Merge branch 'staging-next'

Rebuild on Hydra seems OK-ish.
mongodb.nix needed some conflict resolution (scons versions);
all four versions seem to build fine.

nixos/modules/config/fonts/fontconfig.nix

@@ -214,15 +214,7 @@ let
     # fontconfig default config files
     ln -s ${supportPkg.out}/etc/fonts/conf.d/*.conf \
           $support_folder/
-    ln -s ${latestPkg.out}/etc/fonts/conf.d/*.conf \
-          $latest_folder/
-
-    # update latest 51-local.conf path to look at the latest local.conf
-    rm    $latest_folder/51-local.conf
-
-    substitute ${latestPkg.out}/etc/fonts/conf.d/51-local.conf \
-               $latest_folder/51-local.conf \
-               --replace local.conf /etc/fonts/${latestVersion}/local.conf
+    # Latest fontconfig is configured to look for the upstream defaults inside the package.
 
     # 00-nixos-cache.conf
     ln -s ${cacheConfSupport} \
@@ -236,7 +228,11 @@ let
     # 50-user.conf
     ${optionalString (!cfg.includeUserConf) ''
     rm $support_folder/50-user.conf
-    rm $latest_folder/50-user.conf
+    ''}
+    # Since latest fontconfig looks for default files inside the package,
+    # we had to move this one elsewhere to be able to exclude it here.
+    ${optionalString cfg.includeUserConf ''
+    ln -s ${latestPkg.out}/etc/fonts/conf.d.bak/50-user.conf $latest_folder/50-user.conf
     ''}
 
     # local.conf (indirect priority 51)

nixos/modules/system/boot/stage-1.nix

@@ -111,8 +111,8 @@ let
       copy_bin_and_libs ${pkgs.utillinux}/sbin/blkid
 
       # Copy dmsetup and lvm.
-      copy_bin_and_libs ${pkgs.lvm2}/sbin/dmsetup
-      copy_bin_and_libs ${pkgs.lvm2}/sbin/lvm
+      copy_bin_and_libs ${getBin pkgs.lvm2}/bin/dmsetup
+      copy_bin_and_libs ${getBin pkgs.lvm2}/bin/lvm
 
       # Add RAID mdadm tool.
       copy_bin_and_libs ${pkgs.mdadm}/sbin/mdadm
@@ -235,7 +235,7 @@ let
             --replace cdrom_id ${extraUtils}/bin/cdrom_id \
             --replace ${pkgs.coreutils}/bin/basename ${extraUtils}/bin/basename \
             --replace ${pkgs.utillinux}/bin/blkid ${extraUtils}/bin/blkid \
-            --replace ${pkgs.lvm2}/sbin ${extraUtils}/bin \
+            --replace ${getBin pkgs.lvm2}/bin ${extraUtils}/bin \
             --replace ${pkgs.mdadm}/sbin ${extraUtils}/sbin \
             --replace ${pkgs.bash}/bin/sh ${extraUtils}/bin/sh \
             --replace ${udev} ${extraUtils}

nixos/modules/tasks/lvm.nix

@@ -1,17 +1,70 @@
 { config, lib, pkgs, ... }:
 
 with lib;
-
-{
-
-  ###### implementation
-
-  config = mkIf (!config.boot.isContainer) {
-
-    environment.systemPackages = [ pkgs.lvm2 ];
-
-    services.udev.packages = [ pkgs.lvm2 ];
-
+let
+  cfg = config.services.lvm;
+in {
+  options.services.lvm = {
+    package = mkOption {
+      type = types.package;
+      default = if cfg.dmeventd.enable then pkgs.lvm2_dmeventd else pkgs.lvm2;
+      internal = true;
+      defaultText = "pkgs.lvm2";
+      description = ''
+        This option allows you to override the LVM package that's used on the system
+        (udev rules, tmpfiles, systemd services).
+        Defaults to pkgs.lvm2, or pkgs.lvm2_dmeventd if dmeventd is enabled.
+      '';
+    };
+    dmeventd.enable = mkEnableOption "the LVM dmevent daemon";
+    boot.thin.enable = mkEnableOption "support for booting from ThinLVs";
   };
 
+  config = mkMerge [
+    (mkIf (!config.boot.isContainer) {
+      environment.etc."tmpfiles.d/lvm2.conf".source = "${cfg.package}/lib/tmpfiles.d/lvm2.conf";
+      environment.systemPackages = [ cfg.package ];
+      systemd.packages = [ cfg.package ];
+
+      # TODO: update once https://github.com/NixOS/nixpkgs/pull/93006 was merged
+      services.udev.packages = [ cfg.package.out ];
+    })
+    (mkIf cfg.dmeventd.enable {
+      systemd.sockets."dm-event".wantedBy = [ "sockets.target" ];
+      systemd.services."lvm2-monitor".wantedBy = [ "sysinit.target" ];
+
+      environment.etc."lvm/lvm.conf".text = ''
+        dmeventd/executable = "${cfg.package}/bin/dmeventd"
+      '';
+    })
+    (mkIf cfg.boot.thin.enable {
+      boot.initrd = {
+        kernelModules = [ "dm-snapshot" "dm-thin-pool" ];
+
+        extraUtilsCommands = ''
+          copy_bin_and_libs ${pkgs.thin-provisioning-tools}/bin/pdata_tools
+          copy_bin_and_libs ${pkgs.thin-provisioning-tools}/bin/thin_check
+        '';
+      };
+
+      environment.etc."lvm/lvm.conf".text = ''
+        global/thin_check_executable = "${pkgs.thin-provisioning-tools}/bin/thin_check"
+      '';
+    })
+    (mkIf (cfg.dmeventd.enable || cfg.boot.thin.enable) {
+      boot.initrd.preLVMCommands = ''
+          mkdir -p /etc/lvm
+          cat << EOF >> /etc/lvm/lvm.conf
+          ${optionalString cfg.boot.thin.enable ''
+            global/thin_check_executable = "$(command -v thin_check)"
+          ''}
+          ${optionalString cfg.dmeventd.enable ''
+            dmeventd/executable = "$(command -v false)"
+            activation/monitoring = 0
+          ''}
+          EOF
+      '';
+    })
+  ];
+
 }