zfs: Enable systemd

Also remove custom zfs services from NixOS.  This makes NixOS more aligned with
upstream.

More importantly, it prepares the way for NixOS to use ZED (the ZFS event
daemon). This service will automatically be enabled but it is not possible to
configure it via configuration.nix yet.

nixos/modules/tasks/filesystems/zfs.nix

@@ -152,40 +152,20 @@ in
         zfsSupport = true;
       };
 
-      systemd.services."zpool-import" = {
-        description = "Import zpools";
-        after = [ "systemd-udev-settle.service" ];
-        wantedBy = [ "local-fs.target" ];
-        serviceConfig = {
-          Type = "oneshot";
-          RemainAfterExit = true;
-          ExecStart = "${zfsPkg}/sbin/zpool import -f -a";
-        };
-        restartIfChanged = false;
-      };
-
-      systemd.services."zfs-mount" = {
-        description = "Mount ZFS Volumes";
-        after = [ "zpool-import.service" ];
-        wantedBy = [ "local-fs.target" ];
-        serviceConfig = {
-          Type = "oneshot";
-          RemainAfterExit = true;
-          ExecStart = "${zfsPkg}/sbin/zfs mount -a";
-          ExecStop = "${zfsPkg}/sbin/zfs umount -a";
-        };
-        restartIfChanged = false;
-      };
+      environment.etc."zfs/zed.d".source = "${zfsPkg}/etc/zfs/zed.d/*";
 
       system.fsPackages = [ zfsPkg ];                  # XXX: needed? zfs doesn't have (need) a fsck
       environment.systemPackages = [ zfsPkg ];
       services.udev.packages = [ zfsPkg ];             # to hook zvol naming, etc.
+      systemd.packages = [ zfsPkg ];
+
+      systemd.targets."zfs".wantedBy = [ "multi-user.target" ];
     })
 
     (mkIf enableAutoSnapshots {
       systemd.services."zfs-snapshot-frequent" = {
         description = "ZFS auto-snapshotting every 15 mins";
-        after = [ "zpool-import.service" ];
+        after = [ "zfs-import-scan.service" "zfs-import-cache.service" ];
         serviceConfig = {
           Type = "oneshot";
           ExecStart = "${zfsAutoSnap} frequent ${toString cfgSnapshots.frequent}";
@@ -196,7 +176,7 @@ in
 
       systemd.services."zfs-snapshot-hourly" = {
         description = "ZFS auto-snapshotting every hour";
-        after = [ "zpool-import.service" ];
+        after = [ "zfs-import-scan.service" "zfs-import-cache.service" ];
         serviceConfig = {
           Type = "oneshot";
           ExecStart = "${zfsAutoSnap} hourly ${toString cfgSnapshots.hourly}";
@@ -207,7 +187,7 @@ in
 
       systemd.services."zfs-snapshot-daily" = {
         description = "ZFS auto-snapshotting every day";
-        after = [ "zpool-import.service" ];
+        after = [ "zfs-import-scan.service" "zfs-import-cache.service" ];
         serviceConfig = {
           Type = "oneshot";
           ExecStart = "${zfsAutoSnap} daily ${toString cfgSnapshots.daily}";
@@ -218,7 +198,7 @@ in
 
       systemd.services."zfs-snapshot-weekly" = {
         description = "ZFS auto-snapshotting every week";
-        after = [ "zpool-import.service" ];
+        after = [ "zfs-import-scan.service" "zfs-import-cache.service" ];
         serviceConfig = {
           Type = "oneshot";
           ExecStart = "${zfsAutoSnap} weekly ${toString cfgSnapshots.weekly}";
@@ -229,7 +209,7 @@ in
 
       systemd.services."zfs-snapshot-monthly" = {
         description = "ZFS auto-snapshotting every month";
-        after = [ "zpool-import.service" ];
+        after = [ "zfs-import-scan.service" "zfs-import-cache.service" ];
         serviceConfig = {
           Type = "oneshot";
           ExecStart = "${zfsAutoSnap} monthly ${toString cfgSnapshots.monthly}";

pkgs/os-specific/linux/zfs/default.nix

@@ -20,24 +20,32 @@ stdenv.mkDerivation {
   NIX_CFLAGS_LINK = "-lgcc_s";
 
   preConfigure = ''
-    ./autogen.sh
+    substituteInPlace ./module/zfs/zfs_ctldir.c   --replace "umount -t zfs"           "${utillinux}/bin/umount -t zfs"
+    substituteInPlace ./module/zfs/zfs_ctldir.c   --replace "mount -t zfs"            "${utillinux}/bin/mount -t zfs"
+    substituteInPlace ./lib/libzfs/libzfs_mount.c --replace "/bin/umount"             "${utillinux}/bin/umount"
+    substituteInPlace ./lib/libzfs/libzfs_mount.c --replace "/bin/mount"              "${utillinux}/bin/mount"
+    substituteInPlace ./udev/rules.d/*            --replace "/lib/udev/vdev_id"       "$out/lib/udev/vdev_id"
+    substituteInPlace ./cmd/ztest/ztest.c         --replace "/usr/sbin/ztest"         "$out/sbin/ztest"
+    substituteInPlace ./cmd/ztest/ztest.c         --replace "/usr/sbin/zdb"           "$out/sbin/zdb"
+    substituteInPlace ./config/user-systemd.m4    --replace "/usr/lib/modules-load.d" "$out/etc/modules-load.d"
+    substituteInPlace ./config/zfs-build.m4       --replace "\$sysconfdir/init.d"     "$out/etc/init.d"
+    substituteInPlace ./etc/zfs/Makefile.am       --replace "\$(sysconfdir)"          "$out/etc"
+    substituteInPlace ./cmd/zed/Makefile.am       --replace "\$(sysconfdir)"          "$out/etc"
 
