dotcloud/docker

//go:build linux

package overlay2 // import "github.com/docker/docker/daemon/graphdriver/overlay2"

import (
    "runtime"

    "golang.org/x/sys/unix"
)

func mountFrom(dir, device, target, mType string, flags uintptr, label string) error {
    chErr := make(chan error, 1)

    go func() {
        runtime.LockOSThread()
        // Do not unlock this thread as the thread state cannot be restored
        // We do not want go to re-use this thread for anything else.

        if err := unix.Unshare(unix.CLONE_FS); err != nil {
            chErr <- err
            return
        }
        if err := unix.Chdir(dir); err != nil {
            chErr <- err
            return
        }
        chErr <- unix.Mount(device, target, mType, flags, label)
    }()
    return <-chErr
}