Explicitly closing all directory file descriptors (facebook#10049)

Summary:
Currently, the DB directory file descriptor is left open until the deconstruction process (`DB::Close()` does not close the file descriptor). To verify this, comment out the lines between `db_ = nullptr` and `db_->Close()` (line 512, 513, 514, 515 in ldb_cmd.cc) to leak the ``db_'' object, build `ldb` tool and run
```
strace --trace=open,openat,close ./ldb --db=$TEST_TMPDIR --ignore_unknown_options put K1 V1 --create_if_missing
```
There is one directory file descriptor that is not closed in the strace log.

Pull Request resolved: facebook#10049

Test Plan: Add a new unit test DBBasicTest.DBCloseAllDirectoryFDs: Open a database with different WAL directory and three different data directories, and all directory file descriptors should be closed after calling Close(). Explicitly call Close() after a directory file descriptor is not used so that the counter of directory open and close should be equivalent.

Reviewed By: ajkr, hx235

Differential Revision: D36722135

Pulled By: littlepig2013

fbshipit-source-id: 07bdc2abc417c6b30997b9bbef1f79aa757b21ff

db/column_family.cc

@@ -675,6 +675,19 @@ ColumnFamilyData::~ColumnFamilyData() {
           id_, name_.c_str());
     }
   }
+
+  if (data_dirs_.size()) {  // Explicitly close data directories
+    Status s = Status::OK();
+    for (auto& data_dir_ptr : data_dirs_) {
+      if (data_dir_ptr) {
+        s = data_dir_ptr->Close(IOOptions(), nullptr);
+        if (!s.ok()) {
+          ROCKS_LOG_WARN(ioptions_.logger, "Ignoring error %s",
+                         s.ToString().c_str());
+        }
+      }
+    }
+  }
 }
 
 bool ColumnFamilyData::UnrefAndTryDelete() {

db/db_basic_test.cc

@@ -25,6 +25,7 @@
 #endif
 #include "util/file_checksum_helper.h"
 #include "util/random.h"
+#include "utilities/counted_fs.h"
 #include "utilities/fault_injection_env.h"
 #include "utilities/merge_operators.h"
 #include "utilities/merge_operators/string_append/stringappend.h"
@@ -1153,6 +1154,39 @@ TEST_F(DBBasicTest, DBClose) {
   ASSERT_EQ(env->GetCloseCount(), 3);
 }
 
+TEST_F(DBBasicTest, DBCloseAllDirectoryFDs) {
+  Options options = GetDefaultOptions();
+  std::string dbname = test::PerThreadDBPath("db_close_all_dir_fds_test");
+  // Configure a specific WAL directory
+  options.wal_dir = dbname + "_wal_dir";
+  // Configure 3 different data directories
+  options.db_paths.emplace_back(dbname + "_1", 512 * 1024);
+  options.db_paths.emplace_back(dbname + "_2", 4 * 1024 * 1024);
+  options.db_paths.emplace_back(dbname + "_3", 1024 * 1024 * 1024);
+
+  ASSERT_OK(DestroyDB(dbname, options));
+
+  DB* db = nullptr;
+  std::unique_ptr<Env> env = NewCompositeEnv(
+      std::make_shared<CountedFileSystem>(FileSystem::Default()));
+  options.create_if_missing = true;
+  options.env = env.get();
+  Status s = DB::Open(options, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  // Explicitly close the database to ensure the open and close counter for
+  // directories are equivalent
+  s = db->Close();
+  auto* counted_fs =
+      options.env->GetFileSystem()->CheckedCast<CountedFileSystem>();
+  assert(counted_fs);
+  ASSERT_TRUE(counted_fs->counters()->dir_opens ==
+              counted_fs->counters()->dir_closes);
+  ASSERT_OK(s);
+  delete db;
+}
+
 TEST_F(DBBasicTest, DBCloseFlushError) {
   std::unique_ptr<FaultInjectionTestEnv> fault_injection_env(
       new FaultInjectionTestEnv(env_));

db/db_impl/db_impl.cc

@@ -714,12 +714,17 @@ Status DBImpl::CloseHelper() {
     write_buffer_manager_->RemoveDBFromQueue(wbm_stall_.get());
   }
 
