fix default tmpfs size to prevent breakage

Signed-off-by: Jess Frazelle <me@jessfraz.com>

daemon/oci_linux.go

@@ -480,7 +480,7 @@ func setMounts(daemon *Daemon, s *specs.Spec, c *container.Container, mounts []c
 		}
 
 		if m.Source == "tmpfs" {
-			options := []string{"noexec", "nosuid", "nodev", volume.DefaultPropagationMode, "size=65536k"}
+			options := []string{"noexec", "nosuid", "nodev", volume.DefaultPropagationMode}
 			if m.Data != "" {
 				options = append(options, strings.Split(m.Data, ",")...)
 			}

integration-cli/docker_cli_run_unix_test.go

@@ -833,17 +833,19 @@ func (s *DockerSuite) TestRunTmpfsMounts(c *check.C) {
 func (s *DockerSuite) TestRunTmpfsMountsWithOptions(c *check.C) {
 	testRequires(c, DaemonIsLinux)
 
-	expectedOptions := []string{"rw", "nosuid", "nodev", "noexec", "relatime", "size=65536k"}
+	expectedOptions := []string{"rw", "nosuid", "nodev", "noexec", "relatime"}
 	out, _ := dockerCmd(c, "run", "--tmpfs", "/tmp", "busybox", "sh", "-c", "mount | grep 'tmpfs on /tmp'")
 	for _, option := range expectedOptions {
 		c.Assert(out, checker.Contains, option)
 	}
+	c.Assert(out, checker.Not(checker.Contains), "size=")
 
-	expectedOptions = []string{"rw", "nosuid", "nodev", "noexec", "relatime", "size=65536k"}
+	expectedOptions = []string{"rw", "nosuid", "nodev", "noexec", "relatime"}
 	out, _ = dockerCmd(c, "run", "--tmpfs", "/tmp:rw", "busybox", "sh", "-c", "mount | grep 'tmpfs on /tmp'")
 	for _, option := range expectedOptions {
 		c.Assert(out, checker.Contains, option)
 	}
+	c.Assert(out, checker.Not(checker.Contains), "size=")
 
 	expectedOptions = []string{"rw", "nosuid", "nodev", "relatime", "size=8192k"}
 	out, _ = dockerCmd(c, "run", "--tmpfs", "/tmp:rw,exec,size=8192k", "busybox", "sh", "-c", "mount | grep 'tmpfs on /tmp'")