diff --git a/plinth/modules/storage/__init__.py b/plinth/modules/storage/__init__.py
index a823ccba6..7b29265e6 100644
--- a/plinth/modules/storage/__init__.py
+++ b/plinth/modules/storage/__init__.py
@@ -1,25 +1,21 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-FreedomBox app to manage storage.
-"""
+"""FreedomBox app to manage storage."""
 
 import base64
 import logging
-import subprocess
 
 import psutil
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import gettext_noop
 
-from plinth import actions
 from plinth import app as app_module
 from plinth import cfg, glib, menu
-from plinth.errors import ActionError, PlinthError
+from plinth.errors import PlinthError
 from plinth.modules.backups.components import BackupRestore
 from plinth.package import Packages
 from plinth.utils import format_lazy
 
-from . import manifest, udisks2
+from . import manifest, privileged, udisks2
 
 _description = [
     format_lazy(
@@ -77,19 +73,19 @@ class StorageApp(app_module.App):
     def setup(self, old_version):
         """Install and configure the app."""
         super().setup(old_version)
-        actions.superuser_run('storage', ['setup'])
+        privileged.setup()
         self.enable()
         disks = get_disks()
         root_device = get_root_device(disks)
         if is_expandable(root_device):
             try:
-                expand_partition(root_device)
-            except ActionError:
+                privileged.expand_partition(root_device)
+            except Exception:
                 pass
 
 
 def get_disks():
-    """Returns list of disks and their free space.
+    """Return list of disks and their free space.
 
     The primary source of information is UDisks' list of block devices.
     Information from df is used for free space available.
@@ -136,8 +132,8 @@ def get_mounts():
 def _get_disks_from_df():
     """Return the list of disks and free space available using 'df'."""
     try:
-        output = actions.superuser_run('storage', ['usage-info'])
-    except subprocess.CalledProcessError as exception:
+        output = privileged.usage_info()
+    except Exception as exception:
         logger.exception('Error getting disk information: %s', exception)
         return []
 
@@ -162,7 +158,7 @@ def _get_disks_from_df():
 
 
 def get_filesystem_type(mount_point='/'):
-    """Returns the type of the filesystem mounted at mountpoint."""
+    """Return the type of the filesystem mounted at mountpoint."""
     for partition in psutil.disk_partitions():
         if partition.mountpoint == mount_point:
             return partition.fstype
@@ -204,19 +200,10 @@ def is_expandable(device):
         return False
 
     try:
-        output = actions.superuser_run('storage',
-                                       ['is-partition-expandable', device],
-                                       log_error=False)
-    except actions.ActionError:
+        return privileged.is_partition_expandable(device, _log_error=False)
+    except Exception:
         return False
 
-    return int(output.strip())
-
-
-def expand_partition(device):
-    """Expand a partition."""
-    actions.superuser_run('storage', ['expand-partition', device])
-
 
 def format_bytes(size):
     """Return human readable disk size from bytes."""
diff --git a/plinth/modules/storage/forms.py b/plinth/modules/storage/forms.py
index be419a827..232cdc9bb 100644
--- a/plinth/modules/storage/forms.py
+++ b/plinth/modules/storage/forms.py
@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-Forms for directory selection.
-"""
+"""Forms for directory selection."""
 
 import os
 
@@ -9,11 +7,12 @@ from django import forms
 from django.core.exceptions import ValidationError
 from django.utils.translation import gettext_lazy as _
 
-from plinth import actions
 from plinth import app as app_module
 from plinth.modules import storage
 from plinth.modules.samba import privileged as samba_privileged
 
+from . import privileged
+
 
 def get_available_samba_shares():
     """Get available samba shares."""
@@ -40,6 +39,8 @@ def _is_app_enabled(app_id):
 
 
 class DirectoryValidator:
+    """Validation helper to check a directory."""
+
     username = None
     check_writable = False
     check_creatable = False
@@ -48,6 +49,7 @@ class DirectoryValidator:
 
     def __init__(self, username=None, check_writable=None,
                  check_creatable=None):
+        """Initialize the validator."""
         if username is not None:
             self.username = username
         if check_writable is not None:
@@ -60,29 +62,22 @@ class DirectoryValidator:
         if not value.startswith('/'):
             raise ValidationError(_('Invalid directory name.'), 'invalid')
 
-        command = ['validate-directory', '--path', value]
-        if self.check_creatable:
-            command.append('--check-creatable')
-        elif self.check_writable:
-            command.append('--check-writable')
+        try:
+            if not self.username:
+                raise ValueError('Invalid username for directory validator')
 
