nixos/stage-1-systemd: ZFS support

nixos/modules/tasks/filesystems/zfs.nix

@@ -58,6 +58,13 @@ let
   # latter case it makes one last attempt at importing, allowing the system to
   # (eventually) boot even with a degraded pool.
   importLib = {zpoolCmd, awkCmd, cfgZfs}: ''
+    for o in $(cat /proc/cmdline); do
+      case $o in
+        zfs_force|zfs_force=1)
+          ZFS_FORCE="-f"
+          ;;
+      esac
+    done
     poolReady() {
       pool="$1"
       state="$("${zpoolCmd}" import 2>/dev/null | "${awkCmd}" "/pool: $pool/ { found = 1 }; /state:/ { if (found == 1) { print \$2; exit } }; END { if (found == 0) { print \"MISSING\" } }")"
@@ -78,6 +85,83 @@ let
     }
   '';
 
+  getPoolFilesystems = pool:
+    filter (x: x.fsType == "zfs" && (fsToPool x) == pool) config.system.build.fileSystems;
+
+  getPoolMounts = prefix: pool:
+    let
+      # Remove the "/" suffix because even though most mountpoints
+      # won't have it, the "/" mountpoint will, and we can't have the
+      # trailing slash in "/sysroot/" in stage 1.
+      mountPoint = fs: escapeSystemdPath (prefix + (lib.removeSuffix "/" fs.mountPoint));
+    in
+      map (x: "${mountPoint x}.mount") (getPoolFilesystems pool);
+
+  createImportService = { pool, systemd, force, prefix ? "" }:
+    nameValuePair "zfs-import-${pool}" {
+      description = "Import ZFS pool \"${pool}\"";
+      # we need systemd-udev-settle until https://github.com/zfsonlinux/zfs/pull/4943 is merged
+      requires = [ "systemd-udev-settle.service" ];
+      after = [
+        "systemd-udev-settle.service"
+        "systemd-modules-load.service"
+        "systemd-ask-password-console.service"
+      ];
+      wantedBy = (getPoolMounts prefix pool) ++ [ "local-fs.target" ];
+      before = (getPoolMounts prefix pool) ++ [ "local-fs.target" ];
+      unitConfig = {
+        DefaultDependencies = "no";
+      };
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+      };
+      environment.ZFS_FORCE = optionalString force "-f";
+      script = (importLib {
+        # See comments at importLib definition.
+        zpoolCmd = "${cfgZfs.package}/sbin/zpool";
+        awkCmd = "${pkgs.gawk}/bin/awk";
+        inherit cfgZfs;
+      }) + ''
+        poolImported "${pool}" && exit
+        echo -n "importing ZFS pool \"${pool}\"..."
+        # Loop across the import until it succeeds, because the devices needed may not be discovered yet.
+        for trial in `seq 1 60`; do
+          poolReady "${pool}" && poolImport "${pool}" && break
+          sleep 1
+        done
+        poolImported "${pool}" || poolImport "${pool}"  # Try one last time, e.g. to import a degraded pool.
+        if poolImported "${pool}"; then
+          ${optionalString (if isBool cfgZfs.requestEncryptionCredentials
+                            then cfgZfs.requestEncryptionCredentials
+                            else cfgZfs.requestEncryptionCredentials != []) ''
+            ${cfgZfs.package}/sbin/zfs list -rHo name,keylocation ${pool} | while IFS=$'\t' read ds kl; do
+              {
+                ${optionalString (!isBool cfgZfs.requestEncryptionCredentials) ''
+                   if ! echo '${concatStringsSep "\n" cfgZfs.requestEncryptionCredentials}' | grep -qFx "$ds"; then
+                     continue
+                   fi
+                 ''}
+              case "$kl" in
+                none )
+                  ;;
+                prompt )
+                  ${systemd}/bin/systemd-ask-password "Enter key for $ds:" | ${cfgZfs.package}/sbin/zfs load-key "$ds"
+                  ;;
+                * )
+                  ${cfgZfs.package}/sbin/zfs load-key "$ds"
+                  ;;
+              esac
+              } < /dev/null # To protect while read ds kl in case anything reads stdin
+            done
+          ''}
+          echo "Successfully imported ${pool}"
+        else
+          exit 1
+        fi
+      '';
+    };
+
   zedConf = generators.toKeyValue {
     mkKeyValue = generators.mkKeyValueDefault {
       mkValueString = v:
@@ -428,14 +512,6 @@ in
           '';
         postDeviceCommands = concatStringsSep "\n" ([''
             ZFS_FORCE="${optionalString cfgZfs.forceImportRoot "-f"}"
-
-            for o in $(cat /proc/cmdline); do
-              case $o in
-                zfs_force|zfs_force=1)
-                  ZFS_FORCE="-f"
-                  ;;
-              esac
-            done
           ''] ++ [(importLib {
             # See comments at importLib definition.
             zpoolCmd = "zpool";
@@ -464,6 +540,21 @@ in
                 zfs load-key ${fs}
               '') cfgZfs.requestEncryptionCredentials}
         '') rootPools));
+
+        # Systemd in stage 1
+        systemd = {
+          packages = [cfgZfs.package];
+          services = listToAttrs (map (pool: createImportService {
+            inherit pool;
+            systemd = config.boot.initrd.systemd.package;
+            force = cfgZfs.forceImportRoot;
+            prefix = "/sysroot";
+          }) rootPools);
+          extraBin = {
+            # zpool and zfs are already in thanks to fsPackages
+            awk = "${pkgs.gawk}/bin/awk";
+          };
+        };
       };
 
