diff --git a/metropolis/pkg/fsquota/quotactl/BUILD.bazel b/metropolis/pkg/fsquota/quotactl/BUILD.bazel
new file mode 100644
index 0000000..406c784
--- /dev/null
+++ b/metropolis/pkg/fsquota/quotactl/BUILD.bazel
@@ -0,0 +1,9 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["quotactl.go"],
+    importpath = "git.monogon.dev/source/nexantic.git/metropolis/pkg/fsquota/quotactl",
+    visibility = ["//visibility:public"],
+    deps = ["@org_golang_x_sys//unix:go_default_library"],
+)
diff --git a/metropolis/pkg/fsquota/quotactl/quotactl.go b/metropolis/pkg/fsquota/quotactl/quotactl.go
new file mode 100644
index 0000000..5ed77d7
--- /dev/null
+++ b/metropolis/pkg/fsquota/quotactl/quotactl.go
@@ -0,0 +1,233 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package quotactl implements a low-level wrapper around the modern portion of Linux's
+// quotactl() syscall. See the fsquota package for a nicer interface to the most common part
+// of this API.
+package quotactl
+
+import (
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+type QuotaType uint
+
+const (
+	QuotaTypeUser QuotaType = iota
+	QuotaTypeGroup
+	QuotaTypeProject
+)
+
+const (
+	Q_SYNC uint = ((0x800001 + iota) << 8)
+	Q_QUOTAON
+	Q_QUOTAOFF
+	Q_GETFMT
+	Q_GETINFO
+	Q_SETINFO
+	Q_GETQUOTA
+	Q_SETQUOTA
+	Q_GETNEXTQUOTA
+)
+
+const (
+	FlagBLimitsValid = 1 << iota
+	FlagSpaceValid
+	FlagILimitsValid
+	FlagInodesValid
+	FlagBTimeValid
+	FlagITimeValid
+)
+
+type DQInfo struct {
+	Bgrace uint64
+	Igrace uint64
+	Flags  uint32
+	Valid  uint32
+}
+
+type Quota struct {
+	BHardLimit uint64 // Both Byte limits are prescaled by 1024 (so are in KiB), but CurSpace is in B
+	BSoftLimit uint64
+	CurSpace   uint64
+	IHardLimit uint64
+	ISoftLimit uint64
+	CurInodes  uint64
+	BTime      uint64
+	ITime      uint64
+	Valid      uint32
+}
+
+type NextDQBlk struct {
+	HardLimitBytes  uint64
+	SoftLimitBytes  uint64
+	CurrentBytes    uint64
+	HardLimitInodes uint64
+	SoftLimitInodes uint64
+	CurrentInodes   uint64
+	BTime           uint64
+	ITime           uint64
+	Valid           uint32
+	ID              uint32
+}
+
+type QuotaFormat uint32
+
+// Collected from quota_format_type structs
+const (
+	// QuotaFormatNone is a special case where all quota information is
+	// stored inside filesystem metadata and thus requires no quotaFilePath.
+	QuotaFormatNone   QuotaFormat = 0
+	QuotaFormatVFSOld QuotaFormat = 1
+	QuotaFormatVFSV0  QuotaFormat = 2
+	QuotaFormatOCFS2  QuotaFormat = 3
+	QuotaFormatVFSV1  QuotaFormat = 4
+)
+
+// QuotaOn turns quota accounting and enforcement on
+func QuotaOn(device string, qtype QuotaType, quotaFormat QuotaFormat, quotaFilePath string) error {
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return err
+	}
+	pathArg, err := unix.BytePtrFromString(quotaFilePath)
+	if err != nil {
+		return err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_QUOTAON|uint(qtype)), uintptr(unsafe.Pointer(devArg)), uintptr(quotaFormat), uintptr(unsafe.Pointer(pathArg)), 0, 0)
+	if err != unix.Errno(0) {
+		return err
+	}
+	return nil
+}
+
+// QuotaOff turns quotas off
+func QuotaOff(device string, qtype QuotaType) error {
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_QUOTAOFF|uint(qtype)), uintptr(unsafe.Pointer(devArg)), 0, 0, 0, 0)
+	if err != unix.Errno(0) {
+		return err
+	}
+	return nil
+}
+
+// GetFmt gets the quota format used on given filesystem
+func GetFmt(device string, qtype QuotaType) (uint32, error) {
+	var fmt uint32
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return 0, err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_GETFMT|uint(qtype)), uintptr(unsafe.Pointer(devArg)), 0, uintptr(unsafe.Pointer(&fmt)), 0, 0)
+	if err != unix.Errno(0) {
+		return 0, err
+	}
+	return fmt, nil
+}
+
+// GetInfo gets information about quota files
+func GetInfo(device string, qtype QuotaType) (*DQInfo, error) {
+	var info DQInfo
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return nil, err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_GETINFO|uint(qtype)), uintptr(unsafe.Pointer(devArg)), 0, uintptr(unsafe.Pointer(&info)), 0, 0)
+	if err != unix.Errno(0) {
+		return nil, err
+	}
+	return &info, nil
+}
+
+// SetInfo sets information about quota files
+func SetInfo(device string, qtype QuotaType, info *DQInfo) error {
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_SETINFO|uint(qtype)), uintptr(unsafe.Pointer(devArg)), 0, uintptr(unsafe.Pointer(info)), 0, 0)
+	if err != unix.Errno(0) {
+		return err
+	}
+	return nil
+}
+
+// GetQuota gets user quota structure
+func GetQuota(device string, qtype QuotaType, id uint32) (*Quota, error) {
+	var info Quota
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return nil, err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_GETQUOTA|uint(qtype)), uintptr(unsafe.Pointer(devArg)), uintptr(id), uintptr(unsafe.Pointer(&info)), 0, 0)
+	if err != unix.Errno(0) {
+		return nil, err
+	}
+	return &info, nil
+}
+
+// GetNextQuota gets disk limits and usage > ID
+func GetNextQuota(device string, qtype QuotaType, id uint32) (*NextDQBlk, error) {
+	var info NextDQBlk
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return nil, err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_GETNEXTQUOTA|uint(qtype)), uintptr(unsafe.Pointer(devArg)), uintptr(id), uintptr(unsafe.Pointer(&info)), 0, 0)
+	if err != unix.Errno(0) {
+		return nil, err
+	}
+	return &info, nil
+}
+
+// SetQuota sets the given quota
+func SetQuota(device string, qtype QuotaType, id uint32, quota *Quota) error {
+	devArg, err := unix.BytePtrFromString(device)
+	if err != nil {
+		return err
+	}
+	_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_SETQUOTA|uint(qtype)), uintptr(unsafe.Pointer(devArg)), uintptr(id), uintptr(unsafe.Pointer(quota)), 0, 0)
+	if err != unix.Errno(0) {
+		return fmt.Errorf("failed to set quota: %w", err)
+	}
+	return nil
+}
+
+// Sync syncs disk copy of filesystems quotas. If device is empty it syncs all filesystems.
+func Sync(device string) error {
+	if device != "" {
+		devArg, err := unix.BytePtrFromString(device)
+		if err != nil {
+			return err
+		}
+		_, _, err = unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_SYNC), uintptr(unsafe.Pointer(devArg)), 0, 0, 0, 0)
+		if err != unix.Errno(0) {
+			return err
+		}
+	} else {
+		_, _, err := unix.Syscall6(unix.SYS_QUOTACTL, uintptr(Q_SYNC), 0, 0, 0, 0, 0)
+		if err != unix.Errno(0) {
+			return err
+		}
+	}
+	return nil
+}