Rename pkg/volume/util/quota -> pkg/volume/util/fsquota

pkg/volume/util/fsquota/common/quota_linux_common_impl.go

@@ -0,0 +1,286 @@
+// +build linux
+
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 common
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+
+	"k8s.io/klog"
+)
+
+var quotaCmd string
+var quotaCmdInitialized bool
+var quotaCmdLock sync.RWMutex
+
+// If we later get a filesystem that uses project quota semantics other than
+// XFS, we'll need to change this.
+// Higher levels don't need to know what's inside
+type linuxFilesystemType struct {
+	name             string
+	typeMagic        int64 // Filesystem magic number, per statfs(2)
+	maxQuota         int64
+	allowEmptyOutput bool // Accept empty output from "quota" command
+}
+
+const (
+	bitsPerWord = 32 << (^uint(0) >> 63) // either 32 or 64
+)
+
+var (
+	linuxSupportedFilesystems = []linuxFilesystemType{
+		{
+			name:             "XFS",
+			typeMagic:        0x58465342,
+			maxQuota:         1<<(bitsPerWord-1) - 1,
+			allowEmptyOutput: true, // XFS filesystems report nothing if a quota is not present
+		}, {
+			name:             "ext4fs",
+			typeMagic:        0xef53,
+			maxQuota:         (1<<(bitsPerWord-1) - 1) & (1<<58 - 1),
+			allowEmptyOutput: false, // ext4 filesystems always report something even if a quota is not present
+		},
+	}
+)
+
+// VolumeProvider supplies a quota applier to the generic code.
+type VolumeProvider struct {
+}
+
+var quotaCmds = []string{"/sbin/xfs_quota",
+	"/usr/sbin/xfs_quota",
+	"/bin/xfs_quota"}
+
+var quotaParseRegexp = regexp.MustCompilePOSIX("^[^ \t]*[ \t]*([0-9]+)")
+
+var lsattrCmd = "/usr/bin/lsattr"
+var lsattrParseRegexp = regexp.MustCompilePOSIX("^ *([0-9]+) [^ ]+ (.*)$")
+
+// GetQuotaApplier -- does this backing device support quotas that
+// can be applied to directories?
+func (*VolumeProvider) GetQuotaApplier(mountpoint string, backingDev string) LinuxVolumeQuotaApplier {
+	for _, fsType := range linuxSupportedFilesystems {
+		if isFilesystemOfType(mountpoint, backingDev, fsType.typeMagic) {
+			return linuxVolumeQuotaApplier{mountpoint: mountpoint,
+				maxQuota:         fsType.maxQuota,
+				allowEmptyOutput: fsType.allowEmptyOutput,
+			}
+		}
+	}
+	return nil
+}
+
+type linuxVolumeQuotaApplier struct {
+	mountpoint       string
+	maxQuota         int64
+	allowEmptyOutput bool
+}
+
+func getXFSQuotaCmd() (string, error) {
+	quotaCmdLock.Lock()
+	defer quotaCmdLock.Unlock()
+	if quotaCmdInitialized {
+		return quotaCmd, nil
+	}
+	for _, program := range quotaCmds {
+		fileinfo, err := os.Stat(program)
+		if err == nil && ((fileinfo.Mode().Perm() & (1 << 6)) != 0) {
+			klog.V(3).Infof("Found xfs_quota program %s", program)
+			quotaCmd = program
+			quotaCmdInitialized = true
+			return quotaCmd, nil
+		}
+	}
+	quotaCmdInitialized = true
+	return "", fmt.Errorf("No xfs_quota program found")
+}
+
+func doRunXFSQuotaCommand(mountpoint string, mountsFile, command string) (string, error) {
+	quotaCmd, err := getXFSQuotaCmd()
+	if err != nil {
+		return "", err
+	}
+	// We're using numeric project IDs directly; no need to scan
+	// /etc/projects or /etc/projid
+	klog.V(4).Infof("runXFSQuotaCommand %s -t %s -P/dev/null -D/dev/null -x -f %s -c %s", quotaCmd, mountsFile, mountpoint, command)
+	cmd := exec.Command(quotaCmd, "-t", mountsFile, "-P/dev/null", "-D/dev/null", "-x", "-f", mountpoint, "-c", command)
+
+	data, err := cmd.Output()
+	if err != nil {
+		return "", err
+	}
+	klog.V(4).Infof("runXFSQuotaCommand output %q", string(data))
+	return string(data), nil
+}
+
+// Extract the mountpoint we care about into a temporary mounts file so that xfs_quota does
+// not attempt to scan every mount on the filesystem, which could hang if e. g.
+// a stuck NFS mount is present.
+// See https://bugzilla.redhat.com/show_bug.cgi?id=237120 for an example
+// of the problem that could be caused if this were to happen.
+func runXFSQuotaCommand(mountpoint string, command string) (string, error) {
+	tmpMounts, err := ioutil.TempFile("", "mounts")
+	if err != nil {
+		return "", fmt.Errorf("Cannot create temporary mount file: %v", err)
+	}
+	tmpMountsFileName := tmpMounts.Name()
+	defer tmpMounts.Close()
+	defer os.Remove(tmpMountsFileName)
+
+	mounts, err := os.Open(MountsFile)
+	if err != nil {
+		return "", fmt.Errorf("Cannot open mounts file %s: %v", MountsFile, err)
+	}
+	defer mounts.Close()
+
+	scanner := bufio.NewScanner(mounts)
+	for scanner.Scan() {
+		match := MountParseRegexp.FindStringSubmatch(scanner.Text())
+		if match != nil {
+			mount := match[2]
+			if mount == mountpoint {
+				if _, err := tmpMounts.WriteString(fmt.Sprintf("%s\n", scanner.Text())); err != nil {
+					return "", fmt.Errorf("Cannot write temporary mounts file: %v", err)
+				}
+				if err := tmpMounts.Sync(); err != nil {
+					return "", fmt.Errorf("Cannot sync temporary mounts file: %v", err)
+				}
+				return doRunXFSQuotaCommand(mountpoint, tmpMountsFileName, command)
+			}
+		}
+	}
+	return "", fmt.Errorf("Cannot run xfs_quota: cannot find mount point %s in %s", mountpoint, MountsFile)
+}
+
+// SupportsQuotas determines whether the filesystem supports quotas.