       systemd.shutdownRamfs.contents."/etc/systemd/system-shutdown/zpool".source = pkgs.writeShellScript "zpool-sync-shutdown" ''
@@ -521,78 +612,10 @@ in
       systemd.packages = [ cfgZfs.package ];
 
       systemd.services = let
-        getPoolFilesystems = pool:
+        createImportService' = pool: createImportService {
-          filter (x: x.fsType == "zfs" && (fsToPool x) == pool) config.system.build.fileSystems;
+          inherit pool;
-
+          systemd = config.systemd.package;
-        getPoolMounts = pool:
+          force = cfgZfs.forceImportAll;
-          let
-            mountPoint = fs: escapeSystemdPath fs.mountPoint;
-          in
-            map (x: "${mountPoint x}.mount") (getPoolFilesystems pool);
-
-        createImportService = pool:
-          nameValuePair "zfs-import-${pool}" {
-            description = "Import ZFS pool \"${pool}\"";
-            # we need systemd-udev-settle until https://github.com/zfsonlinux/zfs/pull/4943 is merged
-            requires = [ "systemd-udev-settle.service" ];
-            after = [
-              "systemd-udev-settle.service"
-              "systemd-modules-load.service"
-              "systemd-ask-password-console.service"
-            ];
-            wantedBy = (getPoolMounts pool) ++ [ "local-fs.target" ];
-            before = (getPoolMounts pool) ++ [ "local-fs.target" ];
-            unitConfig = {
-              DefaultDependencies = "no";
-            };
-            serviceConfig = {
-              Type = "oneshot";
-              RemainAfterExit = true;
-            };
-            environment.ZFS_FORCE = optionalString cfgZfs.forceImportAll "-f";
-            script = (importLib {
-              # See comments at importLib definition.
-              zpoolCmd = "${cfgZfs.package}/sbin/zpool";
-              awkCmd = "${pkgs.gawk}/bin/awk";
-              inherit cfgZfs;
-            }) + ''
-              poolImported "${pool}" && exit
-              echo -n "importing ZFS pool \"${pool}\"..."
-              # Loop across the import until it succeeds, because the devices needed may not be discovered yet.
-              for trial in `seq 1 60`; do
-                poolReady "${pool}" && poolImport "${pool}" && break
-                sleep 1
-              done
-              poolImported "${pool}" || poolImport "${pool}"  # Try one last time, e.g. to import a degraded pool.
-              if poolImported "${pool}"; then
-                ${optionalString (if isBool cfgZfs.requestEncryptionCredentials
-                                  then cfgZfs.requestEncryptionCredentials
-                                  else cfgZfs.requestEncryptionCredentials != []) ''
-                  ${cfgZfs.package}/sbin/zfs list -rHo name,keylocation ${pool} | while IFS=$'\t' read ds kl; do
-                    {
-                      ${optionalString (!isBool cfgZfs.requestEncryptionCredentials) ''
-                         if ! echo '${concatStringsSep "\n" cfgZfs.requestEncryptionCredentials}' | grep -qFx "$ds"; then
-                           continue
-                         fi
-                       ''}
-                    case "$kl" in
-                      none )
-                        ;;
-                      prompt )
-                        ${config.systemd.package}/bin/systemd-ask-password "Enter key for $ds:" | ${cfgZfs.package}/sbin/zfs load-key "$ds"
-                        ;;
-                      * )
-                        ${cfgZfs.package}/sbin/zfs load-key "$ds"
-                        ;;
-                    esac
-                    } < /dev/null # To protect while read ds kl in case anything reads stdin
-                  done
-                ''}
-                echo "Successfully imported ${pool}"
-              else
-                exit 1
-              fi
-            '';
         };
 
         # This forces a sync of any ZFS pools prior to poweroff, even if they're set
@@ -619,7 +642,7 @@ in
             wantedBy = [ "zfs.target" ];
           };
 
-      in listToAttrs (map createImportService dataPools ++
+      in listToAttrs (map createImportService' dataPools ++
                       map createSyncService allPools ++
                       map createZfsService [ "zfs-mount" "zfs-share" "zfs-zed" ]);