-        if self.username:
-            output = actions.run_as_user('storage', command,
-                                         become_user=self.username)
-        else:
-            output = actions.run('storage', command)
-
-        if 'ValidationError' in output:
-            error_nr = int(output.strip().split()[1])
-            if error_nr == 1:
-                raise ValidationError(_('Directory does not exist.'),
-                                      'invalid')
-            elif error_nr == 2:
-                raise ValidationError(_('Path is not a directory.'), 'invalid')
-            elif error_nr == 3:
+            privileged.validate_directory(value, self.check_creatable,
+                                          self.check_writable,
+                                          _run_as_user=self.username)
+        except FileNotFoundError:
+            raise ValidationError(_('Directory does not exist.'), 'invalid')
+        except NotADirectoryError:
+            raise ValidationError(_('Path is not a directory.'), 'invalid')
+        except PermissionError as exception:
+            if exception.args[0] == 'read':
                 raise ValidationError(
                     _('Directory is not readable by the user.'), 'invalid')
-            elif error_nr == 4:
+            else:
                 raise ValidationError(
                     _('Directory is not writable by the user.'), 'invalid')
 
diff --git a/actions/storage b/plinth/modules/storage/privileged.py
old mode 100755
new mode 100644
similarity index 66%
rename from actions/storage
rename to plinth/modules/storage/privileged.py
index ec682ec17..9138a7373
--- a/actions/storage
+++ b/plinth/modules/storage/privileged.py
@@ -1,85 +1,31 @@
-#!/usr/bin/python3
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-Configuration helper for disks manager.
-"""
+"""Configure disks manager."""
 
-import argparse
-import json
 import os
 import re
 import stat
 import subprocess
-import sys
 
 from plinth import utils
+from plinth.actions import privileged
 
 
-def parse_arguments():
-    """Return parsed command line arguments as dictionary."""
-    parser = argparse.ArgumentParser()
-    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')
-
-    subparsers.add_parser('setup', help='Configure storage after install')
-
-    subparser = subparsers.add_parser(
-        'is-partition-expandable',
-        help='Return whether a given partition can be expanded')
-    subparser.add_argument(
-        'device', help='Partition for which check needs to be performed')
-
-    subparser = subparsers.add_parser(
-        'expand-partition',
-        help='Expand a partition to take adjacent free space')
-    subparser.add_argument('device',
-                           help='Partition which needs to be resized')
-    subparser.add_argument(
-        '--mount-point', default='/',
-        help=('Mount point which the device is mounted. '
-              'Needed for btrfs filesystems'))
-
-    subparser = subparsers.add_parser('mount', help='Mount a filesystem')
-    subparser.add_argument('--block-device',
-                           help='Block device of the filesystem to mount')
-
-    subparser = subparsers.add_parser('eject', help='Eject a storage device')
-    subparser.add_argument('device', help='Path of the device to eject')
-
-    subparsers.add_parser('usage-info',
-                          help='Get information about disk space usage')
-
-    subparser = subparsers.add_parser('validate-directory',
-                                      help='Validate a directory')
-    subparser.add_argument('--path', help='Path of the directory',
-                           required=True)
-    subparser.add_argument('--check-creatable', required=False, default=False,
-                           action='store_true',
-                           help='Check that the directory is creatable')
-    subparser.add_argument('--check-writable', required=False, default=False,
-                           action='store_true',
-                           help='Check that the directory is writable')
-
-    subparsers.required = True
-    return parser.parse_args()
-
-
-def subcommand_is_partition_expandable(arguments):
+@privileged
+def is_partition_expandable(device: str) -> int:
     """Return a list of partitions that can be expanded."""
-    _, _, free_space = _get_free_space(arguments.device)
-    print(free_space['size'])
+    _, _, free_space = _get_free_space(device)
+    return int(free_space['size'])
 