+func SupportsQuotas(mountpoint string, qType QuotaType) (bool, error) {
+	data, err := runXFSQuotaCommand(mountpoint, "state -p")
+	if err != nil {
+		return false, err
+	}
+	if qType == FSQuotaEnforcing {
+		return strings.Contains(data, "Enforcement: ON"), nil
+	}
+	return strings.Contains(data, "Accounting: ON"), nil
+}
+
+func isFilesystemOfType(mountpoint string, backingDev string, typeMagic int64) bool {
+	var buf syscall.Statfs_t
+	err := syscall.Statfs(mountpoint, &buf)
+	if err != nil {
+		klog.Warningf("Warning: Unable to statfs %s: %v", mountpoint, err)
+		return false
+	}
+	if int64(buf.Type) != typeMagic {
+		return false
+	}
+	if answer, _ := SupportsQuotas(mountpoint, FSQuotaAccounting); answer {
+		return true
+	}
+	return false
+}
+
+// GetQuotaOnDir retrieves the quota ID (if any) associated with the specified directory
+// If we can't make system calls, all we can say is that we don't know whether
+// it has a quota, and higher levels have to make the call.
+func (v linuxVolumeQuotaApplier) GetQuotaOnDir(path string) (QuotaID, error) {
+	cmd := exec.Command(lsattrCmd, "-pd", path)
+	data, err := cmd.Output()
+	if err != nil {
+		return BadQuotaID, fmt.Errorf("cannot run lsattr: %v", err)
+	}
+	match := lsattrParseRegexp.FindStringSubmatch(string(data))
+	if match == nil {
+		return BadQuotaID, fmt.Errorf("Unable to parse lsattr -pd %s output %s", path, string(data))
+	}
+	if match[2] != path {
+		return BadQuotaID, fmt.Errorf("Mismatch between supplied and returned path (%s != %s)", path, match[2])
+	}
+	projid, err := strconv.ParseInt(match[1], 10, 32)
+	if err != nil {
+		return BadQuotaID, fmt.Errorf("Unable to parse project ID from %s (%v)", match[1], err)
+	}
+	return QuotaID(projid), nil
+}
+
+// SetQuotaOnDir applies a quota to the specified directory under the specified mountpoint.
+func (v linuxVolumeQuotaApplier) SetQuotaOnDir(path string, id QuotaID, bytes int64) error {
+	if bytes < 0 || bytes > v.maxQuota {
+		bytes = v.maxQuota
+	}
+	_, err := runXFSQuotaCommand(v.mountpoint, fmt.Sprintf("limit -p bhard=%v bsoft=%v %v", bytes, bytes, id))
+	if err != nil {
+		return err
+	}
+
+	_, err = runXFSQuotaCommand(v.mountpoint, fmt.Sprintf("project -s -p %s %v", path, id))
+	return err
+}
+
+func getQuantity(mountpoint string, id QuotaID, xfsQuotaArg string, multiplier int64, allowEmptyOutput bool) (int64, error) {
+	data, err := runXFSQuotaCommand(mountpoint, fmt.Sprintf("quota -p -N -n -v %s %v", xfsQuotaArg, id))
+	if err != nil {
+		return 0, fmt.Errorf("Unable to run xfs_quota: %v", err)
+	}
+	if data == "" && allowEmptyOutput {
+		return 0, nil
+	}
+	match := quotaParseRegexp.FindStringSubmatch(data)
+	if match == nil {
+		return 0, fmt.Errorf("Unable to parse quota output '%s'", data)
+	}
+	size, err := strconv.ParseInt(match[1], 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("Unable to parse data size '%s' from '%s': %v", match[1], data, err)
+	}
+	klog.V(4).Infof("getQuantity %s %d %s %d => %d %v", mountpoint, id, xfsQuotaArg, multiplier, size, err)
+	return size * multiplier, nil
+}
+
+// GetConsumption returns the consumption in bytes if available via quotas
+func (v linuxVolumeQuotaApplier) GetConsumption(_ string, id QuotaID) (int64, error) {
+	return getQuantity(v.mountpoint, id, "-b", 1024, v.allowEmptyOutput)
+}
+
+// GetInodes returns the inodes in use if available via quotas
+func (v linuxVolumeQuotaApplier) GetInodes(_ string, id QuotaID) (int64, error) {
+	return getQuantity(v.mountpoint, id, "-i", 1, v.allowEmptyOutput)
+}
+
+// QuotaIDIsInUse checks whether the specified quota ID is in use on the specified
+// filesystem
+func (v linuxVolumeQuotaApplier) QuotaIDIsInUse(id QuotaID) (bool, error) {
+	bytes, err := v.GetConsumption(v.mountpoint, id)
+	if err != nil {
+		return false, err
+	}
+	if bytes > 0 {
+		return true, nil
+	}
+	inodes, err := v.GetInodes(v.mountpoint, id)
+	return inodes > 0, err
+}