From 932c8abd0f739bec295ff62cf8fce3dcb7e2d866 Mon Sep 17 00:00:00 2001 From: Rahat Mahmood Date: Fri, 2 Apr 2021 21:08:53 -0700 Subject: Implement cgroupfs. A skeleton implementation of cgroupfs. It supports trivial cpu and memory controllers with no support for hierarchies. PiperOrigin-RevId: 366561126 --- test/syscalls/linux/BUILD | 21 +++ test/syscalls/linux/cgroup.cc | 370 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 391 insertions(+) create mode 100644 test/syscalls/linux/cgroup.cc (limited to 'test/syscalls/linux') diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 043ada583..a9fa93437 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -4205,3 +4205,24 @@ cc_binary( "//test/util:test_util", ], ) + +cc_binary( + name = "cgroup_test", + testonly = 1, + srcs = ["cgroup.cc"], + linkstatic = 1, + deps = [ + "//test/util:capability_util", + "//test/util:cgroup_util", + "//test/util:file_descriptor", + "//test/util:fs_util", + "@com_google_absl//absl/strings", + gtest, + "//test/util:posix_error", + "//test/util:temp_path", + "//test/util:test_main", + "//test/util:test_util", + "@com_google_absl//absl/container:flat_hash_map", + "@com_google_absl//absl/container:flat_hash_set", + ], +) diff --git a/test/syscalls/linux/cgroup.cc b/test/syscalls/linux/cgroup.cc new file mode 100644 index 000000000..3a51348ba --- /dev/null +++ b/test/syscalls/linux/cgroup.cc @@ -0,0 +1,370 @@ +// Copyright 2021 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// All tests in this file rely on being about to mount and unmount cgroupfs, +// which isn't expected to work, or be safe on a general linux system. + +#include +#include + +#include "gtest/gtest.h" +#include "absl/container/flat_hash_map.h" +#include "absl/container/flat_hash_set.h" +#include "test/util/capability_util.h" +#include "test/util/cgroup_util.h" +#include "test/util/temp_path.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { +namespace { + +using ::testing::_; +using ::testing::Gt; + +std::vector known_controllers = {"cpu", "cpuset", "cpuacct", + "memory"}; + +bool CgroupsAvailable() { + return IsRunningOnGvisor() && !IsRunningWithVFS1() && + TEST_CHECK_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)); +} + +TEST(Cgroup, MountSucceeds) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("")); + EXPECT_NO_ERRNO(c.ContainsCallingProcess()); +} + +TEST(Cgroup, SeparateMounts) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + + for (const auto& ctl : known_controllers) { + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs(ctl)); + EXPECT_NO_ERRNO(c.ContainsCallingProcess()); + } +} + +TEST(Cgroup, AllControllersImplicit) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("")); + + absl::flat_hash_map cgroups_entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + for (const auto& ctl : known_controllers) { + EXPECT_TRUE(cgroups_entries.contains(ctl)) + << absl::StreamFormat("ctl=%s", ctl); + } + EXPECT_EQ(cgroups_entries.size(), known_controllers.size()); +} + +TEST(Cgroup, AllControllersExplicit) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("all")); + + absl::flat_hash_map cgroups_entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + for (const auto& ctl : known_controllers) { + EXPECT_TRUE(cgroups_entries.contains(ctl)) + << absl::StreamFormat("ctl=%s", ctl); + } + EXPECT_EQ(cgroups_entries.size(), known_controllers.size()); +} + +TEST(Cgroup, ProcsAndTasks) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("")); + absl::flat_hash_set pids = ASSERT_NO_ERRNO_AND_VALUE(c.Procs()); + absl::flat_hash_set tids = ASSERT_NO_ERRNO_AND_VALUE(c.Tasks()); + + EXPECT_GE(tids.size(), pids.size()) << "Found more processes than threads"; + + // Pids should be a strict subset of tids. + for (auto it = pids.begin(); it != pids.end(); ++it) { + EXPECT_TRUE(tids.contains(*it)) + << absl::StreamFormat("Have pid %d, but no such tid", *it); + } +} + +TEST(Cgroup, ControllersMustBeInUniqueHierarchy) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + // Hierarchy #1: all controllers. + Cgroup all = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("")); + // Hierarchy #2: memory. + // + // This should conflict since memory is already in hierarchy #1, and the two + // hierarchies have different sets of controllers, so this mount can't be a + // view into hierarchy #1. + EXPECT_THAT(m.MountCgroupfs("memory"), PosixErrorIs(EBUSY, _)) + << "Memory controller mounted on two hierarchies"; + EXPECT_THAT(m.MountCgroupfs("cpu"), PosixErrorIs(EBUSY, _)) + << "CPU controller mounted on two hierarchies"; +} + +TEST(Cgroup, UnmountFreesControllers) { + SKIP_IF(!CgroupsAvailable()); + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup all = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("")); + // All controllers are now attached to all's hierarchy. Attempting new mount + // with any individual controller should fail. + EXPECT_THAT(m.MountCgroupfs("memory"), PosixErrorIs(EBUSY, _)) + << "Memory controller mounted on two hierarchies"; + + // Unmount the "all" hierarchy. This should enable any controller to be + // mounted on a new hierarchy again. + ASSERT_NO_ERRNO(m.Unmount(all)); + EXPECT_NO_ERRNO(m.MountCgroupfs("memory")); + EXPECT_NO_ERRNO(m.MountCgroupfs("cpu")); +} + +TEST(Cgroup, OnlyContainsControllerSpecificFiles) { + SKIP_IF(!CgroupsAvailable()); + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup mem = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("memory")); + EXPECT_THAT(Exists(mem.Relpath("memory.usage_in_bytes")), + IsPosixErrorOkAndHolds(true)); + // CPU files shouldn't exist in memory cgroups. + EXPECT_THAT(Exists(mem.Relpath("cpu.cfs_period_us")), + IsPosixErrorOkAndHolds(false)); + EXPECT_THAT(Exists(mem.Relpath("cpu.cfs_quota_us")), + IsPosixErrorOkAndHolds(false)); + EXPECT_THAT(Exists(mem.Relpath("cpu.shares")), IsPosixErrorOkAndHolds(false)); + + Cgroup cpu = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("cpu")); + EXPECT_THAT(Exists(cpu.Relpath("cpu.cfs_period_us")), + IsPosixErrorOkAndHolds(true)); + EXPECT_THAT(Exists(cpu.Relpath("cpu.cfs_quota_us")), + IsPosixErrorOkAndHolds(true)); + EXPECT_THAT(Exists(cpu.Relpath("cpu.shares")), IsPosixErrorOkAndHolds(true)); + // Memory files shouldn't exist in cpu cgroups. + EXPECT_THAT(Exists(cpu.Relpath("memory.usage_in_bytes")), + IsPosixErrorOkAndHolds(false)); +} + +TEST(Cgroup, InvalidController) { + SKIP_IF(!CgroupsAvailable()); + + TempPath mountpoint = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + std::string mopts = "this-controller-is-invalid"; + EXPECT_THAT( + mount("none", mountpoint.path().c_str(), "cgroup", 0, mopts.c_str()), + SyscallFailsWithErrno(EINVAL)); +} + +TEST(Cgroup, MoptAllMustBeExclusive) { + SKIP_IF(!CgroupsAvailable()); + + TempPath mountpoint = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + std::string mopts = "all,cpu"; + EXPECT_THAT( + mount("none", mountpoint.path().c_str(), "cgroup", 0, mopts.c_str()), + SyscallFailsWithErrno(EINVAL)); +} + +TEST(MemoryCgroup, MemoryUsageInBytes) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("memory")); + EXPECT_THAT(c.ReadIntegerControlFile("memory.usage_in_bytes"), + IsPosixErrorOkAndHolds(Gt(0))); +} + +TEST(CPUCgroup, ControlFilesHaveDefaultValues) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("cpu")); + EXPECT_THAT(c.ReadIntegerControlFile("cpu.cfs_quota_us"), + IsPosixErrorOkAndHolds(-1)); + EXPECT_THAT(c.ReadIntegerControlFile("cpu.cfs_period_us"), + IsPosixErrorOkAndHolds(100000)); + EXPECT_THAT(c.ReadIntegerControlFile("cpu.shares"), + IsPosixErrorOkAndHolds(1024)); +} + +TEST(ProcCgroups, Empty) { + SKIP_IF(!CgroupsAvailable()); + + absl::flat_hash_map entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + // No cgroups mounted yet, we should have no entries. + EXPECT_TRUE(entries.empty()); +} + +TEST(ProcCgroups, ProcCgroupsEntries) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + + Cgroup mem = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("memory")); + absl::flat_hash_map entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + EXPECT_EQ(entries.size(), 1); + ASSERT_TRUE(entries.contains("memory")); + CgroupsEntry mem_e = entries["memory"]; + EXPECT_EQ(mem_e.subsys_name, "memory"); + EXPECT_GE(mem_e.hierarchy, 1); + // Expect a single root cgroup. + EXPECT_EQ(mem_e.num_cgroups, 1); + // Cgroups are currently always enabled when mounted. + EXPECT_TRUE(mem_e.enabled); + + // Add a second cgroup, and check for new