Add DKMS package on Debian-based distributions

* config/deb.am: Enable building DKMS packages for Debian
* rpm/generic/zfs-dkms.spec.in: Adjust spec to be Debian-compatible
  * Condition kernel-devel Req to RPM distros
  * Adjust the DKMS Req to have a minimum of a version only
  * Ensure that --rpm_safe_upgrade isn't used on non-RPM distros
* config/deb.am: Drop CONFIG_KERNEL and CONFIG_USER guards
* Makefile.am: Add pkg-dkms target

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Neal Gompa <ngompa@datto.com>
Closes #6044 
Closes #6731

Makefile.am

@@ -98,5 +98,6 @@ etags:
 tags: ctags etags
 
 pkg: @DEFAULT_PACKAGE@
+pkg-dkms: @DEFAULT_PACKAGE@-dkms
 pkg-kmod: @DEFAULT_PACKAGE@-kmod
 pkg-utils: @DEFAULT_PACKAGE@-utils

config/deb.am

@@ -15,17 +15,23 @@ deb-local:
 	fi)
 
 deb-kmod: deb-local rpm-kmod
-if CONFIG_KERNEL
 	name=${PACKAGE}; \
 	version=${VERSION}-${RELEASE}; \
 	arch=`$(RPM) -qp $${name}-kmod-$${version}.src.rpm --qf %{arch} | tail -1`; \
 	pkg1=kmod-$${name}*$${version}.$${arch}.rpm; \
 	fakeroot $(ALIEN) --bump=0 --scripts --to-deb $$pkg1; \
 	$(RM) $$pkg1
-endif
+
+
+deb-dkms: deb-local rpm-dkms
+	name=${PACKAGE}; \
+	version=${VERSION}-${RELEASE}; \
+	arch=`$(RPM) -qp $${name}-dkms-$${version}.src.rpm --qf %{arch} | tail -1`; \
+	pkg1=$${name}-dkms-$${version}.$${arch}.rpm; \
+	fakeroot $(ALIEN) --bump=0 --scripts --to-deb $$pkg1; \
+	$(RM) $$pkg1
 
 deb-utils: deb-local rpm-utils
-if CONFIG_USER
 	name=${PACKAGE}; \
 	version=${VERSION}-${RELEASE}; \
 	arch=`$(RPM) -qp $${name}-$${version}.src.rpm --qf %{arch} | tail -1`; \
@@ -58,6 +64,5 @@ if CONFIG_USER
 	rmdir $${path_prepend}; \
 	$(RM) $$pkg1 $$pkg2 $$pkg3 $$pkg4 $$pkg5 $$pkg6 $$pkg7 \
 	    $$pkg8 $$pkg9;
-endif
 
-deb: deb-kmod deb-utils
+deb: deb-kmod deb-dkms deb-utils

rpm/generic/zfs-dkms.spec.in

@@ -1,5 +1,9 @@
 %{?!packager: %define packager Brian Behlendorf <behlendorf1@llnl.gov>}
 
+%if ! 0%{?rhel}%{?fedora}%{?mageia}%{?suse_version}
+%define not_rpm 1
+%endif
+
 %define module  @PACKAGE@
 %define mkconf  scripts/dkms.mkconf
 
@@ -16,10 +20,12 @@ Source0:        %{module}-%{version}.tar.gz
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 BuildArch:      noarch
 
-Requires:       dkms >= 2.2.0.3-20
+Requires:       dkms >= 2.2.0.3
 Requires:       spl-dkms = %{version}
 Requires:       gcc, make, perl
+%if 0%{?rhel}%{?fedora}%{?mageia}%{?suse_version}
 Requires:       kernel-devel
+%endif
 Provides:       %{module}-kmod = %{version}
 
 %description
@@ -69,7 +75,7 @@ DKMS_META_ALIAS=`cat $CONFIG_H 2>/dev/null |
 if [ "$SPEC_META_ALIAS" = "$DKMS_META_ALIAS" ]; then
     echo -e
     echo -e "Uninstall of %{module} module ($SPEC_META_ALIAS) beginning:"
-    dkms remove -m %{module} -v %{version} --all --rpm_safe_upgrade
+    dkms remove -m %{module} -v %{version} --all %{!?not_rpm:--rpm_safe_upgrade}
 fi
 exit 0