DockerCLI/vendor/github.com/moby/sys/mountinfo/mounted_unix.go

67 lines
1.6 KiB
Go

// +build linux freebsd,cgo openbsd,cgo
package mountinfo
import (
"errors"
"fmt"
"os"
"path/filepath"
"golang.org/x/sys/unix"
)
func mountedByStat(path string) (bool, error) {
var st unix.Stat_t
if err := unix.Lstat(path, &st); err != nil {
if err == unix.ENOENT {
// Treat ENOENT as "not mounted".
return false, nil
}
return false, &os.PathError{Op: "stat", Path: path, Err: err}
}
dev := st.Dev
parent := filepath.Dir(path)
if err := unix.Lstat(parent, &st); err != nil {
return false, &os.PathError{Op: "stat", Path: parent, Err: err}
}
if dev != st.Dev {
// Device differs from that of parent,
// so definitely a mount point.
return true, nil
}
// NB: this does not detect bind mounts on Linux.
return false, nil
}
func normalizePath(path string) (realPath string, err error) {
if realPath, err = filepath.Abs(path); err != nil {
return "", fmt.Errorf("unable to get absolute path for %q: %w", path, err)
}
if realPath, err = filepath.EvalSymlinks(realPath); err != nil {
return "", fmt.Errorf("failed to canonicalise path for %q: %w", path, err)
}
if _, err := os.Stat(realPath); err != nil {
return "", fmt.Errorf("failed to stat target of %q: %w", path, err)
}
return realPath, nil
}
func mountedByMountinfo(path string) (bool, error) {
path, err := normalizePath(path)
if err != nil {
if errors.Is(err, unix.ENOENT) {
// treat ENOENT as "not mounted"
return false, nil
}
return false, err
}
entries, err := GetMounts(SingleEntryFilter(path))
if err != nil {
return false, err
}
return len(entries) > 0, nil
}