Unmounted any mount points in gc paths. In various corner cases, agent may not get chance to properly unmount persistent volumes mounted inside an executor's sandbox. When GC later gets to these sandbox directories, permanent data loss can happen (see MESOS-8830).
Currently, the only mounts in the host mount namespace under the sandbox directories are persistent volumes, so this diff added protection to unmount any dangling mount points before calling `rmdir` on the directory. NOTE: this means agent will not garbage collect any path if it cannot read its own `mountinfo` table. Review: https://reviews.apache.org/r/67264 Project: http://git-wip-us.apache.org/repos/asf/mesos/repo Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/809dd0ff Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/809dd0ff Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/809dd0ff Branch: refs/heads/1.4.x Commit: 809dd0ff12d8f65244eafc9362b79671ea35c387 Parents: c35e06b Author: Zhitao Li <zhitaoli...@gmail.com> Authored: Tue May 22 10:55:50 2018 -0700 Committer: Chun-Hung Hsiao <chhs...@mesosphere.io> Committed: Mon Jul 2 14:26:38 2018 -0700 ---------------------------------------------------------------------- src/local/local.cpp | 2 +- src/slave/gc.cpp | 72 ++++++++++++++++++++++++++++++++++++++----- src/slave/gc.hpp | 9 ++++-- src/slave/main.cpp | 2 +- src/tests/cluster.cpp | 2 +- src/tests/gc_tests.cpp | 6 ++-- src/tests/mock_slave.cpp | 22 ++----------- src/tests/mock_slave.hpp | 20 +----------- 8 files changed, 80 insertions(+), 55 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/local/local.cpp ---------------------------------------------------------------------- diff --git a/src/local/local.cpp b/src/local/local.cpp index 99c1b08..3e671f6 100644 --- a/src/local/local.cpp +++ b/src/local/local.cpp @@ -407,7 +407,7 @@ PID<Master> launch(const Flags& flags, Allocator* _allocator) << slaveFlags.runtime_dir << "': " << mkdir.error(); } - garbageCollectors->push_back(new GarbageCollector()); + garbageCollectors->push_back(new GarbageCollector(slaveFlags.work_dir)); statusUpdateManagers->push_back(new StatusUpdateManager(slaveFlags)); fetchers->push_back(new Fetcher(slaveFlags)); http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/slave/gc.cpp ---------------------------------------------------------------------- diff --git a/src/slave/gc.cpp b/src/slave/gc.cpp index 86d94c8..415fe27 100644 --- a/src/slave/gc.cpp +++ b/src/slave/gc.cpp @@ -21,6 +21,7 @@ #include <process/delay.hpp> #include <process/dispatch.hpp> +#include <stout/adaptor.hpp> #include <stout/foreach.hpp> #include <stout/lambda.hpp> @@ -28,6 +29,10 @@ #include "logging/logging.hpp" +#ifdef __linux__ +#include "linux/fs.hpp" +#endif + #include "slave/gc.hpp" using namespace process; @@ -159,7 +164,62 @@ void GarbageCollectorProcess::remove(const Timeout& removalTime) info->removing = true; } - auto rmdirs = [infos]() { + const string _workDir = workDir; + + auto rmdirs = [_workDir, infos]() mutable -> Future<Nothing> { +#ifdef __linux__ + // Clear any possible persistent volume mount points in `infos`. See + // MESOS-8830. + Try<fs::MountInfoTable> mountTable = fs::MountInfoTable::read(); + if (mountTable.isError()) { + LOG(ERROR) << "Skipping any path deletion because of failure on read " + "MountInfoTable for agent process: " + << mountTable.error(); + + foreach (const Owned<PathInfo>& info, infos) { + info->promise.fail(mountTable.error()); + } + + return Failure(mountTable.error()); + } + + foreach (const fs::MountInfoTable::Entry& entry, + adaptor::reverse(mountTable->entries)) { + // Ignore mounts whose targets are not under `workDir`. + if (!strings::startsWith( + path::join(entry.target, ""), + path::join(_workDir, ""))) { + continue; + } + + for (auto it = infos.begin(); it != infos.end(); ) { + const