-    substituteInPlace ./module/zfs/zfs_ctldir.c    --replace "umount -t zfs"     "${utillinux}/bin/umount -t zfs"
-    substituteInPlace ./module/zfs/zfs_ctldir.c    --replace "mount -t zfs"      "${utillinux}/bin/mount -t zfs"
-    substituteInPlace ./lib/libzfs/libzfs_mount.c  --replace "/bin/umount"       "${utillinux}/bin/umount"
-    substituteInPlace ./lib/libzfs/libzfs_mount.c  --replace "/bin/mount"        "${utillinux}/bin/mount"
-    substituteInPlace ./udev/rules.d/*             --replace "/lib/udev/vdev_id" "$out/lib/udev/vdev_id"
-    substituteInPlace ./cmd/ztest/ztest.c          --replace "/usr/sbin/ztest"   "$out/sbin/ztest"
-    substituteInPlace ./cmd/ztest/ztest.c          --replace "/usr/sbin/zdb"     "$out/sbin/zdb"
+    ./autogen.sh
   '';
 
   configureFlags = [
-    "--disable-systemd"
+    "--enable-systemd"
     "--with-linux=${kernel.dev}/lib/modules/${kernel.modDirVersion}/source"
     "--with-linux-obj=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
     "--with-spl=${spl}/libexec/spl"
     "--with-dracutdir=$(out)/lib/dracut"
     "--with-udevdir=$(out)/lib/udev"
+    "--with-systemdunitdir=$(out)/etc/systemd/system"
+    "--with-systemdpresetdir=$(out)/etc/systemd/system-preset"
+    "--sysconfdir=/etc"
+    "--localstatedir=/var"
   ];
 
   enableParallelBuilding = true;

pkgs/os-specific/linux/zfs/git.nix

@@ -17,24 +17,32 @@ stdenv.mkDerivation {
   NIX_CFLAGS_LINK = "-lgcc_s";
 
   preConfigure = ''
-    ./autogen.sh
+    substituteInPlace ./module/zfs/zfs_ctldir.c   --replace "umount -t zfs"           "${utillinux}/bin/umount -t zfs"
+    substituteInPlace ./module/zfs/zfs_ctldir.c   --replace "mount -t zfs"            "${utillinux}/bin/mount -t zfs"
+    substituteInPlace ./lib/libzfs/libzfs_mount.c --replace "/bin/umount"             "${utillinux}/bin/umount"
+    substituteInPlace ./lib/libzfs/libzfs_mount.c --replace "/bin/mount"              "${utillinux}/bin/mount"
+    substituteInPlace ./udev/rules.d/*            --replace "/lib/udev/vdev_id"       "$out/lib/udev/vdev_id"
+    substituteInPlace ./cmd/ztest/ztest.c         --replace "/usr/sbin/ztest"         "$out/sbin/ztest"
+    substituteInPlace ./cmd/ztest/ztest.c         --replace "/usr/sbin/zdb"           "$out/sbin/zdb"
+    substituteInPlace ./config/user-systemd.m4    --replace "/usr/lib/modules-load.d" "$out/etc/modules-load.d"
+    substituteInPlace ./config/zfs-build.m4       --replace "\$sysconfdir/init.d"     "$out/etc/init.d"
+    substituteInPlace ./etc/zfs/Makefile.am       --replace "\$(sysconfdir)"          "$out/etc"
+    substituteInPlace ./cmd/zed/Makefile.am       --replace "\$(sysconfdir)"          "$out/etc"
 
-    substituteInPlace ./module/zfs/zfs_ctldir.c    --replace "umount -t zfs"     "${utillinux}/bin/umount -t zfs"
-    substituteInPlace ./module/zfs/zfs_ctldir.c    --replace "mount -t zfs"      "${utillinux}/bin/mount -t zfs"
-    substituteInPlace ./lib/libzfs/libzfs_mount.c  --replace "/bin/umount"       "${utillinux}/bin/umount"
-    substituteInPlace ./lib/libzfs/libzfs_mount.c  --replace "/bin/mount"        "${utillinux}/bin/mount"
-    substituteInPlace ./udev/rules.d/*             --replace "/lib/udev/vdev_id" "$out/lib/udev/vdev_id"
-    substituteInPlace ./cmd/ztest/ztest.c          --replace "/usr/sbin/ztest"   "$out/sbin/ztest"
-    substituteInPlace ./cmd/ztest/ztest.c          --replace "/usr/sbin/zdb"     "$out/sbin/zdb"
+    ./autogen.sh
   '';
 
   configureFlags = [
-    "--disable-systemd"
+    "--enable-systemd"
     "--with-linux=${kernel.dev}/lib/modules/${kernel.modDirVersion}/source"
     "--with-linux-obj=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
     "--with-spl=${spl_git}/libexec/spl"
     "--with-dracutdir=$(out)/lib/dracut"
     "--with-udevdir=$(out)/lib/udev"
+    "--with-systemdunitdir=$(out)/etc/systemd/system"
+    "--with-systemdpresetdir=$(out)/etc/systemd/system-preset"
+    "--sysconfdir=/etc"
+    "--localstatedir=/var"
   ];
 
   enableParallelBuilding = true;