147 lines
3.3 KiB
Go
147 lines
3.3 KiB
Go
//go:build linux
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package fusemount
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import (
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"errors"
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"os"
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"os/exec"
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"path/filepath"
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"strings"
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"unicode"
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"litepan/internal/domain"
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"golang.org/x/sys/unix"
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)
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func forceReleaseMountPoint(mountPoint string) error {
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mountPoint = filepath.Clean(mountPoint)
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if mountPoint == "" || mountPoint == "/" {
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return nil
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}
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if err := lazyUnmount(mountPoint); err != nil {
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return err
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}
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if err := execFusermountUnmount(mountPoint); err != nil {
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return err
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}
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return nil
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}
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func lazyUnmount(mountPoint string) error {
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err := unix.Unmount(mountPoint, unix.MNT_DETACH)
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if err == nil || isBenignUnmountErr(err) {
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return nil
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}
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return err
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}
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func execFusermountUnmount(mountPoint string) error {
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for _, bin := range []string{"fusermount3", "fusermount"} {
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if _, err := exec.LookPath(bin); err != nil {
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continue
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}
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cmd := exec.Command(bin, "-u", "-z", mountPoint)
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if err := cmd.Run(); err == nil {
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return nil
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}
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}
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return nil
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}
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func isBenignUnmountErr(err error) bool {
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return errors.Is(err, unix.EINVAL) ||
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errors.Is(err, unix.ENOENT) ||
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errors.Is(err, unix.EPERM)
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}
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func mountPointBusy(mountPoint string) bool {
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mountPoint = filepath.Clean(mountPoint)
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data, err := os.ReadFile("/proc/self/mountinfo")
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if err != nil {
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return false
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}
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for _, line := range strings.Split(string(data), "\n") {
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fields := strings.Fields(line)
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if len(fields) < 5 {
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continue
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}
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if unescapeMountinfo(fields[4]) == mountPoint {
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return true
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}
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}
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return false
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}
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func busyMountAncestor(mountPoint string) string {
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mountPoint = filepath.Clean(mountPoint)
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root := filepath.Clean(MountRoot)
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for cur := mountPoint; cur != root && strings.HasPrefix(cur, root); cur = filepath.Dir(cur) {
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if mountPointBusy(cur) {
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return cur
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}
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}
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return ""
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}
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func reclaimMountPoint(mountPoint string) error {
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mountPoint = filepath.Clean(mountPoint)
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if mountPoint == "" || mountPoint == "/" {
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return nil
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}
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if busy := busyMountAncestor(mountPoint); busy != "" && busy != mountPoint {
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return domain.Errorf(domain.CodeValidation, "挂载点位于已占用路径 %s 之下，请更换挂载点或先在宿主机卸载该路径", busy)
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}
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if err := forceReleaseMountPoint(mountPoint); err != nil {
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return domain.Errorf(domain.CodeValidation, "清理挂载点 %s 失败: %v", mountPoint, err)
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}
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if mountPointBusy(mountPoint) {
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return domain.Errorf(domain.CodeValidation, "挂载点 %s 仍被系统占用，请稍后在宿主机执行 fusermount -u %s", mountPoint, mountPoint)
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}
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if err := os.Remove(mountPoint); err != nil && !os.IsNotExist(err) {
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return domain.Errorf(domain.CodeValidation, "清理挂载目录 %s 失败: %v", mountPoint, err)
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}
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return nil
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}
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func removeMountPointDir(mountPoint string) error {
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if err := reclaimMountPoint(mountPoint); err != nil {
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return err
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}
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return nil
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}
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func unescapeMountinfo(s string) string {
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var b strings.Builder
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b.Grow(len(s))
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for i := 0; i < len(s); i++ {
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if s[i] == '\\' && i+3 < len(s) {
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if c := unescapeOctal(s[i+1 : i+4]); c >= 0 {
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b.WriteByte(byte(c))
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i += 3
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continue
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}
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}
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b.WriteByte(s[i])
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}
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return b.String()
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}
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func unescapeOctal(s string) int {
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if len(s) != 3 {
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return -1
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}
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n := 0
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for i := 0; i < 3; i++ {
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if s[i] < '0' || s[i] > '7' {
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return -1
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}
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n = n*8 + int(s[i]-'0')
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}
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if n > unicode.MaxASCII {
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return -1
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}
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return n
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}
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