From 12bc7834dccdcd21353fc476dc76a5c9bc0d47bb Mon Sep 17 00:00:00 2001
From: Nicolas Lacasse <nlacasse@google.com>
Date: Thu, 17 Jan 2019 11:05:40 -0800
Subject: [PATCH] Allow fsync on a directory.

PiperOrigin-RevId: 229781337
Change-Id: I1f946cff2771714fb1abd83a83ed454e9febda0a
---
 pkg/sentry/fs/fsutil/file.go |  2 +-
 test/syscalls/linux/BUILD    |  1 +
 test/syscalls/linux/fsync.cc | 23 +++++++++++++----------
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/pkg/sentry/fs/fsutil/file.go b/pkg/sentry/fs/fsutil/file.go
index 0970f782b..32f8133fb 100644
--- a/pkg/sentry/fs/fsutil/file.go
+++ b/pkg/sentry/fs/fsutil/file.go
@@ -228,10 +228,10 @@ func (FileNoIoctl) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallAr
 type DirFileOperations struct {
 	waiter.AlwaysReady
 	FileGenericSeek
-	FileNoFsync
 	FileNoIoctl
 	FileNoMMap
 	FileNoopFlush
+	FileNoopFsync
 	FileNoopRelease
 }
 
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 41d476481..19884d55e 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -783,6 +783,7 @@ cc_binary(
     srcs = ["fsync.cc"],
     linkstatic = 1,
     deps = [
+        "//test/util:file_descriptor",
         "//test/util:temp_path",
         "//test/util:test_main",
         "//test/util:test_util",
diff --git a/test/syscalls/linux/fsync.cc b/test/syscalls/linux/fsync.cc
index 536a73bf1..b34229248 100644
--- a/test/syscalls/linux/fsync.cc
+++ b/test/syscalls/linux/fsync.cc
@@ -19,6 +19,7 @@
 #include <string>
 
 #include "gtest/gtest.h"
+#include "test/util/file_descriptor.h"
 #include "test/util/temp_path.h"
 #include "test/util/test_util.h"
 
@@ -28,22 +29,24 @@ namespace testing {
 namespace {
 
 TEST(FsyncTest, TempFileSucceeds) {
-  std::string path = NewTempAbsPath();
-  int fd;
-  EXPECT_THAT(fd = open(path.c_str(), O_RDWR | O_CREAT, 0666),
-              SyscallSucceeds());
+  auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDWR, 0666));
   const std::string data = "some data to sync";
-  EXPECT_THAT(write(fd, data.c_str(), data.size()),
+  EXPECT_THAT(write(fd.get(), data.c_str(), data.size()),
               SyscallSucceedsWithValue(data.size()));
-  EXPECT_THAT(fsync(fd), SyscallSucceeds());
-  ASSERT_THAT(close(fd), SyscallSucceeds());
-  ASSERT_THAT(unlink(path.c_str()), SyscallSucceeds());
+  EXPECT_THAT(fsync(fd.get()), SyscallSucceeds());
+}
+
+TEST(FsyncTest, TempDirSucceeds) {
+  auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(Open(dir.path(), O_RDONLY | O_DIRECTORY));
+  EXPECT_THAT(fsync(fd.get()), SyscallSucceeds());
 }
 
 TEST(FsyncTest, CannotFsyncOnUnopenedFd) {
+  auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
   int fd;
-  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
-  ASSERT_THAT(fd = open(f.path().c_str(), O_RDONLY), SyscallSucceeds());
+  ASSERT_THAT(fd = open(file.path().c_str(), O_RDONLY), SyscallSucceeds());
   ASSERT_THAT(close(fd), SyscallSucceeds());
 
   // fd is now invalid.