Oct 2023 15:13:47 +0200
Subject: [PATCH] Fix dkms installation of deb packages created with Alien.

Alien does not seem to honour the %posttrans hook.
So move the dkms uninstall/install scripts to the
 %pre/%post hooks in case of package install/upgrade.
In case of package removal, handle that in %preun.
Also add more verbose messages about what we are doing.

Signed-off-by: Mart Frauenlob <AllKind@fastest.cc>
---
 rpm/generic/zfs-dkms.spec.in | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/rpm/generic/zfs-dkms.spec.in b/rpm/generic/zfs-dkms.spec.in
index 23c3ed6ff408..677c0bc4f630 100644
--- a/rpm/generic/zfs-dkms.spec.in
+++ b/rpm/generic/zfs-dkms.spec.in
@@ -68,9 +68,37 @@ fi
 %defattr(-,root,root)
 /usr/src/%{module}-%{version}
 
-%preun
-dkms remove -m %{module} -v %{version} --all
+%pre
+# Uninstall this version of zfs dkms modules before installation of the package.
+echo "Running pre installation script: $0"
+if [ `dkms status -m zfs -v %{version} | grep -c zfs` -gt 0 ]; then
+    echo "Removing %{module} dkms modules version %{version} from all kernels."
+    dkms remove -m %{module} -v %{version} --all
+fi
+
+%post
+# After installing the package, dkms install this zfs version
+# (if not there yet) for the current kernel.
+echo "Running post installation script: $0"
+if [ `dkms status -m zfs -v %{version} | grep -c zfs` -eq 0 ]; then
+    echo "Installing %{module} dkms modules version %{version} for the current kernel."
+    dkms install -m %{module} -v %{version}
+fi
 
-%posttrans
-/usr/lib/dkms/common.postinst %{module} %{version}
+%preun
+# Check if we uninstall the package. In that case remove the dkms modules.
+# '0' is the value for the first parameter for rpm packages.
+# 'remove' or 'purge' are the possible names for deb packages.
+echo "Running pre uninstall script: $0"
+if [ "$1" = "0" -o "$1" = "remove" -o "$1" = "purge" ] ; then
+    echo "Removing %{module} dkms modules version %{version} from all kernels."
+    dkms remove -m %{module} -v %{version} --all
+else
+    # If the above check fails, i.e. rpm or deb script invocation parameters changed,
+    # fall back to checking dkms status.
+    if [ `dkms status -m zfs -v %{version} | grep -c zfs` -gt 0 ]; then
+        echo "Removing %{module} dkms modules version %{version} from all kernels."
+        dkms remove -m %{module} -v %{version} --all
+    fi
+fi