Owned<PathInfo>& info = *it; + // TODO(zhitao): Validate that both `info->path` and `workDir` are + // real paths. + if (strings::startsWith( + path::join(entry.target, ""), path::join(info->path, ""))) { + LOG(WARNING) + << "Unmounting dangling mount point '" << entry.target + << "' of persistent volume '" << entry.root + << "' inside garbage collected path '" << info->path << "'"; + + Try<Nothing> unmount = fs::unmount(entry.target); + if (unmount.isError()) { + LOG(WARNING) << "Skipping deletion of '" + << info->path << "' because unmount failed on '" + << entry.target << "': " << unmount.error(); + + info->promise.fail(unmount.error()); + it = infos.erase(it); + continue; + } + } + + it++; + } + } +#endif // __linux__ + foreach (const Owned<PathInfo>& info, infos) { // Run the removal operation with 'continueOnError = true'. // It's possible for tasks and isolators to lay down files @@ -198,11 +258,9 @@ void GarbageCollectorProcess::remove(const Timeout& removalTime) } -void GarbageCollectorProcess::_remove(const Future<Nothing>& result, - const list<Owned<PathInfo>> infos) +void GarbageCollectorProcess::_remove(const Future<Nothing>& result, + const list<Owned<PathInfo>> infos) { - CHECK_READY(result); - // Remove path records from `paths` and `timeouts` data structures. foreach (const Owned<PathInfo>& info, infos) { CHECK(paths.remove(timeouts[info->path], info)); @@ -225,9 +283,9 @@ void GarbageCollectorProcess::prune(const Duration& d) } -GarbageCollector::GarbageCollector() +GarbageCollector::GarbageCollector(const string& workDir) { - process = new GarbageCollectorProcess(); + process = new GarbageCollectorProcess(workDir); spawn(process); } http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/slave/gc.hpp ---------------------------------------------------------------------- diff --git a/src/slave/gc.hpp b/src/slave/gc.hpp index f23ffd3..518fb50 100644 --- a/src/slave/gc.hpp +++ b/src/slave/gc.hpp @@ -52,7 +52,7 @@ class GarbageCollectorProcess; class GarbageCollector { public: - GarbageCollector(); + explicit GarbageCollector(const std::string& workDir); virtual ~GarbageCollector(); // Schedules the specified path for removal after the specified @@ -90,8 +90,9 @@ class GarbageCollectorProcess : public process::Process<GarbageCollectorProcess> { public: - GarbageCollectorProcess() - : ProcessBase(process::ID::generate("agent-garbage-collector")) {} + explicit GarbageCollectorProcess(const std::string& _workDir) + : ProcessBase(process::ID::generate("agent-garbage-collector")), + workDir(_workDir) {} virtual ~GarbageCollectorProcess(); @@ -131,6 +132,8 @@ private: const process::Future<Nothing>& result, const std::list<process::Owned<PathInfo>> infos); + const std::string workDir; + // Store all the timeouts and corresponding paths to delete. // NOTE: We are using Multimap here instead of Multihashmap, because // we need the keys of the map (deletion time) to be sorted. http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/slave/main.cpp ---------------------------------------------------------------------- diff --git a/src/slave/main.cpp b/src/slave/main.cpp index a4a8ced..1892000 100644 --- a/src/slave/main.cpp +++ b/src/slave/main.cpp @@ -535,7 +535,7 @@ int main(int argc, char** argv) } Files* files = new Files(READONLY_HTTP_AUTHENTICATION_REALM, authorizer_); - GarbageCollector* gc = new GarbageCollector(); + GarbageCollector* gc = new GarbageCollector(flags.work_dir); StatusUpdateManager* statusUpdateManager = new StatusUpdateManager(flags); Try<ResourceEstimator*> resourceEstimator = http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/tests/cluster.cpp ---------------------------------------------------------------------- diff --git a/src/tests/cluster.cpp b/src/tests/cluster.cpp index d657da6..a5e2037 100644 --- a/src/tests/cluster.cpp +++ b/src/tests/cluster.cpp @@ -474,7 +474,7 @@ Try<process::Owned<Slave>> Slave::start( // If the garbage collector is not provided, create a default one. if (gc.isNone()) { - slave->gc.reset(new slave::GarbageCollector()); + slave->gc.reset(new slave::GarbageCollector(flags.work_dir)); } // If the resource estimator is not provided, create a default one. http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/tests/gc_tests.cpp ---------------------------------------------------------------------- diff --git a/src/tests/gc_tests.cpp b/src/tests/gc_tests.cpp index d4daad3..6906a6c 100644 --- a/src/tests/gc_tests.cpp +++ b/src/tests/gc_tests.cpp @@ -92,7 +92,7 @@ class GarbageCollectorTest : public TemporaryDirectoryTest {}; TEST_F(GarbageCollectorTest, Schedule) { - GarbageCollector gc; + GarbageCollector gc("work_dir"); // Make some temporary files to gc. const string& file1 = "file1"; @@ -153,7 +153,7 @@ TEST_F(GarbageCollectorTest, Schedule) TEST_F(GarbageCollectorTest, Unschedule) { - GarbageCollector gc; + GarbageCollector gc("work_dir"); // Attempt to unschedule a file that is not scheduled. AWAIT_ASSERT_FALSE(gc.unschedule("bogus")); @@ -202,7 +202,7 @@ TEST_F(GarbageCollectorTest, Unschedule) TEST_F(GarbageCollectorTest, Prune) { - GarbageCollector gc; + GarbageCollector gc("work_dir"); // Make some temporary files to prune. const string& file1 = "file1"; http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/tests/mock_slave.cpp ---------------------------------------------------------------------- diff --git a/src/tests/mock_slave.cpp b/src/tests/mock_slave.cpp index c435ec7..6e69fac 100644 --- a/src/tests/mock_slave.cpp +++ b/src/tests/mock_slave.cpp @@ -49,25 +49,6 @@ namespace mesos { namespace internal { namespace tests { -MockGarbageCollector::MockGarbageCollector() -{ - // NOTE: We use 'EXPECT_CALL' and 'WillRepeatedly' here instead of - // 'ON_CALL' and 'WillByDefault'. See 'TestContainerizer::SetUp()' - // for more details. - EXPECT_CALL(*this, schedule(_, _)) - .WillRepeatedly(Return(Nothing())); - - EXPECT_CALL(*this, unschedule(_)) - .WillRepeatedly(Return(true)); - - EXPECT_CALL(*this, prune(_)) - .WillRepeatedly(Return()); -} - - -MockGarbageCollector::~MockGarbageCollector() {} - - MockResourceEstimator::MockResourceEstimator() { ON_CALL(*this, initialize(_)) @@ -116,7 +97,7 @@ MockSlave::MockSlave( detector, containerizer, &files, - &gc, + gc = new slave::GarbageCollector(flags.work_dir), statusUpdateManager = new slave::StatusUpdateManager(flags), &resourceEstimator, _qosController.isSome() ? _qosController.get() : &qosController, @@ -150,6 +131,7 @@ MockSlave::MockSlave( MockSlave::~MockSlave() { + delete gc; delete statusUpdateManager; } http://git-wip-us.apache.org/repos/asf/mesos/blob/809dd0ff/src/tests/mock_slave.hpp ---------------------------------------------------------------------- diff --git a/src/tests/mock_slave.hpp b/src/tests/mock_slave.hpp index 767ed3d..3e960ed 100644 --- a/src/tests/mock_slave.hpp +++ b/src/tests/mock_slave.hpp @@ -49,24 +49,6 @@ namespace mesos { namespace internal { namespace tests { -class MockGarbageCollector : public slave::GarbageCollector -{ -public: - MockGarbageCollector(); - virtual ~MockGarbageCollector(); - - MOCK_METHOD2( - schedule, - process::Future<Nothing>(const Duration& d, const std::string& path)); - MOCK_METHOD1( - unschedule, - process::Future<bool>(const std::string& path)); - MOCK_METHOD1( - prune, - void(const Duration& d)); -}; - - class MockResourceEstimator : public mesos::slave::ResourceEstimator { public: @@ -213,7 +195,7 @@ public: private: Files files; - MockGarbageCollector gc; + slave::GarbageCollector* gc; MockResourceEstimator resourceEstimator; MockQoSController qosController; slave::StatusUpdateManager* statusUpdateManager;