 
-def subcommand_expand_partition(arguments):
+@privileged
+def expand_partition(device: str, mount_point: str = '/'):
     """Expand a partition to take adjacent free space."""
-    device = arguments.device
-    mount_point = arguments.mount_point
     device, requested_partition, free_space = _get_free_space(device)
 
     if requested_partition['table_type'] == 'msdos' and \
        int(requested_partition['number']) >= 5:
-        print('Expanding logical partitions currently unsupported',
-              file=sys.stderr)
-        sys.exit(4)
+        raise RuntimeError(
+            'Expanding logical partitions currently unsupported')
 
     if requested_partition['table_type'] == 'gpt':
         _move_gpt_second_header(device)
@@ -102,8 +48,7 @@ def _move_gpt_second_header(device):
     try:
         subprocess.run(command, check=True)
     except subprocess.CalledProcessError:
-        print('Error moving GPT second header to the end')
-        sys.exit(6)
+        raise RuntimeError('Error moving GPT second header to the end')
 
 
 def _resize_partition(device, requested_partition, free_space):
@@ -127,8 +72,7 @@ def _resize_partition(device, requested_partition, free_space):
             subprocess.run(fallback_command, check=True,
                            input=input_text.encode())
         except subprocess.CalledProcessError as exception:
-            print('Error expanding partition:', exception, file=sys.stderr)
-            sys.exit(5)
+            raise RuntimeError(f'Error expanding partition: {exception}')
 
 
 def _resize_file_system(device, requested_partition, free_space,
@@ -149,8 +93,7 @@ def _resize_ext4(device, requested_partition, _free_space, _mount_point):
         subprocess.run(command, stdout=subprocess.DEVNULL,
                        stderr=subprocess.DEVNULL, check=True)
     except subprocess.CalledProcessError as exception:
-        print('Error expanding filesystem:', exception, file=sys.stderr)
-        sys.exit(6)
+        raise RuntimeError(f'Error expanding filesystem: {exception}')
 
 
 def _resize_btrfs(_device, _requested_partition, _free_space, mount_point='/'):
@@ -159,8 +102,7 @@ def _resize_btrfs(_device, _requested_partition, _free_space, mount_point='/'):
         command = ['btrfs', 'filesystem', 'resize', 'max', mount_point]
         subprocess.run(command, stdout=subprocess.DEVNULL, check=True)
     except subprocess.CalledProcessError as exception:
-        print('Error expanding filesystem:', exception, file=sys.stderr)
-        sys.exit(6)
+        raise RuntimeError(f'Error expanding filesystem: {exception}')
 
 
 def _get_free_space(device):
@@ -172,21 +114,18 @@ def _get_free_space(device):
         requested_partition, free_spaces = \
             _get_partitions_and_free_spaces(device, partition_number)
     except Exception as exception:
-        print('Error getting partition details: ', exception, file=sys.stderr)
-        sys.exit(2)
+        raise RuntimeError(f'Error getting partition details: {exception}')
 
     # Don't accept extended partitions for now
     if requested_partition['table_type'] == 'msdos' and \
        int(requested_partition['number']) >= 5:
-        print('Expanding logical partitions currently unsupported',
-              file=sys.stderr)
-        sys.exit(3)
+        raise RuntimeError(
+            'Expanding logical partitions currently unsupported')
 
     # Don't accept anything but btrfs and ext4 filesystems
     if requested_partition['type'] not in ('btrfs', 'ext4'):
-        print('Unsupported file system type: ', requested_partition['type'],
-              file=sys.stderr)
-        sys.exit(4)
+        raise RuntimeError(
+            f'Unsupported file system type: {requested_partition["type"]}')
 
     found_free_space = None
     for free_space in free_spaces:
@@ -199,7 +138,7 @@ def _get_free_space(device):
         found_free_space = free_space
 
     if not found_free_space:
-        sys.exit(5)
+        raise RuntimeError('No free space available')
 
     return device, requested_partition, found_free_space
 
@@ -218,8 +157,7 @@ def _get_root_device_and_partition_number(device):
     if not match:
         match = re.match(r'(.+[a-zA-Z])(\d+)$', device)
         if not match:
-            print('Invalid device, must be a partition', file=sys.stderr)
-            sys.exit(1)
+            raise ValueError('Invalid device, must be a partition')
 
     return match.group(1), match.group(2)
 
@@ -263,7 +201,8 @@ def _interpret_unit(value):
     return int(value)
 
 
-def subcommand_mount(arguments):
+@privileged
+def mount(block_device: str):
     """Mount a disk are root user.
 
     XXX: This is primarily to provide compatibility with older code that used
@@ -276,22 +215,16 @@ def subcommand_mount(arguments):
     UDISKS_FILESYSTEM_SHARED=1 by writing a udev rule.
 
