minio/pkg/utils/scsi/mountinfo.go

123 lines
3.0 KiB
Go

// +build linux
/*
* Mini Object Storage, (C) 2014 Minio, Inc.
*
* 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 scsi
import (
"bufio"
"errors"
"io/ioutil"
"os"
"path/filepath"
"strconv"
"strings"
"syscall"
"github.com/minio/minio/pkg/iodine"
)
// Mountinfo container to capture /etc/mtab mount structure
type Mountinfo struct {
FSName string /* name of mounted filesystem */
Dir string /* filesystem path prefix */
Type string /* mount type (see mntent.h) */
Opts string /* mount options (see mntent.h) */
Freq int /* dump frequency in days */
Passno int /* pass number on parallel fsck */
}
var supportedFSType = map[string]bool{
"ext4": true,
"xfs": true,
"ext3": true,
"btrfs": true,
"tmpfs": true,
"nfs": true,
}
func isSupportedType(t string) bool {
_, ok := supportedFSType[t]
return ok
}
// GetMountInfo - get mount info map
func GetMountInfo() (map[string]Mountinfo, error) {
f, err := os.Open("/etc/mtab")
if err != nil {
return nil, iodine.New(err, nil)
}
mntEnt := make(map[string]Mountinfo)
scanner := bufio.NewScanner(f)
for scanner.Scan() {
mtabEnt := strings.Split(scanner.Text(), " ")
mntInfo := Mountinfo{}
if len(mtabEnt) == 6 {
var err error
if !isSupportedType(mtabEnt[2]) {
continue
}
mntInfo.FSName, err = filepath.EvalSymlinks(mtabEnt[0])
if err != nil {
continue
}
mntInfo.Dir = mtabEnt[1]
mntInfo.Type = mtabEnt[2]
mntInfo.Opts = mtabEnt[3]
mntInfo.Freq, err = strconv.Atoi(mtabEnt[4])
if err != nil {
continue
}
mntInfo.Passno, err = strconv.Atoi(mtabEnt[5])
if err != nil {
continue
}
mntEnt[mntInfo.FSName] = mntInfo
}
}
return mntEnt, nil
}
// IsUsable provides a comprehensive way of knowing if the provided mountPath is mounted and writable
func IsUsable(mountPath string) (bool, error) {
mntpoint, err := os.Stat(mountPath)
if err != nil {
return false, iodine.New(err, nil)
}
parent, err := os.Stat(filepath.Join(mountPath, ".."))
if err != nil {
return false, iodine.New(err, nil)
}
mntpointSt := mntpoint.Sys().(*syscall.Stat_t)
parentSt := parent.Sys().(*syscall.Stat_t)
if mntpointSt.Dev == parentSt.Dev {
return false, iodine.New(errors.New("not mounted"), nil)
}
testFile, err := ioutil.TempFile(mountPath, "writetest-")
if err != nil {
return false, iodine.New(err, nil)
}
testFileName := testFile.Name()
// close the file, to avoid leaky fd's
testFile.Close()
if err := os.Remove(testFileName); err != nil {
return false, iodine.New(err, nil)
}
return true, nil
}