diff --git a/mount/mount_linux.go b/mount/mount_linux.go index d12a9c5a2..6d28f0a97 100644 --- a/mount/mount_linux.go +++ b/mount/mount_linux.go @@ -106,26 +106,37 @@ func Unmount(target string, flags int) error { return nil } -func isFUSE(dir string) (bool, error) { - // fuseSuperMagic is defined in statfs(2) - const fuseSuperMagic = 0x65735546 +// fuseSuperMagic is defined in statfs(2) +const fuseSuperMagic = 0x65735546 + +func isFUSE(dir string) bool { var st unix.Statfs_t if err := unix.Statfs(dir, &st); err != nil { - return false, err + return false } - return st.Type == fuseSuperMagic, nil + return st.Type == fuseSuperMagic +} + +// unmountFUSE attempts to unmount using fusermount/fusermount3 helper binary. +// +// For FUSE mounts, using these helper binaries is preferred, see: +// https://github.com/containerd/containerd/pull/3765#discussion_r342083514 +func unmountFUSE(target string) error { + var err error + for _, helperBinary := range []string{"fusermount3", "fusermount"} { + cmd := exec.Command(helperBinary, "-u", target) + err = cmd.Run() + if err == nil { + return nil + } + } + return err } func unmount(target string, flags int) error { - // For FUSE mounts, attempting to execute fusermount helper binary is preferred - // https://github.com/containerd/containerd/pull/3765#discussion_r342083514 - if ok, err := isFUSE(target); err == nil && ok { - for _, helperBinary := range []string{"fusermount3", "fusermount"} { - cmd := exec.Command(helperBinary, "-u", target) - if err := cmd.Run(); err == nil { - return nil - } - // ignore error and try unix.Unmount + if isFUSE(target) { + if err := unmountFUSE(target); err == nil { + return nil } } for i := 0; i < 50; i++ {