     """
-    process = subprocess.run([
-        'udisksctl', 'mount', '--block-device', arguments.block_device,
+    subprocess.run([
+        'udisksctl', 'mount', '--block-device', block_device,
         '--no-user-interaction'
-    ], check=False)
-    sys.exit(process.returncode)
+    ], check=True)
 
 
-def subcommand_eject(arguments):
+@privileged
+def eject(device_path: str) -> str:
     """Eject a device by its path."""
-    device_path = arguments.device
-    try:
-        drive = eject_drive_of_device(device_path)
-        print(json.dumps(drive))
-    except Exception as exception:
-        print(exception, file=sys.stderr)
-        sys.exit(1)
+    return _eject_drive_of_device(device_path)
 
 
 def _get_options():
@@ -302,7 +235,7 @@ def _get_options():
     return options
 
 
-def eject_drive_of_device(device_path):
+def _eject_drive_of_device(device_path):
     """Eject a device after unmounting all of its partitions.
 
     Return the details (model, vendor) of drives ejected.
@@ -327,10 +260,10 @@ def eject_drive_of_device(device_path):
     block_device = obj.get_block()
     drive_object_path = block_device.props.drive
     if drive_object_path != '/':
-        umount_all_filesystems_of_drive(drive_object_path)
+        _umount_all_filesystems_of_drive(drive_object_path)
     else:
         # Block device has not associated drive
-        umount_filesystem(obj.get_filesystem())
+        _umount_filesystem(obj.get_filesystem())
 
     # Eject the drive
     drive = client.get_drive_for_block(block_device)
@@ -350,13 +283,13 @@ def eject_drive_of_device(device_path):
     return None
 
 
-def umount_filesystem(filesystem):
-    """Unmount a filesystem """
+def _umount_filesystem(filesystem):
+    """Unmount a filesystem."""
     if filesystem and filesystem.props.mount_points:
         filesystem.call_unmount_sync(_get_options())
 
 
-def umount_all_filesystems_of_drive(drive_object_path):
+def _umount_all_filesystems_of_drive(drive_object_path):
     """Unmount all filesystems on block devices of a drive."""
     udisks = utils.import_from_gi('UDisks', '2.0')
     client = udisks.Client.new_sync()
@@ -367,10 +300,11 @@ def umount_all_filesystems_of_drive(drive_object_path):
         if not block_device or block_device.props.drive != drive_object_path:
             continue
 
-        umount_filesystem(obj.get_filesystem())
+        _umount_filesystem(obj.get_filesystem())
 
 
-def subcommand_setup(_):
+@privileged
+def setup():
     """Configure storage."""
     # create udisks2 default mount directory
     mounts_directory = '/media/root'
@@ -384,58 +318,43 @@ def subcommand_setup(_):
     os.chmod(mounts_directory, stats.st_mode | stat.S_IROTH | stat.S_IXOTH)
 
 
-def subcommand_usage_info(_):
+@privileged
+def usage_info() -> str:
     """Get information about disk space usage."""
     command = [
         'df', '--exclude-type=tmpfs', '--exclude-type=devtmpfs',
         '--block-size=1', '--output=source,fstype,size,used,avail,pcent,target'
     ]
-    subprocess.run(command, check=True)
+    return subprocess.check_output(command).decode()
 
 
-def subcommand_validate_directory(arguments):
-    """Validate a directory"""
+@privileged
+def validate_directory(directory: str, check_creatable: bool,
+                       check_writable: bool):
+    """Validate a directory."""
     if os.geteuid() == 0:
         raise RuntimeError('You must not be root to run this command')
 
-    directory = arguments.path
-
     def part_exists(path):
-        """Returns part of the path that exists."""
+        """Return part of the path that exists."""
         if not path or os.path.exists(path):
             return path
         return part_exists(os.path.dirname(path))
 
-    if arguments.check_creatable:
+    if check_creatable:
         directory = part_exists(directory)
         if not directory:
             directory = '.'
     else:
         if not os.path.exists(directory):
-            # doesn't exist
-            print('ValidationError: 1')
-            return
+            raise FileNotFoundError
 
     if not os.path.isdir(directory):
-        # is not a directory
-        print('ValidationError: 2')
-    elif not os.access(directory, os.R_OK):
-        # is not readable
-        print('ValidationError: 3')
-    elif arguments.check_writable or arguments.check_creatable:
+        raise NotADirectoryError
+
+    if not os.access(directory, os.R_OK):
+        raise PermissionError('read')
+
+    if check_writable or check_creatable:
         if not os.access(directory, os.W_OK):
-            # is not writable
-            print('ValidationError: 4')
-
-
-def main():
-    """Parse arguments and perform all duties."""
-    arguments = parse_arguments()
-
-    subcommand = arguments.subcommand.replace('-', '_')
-    subcommand_method = globals()['subcommand_' + subcommand]
-    subcommand_method(arguments)
-
-
-if __name__ == '__main__':
-    main()
+            raise PermissionError('write')
diff --git a/plinth/modules/storage/tests/test_storage.py b/plinth/modules/storage/tests/test_storage.py
index 4877ee81b..cb2672bd4 100644
--- a/plinth/modules/storage/tests/test_storage.py
+++ b/plinth/modules/storage/tests/test_storage.py
@@ -4,14 +4,17 @@ Test module for storage module operations.
 """
 