entry. + + Cgroup cpu = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("cpu")); + entries = ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + EXPECT_EQ(entries.size(), 2); + EXPECT_TRUE(entries.contains("memory")); // Still have memory entry. + ASSERT_TRUE(entries.contains("cpu")); + CgroupsEntry cpu_e = entries["cpu"]; + EXPECT_EQ(cpu_e.subsys_name, "cpu"); + EXPECT_GE(cpu_e.hierarchy, 1); + EXPECT_EQ(cpu_e.num_cgroups, 1); + EXPECT_TRUE(cpu_e.enabled); + + // Separate hierarchies, since controllers were mounted separately. + EXPECT_NE(mem_e.hierarchy, cpu_e.hierarchy); +} + +TEST(ProcCgroups, UnmountRemovesEntries) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup cg = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("cpu,memory")); + absl::flat_hash_map entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + EXPECT_EQ(entries.size(), 2); + + ASSERT_NO_ERRNO(m.Unmount(cg)); + + entries = ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + EXPECT_TRUE(entries.empty()); +} + +TEST(ProcPIDCgroup, Empty) { + SKIP_IF(!CgroupsAvailable()); + + absl::flat_hash_map entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + EXPECT_TRUE(entries.empty()); +} + +TEST(ProcPIDCgroup, Entries) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("memory")); + + absl::flat_hash_map entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + EXPECT_EQ(entries.size(), 1); + PIDCgroupEntry mem_e = entries["memory"]; + EXPECT_GE(mem_e.hierarchy, 1); + EXPECT_EQ(mem_e.controllers, "memory"); + EXPECT_EQ(mem_e.path, "/"); + + Cgroup c1 = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("cpu")); + entries = ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + EXPECT_EQ(entries.size(), 2); + EXPECT_TRUE(entries.contains("memory")); // Still have memory entry. + PIDCgroupEntry cpu_e = entries["cpu"]; + EXPECT_GE(cpu_e.hierarchy, 1); + EXPECT_EQ(cpu_e.controllers, "cpu"); + EXPECT_EQ(cpu_e.path, "/"); + + // Separate hierarchies, since controllers were mounted separately. + EXPECT_NE(mem_e.hierarchy, cpu_e.hierarchy); +} + +TEST(ProcPIDCgroup, UnmountRemovesEntries) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup all = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("")); + + absl::flat_hash_map entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + EXPECT_GT(entries.size(), 0); + + ASSERT_NO_ERRNO(m.Unmount(all)); + + entries = ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + EXPECT_TRUE(entries.empty()); +} + +TEST(ProcCgroup, PIDCgroupMatchesCgroups) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("memory")); + Cgroup c1 = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("cpu")); + + absl::flat_hash_map cgroups_entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + absl::flat_hash_map pid_entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + + CgroupsEntry cgroup_mem = cgroups_entries["memory"]; + PIDCgroupEntry pid_mem = pid_entries["memory"]; + + EXPECT_EQ(cgroup_mem.hierarchy, pid_mem.hierarchy); + + CgroupsEntry cgroup_cpu = cgroups_entries["cpu"]; + PIDCgroupEntry pid_cpu = pid_entries["cpu"]; + + EXPECT_EQ(cgroup_cpu.hierarchy, pid_cpu.hierarchy); + EXPECT_NE(cgroup_mem.hierarchy, cgroup_cpu.hierarchy); + EXPECT_NE(pid_mem.hierarchy, pid_cpu.hierarchy); +} + +TEST(ProcCgroup, MultiControllerHierarchy) { + SKIP_IF(!CgroupsAvailable()); + + Mounter m(ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir())); + Cgroup c = ASSERT_NO_ERRNO_AND_VALUE(m.MountCgroupfs("memory,cpu")); + + absl::flat_hash_map cgroups_entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcCgroupsEntries()); + + CgroupsEntry mem_e = cgroups_entries["memory"]; + CgroupsEntry cpu_e = cgroups_entries["cpu"]; + + // Both controllers should have the same hierarchy ID. + EXPECT_EQ(mem_e.hierarchy, cpu_e.hierarchy); + + absl::flat_hash_map pid_entries = + ASSERT_NO_ERRNO_AND_VALUE(ProcPIDCgroupEntries(getpid())); + + // Expecting an entry listing both controllers, that matches the previous + // hierarchy ID. Note that the controllers are listed in alphabetical order. + PIDCgroupEntry pid_e = pid_entries["cpu,memory"]; + EXPECT_EQ(pid_e.hierarchy, mem_e.hierarchy); +} + +} // namespace +} // namespace testing +} // namespace gvisor -- cgit v1.2.3