Support update swap memory only

We should support update swap memory without memory.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

daemon/create.go

@@ -21,7 +21,7 @@ func (daemon *Daemon) ContainerCreate(params types.ContainerCreateConfig) (types
 		return types.ContainerCreateResponse{}, derr.ErrorCodeEmptyConfig
 	}
 
-	warnings, err := daemon.verifyContainerSettings(params.HostConfig, params.Config)
+	warnings, err := daemon.verifyContainerSettings(params.HostConfig, params.Config, false)
 	if err != nil {
 		return types.ContainerCreateResponse{Warnings: warnings}, err
 	}

daemon/daemon.go

@@ -1450,7 +1450,7 @@ func setDefaultMtu(config *Config) {
 
 // verifyContainerSettings performs validation of the hostconfig and config
 // structures.
-func (daemon *Daemon) verifyContainerSettings(hostConfig *containertypes.HostConfig, config *containertypes.Config) ([]string, error) {
+func (daemon *Daemon) verifyContainerSettings(hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) ([]string, error) {
 
 	// First perform verification of settings common across all platforms.
 	if config != nil {
@@ -1487,7 +1487,7 @@ func (daemon *Daemon) verifyContainerSettings(hostConfig *containertypes.HostCon
 	}
 
 	// Now do platform-specific verification
-	return verifyPlatformContainerSettings(daemon, hostConfig, config)
+	return verifyPlatformContainerSettings(daemon, hostConfig, config, update)
 }
 
 // Checks if the client set configurations for more than one network while creating a container

daemon/daemon_unix.go

@@ -221,7 +221,7 @@ func (daemon *Daemon) adaptContainerSettings(hostConfig *containertypes.HostConf
 	return nil
 }
 
-func verifyContainerResources(resources *containertypes.Resources, sysInfo *sysinfo.SysInfo) ([]string, error) {
+func verifyContainerResources(resources *containertypes.Resources, sysInfo *sysinfo.SysInfo, update bool) ([]string, error) {
 	warnings := []string{}
 
 	// memory subsystem checks and adjustments
@@ -242,7 +242,7 @@ func verifyContainerResources(resources *containertypes.Resources, sysInfo *sysi
 	if resources.Memory > 0 && resources.MemorySwap > 0 && resources.MemorySwap < resources.Memory {
 		return warnings, fmt.Errorf("Minimum memoryswap limit should be larger than memory limit, see usage.")
 	}
-	if resources.Memory == 0 && resources.MemorySwap > 0 {
+	if resources.Memory == 0 && resources.MemorySwap > 0 && !update {
 		return warnings, fmt.Errorf("You should always set the Memory limit when using Memoryswap limit, see usage.")
 	}
 	if resources.MemorySwappiness != nil && *resources.MemorySwappiness != -1 && !sysInfo.MemorySwappiness {
@@ -383,7 +383,7 @@ func (daemon *Daemon) usingSystemd() bool {
 
 // verifyPlatformContainerSettings performs platform-specific validation of the
 // hostconfig and config structures.
-func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.HostConfig, config *containertypes.Config) ([]string, error) {
+func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) ([]string, error) {
 	warnings := []string{}
 	sysInfo := sysinfo.New(true)
 
@@ -392,7 +392,7 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.
 		return warnings, err
 	}
 
-	w, err := verifyContainerResources(&hostConfig.Resources, sysInfo)
+	w, err := verifyContainerResources(&hostConfig.Resources, sysInfo, update)
 	if err != nil {
 		return warnings, err
 	}

daemon/daemon_windows.go

@@ -85,7 +85,7 @@ func (daemon *Daemon) adaptContainerSettings(hostConfig *containertypes.HostConf
 
 // verifyPlatformContainerSettings performs platform-specific validation of the
 // hostconfig and config structures.
-func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.HostConfig, config *containertypes.Config) ([]string, error) {
+func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) ([]string, error) {
 	return nil, nil
 }
 

daemon/start.go

@@ -58,7 +58,7 @@ func (daemon *Daemon) ContainerStart(name string, hostConfig *containertypes.Hos
 
 	// check if hostConfig is in line with the current system settings.
 	// It may happen cgroups are umounted or the like.
-	if _, err = daemon.verifyContainerSettings(container.HostConfig, nil); err != nil {
+	if _, err = daemon.verifyContainerSettings(container.HostConfig, nil, false); err != nil {
 		return err
 	}
 	// Adapt for old containers in case we have updates in this function and

daemon/update.go

@@ -12,7 +12,7 @@ import (
 func (daemon *Daemon) ContainerUpdate(name string, hostConfig *container.HostConfig) ([]string, error) {
 	var warnings []string
 
-	warnings, err := daemon.verifyContainerSettings(hostConfig, nil)
+	warnings, err := daemon.verifyContainerSettings(hostConfig, nil, true)
 	if err != nil {
 		return warnings, err
 	}

integration-cli/docker_cli_update_unix_test.go

@@ -139,6 +139,22 @@ func (s *DockerSuite) TestUpdateKernelMemory(c *check.C) {
 	c.Assert(strings.TrimSpace(out), checker.Equals, "104857600")
 }
 
+func (s *DockerSuite) TestUpdateSwapMemoryOnly(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")
+	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)