 import contextlib
-import os
-import pathlib
 import re
 import subprocess
 import tempfile
 
 import pytest
 
+from plinth.modules.storage import privileged
+
+pytestmark = pytest.mark.usefixtures('mock_privileged')
+privileged_modules_to_mock = ['plinth.modules.storage.privileged']
+
 
 class Disk():
     """Context manager to create/destroy a disk."""
@@ -255,8 +258,11 @@ def test_ext4_expansion(partition_table_type):
 def _assert_free_space(disk, partition_number, space=True):
     """Verify that free is available/not available after a partition."""
     device = disk.get_partition_device(partition_number)
-    result = _check_action(['storage', 'is-partition-expandable', device])
-    assert result == space
+    if space:
+        privileged.is_partition_expandable(device)
+    else:
+        with pytest.raises(RuntimeError):
+            privileged.is_partition_expandable(device)
 
 
 def _expand_partition(disk, partition_number, success=True):
@@ -264,34 +270,15 @@ def _expand_partition(disk, partition_number, success=True):
     _assert_aligned(disk, partition_number)
     with disk.mount_partition(partition_number) as mount_point:
         device = disk.get_partition_device(partition_number)
-        result = _check_action([
-            'storage', 'expand-partition', device, '--mount-point', mount_point
-        ])
+        if success:
+            privileged.expand_partition(device, mount_point)
+        else:
+            with pytest.raises(RuntimeError):
+                privileged.expand_partition(device, mount_point)
 
-    assert result == success
     _assert_aligned(disk, partition_number)
 
 
-def _call_action(action_command, check=True, **kwargs):
-    """Call the action script."""
-    test_directory = pathlib.Path(__file__).parent
-    top_directory = (test_directory / '..' / '..' / '..' / '..').resolve()
-    action_command[0] = top_directory / 'actions' / action_command[0]
-    kwargs['stdout'] = kwargs.get('stdout', subprocess.DEVNULL)
-    kwargs['stderr'] = kwargs.get('stderr', subprocess.DEVNULL)
-    env = dict(os.environ, PYTHONPATH=str(top_directory))
-    return subprocess.run(action_command, env=env, check=check, **kwargs)
-
-
-def _check_action(action_command):
-    """Return success/failure result of the action command."""
-    try:
-        _call_action(action_command)
-        return True
-    except subprocess.CalledProcessError:
-        return False
-
-
 def _assert_aligned(disk, partition_number):
     """Test that partition is optimally aligned."""
     subprocess.run([
@@ -319,43 +306,40 @@ def _assert_ext4_file_system_healthy(disk, partition_number):
 def _assert_validate_directory(path, error, check_writable=False,
                                check_creatable=False):
     """Perform directory validation checks."""
-    action_command = ['storage', 'validate-directory', '--path', path]
-    if check_writable:
-        action_command += ['--check-writable']
-    if check_creatable:
-        action_command += ['--check-creatable']
-    proc = _call_action(action_command, stderr=subprocess.PIPE,
-                        stdout=subprocess.PIPE)
-    output = proc.stdout.decode()
-    if 'ValidationError' in output:
-        error_nr = output.strip().split()[1]
-        assert error_nr == error
+    if error:
+        match = None if not error.args else error.args[0]
+        with pytest.raises(error.__class__, match=match):
+            privileged.validate_directory(path, check_creatable,
+                                          check_writable)
     else:
-        assert output == error
+        privileged.validate_directory(path, check_creatable, check_writable)
 
 
 @pytest.mark.usefixtures('needs_not_root')
-@pytest.mark.parametrize('path,error', [('/missing', '1'),
-                                        ('/etc/os-release', '2'),
-                                        ('/root', '3'), ('/', ''),
-                                        ('/etc/..', '')])
+@pytest.mark.parametrize('path,error',
+                         [('/missing', FileNotFoundError()),
+                          ('/etc/os-release', NotADirectoryError()),
+                          ('/root', PermissionError('read')), ('/', None),
+                          ('/etc/..', None)])
 def test_validate_directory(path, error):
     """Test that directory validation returns expected output."""
     _assert_validate_directory(path, error)
 