+  IOStatus io_s = directories_.Close(IOOptions(), nullptr /* dbg */);
+  if (!io_s.ok()) {
+    ret = io_s;
+  }
   if (ret.IsAborted()) {
     // Reserve IsAborted() error for those where users didn't release
     // certain resource and they can release them and come back and
     // retry. In this case, we wrap this exception to something else.
     return Status::Incomplete(ret.ToString());
   }
+
   return ret;
 }
 
@@ -4382,6 +4387,9 @@ Status DBImpl::RenameTempFileToOptionsFile(const std::string& file_name) {
       s = dir_obj->FsyncWithDirOptions(IOOptions(), nullptr,
                                        DirFsyncOptions(options_file_name));
     }
+    if (s.ok()) {
+      s = dir_obj->Close(IOOptions(), nullptr);
+    }
   }
   if (s.ok()) {
     InstrumentedMutexLock l(&mutex_);

db/db_impl/db_impl.h

@@ -113,6 +113,39 @@ class Directories {
 
   FSDirectory* GetDbDir() { return db_dir_.get(); }
 
+  IOStatus Close(const IOOptions& options, IODebugContext* dbg) {
+    // close all directories for all database paths
+    IOStatus s = IOStatus::OK();
+    if (db_dir_) {
+      s = db_dir_->Close(options, dbg);
+    }
+
+    if (!s.ok()) {
+      return s;
+    }
+
+    if (wal_dir_) {
+      s = wal_dir_->Close(options, dbg);
+    }
+
+    if (!s.ok()) {
+      return s;
+    }
+
+    if (data_dirs_.size() > 0 && s.ok()) {
+      for (auto& data_dir_ptr : data_dirs_) {
+        if (data_dir_ptr) {
+          s = data_dir_ptr->Close(options, dbg);
+          if (!s.ok()) {
+            return s;
+          }
+        }
+      }
+    }
+
+    return s;
+  }
+
  private:
   std::unique_ptr<FSDirectory> db_dir_;
   std::vector<std::unique_ptr<FSDirectory>> data_dirs_;

db/db_test_util.h

@@ -588,6 +588,7 @@ class SpecialEnv : public EnvWrapper {
         ~NoopDirectory() {}
 
         Status Fsync() override { return Status::OK(); }
+        Status Close() override { return Status::OK(); }
       };
 
       result->reset(new NoopDirectory());

env/composite_env.cc

@@ -276,6 +276,13 @@ class CompositeDirectoryWrapper : public Directory {
     IODebugContext dbg;
     return target_->FsyncWithDirOptions(io_opts, &dbg, DirFsyncOptions());
   }
+
+  Status Close() override {
+    IOOptions io_opts;
+    IODebugContext dbg;
+    return target_->Close(io_opts, &dbg);
+  }
+
   size_t GetUniqueId(char* id, size_t max_size) const override {
     return target_->GetUniqueId(id, max_size);
   }

env/env.cc

@@ -350,6 +350,10 @@ class LegacyDirectoryWrapper : public FSDirectory {
                  IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->Fsync());
   }
+  IOStatus Close(const IOOptions& /*options*/,
+                 IODebugContext* /*dbg*/) override {
+    return status_to_io_status(target_->Close());
+  }
   size_t GetUniqueId(char* id, size_t max_size) const override {
     return target_->GetUniqueId(id, max_size);
   }

env/fs_posix.cc

@@ -550,7 +550,7 @@ class PosixFileSystem : public FileSystem {
     if (fd < 0) {
       return IOError("While open directory", name, errno);
     } else {
-      result->reset(new PosixDirectory(fd));
+      result->reset(new PosixDirectory(fd, name));
     }
     return IOStatus::OK();
   }

env/io_posix.cc

@@ -1639,7 +1639,8 @@ PosixMemoryMappedFileBuffer::~PosixMemoryMappedFileBuffer() {
 // The magic number for BTRFS is fixed, if it's not defined, define it here
 #define BTRFS_SUPER_MAGIC 0x9123683E
 #endif
-PosixDirectory::PosixDirectory(int fd) : fd_(fd) {
+PosixDirectory::PosixDirectory(int fd, const std::string& directory_name)
+    : fd_(fd), directory_name_(directory_name) {
   is_btrfs_ = false;
 #ifdef OS_LINUX
   struct statfs buf;
@@ -1649,12 +1650,28 @@ PosixDirectory::PosixDirectory(int fd) : fd_(fd) {
 #endif
 }
 
