Addition of "--shm-size" to which size of /dev/shm is changed.

- Optional "--shm-size=" was added to the sub-command(run, create,and build).
- The size of /dev/shm in the container can be changed
  when container is made.
- Being able to specify is a numerical value that applies number,
  b, k, m, and g.
- The default value is 64MB, when this option is not set.
- It deals with both native and lxc drivers.

Signed-off-by: NIWA Hideyuki <niwa.hiedyuki@jp.fujitsu.com>
Upstream-commit: 5aeaf2a0c4236711e0981515d8627b30e22a1637
Component: engine

components/engine/daemon/container_unix.go

@@ -1357,7 +1357,12 @@ func (daemon *Daemon) setupIpcDirs(container *Container) error {
 			return err
 		}
 
-		if err := syscall.Mount("shm", shmPath, "tmpfs", uintptr(syscall.MS_NOEXEC|syscall.MS_NOSUID|syscall.MS_NODEV), label.FormatMountLabel("mode=1777,size=65536k", container.getMountLabel())); err != nil {
+		// When ShmSize is 0 or less, the SHM size is set to 64MB.
+		if container.hostConfig.ShmSize <= 0 {
+			container.hostConfig.ShmSize = 67108864
+		}
+		shmproperty := "mode=1777,size=" + strconv.FormatInt(container.hostConfig.ShmSize, 10)
+		if err := syscall.Mount("shm", shmPath, "tmpfs", uintptr(syscall.MS_NOEXEC|syscall.MS_NOSUID|syscall.MS_NODEV), label.FormatMountLabel(shmproperty, container.getMountLabel())); err != nil {
 			return fmt.Errorf("mounting shm tmpfs: %s", err)
 		}
 		if err := os.Chown(shmPath, rootUID, rootGID); err != nil {