@@ -45,6 +45,17 @@ func (daemon *Daemon) update(name string, hostConfig *container.HostConfig) erro

 		return err

 	}

+	restoreConfig := false

+	backupHostConfig := *container.HostConfig

+	defer func() {

+		if restoreConfig {

+			container.Lock()

+			container.HostConfig = &backupHostConfig

+			container.ToDisk()

+			container.Unlock()

+		}

+	}()

+

 	if container.RemovalInProgress || container.Dead {

 		errMsg := fmt.Errorf("Container is marked for removal and cannot be \"update\".")

 		return derr.ErrorCodeCantUpdate.WithArgs(container.ID, errMsg)

@@ -56,6 +67,7 @@ func (daemon *Daemon) update(name string, hostConfig *container.HostConfig) erro

 	}

 	if err := container.UpdateContainer(hostConfig); err != nil {

+		restoreConfig = true

 		return derr.ErrorCodeCantUpdate.WithArgs(container.ID, err.Error())

 	}

@@ -73,6 +85,7 @@ func (daemon *Daemon) update(name string, hostConfig *container.HostConfig) erro

 	// to the real world.

 	if container.IsRunning() && !container.IsRestarting() {

 		if err := daemon.execDriver.Update(container.Command); err != nil {

+			restoreConfig = true

 			return derr.ErrorCodeCantUpdate.WithArgs(container.ID, err.Error())

 		}

 	}

@@ -155,6 +155,31 @@ func (s *DockerSuite) TestUpdateSwapMemoryOnly(c *check.C) {

 	c.Assert(strings.TrimSpace(out), checker.Equals, "629145600")

 }

+func (s *DockerSuite) TestUpdateInvalidSwapMemory(c *check.C) {

+	testRequires(c, DaemonIsLinux)

+	testRequires(c, memoryLimitSupport)

+	testRequires(c, swapMemorySupport)

+

+	name := "test-update-container"

+	dockerCmd(c, "run", "-d", "--name", name, "--memory", "300M", "--memory-swap", "500M", "busybox", "top")

+	_, _, err := dockerCmdWithError("update", "--memory-swap", "200M", name)

+	// Update invalid swap memory should fail.

+	// This will pass docker config validation, but failed at kernel validation

+	c.Assert(err, check.NotNil)

+

+	// Update invalid swap memory with failure should not change HostConfig

+	c.Assert(inspectField(c, name, "HostConfig.Memory"), checker.Equals, "314572800")

+	c.Assert(inspectField(c, name, "HostConfig.MemorySwap"), checker.Equals, "524288000")

+

+	dockerCmd(c, "update", "--memory-swap", "600M", name)

+

+	c.Assert(inspectField(c, name, "HostConfig.MemorySwap"), checker.Equals, "629145600")

+

+	file := "/sys/fs/cgroup/memory/memory.memsw.limit_in_bytes"

+	out, _ := dockerCmd(c, "exec", name, "cat", file)

+	c.Assert(strings.TrimSpace(out), checker.Equals, "629145600")

+}

+

 func (s *DockerSuite) TestUpdateStats(c *check.C) {

 	testRequires(c, DaemonIsLinux)

 	testRequires(c, memoryLimitSupport)