-PosixDirectory::~PosixDirectory() { close(fd_); }
+PosixDirectory::~PosixDirectory() {
+  if (fd_ >= 0) {
+    IOStatus s = PosixDirectory::Close(IOOptions(), nullptr);
+    s.PermitUncheckedError();
+  }
+}
 
 IOStatus PosixDirectory::Fsync(const IOOptions& opts, IODebugContext* dbg) {
   return FsyncWithDirOptions(opts, dbg, DirFsyncOptions());
 }
 
+IOStatus PosixDirectory::Close(const IOOptions& /*opts*/,
+                               IODebugContext* /*dbg*/) {
+  IOStatus s = IOStatus::OK();
+  if (close(fd_) < 0) {
+    s = IOError("While closing directory ", directory_name_, errno);
+  } else {
+    fd_ = -1;
+  }
+  return s;
+}
+
 IOStatus PosixDirectory::FsyncWithDirOptions(
     const IOOptions& /*opts*/, IODebugContext* /*dbg*/,
     const DirFsyncOptions& dir_fsync_options) {
@@ -1686,15 +1703,19 @@ IOStatus PosixDirectory::FsyncWithDirOptions(
     }
     // fallback to dir-fsync for kDefault, kDirRenamed and kFileDeleted
   }
+
+  // skip fsync/fcntl when fd_ == -1 since this file descriptor has been closed
+  // in either the de-construction or the close function, data must have been
+  // fsync-ed before de-construction and close is called
 #ifdef HAVE_FULLFSYNC
   // btrfs is a Linux file system, while currently F_FULLFSYNC is available on
   // Mac OS.
   assert(!is_btrfs_);
-  if (::fcntl(fd_, F_FULLFSYNC) < 0) {
+  if (fd_ != -1 && ::fcntl(fd_, F_FULLFSYNC) < 0) {
     return IOError("while fcntl(F_FULLFSYNC)", "a directory", errno);
   }
 #else   // HAVE_FULLFSYNC
-  if (fsync(fd_) == -1) {
+  if (fd_ != -1 && fsync(fd_) == -1) {
     s = IOError("While fsync", "a directory", errno);
   }
 #endif  // HAVE_FULLFSYNC

env/io_posix.h

@@ -450,17 +450,20 @@ struct PosixMemoryMappedFileBuffer : public MemoryMappedFileBuffer {
 
 class PosixDirectory : public FSDirectory {
  public:
-  explicit PosixDirectory(int fd);
+  explicit PosixDirectory(int fd, const std::string& directory_name);
   ~PosixDirectory();
   virtual IOStatus Fsync(const IOOptions& opts, IODebugContext* dbg) override;
 
+  virtual IOStatus Close(const IOOptions& opts, IODebugContext* dbg) override;
+
   virtual IOStatus FsyncWithDirOptions(
       const IOOptions&, IODebugContext*,
       const DirFsyncOptions& dir_fsync_options) override;
 
  private:
   int fd_;
   bool is_btrfs_;
+  const std::string directory_name_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

env/mock_env.cc

@@ -447,6 +447,11 @@ class MockEnvDirectory : public FSDirectory {
                  IODebugContext* /*dbg*/) override {
     return IOStatus::OK();
   }
+
+  IOStatus Close(const IOOptions& /*options*/,
+                 IODebugContext* /*dbg*/) override {
+    return IOStatus::OK();
+  }
 };
 
 class MockEnvFileLock : public FileLock {

file/filename.cc

@@ -443,6 +443,9 @@ Status SetIdentityFile(Env* env, const std::string& dbname,
     s = dir_obj->FsyncWithDirOptions(IOOptions(), nullptr,
                                      DirFsyncOptions(identify_file_name));
   }
+  if (s.ok()) {
+    s = dir_obj->Close(IOOptions(), nullptr);
+  }
   if (!s.ok()) {
     env->DeleteFile(tmp).PermitUncheckedError();
   }

include/rocksdb/env.h

@@ -1148,6 +1148,8 @@ class Directory {
   virtual ~Directory() {}
   // Fsync directory. Can be called concurrently from multiple threads.
   virtual Status Fsync() = 0;
+  // Close directory.
+  virtual Status Close() = 0;
 
   virtual size_t GetUniqueId(char* /*id*/, size_t /*max_size*/) const {
     return 0;
@@ -1810,6 +1812,7 @@ class DirectoryWrapper : public Directory {
   explicit DirectoryWrapper(Directory* target) : target_(target) {}
 