 
 @pytest.mark.usefixtures('needs_not_root')
-@pytest.mark.parametrize('path,error', [('/', '4'), ('/tmp', '')])
+@pytest.mark.parametrize('path,error', [('/', PermissionError('write')),
+                                        ('/tmp', None)])
 def test_validate_directory_writable(path, error):
     """Test that directory writable validation returns expected output."""
     _assert_validate_directory(path, error, check_writable=True)
 
 
 @pytest.mark.usefixtures('needs_not_root')
-@pytest.mark.parametrize('path,error',
-                         [('/var/lib/plinth_storage_test_not_exists', '4'),
-                          ('/tmp/plint_storage_test_not_exists', ''),
-                          ('/var/../tmp/plint_storage_test_not_exists', '')])
+@pytest.mark.parametrize(
+    'path,error',
+    [('/var/lib/plinth_storage_test_not_exists', PermissionError('write')),
+     ('/tmp/plint_storage_test_not_exists', None),
+     ('/var/../tmp/plint_storage_test_not_exists', None)])
 def test_validate_directory_creatable(path, error):
     """Test that directory creatable validation returns expected output."""
     _assert_validate_directory(path, error, check_creatable=True)
diff --git a/plinth/modules/storage/udisks2.py b/plinth/modules/storage/udisks2.py
index a98d985c8..9b536b40e 100644
--- a/plinth/modules/storage/udisks2.py
+++ b/plinth/modules/storage/udisks2.py
@@ -1,15 +1,14 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-Handle disk operations using UDisk2 DBus API.
-"""
+"""Handle disk operations using UDisk2 DBus API."""
 
 import logging
 import threading
 
-from plinth import actions, cfg
-from plinth.errors import ActionError
+from plinth import cfg
 from plinth.utils import import_from_gi
 
+from . import privileged
+
 glib = import_from_gi('GLib', '2.0')
 gio = import_from_gi('Gio', '2.0')
 
@@ -195,11 +194,8 @@ def _mount(object_path):
     logger.info('Auto-mounting device: %s %s', block_device.id,
                 block_device.preferred_device)
     try:
-        actions.superuser_run(
-            'storage',
-            ['mount', '--block-device', block_device.preferred_device],
-            log_error=False)
-    except ActionError as exception:
+        privileged.mount(block_device.preferred_device, _log_error=False)
+    except Exception as exception:
         parts = exception.args[2].split(':')
         if parts[1].strip() != 'GDBus.Error':
             raise
diff --git a/plinth/modules/storage/views.py b/plinth/modules/storage/views.py
index 749c27e8d..851929cb7 100644
--- a/plinth/modules/storage/views.py
+++ b/plinth/modules/storage/views.py
@@ -1,9 +1,6 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-Views for storage module.
-"""
+"""Views for storage module."""
 
-import json
 import logging
 import urllib.parse
 
@@ -14,17 +11,17 @@ from django.urls import reverse
 from django.utils.translation import gettext as _
 from django.views.decorators.http import require_POST
 
-from plinth import actions, views
-from plinth.errors import ActionError
+from plinth import views
 from plinth.modules import storage
 
-from . import get_error_message
+from . import get_error_message, privileged
 
 logger = logging.getLogger(__name__)
 
 
 class StorageAppView(views.AppView):
     """Show storage information."""
+
     app_id = 'storage'
     template_name = 'storage.html'
 
@@ -63,7 +60,7 @@ def expand(request):
 def expand_partition(request, device):
     """Expand the partition."""
     try:
-        storage.expand_partition(device)
+        privileged.expand_partition(device)
     except Exception as exception:
         messages.error(
             request,
@@ -83,8 +80,7 @@ def eject(request, device_path):
     device_path = urllib.parse.unquote(device_path)
 
     try:
-        drive = json.loads(
-            actions.superuser_run('storage', ['eject', device_path]))
+        drive = privileged.eject(device_path)
         if drive:
             messages.success(
                 request,
@@ -93,8 +89,8 @@ def eject(request, device_path):
                        drive_model=drive['model']))
         else:
             messages.success(request, _('Device can be safely unplugged.'))
-    except ActionError as exception:
-        message = get_error_message(exception.args[2])
+    except Exception as exception:
+        message = get_error_message(exception.args[-2].decode())  # stdout
 
         logger.error('Error ejecting device - %s', message)
         messages.error(