   Status Fsync() override { return target_->Fsync(); }
+  Status Close() override { return target_->Close(); }
   size_t GetUniqueId(char* id, size_t max_size) const override {
     return target_->GetUniqueId(id, max_size);
   }

include/rocksdb/file_system.h

@@ -1267,6 +1267,9 @@ class FSDirectory {
     return Fsync(options, dbg);
   }
 
+  // Close directory
+  virtual IOStatus Close(const IOOptions& options, IODebugContext* dbg) = 0;
+
   virtual size_t GetUniqueId(char* /*id*/, size_t /*max_size*/) const {
     return 0;
   }
@@ -1811,6 +1814,10 @@ class FSDirectoryWrapper : public FSDirectory {
     return target_->FsyncWithDirOptions(options, dbg, dir_fsync_options);
   }
 
+  IOStatus Close(const IOOptions& options, IODebugContext* dbg) override {
+    return target_->Close(options, dbg);
+  }
+
   size_t GetUniqueId(char* id, size_t max_size) const override {
     return target_->GetUniqueId(id, max_size);
   }

port/win/env_win.cc

@@ -601,7 +601,7 @@ IOStatus WinFileSystem::NewDirectory(const std::string& name,
     return s;
   }
 
-  result->reset(new WinDirectory(handle));
+  result->reset(new WinDirectory(name, handle));
 
   return s;
 }

port/win/io_win.cc

@@ -1064,6 +1064,22 @@ IOStatus WinDirectory::Fsync(const IOOptions& /*options*/,
   return IOStatus::OK();
 }
 
+IOStatus WinDirectory::Close(const IOOptions& /*options*/,
+                             IODebugContext* /*dbg*/) {
+  IOStatus s = IOStatus::OK();
+  BOOL ret __attribute__((__unused__));
+  if (handle_ != INVALID_HANDLE_VALUE) {
+    ret = ::CloseHandle(handle_);
+    if (!ret) {
+      auto lastError = GetLastError();
+      s = IOErrorFromWindowsError("Directory closes failed for : " + GetName(),
+                                  lastError);
+    }
+    handle_ = NULL;
+  }
+  return s;
+}
+
 size_t WinDirectory::GetUniqueId(char* id, size_t max_size) const {
   return GetUniqueIdFromFile(handle_, id, max_size);
 }

port/win/io_win.h

@@ -472,14 +472,23 @@ class WinMemoryMappedBuffer : public MemoryMappedFileBuffer {
 };
 
 class WinDirectory : public FSDirectory {
+  const std::string filename_;
   HANDLE handle_;
 
  public:
-  explicit WinDirectory(HANDLE h) noexcept : handle_(h) {
+  explicit WinDirectory(const std::string& filename, HANDLE h) noexcept
+      : filename_(filename), handle_(h) {
     assert(handle_ != INVALID_HANDLE_VALUE);
   }
-  ~WinDirectory() { ::CloseHandle(handle_); }
+  ~WinDirectory() {
+    if (handle_ != NULL) {
+      IOStatus s = WinDirectory::Close(IOOptions(), nullptr);
+      s.PermitUncheckedError();
+    }
+  }
+  const std::string& GetName() const { return filename_; }
   IOStatus Fsync(const IOOptions& options, IODebugContext* dbg) override;
+  IOStatus Close(const IOOptions& options, IODebugContext* dbg) override;
 
   size_t GetUniqueId(char* id, size_t max_size) const override;
 };

tools/ldb_cmd.cc

@@ -509,6 +509,8 @@ void LDBCommand::CloseDB() {
     for (auto& pair : cf_handles_) {
       delete pair.second;
     }
+    Status s = db_->Close();
+    s.PermitUncheckedError();
     delete db_;
     db_ = nullptr;
   }